Synthesis, microstructure and magnetic properties of Fe{sub 3}Si{sub 0.7}Al{sub 0.3}@SiO{sub 2} core–shell particles and Fe{sub 3}Si/Al{sub 2}O{sub 3} soft magnetic composite core

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian, E-mail: snove418562@163.com; Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan, Hubei 430081; Fan, Xi’an, E-mail: groupfxa@163.com

2015-11-15

Fe{sub 3}Si{sub 0.7}Al{sub 0.3}@SiO{sub 2} core–shell particles and Fe{sub 3}Si/Al{sub 2}O{sub 3} soft magnetic composite core have been synthesized via a modified stöber method combined with following high temperature sintering process. Most of conductive Fe{sub 3}Si{sub 0.7}Al{sub 0.3} particles could be uniformly coated by insulating SiO{sub 2} using the modified stöber method. The Fe{sub 3}Si{sub 0.7}Al{sub 0.3}@SiO{sub 2} core–shell particles exhibited good soft magnetic properties with low coercivity and high saturation magnetization. The reaction 4Al+3SiO{sub 2}=2α-Al{sub 2}O{sub 3}+3Si took place during the sintering process. As a result the new Fe{sub 3}Si/Al{sub 2}O{sub 3} composite was formed. The Fe{sub 3}Si/Al{sub 2}O{submore » 3} composite core displayed more excellent soft magnetic properties, better frequency stability at high frequencies, much higher electrical resistivity and lower core loss than the pure Fe{sub 3}Si{sub 0.7}Al{sub 0.3} core. The method of introducing insulating layers surrounding magnetic particles provides a promising route to develop new and high compact soft magnetic materials with good magnetic and electric properties. - Graphical abstract: In Fe{sub 3}Si/Al{sub 2}O{sub 3} composite, Fe{sub 3}Si phases are separated by Al{sub 2}O{sub 3} layers and the eddy currents are confined in Fe{sub 3}Si phases, thus increasing resistivity and reducing core loss. - Highlights: • Fe{sub 3}Si{sub 0.7}Al{sub 0.3}@SiO{sub 2} core–shell particles and Fe{sub 3}Si/Al{sub 2}O{sub 3} cores were prepared. • Fe{sub 3}Si{sub 0.7}Al{sub 0.3} particles could be uniformly coated by nano-sized SiO{sub 2} clusters. • Fe{sub 3}Si{sub 0.7}Al{sub 0.3}@SiO{sub 2} particles and Fe{sub 3}Si/Al{sub 2}O{sub 3} cores showed good soft magnetic properties. • Fe{sub 3}Si/Al{sub 2}O{sub 3} had lower core loss and better frequency stability than Fe{sub 3}Si{sub 0.7}Al{sub 0.3} cores.« less

Hydrothermal synthesis of Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} nanotubes for enhanced photoluminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Linhui, E-mail: gaolhui@zstu.edu.cn; Wang, Guangfa; Zhu, Hongliang

Highlights: • Eu{sup 3+} doped Y{sub 2}O{sub 3} nanotubes. • Hydrothermal synthesis of Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} nanostructures assissted with a further heat treatment. • Tunable coating ratios of Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} nanophosphor. • Enhanced photoluminescence intensity of Y{sub 2}O{sub 3}:Eu{sup 3+} more than 60% by Y{sub 2}O{sub 3} surface coating. - Abstract: Novel Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} nanotubes with different coating ratios were synthesized successfully by a facile two-step process, including hydrothermal synthesis of Y(OH){sub 3} coated Y(OH){sub 3}:Eu{sup 3+} as precursors and then calcination ofmore » them at 1000 °C for 2 h. X-ray diffraction patterns and field emission scanning electron microscope images indicated these Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} phosphors possess tubular nanostructures. The photoluminescence properties of Y{sub 2}O{sub 3} coated Y{sub 2}O{sub 3}:Eu{sup 3+} were systematically investigated by photoluminescence spectra, and photoluminescence enhancement was observed after proper coating. In other words, the coating ratio played a crucial role in photoluminescence efficiency. When it was 1/9, the photoluminescence intensity of {sup 5}D{sub 0} → {sup 7}F{sub 2} emission (about 613 nm) was 60% higher than that of Y{sub 2}O{sub 3}: Eu{sup 3+} phosphors under 255 nm excitation. Therefore, surface coating may be an alternative route for enhanced photoluminescence properties of the Y{sub 2}O{sub 3}:Eu{sup 3+} red-emitting phosphor.« less

Dy–Mn–Si as a representative of family of ‘Dy–Transition Metal–Si’ systems: Its isothermal sections, empirical rProd. Type: FTPules and new rare-earth manganese silicides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@general.chem.msu.ru; Knotko, A.V.; Yapaskurt, V.O.

2013-10-15

X-ray and microprobe analyses were employed for the investigation of Dy–Mn–Si system at 870/1070/1170 K. The Dy–Mn–Si system, contains the known DyMn{sub 2}Si{sub 2}, DyMnSi and Dy{sub 2}Mn{sub 3}Si{sub 5} compounds and DyMn{sub 4}Si{sub 2}, Dy{sub 2}MnSi{sub 2} and Dy{sub 3}Mn{sub 2}Si{sub 3} were new compounds identified first time and their structure are of the type TmCu{sub 4}Sb{sub 2}, Sc{sub 2}CoSi{sub 2} and Hf{sub 3}Ni{sub 2}Si{sub 3} respectively. The quasi-binary solid solutions were detected at 870/1070/1170 K: the ThMn{sub 12}-type Dy{sub 8}Mn{sub 87}Si{sub 5}, Th{sub 6}Mn{sub 23}-type Dy{sub 23}Mn{sub 72}Si{sub 5}, MgCu{sub 2}-type Dy{sub 33}Mn{sub 58}Si{sub 9} and AlB{sub 2}-typemore » Dy{sub 38}Mn{sub 2}Si{sub 58}. The other binary compounds of the Dy–Mn–Si system do not show any visible solubility. New phases R{sub 2}MnSi{sub 2} and R{sub 3}Mn{sub 2}Si{sub 3} (R=Gd, Tb, Ho–Tm) were found out and their structure of the type Sc{sub 2}CoSi{sub 2} and Hf{sub 3}Ni{sub 2}Si{sub 3} respectively. The specific features of ‘Dy–Transition Metal–Si’ systems were discussed. - Graphical abstract: The isothermal section of Dy–Mn–Si contains the known DyMn{sub 2}Si{sub 2}, DyMnSi, Dy{sub 2}Mn{sub 3}Si{sub 5} and new TmCu{sub 4}Sb{sub 2}-type DyMn{sub 4}Si{sub 2}, Sc{sub 2}CoSi{sub 2}-type Dy{sub 2}MnSi{sub 2} and Hf{sub 3}Ni{sub 2}Si{sub 3}-type Dy{sub 3}Mn{sub 2}Si{sub 3} ternary compounds. The ternary solid solution based on the binary compounds of the Dy–Mn and Dy–Si systems: the ThMn{sub 12}-type Dy{sub 8}Mn{sub 87}Si{sub 5}, Th{sub 6}Mn{sub 23}-type Dy{sub 23}Mn{sub 72}Si{sub 5}, MgCu{sub 2}-type Dy{sub 33}Mn{sub 58}Si{sub 9} and AlB{sub 2}-type Dy{sub 38}Mn{sub 2}Si{sub 58}. The other binary compounds of the Dy–Mn–Si system do not show any visible solubility. New Sc{sub 2}CoSi{sub 2}-type R{sub 2}MnSi{sub 2} and Hf{sub 3}Ni{sub 2}Si{sub 3}-type R{sub 3}Mn{sub 2}Si{sub 3} phases were discovered for R=Gd, Tb, Ho–Tm. Display Omitted - Highlights: • The Dy–Mn–Si section contains three known and three new ternary compounds (phases). • New phase the TmCu{sub 4}Sb{sub 2}-type DyMn{sub 4}Si{sub 2} compound. • New Sc{sub 2}CoSi{sub 2}-type R{sub 2}MnSi{sub 2} and Hf{sub 3}Ni{sub 2}Si{sub 3}-type R{sub 3}Mn{sub 2}Si{sub 3} were detected for R=Gd–Tm. • Dy–Mn–Si supplements the ‘Dy–3d metal–Si’ series and leads to the ‘RT{sub m}X{sub n}’ row's rule.« less

Crystal structures and electronic properties for the over-lithiated and Li–Ag substituted phases of Li{sub 9}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} insertion electrode system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onoda, Masashige, E-mail: onoda.masashige.ft@u.tsukuba.ac.jp; Inagaki, Makoto; Saito, Hiroaki

2014-11-15

For the Li{sub 9}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} insertion electrode system with a multiple-electron reaction, the over-lithiated phase Li{sub x}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} with 99) and Li{sub 9−y}Ag{sub y}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} (0

The effect of glass additives on the microwave dielectric properties of Ba(Mg{sub 1/3}Ta{sub 2/3})O{sub 3} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Surendran, K.P.; Mohanan, P.; Sebastian, M.T.

2004-11-01

The effect of glass additives on the densification, phase evolution, microstructure and microwave dielectric properties of Ba(Mg{sub 1/3}Ta{sub 2/3})O{sub 3} (BMT) was investigated. Different weight percentages of quenched glass such as B{sub 2}O{sub 3}, SiO{sub 2}, B{sub 2}O{sub 3}-SiO{sub 2}, ZnO-B{sub 2}O{sub 3}, 5ZnO-2B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}-SiO{sub 2}, Na{sub 2}O-2B{sub 2}O{sub 3}.10H{sub 2}O, BaO-B{sub 2}O{sub 3}-SiO{sub 2}, MgO-B{sub 2}O{sub 3}-SiO{sub 2}, PbO-B{sub 2}O{sub 3}-SiO{sub 2}, ZnO-B{sub 2}O{sub 3}-SiO{sub 2} and 2MgO-Al{sub 2}O{sub 3}-5SiO{sub 2} were added to calcined BMT precursor. The sintering temperature of the glass-added BMT samples were lowered down to 1300 deg. C compared to solid-statemore » sintering where the temperature was 1650{sup o}C. The formation of high temperature satellite phases such as Ba{sub 5}Ta{sub 4}O{sub 15} and Ba{sub 7}Ta{sub 6}O{sub 22} were found to be suppressed by the glass addition. Addition of glass systems such as B{sub 2}O{sub 3}, ZnO-B{sub 2}O{sub 3}, 5ZnO-2B{sub 2}O{sub 3} and ZnO-B{sub 2}O{sub 3}-SiO{sub 2} improved the densification and microwave dielectric properties. Other glasses were found to react with BMT to form low-Q phases which prevented densification. The microwave dielectric properties of undoped BMT with a densification of 93.1% of the theoretical density were {epsilon}r=24.8, {tau}f=8ppm/{sup o}C and Q{sub u}xf=80,000GHz. The BMT doped with 1.0wt% of B{sub 2}O{sub 3} has Q{sub u}xf=124,700GHz, {epsilon}r=24.2, and {tau}f=-1.3ppm/ deg/ C. The unloaded Q factor of 0.2wt% ZnO-B{sub 2}O{sub 3}-doped BMT was 136,500GHz while that of 1.0wt% of 5ZnO-2B{sub 2}O{sub 3} added ceramic was Q{sub u}xf=141,800GHz. The best microwave quality factor was observed for ZnO-B{sub 2}O{sub 3}-SiO{sub 2} (ZBS) glass-added ceramics which can act as a perfect liquid-phase medium for the sintering of BMT. The microwave dielectric properties of 0.2wt% ZBS-added BMT dielectric was Q{sub u}xf=152,800GHz, {epsilon}r=25.5, and {tau}f=-1.5ppm/ deg. C.« less

Non-noble metal vanadium phosphites with broad absorption for photocatalytic hydrogen evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Jun-Ling, E-mail: s070054@e.ntu.edu.sg; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Zhang, Jian-Han

2016-05-15

We reported the synthesis and crystal structures of alkali metal and alkali-earth metal phosphite, namely, CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} (1), and Ba{sub 3}V{sub 2}(HPO{sub 3}){sub 6} (2). Both compounds were prepared by hydrothermal reactions and feature unique new structures. They both exhibit 3D complicated frameworks based on VO{sub 6} octahedra which are connected by HPO{sub 3} tetrahedra via corner-sharing. Alkali or alkali earth metal cations are filled in the different channels of the frameworks. Topological analysis shows that the framework of CsV{sub 2}(H{sub 3}O) (HPO{sub 3}){sub 4} (1) is a new 3,3,3,4,5-connected network with the Schläfli symbol of {4.6"2}{submore » 2}{4"2.6"6.8"2}{6"3}{6"5.8}. The investigations of X-ray photoelectron spectroscopy (XPS) and magnetic measurement on CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} suggest a +3 oxidation state of the vanadium ions in compound 1. Photocatalytic performance was evaluated by photocatalytic H{sub 2} evolution and degradation of methylene blue, which shows that both compounds exhibit activity under visible-light irradiation. IR spectrum, UV–vis-NIR spectrum and thermogravimetric analysis (TGA) of compounds were also investigated. - Graphical abstract: Metal vanadium phosphites with broad absorption for photocatalytic hydrogen evolution and the degradation of methylene blue aqueous solution. - Highlights: • Two new vanadium phosphites, CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} and Ba{sub 3}V{sub 2}(HPO{sub 3}){sub 6}, are reported. • CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} and Ba{sub 3}V{sub 2}(HPO{sub 3}){sub 6} feature complicated 3D framework structures with different channels. • CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} and Ba{sub 3}V{sub 2}(HPO{sub 3}){sub 6} exhibit strong and broad absorptions in the visible and Near IR region. • Photocatalytic properties of CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} and Ba{sub 3}V{sub 2}(HPO{sub 3}){sub 6} are investigated. • The magnetic measurement of CsV{sub 2}(H{sub 3}O)(HPO{sub 3}){sub 4} was performed in the temperature range of 2–300 K.« less

Syntheses, crystal structures and optical spectroscopy of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazmierczak, Karolina; Hoeppe, Henning A., E-mail: henning@ak-hoeppe.d

2011-05-15

The lanthanide sulphate octahydrates Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and the respective tetrahydrate Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O were obtained by evaporation of aqueous reaction mixtures of trivalent rare earth oxides and sulphuric acid at 300 K. Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) crystallise in space group C2/c (Z=4, a{sub Ho}=13.4421(4) A, b{sub Ho}=6.6745(2) A, c{sub Ho}=18.1642(5) A, {beta}{sub Ho}=102.006(1) A{sup 3} and a{sub Tm}=13.4118(14) A, b{sub Tm}=6.6402(6) A, c{sub Tm}=18.1040(16) A, {beta}{sub Tm}=101.980(8) A{sup 3}), Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O adopts space group P2{sub 1}/n (a=13.051(3) A, b=7.2047(14) A, c=13.316(3) A, {beta}=92.55(3) A{sup 3}). The vibrationalmore » and optical spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O are also reported. -- Graphical abstract: In the lanthanide sulphate octahydrates the cations form slightly undulated layers. Between the layers are voids in which sulphate tetrahedra and water molecules are located. The holmium compound exhibits an Alexandrite effect. Display Omitted Highlights: {yields} Determination of the optimum conditions for the growth of single-crystals of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O. {yields} Single-crystal structure elucidation of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) including hydrogen bonds. {yields} Single-crystal structure determination of Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O including hydrogen bonds. {yields} UV-vis spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted: Assignation of bands and clarification of the Alexandrite effect of the Ho compound. {yields} IR and Raman spectra of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted.« less

Impact of La{sub 2}O{sub 3} interfacial layers on InGaAs metal-oxide-semiconductor interface properties in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks deposited by atomic-layer-deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C.-Y., E-mail: cychang@mosfet.t.u-tokyo.ac.jp; Takenaka, M.; Takagi, S.

We examine the electrical properties of atomic layer deposition (ALD) La{sub 2}O{sub 3}/InGaAs and Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs metal-oxide-semiconductor (MOS) capacitors. It is found that the thick ALD La{sub 2}O{sub 3}/InGaAs interface provides low interface state density (D{sub it}) with the minimum value of ∼3 × 10{sup 11} cm{sup −2} eV{sup −1}, which is attributable to the excellent La{sub 2}O{sub 3} passivation effect for InGaAs surfaces. It is observed, on the other hand, that there are a large amount of slow traps and border traps in La{sub 2}O{sub 3}. In order to simultaneously satisfy low D{sub it} and small hysteresis, the effectivenessmore » of Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks with ultrathin La{sub 2}O{sub 3} interfacial layers is in addition evaluated. The reduction of the La{sub 2}O{sub 3} thickness to 0.4 nm in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks leads to the decrease in hysteresis. On the other hand, D{sub it} of the Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs interfaces becomes higher than that of the La{sub 2}O{sub 3}/InGaAs ones, attributable to the diffusion of Al{sub 2}O{sub 3} through La{sub 2}O{sub 3} into InGaAs and resulting modification of the La{sub 2}O{sub 3}/InGaAs interface structure. As a result of the effective passivation effect of La{sub 2}O{sub 3} on InGaAs, however, the Al{sub 2}O{sub 3}/10 cycle (0.4 nm) La{sub 2}O{sub 3}/InGaAs gate stacks can realize still lower D{sub it} with maintaining small hysteresis and low leakage current than the conventional Al{sub 2}O{sub 3}/InGaAs MOS interfaces.« less

The Ce-Ni-Si system as a representative of the rare earth-Ni-Si family: Isothermal section and new rare-earth nickel silicides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru; Knotko, A.V.; Garshev, A.V.

The Ce-Ni-Si system has been investigated at 870/1070 K by X-ray and microprobe analyses. The existence of the known compounds, i.e.: Ce{sub 2}Ni{sub 15.8}Si{sub 1.2} (Th{sub 2}Ni{sub 17}-type), Ce{sub 2}Ni{sub 15-14}Si{sub 2-3} (Th{sub 2}Zn{sub 17}-type), CeNi{sub 8.6}Si{sub 2.4} (BaCd{sub 11}-type), CeNi{sub 8.8}Si{sub 4.2} (LaCo{sub 9}Si{sub 4}-type), CeNi{sub 6}Si{sub 6} (CeNi{sub 6}Si{sub 6}-type), CeNi{sub 5}Si{sub 1-0.3} (TbCu{sub 7}-type), CeNi{sub 4}Si (YNi{sub 4}Si-type), CeNi{sub 2}Si{sub 2} (CeGa{sub 2}Al{sub 2}-type), Ce{sub 2}Ni{sub 3}Si{sub 5} (U{sub 2}Co{sub 3}Si{sub 5}-type), Ce{sub 3}Ni{sub 6}Si{sub 2} (Ce{sub 3}Ni{sub 6}Si{sub 2}-type), Ce{sub 3}Ni{sub 4}Si{sub 4} (U{sub 3}Ni{sub 4}Si{sub 4}-type), CeNiSi{sub 2} (CeNiSi{sub 2}-type), ~CeNi{sub 1.3}Si{sub 0.7} (unknown typemore » structure), Ce{sub 6}Ni{sub 7}Si{sub 4} (Pr{sub 6}Ni{sub 7}Si{sub 4}-type), CeNiSi (LaPtSi-type), CeNi{sub 0.8-0.3}Si{sub 1.2-1.7} (AlB{sub 2}-type), ~Ce{sub 2}Ni{sub 2}Si (unknown type structure), ~Ce{sub 4.5}Ni{sub 3.5}Si{sub 2} (unknown type structure), Ce{sub 15}Ni{sub 7}Si{sub 10} (Pr{sub 15}Ni{sub 7}Si{sub 10}-type), Ce{sub 5}Ni{sub 1.85}Si{sub 3} (Ce{sub 5}Ni{sub 1.85}Si{sub 3}-type), Ce{sub 6}Ni{sub 1.4}Si{sub 3.4} (Ce{sub 6}Ni{sub 1.67}Si{sub 3}-type), Ce{sub 7}Ni{sub 2}Si{sub 5} (Ce{sub 7}Ni{sub 2}Si{sub 5}-type) and Ce{sub 3}NiSi{sub 3} (Y{sub 3}NiSi{sub 3}-type) has been confirmed in this section. Moreover, the type structure has been determined for ~Ce{sub 2}Ni{sub 2}Si (Mo{sub 2}NiB{sub 2}-type Ce{sub 2}Ni{sub 2.5}Si{sub 0.5}) and ~Ce{sub 4.5}Ni{sub 3.5}Si{sub 2} (W{sub 3}CoB{sub 3}-type Ce{sub 3}Ni{sub 3-2.7}Si{sub 1-1.3}) and new ternary phases Ce{sub 2}Ni{sub 6.25}Si{sub 0.75} (Gd{sub 2}Co{sub 7}-type), CeNi{sub 7-7.6}Si{sub 6-5.4} (GdNi{sub 7}Si{sub 6}-type) and ~Ce{sub 27}Ni{sub 42}Si{sub 31} (unknown type structure) have been identified in this system. Quasi-binary phases, solid solutions, were detected at 870/1070 K for CeNi{sub 5}, CeNi{sub 3} and CeSi{sub 2}; while no appreciable solubility was observed for the other binary compounds of the Ce-Ni-Si system. As a prolongation of Rare Earth-Ni-Si system’s isostructural rows, LaNi{sub 7}Si{sub 6} and YNi{sub 6.6}Si{sub 6.1} (GdNi{sub 7}Si{sub 6}-type), ScNi{sub 6}Si{sub 6} (YCo{sub 6}Ge{sub 6}-type), NdNi{sub 6}Si{sub 6} (YNi{sub 6}Si{sub 6}-type), (Tb, Ho){sub 2}Ni{sub 15}Si{sub 2} (Th{sub 2}Zn{sub 17}-type), Nd{sub 2}Ni{sub 2.3}Si{sub 0.7} and Sm{sub 2}Ni{sub 2.2}Si{sub 0.8} (Mo{sub 2}NiB{sub 2}-type), Nd{sub 3}Ni{sub 2.55}Si{sub 1.45} (W{sub 3}CoB{sub 3}-type) and (Tb, Dy){sub 7}Ni{sub 50}Si{sub 19} (Y{sub 7}Ni{sub 49}Si{sub 20}-type) compounds were synthesized and investigated. Magnetic properties of the CeNi{sub 6}Si{sub 6}, CeNi{sub 7}Si{sub 6}, CeNi{sub 8.8}Si{sub 4.2}, Ce{sub 6}Ni{sub 7}Si{sub 4}, CeNi{sub 5}Si, Ce{sub 2}Ni{sub 2.5}Si{sub 0.5}, Nd{sub 2}Ni{sub 2.3}Si{sub 0.7} and Dy{sub 7}Ni{sub 50}Si{sub 19} compounds have also been investigated and are presented here. - Highlights: • Ce-Ni-Si isothermal section was obtained at 870/1070 K. • Twenty one known ternary cerium nickel silicides were confirmed in Ce-Ni-Si. • Five new cerium nickel silicides were detected in Ce-Ni-Si. • Eleven new rare earth nickel silicides were detected in R-Ni-Si. • Magnetic properties of eight rare earth nickel silicides were investigated.« less

Syntheses and structural characterization of vanado-tellurites and vanadyl-selenites: SrVTeO{sub 5}(OH), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}, Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konatham, Satish; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

Four new quaternary vanado-tellurites and vanadyl-selenites, namely, SrVTeO{sub 5}(OH)(1), Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2), Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3) and Ba{sub 2}VSe{sub 3}O{sub 10}(4) have been synthesized and structurally characterized by single crystal X-ray diffraction. The oxidation state of vanadium is +5 in tellurites 1 and 2 and +4 in selenites 3 and 4. The structures of SrVTeO{sub 5}(OH)(1) and Cd{sub 2}V{sub 2}Te{sub 2}O{sub 11}(2) compounds consist of (VTeO{sub 5}(OH)){sup 2-} and (V{sub 2}Te{sub 2}O{sub 11}){sup 4-}anionic chains respectively, which are built from tetrahedral VO{sub 4} and disphenoidal TeO{sub 4} moieties. Similarly the structures of Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O(3)more » and Ba{sub 2}VSe{sub 3}O{sub 10}(4) respectively contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} anionic chains, which are made up of octahedral VO{sub 6} and pyramidal SeO{sub 3} units. Compounds 1 and 3 have been characterized by thermogravimetric and infrared spectroscopic methods. Compounds 1 and 2 are wide band gap semiconductors. - Graphical abstract: Ca{sub 3}VSe{sub 4}O{sub 13}·H{sub 2}O and Ba{sub 2}VSe{sub 3}O{sub 10} compounds contain (VSe{sub 2}O{sub 7}){sup 2-} and (VSe{sub 3}O{sub 10}){sup 4-} chains. - Highlights: • Four new vanado-tellurites and vanadyl-selenites are synthesized. • Their structural features are different. • The vanado-tellurites are wide band gap semiconductors.« less

Synthesis and morphology of Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals with tungsten bronze structure in RE{sub 2}O{sub 3}-BaO-Nb{sub 2}O{sub 5}-B{sub 2}O{sub 3} glasses (RE: Sm, Eu, Gd, Dy, Er)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ida, H.; Shinozaki, K.; Honma, T.

2012-12-15

Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals with a tetragonal tungsten bronze (TTB) structure are synthesized using a conventional glass crystallization technique in 2.3RE{sub 2}O{sub 3}-27.4BaO-34.3Nb{sub 2}O{sub 5}-36B{sub 2}O{sub 3} (mol%) (RE=Sm, Eu, Gd, Dy, and Er) glasses. One sharp crystallization peak is observed at {approx}670 Degree-Sign C in both powdered and bulk glasses, and the formation of Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals with unit cell parameters of a{approx}1.24 nm and c{approx}0.39 nm was confirmed. It is found from high resolution transmission electron microscope observations that the morphology of Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals is ellipsoidal. Their average particlemore » size is in the range of 15-60 nm and decreases with decreasing ionic radius of RE{sup 3+} being present in the precursor glasses. The optical transparent crystallized glass (bulk) shows the total photoluminescence (PL) quantum yield of 53% in the visible region of Eu{sup 3+} ions, suggesting a high potential of Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals as PL materials. - Graphical abstract: This figure shows a TEM photograph for the heat-treated (667 Degree-Sign C, 3 h) sample of 2.3Dy{sub 2}O{sub 3}-27.4BaO-34.3Nb{sub 2}O{sub 5}-36B{sub 2}O{sub 3}. An ellipsoidal-shaped Ba{sub 1-x}Dy{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystal with diameters of 17 and 28 nm is observed. The ellipsoidal morphology is a common feature in Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals synthesized by the crystallization of 2.3RE{sub 2}O{sub 3}-27.4BaO-34.3Nb{sub 2}O{sub 5}-36B{sub 2}O{sub 3} glasses. Highlights: Black-Right-Pointing-Pointer Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals with a tetragonal tungsten bronze structure are synthesized. Black-Right-Pointing-Pointer A glass crystallization technique was applied. Black-Right-Pointing-Pointer The morphology of Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals is ellipsoidal. Black-Right-Pointing-Pointer The average particle size with 15-60 nm decreases with decreasing ionic radius of RE{sup 3+}. Black-Right-Pointing-Pointer Ba{sub 1-x}RE{sub 2x/3}Nb{sub 2}O{sub 6} nanocrystals have a high potential as photoluminescence materials.« less

Hg-sensitized photolysis of diethylamine in the absence and presence of O/sub 2/ or N/sub 2/O

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeStefano, G.; Heicklen, J.

1986-09-11

The Hg-sensitized photolysis of diethylamine (DEA) was studied in the absence and presence of O/sub 2/ or N/sub 2/O at room temperature. In the absence of foreign gases, the products were H/sub 2/, CH/sub 3/CH=NC/sub 2/H/sub 5/ and N,N'-diethylbutane-2,3-diamine (III), with respective quantum yields of 1.0, 1.0, and similarly ordered 0.02. Thus CH/sub 3/CHNHC/sub 2/H/sub 5/ radicals are produced exclusively and they are removed by self reaction: 2CH/sub 3/CHNHC/sub 2/H/sub 5/ ..-->.. DEA + CH/sub 3/CH=NC/sub 2/H/sub 5/ (4a) and 2CH/sub 3/CHNHC/sub 2/H/sub 5/ ..-->.. diamine III (4b), with k/sub 4a//k/sub 4b/ = 47.0 +/- 5.6. In the presence ofmore » O/sub 2/ the radicals are scavenged exclusively by abstraction of the H atom on the nitrogen to give the imine CH/sub 3/CH=NC/sub 2/H/sub 5/ as the exclusive product: (CH/sub 3/CHNHC/sub 2/H/sub 5/ + O/sub 2/ ..-->.. CH/sub 3/CH=NC/sub 2/H/sub 5/ + HO/sub 2/ (5). The Hg-sensitized photolysis of N/sub 2/O gives O(/sup 3/P) atoms, which in the presence of DEA react to give the imine and (C/sub 2/H/sub 5/)/sub 2/NOH (DEHA) as products in concerted parallel steps: O(/sup 3/P) + (C/sub 2/H/sub 5/)/sub 2/NH ..-->.. CH/sub 3/CH=NC/sub 2/H/sub 5/ + H/sub 2/O (9a) and O(/sup 3/P) + (C/sub 2/H/sub 5/)/sub 2/NH ..-->.. (C/sub 2/H/sub 5/)/sub 2/NOH (9b), with k/sub 9a//k/sub 9b/ similarly ordered 9.5 +/- 1.7.« less

Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yahia, H. Ben; Essehli, R., E-mail: ressehli@qf.org.qa; Avdeev, M.

The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structuresmore » of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.« less

Infrared and TPD studies of nitrates adsorbed on Tb{sub 4}O{sub 7}, La{sub 2}O{sub 3}, BaO, and MgO/{gamma}-Al{sub 2}O{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chi, Y.; Chuang, S.S.C.

2000-05-18

NO and O{sub 2} coadsorption on {gamma}-Al{sub 2}O{sub 3}-supported Tb{sub 4}O{sub 7}, La{sub 2}O{sub 3}, BaO, and MgO has been investigated by in situ infrared spectroscopy coupled with temperature-programmed decomposition and desorption. BaO/{gamma}-Al{sub 2}O{sub 3} and MgO/{gamma}-Al{sub 2}O{sub 3} possess a higher NO{sub x} storage capability than Tb{sub 4}O{sub 7}/{gamma}-Al{sub 2}O{sub 3} and La{sub 2}O{sub 3}/{gamma}-Al{sub 2}O{sub 3}. NO/O{sub 2} coadsorbed on Tb{sub 4}O{sub 7}, La{sub 2}O{sub 3}, and BaO in the form of bridging bidentate, chelating bidentate, and monodentate nitrates, and on MgO in the form of bridging bidentate and monodentate nitrates via the reaction of adsorbed NO withmore » adsorbed oxygen at 298 K. NO/O{sub 2} coadsorbed as a chelating bidentate nitrate on Tb{sub 4}O{sub 7} and La{sub 2}O{sub 3}, and as a distinctive bridging bidentate nitrate on BaO and MgO via the reaction of adsorbed NO with surface lattice oxygen at 523 K. These various forms of adsorbed nitrate differ in structure and reactivity from Tb(NO{sub 3}){sub 3}, La(NO{sub 3}){sub 3}, Ba(NO{sub 3}){sub 2}, and Mg(NO{sub 3}){sub 2}, the precursor used to prepare metal oxides for NO/O{sub 2} coadsorption. Temperature-programmed desorption (TPD) of chelating bidentate nitrate on Tb{sub 4}O{sub 7}, La{sub 2}O{sub 3}, and BaO produced primarily NO and O{sub 2}, with maxima at 640 and 670 K, respectively. TPD of bridging bidentate nitrate and monodentate nitrate on Tb{sub 4}O{sub 7}, La{sub 2}O{sub 3}, and BaO produced NO and O{sub 2} as major products and N{sub 2} and N{sub 2}O as minor products, at 320--500 K. Decomposition of bridging bidentate on MgO produced NO as a major product and N{sub 2}O as a minor product at a peak temperature of 690 K. Peak temperatures for Tb(NO{sub 3}){sub 3}, La(NO{sub 3}){sub 3}, Ba(NO{sub 3}){sub 2}, and Mg(NO{sub 3}){sub 2} decomposition occurred between those for bridging and chelating nitrates. The difference in stability between chelating and bridging bidentate nitrates on various metal oxides/{gamma}-Al{sub 2}O{sub 3} may provide a wide range of operating temperatures for NO{sub x} storage.« less

Method of detecting sulfur dioxide

DOEpatents

Spicer, Leonard D.; Bennett, Dennis W.; Davis, Jon F.

1985-01-01

(CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy.

Topologically and geometrically flexible structural units in seven new organically templated uranyl selenates and selenite–selenates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gurzhiy, Vladislav V., E-mail: vladgeo17@mail.ru; Kovrugin, Vadim M.; Tyumentseva, Olga S.

2015-09-15

Single crystals of seven novel uranyl oxysalts of selenium with protonated methylamine molecules, [C{sub 2}H{sub 8}N]{sub 2}[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)] (I), [C{sub 2}H{sub 8}N]{sub 2}[(UO{sub 2}){sub 2}(SeO{sub 4}){sub 3}(H{sub 2}O)] (II), [C{sub 4}H{sub 15}N{sub 3}][H{sub 3}O]{sub 0.5}[(UO{sub 2}){sub 2}(SeO{sub 4}){sub 2.93}(SeO{sub 3}){sub 0.07}(H{sub 2}O)](NO{sub 3}){sub 0.5} (III), [C{sub 2}H{sub 8}N]{sub 3}[H{sub 5}O{sub 2}][(UO{sub 2}){sub 2}(SeO{sub 4}){sub 3}(H{sub 2}O){sub 2}]{sub 2}(H{sub 2}O){sub 5} (IV), [C{sub 2}H{sub 8}N]{sub 2}[H{sub 3}O][(UO{sub 2}){sub 3}(SeO{sub 4}){sub 4}(HSeO{sub 3})(H{sub 2}O)](H{sub 2}SeO{sub 3}){sub 0.2} (V), [C{sub 4}H{sub 12}N]{sub 3}[H{sub 3}O][(UO{sub 2}){sub 3}(SeO{sub 4}){sub 5}(H{sub 2}O)] (VI), and [C{sub 2}H{sub 8}N]{sub 3}(C{sub 2}H{sub 7}N)[(UO{sub 2}){sub 3}(SeO{sub 4}){submore » 4}(HSeO{sub 3})(H{sub 2}O)] (VII) have been prepared by isothermal evaporation from aqueous solutions. Their crystal structures have been solved by direct methods and their uranyl selenate and selenite–selenate units investigated using black-and-white graphs from the viewpoints of topology of interpolyhedral linkages and isomeric variations. The crystal structure of IV is based upon complex layers with unique topology, which has not been observed previously in uranyl selenates. Investigations of the statistics and local distribution of the U–O{sub br}–Se bond angles demonstrates that shorter angles associate with undulations, whereas larger angles correspond to planar areas of the uranyl selenite layers. - Graphical abstract: Crystal structures of the seven novel Se-contaning uranyl oxysalts that contain protonated organic molecules as interlayer species have been investigated from the viewpoints of topology of interpolyhedral linkages, isomeric variations and flexibility of structural units. - Highlights: • Single crystals of seven novel uranyl oxysalts were prepared by evaporation method. • The graph theory was used for investigation of topologies of structural units. • The method of orientation matrices was applied to distinguish geometrical isomers. • The flexibility of structural complexes specifies the undulation of layered structural units.« less

Uranyl carboxyphosphonates that incorporate Cd(II)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alsobrook, Andrea N.; Alekseev, Evgeny V.; Depmeier, Wulf

2011-05-15

The hydrothermal treatment of UO{sub 3}, Cd(CH{sub 3}CO{sub 2}){sub 2}.2H{sub 2}O, and triethyl phosphonoacetate results in the formation of Cd{sub 2}[(UO{sub 2}){sub 6}(PO{sub 3}CH{sub 2}CO{sub 2}){sub 3}O{sub 3}(OH)(H{sub 2}O){sub 2}].16H{sub 2}O (CdUPAA-1), [Cd{sub 3}(UO{sub 2}){sub 6}(PO{sub 3}CH{sub 2}CO{sub 2}){sub 6}(H{sub 2}O){sub 13}].6H{sub 2}O (CdUPAA-2), and Cd(H{sub 2}O){sub 2}[(UO{sub 2})(PO{sub 3}CH{sub 2}CO{sub 2})(H{sub 2}O)]{sub 2} (CdUPAA-3). CdUPAA-1 adopts a cubic three-dimensional structure constructed from planar uranyl oxide clusters containing both UO{sub 7} pentagonal bipyramids and UO{sub 8} hexagonal bipyramids that are linked by Cd(II) cations and phosphonoacetate to yield large cavities approximately 16 A across that are filled with disordered watermore » molecules. CdUPAA-2 forms a rhombohedral three-dimensional channel structure that is assembled from UO{sub 7} pentagonal bipyramids that are bridged by phosphonoacetate. CdUPAA-3 is layered with the hydrated Cd(II) cations incorporated directly into the layers linking one-dimensional uranyl phosphonate substructures together. In this structure, there are complex networks of hydrogen bonds that exist within the sheets, and also stitch the sheets together. -- Graphical abstract: A view of part of the cubic structure of Cd{sub 2}[(UO{sub 2}){sub 6}(PO{sub 3}CH{sub 2}CO{sub 2}){sub 3}O{sub 3}(OH)(H{sub 2}O){sub 2}].16H{sub 2}O. Display Omitted highlights: > High symmetry uranyl compounds. > Three-dimensional structures. > Porous materials. > Heterobimetallic compounds.« less

Method of preparing (CH.sub.3).sub.3 SiNSO and byproducts thereof

DOEpatents

Spicer, Leonard D.; Bennett, Dennis W.; Davis, Jon F.

1984-01-01

(CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy.

The Dy–Ni–Si system as a representative of the rare earth–Ni–Si family: Its isothermal section and new rare-earth nickel silicides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Fang; Mozharivskyj, Y.; Morozkin, A.V., E-mail: morozkin@general.chem.msu.ru

The Dy–Ni–Si system has been investigated at 1070 K by X-ray and microprobe analysis. The system contains the 12 known compounds DyNi{sub 10}Si{sub 2}, DyNi{sub 5}Si{sub 3}, DyNi{sub 6}Si{sub 6}, DyNi{sub 4}Si, DyNi{sub 2}Si{sub 2}, Dy{sub 2}Ni{sub 3}Si{sub 5}, DyNiSi{sub 3}, Dy{sub 3}Ni{sub 6}Si{sub 2}, DyNiSi{sub 2}, DyNiSi, Dy{sub 3}NiSi{sub 3}, Dy{sub 3}NiSi{sub 2}, and the new compounds Dy{sub 34}Ni{sub 16−27}Si{sub 50−39} (AlB{sub 2}-type), Dy{sub 2}Ni{sub 15.2−14.1}Si{sub 1.8−2.9} (Th{sub 2}Zn{sub 17}-type), ∼Dy{sub 11}Ni{sub 65}Si{sub 24}, ∼Dy{sub 16}Ni{sub 62}Si{sub 22} (unknown structures), DyNi{sub 7}Si{sub 6} (GdNi{sub 7}Si{sub 6}-type), Dy{sub 3}Ni{sub 8}Si (Ce{sub 3}Co{sub 8}Si-type), DyNi{sub 2}Si (YPd{sub 2}Si-type), ∼Dy{sub 40}Ni{sub 47}Si{submore » 13} and ∼Dy{sub 5}Ni{sub 2}Si{sub 3} (unknown structures). Quasi–binary solid solutions were detected at 1070 (870 K) for Dy{sub 2}Ni{sub 17}, DyNi{sub 5}, DyNi{sub 7}, DyNi{sub 3}, DyNi{sub 2}, DyNi, DySi{sub 2} and DySi{sub 1.67}. No detectable solubility is observed for the other binary compounds of the Dy–Ni–Si system. The crystal structures of new phases RNi{sub 7}Si{sub 6} (GdNi{sub 7}Si{sub 6}-type), R{sub 3}Ni{sub 8}Si (Ce{sub 3}Co{sub 8}Si-type), RNi{sub 2}Si (YPd{sub 2}Si-type) and R{sub 3}Ni{sub 12}Si{sub 4} (Gd{sub 3}Ru{sub 4}Al{sub 12}-type), with R=Y, Gd–Tm, has been studied. Magnetic properties of few representative compounds are also reported. - Graphical abstract: The Dy–Ni–Si system has been investigated at 1070 K by X-ray and microprobe analysis. The system contains the 12 known compounds DyNi{sub 10}Si{sub 2}, DyNi{sub 5}Si{sub 3}, DyNi{sub 6}Si{sub 6}, DyNi{sub 4}Si, DyNi{sub 2}Si{sub 2}, Dy{sub 2}Ni{sub 3}Si{sub 5}, DyNiSi{sub 3}, Dy{sub 3}Ni{sub 6}Si{sub 2}, DyNiSi{sub 2}, DyNiSi, Dy{sub 3}NiSi{sub 3}, Dy{sub 3}NiSi{sub 2}, and the new compounds Dy{sub 34}Ni{sub 16−27}Si{sub 50−39}, Dy{sub 2}Ni{sub 15.2−14.1}Si{sub 1.8−2.9}, ∼Dy{sub 11}Ni{sub 65}Si{sub 24}, ∼Dy{sub 16}Ni{sub 62}Si{sub 22}, DyNi{sub 7}Si{sub 6}, Dy{sub 3}Ni{sub 8}Si, DyNi{sub 2}Si, ∼Dy{sub 40}Ni{sub 47}Si{sub 13} and ∼Dy{sub 5}Ni{sub 2}Si{sub 3}. Quasi–binary solid solutions were detected for Dy{sub 2}Ni{sub 17}, DyNi{sub 5}, DyNi{sub 7}, DyNi{sub 3}, DyNi{sub 2}, DyNi, DySi{sub 2} and DySi{sub 1.67}. The crystal structures and magnetic properties of new phases RNi{sub 7}Si{sub 6} (GdNi{sub 7}Si{sub 6}-type), R{sub 3}Ni{sub 8}Si (Ce{sub 3}Co{sub 8}Si-type), RNi{sub 2}Si (YPd{sub 2}Si-type) and R{sub 3}Ni{sub 12}Si{sub 4} (Gd{sub 3}Ru{sub 4}Al{sub 12}-type), with R=Y, Gd–Tm, are also reported. - Highlights: • Dy–Ni–Si isothermal section was obtained at 870 K/1070 K. • Twelve known ternary dysprosium nickel silicides were confirmed in Dy–Ni–Si. • Nine new dysprosium nickel silicides were detected in Dy–Ni–Si. • Seventeen new rare earth nickel silicides were detected in (Y, Gd–Tm)–Ni–Si. • Tb{sub 3}Ni{sub 8}Si, Dy{sub 3}Ni{sub 8}Si, Ho{sub 3}Ni{sub 12}Si{sub 4} and DyNi{sub 2}Si show ferromagnetic-like ordering.« less

The Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram refinement, Bi{sub 3}FeSb{sub 2}O{sub 11} structure peculiarities and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Egorysheva, A.V., E-mail: anna_egorysheva@rambler.ru; Ellert, O.G.; Gajtko, O.M.

2015-05-15

The refinement of the Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram has been performed and the existence of the two ternary compounds has been confirmed. The first one with a pyrochlore-type structure (sp. gr. Fd 3-barm) exists in the wide solid solution region, (Bi{sub 2−x}Fe{sub x})Fe{sub 1+y}Sb{sub 1−y}O{sub 7±δ}, where x=0.1–0.4 and y=−0.13–0.11. The second one, Bi{sub 3}FeSb{sub 2}O{sub 11}, corresponds to the cubic KSbO{sub 3}-type structure (sp. gr. Pn 3-bar) with unit cell parameter a=9.51521(2) Å. The Rietveld structure refinement showed that this compound is characterized by disordered structure. The Bi{sub 3}FeSb{sub 2}O{sub 11} factor groupmore » analysis has been carried out and a Raman spectrum has been investigated. According to magnetization measurements performed at the temperature range 2–300 K it may be concluded that the Bi{sub 3}FeSb{sub 2}O{sub 11} magnetic properties can be substantially described as a superposition of strong short-range antiferromagnetic exchange interactions realizing inside the [(FeSb{sub 2})O{sub 9}] 3D-framework via different pathways. - Graphical abstract: The refinement of the Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram has been performed and the existence of the solid solution with a pyrochlore-type structure (sp. gr. Fd 3-barm) and Bi{sub 3}FeSb{sub 2}O{sub 11}, correspond of the cubic KSbO{sub 3}-type structure (sp. gr. Pn 3-bar has been confirmed. The structure refinement, Raman spectroscopy as well as magnetic measurements data of Bi{sub 3}FeSb{sub 2}O{sub 11} are presented. - Highlights: • The Bi{sub 2}O{sub 3}–Fe{sub 2}O{sub 3}–Sb{sub 2}O{sub 5} system phase diagram refinement has been performed. • The Bi{sub 3}FeSb{sub 2}O{sub 11} existence along with pyrochlore structure compound is shown. • It was determined that the Bi{sub 3}FeSb{sub 2}O{sub 11} is of disordered cubic KSbO{sub 3}-type structure. • Factor group analysis of Bi{sub 3}FeSb{sub 2}O{sub 11} vibrational spectrum has been performed. • Short-range antiferromagnetic interactions govern Bi{sub 3}FeSb{sub 2}O{sub 11} magnetic behavior.« less

Ion-beam irradiation of lanthanum compounds in the systems La{sub 2}O{sub 3}-Al{sub 2}O{sub 3} and La{sub 2}O{sub 3}-TiO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whittle, Karl R., E-mail: karl.whittle@ansto.gov.a; Lumpkin, Gregory R.; Blackford, Mark G.

2010-10-15

Thin crystals of La{sub 2}O{sub 3}, LaAlO{sub 3}, La{sub 2/3}TiO{sub 3}, La{sub 2}TiO{sub 5}, and La{sub 2}Ti{sub 2}O{sub 7} have been irradiated in situ using 1 MeV Kr{sup 2+} ions at the Intermediate Voltage Electron Microscope-Tandem User Facility (IVEM-Tandem), Argonne National Laboratory (ANL). We observed that La{sub 2}O{sub 3} remained crystalline to a fluence greater than 3.1x10{sup 16} ions cm{sup -2} at a temperature of 50 K. The four binary oxide compounds in the two systems were observed through the crystalline-amorphous transition as a function of ion fluence and temperature. Results from the ion irradiations give critical temperatures for amorphisationmore » (T{sub c}) of 647 K for LaAlO{sub 3}, 840 K for La{sub 2}Ti{sub 2}O{sub 7}, 865 K for La{sub 2/3}TiO{sub 3}, and 1027 K for La{sub 2}TiO{sub 5}. The T{sub c} values observed in this study, together with previous data for Al{sub 2}O{sub 3} and TiO{sub 2}, are discussed with reference to the melting points for the La{sub 2}O{sub 3}-Al{sub 2}O{sub 3} and La{sub 2}O{sub 3}-TiO{sub 2} systems and the different local environments within the four crystal structures. Results suggest that there is an observable inverse correlation between T{sub c} and melting temperature (T{sub m}) in the two systems. More complex relationships exist between T{sub c} and crystal structure, with the stoichiometric perovskite LaAlO{sub 3} being the most resistant to amorphisation. - Graphical abstract: La{sub 2}TiO{sub 5} with atypical co-ordination for Ti, TiO{sub 5} is found to be different in radiation resistance to La{sub 2}Ti{sub 2}O{sub 7} and La{sub 2/3}TiO{sub 3}. Irradiation of La-Ti-O, and La-Al-O based systems has found that radiation damage resistance is related to the ability of the system to disorder.« less

New ternary phosphides and arsenides. Syntheses, crystal structures, physical properties of Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian; Xia, Sheng-Qing, E-mail: shqxia@sdu.edu.cn; Tao, Xu-Tang

2013-09-15

Three new europium pnictides Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3} have been synthesized and their structures were determined by single-crystal X-ray diffraction. Eu{sub 2}ZnP{sub 2} is isotypic with Yb{sub 2}CdSb{sub 2} (Cmc2{sub 1} (No. 36); cell parameters a=4.1777(7) Å, b=15.925(3) Å, c=7.3008(12) Å), while the latter two compounds crystallize with the Ba{sub 2}Cd{sub 2}Sb{sub 3} structure type (C2/m (No. 12); cell parameters a=15.653(5)/16.402(1) Å, b=4.127(1)/4.445(4) Å, c=11.552(4)/12.311(1) Å and β=126.647(4)/126.515(7)° for Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, respectively). Magnetic susceptibility measurements in the interval 5–300 K confirm paramagnetic behavior and effectivemore » magnetic moments characteristic of Eu{sup 2+} ([Xe] 4f{sup 7}) ground states. Temperature-dependent electrical conductivity measurements also prove that Eu{sub 2}Cd{sub 2}As{sub 3} is a semiconducting compound with a narrow band gap of 0.059 eV below 100 K. According to TG/DSC analyses, Eu{sub 2}Cd{sub 2}As{sub 3} starts to decompose at about 950 K. - Graphical abstract: A polyhedral view of the crystal structure of new pnictides Eu{sub 2}T{sub 2}Pn{sub 3} (T=Zn or Cd; Pn=P or As). Display Omitted - Highlights: • Three new ternary pnictide Zintl compounds, Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, have been synthesized and characterized. • The europium cations are divalent and ferromagnetically coupled in both Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}. • Eu{sub 2}Cd{sub 2}As{sub 3} has a very small band gap of 0.06 eV and starts to decompose over 950 K.« less

Metal complexes with mixed acido ligands. Communication 11. Nitratochloride compounds of bismuth(III)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidovich, R.L.; Medkov, M.A.; Irkhina, E.B.

1987-01-10

Two types of Bi(III) nitratochloride compounds were synthesized: MBiCl/sub 3/NO/sub 3/ (M = K, CN/sub 3/H/sub 6/) and K/sub 5/Bi/sub 2/Cl/sub 9/(NO/sub 3/)/sub 2/ (Table 1). The compound KBiCl/sub 3/NO/sub 3/ crystallized from a solution containing KCl and Bi/sub 2/O/sub 3/ in a molar ration of 2:1. Upon increasing the KCl content to a ratio of 4:1 a compound having the composition K/sub 5/Bi/sub 2/Cl/sub 9/ (NO/sub 3/)/sub 2/ is formed. The compound (CN/sub 3/H/sub 6/)BiCl/sub 3/NO/sub 3/ forms at a molar ratio of CN/sub 3/H/sub 6/Cl:Bi/sub 2/O/sub 3/ = 2:1. The nitratochloride compounds of Bi(III) separate out of solutionmore » in the form of colorless prismatic crystals, hexagonal in the case of K/sup +/ salts and rhombic in the case of the guanidine. In the x-ray spectrum of K/sub 5/Bi/sub 2/Cl/sub 9/NO/sub 3/)/sub 2/, as in the spectra of the simple nitrates, NO/sub 3/ stretching vibration is represented by one intense band with a maximum at 1390 cm/sup -1/. Out-of-plane deformation vibration of the NO/sub 3//sup -/ in the spectrum of K/sub 5/Bi/sub 2/Cl/sub 9/(NO/sub 3/)/sub 2/ appears as a very weak band at 846 cm/sup -1/, and the band corresponding to deformation stretching nu/sub 4/(E') is essentially absent. The IR spectrum of K/sub 5/Bi/sub 2/Cl/sub 9/(NO/sub 3/)/sub 2/ in the region of NO/sub 3/ stretching resembles that of KNO/sub 3/, on the basis of which they conclude that there are isolated NO/sub 3//sup -/ ions in K/sub 5/Bi/sub 2/Cl/sub 9/(NO/sub 3/)/sub 2/.« less

The isothermal section of Gd–Ni–Si system at 1070 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru; Knotko, A.V.; Yapaskurt, V.O.

2016-03-15

The Gd–Ni–Si system has been investigated at 1070 K by X-ray and microprobe analyses. The existence of the known compounds, i.e.: GdNi{sub 10}Si{sub 2}, GdNi{sub 8}Si{sub 3}, GdNi{sub 5}Si{sub 3}, GdNi{sub 7}Si{sub 6}, GdNi{sub 6}Si{sub 6}, GdNi{sub 4}Si, GdNi{sub 2}Si{sub 2}, GdNiSi{sub 3}, Gd{sub 3}Ni{sub 6}Si{sub 2}, GdNiSi, GdNiSi{sub 2}, GdNi{sub 0.4}Si{sub 1.6}, Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Gd{sub 3}NiSi{sub 2}, Gd{sub 3}NiSi{sub 3} and Gd{sub 6}Ni{sub 1.67}Si{sub 3}, has been confirmed. Moreover, five new phases have been identified in this system. The crystal structure for four of them has been determined: Gd{sub 2}Ni{sub 16−12.8}Si{sub 1−4.2} (Th{sub 2}Zn{sub 17}-type), GdNi{sub 6.6}Si{submore » 6} (GdNi{sub 7}Si{sub 6}-type), Gd{sub 3}Ni{sub 8}Si (Y{sub 3}Co{sub 8}Si-type) and Gd{sub 3}Ni{sub 11.5}Si{sub 4.2}(Gd{sub 3}Ru{sub 4}Ga{sub 12}-type). The compound with composition ~Gd{sub 2}Ni{sub 4}Si{sub 3} still remains with unknown structure. Quasi-binary phases, solid solutions, were detected at 1070 K to be formed by the binaries GdNi{sub 5}, GdNi{sub 3}, GdNi{sub 2}, GdNi, GdSi{sub 2} and GdSi{sub 1.67}; while no appreciable solubility was observed for the other binary compounds of the Gd–Ni–Si system. Magnetic properties of the GdNi{sub 6}Si{sub 6}, GdNi{sub 6.6}Si{sub 6} and Gd{sub 3}Ni{sub 11.5}Si{sub 4.2} compounds have also been investigated and are here reported. - Graphical abstract: The Gd–Ni–Si system has been investigated at 1070 K by X-ray and microprobe analyses. The known GdNi{sub 10}Si{sub 2}, GdNi{sub 8}Si{sub 3}, GdNi{sub 5}Si{sub 3}, GdNi{sub 7}Si{sub 6}, GdNi{sub 6}Si{sub 6}, GdNi{sub 4}Si, GdNi{sub 2}Si{sub 2}, GdNiSi{sub 3}, Gd{sub 3}Ni{sub 6}Si{sub 2}, GdNiSi, GdNiSi{sub 2}, GdNi{sub 0.4}Si{sub 1.6}, Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Gd{sub 3}NiSi{sub 2}, Gd{sub 3}NiSi{sub 3} and Gd{sub 6}Ni{sub 1.67}Si{sub 3} compounds have been confirmed and five new ~Gd{sub 2}Ni{sub 4}Si{sub 3} (unknown type), Gd{sub 2}Ni{sub 16−12.8}Si{sub 1−4.2} (Th{sub 2}Zn{sub 17}-type), GdNi{sub 6.6}Si{sub 6} (GdNi{sub 7}Si{sub 6}-type), Gd{sub 3}Ni{sub 8}Si (Y{sub 3}Co{sub 8}Si-type) and Gd{sub 3}Ni{sub 11.5}Si{sub 4.2} (Gd{sub 3}Ru{sub 4}Ga{sub 12}-type) compounds have been detected in Gd–Ni–Si system at 1070 K. Quasi-binary phases, solid solutions, were detected at 1070 K to be formed by the binaries GdNi{sub 5}, GdNi{sub 3}, GdNi{sub 2}, GdNi, GdSi{sub 2} and GdSi{sub 1.67}; while no detectable solubility was observed for the other binary compounds of the Gd–Ni–Si system. Magnetic properties of the GdNi{sub 6}Si{sub 6}, GdNi{sub 6.6}Si{sub 6} and Gd{sub 3}Ni{sub 11.5}Si{sub 4.2} compounds have also been investigated and are here reported. - Highlights: • Gd–Ni–Si isothermal section was obtained at 1070 K. • Sixteen known ternary gadolinium nickel silicides were confirmed in Gd–Ni–Si. • Five new gadolinium nickel silicides were detected in Gd–Ni–Si. • GdNi{sub 6}Si{sub 6}, GdNi{sub 6.6}Si{sub 6} and Gd{sub 3}Ni{sub 11.5}Si{sub 4.2} show ferromagnetic-type ordering.« less

Reversible flexible structural changes in multidimensional MOFs by guest molecules (I{sub 2}, NH{sub 3}) and thermal stimulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yang; Li, Libo; Yang, Jiangfeng

Three metal–organic frameworks (MOFs), [Cu(INA){sub 2}], [Cu(INA){sub 2}I{sub 2}] and [Cu(INA){sub 2}(H{sub 2}O){sub 2}(NH{sub 3}){sub 2}], were synthesized with 3D, 2D, and 0D structures, respectively. Reversible flexible structural changes of these MOFs were reported. Through high temperature (60–100 °C) stimulation of I{sub 2} or ambient temperature stimulation of NH{sub 3}, [Cu(INA){sub 2}] (3D) converted to [Cu(INA){sub 2}I{sub 2}] (2D) and [Cu(INA){sub 2}(H{sub 2}O){sub 2}(NH{sub 3}){sub 2}] (0D); as the temperature increased to 150 °C, the MOFs changed back to their original form. In this way, this 3D MOF has potential application in the capture of I{sub 2} and NH{sub 3}more » from polluted water and air. XRD, TGA, SEM, NH{sub 3}-TPD, and the measurement of gas adsorption were used to describe the changes in processes regarding the structure, morphology, and properties. - Graphical abstract: Through I{sub 2}, NH{sub 3} molecules and thermal stimulation, the three MOFs can achieve reversible flexible structural changes. Different methods were used to prove the flexible reversible changes. - Highlights: • [Cu(INA){sub 2}] can flexible transform to [Cu(INA){sub 2}I{sub 2}] and [Cu(INA){sub 2}(H{sub 2}O){sub 2}(NH{sub 3}){sub 2}] by adsorbing I{sub 2} or NH{sub 3}. • The reversible flexible transformation related to material source, temperature and concentration. • Potential applications for the capture of I{sub 2} and NH{sub 3} from polluted water or air.« less

Synthesis, structure, and polymorphism of A{sub 3}LnSi{sub 2}O{sub 7} (A=Na, K; Ln=Sm, Ho, Yb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latshaw, Allison M.; Yeon, Jeongho; Smith, Mark D.

2016-03-15

Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family, K{sub 3}SmSi{sub 2}O{sub 7}, Na{sub 3}HoSi{sub 2}O{sub 7}, and two polymorphs of Na{sub 3}YbSi{sub 2}O{sub 7}, are reported. K{sub 3}SmSi{sub 2}O{sub 7} crystallizes in the hexagonal space group P6{sub 3}/mcm, Na{sub 3}HoSi{sub 2}O{sub 7} and Na{sub 3}YbSi{sub 2}O{sub 7} crystallize in the hexagonal space group P6{sub 3}/m, and Na{sub 3}YbSi{sub 2}O{sub 7} crystallizes in the trigonal space group P31c. The Na{sub 3}YbSi{sub 2}O{sub 7} composition that crystallizes in P31c is a new structure type. The magnetic properties for the Ho and Yb analogs are reported. - Graphical abstract: The differentmore » structure types and polymorphs of the A{sub 3}LnSi{sub 2}O{sub 7} family reported. - Highlights: • Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family are presented. • Na{sub 3}YbSi{sub 2}O{sub 7} is reported as two polymorphs, one is a new structure type. • Crystals synthesized out of molten fluoride fluxes.« less

Ring opening and carbonylation of 3,3-dimethylthietane ligands in ruthenium carbonyl cluster complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, R.D.; Belinski, J.A.; Yamamoto, J.H.

1992-10-01

When heated to 97{degrees}C, the complex Ru{sub 4}(CO){sub 12}[{mu}-SCH{sub 2}CMe{sub 2}CH{sub 2}]2 (1) was transformed into two new hexaruthenium cluster complexes, Ru{sub 6}(CO){sub 13}({mu}{sub 3}-SCH{sub 2}CMe{sub 2}CH{sub 2}){sub 4} (2) and Ru{sub 6}(CO){sub 12}({mu}-SCH{sub 2}CMe{sub 2}CH{sub 2})({mu}{sub 3}-SCH{sub 2}CMe{sub 2}CH{sub 2}){sub 3}[{mu}{sub 3}-SCH{sub 2}C(Me)(CH{sub 2})CH{sub 2}] ({mu}-H) (3), that contain four and five ring-opened 3,3-dimethylthietane (3,3-DMT) ligands, respectively. In compound 3 one of the ring-opened DMT ligands has also undergone a CH activation on one of the methyl groups. Compound 2 reacts with additional 3,3-DMT at 97{degrees}C to form 3 in 18% yield. When treated with CO at 95{degrees}C (500more » psi), compound 2 yielded 4,4-dimethylthiobutyrolactone and Ru{sub 3}(CO){sub 12}. It was also found that the complex Os{sub 3}(CO){sub 11-}(SCH{sub 2}CMe{sub 2}CH{sub 2}C{double_bond}O) (4) yields 4,4-dimethylthiobutyrolactone when treated with CO at 120{degrees}C (1200 psi). Crystal data for 2: space group P2{sub 1}/n, {alpha} = 22.652 (7) A, {beta} = 11.712 (2) A, c = 19.965 (6) A, {Beta} = 115.75 (2){degrees} Z = 4, 3665 reflections, R = 0.021. Crystal data for 3: space group P2{sub 1}/c, {alpha} = 17.332 (8) A, {Beta} = 14.668 (9) A, c = 19.823 (9) A, {Beta} = 91.27 (4){degrees}, Z = 4, 1875 reflections, R = 0.050. 13 refs., 2 figs., 13 refs.« less

Cyclopentadienylniobium and -molybdenum phosphorodithioate complexes. X-ray crystal structures of CpNbCl sub 3 (S sub 2 P(OPr sup i ) sub 2 ), CpNbCl(. mu. -Cl) sub 2 Nb(S sub 2 P(OPr sup i ) sub 2 )Cp, and cis-Cp prime Mo(CO) sub 2 (S sub 2 P(OPr sup i ) sub 2 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodward, S.; Riaz, U.; Curtis, M.D.

1990-10-01

Reaction of CpNbCl{sub 4} (Cp = {eta}-C{sub 5}H{sub 5}) with (Pr{sup i}O){sub 2}P(S)(SH) in the presence of NEt{sub 3} yields CpNbCl{sub 3}(S{sub 2}P(S{sub 2}Pr{sup i}){sub 2}) (1). Reduction of 1 with Na/Hg affords the Nb-Nb-bonded complex CpNbCl({mu}-Cl){sub 2}Nb(S{sub 2}P(OR){sub 2})Cp (2). In refluxing toluene, (Pr{sup i}O){sub 2}P(S)(SH) with (Cp{prime}Mo(CO){sub 3}){sub 2} (Cp{prime} = {eta}-C{sub 5}H{sub 4}Me) gives cis-Cp{prime}Mo(CO){sub 2}(S{sub 2}P(OPr{sup i}){sub 2}) (3). Oxidation of 3 with I{sub 2} affords Cp{prime}MoI{sub 2}(CO)(S{sub 2}P(OPr{sup i}){sub 2}) (4). The crystal structures of 1-3 are compared. For 1, triclinic, P{bar 1}, a = 7.122 (3) {angstrom}, b = 11.365 (4) {angstrom}, c =more » 12.532 (4) {angstrom}, {alpha} = 77.38 (3){degree}, {beta} = 89.08 (3){degree}, {gamma} = 72.87 (3){degree}, V = 944.5 (8) {angstrom}{sup 3}. For 2, triclinic, P{bar 1}, a = 7.251 (3) {angstrom}, b = 12.386 (5) {angstrom}, c = 13.988 (5) {angstrom}, {alpha} = 102.66 (3){degree}, {beta} = 103.56 (3){degree}, {gamma} = 94.66 (3){degree}, V = 1180.0 (8) {angstrom}{sup 3}, Z = 2. For 3, orthorhombic, Pbca, a = 12.703 (3) {angstrom}, b = 16.707 (4) {angstrom}, c = 18.398 (4) {angstrom}, V = 3904.4 (17) {angstrom}{sup 3}, Z = 8.« less

Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, F.; Flores, M.J.R.; Kimizuka, N.

1999-04-01

Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air are determined by means of a classic quenching method. There exist In{sub 2}TiO{sub 5}, Fe{sub 2}TiO{sub 5} having a pseudo-Brookite-type phase and a new phase, In{sub 3}Ti{sub 2}FeO{sub 10} having a solid solution range from In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 4:6:1 to In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 0.384:0.464:0.152 (mole ratio) on the line InFeO{sub 3}-In{sub 2}Ti{sub 2}O{sub 7}. The crystal structures of In{sub 3}Ti{sub 2}FeO{sub 10} are pyrochlore related with a{sub m} = 5.9171 (5) {angstrom}, b{sub m} = 3.3696more » (3) {angstrom}, c{sub m} = 6.3885 (6) {angstrom}, and {beta} = 108.02 (1){degree} in a monoclinic crystal system at 1100 C, and a{sub 0} = 5.9089 (5) {angstrom}, b{sub 0} = 3.3679 (3) {angstrom}, and c{sub 0} = 12.130 (1) {angstrom} in an orthorhombic system at 1200 C. The relationship between the lattice constants of these phases and those of the cubic pyrochlore type are approximately as follows: a{sub m} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub m} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, c{sub m} = {1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({1/4})c{sub p} and {beta} = 109.47{degree} in the monoclinic system, and a{sub 0} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub 0} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, and c{sub 0} = 2/3a{sub p} + ({minus}2/3)b{sub p} + (2/3)c{sub p} in the orthorhombic system, where a{sub p} = b{sub p} = c{sub p} = 9.90 ({angstrom}) are the lattice constants of In{sub 2}Ti{sub 2}O{sub 7} having the cubic pyrochlore type. All solid solutions of In{sub 3}Ti{sub 2}FeO{sub 10} have incommensurate structures with a periodicity of q {times} b{sup *} (q = 0.281--0.356) along the b{sup *} axis and the stoichiometric phase has q = 1/3. In FeO{sub 3} having a layered structure type is unstable between 750 and 1100 C.« less

A first-principles density functional theory study of the electronic structural and thermodynamic properties of M2ZrO3 and M2CO3 (M=Na, K) and their capabilities for CO2 capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuhua Duan

2012-01-01

Alkali metal zirconates could be used as solid sorbents for CO{sub 2} capture. The structural, electronic, and phonon properties of Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3} are investigated by combining the density functional theory with lattice phonon dynamics. The thermodynamics of CO{sub 2} absorption/desorption reactions of these two zirconates are analyzed. The calculated results show that their optimized structures are in a good agreement with experimental measurements. The calculated band gaps are 4.339 eV (indirect), 3.641 eV (direct), 3.935 eV (indirect), and 3.697 eV (direct) for Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{submore » 2}CO{sub 3}, and K{sub 2}CO{sub 3}, respectively.The calculated phonon dispersions and phonon density of states for M{sub 2}ZrO{sub 3} and M{sub 2}CO{sub 3} (M = K, Na, Li) revealed that from K to Na to Li, their frequency peaks are shifted to high frequencies due to the molecular weight decreased from K to Li. From the calculated reaction heats and relationships of free energy change versus temperatures and CO{sub 2} pressures of the M{sub 2}ZrO{sub 3} (M = K, Na, Li) reacting with CO{sub 2}, we found that the performance of Na{sub 2}ZrO{sub 3} capturing CO{sub 2} is similar to that of Li{sub 2}ZrO{sub 3} and is better than that of K{sub 2}ZrO{sub 3}. Therefore, Na{sub 2}ZrO{sub 3} and Li{sub 2}ZrO{sub 3} are good candidates of high temperature CO{sub 2} sorbents and could be used for post combustion CO{sub 2} capture technologies.« less

Ionic ASi{sub 2}N{sub 3} (A=Li, Na, K and Rb) stabilized by the covalent Si–N bonding: First-principles calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Huijun; Ren, Jiadong, E-mail: jdren@ysu.edu.cn; Wu, Lailei

The structural, elastic and electronic properties of LiSi{sub 2}N{sub 3} and its substitutions by Na, K and Rb were investigated through first-principles computations. The expansion of lattice parameters of ASi{sub 2}N{sub 3} from Li, Na, K to Rb is found to be determined by the bond angle of Si–N1–Si, which suggests a possible way to improve the lithium ionic conductivity by substitutions. ASi{sub 2}N{sub 3} (A=Li, Na, K and Rb) shows the similar elastic behaviors, while the electronic band gap gradually decreases from 5.1 to 3.4 eV from LiSi{sub 2}N{sub 3} to RbSi{sub 2}N{sub 3}. Interestingly, the analysis of electronicmore » structure, crystal orbital Hamiltonian populations and Bader charges shows that the covalence of Si–N bonding is critical for the stability of ASi{sub 2}N{sub 3} phase. Among ASi{sub 2}N{sub 3} phases, there is a relatively high ionicity in NaSi{sub 2}N{sub 3}; the Si–N bond strength in [Si{sub 2}N{sub 3}]{sup −} net for KSi{sub 2}N{sub 3} and RbSi{sub 2}N{sub 3} is comparable to LiSi{sub 2}N{sub 3}, but stronger than NaSi{sub 2}N{sub 3}. - Graphic abstract: Universal trend of structural and electronic properties in alkaline metal silicon nitrides, ASi{sub 2}N{sub 3}, A=Li, Na, K and Rb. - Highlights: • Trend in structure, electronic and mechanical properties of ASi{sub 2}N{sub 3} (A=Li-Rb) were predicted. • Lattice expansion of ASi{sub 2}N{sub 3} induced by the bond angle of Si–N1–Si was found. • Calculated band gap decreases from 5.1 to 3.4 eV from LiSi{sub 2}N{sub 3} to RbSi{sub 2}N{sub 3}. • Covalent Si–N bonding is critical for the stability of ASi{sub 2}N{sub 3}.« less

Refractory concretes

DOEpatents

Holcombe, Jr., Cressie E.

1979-01-01

Novel concrete compositions comprise particles of aggregate material embedded in a cement matrix, said cement matrix produced by contacting an oxide selected from the group of Y.sub.2 O.sub.3, La.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Eu.sub.2 O.sub.3 and Gd.sub.2 O.sub.3 with an aqueous solution of a salt selected from the group of NH.sub.4 NO.sub.3, NH.sub.4 Cl, YCl.sub.3 and Mg(NO.sub.3).sub.2 to form a fluid mixture; and allowing the fluid mixture to harden.

Thermal barrier coatings for turbine components

DOEpatents

Subramanian, Ramesh; Sabol, Stephen M.; Goedjen, John G.; Sloan, Kelly M.; Vance, Steven J.

2002-01-01

A turbine component, such as a turbine blade having a metal substrate (22) is coated with a metal MCrAlY alloy layer (24) and then a thermal barrier layer (20) selected from LaAlO.sub.3, NdAlO.sub.3, La.sub.2 Hf.sub.2 O.sub.7, Dy.sub.3 Al.sub.5 O.sub.12, HO.sub.3 Al.sub.3 O.sub.12, ErAlO.sub.3, GdAlO.sub.3, Yb.sub.2 Ti.sub.2 O.sub.7, LaYbO.sub.3, Gd.sub.2 Hf.sub.2 O.sub.7 or Y.sub.3 Al.sub.5 O.sub.12.

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Hongmei; Zhang, Youjin, E-mail: zyj@ustc.edu.cn; Zhu, Wei

Highlights: {yields} Flower-like Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O was gained with Na{sub 3}Cit assisted precipitation method. {yields} The mechanism of the flower-like Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O formation was proposed. {yields} The Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O and Sm{sub 2}O{sub 3} samples exhibited obviously different PL spectra. {yields} Ln{sub 2}(C{sub 2}O{sub 4}){sub 3}.nH{sub 2}O (Ln = Gd, Dy, Lu, Y) also were achieved by the simple method. -- Abstract: Flower-like Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O had been synthesized by a facile complex agent assisted precipitation method. The flower-like Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O was characterizedmore » by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, thermogravimetry-differential thermal analysis and photoluminescence. The possible growth mechanism of the flower-like Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O was proposed. To extend this method, other Ln{sub 2}(C{sub 2}O{sub 4}){sub 3}.nH{sub 2}O (Ln = Gd, Dy, Lu, Y) with different morphologies also had been prepared by adjusting different rare earth precursors. Further studies revealed that besides the reaction conditions and the additive amount of complex agents, the morphologies of the as-synthesised lanthanide oxalates were also determined by the rare earth ions. The Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}.10H{sub 2}O and Sm{sub 2}O{sub 3} samples exhibited different photoluminescence spectra, which was relevant to Sm{sup 3+} energy level structure of 4f electrons. The method may be applied in the synthesis of other lanthanide compounds, and the work could explore the potential optical materials.« less

Tin(II) alkoxide hydrolysis products for use as base catalysts

DOEpatents

Boyle, Timothy J.

2002-01-01

Tin alkoxide compounds are provided with accessible electrons. The compounds are a polymeric tin alkoxide, [Sn(OCH.sub.2 C(CH.sub.3).sub.3).sub.2 ].sub.n, and the hydrolysis products Sn.sub.6 O.sub.4 (OCH.sub.2 C(CH.sub.3).sub.3).sub.4 and Sn.sub.5 O.sub.2 (OCH.sub.2 C(CH.sub.3).sub.3).sub.6. The hydrolysis products are formed by hydrolyzing the [Sn(OCH.sub.2 C(CH.sub.3).sub.3).sub.2 ].sub.n in a solvent with controlled amounts of water, between 0.1 and 2 moles of water per mole of the polymeric tin alkoxide.

Nucleophilic ring opening of bridging thietanes in open triosmium cluster complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, R.D.; Belinski, J.A.

1992-07-01

The complexes Os{sub 3}(CO){sub 9}({mu}{sub 3}-S)[{mu}-SCH{sub 2}CMe{sub 2}CMe{sub 2}CH{sub 2}] (1) and Os{sub 3}(CO){sub 9}({mu}{sub 3}-S)[{mu}-SCH{sub 2}CH{sub 2}CH{sub 2}] (2) were obtained from the reactions of Os{sub 3}(CO){sub 10}({mu}{sub 3}-S) with 3,3-dimethylthietane (DMT) and thietane, respectively, at -42 {degree}C in the presence of Me{sub 3}NO. Compound 1 was characterized by a single-crystal X-ray diffraction analysis and was found to contain a DMT group bridging two of the nonbonded metal atoms in the open cluster of three metal atoms by using both lone pairs of electrons on the sulfur atom. Compound 1 reacted with bis(triphenylphosphine)nitrogen(1+) chloride ([PPN]Cl) at 25 {degrees}C tomore » yield the salt [PPN][Os{sub 3}-(CO){sub 9}({mu}-SCH{sub 2}CMe{sub 2}CH{sub 2}Cl)({mu}{sub 3}-S)] (3; 76%), in which the chloride ion was added to one of the methylene groups of the DMT ring in a process that caused the ring to open by cleavage of one of the carbon-sulfur bonds. A 4-chloro-3,3-dimethylpropanethiolate ligand bridges the open edge of the anionic triosmium cluster. Compound 3 was converted to the neutral complex Os{sub 3}(CO){sub 9}[{mu}-SCH{sub 2}CMe{sub 2}CMe{sub 2}CH{sub 2}Cl]({mu}{sub 3}-S)({mu}-H) (4) by reaction with HCl at 25 {degrees}C. Compound 4 is structurally similar to 3, except that is contains a hydride ligand bridging one of the two metal-metal bonds. Compounds 1 and 2 react with HCl in CH{sub 2}Cl{sub 2} solvent to yield the neutral compounds 4 and Os{sub 3}(CO){sub 9}[{mu}-SCH{sub 2}CH{sub 2}CH{sub 2}Cl]({mu}{sub 3}-S)({mu}-H) (5) in 89% and 90% yields, respectively, in one step. 11 refs., 3 figs., 10 tabs.« less

β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3}/Ga{sub 2}O{sub 3} (010) heterostructures grown on β-Ga{sub 2}O{sub 3} (010) substrates by plasma-assisted molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaun, Stephen W., E-mail: skaun@umail.ucsb.edu; Wu, Feng; Speck, James S.

2015-07-15

By systematically changing growth parameters, the growth of β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3}/Ga{sub 2}O{sub 3} (010) heterostructures by plasma-assisted molecular beam epitaxy was optimized. Through variation of the Al flux under O-rich conditions at 600 °C, β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3} (010) layers spanning ∼10% to ∼18% Al{sub 2}O{sub 3} were grown directly on β-Ga{sub 2}O{sub 3} (010) substrates. Nominal β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3} (010) compositions were determined through Al:Ga flux ratios. With x = ∼0.18, the β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3} (020) layer peak in a high-resolution x-ray diffraction (HRXRD) ω-2θ scan was barely discernible, and Pendellösung fringes were not visible.more » This indicated that the phase stability limit of Al{sub 2}O{sub 3} in β-Ga{sub 2}O{sub 3} (010) at 600 °C was less than ∼18%. The substrate temperature was then varied for a series of β-(Al{sub ∼0.15}Ga{sub ∼0.85}){sub 2}O{sub 3} (010) layers, and the smoothest layer was grown at 650 °C. The phase stability limit of Al{sub 2}O{sub 3} in β-Ga{sub 2}O{sub 3} (010) appeared to increase with growth temperature, as the β-(Al{sub x}Ga{sub 1−x}){sub 2}O{sub 3} (020) layer peak with x = ∼0.18 was easily distinguishable by HRXRD in a sample grown at 650 °C. Cross-sectional transmission electron microscopy (TEM) indicated that β-(Al{sub ∼0.15}Ga{sub ∼0.85}){sub 2}O{sub 3} (010) layers (14.4% Al{sub 2}O{sub 3} by energy dispersive x-ray spectroscopy) grown at 650 °C were homogeneous. β-(Al{sub ∼0.20}Ga{sub ∼0.80}){sub 2}O{sub 3} (010) layers, however, displayed a phase transition. TEM images of a β-(Al{sub ∼0.15}Ga{sub ∼0.85}){sub 2}O{sub 3}/Ga{sub 2}O{sub 3} (010) superlattice grown at 650 °C showed abrupt layer interfaces and high alloy homogeneity.« less

Cladding glass ceramic for use in high powered lasers

DOEpatents

Marker, A.J.; Campbell, J.H.

1998-02-17

A Cu-doped/Fe-doped low expansion glass ceramic composition comprising in Wt. %: SiO{sub 2} 50--65; Al{sub 2}O{sub 3} 18--27; P{sub 2}O{sub 5} 0--10; Li{sub 2}O 2--6; Na{sub 2}O 0--2; K{sub 2}O 0--2; B{sub 2}O{sub 3} 0--1; MgO 0--4; ZnO 0--5; CaO 0--4; BaO 0--5; TiO{sub 2} 1--3; ZrO{sub 3} 1--3; As{sub 2}O{sub 3} 0--1.5; Sb{sub 2}O{sub 3} 0--1.5; CuO 0--3; and Fe{sub 2}O{sub 3} 0--1 wherein the total amount of SiO{sub 2}, Al{sub 2}O{sub 3} and P{sub 2}O{sub 5} is 80--89 wt. %, and said glass ceramic contains as a dopant 0.1--3 wt. % CuO, 0.1--1 wt. % Fe{sub 2}O{sub 3} or a combined CuO+Fe{sub 2}O{sub 3} amount of 0.1--4 wt. %. The glass ceramic composition is suitable for use as a cladding material for solid laser energy storage mediums as well as for use in beam attenuators for measuring laser energy level and beam blocks or beam dumps used for absorbing excess or unused laser energy.

Cladding glass ceramic for use in high powered lasers

DOEpatents

Marker, Alexander J.; Campbell, John H.

1998-01-01

A Cu-doped/Fe-doped low expansion glass ceramic composition comprising in Wt. %: SiO{sub 2} 50--65; Al{sub 2}O{sub 3} 18--27; P{sub 2}O{sub 5} 0--10; Li{sub 2}O 2--6; Na{sub 2}O 0--2; K{sub 2}O 0--2; B{sub 2}O{sub 3} 0--1; MgO 0--4; ZnO 0--5; CaO 0--4; BaO 0--5; TiO{sub 2} 1--3; ZrO{sub 3} 1--3; As{sub 2}O{sub 3} 0--1.5; Sb{sub 2}O{sub 3} 0--1.5; CuO 0--3; and Fe{sub 2}O{sub 3} 0--1 wherein the total amount of SiO{sub 2}, Al{sub 2}O{sub 3} and P{sub 2}O{sub 5} is 80--89 wt. %, and said glass ceramic contains as a dopant 0.1--3 wt. % CuO, 0.1--1 wt. % Fe{sub 2}O{sub 3} or a combined CuO+Fe{sub 2}O{sub 3} amount of 0.1--4 wt. %. The glass ceramic composition is suitable for use as a cladding material for solid laser energy storage mediums as well as for use in beam attenuators for measuring laser energy level and beam blocks or beam dumps used for absorbing excess or unused laser energy.

Phase equilibria in the quasi-ternary system Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} and physical properties of (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivashchenko, I.A., E-mail: inna.ivashchenko@mail.ru; Danyliuk, I.V.; Olekseyuk, I.D.

2014-02-15

The quasi-ternary system Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} was investigated by differential thermal, X-ray phase, X-ray structure, microstructure analysis and microhardness measurements. Five quasi-binary phase diagrams, six polythermal sections, isothermal section at 820 K and the liquidus surface projection were constructed. The character and temperature of the invariant processes were determined. The specific resistance of the single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} was measured, 7.5×10{sup 5} and 3.15×10{sup 5} Ω m, respectively, optical absorption spectra in the 600–1050 nm range were recorded at room temperature, and the band gap energy was estimatedmore » which is 1.95±0. 01 eV for both samples. - Graphical abstract: The article reports for the first time the investigated liquidus surface projection of the Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system and isothermal section at 820 K of the system. Five phase diagrams, six polythermal sections, isothermal section at 820 K and the liquidus surface projection were built at the first time. The existence of the large region of the solid solutions based on AgIn{sub 5}Se{sub 8}, Ga{sub 2}Se{sub 3} and AgGa{sub 1−x}In{sub x}Se{sub 2} was investigated. The existence of two ternary phases was established in the Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system. Two single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} were grown and some of optical properties of them were studied at first time. Display Omitted - Highlights: • Liquidus surface projection was built for Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system. • Solid solution ranges of AgIn{sub 5}Se{sub 8}, Ga{sub 2}Se{sub 3} and AgGa{sub 1−x}In{sub x}Se{sub 2} were investigated. • Two single crystals (Ga{sub 0.6}In{sub 0.4}){sub 2}Se{sub 3}, (Ga{sub 0.594}In{sub 0.396}Er{sub 0.01}){sub 2}Se{sub 3} were grown. • Some optical properties of these single crystals were studied.« less

Facile synthesis of nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite with enhanced photocatalytic performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jiangpeng; Li, Changqing; Cong, Jingkun

2016-06-15

Here we report a facile synthesis of nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) by using Fe-melamine supramolecular framework as precursor. The chemical and optical properties of the nanocomposites are well-characterized. The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities under visible light due to the efficient utilization of sunlight and the construction of Z-scheme electron transfer pathway. The results indicated that it could be a promising approach for the preparation of efficient g-C{sub 3}N{sub 4} nanocomposites photocatalysts by using metal-melamine supramolecular framework as precursors. - Graphical abstract: Nanorod-type graphitic carbon nitride/Fe{sub 2}O{submore » 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) was synthesized by using Fe-melamine supramolecular framework as precursor. The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities under visible light. Display Omitted - Highlights: • Nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) was synthesized. • Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} showed strong optical absorption in the visible-light region. • The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities.« less

Thermodynamic properties of seven gaseous halogenated hydrocarbons from acoustic measurements: CHClFCF{sub 3}, CHF{sub 2}CF{sub 3}, CF{sub 3}CH{sub 3}, CHF{sub 2}CH{sub 3}, CF{sub 3}CHFCHF{sub 2},CF{sub 3}CH{sub 2}CF{sub 3}, and CHF{sub 2}CF{sub 2}CH{sub 2}F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillis, K.A.

1997-01-01

Measurements of the speed of sound in seven halogenated hydrocarbons are presented. The compounds in this study are 1-chloro-,2,2,2-tetrafluoroethane (CHCIFCF{sub 3} or HCFC-124), pentafluoroethane (CHF{sub 2}CF{sub 3} or HFC-125), 1,1,1-trifluoroethane (CF{sub 3}CH{sub 3} or HFC-143a), 1,1-difluoroethane (CHF{sub 2}CH{sub 3} or HFC-152a), 1,1,2,3,3-hexafluoropropane (CF{sub 3}CHFCHF{sub 2} or HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (CF{sub 3}CH{sub 2}CF{sub 3} or HFC-236fa), and 1,1,2,2,3-pentafluoropropane (CHF{sub 2}CF{sub 2}CH{sub 2}F or HFC-245ca). The measurements were performed with a cylindrical resonator at temperatures between 240 and 400 K and at pressures up to 1.0 MPa. Ideal-gas heat capacities and acoustic virial coefficients were directly deduced from the data. The ideal-gas heatmore » capacity of HFC-125 from this work differs from spectroscopic calculations by less than 0.2% over the measurement range. The coefficients for virial equations of state were obtained from the acoustic data and hard-core square-well intermolecular potentials. Gas densities that were calculated from the virial equations of state for HCFC-124 and HFC-125 differ from independent density measurements by at most 0.15%, for the ranges of temperature and pressure over which both acoustic and Burnett data exist. The uncertainties in the derived properties of the other five compounds are comparable to those for HCFC-124 and HFC-125.« less

Kinetic control in the synthesis of metastable polymorphs: Bixbyite-to-Rh{sub 2}O{sub 3}(II)-to-corundum transition in In{sub 2}O{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bekheet, Maged F., E-mail: maged.bekheet@ceramics.tu-berlin.de; Fachgebiet Keramische Werkstoffe, Institut für Werkstoffwissenschaften und -technologien, Technische Universität Berlin, Hardenbergstraße 40, 10623 Berlin; Schwarz, Marcus R.

2015-09-15

An example for kinetic control of a solid-state phase transformation, in which the system evolves via the path with the lowest activation barrier rather than ending in the thermodynamically most favorable state, has been demonstrated. As a case study, the phase transitions of indium sesquioxide (In{sub 2}O{sub 3}) have been guided by theoretical calculations and followed in situ under high-pressure high-temperature conditions in multi-anvil assemblies. The corundum-type rh-In{sub 2}O{sub 3} has been synthesized from stable bixbyite-type c-In{sub 2}O{sub 3} in two steps: first generating orthorhombic Rh{sub 2}O{sub 3}-II-type o′-In{sub 2}O{sub 3} which is thermodynamically stable at 8.5 GPa/850 °C and,more » thereafter, exploiting the preferred kinetics in the subsequent transformation to the rh-In{sub 2}O{sub 3} during decompression. This synthesis strategy of rh-In{sub 2}O{sub 3} was confirmed ex situ in a toroid-type high-pressure apparatus at 8 GPa and 1100 °C. The pressure–temperature phase diagrams have been constructed and the stability fields of In{sub 2}O{sub 3} polymorphs and the crystallographic relationship between them have been discussed. - Graphical abstract: In situ energy-dispersive XRD patterns in multi-anvil assemblies show the sequence of phase transition c-In{sub 2}O{sub 3}→o′-In{sub 2}O{sub 3}→rh-In{sub 2}O{sub 3} under particular pressure and temperature conditions. The tick marks refer to the calculated Bragg positions of bixbyite-type (c-In{sub 2}O{sub 3}), Rh{sub 2}O{sub 3}-II-type (o–-In2O{sub 3}) and corundum-type (rh-In{sub 2}O{sub 3}). - Highlights: • The solid-state synthesis methods can be employed for obtaining metastable phases. • The phase transition of In{sub 2}O{sub 3} was guided by DFT calculations. • The phase transition of In{sub 2}O{sub 3} was followed in situ under HP–HT conditions. • Orthorhombic o′-In{sub 2}O{sub 3} polymorph was synthesized from c-In{sub 2}O{sub 3} at 8.5 GPa/850 °C. • Metastable rh-In{sub 2}O{sub 3} was obtained from o′-In{sub 2}O{sub 3} at 5.5 GPa during decompression.« less

Method of using a nuclear magnetic resonance spectroscopy standard

DOEpatents

Spicer, Leonard D.; Bennett, Dennis W.; Davis, Jon F.

1985-01-01

(CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy, wherein the resonance peaks of either .sup.1 H, .sup.13 C, .sup.15 N, or .sup.29 Si may be used as a reference.

(Tetramethylthiophene)ruthenium in dichloride dimer: A versatile synthetic intermediate in thiophene coordination chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockemeyer, J.R.; Rauchfuss, T.B.; Wilson, S.R.

1989-11-22

The thermal reaction of ((cymene)RuCl{sub 2}){sub 2} and tetramethylthiophene (TMT) gives ((TMT)RuCl{sub 2}){sub 2} (1). Treatment of 1 with silver salts in the presence of various ligands gives salts of ((TMT)RuL{sub 3}){sup 2+} where L{sub 3} = (H{sub 2}O){sub 3}, (CH{sub 3}CN){sub 3}, and TMT. A crystallographic study demonstrated that ((TMT){sub 2}Ru)(BF{sub 4}){sub 2} {times} 2CH{sub 3}NO{sub 2} adopts a sandwich structure with sulfur atoms sited cis on the pseudooctahedron. Cyclic voltammetry studies show that ((TMT){sub 2}Ru){sup 2+} undergoes 2 reversible one-electron reductions. Solutions of 1 and phosphine and amine donors react to give well-behaved monometallic derivatives of the typemore » (TMT)RuCl{sub 2}L where L is PR{sub 3} and NH{sub 2}C{sub 6}H{sub 4}Me. For bulky L = PPh{sub 3} and P(C{sub 6}H{sub 4}Me){sub 3}, variable-temperature NMR studies demonstrate hindered rotation about the Ru-P and Ru{hor ellipsis} TMT axes. Treatment of 1 with (Me{sub 3}Si){sub 2}S gives the cluster ((TMT)RuCl){sub 3}S{sup +} whose PF{sub 6}{sup {minus}} salt was examined by X-ray crystallography. The cluster is comprised of 3 conjoined pseudooctahedral Ru centers bridged by 1 {mu}{sub 3}-S and 3 {mu}-Cl atoms.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Baulin, V. E.; Ivanova, I. S.

The coordination compounds of Er{sup 3+} with 1-(methoxydiphenylphosphoryl)-2-diphenylphosphorylbenzene [ErL{sub 2}{sup 1}(NO{sub 3}){sub 2}]{sub 2}[Er(NO{sub 3}){sub 2}(H{sub 2}O){sub 5}]{sub 0.333}(NO{sub 3}){sub 2.333} · 2.833H{sub 2}O (I) and its ethyl substituted derivative [ErL{sub 2}{sup 2}(NO{sub 3}){sub 2}][Er(NO{sub 3}){sub 5}]{sub 0.5} · 0.5H{sub 2}O (II) are synthesized and their crystal structures are studied. I and II contain [ErL{sub 2}(NO{sub 3}){sub 2}]{sup +} complex cations of identical composition and close structure. The eight-vertex polyhedron of the Er atom in the shape of a distorted octahedron with two split trans vertices is formed by the O atoms of the phosphoryl groups of L ligands andmore » nitrate anions. L ligands close nine-membered metallocycles. The structures contain spacious channels which are populated differently, namely, by disordered [Er(NO{sub 3}){sub 2}(H{sub 2}O){sub 5}]{sup +} complex cations, NO{sub 3}{sup −} anions, and crystallization water molecules in I and disordered [Er(NO{sub 3}){sub 5}]{sup 2−} complex anions and crystallization water molecules in II. The IR spectra of I and II are studied.« less

Synthesis and physico-chemical studies on neodymium(III) and samarium(III) complexes with tetraaza macrocyclic ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goel, S.; Pandey, U.K.; Pandey, O.P.

1988-05-01

Reactions of neodymium trichloride and samarium trichloride with 6,7,13,14-R/sub 4/ - 3,10-X/sub 2/-(14)-5,7,12,14-tetraene-1,5,8,12-N/sub 4/-(2,4,9,11-N/sub 4/) (R = CH/sub 3/, X = 0 (L/sub 1//sup (1)/); R = C/sub 6/H/sub 5/, X = O (L/sub 1//sup (2)/); R = CH/sub 3/, X = S(L/sub 2//sup (1)/)) and R = C/sub 6/H/sub 5/, X = S(/sub 2//sup (2)/)) have been studied in ethanol and complexes of the type (M(L/sub 1//sup (1)/ or L/sub 1//sup (2)/))Cl/sub 3/ and (M(L/sub 2//sup (1)/ or L/sub 2//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been isolated. In addition, macrocyclic complexes of Nd(III) andmore » Sm(III) with another series of tetraaza ligands, viz, 5,6,11,12-R/sub 4/-3,8-X/sub 2/-(12)-4,6,10,12-tetraene-1,4,7,10-N/sub 4/-(2,9-N/sub 2/) (R = CH/sub 3/, X = O (L/sub 3//sup (1)/); R = C/sub 6/H/sub 5/, X = O(L/sub 3//sup (2)/); R = CH/sub 3/, X = S(L/sub 4//sup (1)/); R = C/sub 6/H/sub 5/, X = S(L/sub 4//sup (2)/)), formulated as (M(L/sub 3//sup (1)/, L/sub 3//sup (2)/, L/sub 4//sup (1)/ or L/sub 4//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been prepared by template condensation of Nd(III) and Sm(III) complexes of diacetylbis(semicarbazonethiosemicarbazone) or benzilibis(semicarbazonethiosemicarbazone) with diacetyl or benzil. The complexes have been identified by elemental analysis, electrical conductance, spectral and thermal measurements.« less

Synthesis of phospholyl-bridged heterobimetallic ruthenium hydrides in combination with zirconium and ytterbium and the crystal structure of (THF){sub 2}Yb[{mu}({eta}{sup 5}, {eta}{sup 1})-C{sub 4}Me{sub 4}P]{sub 2 }Ru(H){sub 2}(Ph{sub 3}P){sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desmurs, P.; Visseaux, M.; Baudry, D.

1996-10-01

Heterobimetallic zirconium-ruthenium and ytterbium-ruthenium dihydrides, having bridging phospholyl ligands, have been obtained for the first time. Reaction of bis({eta}{sup 5}-tetramethylphospholyl)dichlorozirconium [(TMP){sub 2}ZrCl{sub 2}] with RuH{sub 4}(PPh{sub 3}){sub 3} gave the zirconium-ruthenium heterobimetallic Cl{sub 2}Zr[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H){sub 2} (PPh{sub 3}){sub 2}. This compound was transformed into the hydridochloride Cl{sub 2}Zr[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H)(Cl)( PPh{sub 3}){sub 2} by the action of CCl{sub 4}. Similarly, reaction of [(TMP){sub 2}Yb] with RuH{sub 4}(PPh{sub 3}){sub 3} afforded (THF){sub 2}Yb[{mu}({eta}{sup 5}, meta{sup 1})-TMP]{sub 2}Ru(H){sub 2}(PPh{sub 3}){sub 2}. The structure of this compound, which has been determined by X-ray crystallography, confirms the trans configuration of themore » dihydride deduced previously from NMR data. Attempts to isolate products from the reaction of [(TMP){sub 2}UCl{sub 2}] or [(TMP){sub 2}U(BH{sub 4}){sub 2}] with RuH{sub 4}(PPh{sub 3}){sub 3} were unsuccessful, but NMR data show the formation of both heterobimetallic trans- and cis-ruthenium dihydride-uranium compounds X{sub 2}U[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H){sub 2}(P Ph{sub 3}){sub 2} (X = BH{sub 4}, Cl) in solution. 19 refs., 1 fig., 2 tabs.« less

Method of using a nuclear magnetic resonance spectroscopy standard. [SO/sub 2/ in gases by fluorescence

DOEpatents

Spicer, L.D.; Bennett, D.W.; Davis, J.F.

1983-05-09

(CH/sub 3/)/sub 3/SiNSO is produced by the reaction of ((CH/sub 3/)/sub 3/SI)/sub 2/NH with SO/sub 2/. Also produced in the reaction are ((CH/sub 3/)/sub 3/Si)/sub 2/O and a new solid compound (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/). Both (CH/sub 3/)/sub 3/SiNSO and (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO/sub 2/ pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH/sub 3/)/sub 3/Si)/sub 2/NH, whereby any SO/sub 2/ present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO/sub 2/ in the original gas sample. The solid product (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) may be used as a standard in solid state NMR spectroscopy, wherein the resonance peaks of either /sup 1/H, /sup 13/C, /sup 15/N, or /sup 29/Si may be used as a reference.

Hydrothermal synthesis and characterization of the first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortner, Teresa S.; Wurst, Klaus; Perfler, Lukas

2015-01-15

The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} was synthesized under hydrothermal conditions from Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O and K{sub 2}B{sub 4}O{sub 7}·4H{sub 2}O using KNO{sub 3} as a nitrate source. The compound crystallizes in the space group Pnnm (no. 58) with the lattice parameters a=1320.8(3), b=910.7(2), and c=1232.5(3) pm (Z=4). Isolated Sechserrings formed by BO{sub 4} and BO{sub 3} groups are linked through hydrogen bridges to form a three-dimensional network. - Graphical abstract: The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} was synthesized under hydrothermal conditions from Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}Omore » and K{sub 2}B{sub 4}O{sub 7}·4H{sub 2}O using KNO{sub 3} as a nitrate source. - Highlights: • The first mixed alkali borate-nitrate K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3} is reported. • Hydrothermal conditions (240 °C, 3d) were used for the synthesis of K{sub 3}Na[B{sub 6}O{sub 9}(OH){sub 3}]NO{sub 3}. • Borate Sechserrings are interconnected through hydrogen-bonding.« less

Solid state reaction synthesis and photoluminescence properties of Dy{sup 3+} doped Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12} phosphor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Qiang; Wang, Chuang; Li, Yanyan

2015-11-15

Highlights: • Ca{sub 3−x}Sc{sub 2}Si{sub 3}O{sub 12}:xDy{sup 3+} (0.01 ≤ x ≤ 0.03) was successfully synthesized under a reducing atmosphere. • The thermal stability of the Ca{sub 2.975}Sc{sub 2}Si{sub 3}O{sub 12}:0.025Dy{sup 3+} is superior to commercial phosphors in theory and experiment. • The optimal chromaticity coordinates of Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} is (x = 0.3425, y = 0.3343) upon 350 nm excitation. - Abstract: The white emission phosphor Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} was synthesized by the solid-state reaction. Phase analysis and characteristic luminescence properties are investigated by X-ray diffraction and photoluminescence spectra measurement. Ca{sub 3}Sc{sub 2}Si{submore » 3}O{sub 12}:Dy{sup 3+} phosphor shows strong absorption in 350–410 nm region and exhibits white emission with CIE chromaticity coordinates of (0.3425, 0.3343). Its emission intensity at 250 °C remained 74% of that measured at room temperature. Moreover, the activation energy is also calculated through the Arrhenius equation. The result shows that the thermostability of Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} is superior than that of commercial phosphor Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Ce{sup 3+}. The outstanding luminescent properties indicate that Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} could be a potential white light emission phosphor.« less

Synthesis and X-ray diffraction study of new uranyl malonate and oxalate complexes with carbamide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medvedkov, Ya. A.; Serezhkina, L. B., E-mail: Lserezh@samsu.ru; Grigor’ev, M. S.

2016-05-15

Two new malonate-containing uranyl complexes with carbamide of the formulas [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Urea){sub 2}] (I) and [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Urea){sub 3}] (II), where Urea is carbamide, and one uranyl oxalate complex of the formula [UO{sub 2}(C{sub 2}O{sub 4})(Urea){sub 3}] (III) were synthesized, and their crystals were studied by X-ray diffraction. The main structural units in crystals I are the electroneutral chains [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Urea){sub 2}]{sub ∞} belonging to the crystal-chemical group AT{sup 11}M{sub 2}{sup 1} (A = UO{sub 2}{sup 2+}, T{sup 11} = C{sub 3}H{sub 2}O{sub 4}{sup 2-}, M{sup 1} = Urea) of uranyl complexes.more » Crystals II and III are composed of the molecular complexes [UO{sub 2}(L)(Urea){sub 3}], where L = C{sub 3}H{sub 2}O{sub 4}{sup 2-} or C{sub 2}O{sub 4}{sup 2-}, belonging to the crystal-chemical group AB{sup 01}M{sub 3}{sup 1} (A = UO{sub 2}{sup 2+}, B{sup 01} = C{sub 3}H{sub 2}O{sub 4}{sup 2-} or C{sub 2}O{sub 4}{sup 2-}, M{sup 1} = Urea). The characteristic features of the packing of the uranium-containing complexes are discussed in terms of molecular Voronoi–Dirichlet polyhedra. The effect of the Urea: U ratio on the structure of uranium-containing structural units is considered.« less

Energy transfer from Tb{sup 3+} to Eu{sup 2+} in Ga{sub 2}S{sub 3}:(Eu{sup 2+}, Tb{sup 3+}) crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tagiev, O. B., E-mail: Oktay58@mail.ru; Ganbarova, Kh. B.

2015-04-15

The photoluminescence of Ga{sub 2}S{sub 3} crystals activated with Eu{sup 2+} and Tb{sup 3+} ions separately and with ions of both types is studied in the temperature range 77–300 K. It is established that, in the range 77–300 K, the observed broadband photoluminescence in (Ga{sub 2}S{sub 3}){sub 0.95}:(Eu{sub 2}O{sub 3}){sub 0.05} crystals with a peak at 545 nm is defined by 4f{sup 6}5d-4f{sup 7}({sup 8}S{sub 7/2}) intracenter transitions in Eu{sup 2+} ions and the photoluminescence with peaks at 492, 544, 584, 625, and 680 nm in (Ga{sub 2}S{sub 3}){sub 0.99}(Tb{sub 2}O{sub 3}){sub 0.01} crystals is due to the 5d →more » {sup 2}F{sub j} (j = 6−2) intracenter transitions in Tb{sup 3+} ions. It is shown that the photoluminescence bands of Tb{sup 3+} ions in the (Ga{sub 2}S{sub 3}){sub 0.94}(Eu{sub 2}O{sub 3}){sub 0.05}(Tb{sub 2}O{sub 3}){sub 0.01} crystals disappears because of excitation energy transfer from Tb{sup 3+} ions to Eu{sup 2+} ions; i.e., the Tb{sup 3+} ion is a sensitizer of the photoluminescence of the Eu{sup 2+} ion.« less

Luminescent properties of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} and its luminescence improvement by incorporating A{sup +} (A=Li, Na, and K)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Panlai, E-mail: li_panlai@126.com; Wang, Zhijun, E-mail: wangzj1998@126.com; Yang, Zhiping

2014-12-15

A novel green phosphor SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} is synthesized by a high temperature solid-state method, and its luminescent property is investigated. X-ray diffraction patterns of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} indicate a similarity crystalline phase to SrZn{sub 2}(PO{sub 4}){sub 2}. SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} shows green emission under 369 nm excitation, and the prominent luminescence in green (544 nm) due to {sup 5}D{sub 4}–{sup 7}F{sub 5} transition of Tb{sup 3+}. For the 544 nm emission, excitation spectrum has several excitation band from 200 nm to 400 nm. Emission intensity of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} is influencedmore » by Tb{sup 3+} concentration, and concentration quenching effect of Tb{sup 3+} in SrZn{sub 2}(PO{sub 4}){sub 2} is also observed. With incorporating A{sup +} (A=Li, Na, and K) as compensator charge, the emission intensity of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can be obviously enhanced. CIE color coordinates of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} locate in the green region. The results indicate this phosphor may be a potential application in white LEDs. - Graphical abstract: SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can produce green emission under near-UV excitation, and its luminescent properties can be improved by incorporating A{sup +} (A=Li, Na, and K). - Highlights: • SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can produce green emission under near-UV excitation. • Concentration quenching effect of Tb{sup 3+} in SrZn{sub 2}(PO{sub 4}){sub 2} is observed. • Emission intensities of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} are enhanced by codoped A{sup +} (A=Li, Na, K)« less

Syntheses and crystal structures of two new hydrated borates, Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Xuean; Zhao Yinghua; Chang Xinan

Two new hydrated borates, Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O, have been prepared by hydrothermal reactions at 170 {sup o}C. Single-crystal X-ray structural analyses showed that Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] crystallizes in a non-centrosymmetric space group R32 with a=8.006(2) A, c=17.751(2) A, Z=3 and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O in a triclinic space group P1-bar with a=6.656(2) A, b=6.714(2) A, c=10.701(2) A, {alpha}=99.07(2){sup o}, {beta}=93.67(2){sup o}, {gamma}=118.87(1){sup o}, Z=2. Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices leading to helical ribbons {submore » {infinity}} {sup 1}[Zn{sub 8}O{sub 15}(OH){sub 3}]{sup 17-} that pack side by side and are further condensed through sharing oxygen atoms to form a three-dimensional {sub {infinity}} {sup 3}[Zn{sub 8}O{sub 11}(OH){sub 3}]{sup 9-} framework. The boron atoms are incorporated into the channels in the framework to complete the final structure. Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O is a layered compound containing double ring [B{sub 5}O{sub 8}(OH)]{sup 2-} building units that share exocyclic oxygen atoms to form a two-dimensional layer. Symmetry-center-related layers are stacked along the c-axis and held together by interlayer Pb{sup 2+} ions and water molecules via electrostatic and hydrogen bonding interactions. The IR spectra further confirmed the existence of both triangular BO{sub 3} and OH groups in Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}], and BO{sub 3}, BO{sub 4}, OH groups as well as guest water molecules in Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O. -- Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices to form a three-dimensional framework. The boron atoms are incorporated into the channels in the framework to strengen the structure via B-O bonds. Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O is a new layered material containing double ring [B{sub 5}O{sub 8}(OH)]{sup 2-} building units that share exocyclic oxygen atoms to form a two-dimensional layer.« less

Blue fluorescence of three metal-organic zinc polymers containing tetrazinc units and asymmetric ligand of btc{sup 3-}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Ling; Graduate School of Chinese Academy of Sciences, Beijing 100039; Liu Bing

2005-11-15

Three new zinc coordination polymers [Zn{sub 2}(btc){sub 2}(H{sub 2}O){sub 2}] {sub n} .n[Zn(H{sub 2}O){sub 6}] (1), [Zn{sub 3}(btc){sub 2}(2,2'-bipy){sub 2}(H{sub 2}O){sub 3}] {sub n} .2nH{sub 2}O (2) and [Zn{sub 3}(btc){sub 2}(H{sub 2}O){sub 6}] {sub n} .nH{sub 2}O (3) (H{sub 3}btc=1,2,4-benzenetricarboxylic acid, 2,2'-bipy=2,2'-bipyridine) were obtained by the diffusion method and their crystal structures were determined by single-crystal X-ray diffraction. Compounds 1-3 have the similar tetrametallic unit [Zn{sub 4}(btc){sub 2}] SBUs and these SBUs are further connected into stair-like structure, 2-D layer and 3-D framework for 1, 2 and 3, in which the btc{sup 3-} ligands adopt {mu} {sub 3}, {mu} {submore » 4} and {mu} {sub 5} coordination modes, respectively. The title compounds show strong blue fluorescence, which may be assigned as {pi}*{sup {yields}}n transition of the ligand mixed with the ligand-to-metal change transfer (LMCT), indicating the fluorescence, indicates the title compounds may be good candidates for blue-light photoactive materials.« less

Structural peculiarities and Raman spectra of TeO{sub 2}/WO{sub 3}-based glasses: A fresh look at the problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirgorodsky, Andreie; Colas, Maggy; Smirnov, Mikhael

2012-06-15

Ideas currently dominating the field of structural studies of TeO{sub 2}-based glasses are critically considered. A new physically and chemically consistent approach to the constitution of binary TeO{sub 2}-WO{sub 3} glasses is proposed, in which the reasoning coming from the Raman spectra reexamination are correlated with the basic principles of thermodynamics. Separation into two phases is suggested in such glasses. One phase is TeO{sub 2}, and another is Te(WO{sub 4}){sub 2} consisting of tetrahedral [WO{sub 4}]{sup 2-} anions and of Te{sup 4+} cations. Supplementary M{sub n}O{sub k} oxides added to the glasses are found incorporated in the former phase, thusmore » producing solid solutions (for M=Ti, Nb) or tellurite compounds (for M=Nd). - Graphical abstract: Raman scattering spectra of TeO{sub 2}-based glasses with the following compositions (mol%): (a) pure TeO{sub 2}, (b) 85TeO{sub 2}-15WO{sub 3}, (c) 80TeO{sub 2}-15WO{sub 3}-5TiO{sub 2} ,(d) 80TeO{sub 2}-10WO{sub 3}-5TiO{sub 2}-5Nb{sub 2}O{sub 5}, (e) 80TeO{sub 2}-12WO{sub 3}-5TiO{sub 2}-3 Nd{sub 2}O{sub 3}, (f) 80TeO{sub 2}-10WO{sub 3}-5TiO{sub 2}-5Nd{sub 2}O{sub 3}. Highlights: Black-Right-Pointing-Pointer Structural studies of TeO{sub 2}-WO{sub 3} glasses are critically considered. Black-Right-Pointing-Pointer The oxide glass formation is analyzed from Raman spectra and thermodynamic principles. Black-Right-Pointing-Pointer Separation into two phases, TeO{sub 2} and Te(WO{sub 4}){sub 2}, is intrinsic in such glasses. Black-Right-Pointing-Pointer TiO{sub 2} or Nb{sub 2}O{sub 5} addition to TeO{sub 2}-WO{sub 3} glasses leads to produce solid solutions. Black-Right-Pointing-Pointer Nd{sub 2}O{sub 3} addition to TeO{sub 2}-WO{sub 3} glasses leads to produce a tellurite compound.« less

X-ray mapping in heterocyclic design: 18. X-ray diffraction study of a series of derivatives of 3-cyanopyridine-2-one with annelated heptane and octane cycles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rybakov, V. B., E-mail: Rybakov20021@yandex.ru; Babaev, E. V.; Paronikyan, E. G., E-mail: Ervand.paronikyan@mail.ru

Seven new, previously unknown, bicyclic and tricyclic heterocycles based on derivatives of 3-cyanopyrid-2-ones are obtained: 2-oxo-2,5,6,7,8,9-hexahydro-1H-cyclohepta[b]pyridine-3-carbonitrile, C{sub 11}H{sub 12}N{sub 2}O (1a); 2-[2-(4-chlorophenyl)-2-oxoethoxy]-6,7,8,9-tetrahydro-5H-cyclohepta[b] pyridine-3-carbonitrile, C{sub 19}H{sub 17}ClN{sub 2}O{sub 2} (2a); (3-amino-6,7,8,9-tetrahydro-5H-cyclohepta[b]furo[3,2-e]pyridin-2-yl)(4- chlorophenyl)methanone, C{sub 19}H{sub 17}ClN{sub 2}O{sub 2} (3); 2-oxo-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carboxamide, C{sub 12}H{sub 16}N{sub 2}O{sub 2} (4); 2-[2-(4-chorophenyl)-2-oxoethoxy]-5,6,7,8,9,10 -hexahydrocycloocta[b]pyridine-3-carboxamide, C{sub 20}H{sub 21}ClN{sub 2}O{sub 3} (5a); 1-[2-(4-chlorophenyl)-2-oxoethyl]-2-oxo-1,2,5,6,7,8,9,10 -octahydrocycloocta[b]pyridine-3-carboxamide, C{sub 20}H{sub 21}ClN{sub 2}O{sub 3} (5b); and 2-[2-(4-chlorophenyl)-2-oxoethoxy]-5,6,7,8,9,10-hexahydrocycloocta[b] pyridine-3-carbonitrile, C{sub 20}H{sub 19}ClN{sub 2}O{sub 2}, (6). All compounds are characterized by {sup 1}H NMR spectroscopy, and their crystal structures are determined by X-ray diffraction.

New μ-SnTe{sub 4} and μ-Sn{sub 2}Te{sub 6} ligands to transition metal: Solvothermal syntheses and characterizations of zinc tellurostannates containing polyamine ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Jialin; Wang, Fang; Shen, Yali

2014-08-15

Zinc tellurostannates [(Zn(teta)){sub 2}(μ-1κ:2κ-SnTe{sub 4})] (1), [(Zn(teta)){sub 3}(μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4})]I{sub 2} (2), [(Zn(tren)){sub 2}(μ-1κ:2κ-Sn{sub 2}Te{sub 6})] (3), and [Zn(dien){sub 2}]{sub 4}(Sn{sub 2}Te{sub 6}){sub 1.75}(Sn{sub 2}Te{sub 8}){sub 0.25}·dien (4) were prepared by the reactions of Zn, Sn, and Te with iodine ion assistant in teta and dien. The tetrahedral [SnTe{sub 4}]{sup 4−} anion coordinates to two [Zn(teta)]{sup 2+} units as a bidentate μ-1κ:2κ-SnTe{sub 4} ligand to form the neutral complex 1. It coordinates to three [Zn(teta)]{sup 2+} units with a tridentate μ{sub 3}-1κ:2κ:3κ coordination modes, generating a complex cation [(Zn(teta)){sub 3}(μ{sub 3}-1κ:2κ:3κ- SnTe{sub 4})]{sup 2+} in 2. In 3, the [Sn{submore » 2}Te{sub 6}]{sup 4−} anion joins two [Zn(tren)]{sup 2+}cations with the trans terminal Te atoms, forming neutral complex 3. The μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands to TM centers in 1–3 have not been observed before. Compound 4 contains a normal [Sn{sub 2}Te{sub 6}]{sup 4−} and an abnormal [(Sn{sub 2}Te{sub 6}){sub 0.75}(Sn{sub 2}Te{sub 8}){sub 0.25}]{sup 4−} anions. Compounds 1–4 exhibit narrow band gaps in the range of 1.47–1.98 eV, and a distinct red-shift of the band gaps is observed from 4 to 1−3. - Graphical abstract: Zinc tellurostannates were prepared with iodine ion assistant in polyamines, and first μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands TM centers were obtained. - Highlights: • Zinc-tellurostannates were first prepared with iodine ion assistant. • Novel μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands were obtained. • The Zinc tellurostannates exhibit optical bandgaps between 1.47 and 1.98 eV.« less

The chemistry of (ring)Ru sup 2+ (ring = tetramethylthiophene, p-cymene)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganja, E.A.; Rauchfuss, T.B.; Stern, C.L.

1991-01-01

Described are the compounds ((ring)Ru(OTf){sub 2}){sub x}, where ring = 2,3,4,5-tetramethylthiophene (TMT, 1), and p-cymene (2). These electrophilic reagents serve as precursors to ((ring)RuL{sub 3}){sup 2+}, where L{sub 3} = (H{sub 2}O){sub 3}, (NH{sub 3}){sub 3}, and (PH{sub 3}){sub 3}. Solutions of 1 and 2 react with carbon monoxide to give (ring)Ru(CO)(OTf){sub 2}. The addition of thiophenes to CH{sub 2}Cl{sub 2} solutions of 1 or 2 leads to the precipitation of the sandwich compounds ((ring)(SC{sub 4}R{sub 4})Ru)(OTf){sub 2}, where SC{sub 4}R{sub 4} = thiophene, 2,5-dimethylthiophene, and TMT. ((TMT)Ru(H{sub 2}O){sub 3})(OTf){sub 2} was characterized by single-crystal X-ray crystallography, which established amore » piano-stool geometry with a planar TMT ligand. ((TMT)Ru(D{sub 2}O){sub 3})(OTf){sub 2} decomposes in D{sub 2}O solution at 150C to give ((TMT){sub 2}Ru){sup 2+}, which undergoes selective deuteration at the 2,5-methyl groups. D{sub 2}O solutions of ((TMT){sub 2}Ru){sup 2+} undergo photochemical loss of one TMT ligand in water to give ((TMT)Ru(H{sub 2}O){sub 3}){sup 2+}. A procedure is described for the reversible loading of 1 onto {gamma}-alumina, which in turn was characterized by {sup 13}C CP-MAS NMR spectroscopy.« less

A flux-free method for synthesis of Ce{sup 3+}-doped YAG phosphor for white LEDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiang, Yaochun; Yu, Yuxi, E-mail: yu_heart@xmu.edu.cn; Chen, Guolong

2016-02-15

Highlights: • A series of CeF{sub 3}-doped YAG phosphors were successfully synthesized. • CeF{sub 3} not only can be used as the Ce{sup 3+} source but also can play the role of a flux. • The QY of YAG:CeF{sub 3} phosphor is 91% but the QY of YAG:Ce{sub 2}O{sub 3} phosphor is just 80%. • YAG:CeF{sub 3} phosphor exhibits excellent thermal stability. • Using CeF{sub 3} as the Ce{sup 3+} source is a promising flux-free method to prepare YAG:Ce{sup 3+}. - Abstract: A series of CeF{sub 3}-doped Y{sub 3}Al{sub 5}O{sub 12} (YAG:CeF{sub 3}) phosphor, CeO{sub 2}-doped Y{sub 3}Al{sub 5}O{sub 12}more » (YAG:Ce{sub 2}O{sub 3}) phosphor and 5 wt% BaF{sub 2} added YAG:Ce{sub 2}O{sub 3} (YAG:Ce{sub 2}O{sub 3} + BaF{sub 2}) phosphor were successfully synthesized by a solid-state reaction method. The microstructure, morphology, luminescence spectra, luminescence quantum yield (QY) and thermal quenching of the phosphors were investigated. The QY of YAG:CeF{sub 3} phosphor is 91% but the QY of YAG:Ce{sub 2}O{sub 3} phosphor is just 80%. At 150 °C, the luminescence intensity of YAG:CeF{sub 3} phosphor, YAG:Ce{sub 2}O{sub 3} phosphor and YAG:Ce{sub 2}O{sub 3} + BaF{sub 2} phosphor was 85%, 86% and 89% of that measured at 25 °C, respectively. The comprehensive performance of the white LED lamp employing YAG:CeF{sub 3} phosphor is even better than that of the white LED lamp employing YAG:Ce{sub 2}O{sub 3} + BaF{sub 2} phosphor. The experimental results show that it is a promising flux-free method to synthesize Ce{sup 3+}-doped YAG phosphor by employing CeF{sub 3} as the Ce{sup 3+} source.« less

Emission Analysis Of Pr{sup 3+}: PVP And Nd{sup 3+}: PVP Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivaiah, K.; Buddhudu, S.

Here we report on the results concerning the absorption and emission spectra of RE{sup 3+} (Pr{sup 3+} or Nd{sup 3+}) doped PVP polymer films. The absorption spectrum of Pr{sup 3+}: PVP polymer film has shown three absorption bands at 444 nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 2}), 469nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 1}) and 481nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 0}). From the Pr{sup 3+}: PVP polymer film, an emission at 603 nm ({sup 1}D{sub 2{yields}}{sup 3}H{sub 4}) has been observed with an excitation at 443 nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 2}). The absorption spectrum of Nd{sup 3+}: PVP polymer film hasmore » exhibited eleven absorption bands at 324 nm, 383 nm, 432 nm, 462 nm, 511 nm, 526 nm, 580 nm, 686 nm, 746 nm, 799 nm, and 869 nm which are assigned to the electronic transitions of {sup 4}I{sub 9/2{yields}}{sup 4}D{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 2}D{sub 3/2}, {sup 4}I{sub 9/2{yields}}{sup 4}P{sub 1/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 11/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 9/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 5/2}, {sup 4}I{sub 9/2{yields}}{sup 2}F{sub 9/2}, {sup 4}I{sub 9/2{yields}}{sup 2}F{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 2}H{sub 9/2} and {sup 4}I{sub 9/2{yields}}{sup 4}F{sub 3/2} respectively. From the Nd{sup 3+}: PVP polymer film, an emission transition has been measured at 1055 nm ({sup 4}F{sub 3/2{yields}}{sup 4}I{sub 11/2}) with an excitation at 324 nm ({sup 4}I{sub 9/2{yields}}{sup 4}D{sub 7/2}). For the host polymer film, structural properties have been studied from the measurement of XRD, FTIR, Raman spectra. For this film thermal properties have also been investigated from the measured profiles of TGA-DTA.« less

High-throughput and in situ EDXRD investigation on the formation of two new metal aminoethylphosphonates - Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 2}) and Ca(OH)(O{sub 3}PC{sub 2}H{sub 4}NH{sub 3}){center_dot}2H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, Corinna; Feyand, Mark; Rothkirch, Andre

2012-04-15

The system Ca{sup 2+}/2-aminoethylphosphonic acid/H{sub 2}O/NaOH was systematically investigated using high-throughput methods. The experiments led to one new compound Ca(O{sub 3}PC{sub 2} H{sub 4}NH{sub 2}) (1) and the crystal structure was determined using in house X-ray powder diffraction data (monoclinic, P2{sub 1}/c, a=9.7753(3), b=6.4931(2), c=8.4473(2) A, {beta}=106.46(2) Degree-Sign , V=514.20(2) A{sup 3}, Z=4). The formation of 1 was investigated by in situ energy dispersive X-ray diffraction measurements (EDXRD) at beamline F3 at HASYLAB (light source DORIS III), DESY, Hamburg. An intermediate, Ca(OH)(O{sub 3}PC{sub 2}H{sub 4}NH{sub 3}){center_dot}2H{sub 2}O (2), was observed and could be isolated from the reaction mixture at ambientmore » temperatures by quenching the reaction. The crystal structure of 2 was determined from XRPD data using synchrotron radiation (monoclinic, P2{sub 1}/m, a=11.2193(7), b=7.1488(3), c=5.0635(2) A, {beta}=100.13(4) Degree-Sign , V=399.78(3) A{sup 3}, Z=2). - Graphical abstarct: The detailed in situ energy dispersive X-ray diffraction (EDXRD) investigation on the formation of the new inorganic-organic hybrid compound Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 2}) leads to the discovery of a new crystalline intermediate phase. Both crystal structures were elucidated using X-ray powder diffraction data. Highlights: Black-Right-Pointing-Pointer High-throughput investigation led to new metal aminoethylphosphonate Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 2}). Black-Right-Pointing-Pointer The formation of Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 2}) was followed by in situ EDXRD measurements. Black-Right-Pointing-Pointer The crystalline intermediate Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 3})(OH){center_dot}2H{sub 2}O was discovered. Black-Right-Pointing-Pointer Isolation of Ca(O{sub 3}PC{sub 2}H{sub 4}NH{sub 3})(OH){center_dot}2H{sub 2}O was accomplished by quenching experiments. Black-Right-Pointing-Pointer The structures were determined using X-ray powder diffraction data.« less

Improve the catalytic activity of {alpha}-Fe{sub 2}O{sub 3} particles in decomposition of ammonium perchlorate by coating amorphous carbon on their surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Yifu; Liu Xinghai, E-mail: liuxh@whu.edu.c; Nie Jiaorong

2011-02-15

Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value of the designed synthetic system, respectively. The sphere-like {alpha}-Fe{sub 2}O{sub 3} particles with diameter about 25 nm on average were encapsulated into carbon shells to fabricate a novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C) through the coating experiments. The catalytic performance of the products on the thermal decomposition of ammonium perchlorate (AP) was investigated by thermal gravimetric analyzer (TG) and differential thermal analysis (DTA). The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3},more » sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which show that {alpha}-Fe{sub 2}O{sub 3}-C core-shell composites have higher catalytic activity than that of {alpha}-Fe{sub 2}O{sub 3}. -- Graphical abstract: The catalytic performance of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C on the thermal decomposition of ammonium perchlorate (AP). Display Omitted Research highlights: {yields} Sphere- and pod-like {alpha}-Fe{sub 2}O{sub 3} particles have been selectively synthesized using NH{sub 3}.H{sub 2}O and NaOH solution to adjust the pH value. {yields} A novel core-shell composite ({alpha}-Fe{sub 2}O{sub 3}-C core-shell structured composite) has been successfully synthesized using sphere-like {alpha}-Fe{sub 2}O{sub 3} particles as the cores and glucose as the source of carbon. {yields} The thermal decomposition temperatures of AP in the presence of pod-like {alpha}-Fe{sub 2}O{sub 3}, sphere-like {alpha}-Fe{sub 2}O{sub 3} and {alpha}-Fe{sub 2}O{sub 3}-C are reduced by 72, 81 and 109 {sup o}C, respectively, which shows that these materials have high catalytic activity.« less

Separations method for polar molecules

DOEpatents

Thoma, Steven G.; Bonhomme, Francois R.

2004-07-27

A method for separating at least one compound from a liquid mixture containing different compounds where anew crystalline manganese phosphate composition with the formula Mn.sub.3 (PO.sub.4).sub.4.2(H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N.6(H.sub.2 O) is dispersed in the liquid mixture, selectively intercalating one or more compounds into the crystalline structure of the Mn.sub.3 (PO.sub.4).sub.4.2(H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N.6(H.sub.2 O).

Synthesis and characterization of homo- and heterobimetallic niobium{sup v} and tantalum{sup v} peroxo-polyaminocarboxylato complexes and their use as single or multiple molecular precursors for Nb-Ta mixed oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayot, Daisy; Degand, Matthieu; Devillers, Michel

2005-09-15

New water-soluble bimetallic peroxo complexes of niobium{sup V} and/or tantalum{sup V} with high-denticity polyaminocarboxylate ligands have been prepared, characterized from the spectroscopic point of view, and used as molecular precursors for Nb-Ta mixed oxides. Four new homobimetallic complexes (gu){sub 3}[Nb{sub 2}(O{sub 2}){sub 4}(dtpaO{sub 3})].3H{sub 2}O 1 (gu){sub 3}[Ta{sub 2}(O{sub 2}){sub 4}(dtpaO{sub 3})].5H{sub 2}O 2 (gu){sub 3}[Nb{sub 2}(O{sub 2}){sub 4}(HtthaO{sub 4})].2H{sub 2}O 4 and (gu){sub 3}[Ta{sub 2}(O{sub 2}){sub 4}(HtthaO{sub 4})].3H{sub 2}O 5 and the corresponding heterometallic complexes (gu){sub 3}[NbTa(O{sub 2}){sub 4}(dtpaO{sub 3})].2.5H{sub 2}O 3 and (gu){sub 3}[NbTa(O{sub 2}){sub 4}(HtthaO{sub 4)}].2H{sub 2}O 6 have been obtained. In these compounds, the in situmore » oxidation of the nitrogen atoms of the PAC ligands into N-oxide groups has been evidenced by IR spectroscopy and mass spectrometry. The thermal treatment of the homonuclear complexes in air at 700 or 800 deg. C, depending on the Ta content, provided Nb{sub 2}O{sub 5} or Ta{sub 2}O{sub 5} while the heteronuclear compounds led to the solid solution TaNbO{sub 5}. BET and SEM measurements have been carried out and comparison of the morphology of the samples prepared from homo- and heterometallic precursors is discussed.« less

Trapped charge densities in Al{sub 2}O{sub 3}-based silicon surface passivation layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, Paul M., E-mail: Paul.Jordan@namlab.com; Simon, Daniel K.; Dirnstorfer, Ingo

2016-06-07

In Al{sub 2}O{sub 3}-based passivation layers, the formation of fixed charges and trap sites can be strongly influenced by small modifications in the stack layout. Fixed and trapped charge densities are characterized with capacitance voltage profiling and trap spectroscopy by charge injection and sensing, respectively. Al{sub 2}O{sub 3} layers are grown by atomic layer deposition with very thin (∼1 nm) SiO{sub 2} or HfO{sub 2} interlayers or interface layers. In SiO{sub 2}/Al{sub 2}O{sub 3} and HfO{sub 2}/Al{sub 2}O{sub 3} stacks, both fixed charges and trap sites are reduced by at least a factor of 5 compared with the value measured inmore » pure Al{sub 2}O{sub 3}. In Al{sub 2}O{sub 3}/SiO{sub 2}/Al{sub 2}O{sub 3} or Al{sub 2}O{sub 3}/HfO{sub 2}/Al{sub 2}O{sub 3} stacks, very high total charge densities of up to 9 × 10{sup 12} cm{sup −2} are achieved. These charge densities are described as functions of electrical stress voltage, time, and the Al{sub 2}O{sub 3} layer thickness between silicon and the HfO{sub 2} or the SiO{sub 2} interlayer. Despite the strong variation of trap sites, all stacks reach very good effective carrier lifetimes of up to 8 and 20 ms on p- and n-type silicon substrates, respectively. Controlling the trap sites in Al{sub 2}O{sub 3} layers opens the possibility to engineer the field-effect passivation in the solar cells.« less

Metal phosphide catalysts and methods for making the same and uses thereof

DOEpatents

Habas, Susan Ellen; Wang, Jun; Ruddy, Daniel A.; Baddour, Frederick Raymond Gabriel; Schaidle, Joshua

2017-05-02

The present disclosure relates to a method that includes heating a mixture that includes a metal phenylphosphine-containing precursor that includes at least one of Mo(PPh.sub.3).sub.2(CO).sub.4, Pd(PPh.sub.3).sub.4, Ru(PPh.sub.3).sub.3Cl.sub.2, Ru(PPh.sub.3).sub.2(CO).sub.2Cl.sub.2, Co(PPh.sub.3)(CO).sub.2(NO), and/or Rh(PPh.sub.3).sub.2(CO)Cl, a surfactant, and a solvent. The heating is to a target temperature to form a heated mixture containing a metal phosphide nanoparticle that includes at least one of MoP, Ru.sub.2P, Co.sub.2P, Rh.sub.2P, and/or Pd.sub.3P, and the metal phosphide nanoparticle is not hollow.

Synthesis and crystal structure analysis of uranyl triple acetates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klepov, Vladislav V., E-mail: vladislavklepov@gmail.com; Department of Chemistry, Samara National Research University, 443086 Samara; Serezhkina, Larisa B.

2016-12-15

Single crystals of triple acetates NaR[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O (R=Mg, Co, Ni, Zn), well-known for their use as reagents for sodium determination, were grown from aqueous solutions and their structural and spectroscopic properties were studied. Crystal structures of the mentioned phases are based upon (Na[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}){sup 2–} clusters and [R(H{sub 2}O){sub 6}]{sup 2+} aqua-complexes. The cooling of a single crystal of NaMg[UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 3}·6H{sub 2}O from 300 to 100 K leads to a phase transition from trigonal to monoclinic crystal system. Intermolecular interactions between the structural units and their mutual packing were studiedmore » and compared from the point of view of the stereoatomic model of crystal structures based on Voronoi-Dirichlet tessellation. Using this method we compared the crystal structures of the triple acetates with Na[UO{sub 2}(CH{sub 3}COO){sub 3}] and [R(H{sub 2}O){sub 6}][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} and proposed reasons of triple acetates stability. Infrared and Raman spectra were collected and their bands were assigned. - Graphical abstract: Single crystals of uranium based triple acetates, analytical reagents for sodium determination, were synthesized and structurally, spectroscopically and topologically characterized. The structures were compared with the structures of compounds from preceding families [M(H{sub 2}O){sub 6})][UO{sub 2}(CH{sub 3}COO){sub 3}]{sub 2} (M = Mg, Co, Ni, Zn) and Na[UO{sub 2}(CH{sub 3}COO){sub 3}]. Analysis was performed with the method of molecular Voronoi-Dirichlet polyhedra to reveal a large contribution of the hydrogen bonds into intermolecular interactions which can be a reason of low solubility of studied complexes.« less

Synthesis of Ruthenium Carbonyl Complexes with Phosphine or Substituted Cp Ligands, and Their Activity in the Catalytic Deoxygenation of 1,2-Propanediol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullock, R.M.; Ghosh, P.; Fagan, P.J.

2009-07-20

A ruthenium hydride with a bulky tetra-substituted Cp ligand, (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H (Cp{sup iPr{sub 4}} = C{sub 5}(i-C{sub 3}H{sub 7}){sub 4}H) was prepared from the reaction of Ru{sub 3}(CO){sub 12} with 1,2,3,4-tetraisopropylcyclopentadiene. The molecular structure of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H was determined by X-ray crystallography. The ruthenium hydride complex (C{sub 5}Bz{sub 5})Ru(CO){sub 2}H (Bz = CH{sub 2}Ph) was similarly prepared. The Ru-Ru bonded dimer, [(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}, was produced from the reaction of 1,2,3-trimethylindene with Ru{sub 3}(CO){sub 12}, and protonation of this dimer with HOTf gives {l_brace}[(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}-({mu}-H){r_brace}{sup +}OTf{sup -}. A series of ruthenium hydride complexes CpRu(CO)(L)H [Lmore » = P(OPh){sub 3}, PCy{sub 3}, PMe{sub 3}, P(p-C{sub 6}H{sub 4}F){sub 3}] were prepared by reaction of Cp(CO){sub 2}RuH with added L. Protonation of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H, Cp*Ru(CO){sub 2}H, or CpRu(CO)[P-(OPh){sub 3}]H by HOTf at -80 C led to equilibria with the cationic dihydrogen complexes, but H{sub 2} was released at higher temperatures. Protonation of CpRu[P(OPh){sub 3}]{sub 2}H with HOTf gave an observable dihydrogen complex, {l_brace}CpRu[P-(OPh){sub 3}]{sub 2}({eta}{sup 2}-H{sub 2}){r_brace}+OTf{sup -} that was converted at -20 C to the dihydride complex {l_brace}CpRu[P(OPh){sub 3}]{sub 2}(H){sub 2}{r_brace}{sup +}OTf{sup -}. These Ru complexes serve as catalyst precursors for the catalytic deoxygenation of 1,2-propanediol to give n-propanol. The catalytic reactions were carried out in sulfolane solvent with added HOTf under H{sub 2} (750 psi) at 110 C.« less

Crystal and molecular structures of pentaammine(pyrazine)ruthenium(II) tetrafluoroborate and pentaammine(pyrazine)ruthenium(III) trifluoromethanesulfonate monohydrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gress, M.E.; Creutz, C.; Quicksall, C.O.

1981-05-01

For (Ru(NH/sub 3/)/sub 5/(C/sub 4/N/sub 2/H/sub 4/))(BF/sub 4/)/sub 2/ the space group is P2/sub 1/2/sub 1/2/sub 1/ with cell parameters a = 12.615 (2) A, b = 15.610 (3) A, c = 7.965 (2) A, and Z = 4. For (Ru(NH/sub 3/)/sub 5/(C/sub 4/N/sub 2/H/sub 4/))(CF/sub 3/SO/sub 3/)/sub 3/.H/sub 2/O the space group is Pnma with cell parameters a = 23.795 (4) A, b = 8.062 (2) A, c = 12.848 (2) A, and Z = 4. The geometries of both the Ru(NH/sub 3/)/sub 5/pz/sup 2 +/ (pz = pyrazine) and Ru(NH/sub 3/)/sub 5/pz/sup 3 +/ cations are approximately octahedral,more » with the plane of the pyrazine ring intersecting at a 45/sup 0/ angle the equatorial plane containing the bound pyrazine N and the three N atoms of the NH/sub 3/ groups, as is expected from steric considerations. The Ru-NH/sub 3/ bond lengths are similar to those found in other ammine complexes: Ru(II)-NH/sub 3/, 2.15 to 2.17 A; Ru(III)-NH/sub 3/, 2.10 to 2.13 A. By contrast the Ru(II)-pz bond (2.006 A) is shorter than the Ru(III)-pz bond (2.076 A) by 0.07 A. This is attributed to ..pi.. back-bonding between Ru(II) and pyrazine. The dimensions of the mononuclear ions Ru(NH/sub 3/)/sub 5/pz/sup 2 +/ and Ru(NH/sub 3/)/sub 5/pz/sup 3 +/ are used to model the structure of valence-localized Ru/sup II/(NH/sub 3/)/sub 5/pzRu/sup III/(NH/sub 3/)/sub 5//sup 5 +/. The observed properties of this ion are then compared with those predicted from Marcus-Hush electron-transfer theory.« less

Growth of nano hexagon-like flake arrays cerium carbonate created with PAH as the substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, M., E-mail: limei@imust.cn; School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Department of Inorganic and Metalloid Materials, Key Laboratory of New Technologies of Modern Metallurgy and Application of Rare Materials, Baotou 014010; Hu, Y.H., E-mail: bthyh@163.com

Petals-like Ce{sub 2}(CO{sub 3}){sub 3} on Ce{sub 2}(CO{sub 3}){sub 3} nano hexagon-like flake arrays have been precipitatingly fabricated using PAH substrates. By changing the way of feeding, PAH concentration and aging time, petals-like Ce{sub 2}(CO{sub 3}){sub 3} was created best when adding PAH into the Ce(NO{sub 3}){sub 3} solution, joined (NH{sub 4}){sub 2}CO{sub 3} solution along with mixing, PAH concentration is 0.9 g/L, aging time is 4 h. A growth mechanism was proposed to account for the growth of the petals-like Ce{sub 2}(CO{sub 3}){sub 3} with PAH as the substrate. Poly allylamine hydrochloride (PAH) is as template agent which formsmore » π-allyl complex with Ce{sup 3+} and controls the morphology of Ce{sub 2}(CO{sub 3}){sub 3} particle. PAH and Ce{sup 3+} form π-allyl complex, and then induce the formation of Ce{sub 2}(CO{sub 3}){sub 3} crystal nucleus. And infrared spectrum analysis verified. XRD show that after adding PAH which is adsorbed on the crystal plane, the growth of Ce{sub 2}(CO{sub 3}){sub 3} crystal is inhibited on (2 4 2), the growth is promoted on (2 0 2) which is differentiated into the new (1 5 1), (2 2 2) is unchanged, Ce{sub 2}(CO{sub 3}){sub 3} crystal is accumulated petals shape by hexagon-like flake. UV absorption spectra show that CeO{sub 2} as prepared precursor Ce{sub 2}(CO{sub 3}){sub 3} after calcinations in air at high temperatures, the petal-like CeO{sub 2} has strong UV absorption and reflection effects, and absorption interval changed significantly by the move to UVA from UVB. - Graphical abstract: Each Ce-atom connects three Cl-atoms and three allyls in three dimensional spaces. To take the plane as a reference plane which is arrayed with three Ce-atom as equilateral triangle. The triangular each vertex is Ce-atom, the triangular center place is Cl-atom, the equilateral triangle which is mutually perpendicular with Ce-triangle surface and the inclined angle is 60° is made up with three Cl-atoms. - Highlights: • Petals-like Ce{sub 2}(CO{sub 3}){sub 3} were synthesized with PAH. • PAH and Ce{sup 3+} form π-allyl complex. • The growth crystal is inhibited on (2 4 2) and promoted on (2 0 2). • CeO{sub 2} absorption interval changed by the move to UVA from UVB.« less

Synthesis, crystal structures and optical properties of two congruent-melting isotypic diphosphates: LiM{sub 3}P{sub 2}O{sub 7} (M=Na, K)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi Yunjing; Wang Ying; Graduate University of the Chinese Academy of Sciences, Beijing 100039

2013-01-15

Two new isotypic diphosphates, LiNa{sub 3}P{sub 2}O{sub 7} (1) and LiK{sub 3}P{sub 2}O{sub 7} (2), have been synthesized by conventional solid-state reaction. The single-crystal X-ray structural analyses have shown that they crystallize in the orthorhombic space group C222{sub 1} (No. 20) with the unit cells: a=5.4966(2) A, b=9.1365(4) A, c=12.2764(5) A for compound 1 and a=6.0373(14) A, b=9.339(2) A, c=13.292(3) A for compound 2. The LiM{sub 3}P{sub 2}O{sub 7} (M=Na, K) consist of two-dimensional [LiP{sub 2}O{sub 7}]{sup 3-} layers, which are composed by LiO{sub 4} tetrahedral and diphosphate groups, the Na or K atoms are filled in the interlayers andmore » balance the charge. Second harmonic generation (SHG) on powder samples have been measured using Kurtz and Perry techniques. Thermal analyses, IR spectroscopy, UV-vis-NIR diffuse reflectance spectra, and band structure calculations are performed on the reported compounds. - Graphical Abstract: LiM{sub 3}P{sub 2}O{sub 7} (M=Na, K) consists of a two-dimensional infinite [LiP{sub 2}O{sub 7}]{sup 3-} layer, which is composed by LiO{sub 4} tetrahedra and diphosphate groups. Highlights: Black-Right-Pointing-Pointer LiNa{sub 3}P{sub 2}O{sub 7} and LiK{sub 3}P{sub 2}O{sub 7} are new compounds in the Li{sub 2}O-M{sub 2}O (M=Na, K)-P{sub 2}O{sub 5} systems. Black-Right-Pointing-Pointer Crystal structures of LiNa{sub 3}P{sub 2}O{sub 7} and LiK{sub 3}P{sub 2}O{sub 7} consist of two-dimensional [LiP{sub 2}O{sub 7}]{sup 3-} layers. Black-Right-Pointing-Pointer LiNa{sub 3}P{sub 2}O{sub 7} and LiK{sub 3}P{sub 2}O{sub 7} are congruent melting compounds.« less

Synergetic effect of MoS{sub 2} and g-C{sub 3}N{sub 4} as cocatalysts for enhanced photocatalytic H{sub 2} production activity of TiO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xixian; Huang, Hongyu, E-mail: huanghy@ms.giec.ac.cn; Kubota, Mitsuhiro

Highlights: • A hydrogen evolution reaction of g-C{sub 3}N{sub 4}/MoS{sub 2}/TiO{sub 2} photocatalyst was synthesized. • g-C{sub 3}N{sub 4}/MoS{sub 2}/TiO{sub 2} presents highly efficient H{sub 2} evolution without noble metals. • The effect of g-C{sub 3}N{sub 4} and MoS{sub 2} co-catalyst content in the composites was studied. • The mechanism of g-C{sub 3}N{sub 4}/MoS{sub 2}/TiO{sub 2} photocatalyst under UV–vis light was discussed. - Abstract: In this paper, we report a new g-C{sub 3}N{sub 4}/MoS{sub 2}/TiO{sub 2} composite material as a high-performance photocatalyst for H{sub 2} evolution. Without a noble-metal cocatalyst, the g-C{sub 3}N{sub 4}/MoS{sub 2}/TiO{sub 2} composite reaches a highmore » H{sub 2} production rate of 125 μmol h{sup −1} when the content of the g-C{sub 3}N{sub 4}/MoS{sub 2} cocatalyst is 1.0 wt.% and the content of g-C{sub 3}N{sub 4} in this cocatalyst is 10 wt.%. This unusual photocatalytic activity is attributed to the positive synergetic effect between the MoS{sub 2} and g-C{sub 3}N{sub 4} components in this cocatalyst, which serve as an electron collector and a source of active adsorption sites, respectively.« less

Hygroscopic La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O: Insight into the evolution of borate fundamental building blocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Biao-Chun, E-mail: zhaobiaochun@sohu.com; Sun, Wei, E-mail: 421221789@qq.com; Ren, Wei-Jian, E-mail: 935428502@qq.com

2013-10-15

Borates have exceptionally diverse fundamental building blocks (FBBs), but factors controlling the formation of borate FBBs are poorly understood. The title compound La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O crystallizes in the space group P2{sub 1}/n with a=6.5396(12) Å, b=15.550(3) Å, c=10.6719(19) Å, β=90.44(1)° and Z=4 at 173(2) K. Its structure has been refined from single-crystal X-ray diffraction data to R{sub 1}=0.049 (for 2465) and wR{sub 2}=0.173 (for 2459 I>2σ(I)). This structure analysis and first-principles calculations show that the change of the FBB from 3Δ2□ in the title compound to 2Δ3□ in La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O is accompanied by amore » rotation of the NO{sub 3} group. FTIR, Rietveld and thermal analysis results show that the hygroscopic title compound is partially changed to La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O, with the conversion of [BO{sub 3}] to [BO{sub 3}(H{sub 2}O)] by water absorption. - Graphical abstract: The change of fundamental building blocks from La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O to La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O is accompanied by a rotation of the NO{sub 3} group . Display Omitted - Highlights: • Synthesis of a new hydrous lanthanum polyborate nitrate. • Single-crystal XRD structure with the 3Δ2⎕ FBB and an oriented NO{sub 3} group. • DFT calculations locate the H positions in three lanthanide polyborate nitrates. • Rietveld, FTIR and DFT results show hygroscopicity changes the FBBs.« less

Carbon Dioxide Gas Sensors and Method of Manufacturing and Using Same

NASA Technical Reports Server (NTRS)

Hunter, Gary W. (Inventor); Xu, Jennifer C. (Inventor)

2014-01-01

A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. A first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON and.beta.''-Alumina. A second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of the electrodes and the first solid electrolyte. The metal carbonates selected from the group consisting of the following ions Na.sup.+, K.sup.+, Li.sup.+, Ag.sup.+, H.sup.+, Pb.sup.2+, Sr.sup.2+, Ba.sup.2+, and any combination thereof. An extra layer of metal oxide selected from the group consisting of SnO.sub.2, In.sub.2O.sub.3, TiO.sub.2, WO.sub.3, ZnO, Fe.sub.2O.sub.3, ITO, CdO, U.sub.3O.sub.8, Ta.sub.2O.sub.5, BaO, MoO.sub.2, MoO.sub.3, V.sub.2O.sub.5, Nb.sub.2O.sub.5, CuO, Cr.sub.2O.sub.3, La.sub.2O.sub.3, RuO.sub.3, RuO.sub.2, ReO.sub.2, ReO.sub.3, Ag.sub.2O, CoO, Cu.sub.2O, SnO, NiO, Pr.sub.2O.sub.3, BaO, PdO.sub.2, HfO.sub.3, HfO.sub.3 or other metal oxide and their mixtures residing above and in engagement with the second electrolyte to improve sensor performance and/or to reduce sensor heating power consumption.

Syntheses, structures, and vibrational spectroscopy of the two-dimensional iodates Ln(IO{sub 3}){sub 3} and Ln(IO{sub 3}){sub 3}(H{sub 2}O) (Ln =Yb, Lu)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assefa, Zerihun; Ling Jie; Haire, Richard G.

2006-12-15

The reaction of Lu{sup 3+} or Yb{sup 3+} and H{sub 5}IO{sub 6} in aqueous media at 180 {sup o}C leads to the formation of Yb(IO{sub 3}){sub 3}(H{sub 2}O) or Lu(IO{sub 3}){sub 3}(H{sub 2}O), respectively, while the reaction of Yb metal with H{sub 5}IO{sub 6} under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO{sub 3}){sub 3}. Under supercritical conditions Lu{sup 3+} reacts with HIO{sub 3} and KIO{sub 4} to yield the isostructural Lu(IO{sub 3}){sub 3}. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (MoK{alpha}, {lambda}=0.71073 A): Yb(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6664(9)more » A, b=5.9904(6) A, c=14.8826(15) A, {beta}=96.931(2){sup o}, V=766.99(13), Z=4, R(F)=4.23% for 114 parameters with 1880 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6410(9), b=5.9961(6), c=14.8782(16) A, {beta}=97.028(2){sup o}, V=765.08(14), Z=4, R(F)=2.65% for 119 parameters with 1756 reflections with I>2{sigma}(I); Yb(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.2476(15), b=5.6296(3), c=12.0157(7) A, {beta}=98.636(1){sup o}, V=1822.2(2), Z=8, R(F)=1.51% for 128 parameters with 2250 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.258(4), b=5.6251(7), c=12.0006(16) A, {beta}=98.704(2){sup o}, V=1818.8(4), Z=8, R(F)=1.98% for 128 parameters with 2242 reflections with I>2{sigma}(I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO{sub 3}){sub 3}(H and Yb(IO{sub 3}){sub 3}(H{sub 2}O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds. - Graphical abstract: Four new metal iodates, Yb(IO{sub 3}){sub 3}, Lu(IO{sub 3}){sub 3}, Yb(IO{sub 3}){sub 3}(H{sub 2}O), and Lu(IO{sub 3}){sub 3}(H{sub 2}O), have all been isolated as single crystals through the use of hydrothermal reactions. Structural determinations using single-crystal X-ray diffraction have shown that the materials are all alike in that they contain two-dimensional structures. Vibrational profiles for all of the materials have been collected, using Raman spectroscopy, and analyzed.« less

Near azeotropic mixture substitute for dichlorodifluoromethane

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor)

1998-01-01

A refrigerant and a process of formulating thereof that consists of a mixture of a first mole fraction of CH.sub.2 FCF.sub.3 and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 and CH.sub.3 CClF.sub.2 ; a mixture of CHF.sub.2 CH.sub.3 and CH.sub.3 CClF.sub.2 ; and a mixture of CHClFCF.sub.3, CH.sub.3 CClF.sub.2 and CHF.sub.2 CH.sub.3.

Polymorph (C{sub 2}N{sub 2}H{sub 10}){sub 0.5}RE{sub 3}F{sub 10}·xH{sub 2}O (RE = Ho-Lu, Y) and REF{sub 3} nanocrystals: Hydrothermal synthesis, characterization and luminescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia, Li-Ping; Zhang, Qiang; Yan, Bing, E-mail: byan@tongji.edu.cn

Graphical abstract: A hydrothermal system is developed to prepare one new polymorph of (C{sub 2}N{sub 2}H{sub 10}){sub 0.5}RE{sub 3}F{sub 10}·xH{sub 2}O and known rare earth fluorides involving REF{sub 3} nanocrystals under mild condition. Highlights: ► A new polymorph of (C{sub 2}N{sub 2}H{sub 10}){sub 0.5}RE{sub 3}F{sub 10}·xH{sub 2}O has been synthesized. ► The RE{sup 3+} radius decides the shape evolution and phase control for REF{sub 3} NCs. ► The RE{sup 3+} radius has influence on the microstructure and morphology of REF{sub 3} NCs. -- Abstract: In this paper, a solvents-thermal system is developed to prepare one new polymorph of (C{sub 2}N{submore » 2}H{sub 10}){sub 0.5}Ho{sub 3}F{sub 10}·xH{sub 2}O and rare earth fluorides REF{sub 3} nanocrystals under mild condition. It is found that the ionic radius of RE{sup 3+} is the key factor responsible for the shape evolution and phase control for rare earth fluorides nanocrystals at selected temperatures, which has an influence on the microstructure and morphology of the products to some extent. With the increase of the atomic number, the shape of fluoride changes from hexagonal REF{sub 3} phase (RE = La, Sm) to orthorhombic REF{sub 3} phase (RE = Eu-Dy), and finally to diamond structure (C{sub 2}N{sub 2}H{sub 10}){sub 0.5}Ho{sub 3}F{sub 10}·xH{sub 2}O (RE = Ho, Er, Tm, Yb, Lu, Y). In addition, the characteristic energy level transition {sup 5}D{sub 0}–{sup 7}F{sub 1} of Eu{sup 3+} splits into 585 and 591 nm emission peaks, and the dominant peak is the orange emission at 591 nm.« less

Phosphate glass useful in high energy lasers

DOEpatents

Hayden, Y.T.; Guesto-Barnak, D.

1992-12-22

Disclosed is a low-or no-silica, low- or no-alkali phosphate glass useful as a laser amplifier in a multiple pass, high energy laser system having a high thermal conductivity, K[sub 90 C] >0.85 W/mK, a low coefficient of thermal expansion, [alpha][sub 20-300 C] <80[times]10[sup [minus]7]/C, low emission cross section, [sigma]<2.5[times]10[sup [minus]20] cm[sup 2], and a high fluorescence lifetime, [tau]>325 [mu]secs at 3 wt. % Nd doping, consisting essentially of (on an oxide composition basis): (Mole %) P[sub 2]O[sub 5], (52-72); Al[sub 2]O[sub 3], (0-<20); B[sub 2]O[sub 3], (>0-25); ZnO, (0-31); Li[sub 2]O, (0-5); K[sub 2]O, (0-5); Na[sub 2]O, (0-5); Cs[sub 2]O, (0-5); Rb[sub 2]O, (0-5); MgO, (>0-<30); CaO, (0-20); BaO, (0-20); SrO, (0-<20); Sb[sub 2]O[sub 3], (0-<1); As[sub 2]O[sub 3], (0-<1); Nb[sub 2]O[sub 5], (0-<1); Ln[sub 2]O[sub 3], (up to 6.5); PbO, (0-<5); and SiO[sub 2], (0-3); wherein Ln[sub 2]O[sub 3] is the sum of lanthanide oxides; [Sigma]R[sub 2]O is <5, R being Li, Na, K, Cs, and Rb; the sum of Al[sub 2]O[sub 3] and MgO is <24 unless [Sigma]R[sub 2]O is 0, then the sum of Al[sub 2]O[sub 3] and MgO is <42; and the ratio of MgO to B[sub 2]O[sub 3] is 0.48-4.20. 7 figs.

Applications of molybdenum-95 NMR spectroscopy. 7. Studies of metal-metal bonded systems including aqueous molybdenum(IV) and molybdenum(V). Crystal and molecular structure of Na/sub 2/(Mo/sub 3/O/sub 4/((O/sub 2/CCH/sub 2/)/sub 2/NCH/sub 3/)/sub 3/). 7H/sub 2/O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghellar, S.F.; Hambley, T.W.; Brownlee, R.T.

1983-03-23

Solution /sup 95/Mo NMR studies are reported on spin-coupled polynuclear systems of Mo(V), Mo(IV), and Mo(II). Resonances occur at low fields compared to mononuclear species. The chemical shifts of the Mo(IV)-aquo ion in 4 M p-toluenesulfonic and methanesulfonic acid media and those of the Mo(IV) complexes containing oxalate, EDTA, and methyliminodiacetate ligands (whose solid-state structures are based on the (Mo/sub 3/O/sub 4/)/sup 4 +/ cluster) fall in the narrow range of 172 ppm spanning 990-1162 ppm. As the known chemical shift scale for the /sup 95/Mo nucleus covers 7000 ppm, this observation indicates that the /sup 95/Mo nucleus is inmore » a similar chemical environment in each of the species examined and, taken with published evidence, confirms formulation of the Mo(IV)-aquo ion as (Mo/sub 3/O/sub 4/(H/sub 2/O)/sub 9/)/sup 4 +/. Two resonances are detected in the above range for Mo(IV)/sub aq/ in 4 M hydrochloric acid and for ((Mo/sub 3/O/sub 4/)/sub 2/(PDTA)/sub 3/)/sup 4 -/. Additional resonances appear at 539-608 ppm in the methanesulfonic acid, hydrochloric acid, and EDTA systems when stored in air. These are assigned to (Mo/sup v//sub 2/O/sub 4/)/sup 2 +/-based species by comparison with the observed resonances of the Mo(V)-aquo ion, (Mo/sup v//sub 2/O/sub 4/(H/sub 2/O)/sub 6/)/sup 2 +/, in the relevant acid media and with (Mo/sup v//sub 2/O/sub 4/(EDTA))/sup 2 -/ in H/sub 2/O. The (Mo/sup v//sub 2/O/sub 4/(PDTA))/sup 2 -/ anion exhibits two resonances associated with inequivalent molybdenum sites. Resonances for (Mo/sup II//sub 2/(O/sub 2/CR)/sub 4/) (R = CF/sub 3/, n-Pr), which contain formal quadruple bonds, have been observed for the first time and are the most deshielded /sup 95/Mo NMR signals detected to date. The methyliminodiacetate complex, Na/sub 2/(Mo/sub 3/O/sub 4/((O/sub 2/CCH/sub 2/)/sub 2/NCH/sub 3/)/sub 3/).7H/sub 2/O, was isolated. Its crystal structure contains a discrete trinuclear (Mo/sup IV//sub 3/O/sub 4/((O/sub 2/CCH/sub 2/)/sub 2/NCH/sub 3/)/sub 3/)/sup 2 -/ anion whose symmetry approaches C/sub 3v/.« less

Relationship between Eu{sup 3+} reduction and glass polymeric structure in Al{sub 2}O{sub 3}-modified borate glasses under air atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiao, Qing; Yu, Xue; Xu, Xuhui

2013-06-15

The reduction of Eu{sup 3+} to Eu{sup 2+} is realized efficiently in Eu{sub 2}O{sub 3}-doped borate glasses prepared under air condition by melting-quenching method. Luminescent spectra show an increasing tendency of Eu{sup 2+} emission with increasing Al{sub 2}O{sub 3} concentration in B{sub 2}O{sub 3}–Na{sub 2}O glasses. It is interesting that significant enhancement appeared of Eu{sup 2+} luminescence in the Al{sub 2}O{sub 3}-rich sample comparing to the samples of Al{sub 2}O{sub 3} less than 6 mol%. FTIR and Raman scattering measurements indicated that some new vibration modes assigned to the low-polymerized structure groups decomposed from the slight Al{sub 2}O{sub 3} dopantmore » samples. These results demonstrated that the polymerization of the glass structure decreased with increasing incorporation of Al{sub 2}O{sub 3} into the borate glasses, linking to the efficiency of Eu{sup 3+} self-reduction in air at high temperature. - graphical abstract: A novel europium valence reduction phenomenon occurred in Al{sub 2}O{sub 3} modified borate glasses, FTIR and Raman measurements revealed that high polymeric groups were destroyed to low polymery structures with Al{sub 2}O{sub 3} addition. - Highlights: • The efficient reduction of Eu{sup 3+} to Eu{sup 2+} is observed in the B{sub 2}O{sub 3}–Na{sub 2}O glasses. • Eu{sup 2+} luminescence is significant enhanced in the Al{sub 2}O{sub 3}-rich glasses. • The introduction of Al{sub 2}O{sub 3} changed the network structure of the borate glasses. • High polymeric borate groups in the glass matrix may be destroyed to the lower ones.« less

Phase equilibria in the quasiternary system Ag{sub 2}S–Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3} and optical properties of (Ga{sub 55}In{sub 45}){sub 2}S{sub 300}, (Ga{sub 54.59}In{sub 44.66}Er{sub 0.75}){sub 2}S{sub 300} single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivashchenko, I.A., E-mail: Ivashchenko.Inna@eenu.edu.ua; Danyliuk, I.V.; Olekseyuk, I.D.

The quasiternary system Ag{sub 2}S–Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3} was investigated by differential thermal, X-ray diffraction analyses. The phase diagram of the Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3} system and nine polythermal sections, isothermal section at 820 K and the liquidus surface projection were constructed. The existence of the large solid solutions ranges of binary and ternary compounds was established. The range of the existence of the quaternary phase AgGa{sub x}In{sub 5−x}S{sub 8} (2.25≤x≤2.85) at 820 K was determined. The single crystals (Ga{sub 55}In{sub 45}){sub 2}S{sub 300} and (Ga{sub 54.59}In{sub 44.66}Er{sub 0.75}){sub 2}S{sub 300} were grown by a directional crystallization methodmore » from solution-melt. Optical absorption spectra in the 500–1600 nm range were recorded. The luminescence of the (Ga{sub 54.59}In{sub 44.66}Er{sub 0.75}){sub 2}S{sub 300} single crystal shows a maximum at 1530 nm for the excitation wavelengths of 532 and 980 nm at 80 and 300 K. - Graphical abstract: Isothermal section of the quasiternary system Ag{sub 2}S–Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3} at 820 K and normalized photoluminescence spectra of the single crystal (Ga{sub 54.59}In{sub 44.66}Er{sub 0.75}){sub 2}S{sub 300} at 300 K. - Highlights: • Isothermal section at 820 K, liquidus surface projection were built for Ag{sub 2}S–Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3}. • Optical properties of single crystals were studied.« less

Synthesis of new structurally related cyanamide compounds LiM(CN{sub 2}){sub 2} where M is Al{sup 3+}, In{sup 3+} or Yb{sup 3+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubus, Mariusz, E-mail: mariusz.kubus@anorg.uni-tuebingen.de; Heinicke, Robert; Ströbele, Markus

2015-02-15

Highlights: • New cyanamide compounds LiM(CN{sub 2}){sub 2} where M is Al{sup 3+}, In{sup 3+} or Yb{sup 3+}. • New luminescent material LiIn(CN{sub 2}){sub 2}:Tb{sup 3+}. • Reduction in efficiency of luminescence with temperature increase. - Abstract: New ternary cyanamide compounds isostructural to LiY(CN{sub 2}){sub 2} were obtained by solid state metathesis reaction. The crystal structure of LiAl(CN{sub 2}){sub 2} was determined by single crystal X-ray diffraction, the structures of LiIn(CN{sub 2}){sub 2} and LiYb(CN{sub 2}){sub 2} were solved from X-ray powder diffraction data. Photoluminescence properties of Tb{sup 3+}-doped LiIn(CN{sub 2}){sub 2} are reported too.

Stereochemical and electronic control of M-SO/sub 2/ bonding geometry in d/sup 6/ molybdenum and tungsten SO/sub 2/ complexes: novel n/sup 1/reverse arrown/sup 2/ SO/sub 2/ linkage isomerization in Mo(CO)/sub 2/(PPh/sub 3/)/sub 2/(CNR)(SO/sub 2/) and structures of Mo(CO)/sub 3/(P-i-Pr/sub 3/)/sub 2/(SO/sub 2/) and (Mo(CO)/sub 2/(py)(PPh/sub 3/)(. mu. -SO/sub 2/))/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubas, G.J.; Jarvinen, G.D.; Ryan, R.R.

1983-04-06

New complexes, mer,trans,M(CO)/sub 3/(PR/sub 3/)/sub 2/(SO/sub 2/) (M = Mo,W; R = Ph,Cy,i-Pr) (I), cis,trans-Mo(CO)/sub 2/-(PPh/sub 3/)/sub 2/(SO/sub 2/)(L) (L = NCMe,py,CNCy,CN-t-Bu and CN(p-tolyl))(II), and (Mo(CO)/sub 2/(py)(PPh/sub 3/)(..mu..-SO/sub 2/))/sub 2/, have been prepared and characterized by infrared spectroscopy, /sup 17/O and /sup 31/P NMR spectroscopy, and X-ray crystallography. Syntheses for fac-Mo(CO)/sub 3/(n/sup 2/-SO/sub 2/)(LL) (LL = dppe,bpy,phen,2 py) have also been developed. Depending upon L, II has been found to coordinate SO/sub 2/ either in the S-bonded (n/sup 1/ planar) or O,S-bonded (n/sup 2/) geometries. Remarkably, for L = CNCy or CN-t-Bu, II has been found to contain, in themore » solid state, an apparent equimixture of both coordination types. Isomerization of fac-M(CO)/sub 3/(dppe)(n/sup 2/-SO/sub 2/) (M=Mo,w; dppe = 1,2-bis(diphenylphosphino)ethane) to an n/sup 1/-planar SO/sub 2/ form, mer-M(CO)/sub 3/(dppe)(SO/sub 2/), has also been found to occur. Thus, control of the SO/sub 2/ coordination geometry has been achieved by varying either the electronic properties of the ancillary ligands or their disposition with respect to the SO/sub 2/. The X-ray crystal structure of mer,trans-Mo(CO)/sub 3/(P-i-Pr/sub 3/)/sub 2/(SO/sub 2/) revealed n/sup 1/-planar SO/sub 2/ binding, the first example of this geometry for group 6 metals. The M-S distance, 2.239 (3) angstrom, is the longest such distance for this geometry recorded to date. Crystal data: Pbca, Z=8, a=24.712(8) angstrom, b=16.033(6) angstrom, c=14.058(5) angstrom, R=0.079 for 2934 reflections with Igreater than or equal to2sigma(I). The structure of (Mo(CO)/sub 2/(py)(PPh/sub 3/)(..mu..-SO/sub 2/))/sub 2/ showed a novel SO/sub 2/ bridging geometry in which all three atoms of SO/sub 2/ are metal coordinated. Crystal data: P1, Z=1, a=14.883(4) angstrom, b=9.264(2) angstrom, c=10.808(2) angstrom, R=0.039 for 3282 reflections with Igreater than or equal to2sigma(I).« less

Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}: A novel blue emitting phosphor for white LEDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Panlai, E-mail: li_panlai@126.com; Wang, Zhijun, E-mail: wangzj1998@126.com; Yang, Zhiping

2014-12-15

Graphical abstract: Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band. When the temperature turned up to 150 °C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ΔE is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs. - Highlights: • Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band under themore » 350 nm radiation excitation. • Emission intensity of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is 63.4% (150 °C) of the initial value (30 °C). • The activation energy ΔE for thermal quenching is 0.25 eV. - Abstract: A novel blue emitting phosphor Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is synthesized by a high temperature solid state method. The luminescent property and the thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} are investigated. Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band, and the peak locates at 417 nm which is assigned to the 5d{sup 1}–4f{sup 1} transition of Ce{sup 3+}. It is further proved that the dipole–dipole interaction results in the concentration quenching of Ce{sup 3+} in Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. When the temperature turned up to 150 °C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ΔE is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs.« less

First-principles study lone-pair effects of Sb (III)-S chromophore influence on SHG response in quaternary potassium containing silver antimony sulfides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Junben; School of Physics Science and Technology, Xinjiang University, Urumqi 830046; Su, Xin

2017-05-15

First-principles studies of the geometric structures, electronic structures and optical properties of non-centrosymmetrical (NCS) KAg{sub 2}SbS{sub 4}, K{sub 2}AgSbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} and centrosymmetrical (CS) KAg{sub 2}SbS{sub 3} and K{sub 3}Ag{sub 9}Sb{sub 4}S{sub 12} have been performed by means of density functional theory. It is indicated that although they have similarity in their anionic groups and, the electronic structures, prominent features of the optical anisotropy or second-order nonlinear optical (NLO) susceptibilities are apparently different. The calculated birefringences are 0.0537, 0.0343, 0.1324, 0.2217 and 0.0604 which are attributed to the different anionic groups [SbS{sub 3}] and trianglesmore » [AgS{sub 3}]. Also, the calculated NLO responses are about 0.5×, 1.0× and 2.0× times than that commercial AgGaS{sub 2} (AGS, d{sub 36}=11 pm/V) for K{sub 2}AgSbS{sub 4}, KAg{sub 2}SbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7}, respectively. In comparison with the absolute magnitude of second harmonic generation (SHG) coefficients, the order K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7}>KAg{sub 2}SbS{sub 4}>K{sub 2}AgSbS{sub 4} is clearly established in the SHG response. Further analysis based on the real-space atom-cutting method reveals that the main sources of the SHG properties of these compounds are from the Sb-S group, especially K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} is mainly attributed to the lone pair stereochemical activity of Sb (III)-S group. - Graphical abstract: Compounds K{sub 2}AgSbS{sub 4}, KAg{sub 2}SbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} exhibit second-order NLO response: 15×, 30× and 62× times than that KDP (KH{sub 2}PO{sub 4}, d{sub 36}=0.39 pm/V), respectively. First-principles methods reveal that the large SHG response of K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} is dominated by the Sb-S chromophore with lone pairs.« less

Reactions of small organic molecules on silver(110)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayre, C.R.

1992-01-01

The interaction of two pairs of molecules (1) acetone (CH[sub 3])[sub 2]C=O and isobutylene (CH[sub 3])[sub 2] C=CH[sub 2] and (2) 1,2-propanediol CH[sub 3] CH (OH)CH[sub 2]OH and 1,3-propanediol HOCH[sub 2]CH[sub 2]CH[sub 2]OH with clean and oxygen-activated Ag(110) has been explored to investigate the effects of molecular structure on reactivity. Experimental techniques employed include temperature programmed reaction spectroscopy, isotopic labelling, surface displacement reactions, and electron energy loss spectroscopy. Acetone and isobutylene were studied to explore the relative importance of C=O and C=C bonds in governing the reactivity of structurally similar compounds. Nucleophilic attack by oxygen at the electron-deficient carbonyl carbonmore » in acetone results in reversible formation of the metallacycle (CH[sub 3])[sub 2]COO[sub (a)] at 110 K. Upon heating C-H bond activation by O[sub (a)] occurs near 215 K to yield acetone enolate CH[sub 2]=C(CH[sub 3])O[sub (a)] and evolve H[sub 2]O[sub (g)]. Atomic oxygen activates methyl C-H bonds in isobutylene via an acid-base mechanism. Although the major products are CO[sub 2(g)] and H[sub 2]O[sub (g)], a small amount of (CH[sub 3])[sub 2]C=CH[sub 2(g)] evolves near 310 K. Evidence for the formation of [pi]-2-methylallyl CH[sub 3]C(CH[sub 2])[sub 2(a)] and trimethylenementhane C(CH[sub 2])[sub 3(a)] is presented. The reaction of 1,2-propanediol CH[sub 3] CH(OH)CH[sub 2] OH with oxygen-activated Ag(110) has been compared with that of 1,3-propanediol HOCH[sub 2]CH[sub 2]CH[sub 2]OH to evaluate the effects of varying the position of O-H bonds in both diols to produce the corresponding dialkoxides.« less

Photodissociation of nitromethane cluster anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goebbert, Daniel J.; Khuseynov, Dmitry; Sanov, Andrei

2010-08-28

Three types of anionic fragments are observed in the photodissociation of nitromethane cluster anions, (CH{sub 3}NO{sub 2}){sub n}{sup -}, n=1-6, at 355 nm: NO{sub 2}{sup -}(CH{sub 3}NO{sub 2}){sub k}, (CH{sub 3}NO{sub 2}){sub k}{sup -}, and OH{sup -} (k

ON THE REACTION OF COMPONENETS IN MeNO$sub 3$-UO$sub 2$(NO$sub 3$)$sub 2$- H$sub 2$O TYPE SYSTEMS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yakimov, M.A.; Nosova, N.F.; Degtyarev, A.Ya.

1963-01-01

Solubility in ternary systems TlNO/sub 3/--UO/sub 2/(NO/sub 3/)/sub 2/-- H/sub 2/ O and CsNO/sub 3/--UO/sub 2/(NO/sub 3/)/sub 2/--H/sub 2/O at 0 to 25 c- C was studi ed by the isothermal method. The first system did not form solid phase compounds; the second system formed two compounds Cs/sub 2/UO/ sub 2/(NO/sub 3/)/sub 4/ and CsUO/sub 2/(NO/sub 3/)/sub 3/ at 25 c- and of water vapor pressure over the systems at 25 c- showed that water activity in the ternary systems at certain concentrations does not exceed the water activity in binary uranyl nitratewater system (at identical uranyl nitrate concentrations) confirmingmore » the observed complex formation in the solution. The mechanism of complex formation was analyzed and expanded for alkali metal - metal salt-complexing agent water systems. (R.V.J.)« less

Study of the ion--molecule half reactions O/sup +//sub 2/(a /sup 4/Pi/sub u/, v)xxx(O/sub 2/)/sub m/. -->. O/sup +//sub 2m/+1+O, m=1, 2, or 3, using the molecular beam photoionization method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linn, S.H.; Ono, Y.; Ng, C.Y.

1981-03-15

The photoionization efficiency (PIE) curve for (O/sub 2/)/sup +//sub 2/ has been obtained in the region 650--1 080 A using the molecular beam photoionization method. The ionization energy (IE) for (O/sub 2/)/sub 2/ is determined to be 11.66 +- 0.03 eV. From the measured IE for (O/sub 2/)/sup +//sub 2/, the known IE for O/sub 2/, and the estimated dissociation energy (0.01 eV) of (O/sub 2/)/sub 2/, the binding energy for (O/sub 2/)/sup +//sub 2/ is deduced to be 0.42 +- 0.03 eV. Comparisons of the PIE spectra for O/sup +//sub 2/ and (O/sub 2/)/sup +//sub m/, where m=2, 3,more » and 4 indicate that the excited dimer complexes O(/sub 2/(n,v)x(O/sub 2/)/sub m/ (m=1, 2, and 3) formed in this wavelength region are almost completely dissociative, and the cluster ions are predominately formed by the direct photoionization processes (O/sub 2/)/sub m/=2, 3, or 4+h..nu -->..(O/sub 2/)/sup +//sub m/=2, 3, or 4+e. The PIE curves for O/sup +//sub 3/, O/sup +//sub 5/, and O/sup +//sub 7/ are measured in the region 650--780 A. The appearance energy 16.66 +- 0.03 eV (744 +- 1.5 A) for O/sup +//sub 3/ is found to be consistent with a zero activation energy for the ion-molecule reaction O/sup +//sub 2/(X/sup 2/Pi/sub g/)+O/sub 2/..-->..O/sup +//sub 3/+O. The appearance energy for O/sup +//sub 5/ is determined to be 16.41 +- 0.06 eV (755.5 +- 3 A). This value has allowed the determination of a binding energy of 0.26 eV for O/sup +//sub 3/xO/sub 2/. The nearly structureless PIE spectra observed for O/sup +//sub 3/, O/sup +//sub 5/, and O/sup +//sub 7/ also suggests that these ions originate mainly from (O/sub 2/)/sup +//sub 2/, (O/sub 2/)/sup +//sub 3/, and (O/sub 2/)/sup +//sub 4/ which are formed by direct ionization processes. Using the relative Franck--Condon factors for the O/sub 2/ a/sup 4/Pi/sub u/reverse arrowX/sup 3/..sigma../sup -//sub g/ transitions, the relative reaction probabilities for the ion--molecule half reactions O/sup +//sub 2/(a/sup 2/Pi/sub u/, v)x(O/sub 2/)/sub m/..-->..O/sup +//sub 2m/+1+O(m=1, 2, and 3): (1): as a function of the vibrational quantum number v have been determined.« less

Dependence of catalytic properties of Al/Fe{sub 2}O{sub 3} thermites on morphology of Fe{sub 2}O{sub 3} particles in combustion reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Ningning; He, Cuicui; Liu, Jianbing

2014-11-15

Three Fe{sub 2}O{sub 3} particle samples with the same crystal structure but different morphologies were prepared by the hydrothermal method and then combined with Al nanoparticles to produce Al/Fe{sub 2}O{sub 3} thermites using ultrasonic mixing. The properties of Fe{sub 2}O{sub 3} and Al/Fe{sub 2}O{sub 3} were studied using a combination of experimental techniques including scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The influences of the three Al/Fe{sub 2}O{sub 3} thermites on the combustion properties of the AP/HTPB (ammonium perchlorate/hydroxyl-terminated polybutadiene) composite propellant were investigated in comparisonmore » to those of Fe{sub 2}O{sub 3}. The results show that the Al/Fe{sub 2}O{sub 3} thermites are better than Fe{sub 2}O{sub 3} in enhancing the combustion performance of AP/HTPB. Furthermore, the surface area, which depends on size and mophology, of Fe{sub 2}O{sub 3} particles was found to play a vital role in improving the burning rate of the thermites-containing propellant formulation, with the smallest particles with the largest surface-to-volume (S/V) ratio performing the best. The enhanced catalytic property of the granular-shape Fe{sub 2}O{sub 3} and the corresponding thermite is attributed to the large specific surface area of Fe{sub 2}O{sub 3}. The different thermal behaviors of these three superthemites were supposed to be attributed to the surface site of Fe{sub 2}O{sub 3} particles. This work provides a better understanding on the catalytic properties of thermites that are important for combustion applications. - Graphical abstract: Effects of Fe{sub 2}O{sub 3} and Al/Fe{sub 2}O{sub 3} have been compared for the first time by analyzing combustion properties of formulations containing them, suggesting their potential application in AP/HTPB composite propellant systems. - Highlights: • Three Fe{sub 2}O{sub 3} particles with different morphologies (polyhedral, oval and granular) were prepared by the hydrothermal method. • Thermal behaviors of thermites Al/Fe{sub 2}O{sub 3} are studied upon DSC data. • Effects of Fe{sub 2}O{sub 3} and Al/Fe{sub 2}O{sub 3} on the combustion properties of the AP/HTPB composite propellant are first investigated.« less

Crystal structures of Boro-AFm and sBoro-AFt phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Champenois, Jean-Baptiste; Mesbah, Adel; Clermont Universite, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand

2012-10-15

Crystal structures of boron-containing AFm (B-AFm) and AFt (B-AFt) phases have been solved ab-initio and refined from X-ray powder diffraction. {sup 11}B NMR and Raman spectroscopies confirm the boron local environment in both compounds: three-fold coordinated in B-AFm corresponding to HBO{sub 3}{sup 2-} species, and four-fold coordinated in B-AFt corresponding to B (OH){sub 4}{sup -} species. B-AFm crystallizes in the rhombohedral R3{sup Macron }c space group and has the 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}CaHBO{sub 3}{center_dot}12H{sub 2}O (4CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}1/2B{sub 2}O{sub 3}{center_dot}12.5H{sub 2}O, C{sub 4}AB{sub 1/2}H{sub 12.5}) general formulae with planar trigonal HBO{sub 3}{sup 2-} anions weakly bonded at the centre of themore » interlayer region. One HBO{sub 3}{sup 2-} anion is statistically distributed with two weakly bonded water molecules on the same crystallographic site. B-AFt crystallizes in the trigonal P3cl space group and has the 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}Ca(OH){sub 2}{center_dot}2Ca(B (OH){sub 4}){sub 2}{center_dot}24H{sub 2}O (6CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}2B{sub 2}O{sub 3}{center_dot}33H{sub 2}O, C{sub 6}AB{sub 2}H{sub 33}) general formulae with tetrahedral B (OH){sub 4}{sup -} anions located in the channel region of the structure. All tetrahedral anions are oriented in a unique direction, leading to a hexagonal c lattice parameter about half that of ettringite.« less

Epitaxial growth of γ-Al{sub 2}O{sub 3} on Ti{sub 2}AlC(0001) by reactive high-power impulse magnetron sputtering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eklund, Per, E-mail: perek@ifm.liu.se; Frodelius, Jenny; Hultman, Lars

2014-01-15

Al{sub 2}O{sub 3} was deposited by reactive high-power impulse magnetron sputtering at 600 °C onto pre-deposited Ti{sub 2}AlC(0001) thin films on α-Al{sub 2}O{sub 3}(0001) substrates. The Al{sub 2}O{sub 3} was deposited to a thickness of 65 nm and formed an adherent layer of epitaxial γ-Al{sub 2}O{sub 3}(111) as shown by transmission electron microscopy. The demonstration of epitaxial growth of γ-Al{sub 2}O{sub 3} on Ti{sub 2}AlC(0001) open prospects for growth of crystalline alumina as protective coatings on Ti{sub 2}AlC and related nanolaminated materials. The crystallographic orientation relationships are γ-Al{sub 2}O{sub 3}(111)//Ti{sub 2}AlC(0001) (out-of-plane) and γ- Al {sub 2}O{sub 3}(22{sup ¯}0)// Timore » {sub 2} AlC (112{sup ¯}0) (in-plane) as determined by electron diffraction. Annealing in vacuum at 900 °C resulted in partial decomposition of the Ti{sub 2}AlC by depletion of Al and diffusion into and through the γ-Al{sub 2}O{sub 3} layer.« less

Method for thermochemical decomposition of water

DOEpatents

Abraham, Bernard M.; Schreiner, Felix

1977-01-11

Water is thermochemically decomposed to produce hydrogen by the following sequence of reactions: KI, NH.sub.3, CO.sub. 2 and water in an organic solvent such as ethyl or propyl alcohol are reacted to produce KHCO 3 and NH.sub.4 I. The KHCO.sub.3 is thermally decomposed to K.sub.2 CO.sub.3, H.sub.2 O and CO.sub.2, while the NH.sub.4 I is reacted with Hg to produce HgI.sub.2, NH.sub.3 and H.sub.2. The K.sub.2 CO.sub.3 obtained by calcining KHCO.sub.3 is then reacted with HgI.sub.2 to produce Hg, KI, CO and O.sub.2. All products of the reaction are recycled except hydrogen and oxygen.

Preparation of high density heavy metal fluoride glasses with extended ultraviolet and infra red ranges, and such high density heavy metal fluoride glasses

NASA Technical Reports Server (NTRS)

Martin, Steven W. (Inventor); Huebsch, Jesse (Inventor)

2001-01-01

A heavy metal fluoride glass composition range (in mol percent) consisting essentially of: (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24)InF.sub.3 or GaF.sub.3.(4-16)CdF.sub.2.(6-24)YbF.sub.3.(4-22)ZnF.sub.2. In an alternative embodiment, a heavy metal fluoride glass composition range (in mol percent) comprises (16-30)BaF.sub.2.(8-26)HfF.sub.4.(6-24) of (0-24)InF.sub.3, (0-24)GaF.sub.3 and (0-19)AlF.sub.3.(1-16)CdF.sub.2.(6-24)YbF.sub.3.(4-26)ZnF.sub.2. A preferred heavy metal fluoride glass produced in accordance with the present invention comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.7InF.sub.3.5GaF.sub.3.10CdF.sub.2.18YbF.sub.3. 16ZnF.sub.2. A preferred heavy metal fluoride glass has maximum thickness of most preferably about 3 mm. Another preferred heavy metal fluoride glass comprises a composition (in mol %) and comprises about 26BaF.sub.2.18HfF.sub.4.12AlF.sub.3.10CdF.sub.2.18YbF.sub.3.16ZnF.sub.2.

Hydrothermal synthesis and structural analysis of new mixed oxyanion borates: Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6}, Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heyward, Carla, E-mail: cheywar@clemson.edu; McMillen, Colin D., E-mail: cmcmill@clemson.edu; Kolis, Joseph, E-mail: kjoseph@clemson.edu

2013-07-15

Several new borate compounds, Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} (1), Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) (2), and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} (3) were synthesized containing other hetero-oxyanion building blocks in addition to the borate frameworks. They were all prepared under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction, and IR spectroscopy. Crystal data: For 1; space group P2{sub 1}/c, a=6.8909 (14) Å, b=13.629 (3) Å, c=25.851 (5) Å, β=90.04 (3)°; For 2; space group P-31c, a=8.8599 (13) Å, c=15.148 (3) Å; For 3; space group P-1, a=5.0414 (10) Å, b=7.5602 (15) Å, c=8.5374 (17)more » Å, α=77.15 (3)°, β=77.84 (3)°, γ=87.41 (3)° for 3. Compounds 1 and 2 contain isolated oxyanions [PO{sub 4}]{sup 3−} and [CO{sub 3}]{sup 2−} respectively, sitting in channels created by the borate framework, while structure 3 has the [SiO{sub 4}]{sup 4−} groups directly bonded to the borate groups creating a B–O–Si framework. - Highlights: • Hydrothermal syntheses of three new mixed oxyanion borates are presented. • Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} contains isolated [PO{sub 4}]{sup 3−} in voids of the borate framework. • Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) contains isolated [CO{sub 3}]{sup 2−} in channels created by the framework. • Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} has direct bonding of [SiO{sub 4}]{sup 4−} and borates creating a B–O–Si framework.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Yue; Yang, Meng-Lin; Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN

Six new coordination polymers, [ZnLCl]{sub n}(1), [ZnL{sub 2}]{sub n}·2nH{sub 2}O (2), [Zn{sub 2}L(o-bdc)(OH)]{sub n}·0.5nH{sub 2}O (3), [Zn{sub 2}L(m-bdc)(OH)]{sub n}·nH{sub 2}O (4), [Zn{sub 2}L{sub 2}(p-bdc) (H{sub 2}O){sub 2}]{sub n}·nH{sub 2}O (5), [Zn{sub 2}L(1,2,4-btc)(H{sub 2}O)]{sub n}(6), (HL=4′-(3-carboxyphenyl)- 3,2′:6′,3″-terpyridine, H{sub 2}(o-bdc)= benzene-1,2-dicarboxylic acid, H{sub 2}(m-bdc)= benzene-1,3-dicarboxylic acid, H{sub 2}(p-bdc)= benzene-1,4-dicarboxylic acid, H{sub 3}(1,2,4-btc)= benzene-1,2,4-tricarboxylic acid) have been synthesized under the hydrothermal conditions. Compound 1 displays a 3-connected 2D network structure with point symbol of {8"2.10}. Compound 2 exhibits 1D infinite loop chain structure. Compound 3 possesses a (3,8)-connected 3D framework composed of tetranuclear units with point symbol of {4"3}{sub 2}{4"6.6"1"8.8"4}. Compound 4 featuresmore » a typical 2D hcb network based on tetranuclear zinc(II) units with point symbol of {4"4.6"2}. Compound 5 presents a classical two-fold penetration sql network with point symbol of {6"3}. Compound 6 can be seen as a (3,3,6)-connected 3D net with point symbol of {4"2.6"4.8"9}{4"2.6}{6"3}. The thermal stability and luminescent properties of compounds 1–6 in the solid state are discussed in detail. - Graphical abstract: Six new Zn(II) coordination polymers based on multicarboxylate and terpyridyl derivative ligands have synthesized under the hydrothermal conditions and the thermal stability and luminescence are discussed. Display Omitted.« less

Play the heavy: An effective mass study for α-Fe{sub 2}O{sub 3} and corundum oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neufeld, Ofer; Caspary Toroker, Maytal, E-mail: maytalc@tx.technion.ac.il

2016-04-28

Iron(III) oxide (α-Fe{sub 2}O{sub 3}) is a known water splitting catalyst commonly used in photoelectrochemical cells. These cells are severely impaired by poor conductivity in α-Fe{sub 2}O{sub 3}, and resolving the conductivity issue is therefore crucial. One of the most intrinsic properties of matter, which governs conductivity, is the carrier effective masses. In this work, we investigate the carrier effective masses in α-Fe{sub 2}O{sub 3} and other corundum oxides, including Al{sub 2}O{sub 3}, Cr{sub 2}O{sub 3}, Ga{sub 2}O{sub 3}, and In{sub 2}O{sub 3} with different theoretical constructs: density functional theory (DFT), DFT+U, hybrid DFT, and G{sub 0}W{sub 0}. We findmore » DFT sufficiently describes the carrier masses and a quasi-particle theory is only required for accuracies better than 30% for the conduction band effective mass. Additionally, we compare the density of states (DOS) and band effective mass approximations and conclude the DOS effective mass provides poor results whenever the band structure is anisotropic. We find that the charge carriers in Fe{sub 2}O{sub 3} “play the heavy” since they have large effective masses that reduce conductivity and device efficiency. Finally, we conclude that the less heavy electron effective masses of other corundum oxides studied relative to Fe{sub 2}O{sub 3} could contribute to efficiency improvements in Fe{sub 2}O{sub 3} upon Al{sub 2}O{sub 3}, Ga{sub 2}O{sub 3}, and In{sub 2}O{sub 3} coverage.« less

Structure–property relations of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haussühl, Eiken, E-mail: haussuehl@kristall.uni-frankfurt.de; Schreuer, Jürgen; Wiehl, Leonore

2014-04-01

Large single crystals of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O with dimensions up to 40×40×30 mm{sup 3} were grown from aqueous solutions. The elastic and piezoelastic coefficients were derived from ultrasonic resonance frequencies and their shifts upon variation of pressure, respectively, using the plate-resonance technique. Additionally, the coefficients of thermal expansion were determined between 95 K and 305 K by dilatometry. The elastic behaviour at ambient conditions is dominated by the 2-dimensional network of strong hydrogen bonds within the (001) plane leading to a corresponding pseudo-tetragonal anisotropy of the longitudinal elastic stiffness. The variation of elastic propertiesmore » with pressure, however, as well as the thermal expansion shows strong deviations from the pseudo-tetragonal symmetry. These deviations are probably correlated with tilts of the elongated tri-nuclear betaine–CuCl{sub 2}–water complexes. Neither the thermal expansion nor the specific heat capacity gives any hint on a phase transition in the investigated temperature range. - Graphical abstract: Single crystal of orthorhombic [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O. - Highlights: • Large single crystals (40 ×40 ×30 mm{sup 3}) of [(CH{sub 3}){sub 3}NCH{sub 2}COO]{sub 2}(CuCl{sub 2}){sub 3}·2H{sub 2}O were grown. • The elastic and piezoelastic coefficients were derived from ultrasonic resonance frequencies. • Thermal expansion (95 K–305 K) and heat capacity (113 K–323 K) were determined. • The orthorhombic structure shows pseudo-tetragonal elastic anisotropy at ambient conditions. • The crystal structure is stable in the investigated range (1–1600 bar, 95–303 K)« less

Structure of complexes of nitrilo tris methylene phosphonic acid with copper, [CuN(CH{sub 2}PO{sub 3}){sub 3}(H{sub 2}O){sub 3}] and Na{sub 4}[CuN(CH{sub 2}PO{sub 3}){sub 3}]{sub 2} · 19H{sub 2}O, as bactericides and inhibitors of scaling and corrosion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somov, N. V., E-mail: somov@phys.unn.ru; Chausov, F. F., E-mail: chaus@uni.udm.ru

2015-03-15

Nitrilotris methylene phosphonate triaqua copper and octasodium bis(nitrilotris methylene phosphonate cuprate(II)) nonadecahydrate have been synthesized and investigated. [CuN(CH{sub 2}PO{sub 3}){sub 3}(H{sub 2}O){sub 3}] is crystallized in the sp. gr. P2{sub 1}/c, Z = 4, a = 9.2506(2) Å, b = 15.9815(2) Å, c = 9.5474(2) Å, β = 113.697(2)°. The copper atom is coordinated by oxygen atoms in the configuration of elongated octahedron; the ligand (of bridge type) links neighboring copper atoms. Na{sub 8}[CuN(CH{sub 2}PO{sub 3}){sub 3}]{sub 2} · 19H{sub 2}O is crystallized in the sp. gr. P2{sub 1}/c, Z = 2, a = 11.24550(10) Å, b = 17.38980(10) Å,more » c = 13.5852(2) Å, β = 127.8120(10)°. This complex is chelating; the copper atom closes three five-membered N-C-P-O-Cu cycles with a shared Cu-N bond. Copper is coordinated in a distorted trigonal-bipyramidal configuration.« less

High temperature redox reactions with uranium: Synthesis and characterization of Cs(UO{sub 2})Cl(SeO{sub 3}), Rb{sub 2}(UO{sub 2}){sub 3}O{sub 2}(SeO{sub 3}){sub 2}, and RbNa{sub 5}U{sub 2}(SO{sub 4}){sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babo, Jean-Marie; Department of Civil and Environmental Engineering and Earth Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556; Albrecht-Schmitt, Thomas E., E-mail: talbrechtschmitt@gmail.com

2013-10-15

Cs(UO{sub 2})Cl(SeO{sub 3}) (1), Rb{sub 2}(UO{sub 2}){sub 3}O{sub 2}(SeO{sub 3}){sub 3} (2), and RbNa{sub 5}U{sub 2}(SO{sub 4}){sub 7} (3) single crystals were synthesized using CsCl, RbCl, and a CuCl/NaCl eutectic mixture as fluxes, respectively. Their lattice parameters and space groups are as follows: P2{sub 1}/n (a=6.548(1) Å, b=11.052(2) Å, c=10.666(2) Å and β=93.897(3)°), P1{sup ¯} (a=7.051(2) Å, b=7.198(2) Å, c=8.314(2) Å, α=107.897(3)°, β=102.687(3)° and γ=100.564(3)°) and C2/c (a=17.862(4) Å, b=6.931(1) Å, c=20.133(4) Å and β=109.737(6)°. The small anionic building units found in these compounds are SeO{sub 3}{sup 2−} and SO{sub 4}{sup 2−} tetrahedra, oxide, and chloride. The crystal structure ofmore » the first compound is composed of [(UO{sub 2}){sub 2}Cl{sub 2}(SeO{sub 3}){sub 2}]{sup 2−} chains separated by Cs{sup +} cations. The structure of (2) is constructed from [(UO{sub 2}){sub 3}O{sub 11}]{sup 16−} chains further connected through selenite units into layers stacked perpendicularly to the [0 1 0] direction, with Rb{sup +} cations intercalating between them. The structure of compound (3) is made of uranyl sulfate layers formed by edge and vertex connections between dimeric [U{sub 2}O{sub 16}] and [SO{sub 4}] polyhedra. These layers contain unusual sulfate–metal connectivity as well as large voids. - Graphical abstract: A new family of uranyl selenites and sulfates has been prepared by high-temperature redox reactions. This compounds display new bonding motifs. Display Omitted - Highlights: • Low-dimensional Uranyl Oxoanion compounds. • Conversion of U(IV) to U(VI) at high temperatures. • Dimensional reduction by both halides and stereochemically active lone-pairs.« less

Mesoporous mixed-phase Ga{sub 2}O{sub 3}: Green synthesis and enhanced photocatalytic activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jin; The Key Laboratory of Rare Earth Functional Materials and Applications, Zhoukou Normal University, Zhoukou 466001; Zhang, Gaoke, E-mail: gkzhang@whut.edu.cn

2015-08-15

Highlights: • Mixed-phase Ga{sub 2}O{sub 3} was synthesized by a facile and green method. • Mixed-phase Ga{sub 2}O{sub 3} exhibited good photocatalytic activity and stability. • The reactive species in the photocatalytic process were investigated. - Abstract: Mesoporous mixed-phase Ga{sub 2}O{sub 3} was synthesized by calcining the GaOOH precursor. The composition, crystal phase and microstructures of Ga{sub 2}O{sub 3} were characterized in detail. The phase composition of the as-prepared Ga{sub 2}O{sub 3} depended on the calcination temperature and the mixed-phase Ga{sub 2}O{sub 3} was obtained at 600–700 °C. As compared to the pure-phase α-Ga{sub 2}O{sub 3} and β-Ga{sub 2}O{sub 3},more » the mixed-phase Ga{sub 2}O{sub 3} exhibited an enhanced photocatalytic property for the degradation of metronidazole solution. The heterojunction in the mixed-phase Ga{sub 2}O{sub 3} was beneficial to the separation of photogenerated electrons and holes. Moreover, the mixed-phase Ga{sub 2}O{sub 3} possessed mesopore structure, which increased more reaction sites and was in favor of the contact of metronidazole molecules with reaction sites. The recycling experiments show that the mixed-phase Ga{sub 2}O{sub 3} has good stability and can be separated easily from the reaction system.« less

Na{sub 6}B{sub 13}O{sub 22.5}, a new noncentrosymmetric sodium borate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penin, N.; Touboul, M.; Nowogrocki, G.

2005-03-15

Na{sub 6}B{sub 13}O{sub 22.5} (B/Na=2.17) single crystals were obtained by heating, melting and appropriately cooling borax, Na{sub 2}[B{sub 4}O{sub 5}(OH){sub 4}].8H{sub 2}O. Its formula has been determined by the resolution of the structure from single-crystal X-ray diffraction data. The compound crystallizes in the noncentrosymmetric orthorhombic Iba2 space group, with the following unit cell parameters: a=33.359(11)A, b=9.554(3)A, c=10.644(4)A; V=3392.4(19)A{sup 3}; Z=8. The crystal structure was solved from 3226 reflections until R{sub 1}=0.0385. It exhibits a three-dimensional framework built up from BO{sub 3} triangles ({delta}) and BO{sub 4} tetrahedra (T). Two kinds of borate groups can be considered forming two different doublemore » B{sub 3}O{sub 3} rings: two B{sub 4}O{sub 9} (linkage by two boron atoms) and one B{sub 5}O{sub 11} (linkage by one boron atom); the shorthand notation of the new fundamental building block (FBB) existing in this compound is: 13: {infinity}{sup 3} [(5: 3{delta}+2T)+2(4: 2{delta}+2T)]. The discovery of this new borate questions the real number of Na{sub 2}B{sub 4}O{sub 7} varieties. The existence of Na{sub 6}B{sub 13}O{sub 22.5} (B/Na=2.17) and of another recently discovered borate, Na{sub 3}B{sub 7}O{sub 12} (B/Na=2.33; FBB 7: {infinity}{sup 3} [(3: 2{delta}+T)+(3: {delta}+2T)+(1: {delta})], with a composition close to the long-known borate {alpha}-Na{sub 2}B{sub 4}O{sub 7} (B/Na=2; FBB 8: {infinity}{sup 3} [(5: 3{delta}+2T)+(3: 2{delta}+T)], may explain the very complex equilibria reported in the Na{sub 2}O-B{sub 2}O{sub 3} phase diagram, especially in this range of composition.« less

The effect of urea on microstructures of Ni{sub 3}S{sub 2} on nickel foam and its hydrogen evolution reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jinlong, Lv, E-mail: ljltsinghua@126.com; State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084; Tongxiang, Liang, E-mail: txliang@mail.tsinghua.edu.cn

The effects of urea concentration on microstructures of Ni{sub 3}S{sub 2}formed on nickel foam and its hydrogen evolution reaction were investigated. The Ni{sub 3}S{sub 2} nanosheets with porous structure were formed on nickel foam during hydrothermal process due to low urea concentration. While high urea concentration facilitated the forming of Ni{sub 3}S{sub 2} nanotube arrays. The resulting Ni{sub 3}S{sub 2} nanotube arrays exhibited higher catalytic activity than Ni3S2nanosheets for hydrogen evolution reaction. This was mainly attributed to a fact that Ni{sub 3}S{sub 2} nanotube arrays facilitated diffusion of electrolyte for hydrogen evolution reaction. - Graphical abstract: The resulting Ni{sub 3}S{submore » 2} nanotube arrays exhibited higher catalytic activity than Ni{sub 3}S{sub 2} nanosheets for hydrogen evolution reaction. This was mainly attributed to a fact that Ni{sub 3}S{sub 2} nanotube arrays facilitated diffusion of electrolyte for hydrogen evolution reaction and hydrogen evolution. - Highlights: • Urea promoted to forming more Ni{sub 3}S{sub 2} nanotube arrays on nickel foam. • Ni{sub 3}S{sub 2} nanotube arrays showed higher catalytic activity in alkaline solution. • Ni{sub 3}S{sub 2} nanotube arrays promoted electron transport and reaction during the HER.« less

Two actinide-organic frameworks constructed by a tripodal flexible ligand: Occurrence of infinite ((UO{sub 2})O{sub 2}(OH){sub 3}){sub 4n} and hexanuclear (Th{sub 6}O{sub 4}(OH){sub 4}) motifs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Lingling; Zhang, Ronglan; Zhao, Jianshe, E-mail: jszhao@nwu.edu.cn

Two new actinide metal-organic frameworks were constructed by using a tripodal flexible ligand tris (2-carboxyethyl) isocyanurate (H{sub 3}tci) under hydrothermal condition. The combination of H{sub 3}tci and uranyl nitrate hexahydrate in aqueous solution leads to the isolation of [(UO{sub 2}){sub 2}(H{sub 2}O){sub 4}]{sub 0.5}(tci){sub 2}(UO{sub 2}){sub 4}(OH){sub 4}·18H{sub 2}O (1), which contains two distinct UO{sub 2}{sup 2+} coordination environments. Four uranyl cations, linked through μ{sub 3}-OH respectively, result in the edge-sharing ribbons. Then, the layer structure is constructed by U-O clusters linked through other eight-coordinated uranyl unions, giving rise to a porous structure in the space. Topological analysis reveals thatmore » complex 1 belongs to a (4, 8)-connected net with a schläfli symbol of (3{sup 4.}2{sup 6.}3){sub 2}(3{sup 4.}4{sup 6.}5{sup 6.}6{sup 8.}7{sup 3.}8). Th{sub 3}(tci){sub 2}O{sub 2}(OH){sub 2}(H{sub 2}O){sub 3}·12H{sub 2}O (2) generated by the reaction of H{sub 3}tci and thorium nitrate tetrahydrate, possesses nine-fold coodinated Th(IV) centers with a monocapped square antiprismatic geometry. The hexamers “Th{sub 6}O{sub 4}(OH){sub 4}” motifs are connected together by the carboxylate groups, showing a three-dimensional structures. Complex 2 takes on an 8-connected architecture and the point symbol is (4{sup 24.}6{sup 4}). - Graphical abstract: Two new 3D actinide metal-organic frameworks were constructed by using a tripodal flexible ligand tris (2-carboxyethyl) isocyanurate (H3tci) and their topological structures were displayed. The infinite ((UO{sub 2})O{sub 2}(OH){sub 3}){sub 4n} and hexanuclear (Th{sub 6}O{sub 4}(OH){sub 4}) motifs were found in the title actinides networks.« less

Phase diagrams of the sections As/sub 2/S/sub 3/-Tl/sub 3/AsS/sub 4/, Tl/sub 3/AsS/sub 4/-S, and Tl/sub 3/AsS/sub 4/-Tl/sub 2/S of the ternary system As-Tl-S

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorob'ev, Yu.I.; Velikova, N.G.; Kirilenko, V.V.

1987-12-01

Using DTA and XPA methods, microstructural investigations, and microhardness measurements, phase diagrams of the quasibinary sections As/sub 2/S/sub 3/-Tl/sub 3/AsS/sub 4/, Tl/sub 3/AsS/sub 4/-S, and Tl/sub 3/AsS/sub 4/-Tl/sub 2/S, are characterized by five ternary compounds Tl/sub 3/As/sub 5/S/sub 10/, Tl/sub 9/As/sub 5/S/sub 15/, Tl/sub 9/As/sub 3/S/sub 13/, Tl/sub 3/AsS/sub 6/, and Tl/sub 8/As/sub 2/S/sub 9/, which decompose by peritectic reactions at 198, 307, 408, 362, and 318/degree/C, respectively. Interplanar spacings and line intensities are given for the detected compounds. Glass formation is considered in the Tl-As-S system.

Multiple bonds between transition metals and main-group elements. 73. Synthetic routes to rhenium(V) alkyl and rhenium(VII) alkylidyne complexes. X-ray crystal structures of (. eta. sup 5 -C sub 5 Me sub 5 )Re( double bond O)(CH sub 3 )(CH sub 2 C(CH sub 3 ) sub 3 ) and (. eta. sup 5 -C sub 5 Me sub 5 )(Br) sub 3 Re triple bond CC(CH sub 3 ) sub 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrmann, W.A.; Felixberger, J.K.; Anwander, R.

1990-05-01

Dialkyloxo({eta}{sup 5}pentamethylcyclopentadienyl)rhenium(V) complexes ({eta}{sup 5}-C{sub 5}Me{sub 5})Re({double bond}O)(CH{sub 3})R{prime}(R{prime} = C{sub 2}H{sub 5}, CH{sub 2}Si(CH{sub 3}){sub 3}, CH{sub 2}C(CH{sub 3}){sub 3}), 1c-e, have become accessible through alkylation of ({eta}{sup 5}-C{sub 5}Me{sub 5})Re({double bond}O)(Cl)(CH{sub 3}) (7) with R{prime}MgCl. 1c-e are the first rhenium complexes containing different alkyl ligands. The neopentyl derivative 1e (R{prime} = CH{sub 2}C(CH{sub 3}){sub 3}) crystallizes in the orthorhombic space group Pbca with a = 960.7 (2), b = 2.844.5 (4), c = 1,260.7 (2) pm, and Z = 8. The X-ray crystal structure was refined to R{sub W} = 3.9%. The chiral molecule shows a distorted tetrahedralmore » geometry around the rhenium center. The tribromide 3b has been structurally characterized. Brown crystals of 3b belong to space group P2{sub 1}/c with unit cell dimensions a = 1,311.5 (2), b = 723.0 (1), c = 1,901.6 (2) pm, {beta} = 92.68 (1){degree}, and Z = 4. The structure exhibits a four-legged piano stool geometry with no trans influence of the neopentylidyne ligand to the bromine atom.« less

Synthesis of the new quaternary sulfides K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11] and BaLnAgS[sub 3] (Ln = Er, Y, Gd) and the structures of K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11] and BaErAgS[sub 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Ping; Ibers, J.A.

1994-05-01

Several new quarternary sulfides, K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11] and BaLnAgS[sub 3] (Ln = Er, Y, Gd), have been synthesized by the reaction of the constituent binary chalcogenides and elements at 1000[degrees]C. The crystal structures of K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11] and BaErAgS[sub 3] have been determined by single-crystal X-ray diffraction techniques. Crystal data: K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11]-space group D[sup 8][sub 4h] - P4/ncc, M = 1023.88, Z = 4, a = 8.587(1), c = 27.892(4) [angstrom] (T = 115 K), V = 2056.7(4) [angstrom][sup 3], R[sub W](F[sup 2]) = 0.093 for 1965 observations having F[sup 2][sub 0] >more » 2[sigma](F[sup 2][sub 0]); BaEr AgS[sub 3]-space group C[sup 3][sub 2H] - C2/m, M = 508.65, Z = 4, a = 17.340(4), b = 4.014(1), x = 8.509(2) [angstrom], [beta] = 103.23(3)[degrees], (T = 115 K), V = 576.5(2) [angstrom][sup 3], R[sub W](F[sup 2]) = 0.049 for 1404 observations and 48 variables, R(F) = 0.018 for 1299 observations having F[sup 2][sub 0] > 2[sigma](F[sup 2][sub 0]). In both structures, the rare-earth atoms have octahedral coordination and the octahedra form slabs through edge- and corner-sharing. These slabs are separated by K[sup +] Ba[sup 2+] cations, and are crosslinked into three-dimensional frameworks by Sn[sub 2]S[sub 6] units as edge-sharing SnS[sub 4] tetrahedral pairs in K[sub 2]Y[sub 4]Sn[sub 2]S[sub 11], and by Ag[sub 2]S[sub 9] units as corner-sharing trigonal-bipyramidal AgS[sub 5] pairs in BaEr AgS[sub 3]. From their powder diffraction patterns, BaYAgS[sub 3] and Ba GdAgS[sub 3] appear to be isostructural with BaErAgS[sub 3].« less

Synthetic Coal Slag Infiltration into Varying Refractory Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaneko, Tetsuya K; Thomas, Hugh; Bennett, James P

The infiltrations of synthetic coal slag into 99%Al{sub 2}O{sub 3}, 85%Al{sub 2}O{sub 3}–15%SiO{sub 2}, and 90%Cr{sub 2}O{sub 3}–10%Al{sub 2}O{sub 3} refractories with a temperature gradient induced along the penetration direction were compared to one another. The infiltrating slag was synthesized with a composition that is representative of an average of the ash contents from U S coal feedstock. Experiments were conducted with a hot-face temperature of 1450°C in a CO/CO{sub 2} atmosphere. Minimal penetration was observed in the 90%Cr{sub 2}O{sub 3}–10%Al{sub 2}O{sub 3} material because interactions between the refractory and the slag produced a protective layer of FeCr{sub 2}O{sub 4},more » which impeded slag flow into the bulk of the refractory. After 5 h, the 99%Al{sub 2}O{sub 3} sample exhibited an average penetration of 12.7 mm whereas the 85%Al{sub 2}O{sub 3}–15%SiO{sub 2} sample showed 3.8 mm. Slag infiltrated into the 99%Al{sub 2}O{sub 3} and 85%Al{sub 2}O{sub 3}–15%SiO{sub 2} refractory systems by dissolving the respective refractories' matrix materials, which consist of fine Al{sub 2}O{sub 3} particles and an amorphous alumino-silicate phase. Due to enrichment in SiO{sub 2}, a network-former, infiltration into the 85%Al{sub 2}O{sub 3}–15%SiO{sub 2} system yielded a higher viscosity slag and hence, a shallower penetration depth. The results suggest that slag infiltration can be limited by interactions with the refractory through the formation of either a solid layer that physically impedes fluid flow or a more viscous slag that retards infiltration.« less

Ionothermal syntheses of three transition-metal-containing polyoxotungstate hybrids exhibiting the photocatalytic and electrocatalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, W.-L.; Chen, B.-W.; Tan, H.-Q.

2010-02-15

Employing the ionothermal synthesis approach, three new transition-metal-containing polyoxotungstate hybrids: [Dmim]{sub 2}Na{sub 3}[SiW{sub 11}O{sub 39}Fe(H{sub 2}O)].H{sub 2}O (Dmim=1,3-Dimethylimidazole) (1), [Emim]{sub 9}Na{sub 8}[(SiW{sub 9}O{sub 34}){sub 3}{l_brace}Fe{sub 3}(mu{sub 2}-OH){sub 2}(mu{sub 3}-O){r_brace}{sub 3}(WO{sub 4})].0.5H{sub 2}O (Emim=1-Ethyl-3-meth-ylimidazole) (2) and [Dmim]2[HMim]Na{sub 6}[(AsW{sub 9}O{sub 33}){sub 2}{l_brace}Mn{sup III}(H{sub 2}O){r_brace}{sub 3}].3H{sub 2}O (Dmim=1,3-Dimethylimidazole; Mim=1-Methylimidazole) (3) have been synthesized in 1-ethyl-3-methyl imidazolium bromide ([Emim]Br) ionic liquids (ILs). Compound 1 possesses a 3-D open framework constructed from the mono-iron{sup III}-substituted alpha-Keggin-type anion and the organic cations [Dmim]+ through the hydrogen bond interactions. Compound 2 contains a [{l_brace}Fe{sup III}{sub 3}(mu{sub 2}-OH){sub 2}(mu{sub 3}-O){r_brace}{sub 3}(mu{sub 4}-WO{sub 4})] cluster surrounded by three [SiW{submore » 9}O{sub 34}]{sup 10-} ligands, eight sodium cations and nine dissociative [Emim]{sup +} cations around the polyoxoanion. The polyoxoanion of 3 consists of a high-valent trinuclear-manganese (III)-substituted sandwiching polyoxoanion based on the [alpha-AsW{sub 9}O{sub 33}]{sup 9-} units. All the compounds are characterized by elemental analyses, IR, UV-vis spectra, TG-DTA and XRD analyses. The XPS and EPR spectra of Mn{sup III} in 3 were studied. The photocatalytic and electrocatalytic properties, as well as the stabilities of 1-3 were also investigated. - Graphical abstract: Three new transition-metal-containing polyoxotungstate hybrids were synthesized successfully under the ionothermal condition, which proves that the ionothermal synthesis is a suitable synthetic method for different kinds of polyoxometalates.« less

Stabilization of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} through Si–Ti substitution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Weiwei, E-mail: weiweix@princeton.edu; Fuccillo, M.K.; Phelan, B.F.

2015-07-15

We report a route for designing and synthesizing Ti{sub 3}Co{sub 5}B{sub 2}-type compounds in the Ti–Ru–B system by using chemical substitution of Si for Ti to decrease the d-electron-based antibonding interactions that it is argued would otherwise drive an instability in this structure for unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2}. Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} with x=0.75, 1.00 and 1.25 nominal compositions crystalizes in the Ti{sub 3}Co{sub 5}B{sub 2} structure type using arc melting methods, whereas at lower doping levels (x=0.0, 0.25 and 0.50) the more complex Zn{sub 11}Rh{sub 18}B{sub 8}-type structure is stable. Electronic structure calculations show that in hypothetical,more » unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2} with the Ti{sub 3}Co{sub 5}B{sub 2}-type structure, the antibonding interactions are strong around the Fermi level between the Ti and Ru in the structure that form tetragonal prisms. We propose that weakening these strong interactions through the partial substitution of isovalent Si for Ti leads to the observed stability of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} for x≈1. - Graphical abstract: We present the designing and synthesizing of Ti{sub 3}Co{sub 5}B{sub 2}-type compounds in the Ti–Ru–B system by using chemical substitution of Si for Ti to decrease the d-electron-based antibonding interactions that would otherwise drive an instability in this structure for unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2}. Electronic structure calculations show that in hypothetical, unsubstituted Ti{sub 3}Ru{sub 5}B{sub 2} with the Ti{sub 3}Co{sub 5}B{sub 2}-type structure, the antibonding interactions are strong around the Fermi level between the Ti and Ru in the structure that form tetragonal prisms. We propose that weakening these strong interactions through the partial substitution of isovalent Si for Ti leads to the observed stability of the Ti{sub 3}Co{sub 5}B{sub 2}-type structure for Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} for x≈1. - Highlights: • New quaternary phase Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} in Ti{sub 3}Co{sub 5}B{sub 2}-type structure is reported. • Chemical substitution of isovalent Si for Ti is used to stabilize the phase. • Decreasing the d-electron-based antibonding interactions is proved by calculation. • Physical properties of Ti{sub 3−x}Si{sub x}Ru{sub 5}B{sub 2} are presented down to 0.4 K.« less

Synthesis, characterisation and anion exchange properties of copper, magnesium, zinc and nickel hydroxy nitrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswick, Timothy; Jones, William; Pacula, Aleksandra

2006-01-15

Anion exchange reactions of four structurally related hydroxy salts, Cu{sub 2}(OH){sub 3}NO{sub 3}, Mg{sub 2}(OH){sub 3}NO{sub 3}, Ni{sub 2}(OH){sub 3}NO{sub 3} and Zn{sub 3}(OH){sub 4}(NO{sub 3}){sub 2} are compared and trends rationalised in terms of the strength of the covalent bond between the nitrate group and the matrix cation. Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis are used to characterise the materials. Replacement of the nitrate anions in the zinc and copper salts with benzoate anions is possible although exchange of the zinc salt is accompanied by modification of the layer structure frommore » one where zinc is exclusively six-fold coordinated to a structure where there is both six- and four-fold zinc coordination. Magnesium and nickel hydroxy nitrates, on the other hand, hydrolyse to their respective metal hydroxides. -- Graphical abstract: PXRD patterns of exchange products of (a) Zn{sub 3}(OH){sub 4}(NO{sub 3}){sub 2} (b) Zn{sub 5}(OH){sub 8}(NO{sub 3}){sub 2}.2H{sub 2}O and (c) Cu{sub 2}(OH){sub 3}NO{sub 3} with benzoate anions.« less

Syntheses, structures and characterizations of three novel vanadium selenites with organically bonded copper/nickel complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Cheng; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Kong, Fang

2016-06-15

A series of vanadium selenites covalently bonded with metal-organic complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) (2,2-bipy=2,2-bipyridine) have been hydrothermally synthesized and structurally characterized. They exhibit three different structural dimensions, from 0D cluster, 1D chain to 2D layer. Compound 1 features a 0D {Ni(2,2-bipy)_2V_2O_4(SeO_3)_2}{sub 2} dimeric cluster composed of two {Ni(2,2-bipy)_2}{sup 2+} moieties connected by the {V_4O_8(SeO_3)_4}{sup 4-} cluster. Compound 2 shows a 1D {Cu(2,2-bipy)V_2O_4(SeO_3)_2}{sub n} chain in which the {Cu_2(2,2-bipy)_2}{sup 4+} moieties are bridged by the {V_4O_8(SeO_3)_4}{sup 4−} clusters. Compound 3more » displays a 2D structure consisted of mixed valence vanadium selenites layers {V"I"VV"V_4Se"I"V_2O_1_8}{sub n}{sup 4−} and {Cu(2,2-bipy)}{sup 2+} complex moieties. The adjacent layers are further interconnected via π-π interactions between the 2,2-bipy ligands exhibiting an interesting 3D supramolecular architecture. Both compound 1 and 2 contain a new {V_4O_8(SeO_3)_4}{sup 4−} cluster and compound 3 exhibits the first 2D vanadate polyhedral layer in vanadium selenites/tellurites with organic moieties. - Graphical abstract: We got three new vanadium selenites with organically linked copper/nickel complex, namely, Ni(2,2-bipy){sub 2}V{sub 2}O{sub 4}(SeO{sub 3}){sub 2} (1), Cu(2,2-bipy)V{sub 2}O{sub 4}(SeO{sub 3}){sub 2}·0.5H{sub 2}O (2) and Cu{sub 2}(2,2-bipy){sub 2}V{sub 5}O{sub 12}(SeO{sub 3}){sub 2} (3) by hydrothermally syntheses. They display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. Display Omitted - Highlights: • Three new compounds display three different structural dimensions, from 0D cluster, to 1D chain and 2D layer. • The Tetranuclear {V_4O_8(SeO_3)_4}{sup 4−} cluster and the vanadate {V_5O_1_7}{sub n} 2D layer are observed firstly. • Optical Properties and Magnetic Properties of three compounds are reported.« less

Crystal structure and physical properties of new Ca{sub 2}TGe{sub 3} (T = Pd and Pt) germanides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klimczuk, T., E-mail: tomasz.klimczuk@pg.gda.pl; Xie, Weiwei; Winiarski, M.J.

The crystallographic, electronic transport and thermal properties of Ca{sub 2}PdGe{sub 3} and Ca{sub 2}PtGe{sub 3} are reported. The compounds crystalize in an ordered variant of the AlB{sub 2} crystal structure, in space group P6/mmm, with the lattice parameters a = 8.4876(4) Å/8.4503(5) Å and c = 4.1911(3) Å/4.2302(3) Å for Ca{sub 2}PdGe{sub 3} and Ca{sub 2}PtGe{sub 3}, respectively. The resistivity data exhibit metallic behavior with residual-resistivity-ratios (RRR) of 13 for Ca{sub 2}PdGe{sub 3} and 6.5 for Ca{sub 2}PtGe{sub 3}. No superconducting transition is observed down to 0.4 K. Specific heat studies reveal similar values of the Debye temperatures and Sommerfeldmore » coefficients: Θ{sub D} = 298 K, γ = 4.1 mJ mol{sup −1} K{sup −2} and Θ{sub D} = 305 K, γ = 3.2 mJ mol{sup −1} K{sup −2} for Ca{sub 2}PdGe{sub 3} and Ca{sub 2}PtGe{sub 3}, respectively. The low value of γ is in agreement with the electronic structure calculations.« less

Calcium aluminates hydration in presence of amorphous SiO{sub 2} at temperatures below 90 deg. C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivas Mercury, J.M.; Turrillas, X.; Aza, A.H. de

2006-10-15

The hydration behaviour of Ca{sub 3}Al{sub 2}O{sub 6}, Ca{sub 12}Al{sub 14}O{sub 33} and CaAl{sub 2}O{sub 4} with added amorphous silica at 40, 65 and 90 deg. C has been studied for periods ranging from 1 to 31 days. In hydrated samples crystalline phases like katoite (Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub 3-} {sub x} (OH){sub 4} {sub x} ) and gibbsite, Al(OH){sub 3}, were identified, likewise amorphous phases like Al(OH) {sub x} , calcium silicate hydrates, C-S-H, and calcium aluminosilicate hydrates, C-S-A-H, were identified. The stoichiometry of Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub 3-} {sub x} (OH){sub 4} {sub x} (0{<=}3-x{<=}0.334), which was themore » main crystalline product, was established by Rietveld refinement of X-ray and neutron diffraction data and by transmission electron microscopy. - Graphical abstract: Katoite, Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub 3-} {sub x} (OH){sub 4} {sub x} (0{<=}3-x{<=}0.334), was identified besides gibbsite, Al(OH){sub 3}, as a crystalline stable hydration products in Ca{sub 3}Al{sub 2}O{sub 6}, Ca{sub 12}Al{sub 14}O{sub 33} and CaAl{sub 2}O{sub 4} hydrated with added amorphous silica between 40 and 90 deg. C.« less

Y{sub 2}MoSe{sub 3}O{sub 12} and Y{sub 2}MoTe{sub 3}O{sub 12}: Solid-state synthesis, structure determination, and characterization of two new quaternary mixed metal oxides containing asymmetric coordination environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bang, Seong-eun; Pan, Zhi; Kim, Yeong Hun

Two new quaternary yttrium molybdenum selenium/tellurium oxides, Y{sub 2}MoSe{sub 3}O{sub 12} and Y{sub 2}MoTe{sub 3}O{sub 12} have been prepared by standard solid-state reactions using Y{sub 2}O{sub 3}, MoO{sub 3}, and SeO{sub 2} (or TeO{sub 2}) as reagents. Single-crystal X-ray diffraction was used to determine the crystal structures of the reported materials. Although both of the materials contain second-order Jahn–Teller (SOJT) distortive cations and are stoichiometrically similar, they reveal different structural features: while Y{sub 2}MoSe{sub 3}O{sub 12} shows a three-dimensional framework consisting of YO{sub 8}, MoO{sub 6}, and SeO{sub 3} groups, Y{sub 2}MoTe{sub 3}O{sub 12} exhibits a layered structure composed ofmore » YO{sub 8}, MoO{sub 4}, TeO{sub 3}, and TeO{sub 4} polyhedra. With the Mo{sup 6+} cations in Y{sub 2}MoSe{sub 3}O{sub 12}, a C{sub 3}-type intraoctahedral distortion toward a face is observed, in which the direction of the out-of-center distortion for Mo{sup 6+} is away from the oxide ligand linked to a Se{sup 4+} cation. The Se{sup 4+} and Te{sup 4+} cations in both materials are in asymmetric coordination environment attributed to the lone pairs. Elemental analyses, infrared spectroscopy, thermal analyses, intraoctahedral distortions, and dipole moment calculations for the compounds are also presented. - Graphical abstract: Y{sub 2}MoSe{sub 3}O{sub 12} reveals a three-dimensional framework consisting of YO{sub 8}, MoO{sub 6}, and SeO{sub 3} polyhedra, whereas Y{sub 2}MoTe{sub 3}O{sub 12} exhibits a layered structure composed of YO{sub 8}, MoO{sub 4}, TeO{sub 3}, and TeO{sub 4} groups. - Highlights: • Two new selenite and tellurite (Y{sub 2}MoQ{sub 3}O{sub 12}; Q=Se and Te) are synthesized. • Y{sub 2}MoQ{sub 3}O{sub 12} contain second-order Jahn–Teller distortive cations in asymmetric environments. • The intra-octahedral distortion of the Mo{sup 6+} is influenced by the Se{sup 4+}.« less

Preparation and thermal stability of the spindle α-Fe{sub 2}O{sub 3}@SiO{sub 2} core–shell nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xin; Niu, Yongan; Li, Yang

2014-03-15

The spindle α-Fe{sub 2}O{sub 3}@SiO{sub 2} core–shell nanoparticles (NPs) are prepared via hydrothermal synthesis and modified Stöber method. During these processes, shell thicknesses could be easily adjusted by the amount of tetraethylorthosilicate (TEOS), and the formation of core-free SiO{sub 2} could be effectively avoided. The structures and compositions of α-Fe{sub 2}O{sub 3}@SiO{sub 2} NPs are investigated by transmission electron microscope (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–vis) absorption spectroscopy. These results reveal that the α-Fe{sub 2}O{sub 3}@SiO{sub 2} NPs with certain sizes are monodisperse and homogeneous. To estimate the thermal stability, the α-Fe{sub 2}O{submore » 3}, α-Fe{sub 2}O{sub 3}@SiO{sub 2} and SiO{sub 2} NPs are annealed at 600, 800 and 1000 °C for 1 h under air atmosphere, respectively. Furthermore, the stabilities of these NPs are confirmed by thermal analysis methods. The structure and shape stabilities of these as-prepared α-Fe{sub 2}O{sub 3}@SiO{sub 2} NPs are investigated by XRD and scanning electron microscope (SEM). -- Graphical abstract: Schematic of preparation of the monodisperse spindle α-Fe{sub 2}O{sub 3}@SiO{sub 2} nanoparticles (NPs). Highlights: • The spindle α-Fe{sub 2}O{sub 3}@SiO{sub 2} nanoparticles (NPs) are successfully prepared by hydrothermal synthesis and modified Stöber method. • Optical properties are estimated and calculated by UV vis absorption spectrum. • Thermal stability of the α-Fe{sub 2}O{sub 3}, α-Fe{sub 2}O{sub 3}@SiO{sub 2} and SiO{sub 2} NPs are compared and analyzed by the SEM technique. • The structural changes of α-Fe{sub 2}O{sub 3}@SiO{sub 2} NPs are measured by XRD measurement.« less

Photolysis of CH{sub 3}CHO at 248 nm: Evidence of triple fragmentation from primary quantum yield of CH{sub 3} and HCO radicals and H atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morajkar, Pranay; Schoemaecker, Coralie; Fittschen, Christa, E-mail: christa.fittschen@univ-lille1.fr

2014-06-07

Radical quantum yields have been measured following the 248 nm photolysis of acetaldehyde, CH{sub 3}CHO. HCO radical and H atom yields have been quantified by time resolved continuous wave Cavity Ring Down Spectroscopy in the near infrared following their conversion to HO{sub 2} radicals by reaction with O{sub 2}. The CH{sub 3} radical yield has been determined using the same technique following their conversion into CH{sub 3}O{sub 2}. Absolute yields have been deduced for HCO radicals and H atoms through fitting of time resolved HO{sub 2} profiles, obtained under various O{sub 2} concentrations, to a complex model, while the CH{submore » 3} yield has been determined relative to the CH{sub 3} yield from 248 nm photolysis of CH{sub 3}I. Time resolved HO{sub 2} profiles under very low O{sub 2} concentrations suggest that another unknown HO{sub 2} forming reaction path exists in this reaction system besides the conversion of HCO radicals and H atoms by reaction with O{sub 2}. HO{sub 2} profiles can be well reproduced under a large range of experimental conditions with the following quantum yields: CH{sub 3}CHO + hν{sub 248nm} → CH{sub 3}CHO{sup *}, CH{sub 3}CHO{sup *} → CH{sub 3} + HCO ϕ{sub 1a} = 0.125 ± 0.03, CH{sub 3}CHO{sup *} → CH{sub 3} + H + CO ϕ{sub 1e} = 0.205 ± 0.04, CH{sub 3}CHO{sup *}→{sup o{sub 2}}CH{sub 3}CO + HO{sub 2} ϕ{sub 1f} = 0.07 ± 0.01. The CH{sub 3}O{sub 2} quantum yield has been determined in separate experiments as ϕ{sub CH{sub 3}} = 0.33 ± 0.03 and is in excellent agreement with the CH{sub 3} yields derived from the HO{sub 2} measurements considering that the triple fragmentation (R1e) is an important reaction path in the 248 nm photolysis of CH{sub 3}CHO. From arithmetic considerations taking into account the HO{sub 2} and CH{sub 3} measurements we deduce a remaining quantum yield for the molecular pathway: CH{sub 3}CHO{sup *} → CH{sub 4} + CO ϕ{sub 1b} = 0.6. All experiments can be consistently explained with absence of the formerly considered pathway: CH{sub 3}CHO{sup *} → CH{sub 3}CO + H ϕ{sub 1c} = 0.« less

Selective hydrodesulfurization of 4,6-dimethyldibenzothiophene in the dominant presence of naphthalene over hybrid CoMo/A{sub 2}O{sub 3} and Ru/Al{sub 2}Al{sub 2}O{sub 3} catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isoda, T.; Nagao, S.; Ma, X.

1995-12-31

Hydrodesulfurization of 4,6-dimethyldibenzothiophene (4,6-DMDBT) in decane containing significant amount of naphthalene was examined over a hybrid of CoMo/Al{sub 2}O{sub 3} and Ru/Al{sub 2}O{sub 3} to design the selective hydrogenation and successive desulfurization of 4,6-DMDBT in aromatic moiety, and its activity was compared to those of CoMo/Al{sub 2}O{sub 3}, NiMo/Al{sub 2}O{sub 3} and Ru/Al{sub 2}O{sub 3} in their single use. HDS activity of 4,6-DMDBT over NiMo/Al{sub 2}O{sub 3} was inferior to CoMo/Al{sub 2}O{sub 3}, although that of highest hydrogenation activity for naphthalene. The hybrid showed the highest activity for HDS of 4,6-DMDBT among these catalysts without excess hydrogenation of nahthalene.

Experimental and theoretical identification of a high-pressure polymorph of Ga{sub 2}S{sub 3} with α-Bi{sub 2}Te{sub 3}-type structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Xiaojing; Zhu, Feng; Qin, Shan

Since the discovery of α-phase Bi{sub 2}Te{sub 3}, Sb{sub 2}Te{sub 3}, and Bi{sub 2}Se{sub 3} as 3D topological insulators, many experimental and theoretical studies of A{sub 2}B{sub 3}-type chalcogenides have been performed to search for new materials with interesting elastic and electric properties at ambient and extreme conditions. In this study, high-pressure properties of Ga{sub 2}S{sub 3} have been characterized by in situ synchrotron X-ray diffraction (XRD), X-ray absorption near edge structure measurements, and Density-functional theory (DFT) calculations. At ∼16.0 GPa, a phase transition of α′-Ga{sub 2}S{sub 3} (Cc and Z = 4) is observed experimentally to a new polymorph, which is indentifiedmore » to be the tetradymite-type or α-Bi{sub 2}Te{sub 3}-type crystal structure (R3{sup ¯}m and Z = 3) by laser-annealing XRD experiments and DFT calculations. The isothermal pressure-volume relationship of Ga{sub 2}S{sub 3} is well described by the second-order Birch-Murnaghan equation of state with K{sub 0} = 59(2) GPa and K{sub 0}{sup ′} = 4 (fixed) for the α′-Ga{sub 2}S{sub 3}, and K{sub 0} = 91(3) GPa, and K{sub 0}{sup ′} = 4 (fixed) for the tetradymite-type phase. In addition, band gap of α′-Ga{sub 2}S{sub 3} decreases on compression and the tetradymite-type Ga{sub 2}S{sub 3} exhibits metallization based on DFT calculations. The pressure-induced phase transition accompanying by changes of elastic and electrical properties may give some implications to other chalcogenides under high pressure.« less

Enhancing visible light photocatalytic activity of direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Jin, E-mail: lj328520504@126.com; Zhou, Xiaosong; Ma, Lin

Highlights: • Novel direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts are synthesized. • SnS{sub 2}/Ag{sub 3}PO{sub 4} exhibits much higher photocatalytic activity than pure SnS{sub 2} and Ag{sub 3}PO{sub 4}. • A possible photocatalytic mechanism was discussed in detail. - Abstract: Novel direct Z-scheme SnS{sub 2}/Ag{sub 3}PO{sub 4} heterojunction photocatalysts were successfully fabricated with SnS{sub 2} nanoplates hybridized by Ag{sub 3}PO{sub 4} nanoparticals via a facile hydrothermal and precipitation method and applied for the photocatalytic degradation of methyl orange in aqueous solution under visible light irradiation (λ > 420 nm). It was found that the photocatalytic performance of themore » SnS{sub 2} (2.0 wt%)/Ag{sub 3}PO{sub 4} heterojunction photocatalyst with 2.0 wt% SnS{sub 2} content was much higher than that of individual SnS{sub 2} and Ag{sub 3}PO{sub 4}. The enhanced photocatalytic activity could be ascribed to the efficient separation of photogenerated electrons and holes through the formation of direct Z-scheme system composed of SnS{sub 2} and Ag{sub 3}PO{sub 4}. Furthermore, the recycling experiments revealed that the photocorrosion behavior of Ag{sub 3}PO{sub 4} was strongly inhibited by SnS{sub 2}, it may be due to the photogenerated electrons of Ag{sub 3}PO{sub 4} would be quickly combined with the photogenerated holes of SnS{sub 2}. This work will be useful for the design of other direct Z-scheme visible-light-driven photocatalytic systems for application in energy conversion and environmental remediation.« less

A novel nano-sized BiOBr decorated K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} with enhanced photocatalytic properties under visible light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Wenquan; An, Weijia; Liu, Li

2014-07-01

BiOBr-sensitized–K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} composite photocatalysts (BiOBr/K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}) were fabricated by depositing BiOBr particles on the surface of K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} through a solvothermal method. The deposited BiOBr particles, with a uniform size of approximately 50 nm, were well dispersed on the surface of K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}, and improved the visible light absorption of the composite material. The photocatalytic activities were evaluated by degrading Rhodamine B (RhB) under visible light irradiation. The BiOBr/K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} composites exhibited superior performance over pure BiOBr, and the deposition of BiOBr particles onto themore » host K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} significantly increased the photocatalytic decolorization ability of K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}. An optimum loading of 45 wt% was found, and almost 95% of RhB could be degraded in 60 min under visible light irradiation using this preparation. Furthermore, the photocatalytic activity was stable in up to five consecutive runs. The enhancement in both photocatalytic activity and stability in the composites resulted from the closely contacted interfaces, which were beneficial for charge separation. The roles of the radical species were investigated, and the {sup ·}O{sub 2}{sup −} and h{sup +} were thought to dominate the photocatalytic process, while the {sup ·}OH was found to be relatively negligible. Based on the experimental results, a photocatalytic mechanism for organics degradation over BiOBr/K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} photocatalysts was proposed. - Graphical abstract: Photocatalytic reaction mechanisms of the as-prepared BiOBr/K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}. - Highlights: • BiOBr particle modified K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} were successfully synthesized by solvothermal method. • BiOBr greatly increased visible light absorption for K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}. • The photocatalyst exhibited high activities for organics degradation. • Mechanisms of charge separation in the BiOBr/K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} composites were proposed.« less

Luminescence properties of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+}, R{sup +} (R{sup +}=Li{sup +}, Na{sup +}, and K{sup +}) red emission phosphor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Renping, E-mail: jxcrp@163.com; Chen, Guo; Yu, Xiaoguang

2014-12-15

A series of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+}, Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, R{sup +}, and Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+}, R{sup +} (R{sup +}=Li{sup +}, Na{sup +}, and K{sup +}) phosphors are synthesized by solid-state reaction method in air. All phosphors show bright red emissions centered at ∼617 nm upon excitation with UV light of 397 nm. Bi{sup 3+} is a sensitizer for the luminescence of Eu{sup 3+}, and can improve significantly the PL intensity of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+} phosphor due to energy transfer between Bi{sup 3+} andmore » Eu{sup 3+} ions. The sensitization mechanism is investigated and discussed by energy level diagrams of Bi{sup 3+} and Eu{sup 3+} ions. R{sup +} ion is used as the charge compensator to improve the luminescence intensity of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+} and Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+} phosphors, and their PL intensities are enhanced in the sequence K{sup +}→Na{sup +}→Li{sup +}. These phosphors can be promising red emitting candidate for white LED with a ∼397 nm near UV chip excitation owing to the high brightness. - Graphical abstract: Energy transfer and charge compensation can enhance PL intensity of phosphors obviously. - Highlights: • Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+} phosphor is synthesized. • Energy transfer between Eu{sup 3+} and Bi{sup 3+} ions benefit PL intensity of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+} phosphor. • Alkaline metal ions can further improve the PL intensity of Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+} phosphor. • Ca{sub 3}Ti{sub 2}O{sub 7}:Eu{sup 3+}, Bi{sup 3+}, R{sup +} phosphor may be promising red emitting candidate for white LED.« less

Near azeotropic mixture substitute

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor)

1996-01-01

The present invention comprises a refrigerant mixture consisting of a first mole fraction of 1,1,1,2-tetrafluoroethane (R134a) and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 (R124) and CH.sub.3 CClF.sub.2 (R142b); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CHClFCF.sub.3 (R124); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CH.sub.3 CClF.sub.2 (R142b); and a mixture of CHClFCF.sub.3 (R124), CH.sub.3 CClF.sub.2 (R142b) and CHF.sub.2 CH.sub.3 (R152a).

Structures and chemical bonding of B{sub 3}O{sub 3}{sup −/0} and B{sub 3}O{sub 3}H{sup −/0}: A combined photoelectron spectroscopy and first-principles theory study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Li-Juan; Xu, Hong-Guang; Feng, Gang

We present a combined photoelectron spectroscopy and first-principles theory study on the structural and electronic properties and chemical bonding of B{sub 3}O{sub 3}{sup −/0} and B{sub 3}O{sub 3}H{sup −/0} clusters. The concerted experimental and theoretical data show that the global-minimum structures of B{sub 3}O{sub 3} and B{sub 3}O{sub 3}H neutrals are very different from those of their anionic counterparts. The B{sub 3}O{sub 3}{sup −} anion is characterized to possess a V-shaped OB–B–BO chain with overall C{sub 2v} symmetry (1A), in which the central B atom interacts with two equivalent boronyl (B≡O) terminals via B–B single bonds as well as withmore » one O atom via a B=O double bond. The B{sub 3}O{sub 3}H{sup −} anion has a C{sub s} (2A) structure, containing an asymmetric OB–B–OBO zig-zag chain and a terminal H atom interacting with the central B atom. In contrast, the C{sub 2v} (1a) global minimum of B{sub 3}O{sub 3} neutral contains a rhombic B{sub 2}O{sub 2} ring with one B atom bonded to a BO terminal and that of neutral B{sub 3}O{sub 3}H (2a) is also of C{sub 2v} symmetry, which is readily constructed from C{sub 2v} (1a) by attaching a H atom to the opposite side of the BO group. The H atom in B{sub 3}O{sub 3}H{sup −/0} (2A and 2a) prefers to interact terminally with a B atom, rather than with O. Chemical bonding analyses reveal a three-center four-electron (3c-4e) π hyperbond in the B{sub 3}O{sub 3}H{sup −} (2A) cluster and a four-center four-electron (4c-4e) π bond (that is, the so-called o-bond) in B{sub 3}O{sub 3} (1a) and B{sub 3}O{sub 3}H (2a) neutral clusters.« less

Synthesis, energy transfer and luminescence properties of Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Renping, E-mail: jxcrp@163.com; Xu, Haidong; Luo, Wenjie

Graphical abstract: PL spectra of Ca{sub 2}MgWO{sub 6}:Sm{sup 3+} and Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphors with excitation at 407 nm, and the corresponding CIE chromaticity diagram and chromaticity coordinates. - Highlights: • Novel Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphor is synthesized by solid-state reaction method in air. • Emission intensity of Ca{sub 2}MgWO{sub 6}:Sm{sup 3+} phosphor is enhanced ∼2 times after co-doped Bi{sup 3+} ion. • Charge compensation and energy transfer may be explained via luminescence properties. • Luminous mechanism is analyzed by energy level diagrams of WO{sub 6}{sup 6−} group, Sm{sup 3+} and Bi{sup 3+} ions.more » - Abstract: Novel Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphor is synthesized by solid-state reaction method in air. Host Ca{sub 2}MgWO{sub 6} with excitation 300 nm emits blue light. Ca{sub 2}MgWO{sub 6}:Bi{sup 3+} phosphor with excitation 300 and 338 nm emits yellow light. Ca{sub 2}MgWO{sub 6}:Sm{sup 3+} phosphor with excitation 300 nm exhibits tunable emission from blue to red light by increasing Sm{sup 3+} doping concentration from 0 to 8 mol%, however, only emits red light with excitation 407 nm. Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphor with excitation 300 and 338 nm emits red light. The optimal Sm{sup 3+} doping concentration is ∼5 mol% in Ca{sub 2}MgWO{sub 6}:Sm{sup 3+} phosphor. After Bi{sup 3+} ion is co-doped, luminescence properties of Ca{sub 2}MgWO{sub 6}:Sm{sup 3+} phosphor can be improved obviously because of Bi{sub 2}O{sub 3} as fluxing agent role and energy transfer from Bi{sup 3+} to Sm{sup 3+} ions. The possible luminous mechanism of Ca{sub 2}MgWO{sub 6}:Sm{sup 3+}, Bi{sup 3+} phosphor is analyzed and explained by simplified energy level diagrams of WO{sub 6}{sup 6−} group, Bi{sup 3+} and Sm{sup 3+} ions.« less

Transformations of lead 1,3-propylenediaminetetraacetate to its MOF products for the selective adsorption of methanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Jun-Wei; Li, Xing; Zheng, Jian-Mei

2016-05-15

Water soluble coordination polymer of potassium lead 1,3-propylenediaminetetraacetate {K_4[Pb_2(1,3-pdta)_2]·6H_2O}{sub n} (1) and its insoluble products {[Pb(1,3-H_2pdta)(H_2O)]·2H_2O}{sub n} (2), {[Pb_2(1,3-pdta)(H_2O)_4]·4H_2O}{sub n} (3) and [Pb{sub 2}(1,3-pdta)(H{sub 2}O){sub 2}]{sub n} (4) were obtained from the direct reactions of lead nitrate with 1,3-propylenediaminetetraacetic acid in different conditions (1,3-H{sub 4}pdta=1,3-propylenediaminetetraacetic acid). The former 1 could be converted to the insoluble products of {[Pb_2(1,3-pdta)(H_2O)_4]·4H_2O}{sub n} (3) and [Pb{sub 2}(1,3-pdta)(H{sub 2}O){sub 2}]{sub n} (4) in weak acidic solution. The complexes have been full characterized by EA, FT-IR, solution and solid state {sup 13}C NMR spectra, thermogravimetric and structural analyses. Interestingly, 3 contains a unique (H{sub 2}O){sub 26}more » cluster and a 5.2 Å pore after eliminating the guest water molecules, which exhibits reversible adsorption for methanol. This is confirmed by PXRD and solid state {sup 13}C NMR analyses. Nano-confined methanol in microporous structure has been observed based on the large downfield shift of {sup 13}C NMR signal (Δδ 9.72 ppm), attributing to the methyl group in methanol. - Graphical abstract: Water soluble coordination polymer K{sub 4n}[Pb{sub 2}(1,3-pdta){sub 2}]{sub n}·6nH{sub 2}O (1) is converted to its insoluble product [Pb{sub 2}(1,3-pdta)(H{sub 2}O){sub 4}]{sub n}·4nH{sub 2}O (3), which contains a unique (H{sub 2}O){sub 26} cluster and exhibits reversible adsorption for methanol. - Highlights: • Water-soluble coordination polymer was constructed by lead propylenediaminetetraacetate. • Its MOF product has a unique (H{sub 2}O){sub 26} cluster. • The product exhibits reversible adsorption for methanol.« less

Interaction of tantalum, chromium, and phosphorus at 1070 K: Phase diagram and structural chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lomnytska, Ya.; Babizhetskyy, V., E-mail: v.babizhetskyy@googlemail.com; Oliynyk, A.

2016-03-15

Solid-state phase equilibria have been established in the Ta–Cr–P system in the region of 0–67 at% P at 1070 K through powder X-ray diffraction analysis. Mutual substitution of Ta and Cr in binary phosphides gives rise to significant homogeneity ranges in Ta{sub 1.00–0.66}Cr{sub 0–0.34}P (NbAs-type; a=3.332(3)–3.1366(3) Å, c=11.386(4)–11.364(2) Å), Ta{sub 3.0–2.1}Cr{sub 0–0.9}P (Ti{sub 3}P-type, a=10.156(2)–9.9992(2) Å, c=5.015(1)–4.956(2) Å), and Cr{sub 3.0–2.4}Ta{sub 0–0.6}P (Ni{sub 3}P-type, a=9.186(5)–9.217(4) Å, c=4.557(3)–4.5911(3) Å). A limited homogeneity range is found in the ternary phase Ta{sub 1.0–0.8}Cr{sub 1.0–1.2}P (TiNiSi-type, a=6.2344(5)–6.141(2) Å, b=3.5034(3)–3.3769(6) Å, c=7.3769(6)–7.357(2) Å). The OsGe{sub 2}-type structures (space group C2/m) of a new P-rich compound,more » Ta{sub 0.92(2)}Cr{sub 0.08(2)}P{sub 2} (a=8.8586(3) Å, b=3.2670(2) Å, c=7.4871(2) Å, β=119.315(2)°) as well as of the Ti-containing analogue Ta{sub 0.93(3)}Ti{sub 0.07(3)}P{sub 2} (a=8.8592(5) Å, b=3.2663(3) Å, c=7.4870(5) Å, β=119.309(2)°) were refined from powder X-ray diffraction data. - Graphical abstract: Solid-state phase equilibria have been established in the Ta–Cr–P system in the region of 0–67 at% P at 1070 K through powder X-ray diffraction analysis. Mutual substitution of Ta and Cr in binary phosphides gives rise to significant homogeneity ranges in Ta{sub 1.00–0.66}Cr{sub 0–0.34}P, Ta{sub 3.0–2.1}Cr{sub 0–0.9}P, and Cr{sub 3.0–2.4}Ta{sub 0–0.6}P. A limited homogeneity range is found in the ternary phase Ta{sub 1.0–0.8}Cr{sub 1.0–1.2}P. The OsGe{sub 2}-type structures of a new P-rich compound, Ta{sub 0.92(2)}Cr{sub 0.08(2)}P{sub 2} as well as of the Ti-containing analogue Ta{sub 0.93(3)}Ti{sub 0.07(3)}P{sub 2} were establish from powder X-ray diffraction data. No homogeneity ranges for binary compounds Cr{sub 12}P{sub 7}, Cr{sub 2}P, Ta{sub 5}P{sub 3} were detected. - Highlights: • The phase diagram of Ta–Cr–P at 1070 K has been constructed. • New ternary compounds Ta{sub 0.92(2)}Cr{sub 0.08(2)}P{sub 2} and Ta{sub 0.93(3)}Ti{sub 0.07(3)}P{sub 2} were established. • Ta{sub 1.0−0.8}Cr{sub 1.0−1.2}P and Ta{sub 0.86+x}Ti{sub 0.15-x}P{sub 2}(x= 0−0.07) exhibit homogeneity ranges. • The binary compounds reveal homogeneity ranges by Ta/Cr and Cr/Ta substitutions.« less

Group 4 metal mono-dicarbollide piano stool complexes. Synthesis, structure, and reactivity of ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})M(NR{sub 2}){sub 2}(NHR{sub 2}) (M = Zr, R = Et; M = Ti, R = Me, Et)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, D.E.; Jordan, R.F.; Rogers, R.D.

1995-08-01

The amine elimination reaction of C{sub 2}B{sub 9}H{sub 13} and Zr(NEt{sub 2}){sub 4} yields the mono-dicarbollide complex ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(NHEt{sub 2}), (1), which has been shown to adopt a three-legged piano stool structure by X-ray crystallography. Crystal data for 1: space group P2{sub 1}/c, a = 10.704(4) A, b = 11.066(3) A, c = 20.382(8) A, {beta} = 99.20(3){degree}, V = 2383(1) A{sup 3}, Z = 4. Complex 1 undergoes facile ligand substitution by THF and 4-picoline, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}-(THF) (2) and ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline){sub 2} (3).more » Compound 3 exists as the four-coordinate species ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline) in CH{sub 2}Cl{sub 2} solution. Complex 1 reacts selectively with 2 equiv of [NH{sub 2}ET{sub 2}]Cl, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})ZrCl{sub 2}(NHEt{sub 2}){sub 2} (4). Similarly, the reaction of C{sub 2}B{sub 9}H{sub 13} and Ti(NR{sub 2}){sub 4} yields ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Ti(NR{sub 2}){sub 2}(NHR{sub 2}) (5, R = Me; 6, R = Et). Compounds 1-6 are potential precursors to group 4 metal ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})MR{sub 2}L{sub n} alkyl species. 25 refs., 3 figs., 3 tabs.« less

CH/sub 3/xxx/sup 13/CO/sub 2/ pairs in irradiated single crystals of CH/sub 3//sup 13/CO/sub 2/Lix2D/sub 2/0. [Gamma rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toriyama, K.; Iwasaki, M.

1976-10-01

The CH/sub 3/ radical trapped in irradiated single crystals of CH/sub 3//sup 13/CO/sub 2/Lix2D/sub 2/O has been found to interact with a /sup 13/CO/sub 2/ molecule, which is formed from the C--C bond breakage as a counterpart. The /sup 13/C superhyperfine coupling tensor was determined to be (-4.0, -3.3, -3.5) G. The /sup 13/CO/sub 2/ molecule is located in the direction of the unpaired electron orbital of CH/sub 3/ with the molecular axis perpendicular to it. The spectrum arising from the electron excess center CH/sub 3/ /sup 13/CO/sub 2//sup 2 -/ was also detected together with the CH/sub 3/ radical.more » Our results indicate that the CH/sub 3/xxx/sup 13/CO/sub 2/ pair is essentially a positive hole center formed from one electron loss followed by the C--C bond breakage. (AIP)« less

Electron collisions with methyl-substituted ethylenes: Cross section measurements and calculations for 2-methyl–2-butene and 2,3-dimethyl–2-butene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szmytkowski, Czesław, E-mail: czsz@mif.pg.gda.pl; Stefanowska, Sylwia; Zawadzki, Mateusz

We report electron-scattering cross sections determined for 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}] and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}] molecules. Absolute grand-total cross sections (TCSs) were measured for incident electron energies in the 0.5–300 eV range, using a linear electron-transmission technique. The experimental TCS energy dependences for the both targets appear to be very similar with respect to the shape. In each TCS curve, three features are discernible: the resonant-like structure located around 2.6–2.7 eV, the broad distinct enhancement peaking near 8.5 eV, and a weak hump in the vicinity of 24 eV. Theoretical integral elasticmore » (ECS) and ionization (ICS) cross sections were computed up to 3 keV by means of the additivity rule (AR) approximation and the binary-encounter-Bethe method, respectively. Their sums, (ECS+ICS), are in a reasonable agreement with the respective measured TCSs. To examine the effect of methylation of hydrogen sides in the ethylene [H{sub 2}C = CH{sub 2}] molecule on the TCS, we compared the TCS energy curves for the sequence of methylated ethylenes: propene [H{sub 2}C = CH(CH{sub 3})], 2-methylpropene [H{sub 2}C = C(CH{sub 3}){sub 2}], 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}], and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}], measured in the same laboratory. Moreover, the isomeric effect is also discussed for the C{sub 5}H{sub 10} and C{sub 6}H{sub 12} compounds.« less

Phase transition, crystal water and low thermal expansion behavior of Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Fang; Liu, Xiansheng; Song, Wenbo

2014-10-15

Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} for 0≤x≤1.0 are synthesized to reduce the phase transition temperature of Al{sub 2}W{sub 3}O{sub 12}. It is found that the incorporation of (ZrMg){sup 6+} into the lattice of Al{sub 2}W{sub 3}O{sub 12} not only reduces its orthorhombic-to-monoclinic phase transition temperature but also elevates its softening temperature, broadening its applicable temperature range considerably. Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} with x<0.5 exhibit low coefficients of thermal expansion (CTEs) and non-hygroscopicity, while those for x≥0.7 are obviously hygroscopic and the CETs decrease with increasing the content of (ZrMg){sup 6+} so that Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12} and ZrMgW{submore » 3}O{sub 12} exhibit negative thermal expansion. Temperature-dependent Raman spectroscopic study shows the hardening of W–O bonds above 373 K which is attributed to the release of crystal water. The effect of crystal water on the thermal expansion property is discussed based on the hydrogen bond between H in crystal water and electronegative O in Al(ZrMg)–O–W linkages. - Graphical abstract: (a and b) Temperature dependent Raman spectra of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12} (x=0.1, 0.2), (c and d) Building block of a unit cell of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O) and schematic showing the effect of crystal water on Al(Zr, Mg)–O–W linkages. - Highlights: • (ZrMg){sup 6+} reduces orthorhombic-to-monoclinic phase transition of Al{sub 2}W{sub 3}O{sub 12}. • The incorporation of (ZrMg){sup 6+} elevates the softening temperature of Al{sub 2}W{sub 3}O{sub 12}. • Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} (x<0.5) exhibit low CTEs and non-hygroscopicity. • Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12}·0.8H{sub 2}O and ZrMgW{sub 3}O{sub 12}·2H{sub 2}O present NTE. • Hydrogen bond between H in H{sub 2}O and O in Al(ZrMg)–O–W affects thermal expansion.« less

Scaled Hartree-Fock force field calculations for organothallium compounds: Normal-mode analysis for TlCH sub 3 Tl(CH sub 3 ) sub 2 sup + , Tl(CH sub 3 ) sub 3 , Tl(CH sub 3 ) sub 2 Br, and Tl(CH sub 3 ) sub 4 sup minus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwerdtfeger, P.; Bowmaker, G.A.; Boyd, P.D.W.

1990-02-01

In a recent paper we presented Hartree-Fock (HF) calculations for aliphatic organothallium compounds. The diagonal HF force constants obtained from a Fletcher-Powell geometry optimization are now used for a normal-mode analysis of TlCH{sub 3}, Tl(CH{sub 3}){sub 2}{sup +}, Tl(CH{sub 3}){sub 3}, Tl(CH{sub 3}){sub 2}Br, and Tl(CH{sub 3}){sub 4}{sup {minus}}. In order to calculate frequencies comparable to experimental values, the HF force field has been scaled by using scaling factors obtained from experimental infrared and Raman measurements on Tl(CH{sub 3}){sub 2}{sup +} and TlBr. The vibrational spectra of Tl(CH{sub 3}){sub 2}{sup +} were remeasured (infrared and Raman) in order to obtainmore » an accurate force field. Predictions are made for the vibrational spectrum of the as yet undetected TlCH{sub 3} molecule. Experimental infrared and Raman results for Tl(CH{sub 3}){sub 3} compare reasonably well with our calculated frequencies. Relativistic and correlation effects are analyzed for the vibrational frequencies of Tl(CH{sub 3}){sub 2}{sup +}.« less

Radiolabeled technetium chelates for use in renal function determinations

DOEpatents

Fritzberg, Alan; Kasina, Sudhaker; Johnson, Dennis L.

1994-01-01

The present invention is directed to novel radiopharmaceutical imaging agents incorporating Tc-99m as a radiolabel. In particular, the novel imaging agents disclosed herein have relatively high renal extraction efficiencies, and hence are useful for conducting renal function imaging procedures. The novel Tc-99m compounds of a present invention have the following general formula: ##STR1## wherein X is S or N; and wherein Y is --H or wherein Y is ##STR2## and where R.sub.1 is --H, --CH.sub.3, or --CH.sub.2 CH.sub.3 ; R.sub.2 is --H, --CH.sub.2 CO.sub.2 H, --CH.sub.2 CONH.sub.2, --CH.sub.2 CH.sub.2 CO.sub.2 H, --CH.sub.2 CH.sub.2 CONH.sub.2, --CH.sub.3, --CH.sub.2 CH.sub.3, CH.sub.2 C.sub.6 H.sub.5, or --CH.sub.2 OH; and Z is --H, --CO.sub.2 H, --CONH.sub.2, --SO.sub.3 H, --SO.sub.2 NH.sub.2, or --CONHCH.sub.2 CO.sub.2 H; and the Tc is Tc-99m; and water-soluble salts thereof. Of the foregoing, the presently preferred Tc-99m compound of the present invention is Tc-99m-mercaptoacetylglycylglycylglycine (Tc-99m-MAGGG). The present invention is also directed to novel chelating agents that may be reacted with Tc-99m to form the foregoing compounds. Such novel chelating agents have the following general formula. ##STR3## where X and Y have the same definitions as above, and wherein Y' is --H.sub.2 when X is N, or wherein Y' is --H, or a suitable protective group such as --COCH.sub.3, --COC.sub.6 H.sub.5, --CH.sub.2 NHCOCH.sub.3, --COCF.sub.3, or --COCH.sub.2 OH when X is S. The present invention also provides methods for preparing and using the novel Tc-99m compounds.

Radiolabeled technetium chelates for use in renal function determinations

DOEpatents

Fritzberg, Alan; Kasina, Sudhakar; Johnson, Dennis L.

1990-01-01

The present invention is directed to novel radiopharmaceutical imaging agents incorporating Tc-99m as a radiolabel. In particular, the novel imaging agents disclosed herein have relatively high renal extraction efficiencies, and hence are useful for conducting renal function imaging procedures. The novel Tc-99m compounds of a present invention have the following general formula: ##STR1## wherein X is S or N; and wherein Y is--H or wherein Y is ##STR2## and where R.sub.1 is --H, --CH.sub.3, or --CH.sub.2 CH.sub.3 ; R.sub.2 is --H, --CH.sub.2 CO.sub.2 H, --CH.sub.2 CONH.sub.2, --CH.sub.2 CH.sub.2 CO.sub.2 H, --CH.sub.2 CH.sub.2 CONH.sub.2, --CH.sub.3, --CH.sub.2 CH.sub.3, CH.sub.2 C.sub.6 H.sub.5, or --CH.sub.2 OH; and Z is --H, --CO.sub.2 H, --CONH.sub.2, --SO.sub.3 H, --SO.sub.2 NH.sub.2, or --CONHCH.sub.2 CO.sub.2 H; and the Tc is Tc-99m; and water-soluble salts thereof. Of the foregoing, the presently preferred Tc-99m compound of the present invention is Tc-99m-mercaptoacetylglycylglycylglycine (Tc-99m-MAGGG). The present invention is also directed to novel chelating agents that may be reacted with Tc-99m to form the foregoing compounds. Such novel chelating agents have the following general formula. ##STR3## where X and Y have the same definitions as above, and wherein Y' is --H.sub.2 when X is N, or wherein Y' is --H, or a suitable protective group such as --COCH.sub.3, --COC.sub.6 H.sub.5, --CH.sub.2 NHCOCH.sub.3, --COCF.sub.3, or --COCH.sub.2 OH when X is S. The present invention also provides methods for preparing and using the novel Tc-99m compounds.

Synthesis, structure and characterization of two new copper(I)-thioarsenates (III) constructed by the [AsS{sub 3}]{sup 3-} and CuS{sub x} units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Hua-Gang; Ji, Min; Ji, Shou-Hua

2013-02-15

Two new copper(I)-thioarsenates(III), CsCu{sub 2}AsS{sub 3}(1) and KCu{sub 4}AsS{sub 4}(2), have been synthesized solvothermally in the presence of copper powder. Compound 1 is built up of trigonal AsS{sub 3} pyramid, tetrahedral CuAsS{sub 3} and CuS{sub 3} moieties forming 4-membered, 5-membered and 6-membered rings. The fusion of these rings produces layered anions [Cu{sub 2}AsS{sub 3}]{sup -}, and cesium cations are located between metal-sulfide layers. The structure of 2 consists of infinite [Cu{sub 2}S{sub 2}]{sup 2-} chain and layered [Cu{sub 6}As{sub 2}S{sub 6}] linked to form a three-dimensional anionic framework, [Cu{sub 4}AsS{sub 4}]{sup -}, and containing channels in which the potassium cationsmore » reside. - Graphical abstract: Qne layered CsCu{sub 2}AsS{sub 3} and one framework KCu{sub 4}AsS{sub 4} possessing noncondensed [AsS{sub 3}]{sup 3-} unit have been synthesized solvothermally. The optical band gaps of the two compounds are 2.3 and 1.8 eV, respectively. Highlights: Black-Right-Pointing-Pointer We obtained two new copper(I)-thioarsenate(III), CsCu{sub 2}AsS{sub 3} and KCu{sub 4}AsS{sub 4}. Black-Right-Pointing-Pointer Both compounds possess noncondensed [AsS{sub 3}]{sup 3-} unit and represent new structure types. Black-Right-Pointing-Pointer The optical band gaps of the two compounds are 2.3 eV and 1.8 eV, respectively.« less

Two-dimensional titanium carbonitrides and their hydroxylated derivatives: Structural, electronic properties and stability of MXenes Ti{sub 3}C{sub 2−x}N{sub x}(OH){sub 2} from DFTB calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Enyashin, A.N.; Ivanovskii, A.L., E-mail: ivanovskii@ihim.uran.ru

2013-11-15

The structural, electronic properties and stability of the new MXene compounds—two-dimensional pristine carbonitrides Ti{sub 3}C{sub 2−x}N{sub x} and their hydroxylated derivatives Ti{sub 3}C{sub 2−x}N{sub x}(OH){sub 2} are studied by means of DFTB calculations. The genesis of the properties is discussed in the sequence: binary MXenes Ti{sub 3}C{sub 2} (Ti{sub 3}N{sub 2})→hydroxylated forms Ti{sub 3}C{sub 2}(OH){sub 2} (Ti{sub 3}N{sub 2}(OH){sub 2})→pristine MXene Ti{sub 3}C{sub 2−x}N{sub x}→hydroxylated Ti{sub 3}C{sub 2−x}N{sub x}(OH){sub 2}. All examined materials are metallic-like. The most favorable type of OH-covering is presented by the occupation of the hollow sites between three neighboring carbon (nitrogen) atoms. Two-dimensional MXene carbonitrides withmore » random distribution of C and N atoms are found to be thermodynamically more favorable. - Graphical abstract: The side views of the optimized atomic structures of some examined hydroxylated derivatives of MXene Ti{sub 3}CN and their electronic band structures. Display Omitted - Highlights: • Very recently 2D titanium carbonitrides have been synthesized. • Structural, electronic properties and stability for these materials were evaluated. • The hydroxylated derivatives of 2D titanium carbonitrides are examined.« less

Crystal structure of Rb{sub 2}Mn{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2}, a new representative of the family of hydrated diphosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiriukhina, G. V., E-mail: g-biralo@yandex.ru; Yakubovich, O. V.; Dimitrova, O. V.

2016-09-15

The crystal structure of Rb{sub 2}Mn{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2}, a new phase obtained in the form of single crystals under hydrothermal conditions in the MnCl{sub 2}–Rb{sub 3}PO{sub 4}–H{sub 2}O system, is determined by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.0270): a = 9.374(2), b = 8.367(2), c = 9.437(2) Å, ß = 99.12(2)°, space group P2{sub 1}/c, Z = 2, D{sub x} = 3.27 g/cm{sup 3}. A correlation between the unit-cell parameters and the size of cations forming the crystal structures of isostructural A{sub 2}M{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2} diphosphates (A = K, NH{sub 4},more » Rb, or Na; {sub M} = Mn, Fe, Co, or Ni) is revealed. It is shown that, due to the topological similarity, the structures of diphosphates and orthophosphates of the farringtonite structural type can undergo mutual transformations.« less

Study of phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system. Phase diagram and thermal characteristics of phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matraszek, Aleksandra, E-mail: aleksandra.matraszek@ue.wroc.pl

2013-07-15

A diagram representing phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} phosphate system has been developed on the basis of results obtained by thermal analysis (DTA/DSC/TGA) and X-ray diffraction (XRD) methods. One intermediate compound with the formula Sr{sub 3}Ce(PO{sub 4}){sub 3} occurs in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system at temperatures exceeding 1045 °C. The compound has a eulytite structure with the following structural parameters: a=b=c=10.1655(8) Å, α=β=γ=90.00°, V=1050.46(6) Å{sup 3}. It's melting point exceeds 1950 °C. A limited solid solution exists in the system, which possesses the structure of a low-temperature form of Sr{sub 3}(PO{sub 4}){sub 2}.more » At 1000 °C the maximal concentration of CePO{sub 4} in the solid solution is below 20 mol%. The solid solution phase field narrows with increased temperature. There is a eutectic point in the (Sr{sub 3}(PO{sub 4}){sub 2}+Sr{sub 3}Ce(PO{sub 4}){sub 3}) phase field at 1765 °C and 15 mol% of CePO{sub 4}. The melting temperature of Sr{sub 3}(PO{sub 4}){sub 2} is 1882±15 °C. - Graphical abstract: The phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system showing the stability ranges of limited solid solution and Sr{sub 3}Ce(PO{sub 4}){sub 3} phases. - Highlights: • Sr{sub 3}(PO{sub 4}){sub 2} melts at 1882 °C. • Phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system has been proposed. • Limited solid solution of CePO{sub 4} in Sr{sub 3}(PO{sub 4}){sub 2} forms in the system. • The Sr{sub 3}Ce(PO{sub 4}){sub 2} phosphate is stable at temperatures above 1045 °C.« less

Surfactant-assisted hydrothermal crystallization of nanostructured lithium metasilicate (Li{sub 2}SiO{sub 3}) hollow spheres: II-Textural analysis and CO{sub 2}-H{sub 2}O sorption evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz-Landeros, Jose; Gomez-Yanez, Carlos; Pfeiffer, Heriberto, E-mail: pfeiffer@iim.unam.mx

In a previous work, the synthesis and structural-microstructural characterization of different nanocrystalline lithium metasilicate (Li{sub 2}SiO{sub 3}) samples were performed. Then, in this work, initially, a textural analysis was performed over the same samples. Li{sub 2}SiO{sub 3} samples prepared with a non-ionic surfactant (TRITON X-114) presented the best textural properties. Therefore, this sample was selected to evaluate its water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties. Sorption experiments were performed at low temperatures (30-80 deg. C) in presence of water vapor using N{sub 2} or CO{sub 2} as carrier gases. Results clearly evidenced that CO{sub 2} sorptionmore » on these materials is highly improved by H{sub 2}O vapor, and of course, textural properties enhanced the H{sub 2}O-CO{sub 2} sorption efficiency, in comparison with the solid-state reference sample. - Graphical abstract: Li{sub 2}SiO{sub 3} varied significantly its capacity of CO{sub 2} absorption as a function of the microstructural properties and by the water presence. Highlights: > We studied the CO{sub 2} absorption on different Li{sub 2}SiO{sub 3} samples in presence of H{sub 2}O vapor. > It was proved that CO{sub 2} absorption on Li{sub 2}SiO{sub 3} is controlled by different factors. > Li{sub 2}SiO{sub 3} with a porous microstructure produces a higher CO{sub 2} absorption. > H{sub 2}O vapor favors the CO{sub 2} absorption on Li{sub 2}SiO{sub 3} due to a surface hydroxylation.« less

Spectroscopic and dielectric response of zinc bismuth phosphate glasses as a function of chromium content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, P. Srinivasa; Babu, P. Ramesh; Vijay, R.

2014-09-15

Graphical abstract: 20ZnF{sub 2}–(20 − x)Bi{sub 2}O{sub 3}–60P{sub 2}O{sub 5}:xCr{sub 2}O{sub 3} (0 ≤ x ≤2 mol%) glasses are prepared by melt quenching technique. The optical absorption spectra of present glasses are analyzed as a function of chromium content. The absorption bands are assigned to {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 1g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 2g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 2}T{sub 1g}(G) and {sup 4}A{sub 2g}(F) ⟶ {sup 2}E{sub g}(G) transitions of Cr{sup 3+} ions. - Highlights: • ZnF{sub 2}–Bi{sub 2}O{sub 3}–P{sub 2}O{sub 5}:Cr{sub 2}O{sub 3} glasses were prepared by melt quenching and annealing. • Spectroscopicmore » and dielectric properties of chromium ions were investigated. • ESR and optical absorption spectra indicate the co-existence of Cr{sup 6+} ions with Cr{sup 5+} ions and Cr{sup 3+} ions. • Cr{sup 3+} ions act as modifiers and influence the semiconducting nature of the glass system. - Abstract: 20ZnF{sub 2}–(20 − x)Bi{sub 2}O{sub 3}–60P{sub 2}O{sub 5}:xCr{sub 2}O{sub 3} (0 ≤ x ≤2 mol%) glasses are prepared by melt quenching technique. Amorphous nature of these samples is confirmed by X-ray diffraction (XRD) analysis. FTIR study reveals bands due to CrO{sub 6}(o{sub d}) and CrO{sub 4}{sup 2−}(T{sub d}) units along with conventional phosphate groups. The optical absorption and ESR studies of present glasses are analyzed as a function of chromium content. The absorption bands are assigned to {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 1g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 2g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 2}T{sub 1g}(G) and {sup 4}A{sub 2g}(F) ⟶ {sup 2}E{sub g}(G) transitions of Cr{sup 3+} ions. The highest concentration of Cr{sup 3+} ions (in octahedral sites, with network modifying positions) is found in the sample with 2.0 mol% of Cr{sub 2}O{sub 3}. The analysis of dielectric properties indicates a gradual increase in semiconducting character with increase in the concentration of Cr{sub 2}O{sub 3} from 0.2 to 2.0 mol%. The studies on dielectric breakdown strength identify the highest insulating strength for lowest mol% of Cr{sub 2}O{sub 3} in the present samples.« less

Interactions of methylamine and ammonia with atmospheric nucleation precursor H{sub 2}SO{sub 4} and common organic acids: Thermodynamics and atmospheric implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Y.; Jiang, L.; Bai, Z.

Interactions of the two common atmospheric bases, ammonia (NH{sub 3}) and methylamine MA (CH{sub 3}NH{sub 2}), which are considered to be important stabilizers of binary clusters in the Earth’s atmosphere, with H{sub 2}SO{sub 4}, the key atmospheric precursor, and 14 common atmospheric organic acids (COA) (formic (CH{sub 2}O{sub 2}), acetic (C{sub 2}H{sub 4}O{sub 2}), oxalic (C{sub 2}H{sub 2}O{sub 4}), malonic (C{sub 3}H{sub 4}O{sub 4}), succinic (C{sub 4}H{sub 6}O{sub 4}), glutaric acid (C{sub 5}H{sub 8}O{sub 4}), adipic (C{sub 6}H{sub 10}O{sub 4}), benzoic (C{sub 6}H{sub 5}COOH), phenylacetic (C{sub 6}H{sub 5}CH{sub 2}COOH), pyruvic (C{sub 3}H{sub 4}O{sub 3}), maleic acid (C{sub 4}H{sub 4}O{sub 4}),more » malic (C{sub 4}H{sub 6}O{sub 5}), tartaric (C{sub 4}H{sub 6}O{sub 6}) and pinonic acid (C{sub 10}H{sub 16}O{sub 3})) have been studied using the composite high-accuracy G3MP2 method. The thermodynamic stability of mixed (COA) (H{sub 2}SO{sub 4}), (COA)(B1) and (COA)(B2) dimers and (COA) (H{sub 2}SO{sub 4}) (B1) and (COA) (H{sub 2}SO{sub 4}) (B1) trimers, where B1 and B2 represent methylamine (CH{sub 3}NH{sub 2}) and ammonia (NH{sub 3}), respectively, have been investigated and their impacts on the thermodynamic stability of clusters containing H{sub 2}SO{sub 4} have been analyzed. It has been shown that in many cases the interactions of H{sub 2}SO{sub 4} with COA, ammonia and methylamine lead to the formation of heteromolecular dimers and trimers, which are certainly more stable than (H{sub 2}SO{sub 4}){sub 2} and (H{sub 2}SO{sub 4}){sub 3}. It has also been found that free energies of (COA) (H{sub 2}SO{sub 4})+ CH{sub 3}NH{sub 2}⇔(COA) (H{sub 2}SO{sub 4})(CH{sub 3}NH{sub 2}) reactions exceed 10-15 kcal mol{sup −1}. This is a clear indication that mixed trimers composed of COA, H{sub 2}SO{sub 4} and methylamine are very stable and can thus serve as possible nucleation sites. The present study leads us to conclude that the interactions of COA coexisting with H{sub 2}SO{sub 4} and common atmospheric bases in the Earth’s atmosphere may be an important factor affecting the stability of nucleating sulfuric acid clusters and that the impacts of COA on atmospheric nucleation should be studied in further details.« less

Studies of energy-transfer and electron-transfer processes involving the /sup 3/Au/sub 2u/ excited states of binuclear rhodium isocyanide complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milder, S.J.; Goldbeck, R.A.; Kliger, D.S.

1980-10-22

The lowest electronic excited states of Rh/sub 2/(br)/sub 4//sup 2 +/ (br = 1,3-diisocyanopropane) and Rh/sub 2/(TMB)/sub 4//sup 2 +/ (TMB = 2,5-dimethyl-2,5-diisocyanohexane) are relatively long-lived emissive triplets (/sup 3/A/sub 2u/). The /sup 3/A/sub 2u/ lifetimes in acetonitrile are 8.5 +- 0.5 ..mu..s for Rh/sub 2/(br)/sub 4//sup 2 +/ and 25 +- 5 ns for Rh/sub 2/(TMB)/sub 4//sup 2 +/ (21/sup 0/C). The triplet energy of Rh/sub 2/(br)/sub 4//sup 2 +/ has been estimated to be about 39 kcal/mol (approximately 1.7 eV, approximately 730 nm) from energy-transfer quenching experiments. The /sup 3/A/sub 2u/ excited states of Rh/sub 2/(br)/sub 4//sup 2more » +/ and Rh/sub 2/(TMB)/sub 4//sup 2 +/ undergo electron-transfer reactions with oxidative and reductive quenchers. Reductive quenching by N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), and oxidative quenching by paraquat (PQ/sup 2 +/) have been studied in detail. In methanol solution, Rh/sub 2/(br)/sub 4//sup 2 +/*(/sup 3/A/sub 2u/) reacts with TMPD to give Rh/sub 2/(br)/sub 4//sup 2 +/ and TMPD/sup +/ (k/sub b/, the back-reaction rate constant, is 1 x 10/sup 9/ M/sup -1/s/sup -1/); similarly, Rh/sub 2/(TMB)/sub 4//sup 2 +/*(/sup 3/A/sub 2u/) reacts with TMPD to give Rh/sub 2/(TMB)/sub 4//sup +/ and TMPD/sup +/ (k/sub b/ = 1.4 x 10/sup 9/ M/sup -1/s/sup -1/). Oxidation of Rh/sub 2/(TMB)/sub 4//sup 2 +/*(/sup 3/A/sub 2u/) by PQ/sup 2 +/ in methanol gives Rh/sub 2/(TMB)/sub 4//sup 3 +/ and PQ/sup +/ (k/sub b/ = 2.2 x 10/sup 8/ M/sup -1/s/sup -1/; ..mu.. = 1.95 x 10/sup -2/ M). One-electron oxidation of Rh/sub 2/(br)/sub 4//sup 2 +/*(/sup 3/A/sub 2u/) by PQ/sup 2 +/ is observed, but the kinetics of the back-reaction are complex, owing to competing oligomerization processes.« less

THERMODYNAMIC PROPERTIES OF Zr AND Hf HALIDES (in Rumanian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lungu, S.N.

1962-01-01

The following standard heats of formation were found: ZrCl/sub 3/, 178.6 plus or minus 3.2; ZrCl/sub 2/, 124.3 plus or minus 3; ZrBr/sub 3/, 151 plus or minus 7; Zr Br/sbu 2/, 100 plus or minus 6; ZrI/sub 3/, 103 plus or minus 6; ZrI/sub 2/, 68 plus or minus 4; and HfCl/sub 4/, 239.4 plus or minus 5.5; HfCl/sub 3/, 186.6; HfCl/sub 2/, 130; HfBr/sub 4/, 200; HfBr/sub 3/, 157; HfBr / sub 2/, 108; HfI/sub 4/, 140; HfI/sub 3/, 113; and HfI/sub 2/, 72 kcal/mole. (R.V.J.)

Natural and anthropogenic trace gases in the lower troposphere of the Arctic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rasmussen, R.A.; Khalil, M.A.K.

1983-01-01

Concentrations of CCl/sub 3/F (F-11), CCl/sub 2/F/sub 2/ (F-12), CHClF/sub 2/ (F-22), C/sub 2/Cl/sub 3/F/sub 3/ (F-113), CH/sub 3/CCl/sub 3/, CCl/sub 4/, C/sub 2/HCl/sub 3/ (TCE), CH/sub 3/I, CHCl/sub 3/, CO, CH/sub 3/Cl, CH/sub 4/, and N/sub 2/O were measured in and above the boundary layer (0-4 km) of the Arctic troposphere near Pt. Barrow (70/sup 0/N) during May 1982. The vertical structure of the concentrations is reported graphically and is analyzed statistically to reveal consistent patterns. The results are compared with analogous observations made during spring in the southern hemisphere.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kuo; Hu, Yufei; Wang, Yingxia, E-mail: Wangyx@pku.edu.cn

Isostructural compounds RE{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} (RE=La, Pr, Nd, Sm–Ho) with an ordered pyrochlore structure were synthesized. The structure of La{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} was solved ab initio based on powder XRD data, and refined by combining with high resolution neutron diffraction data. La{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} crystallizes in the space group R-3m with the unit cell parameters a=7.52954(2) Å and c=17.59983(6) Å. The structures of other members in this family are confirmed by Rietveld refinement using powder X-ray diffraction data. The cations (RE, Sb and Co) in RE{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} are orderly distributed, presentingmore » as [RE{sub 3}Co][Sb{sub 3}Co]O{sub 14} formula, and giving rise to two distinctive Kagome lattices constructed by RE{sup 3+} and Sb{sup 5+}, respectively. Co{sup 2+} occupies 8-coordinated and 6-coordinated environments, showing low spin (S=1/2) and high spin (S=3/2) states respectively. The magnetic susceptibility and UV–visual spectroscopy supports the magnetic observation. TDDFT calculation was performed to interpret the electronic states. The compounds [RE{sub 3}Co][Sb{sub 3}Co]O{sub 14} provide a profound example in which the ideal 2D Kagome lattice is derived from the 3D pyrochlore-type structure by an ordered distribution of the metal cations. - Graphical abstract: La{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} crystallizes in a pyrochlore related structure with an ordered distribution of cations, giving rise to two sets of ideal 2D Kagome lattices formed by La{sup 3+} or Sb{sup 5+} respectively. This rhombohedral pyrochlore is a tolerant structure for stable compounds composed by many light rare-earth and d-transition elements. Substituting Zn{sup 2+} or Mg{sup 2+} for Co{sup 2+} will provide a series of compounds useful for studying magnetic interactions in the rare-earth Kagome lattices. - Highlights: • Pyrochlore-type La{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} shows an ordered distribution of cations in its structure. • It presents two sets of ideal 2D Kagome lattices formed by La{sup 3+} or Sb{sup 5+}, respectively. • A family of isostructural compounds RE{sub 3}Sb{sub 3}Co{sub 2}O{sub 14} (RE=Pr, Nd, Sm–Ho) were realized. • Co{sup 2+} presents two spin states with S=1/2, 3/2 due to two coordinated environments.« less

Preparation of grape-like Bi{sub 2}O{sub 3}/Ti photoanode and its visible light activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Guoting; Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR; Yip, H.Y.

2011-02-15

Graphical abstract: Compact and grape-like bismuth oxide (Bi{sub 2}O{sub 3}) coated titania (Ti) anode was prepared by oxalic acid (H{sub 2}C{sub 2}O{sub 4}) etching, electrodeposition and calcination in order to explore its photoelectrocatalytic activities. The Bi{sub 2}O{sub 3} coating was demonstrated to be full of pores, and a good combination between Bi{sub 2}O{sub 3} layer and honeycomb-like Ti substrate was observed by scanning electron microscopy. A synergy was found between electrolysis and photocatalysis using the prepared Bi{sub 2}O{sub 3}/Ti anode for photoelectrocatalytic oxidation of azo dye Acid Orange 7 under visible light irradiation (420 nm). Research highlights: {yields} Bi{sub 2}O{submore » 3}/Ti anode was prepared by H{sub 2}C{sub 2}O{sub 4} etching, electrodeposition and calcination. {yields} A compact and grape-like Bi{sub 2}O{sub 3} coated Ti anode was obtained. {yields} Bi{sub 2}O{sub 3} coating was full of pores, and have a good combination with Ti substrate. {yields} A synergy was observed in photoelectrocatalytic oxidation under visible light. -- Abstract: Compact and grape-like bismuth oxide (Bi{sub 2}O{sub 3}) coated titania (Ti) anode was prepared by oxalic acid (H{sub 2}C{sub 2}O{sub 4}) etching, electrodeposition and calcination in order to explore its photoelectrocatalytic activities. The Bi{sub 2}O{sub 3} coating was demonstrated to be full of pores, and a good combination between Bi{sub 2}O{sub 3} layer and honeycomb-like Ti substrate was observed by scanning electron microscopy. The characteristic morphology of Bi{sub 2}O{sub 3} coating indicated that the electrode is stable during degradation. The Bi{sub 2}O{sub 3}/Ti electrode was used in oxidative degradation of Acid Orange 7 by electrolysis, photocatalytic oxidation and photoelectrocatalytic oxidation processes. The pseudo-first order kinetics parameter (K{sub app}) of photoelectrocatalytic process was 1.15 times of the sum of electrolysis and photocatalytic oxidation under visible light irradiation at 420 nm. The results indicated that the synergy of electrolysis and photocatalysis lead to an excellent photoelectrocatalytic property of the Bi{sub 2}O{sub 3}/Ti electrode.« less

Preparation, structure and some chemistry of FcC[identically equal to]CC[identically equal to]CC[identically equal to]CRu(dppe)Cp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruce, Michael I.; Humphrey, Paul A.; Jevric, Martyn

The synthesis of Fc(C{triple_bond}C){sub 3}Ru(dppe)Cp (2) from Fc(C{triple_bond}C){sub 3}SiMe{sub 3} and RuCl(dppe)Cp is described, together with its reactions with tcne to give the tetracyano-dienyl FcC{triple_bond}CC{triple_bond}C{l_brace}C[{triple_bond}C(CN){sub 2}]{r_brace}{sub 2}Ru(dppe)Cp (3) and -cyclobutenyl FcC{triple_bond}CC{triple_bond}C{l_brace}C{triple_bond}CC(CN){sub 2}C(CN){sub 2}{r_brace}Ru(dppe)Cp (4), with Co{sub 2}({mu}-dppm){sub n}(CO){sub 8-2n} (n = 0, 1) to give FcC{sub 2}{l_brace}Co{sub 2}(CO){sub 6}{r_brace}C{sub 2}{l_brace}Co{sub 2}(CO){sub 6}{r_brace}CCRu(dppe)Cp (5) and FcC{triple_bond}CC{triple_bond}CC{sub 2}{l_brace}Co{sub 2}({mu}-dppm)(CO){sub 4}{r_brace}Ru(dppe)Cp (6), respectively, and with Os{sub 3}(CO){sub 10}(NCMe){sub 2} to give Os{sub 3}{l_brace}{mu}{sub 3}-C{sub 2}C{triple_bond}CC{triple_bond}C[Ru(dppe)Cp]{r_brace}(CO){sub 10} (7). On standing in solution, the latter isomerises to the cyclo-metallated derivative Os{sub 3}({mu}-H){l_brace}{mu}{sub 3}-C[Ru(dppe)Cp]CCC[({eta}-C{sub 5}H{sub 3})FeCp]{r_brace}(CO){sub 8} (8). X-ray structural determinations of 1, 2, 6 andmore » 7 are reported.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun

From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H{sub 2}CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn{sub 5}(μ{sub 3}-OH){sub 2}(2,7-CDC){sub 4}(DEF){sub 2}] (1) (DEF=N,N-diethylformamide), [Zn{sub 2}(2,7-CDC){sub 2}(DABCO)(H{sub 2}O)]·5DMF·H{sub 2}O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn{sub 2}(2,7-CDC){sub 2}(bpea)]·3DMA·2 H{sub 2}O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle–wheel [Zn{sub 2}(COO){sub 4}] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2more » shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle–wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied. - Graphical abstract: A new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid, was used to construct Zn(II) metal-organic frameworks, including a novel self-catenated network with the rare 3D alb-3,6-C2/c net and two pcu-type networks based on an unprecedented pentanuclear clusters and the common paddle–wheel units. The compounds show blue fluorescent properties. Display Omitted - Highlights: • MOFs with a new carbazole-based dicarboxylate ligand. • New pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building unit. • The rare self-catenated 3D alb-3,6-C2/c net.« less

Improved solar-driven photocatalytic performance of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} prepared in-situ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Junbo, E-mail: junbozhong@163.com; Li, Jianzhang, E-mail: lschmanuscript@163.com; Huang, Shengtian

Highlights: • Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} photocatalysts were prepared in-situ. • The photo-induced charge separation rate has been greatly increased. • The photocatalytic activity has been greatly promoted. - Abstract: Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} composites have been fabricated in-situ via a facile parallel flaw co-precipitation method. The specific surface area, structure, morphology, and the separation rate of photo-induced charge pairs of the photocatalysts were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy(DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and surface photovoltage (SPV) spectroscopy, respectively. XRD patterns and DRS demonstrated that Ag{submore » 2}CO{sub 3} has no effect on the crystal phase and bandgap of (BiO){sub 2}CO{sub 3}. The existence of Ag{sub 2}CO{sub 3} in the composites enhances the separation rate of photo-induced charge pairs of the photocatalysts. The photocatalytic performance of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} was evaluated by the decolorization of methyl orange (MO) aqueous solution under simulated solar irradiation. It was found that the simulated solar-induced photocatalytic activity of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} copmposites was significantly improved, which was mainly attributed to the enhanced surface area and the separation rate of photo-induced charge pairs.« less

Searching for “LiCr{sup II}PO{sub 4}”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosymow, E.; Glaum, R., E-mail: rglaum@uni-bonn.de; Kremer, R.K.

The two new phosphates LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} and Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data (LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}: violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R{sub 1}=0.028, wR{sub 2}=0.08, 2060 unique reflections with F{sub o}>4σ(F{sub o}); Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}: greyish-green, P1{sup ¯} (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R{sub 1}=0.022, wR{sub 2}=0.067, 1594 unique reflectionsmore » with F{sub o}>4σ(F{sub o})). Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} adopts an hitherto unknown structure type. The crystal structure of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} is isotypic to that of NaCd{sup II}{sub 4}(PO{sub 4}){sub 3} and related to that of the mineral silicocarnotite Ca{sub 5}(PO{sub 4}){sub 2}(SiO{sub 4}). Significant disorder between Li{sup +} and Cr{sup 2+} is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCr{sup II}PO{sub 4}” mixtures of LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, Cr{sub 2}O{sub 3}, and CrP are observed at equilibrium. Instead of “Li{sub 2}Cr{sup II}P{sub 2}O{sub 7}” four-phase mixtures consisting of Li{sub 9}Cr{sup III}{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2}, Li{sub 3}Cr{sup III}{sub 2}(PO{sub 4}){sub 3}, LiCrP{sub 2}O{sub 7}, and CrP were obtained. - Graphical abstract: Investigations on the equilibrium relations in the system Li/Cr/P/O revealed the two hitherto unknown phosphates Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} and LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}. They form instead of “LiCr{sup II}PO{sub 4}”. The crystal structures, magnetic behavior and optical spectra of these phosphates are reported. - Highlights: • The two new phosphates Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} and LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} have been characterized. • Optical spectra and paramagnetism of the these phosphates are explained by AOM. • Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Cr{sub 2}O{sub 3}, and CrP occur instead of “LiCr{sup II}PO{sub 4}”. • LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} is structurally closely related to Silicocarnotite Ca{sub 5}(PO{sub 4}){sub 2}(SiO{sub 4}). • Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4} and LiCr{sup II}{sub 4}(PO{sub 4}){sub 3} exhibit significant cation disorder Li{sup +}/Cr{sup 2+}.« less

Potassium and magnesium succinatouranilates – Synthesis and crystal structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novikov, S.A., E-mail: serg.alex.novikov@gmail.com; Grigoriev, M.S.; Serezhkina, L.B.

2017-04-15

Single crystal X-ray diffraction has been applied to determine the structures of two new uranyl coordination polymers: K{sub 2}[(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}] (1) and [Mg(H{sub 2}O){sub 6}] [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]·2H{sub 2}O (2), where C{sub 4}H{sub 4}O{sub 4}{sup 2-} is succinate anion. Crystals of 1 and 2 contain polymeric complex anions [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]{sup 2-} with the same A{sub 2}Q{sup 02}{sub 3} crystallochemical formula (A=UO{sub 2}{sup 2+}, Q{sup 02}=C{sub 4}O{sub 4}H{sub 4}{sup 2-}), and have layered (1) or chain (2) structure. It has been found, that conformation of succinate ionsmore » is one of the factors, which affects the structure of [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]{sup 2-} anions. IR spectra of these new compounds are in good agreement with crystallographic data. Topological analysis of the uranium dicarboxylates with A{sub 2}Q{sup 02}{sub 3} crystallochemical formula has shown the presence of five isomers which differ from each other in coordination sequences and / or dimensionality. - Graphical abstract: Crystal structures of two new uranium(VI) coordination polymers with succinate linkers, namely K{sub 2}[(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}] (1) and [Mg(H{sub 2}O){sub 6}][(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]·2H{sub 2}O (2), were determined by single-crystal XRD. Crystals of studied compounds are based on 2D or 1D structural units with the same composition and crystallochemical formula. Topological isomerism in A{sub 2}Q{sup 02}{sub 3} crystallochemical group and conformations of succinate anions in uranyl complexes are under discussion. - Highlights: • Two new uranium coordination polymers were synthesized. • Their structural units have the same composition and crystallochemical formula. • In spite the same composition and CCF dimensionality of units is different. • Structural features of uranyl CPs are affected by linker conformations.« less

Membranes for separation of carbon dioxide

DOEpatents

Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Ramaswamy, Vidya [Niskayuna, NY; Willson, Patrick Daniel [Latham, NY; Gao, Yan [Niskayuna, NY

2011-03-01

Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

The synthesis and structure of a chiral 1D aluminophosphate chain compound: d-Co(en){sub 3}[AlP{sub 2}O{sub 8}].6.5H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Peng; Li Jiyang; Yu Jihong

2005-06-15

A new chiral one-dimensional (1D) aluminophosphate chain compound [d-Co(en){sub 3}][AlP{sub 2}O{sub 8}].6.5H{sub 2}O (designated AlPO-CJ22) has been hydrothermally synthesized by using the optically pure d-Co(en){sub 3}I{sub 3} complex as the template. Single-crystal structural analysis reveals that its structure is built up from alternating connection of AlO{sub 4} and PO{sub 2}(=O{sub 2}) tetrahedra to form corner-shared Al{sub 2}P{sub 2} four-membered ring (4-MR) chains. The d-Co(en){sub 3}{sup 3+} complex cations extended along the 2{sub 1} screw axis interact with the inorganic chains through hydrogen-bonds of N...O atoms in a helical fashion. Optical rotation measurement shows that AlPO-CJ22 is chiral as with d-Co(en){submore » 3}{sup 3+} complex cations. Crystal data: orthorhombic, I2{sub 1}2{sub 1}2{sub 1}, a=8.5573(8)A, b=22.613(2)A, c=22.605(2)A, Z=8, R{sub 1}=0.067, wR{sub 2}=0.1291, and Flack parameter: -0.02(3). CCDC number: 254179. -0.02(3). CCDC number: 254179.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dan; Yang, Ping, E-mail: mse_yangp@ujn.edu.cn; Huang, Baibiao

Graphical abstract: The iron alkoxide precursors are calcined into α-Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4} microstructures with different morphologies by changing calcination atmosphere, reaction time of precursors and calcination temperature simply. The Fe{sub 2}O{sub 3}/Ag hybrid composites prepared through aqueous synthesis and light irradiation. - Highlights: • α-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} microstructures with different morphologies were created. • Solvents play an important role for the solvothermal treatment of precursors. • The α-Fe{sub 2}O{sub 3} microstructures show excellent adsorption properties. • Fe{sub 2}O{sub 3}/Ag hybrid composites were prepared to improve their properties. - Abstract: The flower-like precursors ofmore » Fe alkoxide constructed by the self-assembly of nanoflakes were prepared. Time-dependent experiments confirmed the formation mechanism of flower-like precursors. After calcination, α-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} nanostructures with different morphologies were created. Fe{sub 3}O{sub 4} nanostructures containing blocks with a truncated octahedron structure were obtained under N{sub 2} protection. α-Fe{sub 2}O{sub 3} nanostructures were prepared in an air atmosphere. The values of maximum adsorption capacity of α-Fe{sub 2}O{sub 3} nanostructures for Cr{sup 6+} ions were much higher than that of commercial bulk α-Fe{sub 2}O{sub 3}. Ag NPs were deposited on α-Fe{sub 2}O{sub 3} nanostructures through an aqueous synthesis and light irradiation using L-cysteine as a linker. Such procedure is utilizable for the preparation of the composites of noble metals and magnetic materials.« less

Production of complex rubidium and cesium hydrogen sulfate‒phosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komornikov, V. A., E-mail: v.a.kom@mail.ru; Grebenev, V. V.; Makarova, I. P.

2016-07-15

The solubility in the CsH{sub 2}PO{sub 4}‒CsHSO{sub 4}‒H{sub 2}O system at different temperatures (25, 50, and 75°C) is studied and the phase equilibria in the Rb{sub 3}H(SO{sub 4}){sub 2}‒RbH{sub 2}PO{sub 4}‒H{sub 2}O system under isothermal conditions (at 25°C) are analyzed. The temperature and concentration conditions for forming Rb{sub 2}(HSO{sub 4})(H{sub 2}PO{sub 4}), Rb{sub 4}(HSO{sub 4}){sub 3}(H{sub 2}PO{sub 4}), Cs{sub 4}(HSO{sub 4}){sub 3}(H{sub 2}PO{sub 4}), Cs{sub 3}(HSO{sub 4}){sub 2}(H{sub 2}PO{sub 4}), Cs{sub 2}(HSO{sub 4})(H{sub 2}PO{sub 4}), and Cs{sub 6}H(HSO{sub 4}){sub 3}(H{sub 2}PO{sub 4}){sub 4} compounds (the latter has been obtained for the first time) are determined. The conditions for growing largemore » single crystals of complex acid rubidium and cesium salts are found.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Yu-Fang; Kong, Lin-Jun; Lee, Yuan-Pern

Irradiation at 239 {+-} 20 nm of a p-H{sub 2} matrix containing methoxysulfinyl chloride, CH{sub 3}OS(O)Cl, at 3.2 K with filtered light from a medium-pressure mercury lamp produced infrared (IR) absorption lines at 3028.4 (attributable to {nu}{sub 1}, CH{sub 2} antisymmetric stretching), 2999.5 ({nu}{sub 2}, CH{sub 3} antisymmetric stretching), 2950.4 ({nu}{sub 3}, CH{sub 3} symmetric stretching), 1465.2 ({nu}{sub 4}, CH{sub 2} scissoring), 1452.0 ({nu}{sub 5}, CH{sub 3} deformation), 1417.8 ({nu}{sub 6}, CH{sub 3} umbrella), 1165.2 ({nu}{sub 7}, CH{sub 3} wagging), 1152.1 ({nu}{sub 8}, S=O stretching mixed with CH{sub 3} rocking), 1147.8 ({nu}{sub 9}, S=O stretching mixed with CH{sub 3} wagging),more » 989.7 ({nu}{sub 10}, C-O stretching), and 714.5 cm{sup -1} ({nu}{sub 11}, S-O stretching) modes of syn-CH{sub 3}OSO. When CD{sub 3}OS(O)Cl in a p-H{sub 2} matrix was used, lines at 2275.9 ({nu}{sub 1}), 2251.9 ({nu}{sub 2}), 2083.3 ({nu}{sub 3}), 1070.3 ({nu}{sub 4}), 1056.0 ({nu}{sub 5}), 1085.5 ({nu}{sub 6}), 1159.7 ({nu}{sub 7}), 920.1 ({nu}{sub 8}), 889.0 ({nu}{sub 9}), 976.9 ({nu}{sub 10}), and 688.9 ({nu}{sub 11}) cm{sup -1} appeared and are assigned to syn-CD{sub 3}OSO; the mode numbers correspond to those used for syn-CH{sub 3}OSO. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers, infrared intensities, and deuterium isotopic shifts with those predicted with the B3P86/aug-cc-pVTZ method. Our results extend the previously reported four transient IR absorption bands of gaseous syn-CH{sub 3}OSO near 2991, 2956, 1152, and 994 cm{sup -1} to 11 lines, including those associated with C-O, O-S, and S=O stretching modes. Vibrational wavenumbers of syn-CD{sub 3}OSO are new. These results demonstrate the advantage of a diminished cage effect of solid p-H{sub 2} such that the Cl atom, produced via UV photodissociation of CH{sub 3}OS(O)Cl in situ, might escape from the original cage to yield isolated CH{sub 3}OSO radicals.« less

The products of the thermal decomposition of CH{sub 3}CHO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vasiliou, AnGayle; National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401; Piech, Krzysztof M.

2011-07-07

We have used a heated 2 cm x 1 mm SiC microtubular ({mu}tubular) reactor to decompose acetaldehyde: CH{sub 3}CHO +{Delta}{yields} products. Thermal decomposition is followed at pressures of 75-150 Torr and at temperatures up to 1675 K, conditions that correspond to residence times of roughly 50-100 {mu}s in the {mu}tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: vacuum ultraviolet photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscopy after isolation in a cryogenic matrix. Besides CH{sub 3}CHO, we have studied three isotopologues, CH{sub 3}CDO, CD{sub 3}CHO, and CD{sub 3}CDO. We have identified the thermal decomposition productsmore » CH{sub 3} (PIMS), CO (IR, PIMS), H (PIMS), H{sub 2} (PIMS), CH{sub 2}CO (IR, PIMS), CH{sub 2}=CHOH (IR, PIMS), H{sub 2}O (IR, PIMS), and HC{identical_to}CH (IR, PIMS). Plausible evidence has been found to support the idea that there are at least three different thermal decomposition pathways for CH{sub 3}CHO; namely, radical decomposition: CH{sub 3}CHO +{Delta}{yields} CH{sub 3}+[HCO]{yields} CH{sub 3}+ H + CO; elimination: CH{sub 3}CHO +{Delta}{yields} H{sub 2}+ CH{sub 2}=C=O; isomerization/elimination: CH{sub 3}CHO +{Delta}{yields}[CH{sub 2}=CH-OH]{yields} HC{identical_to}CH + H{sub 2}O. An interesting result is that both PIMS and IR spectroscopy show compelling evidence for the participation of vinylidene, CH{sub 2}=C:, as an intermediate in the decomposition of vinyl alcohol: CH{sub 2}=CH-OH +{Delta}{yields}[CH{sub 2}=C:]+ H{sub 2}O {yields} HC{identical_to}CH + H{sub 2}O.« less

Electronic polarizability and interaction parameter of gadolinium tungsten borate glasses with high WO{sub 3} content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taki, Yukina; Shinozaki, Kenji; Honma, Tsuyoshi

2014-12-15

Glasses with the compositions of 25Gd{sub 2}O{sub 3}–xWO{sub 3}–(75−x)B{sub 2}O{sub 3} with x=25–65 were prepared by using a conventional melt quenching method, and their electronic polarizabilities, optical basicities Λ(n{sub o}), and interaction parameters A(n{sub o}) were estimated from density and refractive index measurements in order to clarify the feature of electronic polarizability and bonding states in the glasses with high WO{sub 3} contents. The optical basicity of the glasses increases monotonously with the substitution of WO{sub 3} for B{sub 2}O{sub 3}, and contrary the interaction parameter decreases monotonously with increasing WO{sub 3} content. A good linear correlation was observed betweenmore » Λ(n{sub o}) and A(n{sub o}) and between the glass transition temperature and A(n{sub o}). It was proposed that Gd{sub 2}O{sub 3} oxide belongs to the category of basic oxide with a value of A(n{sub o})=0.044 Å{sup −3} as similar to WO{sub 3}. The relationship between the glass formation and electronic polarizability in the glasses was discussed, and it was proposed that the glasses with high WO{sub 3} and Gd{sub 2}O{sub 3} contents would be a floppy network system consisting of mainly basic oxides. - Graphical abstract: This figure shows the correlation between the optical basicity and interaction parameter in borate-based glasses. The data obtained in the present study for Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses are locating in the correlation line for other borate glasses. These results shown in Fig. 8 clearly demonstrate that Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses having a wide range of optical basicity and interaction parameter are regarded as glasses consisting of acidic and basic oxides. - Highlights: • Gd{sub 2}O{sub 3}–WO{sub 3}–B{sub 2}O{sub 3} glasses with high WO{sub 3} contents were prepared. • Electronic polarizability and interaction parameter were estimated. • Optical basicity increases monotonously with increasing WO{sub 3} content. • Interaction parameter decreases monotonously with increasing WO{sub 3} content. • Glasses with high WO{sub 3}contents is regarded as a floppy network system.« less

Preparation, structure, and luminescence of dinuclear lanthanide complexes of a novel imine-amine phenolate macrocycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, K.D.; Kahwa, I.A.; Williams, D.J.

1994-03-30

Metal-free condensation of 2,6-diformyl-p-cresol with 3,6-dioxa-1,8-octanediamine followed by reduction with sodium tetrahydroborate and addition of lanthanide(III) nitrate salts, in that order, yield (slowly) crystalline dinuclear complexes of a novel imine-amine phenolate macrocycle 2. The decacoordination geometry of the identical Pr[sup 3+] ions in a C[sub 2v] 4A,6B-extended dodecahedron made up of two bidentate NO[sub 3]-ions, two phenolate and two either oxygens, and one imine and one amine nitrogens. Dinuclear lanthanide complexes of 2 appear to be more stable than those of the totally reduced chelate 2 in alcoholic media. The Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]-OH and (La[sub 0.97]Tb[sub 0.03])[submore » 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH compounds exhibit strong Tb[sup 3+] ([sup 5]D[sub 4] [yields] [sup 7]F[sub J]) emission sensitized by the single state of 2 at both 77 and 295 K. No Tb[sup 3+]-Tb[sup 3+] self-quenching or N-H trapping effects are observed at 77 K (decay rate is 598 s[sup [minus]1]); the coordination cavities of 2 are therefore potentially good hosts for Tb[sup 3+] in luminescent diagnostic agents. At room temperature the complex decay kinetics of Tb[sup 3+] in Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH are similar to those of Tb[sub 2]1(NO[sub 3])[sub 4][center dot]H[sub 2]O. But for the dilute complex, (La[sub 0.97]-Tb[sub 0.03])[sub 2]2(NO[sub 3])[sub 4][center dot]1.35CH[sub 3]OH, unusual thermal equilibration of the ligand triplet and Tb[sup 3+] [sup 5]D[sub 4] states occurs at room temperature; the ligand-to-Tb[sup 3+] energy-transfer rate is [approx]4.36 x 10[sup 4] s[sup [minus]1], while Tb[sup 3+]-to-ligand back-energy-transfer is [approx]7.1 x 10[sup 4] s[sup [minus]1].« less

Photoluminescence and thermoluminescence properties of Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Palvi; Bedyal, A.K.; Kumar, Vinay, E-mail: vinaykdhiman@yahoo.com

2014-12-15

Energy level diagram of Tb{sup 3+} ion in the K{sub 3}Gd(PO{sub 4}){sub 2} host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Combustion method was employed to synthesize the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Mechanism of excitation and emission in undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor was given. - Abstract: Tb{sup 3+} doped nanoparticulate K{sub 3}Gd(PO{sub 4}){sub 2} phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties ofmore » the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K{sub 3}Gd(PO{sub 4}){sub 2}, the excitation and emission peaks at 273 nm and 323 nm belongs to the {sup 8}S{sub 7/2} → {sup 6}I{sub J(J=7/2)} and {sup 6}P{sub J(J=7/2)} → {sup 8} S{sub 7/2} transitions of Gd{sup 3+} while green emission was observed in the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2}. TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K{sub 3}Gd(PO{sub 4}){sub 2}:Tb{sup 3+} (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb{sup 3+} ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors.« less

Dimensional modulation and magnetic properties of triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ju-Wen; Zhao, Wei; Lu, Qi-Lin

2014-04-01

Five new metal–organic coordination polymers ([Cu{sub 3}(μ{sub 2}-OH){sub 2}(atrz){sub 2}(nph){sub 2}(H{sub 2}O){sub 2}]·2H{sub 2}O){sub n} (1), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)]·2H{sub 2}O){sub n} (2), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)(H{sub 2}O)]·H{sub 2}O){sub n} (3), [Cu(dth){sub 0.5}(nph)(H{sub 2}O)]{sub n} (4) and [Cu(dth)(Hnip){sub 2}]{sub n} (5) [atrz=4-amino-1,2,4-triazole, dth=N,N'-di(4H-1,2,4-triazole)hexanamide, H{sub 2}nph=3-nitrophthalic acid, 1,2,4-H{sub 3}btc=1,2,4-benzenetricarboxylic acid and H{sub 2}nip=5-nitroisophthalic acid] were hydrothermally synthesized and structurally characterized. Polymer 1 shows a one-dimensional (1D) chain. Polymers 2 and 3 exhibit similar tetranuclear Cu{sup II}{sub 4} cluster-based three-dimensional (3D) frameworks with the same components. Polymer 4 possesses a 3D framework with a 4{sup 12}·6{sup 3}-pcu topology. Polymer 5 displays a 3D frameworkmore » with a 4{sup 4}·6{sup 10}·8-mab topology. The magnetic properties of 1–4 were investigated. - Graphical abstract: Five triazole-based copper(II) polymers modulated by polycarboxylates were synthesized. Bis-triazole-bis-amide ligand and polycarboxylates play important roles in tuning dimensionality of polymers. Magnetic properties of polymers were investigated. - Highlights: • Five triazole- and bis(triazole)-based copper(II) coordination polymers tuned by aromatic polycarboxylates were obtained. • The aromatic polycarboxylates have an important influence on the dimensionality of five polymers. • The magnetic properties of four polymers were investigated.« less

Synthesis of gadolinium carbonate-conjugated-poly(ethylene)glycol (Gd{sub 2}(CO{sub 3}){sub 3}@PEG) particles via a modified solvothermal method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nasution, Erika L. Y.; Ahab, Atika; Nuryadin, Bebeh W.

2016-02-08

PEGylated gadolinium carbonate ((Gd{sub 2}(CO{sub 3}){sub 3})@PEG) powder was successfully synthesized by a modified solvothermal method. The synthesized products were characterized by means of X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). A systematic change in the chemical surface composition, crystallinity and size properties of the Gd{sub 2}(CO{sub 3}){sub 3}@PEG particles was observed by increasing the reaction time at 5 hours, 7 hours, and 8 hours. The corresponding XRD patterns showed that the Gd{sub 2}(CO{sub 3}){sub 3} particles had hexagonal symmetry (JCPDS No. 37-0559) with a crystallite size of 3.5,more » 2.9, and 4.6 nm. FTIR spectra showed that the Gd{sub 2}(CO{sub 3}){sub 3})@PEG particles were formed with the PEG as carbonyl and hydroxyl group attached to the surface. SEM analysis showed that the Gd{sub 2}(CO{sub 3}){sub 3})@PEG particles had a flake-like morphology of homogeneous sized particles and agglomerates. EDS analysis confirmed the presence of constituent Gd{sub 2}(CO{sub 3}){sub 3} elements.« less

Synthesis of mesoporous Bi{sub 2}O{sub 3}/CeO{sub 2} microsphere for photocatalytic degradation of Orange II dye

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsieh, Shu-Han; Manivel, Arumugam; Lee, Gang-Juan

2013-10-15

Graphical abstract: - Highlights: • Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were successfully synthesized by a hydrothermal procedure. • Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were used to remove wastewater pollutant containing azo dye. • The activity of Bi{sub 2}O{sub 3}/CeO{sub 2} is synergically enhanced compared to its pristine forms. - Abstract: We report on the visible-light responsive porous assembly of Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres, which were synthesized via a simple hydrothermal reaction between Bi(NO{sub 3}){sub 3}·5H{sub 2}O and Ce(NO{sub 3}){sub 3}·6H{sub 2}O in the presence of ethylene glycol and ethanol. Systematic structural (X-ray diffraction (XRD)), morphological (field emission scanning electronmore » microscopy (FE-SEM) and transmission electron microscopic (TEM)), BET surface area and diffuse reflectance spectral (DRS) analyses were carried out to characterize the formed product. The effects of experimental parameters on the microstructural and morphological behavior of Bi{sub 2}O{sub 3}/CeO{sub 2} composites were discussed. The semiconductor material as obtained was evaluated as a heterogeneous photocatalyst for the photolytic degradation of an azo dye in water and the degradation was found to follow pseudo-first-order rate kinetics. The study compares the rate constants of the new hybrid catalyst to a pristine Bi{sub 2}O{sub 3} and CeO{sub 2}, which has excellent catalytic properties under visible light irradiation for the degradation of Orange II dye.« less

Conformational stability and force field of short-chain linear chlorophosphazenes: MNDO calculations, {sup 31}P NMR, vibrational spectra, and normal coordinate analyses of Cl{sub 3}PN(PCl{sub 2}N){sub n}P(O)Cl{sub 2} and [Cl{sub 3}PN(PCl{sub 2}N){sub n}PCl{sub 3}][PCl{sub 6}] (n = 1,2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bougeard, D.; Bremard, C.; De Jaeger, R.

1992-10-29

The Raman spectra of Cl{sub 3}PN(PCl{sub 2}N){pi}P(O)Cl{sub 2} and [Cl{sub 3}PN(PCl{sub 2}N){pi}PCl{sub 3}]{sup +}PCl{sub 6}{sup {minus}} (n = 1,2) were recorded in the solid and liquid states at different temperatures. The qualitative depolarization ratios were obtained in the liquid phase. A {sup 31}P NMR study for the molecular compounds showed a coalescence phenomenon near 220 K. The potential energy around the PN bonds for the Cl{sub 3}PN(PCl{sub 2}N)P(O)Cl{sub 2} molecule and [Cl{sub 3}PN(PCl{sub 2}N){sub 2}PCl{sub 3}]{sup +} cation are derived from MNDO (modified neglect of diatomic overlap) calculations. The stable conformations are found to be trans-cis for Cl{sub 3}PN(PCl{sub 2}N)P(O)Cl{submore » 2} and [Cl{sub 3}PN(PCl{sub 2}N){sub 2}PCl{sub 3}]{sup +}. The calculated structural parameters agree well with the X-ray experimental data. The frequencies obtained by normal coordinate analysis are in good agreement with the observed ones. The MNDO calculation of the harmonic force field is in reasonable agreement with the experimental values. The force constant values assigned to torsional modes around the PN bonds correspond to low barriers for the internal rotations. The easy internal rotation around the P-N and P{double_bond}N bonds can explain the flexibility of the phosphazene backbone and the elastomeric properties of the phosphazene polymers. 46 refs., 6 figs., 3 tabs.« less

Phosphate glass useful in high energy lasers

DOEpatents

Hayden, Yuiko T.; Payne, Stephen A.; Hayden, Joseph S.; Campbell, John H.; Aston, Mary Kay; Elder, Melanie L.

1996-01-01

In a high energy laser system utilizing phosphate laser glass components to amplify the laser beam, the laser system requires a generated laser beam having an emission bandwidth of less than 26 nm and the laser glass components consist essentially of (on an oxide composition basis) in mole percent: P{sub 2}O{sub 5}, 50--75; Al{sub 2}O{sub 3}, {gt}0--10; K{sub 2}O, {gt}0--30; MgO, 0--30; CaO, 0--30; Li{sub 2}O, 0--20; Na{sub 2}O, 0--20; Rb{sub 2}O, 0--20; Cs{sub 2}O, 0--20; BeO, 0--20; SrO, 0--20; BaO, 0--20; ZnO, 0--20; PbO, 0--20; B{sub 2}O{sub 3}, 0--10; Y{sub 2}O{sub 3}, 0--10; La{sub 2}O{sub 3}, 0--8; Ln{sub 2}O{sub 3}, 0.01--8; wherein the sum of MgO and CaO is >0--30; the sum of Li{sub 2}O, Na{sub 2}O, Rb{sub 2}O, and Cs{sub 2}O is 0--20; the sum of BeO, SrO, BaO, ZnO, and PbO is 0--20; the sum of B{sub 2}O{sub 3} and Y{sub 2}O{sub 3} is 0--10; and Ln{sub 2}O{sub 3} represents the sum of the oxides of active lasing lanthanides of atomic number 58--71. 21 figs.

Phosphate glass useful in high energy lasers

DOEpatents

Hayden, Y.T.; Payne, S.A.; Hayden, J.S.; Campbell, J.H.; Aston, M.K.; Elder, M.L.

1996-06-11

In a high energy laser system utilizing phosphate laser glass components to amplify the laser beam, the laser system requires a generated laser beam having an emission bandwidth of less than 26 nm and the laser glass components consist essentially of (on an oxide composition basis) in mole percent: P{sub 2}O{sub 5}, 50--75; Al{sub 2}O{sub 3}, {gt}0--10; K{sub 2}O, {gt}0--30; MgO, 0--30; CaO, 0--30; Li{sub 2}O, 0--20; Na{sub 2}O, 0--20; Rb{sub 2}O, 0--20; Cs{sub 2}O, 0--20; BeO, 0--20; SrO, 0--20; BaO, 0--20; ZnO, 0--20; PbO, 0--20; B{sub 2}O{sub 3}, 0--10; Y{sub 2}O{sub 3}, 0--10; La{sub 2}O{sub 3}, 0--8; Ln{sub 2}O{sub 3}, 0.01--8; wherein the sum of MgO and CaO is >0--30; the sum of Li{sub 2}O, Na{sub 2}O, Rb{sub 2}O, and Cs{sub 2}O is 0--20; the sum of BeO, SrO, BaO, ZnO, and PbO is 0--20; the sum of B{sub 2}O{sub 3} and Y{sub 2}O{sub 3} is 0--10; and Ln{sub 2}O{sub 3} represents the sum of the oxides of active lasing lanthanides of atomic number 58--71. 21 figs.

Synthesis and characterization of flower-like CuIn{sub 1-x}Ga{sub x}S{sub 2} (x = 0.3) microspheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Jiasong; Xiang, Weidong, E-mail: xiangweidong001@126.com; College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035

Graphical abstract: In this paper, flower-like CuIn{sub 1-x}Ga{sub x}S{sub 2} (x = 0.3) microspheres were prepared via biomolecule-assisted solvothermal rate with CuCl{sub 2}{center_dot}2H{sub 2}O, GaCl{sub 3}, InCl{sub 3} and L-cystine as raw materials. UV-vis absorption spectrum showed that the band gap of CuIn{sub 0.7}Ga{sub 0.3}S{sub 2} microspheres was about 2.427 eV. Highlights: Black-Right-Pointing-Pointer We reported a small biomolecule-assisted route to synthesis CuIn{sub 0.3}Ga{sub 0.7}S{sub 2}. Black-Right-Pointing-Pointer The possible mechanisms of flower-like CuIn{sub 0.3}Ga{sub 0.7}S{sub 2} microspheres were proposed. Black-Right-Pointing-Pointer The as-prepared CuIn{sub 0.3}Ga{sub 0.7}S{sub 2} products were investigated by XRD, XPS, FESEM and TEM. Black-Right-Pointing-Pointer The optical properties were investigatedmore » by UV-vis spectroscopy and Raman spectrum. -- Abstract: We report the formation and characterization of the flower-like CuIn{sub 1-x}Ga{sub x}S{sub 2} (x = 0.3) microspheres using CuCl{sub 2}{center_dot}2H{sub 2}O, GaCl{sub 3}, InCl{sub 3} and L-cystine in the mixed solvent of ethylene glycol and distilled water (1:2, v/v) at 200 Degree-Sign C for 24 h. XRD results indicated that the CuIn{sub 0.7}Ga{sub 0.3}S{sub 2} nanostructures have a (1 1 2) preferred orientation. The EDS and XPS analyses of the sample revealed that Cu, In, Ga and S were present in an atomic ratio of approximately 1:0.7:0.3:2. FESEM and TEM images showed that the product was microspheres, consisting of nanoplates with the thickness of about 20 nm. The optical properties were investigated by ultraviolet-visible (UV-vis) absorption spectroscopy and Raman spectroscopy. UV-vis absorption spectrum indicated that the band gap of as-synthesized flower-like CuIn{sub 0.7}Ga{sub 0.3}S{sub 2} microspheres was about 2.427 eV. Raman spectrum of the obtained CuIn{sub 0.7}Ga{sub 0.3}S{sub 2} exhibited a high-intensity peak at 302 cm{sup -1} could be assigned as A1-mode.« less

Formation of homologous In{sub 2}O{sub 3}(ZnO){sub m} thin films and its thermoelectric properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia, Junjun; Nakamura, Shin-ichi; Shigesato, Yuzo, E-mail: yuzo@chem.aoyama.ac.jp

Homologous In{sub 2}O{sub 3}(ZnO){sub 5} thin films were produced on a synthetic quartz glass substrate by thermal annealing of magnetron sputtered In{sub 2}O{sub 3}-ZnO compound films. When the annealing temperature was increased to 700 °C, the sputtered In{sub 2}O{sub 3}-ZnO film with In{sub 2}O{sub 3} microcrystalline changed to a c-oriented homologous In{sub 2}O{sub 3}(ZnO){sub 5} structure, for which the crystallization is suggested to begin from the surface and proceed along with the film thickness. The annealing temperature of 700 °C to form the In{sub 2}O{sub 3}(ZnO){sub 5} structure was substantially lower than temperatures of conventional solid state synthesis from In{sub 2}O{sub 3}more » and ZnO powders, which is attributed to the rapid diffusional transport of In and Zn due to the mixing of In{sub 2}O{sub 3} and ZnO in the atomic level for sputtered In{sub 2}O{sub 3}-ZnO compound films. The homologous structure collapsed at temperatures above 900 °C, which is attributed to (1) zinc vaporization from the surface and (2) a gradual increase of zinc silicate phase at the interface. This c-oriented layer structure of homologous In{sub 2}O{sub 3}(ZnO){sub 5} thin films along the film thickness allowed the thin film to reach a power factor of 1.3 × 10{sup −4} W/m K{sup 2} at 670 °C, which is comparable with the reported maximum value for the textured In{sub 2}O{sub 3}(ZnO){sub 5} powder (about 1.6 × 10{sup −4} W/m K{sup 2} at 650 °C).« less

Synthesis and structure of R{sub 2}[UO{sub 2}(NO{sub 3}){sub 2}(NCS){sub 2}] (R = Rb or Cs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serezhkin, V. N., E-mail: lserezh@samsu.ru; Peresypkina, E. V.; Grigor’eva, V. A.

2015-01-15

Crystals Rb{sub 2}[UO{sub 2}(NO{sub 3}){sub 2}(NCS){sub 2}] (I) and Cs{sub 2}[UO{sub 2}(NO{sub 3}){sub 2}(NCS){sub 2}] (II) have been synthesized and studied by IR spectroscopy and X-ray diffraction. Crystals I are monoclinic, with the following parameters: a = 12.2118(5) Å, b = 10.2545(3) Å, c = 11.8754(4) Å, β = 110.287(1)°, sp. gr. C2/c, Z = 4, and R = 0.0523. Crystals II are orthorhombic, with a = 13.7309(3) Å, b = 10.5749(2) Å, c = 10.1891(2) Å, sp. gr. Pnma, Z = 4, and R = 0.0411. The basic structural units of crystals I and II are one-core complexes [UO{submore » 2}(NO{sub 3}){sub 2}(NCS){sub 2}]{sup 2−}, which belong to the crystallochemical group cis-AB{sub 2}{sup 01}M{sub 2}{sup 1} (A = UO{sub 2}{sup 2+}, B{sup 01} = NO{sub 3}{sup −}, M{sup 1} = NCS{sup −}), which are combined into a framework via electrostatic interactions with ions of alkaline metals R (R = Rb or Cs). The structural features of crystals I and II, which condition the formation of [UO{sub 2}(NO{sub 3}){sub 2}(NCS){sub 2}]{sup 2−} complexes with a cis rather than a trans position of isothiocyanate ions in the coordination sphere of uranyl ions, are discussed.« less

Hydrothermal syntheses, crystal structures and luminescence properties of zinc(II) and cadmium(II) coordination polymers based on bifunctional 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Na; Guo, Hui-Lin; Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN

2013-02-15

Five new coordination polymers, [Zn{sub 2}(ctpy){sub 2}Cl{sub 2}]{sub n} (1), [Zn{sub 2}(ctpy){sub 2}(ox)(H{sub 2}O){sub 2}]{sub n} (2), [Zn{sub 2}(ctpy)(3-btc)(H{sub 2}O)]{sub n}{center_dot}0.5nH{sub 2}O (3), [Cd(ctpy){sub 2}(H{sub 2}O)]{sub n} (4), [Cd{sub 4}(ctpy){sub 2}(2-btc){sub 2}(H{sub 2}O){sub 2}]{sub n}{center_dot}2nH{sub 2}O (5), (Hctpy=3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid, H{sub 2}ox=oxalic acid, H{sub 3}(3-btc)=1,3,5-benzenetricarboxylic acid, H{sub 3}(2-btc)=1,2,4-benzenetricarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1-2 are a one-dimensional chain with weak interactions to form 3D supramolecular structures. Compound 3 is a 4-nodal 3D topology framework comprised of binuclear zincmore » units and (ctpy){sup -} anions. Compound 4 shows two dimensional net. Compound 5 is a (4,5,6)-connected framework with {l_brace}4{sup 4}{center_dot}6{sup 2}{r_brace}{l_brace}4{sup 6}{center_dot}6{sup 4}{r_brace}{sub 2}{l_brace}4{sup 9}{center_dot}6{sup 6}{r_brace} topology. In addition, the thermal stabilities and photoluminescence properties of 1-5 were also studied in the solid state. - Graphical abstract: Five new Zn/Cd compounds with 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid were prepared. The photoluminescence and thermal stabilities properties of 1-5 were investigated in the solid state. Highlights: Black-Right-Pointing-Pointer Five new zinc/cadmium metal-organic frameworks have been hydrothermal synthesized. Black-Right-Pointing-Pointer The structural variation is attributed to the diverse metal ions and auxiliary ligand. Black-Right-Pointing-Pointer Compounds 1-5 exhibit 1D ring chain, 2D layer and 3D open-framework, respectively. Black-Right-Pointing-Pointer These compounds exhibit strong solid state luminescence emission at room temperature.« less

New high-pressure polymorph of In{sub 2}S{sub 3} with defect Th{sub 3}P{sub 4}-type structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Xiaojing; Zhu, Feng; Wu, Ye

The high pressure behavior of β-In{sub 2}S{sub 3} (I4{sub 1}/amd and Z=16) has been studied by in situ synchrotron radiation X-ray diffraction combined with diamond anvil cell up to 71.7 GPa. Three pressure-induced phase transitions are evidenced at ∼6.6 GPa, ∼11.1 GPa at room temperature and 35.6 GPa after the high-temperature annealing using a portable laser heating system. The new polymorph of In{sub 2}S{sub 3} at 35.6 GPa is assigned to the denser cubic defect Th{sub 3}P{sub 4} structure (I4¯3d and Z=5.333), whose unit-cell parameters are a=7.557(1) Å and V=431.6(2) Å{sup 3}. The Th{sub 3}P{sub 4}-type phase can be stablemore » at least up to 71.7 GPa and cannot be preserved at ambient pressure. The pressure–volume relationship is well described by the second-order Birch–Murnaghan Equation of State, which yields B{sub 0}=63(3) GPa and B{sub 0}′=4 (fixed) for the β-In{sub 2}S{sub 3} phase and B{sub 0}=87(3) GPa and B{sub 0}′=4 (fixed) for the defect Th{sub 3}P{sub 4}-type phase respectively. - Graphical abstract: The structure and Rietveld refinement of new polymorph the defect Th{sub 3}P{sub 4}-type In{sub 2}S{sub 3}. This structure was observed at 35.6 GPa after laser heating by X-ray diffraction. Display Omitted - Highlights: Three pressure-induced phase transitions of β-In{sub 2}S{sub 3} were observed. β-In{sub 2}S{sub 3} was stable up to 6.6 GPa. The defect Th{sub 3}P{sub 4}-type In{sub 2}S{sub 3} was identified at 35.6 GPa after laser heating and was stable up to 71.7 GPa. Elastic properties of β-In{sub 2}S{sub 3} and Th{sub 3}P{sub 4}-type In{sub 2}S{sub 3} are well presented by Birch–Murnaghan EoS.« less

A three-dimensional coordination polymer based on 1,2,3-triazole-4,5-dicarboxylic acid (H{sub 3}tda): ([Cd{sub 12}(tda){sub 8}(H{sub 2}O){sub 11}] · (H{sub 2}O)6.25){sub n}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Xin-Hui, E-mail: iamxhzhou@njupt.edu.cn; Chen, Qiang

The title coordination polymer ([Cd{sub 12}(tda){sub 8}(H{sub 2}O){sub 11}] · (H{sub 2}O){sub 6.25}){sub n} (H{sub 3}tda = 1,2,3-triazole-4,5-dicarboxylic acid), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex crystallizes in orthorhombic sp. gr. Pmn2{sub 1} with Z = 4. The Cd{sub 2} unit doublebridged by one carboxylate oxygen atom and two neighboring nitrogen atoms from the tda{sup 3–} ligands are linked by the tda{sup 3–}ligands to lead to the 2D (4,4) network in the ac plane. The almost coplanar Cd{sub 2}(μ{sub 5}-tda){sub 2} unit comprised of two Cd ions double-bridged by two tda{sup 3–} ligands through themore » neighboring nitrogen atoms is connected with the other four Cd{sub 2}(μ{sub 5}-tda){sub 2} units form the undulating 2D network in the ac plane. The (4,4) networks and undulating 2D networks are alternatively connected along the b axis by the tda{sup 3–} ligands coordinating to the Cd ions to form the 3D framework.« less

Enhancing visible light photocatalytic and photocharge separation of (BiO){sub 2}CO{sub 3} plate via dramatic I{sup −} ions doping effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Lei; Cao, Jing; Anhui Collaborative Innovation Center of Advanced Functional Composite, Huaibei, 235000, Anhui

Highlights: • Novel I-(BiO){sub 2}CO{sub 3} was prepared by a facile chemical precipitation method. • I{sup −} ions impurity level located on the top of valence band of (BiO){sub 2}CO{sub 3}. • I{sup −} ions doping largely improved photocatalytic activity of I-(BiO){sub 2}CO{sub 3}. • I-(BiO){sub 2}CO{sub 3} displayed excellent photocharge separation efficiency. - Abstract: Novel I{sup −} ions doped (BiO){sub 2}CO{sub 3} (I-(BiO){sub 2}CO{sub 3}) photocatalysts were successfully synthesized via a facile chemical precipitation method. Under visible light (λ > 400 nm), I-(BiO){sub 2}CO{sub 3} displayed much higher activity for rhodamine B and dichlorophenol degradation than the undoped (BiO){submore » 2}CO{sub 3}. The pseudo-first-order rate constant k{sub app} of RhB degradation over 15.0% I-(BiO){sub 2}CO{sub 3} was 0.54 h{sup −1}, which is 11.3 times higher than that of (BiO){sub 2}CO{sub 3}. The doped I{sup −} ions formed an impurity level on the top of valence band of (BiO){sub 2}CO{sub 3} and induced much more visible light to be absorbed. The enhanced photocurrent and surface photovoltage properties were detected, which strongly ensures the efficient separation of electrons and holes in I-(BiO){sub 2}CO{sub 3} system under visible light. It provides a facile way to improve the photocatalytic activity of the wide-band-gap (BiO){sub 2}CO{sub 3} via intense doping effect of I{sup −} ions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafeie, S.; Dreyer, B.; Awater, R.H.P

New La-deficient double perovskites with P2{sub 1}/n symmetry, La{sub ∼1.90}(Co{sup 2+}{sub 1−x}Mg{sup 2+}{sub x})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} with x=0, 0.13 and 0.33, and La{sub 2}(Co{sup 2+}{sub 1/2}Mg{sup 2+}{sub 1/2}) (Co{sup 3+}{sub 1/2}Nb{sup 5+}{sub 1/2})O{sub 6} were prepared by solid state reaction at 1450 °C. Their crystal structures were refined using time-of-flight neutron powder diffraction data. Our results show that certain cations such as Nb{sup 5+}, with very strong B–O bonds in the perovskite structure, can induce A-site vacancies in double perovskites. Upon heating in N{sub 2} gas atmosphere at 1200 °C ∼1% O atom vacancies are formed togethermore » with a partial reduction of the Co{sup 3+} content. The average thermal expansion coefficient between 25 and 900 °C of La{sub 1.90}(Co{sup 2+}{sub 2/3}Mg{sup 2+}{sub 1/3})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} was determined to be 17.4 ppm K{sup −1}. Four-point electronic conductivity measurements showed that the compounds are semiconductors, with conductivities varying between 3.7·10{sup −2} and 7.7·10{sup −2} S cm{sup −1} at 600 °C and activation energies between 0.77 and 0.81 eV. Partial replacement of La{sup 3+} with Sr{sup 2+} does not lead to any increase of conductivity, while replacement of Mg{sup 2+} with Cu{sup 2+} in La{sub 1.9}CoCu{sub 1/3}Nb{sub 2/3}O{sub 6} and La{sub 1.8}CoCu{sub 1/2}Nb{sub 1/2}O{sub 6} leads to ∼100 times larger conductivities at 600 °C, 0.35 and 1.0 S cm{sup −1}, respectively, and lower activation energies, 0.57 and 0.73 eV, respectively. - Highlights: • Double perovskites, P2{sub 1}/n, La{sub 2−z}(Co{sup 2+}{sub 1−x}Mg{sup 2+}{sub x})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} have been synthesized. • Crystal structures have been refined using neutron powder diffraction data. • Strong Nb–O bond and size ordering of Mg{sup 2+}/Co{sup 2+} and Nb{sup 5+}/Co{sup ~3+} leads to La-deficiency. • The compounds are semi conductors (~10{sup −2} S cm{sup −1}) at 600 °C. • Replacement of Mg{sup 2+} with Cu{sup 2+} leads to higher conductivity (~1.0 S cm{sup −1}) at 600 °C.« less

Two isotypic diphosphates LiM{sub 2}H{sub 3}(P{sub 2}O{sub 7}){sub 2} (M=Ni, Co) containing ferromagnetic zigzag MO{sub 6} chains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang Tao; Yang Sihai; Liao Fuhui

2008-06-15

Two new isotypic phosphates LiNi{sub 2}H{sub 3}(P{sub 2}O{sub 7}){sub 2} (1) and LiCo{sub 2}H{sub 3}(P{sub 2}O{sub 7}){sub 2} (2) have been hydrothermally synthesized and structurally characterized by the single-crystal X-ray diffraction technique. They crystallize in the monoclinic space group C2/c with the lattice: a=10.925(2) A, b=12.774(3) A, c=8.8833(18) A, {beta}=123.20(3){sup o} for 1 and a=10.999(2) A, b=12.863(3) A, c=8.9419(18) A, {beta}=123.00(3){sup o} for 2. The transition metal atoms are octahedrally coordinated, whereas the lithium and phosphorus atoms are all tetrahedrally coordinated. As the lithium-induced derivatives of MH{sub 2}P{sub 2}O{sub 7} (M=Ni, Co), 1 and 2 possess the same structure withmore » MH{sub 2}P{sub 2}O{sub 7} in terms of topology, comprising the MO{sub 6} zigzag chains and P{sub 2}O{sub 7} as the interchain groups. The magnetisms of 1 and 2 could be interpreted by adopting a quasi-one-dimensional (1D) zigzag chain model as that in their parent compounds: both 1 and 2 have ferromagnetic (FM) NiO{sub 6}/CoO{sub 6} chains; 1 shows a FM cluster glass behavior at low temperatures, which is originated from the possible antiferromagnetic (AFM) next-nearest-neighbour intrachain interactions; 2 shows a AFM ordering at T{sub N}=2.6 K and a metamagnetic transition at H{sub C}=4.2 kOe at 1.8 K. - Graphical abstract: LiNi{sub 2}H{sub 3}(P{sub 2}O{sub 7}){sub 2} (1) and LiCo{sub 2}H{sub 3}(P{sub 2}O{sub 7}){sub 2} (2) have been hydrothermally synthesized and structurally characterized. The MO{sub 6} octahedra share edges forming zigzag chains with P{sub 2}O{sub 7} as the interchain groups. Both of them are quasi-one-dimensional magnets and have ferromagnetic MO{sub 6} chains; 1 is a ferromagnet, whereas 2 is a metamagnet.« less

Synthesis of layered perovskite oxides, ACa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (A = K, Rb, Cs), and characterization of new solid acids, HCa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (O < x [le] 2), exhibiting variable Bronsted acidity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopalakrishnan, J.; Uma, S.; Bhat, V.

1993-01-01

Layered perovskite oxides of the formula ACa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10] (A = K, Rb, Cs and 0 , x [le] 2) have been prepared. The members adopt the structures of the parent ACa[sub 2]Nb[sub 3]O[sub 10]. Interlayer alkali cations in the niobium-titanium oxide series can be ion-exchanged with Li[sup +], Na[sup +], NG[sub 4][sup +], of H[sup +] to give new derivatives. Intercalation of the protonated derivatives with organic bases reveals that the Bronsted acidity of the solid solution series, HCa[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10], depends on the titanium content. While the x = 1 member (HCaLaNb[submore » 2]TiO[sub 10]) is nearly as acidic as the parent HCa[sub 2]Nb[sub 3]O[sub 10], the x = 2 member (HLA[sub 2]NbTi[sub 2]O[sub 10]) is a weak acid hardly intercalating organic bases with pK[sub a] [approximately] 11.3. The variation of acidity is probably due to an ordering of Nb/Ti atoms in the triple octahedral perovskite slabs, [Ca[sub 2-x]La[sub x]Nb[sub 3-x]Ti[sub x]O[sub 10

Photocatalytic degradation of gaseous toluene over hollow “spindle-like” α-Fe{sub 2}O{sub 3} loaded with Ag

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hong; Department of Basic, Dalian Naval Academy, Dalian 116018; Zhao, Qidong

2012-06-15

Highlights: ► Hollow α-Fe{sub 2}O{sub 3} spindle-shaped microparticles were prepared for Ag support. ► The hollow α-Fe{sub 2}O{sub 3} and Ag/α-Fe{sub 2}O{sub 3} materials were used to degrade gaseous toluene. ► Complete degradation of toluene occurred on the Ag/α-Fe{sub 2}O{sub 3} surface. -- Abstract: In this work, hollow “spindle-like” α-Fe{sub 2}O{sub 3} nanoparticles were synthesized by a hydrothermal route. The Ag/α-Fe{sub 2}O{sub 3} catalyst was prepared based on the spindle-shaped α-Fe{sub 2}O{sub 3} with CTAB as the surfactant, which showed excellent photoelectric property and photocatalytic activity. The structural properties of these samples were systematically investigated by X-ray powder diffraction, scanningmore » electronic microscopy, transmission electronic microscopy, energy-dispersive X-ray spectra, and UV–Vis diffuse reflectance spectroscopy techniques. The photo-induced charge separation in the samples was demonstrated by surface photovoltage measurement. The photocatalytic performances of the Ag/α-Fe{sub 2}O{sub 3} and α-Fe{sub 2}O{sub 3} samples were comparatively studied in the degradation of toluene under xenon lamp irradiation by in situ FTIR spectroscopy. Benzaldehyde and benzoic acid species could be observed on the α-Fe{sub 2}O{sub 3} surface rather than Ag/α-Fe{sub 2}O{sub 3} surface. The results indicate that the Ag/α-Fe{sub 2}O{sub 3} sample exhibited higher photocatalytic efficiency.« less

Electrocatalytic properties of three new POMs-based inorganic–organic frameworks with flexible zwitterionic dicarboxylate ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Yanli; Li, Ling; Mu, Bao

2017-05-15

Three POMs–based inorganic–organic frameworks, namely, [Cu{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 2}]·6H{sub 2}O (1), [Co{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 8}]·8H{sub 2}O (2) and [Ni{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 8}]·6H{sub 2}O (3), (L=1,1′-(1,4-phenylene-bis(methylene))-bis(pyridine-3-carboxylic acid)), have been synthesized and characterized by elemental analyses, IR, XRPD, TG, and single crystal X-ray diffraction. Compound 1 contains 1D double chains decorated by (Cu{sub 2}(L){sub 4}(H{sub 2}O){sub 2}) units and the 1D chains and POMs are stacked to yield 2D frameworks. Compound 2 displays a 2D network constructed from 1D zigzag chains and POMs arranged in ABAB mode. Compound 3 consists of big squaremore » girds and the POMs are dispersed in the middle of the two adjacent girds, forming 2D networks. Compounds 1–3 all show structural integrity in aqueous solutions at different pH values and in common organic solvents. Additionally, the fluorescence and electrochemical properties of compounds 1–3 are also investigated. Compounds 1–3 exhibit good electrocatalytic activities for the reduction of NaNO{sub 2} and H{sub 2}O{sub 2}. - Highlights: • Compound 1–3 all contain different 1D chains. The noncovalent interaction of metal–organic moieties from compounds 1–3 and POMs to construct three new host–guest supramolecular compounds. • Compounds 1–3 show good electrocatalytic activities towards the reduction of NaNO{sub 2} and H{sub 2}O{sub 2}. • Compounds 1–3 all show structural integrity in aqueous solutions at different pH values and in common organic solvents. • Compounds 1–3 may be promising luminescent materials due to their luminescent properties.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niu, Yan-Fei; Cui, Li-Ting; Han, Jie, E-mail: chan@ouhk.edu.hk

The role of auxiliary solvents in the formation of MOFs has been investigated for a series of Mn{sup II}-based framework systems. Reactions of 4,4′,4″-nitrilotribenzoic acid (H{sub 3}L) with Mn{sup II} through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear Mn{sup II} subunits in four new coordination polymers: [Mn{sub 3}(L)(HCOO){sub 3}(DEF){sub 3}] (1), [Mn{sub 3}(L){sub 2}(EtOH){sub 2}]·DMF (2), [Mn{sub 5}(L){sub 4}(H{sub 2}O){sub 2}]·2(H{sub 2}NMe{sub 2}){sup +}·4DMF·2H{sub 2}O (3), and [Mn{sub 3}(L){sub 2}(py){sub 4}(H{sub 2}O)]·H{sub 2}O (4) (H{sub 3}L=4,4′,4′-nitrilotribenzoic acid, DMF=dimethylformamide, DEF=N,N-diethylformamide, py=pyridine). These four compounds were fully characterized by single-crystal X-ray diffraction, showing interesting SBUs variations.more » For compound 1, it displays a (3,6)-connected kgd net with wheel [Mn{sub 6}] cluster serving as SBU, whereas in 2, the sequence of Mn{sub 3}(COO){sub 9}(EtOH){sub 2} is repeated by inversion centers located between Mn1 and Mn3 to form an infinite Mn-carboxylate chain, which are further interlinked by L{sup 3−} ligands to form a 3D architecture. In 3, the pentanuclear Mn{sub 5}(CO{sub 2}){sub 12} clusters are interlinked to form a layer, which are further pillared by L{sup 3−} to generate a 3D network. Compound 4 has a (3,6)-connected network in which the SBU is a linear trimeric Mn{sub 3}(COO){sub 6}(py){sub 4}(H{sub 2}O) cluster. In addition, the thermal stabilities, X-ray powder diffraction of all the compounds were studied, photoluminescence behaviors of compounds 1, 3 and 4 are discussed. - Graphical abstract: Supramolecular assembly of C{sub 3}-symmetric ligand 4,4′,4″-nitrilotribenzoic acid (H{sub 3}L) with Mn{sup II} through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear Mn{sup II} subunits in four new coordination polymers. The results exhibit the structures of Mn-SBUs in these MOFs largely depend on the ancillary solvents involved in the reactions. Display Omitted.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matetskiy, A. V., E-mail: mateckij@iacp.dvo.ru; Kibirev, I. A.; Saranin, A. A.

The formation, structure and electronic properties of SnSe{sub 2}–Bi{sub 2}Se{sub 3} van der Waals heterostructures were studied. Both heterostructures, SnSe{sub 2} on Bi{sub 2}Se{sub 3} and Bi{sub 2}Se{sub 3} on SnSe{sub 2}, were grown epitaxially with high crystallinity and sharp interfaces. Their electron band structures are of trivial and topological insulators, respectively. The Dirac surface states of Bi{sub 2}Se{sub 3} survive under the SnSe{sub 2} overlayer. One triple layer of SnSe{sub 2} was found to be an efficient spacer for separating a Bi{sub 2}Se{sub 3} topological-insulator slab into two and creating the corresponding topological surface states.

Isothermal sections of the quasi-ternary systems Ag{sub 2}S(Se)–Ga{sub 2}S(Se){sub 3}–In{sub 2}S(Se){sub 3} at 820 K and the physical properties of the ternary phases Ga{sub 5.5}In{sub 4.5}S{sub 15}, Ga{sub 6}In{sub 4}Se{sub 15} and Ga{sub 5.5}In{sub 4.5}S{sub 15}:Er{sup 3+}, Ga{sub 6}In{sub 4}Se{sub 15}:Er{sup 3+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivashchenko, I.A., E-mail: Ivashchenko.Inna@eenu.edu.ua; Danyliuk, I.V.; Gulay, L.D.

Isothermal sections of the quasi-ternary systems Ag{sub 2}S(Se)–Ga{sub 2}S(Se){sub 3}–In{sub 2}S(Se){sub 3} at 820 K were compared. Along the 50 mol% Ag{sub 2}S(Se), both systems feature continuous solid solutions with the chalcopyrite structure. Along the 17 mol% Ag{sub 2}S(Se), the interactions at the AgIn{sub 5}S(Se){sub 8}–'AgGa{sub 5}S(Se){sub 8}' sections are different. In the Ag{sub 2}S–Ga{sub 2}S{sub 3}–In{sub 2}S{sub 3} system the existence of the layered phase AgGa{sub x}In{sub 5–x}S{sub 8}, 2.25≤x≤2.85, was confirmed (S.G. P6{sub 3}mc). The Ag{sub 2}Se–Ga{sub 2}Se{sub 3}–In{sub 2}Se{sub 3} system features the formation of solid solution (up to 53 mol% Ga{sub 2}Se{sub 3}) based on AgIn{submore » 5}Se{sub 8} (S.G. P-42m). Crystal structure, atomic coordinates were determined by powder diffraction method for samples from the homogeneity region of AgIn{sub 5}Se{sub 8}. Specific conductivities of the crystals Ga{sub 6}In{sub 4}Se{sub 15} (1.33·10{sup −6} Ω{sup −1} m{sup −1}), Ga{sub 5.94}In{sub 3.96}Er{sub 0.1}Se{sub 15} (3.17·10{sup −6} Ω{sup −1} m{sup −1}), Ga{sub 5.5}In{sub 4.5}S{sub 15} (7.94·10{sup −6} Ω{sup −1} m{sup −1}), Ga{sub 5.46}In{sub 4.47}Er{sub 0.07}S{sub 15} (1·10{sup −9} Ω{sup −1} m{sup −1}) were measured at room temperature. Optical absorption and photoconductivity spectra were recorded in the range 400–760 nm. The introduction of erbium leads to an increase in the absorption coefficient and to the appearance of absorption bands at 530, 660, 810, 980, 1530 nm. - Highlights: • Nature of solid solutions in Ag{sub 2}S(Se)–Ga{sub 2}S(Se){sub 3}–In{sub 2}S(Se){sub 3} (820 K) were discussed. • Crystal structures of ternary and quaternary compounds were discussed. • Specific conductivity, optical properties of four single crystals were measured. • Photoconductivity of the Ga{sub 5.5}In{sub 4.5}S{sub 15} in the range 400–760 nm were recorded.« less

Near-infrared quantum-cutting luminescence and energy transfer properties of Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, S. L.; Lin, H. H., E-mail: linhh@hstc.edu.cn, E-mail: qyzhang@scut.edu.cn; Yu, T.

2014-07-14

The phosphors Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} by co-doping Ce{sup 3+} have been synthesized by conventional high-temperature solid-state reaction method. Their spectroscopic properties in the UV-VIS-NIR range have been investigated. The first 5d crystal field level location and stokes shift have been determined from the UV excitation and emission spectra of Ca{sub 3}(PO{sub 4}){sub 2}:Ce{sup 3+}. The three-photon NIR quantum-cutting luminescence of Tm{sup 3+} assigned to the electronic transitions of {sup 1}G{sub 4}→{sup 3}H{sub 4}, {sup 3}H{sub 4}→{sup 3}F{sub 4} and {sup 3}F{sub 4}→{sup 3}H{sub 6} is observed, whether in Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} or Ca{sub 3}(PO{sub 4}){sub 2}:Tm{supmore » 3+},Ce{sup 3+}. The energy transfer from Ce{sup 3+} to Tm{sup 3+} takes place with energy-transfer efficiency up to 34.5% for the Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+}. A cross relaxation scheme using the 5d states of Ce{sup 3+} and f-f transition of Tm{sup 3+} is proposed. The mechanism is revealed from energy level and decay measurements. The results show that the broadband absorption of Ce{sup 3+} sensitizer not only extends the spectrum conversion in UV region but also greatly enhances the photoluminescence intensities of the three-photon quantum cutting luminescence of Tm{sup 3+} doped Ca{sub 3}(PO{sub 4}){sub 2}.« less

Crystal structures and magnetic properties of lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doi, Yoshihiro, E-mail: doi@sci.hokudai.ac.jp; Satou, Tatsuya; Hinatsu, Yukio

2013-10-15

The synthesis, crystal structures and magnetic properties of LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) were investigated. The LnCr(BO{sub 3}){sub 2} compounds crystallize in the dolomite-type structure with space group R3{sup ¯}, in which the Ln and Cr ions occupy two octahedral sites. From the result of structural analysis, it was found that there is an anti-site disorder between these two sites and its chemical formula is more exactly Ln{sub 1−r}Cr{sub r}[Cr{sub 1−r}Ln{sub r}](BO{sub 3}){sub 2}. On the other hand, the LnSc(BO{sub 3}){sub 2} adopt the calcite-type structure with space group R3{sup ¯}c. The Ln and Sc ions randomly occupymore » an octahedral site and the chemical formula is represented as (Ln{sub 0.5}Sc{sub 0.5})BO{sub 3}. From the magnetic susceptibility and specific heat measurements, we found that all the LnCr(BO{sub 3}){sub 2} show an antiferromagnetic transition at 6.1–8.1 K. This transition is mainly due to the ordering of Cr{sup 3+} magnetic moments. Among the compounds with magnetic Ln{sup 3+} ions, only YbCr(BO{sub 3}){sub 2} shows an antiferromagnetic ordering of Ln{sup 3+} ion at 2.1 K. - Graphical abstract: The lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) have the dolomite-type (Ln=Cr) and calcite-type (Ln=Sc) structures. Both structures are similar to each other except for the difference in the partially or fully disordered arrangements of octahedral sites. At low temperatures, the LnCr(BO{sub 3}){sub 2} compounds show an antiferromagnetic transition due to a long-range ordering of Cr{sup 3+} moments. Among them only YbCr(BO{sub 3}){sub 2} shows an antiferromagnetic ordering of Ln{sup 3+} ion at 2.1 K. Display Omitted - Highlights: • Lanthanide containing borates LnM(BO{sub 3}){sub 2} (Ln=Y, Ho–Lu; M=Sc, Cr) have been synthesized. • LnCr(BO{sub 3}){sub 2} has the dolomite-type structure with an anti-site disorder between Ln and Cr sites. • LnSc(BO{sub 3}){sub 2} has the calcite-type structure in which the Ln and Cr randomly occupy the same site. • LnCr(BO{sub 3}){sub 2} shows an antiferromagnetic transition at 6.1–8.1 K due to the long-range magnetic ordering of Cr{sup 3+} moments. • Only YbCr(BO{sub 3}){sub 2} shows the two-step antiferromagnetic ordering: Cr{sup 3+} (6.1 K) and Yb{sup 3+} (2.1 K)« less

Synthesis and anisotropic properties of single crystalline Ln{sub 2}Ru{sub 3}Al{sub 15+x} (Ln=Gd, Tb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrison, Gregory; Prestigiacomo, Joseph; Haldolaarachchige, Neel

2016-04-15

Single crystals of Ln{sub 2}Ru{sub 3}Al{sub 15+x} (Ln=Gd, Tb) have been grown using the self-flux method under Ru-poor conditions. The structure of the Gd analog is found to be highly dependent on the synthesis method. Gd{sub 2}Ru{sub 3}Al{sub 15.08} orders antiferromagnetically at 17.5 K. Tb{sub 2}Ru{sub 3}Al{sub 15.05} enters an antiferromagnetic state at 16.6 K followed by a likely incommensurate-to-commensurate transition at 14.9 K for crystals oriented with H//ab. For crystals oriented with H//c, a broad maximum is observed in the temperature dependent M/H, indicative of a highly anisotropic magnetic system with the hard axis in the c-direction. The magnetizationmore » as a function of field and magnetoresistance along the ab-direction of Tb{sub 2}Ru{sub 3}Al{sub 15.05} display a stepwise behavior and indicate strong crystalline electric field effects. - Graphical abstract: Single crystal, structure, and highly anisotropic magnetoresistance due to strong crystalline electric field effects of Tb{sub 2}Ru{sub 3}Al{sub 15.05}. - Highlights: • Single crystals of Ln{sub 2}Ru{sub 3}Al{sub 15+x} were grown for the first time via flux growth. • The structure of Gd{sub 2}Ru{sub 3}Al{sub 15.09} differs from that of arc melted Gd{sub 2}Ru{sub 3.08}Al{sub 15}. • Tb{sub 2}Ru{sub 3}Al{sub 15.05} exhibits highly anisotropic magnetic and transport properties. • The properties of Tb{sub 2}Ru{sub 3}Al{sub 15.05} arise due to crystalline electric field effects.« less

High-pressure synthesis and electrochemical behavior of layered (1-a)LiNi{sub 1-y}Al{sub y}O{sub 2}.aLi[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinova, E.; Zhecheva, E.; Stoyanova, R.

Layered (1-a)LiNi{sub 1-y}Al{sub y}O{sub 2}.aLi[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} oxides, 0=1.2. While pure NiO{sub 2}-layersmore » are able to incorporate under high-pressure up to 1/3Li, the appearance of Al in the NiO{sub 2}-layers hinders Li{sup +} dissolution (Li<(1-y)/3). In addition, with increasing Al content there is a strong cationic mixing between the layers. High-frequency EPR of Ni{sup 3+} indicates that the structural interaction of LiAl{sub y}Ni{sub 1-y}O{sub 2} with Li[Li{sub 1/3}Ni{sub 2/3}]O{sub 2} proceeds via the formation of domains comprising different amount of Ni{sup 3+} ions. The use of Li{sub 1.08}Al{sub 0.09}Ni{sub 0.83}O{sub 2} as a cathode material in a lithium ion cells displays a first irreversible Li extraction at 4.8V, after which a reversible lithium insertion/extraction between 3.0 and 4.5V is observed on further cycling.« less

Synthesis and novel luminescence properties of one-dimension BaMoO{sub 4}:Ln{sup 3+} nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuping; Li, Mingxia; Pan, Kai

2015-12-15

Highlights: • String BaMoO{sub 4}:Ln{sup 3+} nanobeans were prepared by a hydrothermal method. • The Decay dynamics were performed to study the photoluminescence of the BaMoO{sub 4}:Eu{sup 3+} nanobeans. • For BaMoO{sub 4}:Er{sup 3+}/Eu{sup 3+}, the {sup 2}P{sub 3/2} → {sup 4}I{sub 11/2} and {sup 2}H{sub 11/2}/{sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} transitions were observed. - Abstract: String BaMoO{sub 4}:Ln{sup 3+} (Ln = Eu, Tb, Er, and Gd) nanobeans were prepared by a hydrothermal method. The samples were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscope, and Raman spectrometer. Under direct excitation in themore » charge transfer absorption band, concentration quenching phenomenon occurs and decay dynamics were performed to study the photoluminescence of the string BaMoO{sub 4}:Eu{sup 3+} nanobeans. In the emission spectra of BaMoO{sub 4}:Er{sup 3+}/Eu{sup 3+} under 274 nm excitation, the {sup 2}P{sub 3/2} → {sup 4}I{sub 11/2}, {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, and {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} transitions from Er{sup 3+} ions were observed for the first time. In addition, the photoluminescence properties of BaMoO{sub 4}:Tb{sup 3+}/Eu{sup 3+} and BaMoO{sub 4}:Gd{sup 3+}/Eu{sup 3+} were also investigated.« less

Electrolytes For Electrooptic Devices Comprising Ionic Liqu Ids

DOEpatents

Warner, Benjamin P.; McCleskey, T. Mark; Agrawal, Anoop; Cronin, John P.; Tonazzi, Juan C. L.; Burrell, Anthony K.

2005-02-08

Electrolyte solutions of soluble bifunctional redox dyes in molten salt solvent may be used to prepare electrooptic devices with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3 SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3 SO.sub.2).sub.2 N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3 CF.sub.2 SO.sub.2).sub.2 N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3 SO.sub.2).sub.3 C.sup.-).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uemura, Kazuhiro, E-mail: k_uemura@gifu-u.ac.j; Onishi, Fumiaki; Yamasaki, Yukari

NO{sub 2} containing dicarboxylate bridging ligands, nitroterephthalate (bdc-NO{sub 2}) and 2,5-dinitroterephthalate (bdc-(NO{sub 2}){sub 2}), afford porous coordination polymers, {l_brace}[Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)].solvents{r_brace}{sub n} (2 contains solvents) and {l_brace}[Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)].solvents{r_brace}{sub n} (3 contains solvents). Both compounds form jungle-gym-type regularities, where a 2D square grid composed of dinuclear Zn{sub 2} units and dicarboxylate ligands is bridged by dabco molecules to extend the 2D layers into a 3D structure. In 2 contains solvents and 3 contains solvents, a rectangle pore surrounded by eight Zn{sub 2} corners contains two and four NO{sub 2} moieties, respectively. Thermal gravimetry (TG) and X-ray powdermore » diffraction (XRPD) measurements reveal that both compounds maintain the frameworks regularities without guest molecules and with solvents such as MeOH, EtOH, i-PrOH, and Me{sub 2}CO. Adsorption measurements reveal that dried 2 and 3 adsorb H{sub 2}O molecules to be {l_brace}[Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)].4H{sub 2}O{r_brace}{sub n} (2 contains 4H{sub 2}O) and {l_brace}[Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)].6H{sub 2}O{r_brace}{sub n} (3 contains 6H{sub 2}O), showing the pore hydrophilicity enhancement caused by NO{sub 2} group introduction. - Graphical abstract: Two hydrophilic porous coordination polymers, [Zn{sub 2}(bdc-NO{sub 2}){sub 2}(dabco)]{sub n} (2, bdc-NO{sub 2}=nitroterephthalate, dabco=1,4-diazabicyclo[2.2.2]octane) and [Zn{sub 2}(bdc-(NO{sub 2}){sub 2}){sub 2}(dabco)]{sub n} (3, bdc-(NO{sub 2}){sub 2}=2,5-dinitroterephthalate), have been synthesized and characterized by single X-ray analyses, thermal gravimetry, and adsorption measurements.« less

Amine templating effect absent in uranyl sulfates synthesized with 1,4-n-butyldiamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jouffret, Laurent J., E-mail: ljouffret@nd.edu; Wylie, Ernest M.; Burns, Peter C.

2013-01-15

Two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3), were synthesized and their crystal structures determined. NDUS2 was obtained in highly acidic media heat-treated at 373 K and subsequently maintained at 278 K until crystals formed after two months. NDUS3 results from the degradation of NDUS2 over the course of a few days. NDUS2 and NDUS3 crystallize in the monoclinic space group P2{sub 1}/n, a=10.9075(4) A, b=10.4513(4) A, c=17.7881(7) A, {beta}=97.908(2) Degree-Sign , V=2008.52(13) A{sup 3}, Z=4, at 140 K and a=8.8570(4) A,more » b=7.3299(3) A, c=20.4260(9) A, {beta}=95.140(2) Degree-Sign , V=1320.74(10) A{sup 3}, Z=4, at 140 K, respectively. The compounds contain interlayer 1,4-n-butyldiammonium cations that charge-balance the anionic structural units. - Graphical abstract: Amine templating effect absent in uranyl sulfates synthesized with 1,4-diaminobutane, as shown by the synthesis of two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3). Highlights: Black-Right-Pointing-Pointer Two layered uranyl sulfates were synthesized. Black-Right-Pointing-Pointer Amine molecules are located in the interlayers of the compounds. Black-Right-Pointing-Pointer No templating effect of the amine was observed. Black-Right-Pointing-Pointer Amine molecules are only charge balancing cations in the structures.« less

Synthesis, structures, and phase transitions of barium bismuth iridium oxide perovskites Ba{sub 2}BiIrO{sub 6} and Ba{sub 3}BiIr{sub 2}O{sub 9}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ling, Chris D., E-mail: c.ling@chem.usyd.edu.a; Bragg Institute, ANSTO, PMB 1, Menai 2234; Kennedy, Brendan J.

The Ba-Bi-Ir-O system is found to contain two distinct perovskite-type phases: a rock-salt ordered double perovskite Ba{sub 2}BiIrO{sub 6}; and a 6H-type hexagonal perovskite Ba{sub 3}BiIr{sub 2}O{sub 9}. Ba{sub 2}BiIrO{sub 6} undergoes a series of symmetry-lowering phase transitions on cooling Fm3-barm->R3-barc->12/m(C2/m)->I1-bar(P1-bar), all of which are second order except the rhombohedral->monoclinic one, which is first order. The monoclinic phase is only observed in a 2-phase rhombohedral+monoclinic regime. The transition and 2-phase region lie very close to 300 K, making the room-temperature X-ray diffraction patterns extremely complex and potentially explaining why Ba{sub 2}BiIrO{sub 6} had not previously been identified and reported. Amore » solid solution Ba{sub 2}Bi{sub 1+x}Ir{sub 1-x}O{sub 6}, analogous to Ba{sub 2}Bi{sub 1+x}Ru{sub 1-x}O{sub 6}, 0<=x<=2/3, was not observed. The 6H-type phase Ba{sub 3}BiIr{sub 2}O{sub 9} undergoes a clean second-order phase transition P6{sub 3}/mmc->C2/c at 750 K, unlike 6H-type Ba{sub 3}LaIr{sub 2}O{sub 9}, the P6{sub 3}/mmc structure of which is highly strained below {approx}750 K but fails to distort coherently to the monoclinic phase. - Graphical abstract: Structure of Ba{sub 3}BiIr{sub 2}O{sub 9} at 300 K. BiO{sub 6} octahedra are purple, IrO{sub 6} octahedra are gold, and Ba atoms are green. Thermal ellipsoids at 90% probability.« less

Preparation of LTCC materials with adjustable permittivity based on BaO–B{sub 2}O{sub 3}–SiO{sub 2}/BaTiO{sub 3} system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Kai-tuo; He, Yan; Liang, Zhong-yuan

2015-05-15

Graphical abstract: The dielectric constant (ϵ) of the sintered BaO–B{sub 2}O{sub 3}–SiO{sub 2}/BaTiO{sub 3} glass/ceramics (the sintered samples with line shrinkage of 10%) changed from 5 to 30 and the dielectric losses (tanδ) was lower than 0.05 at 100 MHz with the amount of BaTiO{sub 3} additive increment from 60 wt% to 90 wt% fraction. - Highlights: • The ϵ of BaO–B{sub 2}O{sub 3}–SiO{sub 2} glass can be adjusted from 5 to 30 by adding BaTiO{sub 3}. • The influence factors on dielectric are the secondary phase and microstructure. • BaO–B{sub 2}O{sub 3}–SiO{sub 2}/BaTiO{sub 3} system can fabricate LTCC whenmore » BaTiO{sub 3} located in 60–80 wt%. - Abstract: This paper studied the preparation and characterization of LTCC (low temperature co-fired ceramics) materials based on BaO–B{sub 2}O{sub 3}–SiO{sub 2}/BaTiO{sub 3} glass–ceramics, where the sintering temperature was about 900 °C and dielectric constant was effectively adjustable from 5 to 30 by changing the BaTiO{sub 3} fraction from 60 wt% to 90 wt%. X-ray diffractometer (XRD), scanning electron microscopy (SEM) were used to examine the effect of different amounts additive on the dielectric properties of this LTCC system and the crystal structure change. The results indicated that BaTiO{sub 3} can be used as a dielectric additive aim to adjust the permittivity of BaO–B{sub 2}O{sub 3}–SiO{sub 2} glass, which the main influence factors on dielectric are the contents of the secondary phase, the BaTiO{sub 3} phase fraction and the porous structure of the sintered body. Therefore, the microstructure and dielectric property of BaO–B{sub 2}O{sub 3}–SiO{sub 2}/BaTiO{sub 3} glass–ceramics composites could be controlled by adjusting the content of BaTiO{sub 3} additive.« less

A first-principles study on the B{sub 5}O{sub 5}{sup +/0} and B{sub 5}O{sub 5}{sup −} clusters: The boron oxide analogs of C{sub 6}H{sub 5}{sup +/0} and CH{sub 3}Cl

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Wen-Juan; You, Xue-Rui; Ou, Ting

2015-08-14

The concept of boronyl (BO) and the BO/H isolobal analogy build an interesting structural link between boron oxide clusters and hydrocarbons. Based upon global-minimum searches and first-principles electronic structural calculations, we present here the perfectly planar C{sub 2v} B{sub 5}O{sub 5}{sup +} (1, {sup 1}A{sub 1}), C{sub 2v} B{sub 5}O{sub 5} (2, {sup 2}A{sub 1}), and tetrahedral C{sub s} B{sub 5}O{sub 5}{sup −} (3, {sup 1}A′) clusters, which are the global minima of the systems. Structural and molecular orbital analyses indicate that C{sub 2v} B{sub 5}O{sub 5}{sup +} (1) [B{sub 3}O{sub 3}(BO){sub 2}{sup +}] and C{sub 2v} B{sub 5}O{sub 5}more » (2) [B{sub 3}O{sub 3}(BO){sub 2}] feature an aromatic six-membered boroxol (B{sub 3}O{sub 3}) ring as the core with two equivalent boronyl terminals, similar to the recently reported boronyl boroxine D{sub 3h} B{sub 6}O{sub 6} [B{sub 3}O{sub 3}(BO){sub 3}]; whereas C{sub s} B{sub 5}O{sub 5}{sup −} (3) [B(BO){sub 3}(OBO){sup −}] is characterized with a tetrahedral B{sup −} center, terminated with three BO groups and one OBO unit, similar to the previously predicted boronyl methane T{sub d} B{sub 5}O{sub 4}{sup −} [B(BO){sub 4}{sup −}]. Alternatively, the 1–3 clusters can be viewed as the boron oxide analogs of phenyl cation C{sub 6}H{sub 5}{sup +}, phenyl radical C{sub 6}H{sub 5}, and chloromethane CH{sub 3}Cl, respectively. Chemical bonding analyses also reveal a dual three-center four-electron (3c-4e) π hyperbond in C{sub s} B{sub 5}O{sub 5}{sup −} (3). The infrared absorption spectra of B{sub 5}O{sub 5}{sup +} (1), B{sub 5}O{sub 5} (2), and B{sub 5}O{sub 5}{sup −} (3) and anion photoelectron spectrum of B{sub 5}O{sub 5}{sup −} (3) are predicted to facilitate their forthcoming experimental characterizations. The present work completes the B{sub n}O{sub n}{sup +/0/−} series for n = 1–6 and enriches the analogous relationship between boron oxides and hydrocarbons.« less

The formation of crystals in glasses containing rare earth oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fadzil, Syazwani Mohd; Hrma, Pavel; Crum, Jarrod

Korean spent nuclear fuel will reach the capacity of the available temporary storage by 2016. Pyroprocessing and direct disposal seems to be an alternative way to manage and reuse spent nuclear fuel while avoiding the wet reprocessing technology. Pyroprocessing produces several wastes streams, including metals, salts, and rare earths, which must be converted into stabilized form. A suitable form for rare earth immobilization is borosilicate glass. The borosilicate glass form exhibits excellent durability, allows a high waste loading, and is easy to process. In this work, we combined the rare earths waste of composition (in wt%) 39.2Nd{sub 2}O{sub 3}–22.7CeO{sub 2}–11.7La{submore » 2}O{sub 3}–10.9PrO{sub 2}–1.3Eu{sub 2}O{sub 3}–1.3Gd{sub 2}O{sub 3}–8.1Sm{sub 2}O{sub 3}–4.8Y{sub 2}O{sub 3} with a baseline glass of composition 60.2SiO{sub 2}–16.0B{sub 2}O{sub 3}–12.6Na{sub 2}O–3.8Al{sub 2}O{sub 3}–5.7CaO–1.7ZrO{sub 2}. Crystallization in waste glasses occurs as the waste loading increases. It may produce complicate glass processing and affect the product quality. To study crystal formation, we initially made glasses containing 5%, 10% and 15% of La{sub 2}O{sub 3} and then glasses with 5%, 10% and 15% of the complete rare earth mix. Samples were heat-treated for 24 hours at temperatures 800°C to 1150°C in 50°C increments. Quenched samples were analyzed using an optical microscope, scanning electron microscope with energy dispersive spectroscopy, and x-ray diffraction. Stillwellite (LaBSiO{sub 5}) and oxyapatite (Ca{sub 2}La{sub 8}Si{sub 6}O{sub 26}) were found in glasses containing La{sub 2}O{sub 3}, while oxyapatite (Ca{sub 2}La{sub 8}Si{sub 6}O{sub 26} and NaNd{sub 9}Si{sub 6}O{sub 26}) precipitated in glasses with additions of mixed rare earths. The liquidus temperature (T{sub L}) of the glasses containing 5%, 10% and 15% La{sub 2}O{sub 3} were 800°C, 959°C and 986°C, respectively; while T{sub L} was 825°C, 1059°C and 1267°C for glasses with 5%, 10% and 15% addition of mixed rare earth oxides. The component coefficients T{sub B2O3}, T{sub SiO2}, T{sub CaO}, and T{sub RE2O3} were also evaluated using a recently published study.« less

Tuning the reactivity of Al/Fe{sub 2}O{sub 3} nanoenergetic materials via an approach combining soft template self-assembly with sol–gel process process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Tianfu; Wang, Zhen; Li, Guoping

2015-10-15

A bottom-up approach combining soft template self-assembly with sol–gel process, was adopted to prepare the assembled Al/Fe{sub 2}O{sub 3} nanoenergetic materials, assembly-Al/Fe{sub 2}O{sub 3} sample. The other two unassembled Al/Fe{sub 2}O{sub 3}a nanoenergetic materials, sol–gel–Al/Fe{sub 2}O{sub 3} sample and mixing-Al/Fe{sub 2}O{sub 3} sample, were prepared by sol–gel method and physical mixing method respectively. The assembly process within the preparation of the assembly-Al/Fe{sub 2}O{sub 3} sample was analyzed through the changes in the average hydrodynamic diameters of the particles and the micelles in solution. SEM, EDS and TEM tests were performed to demonstrate a significant improvement regarding to dispersity and arrangementsmore » of the Al and Fe{sub 2}O{sub 3} particles in the assembled samples, compared to that of the unassembled Al/Fe{sub 2}O{sub 3} samples. DSC test was employed to characterize the reactivity of the samples. The heat release of the assembled Al/Fe{sub 2}O{sub 3} sample was 2088 J/g, about 400 and 990 J/g more than that of the sol–gel–Al/Fe{sub 2}O{sub 3} sample and mixing-Al/Fe{sub 2}O{sub 3} sample, respectively. - Graphical abstract: Modified aluminum (Al) nanoparticles with hydrophobic surface assembled into the Brij S10 micelle in Fe(III) sol, then the well dispersed system was transformed into Al/Fe{sub 2}O{sub 3} nanoenergetic materials with high reactivity. - Highlights: • An approach combining soft template self-assembly with sol–gel process was adopted. • The aggregation of Al nanoparticles in the final product was reduced significantly. • The reactivity of Al/Fe{sub 2}O{sub 3} nanoenergetic materials was improved to a large extent.« less

Syntheses, structures and magnetisms of copper(II)–azido coordination compounds with p-substituted benzoates as coligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Cuiyu; Yu, Nan; Bu, Huaitian

2016-01-15

Employing p-substituted benzoates with electron-withdrawing/electron-donating groups as coligands, four copper–azido compounds, [Cu{sub 1.5}(p-NO{sub 2}-benzoate)(N{sub 3}){sub 2}(H{sub 2}O)]{sub n} (1), [Cu(p-NO{sub 2}-benzoate)(N{sub 3})(H{sub 2}O)]{sub n} (2), [Cu(p-OH-benzoate)(N{sub 3})(H{sub 2}O)]{sub n}·nH{sub 2}O (3) and [Cu(p-CH{sub 3}-benzoate)(N{sub 3})]{sub n} (4), have been hydrothermally synthesized and structurally charactierized by single crystal X-ray diffraction. Structural analysis reveals that all compounds are composed of mixed EO-azido and syn–syn carboxylato-bridged Cu-N{sub 3}/COO chains. Compound 1 features the alternating triple-bridged (μ-EO-N{sub 3})(μ-COO)(μ-H{sub 2}O) and the double-bridged (EO-N{sub 3}){sub 2} modes. Both of 2 and 3 display the triple-bridged fashion (μ-EO-N{sub 3})(μ-COO)(μ-H{sub 2}O). While 4 exhibits the double-bridged modemore » (μ-EO-N{sub 3})(μ-COO). Based on hydrogen-bonding interactions, Cu–N{sub 3}/COO chains in 1–3 are further connected to form 3D supramolecular frameworks. As for compound 4, there are not hydrogen-bonding interactions when the p-CH{sub 3} substituted benzoate is employed as coligand. These compounds show intrachain ferromagnetic performance and different bulk properties. Remarkably, 1 features metamagnetism from antiferromagnetism to ferrimagnetism, while 3 reveals long-range ferromagnetic ordering between Cu(II) ions. Magneto-structural correlation has been also investigated. - Graphical abstract: With p-substituted benzoates as coligands, copper–azido compounds were isolated and structrually, magnetically characterized. Magneto-structural correlation has been investigated in detail.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Zhi-Hao; Zhao, Yue; Chen, Shui-Sheng

Seven new coordination polymers [Zn(H{sub 2}L)(mbdc)] (1), [Zn(H{sub 3}L)(btc)] (2), [Zn(H{sub 2}L)(Hbtc)] (3), [Zn(H{sub 2}L)(Hbtc)]·H{sub 2}O (4), [Zn{sub 2}(H{sub 2}L)(btc)(μ{sub 2}-OH)] (5), [Cd(H{sub 2}L)(mbdc)] (6) and [Cd{sub 3}(H{sub 2}L){sub 2}(btc){sub 2}(H{sub 2}O)]·5H{sub 2}O (7) were synthesized by reactions of the corresponding metal salt with rigid ligand 1,3-di(1H-imidazol-4-yl)benzene (H{sub 2}L) and different carboxylic acids of 1,3-benzenedicarboxylic acid (H{sub 2}mbdc) and benzene-1,3,5-tricarboxylic acid (H{sub 3}btc), respectively. The results of X-ray crystallographic analysis indicate that complex 1 is 1D chain while 2 is a (3,3)-connected 2D network with Point (Schläfli) symbol of (4,8{sup 2}). Complexes 3 and 6 are 2D networks, 4 ismore » a 3-fold interpenetrating 3D framework with Point (Schläfli) symbol of (6{sup 5},8) and 5 is a (3,8)-connected 2D network with Point (Schläfli) symbol of (3,4{sup 2}){sub 2}(3{sup 4},4{sup 6},5{sup 6},6{sup 8},7{sup 3},8), while 7 is a (3,10)-connected 3D net with Schläfli symbol of (3,4,5){sub 2}(3{sup 4},4{sup 8},5{sup 18},6{sup 12},7{sup 2},8). The thermal stability and photoluminescence of the complexes were investigated. Furthermore, DFT calculations were performed for 2–4 to discuss the temperature controlled self-assembly of the complexes. - Graphical abstract: Seven new coordination polymers with multicarboxylate and rigid ditopic 4-imidazole containing ligands have been obtained and found to show different structures and topologies. - Highlights: • Metal complexes with diverse structures of 1D chain, 2D network and 3D framework. • Mixed ligands of 1,3-di(1H-imidazol-4-yl)benzene and multicarboxylate. • Photoluminescence property.« less

2:1 Charge disproportionation in perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Haichuan; Hosaka, Yoshiteru; Seki, Hayato

La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. The compound crystallizes in a √2a×2a×√2a perovskite cell in which the La and Ca ions at the A site are disordered. At 217 K the Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and this disproportionation is accompanied by transitions in magnetic and transport properties. The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. The local electronic and magnetic environments of Fe in La{sub 1/3}Ca{sub 2/3}FeO{submore » 3} are quite similar to those of Fe in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}, and the 2:1 charge disproportionation pattern of Fe{sup 3+} and Fe{sup 5+} in La{sub 1/3}Ca{sub 2/3}FeO{sub 3} is also the same as that in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}. - Graphical abstract: The perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and the charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. - Highlights: • La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. • At 217 K the Fe{sup 3.67+} shows charge disproportionation (CD) to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1. • The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. • The disproportionation is accompanied by transitions in magnetic and transport properties.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danilina, L.I.; Iretskii, A.V.; Kukushkin, Yu.N.

The phosphoniodithiocarboxylato complexes (RhCOA(PPh/sub 3/)(S/sub 2/CPPh/sub 3/))/sup +/ have been obtained by reacting (RhCOA(PPh/sub 3/)/sub 2/)Y (Y = ClO/sub 4//sup -/, NO/sub 3//sup -/) and (Rh(CO)/sub 2/ACl) with CS/sub 2/ in the presence of PPh/sub 3/. In solution they readily eliminate CS/sub 2/ and are converted into (RhCOA(PPh/sub 3/)/sub 2/)/sup +/ (A = py, ..gamma..-pic). Analogous reactions also take place in the case of the bridged complexes with A = 4,4'bipy, the bridged structure of the complexes formed being maintained.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Qing-Song; Feng, Yan; Zhang, Guo-Ying, E-mail: gyzhangtj@yahoo.cn

Graphical abstract: - Highlights: • α-Fe{sub 2}O{sub 3}/Bi{sub 2}WO{sub 6} heterostructures were facilely fabricated by an impregnation method. • The Bi{sub 2}WO{sub 6} matrix was modified by α-Fe{sub 2}O{sub 3} nanoparticles of 10–20 nm on the surface. • The visible-light absorption region of the composite was effectively red-shifted. • The composite exhibited enhanced photocatalytic activity to RhB below Fe-0.4%. • The band gap coupling effect between α-Fe{sub 2}O{sub 3} and Bi{sub 2}WO{sub 6} was interpreted. - Abstract: α-Fe{sub 2}O{sub 3} modified Bi{sub 2}WO{sub 6} mesostructures were facilely prepared by an impregnation method. The characterizations of phase structure, morphology, microstructure, UV–vismore » absorption, photoluminescence, BET and solar simulated photocatalytic behavior were systematically conducted. The Fe{sub 2}O{sub 3}/Bi{sub 2}WO{sub 6} heterostructure with a Fe mass percentage in 0.05–0.2% presented obviously enhanced photocatalytic activity for the degradation of Rhodamine B than pristine Bi{sub 2}WO{sub 6}. In particular, the apparent reaction rate constant with Fe-0.1% was 2.24-folds of that of pure Bi{sub 2}WO{sub 6}. UV–vis diffuse reflectance spectra showed that the modification of α-Fe{sub 2}O{sub 3} broadened the visible light absorption of Bi{sub 2}WO{sub 6}. The decreased photoluminescence indicated an effective suppression of the recombination of electron–hole pairs at Fe{sub 2}O{sub 3}/Bi{sub 2}WO{sub 6} interface. The band-gap coupling effect between Fe{sub 2}O{sub 3} and Bi{sub 2}WO{sub 6} was interpreted via comparison of relative valence and conductance potentials, which confirmed an irreversible flow of electrons and holes in the interface of Fe{sub 2}O{sub 3}/Bi{sub 2}WO{sub 6}. Moreover, the composite showed excellent circulation stability, suggesting potential application in dealing with environmental pollutions.« less

Structural, magnetic and optical properties of Y bFe{sub 2}O{sub 4} films deposited by spin coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Tatsuo, E-mail: tfujii@cc.okayama-u.ac.jp; Okamura, Naoya; Hashimoto, Hideki

Rare-earth iron oxides (RFe{sub 2}O{sub 4}) have attracting attention as new electronic device materials because of their numerous functionalities, such as electronic ferroelectricity, ferrimagnetism, and high infrared absorption. In this paper, nearly monophasic Y bFe{sub 2}O{sub 4} films were prepared on α-Al{sub 2}O{sub 3}(001) substrates by the spin coating method using an aqueous-based Y bFe{sub 2}O{sub 4} solution. The solution was composed of a stoichiometric ratio of Y b(CH{sub 3}COO){sub 3} and Fe(NO{sub 3}){sub 3} with excess chelating agents. After heat treatment above 800 °C, well-crystallized and highly (001)-oriented Y bFe{sub 2}O{sub 4} started to epitaxially form on the substrate undermore » controlled oxygen partial pressure with H{sub 2}/CO{sub 2} gas mixtures. X-ray pole figure analysis confirmed the following epitaxial relationship: Y bFe{sub 2}O{sub 4}[100](001)//α-Al{sub 2}O{sub 3}[100](001). Moreover formation of an Fe{sub 3}O{sub 4} interracial layer between Y bFe{sub 2}O{sub 4} and α-Al{sub 2}O{sub 3} was detected by high-resolution transmission electron microscopy. Presence of the Fe{sub 3}O{sub 4} interracial layer seemed to release the lattice misfit with the substrate. The Fe{sup 2+}/Fe{sup 3+} ratio in the obtained Y bFe{sub 2}O{sub 4} films was nearly stoichiometric and the indirect bandgap assigned to Fe{sup 2+} → Fe{sup 3+} charge transfer excitation was found to be ∼0.4 eV by optical spectroscopy. A clear magnetic transition from the paramagnetic state to the ferrimagnetic state occurred at ∼230 K.« less

Reaction path in the formation of titanium diboride by a magnesium thermite process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundaram, V.; Logan, K.V.; Speyer, R.F.

1995-12-31

TiB{sub 2} was formed by a thermite reaction amongst Mg, amorphous B{sub 2}O{sub 3} and TiO{sub 2} powders. Mixtures consisting of 2Mg-TiO{sub 2}, 3Mg-B{sub 2}O{sub 3} and 5Mg-TiO{sub 2}-B{sub 2}O{sub 3} were heat treated using DTA and separately via ignition with a nichrome wire; product phases were identified using XRD. MgO and Ti were products from the first mixture reacted in argon, whereas an incomplete transformation forming Mg{sub 3}TiO{sub 4} occurred in air. For the second mixture, a reaction forming Mg{sub 3}B{sub 2}O{sup 6} occurred in air, but no reaction occurred in argon due to deficiency of oxygen. Minor amountsmore » Of Mg{sub 3}B{sub 2}O{sub 6} and Mg{sub 2}TiO{sub 4} were detected in addition to the predicted product phases of MgO and TiB{sub 2} for the third mixture ignited both in air and argon. Based on available evidence, a path for this reaction was deduced; Mg particles in contact with TiO{sub 2} reacted to form Ti, which in turn reacted with B{sub 2}O{sub 3} to form TiB{sub 2}. TiB{sub 2} product particles from the reaction in argon had a more faceted appearance than those formed during the reaction in air. This was interpreted to be the result of glassy B{sub 2}O{sub 3} surface layer formation on TiB{sub 2} particles in air.« less

On the synthesis, characterization and magnetic properties of two new phases discovered in the PbO–Fe{sub 2}O{sub 3}–P{sub 2}O{sub 5} system

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Hafid, Hassan; Velázquez, Matias, E-mail: matias.velazquez@icmcb-bordeaux.cnrs.fr; Pérez, Olivier

2013-06-15

The PbFe{sub 3}O(PO{sub 4}){sub 3} powder compound was studied by means of X-ray diffraction (XRD) from 300 to 6 K, electron-probe microanalysis (EPMA) coupled with wavelength dispersion spectroscopy (WDS), calorimetric (DSC and specific heat) and magnetic properties measurements. Magnetization, magnetic susceptibility and specific heat measurements carried out on PbFe{sub 3}O(PO{sub 4}){sub 3} powders firmly establish a series of three ferromagnetic (FM)-like second order phase transitions spanned over the 32–8 K temperature range. Discrepancies between magnetization and specific heat data obtained in PbFe{sub 3}O(PO{sub 4}){sub 3} powders and single crystals are highlighted. A first extraction of the critical exponents (β,γ,δ) wasmore » performed by ac magnetic susceptibility in both PbFe{sub 3}O(PO{sub 4}){sub 3} powders and single crystals and the values were found to be consistent with mean-field theory. Further exploration of the PbO–Fe{sub 2}O{sub 3}–P{sub 2}O{sub 5} system led to the discovery of a new langbeinite phase, Pb{sub 1.5}Fe{sub 2}(PO{sub 4}){sub 3}, the crystal structure of which was solved by room temperature single crystal XRD (P2{sub 1}3, Z=4, a=9.7831(2) Å). This phase does not undergo any structural phase transition down to 6 K nor any kind of long range ordering down to 2 K. - Graphical abstract: Three ferromagnetic-like phase transitions discovered in the new compound PbFe{sub 3}O(PO{sub 4}){sub 3} by specific heat and ZFC/FC magnetization measurements. - Highlights: • Three FM-like second order phase transitions in PbFe{sub 3}O(PO{sub 4}){sub 3} powders. • Critical exponents (β,γ,δ) in PbFe{sub 3}O(PO{sub 4}){sub 3} consistent with mean-field behavior. • Discovery of a new langbeinite phase, Pb{sub 1.5}Fe{sub 2}(PO{sub 4}){sub 3}.« less

Estimation of Hamaker constants of ceramic materials from optical data using Lifshitz theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergstroem, L.; Meurk, A.; Rowcliffe, D.J.

1996-02-01

The Hamaker constants of eight different ceramic materials, 6H-SiC, tetragonal, partially stabilized ZrO{sub 2} (3% Y{sub 2}O{sub 3}), {beta}-Si{sub 3}N{sub 4}, {alpha}-Al{sub 2}O{sub 3}, Y{sub 2}O{sub 3}, sapphire (single-crystal {alpha}-Al{sub 2}O{sub 3}), MgO, MgAl{sub 2}O{sub 4}, and fused silica, across air, water, and n-dodecane at room temperature and across silica at 2,000 K have been calculated from optical data using the Lifshitz theory. Spectroscopic ellipsometry was used to measure the photon energy dependence of the refractive index, n, and the extinction coefficient, k, in the visible and near-UV range on several important ceramic materials. This relatively simple, nondestructive technique hasmore » proved to yield reliable optical data on sintered, polycrystalline materials such as Si{sub 3}N{sub 4}, SiC, ZrO{sub 2}, Al{sub 2}O{sub 3}, and ZnO. For the other materials, Y{sub 2}O{sub 3}, sapphire, MgO, MgAl{sub 2}O{sub 4}, and fused silica, optical data from the literature were used to calculate the Hamaker constants. The calculated Hamaker constants were estimated to be accurate within {+-} 10%.« less

Characterisation of iron inclusion during the formation of calcium sulfoaluminate phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Idrissi, M., E-mail: mari_idrissi@yahoo.f; Diouri, A.; Damidot, D.

The iron distribution among the sulfoaluminate clinker phases and its ability to enter the calcium sulfoaluminate lattice in solid solution can have a significant influence on manufacturing process and reactivity of calcium sulfoaluminate (CSA) cements. X-ray diffraction (XRD) analysis, Moessbauer spectroscopy, scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis system (EDAX) and infrared spectroscopy were used to identify the mineralogical conditions of iron inclusion during the formation of calcium sulfoaluminate (C{sub 4}A{sub 3}S) phase from different mixtures in the CaO-Al{sub 2}O{sub 3}-Fe{sub 2}O{sub 3}-SO{sub 3} system. The mixtures, heated in a laboratory electric oven, contained stoichiometric amountsmore » of reagent grade CaCO{sub 3}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3} and CaSO{sub 4.2}H{sub 2}O for the synthesis of Ca{sub 4}Al{sub (6-2x)}Fe{sub 2x}SO{sub 16}, where x, comprised between 0 and 3, is the mole number of Al{sub 2}O{sub 3} substituted by Fe{sub 2}O{sub 3}. With x increasing from 0 to 1.5, both the iron content of C{sub 4}A{sub 3}S phase and the amounts of side components such as C{sub 2}F and CS increased. For x values included in the range of 1.5-3.0, at temperatures higher than 1200 {sup o}C, melting phenomena were observed and, instead of the C{sub 4}A{sub 3}S solid solution, ferritic phases and anhydrite were formed.« less

Anion exchange polymer electrolytes

DOEpatents

Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo

2013-07-23

Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

A magnesium-carboxylate framework showing luminescent sensing for CS{sub 2} and nitroaromatic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Zhao-Feng; Tan, Bin; University of Chinese Academy of Sciences, Beijing 100049

2015-03-15

A magnesium metal-organic framework compound, namely [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid, DMF=N,N′-dimethylformamide), has been synthesized in solvothermal conditions and structurally characterized. It features a three-dimensionally anionic framework with aligned channels parallel to the b-axis. Luminescent studies indicated that it showed significant luminescence quenching for carbon disulfide (CS{sub 2}) and nitrobenzene after being activated, at a content of only 3.0 and 0.1 vol% in DMF, respectively. In addition, the activated sample showed sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L. - Graphical abstract: Presentedmore » is a microporous 3D Mg-MOF, namely, [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid) showing significant luminescence quenching for carbon disulfide and nitrobenzene. - Highlights: • A microporous 3D metal-organic framework based on Mg. • The compound shows significant luminescence quenching for CS{sub 2} and nitrobenzene after activated. • The compound shows sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L.« less

Experimental and theoretical investigations of the polar intermetallics SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stegemann, Frank; Benndorf, Christopher; Touzani, Rachid St.

SrPt{sub 3}Al{sub 2}, a CaCu{sub 5} relative (P6/mmm; a = 566.29(3), c = 389.39(3) pm; wR{sub 2} = 0.0202, 121 F{sup 2} values, 9 parameters), and Sr{sub 2}Pd{sub 2}Al, isostructural to Ca{sub 2}Pt{sub 2}Ge (Fdd2; a = 1041.45(5), b = 1558.24(7), c = 604.37(3) pm; wR{sub 2} = 0.0291, 844 F{sup 2} values, 25 parameters) have been prepared from the elements. The crystal structures have been investigated by single crystal X-ray diffraction. Structural relaxation confirmed the electronic stability of SrPt{sub 3}Al{sub 2}, while orthorhombic Sr{sub 2}Pd{sub 2}Al might be a metastable polymorph as it is energetically competitive to its monoclinicmore » variant. Both compounds are predicted to be metallic conductors as their density-of-states (DOS) are non-zero at the Fermi level. COHP bonding analysis coupled with Bader effective charge analysis suggest that the title compounds are polar intermetallic phases in which strong Pt–Al and Pd–Al covalent bonds are present, while a significant electron transfer from Sr atoms to the [Pt{sub 3}Al{sub 2}]{sup δ–} or [Pd{sub 2}Al]{sup δ–} network is found. - Graphical abstract: Chains of Pd atoms in the crystal structure of Sr{sub 2}Pd{sub 2}Al get connected by Al atoms in the shape of a distorted tetrahedra. The band structure calculations confirm weak Pd–Pd interactions. - Highlights: • SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al discovered and crystallographically investigated. • DFT predicts the here reported orthorhombic Sr{sub 2}Pd{sub 2}Al to be competitive in energy to the presently unknown monoclinic Sr{sub 2}Pd{sub 2}Al. • Bader charge analysis indicates SrPt{sub 3}Al{sub 2} and Sr{sub 2}Pd{sub 2}Al are polar intermetallics.« less

Preparation and characterization of Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2} composites and its functionally graded materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo Yongming; Li Shuqin; Chen Jian

2003-01-01

Alumina/titanium silicon carbide (Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2}) composites and its functionally graded materials (FGMs) were fabricated by a powder metallurgy processes and their microstructure and properties were investigated, respectively. The experimental results showed that the Vickers hardness of composites decreased with increasing Ti{sub 3}SiC{sub 2} content while the fracture toughness and strength exhibited the opposite trend. Minimum Vickers hardness (4 GPa), maximum strength (598 MPa) and maximum toughness (11.24 MPa m{sup 1/2}) were reached in the pure Ti{sub 3}SiC{sub 2} material. Strength and hardness of FGMs were evaluated. Observation using an scanning electron microscope (SEM) indicated that the presencemore » of Ti{sub 3}SiC{sub 2} of FGMs inhibited the growth of alumina grains through a pinning mechanism. The study shows that the combination of the layered Ti{sub 3}SiC{sub 2} structure and the fine alumina grains can result in a Al{sub 2}O{sub 3}-Ti{sub 3}SiC{sub 2} composites possessing a high toughness and low Vickers hardness without a sacrifice in the strength.« less

Crystal structures of two new low-symmetry calcium-deficient analogs of eudialyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rastsvetaeva, R. K.; Rozenberg, K. A.; Pekov, I. V.

2006-03-15

The crystal structures of two new low-symmetry (sp. gr. R3) representatives of the eudialyte group from Mont Saint-Hilaire (Quebec, Canada) and the Lovozero massif (Kola Peninsula, Russia) were studied by single-crystal X-ray diffraction analysis and refined to R = 0.068 and 0.054 using 2899 reflections with F > 5{sigma}(F) and 2927 reflections with F > 3{sigma}(F), respectively. The idealized formulas of these representatives are Na{sub 13}(Ca{sub 3}Mn{sub 3})Zr{sub 3}(Fe, Mn){sub 3}({open_square})(Si)[Si{sub 3}O{sub 9}]{sub 2}[Si{sub 9}O{sub 27}]{sub 2}(O, OH, Cl){sub 3} . 2H{sub 2}O and Na{sub 15}(Ca{sub 3}Mn{sub 3})Zr{sub 3}(Fe, Zr){sub 3}(Si)(Si) . [Si{sub 3}O{sub 9}]{sub 2}[Si{sub 9}O{sub 27}]{sub 2}O{sub 2}(OH,more » F, Cl){sub 2} . 2H{sub 2}O. Both minerals are analogs of oneillite and are characterized by a low Ca content. The distinguishing features of the mineral from Quebec are that the M(4) site is essentially vacant (>50%) and Ca atoms occupy one independent site in the six-membered ring, whereas another site is occupied by Mn along with a small impurity of Na. In the mineral from the Lovozero massif, both the M(3) and M(4) sites are occupied predominantly by silicon, while Ca atoms are distributed between both octahedral sites of the six-membered ring, one of these sites being occupied predominantly by Mn.« less

Sodium citrate-assisted anion exchange strategy for construction of Bi{sub 2}O{sub 2}CO{sub 3}/BiOI photocatalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Peng-Yuan; Xu, Ming; Zhang, Wei-De, E-mail: zhangwd@scut.edu.cn

Highlights: • Heterostructured Bi{sub 2}O{sub 2}CO{sub 3}/BiOI microspheres were prepared via anion exchange. • Sodium citrate-assisted anion exchange for construction of composite photocatalysts. • Bi{sub 2}O{sub 2}CO{sub 3}/BiOI composites show high visible light photocatalytic activity. - Abstract: Bi{sub 2}O{sub 2}CO{sub 3}/BiOI heterojuncted photocatalysts were constructed through a facile partial anion exchange strategy starting from BiOI microspheres and urea with the assistance of sodium citrate. The content of Bi{sub 2}O{sub 2}CO{sub 3} in the catalysts was regulated by modulating the amount of urea as a precursor, which was decomposed to generate CO{sub 3}{sup 2−} in the hydrothermal process. Citrate anion playsmore » a key role in controlling the morphology and composition of the products. The Bi{sub 2}O{sub 2}CO{sub 3}/BiOI catalysts display much higher photocatalytic activity than pure BiOI and Bi{sub 2}O{sub 2}CO{sub 3} towards the degradation of rhodamine B (RhB) and bisphenol A (BPA). The enhancement of photocatalytic activity of the heterojuncted catalysts is attributed to the formation of p–n junction between p-BiOI and n-Bi{sub 2}O{sub 2}CO{sub 3}, which is favorable for retarding the recombination of photoinduced electron-hole pairs. Moreover, the holes are demonstrated to be the main active species for the degradation of RhB and BPA.« less

GRAVIMETRIC DETERMINATION OF PLATINIUM, PALLADIUM, RUTHENIUM, RHODIUM AS TlPtS$sub 3$, TlPd$sub 2$S$sub 3$, TlRu$sub 2$S$sub 6$, TlRh$sub 2$S$sub 4$ (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudnev, N.A.; Malofeeva, G.I.

1963-07-01

Gravimetric methods were developed for the determination of microamounts of Ru, Rh, Pt, and Pd as TlRu/sub 2/S/sub 6/, TlRh/sub 2/S/sub 4/ TlPtS/sub 3/, and TlPd/sub 2/S/sub 3/. The methods are simpl e, rapid, and satisfactorily accurate. (auth)

Synthesis and X-ray crystal structures of (Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2}){sub 2}({mu}-N{sub 2}) with an end-on bridging dinitrogen ligand and Mo(CO)(Bu{sup i}{sub 2}PC{sub 2}H{sub 4}PBu{sup i}{sub 2}){sub 2} containing an agostic Mo...H-C interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, X.L.; Kubas, G.J.; Burns, C.J.

1995-12-20

The compound formed by the reaction of trans-Mo(N{sub 2})(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2} with ethyl acetate in refluxing toluene under argon has been formulated as the bridging dinitrogen complex (Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2}){sub 2}({mu}-N{sub 2}) (1), in contrast with the previously proposed formulation of Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2} (2). In refluxing p-xylene and under argon, compound 1 eliminates the bridging dinitrogen ligand to form the nitrogen-free compound 2. The reaction of trans-Mo(N{sub 2})(Bu{sup i}{sub 2}PC{sub 2}H{sub 4}PBu{sup i}{sub 2}){sub 2} (3). The molecular structures of compounds 1 and 3 have been determined by single-crystal X-raymore » diffraction studies. Compound 1 contains an end-on bridging dinitrogen ligand. Compound 3 attains a formal 18-electron configuration by virtue of an agostic Mo...H-C interaction between the molybdenum atom and an alphiatic {gamma}-C-H bond of the alkyldiphosphine ligand. On the basis of the agostic Mo...C and Mo...H distances, the agostic interaction in 3 appears to be stronger than that in the related compound Mo(CO)(Ph{sub 2}PC{sub 2}H{sub 4}PPh{sub 2}){sub 2} which involves an ortho aromatic C-H bond of the diphosphine ligand. Crystallographic data for 1: monoclinic, space group C2/c, a=24.270(2){angstrom}, b=44.233(4){angstrom}, c=20.378(2){angstrom}, {beta}=90.725(9){angstrom}, V=21875(3){angstrom}{sup 3}, Z=16, and R=0.048. Crystallographic data for 3: orthorhombic, space group Pna2{sub 1}, a=18.332(4){angstrom}, b=22.0664(4){angstrom}, c=10.589(2){angstrom}, V=4283(2){angstrom}{sup 3}, Z=4, and R=0.034.« less

Synthesis, structure and electrical properties of Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} and the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} pseudoternary phase diagram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reeves-McLaren, Nik, E-mail: n.reeves@sheffield.ac.uk; Ferrarelli, Matthew C.; Tung, Yuan-Wei

2011-07-15

Subsolidus phase relations in the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} system were determined at 935 deg. C. The phase diagram contains one new phase, Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} (CTNO) and one rutile-structured solid solution series, Ti{sub 1-3x}Cu{sub x}Nb{sub 2x}O{sub 2}: 0 Subsolidus phase relations in the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} system were determined at 935 deg. C. > A new phase, Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} (CTNO), was found with a CaCu{sub 3}Ti{sub 4}O{sub 12}-like crystal structure. > We discovered one rutile-structured solid solution series, Ti{sub 1-3x}Cu{sub x}Nb{sub 2x}O{sub 2}: 0 CTNO has square planar Cu{sup 2+}, A site vacancies and Cu{sup +}, Ti{sup 4+} and Nb{sup 5+} disordered on octahedral sites. > CTNO is a modest semiconductor with relative permittivity {approx}63.« less

The crystal structure of the monohydrate R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O (R=Pr, Nd, Sm, and Eu): a layer structure containing disordered [Mo{sub 2}O{sub 7}]{sup 2-} groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naruke, Haruo; Yamase, Toshihiro

2005-03-15

Although R{sub 2}O{sub 3}:MoO{sub 3}=1:6 (R=rare earth) compounds are known in the R{sub 2}O{sub 3}-MoO{sub 3} phase diagrams since a long time, no structural characterization has been achieved because a conventional solid-state reaction yields powder samples. We obtained single crystals of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O (R=Pr, Nd, Sm, and Eu) by thermal decomposition of [R{sub 2}(H{sub 2}O){sub 12}Mo{sub 8}O{sub 27}].nH{sub 2}O at around 685-715{sup o}C for 2h, and determined their crystal structures. The simulated XRD patterns of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O were consistent with those of previously reported R{sub 2}O{sub 3}:MoO{sub 3}=1:6 compounds. All R{sub 2}Mo{sub 6}O{sub 21}.H{submore » 2}O compounds crystallize isostructurally in tetragonal, P4/ncc (No. 130), a=8.9962(5), 8.9689(6), 8.9207(4), and 8.875(2)A; c=26.521(2), 26.519(2), 26.304(2), and 26.15(1)A; Z=4; R{sub 1}=0.026, 0.024, 0.024, and 0.021, for R=Pr, Nd, Sm, and Eu, respectively. The crystal structure of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O consists of two [Mo{sub 2}O{sub 7}]{sup 2-}-containing layers (A and B layers) and two interstitial R(1){sup 3+} and R(2){sup 3+} cations. Each [Mo{sub 2}O{sub 7}]{sup 2-} group is composed of two corner-sharing [MoO{sub 4}] tetrahedra. The [Mo{sub 2}O{sub 7}]{sup 2-} in the B layer exhibits a disorder to form a pseudo-[Mo{sub 4}O{sub 9}] group, in which four Mo and four O sites are half occupied. R(1){sup 3+} achieves 8-fold coordination by O{sup 2-} to form a [R(1)O{sub 8}] square antiprism, while R(2){sup 3+} achieves 9-fold coordination by O{sup 2-} and H{sub 2}O to form a [R(2)(H{sub 2}O)O{sub 8}] monocapped square antiprism. The disorder of the [Mo{sub 2}O{sub 7}]{sup 2-} group in the B layer induces a large displacement of the O atoms in another [Mo{sub 2}O{sub 7}]{sup 2-} group (in the A layer) and in the [R(1)O{sub 8}] and [R(2)(H{sub 2}O)O{sub 8}] polyhedra. A remarkable broadening of the photoluminescence spectrum of Eu{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O supported the large displacement of O ligands coordinating Eu(1) and Eu(2)« less

Solvothermal synthesis of graphene-Sb{sub 2}S{sub 3} composite and the degradation activity under visible light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Wenguang; Chang, Jiuli; Wu, Dapeng

2013-02-15

Graphical abstract: Display Omitted Highlights: ► Graphene-Sb{sub 2}S{sub 3} composites were synthesized through a facile solvothermal method. ► Hydroxyl radicals are the main species responsible for the photodegradation activity. ► Graphene-Sb{sub 2}S{sub 3} demonstrated dramatically improved visible light degradation activity. -- Abstract: Novel graphene-Sb{sub 2}S{sub 3} (G-Sb{sub 2}S{sub 3}) composites were synthesized via a facile solvothermal method with graphene oxide (GO), SbCl{sub 3} and thiourea as the reactants. GO played an important role in controlling the size and the distribution of the formed Sb{sub 2}S{sub 3} nanoparticles on the graphene sheets with different density. Due to the negative surface charge,more » smaller Sb{sub 2}S{sub 3} particles size and efficient electrons transfer from Sb{sub 2}S{sub 3} to graphene, the composites demonstrated improved photodegradation activity on rhodamine B (RhB). Among these composites, the product G-Sb{sub 2}S{sub 3} 0.1, which was synthesized with the GO concentration of 0.1 mg/mL, exhibited the highest photodegradation activity owing to the considerable density of Sb{sub 2}S{sub 3} nanoparticles onto graphene sheet free of aggregation. Hydroxyl radicals (·OH) derived from conduction band (CB) electrons of Sb{sub 2}S{sub 3} is suggested to be responsible for the photodegradation of RhB. The high visible light degradation activity and the satisfactory cycling stability made the as-prepared G-Sb{sub 2}S{sub 3} 0.1 an applicable photocatalyst.« less

Crystal Chemistry of the Potassium and Rubidium Uranyl Borate Families Derived from Boric Acid Fluxes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shuao; Alekseev, Evgeny V.; Stritzinger, Jared T.

2010-07-19

The reaction of uranyl nitrate with a large excess of molten boric acid in the presence of potassium or rubidium nitrate results in the formation of three new potassium uranyl borates, K{sub 2}[(UO{sub 2}){sub 2}B{sub 12}O{sub 19}(OH){sub 4}]·0.3H{sub 2}O (KUBO-1), K[(UO{sub 2}){sub 2}B{sub 10}O{sub 15}(OH){sub 5}] (KUBO-2), and K[(UO{sub 2}){sub 2}B{sub 10}O{sub 16}(OH){sub 3}]·0.7H{sub 2}O (KUBO-3) and two new rubidium uranyl borates Rb{sub 2}[(UO{sub 2}){sub 2}B{sub 13}O{sub 20}(OH){sub 5}] (RbUBO-1) and Rb[(UO{sub 2}){sub 2}B{sub 10}O{sub 16}(OH){sub 3}]·0.7H{sub 2}O (RbUBO-2). The latter is isotypic with KUBO-3. These compounds share a common structural motif consisting of a linear uranyl, UO{sub 2}{sup 2+},more » cation surrounded by BO{sub 3} triangles and BO{sub 4} tetrahedra to create an UO{sub 8} hexagonal bipyramidal environment around uranium. The borate anions bridge between uranyl units to create sheets. Additional BO{sub 3} triangles extend from the polyborate layers and are directed approximately perpendicular to the sheets. All of these compounds adopt layered structures. With the exception of KUBO-1, the structures are all centrosymmetric. All of these compounds fluoresce when irradiated with long-wavelength UV light. The fluorescence spectrum yields well-defined vibronically coupled charge-transfer features.« less

Structures, thermal expansion properties and phase transitions of Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} (0.0 {le} x {le} 2.0).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Y. Z.; Wu, M. M.; Peng, J.

2007-05-03

Structures, thermal expansion properties and phase transitions of Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} (0.0 {le} x {le} 2.0) have been investigated by X-ray diffraction and differential thermal analysis. The partial substitution of Er{sup 3+} for Fe{sup 3+} induces pronounced decreases in the phase transition temperature from monoclinic to orthorhombic structure. Rietveld analysis of the XRD data shows that both the monoclinic and orthorhombic Fe{sub 2}(MoO{sub 4}){sub 3}, as well as the orthorhombic Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} (x {le} 0.8) have positive thermal expansion coefficients. However, the linear thermal expansion coefficients of Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} (x = 0.6-2.0)more » decrease with increasing content of Er{sup 3+} and for x {ge} 1.0, compounds Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} show negative thermal expansion properties. Attempts for making zero thermal expansion coefficient materials result in that very low negative thermal expansion coefficient of -0.60 x 10{sup -6} C in Er{sub 1.0}Fe{sub 1.0}(MoO{sub 4}){sub 3} is observed in the temperature range of 180-400 C, and zero thermal expansion is observed in Er{sub 0.8}Fe{sub 1.2}(MoO{sub 4}){sub 3} in the temperature range of 350-450 C. In addition, anisotropic thermal expansions are found for all the orthorhombic Er{sub x}Fe{sub 2-x}(MoO{sub 4}){sub 3} compounds, with negative thermal expansion coefficients along the a axes.« less

Influence of Ga{sup 3+} ions on spectroscopic and dielectric features of multi component lithium lead boro bismuth silicate glasses doped with manganese ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramesh Babu, P.; Vijay, R.; Nageswara Rao, P.

2013-11-15

Graphical abstract: The plots between ε″(ω)ω vs. ε′(ω) and ε″(ω)/ω vs. ε′(ω) yield straight lines with slope 1/τ and τ, respectively. Considerable deviation from the straight line is observed in the high frequency region. Such deviation suggests spreading of relaxation times and this is attributed to the presence of multiple type of dipoles in the glass matrix. Variation of the parameters ωε″(ω) and ε″(ω)/ω with ε′(ω) of glass Li{sub 2}O–PbO–B{sub 2}O{sub 3}–SiO{sub 2}–Bi{sub 2}O{sub 3}–MnO multi-component glasses mixed with 2.0 mol% of Ga{sub 2}O{sub 3} measured at 373 K. - Highlights: • A series of Li{sub 2}O–PbO–B{sub 2}O{sub 3}–SiO{sub 2}–Bi{submore » 2}O{sub 3}–MnO:Ga{sub 2}O{sub 3} glasses have been synthesized. • A variety of spectroscopic and dielectric properties have been investigated. • Analysis of the results indicated that glasses with below 3.0 mol% Ga{sub 2}O{sub 3} are good conducting materials. - Abstract: Multi-component glasses of the chemical composition 19.5Li{sub 2}O–20PbO–20B{sub 2}O{sub 3}–30SiO–(10 − x)Bi{sub 2}O{sub 3}–0.5MnO:xGa{sub 2}O{sub 3} with 0 ≤ x ≤ 5.0 have been synthesized. Spectroscopic (optical absorption, IR, Raman and ESR) and dielectric properties were investigated. Optical absorption and ESR spectral studies have indicated that managanese ions do exist in Mn{sup 3+} state in addition to Mn{sup 2+} state in the samples containing low concentration of Ga{sub 2}O{sub 3}. The IR and Raman studies indicated increasing degree of disorder in the glass network with the concentration of Ga{sub 2}O{sub 3} up to 3.0 mol%. The dielectric constant, loss and ac conductivity are observed to increase with the concentration of Ga{sub 2}O{sub 3} up to 3.0 mol%. The quantitative analysis of the results of dielectric properties has indicated an increase in the insulating strength of the glasses as the concentration of Ga{sub 2}O{sub 3} is raised beyond 3.0 mol%. This has been attributed to adaption of gallium ions from octahedral to tetrahedral coordination.« less

Microwave sol–gel synthesis and upconversion photoluminescence properties of CaGd{sub 2}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with incommensurately modulated structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Chang Sung; Aleksandrovsky, Aleksandr; Department of Photonics and Laser Technologies, Siberian Federal University, Krasnoyarsk 660079

2015-08-15

CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with the doping concentrations of Er{sup 3+} and Yb{sup 3+} (x=Er{sup 3+}+Yb{sup 3+}, Er{sup 3+}=0.05, 0.1, 0.2 and Yb{sup 3+}=0.2, 0.45) have been successfully synthesized by the microwave sol–gel method. The crystal structure of CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} tungstates have been refined, and upconversion photoluminescence properties have been investigated. The synthesized particles, being formed after the heat-treatment at 900 °C for 16 h, showed a well crystallized morphology. Under the excitation at 980 nm, CaGd{sub 2}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} particles exhibited a strong 525-nm and a weak 550-nm emission bandsmore » in the green region and a very weak 655-nm emission band in the red region. The Raman spectrum of undoped CaGd{sub 2}(WO{sub 4}){sub 4} revealed about 12 narrow lines. The strongest band observed at 903 cm{sup −1} was assigned to the ν{sub 1} symmetric stretching vibration of WO{sub 4} tetrahedrons. The spectra of the samples doped with Er and Yb obtained under the 514.5 nm excitation were dominated by Er{sup 3+} luminescence preventing the recording of these samples Raman spectra. Concentration quenching of the erbium luminescence at {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} transition is weak in the range of erbium doping level x{sub Er}=0.05–0.2, while, for transition {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}, the signs of concentration quenching become pronounced at x{sub Er}=0.2. - Graphical abstract: CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with the doping concentrations of Er{sup 3+} and Yb{sup 3+} (x=Er{sup 3+}+Yb{sup 3+}, Er{sup 3+}=0.05, 0.1, 0.2 and Yb{sup 3+}=0.2, 0.45) have been successfully synthesized by the microwave sol–gel method and the crystal structure refinement, and upconversion photoluminescence properties have been investigated. - Highlights: • CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors have been synthesized by the microwave sol–gel method. • The crystal structure of CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} tungstates have been refined. • The upconversion photoluminescence properties have been investigated.« less

Morin transition temperature in (0001)-oriented α-Fe{sub 2}O{sub 3} thin film and effect of Ir doping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimomura, Naoki, E-mail: shimomura@ecei.tohoku.ac.jp; Pati, Satya Prakash; Sato, Yuji

2015-05-07

The structural properties and Morin transition in c-plane-oriented α-Fe{sub 2}O{sub 3} and Ir-doped α-Fe{sub 2}O{sub 3} thin films have been investigated. The enhancement of the Morin transition temperature (T{sub M}) in α-Fe{sub 2}O{sub 3} film by Ir doping has been demonstrated. The T{sub M} in the c-plane-oriented α-Fe{sub 2}O{sub 3} thin film was determined from the temperature-dependent in-plane magnetization and change of coercivity (H{sub c}); this T{sub M} value was found close to that of bulk α-Fe{sub 2}O{sub 3}. The spin directions of non-doped and Ir-doped α-Fe{sub 2}O{sub 3} at room temperature were also estimated from conversion electron Mössbauer spectroscopymore » measurements. We confirmed that Ir doping dramatically enhances the T{sub M} of α-Fe{sub 2}O{sub 3} thin film.« less

Hydrothermal synthesis of zinc(II)-phosphonate coordination polymers with different dimensionality (0D, 2D, 3D) and dimensionality change in the solid phase (0D→3D) induced by temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernández-Zapico, Eva; Montejo-Bernardo, Jose; Fernández-González, Alfonso

2015-05-15

Three new zinc(II) coordination polymers, [Zn(HO{sub 3}PCH{sub 2}CH{sub 2}COO)(C{sub 12}H{sub 8}N{sub 2})(H{sub 2}O)] (1), [Zn{sub 3}(O{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2})](H{sub 2}O){sub 3.40} (2) and [Zn{sub 5}(HO{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(O{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2}){sub 4}](H{sub 2}O){sub 0.32} (3), with different structural dimensionality (0D, 2D and 3D, respectively) have been prepared by hydrothermal synthesis, and their structures were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system (P2{sub 1}/c) forming discrete dimeric units bonded through H-bonds, while compounds 2 and 3 crystallize in the triclinic (P−1) and the monoclinic (C2/c) systems, respectively.more » Compound 3, showing three different coordination numbers (4, 5 and 6) for the zinc atoms, has also been obtained by thermal treatment of 1 (probed by high-temperature XRPD experiments). The crystalline features of these compounds, related to the coordination environments for the zinc atoms in each structure, provoke the increase of the relative fluorescence for 2 and 3, compared to the free phenanthroline. Thermal analysis (TG and DSC) and XPS studies have been also carried out for all compounds. - Graphical abstract: Three new coordination compounds of zinc with 2-carboxyethylphosphonic acid (H{sub 2}PPA) and phenanthroline have been obtained by hydrothermal synthesis. The crystalline structure depends on the different coordination environments of the zinc atoms (see two comparative Zn{sub 6}-moieties). The influence of the different coordination modes of H{sub 2}PPA with the central atom in all structures have been studied, being found new coordination modes for this ligand. Several compounds show a significant increase in relative fluorescence with respect to the free phenanthroline. - Highlights: • Compounds have been obtained modifying the reaction time and the rate of reagents. • Dimensionality and crystalline structure is a function of the zinc environments. • New coordination modes for 2-carboxyethylphosphonic acid are reported. • 3D-compound presents three different coordination environments for the zinc atoms. • Fluorescence properties are related to the structural dimensionality.« less

New vanadium tellurites: Syntheses, structures, optical properties of noncentrosymmetric VTeO{sub 4}(OH), centrosymmetric Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Ming-Li; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Marsh, Matthew

Two new vanadium tellurites, VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2), have been synthesized successfully with the use of hydrothermal reactions. The crystal structures of the two compounds were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the polar space group Pca2{sub 1} (No. 29) while compound 2 crystallizes in the centrosymmetric space group C2/c (No. 15). The topography of compound 1 reveals a two-dimensional, layered structure comprised of VO{sub 6} octahedral chains and TeO{sub 3}(OH) zig-zag chains. Compound 2, on the contrary, features a three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework withmore » Ba{sup 2+} ions filled into the 10-member ring helical tunnels. The [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic network is the first 3D vanadium tellurite framework to be discovered in the alkaline-earth vanadium tellurite system. Powder second harmonic generation (SHG) measurements indicate that compound 1 shows a weak SHG response of about 0.3×KDP (KH{sub 2}PO{sub 4}) under 1064 nm laser radiation. Infrared spectroscopy, elemental analysis, thermal analysis, and dipole moment calculations have also been carried out. - Graphical abstract: VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} (No. 29) while Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) crystallizes in the centrosymmetric space group C2/c (No. 15). - Highlights: • VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) have been synthesized successfully with the use of hydrothermal reactions. • VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} and displays a weak SHG response. • VTeO{sub 4}(OH) (1) represents only the fourth SHG-active material found in vanadium tellurite systems. • Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) exhibits a novel three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework.« less

Electron diffraction and high-resolution electron microscopy studies on layered Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Hiroki, E-mail: fujii.hiroki@nims.go.jp; Ozawa, Kiyoshi; Mochiku, Takashi

2013-07-15

The structure of Li{sub 2}MnO{sub 3}–LiCoO{sub 2} solid solutions or Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3} (LMCO) which are promising lithium-battery cathodes was studied by high-resolution electron microscopy (HREM). X-ray diffraction (XRD) analyses indicate that Li{sub 1.6}Mn{sub 0.2}Co{sub 1.2}O{sub 3} and Li{sub 1.7}Mn{sub 0.4}Co{sub 0.9}O{sub 3} take a rhombohedral (R3-bar m space group) structure, whereas Li{sub 1.85}Mn{sub 0.7}Co{sub 0.45}O{sub 3} and Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3} take a monoclinic (C2/m) superstructure. HREM studies on those samples reveal that all of the observed crystallites in sample Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3} contain sharp stripe structures due to the planar defects alongmore » the c{sub h}-axis (stacking direction of the hexagonal close-packed planes) of parent rhombohedral R3-bar m cell. Such stripe structures become faint with increasing x, Co content. The origin of the planar defects is mainly attributed not to the different structures but to the different local orientations of the monoclinic LMCO. Local disordering of Li and (Mn,Co) in (Li,Mn,Co) planes is developed with increasing x and the structures are transformed from C2/m to R3-bar m. The alternative (Li,Mn,Co)-plane stacking structure, trigonal P3{sub 1}12 LMCO, was occasionally observed. However, only P3{sub 1}12 LMCO platelets with a thickness of a single unit cell were detected. - Graphical abstract: An HREM image for Li{sub 1.95}(Mn{sub 0.9}Co{sub 0.15})O{sub 3} and schematic drawings of C2/m and P3{sub 1}12 Li{sub 2}MnO{sub 3} projected along the various zone axes. Each projected unit cell is indicated by rectangles and parallelograms . - Highlights: • Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3} was studied by high-resolution electron microscopy (HREM). • HREM studies revealed a large amount of planar defects in C2/m Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3}. • The origin of the defects is the different local orientations of the C2/m platelets. • P3{sub 1}12 platelets with only single unit cell sequence were detected.« less

Synthesis and structural characterization of (C sub 5 Me sub 5 )Zr(R) sub 2 (L) sub n sup + complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowther, D.J.; Jordan, R.F.; Baenziger, N.C.

1990-09-01

The reaction of (C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 3} with ((C{sub 5}H{sub 4}Me){sub 2}Fe)(BPh{sub 4}) in THF yields ((C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 2}(THF){sub 2})(BPh{sub 4}) (1) via oxidative cleavage of a Zr-CH{sub 3} bond. X-ray diffraction reveals that the cation of 1 adopts a square-pyramidal/four-legged piano-stool structure with cis CH{sub 3} groups. The orientations of the THF ligands and the Zr-O bond distances suggest that Zr-O {pi}-bonding is important for at least one of the THF ligands. Data for 1: a = 14.551 (2) {angstrom}, b = 15.191 (4) {angstrom}, c = 17.852 (19) {angstrom}, {beta} = 92.26 (3){degree}, V =more » 3,943 (6) {angstrom}{sup 3}, Z = 4 in space group P2{sub 1}/c. Reaction of 1 with excess dmpe in THF solution yields ((C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 2}(dmpe)(THF))(BPh{sub 4}) (2), which also has been characterized by X-ray diffraction.« less

Ancillary ligand-assisted assembly of C{sub 3}-symmetric 4,4′,4″-nitrilotribenzoic acid with divalent Zn{sup 2+} ions: Syntheses, topological structures, and photoluminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Li-Ting; Niu, Yan-Fei; Han, Jie, E-mail: chan@ouhk.edu.hk

4,4′,4″-nitrilotribenzoic acid (H{sub 3}L), a C{sub 3}-symmetric ligand, was found to self-assemble into two polymorphs driven by intermolecular hydrogen-bonding interactions. Reactions of this ligand with Zn{sup 2+} under solvothermal conditions resulted in four new coordination polymers bearing interesting structural motifs: [Zn{sub 2}(L){sub 2}(py){sub 2}]·2(H{sub 2}NMe{sub 2}){sup +}·DMF·2H{sub 2}O (1), [Zn{sub 2}(L)(H{sub 2}L)(bipy)]·1.5H{sub 2}O·Guest (2), [Zn{sub 2}(L){sub 2}(bipy)]·2(H{sub 2}NMe{sub 2}){sup +}·2DMF (3), and [Zn{sub 3}(L){sub 2}(bpa)]·2H{sub 2}O·Guest (4) (H{sub 3}L=4,4′,4′′-nitrilotribenzoic acid, DMF=dimethylformamide, py=pyridine, bipy=4,4′-bipyridine, bpa=1,2-bis(4-pyridyl)diazene). Single-crystal structural analysis revealed that compound 1 exhibits a rare example of twofold interpenetrating anionic 3D (3,3)-net framework containing helical channels, whereas in 2, the 3Dmore » pillar-layer structure generated from bipy-pillared Zn{sub 2}(L)(H{sub 2}L) layer is further reinforced by intermolecular hydrogen bonding among pairs of free –COOH units. Compound 3 shows an interesting entangled architecture of 2D→3D parallel polycatenation consisting five-coordinated Zn{sup 2+} ions. Compound 4 displays a 3D pillar-layer framework with trimeric Zn{sub 3}(CO{sub 2}){sub 6} serving as secondary building unit (SBU). The syntheses, structures, thermal stabilities, powder X-ray diffractions and solid-state photoluminescence properties for these crystalline materials have been carried out. In addition, supramolecular assembly of H{sub 3}L under solvothermal conditions will also be addressed. - Graphical abstract: Supramolecular assembly of 4,4′,4′′-nitrilotribenzoic acid and its ligand behavior toward Zn{sup 2+} were investigated, which exhibit two polymorphs of the free acid and four metal coordination polymers bearing interesting structural motifs. - Highlights: • Two polymorphs of H{sub 3}L showing different hydrogen-bonded network were obtained. • Tune over the structure of MOFs was achieved. • 1 has a 2-fold interpenetrating anionic 3D network containing helical channels. • Structures bearing free carboxylic acid (–COOH) unit are constructed in 2. • 3 represents a rare 2D+2D→3D catenation array containing five-coordinated Zn{sup 2+}.« less

Synthesis and structure of heptaaqua(nitrilotris(methylenephosphonato))(dibarium)sodium monohydrate [Na(H{sub 2}O){sub 3}(μ{sup 6}-NH(CH{sub 2}PO{sub 3}){sub 3})(μ-H{sub 2}O){sub 3}Ba{sub 2}(H{sub 2}O)] · H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somov, N. V., E-mail: somov@phys.unn.ru; Chausov, F. F., E-mail: xps@ftiudm.ru; Zakirova, R. M., E-mail: ftt@udsu.ru

Crystals of the monohydrate form of heptaaqua(nitrilotris(methylenephosphonato))(dibarium) sodium [Na(H{sub 2}O{sub )3}(µ{sup 6}-NH(CH{sub 2}PO{sub 3}){sub 3})(µ-H{sub 2}O){sub 3}Ba{sub 2}(H{sub 2}O)] · H{sub 2}O are obtained; space group P2{sub 1}/c, Z = 4; a = 13.9117(10) Å, b = 11.54030(10) Å, and c = 24.1784(17) Å, ß = 148.785(18)°. The Na atom is coordinated octahedrally by one oxygen atom of a phosphonate group and five water molecules, including two bridging molecules. Ba atoms occupy two inequivalent crystallographic positions with coordination number eight and nine. The coordination spheres of both Ba atoms include two water molecules. Each ligand is bound to one Namore » atom and five Ba atoms forming three Ba–O–P–O and five Ba–O–P–C–N–C–P–O chelate cycles. In addition to the coordination bonds, molecules, including the solvate water molecule, are involved in hydrogen bonds in the crystal packing.« less

Microstructural and strength improvements through the use of Na{sub 2}CO{sub 3} in a cementless Ca(OH){sub 2}-activated Class F fly ash system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeon, Dongho; Jun, Yubin; Jeong, Yeonung

2015-01-15

This study explores the beneficial effects of Na{sub 2}CO{sub 3} as an additive for microstructural and strength improvements in a Ca(OH){sub 2}-activated fly ash system. NaOH-activated fly ash samples were also tested to compare the effect of Na{sub 2}CO{sub 3}. Compressive strength testing, XRD, SEM/BSE/EDS, {sup 29}Si/{sup 27}Al MAS-NMR, MIP and TGA were performed. The testing results indicate that the use of Na{sub 2}CO{sub 3} for Ca(OH){sub 2}-activation led to a noticeable improvement in strength and microstructure, primarily due to (1) more dissolution of raw fly ash at an early age, (2) more formation of C–S–H [or C–S–H(I)], (3) porositymore » reduction, and (4) pore-size refinement. We also found that (1) an early high alkalinity from the NaOH formation was not a major cause of strength, (2) geopolymer was not formed despite the early NaOH formation, and (3) no visible pore-filling action of CaCO{sub 3} was observed. However, Na{sub 2}CO{sub 3} did not produce any improvement in strength for NaOH-activated fly ash. -- Highlights: •The use of Na{sub 2}CO{sub 3} significantly improved strength and microstructure. •The use of Na{sub 2}CO{sub 3} induced more dissolution of raw fly ash at early ages. •The use of Na{sub 2}CO{sub 3} promoted more C–S–H [or C–S–H(I)] formation. •The use of Na{sub 2}CO{sub 3} reduced total porosity and refined pore-size distribution. •The use of Na{sub 2}CO{sub 3} produced neither geopolymer formations nor pore-filling actions from CaCO{sub 3}.« less

Structural characterizations and magnetic properties of three new reduced molybdenum phosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Xiao; Xu Jiqing; Yu Jiehui

2007-06-15

Three new molybdophosphates, [Co(dien){sub 2}].(H{sub 3}dien){sub 6}.{l_brace}[CoMo{sub 12}O{sub 24}(OH){sub 6}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 6}][Co(Hdien)]{sub 2}[CoMo{sub 12}O{sub 24} (OH){sub 6}(PO{sub 4}){sub 8}]{r_brace}.(dien).4H{sub 3}O.5H{sub 2}O (1) (H{sub 3}dien){sub 4}[MMo{sub 12}O{sub 24}(OH){sub 6}(HPO{sub 4}){sub 4}(PO{sub 4}){sub 4}].10H{sub 2}O [M=Co for (2), Ni for (3); dien=diethylenetriamine], have been synthesized by employing hydrothermal method and characterized by single crystal X-ray diffraction. Compound 1 is built up of Co[P{sub 4}Mo{sub 6}]{sub 2} units as the structural motif covalently linked by [Co(Hdien)] complex subunits to yield an unusual 1-D chain. Compounds 2 and 3 are isomorphic and both display covalent discrete M[P{sub 4}Mo{sub 6}]{sub 2} cluster structuresmore » which are linked by the hydrogen bonds to form 3-D supramolecular networks. Both 1 and 2 display antiferromagnetic interaction and these three compounds all exhibit intensive photoluminescence. - Graphical abstract: Three new reduced molybdophoshpates based on P{sub 4}MO{sub 6} building blocks have been hydrothermally synthesized. 1 is the first covalent 1-D chain consisting of two kinds of forms of M[P{sub 4}MO{sub 6}]{sub 2} units, standing forms A and lying forms B, while 2 and 3 possess 3-D supramolecular network structures. These three compounds all display photoluminescence.« less

Synthesis, structure, and properties of nickel complexes with nitrilotris(methylenephosphonic acid) [Ni(H{sub 2}O)3N(CH2PO{sub 3}H){sub 3}] and Na{sub 4}[Ni(H{sub 2}O)N(CH{sub 2}PO{sub 3}){sub 3}] ∙ 11H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somov, N. V., E-mail: somov@phys.unn.ru; Chausov, F. F., E-mail: chaus@yandex.ru; Zakirova, R. M.

2016-03-15

Nitrilotris(methylenephosphonato)triaquanickel and tetrasodium nitrilotris(methylenephosphonato) aquanickelate undecahydrate were synthesized and characterized. The crystal of [Ni(H{sub 2}O){sub 3}N(CH{sub 2}PO{sub 3}H){sub 3}] is composed of linear coordination polymers and belongs to sp. gr. P2{sub 1}/c, Z = 4, a = 9.17120(10) Å, b = 16.05700(10) Å, c = 9.70890(10) Å, β = 115.830(2)°. The Ni atom is in an octahedral coordination formed by two oxygen atoms of one phosphonate ligand, one oxygen atom of another ligand molecule, and three water molecules in a meridional configuration. The crystal of Na{sub 4}[Ni(H{sub 2}O)N(CH{sub 2}PO{sub 3}){sub 3}] ∙ 11H{sub 2}O has an island dimeric chelate structuremore » and belongs to sp. gr. C2/c, Z = 8, a = 18.7152(2) Å, b = 12.05510(10) Å, c = 21.1266(2) Å, β = 104.4960(10)°. The Ni atom has a slightly distorted octahedral coordination involving one nitrogen atom and closes three five-membered N–C–P–O–Ni rings sharing the Ni–N bond.« less

Functionalized inorganic membranes for gas separation

DOEpatents

Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Molaison, Jennifer Lynn [Marietta, GA; Schick, Louis Andrew ,; Ramaswamy, Vidya [Niskayuna, NY

2008-07-08

A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

High pressure structural investigation on alluaudites Na{sub 2}Fe{sub 3}(PO{sub 4}){sub 3}-Na{sub 2}FeMn{sub 2}(PO{sub 4}){sub 3} system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Jing; Huang, Weifeng; Qin, Shan

Alluaudites are promising electrochemical materials benefited from the open structure. Structural variations of alluaudites Na{sub 2}M{sub 3}(PO{sub 4}){sub 3} (M{sub 3}=Fe{sub 3}, Fe{sub 2}Mn and FeMn{sub 2}) system have been studied by synchrotron radiation X-ray diffraction combined with diamond anvil cell technique up to ~10 GPa at room temperature. No phase transition is observed. The excellent structural stability is mainly due to the flexible framework plus strong covalent P-O bond. Mn{sup 2+} instead of Fe can be described as Na{sup +}+2Fe{sup 2+}→Mn{sup 2+}+Fe{sup 3+}+□ where □ represents a lattice vacancy. The replacement of Fe with larger Mn{sup 2+} is equivalentmore » to applying negative chemical pressure to the material. And it causes a more compressible b-axis, lattice expansion, structural compressibility and intensifies the core/electron-electron interactions of Fe. External pressure effect produces anisotropic lattice shrinkage. Structural considerations related to these variations and promising application prospects are discussed. - Graphical abstract: Figure 1 The crystal structure of alluaudites Na{sub 2}M{sub 3}(PO{sub 4}){sub 3} (M{sub 3}=Fe{sub 3}, Fe{sub 2}Mn and FeMn{sub 2}) projected along the c-axis. Alluaudites adopt a flexible framework plus strong covalent P-O bond, which contribute to excellent structural stability up to ~10 GPa. Mn{sup 2+} instead of Fe can be described as Na{sup ++}2Fe{sup 2+}→Mn{sup 2+}+Fe{sup 3+}+□ where □ represents a lattice vacancy, and it is equivalent to applying negative chemical pressure to the host. The substitution causes a more compressible b-axis, lattice expansion, structural compressibility and intensifies the core/electron-electron interactions of Fe.« less

Cluster self-organization of inorganic crystal-forming systems: Templated nanocluster precursors and self-assembly of framework MT structures of A/B,Zr silicates (A = Na, K; B = Ca, Sr)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilyushin, G. D., E-mail: ilyushin@ns.crys.ras.ru

The basic concepts that are used to describe crystallization as a phenomenon of the hierarchical (cluster) self-organization of a chemical system are considered. The templation of theoretically possible nan-ocluster precursors composed of M octahedra and T tetrahedra by atoms of (A) alkaline and (B) alkaline earth metals is considered for the first time. A relationship between the A/B,M,T composition of templated nanocluster precursors with the composition of A/B,M silicates is established. The model that is developed is used to search for nanocluster precursors in framework MT structures of A/B,Zr silicates. Computer methods (TOPOS 4.0 program package) were used to performmore » complete 3D reconstruction of the self-assembly of all (four) structural types of A/B,Zr silicates (A = Na, K; B = Ca, Sr) with frameworks of the MT{sub 2}O{sub 7} type: nan-ocluster precursor S{sub 3}{sup 0}-primary chain S{sub 3}{sup 1}-microlayer S{sub 3}{sup 2}-microframework S{sub 3}{sup 3}. The invariant type of mono-cyclic nanocluster precursor M{sub 2}T{sub 4} (with the point symmetries 1-bar and 2), stabilized by one or two template cations (A and B), is determined. Bifurcations of the paths of evolution at the S{sub 3}{sup 1} level (structural branching point) are established for the self-assembly of the following frameworks: MT-1 in CaZrSi{sub 2}O{sub 7} (gittinsite, C2), MT-2 in SrZrSi{sub 2}O{sub 7} (P2{sub 1}/c); MT-3 in Na{sub 2}ZrSi{sub 2}O{sub 7} (parakeldyshite,), K{sub 2}ZrSi{sub 2}O{sub 7} (khibinskite, P2{sub 1}/b), and K{sub 2}ZrGe{sub 2}O{sub 7} (C2/c); and MT-4 in Na{sub 2}ZrSi{sub 2}O{sub 7} (H{sub 2}O)(C2/c), Na{sub 3}ScSi{sub 2}O{sub 7} (Pbnm), and K{sub 3}ScSi{sub 2}O{sub 7} (P6{sub 3}/mmc).« less

Folate conjugated Mn{sub 3}O{sub 4}@SiO{sub 2} nanoparticles for targeted magnetic resonance imaging in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xinyi; Zhou, Zhiguo, E-mail: zgzhou@shnu.edu.cn; Wang, Li

2014-09-15

Graphical abstract: The Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA has been used as a T{sub 1}-MRI probe for in vivo. - Highlights: • The PEG and FA modified Mn{sub 3}O{sub 4}@SiO{sub 2} nanoparticles (Mn{sub 3}O{sub 4}@SiO{sub 2}–FA) were prepared. • Mn{sub 3}O{sub 4}@SiO{sub 2}–FA exhibited the good colloidal stability in the simulated biological medium. • Mn{sub 3}O{sub 4}@SiO{sub 2}–FA showed the targeting ability to HeLa cells overexpressed the FA receptor. • The T{sub 1}-weighted magnetic resonance (MR) imaging demonstrated the targeting ability of Mn{sub 3}O{sub 4}@SiO{sub 2}–FA in vivo tumor. - Abstract: The monodisperse silica-coated manganese oxide nanoparticles (Mn{sub 3}O{sub 4}@SiO{sub 2}more » NPs) were synthesized via the high temperature pyrolysis approach and were aminated through silanization. The amine-functionalized Mn{sub 3}O{sub 4} NPs enabled the covalent conjugation of hydrophilic methoxypoly(ethylene glycol) (PEG) and the targeting ligand of folate (FA) onto their surface. The formed PEG and FA modified Mn{sub 3}O{sub 4} NPs (Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA) exhibited the good colloidal stability in the simulated biological medium and the targeting ability to HeLa cells overexpressed the FA receptor. The T{sub 1}-weighted magnetic resonance (MR) imaging and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis of Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA NPs further demonstrated their targeting ability in tumor.« less

K{sub 2}Mg{sub 5-x}Sn{sub 3} and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, pb) with two types of Mg-Sn/Pb frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lei, Xiao-Wu, E-mail: xwlei10@163.co

2011-04-15

K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) have been synthesized by reacting the mixture of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction studies. K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) is isostructural with Ni{sub 7-x}SbQ{sub 2} (Q=Se, Te) series and features 2D corrugated [Mg{sub 5-x}Sn{sub 3}] layers that are separated by K{sup +} cations. The structure of K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) is closely related to the Ho{sub 2}Rh{sub 12}As{sub 7} structural type and features 3D [Mg{sub 18}Tt{sub 11}] framework composed of 1D [Mg{sub 18}Tt{sub 11}] columns that aremore » interconnected via Mg-Tt bonds, forming 1D hexagonal tunnels occupied by the K+ cations. Electronic structure calculations indicate that Mg atoms can function as either electron donor or as a participator in the network along with Tt atoms. Magnetic property measurements and band structure calculations indicate that these compounds are metallic. -- Graphical abstract: Two new K-Mg-Tt phases, K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb), have been synthesized and structurally characterized. K{sub 2}Mg{sub 5-x}Sn{sub 3} is isostructural with Ni{sub 7-x}SbQ{sub 2} (Q=Se, Te) and features a 2D corrugated [Mg{sub 5}Sn{sub 3}] layer that is separated by K{sup +} cations, and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb) is closely related to the Ho{sub 2}Rh{sub 12}As{sub 7} structure type and features a 3D [Mg{sub 18}Tt{sub 11}] network with 1D hexagonal tunnels along the c-axis occupied by K{sup +} cations. Display Omitted Research highlights: Two new polar intermetallics, K{sub 2}Mg{sub 5-x}Sn{sub 3} (x=0.28) and K{sub 3}Mg{sub 18}Tt{sub 11} (Tt=Sn, Pb). Electronic structure calculations were performed by both TB-LMTO and EHTB methods. Mg atom can function as either electron donor or participator in the network.« less

Radiofrequency attenuator and method

DOEpatents

Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

2009-01-20

Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

Radiofrequency attenuator and method

DOEpatents

Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

2009-11-10

Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3 C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurishima, Kazunori, E-mail: ce41034@meiji.ac.jp; Nabatame, Toshihide, E-mail: NABATAME.Toshihide@nims.go.jp; Shimizu, Maki

To investigate the influence of ionic/covalent interface of Al{sub 2}O{sub 3}/SiO{sub 2} gate insulator on the electrical properties of thin-film transistors (TFTs) with ionic Ga-In-Zn-O (GIZO) semiconducting channel layers, Al{sub 2}O{sub 3} layers of different thickness were introduced between SiO{sub 2} and GIZO using plasma-enhanced atomic layer deposition. The GIZO layers were obtained by DC magnetron sputtering using a GIZO target (Ga:In:Zn = 1:1:1 mol. %). The GIZO TFTs with an Al{sub 2}O{sub 3}/SiO{sub 2} gate insulator exhibited positive threshold voltage (V{sub th}) shift (about 1.1 V), V{sub th} hysteresis suppression (0.23 V), and electron mobility degradation (about 13%) compared with thosemore » of a GIZO TFT with SiO{sub 2} gate insulator by the influence of ionic/ionic and ionic/covalent interface at Al{sub 2}O{sub 3}/GIZO and Al{sub 2}O{sub 3}/SiO{sub 2}, respectively. To clarify the origin of the positive V{sub th} shift, the authors estimated the shifts of flatband voltage (0.4 V) due to the dipole and the fixed charge (−1.1 × 10{sup 11}/cm{sup 2}) at Al{sub 2}O{sub 3}/SiO{sub 2} interface, from capacitance–voltage data for Pt/Al{sub 2}O{sub 3}/SiO{sub 2}/p-Si capacitors. Based on these experimental data, the authors found that the positive V{sub th} shift (1.1 V) could be divided into three components: the dipole (−0.4 V) and fixed charge (0.15 V) at the SiO{sub 2}/Al{sub 2}O{sub 3} interface, and the fixed charge (1.35 V) at the Al{sub 2}O{sub 3}/GIZO interface. Finally, it is noted that heterointerface of SiO{sub 2}/Al{sub 2}O{sub 3}/GIZO stacks is important not only to recognize mechanism of V{sub th} shift but also to design future TFTs with high-k dielectrics and low operating voltage.« less

Transition metal-free olefin polymerization catalyst

DOEpatents

Sen, Ayusman; Wojcinski, II, Louis M.; Liu, Shengsheng

2001-01-01

Ethylene and/or propylene are polymerized to form high molecular weight, linear polymers by contacting ethylene and/or propylene monomer, in the presence of an inert reaction medium, with a catalyst system which consists essentially of (1) an aluminum alkyl component, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-octylaluminum and diethylaluminum hydride and (2) a Lewis acid or Lewis acid derivative component, such as B (C.sub.6 F.sub.5).sub.3, [(CH.sub.3).sub.2 N (H) (C.sub.6 H.sub.5)].sup.+ [B (C.sub.6 F.sub.5)4].sup.-, [(C.sub.2 H.sub.5).sub.3 NH].sup.+ [B C.sub.6 F.sub.5).sub.4 ],.sup.-, [C(C.sub.6 F.sub.5).sub.3 ].sup.+ [B(C.sub.6 F.sub.5).sub.4 ].sup.-, (C.sub.2 H.sub.5).sub.2 Al(OCH.sub.3), (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butyl-4-methylphenoxide), (C.sub.2 H.sub.5)Al(2,6 -di-t-butylphenoxide).sub.2, (C.sub.2 H.sub.5).sub.2 Al(2,6-di-t-butylphonoxide) , 2,6 -di-t-butylphenol.multidot.methylaluminoxane or an alkylaluminoxane, and which may be completely free any transition metal component(s).

Effect of the addition of B{sub 2}O{sub 3} and BaO-B{sub 2}O{sub 3}-SiO{sub 2} glasses on the microstructure and dielectric properties of giant dielectric constant material CaCu{sub 3}Ti{sub 4}O{sub 12}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shri Prakash, B.; Varma, K.B.R.

2007-06-15

The effect of the addition of glassy phases on the microstructure and dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) ceramics was investigated. Both single-component (B{sub 2}O{sub 3}) and multi-component (30 wt% BaO-60 wt% B{sub 2}O{sub 3}-10 wt% SiO{sub 2} (BBS)) glass systems were chosen to study their effect on the density, microstructure and dielectric properties of CCTO. Addition of an optimum amount of B{sub 2}O{sub 3} glass facilitated grain growth and an increase in dielectric constant. However, further increase in the B{sub 2}O{sub 3} content resulted in its segregation at the grain boundaries associated with a reduction in themore » grain size. In contrast, BBS glass addition resulted in well-faceted grains and increase in the dielectric constant and decrease in the dielectric loss. An internal barrier layer capacitance (IBLC) model was invoked to correlate the dielectric constant with the grain size in these samples. - Graphical abstract: Scanning electron micrograph of 30 wt% BaO-60 wt% B{sub 2}O{sub 3}-10 wt% SiO{sub 2} (BBS) glass-added CaCu{sub 3}Ti{sub 4}O{sub 12} ceramic on sintering.« less

Silica and boron-containing ultraphosphate laser glass with low concentration quenching and improved thermal shock resistance

DOEpatents

Cook, Lee M.; Stokowski, Stanley E.

1987-04-28

Neodymium-doped phosphate glasses having a refractive index, nd>1.520; an Abbe number, Vd, <60; a density <3.0 g/cm.sup.3, a thermal expansion coefficient, .alpha., .ltoreq.110.times.10.sup.-7 .degree.C..sup.-1 ; a Young's Modulus, E, <70.times.10.sup.3 N/mm.sup.2 ; a Poisson's Ratio, .nu., <0.28; a thermal conductivity, K, >0.5 W/m.multidot.K, a thermal FOM=(1-.nu.).multidot.K/.alpha.E>0.7, consisting essentially of, in mol. %: P.sub.2 O.sub.5 : 40-70% SiO.sub.2 : 0-20% B.sub.2 O.sub.3 : 5-20% Sum SiO.sub.2 +B.sub.2 O.sub.3 : 5-35% Sum Li.sub.2 O+Na.sub.2 O+K.sub.2 O: 5-20% Sum La.sub.2 O.sub.3 +Nd.sub.2 O.sub.3 : 3-10% Sum MgO+CaO+SrO+BaO+ZnO: 0-10% and preferably containing an amount of Nd.sub.2 O.sub.3 effective for laser activity having an emission cross-section, .sigma., >3.5.times.10.sup.-20 cm.sup.2 ; a fluorescence linewidth (.DELTA..lambda..sub.f1)<23.5 nm; a first e-folding time of the Nd.sup.3+ fluorescence at 0.5 wt. % Nd.sub.2 O.sub.3 >375 .mu.sec, and a first e-folding time of the Nd.sup.3+ fluorescence at 10 wt. % >175 .mu.sec at 10 wt. %, have very low self-concentration quenching rates.

STEAM REFORMING OF CHLOROCARBONS: CHLORINATED AROMATICS. (R826694C633)

EPA Science Inventory

Effective dechlorination of chloroaromatics, such as C₆H₅Cl, 1,2-C₆H₄Cl₂, 1,3-C₆H₄Cl₂ and 1,2,4-C₆H₃Cl₃, using catalytic steam reforming has been confirmed ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pangaro, L.; Burman, K.D.; Wartofsky, L.

The present report describes a RIA for 3,5-diiodothyronine (3,5T/sub 2/) which uses inner ring-labeled 3,5-(/sup 125/I)T/sub 2/ as the ligand and has a lower limit of detectability of 0.5 ng/dl. Cross-reaction was 0.14% with T/sub 3/, less than 0.001% with T/sub 4/, 1.2% with 3,3',5-triiodothyroacetic acid, and 6.1% with 3,5-diiodothyroacetic acid. No cross-reaction was detectable for iodothyronines within their physiological ranges. Intraassay variation ranged from 2.2 to 7.8%, and interassay variation ranged from 12.7 to 14%. The mean (+-SE) serum 3.5T/sub 2/ concentration in 70 normal subjects was 4.3 +- 0.2 ng/dl. The mean (+-SE) 3.5T/sub 2/ in 14 hyperthyroidmore » patients was increased to 18.4 +- 2.3 ng/dl (P < 0.001), and all but 1 patient had an elevated level. In 10 hypothyroid patients the mean (+-SE) 3,5T/sub 2/ level was decreased to 1.4 +- 0.3 ng/dl (P < 0.001). In 4 patients, levels overlapped with the normal range. In 4 hypothyroid subjects treated with L-T/sub 1/, 3,5T/sub 2/ levels were normal, suggesting that the majority of 3,5T/sub 2/ originates from extrathyroidal conversion from T/sub 3/. Studies in fasting obese subjects demonstrated that serum 3,5T/sub 2/ (mean +- SE) levels fell from 3.4 +- 0.3 to 2.5 +- 0.7 ng/dl during fasting. This fall was significant (P < 0.001) and in parallel with the fall in T/sub 3/ levels of 182 +- 20 to 126 +- 12 ng/dl. In fasting subjects given 100 ..mu..g oral L-T/sub 3//day T/sub 3/ levels rose from 138 +- 11 to 362 +- 26 ng/dl. 3,5T/sub 2/ levels (corrected for cross-reaction and for contamination of oral T/sub 3/ with 3,5T/sub 2/) rose from 2.2 +- 0.7 to 6.4 +- 1.0 ng/dl. In fasting subjects given 25 ..mu..g oral L-T/sub 3//day, T/sub 3/ levels fell from 165 +- 5.1 to 139 +- 6.9 ng/dl. Corrected 3,5T/sub 2/ levels changed from 3.7 +- 0.4 to 2.5 +- 0.3 ng/dl. Neither change were significant.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Gan; Zou, Kang-Yu; Yang, Ying

In this work, the rod-like ligand 1,4-bis(imidazol-1-yl)-benzene (bib) has been utilized as a building block to perform counterion researches on the structural diversities of coordination polymers. A series of new manganese compounds, ([Mn(bib){sub 3}(ClO{sub 4}){sub 2}](CHCl{sub 3}){sub 2}){sub n} (1), [Mn(bib){sub 2}(N{sub 3}){sub 2}]{sub n} (2), [Mn(bib){sub 2}(HCO{sub 2}){sub 2}]{sub n} (3), [Mn(bib){sub 2}(Ac){sub 2}]{sub n} (4), ([Mn(bib){sub 2}(CF{sub 3}SO{sub 3}){sub 2}](CH{sub 2}Cl{sub 2}){sub 4}){sub n} (5), and [Mn(bib){sub 2}(SO{sub 4})]{sub n} (6) have been successfully synthesized. Compound 1 shows a 3D interpenetrating α-Po network only based on the bib linker. Compounds 2 and 3 exhibit a 2D (4,4) layermore » with parallel and incline interpenetration, respectively. Compounds 4 and 5 display a parallel-packing 2D (4,4) layer with the porosity of 23.4% and 61.4%, respectively. Compound 6 furnishes a 3D α-Po framework with a 2D (4,4) layer pillared by the μ{sub 2}-SO{sub 4}{sup 2−} ion. The structural diversities among 1–6 have been carefully discussed, and the roles of counterions (from coordination affinity and molecular size) in the self-assembly of coordination polymers have also been well documented. Furthermore, magnetic properties of 6 have been carefully studied. - Graphical abstract: Six new compounds have been successfully synthesized. Structural studies reveal that the topology, entanglement and porosity are tunable by the counterion. Furthermore, the weak ferromagnetic coupling is conducted in 6. - Highlights: • Six new Mn{sup II} compounds have been synthesized. • Compounds 1–3 exhibit diverse interpenetrating frameworks. • Compounds 4 and 5 exhibit 3D packing porous architectures. • The tunable effect of counterion has been documented. • Magnetic properties of 6 have been studied by fitting the data.« less

Syntheses, crystal structures and Raman spectra of Ba(BF{sub 4})(PF{sub 6}), Ba(BF{sub 4})(AsF{sub 6}) and Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}); the first examples of metal salts containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozinsek, Matic; Bunic, Tina; Goreshnik, Evgeny, E-mail: evgeny.goreshnik@ijs.s

2009-10-15

In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) a compound Ba(BF{sub 4})(PF{sub 6}) was isolated and characterized by Raman spectroscopy and X-ray diffraction on the single crystal. Ba(BF{sub 4})(PF{sub 6}) crystallizes in a hexagonal P6-bar2m space group with a=10.2251(4) A, c=6.1535(4) A, V=557.17(5) A{sup 3} at 200 K, and Z=3. Both crystallographically independent Ba atoms possess coordination polyhedra in the shape of tri-capped trigonal prisms, which include F atoms from BF{sub 4}{sup -} and PF{sub 6}{sup -} anions. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was isolated and characterized.more » It crystallizes in an orthorhombic Pnma space group with a=10.415(2) A, b=6.325(3) A, c=11.8297(17) A, V=779.3(4) A{sup 3} at 200 K, and Z=4. The coordination around Ba atom is in the shape of slightly distorted tri-capped trigonal prism which includes five F atoms from AsF{sub 6}{sup -} and four F atoms from BF{sub 4}{sup -} anions. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was obtained. It crystallizes in a hexagonal P6{sub 3}/mmc space group with a=6.8709(9) A, c=17.327(8) A, V=708.4(4) A{sup 3} at 200 K, and Z=2. The barium environment in the shape of tetra-capped distorted trigonal prism involves 10 F atoms from four BF{sub 4}{sup -}, three AsF{sub 6}{sup -} and three H{sub 3}F{sub 4}{sup -} anions. All F atoms, except the central atom in H{sub 3}F{sub 4} moiety, act as mu{sub 2}-bridges yielding a complex 3-D structural network. - Graphical abstract: The first three compounds, containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} (A=P, As) anions have been synthesized and characterized by Raman spectroscopy and X-ray single crystal diffraction. In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) the compound Ba(BF{sub 4})(PF{sub 6}) was isolated. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was obtained. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was prepared.« less

Electric field induced cubic to monoclinic phase transition in multiferroic 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Rishikesh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com

2014-10-20

The results of x-ray diffraction studies on 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution poled at various electric fields are presented. After poling, significant value of planar electromechanical coupling coefficient (k{sub P}) is observed for this composition having cubic structure in unpoled state. The cubic structure of 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} transforms to monoclinic structure with space group Pm for the poling field ≥5 kV/cm. Large c-axis microscopic lattice strain (1.6%) is achieved at 30 kV/cm poling field. The variation of the c-axis strain and unit cell volume with poling field shows a drastic jump similar to that observed for strainmore » versus electric field curve in (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3}) O{sub 3}-xPbTiO{sub 3} and (1 − x)Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3}.« less

Electronic structure of Pr{sub 1{minus}x}Y{sub x}Ba{sub 2}Cu{sub 3}O{sub y} (x=0, 0.5, and 1.0)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kakinuma, K.; Fueki, K.

1997-08-01

In order to elucidate the reason why PrBa{sub 2}Cu{sub 3}O{sub y}is not a superconductor, we examined the Pr valence and measured the oxygen nonstoichiometry and the conductivity at temperatures up to 1200 K for three kinds of oxides, PrBa{sub 2}Cu{sub 3}O{sub y}, (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y}, and YBa{sub 2}Cu{sub 3}O{sub y}. The valence of Pr was found to be +3. Any difference was not found in oxygen nonstoichiometry and conductivity among three kinds of oxides. We analyzed the data of oxygen nonstoichiometry on the basis of defect thermodynamics and calculated the numbers of Cu{sup +}, Cu{sup 2+}, andmore » Cu{sup 3+} ions in the unit cell as a function of y. The number of Cu{sup 3+} ions (the amount of holes) was found to be proportional to ({Delta}y){sup 1.6}({Delta}y=y{minus}6.0), whereas the conductivity was found to be proportional to ({Delta}y){sup 3.2} in these oxides. We interpreted the remarkable increase of {sigma} with {Delta}y as an evidence of the increase of both mobility and hole concentration with {Delta}y. At high temperatures, we detected the conductivity minimum {sigma}{sub min} which was found in the log{sub 10}{sigma}{minus}log{sub 10}P{sub O{sub 2}} plot at constant temperatures. From the slope of the Arrhenius plot for {sigma}{sub min}, the band gap was determined to be 1.21, 1.32, and 1.37 eV for PrBa{sub 2}Cu{sub 3}O{sub y}, (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y} and YBa{sub 2}Cu{sub 3}O{sub y}, respectively. We determined the conductivity of the same oxygen content as a function of temperature from 4.2 to 1200 K. The energy gap {Delta}E between the acceptor level and the top of the valence band was calculated from the slope of the Arrhenius plot for conductivity. {Delta}E for superconducting YBa{sub 2}Cu{sub 3}O{sub y} and (Pr{sub 0.5}Y{sub 0.5})Ba{sub 2}Cu{sub 3}O{sub y} were zero at 300 K but that for nonsuperconducting PrBa{sub 2}Cu{sub 3}O{sub y} was 20 meV at 100 K even for y=6.93. (Abstract Truncated)« less

Methane-methanol cycle for the thermochemical production of hydrogen

DOEpatents

Dreyfuss, Robert M.; Hickman, Robert G.

1976-01-01

A thermochemical reaction cycle for the generation of hydrogen from water comprising the following sequence of reactions wherein M represents a metal: CH.sub.4 + H.sub.2 O .fwdarw. CO + 3H.sub.2 (1) co + 2h.sub.2 .fwdarw. ch.sub.3 oh (2) ch.sub.3 oh + so.sub.2 + mo .fwdarw. mso.sub.4 + ch.sub.4 (3) mso.sub.4 .fwdarw. mo + so.sub.2 + 1/2o.sub.2 (4) the net reaction is the decomposition of water into hydrogen and oxygen.

Synthesis, structure, and photochemistry of a novel rhenium (I) enolate and photochemistry and second harmonic generation in Langmuir-Blodgett films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gron, L.U.

1987-01-01

A background of cyclopentadienyl ring-slippage reactions is presented along with a brief discussion of the transformations of the related indenyl and fluorenyl ligands. Subsequently a review of oxygen-bonded transition metal enolate complexes is given. Synthesis, structure, and photochemistry of fac-(CO)/sub 3/(P(CH/sub 3/)/sub 3/)/sub 2/Re(OC(CH/sub 3/)C/sub 5/H/sub 4/), 5, is presented. The Re(I) enolate complex was prepared from the reaction of (eta/sup 5/-C/sub 5/H/sub 4/C(O)CH/sub 3/)Re(CO)/sub 3/, 4, with P(CH/sub 3/)/sub 3/. Compound 5 was characterized structurally in the solid state by x-ray crystallography and in solution by ir, and /sup 1/H, /sup 13/C, and /sup 31/P NMR spectroscopy. Photolysis ofmore » 5 at 337 nm in CH/sub 2/Cl/sub 2/ solution cleaves the Re-O bond: smooth conversion to fac-(CO)/sub 3/(P(CH/sub 3/)/sub 3/)/sub 2/ReCl, 6, is observed with a quantum yield of 0.04. The photochemistry of 5 in benzene solution and the synthesis and photochemistry of fac-(CO)/sub 3/(P(CH/sub 3/)/sub 2/-Re(OC(CH/sub 3/)C/sub 5/H/sub 3/CH/sub 3/), 14, is also presented. The Langmuir-Blodgett method of monolayer film formation, characteristics of good film formation and structure of the supported film are reviewed. The basics of second harmonic generation are also presented along with useful applications of the Langmuir-Blodgett films to these studies. Synthesis, structure, and photochemistry of Langmuir-Blodgett stearate films incorporated the emissive Eu/sup 3 +/ and UO/sub 2//sup 2 +/ cations are described. A mixed film containing UO/sub 2/2/sup +//stearate and Eu/sup 3 +//stearate in alternating layers exhibited energy transfer from the UO/sub 2//sup 2 +/ ions to the Eu/sup 3 +/ ions.« less

Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

DOEpatents

Alvarez, Marc A [Santa Fe, NM; Martinez, Rodolfo A [Santa Fe, NM; Unkefer, Clifford J [Los Alamos, NM

2008-01-22

The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S--, --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group. The present invention is also directed to a process of preparing labeled compounds, e.g., process of preparing [.sup.13C]methacrylic acid by reacting a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13CH.sub.2)-- aryl sulfone precursor with .sup.13CHI to form a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate, and, reacting the (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate with sodium hydroxide, followed by acid to form [.sup.13C]methacrylic acid. The present invention is further directed to a process of preparing [.sup.2H.sub.8]methyl methacrylate by reacting a (HOOC--C(C.sup.2H.sub.3).sub.2-- aryl sulfinyl intermediate with CD.sub.3I to form a (.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate, and heating the(.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate at temperatures and for time sufficient to form [.sup.2H.sub.8]methyl methacrylate.

Crystal chemistry of thorium nitrates and chromates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sigmon, Ginger E.; Burns, Peter C., E-mail: pburns@nd.ed

2010-07-15

The structures and infrared spectra of six novel thorium compounds are reported. Th(NO{sub 3}){sub 2}(OH){sub 2}(H{sub 2}O){sub 2} (1) crystallizes in space group C2/c, a=14.050(1), b=8.992(7), c=5.954(5) A, {beta}=101.014(2){sup o}. K{sub 2}Th(NO{sub 3}){sub 6} (2), P-3, a=13.606(1), c=6.641(6) A. (C{sub 12}H{sub 28}N){sub 2}Th(NO{sub 3}){sub 6} (3), P2{sub 1}/c, a=14.643(4), b=15.772(5), c=22.316(5) A, {beta}=131.01(1){sup o}. KTh(NO{sub 3}){sub 5}(H{sub 2}O){sub 2} (4), P2{sub 1}/c, a=10.070(8), b=12.731(9), c=13.231(8) A, {beta}=128.647(4){sup o}. Th(CrO{sub 4}){sub 2}(H{sub 2}O){sub 2} (5), P2{sub 1}/n, a=12.731(1), b=9.469(8), c=12.972(1) A, {beta}=91.793(2){sup o}. K{sub 2}Th{sub 3}(CrO{sub 4}){sub 7}(H{sub 2}O){sub 10} (6), Ama2, a=19.302(8), b=15.580(6), c=11.318(6) A. The coordination polyhedra about Thmore » in these structures are diverse. Th is coordinated by 9 O atoms in 5 and 6, seven of which are from monodentate (CrO{sub 4}) tetrahedra and two are (H{sub 2}O). The Th in compound 1 is coordinated by ten O atoms, four of which are O atoms of two bidentate (NO{sub 3}) triangles and six of which are (OH) and (H{sub 2}O). In compounds 2, 3 and 4 the Th is coordinate by 12 O atoms. In 2 and 3 there are six bidentate (NO{sub 3}) triangles, and in 4 ten of the O atoms are part of five bidentate (NO{sub 3}) triangles and the others are (H{sub 2}O) groups. The structural units of these compounds consist of a chain of thorium and nitrate polyhedra (1), isolated thorium hexanitrate clusters (2, 3), an isolated thorium pentanitrate dihydrate cluster (4), and a sheet (6) and framework (5) of thorium and chromate polyhedra. These structures illustrate the complexity inherent in the crystal chemistry of Th. - Graphical Abstract: The structures and infrared spectra of four new Th nitrates and two Th chromates are reported. The coordination numbers of the Th cations range from nine to 12 in these compounds. Structural units consist of isolated clusters, chains, sheets and frameworks.« less

A pair of novel Cd(II) enantiomers based on lactate derivatives: Synthesis, crystal structures and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Zhong-Xuan, E-mail: xuzhongxuan1974@163.com; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, the Chinese Academy of Sciences, Fuzhou, Fujian 350002; Ao, Ke-Hou

A pair of novel 3D homochiral metal−organic frameworks (HMOFs), namely [Cd{sub 2.5}((R)-CIA){sub 6}(1,4-DIB)(H{sub 2}O){sub 2}]·((CH{sub 3}){sub 2}NH{sub 2})·H{sub 2}O (1-D), [Cd{sub 2.5}((S)-CIA){sub 6}(1,4-DIB)(H{sub 2}O){sub 2}]·((CH{sub 3}){sub 2}NH{sub 2})·H{sub 2}O (1-L), have been synthesized using lactic acid derivative ligands ((R)-H{sub 3}CIA and (S)-H{sub 3}CIA) and 1,4-DIB. Crystallographic analyses indicate that the complexes 1-D and 1-L are packed by cage substructures. Some physical characteristics, such as solid-state circular dichroism (CD), thermal stabilities and photoluminescent properties are also investigated. Our results highlight the effective method to apply lactic acid derivative ligands to form interesting HMOFs. - Graphical abstract: Using lactic acid derivative ligandsmore » ((R)-H{sub 3}CIA and (S)-H{sub 3}CIA) and 1,4-DIB to assemble with Cd{sup 2+} ions, a pair of novel 3D homochiral metal-organic frameworks (HMOFs) with cage substructures have been synthesized. Display Omitted - Highlights: • Lactic acid derivative ligands • Cage substructure • Enantiomers.« less

Thermal expansion of phosphates with the NaZr{sub 2}(PO{sub 4}){sub 3} structure containing lanthanides and zirconium: R{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} (R = Nd, Eu, Er) and Er{sub 0.33(1–x)} Zr{sub 0.25x}Zr{sub 2}(PO{sub 4}){sup 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volgutov, V. Yu., E-mail: Valeriy.Volgutov@inbox.ru; Orlova, A. I.

Phosphates R{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} (R = Nd, Eu, or Er) and Er{sub 0.33(1–x)}Zr{sub 0.25}Zr{sub 2}(PO{sub 4}){sub 3} (x = 0, 0.25, 0.5, 0.75, 1.0) of the NaZr{sub 2}(PO{sub 4}){sub 3} family have been synthesized and investigated by high-temperature X-ray diffraction. The crystallochemical approach is used to obtain compounds with expected small and controllable thermal-expansion parameters. Phosphates with close-to-zero thermal-expansion parameters, including those with low thermal-expansion anisotropy, have been obtained: Nd{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} with α{sub a} =–2.21 × 10{sup −6} °C{sup −1}, α{sub c} = 0.81 × 10{sup −6} °C{sup −1}, and Δα = 3.02 × 10{supmore » −6} °C{sup –1} and Er{sub 0.08}Zr{sub 0.19}Zr{sub 2}(PO{sub 4}){sub 3} with α{sub a} =–1.86 × 10{sup −6} °C{sup −1}, α{sub c} = 1.73 × 10{sup −6} °C{sup −1}, and Δα = 3.58 × 10{sup −6} °C{sup −1}.« less

Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} heterogeneous photocatalyst prepared by a facile hydrothermal synthesis with enhanced photocatalytic performance under visible light irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ran, Rong; McEvoy, Joanne Gamage; Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5

Highlights: • The photocatalyst was hydrothermally prepared by adjusting the ratio of Ag to V. • Multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} obtained exhibited multi-morphological features. • The photocatalyst exhibited strong visible light driven photoactivity towards RhB. - Abstract: A novel Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst was synthesized by adjusting the molar ratio of silver–vanadium (Ag–V) in a facile hydrothermal method to obtain multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst. The photocatalytic activity of the prepared samples was quantified by the degradation of Rhodamine B (RhB) model organic pollutant under visible light irradiation.more » Compared to pure Ag{sub 3}VO{sub 4}, Ag{sub 4}V{sub 2}O{sub 7} and P25 TiO{sub 2}, respectively, the as-synthesized multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} powders gave rise to a significantly higher photocatalytic activity, achieving up to 99% degradation of RhB in 2 h under visible light. This enhanced photocatalytic performance was attributed to the effect of the multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst and the surface plasmon resonance (SPR) of the incorporated metallic silver (Ag{sup 0}) nanoparticles (NPs) generated during the photocatalysis, as evidenced by post-use characterization, resulting in improved visible light absorption and electron-hole (e{sup −}-h{sup +}) separation. A mechanism was proposed for the photocatalytic degradation of RhB on the surface of Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7}.« less

Simultaneous presence of (Si{sub 3}O{sub 10}){sup 8−} and (Si{sub 2}O{sub 7}){sup 6−} groups in new synthetic mixed sorosilicates: BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and isotypic compounds, studied by single-crystal X-ray diffraction, Raman spectroscopy and DFT calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wierzbicka-Wieczorek, Maria, E-mail: maria.wierzbicka-wieczorek@uni-jena.de; Többens, Daniel M.; Kolitsch, Uwe

2013-11-15

Three new, isotypic silicate compounds, BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), SrYb{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and SrSc{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), were synthesized using high-temperature flux growth techniques, and their crystal structures were solved from single-crystal X-ray intensity data: monoclinic, P2{sub 1}/m, with a=5.532(1)/5.469(1)/5.278(1), b=19.734(4)/19.447(4)/19.221(4), c=6.868(1)/6.785(1)/6.562(1) Å, β=106.53(3)/106.20(3)/106.50(3)°, V=718.8(2)/693.0(2)/638.3(2) Å{sup 3}, R(F)=0.0225/0.0204/0.0270, respectively. The topology of the novel structure type contains isolated horseshoe-shaped Si{sub 3}O{sub 10} groups (Si–Si–Si=93.15–95.98°), Si{sub 2}O{sub 7} groups (Si–O{sub bridge}–Si=180°, symmetry-restricted) and edge-sharing M(1)O{sub 6} and M(2)O{sub 6} octahedra. Single-crystal Raman spectra of the title compounds were measured and compared with Raman spectroscopicmore » data of chemically and topologically related disilicates and trisilicates, including BaY{sub 2}(Si{sub 3}O{sub 10}) and SrY{sub 2}(Si{sub 3}O{sub 10}). The band assignments are supported by additional theoretical calculation of Raman vibrations by DFT methods. - Graphical abstract: View of BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) along [100], showing zigzag chains and the tri- and disilicate groups. The unit cell is outlined. Display Omitted - Highlights: • We report a novel interesting crystal structure type for mixed sorosilicates containing Y, Yb, and Sc. • Synthesis of such mixed sorosilicates is possible by a high-temperature flux-growth technique. • Calculation of Raman vibrations by advanced DFT methods allows a considerably improved interpretation of measured Raman spectra.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rani, Jyoti; Yadav, K.L., E-mail: klyadav35@yahoo.com; Prakash, Satya

Highlights: • Spinel–perovskite xCoFe{sub 2}O{sub 4}–(1 − x)(0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3}) composites have been synthesized by solid state reaction method. • Two anomalies in dielectric constant have been identified, and the composites show relaxor behaviour. • The magnetic properties of the composites improve with increasing concentration of CoFe{sub 2}O{sub 4}. • Enhanced magnetodielectric effect is found, and magnetoelectric coupling has been confirmed by Δϵ ∼ γM{sup 2} relation. • Optical band gap energy of these composites has been reported for the first time. - Abstract: xCoFe{sub 2}O{sub 4}–(1 − x)(0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3}) compositesmore » with x = 0.1, 0.2, 0.3 and 0.4 have been synthesized by solid state reaction method. X-ray diffraction analysis and field emission secondary electron microscopy have been used for structural and morphological analysis, respectively. The spinel CoFe{sub 2}O{sub 4} and perovskite 0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} phase could be identified in the composites. Two anomalies in dielectric constant have been identified: first one is close to ferroelectric to paraelectric phase transition of 0.5Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–0.5(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} ceramic and the other lies near the magnetic transition temperature of CoFe{sub 2}O{sub 4}. There is an increase in magnetocapacitance and saturation magnetization of the composites at room temperature with increase in CoFe{sub 2}O{sub 4} content. The magnetoelectric coupling coefficient (γ) was approximated by Δϵ ∼ γM{sup 2} relation. The optical band gap energy of the composites decreases with increase in CoFe{sub 2}O{sub 4} content.« less

In-situ X-ray diffraction study of phase transformations in the Am-O system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebreton, Florent, E-mail: florent.lebreton@cea.fr; GEMH, ENSCI, 87065 Limoges; Belin, Renaud C., E-mail: renaud.belin@cea.fr

2012-12-15

In the frame of minor actinides recycling, americium can be transmuted by adding it in UO{sub 2} or (U, Pu)O{sub 2} fuels. Americium oxides exhibiting a higher oxygen potential than U or Pu oxides, its addition alters the fuel properties. To comprehend its influence, a thorough knowledge of the Am-O phase equilibria diagram and of thermal expansion behavior is of main interest. Due to americium scarcity and high radiotoxicity, few experimental reports on this topic are available. Here we present in-situ high-temperature XRD results on the reduction from AmO{sub 2} to Am{sub 2}O{sub 3}. We show that fluorite (Fm-3m) AmO{submore » 2} is reduced to cubic (Ia-3) C Prime -type Am{sub 2}O{sub 3+{delta}}, and then into hexagonal (P6{sub 3}/mmc) A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. We also demonstrate the transitional existence of the monoclinic (C2/m) B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion behavior of the hexagonal Am{sub 2}O{sub 3} between room temperature and 1840 K. - Graphical abstract: Americium dioxide was in situ studied by high-temperature X-ray diffraction. First, fluorite AmO{sub 2} is reduced to cubic C Prime -type Am{sub 2}O{sub 3+{delta}} and then transforms into hexagonal A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. Then, we demonstrate the transitional existence of monoclinic B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion of A-type Am{sub 2}O{sub 3} between room temperature and 1840 K. This work may contribute to a better understanding of Am oxide behavior. Highlights: Black-Right-Pointing-Pointer We realize an in-situ high-temperature X-ray diffraction study on an AmO{sub 2} sample. Black-Right-Pointing-Pointer Fluorite AmO{sub 2} transforms to cubic Am{sub 2}O{sub 3+{delta}} and then to hexagonal Am{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Little-known monoclinic Am{sub 2}O{sub 3} is observed during the cubic-to-hexagonal transition. Black-Right-Pointing-Pointer Lattice parameter thermal expansion of hexagonal Am{sub 2}O{sub 3} is given up to 1840 K. Black-Right-Pointing-Pointer We give additional data on AmO{sub 2} lattice parameter expansion under self-irradiation.« less

Fe{sub 2.5}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, a new phosphate-borophosphate with a microporous structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belokoneva, E. L., E-mail: elbel@geol.msu.ru; Dimitrova, O. V.

2015-05-15

A new phosphate-borophosphate Fe{sub 2.5}{sup 3+}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, space group P12{sub 1}/n, is obtained under hydrothermal conditions. Blocks (Fe{sup 3+}(PO{sub 4}){sub 6}){sup 15−} consisting of vertex-sharing (Fe1,Fe2)O{sub 6} octahedra and six PO{sub 4} tetrahedra are distinguished in the structure of the new phase, which was determined without preliminary knowledge of the chemical formula. Such blocks are known for many phosphates (borophosphates), germanates, gallates, and silicates. Blocks form layers connected by BO{sub 4} tetrahedra into a framework with large pores reaching ∼9.5 Å, which are occupied by water molecules. The out-of-layer octahedral positionmore » of the Fe3 atom is split and occupied statistically. The anion radical is characterized as a phosphate-borophosphate: it consists of two isolated PO4 tetrahedra and a borophosphate soro group [BP{sub 2}O{sub 7}(OH){sub 2}] first found in NaIn[BP{sub 2}O{sub 8}(OH)]. A layer of octahedra is characterized by higher local symmetry corresponding to the orthorhombic group Pm2{sub 1}n.« less

Phase equilibria in the La–Mg–Ge system at 500 °C and crystal structure of the new ternary compounds La{sub 11}Mg{sub 2}Ge{sub 7} and LaMg{sub 3−x}Ge{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Negri, S., E-mail: serena.denegri@unige.it; Solokha, P.; Skrobańska, M.

2014-10-15

The whole 500 °C isothermal section of the La–Mg–Ge ternary system was constructed. The existence and crystal structure of three ternary compounds were confirmed: La{sub 2+x}Mg{sub 1−x}Ge{sub 2} (τ{sub 2}, P4/mbm, tP10–Mo{sub 2}FeB{sub 2}, 0≤x≤0.25), La{sub 4}Mg{sub 5}Ge{sub 6} (τ{sub 3}, Cmc2{sub 1}, oS60–Gd{sub 4}Zn{sub 5}Ge{sub 6}) and La{sub 4}Mg{sub 7}Ge{sub 6} (τ{sub 4}, C2/m, mS34, own structure type). Five novel compounds were identified and structurally characterized: La{sub 11}Mg{sub 2}Ge{sub 7} (τ{sub 1}, P4{sub 2}/ncm, tP88-8, own structure type, a=1.21338(5), c=1.57802(6) nm), LaMg{sub 3−x}Ge{sub 2} (τ{sub 5}, P3{sup ¯}1c, hP34-0.44, own structure type, x=0.407(5), a=0.78408(4), c=1.45257(7) nm), La{sub 6}Mg{sub 23}Gemore » (τ{sub 6}, Fm3{sup ¯}m, cF120–Zr{sub 6}Zn{sub 23}Si, a=1.46694(6) nm), La{sub 4}MgGe{sub 10−x} (τ{sub 7}, x=0.37(1), C2/m, mS60-1.46, own structure type, a=0.88403(8), b=0.86756(8), c=1.7709(2) nm, β=97.16°(1) and La{sub 2}MgGe{sub 6} (τ{sub 8}, Cmce, oS72–Ce{sub 2}(Ga{sub 0.1}Ge{sub 0.9}){sub 7}, a=0.8989(2), b=0.8517(2), c=2.1064(3) nm). Disordering phenomena were revealed in several La–Mg–Ge phases in terms of partially occupied sites. The crystal structures of La{sub 11}Mg{sub 2}Ge{sub 7} and LaMg{sub 3−x}Ge{sub 2} are discussed in details. The latter is a √3a×√3a×2c superstructure of the LaLi{sub 3}Sb{sub 2} structure type; the symmetry reduction scheme is shown in the Bärnighausen formalism terms. - Graphical abstract: La–Mg–Ge isothermal section at 500 °C and group–subgroup relation between the LaLi{sub 3}Sb{sub 2} (parent type) and LaMg{sub 3−x}Ge{sub 2} (derivative) structures. - Highlights: • Novel La−Mg−Ge compounds structure determination from X-ray single crystal data. • Disordering phenomena as common features of the studied germanides. • Bärnighausen formalism as a useful tool for accurate structure determination. • Full isothermal section of the La–Mg–Ge ternary system at 500 °C.« less

Up-conversion luminescence properties and energy transfer of Tm{sup 3+}/Yb{sup 3+} co-doped BaLa{sub 2}ZnO{sub 5}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Jing; Mei, Lefu, E-mail: mlf@cugb.edu.cn; Deng, Junru

2015-11-15

Tm{sup 3+}/Yb{sup 3+} co-doped BaLa{sub 2}ZnO{sub 5} up-conversion (UC) phosphors were successfully synthesized by high temperature solid-state reaction method. The X-ray diffraction (XRD) results show that synthesized phosphor co-doped with 0.75% Tm/10% Yb has the optimum pure phase of BaLa{sub 2}ZnO{sub 5} among different co-doping concentrations. The structure of BaLa{sub 2}ZnO{sub 5}:0.75% Tm/10% Yb phosphor was refined by the Rietveld method and results show the decreased unit cell parameters and cell volume after doping Tm{sup 3+}/Yb{sup 3+}, indicating that Tm{sup 3+}/Yb{sup 3+} have successfully replaced La{sup 3+}. Under excitation at 980 nm, Tm{sup 3+}/Yb{sup 3+} co-doped BaLa{sub 2}ZnO{sub 5} phosphorsmore » present bright blue emission near 478 nm generated by the {sup 1}G{sub 4}→{sup 3}H{sub 6} transition and weak red emissions around 653 nm and 692 nm generated by the {sup 1}G{sub 4}→{sup 3}F{sub 4} and {sup 3}F{sub 3}→{sup 3}H{sub 6} transitions of Tm{sup 3+}, respectively. The UC luminescence properties of BaLa{sub 2}ZnO{sub 5} phosphors co-doped with different Tm{sup 3+}/Yb{sup 3+} concentrations were investigated, and the related UC mechanisms of Tm{sup 3+}/Yb{sup 3+} co-doped BaLa{sub 2}ZnO{sub 5} depending on pump power were studied in detail. - Graphical abstract: Up-conversion luminescence of BaLa{sub 2}ZnO{sub 5}:Tm{sup 3+}/Yb{sup 3+} and its crystal structure and up-conversion mechanisms. - Highlights: • Up-conversion phosphors BaLa{sub 2}ZnO{sub 5} co-doped with Tm{sup 3+}/Yb{sup 3+} were synthesized by high temperature solid-state reaction method. • The crystal structure of BaLa{sub 2}ZnO{sub 5} and the changes of cell parameters and volume of BaLa{sub 2}ZnO{sub 5} after doping Tm{sup 3+} and Yb{sup 3+} have been discussed. • Up-conversion luminescence properties and energy transfer between Tm{sup 3+} and Yb{sup 3+} in BaLa{sub 2}ZnO{sub 5} have been discussed in detail.« less

TiO{sub 2} nanobelts with a uniform coating of g-C{sub 3}N{sub 4} as a highly effective heterostructure for enhanced photocatalytic activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Xing; Jin, Meimei; Dong, Huaqing

2014-12-15

A novel g-C{sub 3}N{sub 4}/TiO{sub 2} nanobelt (NB) heterostructure was successfully designed and prepared. The as-prepared g-C{sub 3}N{sub 4}/TiO{sub 2} NB heterostructure exhibited high photocatalytic activity not only in the photodegradation of Rhodamine B (RhB) but also in photocatalytic H{sub 2} production. The g-C{sub 3}N{sub 4}/TiO{sub 2} NB heterostructure with a mass ratio of 1:1 demonstrated the best performance in the photodegradation of RhB, whereas a mass ratio of 3:1 demonstrated the highest H{sub 2} production rate of 46.6 μmol h{sup −1} in photocatalytic H{sub 2} production. We conclude that the synergistic effect between g-C{sub 3}N{sub 4} and TiO{sub 2}more » NBs promotes the photogenerated carrier separation in space. This valuable insight into the rational architectural design of nanostructure-based photocatalysts is expected to shed light on other photocatalytic reaction systems in the future. - Graphical abstract: A novel strategy to fabricate the g-C{sub 3}N{sub 4}/TiO{sub 2} nanobelt (NB) heterostructures was reported. The g-C{sub 3}N{sub 4}/TiO{sub 2} NB heterostructures exhibited highly effective photocatalytic activities for photodegradation of Rhodamine B and H{sub 2} production. - Highlights: • A novel strategy to fabricate the g-C{sub 3}N{sub 4}/TiO{sub 2} NB heterostructures was reported. • The heterostructure exhibited high catalytic activity in photodegradation of RhB. • The heterostructure showed good H{sub 2} productivity in photocatalytic water splitting. • The synergistic effect between g-C{sub 3}N{sub 4} and TiO{sub 2} NBs are important. • This study shows that the heterostructure can be an effective photocatalyst.« less

Hydrothermal synthesis of iron phosphate microspheres constructed by mesoporous polyhedral nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Haojie; Sun, Yali; Jia, Xiaohua, E-mail: Jiaxh@ujs.edu.cn

2015-09-15

Novel monodispersed Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·2H{sub 2}O microspheres with the diameters of several micrometers were prepared by a facile one-step hydrothermal method without using any templates, only employing FeCl{sub 3}·6H{sub 2}O and NaNH{sub 4}HPO{sub 4} as the initial materials. The obtained samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM), respectively. The characterizations revealed that the as-prepared microspheres are constructed by the polyhedral nanoparticles with an average diameter of 100 nm. The corresponding FePO{sub 4} microspheres assembled by mesoporous polyhedral nanocrystals can be easily obtained by calcining a sphere-like Fe{sub 5}(PO{submore » 4}){sub 4}(OH){sub 3}·2H{sub 2}O precursor. - Graphical abstract: Novel monodispersed Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·H{sub 2}O microspheres with a diameter of several micrometers were successfully obtained by a simple, template-free hydrothermal route. FePO{sub 4} microspheres constructed by mesoporous polyhedral FePO{sub 4} nanocrystals could be easily prepared by calcining an Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·2H{sub 2}O precursor. Display Omitted - Highlights: • Monodispersed Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·2H{sub 2}O microspheres were prepared by a facile hydrothermal method without using any templates • Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·2H{sub 2}O microspheres present a novel morphology, which was constructed by closely polyhedral nanoparticles. • The FePO{sub 4} microspheres assembled by mesoporous polyhedral nanocrystals obtained by calcining Fe{sub 5}(PO{sub 4}){sub 4}(OH){sub 3}·2H{sub 2}O precursor.« less

UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6}: A ribbon structure containing a heterobimetallic 5d-5f M{sub 3} cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, Daniel M.; Chan, George H.; Ellis, Donald E.

2010-02-15

A new solid-state compound containing a heterobimetallic cluster of U and Ta, UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6}, has been synthesized and its structure has been characterized by single-crystal X-ray diffraction methods. UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6} was synthesized from UCl{sub 4} and Ta{sub 1.2}S{sub 2} at 883 K. The O is believed to have originated in the Ta{sub 1.2}S{sub 2} reactant. The compound crystallizes in the space group P1-bar of the triclinic system. The structure comprises a UTa{sub 2} unit bridged by mu{sub 2}-S{sub 2} and mu{sub 3}-O groups. Each Ta atom bonds to two mu{sub 2}-S{sub 2}, the mu{submore » 3}-O, and two terminal Cl atoms. Each U atom bonds to two mu{sub 2}-S{sub 2}, the mu{sub 3}-O, and four Cl atoms. The Cl atoms bridge in pairs to neighboring U atoms to form a ribbon structure. The bond distances are normal and are consistent with formal oxidation states of +IV/+V/-II/-I/-I for U/Ta/O/S/Cl, respectively. The optical absorbance spectrum displays characteristic transition peaks near the absorption edge. Density functional theory was used to assign these peaks to transitions between S{sup 1-} valence-band states and empty U 5f-6d hybrid bands. Density-of-states analysis shows overlap between Ta 5d and U bands, consistent with metal-metal interactions. - The UTa2O(S2)3Cl6 cluster with completed coordination sphere around uranium« less

Thin film dielectric composite materials

DOEpatents

Jia, Quanxi; Gibbons, Brady J.; Findikoglu, Alp T.; Park, Bae Ho

2002-01-01

A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

Phase transition and multicolor luminescence of Eu{sup 2+}/Mn{sup 2+}-activated Ca{sub 3}(PO{sub 4}){sub 2} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kai; Chen, Daqin, E-mail: dqchen@fjirsm.ac.cn; Xu, Ju

2014-01-01

Graphical abstract: We have synthesized Eu{sup 2+} doped and Eu{sup 2+}/Mn{sup 2+} co-doped Ca{sub 3}(PO{sub 4}){sub 2} phosphors. The emitting color varies from blue to green with increasing of Eu{sup 2+} content for the Eu{sup 2+}-doped phosphor, and the quantum yield of the 0.05Eu{sup 2+}: Ca{sub 2.95}(PO{sub 4}){sub 2} sample reaches 56.7%. Interestingly, Mn{sup 2+} co-doping into Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu{sup 2+} → Mn{sup 2+} energy transfer. - Highlights: • A series of novel Eu{sup 2+}: Ca{submore » 3}(PO{sub 4}){sub 2} phosphors were successfully synthesized. • Phase transition of Ca{sub 3}(PO{sub 4}){sub 2} from orthorhombic to rhombohedral occurred when Mn{sup 2+} ions were doped. • The phosphors exhibited tunable multi-color luminescence. • The quantum yield of 0.05Eu{sup 2+}: Ca{sub 2.95}(PO{sub 4}){sub 2} phosphor can reach 56.7%. • The analyses of phosphors were carried out by many measurements. - Abstract: Intense blue-green-emitting Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} and tunable multicolor-emitting Eu{sup 2+}/Mn{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} phosphors are prepared via a solid-state reaction route. Eu{sup 2+}-doped orthorhombic Ca{sub 3}(PO{sub 4}){sub 2} phosphor exhibits a broad emission band in the wavelength range of 400–700 nm with a maximum quantum yield of 56.7%, and the emission peak red-shifts gradually from 479 to 520 nm with increase of Eu{sup 2+} doping content. Broad excitation spectrum (250–420 nm) of Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} matches well with the near-ultraviolet LED chip, indicating its potential applications as tri-color phosphors in white LEDs. Interestingly, Mn{sup 2+} co-doping into Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu{sup 2+} → Mn{sup 2+} energy transfer, under 365 nm UV lamp excitation.« less

Step-by-step thermal transformations of a new porous coordination polymer [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} (Me{sub 2}mal{sup 2-}=dimethylmalonate): Thermal degradation to barium cuprate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zauzolkova, Natalya, E-mail: zauzolkova@igic.ras.ru; Dobrokhotova, Zhanna; Lermontov, Anatoly

The reactions of CuSO{sub 4}{center_dot}5H{sub 2}O, dimethylmalonic acid and Ba(OH){sub 2}{center_dot}H{sub 2}O (Cu: H{sub 2}Me{sub 2}mal: Ba=1: 2: 2) in aqueous and aqueous-ethanol solutions (H{sub 2}O: EtOH=1: 1) resulted in formation of 3D-porous coordination polymers [(H{sub 2}O){sub 3}({mu}-H{sub 2}O){sub 2}CuBa({mu}{sub 3}-Me{sub 2}mal)(Me{sub 2}mal)]{sub n} (1) and [({mu}-H{sub 2}O)CuBa({mu}{sub 3}-Me{sub 2}mal)({mu}{sub 4}-Me{sub 2}mal)]{sub n} (2), respectively. It has been shown that compound 2 was an intermediate in the thermal degradation of compound 1. Thorough studies of solid-state thermolysis of 1 and 2 allowed to detect formation of coordination polymer [CuBa({mu}{sub 4}-Me{sub 2}mal)({mu}{sub 5}-Me{sub 2}mal)]{sub n} (3), structure of which was determinedmore » by X-ray powder diffraction. It has been found that the channels in polymer 3 were accessible for guest molecules (MeOH). Theoretical estimation of methanol diffusion barrier was carried out. Complete solid-phase thermolysis of 1 and 2 leads to a mixture of BaCuO{sub 2}, BaCO{sub 3}, and CuO. Special conditions for obtaining of a crystalline phase of pure cubic BaCuO{sub 2} were determined. - Graphical abstract: Step-by-step transformation of new coordination polymer [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} to [(H{sub 2}O)CuBa(Me{sub 2}mal){sub 2}]{sub n} and [CuBa(Me{sub 2}mal){sub 2}]{sub n} were performed. Dehydration of initial compound leads to structural changes of 12-membered ring fragment. All compounds have porous structure. The final product of thermal decomposition is crystalline phase of individual cubic BaCuO{sub 2}. Highlights: Black-Right-Pointing-Pointer New 3D-polymers [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} and [(H{sub 2}O)CuBa(Me{sub 2}mal){sub 2}]{sub n} were synthesized. Black-Right-Pointing-Pointer Thermal analysis showed step-by-step transformations of [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n}. Black-Right-Pointing-Pointer Crystalline phase of pure cubic BaCuO{sub 2} is the product solid-phase thermolysis.« less

Catalytic functionalities of supported sulfides. I. Effect of support and additives on the CoMo catalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muralidhar, G.; Massoth, F.E.; Shabtai, J.

1984-01-01

C-S hydrogenolysis (HDS) of thiophene, hydrogenation (HYD) of 1-hexene, and hydrocracking (HCG) of 2,4,4-trimethyl-1-pentene, were used as separate model test reactions to differentiate and assess the catalytic functionalities of sulfided CoMo catalysts, and their dependence on the nature of the support and incorporation of additives. Rate constants and relative catalyst activities for these three reaction types were determined. HDS and HYD activities of CoMo supported on different types of Al/sub 2/O/sub 3/ were higher, while the HCG activity was lower compared with CoMo supported on SiO/sub 2/-Al/sub 2/O/sub 3/, SiO/sub 2/-MgO, or TiO/sub 2/. For SiO/sub 2/-Al/sub 2/O/sub 3/ supportsmore » both HDS and HYD activities decreased with increase in SiO/sub 2/ content from 10 to 75%, while HCG activity showed the opposite trend. Additives to a finished CoMo catalyst at 0.5% level caused variations in HDS and HCG activities, while HYD was essentially unaffected. HDS was promoted by NH/sub 4/HF/sub 2/ and NH/sub 4/Cl, but depressed by NaNO/sub 3/, Ca(NO/sub 3/)/sub 2/, and H/sub 3/BO/sub 3/. HCG was promoted by NH/sub 4/HF/sub 2/, NH/sub 4/Cl, and H/sub 3/BO/sub 3/. Additives at 5% level, prior to or after CoMo impregnation, showed a strong depressing effect on HDS and a lesser effect on HYD, while HCG was strongly promoted by NH/sub 4/HF/sub 2/, Ti isopropoxide, and H/sub 3/BO/sub 3/. The changes in catalytic functionalities are rationalized in terms of different interactions between CoMo phase, support, and additives. 3 tables, 1 figure.« less

Investigation on the reaction mechanisms of generation and loss of oxygen-related species in atmospheric-pressure pulsed dielectric barrier discharge in argon/oxygen mixture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Jie; Tan, Zhenyu, E-mail: tzy@sdu.edu.cn; Pan, Guangsheng

This work presents a numerical investigation, using a 1-D fluid model, on the generation and loss of oxygen-related species and the spatial-temporal evolutions of the species densities in the atmospheric-pressure pulsed dielectric barrier discharge in the argon/oxygen mixture. The reaction pathways as well as their contributions to the generation and loss of oxygen-related species are given. The considered oxygen-related species include O, O({sup 1}D), O{sub 2}({sup 1}Δ{sub g}), O{sub 3}, O{sup +}, O{sub 2}{sup +}, O{sup −}, O{sub 2}{sup −}, and O{sub 3}{sup −}. The following significant results are obtained. O, O({sup 1}D), O{sub 2}({sup 1}Δ{sub g}), and O{sup −}more » are produced mainly via the electron impact with O{sub 2}. Ar{sup +} plays an essential role in the generation of O{sup +} and O{sub 2}{sup +}. Almost all of O{sub 3} derives from the reaction O{sub 2} + O{sub 2} + O → O{sub 3} + O{sub 2}. The O{sub 3}-related reactions produce an essential proportion of O{sub 2}{sup −} and O{sub 3}{sup −}. The substantial loss of O{sup −}, O{sub 2}{sup −}, and O{sub 3}{sup −} is induced by their reactions with O{sub 2}{sup +}. Loss of O{sup +}, O, and O({sup 1}D) is mainly due to their reactions with O{sub 2}, loss of O{sub 2}({sup 1}Δ{sub g}) due to O{sub 2}({sup 1}Δ{sub g}) impacts with O{sub 3} as well as the de-excitation reactions between O{sub 2}({sup 1}Δ{sub g}) and e, O{sub 2}, and O, and loss of O{sub 3} due to the reactions between O{sub 3} and other neutral species. In addition, the densities of O{sup +} and O({sup 1}D) present two obvious peaks at the pulse duration, but the densities of O{sub 2}{sup +}, O, O{sub 2}({sup 1}Δ{sub g}), and O{sub 3} are almost unchanged. The densities of negative oxygen ions increase at the pulse duration and then decline. O{sup −} density is obviously large nearby the dielectric surfaces and the densities of O{sub 2}{sup −} and O{sub 3}{sup −} present generally uniform distributions.« less

AsS-Tl/sub 3/AsS/sub 4/ and AsS-Tl/sub 2/S systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorob'ev, Yu.I.; Velikova, N.G.; Kirilenko, V.V.

1987-11-01

Using DTA and XPA as well as microstructural analysis and microhardness measurements, the AsS-Tl/sub 3/AsS/sub 4/ and AsS-Tl/sub 2/S phase diagrams are studied. Two new ternary compounds, Tl/sub 2/As/sub 3/S/sub 4/ and Tl/sub 2/As/sub 2/S/sub 3/, are revealed and their interplanar distances are calculated.

Photoluminescence analysis of Ce{sup 3+}:Zn{sub 2}SiO{sub 4} & Li{sup +}+ Ce{sup 3+}:Zn{sub 2}SiO{sub 4}: phosphors by a sol-gel method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babu, B. Chandra, E-mail: chandrababuphd@gmail.com; Vandana, C. Sai; Guravamma, J.

2015-06-24

Here, we report on the development and photoluminescence analysis of Zn{sub 2}SiO{sub 4}, Ce{sup 3+}:Zn{sub 2}SiO{sub 4} & Li{sup +} + Ce{sup 3+}: Zn{sub 2}SiO{sub 4} novel powder phosphors prepared by a sol-gel technique. The total amount of Ce{sup 3+} ions was kept constant in this experiment at 0.05 mol% total doping. The excitation and emission spectra of undoped (Zn{sub 2}SiO{sub 4}) and Ce{sup 3+} doped Zn{sub 2}SiO{sub 4} and 0.05 mol% Li{sup +} co-doped samples have been investigated. Cerium doped Zn{sub 2}SiO{sub 4} powder phosphors had broad blue emission corresponding to the 2D{sub 3/2}→2F{sub J} transition at 443nm. Stable green-yellow-red emissionmore » has been observed from Zn{sub 2}SiO{sub 4} host matrix and also we have been observed the enhanced luminescence of Li{sup +} co-doped Zn{sub 2}SiO{sub 4}:Ce{sup 3+}. Excitation and emission spectra of these blue luminescent phosphors have been analyzed in evaluating their potential as luminescent screen coating phosphors.« less

Enhanced performance of dye-sensitized solar cells based on organic dopant incorporated PVDF-HFP/PEO polymer blend electrolyte with g-C{sub 3}N{sub 4}/TiO{sub 2} photoanode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senthil, R.A.; Theerthagiri, J.; Madhavan, J., E-mail: jagan.madhavan@gmail.com

This work describes the effect of 2-aminopyrimidine (2-APY) on poly(vinylidinefluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) blend polymer electrolyte along with binary iodide salts (tetrabutylammonium iodide (TBAI) and potassium iodide (KI)) and iodine (I{sub 2}) were studied for enhancing the efficiency of the dye-sensitized solar cells (DSSCs) consisting of g-C{sub 3}N{sub 4}/TiO{sub 2} composite as photoanode. The g-C{sub 3}N{sub 4} was synthesized from low cost urea by thermal condensation method. It was used as a precursor to synthesize the various weight percentage ratios (5%, 10% and 15%) of g-C{sub 3}N{sub 4}/TiO{sub 2} composites by wet-impregnation method. The pure and 2-APY incorporated PVDF-HFP/PEO polymermore » blend electrolytes were arranged by wet chemical process (casting method) using DMF as a solvent. The synthesized g-C{sub 3}N{sub 4}/TiO{sub 2} composites and polymer blend electrolytes were studied and analyzed by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The ionic conductivity values of the pure and 2-APY incorporated PVDF-HFP/PEO blend electrolytes were estimated to be 4.53×10{sup −5} and 1.87×10{sup −4} Scm{sup −1} respectively. The UV–vis absorption spectroscopy was carried out for the pure and different wt% of g-C{sub 3}N{sub 4}/TiO{sub 2} composites coated FTO films after N3 dye-sensitization. The 10 wt% g-C{sub 3}N{sub 4}/TiO{sub 2} composite film showed a maximum absorption compared to the others. The DSSC assembled with 10 wt% g-C{sub 3}N{sub 4}/TiO{sub 2} as photoanode using the pure polymer blend electrolyte exhibited a power conversion efficiency (PCE) of 3.17% , which was superior than that of DSSC based pure TiO{sub 2} (2.46%). However, the PCE was increased to 4.73% for the DSSC assembled using 10 wt% g-C{sub 3}N{sub 4}/TiO{sub 2} as photoanode with 2-APY incorporated polymer blend electrolyte. Hence, the present study is a successful attempt to provide a new pathway to enhance the performance of DSSCs. - Graphical abstract: In this study, the g-C{sub 3}N{sub 4} was synthesized from low cost urea and it was used as a precursor to synthesize of g-C{sub 3}N{sub 4}/TiO{sub 2} composite. The pure and 2-APY incorporated PVDF-HFP/PEO electrolytes were fabricated by solution casting method. A remarkably enhanced PCE of 4.73% was observed for 2-APY incorporated PVDF-HFP/PEO electrolyte with g-C{sub 3}N{sub 4}/TiO{sub 2} composite photoanode based DSSC. - Highlights: • 2-APY added PVDF-HFP/PEO electrolyte was prepared by solution casting method. • The g-C{sub 3}N{sub 4}/TiO{sub 2} composites were synthesized by wet-impregnation method. • DSSC with g-C{sub 3}N{sub 4}/TiO{sub 2} and 2-APY added electrolyte showed the efficiency of 4.73 %. • The g-C{sub 3}N{sub 4} and 2-APY can be a useful dopant to enhance the performance of DSSCs.« less

Effect of transition metal composition on electrochemical performance of nickel-manganese-based lithium-rich layer-structured cathode materials in lithium-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konishi, Hiroaki, E-mail: hiroaki.konishi.yj@hitachi.com; Gunji, Akira; Feng, Xiaoliang

2017-05-15

To evaluate the effect of transition metal composition on the electrochemical properties of Li-rich layer-structured cathode materials, Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4) were synthesized, and their electrochemical properties were investigated. As nickel content x increased in Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4), charge-discharge capacities at a low C-rate (0.05 C) decreased. The results obtained by dQ/dV curves indicate that, as the nickel content increased, the discharge capacity below 3.6 V greatly decreased, but that above 3.6 V increased. As the C-rate of the discharge process increased, the discharge reaction of Li{submore » 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2) below 3.6 V greatly decreased. In contrast, that above 3.6 V slightly decreased. This indicates that the discharge reaction above 3.6 V exhibits higher rate performance than that below 3.6 V. For the high-nickel-content cathodes, the ratio of the discharge capacity above 3.6 V to the total discharge capacity was high. Therefore, they exhibited high rate performance. - Graphical abstract: Figure shows the discharge curves of Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2 and 0.3) within potential range of 2.5−4.6 V (vs. Li/Li{sup +}) at 0.05 and 3 C. At low C-rate (0.05 C), the discharge capacity of high-nickel-content cathode (Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2}) was less than that of low-nickel-content cathode (Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2}); however, the discharge potential and capacity of Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2} was higher than those of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} at high C-rate (3 C). This means that the increase in Ni/Mn ratio was effective in improving rate-performance.« less

Spectra of surface plasmon polariton enhanced electroluminescence from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickmott, T. W.

Narrow band-pass filters have been used to measure the spectral distribution of electroluminescent photons with energies between 1.8 eV and 3.0 eV from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes with anodic Al{sub 2}O{sub 3} thicknesses between 12 nm and 18 nm. Electroforming of metal-insulator-metal (MIM) diodes is a non-destructive dielectric breakdown that results in a conducting channel in the insulator and changes the initial high resistance of the MIM diode to a low resistance state. It is a critical step in the development of resistive-switching memories that utilize MIM diodes as the active element. Electroforming of Al-Al{sub 2}O{sub 3}-Ag diodes in vacuum results in voltage-controlledmore » negative resistance (VCNR) in the current-voltage (I-V) characteristics. Electroluminescence (EL) and electron emission into vacuum (EM) develop simultaneously with the current increase that results in VCNR in the I-V characteristics. EL is due to recombination of electrons injected at the Al-Al{sub 2}O{sub 3} interface with radiative defect centers in Al{sub 2}O{sub 3}. Measurements of EL photons between 1.8 eV and 3.0 eV using a wide band-pass filter showed that EL intensity is exponentially dependent on Al{sub 2}O{sub 3} thickness for Al-Al{sub 2}O{sub 3}-Ag diodes between 12 nm and 20 nm thick. Enhanced El intensity in the thinnest diodes is attributed to an increase in the spontaneous emission rate of recombination centers due to high electromagnetic fields generated in Al{sub 2}O{sub 3} when EL photons interact with electrons in Ag or Al to form surface plasmon polaritons at the Al{sub 2}O{sub 3}-Ag or Al{sub 2}O{sub 3}-Al interface. El intensity is a maximum at 2.0–2.2 eV for Al-Al{sub 2}O{sub 3}-Ag diodes with Al{sub 2}O{sub 3} thicknesses between 12 nm and 18 nm. EL in diodes with 12 nm or 14 nm of Al{sub 2}O{sub 3} is enhanced by factors of 8–10 over EL from a diode with 18 nm of Al{sub 2}O{sub 3}. The extent of EL enhancement in the thinnest diodes can vary significantly between samples. A narrow band of recombination centers was found in one Al-Al{sub 2}O{sub 3}-Ag diode with 12 nm of Al{sub 2}O{sub 3}; it had EL intensity 100 times greater at 2.15 eV than the diode with 18 nm of Al{sub 2}O{sub 3}. EL intensity for photons with energies greater than 2.6 eV is nearly the same for all diodes.« less

Crystal structures of the new ternary stannides La{sub 3}Mg{sub 4−x}Sn{sub 2+x} and LaMg{sub 3−x}Sn{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solokha, P., E-mail: pavlo.solokha@unige.it; De Negri, S.; Minetti, R.

2016-01-15

Synthesis and structural characterization of the two new lanthanum–magnesium–stannides La{sub 3}Mg{sub 4−x}Sn{sub 2+x} (0.12≤x≤0.40) and LaMg{sub 3−x}Sn{sub 2} (0.33≤x≤0.78) are reported. The crystal structures of these intermetallics were determined by single crystal X-ray diffraction analysis and confirmed by Rietveld refinement of powder X-ray diffraction patterns of the corresponding samples. The La{sub 3}Mg{sub 4−x}Sn{sub 2+x} phase crystallizes in the hexagonal Zr{sub 3}Cu{sub 4}Si{sub 2} structure type (P6¯2m, hP9, Z=3, x=0.12(1), a=7.7974(7), c=4.8384(4) Å), which represents an ordered derivative of the hP9-ZrNiAl prototype, ubiquitous among equiatomic intermetallics. The LaMg{sub 3–x}Sn{sub 2} phase is the second representative of the trigonal LaMg{sub 3−x}Ge{sub 2}more » type, which is a superstructure of the LaLi{sub 3}Sb{sub 2} structure type (P3¯1c, hP34-0.12, Z=6, x=0.35(1), a=8.3222(9), c=14.9546(16) Å). The scheme describing the symmetry reduction/coloring with respect to the parent type is reported here with the purpose to discuss the LaMg{sub 3−x}Sn{sub 2} off-stoichiometry from the geometrical point of view. Structural relationships between the La–Mg–Sn ternary phases, including the already known equiatomic LaMgSn compound (oP12-TiNiSi), are presented in the framework of the AlB{sub 2}-related compounds family and discussed with the aid of group-subgroup relations in the Bärnighausen formalism. - Graphical abstract: Crystal structure of LaMg{sub 3−x}Sn{sub 2} viewed along the (001) direction together with the puckered layer of Mg and Sn atoms hosting Mg2, Mg3 and vacancy □. - Highlights: • Crystal structures of the new La{sub 3}Mg{sub 4−x}Sn{sub 2+x} and LaMg{sub 3−x}Sn{sub 2} phases were determined. • The off-stoichiometry of LaMg{sub 3−x}Sn{sub 2} was discussed from geometrical point of view. • Structural relations between the known La–Mg–Sn phases were established. • The studied compounds are related to the AlB{sub 2} type by symmetry reduction.« less

Mapping Vinyl Cyanide and Other Nitriles in Titan’s Atmosphere Using ALMA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, J. C.-Y.; Cordiner, M. A.; Nixon, C. A.

Vinyl cyanide (C{sub 2}H{sub 3}CN) is theorized to form in Titan’s atmosphere via high-altitude photochemistry and is of interest regarding the astrobiology of cold planetary surfaces due to its predicted ability to form cell membrane-like structures (azotosomes) in liquid methane. In this work, we follow up on the initial spectroscopic detection of C{sub 2}H{sub 3}CN on Titan by Palmer et al. with the detection of three new C{sub 2}H{sub 3}CN rotational emission lines at submillimeter frequencies. These new, high-resolution detections have allowed for the first spatial distribution mapping of C{sub 2}H{sub 3}CN on Titan. We present simultaneous observations of C{submore » 2}H{sub 5}CN, HC{sub 3}N, and CH{sub 3}CN emission, and obtain the first (tentative) detection of C{sub 3}H{sub 8} (propane) at radio wavelengths. We present disk-averaged vertical abundance profiles, two-dimensional spatial maps, and latitudinal flux profiles for the observed nitriles. Similarly to HC{sub 3}N and C{sub 2}H{sub 5}CN, which are theorized to be short-lived in Titan’s atmosphere, C{sub 2}H{sub 3}CN is most abundant over the southern (winter) pole, whereas the longer-lived CH{sub 3}CN is more concentrated in the north. This abundance pattern is consistent with the combined effects of high-altitude photochemical production, poleward advection, and the subsequent reversal of Titan’s atmospheric circulation system following the recent transition from northern to southern winter. We confirm that C{sub 2}H{sub 3}CN and C{sub 2}H{sub 5}CN are most abundant at altitudes above 200 km. Using a 300 km step model, the average abundance of C{sub 2}H{sub 3}CN is found to be 3.03 ± 0.29 ppb, with a C{sub 2}H{sub 5}CN/C{sub 2}H{sub 3}CN abundance ratio of 2.43 ± 0.26. Our HC{sub 3}N and CH{sub 3}CN spectra can be accurately modeled using abundance gradients above the tropopause, with fractional scale-heights of 2.05 ± 0.16 and 1.63 ± 0.02, respectively.« less

Electrical and structural characterizations of crystallized Al{sub 2}O{sub 3}/GaN interfaces formed by in situ metalorganic chemical vapor deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X., E-mail: xliu@ece.ucsb.edu; Yeluri, R.; Kim, J.

2016-01-07

Al{sub 2}O{sub 3} films were grown in situ by metalorganic chemical vapor deposition at 900 °C on GaN of both Ga- and N-face polarities. High-resolution transmission electron microscopy revealed that the Al{sub 2}O{sub 3} films were crystalline and primarily γ-phase. The Al{sub 2}O{sub 3}/Ga-GaN and Al{sub 2}O{sub 3}/N-GaN interfaces were both atomically sharp, and the latter further exhibited a biatomic step feature. The corresponding current-voltage (J-V) characteristics were measured on a metal-Al{sub 2}O{sub 3}-semiconductor capacitor (MOSCAP) structure. The leakage current was very high when the Al{sub 2}O{sub 3} thickness was comparable with the size of the crystalline defects, but was suppressedmore » to the order of 1 × 10{sup −8} A/cm{sup 2} with larger Al{sub 2}O{sub 3} thicknesses. The interface states densities (D{sub it}) were measured on the same MOSCAPs by using combined ultraviolet (UV)-assisted capacitance-voltage (C-V), constant capacitance deep level transient spectroscopy (CC-DLTS), and constant capacitance deep level optical spectroscopy (CC-DLOS) techniques. The average D{sub it} measured by CC-DLTS and CC-DLOS were 6.6 × 10{sup 12} and 8.8 × 10{sup 12} cm{sup −2} eV{sup −1} for Al{sub 2}O{sub 3}/Ga-GaN and 8.6 × 10{sup 12} and 8.6 × 10{sup 12 }cm{sup −2} eV{sup −1} for Al{sub 2}O{sub 3}/N-GaN, respectively. The possible origins of the positive (negative) polarization compensation charges in Al{sub 2}O{sub 3}/Ga-GaN (Al{sub 2}O{sub 3}/N-GaN), including the filling of interface states and the existence of structure defects and impurities in the Al{sub 2}O{sub 3} layer, were discussed in accordance with the experimental results and relevant studies in the literature.« less

Synthesis and photoluminescence properties of Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} red phosphor for white light emitting diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Ge; Ci, Zhipeng; Shi, Yurong

2014-07-01

Highlights: • A novel red phosphor Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} was synthesized and investigated firstly. • The structure and characteristic luminescence properties are discussed. • The excellent thermal stability was found and investigated. • It has good color saturation, the CIE is close to that of commercial Y{sub 2}O{sub 3}:Eu{sup 3+}. - Abstract: A series of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} red phosphors were successfully synthesized. X-ray diffraction analysis indicates that all the samples are single phased. The luminescence property is investigated in detail by measuring their photoluminescence excitation and emission spectra. Ca{sub 19}Mg{sub 2}(PO{submore » 4}){sub 14}:Sm{sup 3+} phosphors show strong absorption in 400–410 nm region, which is suitable for application in LEDs. When excited at 403 nm, Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphor can emit red emission with CIE chromaticity coordinates (0.615, 0.384). The optimal doping concentration of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} is measured to be 0.02. The thermal quenching property is also measured and compared with the commercial red phosphor Y{sub 2}O{sub 3}:Eu{sup 3+} (Topstar, TXC-RIA). The results indicate Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphors have potential to serve as a red phosphor for white LEDs.« less

(Ag{sub 2}TeS{sub 3}){sub 2} {small_bullet} A{sub 2}S{sub 6} (A = Rb, Cs) : layers of silver thiotellurite intergrown with alkali-metal polysulfides.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, S. L.; Jang, J. I.; Ketterson, J. B.

2010-09-22

The layered compounds RbAg{sub 2}TeS{sub 6} and CsAg{sub 2}TeS{sub 6} crystallize in the noncentrosymmetric space group P6{sub 3}cm, with a = 19.15 {angstrom}, c = 14.64 {angstrom}, and V = 4648 {angstrom}{sup 3} and a = 19.41 {angstrom}, c = 14.84 {angstrom}, and V = 4839 {angstrom}{sup 3}, respectively. The structures are composed of neutral [Ag{sub 2}TeS{sub 3}] layers alternating with charge-balanced salt layers containing polysulfide chains of [S{sub 6}]{sup 2-} and alkali-metal ions. RbAg{sub 2}TeS{sub 6} and CsAg{sub 2}TeS{sub 6} are air- and water-stable, wide-band-gap semiconductors (E{sub g} {approx} 2.0 eV) exhibiting nonlinear-optical second-harmonic generation.

Strong electroluminescence from SiO{sub 2}-Tb{sub 2}O{sub 3}-Al{sub 2}O{sub 3} mixed layers fabricated by atomic layer deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rebohle, L., E-mail: l.rebohle@hzdr.de; Braun, M.; Wutzler, R.

2014-06-23

We report on the bright green electroluminescence (EL) with power efficiencies up to 0.15% of SiO{sub 2}-Tb{sub 2}O{sub 3}-mixed layers fabricated by atomic layer deposition and partly co-doped with Al{sub 2}O{sub 3}. The electrical, EL, and breakdown behavior is investigated as a function of the Tb and the Al concentration. Special attention has been paid to the beneficial role of Al{sub 2}O{sub 3} co-doping which improves important device parameters. In detail, it increases the maximum EL power efficiency and EL decay time, it nearly doubles the fraction of excitable Tb{sup 3+} ions, it shifts the region of high EL powermore » efficiencies to higher injection currents, and it reduces the EL quenching over the device lifetime by an approximate factor of two. It is assumed that the presence of Al{sub 2}O{sub 3} interferes the formation of Tb clusters and related defects. Therefore, the system SiO{sub 2}-Tb{sub 2}O{sub 3}-Al{sub 2}O{sub 3} represents a promising alternative for integrated, Si-based light emitters.« less

Syntheses and structural characterization of non-centrosymmetric Na{sub 2}M{sub 2}M'S{sub 6} (M, M′=Ga, In, Si, Ge, Sn, Zn, Cd) sulfides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

Seven new non-centrosymmetric Na{sub 2}M{sub 2}M’S{sub 6} sulfides, namely, Na{sub 2}Sn{sub 2}ZnS{sub 6}(1){sub ,} Na{sub 2}Ga{sub 2}GeS{sub 6}(2), Na{sub 2}Ga{sub 2}SnS{sub 6}(3-α), Na{sub 2}Ga{sub 2}SnS{sub 6}(3-β){sub ,} Na{sub 2}Ge{sub 2}ZnS{sub 6}(4){sub ,} Na{sub 2}Ge{sub 2}CdS{sub 6}(5){sub ,} Na{sub 2}In{sub 2}SiS{sub 6}(6) and Na{sub 2}In{sub 2}GeS{sub 6}(7), were synthesized by high temperature solid state reactions and structurally characterized by single crystal X-ray diffraction. They crystallize in non-centrosymmetric Fdd2 and Cc space groups and their three-dimensional [M{sub 2}M′S{sub 6}]{sup 2-}framework structures consist of MS{sub 4} and M′S{sub 4} tetrahedra corner-connected to one another in either orderly or disordered fashion. Sodium ions residemore » in the tunnels of the anionic framework. Compounds 1, 2 and 3-α have the structure of known Li{sub 2}Ga{sub 2}GeS{sub 6}, whereas compounds 6 and 7 are isostructural with known Li{sub 2}In{sub 2}GeS{sub 6} compound. Isostructural compounds 4 and 5 represent a new structural variant. Compounds 3-α and its new monoclinic structural variant 3-β have disordered structural framework. All of them are wide band gap semiconductors. Na{sub 2}Ga{sub 2}GeS{sub 6}(2), Na{sub 2}Ga{sub 2}SnS{sub 6}(3), Na{sub 2}Ge{sub 2}ZnS{sub 6}(4) and Na{sub 2}In{sub 2}GeS{sub 6}(7) compounds are found to be second-harmonic generation (SHG) active. Compounds 1, 2 and 3-α melt congruently. - Graphical abstract: Na{sub 2}Ga{sub 2}GeS{sub 6}, Na{sub 2}Ga{sub 2}SnS{sub 6}, Na{sub 2}Ge{sub 2}ZnS{sub 6}, Na{sub 2}In{sub 2}GeS{sub 6}, Na{sub 2}Sn{sub 2}ZnS{sub 6}, Na{sub 2}Ge{sub 2}CdS{sub 6} and Na{sub 2}In{sub 2}SiS{sub 6} have non-centrosymmetric structures and the first four compounds are SHG active. Display Omitted - Highlights: • Seven new Na{sub 2}M{sub 2}M′S{sub 6} compounds with non-centrosymmetric structures were synthesized. • They are wide band gap semiconductors. • Na{sub 2}Ga{sub 2}GeS{sub 6}, Na{sub 2}Ga{sub 2}SnS{sub 6}, Na{sub 2}Ge{sub 2}ZnS{sub 6} and Na{sub 2}In{sub 2}GeS{sub 6} are SHG active.« less

Electrocatalysts for carbon dioxide conversion

DOEpatents

Masel, Richard I; Salehi-Khojin, Amin

2015-04-21

Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

Hydrothermal synthesis of Bismuth(III) coordination polymer and its transformation to nano α-Bi{sub 2}O{sub 3} for photocatalytic degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Ya-Jing; Zheng, Yue-Qing, E-mail: zhengnbu@163.com; Zhu, Hong-Lin

A new Bi(III) coordination polymer Bi{sub 2}(Hpdc){sub 2}(pdc){sub 2}·2H{sub 2}O (H{sub 2}pdc=pyridine-2,6-dicarboxylic acid) was synthesized by hydrothermal method. Solid state thermal decomposition of this complex under 500 °C for 1 h led to the foliated Bi{sub 2}O{sub 3} nanoparticles, which were then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Comparative study on their photocatalytic activity toward the degradation of rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) in polluted water was explored, and the mechanism of these photocatalytic degradation was discussed. These results provided some interesting insights into their photocatalytic applications. - Graphical abstract: Wemore » regard Bi{sub 2}(Hpdc){sub 2}(pdc){sub 2}·2H{sub 2}O with 1D chain structures as the precursor, then calcinate the complex to prepare nano-powder α-Bi{sub 2}O{sub 3}. The photochemical experiment indicates that Bi{sub 2}(Hpdc){sub 2}(pdc){sub 2}·2H{sub 2}O can be used as an efficient photocatalyst for the degradation of RhB and MB. Interestingly, nano α-Bi{sub 2}O{sub 3} shows higher activity than the commercial Bi{sub 2}O{sub 3} for the degradation of RhB, MB or MO. Display Omitted - Highlights: • A novel dinuclear Bi(III) coordination polymer is hydrothermally synthesized. • Calcinating the precursor Bi-CP will result in the nano Bi{sub 2}O{sub 3} with foliated morphology. • Nano Bi{sub 2}O{sub 3} shows higher activity than the commercial Bi{sub 2}O{sub 3} for the degradation of dyes.« less

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinert, R.A.; Sanders, J.S.

Radish and marigold plants were exposed to 0.3 ppm of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and/or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presencemore » of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 3/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present.« less

Synthesis and an X-ray diffraction study of Rb{sub 2}[(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serezhkina, L. B., E-mail: Lserezh@ssu.samara.ru; Peresypkina, E. V.; Neklyudova, N. A.

2010-09-15

The synthesis and X-ray diffraction study of compound Rb{sub 2}[(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}], which crystallizes in the monoclinic crystal system, are performed. The unit cell parameters are as follows: a = 7.9996(6) A, b = 8.8259(8) A, c = 11.3220(7) A, {beta} = 105.394(2){sup o}, and V = 770.7(1) A{sup 3}; space group P2{sub 1}/n, Z = 2, and R{sub 1} = 0.0271. [(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}]{sup 2-} layers belonging to the AK{sub 0.5}{sup 02}T{sup 11} crystal chemical group of uranyl complexes (A = UO{sub 2}{sup 2+}, K{sup 02} = C{sub 2}O{sub 4}{sup 2-}, and T{supmore » 11} = C{sub 2}O{sub 4}{sup 2-}) are uranium-containing structural units of the crystals. The layers are connected with outer-sphere rubidium cations by electrostatic interactions.« less

From {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}]{sup 6-} to {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})]{sup 6-} infinite chains in A{sub 6}U{sub 2}Mo{sub 4}O{sub 21} (A=Na, K, Rb, Cs) compounds: Synthesis and crystal structure of Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yagoubi, S.; Groupe de Radiochimie, Institut de Physique Nucleaire d'Orsay, Universite Paris-Sud XI, 91406 Orsay Cedex; Obbade, S., E-mail: said.obbade@phelma.grenoble-inp.f

2011-05-15

A new caesium uranyl molybdate belonging to the M{sub 6}U{sub 2}Mo{sub 4}O{sub 21} family has been synthesized by solid-state reaction and its structure determined from single-crystal X-ray diffraction data. Contrary to the other alkali uranyl molybdates of this family (A=Na, K, Rb) where molybdenum atoms adopt only tetrahedral coordination and which can be formulated A{sub 6}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}], the caesium compound Cs{sub 6}U{sub 2}Mo{sub 4}O{sub 21} should be written Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})] with molybdenum atoms in tetrahedral and square pyramidal environments. Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})] crystallizes in the triclinic symmetry withmore » space group P1-bar and a=10.4275(14) A, b=15.075(2) A, c=17.806(2) A, {alpha}=70.72(1){sup o}, {beta}=80.38(1){sup o} and {gamma}=86.39(1){sup o}, V=2604.7(6) A{sup 3}, Z=4, {rho}{sub mes}=5.02(2) g/cm{sup 3} and {rho}{sub cal}=5.08(3) g/cm{sup 3}. A full-matrix least-squares refinement on the basis of F{sup 2} yielded R{sub 1}=0.0464 and wR{sub 2}=0.0950 for 596 parameters with 6964 independent reflections with I{>=}2{sigma}(I) collected on a BRUKER AXS diffractometer with Mo(K{alpha}) radiation and a CCD detector. The crystal structure of Cs compound is characterized by {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})]{sup 6-} parallels chains built from U{sub 2}O{sub 13} dimeric units, MoO{sub 4} tetrahedra and MoO{sub 5} square pyramids, whereas, Na, K and Rb compounds are characterized by {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}]{sup 6-} parallel chains formulated simply of U{sub 2}O{sub 13} units and MoO{sub 4} tetrahedra. Infrared spectroscopy measurements using powdered samples synthesized by solid-state reaction, confirm the structural results. The thermal stability and the electrical conductivity are also studied. The four compounds decompose at low temperature (between 540 and 610 {sup o}C). -- Graphical abstract: The staking of {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})]{sup 6-} infinite uranyl molybdate ribbons in the Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})] structure. Display Omitted Highlights: {yields} Cs{sub 6}U{sub 2}Mo{sub 4}O{sub 2} a new compound with bidimensional crystal structure, characterized by infinite uranyl molybdate chains. {yields} Crystal structure similar to these of the compounds containing Na, K, Rb. {yields} Molybdenum atoms surrounded by five oxygen atoms to form an original and strongly distorted MoO{sub 5} environment. {yields} The chains arrangement illustrates the key role of the alkaline ionic radius, in the crystal structure distortion for Cs compound.« less

Syntheses and characterization of one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

2015-01-15

Three new isostructural quaternary antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) have been synthesized by using alkali metal thiosulfate flux and structurally characterized by X-ray diffraction. Their structures contain A{sup +} ions around the [Sb{sub 2}Sn{sub 3}S{sub 10}]{sup 2−} chains, which are built from SbS{sub 3} pyramids, SnS{sub 6} octahedra and SnS{sub 4} tetrahedra. Raman and Mössbauer spectroscopic measurements corroborate the oxidation states and coordination environments of Sb(III) and Sn(IV). All three compounds are wide band gap semiconductors. Potassium compound undergoes partial exchange with strontium, cadmium and lead ions. - Graphical abstract: Syntheses, crystal structure, spectroscopic andmore » partial ion-exchange studies of new one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) are described. - Highlights: • Syntheses of new alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs). • Wide band gap semiconductors with one-dimensional structure. • Topotactic partial exchange of K{sup +} ions of K{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} with Sr{sup 2+}, Cd{sup 2+} and Pb{sup 2+} ions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sutherland, J.W.

Pulse radiolysis of aqueous hydrazine solutions has been studied in the pH range 2 to 13. At times greater than about 1 ms after the pulse, a single transient species is observed (lambda/sub max/230nm). This species decayed by first-order kinetics under all conditions studied. A mechanism which accounts satisfactorily for the observed kinetic behavior is proposed. This species, identified as triazene (N/sub 3/H/sub 3/) is amphiprotic and the following acid--base equilibria are rapidly established: N/sub 3/H/sub 4//sup +/in equilibrium N/sub 3/H/sub 3//sup +/H/sup +/ (pK/sub 1/ = 4.95, ..delta..H/sub 1//sup 0/ = -4.9 kcal mol/sup -1/, ..delta..S/sub 1//sup 0/ =more » -39.2 eu) N/sub 3/H/sub 3/in equilibrium N/sub 3/H/sub 2//sup -/ + H/sup +/ or N/sub 3/H/sub 3/ + OH/sup -/ = N/sub 3/H/sub 4/O/sup -/ (pK/sub 2/ = 11.37, ..delta..H/sub 2//sup 0/ = -4.2 kcal mol/sup -1/, ..delta..S/sub 2//sup 0/ = -67 eu). pK values derived from the dependence of the first-order rate constant on pH, from the dependence of initial absorbance on pH, and from the dependence of the first-order rate constant on temperature at selected values of pH are in satisfactory agreement. The rate constants for decomposition of the acidic and basic forms of triazene are k/sub N3H4/sup +// = 1.97 X 10/sup 11/ exp(-12600/RT)s/sup -1/ and k/sub N3H2/sup -// = 2.14 X 10/sup 14/. exp(-19200/RT)s/sup -1/. For N/sub 3/H/sub 3/, which is stable relative to the faster reaction rates of its conjugate acid and base forms, k is estimated to be less than or equal to 0.001 s/sup -1/ at 24/sup 0/C. The dependence of the observed first-order rate constant on pH at constant temperature is expressed by the following equation: k/sub obsd/ = (k/sub 3//(1 + (K/sub 1//(H/sup +/)))) + (k;/sub 4//(1 + ((H/sup +/)/K/sub 2/))) (k/sub 3/ = k/sub N3H4/sup +// = 133 s/sup -1/, k/sub 4/ = k/sub N3H2/sup -// = 2 s/sup -1/, pK/sub 1/ = 4.9/sub 5/ and pK/sub 2/ = 11.3/sub 7/). Phosphate is a catalyst for the decomposition of triazene. It is shown that the conjugate acid of neutral triazene has unit positive charge and its conjugate base has unit negative charge.« less

Rare earth doped zinc oxide varistors

DOEpatents

McMillan, A.D.; Modine, F.A.; Lauf, R.J.; Alim, M.A.; Mahan, G.D.; Bartkowiak, M.

1998-12-29

A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2--4.0% oxide of at least one rare earth element, 0.5--4.0% Co{sub 3}O{sub 4}, 0.05--0.4% K{sub 2}O, 0.05--0.2% Cr{sub 2}O{sub 3}, 0--0.2% CaO, 0.00005--0.01% Al{sub 2}O{sub 3}, 0--2% MnO, 0--0.05% MgO, 0--0.5% TiO{sub 3}, 0--0.2% SnO{sub 2}, 0--0.02% B{sub 2}O{sub 3}, balance ZnO. 4 figs.

Rare earth doped zinc oxide varistors

DOEpatents

McMillan, April D.; Modine, Frank A.; Lauf, Robert J.; Alim, Mohammad A.; Mahan, Gerald D.; Bartkowiak, Miroslaw

1998-01-01

A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2-4.0% oxide of at least one rare earth element, 0.5-4.0% Co.sub.3 O.sub.4, 0.05-0.4% K.sub.2 O, 0.05-0.2% Cr.sub.2 O.sub.3, 0-0.2% CaO, 0.00005-0.01% Al.sub.2 O.sub.3, 0-2% MnO, 0-0.05% MgO, 0-0.5% TiO.sub.3, 0-0.2% SnO.sub.2, 0-0.02% B.sub.2 O.sub.3, balance ZnO.

Vanadium dioxide film protected with an atomic-layer-deposited Al{sub 2}O{sub 3} thin film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiao; Cao, Yunzhen, E-mail: yzhcao@mail.sic.ac.cn; Yang, Chao

2016-01-15

A VO{sub 2} film exposed to ambient air is prone to oxidation, which will degrade its thermochromic properties. In this work, the authors deposited an ultrathin Al{sub 2}O{sub 3} film with atomic layer deposition (ALD) to protect the underlying VO{sub 2} film from degradation, and then studied the morphology and crystalline structure of the films. To assess the protectiveness of the Al{sub 2}O{sub 3} capping layer, the authors performed a heating test and a damp heating test. An ultrathin 5-nm-thick ALD Al{sub 2}O{sub 3} film was sufficient to protect the underlying VO{sub 2} film heated at 350 °C. However, in amore » humid environment at prolonged durations, a thicker ALD Al{sub 2}O{sub 3} film (15 nm) was required to protect the VO{sub 2}. The authors also deposited and studied a TiO{sub 2}/Al{sub 2}O{sub 3} bilayer, which significantly improved the protectiveness of the Al{sub 2}O{sub 3} film in a humid environment.« less

A series of Zn/Cd coordination polymers constructed from 1,4-naphthalenedicarboxylate and N-donor ligands: Syntheses, structures and luminescence sensing of Cr{sup 3+} in aqueous solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Dong-Cheng; Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou 515063; Fan, Yan

A novel series of Zn/Cd coordination polymers based on H{sub 3}L, namely, [Zn{sub 2}(HL){sub 2}(bipy){sub 2}(H{sub 2}O){sub 6}]{sub n} (1), [Zn(HL)(phen)]{sub n} (2), [Cd{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (3), [Zn{sub 3}L{sub 2}(bbi){sub 3}]{sub n} (4) [(H{sub 3}L =4-[(1-carboxynaphthalen-2-yl)oxy]phthalic acid, bipy =4,4′-bipyridine, phen =1,10-phenanthroline, bbi =1,1′-(1,4-butanediyl)bis(imidazole] have been successfully synthesized by solvothermal reaction. Compound 1 possesses two diverse 1D chains constructed by different bipy coligands, which were further connected to form a 3D supramolecular architecture by hydrogen bonding interactions. Compound 2 possesses a complicated 1D chain based on secondary building unit (SBU) with binuclear Zn cluster. Compounds 3 and 4 exhibitmore » similar 2D→3D framework, which can be rationalized as (3,4,4)-connected 3D net with a Schläfli symbol of (6{sup 3}.8.10{sup 2}){sub 2}(6{sup 3}){sub 2}(6{sup 4}.8.10). In particular, compound 3 exhibited a high sensitivity for Cr{sup 3+} in aqueous solutions, which suggest that compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+}. - Graphical abstract: A series of novel Zn/Cd coordination polymers have been successfully synthesized by solvothermal reaction. The unique 3D Cd{sup 2+} polymer containing bbi as second ligand demonstrates high sensitivity for detection of toxic Cr{sup 3+} in aqueous solutions. Display Omitted - Highlights: • π-conjugated semirigid tricarboxylate ligands with naphthalene rings(H{sub 3}L) were rationally designed. • Four Zn/Cd coordination polymers based on H{sub 3}L have been successfully synthesized by solvothermal reaction. • Compound 3 is a promising luminescent probe for selectively sensing Cr{sup 3+} with high sensitivity in aqueous solutions.« less

Stabilization of the high coercivity {epsilon}-Fe{sub 2}O{sub 3} phase in the CeO{sub 2}-Fe{sub 2}O{sub 3}/SiO{sub 2} nanocomposites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mantlikova, A., E-mail: mantlikova@fzu.cz; Poltierova Vejpravova, J.; Bittova, B.

2012-07-15

We have investigated the processes leading to the formation of the Fe{sub 2}O{sub 3} and CeO{sub 2} nanoparticles in the SiO{sub 2} matrix in order to stabilize the {epsilon}-Fe{sub 2}O{sub 3} as the major phase. The samples with two different concentrations of the Fe were prepared by sol-gel method, subsequently annealed at different temperatures up to 1100 Degree-Sign C, and characterized by the Moessbauer spectroscopy, Transmission Electron Microscopy (TEM), Powder X-ray Diffraction (PXRD), Energy Dispersive X-ray analysis (EDX) and magnetic measurements. The evolution of the different Fe{sub 2}O{sub 3} phases under various conditions of preparation was investigated, starting with themore » preferential appearance of the {gamma}-Fe{sub 2}O{sub 3} phase for the sample with low Fe concentration and low annealing temperature and stabilization of the major {epsilon}-Fe{sub 2}O{sub 3} phase for high Fe concentration and high annealing temperature, coexisting with the most stable {alpha}-Fe{sub 2}O{sub 3} phase. A continuous increase of the particle size of the CeO{sub 2} nanocrystals with increasing annealing temperature was also observed. - Graphical abstract: The graphical abstract displays the most important results of our work. The significant change of the phase composition due to the variation of preparation conditions is demonstrated. As a result, significant change of the magnetic properties from superparamagnetic {gamma}-Fe{sub 2}O{sub 3} phase with negligible coercivity to the high coercivity {epsilon}-Fe{sub 2}O{sub 3} phase has been observed. Highlights: Black-Right-Pointing-Pointer Research of the stabilization of the high coercivity {epsilon}-Fe{sub 2}O{sub 3} in CeO{sub 2}-Fe{sub 2}O{sub 3}/SiO{sub 2}. Black-Right-Pointing-Pointer Samples with two different concentrations of Fe and three annealing temperatures. Black-Right-Pointing-Pointer Phase transition {gamma}{yields}{epsilon}{yields}({beta}){yields}{alpha} with increasing annealing temperature and particle size. Black-Right-Pointing-Pointer Elimination of the superparamagnetic phases in samples with higher content of Fe. Black-Right-Pointing-Pointer Best conditions for high coercivity {epsilon}-Fe{sub 2}O{sub 3}-higher Fe content and T{sub A}=1100 Degree-Sign C.« less

Synthesis, x-ray, and low-temperature neutron diffraction study of a rhodium (V) complex: dihydridobis(triethylsilyl)-pentamethylcyclopentadienylrhodium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, M.J.; Bailey, P.M.; Bentz, P.O.

1984-09-19

Reaction of (C/sub 5/ qentamethyl Rh)/sub 2/Cl/sub 4/) (1) with triethylsilane leads to the novel rhodium(V) complex (eta/sup 5/-C/sub 5/Me/sub 5/Rh(H)/sub 2/(SiE-triethyl/sub 3/)/sub 2/) (2) characterized by NMR spectra (/sup 1/H, /sup 13/C, /sup 29/Si, and /sup 103/Rh), X-ray diffraction, and neutron diffraction at 20 K. The complex shows a four-legged piano stool geometry with the pentamethylcyclopentadienyl eta/sub 5/-bonded to the rhodium (average Rh-C, 2.283 (9) A) on top and the two triethylsilyl ligands trans in the basal plane (Rh-Si, 2.379 (2) A). The neutron diffraction analysis located the two hydrides, which are trans to each other and cis tomore » the triethylsilyls in the basal plane. The mean Rh-H distance is 1.581 (3) A, and the H-Rh-H angle is 94.8 (2)/sup 0/. Complex 2 is rather stable, but it reacts under forcing conditions with neutral ligands (triphenylphosphine, CO, or maleic anhydride) to give (C/sub 5/Me/sub 5/Rh(PPh/sub 3/)H(SiEt/sub 3/)), (C/sub 5/Me/sub 5/Rh(CO)/sub 2/), or (C/sub 5/M3/5Rh(maleic anhydride)/sup 2/). It reacts more easily with electrophiles such as HBF/sub 4/ to give (C/sub 5/Me/sub 5/Rh)/sub 4/H/sub 4/)/sup 2 +/, with HCl to give 1, with AgBF/sub 4/ in MeCN to give (C/sub 5/Me/sub 5/Rh(MeCN)/sub 3/)/sup 2 +/, and with I/sub 2/ to give ((C/sub 5/Me/sub 5/Rh)/sub 2/I/sub 4/). The predominant mode of reaction involves reductive elimination of Et/sub 3/Si-H, which can be strongly promoted by an electrophile. 43 references, 3 figures, 3 tables.« less

Short-length and high-density TiO{sub 2} nanorod arrays for the efficient charge separation interface in perovskite solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Guannan; Shi, Chengwu, E-mail: shicw506@foxmail.com; Zhang, Zhengguo

The TiO{sub 2} nanorod arrays with the length of 70 nm, the diameter of 20 nm, and the areal density of 1000 µm{sup −2} were firstly prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 60 min. Over-500 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layers were successfully obtained by sequential deposition routes using 1.7 M PbI{sub 2}·DMSO complex precursor solution and 0.465 M isopropanol solution of the methylammonium halide mixture with the molar ratio of CH{sub 3}NH{sub 3}I/CH{sub 3}NH{sub 3}Br=85/15. The perovskite solar cellsmore » based on the TiO{sub 2} nanorod array and 560 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer exhibited the best photoelectric conversion efficiency (PCE) of 15.93%, while the corresponding planar perovskite solar cells without the TiO{sub 2} nanorod array and with 530 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer gave the best PCE of 12.82% at the relative humidity of 50–54%. - Graphical abstract: The TiO{sub 2} nanorod arrays with the length of 70 nm, the diameter of 20 nm, and the areal density of 1000 µm{sup −2} were prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 60 min. The optimal annealing temperature of TiO{sub 2} nanorod arrays was 450 °C. The perovskite solar cells based on the TiO{sub 2} nanorod array and 560 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer exhibited the best photoelectric conversion efficiency (PCE) of 15.93% and the average PCE of 13.41±2.52%, while the corresponding planar perovskite solar cells without the TiO{sub 2} nanorod array and with 530 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer gave the best PCE of 12.82% and the average PCE of 10.54±2.28% at the relative humidity of 50–54%. - Highlights: • Preparation of TiO{sub 2} nanorod array with length of 70 nm and density of 1000 µm{sup −2}. • Influence of annealing temperatures on the -OH content of TiO{sub 2} nanorod arrays. • Preparation of over-500 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer. • Combination of short-length TiO{sub 2} nanorod array and high-thickness perovskite layer. • The best and average PCE with TiO{sub 2} array of 15.93% and 13.41±2.52% at 50–54% RH.« less

Solvothermal syntheses, crystal structures, and properties of lanthanide(III) thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln==Sm, Eu, Gd) and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln==Tb, Dy, Ho)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Fang; Tang, Chunying; Chen, Ruihong

2013-10-15

Solvothermal reactions of Ln{sub 2}O{sub 3}, As and S in diethylenetriamine (dien) at 170 °C for 6 days afforded two structural types of lanthanide thioarsenates with the general formulae [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} [Ln=Sm(1), Eu(2), Gd(3)] and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] [Ln=Tb(4), Dy(5), Ho(6)]. The Ln{sub 2}O{sub 3} oxides were converted to [Ln(dien){sub 2}]{sup 3+} complex units in the solvothermal reactions. The As atom binds four S atoms, forming a tetrahedral AsS{sub 4} unit. In 1−3, the AsS{sub 4} units interconnect the [Ln(dien){sub 2}]{sup 3+} cations via Ln−S bonds as tridentate μ-1κ,2κ{sup 2}-AsS{sub 4} bridging ligands, resulting in themore » neutral coordination polymers [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} (Ln1). In 4−6, the AsS{sub 4} units coordinate with the Ln{sup 3+} ion of [Ln(dien){sub 2}]{sup 3+} as 1κ{sup 2}-AsS{sub 4} chelating ligands to form neutral coordination compounds [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] (Ln2). The Ln{sup 3+} ions are in nine- and eight-coordinated environments in Ln1 and Ln2, respectively. The formation of Ln1 and Ln2 is related with ionic size of the Ln{sup 3+} ions. Optical absorption spectra showed that 1−6 have potential use as semiconductors with the band gaps in the range 2.18−3.21 eV. - Graphical abstract: Two types of Ln-thioarsenates [Ln(dien){sub 2}(μ-1κ,2κ{sup 2}-AsS{sub 4})]{sub n} and [Ln(dien){sub 2}(1κ{sup 2}-AsS{sub 4})] were prepared by solvothermal methods and the soft Lewis basic AsS{sub 4}{sup 3–} ligand to Ln(III) centers with polyamine co-ligand was obtained. Display Omitted - Highlights: • Lanthanide thioarsenates were prepared by solvothermal methods. • The soft Lewis basic AsS{sub 4} ligand coordinate Ln{sup 3+} ions with coexistence polyamine ligands. • Two structural types of Ln-thioarsenates with structural turnover at Tb were obtained along Ln series. • The Ln-thioarsenates are potential semiconductors with optical band gaps in the range 2.18−3.21 eV.« less

Structural characterization of a new vacancy ordered perovskite modification found for Ba{sub 3}Fe{sub 3}O{sub 7}F (BaFeO{sub 2.333}F{sub 0.333}): Towards understanding of vacancy ordering for different perovskite-type ferrites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clemens, Oliver, E-mail: oliver.clemens@kit.edu; Karlsruher Institut für Technologie, Institut für Nanotechnologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen

2015-05-15

The new vacancy ordered perovskite-type compound Ba{sub 3}Fe{sub 3}O{sub 7}F (BaFeO{sub 2.33}F{sub 0.33}) was prepared by topochemical low-temperature fluorination of Ba{sub 2}Fe{sub 2}O{sub 5} (BaFeO{sub 2.5}) using stoichiometric amounts of polyvinylidene difluoride (PVDF). The vacancy order was found to be unique so far for perovskite compounds, and the connectivity pattern can be explained by the formula Ba{sub 3}(FeX{sub 6/2}) (FeX{sub 5/2}) (FeX{sub 3/2}X{sub 1/1}), with X=O/F. Mössbauer measurements were used to confirm the structural analysis and agree with the presence of Fe{sup 3+} in the above mentioned coordination environments. Group–subgroup relationships were used to build a starting model for themore » structure solution and to understand the relationship to the cubic perovskite structure. Furthermore, a comparison of a variety of vacancy-ordered iron-containing perovskite-type structures is given, highlighting the factors which favour one structure type over the other depending on the composition. - Graphical abstract: The crystal structure of Ba{sub 3}Fe{sub 3}O{sub 7}F in comparison to other perovskite type ferrites. - Highlights: • The crystal structure of Ba{sub 3}Fe{sub 3}O{sub 7}F in comparison to other perovskite type ferrites. • Ba{sub 3}Fe{sub 3}O{sub 7}F was synthesized by low temperature fluorination of Ba{sub 2}Fe{sub 2}O{sub 5}. • Ba{sub 3}Fe{sub 3}O{sub 7}F shows a unique vacancy order not found for other perovskite type compounds. • The structure of Ba{sub 3}Fe{sub 3}O{sub 7}F was solved using group–subgroup relationships. • A systematic comparison to other ferrite type compounds reveals structural similarities and differences. • The A-site coordination of the cation is shown to play an important role for the type of vacancy order found.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janeoo, Shashi; Sharma, Mamta, E-mail: mamta.phy85@gmail.com; Goswamy, J.

Polyaniline-indium oxide (In{sub 2}O{sub 3}/PANI) nanocomposite have been prepared by in-situ polymerization of aniline and as-synthesized In{sub 2}O{sub 3} nanoparticles. X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transformation infrared (FTIR) and UV/Vis spectroscopy techniques are used to investigate the structural and optical properties of In{sub 2}O{sub 3}/PANI nanocomposite. TEM analysis shows In{sub 2}O{sub 3} nanoparticles are embedded in PANI nanofibers. FTIR spectra show the good interactions between PANI nanofibers and In{sub 2}O{sub 3} nanoparticles. The band gap and electronic transitions in In{sub 2}O{sub 3}/PANI nanocomposite is determined by using UV/Vis spectra.

Synthesis, characterization and electrochemmistry of lithium battery electrodes : xLi{sub 2}MnO{sub 3}{center_dot}(1-x)LiMn{sub 0.333}Ni{sub 0.333}Co{sub 0.333}O{sub2} (0{le}x{le}0.7).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, C. S.; Li, N.; Lefief, C.

2008-01-01

Lithium- and manganese-rich layered electrode materials, represented by the general formula xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMO{sub 2} in which M is Mn, Ni, and Co, are of interest for both high-power and high-capacity lithium ion cells. In this paper, the synthesis, structural and electrochemical characterization of xLi{sub 2}MnO{sub 3} {center_dot} (1-x)LiMn{sub 0.333}Ni{sub 0.333}Co{sub 0.333}O{sub 2} electrodes over a wide compositional range (0 {le} x {le} 0.7) is explored. Changes that occur to the compositional, structural, and electrochemical properties of the electrodes as a function of x and the importance of using a relatively high manganese content and a high chargingmore » potential (>4.4 V) to generate high capacity (>200 mAh/g) electrodes are highlighted. Particular attention is given to the electrode composition 0.3Li{sub 2}MnO{sub 3} {center_dot} 0.7LiMn{sub 0.333}Ni{sub 0.333}Co{sub 0.333}O{sub 2} (x = 0.3) which, if completely delithiated during charge, yields Mn{sub 0.533}Ni{sub 0.233}Co{sub 0.233}O{sub 2}, in which the manganese ions are tetravalent and, when fully discharged, LiMn{sub 0.533}Ni{sub 0.233}Co{sub 0.233}O{sub 2}, in which the average manganese oxidation state (3.44) is marginally below that expected for a potentially damaging Jahn-Teller distortion (3.5). Acid treatment of 0.3Li{sub 2}MnO{sub 3} {center_dot} 0.7LiMn{sub 0.333}Ni{sub 0.333}Co{sub 0.333}O{sub 2} composite electrode structures with 0.1 M HNO{sub 3} chemically activates the Li{sub 2}MnO{sub 3} component and essentially eliminates the first cycle capacity loss but damages electrochemical behavior, consistent with earlier reports for Li{sub 2}MnO{sub 3}-stabilized electrodes. Differences between electrochemical and chemical activation of the Li{sub 2}MnO{sub 3} component are discussed. Electrochemical charge/discharge profiles and cyclic voltammogram data suggest that small spinel-like regions, generated in cycled manganese-rich electrodes, serve to stabilize the electrodes, particularly at low lithium loadings (high potentials). The study emphasizes that, for high values of x, a relatively small LiMO{sub 2} concentration stabilizes a layered Li{sub 2}MnO{sub 3} electrode to reversible lithium insertion and extraction when charged to a high potential.« less

Morphology-controlled synthesis of Co{sub 3}O{sub 4} by one step template-free hydrothermal method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Keqing; Liu, Jiajia; Wen, Panyue

2015-07-15

Highlights: • Co{sub 3}O{sub 4} crystals had been synthesized by one step template-free hydrothermal method. • The H{sub 2}O{sub 2} plays a crucial role in morphological control of Co{sub 3}O{sub 4} nanostructures. • The morphology has significant effect on the optical property of Co{sub 3}O{sub 4}. - Abstract: We had developed a facile synthetic route of Co{sub 3}O{sub 4} crystals with different morphologies via one step template-free hydrothermal method. The phase and composition of the Co{sub 3}O{sub 4} were investigated by X-ray powder diffraction and Raman spectrum. The morphology and structure of the synthesized samples were characterized by scanning electronmore » microscopy and transmission electron microscopy. The H{sub 2}O{sub 2} played a crucial role in morphological control of Co{sub 3}O{sub 4} nanostructures. It only obtained Co-based precursor in the absence of H{sub 2}O{sub 2}. On the contrary, the Co{sub 3}O{sub 4} with different morphologies including nanoparticles, nano-discs and well-defined octahedral nanostructures were synthesized in the presence of H{sub 2}O{sub 2}. In addition, the optical property of the obtained Co{sub 3}O{sub 4} samples was investigated by UV–vis spectra.« less

Novel lead(II) carboxylate-arsonate hybrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi Feiyan; Song Junling; Zhao Na

2008-06-15

Hydrothermal reactions of lead(II) acetate with phenylarsonic acid (H{sub 2}L{sup 1}) (or 4-hydroxy-3-nitrophenylarsonic acid, H{sub 3}L{sup 2}) and 5-sulfoisophthalic acid monosodium salt (NaH{sub 2}SIP) (or 1,3,5-benzenetricarboxylic acid (H{sub 3}BTC)) as the second metal linkers afforded three novel mixed-ligand lead(II) carboxylate-arsonates, namely, Pb{sub 5}(SIP){sub 2}(L{sup 1}){sub 2}(H{sub 2}O) 1, Pb{sub 3}(SIP)(L{sup 2})(H{sub 2}O) 2 and Pb(H{sub 2}L{sup 2})(H{sub 2}BTC) 3. The structure of 1 features a complicated 3D network composed of 2D double layers of lead(II) sulfoisophthalate bridged by 1D chains of lead(II) arsonates along b-axis, forming large tunnels along b-axis which are occupied by phenyl rings of the arsonate ligands.more » In 2, the Pb(II) ions are bridged by {l_brace}L{sup 2}{r_brace}{sup 3-} anions into a 2D double layer whereas the interconnection of the Pb(II) ions via bridging and chelating SIP anions gave a 2D double layer. The cross-linkage of the above two building units leads to a complicated 3D network. In 3, the interconnection of the Pb(II) ions via bridging {l_brace}H{sub 2}L{sup 2}{r_brace}{sup -} and {l_brace}H{sub 2}BTC{r_brace}{sup -} anions leads to a 1D double chain down a-axis. These 1D chains are further interconnected via hydrogen bonds among non-coordination carboxylate groups and arsonate oxygens into a 3D supramolecular architecture. - Graphical abstract: Three novel mixed-ligand lead(II) carboxylate-arsonates, namely, Pb{sub 5}(SIP){sub 2}(L{sup 1}){sub 2}(H{sub 2}O) 1, Pb{sub 3}(SIP)(L{sup 2})(H{sub 2}O) 2 and Pb(H{sub 2}L{sup 2})(H{sub 2}BTC) 3 have been synthesized and structurally characterized. Compounds 1 and 2 feature complicated 3D network structures whereas compound 3 features 1D lead(II) carboxylate-arsonate chains that are further interlinked by strong hydrogen bonds into a 3D supramolecular assembly.« less

Color-tunable photoluminescence phosphors of Ce{sup 3+} and Tb{sup 3+} co-doped Sr{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2} for UV w-LEDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Qingfeng; Liao, Libing, E-mail: clayl@cugb.edu.cn; Mei, Lefu

2015-05-15

A series of new luminescent emission-tunable phosphors Sr{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Ce{sup 3+}, Tb{sup 3+} with apatite structure have been synthesized by a high temperature solid-state reaction. The phase structure, photoluminescence emission and excitation spectra, lifetime, as well as the effect of Tb{sup 3+} concentration are investigated to characterize the resulting samples. The critical distance was calculated to be 8.26 Å by using the concentration quenching method. The intense green emission was observed in the Sr{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Ce{sup 3+}, Tb{sup 3+} phosphors on the basis of the efficient energy transfer from Ce{sup 3+} to Tb{sup 3+}more » with an efficiency of 68.55%. And a possible mechanism of the energy-transfer from Ce{sup 3+} to Tb{sup 3+} ion is also proposed. The results indicate that Sr{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Ce{sup 3+}, Tb{sup 3+} phosphors have potential applications to be used as near UV-convertible phosphors for white light-emitting diodes because of the broad excitation in the near-ultraviolet range and the efficient green emission light. - Graphical abstract: Crystal structure and luminescence properties of Sr{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2}:Ce{sup 3+},Tb{sup 3+} phosphors have been discussed. - Highlights: • Ce{sup 3+} and Tb{sup 3+} ions entered both La sites in SLSO. • The energy transfer efficiency can reach at 68.55%. • The emitting color of SLSO phosphors shifted from the blue to green region.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Javahery, G.; Petrie, S.; Wang, J.

Results are reported for the reactions of the fullerene ions C[sub 60[center dot]+], C[sub 70[center dot]+], C[sub 60][sup 2+], C[sub 70][sup 2+], and C[sub 60[center dot]3+] with the nitriles HCN, CH[sub 3]CN, CH[sub 2]CHCN, CH[sub 3]CH[sub 2]CN, CH[sub 2]CHCH[sub 2]CN, CH[sub 3]CH[sub 2]CH[sub 2]CN, (CH[sub 3])[sub 2]CHCN, C[sub 2]N[sub 2], and CH[sub 2](CN)[sub 2]. The reactions were studied using a selected-ion flow tube (SIFT) at 294 [+-] 2 K and a helium buffer gas pressure of 0.35 [+-] 0.01 Torr and exhibited a wide range of chemical behavior. For the monocations C[sub 60][sup [center dot]+] and C[sub 70][sup [center dot]+],more » no detectable reaction occurred with any of the nitriles. For the dications C[sub 60][sup 2+], and C[sub 70][sup 2+], the only primary or secondary product channel evident in all instances was addition: tertiary association was seen to be considerably less efficient than the primary and secondary reactions, and the formation of a quadruple adduct C[sub 60](RCN)[sub 4][sup 2+] was only detected in the reaction with butyronitrile, CH[sub 3]CH[sub 2]CH[sub 2]CN. The observed primary rate coefficients show a very clear dependence upon the molecular complexity of the nitrile: association proceeds more efficiently for nitriles with a higher number of hydrogen atoms. This observation is explained in terms of a model which relates the number of C-H bonds - or, alternatively, the number of internal rotational modes - in the collision complex to the lifetime and probability of stabilization of this complex. 42 refs., 5 figs., 3 tabs.« less

Selective adsorption in two porous triazolate–oxalate-bridged antiferromagnetic metal-azolate frameworks obtained via in situ decarboxylation of 3-amino-1,2,4-triazole-5-carboxylic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Juan-Juan; Xu, Xia; Jiang, Ning

2015-03-15

Solvothermal reactions of metal salts, 3-amino-1,2,4-triazole-5-carboxylic acid (H{sub 2}atzc) and ammonium oxalate in different temperature produced two metal azolate frameworks, namely, [Cu{sub 3}(atzc){sub 2}(atz)(ox)]·1.5H{sub 2}O (1) and [Co{sub 5}(atz){sub 4}(ox){sub 3}(HCOO){sub 2}]·DMF (2) (H{sub 2}atzc=3-amino-1,2,4-triazole-5-carboxylic acid, Hatz=3-amino-1,2,4-triazole, and ox=oxalate), in which the atzc precusor was in situ decarboxylated. Structural determination reveals that 1 contains [Cu{sub 3}(atzc){sub 2}(atz)]{sup 2−} layers of mixed μ{sub 4}-atzc and μ{sub 3}-atz ligands, which are pillared by ox{sup 2−} groups to form a 3D porous framework. Compound 2 contains 2D layers with basic spindle-shaped decanuclear units, which extended by ox{sup 2−} and formates to form 3Dmore » porous framework. Gas adsorption investigation revealed that two kinds of frameworks exhibited selective CO{sub 2} over N{sub 2} sorption. Moreover, activated 2 shows H{sub 2} storage capacity. Additionally, magnetic properties of both the compounds have been investigated. - Graphical abstract: Solvothermal reactions of metal salts, 3-amino-1,2,4-triazole-5-carboxylate and oxalate produced two metal azolate frameworks, which could store gas molecules, especially H{sub 2} due to small pores. in situ decarboxylation of precursor was observed. - Highlights: • Two MAFs were synthesized via in situ decarboxylation of H{sub 2}atzc. • Both activated frameworks exhibited selective CO{sub 2} over N{sub 2} sorption. • Activated 2 could adsorb H{sub 2}, which makes it promising candidates for gas storage.« less

Alkylation of a bioinspired high spin Ni(II)N{sub 3}S{sub 2} complex with bifunctional reagents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chohan, B. S., E-mail: bsc12@psu.edu

2013-12-15

Crystal structures of two S-alkylated complexes generated from the reaction of iodoacetamide and iodoethanol with an air and moisture sensitive high spin Ni(II) pentacoordinate triaminodithiolate complex, 1 are determined by X-ray structure analysis. Crystals of complex 2, [NiC{sub 16}H{sub 31}N{sub 5}O{sub 2}S{sub 2}]I{sub 2}, are triclinic, sp. gr. P-bar1 , Z = 2. Crystals of complex 3, [NiC{sub 16}H{sub 28}N{sub 3}O{sub 2}S{sub 2}]I{sub 2}, are monoclinic, sp. gr. P2{sub 1}/c, Z = 4. Structures of complexes 2 and 3 are very similar: one of the S-acetamide (2) or S-ethanol (3) groups coordinates to the Ni center through the oxygen atom formingmore » N{sub 3}S{sub 2}O hexacoordination; the other group remains unbound to the Ni and left dangling. Crystal packing shows that complexes 2 and 3 interact with the iodide counterions, and that only complex 2 interact with neighboring molecules; some of these close intermolecular contacts include H-bonding interactions.« less

Sulfate-bicarbonate exchange in brush-border membranes from rat renal cortex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pritchard, J.B.

1987-02-01

Under Na/sup +/-free conditions /sup 35/SO/sub 4//sup 2 -/ uptake by rat renal brush-border membrane (BBM) vesicles could be driven by imposition of a HCO/sup -//sub 3/ gradient (in greater than out). The initial rate of /sup 35/SO/sub 4//sup 2 -/ uptake was stimulated 10-fold, and peak overshoot exceeded equilibrium uptake by 2-3 times. Cl/sup -/, SCN/sup -/, NO/sub 3//sup -/, I/sup -/, and OH/sup -/ were able to substitute for HCO/sub 3//sup -/. Divalent anions, including /sup 35/SO/sub 4//sup 2 -/ itself, were less effective as counterions. HCO/sub 3//sup -/-SO/sub 4//sup 2 -/ exchange was cis-inhibited by disulfonic stilbenes,more » ((SITS)(DIDS)), phloretin, Hg, and S/sub 2/O/sub 3//sup 2 -/. HCO/sub 3//sup -/-driven /sup 35/SO/sub 4//sup 2 -/ uptake was saturable, with an apparent K/sub m/ of 0.4 mM for SO/sub 4//sup 2 -/. Simultaneous imposition of Na/sup +/ and HCO/sub 3//sup -/ gradients produced approximately additive stimulation of /sup 35/SO/sub 4//sup 2 -/ uptake. The HCO/sub 3//sup -/-driven component of /sup 35/SO/sub 4//sup 2 -/ uptake, but not the component driven by Na/sup +/, was inhibited by SITS. Finally, Na/sup +/-driven SO/sub 4//sup 2 -/ accumulation could be reduced by imposing an out greater than in HCO/sub 3//sup +/ gradient, conditions accelerating exchange driven SO/sub 4//sup 2 -/ efflux. These findings indicate the presence of separate Na/sup +/-SO/sub 4//sup 2 -/ cotransport and SO /sub 4//sup 2 -/-anion exchange pathways in the same BBM vesicles.« less

One-pot solvothermal synthesis of ordered intermetallic Pt{sub 2}In{sub 3} as stable and efficient electrocatalyst towards direct alcohol fuel cell application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jana, Rajkumar; Peter, Sebastian C., E-mail: sebastiancp@jncasr.ac.in

Ordered intermetallic Pt{sub 2}In{sub 3} nanoparticles have been synthesized by superhydride reduction of K{sub 2}PtCl{sub 4} and InCl{sub 3}.xH{sub 2}O precursors using facile, one-pot solvothermal method. We report surfactant free solvothermal synthesis of a novel ordered Pt{sub 2}In{sub 3} intermetallic nanoparticles for the first time. The structure and morphology of the catalyst has been confirmed by powder X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive spectrometry and X-ray photoelectron spectroscopy. The electrocatalytic properties of the catalysts have been investigated by cyclic voltammetry and chronoamperometry. The as prepared Pt{sub 2}In{sub 3} catalyst exhibit far superior electrocatalytic activity andmore » stability towards alcohol oxidation over commercial Pt/C. The specific activity of as synthesized catalyst was found to be ~3.2 and ~2.3 times higher than commercial Pt/C for methanol and ethanol oxidation, respectively. This improved activity and durability of the Pt{sub 2}In{sub 3} nanoparticles can make the catalyst an ideal catalyst candidate for direct alcohol fuel cell. - Graphical abstract: The ordered structure of Pt{sub 2}In{sub 3} nanoparticles synthesized by solvothermal method has confirmed through XRD and TEM. Cyclic voltametry and chronoamperometry showed improved catalytic activity and stability compared to commercial Pt/C. - Highlights: • Ordered Pt{sub 2}In{sub 3} nanoparticles were synthesized by solvothermal method. • Electrooxidation of alcohols on Pt{sub 2}In{sub 3} catalyst was investigated in acidic medium. • Pt{sub 2}In{sub 3} catalyst has superior catalytic activity compared to commercial Pt/C. • Pt{sub 2}In{sub 3} catalyst exhibited much higher stability than commercial Pt/C.« less

Difference in the luminescence properties of orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}:Ln (Ln = Tb{sup 3+} and Dy{sup 3+})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyagi, Adish; Shah, Alpa; Sudarsan, V., E-mail: vsudar@barc.gov.in

2015-04-15

Highlights: • Improved emission colour purity with orthorhombic form of Y{sub 2}GeO{sub 5}. • Non-stationary quenching exists in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}:Tb. • Ion pair formation and cross relaxation quenching operating for Y{sub 2}GeO{sub 5}:Dy samples. - Abstract: The luminescence properties of Tb{sup 3+} and Dy{sup 3+} doped orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5} are significantly different. Orthorhombic Y{sub 2}GeO{sub 5} doped with Tb{sup 3+} and Dy{sup 3+} ions gives bright green and blue emission upon UV light excitation with CIE coordinates (0.25, 0.46) and (0.25, 0.24), respectively. The monoclinic Y{sub 2}GeO{sub 5} dopedmore » with these ions exhibits light green and yellowish white emissions, respectively. This has been attributed to the differences in crystallographic environments around Y{sup 3+} ions in orthorhombic and monoclinic forms of Y{sub 2}GeO{sub 5}. Quantum yield of emission for orthorhombic Y{sub 2}GeO{sub 5}:Tb (∼29%) is significantly higher than that of the monoclinic Y{sub 2}GeO{sub 5}:Tb (∼14%). Lifetime values corresponding to {sup 4}F{sub 9/2} level of Dy{sup 3+} ions in both monoclinic and orthorhombic forms of Y{sub 2}GeO{sub 5} follow an opposite trend with respect to {sup 5}D{sub 4} level of Tb{sup 3+} ions. This is attributed to difference in the concentration quenching mechanism operating for Tb{sup 3+} and Dy{sup 3+} ions.« less

A series of coordination polymers constructed from R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands: Syntheses, structures and fluorescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yong-Hong, E-mail: zhou21921@sina.com; Zhou, Xu-Wan; Zhou, Su-Rong

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn{sub 2}Na(sip){sub 2}(bpp){sub 3}(Hbpp)(H{sub 2}O){sub 2}]·8H{sub 2}O (1), [Cd{sub 3}(sip){sub 2}(nbi){sub 6}(H{sub 2}O){sub 2}]·7H{sub 2}O (2), [Zn(sip)(nbi){sub 2}(H{sub 2}O)]·Hnbi·3H{sub 2}O (3), [Cd(hip)(nbi){sub 2}(H{sub 2}O)]·nbi·5H{sub 2}O (4), [Cd{sub 2}(nip){sub 2}(nbi){sub 2}(H{sub 2}O){sub 2}]·DMF (5), and [Cu(nip)(nbi)(H{sub 2}O){sub 2}]·H{sub 2}O (6) (H{sub 3}sip=5-sulfoisophthalic acid, H{sub 2}hip=5-hydroxylisophthalic acid, H{sub 2}nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through Omore » atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip{sup 3−} anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3–5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip{sup 2−} ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied. - Graphical abstract: A series of Cd(II)/Zn(II)/ Cu(II) coordination polymers based on R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands have been synthesized under hydrothermal conditions and structurally characterized. Photoluminescent properties have been discussed. - Highlights: • Six coordination polymers were synthesized based on mixed-ligand strategy. • The polycarboxylate acids play a crucial role in determining the final structures. • Each complex shows diverse structures and different supramolecular interactions.« less

Ba{sub 3}ZnTa{sub 2-x}Nb{sub x}O{sub 9} and Ba{sub 3}MgTa{sub 2-x}Nb{sub x}O{sub 9} (0{<=}x{<=}1): synthesis, structure and dielectric properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thirumal, M.; Jawahar, I.N.; Surendiran, K.P.

2002-11-20

Oxides belonging to the families Ba{sub 3}ZnTa{sub 2-x}Nb{sub x}O{sub 9} and Ba{sub 3}MgTa{sub 2-x}Nb{sub x}O{sub 9} were synthesized by the solid state reaction route. Sintering temperatures of 1300 deg. C led to oxides with disordered (cubic) perovskite structure. However, on sintering at 1425 deg. C hexagonally ordered structures were obtained for Ba{sub 3}MgTa{sub 2-x}Nb{sub x}O{sub 9} over the entire range (0{<=}x{<=}1) of composition, while for Ba{sub 3}ZnTa{sub 2-x}Nb{sub x}O{sub 9} the ordered structure exists in a limited range (0{<=}x{<=}0.5). The dielectric constant is close to 30 for the Ba{sub 3}ZnTa{sub 2-x}Nb{sub x}O{sub 9} family of oxides while the Mg analoguesmore » have lower dielectric constant of {approx}18 in the range 50 Hz to 500 kHz. At microwave frequencies (5-7 GHz) dielectric constant increases with increase in niobium concentration (22-26) for Ba{sub 3}ZnTa{sub 2-x}Nb{sub x}O{sub 9}; for Ba{sub 3}MgTa{sub 2-x}Nb{sub x}O{sub 9} it varies between 12 and 14. The 'Zn' compounds have much higher quality factors and lower temperature coefficient of resonant frequency compared to the 'Mg' analogues.« less

Magnetic relaxation behavior of lanthanide substituted Dawson-type tungstoarsenates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Lizhen; Li Fengyan; Xu Lin, E-mail: linxu@nenu.edu.c

2010-02-15

Two new polyoxometalate compounds [(CH{sub 3}){sub 4}N]{sub 8}[Ln(H{sub 2}O){sub 8}]{sub 2}[(alpha{sub 2}-As{sub 2}W{sub 17}O{sub 61})Ln(H{sub 2}O){sub 2}]{sub 2}.nH{sub 2}O (Ln=Er (1), Dy (2)) have been prepared by the trivacant Dawson-type anion [alpha-As{sub 2}W{sub 15}O{sub 56}]{sup 12-} and trivalent rare earth ion and characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric and electrochemical analyses. The centrosymmetric polyoxoanion, {l_brace}[(alpha{sub 2}-As{sub 2}W{sub 17}O{sub 61})Ln(H{sub 2}O){sub 2}]{sub 2}{r_brace}{sup 14-}, bounded to each other via Ln{sup 3+} connecting to terminal W-O oxygen atoms. Furthermore, the polyoxoanions are linked by [Ln(H{sub 2}O){sub 8}]{sup 3+} to form an extensive 3D supramolecular network structure depending on hydrogen bond.more » The magnetic properties of the two compounds have been studied by measuring their magnetic susceptibilities in the temperature range 2.0-300.0 K, indicating the depopulation of the stark components at low temperature and/or very weak antiferromagnetic interactions between magnetic centers. Low-temperature ac magnetic susceptibility measurements reveal a slow magnetic relaxation behavior for 2. - Graphical abstract: Two polyoxometalate compounds [(CH{sub 3}){sub 4}N]{sub 8}[Ln(H{sub 2}O){sub 8}]{sub 2}[(alpha{sub 2}-As{sub 2}W{sub 17}O{sub 61})Ln(H{sub 2}O){sub 2}]{sub 2}.nH{sub 2}O (Ln=Er (1), Dy (2)) have been prepared. The dynamic magnetic measurements for 2 display a slow relaxation of magnetization, showing a frequency-dependent susceptibility.« less

Synthesis and electrochemistry of heterobimetallic ruthenium/platinum and molybdenum/platinum complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orth, S.D.; Terry, M.R.; Abboud, K.A.

1996-02-14

As starting materials for heterobimetallic complexes, [RuCp(PPh{sub 3})CO(PPh{sub 2}H)]PF{sub 6} and [RuCp(PPh{sub 3})CO({eta}-dppm)]-PF{sub 6} were prepared from RuCp(PPh{sub 3})(CO)Cl. In the course of preparing [RuCp({eta}{sup 2}-dppm)({eta}-dppm)]Cl from RuCp(Ph{sub 3}P)({eta}-dppm)Cl, the monomer RuCpCl({eta}-dppm){sub 2} was isolated. The uncommon coordination mode of the two monodentatebis(phosphines) was confirmed by X-ray crystallography [a = 11.490(1) {angstrom}, b = 14.869(2) {angstrom}, c = 15.447(2) {angstrom}, {alpha} = 84.63(1){degrees}, {beta} = 70.55(1){degrees}, {gamma} = 72.92(1){degrees}, V = 2378.7(5) {angstrom}{sup 3}, d{sub calc} = 1.355 g cm{sup -3} (298 K), triclinic, P1, Z = 2]. The dppm-bridged bimetallic complexes RuCp(PPh{sub 3})Cl({mu}-dppm)PtCl{sub 2}, RuCpCl({mu}-dppm){sub 2}PtCl{sub 2}, and [RuCp(PPh{submore » 3})CO({mu}-dppm)PtCl{sub 2}]PF{sub 6} each exhibit electrochemistry consistent with varying degrees of metal-metal interaction. The cationic heterobimetallic complexes [Mo(CO){sub 3}({mu}-dppm){sub 2}Pt(H)]PF{sub 6} and [MoCp-(CO){sub 2}-({mu}-PPh{sub 2})({mu}-H)Pt(PPh{sub 3})(MeCN)]PF{sub 6} were prepared by chloride abstraction from the corresponding neutral bimetallic species and show electrochemical behavior similar to the analogous Ru/Pt complexes.« less

Synthesis, crystal structures and luminescent properties of zinc(II) metal–organic frameworks constructed from terpyridyl derivative ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xiao-Le; Shangguan, Yi-Qing; Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN

2014-08-15

Five zinc(II) metal–organic frameworks, [Zn{sub 3}(344-pytpy){sub 2}Cl{sub 6}]{sub n}·n(H{sub 2}O) (1), [Zn(344-pytpy)(ox)]{sub n} (2), [Zn{sub 2}(344-pytpy)(bdc){sub 2}]{sub n}·1.5n(H{sub 2}O) (3), [Zn{sub 2}(344-pytpy){sub 2} (sfdb){sub 2}]{sub n}·1.5n(H{sub 2}O) (4) and [Zn{sub 3}(344-pytpy){sub 2}(btc){sub 2}]{sub n}·2n(H{sub 2}O) (5), (344-pytpy=4′-(3-pyridyl)-4,2′:6′,4″-terpyridine, H{sub 2}ox=oxalic acid, H{sub 2}bdc=1,4-benzenedi-carboxylic acid, H{sub 2}sfdb=4,4′-sulfonyldibenzoic acid and H{sub 3}btc=1,3,5-benzene-tricarboxylic acid) have been prepared by hydrothermal reactions. Compound 1 is a 1D chain structure, in which 344-pytpy ligand links three Zn{sup II} centers through three of terminal N-donors. Compound 2 is a 4-connected 3D framework with the dia topological net and the Schläfli symbol of 6{sup 6}. Compound 3 displays amore » unusual 3-fold interpenetrating 3D coordination network which exhibits a new intriguing (3,3,4)-connected topological net with the Schläfli symbol of (4.8{sup 2})(4.8{sup 5})(8{sup 3}). Compound 4 features a two-fold interpenetrating 4-connected 2D framework with the sql topological net and the Schläfli symbol of (4{sup 4}.6{sup 2}). Compound 5 is a new self-interpenetrating (3,3,4,4)-connected topological net with the Schläfli symbol of (6.8{sup 2}){sub 2}(6{sup 2}.8{sup 2}.10.12)(6{sup 2}.8{sup 3}.10){sub 2}(6{sup 2}.8){sub 2}. The luminescence properties of 1–5 have been investigated by emission spectra and they possess great thermal stabilities which can be stable up to around 400 °C. - Graphical abstract: Five new Zn(II) metal–organic frameworks based on dicarboxylate and terpyridyl derivative ligands have been synthesized by hydrothermal reactions, giving networks from 1D to 3D structures. The thermal stability and luminescent property have been investigated. - Highlights: • Five zinc(II) metal–organic frameworks have been prepared under hydrothermal conditions. • Their crystal and topological structures have been investigated. • The luminescent properties have been investigated. • They possess great thermal stabilities which can be stable up to around 400 °C.« less

Hydroxy double salts loaded with bioactive ions: Synthesis, intercalation mechanisms, and functional performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaassis, Abdessamad Y.A.; Xu, Si-Min; Guan, Shanyue

The intercalation of the anions of diclofenac (Dic), naproxen (Nap), and valproic acid (Val) into three hydroxy double salts (HDSs) has been explored in this work. Experiments were performed with [Co{sub 1.2}Zn{sub 3.8}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (CoZn-NO{sub 3}), [Ni{sub 2}Zn{sub 3}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (NiZn-NO{sub 3}) and [Zn{sub 5}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (Zn-NO{sub 3}). It proved possible to intercalate diclofenac and naproxen into all three HDSs. In contrast, Val could be intercalated into CoZn-NO{sub 3} but when it was reacted with Zn-NO{sub 3} the HDS structure was destroyed, and the product comprised ZnO. Successful intercalation was verifiedmore » by X-ray diffraction, IR spectroscopy, and elemental microanalysis. Molecular dynamics simulations showed the Dic and Nap ions to arrange themselves in an “X” shape in the interlayer space, forming a bilayer. Val was found to adopt a position with its aliphatic groups parallel to the HDS layer, again in a bilayer. In situ time resolved X-ray diffraction experiments revealed that intercalation of Dic and Nap into CoZn-NO{sub 3} and Zn-NO{sub 3} is mechanistically complex, with a number of intermediate phases observed. In contrast, the intercalation of all three guests into NiZn-NO{sub 3} and of Val into CoZn-NO{sub 3} are simple one step reactions proceeding directly from the starting material to the product. The HDS-drug composites were found to have sustained release profiles. - Graphical abstract: Seven new drug intercalates of hydroxy double salts (HDSs) have been prepared and characterised. The intercalation mechanisms have been explored, and the drug release properties of the HDS/drug composites quantified. Display Omitted.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivenet, Murielle; Vigier, Nicolas; Roussel, Pascal

Six new layered uranyl vanadates (NH{sub 4}){sub 2}[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (1), (H{sub 2}EN)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (2), (H{sub 2}DAP)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (3), (H{sub 2}PIP)[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}].0,8H{sub 2}O (4), (H{sub 2}DMPIP)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (5), (H{sub 2}DABCO)[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}] (6) were prepared from mild-hydrothermal reactions using 1,2-ethylenediamine (EN); 1,3-diaminopropane (DAP); piperazine (PIP); 1-methylpiperazine (MPIP); 1,4-diazabicyclo[2,2,2]octane (DABCO). The structures of 1, 4, 5 and 6 were solved using single-crystal X-ray diffraction data while the structural models of 2 and 3 were established from powder X-ray diffraction data. In compounds 1, 2, 3more » and 5, the uranyl-vanadate layers are built from dimers of edge-shared UO{sub 7} pentagonal bipyramids and dimers of edge-shared VO{sub 5} square pyramids further connected through edge-sharing. In 1 and 3, the layers are identical to that occurring in the carnotite group of uranyl-vanadates. In 2 and 5, the V{sub 2}O{sub 8} dimers differ in orientation leading to a new type of layer. The layers of compound 4 and 6 are built from chains of edge-shared UO{sub 7} pentagonal bipyramids connected by VO{sub 4} tetrahedra and are of uranophane-type anion topology. For the six compounds, the ammonium or organoammonium cation resides in the space between the inorganic layers. Crystallographic data: 1 monoclinic, space group P2{sub 1}/c with a=6.894(2), b=8.384(3), c=10.473(4) A and {beta}=106.066(5){sup o}, 2 monoclinic, space group P2{sub 1}/a with a=13.9816(6), b=8.6165(3), c=10.4237(3) A and {gamma}=93.125(3){sup o}, 3 orthorhombic, space group Pmcn with a=14.7363(8), b=8.6379(4) and c=10.4385(4) A, 4 monoclinic, space group C2/m with a=15.619(2), b=7.1802(8), c=6.9157(8) A and {beta}=101.500(2){sup o}, 5 monoclinic, space group P2{sub 1}/b with a=9.315(2), b=8.617(2), c=10.5246(2) A and {gamma}=114.776(2){sup o}, 6 monoclinic, space group C2/m with a=17.440(2), b=7.1904(9), c=6.8990(8) A and {beta}=98.196(2){sup o}. - Graphical abstract: The three types of layer in layered uranyl-vanadates using diamine as a structure-directing agent.« less

Luminescent Copper(I) Halide Butterfly Dimers Coordinated to [Au(CH3imCH2py)2]BF4 and [Au(CH3imCH2quin)2]BF4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catalano, V.; Moore, A; Shearer, J

2009-01-01

The coordination chemistry of copper(I) halides to the homoleptic, N-heterocyclic carbene Au(I) complexes [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} and [Au(CH{sub 3}imCH{sub 2}py){sub 2}]BF{sub 4} was explored. The reaction of CuX (X = Cl, Br, I) with either [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} or [Au(CH{sub 3}imCH{sub 2}py){sub 2}]BF{sub 4} produces trimetallic complexes containing Cu{sub 2}X{sub 2}-butterfly copper clusters coordinated to the two imine moieties. The triangular arrangement of the metals places the gold(I) center in close proximity ({approx}2.5-2.6 {angstrom}) to the centroid of the Cu-Cu vector. The Cu-Cu separations vary as a function of bridging halide with the shortest Cu-Cu separationsmore » of {approx}2.5 {angstrom} found in the iodo-complexes and the longest separations of 2.9 {angstrom} found in the bridging chloride complexes. In all six complexes the Au-Cu separations range from {approx}2.8 to 3.0 {angstrom}. In the absence of halides, the dimetallic complex [AuCu(CH{sub 3}imCH{sub 2}py){sub 2}(NCCH{sub 3}){sub 2}](BF{sub 4}){sub 2}, containing a long Au-Cu distance of {approx}4.72 {angstrom} is formed. Additionally, as the byproduct of the reaction of CuBr with [Au(CH{sub 3}imCH{sub 2}quin){sub 2}]BF{sub 4} the deep-red, dimetallic compound, AuCuBr{sub 2}(CH{sub 3}imCH{sub 2}quin){sub 2}, was isolated in very low yield. All of these complexes were studied by NMR spectroscopy, mass spectrometry, and the copper containing species were additionally characterized by X-ray crystallography. In solution the copper centers dissociate from the gold complexes, but as shown by XANES and EXAFS spectroscopy, at low temperature the Cu-Cu linkage is broken, and the individual copper(I) halides reposition themselves to opposite sides of the gold complex while remaining coordinated to one imine moiety. In the solid state all of the complexes are photoluminescent, though the nature of the excited state was not determined.« less

Design and construction of diverse structures of coordination polymers: Photocatalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yu, E-mail: wuyuhlj@163.com; Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000; Lu, Lu

2017-01-15

The reaction of Cu(NO{sub 3}){sub 2}·3H{sub 2}O/Ni(NO{sub 3}){sub 2}·6H{sub 2}O with 4′-(4-(3,5-dicarboxylphenoxy)phenyl)-4,2′:6′,4′′-terpyridine (H{sub 2}dbp) gave [Cu{sub 0.5}(Hdbp)]{sub n} (1) and [Ni(dbp)(H{sub 2}O)]{sub n} (2), while the reactions of Co(NO{sub 3}){sub 2}·6H{sub 2}O with H{sub 2}dbp in the presence of 4,4′-bipy and 2,2′-bpy generated [Co(dbp)(4,4′-bipy)]{sub n} (3) and ([Co(dbp)(2,2′-bipy)]{sub n}·H{sub 2}O) (4), respectively (4,4′-bipy=4.4′-pyridine and 2,2′-bipy=2,2′-bipyridine). X-Ray single-crystal analyses reveal that 1 contains a 1D double chain. 2 possesses a 3D architecture with (4.6{sup 2}0.8{sup 3}){sub 2} topology that is interpenetrated with each other to form a 2-fold network. In 3, the 2D [Co(dbp)]n sheets are pillared by 4,4′-bpy to formmore » a 3D framework with 1D open channel. Compound 4 consists of a 1D ladder-like chain. The results showed that the structural diversity of the coordination polymers resulted from the different geometries of metal ions and effect of assistant ligands. Furthermore, the photocatalytic properties of 1–4 for degradation of the methyl violet (MV) have been examined. - Graphical abstract: The photocatalytic activity and selectivity of complexes 1–4 prove that they may be good and stable photocatalysts for degradation of organic dyes.« less

Ab initio study of irradiation tolerance for different M{sub n+1}AX{sub n} phases: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Shijun; Xue, Jianming, E-mail: jmxue@pku.edu.cn; Wang, Yugang

2014-01-14

Layered ternary M{sub n+1}AX{sub n} (MAX) materials are recently proposed to be promising candidates for future fission and fusion programmes because of their unique properties inherited from both ceramics and metals. However, different M{sub n+1}AX{sub n} materials demonstrate different behaviors when exposed to energetic neutron or ion irradiations. Based on first-principles calculations, we have investigated the irradiation tolerance of two typical M{sub n+1}AX{sub n} materials: Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} from two aspects. First, we make a detailed analysis on the interatomic bonding characters, which are believed to be responsible for the resistance to radiation-induced amorphization. Second, themore » formation energies of various intrinsic and antisite defects in these two compounds are calculated in order to elucidate their amorphization mechanism. Our results show that the absence of orbitals overlap of Al-C in Ti{sub 3}AlC{sub 2} renders it more resistant to amorphization compared to Ti{sub 3}SiC{sub 2}. In addition, the antisite defects Al{sub Ti(1)} and Al{sub Ti(2)} in Ti{sub 3}AlC{sub 2} have much lower formation energies compared to Si{sub Ti(1)} and Si{sub Ti(2)} in Ti{sub 3}SiC{sub 2}, which implies that the replacement of Ti with Al is easier than Si, thus providing an alternative way to accommodate the defects resulted from irradiation damage cascades. These results indicate that Ti{sub 3}AlC{sub 2} is more irradiation tolerant than Ti{sub 3}SiC{sub 2}, in accordance with experimental observations. Our results have profound implications for the choice of appropriate MAX phase with best performance to be used in next reaction reactors.« less

Lead(II) coordination polymers based on rigid-flexible 3,5-bis-oxyacetate-benzoic acid: Structural transition driven by temperature control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yong-Qiang, E-mail: chenjzxy@126.com; Tian, Yuan

2017-03-15

Three Pb(II) complexes ([Pb{sub 3}(BOABA){sub 2}(H{sub 2}O)]·H{sub 2}O){sub n} (1), ([Pb{sub 4}(BOABA){sub 2}(µ{sub 4}-O)(H{sub 2}O){sub 2}]·H{sub 2}O){sub n} (2), and [Pb{sub 3}(BOABA){sub 2}(H{sub 2}O)]{sub n} (3) (H{sub 3}BOABA=3,5-bis-oxyacetate-benzoic acid) were obtained under the same reaction systems with different temperatures. Complexes 1 and 2 are two dimensional (2D) networks based on Pb-BOABA chains and Pb{sub 4}(µ{sub 4}-O)(COO){sub 6} SBUs, respectively. Complex 3 presents an interesting three dimensional (3D) framework, was obtained by increasing the reaction temperature. Structural transition of the crystallization products is largely dependent on the reaction temperature. Moreover, the fluorescence properties of complexes 1–3 have been investigated. - Graphicalmore » abstract: Three Pb(II) coordination polymers were obtained under the same reaction systems with different temperatures. Both of complexes 1 and 2 are 2D network. 3 presents a 3D framework based on Pb–O–C rods SBUs. The 2D to 3D structures transition between three complexes was achieved successfully by temperature control. - Highlights: • Three Pb(II) complexes were obtained under the same reaction systems with different temperatures. • Structural transition of the crystallization products is largely dependent on the reaction temperature. • The luminescence properties studies reveal that three complexes exhibit yellow fluorescence emission behavior, which might be good candidates for obtaining photoluminescent materials.« less

Synthesis, crystal structures and luminescence properties of two metal carboxyphosphonates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chaonan; Feng, Pingjing; Li, Jintang, E-mail: leejt@xmu.edu.cn

2017-05-15

Two metal carboxyphosphonates, [Co{sub 2}(OOCC{sub 5}H{sub 3}NPO{sub 3}){sub 2·}(H{sub 2}O){sub 3}] (Compound1) and Zn{sub 3}[OOCC{sub 6}H{sub 3}CH(OH)PO{sub 3}]{sub 2·}2H{sub 2}O (Compound2) were successfully synthesized under the hydrothermal reactions. In compound 1, two (Co1-NO{sub 5}) octahedra link the (CPO{sub 3}) by sharing the corner, which link the two (Co2-O{sub 6}) octahedra. From a-axis the six clusters form the layer. Each layer is linked through hydrogen bond. In compound 2, the (Zn-O{sub 4}) tetrahedron and (CPO{sub 3}) tetrahedron are corner-shared, which arrange in line. From a-axis, each line forms the columnar. The thermal and luminescence properties of these compounds were investigated. -more » Graphical abstract: The synthesis conditions of the two compounds and the crystal morphology. Compound 1 shows the layer and the compound 2 shows the pillared-layer. - Highlights: • Two new carboxyphosphonate ligands have been prepared. • Using the two ligands, two metal carboxyphosphonates have been synthesized. • The two MOFs may be candidates for fluorescent materials.« less

CHEMICAL PROCESSING OF PURE AMMONIA AND AMMONIA-WATER ICES INDUCED BY HEAVY IONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bordalo, V.; Da Silveira, E. F.; Lv, X. Y.

Cosmic rays are possibly the main agents to prevent the freeze-out of molecules onto grain surfaces in cold dense clouds. Ammonia (NH{sub 3}) is one of the most abundant molecules present in dust ice mantles, with a concentration of up to 15% relative to water (H{sub 2}O). FTIR spectroscopy is used to monitor pure NH{sub 3} and NH{sub 3}-H{sub 2}O ice samples as they are irradiated with Ni and Zn ion beams (500-600 MeV) at GANIL/France. New species, such as hydrazine (N{sub 2}H{sub 4}), diazene (N{sub 2}H{sub 2} isomers), molecular hydrogen (H{sub 2}), and nitrogen (N{sub 2}) were identified aftermore » irradiation of pure NH{sub 3} ices. Nitrous oxide (N{sub 2}O), nitrogen oxide (NO), nitrogen dioxide (NO{sub 2}), and hydroxylamine (NH{sub 2}OH) are some of the products of the NH{sub 3}-H{sub 2}O ice radiolysis. The spectral band at 6.85 {mu}m was observed after irradiation of both types of ice. Besides the likely contribution of ammonium (NH{sub 4}{sup +}) and amino (NH{sub 2}) radicals, data suggest a small contribution of NH{sub 2}OH to this band profile after high fluences of irradiation of NH{sub 3}-H{sub 2}O ices. The spectral shift of the NH{sub 3} ''umbrella'' mode (9.3 {mu}m) band is parameterized as a function of NH{sub 3}/H{sub 2}O ratio in amorphous ices. Ammonia and water destruction cross-sections are obtained, as well as the rate of NH{sub 3}-H{sub 2}O (1:10) ice compaction, measured by the OH dangling bond destruction cross-section. Ammonia destruction is enhanced in the presence of H{sub 2}O in the ice and a power law relationship between stopping power and NH{sub 3} destruction cross-section is verified. Such results may provide relevant information for the evolution of molecular species in dense molecular clouds.« less

Synthesis and up-conversion luminescence of Er{sup 3+} and Y b{sup 3+} codoped nanocrystalline tetra- (KLaP{sub 4}O{sub 12}) and pentaphosphates (LaP{sub 5}O{sub 14})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marciniak, L., E-mail: l.marciniak@int.pan.wroc.pl; Stefanski, M.; Tomala, R.

2015-09-07

The up-converting nanocrystals of KLa{sub 0.95}Er{sub 0.05}Y b{sub x}P{sub 4}O{sub 12} and La{sub 0.95−x}Er{sub 0.05}Y b{sub x}P{sub 5}O{sub 14} were prepared using co-precipitation method. The spectroscopic properties of these materials were investigated in a function of Y b{sup 3+} concentration. The up-conversion emission, power dependence of emission intensities, and the luminescence decay times were investigated. It was found that the green to red and {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} to {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} emission intensity ratio were strongly affected by the Y b{sup 3+} concentration. Moreover, the order of up-conversion emission and threshold powermore » rises up with Y b{sup 3+} concentration for {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} transition. The luminescence decay time of the {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} emission increases with Y b{sup 3+} concentration while the {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} emission is independent of dopant concentration. The influence of the Y b{sup 3+} concentration on the up-conversion emission intensities was discussed in terms of concentration dependent hetero looped photon avalanche process. A comparison of the up-conversion properties of KLa{sub 0.95}Er{sub 0.05}Y b{sub x}P{sub 4}O{sub 12} and La{sub 0.95−x}Er{sub 0.05}Y b{sub x}P{sub 5}O{sub 14} nanocrystals was presented.« less

Syntheses, crystal structures, and properties of new metal-5-bromonicotinate coordination polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wenjie; Li, Guoting; Lv, Lulu

2015-05-15

Four metal–5-bromonicotinate (Brnic) coordination polymers [Fe(Brnic){sub 2}(H{sub 2}O){sub 2}]{sub n} (1), [Ni(Brnic){sub 2}]{sub n} (2), [Ni(Brnic)(bpy)(H{sub 2}O){sub 2}]{sub n}·n(Brnic)·4.5nH{sub 2}O (3), and [Co{sub 2}(Brnic){sub 3}(bpy){sub 2}(OH)]{sub n}·nH{sub 2}O (4) have been synthesized and structurally characterized (bpy=4,4′-bipyridine). Complex 1 has corrugated (4,4) sheets formed by μ-Brnic ligands and planar nodes Fe(II). As for 2–4, they all built up from Brnic-bridged dinuclear subunits, but have very different structure features. Complex 2 is a twin-like polymer with (4,4) layers formed by twin paddle-wheel [Ni{sub 2}(Brnic){sub 4}] subunits. Through the bridge coordination of bpy ligands with dinuclear rings [Ni{sub 2}(Brnic){sub 2}] and trigons [Co{submore » 2}(Brnic){sub 3}(OH)], 6{sup 3}-topological cationic layers with nanosized grids of 3 and chiral ladder-type double chains of 4 formed, respectively. Notably, halogen-related interactions play an important role in the formation of 3D metallosupermolecules 1–4. The thermostabilities of all compounds have been discussed in detail. Moreover, the magnetic investigations of 2 and 4 indicate that there exist antiferromagnetic interactions in the paddle-wheel [Ni{sub 2}(Brnic){sub 4}] and trigon [Co{sub 2}(Brnic){sub 3}(OH)] cores, respectively. - Highlights: • Four novel metal–5-bromonicotinate coordination polymers have been synthesized. • Notably, halogen-related interactions play an important role in the formation of 3D metallosupermolecules. • Antiferromagnetic interactions in nickel(II) paddle-wheel and cobalt(II) trigon cores were observed.« less

Comparison of B{sub 2}O{sub 3} and BN deposited by atomic layer deposition for forming ultrashallow dopant regions by solid state diffusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Consiglio, Steven, E-mail: steve.consiglio@us.tel.com; Clark, Robert D.; O'Meara, David

2016-01-15

In this study, the authors investigated atomic layer deposition (ALD) of B{sub 2}O{sub 3} and BN for conformal, ultrashallow B doping applications and compared the effect of dopant-containing overlayers on sheet resistance (R{sub s}) and B profiles for both types of films subjected to a drive-in thermal anneal. For the deposition of B{sub 2}O{sub 3}, tris(dimethylamido)borane and O{sub 3} were used as coreactants and for the deposition of BN, BCl{sub 3} and NH{sub 3} were used as coreactants. Due to the extreme air instability of B{sub 2}O{sub 3} films, physical analysis was performed on B{sub 2}O{sub 3} films, which weremore » capped in-situ with ∼30 Å ALD grown Al{sub 2}O{sub 3} layers. For the BN films, in-situ ALD grown Si{sub 3}N{sub 4} capping layers (∼30 Å) were used for comparison. From spectroscopic ellipsometry, a thickness decrease was observed after 1000 °C, 30 s anneal for the B{sub 2}O{sub 3} containing stack with 60 ALD cycles of B{sub 2}O{sub 3}, whereas the BN containing stacks showed negligible thickness decrease after the annealing step, regardless of the number of BN cycles tested. The postanneal reduction in film thickness as well as decrease in R{sub s} for the B{sub 2}O{sub 3} containing stack suggests that the solid state diffusion dopant mechanism is effective, whereas for the BN containing stacks this phenomenon seems to be suppressed. Further clarification of the effectiveness of the B{sub 2}O{sub 3} containing layer compared to the film stacks with BN was evidenced in backside secondary ion mass spectrometry profiling of B atoms. Thus, B{sub 2}O{sub 3} formed by an ALD process and subsequently capped in-situ followed by a drive-in anneal offers promise as a dopant source for ultrashallow doping, whereas the same method using BN seems ineffective. An integrated approach for B{sub 2}O{sub 3} deposition and annealing on a clustered tool also demonstrated controllable R{sub s} reduction without the use of a capping layer.« less

Wavelength dependence of Verdet constant of Tb{sup 3+}:Y{sub 2}O{sub 3} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snetkov, I. L., E-mail: snetkov@appl.sci-nnov.ru; Palashov, O. V.; Permin, D. A.

2016-04-18

Samples of the magneto-active material—Tb{sup 3+}:Y{sub 2}O{sub 3} ceramics with Tb{sup 3+} ion concentrations of 10%, 20%, 30%, and 100% (Tb{sub 2}O{sub 3})—were prepared and studied. The wavelength dependence of Verdet constant in the 380 nm–1750 nm range was approximated for all investigated ceramic samples and was predicted for a pure Tb{sub 2}O{sub 3} material. Tb{sub 2}O{sub 3} ceramics demonstrates a more than three times higher Verdet constant in comparison with terbium gallium garnet crystal or ceramics. The linear dependence of the Verdet constant on Tb{sup 3+} ion concentration in the Tb{sup 3+}:Y{sub 2}O{sub 3} ceramics was demonstrated. The obtained data willmore » be useful for fabricating magneto-optical elements of Faraday devices based on Tb{sup 3+}:Y{sub 2}O{sub 3} with arbitrary Tb{sup 3+} ion concentration operating at room temperature in the wavelength range of 380 nm–1750 nm.« less

Optical emission spectroscopic studies and comparisons of CH{sub 3}F/CO{sub 2} and CH{sub 3}F/O{sub 2} inductively coupled plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lou, Qiaowei; Kaler, Sanbir; Donnelly, Vincent M., E-mail: vmdonnelly@uh.edu

2015-03-15

A CH{sub 3}F/CO{sub 2} inductively coupled plasma (ICP), sustained in a compact plasma reactor, was investigated as a function of power (5–400 W) and feed gas composition, at a pressure of 10 mTorr, using optical emission spectroscopy and rare gas actinometry. Number densities of H, F, and O increased rapidly between 74% and 80% CO{sub 2}, ascribed to the transition from polymer-covered to polymer-free reactor walls, similar to that found previously in CH{sub 3}F/O{sub 2} ICPs at 48% O{sub 2}. Below 40% O{sub 2} or CO{sub 2}, relative emission intensity ratios were almost identical for most key species in CH{sub 3}F/O{submore » 2} and CH{sub 3}F/CO{sub 2} ICPs except for higher OH/Xe (a qualitative measure of OH and H{sub 2}O densities) over the full range of CH{sub 3}F/O{sub 2} composition. The number density of H, F, and O increased with power in CH{sub 3}F/CO{sub 2} (20%/80%) plasmas (polymer-free walls), reaching 4.0, 0.34, and 1.6 × 10{sup 13}/cm{sup 3}, respectively, at 300 W. The CO number density increased with power and was estimated, based on self-actinometry, to be 8.8 × 10{sup 13}/cm{sup 3} at 300 W. The CO{sub 2} number density was independent of power below 40 W (where very little decomposition occurred), and then decreased rapidly with increasing power, reaching 2.8 × 10{sup 13}/cm{sup 3} at 300 W, corresponding to 83% dissociation. Films deposited on p-Si, 10 cm from the open, downstream end of the plasma reactor, were analyzed by x-ray photoelectron spectroscopy. Between 10% and 40% CO{sub 2} or O{sub 2} addition to CH{sub 3}F, film deposition rates fell and O content in the films increased. Faster deposition rates in CH{sub 3}F/CO{sub 2} plasmas were ascribed mainly to a larger thermodynamic driving force to form solid carbon, compared with CH{sub 3}F/O{sub 2} plasmas. Oxygen content in the films increased with increasing CO{sub 2} or O{sub 2} addition, but for the same deposition rate, no substantial differences were observed in the composition of the films.« less

Copper(II) perrhenate Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}: Synthesis from isopropanol and CuReO{sub 4}, structure and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mikhailova, D., E-mail: d.mikhailova@ifw-dresden.de; Institute for Complex Materials, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden; Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden

2015-12-15

The crystal structure of Cu{sup +}Re{sup 7+}O{sub 4} is capable of a quasi-reversible incorporation of C{sub 3}H{sub 7}OH molecules. A room-temperature reaction between CuReO{sub 4} and C{sub 3}H{sub 7}OH under oxidizing conditions leads to the formation of a novel metal-organic hybrid compound Cu{sup 2+}(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}. Upon heating under reducing conditions, this compound transforms back into CuReO{sub 4}, albeit with ReO{sub 2} and metallic Cu as by-products. The crystal structure of Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} solved from single-crystal X-ray diffraction (Pbca, a=10.005(3) Å, b=7.833(2) Å, and c=19.180(5) Å) reveals layers of corner-sharing CuO{sub 6}-octahedra andmore » ReO{sub 4}-tetrahedra, whereas isopropyl groups are attached to both sides of these layers, thus providing additional connections within the layers through hydrogen bonds. Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} is paramagnetic down to 4 K because the spatial arrangement of the Cu{sup 2+} half-filled orbitals prevents magnetic superexchange. The paramagnetic effective moment of 2.0(1) μ{sub B} is slightly above the spin-only value and typical for Cu{sup 2+} ions. - Highlights: • Novel Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} compound has a sequence of inorganic and organic layers. • Hydrogen bonds provide an additional bonding Isopropanol molecules serve as a reducing agent during decomposition. • No direct Cu-O-Re-O-Cu connections via d{sub x2-y2} orbital of Cu{sup 2+} explain paramagnetism. • Hydrogen bonds provide an additional bonding. • Isopropanol molecules serve as a reducing agent during decomposition.« less

Planar dicyclic B{sub 6}S{sub 6}, B{sub 6}S{sub 6}{sup −}, and B{sub 6}S{sub 6}{sup 2−} clusters: Boron sulfide analogues of naphthalene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Da-Zhi; Bai, Hui; Ou, Ting

2015-01-07

Inorganic analogues of hydrocarbons or polycyclic aromatic hydrocarbons (PAHs) are of current interest in chemistry. Based upon global structural searches and B3LYP and CCSD(T) calculations, we present herein the perfectly planar dicyclic boron sulfide clusters: D{sub 2h} B{sub 6}S{sub 6} (1, {sup 1}A{sub g}), D{sub 2h} B{sub 6}S{sub 6}{sup −} (2, {sup 2}B{sub 3u}), and D{sub 2h} B{sub 6}S{sub 6}{sup 2−} (3, {sup 1}A{sub g}). These are the global minima of the systems, being at least 0.73, 0.81, and 0.53 eV lower in energy, respectively, than their alternative isomers at the CCSD(T) level. The D{sub 2h} structures feature twin B{submore » 3}S{sub 2} five-membered rings, which are fused together via a B{sub 2} unit and terminated by two BS groups. Bonding analyses show that the closed-shell B{sub 6}S{sub 6}{sup 2−} (3) cluster possesses 10 delocalized π electrons, closely analogous to the bonding pattern of the aromatic naphthalene C{sub 10}H{sub 8}. The B{sub 6}S{sub 6}{sup −} (2) and B{sub 6}S{sub 6} (1) species are readily obtained upon removal of one or two π electrons from B{sub 6}S{sub 6}{sup 2−} (3). The results build a new analogous relationship between boron sulfide clusters and their PAH counterparts. The B{sub 6}S{sub 6}{sup −} (2) monoanion and B{sub 6}S{sub 6}{sup 2−} (3) dianion can be effectively stabilized in neutral LiB{sub 6}S{sub 6} and Li{sub 2}B{sub 6}S{sub 6} salts, respectively.« less

Fabrication and characterization of millimeter-scale translucent La{sub 2}O{sub 3}-doped Al{sub 2}O{sub 3} ceramic hollow spheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Haoting; Liao, Qilong, E-mail: liaoqilong@swust.edu.cn; Dai, Yunya

2016-04-15

Highlights: • Millimeter-scale translucent La{sub 2}O{sub 3}-doped Al{sub 2}O{sub 3} hollow spheres have been prepared. • The diameters of the prepared hollow spheres are 500–1300μm. • The degree of sphericity for the prepared hollow spheres is above 98%. • The mechanisms of transparency are discussed. - Abstract: Millimeter-scale translucent La{sub 2}O{sub 3}-doped Al{sub 2}O{sub 3} ceramic hollow spheres have been successfully prepared using the oil-in-water (paraffin-in-alumina sol) droplets as precursors made by self-made T-shape micro-emulsion device. The main crystalline phase of the obtained hollow sphere is alpha alumina. The prepared translucent La{sub 2}O{sub 3}-containing Al{sub 2}O{sub 3} ceramic hollow spheresmore » have diameters of 500–1300 μm, wall thickness of about 23 μm and the degree of sphericity of above 98%. With the increase of the La{sub 2}O{sub 3} content, grains and grain-boundaries of the alumina spherical shell for the prepared millimeter-scale hollow spheres become regular and clear gradually. When the La{sub 2}O{sub 3} content is 0.1 wt.%, the crystal surface of the obtained Al{sub 2}O{sub 3} spherical shell shows optimal grains and few pores, and its transmittance reaches 42% at 532 nm laser light. This method provides a promising technique of preparing millimeter-scale translucent ceramic hollow spheres for laser inertial confined fusion.« less

Electrical and optical characterization of green synthesized Gd{sub 2}S{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Somnath, E-mail: somnathpaul459@gmail.com; Sarkar, A.

2016-05-06

Gadolinium sulphide (Gd{sub 2}S{sub 3}) is a magnetic semiconductor with large band gap. Gd{sub 2}S{sub 3} was synthesized following chemical and green techniques. Later process provides good stability of the nano clusters (NC) due to in-situ capping of Gd{sub 2}S{sub 3} NC. It has been found that the optical band gap in Gd{sub 2}S{sub 3} developed by green synthesis is lowered considerably over that in chemically synthesized Gd{sub 2}S{sub 3}. The green agencies used in this work are Jatropha Latex and dilute Garlic extract; both are enriched in sulphur and other organic polymer molecules. Simple observation shows that Gd{sub 2}S{submore » 3} NC retains residual magnetization. In this work optical and electrical characterization of the developed Gd{sub 2}S{sub 3} specimens are carried out. The overall results obtained are good.« less

Magnetically separable {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core-shell nanocomposites: Fabrication and visible-light-driven photocatalytic activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Minqiang, E-mail: jbmwgkc@126.com; Li, Di; Jiang, Deli

2012-08-15

Novel visible-light-induced {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts capable of magnetic separation have been synthesized by a facile sol-gel and after-annealing process. The as-obtained core-shell nanocomposite is composed of a central {gamma}-Fe{sub 2}O{sub 3} core with a strong response to external fields, an interlayer of SiO{sub 2}, and an outer layer of Ce-doped TiO{sub 2} nanocrystals. UV-vis spectra analysis indicates that Ce doping in the compound results in a red-shift of the absorption edge, thus offering increased visible light absorption. We show that such a {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite with appreciated Ce doping amount exhibitsmore » much higher visible-light photocatalytic activity than bare TiO{sub 2} and undoped {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-TiO{sub 2} core-shell nanocomposite toward the degradation of rhodamine B (RhB). Moreover, the {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts could be easily separated and reused from the treated water under application of an external magnetic field. - Graphical abstract: Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core/shell nanocomposite photocatalysts with enhanced photocatalytic activity and fast magnetic separability were prepared. Highlights: Black-Right-Pointing-Pointer Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core/shell composite photocatalysts were prepared. Black-Right-Pointing-Pointer The resulting core/shell composite show high visible light photocatalytic activity. Black-Right-Pointing-Pointer The nanocomposite photocatalysts can be easily recycled with excellent durability.« less

Li{sub 3}Gd{sub 3}Te{sub 2}O{sub 12}:Eu{sup 3+}- an intense red phosphor for solid state lighting applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiwari, Hansnath; Asiri Naidu, S.; Varadaraju, U.V., E-mail: varada@iitm.ac.in

Li{sub 3}Gd{sub 3−3x}Eu{sub 3x}Te{sub 2}O{sub 12} (x=0.05−1.0) phases with garnet structure were synthesized by high temperature solid state reaction and the photoluminescence properties were investigated. The appearance of bands due to intra 4 f transitions of Gd{sup 3+} in the excitation spectra recorded by monitoring the 612 nm emission line of the activator indicates Gd{sup 3+}→Eu{sup 3+} energy transfer in this host lattice. Under 395 nm excitation, the electric dipole transition is predominant in the emission spectrum of Eu{sup 3+} and is in agreement with the C{sub 2} point group (noncentrosymmetric) of the EuO{sub 8} polyhedron. The critical concentration ofmore » the Eu{sup 3+} activator in this series was found to be 0.6 (x=0.2) above which, concentration quenching occurs. The emission intensity of the phosphor composition, Li{sub 3}Gd{sub 2.4}Eu{sub 0.6}Te{sub 2}O{sub 12} is ~4 times that of the commercial sample of Y{sub 2}O{sub 3}:Eu{sup 3+} phosphor. - Highlights: • New Eu{sup 3+} doped garnet. • Intense electric dipole emission. • Gd{sup 3+}→Eu{sup 3+} energy transfer.« less

Analysis of the Photomagnetic Properties of Cyano-Bridged Heterobimetallic Complexes by X-Ray Diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Svendsen, Helle; Jørgensen, Mads Ry Vogel; Overgaard, Jacob

2012-10-11

Single crystal synchrotron X-ray diffraction measurements have been carried out on [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O (DMF = dimethyl-formamide), 1; [Y(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 2; [Ce(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 3; [Sm(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 4; [Tb(DMF){sub 4}(H{sub 2}O)3({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 5; [Yb(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 6; and [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Co(CN){sub 5}] {center_dot} H{sub 2}O, 7, at 15(2) K with and without UV illumination of the crystals. Significant changes in unit cell parameters are observed for all of themore » iron-containing complexes, while compound 7 shows no response to UV illumination. These results are consistent with previous results and are furthermore reproduced by powder synchrotron X-ray diffraction for compounds 1 and 7. Photoexcited crystal structures have been determined for 1-6 from refinements of two-conformer models, and excited state occupancies in the range 80-94% are found. Significant bond length changes are observed for the Fe-ligand bonds (up to 0.06 {angstrom}), the cyano bonds (up to 0.02 {angstrom}), and the lanthanide-ligand bonds (up to 0.1 {angstrom}). On the contrary, powder X-ray diffraction on the simple compound K{sub 3}Fe(CN)6, 8, upon UV illumination does not show any structural changes, suggesting that the photomagnetic effect requires the presence of both the transition metal and the lanthanide ion. Photomagnetic measurements show an increase in magnetization of the excited state of 1 of up to 3%, which is much diminished compared with previously published values of 45%. Furthermore, they show that the isostructural complex [La(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 9, exhibits identical magnetic responses in the UV-induced excited crystal structure.« less

Comparative analysis of the effects of tantalum doping and annealing on atomic layer deposited (Ta{sub 2}O{sub 5}){sub x}(Al{sub 2}O{sub 3}){sub 1−x} as potential gate dielectrics for GaN/Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Partida-Manzanera, T., E-mail: sgtparti@liv.ac.uk; Institute of Materials Research and Engineering, A*STAR; Roberts, J. W.

2016-01-14

This paper describes a method to optimally combine wide band gap Al{sub 2}O{sub 3} with high dielectric constant (high-κ) Ta{sub 2}O{sub 5} for gate dielectric applications. (Ta{sub 2}O{sub 5}){sub x}(Al{sub 2}O{sub 3}){sub 1−x} thin films deposited by thermal atomic layer deposition (ALD) on GaN-capped Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistor (HEMT) structures have been studied as a function of the Ta{sub 2}O{sub 5} molar fraction. X-ray photoelectron spectroscopy shows that the bandgap of the oxide films linearly decreases from 6.5 eV for pure Al{sub 2}O{sub 3} to 4.6 eV for pure Ta{sub 2}O{sub 5}. The dielectric constant calculated from capacitance-voltage measurementsmore » also increases linearly from 7.8 for Al{sub 2}O{sub 3} up to 25.6 for Ta{sub 2}O{sub 5}. The effect of post-deposition annealing in N{sub 2} at 600 °C on the interfacial properties of undoped Al{sub 2}O{sub 3} and Ta-doped (Ta{sub 2}O{sub 5}){sub 0.12}(Al{sub 2}O{sub 3}){sub 0.88} films grown on GaN-HEMTs has been investigated. These conditions are analogous to the conditions used for source/drain contact formation in gate-first HEMT technology. A reduction of the Ga-O to Ga-N bond ratios at the oxide/HEMT interfaces is observed after annealing, which is attributed to a reduction of interstitial oxygen-related defects. As a result, the conduction band offsets (CBOs) of the Al{sub 2}O{sub 3}/GaN-HEMT and (Ta{sub 2}O{sub 5}){sub 0.16}(Al{sub 2}O{sub 3}){sub 0.84}/GaN-HEMT samples increased by ∼1.1 eV to 2.8 eV and 2.6 eV, respectively, which is advantageous for n-type HEMTs. The results demonstrate that ALD of Ta-doped Al{sub 2}O{sub 3} can be used to control the properties of the gate dielectric, allowing the κ-value to be increased, while still maintaining a sufficient CBO to the GaN-HEMT structure for low leakage currents.« less

Non-isothermal crystallization kinetics of Fe{sub 2}O{sub 3}–CaO–SiO{sub 2} glass containing nucleation agent P{sub 2}O{sub 5}/TiO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Bin, E-mail: stra-ceo@163.com; Wang, Yongya; Luo, Wenqin

Fe{sub 2}O{sub 3}–CaO–SiO{sub 2} glass ceramics containing nucleation agent P{sub 2}O{sub 5}/TiO{sub 2} were prepared by sol-gel method. The samples were characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The activation energy and kinetic parameters for crystallization of the samples were calculated by the Johnson-Mehi-Avrami (JMA) model and Augis-Bennett method according to the results of DSC. The results showed that the crystallization mechanism of Fe{sub 2}O{sub 3}–CaO–SiO{sub 2} glass, whose non-isothermal kinetic parameter n = 2.3, was consistent with surface crystallization of the JMA model. The kinetics model function of Fe{sub 2}O{sub 3}–CaO–SiO{sub 2} glass, f(α) = 2.3(1–α)[–ln(1–α)]{supmore » 0.57}, was also obtained. The addition of nucleation agent P{sub 2}O{sub 5}/TiO{sub 2} could reduce the activation energy, which made the crystal growth modes change from onedimensional to three-dimensional.« less

Mixed valence and metamagnetism in a metal flux grown compound Eu{sub 2}Pt{sub 3}Si{sub 5}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Sumanta; Subbarao, Udumula; Joseph, Boby

A new compound Eu{sub 2}Pt{sub 3}Si{sub 5} with plate shaped morphology has been grown from excess In flux. The compound crystallizes in the orthorhombic U{sub 2}Co{sub 3}Si{sub 5} structure type, Ibam space group and the lattice parameters are a=10.007(2) Å, b=11.666(2) Å and c=6.0011(12) Å. The crystal structure of this compound can be conceived as inter-twinned chains of [Pt{sub 2}Si{sub 2}] and [PtSi{sub 3}] tetrahedra connected along [100] direction to give rise to a complex three dimensional [Pt{sub 3}Si{sub 5}] network. Temperature dependent magnetic susceptibility data suggests that Eu{sub 2}Pt{sub 3}Si{sub 5} undergoes a strong antiferromagnetic ordering (T{sub N}=19 K)more » followed by a weak ferromagnetic transition (T{sub C}=5.5 K). The effective magnetic moment/Eu obtained from susceptibility data is 6.78 μ{sub B} accounts mixed valent Eu with almost 85% divalent Eu, which is supported by X-ray absorption near edge spectroscopy. The compound undergoes a metamagnetic transition under applied magnetic field through a probable spin flop mechanism. - Graphical abstract: Eu{sub 2}Pt{sub 3}Si{sub 5}, a new member in the U{sub 2}Co{sub 3}Si{sub 5} (Ibam) family undergoes metamagnetic transition at high magnetic field and Eu is in mixed valence state. - Highlights: • A new compound Eu{sub 2}Pt{sub 3}Si{sub 5} has been synthesized using indium as an inactive metal flux. • The compound undergoes metamagnetic transition at higher field. • Eu in this compound resides in a mixed valence state.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Jianqi; College of Physical Science and Technology, Sichuan University, Chengdu 610064; Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064

High-temperature oxide melt solution calorimetry using 3Na{sub 2}O·MoO{sub 3} at 802 °C was performed for interlanthanide perovskites LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) and lanthanide oxides (La{sub 2}O{sub 3}, Ho{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Tm{sub 2}O{sub 3} and Yb{sub 2}O{sub 3}). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO{sub 3}, −9.9±3.0 kJ/mol for LaErO{sub 3}, −10.8±2.7 kJ/mol for LaTmO{sub 3} and −12.3±2.9 kJ/mol for LaYbO{sub 3}. There is a roughly linear relationships between these enthalpy values and the tolerance factor formore » these and for other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites, confirming that the distortion of the perovskites as results from ionic radius difference of A-site and B-site cations, is the main factor determining the stability of these compounds. - Graphical abstract: A linear relationship between the enthalpy of formation and the tolerance factor for interlanthanide LaLn'O{sub 3} (Ln'=Ho, Er, Tm, and Yb) and other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites. - Highlights: • Interlanthanide perovskites were synthesized by solid state reactions. • Their enthalpies of formation were measured by oxide melt solution calorimetry. • ΔH{sub f,ox} shows a linear relationship with tolerance factor.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Zhang; Wanjun, Tang, E-mail: tangmailbox@126.com

Highlights: • Iso-structural garnet-type Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} solid solution were synthesized. • Efficient energy transfer from [VO{sub 4}]{sup 3−} to Eu{sup 3+} ions in this phosphor is observed obviously. • Tuning the Y/Eu ratio generates the varied hues from yellowish-green to reddish-orange. • This kind of phosphor can be potentially used in UV pumped LEDs. - Abstract: A series of solid-solution phosphors Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} were prepared using solution combustion reaction. X-ray diffraction studies verified the formation of single phase Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} with garnet structure. Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} phosphors show notmore » only a broad emission band with a maximum at 510 nm due to the [VO{sub 4}]{sup 3−} group but also several sharp emission lines due to the Eu{sup 3+} ions. The energy transfer from [VO{sub 4}]{sup 3−} to Eu{sup 3+} was discussed on the base of the spectral analysis. The color-tunable emissions of the Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} phosphor as a function of Y/Eu ratio are realized by continuously generating the varied hues from yellowish-green to reddish-orange. This indicates that the obtained phosphor may have potential applications in the field of UV-based white LEDs.« less

Color-tunable up-conversion emission from Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} tri-doped T-AgGd(W,Mo){sub 2}O{sub 8} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jijian; Liu, Ni; Xu, Ling, E-mail: xuling@snnu.edu.cn

Graphical abstract: The doping ions tune the UC luminescence of the T- AgGd(W,Mo){sub 2}O{sub 8}:Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} material. - Highlights: • AgGd(W,Mo){sub 2}O{sub 8}:Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} phosphors show color-tunable blue, green, and red UC emissions. • The samples’ UC emission color can be switched with the concentrations of doped ions. • The blue, green and red UC mechanisms are interpreted reasonably as three- and two- photon process. - Abstract: Tetragonal Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} tri-doped AgGd(W,Mo){sub 2}O{sub 8} phosphors were prepared by the high-temperature solid-state method. When the phosphors were excited at 980 nm, the UC emission ofmore » blue at 475 nm, green at 525 and 550 nm, and red at 656 nm were corresponding to the {sup 1}G{sub 4} → {sup 3}H{sub 6} transition of Tm{sup 3+} ions, the {sup 2}H{sub 11/2},{sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, and the {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transition of Er{sup 3+} ions, respectively. The blue UC emissions originate from a three-photon mechanism, while the green and red ones of Er{sup 3+} from two-photon process. The UC emission color of the Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} tri-doped AgGdW{sub 2}O{sub 8} samples switched from green to white, and then to red depending on the concentrations of Er{sup 3+} and Tm{sup 3+}. After doping with Mo(VI), tetragonal AgGdW{sub 2}O{sub 8} was transformed into tetragonal AgGdMo{sub 2}O{sub 8}, resulting in a slightly enhanced UC luminescence intensity with the favor of the red emission of Er{sup 3+} ion.« less

Photolysis of pure solid O{sub 3} and O{sub 2} films at 193 nm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raut, U.; Loeffler, M. J.; Fama, M.

2011-05-21

We studied quantitatively the photochemistry of solid O{sub 3} and O{sub 2} films at 193 nm and 22 K with infrared spectroscopy and microgravimetry. Photolysis of pure ozone destroyed O{sub 3}, but a small amount of ozone remained in the film at high fluence. Photolysis of pure O{sub 2} produced O{sub 3} in an amount that increased with photon fluence to a stationary level. For both O{sub 2} and O{sub 3} films, the O{sub 3}:O{sub 2} ratio at large fluences is {approx}0.07, about two orders of magnitude larger than those obtained in gas phase photolysis. This enhancement is attributed tomore » the increased photodissociation of O{sub 2} due to photoabsorption by O{sub 2} dimers, a process significant at solid-state densities. We obtain initial quantum yield for ozone synthesis from solid oxygen, {Phi}(O{sub 3}) = 0.24 {+-} 0.06, and quantum yields for destruction of O{sub 3} and O{sub 2} in their parent solids, {Phi}(-O{sub 3}) = 1.0 {+-} 0.2 and {Phi}(-O{sub 2}) = 0.36 {+-} 0.1. Combined with known photoabsorption cross sections, we estimate probabilities for geminate recombination of 0.5 {+-} 0.1 for O{sub 3} fragments and 0.88 {+-} 0.03 for oxygen atoms from O{sub 2} dissociation. Using a single parameter kinetic model, we deduce the ratio of reaction cross sections for an O atom with O{sub 2} vs. O{sub 3} to be 0.1-0.2. The general good agreement of the model with the data suggests the validity of the central assumption of efficient energy and spin relaxation of photofragments in the solid prior to their reactions with other species.« less

Sol-gel synthesis of K{sub 3}InF{sub 6} and structural characterization of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labeguerie, Jessica; Gredin, Patrick; Marrot, Jerome

2005-10-15

K{sub 3}InF{sub 6} is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. Themore » two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K{sub 3}InF{sub 6} by decomposition at high temperature. The crystal structure of K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} is characterized by complex anions [In(CF{sub 3}COO){sub 4}(OH{sub x}){sub 2}]{sup (5-2x)-} and isolated [CF{sub 3}COOH{sub 2-x}]{sup (x-1)-} molecules with x=2 or 1, surrounded by K{sup +} cations. The crystal structure of K{sub 3}InC{sub 12}O{sub 12}F{sub 18} is only constituted by complex anions [In(CF{sub 3}COO){sub 6}]{sup 3-} and K{sup +} cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18} were also performed at room temperature on pulverized crystals.« less

Oxygen potentials and phase equilibria in the system Ca–Co–O and thermodynamic properties of Ca{sub 3}Co{sub 2}O{sub 6} and Ca{sub 3}Co{sub 4}O{sub 9.163}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, K.T., E-mail: katob@materials.iisc.ernet.in; Gupta, Preeti

2015-01-15

Oxygen potentials established by the equilibrium between three condensed phases, CaO{sub ss}+CoO{sub ss}+Ca{sub 3}Co{sub 2}O{sub 6} and CoO{sub ss}+Ca{sub 3}Co{sub 2}O{sub 6}+Ca{sub 3}Co{sub 3.93+α}O{sub 9.36−δ}, are measured as a function of temperature using solid-state electrochemical cells incorporating yttria-stabilized zirconia as the electrolyte and pure oxygen as the reference electrode. Cation non-stoichiometry and oxygen non-stoichiometry in Ca{sub 3}Co{sub 3.93+α}O{sub 9.36−δ} are determined using different techniques under defined conditions. Decomposition temperatures and thermodynamic properties of Ca{sub 3}Co{sub 2}O{sub 6} and Ca{sub 3}Co{sub 4}O{sub 9.163} are calculated from the results. The standard entropy and enthalpy of formation of Ca{sub 3}Co{sub 2}O{sub 6} atmore » 298.15 K are evaluated. Using thermodynamic data from this study and auxiliary information from the literature, phase diagram for the ternary system Ca–Co–O is computed. Isothermal sections at representative temperatures are displayed to demonstrate the evolution of phase relations with temperature. - Graphical abstract: Isothermal section of the phase diagram of the system Ca–Co–O at 1250 K. - Highlights: • Improved definition of cation and oxygen nonstoichiometry of Ca{sub 3}Co{sub 3.93+α}O{sub 9.36−δ}. • Measurement of Δμ{sub O{sub 2}} associated with two 3-phase fields as a function of temperature. • Use of solid-state electrochemical cells for accurate measurement of Δμ{sub O{sub 2}}. • Decomposition temperatures and thermodynamic properties for ternary oxides. • Characterization of ternary phase diagram of the system Ca–Co–O.« less

Electrocatalytic process for carbon dioxide conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masel, Richard I.; Salehi-Khojin, Amin

2017-01-31

An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and Helper Catalyst in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. the reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2,more » and CF.sub.3COOH.« less

Electrocatalytic process for carbon dioxide conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masel, Richard I.; Salehi-Khojin, Amin; Kutz, Robert

An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH,more » C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2, and CF.sub.3COOH.« less

R{sub 4}Ir{sub 13}Ge{sub 9} (R=La, Ce, Pr, Nd, Sm) and RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd): Crystal structures with nets of Ir atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarema, Maksym; Swiss Federal Laboratories for Materials Science and Technology; Zaremba, Oksana

The crystal structures of the new ternary compounds Sm{sub 4}Ir{sub 13}Ge{sub 9} and LaIr{sub 3}Ge{sub 2} were determined and refined on the basis of single-crystal X-ray diffraction data. They belong to the Ho{sub 4}Ir{sub 13}Ge{sub 9} (oP52, Pmmn) and CeCo{sub 3}B{sub 2} (hP5, P6/mmm) structure types, respectively. The formation of isotypic compounds R{sub 4}Ir{sub 13}Ge{sub 9} with R=La, Ce, Pr, Nd, and RIr{sub 3}Ge{sub 2} with R=Ce, Pr, Nd, was established by powder X-ray diffraction. The RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd) compounds exist only in as-cast samples and decompose during annealing at 800 Degree-Sign C with the formationmore » of R{sub 4}Ir{sub 13}Ge{sub 9}. The structure of Sm{sub 4}Ir{sub 13}Ge{sub 9} contains intersecting, slightly puckered nets of Ir atoms (4{sup 4})(4{sup 3}.6){sub 2}(4.6{sup 2}){sub 2} and (4{sup 4}){sub 2}(4{sup 3}.6){sub 4}(4.6{sup 2}){sub 2} that are perpendicular to [0 1 1] as well as to [0 -1 1] and [0 0 1]. The Ir atoms are surrounded by Ge atoms that form tetrahedra or square pyramids (where the layers intersect). The Sm and additional Ir atoms (in trigonal-planar coordination) are situated in channels along [1 0 0] (short translation vector). In the structure of LaIr{sub 3}Ge{sub 2} the Ir atoms form planar Kagome nets (3.6.3.6) perpendicular to [0 0 1]. These nets alternate along the short translation vector with layers of La and Ge atoms. - Graphical abstract: The crystal structures contain the nets of Ir atoms as main structural motif: R{sub 4}Ir{sub 13}Ge{sub 9} contains intersecting slightly puckered nets of Ir atoms, whereas in the structure of RIr{sub 3}Ge{sub 2} the Ir atoms form planar Kagome nets. Highlights: Black-Right-Pointing-Pointer The Ir-rich ternary germanides R{sub 4}Ir{sub 13}Ge{sub 9} (R=La, Ce, Pr, Nd, Sm) and RIr{sub 3}Ge{sub 2} (R=La, Ce, Pr, Nd) have been synthesized. Black-Right-Pointing-Pointer The RIr{sub 3}Ge{sub 2} compounds exist only in as-cast samples and decompose during annealing at 800 Degree-Sign C with the formation of R{sub 4}Ir{sub 13}Ge{sub 9}. Black-Right-Pointing-Pointer The structure of R{sub 4}Ir{sub 13}Ge{sub 9} contains intersecting slightly puckered nets of Ir atoms. Black-Right-Pointing-Pointer In the structure of RIr{sub 3}Ge{sub 2} the Ir atoms form planar Kagome nets.« less

On the Formation of the C{sub 2}H{sub 6}O Isomers Ethanol (C{sub 2}H{sub 5}OH) and Dimethyl Ether (CH{sub 3}OCH{sub 3}) in Star-forming Regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergantini, Alexandre; Maksyutenko, Pavlo; Kaiser, Ralf I., E-mail: ralfk@hawaii.edu

The structural isomers ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}) were detected in several low-, intermediate-, and high-mass star-forming regions, including Sgr B2, Orion, and W33A, with the relative abundance ratios of ethanol/dimethyl ether varying from about 0.03 to 3.4. Until now, no experimental data regarding the formation mechanisms and branching ratios of these two species in laboratory simulation experiments could be provided. Here, we exploit tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) to detect and analyze the production of complex organic molecules (COMs) resulting from the exposure of water/methane (H{sub 2}O/CH{sub 4}) ices to energetic electrons.more » The main goal is to understand the formation mechanisms in star-forming regions of two C{sub 2}H{sub 6}O isomers: ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}). The results show that the experimental branching ratios favor the synthesis of ethanol versus dimethyl ether (31 ± 11:1). This finding diverges from the abundances observed toward most star-forming regions, suggesting that production routes on interstellar grains to form dimethyl ether might be missing; alternatively, ethanol can be overproduced in the present simulation experiments, such as via radical–radical recombination pathways involving ethyl and hydroxyl radicals. Finally, the PI-ReTOF-MS data suggest the formation of methylacetylene (C{sub 3}H{sub 4}), ketene (CH{sub 2}CO), propene (C{sub 3}H{sub 6}), vinyl alcohol (CH{sub 2}CHOH), acetaldehyde (CH{sub 3}CHO), and methyl hydroperoxide (CH{sub 3}OOH), in addition to ethane (C{sub 2}H{sub 6}), methanol (CH{sub 3}OH), and CO{sub 2} detected from infrared spectroscopy. The yield of all the confirmed species is also determined.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Prasanta; Lee, Yuan-Pern; Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan

Irradiation at 193 nm of a p-H{sub 2} matrix containing acryloyl chloride CH{sub 2}CHC(O)Cl at 3.2 K yielded infrared absorption lines at 3143.6 (ν{sub 1}), 3057.0 (ν{sub 2}), 3048.0 (ν{sub 3}), 2103.1 (ν{sub 4}), 1461.0 (ν{sub 5}), 1349.8 (ν{sub 6}), 1223.7 (ν{sub 11}+ν{sub 12} or 2ν{sub 12}), 1092.8 (ν{sub 8}), 918.1 (ν{sub 9}), 691.0 (ν{sub 10}), 624.3 (ν{sub 11}), and 597.1 (ν{sub 12}) cm{sup −1} that are assigned to the 3-propenonyl (⋅CH{sub 2}CHCO) radical. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers and infrared intensities with those predicted with the B3PW91/aug-cc-pVDZ method. Themore » observation is consistent with a major radical formation channel CH{sub 2}CHCO + Cl followed by escape of the Cl atom from the original p-H{sub 2} cage. The observation of 3-propenonyl (⋅CH{sub 2}CHCO) radical but not 3-propenalyl (s-cis- or s-trans-CH{sub 2}CHĊO) radical indicates that the former is the most stable isomer and that the barrier heights for conversion from s-cis- or s-trans-CH{sub 2}CHĊO to ⋅CH{sub 2}CHCO are small.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawamata, S.; Okuda, K.; Sasaki, T.

The magnetic torque of [kappa]-(BEDT-TFF)[sub 2]Cu(NCS)[sub 2] was measured as a function of field direction [theta] with respect to the a*-axis under constant magnetic fields, H, up to 8 kOe in the temperature range from 1.3 to 8 K. A sharp cusp, C[sub 1], in the irreversible region was found at [theta][sub cl] near the H[parallel]bc-plane between 1.3 and 7 K. In addition, extra cusps, C[sub 2] and C[sub 3], were observed at [theta][sub c2] and [theta][sub c3], respectively, between 2.5 and 6 K. At each temperature, the perpendicular component of H giving each cusp is kept constant as Hmore » cos [theta][sub cm] = const [triple bond] H[sub cpm] (n = 1, 2, 3), i.e., cusps C[sub 1], C[sub 2], and C[sub 3] are ruled by the characteristic field perpendicular to the bc-plane H[sub cp1], H[sub cp2], and H[sub ep3], respectively. These behaviors are almost the same as those we found in the oxide superconductor Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]. These results suggest that the cusps are intrinsic for irreversible vortex states of these layered superconductors. 6 refs., 2 figs.« less

DIFFRACTION STUDY ON THE THERMAL STABILITY OF Ti{sub 3}SiC{sub 2}/TiC/TiSi{sub 2} COMPOSITES IN VACUUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pang, W. K.; Low, I. M.; O'Connor, B. H.

2010-01-05

Titanium silicon carbide (Ti{sub 3}SiC{sub 2}) possesses a unique combination of properties of both metals and ceramics, for it is thermally shock resistant, thermally and electrically conductive, damage tolerant, lightweight, highly oxidation resistant, elastically stiff, and mechanically machinable. In this paper, the effect of high vacuum annealing on the phase stability and phase transitions of Ti{sub 3}SiC{sub 2}/TiC/TiSi{sub 2} composites at up to 1550 deg. C was studied using in-situ neutron diffraction. The role of TiC and TiSi{sub 2} on the thermal stability of Ti{sub 3}SiC{sub 2} during vacuum annealing is discussed. TiC reacts with TiSi{sub 2} between 1400-1450 deg.more » C to form Ti{sub 3}SiC{sub 2}. Above 1400 deg. C, decomposition of Ti{sub 3}SiC{sub 2} into TiC commenced and the rate increased with increased temperature and dwell time. Furthermore, the activation energy for the formation and decomposition of Ti{sub 3}SiC{sub 2} was determined.« less

ALD Produced B{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and TiO{sub 2} Coatings on Gd{sub 2}O{sub 3} Burnable Poison Nanoparticles and Carbonaceous TRISO Coating Layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weimer, Alan

2012-11-26

This project will demonstrate the feasibility of using atomic layer deposition (ALD) to apply ultrathin neutron-absorbing, corrosion-resistant layers consisting of ceramics, metals, or combinations thereof, on particles for enhanced nuclear fuel pellets. Current pellet coating technology utilizes chemical vapor deposition (CVD) in a fluidized bed reactor to deposit thick, porous layers of C (or PyC) and SiC. These graphitic/carbide materials degrade over time owing to fission product bombardment, active oxidation, thermal management issues, and long-term irradiation effects. ALD can be used to deposit potential ceramic barrier materials of interest, including ZrO{sub 2}, Y{sub 2}O{sub 3}:ZrO{sub 2} (YSZ), Al{sub 2}O{sub 3},more » and TiO{sub 2}, or neutron-absorbing materials, namely B (in BN or B{sub 2}O{sub 3}) and Gd (in Gd{sub 2}O{sub 3}). This project consists of a two-pronged approach to integrate ALD into the next-generation nuclear plant (NGNP) fuel pellet manufacturing process:« less

Rhenium 2-oxoalkyl (enolate) complexes: Synthesis and carbon-carbon bond-forming reactions with nitriles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stack, J.G.; Doney, J.J.; Bergman, R.G.

1990-02-01

The (2-oxoalkyl)rhenium complexes (rhenium enolates) (CO){sub 5}ReCH{sub 2}COR{sup 1} (R{sup 1} = OEt, Me, Ph, 1-3) can be prepared on a multigram scale by alkylation of (CO){sub 5}ReNa with ClCH{sub 2}COR{sup 1}. The secondary enolate (CO){sub 5}ReCH(Me)CO{sub 2}Et (4) can also be prepared in a similar fashion with use of MsOCH(Me)CO{sub 2}Et (Ms = CH{sub 3}SO{sub 2}{sup {minus}}). The mono(phosphine) enolates cis-(Ph{sub 3}P)(CO){sub 4}ReCH{sub 2}R{sup 2}(R{sup 2} = CO{sub 2}Et, CO{sub 2}Bu{sup t}, CONEt{sub 2}, COMe, COPh, CN, 8-13) are prepared in high yield via alkylation of (Ph{sub 3}P)(CO){sub 4}ReNa with ClCH{sub 2}R{sup 2}. Synthesis of the secondary enolate cis-(Ph{submore » 3}P)(CO){sub 4}ReCH(Me)CO{sub 2}Et (14) is accomplished in 75% yield by alkylation with TfOCH(Me)CO{sub 2}Et (Tf = CF{sub 3}SO{sub 2}{sup {minus}}). The chelating phosphine complex is substitutionally inert under forcing thermal and photochemical conditions. Kinetic studies of the nitrile insertion reaction revealed a weak linear dependence of the rate constant of the reaction on the concentration of added CH{sub 3}CN in benzene; we believe this to be a medium effect.« less

Process for producing hydrogen from water using cobalt and barium compounds

DOEpatents

Bamberger, Carlos E.; Richardson, deceased, Donald M.

1979-01-01

A thermochemical process for producing hydrogen comprises the step of reacting CoO with BaO or Ba(OH).sub.2 in the presence of steam to produce H.sub.2 and novel double oxides of Ba and Co having the empirical formulas BaCoO.sub.2.33 and Ba.sub.2 CoO.sub.3.33. The double oxide can be reacted with H.sub.2 O to form Co.sub.3 O.sub.4 and Ba(OH).sub.2 which can be recycled to the original reaction. The Co.sub.3 O.sub.4 is converted to CoO by either of two procedures. In one embodiment Co.sub.3 O.sub.4 is heated, preferably in steam, to form CoO. In another embodiment Co.sub.3 O.sub.4 is reacted with aqueous HCl solution to produce CoCl.sub.2 and Cl.sub.2. The CoCl.sub.2 is reacted with H.sub.2 O to form CoO and HCl and the CoO is recycled to the initial reaction step. The Cl.sub.2 can be reacted with H.sub.2 O to produce HCl. HCl can be recycled for reaction with Co.sub.3 O.sub.4.

Catalyst mixtures

DOEpatents

Masel, Richard I.; Rosen, Brian A.

2017-02-14

Catalysts that include at least one catalytically active element and one helper catalyst can be used to increase the rate or lower the overpotential of chemical reactions. The helper catalyst can simultaneously act as a director molecule, suppressing undesired reactions and thus increasing selectivity toward the desired reaction. These catalysts can be useful for a variety of chemical reactions including, in particular, the electrochemical conversion of CO.sub.2 or formic acid. The catalysts can also suppress H.sub.2 evolution, permitting electrochemical cell operation at potentials below RHE. Chemical processes and devices using the catalysts are also disclosed, including processes to produce CO, OH.sup.-, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, O.sub.2, H.sub.2, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

Silicon nitride and silicon etching by CH{sub 3}F/O{sub 2} and CH{sub 3}F/CO{sub 2} plasma beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaler, Sanbir S.; Lou, Qiaowei; Donnelly, Vincent M., E-mail: vmdonnelly@uh.edu

2016-07-15

Silicon nitride (SiN, where Si:N ≠ 1:1) films low pressure-chemical vapor deposited on Si substrates, Si films on Ge on Si substrates, and p-Si samples were exposed to plasma beams emanating from CH{sub 3}F/O{sub 2} or CH{sub 3}F/CO{sub 2} inductively coupled plasmas. Conditions within the plasma beam source were maintained at power of 300 W (1.9 W/cm{sup 3}), pressure of 10 mTorr, and total gas flow rate of 10 sccm. X-ray photoelectron spectroscopy was used to determine the thicknesses of Si/Ge in addition to hydrofluorocarbon polymer films formed at low %O{sub 2} or %CO{sub 2} addition on p-Si and SiN. Polymer film thickness decreasedmore » sharply as a function of increasing %O{sub 2} or %CO{sub 2} addition and dropped to monolayer thickness above the transition point (∼48% O{sub 2} or ∼75% CO{sub 2}) at which the polymer etchants (O and F) number densities in the plasma increased abruptly. The C(1s) spectra for the polymer films deposited on p-Si substrates appeared similar to those on SiN. Spectroscopic ellipsometry was used to measure the thickness of SiN films etched using the CH{sub 3}F/O{sub 2} and CH{sub 3}F/CO{sub 2} plasma beams. SiN etching rates peaked near 50% O{sub 2} addition and 73% CO{sub 2} addition. Faster etching rates were measured in CH{sub 3}F/CO{sub 2} than CH{sub 3}F/O{sub 2} plasmas above 70% O{sub 2} or CO{sub 2} addition. The etching of Si stopped after a loss of ∼3 nm, regardless of beam exposure time and %O{sub 2} or %CO{sub 2} addition, apparently due to plasma assisted oxidation of Si. An additional GeO{sub x}F{sub y} peak was observed at 32.5 eV in the Ge(3d) region, suggesting deep penetration of F into Si, under the conditions investigated.« less

Synthesis of highly efficient α-Fe{sub 2}O{sub 3} catalysts for CO oxidation derived from MIL-100(Fe)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Lifeng; Zhao, Di; Yang, Yang

Mesoporous hollow α-Fe{sub 2}O{sub 3} bricks were synthesized via a hydrothermal method to create a precursor MIL-100(Fe) and a subsequent calcination process was applied to prepare the Fe{sub 2}O{sub 3} phase. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results showed the morphology of hollow α-Fe{sub 2}O{sub 3} bricks which inherited from the MIL-100(Fe) template. The catalytic activities of hollow α-Fe{sub 2}O{sub 3} bricks for CO oxidation are studied in this work. Due to better low temperature reduction behavior, mesoporous hollow α-Fe{sub 2}O{sub 3} bricks obtained at calcination temperature of 430 °C displayed high catalytic activity and excellent stabilitymore » with a complete CO conversion temperature (T{sub 100}) of 255 °C. - Graphical abstract: Synthesis of highly efficient α-Fe{sub 2}O{sub 3} catalysts for CO oxidation derived from MIL-100(Fe). - Highlights: • α-Fe{sub 2}O{sub 3} is prepared by the thermolysis of a MIL-100(Fe) template. • The morphology of hollow α-Fe{sub 2}O{sub 3} bricks is inherited from MIL-100(Fe) template. • α-Fe{sub 2}O{sub 3} obtained at calcined temperature of 430 °C displays high activity • Enhanced activity is attributed to crystal plane and reduction behavior.« less

Crystal and molecular structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H{sub 2}L)(NO{sub 3}){sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Egorova, O. A.; Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Sergienko, V. S.

2016-07-15

The crystal structure of 2,2’-(quinoxaline-2,3-diyl)dipyridinium dinitrate (H{sub 2}L)(NO{sub 3}){sub 2} is studied by X-ray diffraction (T = 150 K, R1 = 0.0467). The H{sub 2}L{sup 2+} cation is located on the twofold rotation axis and connected with two NO{sub 3}{sup −} anions by strong N–H···O hydrogen bonds. Planar quinoxaline fragments of cations form stacks with the interplanar spacing of 3.308 Å. The structure of the diprotonated H{sub 2}L{sup 2+} cation is compared with those of the monoprotonated H{sub 2}L{sup 2+} cation and neutral L molecule.

Thermal decomposition behavior of the rare-earth ammonium sulfate R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagai, Tsukasa; Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472; Tamura, Shinji

2010-07-15

Rare-earth ammonium sulfate octahydrates of R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4}.8H{sub 2}O (R=Pr, Nd, Sm, and Eu) were synthesized by a wet process, and the stable temperature region for the anhydrous R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} form was clarified by thermogravimetry/differential thermal analysis, infrared, Raman, and electrical conductivity measurements. Detailed characterization of these double salts demonstrated that the thermal stability of anhydrous R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} is different between the Pr, Nd salts and the Sm, Eu salts, and the thermal decomposition behavior of these salts was quite different from the previous reports. -more » Graphical abstract: Stable temperature range of anhydrous rare-earth ammonium sulfate R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} was clarified by thermogravimetry/differential thermal analysis, infrared, Raman, and electrical conductivity measurements. Since the previous reports were based only on thermal analysis, the present work has more accurately determined the exact thermal stability of rare-earth ammonium sulfate solids.« less

Al{sub 2}TiO{sub 5}-Al{sub 2}O{sub 3}-TiO{sub 2} nanocomposite: Structure, mechanical property and bioactivity studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalita, Samar Jyoti, E-mail: Samar.Kalita@und.nodak.edu; Somani, Vikas

2010-12-15

Novel biomaterials are of prime importance in tissue engineering. Here, we developed novel nanostructured Al{sub 2}TiO{sub 5}-Al{sub 2}O{sub 3}-TiO{sub 2} composite as a biomaterial for bone repair. Initially, nanocrystalline Al{sub 2}O{sub 3}-TiO{sub 2} composite powder was synthesized by a sol-gel process. The powder was cold compacted and sintered at 1300-1500 {sup o}C to develop nanostructured Al{sub 2}TiO{sub 5}-Al{sub 2}O{sub 3}-TiO{sub 2} composite. Nano features were retained in the sintered structures while the grains showed irregular morphology. The grain-growth and microcracking were prominent at higher sintering temperatures. X-ray diffraction peak intensity of {beta}-Al{sub 2}TiO{sub 5} increased with increasing temperature. {beta}-Al{sub 2}TiO{submore » 5} content increased from 91.67% at 1300 {sup o}C to 98.83% at 1500 {sup o}C, according to Rietveld refinement. The density of {beta}-Al{sub 2}TiO{sub 5} sintered at 1300 {sup o}C, 1400 {sup o}C and 1500 {sup o}C were computed to be 3.668 g cm{sup -3}, 3.685 g cm{sup -3} and 3.664 g cm{sup -3}, respectively. Nanocrystalline grains enhanced the flexural strength. The highest flexural strength of 43.2 MPa was achieved. Bioactivity and biomechanical properties were assessed in simulated body fluid. Electron microscopy confirmed the formation of apatite crystals on the surface of the nanocomposite. Spectroscopic analysis established the presence of Ca and P ions in the crystals. Results throw light on biocompatibility and bioactivity of {beta}-Al{sub 2}TiO{sub 5} phase, which has not been reported previously.« less

Crystal and molecular structure of Sr{sub 2}(Edta) . 5H{sub 2}O, Sr{sub 2}(H{sub 2}Edta)(HCO{sub 3}){sub 2} . 4H{sub 2}O, and Sr{sub 2}(H{sub 2}Edta)Cl{sub 2} . 5H{sub 2}O strontium ethylenediaminetetraacetates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polyakova, I. N., E-mail: polyakova@igic.ras.ru; Poznyak, A. L.; Sergienko, V. S.

2009-03-15

Three Sr{sup 2+} compounds with the Edta{sup 4-} and H{sub 2}Edta{sup 2-} ligands-Sr{sub 2}(Edta) . 5H{sub 2}O (I), Sr{sub 2}(H{sub 2}Edta)(HCO{sub 3}){sub 2} . 4H{sub 2}O (II), and Sr{sub 2}(H{sub 2}Edta)Cl{sub 2} . 5H{sub 2}O (III)-are synthesized, and their crystal structures are studied. In I, the Sr(1) atom is coordinated by the hexadentate Edta{sup 4-} ligand following the 2N + 4O pattern and by two O atoms of the neighboring ligands, which affords the formation of zigzag chains. The Sr(2) atom forms bonds with O atoms of five water molecules and attaches itself to a chain via bonds with threemore » O atoms of the Edta{sup 4-} ligands. The Sr(1)-O and Sr(2)-O bond lengths fall in the ranges 2.520(2)-2.656(3) and 2.527(3)-2.683(2) A, respectively. The Sr(1)-N bonds are 2.702(3) and 2.743(3) A long. In II and III, the H{sub 2}Edta{sup 2-} anions have a centrosymmetric structure with the trans configuration of the planar ethylenediamine fragment. The N atoms are blocked by acid protons. In II, the environment of the Sr atom is formed by six O atoms of three H{sub 2}Edta ligands, two O atoms of water molecules, and an O atom of the bicarbonate ion, which is disordered over two positions. In III, the environment of the Sr atom includes six O atoms of four H{sub 2}Edta{sup 2-} ligands and three O atoms of water molecules. The coordination number of the Sr atoms is equal to 8 + 1. In II and III, the main bonds fall in the ranges 2.534(3)-2.732(2) and 2.482(2)-2.746(3) A, whereas the ninth bond is elongated to 2.937(3) and 3.055(3) A, respectively. In II, all the structural elements are linked into wavy layers. The O-H-O interactions contribute to the stabilization of the layer and link neighboring layers. In III, hydrated Sr{sup 2+} cations and H{sub 2}Edta{sup -} anions form a three-dimensional [Sr{sub 2}(H{sub 2}Edta)(H{sub 2}O){sub 3}]{sub n}{sup 2n+} framework. The Cl{sup -} anions are fixed in channels of the framework by hydrogen bonds with four water molecules. In II and III, the N-H groups form four-center N-H-O{sub 3} hydrogen bonds, which include one intermolecular and two intramolecular components. PACS numbers: 61.66.Hq.« less

(Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5}, the first examples of copper platinum borides. Observation of superconductivity in a novel boron filled β-Mn-type compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salamakha, Leonid P.; Sologub, Oksana, E-mail: oksana.sologub@univie.ac.at; Stöger, Berthold

New ternary copper platinum borides have been synthesized by arc melting of pure elements followed by annealing at 600 °C. The structures have been studied by X-ray single crystal and powder diffraction. (Pt{sub 1−x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.33) forms a B-filled β-Mn-type structure (space group P4{sub 1}32; a=0.6671(1) nm). Cu atoms are distributed preferentially on the 8c atom sites, whereas the 12d site is randomly occupied by Pt and Cu atoms (0.670(4) Pt±0.330(4) Cu). Boron is located in octahedral voids of the parent β-Mn-type structure. Pt{sub 9}Cu{sub 3}B{sub 5} (space group P-62m; a=0.9048(3) nm, c=0.2908(1) nm) adopts the Pt{sub 9}Zn{submore » 3}B{sub 5–δ}-type structure. It has a columnar architecture along the short translation vector exhibiting three kinds of [Pt{sub 6}] trigonal prism columns (boron filled, boron semi-filled and empty) and Pt channels with a pentagonal cross section filled with Cu atoms. The striking structural feature is a [Pt{sub 6}] cluster in form of an empty trigonal prism at the origin of the unit cell, which is surrounded by coupled [BPt{sub 6}] and [Pt{sub 6}] trigonal prisms, rotated perpendicularly to the central one. There is no B–B contact as well as Cu–B contact in the structure. The relationships of Pt{sub 9}Cu{sub 3}B{sub 5} structure with the structure of Ti{sub 1+x}Os{sub 2−x}RuB{sub 2} as well as with the structure families of metal sulfides and aluminides have been elucidated. (Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.3) (B-filled β-Mn-type structure) is a bulk superconductor with a transition temperature of about 2.06 K and an upper critical field μ{sub 0}H{sub C2}(0){sup WHH} of 1.2 T, whereas no superconducting transition has been observed up to 0.3 K in Pt{sub 9}Cu{sub 3}B{sub 5} (Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure) from electrical resistivity measurements. - Highlights: • First two copper platinum borides, (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5} were obtained. • (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B forms a B-filled β-Mn-type structure. • Pt{sub 9}Cu{sub 3}B{sub 5} adopts a Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure. • Boron atoms exhibit octahedral and trigonal prismatic coordination. • (Pt{sub 1–x}Cu{sub x})3Cu{sub 2}B (x=0.3) is a bulk superconductor with T{sub c} 2.06 K.« less

Durable electrooptic devices comprising ionic liquids

DOEpatents

Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM

2006-10-10

Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes.

Method for synthesizing N.sub.2 O.sub.5

DOEpatents

McGuire, Raymond R.; Coon, Clifford L.; Harrar, Jackson E.; Pearson, Richard K.

1985-01-01

A method and apparatus for electrochemically synthesizing N.sub.2 O.sub.5 includes oxidizing a solution of N.sub.2 O.sub.4 /HNO.sub.3 at an anode, while maintaining a controlled potential between the N.sub.2 O.sub.4 /HNO.sub.3 solution and the anode. A potential of about 1.35 to 2.0 V vs. SCE is preferred, while a potential of about 1.80 V vs. SCE is most preferred. Thereafter, the N.sub.2 O.sub.5 is reacted with either 1.5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) or 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) to form cyclotetramethylenetetraamine (HMX).

Discussion and Re-Analysis of Experimental Data in the Investigation of Ultradian Rhythms in Humans.

DTIC Science & Technology

1981-03-01

the 51 Subl Sub2 Sub3 Sub4 Subs Sub6 Sub7 Sub8 1 31 30 29 13 7 18 8 5 2 28 28 13 31 31 31 3 26 3 17 9 28 10 16 15 22 16 4 32 29 32 3 14 25 15 21 5 4 17...ARRANGED IN ASCENDING ORDER FROM 1 TO 32 (LEFT HAND COLUMN). 52 I bl Sub2 Sub3 Sub4 Sub5 Sub6 Sub7 Sub8 1 30 29 28 12 6 17 7 4 2 27 27 12 29 29 29 2

In-situ synthesis of MoSi{sub 2}-Al{sub 2}O{sub 3} composite by a thermite reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deevi, S.C.; Deevi, S.

1995-08-01

In this paper, the authors discuss the reaction mechanism involved in the thermite reaction leading to the synthesis of a composite since in an actual combustion synthesis, the reaction propagates at a velocity of 10 to 20 mm/sec. Reaction mechanism was determined by using a differential thermal analysis (DTA) and X-ray diffraction (XRD). During the combustion synthesis of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}, reaction of MoO{sub 3}, Al and Si occurs rapidly and the reactants and products are expected to be in the liquid state at the combustion temperature. MoO{sub 3} is first reduced to MoO{sub 2}, and the reaction betweenmore » MoO{sub 2}, Al and Si leads to a composite of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}. Differential thermal analysis reveals that the onset of exothermic reactions is preceded by melting indicating the necessity of molten Al for the synthesis of the composite. The reaction between MoO{sub 2} + 2Al +2Si can be moderated with Mo-Si mixtures such that the ratio of MoSi{sub 2} to Al{sub 2}O{sub 3} can be increased in the composite of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru; Isnard, O.; Université Grenoble Alpes, Inst. Néel, F-38042 Grenoble

The crystal structure of new Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} (Immm, No. 71, oI10) and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} (Cmce No. 64, oC20) compounds has been established using powder X-ray diffraction studies. Magnetization measurements show that the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} undergoes a ferromagnetic transition at ~66 K, whereas isostructural Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} shows an antiferromagnetic transition at ~52 K and a field-induced metamagnetic transition at low temperatures. Neutron diffraction study shows that, in zero applied field, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} exhibits c-axis antiferromagnetic order with propagation vectormore » K=[1/2, 0, 1/2] below its magnetic ordering temperature and Tb magnetic moment reaches a value of 8.32(5) μ{sub B} at 2 K. The La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibits ferromagnetic like transition at ~42 K with coexisting antiferromagnetic interactions and field induced metamagnetic transition below ~17 K. The magnetocaloric effect of Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −14.3 J/kg K, −5.3 J/kg K and −10.3 J/kg K for a field change of 50 kOe near 66 K, 52 K and 42 K, respectively. Low temperature magnetic ordering with enhanced anisotropic effects in Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} is accompanied by a positive magnetocaloric effect with isothermal magnetic entropy changes of +12.8 J/kg K and ~+9.9 J/kg K, respectively at 7 K for a field change of 50 kOe. - Graphical abstract: The (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} supplement the series of Mo{sub 2}NiB{sub 2}-type rare earth compounds, whereas the (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} supplement the series of La{sub 2}Ni{sub 3}-type rare earth compounds. The variation of alloy’s composition by ~3 at% i.e. from Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} to Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} leads to significant transformation of crystal structure of compound with different variant of distortion of Po-type rare earth sublattice, as in Gd–Co–Ga and Er–Ni–In systems: the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Co{sub 2}Ga and La{sub 2}Ni{sub 3}-type Gd{sub 2}Co{sub 2.9}Ga{sub 0.1}, and Mo{sub 2}FeB{sub 2}-type Er{sub 2}Ni{sub 1.78}In and Mn{sub 2}AlB{sub 2}-type Er{sub 2}Ni{sub 2}In. Magnetization measurements indicate collinear ferromagnetic ordering of Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} and a complex antiferromagnetic ordering with low-temperature metamagnetic nature for Mo{sub 2}NiB{sub 2}-type Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} compounds. However, neutron diffraction study in zero applied field of Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} reveals c-axis pure antiferromagnetic ordering of terbium sublattice with K=[1/2, 0, 1/2] propagation vector. Magnetization measurements indicate ferromagnetic order with coexisting antiferromagnetic interactions and low-temperature metamagnetic state for La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5}. We suggest possible polymorphism in other Mo{sub 2}FeB{sub 2}-type, Mo{sub 2}NiB{sub 2}-type, La{sub 2}Ni{sub 3}-type and Mn{sub 2}AlB{sub 2}-type rare earth compounds with corresponding change in their magnetic properties. - Highlights: • (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} compounds crystallize in the Mo{sub 2}NiB{sub 2}-type structure. • (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} compounds crystallize in the La{sub 2}Ni{sub 3}-type structure. • Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} shows pure ferromagnetic type ordering. • Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} show mixed ferro-antiferromagnetic ordering. • Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibit low-temperature metamagnetic behaviour.« less

METHOD FOR DECONTAMINATION OF REACTOR SOLUTIONS

DOEpatents

Maraman, W.J.; Baxman, H.R.; Baker, R.D.

1959-05-01

A process for U recovery from phosphate fuel solutions is described. To fuel solution drawn from the reactor is added Fe(NO/sub 3/)/sub 3/ which destroys the U complex and forms ferric phosphate complex. The UO/sub 2/(NO/sub 3/)/sub 2/ formed is extracted into TBP-kerosene in a countercurrent column. The TBP contalning UO/sub 2/(NO/sub 3/)/sub 2/ is further purified by an aqueous Al(NO/ sub 3/)/sub 3/ scrub solution. The pregnant solution then goes to an H/sub 3/PO/ sub 4/ stripping and kerosene washing column. The H/sub 3/PO/sub 4/--uranyl phosphate solution is separated at the bottom and boiled to remove HNO/sub 3/ then diluted to fuel solution make-up strength. (T.R.H.)

Structure refinement of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-d} as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zakaria, Nurhamidah, E-mail: nurhamidahzakaria@yahoo.com; Idris, Mohd Sobri, E-mail: sobri@unimap.edu.my; Osman, Rozana A. M., E-mail: rozana@unimap.edu.my

2016-07-19

Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} was successfully prepared using modified solid-state synthesis routes. The lowest temperature to obtained single phase of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} is about 900°C for 15 hours. Longer period of time are required compared to only 5 hours at 950°C as established in literatures. The X-ray Diffraction (XRD) data confirmed that Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} is formed a cubic perovskite with the space group of Pm-3m. The lattice parameters of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} are a = 3.990 (1) Å and unit cell volume is V = 63.5 (1)more » Å{sup 3}. The Rietveld refinement of XRD data revealed that the crystal structure of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} slightly changes as a function of temperature.« less

Influence of mineral matter on pyrolysis of palm oil wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Haiping; Chen, Hanping; Zheng, Chuguang

2006-09-15

The influence of mineral matter on pyrolysis of biomass (including pure biomass components, synthesized biomass, and natural biomass) was investigated using a thermogravimetric analyzer (TGA). First, the mineral matter, KCl, K{sub 2}CO{sub 3}, Na{sub 2}CO{sub 3}, CaMg(CO{sub 3}){sub 2}, Fe{sub 2}O{sub 3}, and Al{sub 2}O{sub 3}, was mixed respectively with the three main biomass components (hemicellulose, cellulose, and lignin) at a weight ratio (C/W) of 0.1 and its pyrolysis characteristics were investigated. Most of these mineral additives, except for K{sub 2}CO{sub 3}, demonstrated negligible influence. Adding K{sub 2}CO{sub 3} inhibited the pyrolysis of hemicellulose by lowering its mass loss ratemore » by 0.3 wt%/{sup o}C, while it enhanced the pyrolysis of cellulose by shifting the pyrolysis to a lower temperature. With increased K{sub 2}CO{sub 3} added, the weight loss of cellulose in the lower temperature zone (200-315 {sup o}C) increased greatly, and the activation energies of hemicellulose and cellulose pyrolysis decreased notably from 204 to 42 kJ/mol. Second, studies on the synthetic biomass of hemicellulose, cellulose, lignin, and K{sub 2}CO{sub 3} (as a representative of minerals) indicated that peaks of cellulose and hemicellulose pyrolysis became overlapped with addition of K{sub 2}CO{sub 3} (at C/W=0.05-0.1), due to the catalytic effect of K{sub 2}CO{sub 3} lowering cellulose pyrolysis to a lower temperature. Finally, a local representative biomass--palm oil waste (in the forms of original material and material pretreated through water washing or K{sub 2}CO{sub 3} addition)--was studied. Water washing shifted pyrolysis of palm oil waste to a higher temperature by 20 {sup o}C, while K{sub 2}CO{sub 3} addition lowered the peak temperature of pyrolysis by {approx}50{sup o}C. It was therefore concluded that the obvious catalytic effect of adding K{sub 2}CO{sub 3} might be attributed to certain fundamental changes in terms of chemical structure of hemicellulose or decomposition steps of cellulose in the course of pyrolysis. (author)« less

Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xuguang, E-mail: liuxuguang@qust.edu.cn; Xu, Lei; Zhang, Baoquan

2014-04-01

Preparation of supported nickel phosphide (Ni{sub 2}P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni{sub 2}P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni{sub 2}P structure, verified by XRD characterization results. The alumina (namely, γ-Al{sub 2}O{sub 3}, θ-Al{sub 2}O{sub 3}, or α-Al{sub 2}O{sub 3}) with distinctmore » physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni{sub 2}P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N{sub 2}-sorption isotherm. The uniform surface energy of α-Al{sub 2}O{sub 3} results only in the nickel phosphosate precursor and thus the Ni{sub 2}P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al{sub 2}O{sub 3}, θ-Al{sub 2}O{sub 3}, and γ-Al{sub 2}O{sub 3}) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni{sub 3}P, Ni{sub 12}P{sub 5}, Ni{sub 2}P). - Highlights: • Preparing pure Ni{sub 2}P. • Elucidating nickel phosphate precursor. • Associating with surface energy.« less

A new structure related to the layered cuprates: The {open_quotes}1201{angstrom} shear-like phase Tl{sub 5}Ba{sub 3}Sr{sub 5}Cu{sub 3}O{sub 19}, third member of the series (TlA{sub 2}CuO{sub 5}){sub m}{center_dot}Tl{sub 2}A{sub 2}O{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Letouze, F.; Martin, C.; Hervieu, M.

1997-01-01

A thallium cuprate, Tl{sub 5}Ba{sub 3}Sr{sub 5}Cu{sub 3}O{sub 19}, whose structure can be derived by systematically shearing the {open_quotes}1201{close_quotes} structure has been synthesized for the first time. It crystallizes in an orthorhombic cell with a=3.7536(2) {angstrom}, b=30.631(2) {angstrom}, c=9.219(1) {angstrom}, and A-type symmetry. This new structure consists of {open_quotes}1201{close_quotes} ribbons parallel to (010) which are three CuO{sub 6} octahedra wide and are interconnected through {open_quotes}Tl{sub 2}A{sub 2}O{sub 4}{close_quotes} ribbons whose cationic configuration is that of the rock salt structure. This phase can be considered to be the m = 3 member of a new series with the generic formulation (TlA{submore » 2}CuO{sub 5}){sub m} {center_dot} Tl{sub 2}A{sub 2}O{sub 4} with A = Ba, Sr.« less

Fe{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses as lithium-free nonsilicate pH responsive glasses – Compatibility between pH responsivity and hydrophobicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, Tadanori, E-mail: hasimoto@chem.mie-u.ac.jp; Hamajima, Mitsuaki; Ohta, Honami

Highlights: • Fe{sub 2}O{sub 3}-rich FeBiB glasses show high pH sensitivity and short pH response time. • Bi{sub 2}O{sub 3}-rich FeBiB glasses show relatively high contact angle for water. • FeBiB glasses are lithium-free nonsilicate pH responsive ones. • pH responsivity and hydrophobicity are obtained for optimum glass compositions. - Abstract: Lithium silicate-based glasses have widely been used as commercially available pH glass electrodes. It was revealed that Ti{sup 3+}-containing titanophosphate (TiO{sub 2}-P{sub 2}O{sub 5}, TP) glasses are pH responsive as lithium-free nonsilicate glasses for the first time. TP glasses with the compatibility between pH responsivity and self-cleaning property weremore » obtained by the sequential post-annealing (oxidation and reduction) of as-prepared glasses. Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} (BiB) glasses are relatively hydrophobic and are expected to show anti-fouling effect. They are unsuitable for pH responsive glasses, because they have high electrical resistivity. In the present study, xFe{sub 2}O{sub 3}·yBi{sub 2}O{sub 3}·(100 − x − y)B{sub 2}O{sub 3} glasses (xFeyBiB, x = 0–20 mol%, y = 20–80 mol%) glasses were selected as new pH responsive glasses with hydrophobicity, because Fe{sub 2}O{sub 3} is a representative component for causing hopping conduction to the glasses. BiB glass did not show pH responsivity, whereas xFeyBiB glasses showed good pH responsivity. xFeyBiB glasses are lithium-free nonsilicate pH responsive ones as well as TP glasses. The electrical resistivity and pH response time decreased with increasing Fe{sub 2}O{sub 3} content. The pH repeatability for standard solutions increased with increasing Bi{sub 2}O{sub 3} content. Silicate glass (20Fe70BiSi) showed better pH responsivity but lower contact angle than those of borate glass (20Fe70BiB). pH sensitivity increased in order of TP glasses (about 80%), xFeyBiB glasses (about 90%) and commercial pH responsive glass (about 100%). xFeyBiB glasses showed short pH response time compared to commercial pH responsive glass. The contact angle for water of xFeyBiB glasses was relatively high (about 90°) as well as BiB glasses, and increased slightly with increasing Bi{sub 2}O{sub 3} content regardless Fe{sub 2}O{sub 3} content. The high contact angle was related to low OH content determined by FT-IR measurement. Thus, 20Fe{sub 2}O{sub 3}·70Bi{sub 2}O{sub 3}·10B{sub 2}O{sub 3} glass was the most suitable one as pH responsive glasses with hydrophobicity. TP glasses are pH responsive ones with self-cleaning property, whereas xFeyBiB glasses are expected as pH responsive ones with anti-fouling property based on hydrophobicity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Tzu-Ling; Yang, Chen-I., E-mail: ciyang@thu.edu.tw

The preparations and properties of three new homochiral three-dimensional (3D) coordination polymers, [M(D-cam)(pyz)(H{sub 2}O){sub 2}]{sub n} (M=Co (1) and Ni (2); D-H{sub 2}cam=(+) D-camphoric acid; pyz=pyrazine) and [Mn{sub 2}(D-cam){sub 2}(H{sub 2}O){sub 2}] (3), under solvothermal conditions is described. Single-crystal X-ray diffraction analyses revealed that all of compounds are homochiral 3D structure. 1 and 2 are isostructural and crystallize in the trigonal space group P3{sub 2}21, while 3 crystallizes in monoclinic space group P2{sub 1}. The structure of 1 and 2 consists of metal-D-cam helical chains which are pillared with pyrazine ligands into a 3D framework structure and 3 features amore » 3D homochiral framework involving one-dimensional manganese-carboxylate chains that are aligned parallel to the b axis. Magnetic susceptibility data of all compounds were collected. The findings indicate that μ{sub 2}-pyrazine dominate weak antiferromagnetic coupling within 1 and 2, while 3 exhibits antiferromagnetic behavior through the carboxylate groups of D-cam ligand. -- Graphical abstract: The preparations and properties of three new homochiral three-dimensional (3D) coordination polymers, [M(D-cam)(pyz)(H{sub 2}O){sub 2}]{sub n} (M=Co (1) and Ni (2); D-H{sub 2}cam=(+) D-camphoric acid; pyz=pyrazine) and [Mn{sub 2}(D-cam){sub 2}(H{sub 2}O){sub 2}] (3), under solvothermal conditions is described. Single-crystal X-ray diffraction analyses revealed that all of compounds are homochiral 3D structure. 1 and 2 are isostructural and crystallize in the trigonal space group P3{sub 2}21, while 3 crystallizes in monoclinic space group P2{sub 1}. The structure of 1 and 2 consists of metal-D-cam helical chains which are pillared with pyrazine ligands into a 3D framework structure and 3 features a 3D homochiral framework involving one-dimensional manganese-carboxylate chains that are aligned parallel to the b axis. Magnetic susceptibility data of all compounds were collected. The findings indicate that μ{sub 2}-pyrazine dominate weak antiferromagnetic coupling within 1 and 2, while 3 exhibits antiferromagnetic behavior through the carboxylate groups of D-cam ligand. Highlights: • Three homochiral 3D coordination polymers were synthesized. • 1 and 2 are 3D structure with metal-D-cam helical chains pillared by pyrazine. • 3 shows a 3D homochiral framework involving 1D manganese-carboxylate chains. • Magnetic data analysis indicates that 1–3 exhibit weak antiferromagnetic coupling.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Peifu; Shi, Penghui, E-mail: shipenghui@shiep.edu.cn; Hong, Yuanchen

Graphical abstract: The photocatalytic performance of Ag{sub 3}PO{sub 4} was highly improved by the in situ deposition of Ag{sub 3}PO{sub 4} particles on graphene-like MoS{sub 2} nanosheets. - Highlights: • A novel composite photocatalyst was synthesized by depositing Ag{sub 3}PO{sub 4} on the graphene-like MoS{sub 2} nanosheets. • Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a high photocatalytic activity for RhB degradation. • Graphene-like MoS{sub 2} nanosheets. • MoS{sub 2} nanosheets play an important role in photocatalytic activity by serving as an effective acceptor of the photogenerated carriers. - Abstract: A facile method for the in situ deposition of Ag{sub 3}PO{submore » 4} on graphene-like MoS{sub 2} nanosheets was developed to improve the photocatalytic performance of Ag{sub 3}PO{sub 4} catalysts. The heterostructure of Ag{sub 3}PO{sub 4}/MoS{sub 2} composites was characterized by using X-ray diffraction spectra (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The prepared Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a much higher photocatalytic activity than that of Ag{sub 3}PO{sub 4} for the degradation of Rhodamine B (RhB) under visible light irradiation (>400 nm). The improved photocatalytic activity of Ag{sub 3}PO{sub 4}/MoS{sub 2} is attributed to the efficient separation of photogenerated electron–hole pairs in the composite. This result provides a new perspective on the design of high-performance photocatalysts which is promising for energy applications.« less

Ionothermal synthesis, structures, properties of cobalt-1,4-benzenedicarboxylate metal–organic frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Zong-Hui; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fsuzhou, Fujian 350002; Xu, Ling, E-mail: xuling@snnu.edu.cn

2016-06-15

Eight kinds of 1-methyl-3-alkylimidazolium halide [RMI]X (R=ethyl (E), propyl (P), butyl (B) and amyl (A); MI = imidazolium; X= Cl{sup −}, I{sup −}) ionic liquids (ILs) were used as reaction media and obtained a series of 2D [RMI]{sub 2}[Co{sub 3}(BDC){sub 3}X{sub 2}] frameworks through the ionothermal reactions of 1,4-benzenedicarboxylic acid (H{sub 2}BDC) with Co(NO{sub 3}){sub 2}·6H{sub 2}O. The 2D [RMI]{sub 2}[Co{sub 3}(BDC){sub 3}X{sub 2}] frameworks exhibit a same (3,6) topology network with [RMI]{sup +} cations locating in the interlayer space. [RMI]{sup +} cations play a template role in the structure constructions, whose influence combining with the effect of X{sup −}more » anions pass to the TG behaviors. The decomposition temperatures of the [RMI]{sub 2}[Co{sub 3}(BDC){sub 3}X{sub 2}] frameworks decrease with the alkyl chains in [RMI]{sup +} cations, and the compounds containing Cl{sup −} show higher thermal stabilities than those with I{sup −}. However, compounds 1–8 exhibit two similar broad emissions at ca. 380 and 390 nm, assigned to ILCT. The RMI{sup +} templates and the X{sup −} anions do not exert their influence on the fluorescence. - Graphical abstract: Eight 2D [RMI]{sub 2}[Co{sub 3}(BDC){sub 3}X{sub 2}] compounds were synthesized through ionothermal reactions. [RMI]{sup +} cations play a template role in the structure constructions, and tune the TG behaviors combining with the effect of X{sup −} anions. Display Omitted.« less

Ab initio study of phase stability of NaZr{sub 2}(PO{sub 4}){sub 3} under pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chinnappan, Ravi; Kaur, Gurpreet; Panigrahi, B. K.

2016-05-23

The elastic constants of NaZr{sub 2}(PO{sub 4}){sub 3} were computed as a function of pressure through Density Functional Theory calculations. The behavior of elastic constants show that the rhombohedral (R-3c) NaZr{sub 2}(PO{sub 4}){sub 3} becomes unstable above 8 GPa and is driven by softening of C{sub 44} through one of the Born stability criteria. High pressure equation of state and enthalpy show further that the ambient rhombohedral (R-3c)) NaZr{sub 2}(PO{sub 4}){sub 3} transforms first to another rhombohedral (R3) phase and subsequently to LiZr{sub 2}(PO{sub 4}){sub 3}-type orthorhombic phase at pressures above 6 and 8 GPa respectively which are in agreement with recentmore » X-ray diffraction study.« less

Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin, E-mail: k.bourhis@argolight.com; Massera, Jonathan; Petit, Laeticia

2015-03-15

Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{submore » 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.« less

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinert, R.A.; Sanders, J.S.

Radish and marigold plants were exposed to 0.3 ppM of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and /or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/ and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in themore » presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 2/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present. 8 references, 2 tables.« less

Piezo-/dielectric properties of perovskite-structure high-temperature relaxor ferroelectrics: The Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ternary ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tao; University of Chinese Academy of Sciences, Beijing 100049; Long, Xifa, E-mail: lxf@fjirsm.ac.cn

2014-03-01

Graphical abstract: - Highlights: • Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-based ternary ferroelectric ceramics were prepared by solid-state synthesis method. • Morphotropic phase boundary region has been determined by XRD, di-/piezoelectric properties. • The compositions near MPB region exhibit excellent piezoelectric properties. - Abstract: A new compositional system of relaxor ferroelectrics was investigated based on the high piezoelectricity Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ferroelectric perovskite family. Compositions were fabricated near an estimated morphotropic phase boundary (MPB) of the Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (PLZNT) ternary system by a two-step synthetic process. Their structures have been analyzed by means ofmore » X-ray diffraction technique. On the basis of X-ray powder diffraction, the morphotropic phase boundary (MPB) region for the ternary system was obtained. The Curie temperature T{sub C} of ternary system varied from 240 °C to 330 °C and the coercive fields E{sub c}s > 10 kV/cm. The values of piezoelectric coefficients d{sub 33} vary in the range of 260–450 pC/N with different PZN contents. It is worth noting that the optimum compositions were located at MPB region but near the tetragonal phase. The new PLZNT ceramics exhibit wider range of T{sub C}s and E{sub c}s, making it a promising material for high-powder ultrasound transducers using in a large temperature range.« less

Crystal structure and ion conductivity of a new mixed-anion phosphate LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sung-Chul; Lee, Mi-Sun; Kang, Jinyeong

2015-05-15

A new lithium-containing phosphate, LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7}, was prepared by a solid-state reaction, and it was characterized by an ab initio structure determination method on the basis of synchrotron powder X-ray diffraction data. LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} was found to be orthorhombic (space group Pnma) with lattice parameters a=9.0387(1) Å, b=10.6072(1) Å, c=8.3065(1) Å, and V=796.39(1) Å{sup 3}. The structure features infinite [Mg{sub 3}O{sub 10}]{sub ∞} layers that are parallel to the bc plane and that are interconnected along the a axis by PO{sub 4} and P{sub 2}O{sub 7} groups. The [Mg{sub 3}O{sub 10}]{sub ∞} layer containsmore » Mg{sub 3}O{sub 14} trimers that are formed by three edge-shared MgO{sub 6} octahedra. The PO{sub 4} and P{sub 2}O{sub 7} groups are located alternatively between [Mg{sub 3}O{sub 10}]{sub ∞} layers. This gives rise to a three-dimensional framework that contains large tunnels along the directions [1 0 0] and [0 1 0]; the Li{sup +} ions are stabilized in these tunnels. AC impedance spectroscopy shows that LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} has an ionic conductivity of 3.40×10{sup −5} S cm{sup −1} at 769 K, with an activation energy of 1.17 eV. - Graphical abstract: Polyhedral view of LiMg3(PO4)P2O7. Li+ ions are represented by orange spheres, MgO6 groups by octahedra, and PO4 groups by tetrahedra. - Highlights: • New compound LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} is reported. • The crystal structure is investigated by synchrotron XRD analysis. • The structure features [Mg{sub 3}O{sub 10}]{sub ∞} layers with interconnecting PO{sub 4} and P{sub 2}O{sub 7} groups. • Correlation between the crystal structure and ionic conductivity is discussed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Peng-Yuan; Zhang, Wei-De, E-mail: zhangwd@scut.edu.cn

Highlights: • Preparation of nanostructured In{sub 2}O{sub 3} microspheres. • Morphology and phase control of In{sub 2}O{sub 3}. • Gas sensors based on the In{sub 2}O{sub 3} microspheres exhibit excellent sensing properties for the detection of formaldehyde. - Abstract: Urchin-like InOOH microspheres were successfully prepared by a convenient and controllable method. Such experimental parameters as solvents and complexing reagents on the formation of the urchin-like InOOH microspheres were investigated. Scanning electron microscopy, X-ray diffraction and infrared spectroscopy were employed to investigate the evolution process of the urchin-like InOOH precursors. Furthermore, the formation mechanism of the urchin-like InOOH microspheres was proposed.more » By annealing the urchin-like InOOH precursor at different temperatures under ambient pressure, rhombohedral corundum-type indium oxide (rh-In{sub 2}O{sub 3}), cubic bixbyite-type indium oxide (c-In{sub 2}O{sub 3}) and mixed phases of rh-In{sub 2}O{sub 3} and c-In{sub 2}O{sub 3} were obtained. The gas sensing properties of the prepared In{sub 2}O{sub 3} samples were examined. It was found that the sensors based on the prepared In{sub 2}O{sub 3} samples exhibited excellent response and selectivity to formaldehyde.« less

Fabrication of flower-like Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} and their electrochemical properties evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kong, Ling-Bin, E-mail: konglb@lut.cn; School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050; Deng, Li

Graphical abstract: Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} nano-flakes materials, which have a flower-like structure, were successfully synthesized by a facile solvothermal method without adding any surfactant. The as-prepared Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} possesses a maximum specific capacitance of 2212.5 F g{sup −1} at the current density of 5 mA, suggesting its potential application in electrode material for secondary batteries and electrochemical capacitors. Highlights: ► Flower-like Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} materials were fabricated in a simple method. ► High specific capacitance of 2212.5 F g{sup −1} has been achieved. ► For the first time the effects of concentration andmore » temperature on its specific capacitance has been studied. -- Abstract: Flower-like Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} was successfully synthesized by a facile solvothermal method. The microstructure and surface morphology of prepared Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} were physically characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The electrochemical properties studies were carried out using cyclic voltammetry (CV), chronopotentiometry technology and AC impedance spectroscopy, respectively. The results indicate that the flower-like structure has a profound impact on electrode performance at high discharge capacitance. A maximum specific capacitance of 2212.5 F g{sup −1} at the current density of 5 mA could be achieved, suggesting its potential application in electrode material for secondary batteries and electrochemical capacitors. Furthermore, the effects of Ni(NO{sub 3}){sub 2}·6H{sub 2}O concentration and temperature on the microstructure and specific capacitance of prepared Ni{sub 3}(NO{sub 3}){sub 2}(OH){sub 4} have also been systematically studied. The results show that flower-like structure can be formed when the concentration is appropriate, while the temperature has just little effect on its electrochemical properties.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Lei; Bai, Yu; Min, Yu-Ting

Three different tetrazole-carboxylate ligands, monotetrazole-carboxylate H{sub 2}tza (H{sub 2}tza=1,5-tetrazole-diacetic acid), Hpztza (Hpztza=5-(2-pyrazinyl)tetrazole-2(1-methyl)acetic acid), ditetrazole-carboxylate H{sub 2}tzpha (H{sub 2}tzpha=1,3-di(tetrazole-5-yl)benzene-N2,N2′-diacetic acid) have been chosen to react with CdCl{sub 2}·6H{sub 2}O, resulting in the formation of three new compounds [Cd{sub 2}(tza){sub 2}] (1), [Cd(pztza){sub 2}] (2) and [Cd(tzpha)(CH{sub 3}OH){sub 2}] (3). The coordinate sites of the three ligands are major influenced by the different substituted group of tetrazole ring. These compounds have been characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 displays a complex 3D structure; compound 2 shows a 3D network and compound 3 features a 2D layermore » network. Furthermore, the luminescence properties investigated at room temperature in the solid state showed excellent ligand-centered luminescence. The obvious enhancement in luminescence makes these compounds potential materials for optical use. The differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses were applied to evaluate the thermal decomposition behavior of such compounds, showing that compounds 2 and 3 can be used as potential energetic materials. The relevant thermodynamic parameters ΔH, ΔS and ΔG were calculated as well. - Graphical abstract: H{sub 2}tza, Hpztza and H{sub 2}tzpha have been prepared. Three novel Cd (II)compounds were synthesized by reactions of CdCl{sub 2}·6H{sub 2}O, namely three dimensional [Cd{sub 2}(tza){sub 2}] (1), three dimensional [Cd(pztza){sub 2}] (2), and two dimensional [Cd(tzpha)(CH{sub 3}O){sub 2}] (3). The luminescences were investigated. Furthermore, the DSC show compounds 1 and 3 can be used as potential explosive materials.« less

Ionothermal synthesis and structural transformation targeted by ion exchange in metal-1,3,5-benzenetricarboxylate compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Qing-Qing; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002; Liu, Bing

Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H{sub 3}BTC) and Ni(NO{sub 3}){sub 2}, Co(NO{sub 3}){sub 2} and Cu(NO{sub 3}){sub 2} gave two discrete 32-membered ring-like allomers, [M{sub 2}(HBTC){sub 2}(NH{sub 2}CONH{sub 2}){sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O (M=Ni(1), Co(2)) and one layered [Cu{sub 2}(BTC)Cl(H{sub 2}O){sub 4}] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N{sub 2} absorption. Cu{sup 2+} has the highest N{sub 2} adsorbance when soaking with 1, and 1 can keep structure stable whenmore » Cu{sup 2+} below 0.16 mol L{sup −1} and the soaking time within 24d. As Cu{sup 2+} beyond 0.16 mol L{sup −1} and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu{sup 2+} amounts obtained Ni{sup 2+}-Cu{sup 2+} hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu{sup 2+}% increases with Cu{sup 2+} additions and close to 100% as Cu{sup 2+} being 1.6 mmol. It suggests that 3 is a controlled product and Cu{sup 2+} can transform discrete compound 1 into 2D compound 3. - Graphical abstract: Three compounds were synthesized through ionothermal reactions. The weak interactions in compound 1 can be deconstructed by ion exchange and discrete compound 1 can be transformed into layered compound 3. - Highlights: • Two discrete ring-like and one layered compounds were ionothermally synthesized. • Metal species, metal concentration and soaking time deconstruct the H-bondings in 1. • 1 can be transformed to 3 through ionothermal reaction, otherwise forbidden.« less

A COMPREHENSIVE EVALUATION OF THE ETA-CMAQ FORECAST MODEL PERFORMANCE FOR O3, ITS RELATED PRECURSORS, AND METEOROLOGICAL PARAMETERS DURING THE 2004 ICARTT STUDY

EPA Science Inventory

In this study, the ability of the Eta-CMAQ forecast model to represent the vertical profiles of O3, related chemical species (CO, NO, NO₂, H₂O₂, CH₂O, HNO₃, SO₂, PAN, isoprene, toluene), and meteorological paramete...

Extraordinary selectivity of CoMo{sub 3}S{sub 13} chalcogel for C{sub 2}H{sub 6} and CO{sub 2} adsorption.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafaei-Fallah, M.; Rothenberger, Z.; Katsoulidis, A. P.

The chalcogel CoMo{sub 3}S{sub 13} is obtained from the reaction of (NH{sub 4}){sub 2}[Mo{sub 3}S{sub 13}] with cobalt acetate in solution. The chalcogel has a BET surface area of 570 m{sup 2} g{sup -1}, and pair distribution function analysis (PDF) and infrared spectroscopy indicate that the [Mo{sub 3}S{sub 13}]{sup 2-} cluster is a building block in the porous network. The CoMo{sub 3}S{sub 13} chalcogel exhibits high selectivity for separating ethane and carbon dioxide from hydrogen and methane.

Fibrous composites comprising carbon nanotubes and silica

DOEpatents

Peng, Huisheng [Shanghai, CN; Zhu, Yuntian Theodore [Cary, NC; Peterson, Dean E [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM

2011-10-11

Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Linzhi; Zhao Jingzhe, E-mail: zhaojz@hnu.edu.cn; Wang Yi

Tungsten oxide hydrate (WO{sub 3}.H{sub 2}O) nanoplates and flower-like assemblies were successfully synthesized via a simple aqueous method. The effects of reaction parameters in solution on the preparation were studied. Nanoplates and nanoflowers can be selectively prepared by changing the amount of H{sub 2}C{sub 2}O{sub 4}. In-situ assembly of nanoplates to nanoflowers was also proposed for the formation of assembled nanostructures. In addition, the reaction time and temperature have important effects on the sizes of the as-obtained samples. Crystal structure, morphology, and composition of final nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties ofmore » the synthesized samples and the growth mechanism were studied by UV-vis detection. Degradation experiments of Rhodamine B (RhB) were also performed on samples of nanoplates and nanoflowers under visible light illumination. Nanoflower sample exhibited preferable photocatalytic property to nanoplate sample. - Graphical abstract: The oxalic acid has a key role for the structure of WO{sub 3}.H{sub 2}O evolution from plates to flowers and the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O. Highlights: > Tungsten oxides hydrate was synthesized via a simple aqueous method. > The size of WO{sub 3}.H{sub 2}O was controlled by the reaction time and temperature. > The assembly of WO{sub 3}.H{sub 2}O nanoplates to nanoflowers was achieved with higher H{sub 2}C{sub 2}O{sub 4}/Na{sub 2}WO{sub 4} ratio. > Oxalic acid has a key role in the dehydration process of WO{sub 3}.2H{sub 2}O to WO{sub 3}.H{sub 2}O.« less

Systematic design and research on a series of cadmium coordination polymers assembled due to tetracarboxylate ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lü, Lei; Mu, Bao; Li, Chang-Xia

A series of metal-organic frameworks (MOFs) have been prepared by tetracarboxylate ligands and Cd(II) ions under the hydrothermal or solvothermal conditions with the formulas of {[Cd_2(L_1)(H_2O)_4]·H_2O}{sub n} (1), {[(CH_3)_2NH_2]_2[Cd(L_1)]}{sub n} (2), [Cd(L{sub 2}){sub 0.5}(H{sub 2}O)]{sub n} (3), {[(CH_3)_2NH_2]_2 [Cd(L_2)]·2DMF}{sub n} (4), [Cd(L{sub 3}){sub 0.5}(H{sub 2}O)]{sub n} (5), {[Cd(L_3)_0_._5(H_2O)]·CH_3OH}{sub n} (6), {[(CH_3)_2NH_2]_2[Cd_3(L_4)_2]}{sub n} (7) (H{sub 4}L{sub 1}=[1,1′:4′,1″-terphenyl]-2,2″,5,5″-tetracarboxylic acid; H{sub 4}L{sub 2}=[1,1′:4′,1″-terphenyl]-2′,4,4″,5′-tetracarboxylic acid; H{sub 4}L{sub 3}=[1,1′:3′,1″-terphenyl]-2′,3,3″,5′-tetracarboxylic acid; H{sub 4}L{sub 4}=[1,1′:4′,1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid), which are characterized by single-crystal X-ray diffraction, elemental analyses, IR, TGA and PXRD. Complex 1 exhibits a three-dimensional (3D) supramolecular framework based on two-dimensional (2D) coordination networks. Complexes 2 and 4more » possess 3D framework based on the 1D right-handed helix channels. Complexes 3 and 7 are a 3D architecture containing two different channels. Isostructural complexes 5 and 6 display 3D framework. The different synthetic methods and coordination modes of the tetracarboxylates ligands have effect on formation of various MOFs. Moreover, the luminescent properties and N{sub 2} adsorption behaviors have been reported. - Graphical abstract: A series of cadmium(II) high-dimensional coordination polymers constructed from four different kinds of tetracarboxylate ligands have been successfully prepared under hydrothermal or solvothermal conditions. The effect of solvents, the coordination modes of the tetracarboxylates and positions of carboxylate groups on the architectures of complexes 1–7 have been investigated in detail. The luminescent properties of the part of complexes, N{sub 2} adsorption behaviors of complexes 2, 4–7 have also been studied. - Highlights: • Tetracarboxylate ligands based on terphenyl moiety have been used. • Several factors that influenced the architecture have been discussed. • Luminescent properties have been investigated.« less

Synthesis and photoluminescence properties of Dy{sup 3+} doped white light emitting CdTa{sub 2}O{sub 6} phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

İlhan, Mustafa, E-mail: mustafa.ilhan@marmara.edu.tr; Ekmekçi, Mete Kaan

2015-03-15

The undoped and CdTa{sub 2}O{sub 6}:Dy{sup 3+} (0.2≤x≤2.0 mol%) phosphors were synthesized at 1100 °C for 12 h by the conventional solid state reaction method. The synthesized CdTa{sub 2}O{sub 6}:Dy{sup 3+} phosphors were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and Photoluminescence (PL) analyses. The PL spectra showed the presence of excitation peaks between 310 and 440 nm due to the 4f–4f transitions of Dy{sup 3+}. The emission of Dy{sup 3+} ions at 353.0 nm excitation was observed at 487.1 nm (blue) and 577.8 nm (yellow) due to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2}more » transitions and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions, respectively. The PL analysis results also showed that the emissions increase with the increasing Dy{sup 3+} ion content. The emissions increased with the doping concentration of up to 1 mol%, and above this level decreased due to concentration quenching effect. The CIE chromaticity color coordinates (x,y) of the CdTa{sub 2}O{sub 6}:Dy{sup 3+} phosphors were found to be in the white light region of the chromaticity diagram. - Graphical abstract: Emission spectra at λ{sub ex}=353.0 nm and CIE chromaticity coordinate diagram of CdTa{sub 2}O{sub 6}:Dy{sup 3+} phosphors. - Highlights: • Pure and CdTa{sub 2}O{sub 6}:Dy{sup 3+} was produced by solid state reaction method. • CdTa{sub 2}O{sub 6}:Dy{sup 3+} phosphor exhibited blue and yellow emissions due to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions. • The CCT value for 1.0 mol% CdTa{sub 2}O{sub 6}:Dy{sup 3+} was 5133 K which was located in the cool white daylight region. • Dy{sup 3+} doped CdTa{sub 2}O{sub 6} phosphor has potential in the production of white LEDs.« less

Synthesis and characterization of g-C{sub 3}N{sub 4}/Cu{sub 2}O composite catalyst with enhanced photocatalytic activity under visible light irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Biyu; Zhang, Shengsen; Yang, Siyuan

2014-08-15

The prepared g-C{sub 3}N{sub 4}/Cu{sub 2}O composite exhibited the enhanced photocatalytic activity under visible-light irradiation due to the stronger ability in separation of electron–hole pairs, which was proven by the transient photocurrent measurement. - Highlights: • The coupled Cu{sub 2}O with g-C{sub 3}N{sub 4} of narrow-band-gap semiconductor has been designed. • g-C{sub 3}N{sub 4}/Cu{sub 2}O is prepared via an alcohol-aqueous based on chemical precipitation method. • g-C{sub 3}N{sub 4}/Cu{sub 2}O exhibits the enhanced photocatalytic activity under visible-light. • The enhanced photocatalytic activity is proven by the transient photocurrent test. • A mechanism for the visible-light-driven photocatalysis of g-C{sub 3}N{sub 4}/Cu{submore » 2}O is revealed. - Abstract: To overcome the drawback of low photocatalytic efficiency brought by electron–hole pairs recombination and narrow photo-response range, a novel g-C{sub 3}N{sub 4}/Cu{sub 2}O composite photocatalyst was designed and prepared successfully. Compared with bare Cu{sub 2}O and g-C{sub 3}N{sub 4}, the g-C{sub 3}N{sub 4}/Cu{sub 2}O composite exhibited significantly enhanced photocatalytic activity for acid orange-II (AO-II) degradation under visible light irradiation. Based on energy band positions, the mechanism of enhanced visible-light photocatalytic activity was proposed.« less

(Pentamethylcyclopentadienyl)molybdenum(IV) chloride. Synthesis, structure, and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abugideiri, F.; Desai, J.U.; Gordon, J.C.

1994-08-17

Three different syntheses of trichloro(pentamethylcyclopentadienyl)molybdenum(IV) are described, I.E. (1) thermal decarbonylation of Cp{sup *}MoCl{sub 3}(CO){sub 2}, (2) reduction of Cp{sup *}MoCl{sub 4}, and (3) chlorination of [Cp{sup *}MoCl{sub 2}]{sub 2}. A fourth route (conproportionation of [Cp{sup *}MoCl{sub 2}]{sub 2} and Cp{sup *}MoCl{sub 4}) has been investigated by {sup 1}H-NMR. The product has a dinuclear, dichloro-bridged structure with a four-legged piano stool geometry around each metal atom; the two piano stools have a mutual anti arrangement and the two metals are 3.888(1) {Angstrom} from each other, indicating the absence of a direct metal-metal bonding interaction. Crystal data: monoclinic, space group P2{submore » 1}/n, a = 8.424(1) {Angstrom}, b = 13.323(4) {Angstrom}, c = 11.266(2) {Angstrom}, {beta} = 93.87(1){degrees}, V = 1261.6(8) {Angstrom}{sup 3}, Z = 2, R = 0.038, R{sub w} = 0.057 for 127 parameters and 1350 observed reflections with F{sub o}{sup 2} > 3{sigma}(F{sub o}{sup 2}). The temperature dependent magnetic moment of the material could be fit to the sum of two Bleany-Bowers equations. [Cp{sup *}MoCl{sub 3}]{sub 2} reacts readily with CO, Cl{sup {minus}}, and PMe{sub 3} to afford Cp{sup *}MoCl{sub 3}(CO){sub 2}, [Cp{sup *}MoCl{sub 4}]{sup {minus}}, and Cp{sup *}MoCl{sub 3}(PMe{sub 3}), respectively, while the reaction with 1,2-bis(diphenylphosphino)ethane (dppe) affords the reduction product Cp{sup *}MoCl{sub 2}(dppe).« less

3-D indium(III)-btc channel frameworks and their ion-exchange properties (btc=1,3,5-benzenetricarboxylate)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Zhengzhong; Chen Lian; Yue Chengyang

2006-04-15

Assembly of InCl{sub 3} with 1,3,5-benzenetricarboxylic acid (H{sub 3}btc) and pyridine or pyridine derivatives under hydrothermal conditions produces a series of isostructural coordination polymers with the interesting frameworks: {l_brace}(HL)[In{sub 4}(OH){sub 4}(btc){sub 3}].L.3H{sub 2}O{r_brace} {sub n} {sub ,} L=pyridine (1); L=2-picoline (2); L=4-picoline (3) and {l_brace}(Hdpea)[In{sub 4}(OH){sub 4}(btc){sub 3}].3H{sub 2}O{r_brace} {sub n} (4) (dpea=1,2-di(4-pyridyl)ethane). In these four complexes, carboxyl and hydroxyl oxygen atoms bridge indium(III) centers to form octahedral chain-like sinusoidal curves, which are further interlinked by btc{sup 3-} moieties to generate 3-D frameworks with 1-D channels. The protonated guests HL in 1-3 located at the channels can be fully exchangedmore » by K{sup +} ion or partially exchanged by Sr{sup 2+}, and Ba{sup 2+} ions.« less

Multiheteromacrocycles that Complex Metal Ions. Second Progress Report, 1 May 1975 -- 30 April 1976

DOE R&D Accomplishments Database

Cram, D. J.

1976-01-15

Objective is to develop cyclic and polycyclic host organic compounds to complex and lipophilize metal ions. Macrorings were synthesized: (OCH{sub 2} CH{sub 2} O CH{sub 2}COCH{sub 2} COCH{sub 2}){sub 2} and (OCH{sub 2} CH{sub 2} O CH{sub 2} COCH{sub 2} COCH{sub 2}){sub 3}. The smaller ring complexes divalent metals 10{sup 1+9} times better than the open-chain model CH{sub 3} O CH{sub 2} CO CH{sub 2} COCH{sub 2} O CH{sub 3}, and the order in which metal ions are complexed is Cu{sup 2+}, UO{sub 2}{sup 2+} greater than Ni{sup 2+} greater than Fe{sup 2+}, Co{sup 2+}, Zn{sup 2+}, Cd{sup 2+} greater than Mn{sup 2+}. The UO{sub 2}{sup 2+} and Cu{sup 2+} complexes were isolated and characterized. The larger ring complexes trivalent metals 10{sup 0.9-1.7} times better than the open- chain model compound, and the order is La{sup 3+}, Ce{sup 3+} greater than Cr{sup 3+}. Five other macrocycles were also synthesized, and their binding constants with Na, K, NH{sub 4}, and Cs picrates were measured. Six compounds containing one macroring and two inward-pointing ArOH or ArOCH{sub 3} groups were also prepared and tested for binding of Li, Na, K, Rb, and NH{sub 4} picrates. Racemic compounds containing two binaphthyls and its sulfur analog were prepared. Cage-shaped multiheteromacrocycles containing ten O ligand sites or four S and six O ligand sites were prepared and the binding capability of the first compound for picrates studied. Two ring systems with phosphonate ester groups were also prepared. (DLC)

The Li–Si–(O)–N system revisited: Structural characterization of Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casas-Cabanas, M.; Santner, H.; Palacín, M.R., E-mail: rosa.palacin@icmab.es

2014-05-01

A systematic study of the Li–Si–(O)–N system is presented. The synthetic conditions to prepare Li{sub 2}SiN{sub 2}, Li{sub 5}SiN{sub 3}, Li{sub 18}Si{sub 3}N{sub 10}, Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are described and the structure of the last two compounds has been solved for the first time. While Li{sub 21}Si{sub 3}N{sub 11} crystallizes as a superstructure of the anti-fluorite structure with Li and Si ordering, Li{sub 7}SiN{sub 3}O exhibits the anti-fluorite structure with both anion and cation disorder. - Graphical abstract: A systematic study of the Li–Si–(O)–N system is presented. Li{sub 21}Si{sub 3}N{sub 11} crystallizes as a superstructuremore » of the anti-fluorite structure with Li and Si ordering, Li{sub 7}SiN{sub 3}O exhibits the anti-fluorite structure with both anion and cation disorder. - Highlights: • Li{sub 2}SiN{sub 2}, Li{sub 5}SiN{sub 3}, Li{sub 18}Si{sub 3}N{sub 10}, Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are prepared. • The structures of Li{sub 21}Si{sub 3}N{sub 11} and Li{sub 7}SiN{sub 3}O are presented. • Li{sub 21}Si{sub 3}N{sub 11} exhibits an anti-fluorite superstructure with Li and Si ordering.« less

Crystallographic isomorphism in the structural type of α-HgI{sub 2} by example of KHgI{sub 3} · H{sub 2}O, β-Ag{sub 2}HgI{sub 4}, and β-Cu{sub 2}HgI{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borisov, S. V., E-mail: borisov@niic.nsc.ru; Magarill, S. A.; Pervukhina, N. V.

The structure of KHgI{sub 3} · H{sub 2}O is assigned to the family of crystal structures having the three-layer cubic packing of iodine anions with cations in the tetrahedral voids (the structures of α-HgI{sub 2}, β-Ag{sub 2}HgI{sub 4}, and β-Cu{sub 2}HgI{sub 4} among them). Crystallographic analysis shows that the nodes of the three-layer close packing are populated by iodine anions and K cations in the ratio 3/4: 1/4. Transformation of the structure of α-HgI{sub 2} into the structure of KHgI{sub 3} · H{sub 2}O can be formally represented as the replacement of (HgI){sub n}{sup +} fragments by (KH{sub 2}O){sub n}{supmore » +} fragments: (Hg{sub 2}I{sub 4})–(HgI){sup +} + (KH{sub 2}O){sub n}{sup +} = KHgI{sub 3} · H{sub 2}O. Perforated layers of vertex-sharing HgI{sub 4} tetrahedra break down into parallel isolated chains. Channels formed in place of I–Hg–I–Hg–fragments are occupied by–H{sub 2}O–K–-H{sub 2}-O-K-H{sub 2}O-chains weakly bound to neighbors.« less

Broadband sensitized white light emission of g-C{sub 3}N{sub 4}/Y{sub 2}MoO{sub 6}:Eu{sup 3+} composite phosphor under near ultraviolet excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Bing, E-mail: hanbing@zzuli.edu.cn; Xue, Yongfei; Li, Pengju

2015-12-15

The g-C{sub 3}N{sub 4}/Y{sub 2}MoO{sub 6}:Eu{sup 3+} composite phosphors were synthesized and characterized by X-ray diffraction, Fourier transform-infrared spectroscopy, ultraviolet visible diffuse reflection spectra, photoluminescence spectra and luminescence decay curves. Under the excitation of 360 nm near ultraviolet light, these composite phosphors show tunable emission from blue to red region, in which white light emission can be obtained in term of appropriate quality proportion of Y{sub 2}MoO{sub 6}:Eu{sup 3+} relative to g-C{sub 3}N{sub 4}/Y{sub 2}MoO{sub 6}:Eu{sup 3+}. In addition, the emission color can be also dependent on the excitation wavelength in g-C{sub 3}N{sub 4}/Y{sub 2}MoO{sub 6}:Eu{sup 3+} composite phosphor. -more » Graphical abstract: Under the excitation of 360 nm near ultraviolet light, the g-C{sub 3}N{sub 4}/Y{sub 2}MoO{sub 6}:Eu{sup 3+} composite phosphors show tunable emission from blue to red region, in which white light emission can be obtained. - Highlights: • The g-C3N4/Y2MoO6:Eu{sup 3+} composite phosphors were synthesized and characterized. • White light emission was realized in the g-C3N4/Y2MoO6:Eu{sup 3+} composites under UV excitation. • A novel idea to realize the broadband sensitized white light emission in phosphors was provided.« less

Comparison of structural and electrical properties of Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} gate dielectrics for α-InGaZnO thin-film transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Tung-Ming, E-mail: tmpan@mail.cgu.edu.tw; Chen, Ching-Hung; Her, Jim-Long

We compared the structural properties and electrical characteristics of high-κ Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} gate dielectrics for amorphous indium-gallium-zinc oxide (α-InGaZnO) thin-film transistor (TFT) applications. The Lu{sub 2}O{sub 3} film has a strong Lu{sub 2}O{sub 3} (400) peak in the X-ray diffraction pattern, while the Lu{sub 2}TiO{sub 5} sample shows a relatively weak Lu{sub 2}TiO{sub 5} (102) peak. Atomic force microscopy reveals that the Lu{sub 2}O{sub 3} dielectric exhibits a rougher surface (about three times) than Lu{sub 2}TiO{sub 5} one. In X-ray photoelectron spectroscopy analysis, we found that the intensity of the O 1s peak corresponding tomore » Lu(OH){sub x} for Lu{sub 2}O{sub 3} film was higher than that of Lu{sub 2}TiO{sub 5} film. Furthermore, compared with the Lu{sub 2}O{sub 3} dielectric, the α-InGaZnO TFT using the Lu{sub 2}TiO{sub 5} gate dielectric exhibited a lower threshold voltage (from 0.43 to 0.25 V), a higher I{sub on}/I{sub off} current ratio (from 3.5 × 10{sup 6} to 1.3 × 10{sup 8}), a smaller subthreshold swing (from 276 to 130 mV/decade), and a larger field-effect mobility (from 14.5 to 24.4 cm{sup 2}/V s). These results are probably due to the incorporation of TiO{sub x} into the Lu{sub 2}O{sub 3} film to form a Lu{sub 2}TiO{sub 5} structure featuring a smooth surface, a low moisture absorption, a high dielectric constant, and a low interface state density at the oxide/channel interface. Furthermore, the stability of Lu{sub 2}O{sub 3} and Lu{sub 2}TiO{sub 5} α-InGaZnO TFTs was investigated under positive gate-bias stress (PGBS) and negative gate-bias stress (NGBS). The threshold voltage of the TFT performed under NGBS is more degradation than that under PGBS. This behavior may be attributed to the electron charge trapping at the dielectric–channel interface under PGBS, whereas the oxygen vacancies occurred in the InGaZnO under NGBS.« less

Synthesis, crystal structure refinement, and nonlinear-optical properties of CaB{sub 3}O{sub 5}(OH): Comparative crystal chemistry of calcium triborates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamnova, N. A., E-mail: aks.crys@gmail.com; Aksenov, S. M.; Stefanovich, S. Yu.

Calcium triborate CaB{sub 3}O5(OH) obtained by hydrothermal synthesis in the Ca(OH){sub 2}–H{sub 3}BO{sub 3}–Na{sub 2}CO{sub 3}–KCl system is studied by single-crystal X-ray diffraction. The parameters of the orthorhombic unit cell are as follows: a = 13.490(1), b = 6.9576(3), and c = 4.3930(2) Å; V = 412.32(3) Å{sup 3} and space group Pna2{sub 1}. The structure is refined in the anisotropic approximation of the atomic displacement parameters to R = 4.28% using 972 vertical bar F vertical bar > 4σ(F). It is confirmed that the crystal structure of Ca triborate CaB{sub 3}O{sub 5}(OH) is identical to that described earlier. Themore » hydrogen atom is localized. An SHG signal stronger than that of the quartz standard is registered. The phase transition of calcium triborate into calciborite is found on heating. The comparative crystal-chemical analysis of a series of borates with the general chemical formula 2CaO · 3B{sub 2}O{sub 3} · nH{sub 2}O (n = 0–13) with the constant CaO: B{sub 2}O{sub 3}= 2: 3 ratio and variable content of water is performed.« less

Magnetic properties of mixed spinel BaTiO{sub 3}-NiFe{sub 2}O{sub 4} composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Babusona; Dalal, Biswajit; Dev Ashok, Vishal

2014-03-28

Solid solution of nickel ferrite (NiFe{sub 2}O{sub 4}) and barium titanate (BaTiO{sub 3}), (100-x)BaTiO{sub 3}–(x) NiFe{sub 2}O{sub 4} has been prepared by solid state reaction. Compressive strain is developed in NiFe{sub 2}O{sub 4} due to mutual structural interaction across the interface of NiFe{sub 2}O{sub 4} and BaTiO{sub 3} phases. Quantitative analysis of X-ray diffraction and X-ray photo electron spectrum suggest mixed spinel structure of NiFe{sub 2}O{sub 4}. A systematic study of composition dependence of composite indicates BaTiO{sub 3} causes a random distribution of Fe and Ni cations among octahedral and tetrahedral sites during non-equilibrium growth of NiFe{sub 2}O{sub 4}. Themore » degree of inversion decreases monotonically from 0.97 to 0.75 with increase of BaTiO{sub 3} content. Temperature dependence of magnetization has been analyzed by four sublattice model to describe complex magnetic exchange interactions in mixed spinel phase. Curie temperature and saturation magnetization decrease with increase of BaTiO{sub 3} concentration. Enhancement of strain and larger occupancy of Ni{sup 2+} at tetrahedral site increase coercivity up to 200 Oe. Magnetostructual coupling induced by BaTiO{sub 3} improves coercivity in NiFe{sub 2}O{sub 4}. An increase in the demagnetization and homogeneity in magnetization process in NiFe{sub 2}O{sub 4} is observed due to the interaction with diamagnetic BaTiO{sub 3}.« less

Reactions of the linear tetranuclear complex Ru sub 4 (CO) sub 10 (CH sub 3 C double bond C(H)C(H) double bond N-i-Pr) sub 2 with oxidizing reagents. Syntheses of halide-bridged (Ru(CO) sub 2 X(CH sub 3 C double bond C(H)C(H) double bond N-i-Pr)) sub 2 and fac-Ru(CO) sub 3 X(CH sub 3 C double bond C(H)C(H) double bond N-i-Pr)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mul, W.P.; Elsevier, C.J.; van Leijen, M.

1991-01-01

The linear tetranuclear complex Ru{sub 4}(CO){sub 10}(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr){sub 2} (1), containing two {eta}{sup 5}-azaruthenacyclopentadienyl systems, reacts with oxidizing reagents (I{sub 2}, Br{sub 2}, NBS, CCl{sub 4}) at elevated temperatures (40-90C) in heptane or benzene to give the new dimeric halide-bridged organoruthenium(II) complexes (Ru(CO){sub 2}X(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr)){sub 2} (X = I (3a), X = Br (3b), Cl (3c); yield 30-80%) together with (Ru(CO){sub 3}X{sub 2}){sub 2}. The reactions of 1 with CX{sub 4} (X = I, Br, Cl) are accelerated by CO, probably because Ru{sub 4}(CO){sub 12}(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr){sub 2} (5), which contains two unbridged metal-metal bonds,more » is formed prior to oxidation. The halide-bridged dimers 3a-c are obtained as mixtures of four isomers, the configurations of which are discussed. Splitting of the halide bridges takes place when a solution of 3a-c is saturated with CO, whereby mononuclear fac-Ru(CO){sub 3}X(CH{sub 3}C{double bond}C(H)C(H){double bond}N-i-Pr) (4a-c) is obtained. This process is reversible; ie., passing a stream of nitrogen through a solution of 4a-c or removal of the solvent under vacuum causes the reverse reaction with reformation of 3a-c. Compounds 3a-c and 4a-c have been characterized by IR (3, 4), FD mass (3), {sup 1}H (3, 4), and {sup 13}C{l brace}H{r brace} NMR (4) spectroscopy and satisfactory elemental analyses have been obtained for 3a-c. Compounds 3 and 4 are suitable precursors for the preparation of new homo- and heteronuclear transition-metal complexes.« less

Chemical bond parameters and photoluminescence of a natural-white-light Ca{sub 9}La(VO{sub 4}){sub 7}:Tm{sup 3+},Eu{sup 3+} with one O{sup 2−}→V{sup 5+} charge transfer and dual f-f transition emission centers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Ling; Liu, Xiao Guang; Department of Physics, Pukyong National University, Busan 608-737

2015-01-15

The relationship between the photoluminescence properties and the crystal structure of undoped, Eu{sup 3+} or/ and Tm{sup 3+} singly or codoped Ca{sub 9}La(VO{sub 4}){sub 7} (CLaVO) samples was discussed. Under the excitation of UV light, CLaVO:Tm{sup 3+}, CLaVO, and CLaVO:Eu{sup 3+} exhibit the characteristic emissions of Tm{sup 3+} ({sup 1}G{sub 4}→{sup 3}H{sub 6}, blue), O{sup 2−}→V{sup 5+} charge transfer (CT), and Eu{sup 3+} ({sup 5}D{sub 0}→{sup 7}F{sub 2}, red), respectively. By adjusting the doping concentration of Tm{sup 3+} and Eu{sup 3+} ions in CLaVO, a natural white emission in a single composition with the color temperature at 6181 K wasmore » obtained. Based on the dielectric theory of complex crystal, the chemical bond parameters of La-O and V-O bonds were quantitatively calculated. The standard deviation of environmental factor of every bond (EFSD), which can be expressed as σ(h{sub e{sub i}})=√((1/N)∑{sub i=1}{sup N}(h{sub e{sub i}}−μ){sup 2}) (h{sub e{sub i}}=(f{sub c{sub i}}α{sub b{sub i}}){sup 1/2}Q{sub B{sub i}} and μ=(1/N)∑{sub i=1}{sup N}h{sub e{sub i}}), was proposed to quantitatively express the distortion degree of VO{sub 4}{sup 3−} from that of an ideal tetrahedron. The maximum change of EFSD comes from the [VO{sub 4}]{sup −} tetrahedra in CLaVO sample by comparison with that of EFSD of isostructural Ca{sub 9}Gd(VO{sub 4}){sub 7}. This is possible the key reason that the undoped CLaVO sample has self-activated emission while the self-activated emission of its isostructural Ca{sub 9}Gd(VO{sub 4}){sub 7} sample cannot be found. The quantitative calculation also demonstrated that the broad excitation bands at 319 nm in CLaVO:Tm and at 335 nm in CLaVO:Eu were due to the O-V2 and O-V3 (overlap with O-V2) CT, not the CT energy of O{sup 2−}-Eu1{sup 3+} (O{sup 2−}-Tm1{sup 3+}), O{sup 2−}-Eu2{sup 3+} (O{sup 2−}-Tm2{sup 3+}), and O{sup 2−}-Eu3{sup 3+} (O{sup 2−}-Tm3{sup 3+}). The environmental factors surrounding the atoms V1, V2 and V3 were calculated to be 1.577, 1.6379 and 1.7554, respectively. It can be demonstrated that the excitation spectra at 319 nm for CLaVO:Tm and 335 nm for CLaVO:Eu came from the O-V2 and O-V3 CT, respectively. - Graphical abstracts: The relationship between the photoluminescence properties and the crystal structure of undoped, Eu{sup 3+} or/ and Tm{sup 3+} singly or codoped Ca{sub 9}La(VO{sub 4}){sub 7} (CLaVO) samples was discussed experimentally and theoretically. - Highlights: ●The photoluminescence properties of Ca{sub 9}La(VO{sub 4}){sub 7}:Eu, Tm were measured. ●The tunable color including white emission can be obtained. ●The important chemical bond parameters of O-V were calculated quantitatively. ●The standard deviation of environmental factor of every bond was proposed. ●The theoretical analysis of the self-activated emission for Ca{sub 9}La(VO{sub 4}){sub 7} was given.« less

A study on the grindability of portland cement clinker containing transition metal oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsivilis, S.; Kakali, G.

1997-05-01

The subject of this paper is to investigate the effect of transition metal oxides on the grindability of clinker. As it is concluded clinker containing ZnO has the lower grindability while clinker containing MnO or Cr{sub 2}O{sub 3} has the higher grindability. The classification of the added oxides, concerning the clinker grindability (descending sort), is: MnO, Cr{sub 2}O{sub 3}, Ni{sub 2}O{sub 3}, ZrO{sub 2}, CuO, Co{sub 2}O{sub 3}, V{sub 2}O{sub 5}, MoO{sub 3}, TiO{sub 2}, ZnO. The study of the clinker by means of X-Ray diffraction and optical microscopy confirms the results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Na; Mu, Bao; Lv, Lei

Four new polyoxometalate(POM)–templated metal–organic frameworks based on flexible ligands, namely, [Cu{sub 6}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40}){sub 2}(PMo{sup V}Mo{sup VI}{sub 11}O{sub 40}O{sub 2})]·8H{sub 2}O(1), [Cu{sup I}{sub 3}Cu{sup II}{sub 3}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40}){sub 2}(PMo{sup V}{sub 12}O{sub 34})]·8H{sub 2}O(2), [Ni{sub 6}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40})(PMo{sup VI}{sub 11}Mo{sup V}O{sub 40}){sub 2}]Cl·6H{sub 2}O(3), [Co{sup II}{sub 3}Co{sup III}{sub 2}(H{sub 2}bib){sub 2}(Hbib){sub 2}(PW{sub 9}O{sub 34}){sub 2}(H{sub 2}O){sub 6}]·6H{sub 2}O(4) (bip=1,3-bis(imidazolyl)propane, bib=1,4-bis(imidazolyl)butane) have been obtained under hydrothermal condition and characterized by single-crystal X-ray diffraction analyses, elemental analyses, and thermogravimetric (TG) analyses. The studies of single crystal X-ray indicate that compounds 1–3 crystallize in the trigonal space groupmore » P-3, and compound 4 crystallizes in the triclinic space group P-1. Compounds 1 and 3 represent 3D frameworks, and POMs as the guest molecules are incorporated into the cages which are composed of the ligands and metals, while compounds 2 and 4 show 3D frameworks by hydrogen bonds. This compounds provide new examples of host–guest compounds based on flexible bis(imidazole) ligands. In addition, the electrochemical property and the catalytic property of compound 1 have also been investigated. - Graphical abstract: Four inorganic–organic hybrid compounds based polyoxometalates (POMs) and flexible ligands, namely, have been obtained under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1–3 are new examples of host–guest compounds based on flexible bis(imidazole) ligands and POMs as the guest molecules are incorporated into the cages which are composed of the ligands and metals. - Highlights: • Polyoxometalate–templated metal–organic frameworks have been prepared. • POMs as the guest molecules are incorporated into the cages. • The cages are flexibility based on flexible bis(imidazole) ligands.« less

Crystal chemistry of elpidite from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grigor'eva, A. A.; Zubkova, N. V., E-mail: nata_zubkova@rambler.ru; Pekov, I. V.

2011-09-15

Elpidite Na{sub 2}ZrSi{sub 6}O{sub 15} {center_dot} 3H{sub 2}O [space group Pbcm, a = 7.1312(12), b = 14.6853(12), and c = 14.6349(15) Angstrom-Sign ] from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms K{sub 1.78}Na{sub 0.16}H{sub 0.06}ZrSi{sub 6}O{sub 15} {center_dot} 0.85H{sub 2}O [Cmce, a = 14.054(3), b = 14.308(3), and c = 14.553(3) Angstrom-Sign ] and Na{sub 1.58}Rb{sub 0.2}H{sub 0.22}ZrSi{sub 6}O{sub 15} {center_dot} 2.69H{sub 2}O [Pbcm, a = 7.1280(10), b = 14.644(3), and c = 14.642(3) Angstrom-Sign ] that were obtained by cation exchange at 90 Degree-Sign C, as well as K{sub 1.84}Na{sub 0.11}H{sub 0.05}ZrSi{sub 6}O{sub 15} {center_dot} 0.91H{sub 2}Omore » [Cmce, a = 14.037(3), b = 14.226(3), and c = 14.552(3) Angstrom-Sign ] and Rb{sub 1.78}Na{sub 0.06}H{sub 0.16}ZrSi{sub 6}O{sub 15} {center_dot} 0.90H{sub 2}O [Cmce, a = 14.2999(12), b = 14.4408(15), and c = 14.7690(12) Angstrom-Sign ], obtained at 150 Degree-Sign C are studied by single-crystal X-ray diffraction and IR spectroscopy. The base of the structures is a heteropolyhedral Zr-Si-O framework whose cavities accommodate Na (K, Rb) cations and H{sub 2}O molecules.« less

Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing austenitic stainless steel composite body and a method of producing the same

DOEpatents

Cassidy, Roger T.

1990-05-01

The present invention relates to a hermetically sealed Li.sub.2 O-Al.sub.2 O.sub.3 -SiO.sub.2 glass ceramic-aluminum containing stainless steel composite body and a method of producing the body. The composite body includes an oxide interfacial region between the glass ceramic and metal, wherein the interfacial region consists essentially of an Al.sub.2 O.sub.3 layer. The interfacial Al.sub.2 O.sub.3 region includes constituents of both the metal and glass ceramic.

Optical resolution of {pi}-thiophene complexes (C{sub 6}Me{sub 6}) Ru(2-RC{sub 4}H{sub 3}S){sup 2+} and related studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dailey, K.K.; Rauchfuss, T.B.

Diasteriomeric iminium thiolato complexes were prepared by the addition of S-(-)-{alpha}-methylbenzylamine to the {pi}-thiophene complexes [(C{sub 6}Me{sub 6})Ru(2-RC{sub 4}H{sub 3}S)]{sup 2+}, where R = Me(1{sup 2+}), CH{sub 2}OH (3{sup 2+}), and 2-C{sub 4}H{sub 3}S(6{sup 2+}). After chromatographic separation, the diastereomers were treated with HOTf to generate optically pure {pi}-thiophene complexes. The absolute configuration of [(C{sub 6}Me{sub 6})RuSCMeC{sub 2}H{sub 2}(CHNHCHMePh)]OTf, (-)-2(OTf), was determined by a single-crystal X-ray diffraction; the monohydrate crystallized in the acentric space group P2{sub 1}2{sub 1}2{sub 1}. Base hydrolysis of (-)-1{sup 2+} gave the formyl thiolato complex (-)-9{sub kin}, which isomerized to (+)-9{sub therm} with inversion of configurationmore » at Ru, as indicated by circular dichroism measurements. The methyl ester of the amino acid (L)-phenylalanine was shown to add to (C{sub 6}Me{sub 6})Ru(C{sub 4}H{sub 4}S){sup 2+} to give a 2:1 mixture of diastereomeric iminium thiolato complexes. 19 refs., 3 figs., 2 tabs.« less

Cd(II)-coordination polymers based on tetracarboxylic acid and diverse bis(imidazole) ligands: Synthesis, structural diversity and photoluminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arıcı, Mürsel, E-mail: marici@ogu.edu.tr; Yeşilel, Okan Zafer; Taş, Murat

Three new Cd(II)-coordination polymers, namely, ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,5-bipe){sub 2}]·2H{sub 2}O){sub n} (1), ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,4-bix){sub 2}]{sub n}·2DMF) (2) and ([Cd{sub 2}(μ{sub 8}-abtc)(μ-1,4-betix)]·DMF·H{sub 2}O){sub n} (3) (ao{sub 2}btc=di-oxygenated form of 3,3′,5,5′-azobenzenetetracarboxylate, 1,5-bipe: 1,5-bis(imidazol-1yl)pentane, 1,4-bix=1,4-bis(imidazol-1ylmethyl)benzene, 1,4-betix=1,4-bis(2-ethylimidazol-1ylmethyl)benzene) were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the raremore » sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. Moreover, thermal and photoluminescence properties of the complexes were determined in detailed. - Graphical abstract: In this study, three novel Cd(II)-coordination polymers were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. - Highlights: • Three new Cd(II)-coordination polymers with azobenzenetetracarboxylic acid and diverse bis(imidazole) linkers. • Complex 1 is 2D structure with 3,6L18 topology. • 3D pillar-layered framework of 2 with the rare sqc27 topology. • 3D framework of 3 with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type SBU.« less

Method of polymerizing exo-methylene cyclic organic compounds using homogeneous ring-opening catalysts

DOEpatents

Marks, Tobin J.; Yang, Xinmin; Jia, Li

1994-01-01

The regiospecific (1,2-Me.sub.2 C.sub.5 H.sub.3).sub.2 ZrMe.sup.+ MeB(C.sub.6 F.sub.5).sub.3.sup.- mediated ring-opening polymerization of methylenecyclobutane and its copolymerization with ethylene to polyolefins of microstructure--{CH.sub.2 CH.sub.2 CH.sub.2 C(CH.sub.2)]--.sub.n and {--[CH.sub.2 CHR]--.sub.x [CH.sub.2 CH.sub.2 CH.sub.2 C(CH.sub.2)]--.sub.y }.sub.n' respectively, is disclosed.

Growth of In/sub 2/S/sub 3/ and CdIn/sub 2/S/sub 4/ single crystals from a solution in a melt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buzhor, V.P.; Lyalikova, R. Yu.; Radautsan, S.I.

1986-08-01

The authors studied the reaction of In/sub 2/S/sub 3/ and CdIn/sub 2/S/sub 4/ with melts based on cadmium chloride. As the initial materials, they used polycrystalline In/sub 2/S/sub 3/ and CdIn/sub 2/S/sub 4/, cadmium chloride, and cadmium sulfide. The studies were carried out by the method of thermal analysis in sealed quartz ampules on an MOM derivatotograph. The solubility curve of In/sub 2/S/sub 3/ in a cadmium chloride melt is given. Nucleation occurs both within the liquid pahse and on the walls of the reaction container. At cooling rates of 4-5 K/h, with a charge of 100 g in amore » reaction container of diameter 20 mm the authors obtained In/sub 2/S/sub 3/ and CdIn/sub 2/S/sub 4/ crystals measuring 10-12 mm in size.« less

Lanthanide contraction effect on crystal structures of lanthanide coordination polymers with cyclohexanocucurbit[6]uril ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Li-Mei; Liu, Jing-Xin, E-mail: jxliu411@ahut.edu.cn

A series of compounds based on the macrocyclic ligand cyclohexanocucurbit[6]uril (Cy6Q[6]) with formulas (Ln(H{sub 2}O){sub 6}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·xH{sub 2}O [isomorphous with Ln=La (1), Ce (2), Pr (3) and Nd (4), x=11 (1), 11 (2), 10 (3) and 11 (4)], (Sm(H{sub 2}O){sub 5}Cy6Q[6])·2(CdCl{sub 4})·H{sub 3}O·10H{sub 2}O (5) and (Ln(H{sub 2}O){sub 5}(NO{sub 3})@Cy6Q[6])·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with Ln=Gd (6), Tb (7) and Dy (8), x=8 (6), 6 (7) and 6 (8)], have been successfully synthesized by the self-assembly of Cy6Q[6] with the corresponding lanthanide nitrate under hydrochloric acid aqueous solution in the presence of CdCl{sub 2}. Single-crystal X-ray diffraction analyses revealedmore » that compounds 1–8 all crystallize in monoclinic space group P2{sub 1}/c, and display 1D coordination polymer structures. The lanthanide contraction effect on the structures of 1–8 has also been investigated and discussed in detail. In contrast, the reaction of Cy6Q[6] with the Ho(NO){sub 3}, Tm(NO){sub 3}, Yb(NO){sub 3} under the same conditions resulted in the compounds 9–11 with formulas Cy6Q[6]·2(CdCl{sub 4})·2H{sub 3}O·xH{sub 2}O [isomorphous with x=10 (9), 10 (10), and 9 (11)], in which no lanthanide cations are observed. The structural difference of these compounds indicates that the Cy6Q[6] may be used in the separation of lanthanide cations. - Graphical abstract: The reaction of cyclohexanocucurbit[6]uril with lanthanide ions (La{sup 3+}, Ce{sup 3+}, Pr{sup 3+}, Nd{sup 3+}, Sm{sup 3+}, Gd{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Ho{sup 3+}, Tm{sup 3+} and Yb{sup 3+}) under hydrochloric acid in the presence of CdCl{sub 2} resulted in eleven compounds, which demonstrate interesting lanthanide contraction effect and provide a means of separating lanthanide ions. - Highlights: • Eleven compounds of the Ln{sup 3+} with the Cy6Q[6] were synthesized and described. • Compounds 1-8 demonstrate interesting lanthanide contraction effect. • In solid-state structures of compounds 9-11, no lanthanide ions were observed. • This study provides a means of separating lanthanides cations.« less

Doping effect of nano-Ho{sub 2}O{sub 3} and naphthalene in MgB{sub 2} superconductor prepared by powder-in-sealed-tube method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansdah, J. S.; Sarun, P. M., E-mail: sarun.res@gmail.com

2015-03-21

The effect on crystal structure, critical temperature (T{sub C}), and critical current density (J{sub C}) of bulk MgB{sub 2} doped with nano-Ho{sub 2}O{sub 3} and naphthalene was studied. Among all the samples studied, the sample doped with 2.5 wt. % nano-Ho{sub 2}O{sub 3} have shown the best field dependent critical current density [J{sub C}(H)], i.e., 0.77 × 10{sup 5 }A/cm{sup 2} at 2 T and 10 K. While naphthalene doped MgB{sub 2} sample has shown the least J{sub C}(H) characteristics. The improved J{sub C}(H) characteristics in the nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples are attributed to improved flux pinning properties due to the formation ofmore » HoB{sub 4} and in naphthalene doped MgB{sub 2} samples. The slight lower T{sub C} value (37.01 K) in naphthalene doped samples is attributed to the occurrence of lattice defect by the substitution of carbon at boron site of MgB{sub 2} superconductor. Lower ΔT{sub C} value implies the lesser anisotropy in all the synthesized samples. The flux pinning force density (F{sub P}/F{sub Pmax}) curves are theoretically analyzed using Dew-Hughes model. The result revealed that point pinning is the dominant pinning mechanism for nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples, while, surface and grain boundary pinning become dominant with increasing naphthalene addition in nano-Ho{sub 2}O{sub 3} doped MgB{sub 2} samples.« less

The formation and structure of mechano-synthesized nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 6.4}: XRD Rietveld, Mössabuer and XPS analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Rawas, A.D., E-mail: arawas@squ.edu.om; Widatallah, H.M.; Al-Harthi, S.H.

2015-05-15

Highlights: • The formation of mechano-synthesized nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 7−δ} is investigated. • Pre-milling the reactants substantially lowers the formation temperature. • The core and surface structures were studied. • XRD and {sup 57}Fe Mössbauer spectroscopic analyses indicate the δ-value to be 0.60. • XPS shows a complex surface structure for the mechanosynthesized Sr{sub 3}Fe{sub 2}O{sub 7−δ} nanoparticles. - Abstract: The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO{sub 3} and α-Fe{sub 2}O{sub 3} on the formation of Sr{sub 3}Fe{sub 2}O{sub 7−δ} double perovskite is investigated with different analytical techniques. Milling the mixturemore » for 110 h leads to the formation of SrCO{sub 3}-α-Fe{sub 2}O{sub 3} nanocomposites and the structural deformation of α-Fe{sub 2}O{sub 3} via the incorporation of Sr{sup 2+} ions. Subsequent sintering of the pre-milled reactants’ mixture has led to the partial formation of an SrFeO{sub 3} perovskite-related phase in the temperature range 400–600 °C. This was followed by the progressive development of an Sr{sub 3}Fe{sub 2}O{sub 7−δ} phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr{sub 3}Fe{sub 2}O{sub 7−δ} phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe{sup 3+}/Fe{sup 4+} ratio derived from the {sup 57}Fe Mössbauer data recorded at both 300 K and 78 K. The Mössbauer data suggests that the Sr{sub 3}Fe{sub 2}O{sub 6.4} nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr{sub 3}Fe{sub 2}O{sub 6.4} nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO{sub 3}, SrO and SrFeO{sub 3−δ} being detected.« less

Syntheses, spectroscopic characterizations, and X-ray structures of new Os({eta}{sup 2}-H{sub 2}) compounds containing azole ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esteruelas, M.A.; Lahoz, F.J.; Oro, L.A.

1994-02-16

The dihydrido-dichloro complex OsH{sub 2}Cl{sub 2}(P-i-Pr{sub 3}){sub 2} (1) reacts with 2,2{prime}-biimidazole (H{sub 2}bim) to give the dihydrogen derivative [OsCl({eta}{sup 2}-H{sub 2})(H{sub 2}bim)(P-i-Pr{sub 3}){sub 2}]Cl (2). The molecular structure of 2 has been determined by X-ray investigation. 2 crystallizes with a dichloromethane molecule in the triclinic space group Pl. The coordination geometry around the osmium center can be rationalized as a distorted octahedron with the two phosphine ligands disposed mutually trans. The remaining coordination sites of the octahedron are occupied by the dihydrogen ligand, the chloride atom, and by two nitrogen atoms of the chelate 2,2{prime}-biimidazole ligand. One of themore » two acidic NH groups of the 2,2{prime}-biimidazole ligand of 2 can be deprotonated by NaBH{sub 4} to give [OsCl({eta}{sup 2}-H{sub 2})(Hbim)(P-i-Pr{sub 3}){sub 2}] (3). Similarly the 2,2{prime}-biimidazole ligand of 2 is deprotonated by dimers of the type [M({mu}-OMe)(diolefin)]{sub 2} to form the heterobimetallic compounds [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(COD)] (5), and [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(TFB)] (TFG = tetrafluorobenzobarrelene, 6). The addition of pyrazole to 1 leads to the complex trans-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (7), which is transformed into its isomer cis-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (8) by stirring in hexane at 60 {degrees}C. The coordination geometry around the osmium center could be described as based on a distorted octahedron with the two phosphine ligands occuping the apical positions. The equatorial plane is formed by the dihydrogen and the pyrazole ligands mutually cis-disposed and the two chloride atoms are also cis-disposed.« less

A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jun; College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000; Bai, Chao

Eight Zn(II)-based coordination polymers, namely, [Zn{sub 2}L{sub 2}(2,2’-bipy)]{sub n}·nH{sub 2}O (1), [Zn{sub 2}L{sub 2}(phen)]{sub n}·nH{sub 2}O (2), [ZnL(phen)(H{sub 2}O)]{sub n} (3), [Zn{sub 3}L{sub 3}(4,4’-bipy)]{sub n} (4), [Zn{sub 2}L{sub 2}(4,4’-bipy){sub 2}]{sub n} [Zn{sub 2}L{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (5), [Zn{sub 4}L{sub 4}(bpp){sub 2}]{sub n} (6), [ZnL(bbi){sub 0.5}]{sub n} (7), [ZnL(bpz)]{sub n} (8) (H{sub 2}L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid statemore » were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives, in which indicates it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multiphotofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials.« less

Di- and tri-benzotriazole substituted tri-hydroxybenzenes

DOEpatents

Vogl, O.; Li, S.

1983-10-06

Ultraviolet light stabilizing compounds of the formula (phenyl) R/sub 1/, R/sub 2/(OH)/sub 3/R/sub 3/, are described, wherein R/sub 1/, R/sub 2/, and R/sub 3/ are hydrogen or 2H-benzotriazole-2-yl groups and wherein no more than one of R/sub 1/, R/sub 2/, and R/sub 3/ is hydrogen, and organic compositions susceptible to ultraviolet light degradation containing these compounds, and method for selectively producing the compounds.

Topologically identical, but geometrically isomeric layers in hydrous α-, β-Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O and anhydrous Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Na; Klepov, Vladislav V.; Villa, Eric M.

2014-07-01

The hydrothermal reaction of uranyl nitrate with rubidium nitrate and arsenic (III) oxide results in the formation of polymorphic α- and β-Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O (α-, β-RbUAs) and the anhydrous phase Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})] (RbUAs). These phases were structurally, chemically and spectroscopically characterized. The structures of all three compounds are based upon topologically identical, but geometrically isomeric layers. The layers are linked with each other by means of the Rb cations and hydrogen bonding. Dehydration experiments demonstrate that water deintercalation from hydrous α- and β-RbUAs yields anhydrous RbUAs via topotactic reactions. - Graphical abstract: Three differentmore » layer geometries observed in the structures of Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})] and α- and β- Rb[UO{sub 2}(AsO{sub 3}OH)(AsO{sub 2}(OH){sub 2})]·H{sub 2}O. Two different coordination environments of uranium polyhedra (types I and II) are shown schematically on the top of the figure. - Highlights: • Three new uranyl arsenates were synthesized from the hydrothermal reactions. • The phases consist of the topologically identical but geometrically different layers. • Topotactic transitions were observed in the processes of mono-hyrates dehydration.« less

Organometallic oxides: Preparation, structure, and chemical and physical properties of paramagnetic ((. eta. -C sub 5 H sub 5 )NbCl(. mu. -A)) sup 3 (. mu. sub 3 -OH)(. mu. sub 3 -O) (A = Cl, OH) and other oxo-hydroxo clusters of niobium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bottomley, F.; Keizer, P.N.; White, P.S.

Hydrolysis of Cp{prime}NbCl{sub 4} (Cp{prime} = {eta}{sup 5}-C{sub 5}H{sub 5} (Cp), {eta}-C{sub 5}H{sub 4}Me (Cp{sup 1})) in tetrahydrofuran (THF) gave a mixture of products of general formula (Cp{prime}NbL{sub 4}){sub 2}({mu}-O), where L{sub 4} is a combination of H{sub 2}O and terminal or bridging Cl that gives eight-coordinate, pentavalent, niobium. For Cp{prime} = Cp, a major constituent of the mixture is (CpNb(H{sub 2}O)Cl{sub 3}){sub 2}({mu}-O) {times} 2THF {times} 0.05Et{sub 2}O (1), the structure of which was determined by X-ray diffraction. Reduction of (Cp{prime}NbL{sub 4}){sub 2}({mu}-O) with aluminum powder gave the cluster (Cp{prime}NbCl({mu}-Cl)){sub 3}({mu}{sub 3}-OH)({mu}{sub 3}-O) (2). The structure of 2 (Cp{prime}more » = Cp) as the THF adduct was determined by X-ray diffraction. Crystal data: monoclinic; P2{sub 1}/c; a = 9.966 (1) {angstrom}, b = 12.471 (2) {angstrom}, c = 20.321 (2) {angstrom}, {beta} = 93.86 (1){degree}.« less

Synthesis, crystal structures, and luminescent properties of Cd(II) coordination polymers assembled from semi-rigid multi-dentate N-containing ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Gang; Shao, Kui-Zhan; Chen, Lei

2012-12-15

Three new polymers, [Cd(L){sub 2}(H{sub 2}O){sub 2}]{sub n} (1), [Cd{sub 3}(L){sub 2}({mu}{sub 3}-OH){sub 2}({mu}{sub 2}-Cl){sub 2}(H{sub 2}O){sub 2}]{sub n} (2), {l_brace}[Cd{sub 2}(L){sub 2}(nic){sub 2}(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O{r_brace}{sub n} (3) (HL=5-(4-((1H-1,2,4-triazol-1-yl)methyl)phenyl)-1H-tetrazole, Hnic=nicotinic acid) have been prepared and structurally characterized. Compounds 1 and 2 display 2D monomolecular layers built by the inter-linking single helical chains and L{sup -} ligands connecting chain-like [Cd({mu}{sub 3}-OH)({mu}{sub 2}-Cl)]{sub n} secondary building units, respectively. Compound 3 is constructed from the mixed ligands and possesses a (3,4)-connected framework with (4{center_dot}8{sup 2})(4{center_dot}8{sup 2}{center_dot}10{sup 3}) topology. Moreover, the fluorescent properties of HL ligand and compounds 1-3 are also been investigated.more » - Graphical abstract: Three new coordination polymers based on the semi-rigid multidentate N-donor ligand have been successfully synthesized by hydrothermal reaction. Complexes 1 and 2 exhibit the 2D layers formed by inter-linking single helices and L{sup -} anions bridging 1D chain-like SBUs, respectively. Complex 3 is buit by L{sup -} and assistant nic{sup -} ligands connecting metal centers and possesses a (3,4)-connected framework with (4 Multiplication-Sign 8{sup 2})(4 Multiplication-Sign 8{sup 2} Multiplication-Sign 10{sup 3}) topology. Moreover, these complexes display fluorescent properties indicating that they may have potential applications as optical materials. Highlights: Black-Right-Pointing-Pointer Three Cd-compounds were prepared from semi-rigid HL ligand with different N-containing groups. Black-Right-Pointing-Pointer They exhibit diverse structures from 2D monomolecular layer to 3D covalent framework. Black-Right-Pointing-Pointer The HL ligands displayed various coordination modes under different reaction conditions. Black-Right-Pointing-Pointer These compounds exhibit good luminescent properties.« less

Coherent 3D nanostructure of γ-Al{sub 2}O{sub 3}: Simulation of whole X-ray powder diffraction pattern

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakharukova, V.P., E-mail: verapakh@catalysis.ru; Novosibirsk State University, Pirogova Street 2, 630090 Novosibirsk; Research and Educational Center for Energy Efficient Catalysis, Novosibirsk State University, Novosibirsk 630090

2017-02-15

The structure and nanostructure features of nanocrystalline γ-Al{sub 2}O{sub 3} obtained by dehydration of boehmite with anisotropic platelet-shaped particles were investigated. The original models of 3D coherent nanostructure of γ-Al{sub 2}O{sub 3} were constructed. The models of nanostructured γ-Al{sub 2}O{sub 3} particles were first confirmed by a direct simulation of powder X–Ray diffraction (XRD) patterns using the Debye Scattering Equation (DSE) with assistance of high-resolution transmission electron microscopy (HRTEM) study. The average crystal structure of γ-Al{sub 2}O{sub 3} was shown to be tetragonally distorted. The experimental results revealed that thin γ-Al{sub 2}O{sub 3} platelets were heterogeneous on a nanometer scalemore » and nanometer-sized building blocks were separated by partially coherent interfaces. The XRD simulation results showed that a specific packing of the primary crystalline blocks in the nanostructured γ-Al{sub 2}O{sub 3} particles with formation of planar defects on (001), (100), and (101) planes nicely accounted for pronounced diffuse scattering, anisotropic peak broadening and peak shifts in the experimental XRD pattern. The identified planar defects in cation sublattice seem to be described as filling cation non-spinel sites in existing crystallographic models of γ-Al{sub 2}O{sub 3} structure. The overall findings provided an insight into the complex nanostructure, which is intrinsic to the metastable γ-Al{sub 2}O{sub 3} oxide. - Highlights: • Thin plate-like crystallites of γ-Al{sub 2}O{sub 3} were obtained. • Models of 3D coherent nanostructure of γ-Al{sub 2}O{sub 3} were constructed. • Models were verified by simulating XRD patterns using the Debye Scattering Equation. • Specific broadening of XRD peaks was explained in terms of planar defects. • Primary crystalline blocks in γ-Al{sub 2}O{sub 3} are separated by partially coherent interfaces.« less

Nanocrystalline Cs{sub x}WO{sub 3} particles: Effects of N{sub 2} annealing on microstructure and near-infrared shielding characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jing-Xiao, E-mail: drliu-shi@dlpu.edu.cn; Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai, 980-8577,Japan; Shi, Fei

2013-10-15

In order to further improve the near-infrared shielding properties of cesium tungsten bronze (Cs{sub x}WO{sub 3}) for solar filter applications, Cs{sub x}WO{sub 3} particles were prepared by solvothermal reaction method and the effects of nitrogen annealing on the microstructure and near-infrared shielding properties of Cs{sub x}WO{sub 3} were investigated. The obtained Cs{sub x}WO{sub 3} samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and spectrophotometer. The results indicate that nanosheet-like Cs{sub x}WO{sub 3} particles with hexagonal structure began to transform into nanorods after annealed at temperature higher than 600 °C. The near-infrared shielding propertiesmore » of Cs{sub x}WO{sub 3} particles could be further improved by N{sub 2} annealing at 500–700 °C. Particularly, the 500 °C-annealed Cs{sub x}WO{sub 3} samples in the N{sub 2} atmosphere showed best near-infrared shielding properties. It was suggested that the excellent near-infrared shielding ability of the 500 °C-annealed Cs{sub x}WO{sub 3} samples is correlated with its minimum O/W atomic ratio and most oxygen vacancies. Highlights: • N{sub 2} annealing could further improve the near-infrared (NIR) shielding of Cs{sub x}WO{sub 3}. • Effects of N{sub 2} annealing on microstructure and NIR shielding of Cs{sub x}WO{sub 3} were studied. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} exhibited minimum O/W ratio and most oxygen vacancies. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} particles exhibited best NIR shielding properties.« less

From Ba{sub 3}Ta{sub 5}O{sub 14}N to LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}: Decreasing the optical band gap of a photocatalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anke, B.; Bredow, T.; Pilarski, M.

Yellow LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was successfully synthesized as phase-pure material crystallizing isostructurally to previously reported Ba{sub 3}Ta{sub 5}O{sub 14}N and mixed-valence Ba{sub 3}Ta{sup V}{sub 4}Ta{sup IV}O{sub 15}. The electronic structure of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} was studied theoretically with the range-separated hybrid method HSE06. The most stable structure was obtained when lanthanum was placed on 2a and nitrogen on 4h sites confirming Pauling's second rule. By incorporating nitrogen, the measured band gap decreases from ∼3.8 eV for the oxide via 2.74 eV for Ba{sub 3}Ta{sub 5}O{sub 14}N to 2.63 eV for the new oxide nitride, giving risemore » to an absorption band well in the visible-light region. Calculated fundamental band gaps confirm the experimental trend. The atom-projected density of states has large contributions from N2p orbitals close to the valence band edge. These are responsible for the observed band gap reduction. Photocatalytic hydrogen formation was investigated and compared with that of Ba{sub 3}Ta{sub 5}O{sub 14}N revealing significantly higher activity for LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} under UV-light. - Graphical abstract: X-ray powder diffraction pattern of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} with the results of the Rietveld refinements. Inset: Unit cell of LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2} and polyhedral representation of the crystal structure. - Highlights: • Synthesis of a new oxide nitride LaBa{sub 2}Ta{sub 5}O{sub 13}N{sub 2}. • Refinement of the crystal structure. • Quantum chemical calculations provided band gap close to the measured value. • New phase shows a higher photocatalytic H{sub 2} evolution rate compared to prior tested Ba{sub 3}Ta{sub 5}O{sub 14}N.« less

Substituted 6-nitroquipazines, methods of preparation, and methods of use

DOEpatents

Mathis, Jr., Chester A.; Biegon, Anat; Taylor, Scott E.; Enas, Joel D.

1994-01-01

Disclosed is a substituted 6-nitroquipazine of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each selected from the group consisting of H, Fl, CL, Br, I, CF.sub.3, CH.sub.2 CH.sub.2 F, CH.sub.3, CH.sub.2 CH.sub.3, and --CH(CH.sub.3).sub.2, and wherein one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is other than H. Also disclosed is a method for measurement of serotonin uptake sites in a sample, in which a radioligand is incubated with a sample and then the radioactivity of the radioligand bound to the sample is determined, utilizing a radio labeled substituted 6-nitroquipazine as the radioligand. Also disclosed is a method of manufacture and method of use.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mancini, Alessandro; Felice, Valeria; Natali Sora, Isabella

Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25} has been extensively investigated by X-ray powder diffraction in a wide temperature range (up to 1573 K). Perovskite-type La{sub 0.8}Sr{sub 0.2}MnO{sub 3−d} and La{sub 0.8}Sr{sub 0.2}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−d} and K{sub 2}NiF{sub 4}-type La{sub 2}NiO{sub 4+d} were selected as cathode materials. The results of this study allow identifying the most suitable electrode material to be used in combination with the melilite-type gallate electrolyte andmore » set the basis for future work on this novel system. - Graphical abstract: Chemical reactivity between cathodes and electrolytes is a crucial issue for long term SOFCs stability and performances. In this study, chemical reactivity between selected cathodic materials and the ionic conducting melilite La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25} has been extensively investigated by means of X-ray powder diffraction. - Highlights: • Chemical compatibility between melilite-type gallate and cathodes for SOFCs up to 1573 K. • No reactivity observed between La{sub 0.8}Sr{sub 0.2}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}. • Reactivity observed between La{sub 0.80}Sr{sub 0.20}MnO{sub 3−d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}. • Significant reactivity observed between La{sub 2}NiO{sub 4+d} and La{sub 1.50}Sr{sub 0.50}Ga{sub 3}O{sub 7.25}.« less

Acidic 1,3-propanediaminetetraacetato lanthanides with luminescent and catalytic ester hydrolysis properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Mao-Long; Shi, Yan-Ru; Yang, Yu-Chen

2014-11-15

In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H{sub 3}pdta)(H{sub 2}O){sub 5}]{sub n}·2Cl{sub n}·3nH{sub 2}O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H{sub 4}pdta=1,3-propanediaminetetraacetic acid, C{sub 11}H{sub 18}N{sub 2}O{sub 8}) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CPs, respectively, two 1D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 3}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 2}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd,more » 14] were isolated at 70 °C. When the crystals of 1–4 were hydrothermally heated at 180 °C with 1–2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)]{sub n}·nH{sub 2}O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 18] were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H{sub 2}O)]{sub n}·4nH{sub 2}O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1–5 are soluble in water and 1 was traced by solution {sup 13}C({sup 1}H) NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature. - Graphical abstract: A series of water-soluble acidic 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H{sub 3}pdta)(H{sub 2}O){sub 5}]n·2Cl{sub n}·3nH{sub 2}O have been converted to their 2D and 3D lanthanides, which are active for the catalytic conversion of ester hydrolysis. - Highlights: • Novel acidic propanediaminetetraacetato lanthanides. • Water-soluble 1D coordination polymers. • Acidic conditions are suitable for the isolations of lanthanide complexes in different structures. • 1 and 5 show good catalytic activity to ester hydrolysis. • Europium coordination polymers 13 and 20 give visible fluorescence.« less

High surface area ThO/sub 2/ catalyst

DOEpatents

Colmenares, C.A.; Somorjai, G.A.; Maj, J.J.

1983-06-21

A ThO/sub 2/ catalyst having a high surface area of about 80 to 125m/sup 2//g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO/sub 3/(NO/sub 3/)/sub 4/.4H/sub 2/O with an aqueous solution of Na/sub 2/CO/sub 3/.H/sub 2/O, to produce a solution and solid ThOCO/sub 3/. The solid ThOCO/sub 3/ is separated from the solution, and then calcined at a temperature of about 225 to 300/sup 0/C for about 40 to 55 hours to produce ThO/sub 2/. The ThO/sub 2/ catalyst produced includes Na present as a substitutional cation in an amount equal to about 5 to 10 at. %.

High surface area ThO.sub.2 catalyst and method of preparing it

DOEpatents

Colmenares, Carlos A.; Somorjai, Gabor A.; Maj, Joseph J.

1985-01-01

A ThO.sub.2 catalyst having a high surface area of about 80-125 m.sup.2 /g is synthesized. The compound is synthesized by simultaneously mixing an aqueous solution of ThNO.sub.3 (NO.sub.3).sub.4.4H.sub.2 O with an aqueous solution of Na.sub.2 CO.sub.3.H.sub.2 O, to produce a solution and solid ThOCO.sub.3. The solid ThOCO.sub.3 is separated from the solution, and then calcined at a temperature of about 225.degree.-300.degree. C. for about 40-55 hours to produce ThO.sub.2. The ThO.sub.2 catalyst produced includes Na present as a substitutional cation in an amount equal to about 5-10 atom percent.

Phosphate glass useful in high power lasers

DOEpatents

Hayden, J.S.; Sapak, D.L.; Ward, J.M.

1990-05-29

A low- or no-silica phosphate glass useful as a laser medium and having a high thermal conductivity, K[sub 90 C] > 0.8 W/mK, and a low coefficient of thermal expansion, [alpha][sub 20--40 C] < 80[times]10[sup [minus]7]/C, consists essentially of (on a batch composition basis Mole %): P[sub 2]O[sub 5], 45-70; Li[sub 2]O, 15-35; Na[sub 2]O, 0-10; Al[sub 2]O[sub 3], 10-15; Nd[sub 2]O[sub 3], 0.01-6; La[sub 2]O[sub 3], 0-6; SiO[sub 2], 0-8; B[sub 2]O[sub 3], 0-8; MgO, 0-18; CaO, 0-15; SrO, 0-9; BaO, 0-9; ZnO, 0-15; the amounts of Li[sub 2]O and Na[sub 2]O providing an average alkali metal ionic radius sufficiently low whereby said glass has K[sub 90 C] > 0.8 W/mK and [alpha][sub 20--40 C] < 80[times]10[sup [minus]7]/C, and wherein, when the batch composition is melted in contact with a silica-containing surface, the final glass composition contains at most about 3.5 mole % of additional silica derived from such contact during melting. The Nd[sub 2]O[sub 3] can be replaced by other lasing species. 3 figs.

Effect of atomic layer deposition temperature on current conduction in Al{sub 2}O{sub 3} films formed using H{sub 2}O oxidant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiraiwa, Atsushi, E-mail: hiraiwa@aoni.waseda.jp, E-mail: qs4a-hriw@asahi-net.or.jp; Matsumura, Daisuke; Kawarada, Hiroshi, E-mail: kawarada@waseda.jp

To develop high-performance, high-reliability gate insulation and surface passivation technologies for wide-bandgap semiconductor devices, the effect of atomic layer deposition (ALD) temperature on current conduction in Al{sub 2}O{sub 3} films is investigated based on the recently proposed space-charge-controlled field emission model. Leakage current measurement shows that Al{sub 2}O{sub 3} metal-insulator-semiconductor capacitors formed on the Si substrates underperform thermally grown SiO{sub 2} capacitors at the same average field. However, using equivalent oxide field as a more practical measure, the Al{sub 2}O{sub 3} capacitors are found to outperform the SiO{sub 2} capacitors in the cases where the capacitors are negatively biased andmore » the gate material is adequately selected to reduce virtual dipoles at the gate/Al{sub 2}O{sub 3} interface. The Al{sub 2}O{sub 3} electron affinity increases with the increasing ALD temperature, but the gate-side virtual dipoles are not affected. Therefore, the leakage current of negatively biased Al{sub 2}O{sub 3} capacitors is approximately independent of the ALD temperature because of the compensation of the opposite effects of increased electron affinity and permittivity in Al{sub 2}O{sub 3}. By contrast, the substrate-side sheet of charge increases with increasing ALD temperature above 210 °C and hence enhances the current of positively biased Al{sub 2}O{sub 3} capacitors more significantly at high temperatures. Additionally, an anomalous oscillatory shift of the current-voltage characteristics with ALD temperature was observed in positively biased capacitors formed by low-temperature (≤210 °C) ALD. This shift is caused by dipoles at the Al{sub 2}O{sub 3}/underlying SiO{sub 2} interface. Although they have a minimal positive-bias leakage current, the low-temperature-grown Al{sub 2}O{sub 3} films cause the so-called blisters problem when heated above 400 °C. Therefore, because of the absence of blistering, a 450 °C ALD process is presently the most promising technology for growing high-reliability Al{sub 2}O{sub 3} films.« less

Reversible electro-optic device employing aprotic molten salts and method

DOEpatents

Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Hall, Simon B [Palmerston North, NZ

2008-01-08

A single-compartment reversible mirror device having a solution of aprotic molten salt, at least one soluble metal-containing species comprising metal capable of being electrodeposited, and at least one anodic compound capable of being oxidized was prepared. The aprotic molten salt is liquid at room temperature and includes lithium and/or quaternary ammonium cations, and anions selected from trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). A method for preparing substantially pure molten salts is also described.

Reversible Electro-Optic Device Employing Aprotic Molten Salts And Method

DOEpatents

Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Hall, Simon B.

2005-03-01

A single-compartment reversible mirror device having a solution of aprotic molten salt, at least one soluble metal-containing species comprising metal capable of being electrodeposited, and at least one anodic compound capable of being oxidized was prepared. The aprotic molten salt is liquid at room temperature and includes lithium and/or quaternary ammonium cations, and anions selected from trifluoromethylsulfonate (CF.sub.3 SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3 SO.sub.2).sub.2 N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3 CF.sub.2 SO.sub.2).sub.2 N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3 SO.sub.2).sub.3 C.sup.-). A method for preparing substantially pure molten salts is also described.

Method and apparatus for synthesizing HMX and N/sub 2/O/sub 5/. [Patent application; cyclotetramethylenetetraamine

DOEpatents

McGuire, R.R.; Coon, C.L.; Harrar, J.E.; Pearson, R.K.

1982-07-20

A method and apparatus for electrochemically synthesizing N/sub 2/O/sub 5/ includes oxidizing a solution of N/sub 2/O/sub 4//HNO/sub 3/ at an anode, while maintaining a controlled potential between the N/sub 2/O/sub 4//HNO/sub 3/ solution and the anode. A potential of about 1.35 to 2.0V vs. SCE is preferred, while a potential of about 1.80V vs. SCE is most preferred. Thereafter, the N/sub 2/O/sub 5/ is reacted with either 1.5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) or 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) to form cyclotetramethylenetetraamine (HMX).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ioakeimidis, Apostolos; Christodoulou, Christos; Lux-Steiner, Martha

In this work we fabricate all-vacuum processed methyl ammonium lead halide perovskite by a sequence of physical vapour deposition of PbI{sub 2} and chemical vapour deposition (CVD) of CH{sub 3}NH{sub 3}I under a static atmosphere. We demonstrate that for higher deposition rate the (001) planes of PbI{sub 2} film show a higher degree of alignment parallel to the sample's surface. From X-ray diffraction data of the resulted perovskite film we derive that the intercalation rate of CH{sub 3}NH{sub 3}I is fostered for PbI{sub 2} films with higher degree of (001) planes alignment. The stoichiometry of the produced perovskite film ismore » also studied by Hard X-ray photoelectron spectroscopy measurements. Complete all-vacuum perovskite solar cells were fabricated on glass/ITO substrates coated by an ultra-thin (5 nm) Zn-phthalocyanine film as hole selective layer. A dependence of residual PbI{sub 2} on the solar cells performance is displayed, while photovoltaic devices with efficiency up to η=11.6% were achieved. - Graphical abstract: A two-step PVD/CVD processed perovskite film with the CVD intercalation rate of CH{sub 3}NCH{sub 3} molecules been fostered by increasing the PVD rate of PbI{sub 2} and prolonging the CVD time. - Highlights: • A simple PVD/CVD process for perovskite film production. • Increased PVD rate yields better alignment of the PbI{sub 2} (001) crystallite planes. • CH{sub 3}NH{sub 3}I intercalation process fostered by increased PbI{sub 2} PVD rate. • Stoichiometric CH{sub 3}NH{sub 3}PbI{sub 3} suitable as absorber in photovoltaic applications • Reduced PbI{sub 2} residue at the bottom of CH{sub 3}NH{sub 3}PbI{sub 3} improves device performance.« less

Controlled synthesis, characterization and photoluminescence property of olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Youjin, E-mail: zyj@ustc.edu.cn; Zheng, Ao; Yang, Xiaozhi

2012-09-15

Highlights: ► The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was gained with EDTA assisted hydrothermal method. ► The product was characterized by XRD, XPS, FTIR, FESEM, and PL. ► The possible formation mechanism for olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. ► The PL in visible region of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied. -- Abstract: The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was obtained by a convenient and facile complex agent assisted hydrothermal method. The product was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM) andmore » photoluminescence (PL). The possible formation mechanism of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. The photoluminescence property in visible region of the olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied.« less

Ag/α-Fe{sub 2}O{sub 3} hollow microspheres: Preparation and application for hydrogen peroxide detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Xinyuan; Wu, Zhiping; Liao, Fang, E-mail: liaozhang2003@163.com

2015-09-15

In this paper, we demonstrated a simple approach for preparing α-Fe{sub 2}O{sub 3} hollow spheres by mixing ferric nitrate aqueous and glucose in 180 °C. The glucose was found to act as a soft template in the process of α-Fe{sub 2}O{sub 3} hollow spheres formation. Ag/α-Fe{sub 2}O{sub 3} hollow nanocomposite was obtained under UV irradiation without additional reducing agents or initiators. Synthesized Ag/α-Fe{sub 2}O{sub 3} hollow composites exhibited remarkable catalytic performance toward H{sub 2}O{sub 2} reduction. The electrocatalytic activity mechanism of Ag/α-Fe{sub 2}O{sub 3}/GCE were discussed toward the reduction of H{sub 2}O{sub 2} in this paper. - Graphical abstract: Glucosemore » is carbonized as carbon balls in the 180 °C hydrothermal carbonization process, which plays a role of a soft template. Carbon spherical shell is rich in many hydroxyls, which have good hydrophilicity and surface reactivity. When Fe(NO{sub 3}){sub 3} is added to the aqueous solution of Glucose, the hydrophilic -OH will adsorb Fe{sup 3+} to form coordination compound by coordination bond. α-FeOOH is formed on the surface of carbon balls by hydrothermal reaction. After calcination at 500 °C, carbon spheres react with oxygen to form carbon dioxide, which disappears in the air. Meanwhile α-FeOOH is calcined to form α-Fe{sub 2}O{sub 3} hollow spheres.« less

Hydrothermal syntheses, structures and characterizations of three one-dimensional polyoxomolybdates with 4,4'-dimethylenebiphenyl diphosphonic acid as bridge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Huishuang; Fu Ruibiao; Zhang Jianjun

2005-05-15

Three heterometallic 1-D polymers, [{l_brace}Ni(1,10-phen){sub 2}(H{sub 2}O){r_brace}{sub 2} {l_brace}(Mo{sub 5}O{sub 15})(4,4'-dbp){r_brace}.(5.75H{sub 2}O)] (4,4'-dbp=O{sub 3}PCH{sub 2}C{sub 6}H{sub 4}C{sub 6}H{sub 4}CH{sub 2}PO{sub 3}) (1), [{l_brace}Co(1,10-phen){sub 2}(H{sub 2}O){r_brace}{sub 2} {l_brace}(Mo{sub 5}O{sub 15})(4,4'-dbp){r_brace}.(5.5H{sub 2}O)] (2) and [{l_brace}Ni(2,2'-bpy){sub 3}{r_brace}{l_brace}Ni(2,2'-bpy){sub 2}(H{sub 2}O){r_brace} {l_brace}(Mo{sub 5}O{sub 15})(4,4'-dbp){r_brace}.(4.75H{sub 2}O)] (3), have been synthesized under hydrothermal conditions. Their structures were determined by single crystal X-ray diffraction. The 1-D chains is constructed of [Mo{sub 5}O{sub 15}(4,4'-dbp)]{sup 4-} units, which are further decorated and charge compensated by [M(1,10-phen){sub 2}] (M=Ni, Co) or [Ni(2,2'-bpy){sub 2}] subunits. The thermogravimetric analyses and magnetic properties of 1 and 2 were studied.

Topotaxial growth of α-Fe{sub 2}O{sub 3} nanowires on iron substrate in thermal annealing method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, Himanshu, E-mail: himsri@rrcat.gov.in; Srivastava, A. K.; Babu, Mahendra

2016-06-28

A detail cross-sectional transmission electron microscopy of as-grown α-Fe{sub 2}O{sub 3} nanowire sample, synthesized on iron substrate by thermal annealing method, was carried out to understand the mechanism of growth in this system. Iron undergoes sequential oxidation to form a layered structure of Fe/FeO/Fe{sub 3}O{sub 4}/α-Fe{sub 2}O{sub 3}. α-Fe{sub 2}O{sub 3} nanowires grow on to the top of α-Fe{sub 2}O{sub 3} layer. It was found that subsequent oxide layers grow topotaxially on the grains of iron, which results in a direct orientation relationship between the α-Fe{sub 2}O{sub 3} nanowire and the parent grain of iron. The results also showed thatmore » the grains of α-Fe{sub 2}O{sub 3} layer, which were uniquely oriented in [110] direction, undergo highly anisotropic growth to form the nanowire. This anisotropic growth occurs at a twin interface, given by (−11−1), in the α-Fe{sub 2}O{sub 3} layer. It was concluded that the growth at twin interface could be the main driving factor for such anisotropic growth. These observations are not only helpful in understanding the growth mechanism of α-Fe{sub 2}O{sub 3} nanowires, but it also demonstrates a way of patterning the nanowires by controlling the texture of iron substrate.« less

Microanalysis of an oxidized cobalt oxide: Zirconia eutectic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bentley, J.; McKernan, S.; Carter, C.B.

The compositions of CoO, Co{sub 3}O{sub 4}, and Ca-stabilized cubic ZrO{sub 2} in an oxidized directionally solidified CoO-ZrO{sub 2} eutectic were determined by PEELS and EDS. An oxygen gradient exists across the Co{sub 3}O{sub 4} with highest levels near the ZrO{sub 2} interface. Oxygen ELNES for CoO and Co{sub 3}O{sub 4} are quite different; published oxygen ELNES have been incorrectly attributed to CoO. Normalized Co-L{sub 23} white line intensity (WLI) ratios for CoO and Co{sub 3}O{sub 4} are similar (0.53 {plus_minus} 0.02) but L{sub 3}/L{sub 2} WLI ratios are 3.88 and 2.58, respectively. ELCE data suggest Co{sub 3}O{sub 4} hasmore » the inverse spinel structure.« less

Enhancing photovoltaic performance of dye-sensitized solar cells by rare-earth doped oxide of SrAl{sub 2}O{sub 4}:Eu{sup 3+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lijun; Guo, Weihua; Liaoning Provincial College Key Laboratory of New Materials and Material Modification, Dalian Polytechnic University, Dalian 116034

2016-04-15

Graphical abstract: Current–voltage characteristics of DSSCs based on the photoanodes doping different SrAl{sub 2}O{sub 4}:Eu{sup 3+} and doping 3% SrAl{sub 2}O{sub 4}. - Highlights: • A down-conversion (DC) nanocrystal (SrAl{sub 2}O{sub 4}:Eu{sup 3+}) was synthesized. • The effect of SrAl{sub 2}O{sub 4}:Eu{sup 3+} doped in photoanode in DSSCs was investigated. • SrAl{sub 2}O{sub 4}:Eu{sup 3+} doped in photoanode appeared the better photovoltaic performances. • The dual function of DC and p-type doping effect were explained. - Abstract: SrAl{sub 2}O{sub 4}:Eu{sup 3+} down-conversion (DC) nanocrystals were synthesized by a sol–gel method and then doped in TiO{sub 2} as a photoanode inmore » dye-sensitized solar cells (DSSCs). Differential thermal analysis, fourier transform infrared spectroscopy, X-ray diffraction and Brunauer–Emmet–Teller analysis confirmed the formation of SrAl{sub 2}O{sub 4}:Eu{sup 3+} nanocrystals with diameters of ∼47 nm, pore size of ∼25 nm, sintering temperature of 1300 °C. The photoluminescence and UV–vis absorption spectra of the SrAl{sub 2}O{sub 4}:Eu{sup 3+} revealed a DC from ultraviolet light to visible light which matched the strong absorbing region of the N719 dye. The photoelectric conversion efficiency of the DSSCs with a TiO{sub 2} photoanode doped with 3 wt% SrAl{sub 2}O{sub 4}:Eu{sup 3+} was 20% higher than that with a pure TiO{sub 2} photoanode. This phenomenon could be mainly explained by SrAl{sub 2}O{sub 4}:Eu{sup 3+} nanocrystals’ ability of DC and increased the short-circuit current density. It could be minorly due to the p-type doping effect and slightly improved the open-circuit voltage.« less

Mössbauer study of metallic iron and iron oxide nanoparticles having environmental purifying ability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubuki, Shiro, E-mail: kubuki@tmu.ac.jp; Watanabe, Yuka, E-mail: kubuki@tmu.ac.jp; Akiyama, Kazuhiko, E-mail: kubuki@tmu.ac.jp

2014-10-27

A relationship between local structure and methylene blue (MB) decomposing ability of nanoparticles (NPs) of metallic iron (Fe{sup 0}) and maghemite (γ‐Fe{sub 2}O{sub 3}) was investigated by {sup 57}Fe Mössbauer spectroscopy, X-ray diffractometry and UV-visible light absorption spectroscopy. γ‐Fe{sub 2}O{sub 3} NPs were successfully prepared by mixing (NH{sub 4}){sub 2}Fe(SO{sub 4}){sub 2}⋅6H{sub 2}O (Mohr's salt) and (NH{sub 4}){sub 3}Fe(C{sub 2}O{sub 4}){sub 3}⋅3H{sub 2}O aqueous solution at 30 °C for 1 h, while those of Fe{sup 0} were obtained by the reduction of Mohr's salt with NaBH{sub 4}. From the Scherrer's equation, the smallest crystallite sizes of γ‐Fe{sub 2}O{sub 3} NPsmore » and Fe{sup 0} NPs were determined to be 9.7 and 1.5 nm, respectively. {sup 57}Fe Mössbauer spectrum of γ‐Fe{sub 2}O{sub 3} NPs consists of a relaxed sextet with isomer shift (δ) of 0.33{sub ±0.01} mm s{sup −1}, internal magnetic field (H{sub int}) of 25.8{sub ±0.5} T, and linewidth (Γ) of 0.62{sub ±0.04} mm s{sup −1}. {sup 57}Fe Mössbauer spectrum of Fe{sup 0} NP is mainly composed of a sextet having δ, Δ, and H{sub int} of 0.00{sub ±0.01} mm s{sup −1} 0.45{sub ±0.01} mm s{sup −1}, and 22.8{sub ±0.1} T, respectively. A bleaching test of the mixture of Fe{sup 0} and γ‐Fe{sub 2}O{sub 3} NPs (3:7 ratio, 100 mg) in MB aqueous solution (20 mL) for 6 h showed a remarkable decrease of MB concentration with the first-order rate constant (k{sub MB}) of 6.7 × 10{sup −1} h{sup −1}. This value is larger than that obtained for the bleaching test using bulk Fe{sup 0}+γ‐Fe{sub 2}O{sub 3} (3:7) mixture (k{sub MB} = 6.5×10{sup −3}h{sup −1}). These results prove that MB decomposing ability is enhanced by the NPs mixture of Fe{sub 0} and γ‐Fe{sub 2}O{sub 3}.« less

The structure, thermal expansion and phase transition properties of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0, 1.0, 2.0) solid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X.Z.; Hao, L.J.; Wu, M.M.

Graphical abstract: A polymorph with Gd{sub 2}Mo{sub 3}O{sub 12}-type structure (space group: Pba2) for negative thermal expansion material Ho{sub 2}Mo{sub 3}O{sub 12} is observed above 700 °C, this polymorphism could be effectively supressed by W-substiution for Mo, the give the temperature dependence of Pba2 phase contents for Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0.0, 1.0, 2.0). - Highlights: • The solid solution Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} was investigated by in situ X-ray diffraction. • It is found that the substitution slightly influence thermal expansion property. • A polymorph of Ho{sub 2}Mo{sub 3}O{sub 12} with Pba2 space group wasmore » observed above 700 °C. • The W-substitution for Mo effectively suppresses this transformation. - Abstract: Three solid solutions of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12}(x = 0, 1.0, 2.0) were prepared by solid state reaction method, the temperature dependent in-situ X-ray diffraction and thermal analysis were performed to investigate their structure and thermal expansion. All samples have orthorhombic structure(space group Pbcn# 60) with negative thermal expansion at the room temperature. the substitution of W for Mo enlarges the lattice constant and slightly influences the negative thermal expansion. An irreversible phase transformation to the Pba2 phase(Tb{sub 2}Mo{sub 3}O{sub 12} structure) was observed at high temperature for Mo-rich samples. This ploymorphism could be effectively suppressed by the W-substitution for Mo, this phenomenon could be explained by the lower electronegativity of W{sup 6+} than Mo{sup 6+}.« less

Method for synthesizing thin film electrodes

DOEpatents

Boyle, Timothy J [Albuquerque, NM

2007-03-13

A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

Synthesis and photoluminescence properties of Pb{sup 2+} doped inorganic borate phosphor NaSr{sub 4}(BO{sub 3}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chauhan, A. O., E-mail: abhi2718@gmail.com; Koparkar, K. A.; Omanwar, S. K.

2016-05-06

A series of Inorganic borate phosphors NaSr{sub 4}(BO{sub 3}){sub 3} doped with Pb{sup 2+} was successfully synthesized by modified solid state diffusion method. The crystal structure and the phase purity of sample were characterized by powder X-ray diffraction (XRD). The photoluminescence properties of synthesized materials were investigated using spectrofluorometer at room temperature. The phosphor show strong broad band emission spectra in UVA region maximum at 370 nm under the excitation of 289 nm. The dependence of the emission intensity on the Pb{sup 2+} concentration for the NaSr{sub 4}(BO{sub 3}){sub 3} were studied in details. The concentration quenching of Pb{sup 2+}more » doped NaSr{sub 4}(BO{sub 3}){sub 3} was observed at 0.02 mol. The Stokes shifts of NaSr{sub 4}(BO{sub 3}){sub 3}: Pb{sup 2+} phosphor was calculated to be 7574 cm{sup −1}.« less

Synthesis and characterization of novel barium iron phosphates: Insight into new structure types tailored by hydrogen atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Li-Zhi, E-mail: tslz2007@163.com; Sun, Wei, E-mail: 421221789@qq.com; Ren, Wei-Jian, E-mail: 935428502@qq.com

A significant gap in our knowledge of phosphate crystal chemistry is the lack of understanding of what controls the depolymerization of [PO{sub 4}] tetrahedra. A new route using phosphoric acid without any added water at 240 °C has been developed to synthesize two new compounds Ba{sub 2}Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{sub 7}){sub 2}] and Ba{sub 2}Fe[H(P{sub 2}O{sub 7}){sub 2}], as well as a new polymorph β-BaFe{sub 2}(P{sub 2}O{sub 7}){sub 2} from annealing the former at ≥500 °C. Structural characterizations show that Ba{sub 2}Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{sub 7}){sub 2}] features a novel 2D {sup 2}{sub ∞}([Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{submore » 7}){sub 2}

Interactions between Eu{sup 3+} ions in inorganic-organic hybrid materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pelle, Fabienne, E-mail: fabienne-pelle@chimie-paristech.f; Aschehoug, Patrick; Surble, Suzy

2010-04-15

The optical properties of two-dimensional lanthanide dicarboxylates EuBDC or Eu{sub 2}(H{sub 2}O){sub 2}(O{sub 2}C-C{sub 6}H{sub 4}-CO{sub 2}){sub 3} and EuCDC (denoted also MIL94) or Eu{sub 2}(H{sub 2}O){sub 4}(O{sub 2}C-C{sub 6}H{sub 10}-CO{sub 2}){sub 3}.2H{sub 2}O are reported. The structures are built up from dimers of corner-sharing polyhedra and 1,3-benzenedicarboxylate (BDC) for EuBDC and from dimers of edge-sharing polyhedra and 1,3-benzenedicarboxylate (CDC) for EuCDC. The high Eu{sup 3+} concentration and the weak luminescence quenching allow the study of Eu{sup 3+} interactions. Anti-Stokes spectra from {sup 5}D{sub 1} are observed with excitation in {sup 5}D{sub 0}. These results are very unusual for Eu{supmore » 3+} ions and reflect strong interactions between ions within a dimer. Excitation spectrum of the Eu{sup 3+} luminescence strongly differs in both compounds in the UV range. In case of EuBDC, an efficient sensitization of the luminescence due to the ligand is observed between 250 and 350 nm while only 4f-4f transitions are recorded on the Eu{sup 3+} excitation spectrum in EuCDC. The efficiency of the sensitization of the rare earth by the host is discussed by taking into account the geometrical arrangement and the electronic delocalization of the ligands. - Graphical abstract: Excitation spectra monitoring the {sup 5}D{sub 0}->{sup 7}F{sub 2} transition with a dimer structure.« less

Phase relations in the system Cu-Gd-O and Gibbs energy of formation of CuGd[sub 2]O[sub 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, K.T.; Mathews, T.; Hajra, J.P.

1993-07-01

The phase relations in the system Cu-Gd-O have been determined at 1,273 K by X-ray diffraction, optical microscopy, and electron microprobe analysis of samples equilibrated in quartz ampules and in pure oxygen. Only one ternary compound, CuGd[sub 2]O[sub 4], was found to be stable. The Gibbs free energy of formation of this compound has been measured using the solid-state cell Pt, Cu[sub 2]O + CuGd[sub 2]O[sub 4] + Gd[sub 2]O[sub 3]//(Y[sub 2]O[sub 3])ZrO[sub 2]//CuO + Cu[sub 2]O, Pt in the temperature range of 900 to 1,350 K. For the formation of CuGd[sub 2]O[sub 4] from its binary component oxides, CuOmore » (s) + Gd[sub 2]O[sub 3] (s) [r arrow] CuGd[sub 2]O[sub 4] (s) [Delta]G[degree] = 8230 - 11.2T([plus minus]50)J/mol. Since the formation is endothermic, CuGd[sub 2]O[sub 4] becomes thermodynamically unstable with respect to CuO and Gd[sub 2]O[sub 3] below 735 K. When the oxygen partial pressure over CuGd[sub 2]O[sub 4] is lowered, it decomposes according to the reaction 4CuGd[sub 2]O[sub 4] (s) [r arrow] 4Gd[sub 2]O[sub 3] (s) + 2Cu[sub 2]O (s) + O[sub 2] (g) for which the equilibrium oxygen potential is given by [Delta][mu][sub o][sub 2] = [minus]227,970 + 143.2T([plus minus]500)J/mol. An oxygen potential diagram for the system Cu-Gd-O at 1,273 is presented.« less

High pressure synthesis and magnetic studies of quasi one dimensional systems Sr{sub n-1} Cu{sub n+1} O{sub 2n} (n=3,5)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azuma, M.; Hiroi, Z.; Takano, M.

1994-12-31

SrCu{sub 2}O{sub 3} and Sr{sub 2}Cu{sub 3}O{sub 5} containing two-leg and three-leg S=1/2 ladders made of antiferromagnetic Cu-O-Cu linear bonds, respectively, were synthesized at high pressure, and their crystallographic and magnetic properties were investigated. Both susceptibility and T{sub 1} data of NMR revealed the existence of a large spin gap only for SrCu{sub 2}O{sub 3}. Superconductivity, which had been predicted theoretically for carrier-doped SrCu{sub 2}O{sub 3} could not be realized although partial substitution of La{sup 3+} for Sr{sup 2+} seemed to be carried out successfully. Electron carriers injected seems to remain localized.

Optical microcavities and enhanced electroluminescence from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickmott, T. W.

Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of Al-Al{sub 2}O{sub 3}-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of Al-Al{sub 2}O{sub 3}-Ag diodes with anodic Al{sub 2}O{sub 3} thicknesses between 12 nm and 30 nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0 eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0 eV, have been used to characterize EL. The voltagemore » threshold for EL with the LP filter, V{sub LP}, is ∼1.5 V. V{sub LP} is nearly independent of Al{sub 2}O{sub 3} thickness and of temperature and is 0.3–0.6 V less than the threshold voltage for EL for the SP filter, V{sub SP}. EL intensity is primarily between 1.8 and 3.0 eV when the bias voltage, V{sub S} ≲ 7 V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing V{sub S}, for diodes with the smallest Al{sub 2}O{sub 3} thicknesses, there is a maximum EL intensity, L{sub MX}, at a voltage, V{sub LMX}, followed by a decrease to a plateau. L{sub MX} and EL intensity at 4.0 V in the plateau region depend exponentially on Al{sub 2}O{sub 3} thickness. The ratio of L{sub MX} at 295 K for a diode with 12 nm of Al{sub 2}O{sub 3} to L{sub MX} for a diode with 25 nm of Al{sub 2}O{sub 3} is ∼140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ∼3 and ∼35; it depends on Al{sub 2}O{sub 3} thickness and V{sub S}. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and Al films to create surface plasmon polaritons (SPPs) at the metal-Al{sub 2}O{sub 3} interfaces. SPPs generate large electromagnetic fields in the filamentary region of the electroformed Al-Al{sub 2}O{sub 3}-Ag diode, which then acts as an optical microcavity. A model is proposed for electronic processes in electroformed Al-Al{sub 2}O{sub 3}-Ag diodes.« less

Crystal chemistry of KCuMn{sub 3}(VO{sub 4}){sub 3} in the context of detailed systematics of the alluaudite family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yakubovich, O. V., E-mail: yakubol@geol.msu.ru; Kiryukhina, G. V.; Dimitrova, O. V.

The crystal structure of new manganese potassium copper vanadate KCuMn{sub 3}(VO{sub 4}){sub 3}, which was prepared by the hydrothermal synthesis in the K{sub 2}CO{sub 3}–CuO–MnCl{sub 2}–V{sub 2}O{sub 5}–H{sub 2}O system, was studied by X-ray diffraction (R = 0.0355): a = 12.396(1) Å, b = 12.944(1) Å, c = 6.9786(5) Å, β = 112.723(1)°, sp. gr. C2/c, Z = 4, ρ{sub calc} = 3.938 g/cm{sup 3}. A comparative analysis of the crystal-chemical features of the new representative of the alluaudite family and related structures of minerals and synthetic phosphates, arsenates, and vanadates of the general formula A(1)A(1)′A(1)″A(2)A(2)′M(1)M(2){sub 2}(TO{sub 4}){sub 3} (wheremore » A are sites in the channels of the framework composed of MO{sub 6} octahedra and TO{sub 4} tetrahedra) was performed. A classification of these structures into subgroups according to the occupancy of A sites is suggested.« less

Thermochemical production of hydrogen

DOEpatents

Dreyfuss, Robert M.

1976-07-13

A thermochemical reaction cycle for the generation of hydrogen from water comprising the following sequence of reactions wherein M represents a metal and Z represents a metalloid selected from the arsenic-antimony-bismuth and selenium-tellurium subgroups of the periodic system: 2MO + Z + SO.sub.2 .fwdarw. MZ + MSO.sub.4 (1) mz + h.sub.2 so.sub.4 .fwdarw. mso.sub.4 + h.sub.2 z (2) 2mso.sub.4 .fwdarw. 2mo + so.sub.2 + so.sub.3 + 1/20.sub.2 (3) h.sub.2 z .fwdarw. z + h.sub.2 (4) h.sub.2 o + so.sub.3 .fwdarw. h.sub.2 so.sub.4 (5) the net reaction is the decomposition of water into hydrogen and oxygen.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yingjie, E-mail: yzx@ansto.gov.au; Bhadbhade, Mohan; Karatchevtseva, Inna

Three new coordination polymers of uranium(VI) with pyromellitic acid (H{sub 4}btca) have been synthesized and structurally characterized. (ED)[(UO{sub 2})(btca)]·(DMSO)·3H{sub 2}O (1) (ED=ethylenediammonium; DMSO=dimethylsulfoxide) has a lamellar structure with intercalation of ED and DMSO. (NH{sub 4}){sub 2}[(UO{sub 2}){sub 6}O{sub 2}(OH){sub 6}(btca)]·~6H{sub 2}O (2) has a 3D framework built from 7-fold coordinated uranyl trinuclear units and btca ligands with 1D diamond-shaped channels (~8.5 Å×~8.6 Å). [(UO{sub 2}){sub 2}(H{sub 2}O)(btca)]·4H{sub 2}O (3) has a 3D network constructed by two types of 7-fold coordinated uranium polyhedron. The unique μ{sub 5}-coordination mode of btca in 3 enables the formation of 1D olive-shaped large channels (~4.5more » Å×~19 Å). Vibrational modes, thermal stabilities and fluorescence properties have been investigated. - Graphical abstract: Table of content: three new uranium(VI) coordination polymers with pyromellitic acid (H{sub 4}btca) have been synthesized via room temperature and hydrothermal synthesis methods, and structurally characterized. Two to three dimensional (3D) frameworks are revealed. All 3D frameworks have unique 1D large channels. Their vibrational modes, thermal stabilities and photoluminescence properties have been investigated. - Highlights: • Three new coordination polymers of U(VI) with pyromellitic acid (H{sub 4}btca). • Structures from a 2D layer to 3D frameworks with unique 1D channels. • Unusual µ{sub 5}-(η{sub 1}:η{sub 2}:η{sub 1}:η{sub 2:}η{sub 1}) coordination mode of btca ligand. • Vibrational modes, thermal stabilities and luminescent properties reported.« less

Study on the adsorption properties of O{sub 3}, SO{sub 2}, and SO{sub 3} on B-doped graphene using DFT calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rad, Ali Shokuhi, E-mail: a.shokuhi@gmail.com; Shabestari, Sahand Sadeghi; Mohseni, Soheil

2016-05-15

We investigated the structure, adsorption, electronic states, and charge transfer of O{sub 3}, SO{sub 2} and SO{sub 3} molecules on the surface of a B-doped graphene using density functional theory (DFT). We found weak physisorption of SO{sub 2} (−10.9 kJ/mole, using B3LYP-D) and SO{sub 3} (−15.7 kJ/mole, using B3LYP-D) on the surface of B-doped graphene while there is strong chemisorption for O{sub 3} (−96.3 kJ/mole, using B3LYP-D ) on this surface. Our results suggest the potential of B-doped graphene as a selective sensor/adsorbent for O{sub 3} molecule. We noticed some change in hybridizing of boron from sp{sup 2} to sp{supmore » 3} upon adsorption of O{sub 3} which cases transformation of the adsorbent from 2D to 3D. - Graphical abstract: The electronic property of B-doped graphene is responsible to highly adsorption of O{sub 3} molecules while the adsorption of SO{sub 2} and SO{sub 3} molecules on this surface exhibits only a weak interaction. - Highlights: • B-doped graphene clearly is n-type semiconductor. • High negatively charge of C-atoms neighboring the boron dopant. • Chemisorption of O{sub 3} and physisorption of SO{sub 2} and SO{sub 3} on the surface of B-doped graphene.« less

Ce{sub 2}PdIn{sub 8}, Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19}—members of homological series based on AuCu{sub 3}- and PtHg{sub 2}-type structural units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tursina, A.; Nesterenko, S.; Seropegin, Y.

Crystal structures of three members of a unique homological series with the general formula Ce{sub m}Pd{sub n}In{sub 3m+2n} based on the AuCu{sub 3} and PtHg{sub 2} structure types were studied by single-crystal X-ray diffraction. The compounds crystallize with space group P4/mmm (Z=1) and the lattice parameters: a=4.6900(9) Å, c=12.185(6) Å for Ce{sub 2}PdIn{sub 8}, a=4.6846(8) Å, c=16.846(8) Å for Ce{sub 3}PdIn{sub 11}, and a=4.70120(10) Å, c=29.1359(4) Å for Ce{sub 5}Pd{sub 2}In{sub 19}. The crystal structures of Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} represent new types. The three structures constitute of [CeIn{sub 3}] cuboctahedra layers and [PdIn{sub 2}] rectangularmore » polyhedra layers, alternating along the tetragonal c-axis in accordance with the m:n proportion. The magnetic and electrical transport properties of the novel compounds Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} were investigated down to 1.72 K. Both indides are Curie–Weiss paramagnets due to the presence of fairly well localized 4f electrons of trivalent cerium ions. The electrical resistivity of both materials is dominated over an extended temperature range by strong spin–flip Kondo interactions with the characteristic temperature scale of 20–30 K. - Graphical abstract: TOC Figure Crystal structures of Ce{sub 3}PdIn{sub 11}, Ce{sub 2}PdIn{sub 8}, and Ce{sub 5}Pd{sub 2}In{sub 19}. Highlights: ► Large section of Ce–Pd–In phase diagram was examined. ► Three distinct ternary phases were identified, two of them for the first time. ► Crystal structures of two novel compounds constitute new structure types. ► The determined crystal structures show close mutual relationship. ► Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} are paramagnetic Kondo lattices.« less

Magnetocaloric effect in gadolinium-oxalate framework Gd{sub 2}(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 6}⋅(0{sub ⋅}6H{sub 2}O)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sibille, Romain, E-mail: rom.sibille@gmail.com; Didelot, Emilie; Mazet, Thomas

2014-12-01

Magnetic refrigerants incorporating Gd{sup 3+} ions and light organic ligands offer a good balance between isolation of the magnetic centers and their density. We synthesized the framework material Gd{sub 2}(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 6}⋅0.6H{sub 2}O by a hydrothermal route and characterized its structure. The honeycomb lattice of Gd{sup 3+} ions interlinked by oxalate ligands in the (a,c) plane ensures their decoupling in terms of magnetic exchange interactions. This is corroborated by magnetic measurements indicating negligible interactions between the Gd{sup 3+} ions in this material. The magnetocaloric effect was evaluated from isothermal magnetization measurements. The maximum entropy change −ΔS{sub M}{supmore » max} reaches 75.9 mJ cm{sup −3} K{sup −1} (around 2 K) for a moderate field change (2 T)« less

The new silver borate Ag{sub 3}B{sub 5}O{sub 9}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sohr, Gerhard; Falkowski, Viktoria; Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.at

2015-05-15

Single crystals of Ag{sub 3}B{sub 5}O{sub 9} were obtained via high-pressure synthesis at 3 GPa and 600 °C, using a Walker-type multianvil high-pressure device. Ag{sub 3}B{sub 5}O{sub 9} crystalizes with a=674.7(2), b=943.5(2), c=1103.5(2) pm, V=0.7025(2) nm{sup 3}, and Z=4 in the noncentrosymmetric space group P2{sub 1}2{sub 1}2{sub 1} (no. 19). The orthorhombic structure was refined from 3740 independent reflections with R1=0.0496 and wR2=0.587 (all data). It is built up from infinite corner-sharing chains of BO{sub 4} tetrahedra along the a axis, which are interconnected by BO{sub 3} groups to form a network. In the structure, three crystallographically independent sites aremore » occupied with Ag{sup +} cations exhibiting argentophillic interactions. The synthetic conditions as well as the results of the single crystal structure analysis are presented. - Graphical abstract: Noncentrosymmetric silver borate: During investigations in the system Ag–B–O, a new noncentrosymmetric silver borate Ag{sub 3}B{sub 5}O{sub 9} was discovered. The new structure type is built up from corner-sharing BO{sub 3} and BO{sub 4} groups, forming a network. Argentophillic interactions are clearly indicated by the Ag{sup +}⋯Ag{sup +} distances present in the structure. - Highlights: • A noncentrosymmetric borate Ag{sub 3}B{sub 5}O{sub 9} is accessible via high-pressure synthesis. • Ag{sub 3}B{sub 5}O{sub 9} is the second high-pressure silver borate. • Ag{sup +}⋯Ag{sup +} distances in Ag3B5O9 clearly indicate the presence of argentophillic interactions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, T.R.

The cyclo-addition of two Mo/sub 2/Cl/sub 4/(P(C/sub 6/H/sub 5/)/sub 3/)/sub 2/(CH/sub 3/OH)/sub 2/ molecules has produced a new type of tetrameric molybdenum cluster, Mo/sub 4/Cl/sub 8/L/sub 4/. Structural characterization of this dimer revealed weak molybdenum-methanol bonding which was consistent with the observed reactivity of the compound. New synthetic methods were devised for the preparation of Mo/sub 4/X/sub 8/L/sub 4/ clusters where X = Cl, Br, I, and L = PR/sub 3/, PO/sub 3/, RCN, CH/sub 3/OH. A scheme for the metal-metal bonding in these clusters was presented which was in agreement with the known structural features of Mo/sub 4/Cl/sub 8/(PR/submore » 3/)/sub 4/, R = C/sub 2/H/sub 5/, n-C/sub 4/H/sub 9/. The preparation of the analogous W/sub 4/Cl/sub 8/(PR/sub 3/)/sub 4/ cluster from WCl/sub 4/ was accomplished by application of techniques used in the molybdenum syntheses. The single crystal x-ray structure revealed slight differences from the molybdenum analog which were rationalized in terms of the known behavior in dimeric tungsten and molybdenum species. The attempted preparation of a tetrameric tungsten cluster from W/sub 2/(mhp)/sub 4/ was unsuccessful (mhp = anion of 2-methyl-6-hydroxypyridine). Instead, the new tungsten dimer, W/sub 2/Cl/sub 2/(mhp)/sub 3/, was isolated which possessed a metal-metal bond order of 3.5. The x-ray crystal structure of the dimer revealed that the chlorine atoms was situated cis, one bound to each tungsten. Cyclic voltammetry showed that the compound could be reversibly reduced, presumably to a W/sub 2//sup 4 +/ dimer containing a quadruple metal-metal bond.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, T.R.

The cyclo-addition of two Mo/sub 2/Cl/sub 4/(P(C/sub 6/H/sub 5/)/sub 3/)/sub 2/(CH/sub 3/OH)/sub 2/ molecules has produced a new type of tetrameric molybdenum cluster, Mo/sub 4/Cl/sub 8/L/sub 4/. Structural characterization of this dimer revealed weak molybdenum-methanol bonding which was consistent with the observed reactivity of the compound. New synthetic methods were devised for the preparation of Mo/sub 4/X/sub 8/L/sub 4/ clusters where X = Cl, Br, I and L = PR/sub 3/, Po/sub 3/, RCN, CH/sub 3/OH. A scheme for the metal-metal bonding in these clusters was presented which was in agreement with the known structural features of Mo/sub 4/Cl/sub 8/(PR/submore » 3/)/sub 4/, R = C/sub 2/H/sub 5/, n-C/sub 4/H/sub 9/. The preparation of the analogous W/sub 4/Cl/sub 8/(PR/sub 3/)/sub 4/ cluster from WCl/sub 4/ was accomplished by application of techniques used in the molybdenum syntheses. The single crystal x-ray structure revealed slight differences from the molybdenum analog which were rationalized in terms of the known behavior in dimeric tungsten and molybdenum species. The attempted preparation of a tetrameric tungsten cluster from W/sub 2/(mhp)/sub 4/ was unsuccessful (mhp = anion of 2-methyl-6-hydroxypyridine). Instead, the new tungsten dimer, W/sub 2/Cl/sub 2/(mhp)/sub 3/, was isolated which possessed a metal-metal bond order of 3.5. The x-ray crystal structure of the dimer revealed that the chlorine atoms were situated cis, one bound to each tungsten. Cyclic voltammetry showed that the compound could be reversibly reduced, presumably to a W/sub 2//sup 4 +/ dimer containing a quadruple metal-metal bond.« less

Solid-state {sup 27}Al and {sup 29}Si NMR characterization of hydrates formed in calcium aluminate-silica fume mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pena, P.; Rivas Mercury, J.M.; Aza, A.H. de

2008-08-15

Partially deuterated Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub y}(OH){sub 12-4y}-Al(OH){sub 3} mixtures, prepared by hydration of Ca{sub 3}Al{sub 2}O{sub 6} (C{sub 3}A), Ca{sub 12}Al{sub 14}O{sub 33} (C{sub 12}A{sub 7}) and CaAl{sub 2}O{sub 4} (CA) phases in the presence of silica fume, have been characterized by {sup 29}Si and {sup 27}Al magic-angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies. NMR spectroscopy was used to characterize anhydrous and fully hydrated samples. In hydrated compounds, Ca{sub 3}Al{sub 2}(OH){sub 12} and Al(OH){sub 3} phases were detected. From the quantitative analysis of {sup 27}Al NMR signals, the Al(OH){sub 3}/Ca{sub 3}Al{sub 2}(OH){sub 12} ratio was deduced. The incorporation of Simore » into the katoite structure, Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub 3-x}(OH){sub 4x}, was followed by {sup 27}Al and {sup 29}Si NMR spectroscopies. Si/OH ratios were determined from the quantitative analysis of {sup 27}Al MAS-NMR components associated with Al(OH){sub 6} and Al(OSi)(OH){sub 5} environments. The {sup 29}Si NMR spectroscopy was also used to quantify the unreacted silica and amorphous calcium aluminosilicate hydrates formed, C-S-H and C-A-S-H for short. From {sup 29}Si NMR spectra, the amount of Si incorporated into different phases was estimated. Si and Al concentrations, deduced by NMR, transmission electron microscopy, energy dispersive spectrometry, and Rietveld analysis of both X-ray and neutron data, indicate that only a part of available Si is incorporated in katoite structures. - Graphical abstract: Transmission electron micrograph of CaAl{sub 2}O{sub 4}-microsilica mixture hydrated at 90 deg. C for 31 days showing a cubic Ca{sub 3}Al{sub 2.0{+-}}{sub 0.2}(SiO{sub 4}){sub 0.9{+-}}{sub 0.2}(OH){sub 1.8} crystal surrounded by unreacted amorphous silica spheres.« less

Dynamics and fragmentation of van der Waals and hydrogen bonded cluster cations: (NH{sub 3}){sub n} and (NH{sub 3}BH{sub 3}){sub n} ionized at 10.51 eV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Bing; Bernstein, Elliot R., E-mail: erb@Colostate.edu; Shin, Joong-Won

A 118 nm laser is employed as a high energy, single photon (10.51 eV/photon) source for study of the dynamics and fragmentation of the ammonia borane (NH{sub 3}BH{sub 3}) cation and its cluster ions through time of flight mass spectrometry. The behavior of ammonia ion and its cluster ions is also investigated under identical conditions in order to explicate the ammonia borane results. Charge distributions, molecular orbitals, and spin densities for (NH{sub 3}BH{sub 3}){sub n} and its cations are explored at both the second-order perturbation theory (MP2) and complete active space self-consistent field (CASSCF) theory levels. Initial dissociation mechanisms andmore » potential energy surfaces for ionized NH{sub 3}BH{sub 3}, NH{sub 3}, and their clusters are calculated at the MP2/6-311++G(d,p) level. Protonated clusters (NH{sub 3}){sub x}H{sup +} dominate ammonia cluster mass spectra: our calculations show that formation of (NH{sub 3}){sub n−1}H{sup +} and NH{sub 2} from the nascent (NH{sub 3}){sub n}{sup +} has the lowest energy barrier for the system. The only common features for the (NH{sub 3}){sub n}{sup +} and (NH{sub 3}BH{sub 3}){sub n}{sup +} mass spectra under these conditions are found to be NH{sub y}{sup +} (y = 0,…,4) at m/z = 14–18. Molecular ions with both {sup 11}B and {sup 10}B isotopes are observed, and therefore, product ions observed for the (NH{sub 3}BH{sub 3}){sub n} cluster system derive from (NH{sub 3}BH{sub 3}){sub n} clusters themselves, not from the NH{sub 3} moiety of NH{sub 3}BH{sub 3} alone. NH{sub 3}BH{sub 2}{sup +} is the most abundant ionization product in the (NH{sub 3}BH{sub 3}){sub n}{sup +} cluster spectra: calculations support that for NH{sub 3}BH{sub 3}{sup +}, an H atom is lost from the BH{sub 3} moiety with an energy barrier of 0.67 eV. For (NH{sub 3}BH{sub 3}){sub 2}{sup +} and (NH{sub 3}BH{sub 3}){sub 3}{sup +} clusters, a B{sup δ+}⋯H{sup δ−}⋯{sup δ−}H⋯{sup δ+}B bond can form in the respective cluster ions, generating a lower energy, more stable ion structure. The first step in the (NH{sub 3}BH{sub 3}){sub n}{sup +} (n = 2, 3) dissociation is the breaking of the B{sup δ+}⋯H{sup δ−}⋯{sup δ−}H⋯{sup δ+}B moiety, leading to the subsequent release of H{sub 2} from the latter cluster ion. The overall reaction mechanisms calculated are best represented and understood employing a CASSCF natural bond orbital description of the valence electron distribution for the various clusters and monomers. Comparison of the present results with those found for solid NH{sub 3}BH{sub 3} suggests that NH{sub 3}BH{sub 3} can be a good hydrogen storage material.« less

Simple analysis of atmospheric NO{sub 2}, SO{sub 2}, and O{sub 3} in mountains by using passive samplers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Etsu; Kimura, Mitsuo; Tomozawa, Kenichi

1999-12-01

A simple analysis of atmospheric NO{sub 2}, SO{sub 2}, and O{sub 3} in mountains by passive samplers was investigated and applied to the spatial analysis of air pollutants at Mt. Hiei in Kyoto City, Passive samplers were exposed for 30 days. Yanagisawa-type samplers were used for NO{sub 2} determination. The absorbed NO{sub 2} was measured as nitrite ion spectro-photometrically by the Saltzman method. On the other hand, SO{sub 2} samplers comprising an absorbent filter containing sodium carbonate solution were made. The absorbed SO{sub 2} was oxidized to SO{sub 4}{sup 2{minus}} with an H{sub 2}O{sub 2} solution and determined by ionmore » chromatography. For O{sub 3} determination, Ogawa ozone samplers were used. The O{sub 3} reacted with nitrite ion to produce nitrate ion, which was measured by ion chromatography. The relative standard deviations for NO{sub 2}, SO{sub 2}, and O{sub 3} samplers were 1.4%, 3--10%, and 2--5%, respectively. Samplers were set up in 13 locations at Mt. Hiei. The NO{sub 2} concentration and its distribution along the slope of Mt. Hiei changed considerably both daily and seasonally. The seasonal variation of atmospheric NO{sub 2} showed a winter maximum and a summer minimum. The concentration of atmospheric SO{sub 2} at Mt. Hiei was lower than that of NO{sub 2} and scarcely changed. Atmospheric O{sub 3} increased gradually with an increase of the altitude, exhibiting a regular pattern with a maximum in spring and a minimum in winter.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yan; Pan, Cheng-Ling; Xiao, Li-Na

Three new supramolecular compounds based on triethylenediamine and different polyoxometalates [W{sup VI}{sub 3}V{sup V}{sub 3}O{sub 19}H]{l_brace}[Cu(HDABCO)]{sub 2}(H{sub 2}O){r_brace} (1), [P{sub 2}Mo{sup VI}{sub 18}O{sub 62}][HDABCO]{sub 2}[H{sub 2}DABCO]{sub 2}.12 H{sub 2}O (2) and [Mo{sup VI}{sub 7.5}W{sup VI}{sub 0.5}O{sub 27}][Cu(HDABCO)]{sub 2}.2 H{sub 3}O.2 H{sub 2}O (3) (DABCO=triethylenediamine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compound 1 exhibits a face-centered cubic packing motif, compound 2 displays a supramolecular structure constructed form the 'chains' arranged hexagonally, compound 3 contains [Mo{sub 7.5}W{sub 0.5}O{sub 27}]{sub {infinity}} chain decorated by [Cu(HDABCO)]{sup 2+} cations, which was thenmore » packed into a layer structure. These results show that the same organonitrogen combining with the different POMs will yield different supramolecular networks. -- Graphical abstract: Three new supramolecular compounds based on triethylenediamine and different polyoxometalates have been hydrothermally synthesized and characterized by IR, XPS, TG, elemental analysis and X-ray diffraction analysis.« less

Chloro-, methyl-, and (tetrahydroborato)tris((hexamethyldisilyl)amido)thorium(IV) and -uranium(IV). Crystal structure of (tetrahydroborato)tris((hexamethyldisilyl)amido)thorium(IV)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, H.W.; Andersen, R.A.; Zalkin, A.

1979-05-01

Reaction of sodium (hexamethyldisilyl)amide with thorium tetrachloride or uranium tetrachloride yields chlorotris-((hexamethyldisilyl)amido)thorium(IV) or -uranium(IV), respectively. The chloroamides of thorium or uranium react with dimethylmagnesium or methyllithium yielding the methyl derivatives MeTh(N(SiMe/sub 3/)/sub 2/)/sub 3/ or MeU(N(SiMe/sub 3/)/sub 2/)/sub 3/, respectively. The chloro compounds yield BH/sub 4/M(N(SiMe/sub 3/)/sub 2/)/sub 3/ upon reaction with lithium tetrahydroborate, where M is thorium or uranium. Infrared spectra of the tetrahydroborate derivatives suggest that BH/sub 4/ is bonded in a tridentate fashion in both compounds, the metal atoms being six-coordinate. Single-crystal X-ray analysis of the thorium borohydride confirms the infrared result. The white BH/sub 4/Th(N(Si(CH/sub 3/))/submore » 2/)/sub 3/ crystals are rhombohedral with cell dimensions a/sub r/ = 11.137 A and ..cap alpha../sub r/ = 113.61/sup 0/; the triply primitive hexagonal cell has a/sub h/ = 18.640 (3) A c/sub h/ = 8.604 (1) A, V = 2489 A/sup 3/, Z = 3, and D/sub x/ = 1.40 g/cm/sup 3/, space group R3m. The structure was refined by full-matrix least squares to a conventional R factor of 0.031 for 1014 data. The Th atom is on a threefold axis 2.32 A from three nitrogen atoms and 2.61 A from the boron atom, a distance which represents a triple bridge bond between Th and B. The three (dimethylsilyl)amide ligands are disordered by a mirror plane parallel to the threefold axis. CH/sub 3/Th(N(Si(CH/sub 3/)/sub 3/)/sub 2/)/sub 3/ is isomorphous with BH/sub 4/Th(N(Si(CH/sub 3/)/sub 3/)/sub 2/)/sub 3/ with cell dimensions a/sub h/ = 18.68 (1) A and c/sub h/ = 8.537 (6) A. The diffraction data yielded integral'' = 12.16 +- 0.33 e for the imaginary scattering term for Th with Cu K..cap alpha.. radiation.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Na; Huang, Rudan, E-mail: huangrd@bit.edu.cn

Six new inorganic–organic hybrids based on rigid triangular N-containing ligands, NaCu{sup I}{sub 2}(tib){sub 4}(H{sub 2}O){sub 4}[H{sub 2}PW{sup V}W{sup VI}{sub 11}O{sub 40}][H{sub 2}PW{sup VI}{sub 12}O{sub 40}]·6H{sub 2}O (1), Cu{sup II}{sub 3}(tib){sub 4}Cl{sub 4}[H{sub 2}PW{sup VI}{sub 12}O{sub 40}]{sub 2}·4H{sub 2}O (2), Co(tib){sub 2}[PW{sup V}{sub 3}W{sup VI}{sub 9}O{sub 38}]·5H{sub 2}O (3), Cu{sup II}{sub 3}(tib){sub 2}[P{sub 2}Mo{sup VI}{sub 5}O{sub 22}(O{sub 2})]·4H{sub 2}O (4), Mn(pytpy){sub 2}Mo{sup VI}{sub 4}O{sub 13} (5) and Co(pytpy){sub 2}Mo{sup VI}{sub 4}O{sub 13} (6) (tib=1,3,5-tris(1-imidazolyl)benzene, pytpy=4’-(4”-pyridyl)2,4’:6’,4”-terpyridine), have been hydrothermally synthesized. Single crystal X-ray diffraction studies revealed that compounds 1–4 display two-dimensional (2D) layered structures, and in compounds 1–3, the adjacent Keggin anionsmore » link with each other by W–O–W covalent interactions to form 1D inorganic chains. Compounds 5–6 are 3D “pillar-layer” frameworks based on bimetal–oxide layers pillared by the pytpy ligands. The compounds have been characterized by elemental analysis, powder X−ray diffraction, X-ray photoelectron spectroscopy and thermo gravimetric analyses. Moreover, the electrochemical and catalytic properties of compound 1 have been investigated as well. - Graphical abstract: Six new inorganic–organic hybrids based on rigid triangular N-containing ligands have been obtained under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1–4 display two-dimensional (2D) layers structure, and in compounds 1–3, the adjacent Keggin anions link with each other by W–O–W covalent interactions to form 1D inorganic Keggin anions chains. Compounds 5–6 are 3D “pillar-layer” frameworks based on bimetal–oxide layers pillared by the pytpy ligands. - Highlights: • MOFs based on POMs have been prepared. • Six new compounds based on rigid triangular N-containing ligands. • The adjacent POMs only share the oxygen atom to form a 1D inorganic Keggin chains.« less

Syntheses, structures and selective dye adsorption of five formic-based coordination polymers prepared by in-situ hydrolysis of N, N′-dimethylformamide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Zheng; Meng, Xiang-min; Zhang, Dong-mei

Five functional coordination polymers (formic-based CPs) namely: ([Cu{sub 2}(CHOO){sub 3}(bibp){sub 2}]·CHOO){sub n} (1), ([Co{sub 2}(CHOO){sub 3}(bibp){sub 2}]·NO{sub 3}·H{sub 2}O)n (2), ([Ni{sub 2}(CHOO){sub 3}(bibp){sub 2}]·NO{sub 3}·H{sub 2}O){sub n} (3) [Co(CHOO){sub 2}(bbibp)]{sub n} (4) and [Zn(CHOO){sub 2}(bbibp)]{sub n} (5) (bibp=4,4′-bis(imidazolyl)biphenyl, bbibp=4,4′-bis(benzoimidazo-1-yl)biphenyl) have been successfully hydrothermally synthesized using the in-situ hydrolysis of N, N′-dimethylformamide (DMF) as the source of formate. All of these five polymers were characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complexes 1–3 have the similar three-dimensional 3D kag topological framework built from the bibp ligand as the support member betweenmore » the neighboring formic planes. Both complexes 4 and 5 have the similar one-dimensional 1D linear chain which is further assembled into 3D supermolecular structure by C–H…O hydrogen bonds. The dyes adsorption experiments have also been investigated systematically. The results show that complexes 2 and 3 exhibit high selective adsorption ability towards anionic dyes in their aqueous solution. Moreover, complex 2 displays good reversibility in the process of the dyes adsorption-release. Meanwhile, the unusual blocking phenomenon was firstly observed when complex 2 was in MO/OIV aqueous solutions with different concentration.« less

Structure, microstructure and infrared studies of Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3}-NaNbO{sub 3} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Sumit K., E-mail: sumit.sxc13@gmail.com; Singh, S. N., E-mail: snsphyru@gmail.com; Prasad, K., E-mail: k.prasad65@gmail.com

2016-05-06

Lead-free solid solutions (1-x)Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3}-xNaNbO{sub 3} (0 ≤ x ≤ 1.0) were prepared by conventional ceramic fabrication technique. X-ray diffraction and Rietveld refinement analyses of these ceramics were carried out using X’Pert HighScore Plus software to determine the crystal symmetry, space group and unit cell dimensions. Rietveld refinement revealed that NaNbO{sub 3} with orthorhombic structure was completely diffused into Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3} lattice having the rhombohedral-tetragonal symmetry. EDS and SEM studies were carried out in order to evaluate the quality and purity of the compounds. SEM images showed a change in grain shapemore » with the increase of NaNbO{sub 3} content. FTIR spectra confirmed the formation of solid solution.« less

Erbium-doped borosilicate glasses containing various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3}: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin; Massera, Jonathan; BioMediTech, Tampere

2015-10-15

Highlights: • Er{sup 3+} doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site. • An increase in the SiO{sub 2} content decreases the Er{sup 3+} absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO{sub 2} exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO{sub 2}. - Abstract: The influence of the silica contentmore » on several properties of Er-doped borosilicate glasses in the presence of various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} has been investigated. The introduction of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO{sub 4} and AlO{sub 4} groups or through the formation of AlPO{sub 4}-like structural units. In this paper, we show that an increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site, resulting in an increased dependence of the Er{sup 3+} ions optical and luminescence properties on the P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO{sub 2}.« less

Room temperature syntheses, crystal structures and properties of two new heterometallic polymers based on 3-ethoxy-2-hydroxybenzaldehyde ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shu-Hua, E-mail: zsh720108@163.com; Zhao, Ru-Xiao; Li, Gui

Two new heterometallic coordination polymers [ZnNa(ehbd){sub 2}(N{sub 3})]{sub n} (1) and [Cu{sub 3}Na{sub 2}(ehbd){sub 2}(N{sub 3}){sub 6}]{sub n} (2) (Hehbd is 3-ethoxy-2-hydroxybenzaldehyde) have been synthesized under room temperature and structurally characterized by elemental analysis, IR, UV, TG and single crystal X-ray diffraction. Complex 1 crystallizes in the orthorhombic space group Pbca, showing a one-dimensional (1-D) chain. Complex 2 crystallizes in the triclinic space group Pī, constructing a heterometallic 2D layer structure. Luminescent properties and magnetic properties have been studied for 1 and 2, respectively and the fluorescence quantum yield of 1 is 0.077. - Highlights: • Two novel complexes 1more » and 2 have been synthesized. • Complex 1 represents a novel qualitative change of luminescence property. • Complex 2 displays ferromagnetic interaction through symmetric μ{sub 1,1}–N{sub 3} bridges. • Complex 2 displays anti-ferromagnetic interaction through asymmetric μ{sub 1,1}–N{sub 3} bridges.« less

Y{sub 2}O{sub 3}:Yb/Er nanotubes: Layer-by-layer assembly on carbon-nanotube templates and their upconversion luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Weishi; Shen, Jianfeng; Wan, Lei

2012-11-15

Graphical abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer assembly on carbon nanotubes templates followed by a subsequent heat treatment process. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm. Display Omitted Highlights: ► Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized. ► CNTs were used as templates for Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► LBL assembly and calcination were used for preparation of Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► The as-preparedmore » Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission. -- Abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer (LBL) assembly on carbon nanotubes (CNTs) templates followed by a subsequent heat treatment process. The crystal structure, element analysis, morphology and upconversion luminescence properties were characterized. XRD results demonstrate that the diffraction peaks of the samples calcinated at 800 °C or above can be indexed to the pure cubic phase of Y{sub 2}O{sub 3}. SEM images indicate that a large quantity of uniform and rough nanotubes with diameters of about 30–60 nm can be observed. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm, which have potential applications in such fields as nanoscale devices, molecular catalysts, nanobiotechnology, photonics and optoelectronics.« less

Microwave dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12}-Al{sub 2}O{sub 3} composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, Mohd Fariz Ab; Abu, Mohamad Johari; Zaman, Rosyaini Afindi

2016-07-19

(1-x)CaCu{sub 3}Ti{sub 4}O{sub 12} + (x)Al{sub 2}O{sub 3} composite (0 ≤ x ≤0.25) was prepared via conventional solid-state reaction method. The fabrication of sample was started with synthesizing stoichiometric CCTO from CaCO{sub 3}, CuO and TiO{sub 2} powders, then wet-mixed in deionized water for 24 h. The process was continued with calcined CCTO powder at 900 °C for 12 h before sintered at 1040 °C for 10 h. Next, the calcined CCTO powder with different amount of Al{sub 2}O{sub 3} were mixed for 24 h, then palletized and sintered at 1040 °C for 10. X-ray diffraction analysis on the sinteredmore » samples showed that CCTO powder was in a single phase, meanwhile the trace of secondary peaks which belong to CaAl{sub 2}O{sub 4} and Corundum (Al{sub 2}O{sub 3}) could be observed in the other samples Scanning electron microscopy analysis showed that the grain size of the sample is firstly increased with addition of Al{sub 2}O{sub 3} (x = 0.01), then become smaller with the x > 0.01. Microwave dielectric properties showed that the addition of Al{sub 2}O{sub 3} (x = 0.01) was remarkably reduced the dielectric loss while slightly increased the dielectric permittivity. However, further addition of Al{sub 2}O{sub 3} was reduced both dielectric loss and permittivity at least for an order of magnitude.« less

Rate constants for CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H and CF{sub 3}H + H {r_arrow} CF{sub 3} + H{sub 2} reactions in the temperature range 1100--1600 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hranisavljevic, J.; Michael, J.V.

1998-09-24

The shock tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reactions (1) CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H and (2) CF{sub 3}H + H {r_arrow} CF{sub 3} + H{sub 2} over the temperature ranges 1168--1673 K and 1111--1550 K, respectively. The results can be represented by the Arrhenius expressions k{sub 1} = 2.56 {times} 10{sup {minus}11} exp({minus}8549K/T) and k{sub 2} = 6.13 {times} 10{sup {minus}11} exp({minus}7364K/T), both in cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. Equilibrium constants were calculated from the two Arrhenius expressions in the overlapping temperature range, andmore » good agreement was obtained with the literature values. The rate constants for reaction 2 were converted into rate constants for reaction 1 using literature equilibrium constants. These data are indistinguishable from direct k{sub 1} measurements, and an Arrhenius fit for the joint set is k{sub 1} = 1.88 {times} 10{sup {minus}11} exp({minus}8185K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. The CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H reaction was further modeled using conventional transition-state theory, which included ab initio electronic structure determinations of reactants, transition state, and products.« less

Suppression of activation energy and superconductivity by the addition of Al{sub 2}O{sub 3} nanoparticles in CuTl-1223 matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jabbar, Abdul; Qasim, Irfan; Mumtaz, M.

2014-05-28

Low anisotropic (Cu{sub 0.5}Tl{sub 0.5})Ba{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10−δ} (CuTl-1223) high T{sub c} superconducting matrix was synthesized by solid-state reaction and Al{sub 2}O{sub 3} nanoparticles were prepared separately by co-precipitation method. Al{sub 2}O{sub 3} nanoparticles were added with different concentrations during the final sintering cycle of CuTl-1223 superconducting matrix to get the required (Al{sub 2}O{sub 3}){sub y}/CuTl-1223, y = 0.0, 0.5, 0.7, 1.0, and 1.5 wt. %, composites. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray, and dc-resistivity (ρ) measurements. The activation energy and superconductivity were suppressed with increasing concentration of Al{sub 2}O{sub 3} nanoparticles in (CuTl-1223) matrix.more » The XRD analysis showed that the addition of Al{sub 2}O{sub 3} nanoparticles did not affect the crystal structure of the parent CuTl-1223 superconducting phase. The suppression of activation energy and superconducting properties is most probably due to weak flux pinning in the samples. The possible reason of weak flux pinning is reduction of weak links and enhanced inter-grain coupling due to the presence of Al{sub 2}O{sub 3} nanoparticles at the grain boundaries. The presence of Al{sub 2}O{sub 3} nanoparticles at the grain boundaries possibly reduced the number of flux pinning centers, which were present in the form of weak links in the pure CuTl-1223 superconducting matrix. The increase in the values of inter-grain coupling (α) deduced from the fluctuation induced conductivity analysis with the increased concentration of Al{sub 2}O{sub 3} nanoparticles is a theoretical evidence of improved inter-grain coupling.« less

Chemical dynamics simulations of the monohydrated OH{sup −}(H{sub 2}O) + CH{sub 3}I reaction. Atomic-level mechanisms and comparison with experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Jing; Hase, William L., E-mail: bill.hase@ttu.edu; Otto, Rico

2015-06-28

Direct dynamics simulations, with B97-1/ECP/d theory, were performed to study the role of microsolvation for the OH{sup −}(H{sub 2}O) + CH{sub 3}I reaction. The S{sub N}2 reaction dominates at all reactant collision energies, but at higher collision energies proton transfer to form CH{sub 2}I{sup −}, and to a lesser extent CH{sub 2}I{sup −} (H{sub 2}O), becomes important. The S{sub N}2 reaction occurs by direct rebound and stripping mechanisms, and 28 different indirect atomistic mechanisms, with the latter dominating. Important components of the indirect mechanisms are the roundabout and formation of S{sub N}2 and proton transfer pre-reaction complexes and intermediates, includingmore » [CH{sub 3}--I--OH]{sup −}. In contrast, for the unsolvated OH{sup −} + CH{sub 3}I S{sub N}2 reaction, there are only seven indirect atomistic mechanisms and the direct mechanisms dominate. Overall, the simulation results for the OH{sup −}(H{sub 2}O) + CH{sub 3}I S{sub N}2 reaction are in good agreement with experiment with respect to reaction rate constant, product branching ratio, etc. Differences between simulation and experiment are present for the S{sub N}2 velocity scattering angle at high collision energies and the proton transfer probability at low collision energies. Equilibrium solvation by the H{sub 2}O molecule is unimportant. The S{sub N}2 reaction is dominated by events in which H{sub 2}O leaves the reactive system as CH{sub 3}OH is formed or before CH{sub 3}OH formation. Formation of solvated products is unimportant and participation of the (H{sub 2}O)CH{sub 3}OH---I{sup −} post-reaction complex for the S{sub N}2 reaction is negligible.« less

Unsaturated Mn complex decorated hybrid thioarsenates: Syntheses, crystal structures and physical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Cheng-Yang; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Lei, Xiao-Wu, E-mail: xwlei_jnu@163.com

2016-03-15

The incorporation of unsaturated [Mn(1,2-dap)]{sup 2+}, [Mn(1,2-dap){sub 2}]{sup 2+}, [Mn(2,2-bipy)]{sup 2+} (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As{sup III}S{sub 3}]{sup 3−} and [As{sup V}S{sub 4}]{sup 3−} led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} (1), [Mn(1,2-dap){sub 2}]{[Mn(1,2-dap)]_2As_2S_8} (2) and (NH{sub 4})[Mn(2,2-bipy){sub 2}]AsS{sub 4} (3). In compound 1, the unsaturated [Mn(1,2-dap)]{sup 2+} complexes, [MnS{sub 4}]{sup 6−} tetrahedra and [As{sup III}S{sub 3}]{sup 3−} trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)]{sup 2+} and [Mn(1,2-dap){sub 2}]{sup 2+} complexes as well as [As{sup V}S{sub 4}]{sup 3−}more » tetrahedral units. For compound 3, two [As{sup V}S{sub 4}]{sup 3−} anions bridge two [Mn(2,2-bipy)]{sup 2+} complex cations into a butterfly like {[Mn(2,2-bipy)]_2As_2S_8}{sup 2−} anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3. The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. - Highlights: Three new hybrid manganese thioarsenates have been prepared and structurally characterized. These hybrid phases feature interesting magnetic and visible light responding photocatalytic properties.« less

Structural variation from heterometallic cluster-based 1D chain to heterometallic tetranuclear cluster: Syntheses, structures and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shu-Hua, E-mail: zsh720108@163.com; Zhao, Ru-Xia; Li, He-Ping

Using the solvothermal method, we present the comparative preparation of ([Co{sub 3}Na(dmaep){sub 3}(ehbd)(N{sub 3}){sub 3}]·DMF){sub n} (1) and [Co{sub 2}Na{sub 2}(hmbd){sub 4}(N{sub 3}){sub 2}(DMF){sub 2}] (2), where Hehbd is 3-ethoxy-2-hydroxy-benzaldehyde, Hhmbd is 3-methoxy-2-hydroxy-benzaldehyde, and Hdmaep is 2-dimethylaminomethyl-6-ethoxy-phenol, which was synthesized by an in-situ reaction. Complexes 1 and 2 were characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Complex 1 is a novel heterometallic cluster-based 1-D chain and 2 is a heterometallic tetranuclear cluster. The (Co{sub 3}{sup II}Na) and (Co{sub 2}{sup II}Na{sub 2}) cores display dominant ferromagnetic interaction from the nature of the binding modes through μ{sub 1,1,1}-N{sub 3}{supmore » –} (end-on, EO). - Graphical abstract: Two novel cobalt complexes have been prepared. Compound 1 consists of tetranuclear (Co{sub 3}{sup II}Na) units, which further formed a 1-D chain. Compound 2 is heterometallic tetranuclear cluster. Two complexes display dominant ferromagnetic interaction. - Highlights: • Two new heterometallic complexes have been synthesized by solvothermal method. • The stereospecific blockade of the ligands in the synthesis system seems to be the most important synthetic parameter. • The magnetism studies show that 1 and 2 exhibit ferromagnetic interactions. • Complex 1 shows slowing down of magnetization and not blocking of magnetization.« less

Facile synthesis of α-Fe{sub 2}O{sub 3} nanoparticles for high-performance CO gas sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuong, Nguyen Duc, E-mail: nguyenduccuong@hueuni.edu.vn; Faculty of Hospitality and Tourism, Hue University, 22 Lam Hoang, Vy Da Ward, Hue City; Khieu, Dinh Quang

2015-08-15

Highlights: • We have demonstrated a facile method to prepare Fe{sub 2}O{sub 3} nanoparticles. • The gas sensing properties of α-Fe{sub 2}O{sub 3} have been invested. • The results show potential application of α-Fe{sub 2}O{sub 3} NPs for CO sensors in environmental monitoring. - Abstract: Iron oxide nanoparticles (NPs) were prepared via a simple hydrothermal method for high performance CO gas sensor. The synthesized α-Fe{sub 2}O{sub 3} NPs were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The SEM, TEM results revealedmore » that obtained α-Fe{sub 2}O{sub 3} particles had a peanut-like geometry with hemispherical ends. The response of the α-Fe{sub 2}O{sub 3} NPs based sensor to carbon monoxide (CO) and various concentrations of other gases were measured at different temperatures. It found that the sensor based on the peanut-like α-Fe{sub 2}O{sub 3} NPs exhibited high response, fast response–recovery, and good selectivity to CO at 300 °C. The experimental results clearly demonstrated the potential application of α-Fe{sub 2}O{sub 3} NPs as a good sensing material in the fabrication of CO sensor.« less

A solid solution series of atacamite type Ni{sub 2x}Mg{sub 2−2x}Cl(OH){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bette, Sebastian; Dinnebier, Robert E.; Röder, Christian

2015-08-15

For the first time a complete solid solution series Ni{sub 2x}Mg{sub 2−2x}Cl(OH){sub 3} of an atacamite type alkaline main group metal chloride, Mg{sub 2}Cl(OH){sub 3}, and a transition group metal chloride, Ni{sub 2}Cl(OH){sub 3}, was prepared and characterized by chemical and thermal analysis as well as by Raman and IR spectroscopy, and high resolution laboratory X-ray powder diffraction. All members of the solid solution series crystallize in space group Pnam (62). The main building units of these crystal structures are distorted, edge-linked Ni/MgO{sub 4}Cl{sub 2} and Ni/MgO{sub 5}Cl octahedra. The distribution of Ni{sup 2+}- and Mg{sup 2+}-ions among these twomore » metal-sites within the solid solution series is discussed in detail. The crystallization of the solid solution phases occurs via an intermediate solid solution series, (Ni/Mg)Cl{sub 2x}(OH){sub 2−2x}, with variable Cl: OH ratio up to the 1:3 ratio according to the formula Ni{sub 2x}Mg{sub 2−2x} Cl(OH){sub 3}. For one isolated intermediate solid solution member, Ni{sub 0.70}Mg{sub 0.30}Cl{sub 0.58}(OH){sub 1.42}, the formation and crystal structure is presented as well. - Graphical abstract: For the first time a complete solid solution series, Ni{sub 2x}Mg{sub 2−2x} Cl(OH){sub 3}, was synthesized and characterized. Structure solution by revealed that Ni{sup 2+} prefers to occupy the Jahn–Teller-like distorted hole, out of two available cation sites. Substitution of Ni{sup 2+} by Mg{sup 2+} in atacamite type Ni{sub 2}Cl(OH){sub 3} results in systematic band shifts in Raman and IR spectra as well as in systematic changes in thermal properties. The α-polymorphs M{sub 2}Cl(OH){sub 3} with M=Mg{sup 2+}, Ni{sup 2+} and other divalent transition metal ions, as described in literature, were identified as separate compounds. - Highlights: • First synthesis of solid solution series between main and transition metal chloride. • Ni{sup 2+} prefers to occupy Jahn–Teller-like distorted octahedral holes. • Substitution of Ni{sup 2+} by Mg{sup 2+} results in systematic Raman and IR band shifts. • α-Polymorphs M{sub 2}Cl(OH){sub 3} with M=Mg{sup 2+}, Ni{sup 2+}, … as described in literature do not exist.« less

Effect of carbonate and phosphate ratios on the transformation of calcium orthophosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eliassi, Mohammad Daoud, E-mail: eliassi2007@gmail.com; Zhao, Wei; Tan, Wen Feng, E-mail: wenfeng.tan@hotmail.com

2014-07-01

Graphical abstract: Complexes among phosphate, carbonate and calcium have been prepared via a facile hydrothermal route. The synthesized product at the low (0.15) and the high (1.8) molar ratio of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} is calcium phosphate hydrate and hydroxylapatite (HAp), respectively. Molar ratios of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} are effective on the reduction of carbonate activity during the crystallization of HAp. - Highlights: • Formation of different complexes from CO{sub 3}{sup 2−}, PO{sub 4}{sup 3−} and Ca{sup 2+} solutions at 60 °C. • Molar ratios of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2} cause changes in phase and sizemore » of synthesized products. • Addition of PO{sub 4}{sup 3} inhibited the activity of CO{sub 3}{sup 2−} during bound with Ca{sup 2+}. • The phase transformation was completed, when CO{sub 3}{sup 2−} peaks disappeared in FTIR. • PO{sub 4}{sup 3−}, CO{sub 3}{sup 2−} and Ca{sup 2+} distributed heterogeneously on the surface of precipitation. - Abstract: Complexes among phosphate, carbonate and calcium have been synthesized by a designed hydrothermal method. Effects of carbonate and phosphate ratios on the transformation of calcium-orthophosphates were investigated. With X-ray diffraction measurement the synthesized product at the low (0.15) and the high (1.8) molar ratio of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} is calcium phosphate hydrate at pH 9.0, and hydroxylapatite (HAp) at pH 8.0, respectively. Fourier transform infrared spectroscopy of product at the high ratio (1.8) of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} shows that the CO{sub 3}{sup 2−} peaks disappear, and the strong peaks at 1412 and 1460 cm{sup −1} are assigned to the vibrations of PO{sub 4}{sup 3−} in HAp. {sup 31}P nuclear magnetic resonance spectra of products at the low (0.15–0.6) to the high (1.2–1.8) ratios of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} are obtained at 2.9 and 2.7 ppm, respectively. Molar ratios of PO{sub 4}{sup 3−}/CO{sub 3}{sup 2−} are effective on the reduction of carbonate activity during the formation and infiltration events of calcium-phosphate surface precipitates, and are subsequently enclosed during HAp formation.« less

Probing the limit of magnesium uptake by β-tricalcium phosphate in biphasic mixtures formed from calcium deficient apatites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, P. Nandha; Mishra, Sandeep K.; Kannan, S., E-mail: para_kanna@yahoo.com

2015-11-15

A series of magnesium doped non-stoichiometric calcium deficient apatites were synthesized through an aqueous precipitation route. The resultant structural changes during heat treatment were investigated by X-ray diffraction, Raman and FT-IR spectroscopy and Rietveld refinement. The results confirmed the formation of biphasic mixtures comprising Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and β-Ca{sub 3}(PO{sub 4}){sub 2} after heat treatment at 1000 °C with the preferential occupancy of Mg{sup 2+} at the crystal lattice of β-Ca{sub 3}(PO{sub 4}){sub 2}. The concentration of Mg{sup 2+} uptake in β-Ca{sub 3}(PO{sub 4}){sub 2} is limited till reaching the stoichiometric ratio of (Ca+Mg)/P=1.67 and beyond this stoichiometricmore » value [(Ca+Mg)/P>1.67], Mg{sup 2+} precipitates as Mg(OH){sub 2} and thereafter gets converted to MgO during heat treatment. Any kind of Mg{sup 2+} uptake in the crystal lattice of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} is discarded from the investigation. - Highlights: • Aqueous co-precipitation of calcium deficient apatites with excess magnesium (Mg{sup 2+}) additions. • Heat treatments beyond 800 °C results in the formation of biphasic apatite mixtures. • Mg{sup 2+} gets accommodated at the β-Ca{sub 3}(PO{sub 4}){sub 2} lattice of biphasic mixtures. • Mg{sup 2+} additions exceeding stoichiometric value (Ca/P>1.67) results in its formation as MgO. • Mg{sup 2+} occupancy at β-Ca{sub 3}(PO{sub 4}){sub 2} lattice delays its allotropic conversion α-Ca{sub 3}(PO{sub 4}){sub 2} till 1350 °C.« less

Effects of electrolytes and surfactants on the morphology and stability of advanced silver nano-materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obaid, Abdullah Yousif; AL-Thabaiti, Shaeel Ahmed; El-Mossalamy, E.H.

2013-03-15

Highlights: ► Stoichiometric ratio of S{sub 2}O{sub 3}{sup 2−} and Ag{sup +} ions are responsible to the formation of prefect transparent yellow colored silver sol. ► Higher S{sub 2}O{sub 3}{sup 2−} concentrations has damping effect. ► Head group of the surfactants and nature of the electrolytes have significant effect on the stability of silver nanoparticles. - Abstract: The impact of electrolytes, stabilizing and/or capping agents on morphology of colloidal silver nano-materials (AgNPs) has been studied spectroscopically. Sodium thiosulfate acts as reducing-, stabilizing- and damping-agents. Stoichiometric ratios of S{sub 2}O{sub 3}{sup 2−} and Ag{sup +} ions were responsible to the formationmore » stable and prefect transparent dark yellow colored AgNPs. The S{sub 2}O{sub 3}{sup 2−}-stabilized AgNPs were significantly more stable in inorganic electrolytes (NaNO{sub 3}, Na{sub 2}SO{sub 4}, Na{sub 2}CO{sub 3} and KBr). S{sub 2}O{sub 3}{sup 2−} is adsorbed more strongly than the used other anions. The addition of cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) has significant effects on the absorbance of S{sub 2}O{sub 3}{sup 2−}-stabilized AgNPs which can be rationalized in terms of electrostatic attraction and repulsion between the adsorbed S{sub 2}O{sub 3}{sup 2−} ions on to the surface of AgNPs and cationic and/or anionic head groups of used surfactants, respectively. Transmission electron microscopy images suggest that AgNPs are polydispersed, spherical and exhibiting an interesting irregular morphology.« less

Method of depositing buffer layers on biaxially textured metal substrates

DOEpatents

Beach, David B.; Morrell, Jonathan S.; Paranthaman, Mariappan; Chirayil, Thomas; Specht, Eliot D.; Goyal, Amit

2002-08-27

A laminate article comprises a substrate and a biaxially textured (RE.sup.1.sub.x RE.sup.2.sub.(1-x)).sub.2 O.sub.3 buffer layer over the substrate, wherein 0

Laminate articles on biaxially textured metal substrates

DOEpatents

Beach, David B.; Morrell, Jonathan S.; Paranthaman, Mariappan; Chirayil, Thomas; Specht, Eliot D.; Goyal, Amit

2003-12-16

A laminate article comprises a substrate and a biaxially textured (RE.sup.1.sub.x RE.sup.2.sub.(1-x)).sub.2 O.sub.3 buffer layer over the substrate, wherein 0