Mechanism of hydrodenitrogenation on phosphides and sulfides.

PubMed

Oyama, S Ted; Lee, Yong-Kul

2005-02-17

The mechanism of hydrodenitrogenation (HDN) of 2-methylpiperidine was studied over a silica-supported nickel phosphide catalyst (Ni2P/SiO2, Ni/P = 1/2) and a commercial Ni-Mo-S/Al2O3 catalyst in a three-phase trickle-bed reactor operated at 3.1 MPa and 450-600 K. Analysis of the product distribution as a function of contact time indicated that the reaction proceeded in both cases predominantly by a substitution mechanism, with a smaller contribution of an elimination mechanism. Fourier transform infrared spectroscopy (FTIR) of the 2-methylpiperidine indicated that at reaction conditions a piperidinium ion intermediate was formed on both the sulfide and the phosphide. It is concluded that the mechanism of HDN on nickel phosphide is very similar to that on sulfides. The mechanism on the nickel phosphide was also probed by comparing the reactivity of piperidine and several of its derivatives in the presence of 3000 ppm S. The relative elimination rates depended on the structure of the molecules, and followed the sequence: 4-methylpiperidine approximately piperidine > 3-methylpiperidine > 2,6-dimethylpiperidine > 2-methylpiperidine. [Chemical structure: see text] This order of reactivity was not dependent on the number of alpha-H or beta-H atoms in the molecules, ruling out their reaction through a single, simple mechanism. It is likely that the unhindered piperidine molecules reacted by an S(N)2 substitution process and the more hindered 2,6-dimethylpiperidine reacted by an E2 elimination process.

One-Step Facile Synthesis of Cobalt Phosphides for Hydrogen Evolution Reaction Catalysts in Acidic and Alkaline Medium.

PubMed

Sumboja, Afriyanti; An, Tao; Goh, Hai Yang; Lübke, Mechthild; Howard, Dougal Peter; Xu, Yijie; Handoko, Albertus Denny; Zong, Yun; Liu, Zhaolin

2018-05-09

Catalysts for hydrogen evolution reaction are in demand to realize the efficient conversion of hydrogen via water electrolysis. In this work, cobalt phosphides were prepared using a one-step, scalable, and direct gas-solid phosphidation of commercially available cobalt salts. It was found that the effectiveness of the phosphidation reaction was closely related to the state of cobalt precursors at the reaction temperature. For instance, a high yield of cobalt phosphides obtained from the phosphidation of cobalt(II) acetate was related to the good stability of cobalt salt at the phosphidation temperature. On the other hand, easily oxidizable salts (e.g., cobalt(II) acetylacetonate) tended to produce a low amount of cobalt phosphides and a large content of metallic cobalt. The as-synthesized cobalt phosphides were in nanostructures with large catalytic surface areas. The catalyst prepared from phosphidation of cobalt(II) acetate exhibited an improved catalytic activity as compared to its counterpart derived from phosphidation of cobalt(II) acetylacetonate, showing an overpotential of 160 and 175 mV in acidic and alkaline electrolytes, respectively. Both catalysts also displayed an enhanced long-term stability, especially in the alkaline electrolyte. This study illustrates the direct phosphidation behavior of cobalt salts, which serve as a good vantage point in realizing the large-scale synthesis of transition-metal phosphides for high-performance electrocatalysts.

Intentional fatal metallic phosphide poisoning in a dog--a case report.

PubMed

Nagy, Andras-Laszlo; Bolfa, Pompei; Mihaiu, Marian; Catoi, Cornel; Oros, Adrian; Taulescu, Marian; Tabaran, Flaviu

2015-07-23

Metallic phosphides are extremely toxic pesticides that are regulated in their usage. Information concerning the impact of metallic phosphides on human health is abundant. Data regarding the clinical pathology of phosphide poisoning in humans or domestic and wild animals is largely incomplete with only a few cases of metallic phosphide poisoning being reported every year, especially in humans. For the majority of cases reported in dogs the data are vague or incomplete. Here we report a complete and detailed description of pathological changes in a case of intentional metallic phosphide poisoning in a dog including an exhaustive examination of the brain. A 1 year old, male, Belgian Shepherd crossbreed dog with a clean medical history and no observed clinical signs prior to death, was submitted for post mortem examination. The dog was found dead by the owner. Near the body a suspect mix of bread, fat and a blackish powder was found. The owner announced the authorities and submitted the animal and the possible bait for forensic examination. At necropsy, multisystemic necrotic and degenerative lesions were observed. Histological exam confirmed the presence of necrotic and degenerative lesions of variable severity in all of the examined organs. The toxicological forensic examination revealed the presence of the phosphine gas in the gastric content and the bait. Metallic phosphide poisoning is a rarely reported entity, since the diagnosis of intentional poisoning with these compounds is a great challenge for forensic pathologists and toxicologists. To our knowledge, this is the first study describing the lesions completely in veterinary forensic toxicology. We assume that the toxic shows systemic endotheliotropism and damage of the endothelial cells responsible for the hemorrhagic lesions and for the secondary ischemic necrosis in various organs. This report will contribute to a better understanding of the pathogenesis in cases of acute metallic phosphide exposure in

Responses of Siberian ferrets to secondary zinc phosphide poisoning

USGS Publications Warehouse

Hill, E.F.; Carpenter, J.W.

1982-01-01

The hazard of operational-type applications of zinc phosphide (Zn3P2) on a species closely related to the black-footed ferret (Mustela nigripes), was evaluated by feeding 16 Siberian ferrets (M. eversmanni) rats that had been killed by consumption of 2% zinc phosphide treated bait or by an oral dose of 40, 80, or 160 mg of Zn3P2. All ferrets accepted rats and a single emesis by each of 3 ferrets was the only evidence of acute intoxication. All ferrets learned to avoid eating gastrointestinal tracts of the rats. Subacute zinc phosphide toxicity in the ferrets was indicated by significant decreases (18-48%) in hemoglobin, increases of 35-91 % in serum iron, and elevated levels of serum globulin, cholesterol, and triglycerides. Hemoglobin/iron, urea nitrogen/creatinine, and albumin/globulin ratios also were altered by the treatments. This study demonstrated that Siberian ferrets, or other species with a sensitive emetic reflex, are afforded a degree of protection from acute zinc phosphide poisoning due to its emetic action. The importance of toxicity associated with possible respiratory, liver, and kidney damage indicated by altered blood chemistries is not known.

Optimal design study of high efficiency indium phosphide space solar cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.; Flood, Dennis J.

1990-01-01

Recently indium phosphide solar cells have achieved beginning of life AMO efficiencies in excess of 19 pct. at 25 C. The high efficiency prospects along with superb radiation tolerance make indium phosphide a leading material for space power requirements. To achieve cost effectiveness, practical cell efficiencies have to be raised to near theoretical limits and thin film indium phosphide cells need to be developed. The optimal design study is described of high efficiency indium phosphide solar cells for space power applications using the PC-1D computer program. It is shown that cells with efficiencies over 22 pct. AMO at 25 C could be fabricated by achieving proper material and process parameters. It is observed that further improvements in cell material and process parameters could lead to experimental cell efficiencies near theoretical limits. The effect of various emitter and base parameters on cell performance was studied.

Influence of tellurite on lifetime for samarium doped lanthanum lead borate glass

NASA Astrophysics Data System (ADS)

Madhu, A.; Eraiah, B.

2018-04-01

Samarium substituted tellurium lanthanum lead borate glass is prepared using melt quenching technique. Luminescence spectra have been recorded upon excitation with 402 nm various transitions from 4G5/2 level, for samarium doped tellurite glasses are studied and also lifetime for all the samples exhibit single exponential behaviour of decay curve. Luminescence spectra of present glasses show quenching effect due to cross-relation channels of samarium ions. The lifetime of glass samples decrease as the tellurite concentration is decreased. So, it evidences that to attain longer lifetime for lasing material one can tune the host by selecting concentration of tellurite.

Thin boron phosphide coating as a corrosion-resistant layer

DOEpatents

Not Available

1982-08-25

A surface prone to corrosion in corrosive environments is rendered anticorrosive by CVD growing a thin continuous film, e.g., having no detectable pinholes, thereon, of boron phosphide. In one embodiment, the film is semiconductive. In another aspect, the invention is an improved photoanode, and/or photoelectrochemical cell with a photoanode having a thin film of boron phosphide thereon rendering it anticorrosive, and providing it with unexpectedly improved photoresponsive properties.

Samarium-145 and its use as a radiation source

DOEpatents

Fairchild, Ralph G.; Laster, Brenda H.; Packer, Samuel

1989-09-05

The present invention covers a new radiation source, samarium-145, with radiation energies slightly above those of I-125 and a half-life of 340 days. The samarium-145 source is produced by neutron irradiation of SM-144. This new source is useful as the implanted radiation source in photon activation therapy of malignant tumors to activate the stable I-127 contained in the IdUrd accumulated in the tumor, causing radiation sensitization and Auger cascades that irreperably damage the tumor cells. This new source is also useful as a brachytherapy source.

Samarium-145 and its use as a radiation source

DOEpatents

Fairchild, Ralph G.; Laster, Brenda H.; Packer, Samuel

1989-01-01

The present invention covers a new radiation source, samarium-145, with radiation energies slightly above those of I-125 and a half-life of 340 days. The samarium-145 source is produced by neutron irradiation of SM-144. This new source is useful as the implanted radiation source in photon activation therapy of malignant tumors to activate the stable I-127 contained in the IdUrd accumulated in the tumor, causing radiation sensitization and Auger cascades that irreperably damage the tumor cells. This new source is also useful as a brachytherapy source.

Gallium phosphide nanowires as a substrate for cultured neurons.

PubMed

Hällström, Waldemar; Mårtensson, Thomas; Prinz, Christelle; Gustavsson, Per; Montelius, Lars; Samuelson, Lars; Kanje, Martin

2007-10-01

Dissociated sensory neurons were cultured on epitaxial gallium phosphide (GaP) nanowires grown vertically from a gallium phosphide surface. Substrates covered by 2.5 microm long, 50 nm wide nanowires supported cell adhesion and axonal outgrowth. Cell survival was better on nanowire substrates than on planar control substrates. The cells interacted closely with the nanostructures, and cells penetrated by hundreds of wires were observed as well as wire bending due to forces exerted by the cells.

Boron Arsenide and Boron Phosphide for High Temperature and Luminescent Devices. [semiconductor devices - crystal growth/crystal structure

NASA Technical Reports Server (NTRS)

Chu, T. L.

1975-01-01

The crystal growth of boron arsenide and boron phosphide in the form of bulk crystals and epitaxial layers on suitable substrates is discussed. The physical, chemical, and electrical properties of the crystals and epitaxial layers are examined. Bulk crystals of boron arsenide were prepared by the chemical transport technique, and their carrier concentration and Hall mobility were measured. The growth of boron arsenide crystals from high temperature solutions was attempted without success. Bulk crystals of boron phosphide were also prepared by chemical transport and solution growth techniques. Techniques required for the fabrication of boron phosphide devices such as junction shaping, diffusion, and contact formation were investigated. Alloying techniques were developed for the formation of low-resistance ohmic contacts to boron phosphide. Four types of boron phosphide devices were fabricated: (1) metal-insulator-boron phosphide structures, (2) Schottky barriers; (3) boron phosphide-silicon carbide heterojunctions; and (4) p-n homojunctions. Easily visible red electroluminescence was observed from both epitaxial and solution grown p-n junctions.

Porous Cobalt Phosphide Polyhedrons with Iron Doping as an Efficient Bifunctional Electrocatalyst.

PubMed

Li, Feng; Bu, Yunfei; Lv, Zijian; Mahmood, Javeed; Han, Gao-Feng; Ahmad, Ishfaq; Kim, Guntae; Zhong, Qin; Baek, Jong-Beom

2017-10-01

Iron (Fe)-doped porous cobalt phosphide polyhedrons are designed and synthesized as an efficient bifunctional electrocatalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The synthesis strategy involves one-step route for doping foreign metallic element and forming porous cobalt phosphide polyhedrons. With varying doping levels of Fe, the optimized Fe-doped porous cobalt phosphide polyhedron exhibits significantly enhanced HER and OER performances, including low onset overpotentials, large current densities, as well as small Tafel slopes and good electrochemical stability during HER and OER. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Indium phosphide nanowires and their applications in optoelectronic devices

PubMed Central

Zafar, Fateen

2016-01-01

Group IIIA phosphide nanocrystalline semiconductors are of great interest among the important inorganic materials because of their large direct band gaps and fundamental physical properties. Their physical properties are exploited for various potential applications in high-speed digital circuits, microwave and optoelectronic devices. Compared to II–VI and I–VII semiconductors, the IIIA phosphides have a high degree of covalent bonding, a less ionic character and larger exciton diameters. In the present review, the work done on synthesis of III–V indium phosphide (InP) nanowires (NWs) using vapour- and solution-phase approaches has been discussed. Doping and core–shell structure formation of InP NWs and their sensitization using higher band gap semiconductor quantum dots is also reported. In the later section of this review, InP NW-polymer hybrid material is highlighted in view of its application as photodiodes. Lastly, a summary and several different perspectives on the use of InP NWs are discussed. PMID:27118920

Indium phosphide nanowires and their applications in optoelectronic devices.

PubMed

Zafar, Fateen; Iqbal, Azhar

2016-03-01

Group IIIA phosphide nanocrystalline semiconductors are of great interest among the important inorganic materials because of their large direct band gaps and fundamental physical properties. Their physical properties are exploited for various potential applications in high-speed digital circuits, microwave and optoelectronic devices. Compared to II-VI and I-VII semiconductors, the IIIA phosphides have a high degree of covalent bonding, a less ionic character and larger exciton diameters. In the present review, the work done on synthesis of III-V indium phosphide (InP) nanowires (NWs) using vapour- and solution-phase approaches has been discussed. Doping and core-shell structure formation of InP NWs and their sensitization using higher band gap semiconductor quantum dots is also reported. In the later section of this review, InP NW-polymer hybrid material is highlighted in view of its application as photodiodes. Lastly, a summary and several different perspectives on the use of InP NWs are discussed.

Synthesis and catalytic activity of the metastable phase of gold phosphide

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

Fernando, Deshani; Nigro, Toni A.E.; Dyer, I.D.

Recently, transition metal phosphides have found new applications as catalysts for the hydrogen evolution reaction that has generated an impetus to synthesize these materials at the nanoscale. In this work, Au{sub 2}P{sub 3} was synthesized utilizing the high temperature decomposition of tri-n-octylphosphine as a source of elemental phosphorous. Gold nanorods were used as morphological templates with the aim of controlling the shape and size of the resulting gold phosphide particles. We demonstrate that the surface capping ligand of the gold nanoparticle precursors can influence the purity and extent to which the gold phosphide phase will form. Gold nanorods functionalized withmore » 1-dodecanethiol undergo digestive ripening to produce discrete spherical particles that exhibit reduced reactivity towards phosphorous, resulting in low yields of the gold phosphide. In contrast, gold phosphide was obtained as a phase pure product when cetyltrimethylammonium bromide functionalized gold nanorods are used instead. The Au{sub 2}P{sub 3} nanoparticles exhibited higher activity than polycrystalline gold towards the hydrogen evolution reaction. - Graphical abstract: Au{sub 2}P{sub 3} was synthesized utilizing the high temperature decomposition of tri-n-octylphosphine as a source of elemental phosphorous and gold nanoparticles as reactants. We demonstrate that the surface capping ligand of the gold nanoparticle precursors influence the purity and extent to which the Au{sub 2}P{sub 3} phase will form. Gold nanorods functionalized with 1-dodecanethiol undergo digestive ripening to produce discrete spherical particles that exhibit reduced reactivity towards phosphorous, resulting in low yields of the gold phosphide. In contrast, gold phosphide was obtained as a phase pure product when cetyltrimethylammonium bromide functionalized gold nanoparticles are used instead. The Au{sub 2}P{sub 3} nanoparticles exhibited higher activity than polycrystalline gold towards the hydrogen

Adverse Events in the Long-Term Follow-Up of Patients Treated With Samarium Sm 153 Lexidronam for Osseous Metastases

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

Paravati, Anthony J., E-mail: Anthony.J.Paravati@dartmouth.edu; Russo, Andrea L.; Aitken, Candice

Purpose: To investigate adverse events after samarium Sm 153 lexidronam and the effect of pre- and post-samarium Sm 153 lexidronam external beam radiation therapy (EBRT) and/or chemotherapy on myelosuppression in patients who received samarium Sm 153 lexidronam for osseous metastases. Methods and Materials: We performed a single-institution retrospective review of 139 patients treated with samarium Sm 153 lexidronam between November 1997 and February 2008. New-onset adverse events after samarium Sm 153 lexidronam were reported. The effect of samarium Sm 153 lexidronam on platelet and peripheral white blood cell counts and the duration of myelosuppression after samarium Sm 153 lexidronam plusmore » EBRT and/or chemotherapy were calculated. Differences in the prevalence of adverse events among patients with varying treatment histories were evaluated with the Pearson chi-square test. Results: Hematologic follow-up was available for 103 patients. Chemotherapy and/or EBRT had no effect on the magnitude or duration of myelosuppression. The most common nonhematologic adverse events were acute lower extremity edema (n = 27) and acute and transient neuropathy (n = 29). Patients treated with chemotherapy after samarium Sm 153 lexidronam had a higher prevalence of lower extremity edema (9 of 18 [50%]) than those who were not treated with chemotherapy after samarium Sm 153 lexidronam (18 of 85 [21.2%]) (p = 0.01, chi-square test). No adverse events were correlated with EBRT. Conclusions: Our observation of new-onset, acute and transient edema and neuropathy after samarium Sm 153 lexidronam and of a relationship between edema and post-samarium Sm 153 lexidronam chemotherapy suggests the need for re-examination of patients in past series or for a prospective investigation with nonhematologic adverse events as a primary endpoint.« less

Method of synthesizing bulk transition metal carbide, nitride and phosphide catalysts

DOEpatents

Choi, Jae Soon; Armstrong, Beth L; Schwartz, Viviane

2015-04-21

A method for synthesizing catalyst beads of bulk transmission metal carbides, nitrides and phosphides is provided. The method includes providing an aqueous suspension of transition metal oxide particles in a gel forming base, dropping the suspension into an aqueous solution to form a gel bead matrix, heating the bead to remove the binder, and carburizing, nitriding or phosphiding the bead to form a transition metal carbide, nitride, or phosphide catalyst bead. The method can be tuned for control of porosity, mechanical strength, and dopant content of the beads. The produced catalyst beads are catalytically active, mechanically robust, and suitable for packed-bed reactor applications. The produced catalyst beads are suitable for biomass conversion, petrochemistry, petroleum refining, electrocatalysis, and other applications.

Synthesis and Hydrodeoxygenation Properties of Ruthenium Phosphide Catalysts

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

Bowker, Richard H.; Smith, Mica C.; Pease, Melissa

2011-07-01

Ru2P/SiO2 and RuP/SiO2 catalysts were prepared by the temperature-programmed reduction (TPR) of uncalcined precursors containing hypophosphite ion (H2PO2-) as the phosphorus source. The Ru2P/SiO2 and RuP/SiO2 catalysts had small average particle sizes (~4 nm) and high CO chemisorption capacities (90-110 umol/g). The Ru phosphide catalysts exhibited similar or higher furan (C4H4O) hydrodeoxygenation (HDO) activities than did a Ru/SiO2 catalyst, and the phosphide catalysts favored C4 hydrocarbon products while the Ru metal catalyst produced primarily C3 hydrocarbons.

Lattice Matched Carbide–Phosphide Composites with Superior Electrocatalytic Activity and Stability

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

Regmi, Yagya N.; Roy, Asa; King, Laurie A.

Composites of electrocatalytically active transition-metal compounds present an intriguing opportunity toward enhanced activity and stability. Here, to identify potentially scalable pairs of a catalytically active family of compounds, we demonstrate that phosphides of iron, nickel, and cobalt can be deposited on molybdenum carbide to generate nanocrystalline heterostructures. Composites synthesized via solvothermal decomposition of metal acetylacetonate salts in the presence of highly dispersed carbide nanoparticles show hydrogen evolution activities comparable to those of state-of-the-art non-noble metal catalysts. Investigation of the spent catalyst using high resolution microscopy and elemental analysis reveals that formation of carbide–phosphide composite prevents catalyst dissolution in acid electrolyte.more » Lattice mismatch between the two constituent electrocatalysts can be used to rationally improve electrochemical stability. Among the composites of iron, nickel, and cobalt phosphide, iron phosphide displays the lowest degree of lattice mismatch with molybdenum carbide and shows optimal electrochemical stability. Turnover rates of the composites are higher than that of the carbide substrate and compare favorably to other electrocatalysts based on earth-abundant elements. Lastly, our findings will inspire further investigation into composite nanocrystalline electrocatalysts that use molybdenum carbide as a stable catalyst support.« less

Lattice Matched Carbide–Phosphide Composites with Superior Electrocatalytic Activity and Stability

DOE PAGES

Regmi, Yagya N.; Roy, Asa; King, Laurie A.; ...

2017-10-19

Composites of electrocatalytically active transition-metal compounds present an intriguing opportunity toward enhanced activity and stability. Here, to identify potentially scalable pairs of a catalytically active family of compounds, we demonstrate that phosphides of iron, nickel, and cobalt can be deposited on molybdenum carbide to generate nanocrystalline heterostructures. Composites synthesized via solvothermal decomposition of metal acetylacetonate salts in the presence of highly dispersed carbide nanoparticles show hydrogen evolution activities comparable to those of state-of-the-art non-noble metal catalysts. Investigation of the spent catalyst using high resolution microscopy and elemental analysis reveals that formation of carbide–phosphide composite prevents catalyst dissolution in acid electrolyte.more » Lattice mismatch between the two constituent electrocatalysts can be used to rationally improve electrochemical stability. Among the composites of iron, nickel, and cobalt phosphide, iron phosphide displays the lowest degree of lattice mismatch with molybdenum carbide and shows optimal electrochemical stability. Turnover rates of the composites are higher than that of the carbide substrate and compare favorably to other electrocatalysts based on earth-abundant elements. Lastly, our findings will inspire further investigation into composite nanocrystalline electrocatalysts that use molybdenum carbide as a stable catalyst support.« less

Lattice dynamics of the rare-earth element samarium

NASA Astrophysics Data System (ADS)

Bauder, Olga; Piekarz, Przemysław; Barla, Alessandro; Sergueev, Ilya; Rüffer, Rudolf; ŁaŻewski, Jan; Baumbach, Tilo; Parlinski, Krzysztof; Stankov, Svetoslav

2013-12-01

The lattice dynamics of samarium is determined by in situ low-temperature nuclear inelastic scattering on a single crystalline (0001)Sm film, a polycrystalline Sm foil, and by first-principles theory. The ab initio calculated phonon dispersion relations and phonon density of states for the Sm-type structure and the double hexagonal-close-packed (dhcp) lattice, characteristic for light lanthanides, are compared. The dhcp unit cell, which is a factor of 2.24 smaller in height, exhibits more pronounced vibrational anisotropy in comparison to the Sm-type structure. The analysis reveals a minor influence of the spin-orbit coupling in the Sm atom on the lattice dynamics. A broadening of the longitudinal peak, not found in the calculations, suggests the influence of electron correlations on lattice dynamics in metallic samarium.

Structure-Activity Relationships for Pt-Free Metal Phosphide Hydrogen Evolution Electrocatalysts.

PubMed

Owens-Baird, Bryan; Kolen'ko, Yury V; Kovnir, Kirill

2018-05-23

In the field of renewable energy, the splitting of water into hydrogen and oxygen fuel gases using water electrolysis is a prominent topic. Traditionally, these catalytic processes have been performed by platinum-group metal catalysts, which are effective at promoting water electrolysis but expensive and rare. The search for an inexpensive and Earth-abundant catalyst has led to the development of 3d-transition-metal phosphides for the hydrogen evolution reaction. These catalysts have shown excellent activity and stability. In this review, we discuss the electronic and crystal structures of bulk and surface of selected Fe, Co, and Ni phosphides, and their relationships to the experimental catalytic activity. The various synthetic protocols towards the state-of-the-art transition metal phosphide electrocatalysts are also discussed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical mixtures of metal oxides and phosphorus pentoxide as novel precursors for the synthesis of transition-metal phosphides.

PubMed

Guo, Lijuan; Zhao, Yu; Yao, Zhiwei

2016-01-21

This study presents a new type of precursor, mechanical mixtures of metal oxides (MOs) and phosphorus pentoxide (P2O5) are used to synthesize Ni2P, Co2P and MoP phosphides by the H2 reduction method. In addition, this is first report of common solid-state P2O5 being used as a P source for the synthesis of metal phosphides. The traditional precursors are usually prepared via a complicated preparation procedure involving dissolution, drying and calcination steps. However, these novel MOs/P2O5 precursors can be obtained only by simple mechanical mixing of the starting materials. Furthermore, unlike the direct transformation from amorphous phases to phosphides, various specific intermediates were involved in the transformation from MOs/P2O5 to phosphides. It is worthy to note that the dispersions of Ni2P, Co2P and MoP obtained from MOs/P2O5 precursors were superior to those of the corresponding phosphides prepared from the abovementioned traditional precursors. It is suggested that the morphology of the as-prepared metal phosphides might be inherited from the corresponding MOs. Based on the results of XRD, XPS, SEM and TEM, the formation pathway of phosphides can be defined as MOs/P2O5 precursors → complex intermediates (metals, metal phosphates and metal oxide-phosphates) → metal phosphides.

Spectroscopic studies on samarium oxide (Sm2O3) doped tungsten tellurite glasses

NASA Astrophysics Data System (ADS)

Shekhawat, M. S.; Basha, S. K. Shahenoor; Rao, M. C.

2018-05-01

Samarium oxide (Sm2O3) doped tungsten tellurite glasses have been prepared by conventional rapid melt quenching method. The optical absorption spectrum of Samarium oxide doped tellurite glasses showed an absorption peak at 301 nm. FT-Raman studies suggested that Sm2O3 could modify the properties of glass and CIE chromaticity coordinates were calculated for the generation of white light from the luminescence spectra.

Novel p-n heterojunction copper phosphide/cuprous oxide photocathode for solar hydrogen production.

PubMed

Chen, Ying-Chu; Chen, Zhong-Bo; Hsu, Yu-Kuei

2018-08-01

A Copper phosphide (Cu 3 P) micro-rod (MR) array, with coverage by an n-Cu 2 O thin layer by electrodeposition as a photocathode, has been directly fabricated on copper foil via simple electro-oxidation and phosphidation for photoelectrochemical (PEC) hydrogen production. The morphology, structure, and composition of the Cu 3 P/Cu 2 O heterostructure are systematically analyzed using a scanning electron microscope (SEM), X-ray diffraction and X-ray photoelectron spectra. The PEC measurements corroborate that the p-Cu 3 P/n-Cu 2 O heterostructural photocathode illustrates efficient charge separation and low charge transfer resistance to achieve the highest photocurrent of 430 μA cm -2 that is greater than other transition metal phosphide materials. In addition, a detailed energy diagram of the p-Cu 3 P/n-Cu 2 O heterostructure was investigated using Mott-Schottky analysis. Our study paves the way to explore phosphide-based materials in a new class for solar energy applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Gallium phosphide energy converters

NASA Technical Reports Server (NTRS)

Sims, P. E.; DiNetta, Louis C.; DuganCavanagh, K.; Goetz, M. A.

1996-01-01

Betavoltaic power supplies based on gallium phosphide can supply long term low-level power with high reliability. Results are presented for GaP devices powered by Ni-63 and tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/cm(exp 2) have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. A small demonstration system has been assembled that generates and stores enough electricity to light up an LED.

Electrochemical Formation of Divalent Samarium Cation and Its Characteristics in LiCl-KCl Melt.

PubMed

Bae, Sang-Eun; Jung, Tae Sub; Cho, Young-Hwan; Kim, Jong-Yun; Kwak, Kyungwon; Park, Tae-Hong

2018-06-28

The electrochemical reduction of trivalent samarium in a LiCl-KCl eutectic melt produced highly stable divalent samarium, whose electrochemical properties and electronic structure in the molten salt were investigated using cyclic voltammetry, UV-vis absorption spectroscopy, laser-induced emission spectroscopy, and density functional theory (DFT) calculations. Diffusion coefficients of Sm 2+ and Sm 3+ were electrochemically measured to be 0.92 × 10 -5 and 1.10 × 10 -5 cm 2 /s, respectively, and the standard apparent potential of the Sm 2+/3+ couple was estimated to be -0.82 V vs Ag|Ag + at 450 °C. The spectroelectrochemical study demonstrated that the redox behavior of the samarium cations obeys the Nernst equation ( E°' = -0.83 V, n = 1) and the trivalent samarium cation was successfully converted to the divalent cation having characteristic absorption bands at 380 and 530 nm with molar absorptivity values of 1470 and 810 M -1 cm -1 , respectively. Density function theory calculations for the divalent samarium complex revealed that the absorption signals originated from the 4f 6 to 4f 5 5d 1 transitions. Additionally, laser-induced emission measurements for the Sm cations in the LiCl-KCl matrix showed that the Sm 3+ ion in the LiCl-KCl melt at 450 °C emitted an orange color of fluorescence, whereas a red colored emission was observed from the Sm 2+ ion in the solidified LCl-KCl salt at room temperature.

A physics-based model for the ionization of samarium by the MOSC chemical releases in the upper atmosphere

NASA Astrophysics Data System (ADS)

Bernhardt, Paul A.; Siefring, Carl L.; Briczinski, Stanley J.; Viggiano, Albert; Caton, Ronald G.; Pedersen, Todd R.; Holmes, Jeffrey M.; Ard, Shaun; Shuman, Nicholas; Groves, Keith M.

2017-05-01

Atomic samarium has been injected into the neutral atmosphere for production of electron clouds that modify the ionosphere. These electron clouds may be used as high-frequency radio wave reflectors or for control of the electrodynamics of the F region. A self-consistent model for the photochemical reactions of Samarium vapor cloud released into the upper atmosphere has been developed and compared with the Metal Oxide Space Cloud (MOSC) experimental observations. The release initially produces a dense plasma cloud that that is rapidly reduced by dissociative recombination and diffusive expansion. The spectral emissions from the release cover the ultraviolet to the near infrared band with contributions from solar fluorescence of the atomic, molecular, and ionized components of the artificial density cloud. Barium releases in sunlight are more efficient than Samarium releases in sunlight for production of dense ionization clouds. Samarium may be of interest for nighttime releases but the artificial electron cloud is limited by recombination with the samarium oxide ion.

Efficient water reduction with gallium phosphide nanowires

PubMed Central

Standing, Anthony; Assali, Simone; Gao, Lu; Verheijen, Marcel A.; van Dam, Dick; Cui, Yingchao; Notten, Peter H. L.; Haverkort, Jos E. M.; Bakkers, Erik P. A. M.

2015-01-01

Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite gallium phosphide, featuring a direct bandgap. This is one of the few materials combining large solar light absorption and (close to) ideal band-edge positions for full water splitting. Here we report the photoelectrochemical reduction of water, on a p-type wurtzite gallium phosphide nanowire photocathode. By modifying geometry to reduce electrical resistance and enhance optical absorption, and modifying the surface with a multistep platinum deposition, high current densities and open circuit potentials were achieved. Our results demonstrate the capabilities of this material, even when used in such low quantities, as in nanowires. PMID:26183949

Solar nebula heterogeneity in p-process samarium and neodymium isotopes.

PubMed

Andreasen, Rasmus; Sharma, Mukul

2006-11-03

Bulk carbonaceous chondrites display a deficit of approximately 100 parts per million (ppm) in 144Sm with respect to other meteorites and terrestrial standards, leading to a decrease in their 142Nd/144Nd ratios by approximately 11 ppm. The data require that samarium and neodymium isotopes produced by the p process associated with photodisintegration reactions in supernovae were heterogeneously distributed in the solar nebula. Other samarium and neodymium isotopes produced by rapid neutron capture (r process) in supernovae and by slow neutron capture (s process) in red giants were homogeneously distributed. The supernovae sources supplying the p- and r-process nuclides to the solar nebula were thus disconnected or only weakly connected.

Hydrodeoxygenation of phenolic compounds to cycloalkanes over supported nickel phosphides

DOE PAGES

Yu, Zhiquan; Wang, Anjie; Liu, Shan; ...

2018-05-07

SiO 2, HZSM-5 and Al 2O 3 were used to support nickel phosphides to prepare hydrodeoxygenation (HDO) catalysts. The nickel loading was kept at 20 wt% while the Ni/P molar ratio was varied among 3, 2, and 1 in the preparation by incipient wetness impregnation. XRD characterization revealed that Ni 3P, Ni 12P 5, and Ni 2P as the major crystal phases were obtained at Ni/P ratio of 3, 2, and 1, respectively, on SiO 2 and HZSM-5. When Al 2O 3 was used as the support, nickel metal rather than nickel phosphides was generated. Among SiO 2-supported nickel phosphides,more » Ni 3P exhibited highest hydrogenation activity and catalytic performance in phenol HDO. Ni 3P/HZSM-5 showed the high catalytic performance in HDO of phenol as well as catechol and o-cresol, with Ni 3P as the hydrogenation site and the acid sites in HZSM-5 zeolite as the dehydration site. In conclusion, the strong acidity in HZSM-5 also facilitated the isomerization of cycloalkanes at elevated temperatures.« less

Indium phosphide space solar cell research: Where we are and where we are going

NASA Technical Reports Server (NTRS)

Jain, R. K.; Flood, D. J.; Weinberg, Irving

1995-01-01

Indium phosphide is considered to be a strong contender for many photovoltaic space applications because of its radiation resistance and its potential for high efficiency. An overview of recent progress is presented, and possible future research directions for indium phosphide space solar cells are discussed. The topics considered include radiation damage studies and space flight experiments.

Use of continuous renal replacement therapy in acute aluminum phosphide poisoning: a novel therapy.

PubMed

Nasa, Prashant; Gupta, Ankur; Mangal, Kishore; Nagrani, S K; Raina, Sanjay; Yadav, Rohit

2013-09-01

Aluminum phosphide is most common cause of poisoning in northern India. There is no specific antidote available and management of such cases is mainly supportive with high mortality. We present two cases of severe acute aluminium phosphide poisoning where continuous renal replacement therapy (CRRT) was started early along with other resuscitative measures and both the patients survived.

A case of accidental fatal aluminum phosphide poisoning involving humans and dogs.

PubMed

Behera, Chittaranjan; Krishna, Karthik; Bhardwaj, Daya Nand; Rautji, Ravi; Kumar, Arvind

2015-05-01

Aluminum phosphide is one of the commonest poisons encountered in agricultural areas, and manner of death in the victims is often suicidal and rarely homicidal or accidental. This paper presents an unusual case, where two humans (owner and housemaid) and eight dogs were found dead in the morning hours inside a room of a house, used as shelter for stray dogs. There was allegation by the son of the owner that his father had been killed. Crime scene visit by forensic pathologists helped to collect vital evidence. Autopsies of both the human victims and the dogs were conducted. Toxicological analysis of viscera, vomitus, leftover food, and chemical container at the crime scene tested positive for aluminum phosphide. The cause of death in both humans and dogs was aluminum phosphide poisoning. Investigation by police and the forensic approach to the case helped in ascertaining the manner of death, which was accidental. © 2015 American Academy of Forensic Sciences.

Scalable and Tunable Carbide-Phosphide Composite Catalyst System for the Thermochemical Conversion of Biomass

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

Regmi, Yagya; Rogers, Bridget; Labbe, Nicole

We have prepared composite materials of hexagonal nickel phosphide and molybdenum carbide (Mo2C) utilizing a simple and scalable two-stage synthesis method comprised of carbothermic reduction followed by hydrothermal incubation. We observe the monophasic hexagonal phosphide Ni2P in the composite at low phosphide-to-carbide (P:C) ratios. Upon increasing the proportion of P:C, the carbide surface becomes saturated, and we detect the emergence of a second hexagonal nickel phosphide phase (Ni5P4) upon annealing. We demonstrate that vapor-phase upgrading (VPU) of whole biomass via catalytic fast pyrolysis is achievable using the composite material as a catalyst, and we monitor the resulting product slates usingmore » pyrolysis gas chromatography/mass spectrometry. Our analysis of the product vapors indicates that variation of the P:C molar ratio in the composite material affords product slates of varying complexity and composition, which is indicated by the number of products and their relative proportions in the product slate. Our results demonstrate that targeted vapor product composition can be obtained, which can potentially be utilized to tune the composition of the bio-oil downstream.« less

Scalable and Tunable Carbide-Phosphide Composite Catalyst System for the Thermochemical Conversion of Biomass

DOE PAGES

Regmi, Yagya; Rogers, Bridget; Labbe, Nicole; ...

2017-07-13

We have prepared composite materials of hexagonal nickel phosphide and molybdenum carbide (Mo2C) utilizing a simple and scalable two-stage synthesis method comprised of carbothermic reduction followed by hydrothermal incubation. We observe the monophasic hexagonal phosphide Ni2P in the composite at low phosphide-to-carbide (P:C) ratios. Upon increasing the proportion of P:C, the carbide surface becomes saturated, and we detect the emergence of a second hexagonal nickel phosphide phase (Ni5P4) upon annealing. We demonstrate that vapor-phase upgrading (VPU) of whole biomass via catalytic fast pyrolysis is achievable using the composite material as a catalyst, and we monitor the resulting product slates usingmore » pyrolysis gas chromatography/mass spectrometry. Our analysis of the product vapors indicates that variation of the P:C molar ratio in the composite material affords product slates of varying complexity and composition, which is indicated by the number of products and their relative proportions in the product slate. Our results demonstrate that targeted vapor product composition can be obtained, which can potentially be utilized to tune the composition of the bio-oil downstream.« less

Development of gallium aluminum phosphide electroluminescent diodes

NASA Technical Reports Server (NTRS)

Chicotka, R. J.; Lorenz, M. R.; Nethercot, A. H.; Pettit, G. D.

1972-01-01

Work done on the development of gallium aluminum phosphide alloys for electroluminescent light sources is described. The preparation of this wide band gap semiconductor alloy, its physical properties (particularly the band structure, the electrical characteristics, and the light emitting properties) and work done on the fabrication of diode structures from these alloys are broadly covered.

Visible light electroluminescent diodes of indium-gallium phosphide

NASA Technical Reports Server (NTRS)

Clough, R.; Richman, D.; Tietjen, J.

1970-01-01

Vapor deposition and acceptor impurity diffusion techniques are used to prepare indium-gallium phosphide junctions. Certain problems in preparation are overcome by altering gas flow conditions and by increasing the concentration of phosphine in the gas. A general formula is given for the alloy's composition.

A Facile Molecular Precursor Route to Metal Phosphide Nanoparticles and Their Evaluation as Hydrodeoxygenation Catalysts

DOE PAGES

Habas, Susan E.; Baddour, Frederick G.; Ruddy, Daniel A.; ...

2015-11-05

Metal phosphides have been identified as a promising class of materials for the catalytic upgrading of bio-oils, which are renewable and potentially inexpensive sources for liquid fuels. Herein, we report the facile synthesis of a series of solid, phase-pure metal phosphide nanoparticles (NPs) (Ni 2P, Rh 2P, and Pd 3P) utilizing commercially available, air-stable metal–phosphine complexes in a one-pot reaction. This single-source molecular precursor route provides an alternative method to access metal phosphide NPs with controlled phases and without the formation of metal NP intermediates that can lead to hollow particles. The formation of the Ni 2P NPs was shownmore » to proceed through an amorphous Ni–P intermediate, leading to the desired NP morphology and metal-rich phase. This low-temperature, rapid route to well-defined metal NPs is expected to have broad applicability to a variety of readily available or easily synthesized metal–phosphine complexes with high decomposition temperatures. Hydrodeoxygenation of acetic acid, an abundant bio-oil component, was performed to investigate H 2 activation and deoxygenation pathways under conditions that are relevant to ex situ catalytic fast pyrolysis (high temperatures, low pressures, and near-stoichiometric H 2 concentrations). The catalytic performance of the silica-supported metal phosphide NPs was compared to the analogous incipient wetness (IW) metal and metal phosphide catalysts over the range 200–500 °C. Decarbonylation was the primary pathway for H 2 incorporation in the presence of all of the catalysts except NP-Pd 3P, which exhibited minimal productive activity, and IW-Ni, which evolved H 2. The highly controlled NP-Ni2P and NP-Rh2P catalysts, which were stable under these conditions, behaved comparably to the IW-metal phosphides, with a slight shift to higher product onset temperatures, likely due to the presence of surface ligands. Most importantly, the NP-Ni 2P catalyst exhibited H 2 activation

Photoelectrochemical cell having photoanode with thin boron phosphide coating as a corrosion resistant layer

DOEpatents

Baughman, Richard J.; Ginley, David S.

1984-01-01

A surface prone to corrosion in corrosive environments is rendered anticorrosive by CVD growing a thin continuous film, e.g., having no detectable pinholes, thereon, of boron phosphide. In one embodiment, the film is semiconductive. In another aspect, the invention is an improved photoanode, and/or photoelectrochemical cell with a photoanode having a thin film of boron phosphide thereon rendering it anitcorrosive, and providing it with unexpectedly improved photoresponsive properties.

Effect of samarium in corrosion and microstructure of Al-5Zn-0.5Cu as low driving voltage sacrificial anode

NASA Astrophysics Data System (ADS)

Pratesa, Yudha; Ferdian, Deni; Ramadhan, Fajar Yusya; Maulana, Bramuda

2018-05-01

Sacrificial Anode Low voltage is the latest generation of the sacrificial anode that can prevent the occurrence of Hydrogen Cracking (HIC) due to overprotection. The Al-5n-0.5Cu alloy showed the potential to be developed as the new sacrificial anode. However, the main problem is copper made Al2Cu intermetallic in grain boundary. Samarium is added to modify the shape of the intermetallic to make it finer and make the corrosion uniform. Several characterizations were conducted to analyze the effect of Samarium. Scanning electron microscope (SEM) and Energy dispersive spectroscopy was used to analyzed the microstructure of the alloy. Metallography preparation was prepared for SEM analysis. Corrosion behavior was characterized by cyclic polarization in 3.5% NaCl solution. The results show samarium can change the shape of intermetallic and refine the grains. In addition, samarium makes better pitting resistance and exhibits a tendency for uniform corrosion. It is indicated by the loop reduction (ΔEpit-prot). Current density increased as an effect of samarium addition from 6x10-5 Ampere (Al-5Zn-0.5Cu) to 2.5x10-4 Ampere (Al-5Zn-0.5Cu-0.5Sm). Steel potential protection increased after addition of samarium which is an indication the possibility of Al-Zn-Cu-Sm to be used as low voltage sacrificial anode.

On the Samarium Substitution Effects in Y3-x Sm x Al5O12 (x = 0.1-3.0)

NASA Astrophysics Data System (ADS)

Skaudzius, Ramunas; Sakirzanovas, Simas; Kareiva, Aivaras

2018-04-01

Yttrium aluminium garnet substituted by samarium Y3-x Sm x Al5O12, (YSmAG, x = 0.1, 0.15, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 2.5 and 3.0) was prepared by an aqueous sol-gel processing using etane-1,2-diol as complexing agent. The end products obtained at 1000°C in air were characterized by x-ray diffraction analysis, infrared spectroscopy (FT-IR) and scanning electron microscopy. It was demonstrated, however, that the total substitution of yttrium by samarium does not proceed in the YSmAG. The single cubic garnet phase was formed only at a low concentration of samarium (x = 0.1, 0.15, 0.25, 0.5, 0.75, 1.0). With further substitutional levels, if the amount of samarium was x = 1.5, 2.0, 2.5 and 3, respectively, the formation a of minor amount of side perovskite samarium aluminate SmAlO3 (SmAP) phase was observed. Surprisingly, when yttrium was totally replaced by the samarium (x = 3.0) the main synthesis product was SmAP. The possible formation of Sm3Al5O12 (SmAG) garnet was also investigated for the first time by variation of the temperature in the range of 780-835°C.

Thermal Properties and Phonon Spectral Characterization of Synthetic Boron Phosphide for High Thermal Conductivity Applications.

PubMed

Kang, Joon Sang; Wu, Huan; Hu, Yongjie

2017-12-13

Heat dissipation is an increasingly critical technological challenge in modern electronics and photonics as devices continue to shrink to the nanoscale. To address this challenge, high thermal conductivity materials that can efficiently dissipate heat from hot spots and improve device performance are urgently needed. Boron phosphide is a unique high thermal conductivity and refractory material with exceptional chemical inertness, hardness, and high thermal stability, which holds high promises for many practical applications. So far, however, challenges with boron phosphide synthesis and characterization have hampered the understanding of its fundamental properties and potential applications. Here, we describe a systematic thermal transport study based on a synergistic synthesis-experimental-modeling approach: we have chemically synthesized high-quality boron phosphide single crystals and measured their thermal conductivity as a record-high 460 W/mK at room temperature. Through nanoscale ballistic transport, we have, for the first time, mapped the phonon spectra of boron phosphide and experimentally measured its phonon mean free-path spectra with consideration of both natural and isotope-pure abundances. We have also measured the temperature- and size-dependent thermal conductivity and performed corresponding calculations by solving the three-dimensional and spectral-dependent phonon Boltzmann transport equation using the variance-reduced Monte Carlo method. The experimental results are in good agreement with that predicted by multiscale simulations and density functional theory, which together quantify the heat conduction through the phonon mode dependent scattering process. Our finding underscores the promise of boron phosphide as a high thermal conductivity material for a wide range of applications, including thermal management and energy regulation, and provides a detailed, microscopic-level understanding of the phonon spectra and thermal transport mechanisms of

Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function.

PubMed

Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N

2013-07-19

Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function

NASA Astrophysics Data System (ADS)

Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N.

2013-07-01

Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

Orientation of Zn3P2 films via phosphidation of Zn precursors

NASA Astrophysics Data System (ADS)

Katsube, Ryoji; Nose, Yoshitaro

2017-02-01

Orientation of solar absorber is an important factor to achieve high efficiency of thin film solar cells. In the case of Zn3P2 which is a promising absorber of low-cost and high-efficiency solar cells, (110)/(001) orientation was only reported in previous studies. We have successfully prepared (101)-oriented Zn3P2 films by phosphidation of (0001)-oriented Zn films at 350 °C. The phosphidation mechanism of Zn is discussed through STEM observations on the partially-reacted sample and the consideration of the relationship between the crystal structures of Zn and Zn3P2 . We revealed that (0001)-oriented Zn led to nucleation of (101)-oriented Zn3P2 due to the similarity in atomic arrangement between Zn and Zn3P2 . The electrical resistivity of the (101)-oriented Zn3P2 film was lower than those of (110)/(001)-oriented films, which is an advantage of the phosphidation technique to the growth processes in previous works. The results in this study demonstrated that well-conductive Zn3P2 films could be obtained by controlling orientations of crystal grains, and provide a guiding principle for microstructure control in absorber materials.

Samarium electrodeposited acetate and oxide thin films on stainless steel substrate characterized by XPS

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

Myhre, Kristian; Burns, Jonathan; Meyer, Harry

Characterization of a samarium thin film deposited on a stainless steel substrate using molecular electrodeposition was carried out using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer. We studied two types of samarium electrodeposition samples, one as-deposited and one heated to 700 °C in an air flow. Survey scans include peaks coming from the stainless steel substrate, such as Fe and Cr. An X-ray photoelectron spectroscopy (XPS) survey spectrum, Sm 3d, C 1s, and O 1s narrow scans are shown. It was determined that the heating process decomposed the deposited Sm acetate to Sm 2O 3 using XPS.

Samarium electrodeposited acetate and oxide thin films on stainless steel substrate characterized by XPS

DOE PAGES

Myhre, Kristian; Burns, Jonathan; Meyer, Harry; ...

2016-06-01

Characterization of a samarium thin film deposited on a stainless steel substrate using molecular electrodeposition was carried out using a Thermo Scientific K-Alpha X-ray photoelectron spectrometer. We studied two types of samarium electrodeposition samples, one as-deposited and one heated to 700 °C in an air flow. Survey scans include peaks coming from the stainless steel substrate, such as Fe and Cr. An X-ray photoelectron spectroscopy (XPS) survey spectrum, Sm 3d, C 1s, and O 1s narrow scans are shown. It was determined that the heating process decomposed the deposited Sm acetate to Sm 2O 3 using XPS.

Influence of samarium substitution on structural, dielectric, and piezoelectric properties of PZT ceramics

NASA Astrophysics Data System (ADS)

Juneja, J. K.; Thakur, O. P.; Prakash, Chandra

2003-10-01

The structural, dielectric and piezoelectric properties have been studied in detail for the samarium modified PZT system. The samples, with chemical formula Pb1-xSmxZr0.52Ti0.48O3 with x varying from 0 to 0.02 in steps of 0.0025, were prepared by standard double sintering ceramic method. XRD analysis showed all the samples to be of single phase with tetragonal structure. Tetragonality (c/a) decreases gradually with samarium concentration (x) and the experimental density increases with x. Dielectric properties were studied as a function of temperature and frequency. All the samples show well-defined ferroelectric behavior. The remanance ratio (Pr/Ps) was found to increase with increasing Sm3+ concentration. Piezoelectric charge coefficient d33 decreases with x.

Clinical characteristics of zinc phosphide poisoning in Thailand.

PubMed

Trakulsrichai, Satariya; Kosanyawat, Natcha; Atiksawedparit, Pongsakorn; Sriapha, Charuwan; Tongpoo, Achara; Udomsubpayakul, Umaporn; Rittilert, Panee; Wananukul, Winai

2017-01-01

The objectives of this study were to describe the clinical characteristics and outcomes of poisoning by zinc phosphide, a common rodenticide in Thailand, and to evaluate whether these outcomes can be prognosticated by the clinical presentation. A 3-year retrospective cohort study was performed using data from the Ramathibodi Poison Center Toxic Exposure Surveillance System. In total, 455 poisonings were identified. Most were males (60.5%) and from the central region of Thailand (71.0%). The mean age was 39.91±19.15 years. The most common route of exposure was oral (99.3%). Most patients showed normal vital signs, oxygen saturation, and consciousness at the first presentation. The three most common clinical presentations were gastrointestinal (GI; 68.8%), cardiovascular (22.0%), and respiratory (13.8%) signs and symptoms. Most patients had normal blood chemistry laboratory results and chest X-ray findings at presentation. The median hospital stay was 2 days, and the mortality rate was 7%. Approximately 70% of patients underwent GI decontamination, including gastric lavage and a single dose of activated charcoal. In all, 31 patients were intubated and required ventilator support. Inotropic drugs were given to 4.2% of patients. Four moribund patients also received hyperinsulinemia-euglycemia therapy and intravenous hydrocortisone; however, all died. Patients who survived and died showed significant differences in age, duration from taking zinc phosphide to hospital presentation, abnormal vital signs at presentation (tachycardia, low blood pressure, and tachypnea), acidosis, hypernatremia, hyperkalemia, in-hospital acute kidney injury, in-hospital hypoglycemia, endotracheal tube intubation, and inotropic requirement during hospitalization ( P <0.05). Zinc phosphide poisoning causes fatalities. Most patients have mild symptoms, and GI symptoms are the most common. Patients who present with abnormal vital signs or electrolytes might have more severe poisoning and should

Recent developments in indium phosphide space solar cell research

NASA Technical Reports Server (NTRS)

Brinker, David J.; Weinberg, Irving

1987-01-01

Recent developments and progress in indium phosphide solar cell research for space application are reviewed. Indium phosphide homojunction cells were fabricated in both the n+p and p+n configurations with total area efficiencies of 17.9 and 15.9% (air mass 0 and 25 C) respectively. Organometallic chemical vapor deposition, liquid phase epitaxy, ion implantation and diffusion techniques were employed in InP cell fabrication. A theoretical model of a radiation tolerant, high efficiency homojunction cell was developed. A realistically attainable AMO efficiency of 20.5% was calculated using this model with emitter and base doping of 6 x 10 to the 17th power and 5 x 10 the the 16th power/cu cm respectively. Cells of both configurations were irradiated with 1 MeV electrons and 37 MeV protons. For both proton and electron irradiation, the n+p cells are more radiation resistant at higher fluences than the p+n cells. The first flight module of four InP cells was assembled for the Living Plume Shield III satellite.

Samarium Cobalt (SmCo) Generator/Engine Integration Study

DTIC Science & Technology

1980-04-01

110o1110 (Cole Ms -W~ Daiwa. to* J11 tuo.in Wfi wee -004"ni Aircraft Generator/starter Samarium Cobalt Turbine Engine , Feasibility Secondary Power...integration into the main rotor system of typical aircraft gas turbine engines . A major objective is the definition of the engine interface for such... Engine The F404 is a low bypass, augmented turbofan Pngine developed for application in advanced fighter aircraft (F-18). This type of engine benefits most

Sparkle/AM1 Parameters for the Modeling of Samarium(III) and Promethium(III) Complexes.

PubMed

Freire, Ricardo O; da Costa, Nivan B; Rocha, Gerd B; Simas, Alfredo M

2006-01-01

The Sparkle/AM1 model is extended to samarium(III) and promethium(III) complexes. A set of 15 structures of high crystallographic quality (R factor < 0.05 Å), with ligands chosen to be representative of all samarium complexes in the Cambridge Crystallographic Database 2004, CSD, with nitrogen or oxygen directly bonded to the samarium ion, was used as a training set. In the validation procedure, we used a set of 42 other complexes, also of high crystallographic quality. The results show that this parametrization for the Sm(III) ion is similar in accuracy to the previous parametrizations for Eu(III), Gd(III), and Tb(III). On the other hand, promethium is an artificial radioactive element with no stable isotope. So far, there are no promethium complex crystallographic structures in CSD. To circumvent this, we confirmed our previous result that RHF/STO-3G/ECP, with the MWB effective core potential (ECP), appears to be the most efficient ab initio model chemistry in terms of coordination polyhedron crystallographic geometry predictions from isolated lanthanide complex ion calculations. We thus generated a set of 15 RHF/STO-3G/ECP promethium complex structures with ligands chosen to be representative of complexes available in the CSD for all other trivalent lanthanide cations, with nitrogen or oxygen directly bonded to the lanthanide ion. For the 42 samarium(III) complexes and 15 promethium(III) complexes considered, the Sparkle/AM1 unsigned mean error, for all interatomic distances between the Ln(III) ion and the ligand atoms of the first sphere of coordination, is 0.07 and 0.06 Å, respectively, a level of accuracy comparable to present day ab initio/ECP geometries, while being hundreds of times faster.

Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass.

PubMed

Emmer, Hal; Chen, Christopher T; Saive, Rebecca; Friedrich, Dennis; Horie, Yu; Arbabi, Amir; Faraon, Andrei; Atwater, Harry A

2017-07-05

Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF 2 vapor etch. The resulting GaP films have surface roughnesses below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 10 17  cm -3 that exhibited mobilities as high as 16 cm 2 V -1 s -1 . Due to their unique optical properties, these films hold much promise for use in advanced optical devices.

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.

A combined spectroscopic and plasma chemical kinetic analysis of ionospheric samarium releases

NASA Astrophysics Data System (ADS)

Holmes, Jeffrey M.; Dressler, Rainer A.; Pedersen, Todd R.; Caton, Ronald G.; Miller, Daniel

2017-05-01

Two rocket-borne releases of samarium vapor in the upper atmosphere occurred in May 2013, as part of the Metal Oxide Space Clouds experiment. The releases were characterized by a combination of optical and RF diagnostic instruments located at the Roi-Namur launch site and surrounding islands and atolls. The evolution of the optical spectrum of the solar-illuminated cloud was recorded with a spectrograph covering a 400-800 nm spectral range. The spectra exhibit two distinct spectral regions centered at 496 and 636 nm within which the relative intensities change insignificantly. The ratio between the integrated intensities within these regions, however, changes with time, suggesting that they are associated with different species. With the help of an equilibrium plasma spectral model we attribute the region centered at 496 nm to neutral samarium atoms (Sm I radiance) and features peaking at 649 nm to a molecular species. No evidence for structure due to Sm+ (Sm II) is identified. The persistence of the Sm I radiance suggests a high dissociative recombination rate for the chemi-ionization product, SmO+. A one-dimensional plasma chemical kinetic model of the evolution of the density ratio NSmO/NSm(t) demonstrates that the molecular feature peaking at 649 nm can be attributed to SmO radiance. SmO+ radiance is not identified. By adjusting the Sm vapor mass of the chemical kinetic model input to match the evolution of the total electron density determined by ionosonde data, we conclude that less than 5% of the payload samarium was vaporized.

Samarium Diiodide-Mediated Reactions in Total Synthesis

PubMed Central

Nicolaou, K. C.; Ellery, Shelby P.; Chen, Jason S.

2009-01-01

Introduced by Henri Kagan more than three decades ago, samarium diiodide (SmI2) has found increasing applications in chemical synthesis. This single-electron reducing agent has been particularly useful in C–C bond formations, including those found in total synthesis endeavors. This Review highlights selected applications of SmI2 in total synthesis, with special emphasis on novel transformations and mechanistic considerations. The examples discussed are both illustrative of the power of this reagent in complex molecule construction and inspirational for the design of synthetic strategies toward such targets, both natural and designed. PMID:19714695

Applicability of samarium(III) complexes for the role of luminescent molecular sensors for monitoring progress of photopolymerization processes and control of the thickness of polymer coatings

NASA Astrophysics Data System (ADS)

Topa, Monika; Ortyl, Joanna; Chachaj-Brekiesz, Anna; Kamińska-Borek, Iwona; Pilch, Maciej; Popielarz, Roman

2018-06-01

Applicability of 15 trivalent samarium complexes as novel luminescent probes for monitoring progress of photopolymerization processes or thickness of polymer coatings by the Fluorescence Probe Technique (FPT) was studied. Three groups of samarium(III) complexes were evaluated in cationic photopolymerization of triethylene glycol divinyl ether monomer (TEGDVE) and free-radical photopolymerization of trimethylolpropane triacrylate (TMPTA). The complexes were the derivatives of tris(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate)samarium(III), tris(4,4,4-trifluoro-1-phenyl-1,3-butanedionate)samarium(III) and tris(4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionate)samarium(III), which were further coordinated with auxiliary ligands, such as 1,10-phenanthroline, triphenylphosphine oxide, tributylphosphine oxide and trioctylphosphine oxide. It has been found that most of the complexes studied are sensitive enough to be used as luminescent probes for monitoring progress of cationic photopolymerization of vinyl ether monomers over entire range of monomer conversions. In the case of free-radical polymerization processes, the samarium(III) complexes are not sensitive enough to changes of microviscosity and/or micropolarity of the medium, so they cannot be used to monitor progress of the polymerization. However, high stability of luminescence intensity of some of these complexes under free-radical polymerization conditions makes them good candidates for application as thickness sensors for polymer coatings prepared by free-radical photopolymerization. A quantitative relationship between a coating thickness and the luminescence intensity of the samarium(III) probes has been derived and verified experimentally within a broad range of the thicknesses.

Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass

DOE PAGES

Emmer, Hal; Chen, Christopher T.; Saive, Rebecca; ...

2017-07-05

Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF 2 vapor etch. The resulting GaP films have surface roughnessesmore » below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 10 17 cm -3 that exhibited mobilities as high as 16 cm 2V -1s -1. Therefore, due to their unique optical properties, these films hold much promise for use in advanced optical devices.« less

Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass

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

Emmer, Hal; Chen, Christopher T.; Saive, Rebecca

Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF 2 vapor etch. The resulting GaP films have surface roughnessesmore » below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 10 17 cm -3 that exhibited mobilities as high as 16 cm 2V -1s -1. Therefore, due to their unique optical properties, these films hold much promise for use in advanced optical devices.« less

Transition Metal Phosphide Nanoparticles Supported on SBA-15 as Highly Selective Hydrodeoxygenation Catalysts for the Production of Advanced Biofuels.

PubMed

Yang, Yongxing; Ochoa-Hernández, Cristina; de la Peña O'Shea, Víctor A; Pizarro, Patricia; Coronado, Juan M; Serrano, David P

2015-09-01

A series of catalysts constituted by nanoparticles of transition metal (M = Fe, Co, Ni and Mo) phosphides (TMP) dispersed on SBA-15 were synthesized by reduction of the corresponding metal phosphate precursors previously impregnated on the mesostructured support. All the samples contained a metal-loading of 20 wt% and with an initial M/P mole ratio of 1, and they were characterized by X-ray diffraction (XRD), N2 sorption, H2-TPR and transmission electron microscopy (TEM). Metal phosphide nanocatalysts were tested in a high pressure continuous flow reactor for the hydrodeoxygenation (HDO) of a methyl ester blend containing methyl oleate (C17H33-COO-CH3) as main component (70%). This mixture constitutes a convenient surrogate of triglycerides present in vegetable oils, and following catalytic hydrotreating yields mainly n-alkanes. The results of the catalytic assays indicate that Ni2P/SBA-15 catalyst presents the highest ester conversion, whereas the transformation rate is about 20% lower for MoP/SBA-15. In contrast, catalysts based on Fe and Co phosphides show a rather limited activity. Hydrocarbon distribution in the liquid product suggests that both hydrodeoxygenation and decarboxylation/decarbonylation reactions occur simultaneously over the different catalysts, although MoP/SBA-15 possess a selectivity towards hydrodeoxygenation exceeding 90%. Accordingly, the catalyst based on MoP affords the highest yield of n-octadecane, which is the preferred product in terms of carbon atom economy. Subsequently, in order to conjugate the advantages of both Ni and Mo phosphides, a series of catalysts containing variable proportions of both metals were prepared. The obtained results reveal that the mixed phosphides catalysts present a catalytic behavior intermediate between those of the monometallic phosphides. Accordingly, only marginal enhancement of the yield of n-octadecane is obtained for the catalysts with a Mo/Ni ratio of 3. Nevertheless, owing to this high selectivity

Gallium phosphide energy converters

NASA Astrophysics Data System (ADS)

Sims, P. E.; Dinetta, L. C.; Goetz, M. A.

1995-10-01

Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.

Gallium phosphide energy converters

NASA Technical Reports Server (NTRS)

Sims, P. E.; Dinetta, L. C.; Goetz, M. A.

1995-01-01

Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp -17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.

Status of indium phosphide solar cell development at Spire

NASA Technical Reports Server (NTRS)

Spitzer, M. B.; Keavney, C. J.; Vernon, S. M.

1987-01-01

On-going development of indium phosphide solar cells for space applications is presented. The development is being carried out with a view towards both high conversion efficiency and simplicity of manufacture. The cell designs comprise the ion-implanted cell, the indium tin oxide top contact cell, and the epitaxial cell grown by metal organic chemical vapor deposition. Modelling data on the limit to the efficiency are presented and comparison is made to measured performance data.

Polypyrrole-coated samarium oxide nanobelts: fabrication, characterization, and application in supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Peng; Wang, Yunjiao; Wang, Xue; Yang, Chao; Yi, Yanfeng

2012-11-01

Polypyrrole-coated samarium oxide nanobelts were synthesized by the in situ chemical oxidative surface polymerization technique based on the self-assembly of pyrrole on the surface of the amine-functionalized Sm2O3 nanobelts. The morphologies of the polypyrrole/samarium oxide (PPy/Sm2O3) nanocomposites were characterized using transmission electron microscope. The UV-vis absorbance of these samples was also investigated, and the remarkable enhancement was clearly observed. The electrochemical behaviors of the PPy/Sm2O3 composites were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge. The results indicated that the PPy/Sm2O3 composite electrode was fully reversible and achieved a very fast Faradaic reaction. After being corrected into the weight percentage of the PPy/Sm2O3 composite at a current density of 20 mA cm-2 in a 1.0 M NaNO3 electrolyte solution, a maximum discharge capacity of 771 F g-1 was achieved in a half-cell setup configuration for the PPy/Sm2O3 composites electrode with the potential application to electrode materials for electrochemical capacitors.

Comparison of effects of overload on parameters and performance of samarium-cobalt and strontium-ferrite radially oriented permanent magnet brushless DC motors

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

Demerdash, N.A.; Nehl, T.W.; Nyamusa, T.A.

1985-08-01

Effects of high momentary overloads on the samarium-cobalt and strontium-ferrite permanent magnets and the magnetic field in electronically commutated brushless dc machines, as well as their impact on the associated machine parameters were studied. The effect of overload on the machine parameters, and subsequently on the machine system performance was also investigated. This was accomplished through the combined use of finite element analysis of the magnetic field in such machines, perturbation of the magnetic energies to determine machine inductances, and dynamic simulation of the performance of brushless dc machines, when energized from voltage source inverters. These effects were investigated throughmore » application of the above methods to two equivalent 15 hp brushless dc motors, one of which was built with samarium-cobalt magnets, while the other was built with strontium- ferrite magnets. For momentary overloads as high as 4.5 p.u. magnet flux reductions of 29% and 42% of the no load flux were obtained in the samarium-cobalt and strontiumferrite machines, respectively. Corresponding reductions in the line to line armature inductances of 52% and 46% of the no load values were reported for the samarium-cobalt and strontium-ferrite cases, respectively. The overload affected the profiles and magnitudes of armature induced back emfs. Subsequently, the effects of overload on machine parameters were found to have significant impact on the performance of the machine systems, where findings indicate that the samarium-cobalt unit is more suited for higher overload duties than the strontium-ferrite machine.« less

Effect of dislocations on the open-circuit voltage, short-circuit current and efficiency of heteroepitaxial indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.; Flood, Dennis J.

1990-01-01

Excellent radiation resistance of indium phosphide solar cells makes them a promising candidate for space power applications, but the present high cost of starting substrates may inhibit their large scale use. Thin film indium phosphide cells grown on Si or GaAs substrates have exhibited low efficiencies, because of the generation and propagation of large number of dislocations. Dislocation densities were calculated and its influence on the open circuit voltage, short circuit current, and efficiency of heteroepitaxial indium phosphide cells was studied using the PC-1D. Dislocations act as predominant recombination centers and are required to be controlled by proper transition layers and improved growth techniques. It is shown that heteroepitaxial grown cells could achieve efficiencies in excess of 18 percent AMO by controlling the number of dislocations. The effect of emitter thickness and surface recombination velocity on the cell performance parameters vs. dislocation density is also studied.

Surface Chemistry in Cobalt Phosphide-Stabilized Lithium-Sulfur Batteries.

PubMed

Zhong, Yiren; Yin, Lichang; He, Peng; Liu, Wen; Wu, Zishan; Wang, Hailiang

2018-01-31

Chemistry at the cathode/electrolyte interface plays an important role for lithium-sulfur batteries in which stable cycling of the sulfur cathode requires confinement of the lithium polysulfide intermediates and their fast electrochemical conversion on the electrode surface. While many materials have been found to be effective for confining polysulfides, the underlying chemical interactions remain poorly understood. We report a new and general lithium polysulfide-binding mechanism enabled by surface oxidation layers of transition-metal phosphide and chalcogenide materials. We for the first time find that CoP nanoparticles strongly adsorb polysulfides because their natural oxidation (forming Co-O-P-like species) activates the surface Co sites for binding polysulfides via strong Co-S bonding. With a surface oxidation layer capable of confining polysulfides and an inner core suitable for conducting electrons, the CoP nanoparticles are thus a desirable candidate for stabilizing and improving the performance of sulfur cathodes in lithium-sulfur batteries. We demonstrate that sulfur electrodes that hold a high mass loading of 7 mg cm -2 and a high areal capacity of 5.6 mAh cm -2 can be stably cycled for 200 cycles. We further reveal that this new surface oxidation-induced polysulfide-binding scheme applies to a series of transition-metal phosphide and chalcogenide materials and can explain their stabilizing effects for lithium-sulfur batteries.

Highly efficient photocatalytic H2 evolution using TiO2 nanoparticles integrated with electrocatalytic metal phosphides as cocatalysts

NASA Astrophysics Data System (ADS)

Song, Rui; Zhou, Wu; Luo, Bing; Jing, Dengwei

2017-09-01

In this work, electrocatalysts like the metal phosphides Ni2P, NiCoP, and FeP, can serve as cocatalysts of TiO2 to form efficient composite photocatalysts for hydrogen generation from an aqueous methanol solution. On comparing Ni2P, NiCoP, and FeP and optimizing their proportions, the NiCoP(1 wt%)/TiO2 composite was found to exhibit the highest activity toward photocatalytic H2 production (1.54 μmol h-1 mg-1), which is about thirteen times that of the naked TiO2 nanoparticles. Mott-Schottky (MS) analysis indicated that the large upward shift or band bending of the Fermi energy level (EF) in metal phosphides was responsible for the enhanced activity of the composites. The steady-state photoluminescence (PL) spectra and photocurrent transient response further confirmed that the enhanced photoinduced charge transfer and band separation after TiO2 was integrated with the metal phosphides. Thus, these electrocatalysts were shown to be efficient cocatalysts that can replace noble metals as low-cost photocatalytic H2 production.

Gallium phosphide energy converters

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

Sims, P.E.; Dinetta, L.C.; Goetz, M.A.

1995-10-01

Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp {minus}17) A/sq cm have been measured andmore » the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.« less

Atomic structure and domain wall pinning in samarium-cobalt-based permanent magnets.

PubMed

Duerrschnabel, M; Yi, M; Uestuener, K; Liesegang, M; Katter, M; Kleebe, H-J; Xu, B; Gutfleisch, O; Molina-Luna, L

2017-07-04

A higher saturation magnetization obtained by an increased iron content is essential for yielding larger energy products in rare-earth Sm 2 Co 17 -type pinning-controlled permanent magnets. These are of importance for high-temperature industrial applications due to their intrinsic corrosion resistance and temperature stability. Here we present model magnets with an increased iron content based on a unique nanostructure and -chemical modification route using Fe, Cu, and Zr as dopants. The iron content controls the formation of a diamond-shaped cellular structure that dominates the density and strength of the domain wall pinning sites and thus the coercivity. Using ultra-high-resolution experimental and theoretical methods, we revealed the atomic structure of the single phases present and established a direct correlation to the macroscopic magnetic properties. With further development, this knowledge can be applied to produce samarium cobalt permanent magnets with improved magnetic performance.Understanding the factors that determine the properties of permanent magnets, which play a central role in many industrial applications, can help in improving their performance. Here, the authors study how changes in the iron content affect the microstructure of samarium cobalt magnets.

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

Cobalt phosphide based nanostructures as bifunctional electrocatalysts for low temperature alkaline water splitting

DOE PAGES

Lambert, Timothy N.; Vigil, Julian A.; Christensen, Ben

2016-08-22

Cobalt phosphide based thin films and nanoparticles were prepared by the thermal phosphidation of spinel Co 3O 4 precursor films and nanoparticles, respectively. CoP films were prepared with overall retention of the Co 3O 4 nanoplatelet morphology while the spherical/cubic Co 3O 4 and Ni 0.15Co 2.85O 4 nanoparticles were converted to nanorods or nanoparticles, respectively. The inclusion of nickel in the nanoparticles resulted in a 2.5 fold higher surface area leading to higher gravimetric performance. In each case high surface area structures were obtained with CoP as the primary phase. All materials were found to act as effective bifunctionalmore » electrocatalysts for both the HER and the OER and compared well to commercial precious metal benchmark materials in alkaline electrolyte. As a result, a symmetrical water electrolysis cell prepared from the CoP-based film operated at a low overpotential of 0.41-0.51 V.« less

Thermally stimulated processes in samarium-modified lead titanate ferroelectric ceramics

NASA Astrophysics Data System (ADS)

Peláiz-Barranco, A.; García-Wong, A. C.; González-Abreu, Y.; Gagou, Y.; Saint-Grégoire, P.

2013-08-01

The thermally stimulated processes in a samarium-modified lead titanate ferroelectric system are analyzed from the thermally stimulated depolarization discharge current. The discharge due to the space charge injected during the poling process, the pyroelectric response and a conduction process related to oxygen vacancies are evaluated considering a theoretical decomposition by using a numerical method. The pyroelectric response is separated from other components to evaluate the polarization behavior and some pyroelectric parameters. High remanent polarization, pyroelectric coefficient and merit figure values are obtained at room temperature.

Electrocatalytic activity of cobalt phosphide-modified graphite felt toward VO2+/VO2+ redox reaction

NASA Astrophysics Data System (ADS)

Ge, Zhijun; Wang, Ling; He, Zhangxing; Li, Yuehua; Jiang, Yingqiao; Meng, Wei; Dai, Lei

2018-04-01

A novel strategy for improving the electro-catalytic properties of graphite felt (GF) electrode in vanadium redox flow battery (VRFB) is designed by depositing cobalt phosphide (CoP) onto GF surface. The CoP powder is synthesized by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Cyclic voltammetry results confirm that the CoP-modified graphite felt (GF-CoP) electrode has excellent reversibility and electro-catalytic activity to the VO2+/VO2+ cathodic reaction compared with the pristine GF electrode. The cell using GF-CoP electrode shows apparently higher discharge capacity over that based on GF electrode. The cell using GF-CoP electrode has the capacity of 67.2 mA h at 100 mA cm-2, 32.7 mA h larger than that using GF electrode. Compared with cell using GF electrode, the voltage efficiency of the cell based on GF-CoP electrode increases by 5.9% and energy efficiency by 5.4% at a current density of 100 mA cm-2. The cell using GF-CoP electrode can reach 94.31% capacity retention after 50 cycles at a current density of 30 mA cm-2. The results show that the CoP can effectively promote the VO2+/VO2+ redox reaction, implying that metal phosphides are a new kind of potential catalytic materials for VRFB.

Dynamic Nuclear Polarization in Samarium Doped Lanthanum Magnesium Nitrate. Ph.D. Thesis - Va. Polytechnic Inst.

NASA Technical Reports Server (NTRS)

Byvik, C. E.

1971-01-01

The dynamic nuclear polarization of hydrogen nuclei by the solid effect in single crystals of samarium doped lanthanum magnesium nitrate (Sm:LMN) was studied theoretically and experimentally. The equations of evolution governing the dynamic nuclear polarization by the solid effect were derived in detail using the spin temperature theory and the complete expression for the steady state enhancement of the nuclear polarization was calculated. Experimental enhancements of the proton polarization were obtained for eight crystals at 9.2 GHz and liquid helium temperatures. The samarium concentration ranged from 0.1 percent to 1.1 percent as determined by X-ray fluorescence. A peak enhancement of 181 was measured for a 1.1 percent Sm:LMN crystal at 3.0 K. The maximum enhancements extrapolated with the theory using the experimental data for peak enhancement versus microwave power and correcting for leakage, agree with the ideal enhancement (240 in this experiment) within experimental error for three of the crystals.

A gallium phosphide high-temperature bipolar junction transistor

NASA Technical Reports Server (NTRS)

Zipperian, T. E.; Dawson, L. R.; Chaffin, R. J.

1981-01-01

Preliminary results are reported on the development of a high temperature (350 C) gallium phosphide bipolar junction transistor (BJT) for geothermal and other energy applications. This four-layer p(+)n(-)pp(+) structure was formed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The initial design suffers from a series resistance problem which limits the transistor's usefulness at high temperatures.

Dependence of samarium-soil interaction on samarium concentration: Implications for environmental risk assessment.

PubMed

Ramírez-Guinart, Oriol; Salaberria, Aitor; Vidal, Miquel; Rigol, Anna

2018-03-01

The sorption and desorption behaviour of samarium (Sm), an emerging contaminant, was examined in soil samples at varying Sm concentrations. The obtained sorption and desorption parameters revealed that soil possessed a high Sm retention capacity (sorption was higher than 99% and desorption lower than 2%) at low Sm concentrations, whereas at high Sm concentrations, the sorption-desorption behaviour varied among the soil samples tested. The fractionation of the Sm sorbed in soils, obtained by sequential extractions, allowed to suggest the soil properties (pH and organic matter solubility) and phases (organic matter, carbonates and clay minerals) governing the Sm-soil interaction. The sorption models constructed in the present work along with the sorption behaviour of Sm explained in terms of soil main characteristics will allow properly assessing the Sm-soil interaction depending on the contamination scenario under study. Moreover, the sorption and desorption K d values of radiosamarium in soils were strongly correlated with those of stable Sm at low concentrations (r = 0.98); indicating that the mobility of Sm radioisotopes and, thus, the risk of radioactive Sm contamination can be predicted using data from low concentrations of stable Sm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic transition temperatures follow crystallographic symmetry in Samarium under high-pressures and low-temperatures

DOE PAGES

Vohra, Yogesh K.; Tsoi, Georgiy M.; Johnson, Craig R.

2016-12-21

Magnetic ordering temperatures in rare earth metal samarium (Sm) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to high-pressure up to 47 GPa and low-temperature to 10 K. The two magnetic transitions at 106 K and 14 K in the α-Sm phase, attributed to antiferromagnetic ordering on hexagonal and cubic layers respectively, collapse in to one magnetic transition near 10 GPa when Sm assumes a double hexagonal close packed (dhcp) phase. On further increase in pressure above 34 GPa, the magnetic transitions split again as Sm adopts a hexagonal-hP3 structure indicating differentmore » magnetic transition temperatures for different crystallographic sites. A model for magnetic ordering for the hexagonal-hP3 phase in samarium has been proposed based on the experimental data. The magnetic transition temperatures closely follow the crystallographic symmetry during α-Sm → dhcp → fcc/dist.fcc → hP3 structure sequence at high-pressures and low-temperatures.« less

Magnetic transition temperatures follow crystallographic symmetry in Samarium under high-pressures and low-temperatures

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

Vohra, Yogesh K.; Tsoi, Georgiy M.; Johnson, Craig R.

Magnetic ordering temperatures in rare earth metal samarium (Sm) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to high-pressure up to 47 GPa and low-temperature to 10 K. The two magnetic transitions at 106 K and 14 K in the α-Sm phase, attributed to antiferromagnetic ordering on hexagonal and cubic layers respectively, collapse in to one magnetic transition near 10 GPa when Sm assumes a double hexagonal close packed (dhcp) phase. On further increase in pressure above 34 GPa, the magnetic transitions split again as Sm adopts a hexagonal-hP3 structure indicating differentmore » magnetic transition temperatures for different crystallographic sites. A model for magnetic ordering for the hexagonal-hP3 phase in samarium has been proposed based on the experimental data. The magnetic transition temperatures closely follow the crystallographic symmetry during α-Sm → dhcp → fcc/dist.fcc → hP3 structure sequence at high-pressures and low-temperatures.« less

Magnetic transition temperatures follow crystallographic symmetry in samarium under high-pressures and low-temperatures

NASA Astrophysics Data System (ADS)

Johnson, Craig R.; Tsoi, Georgiy M.; Vohra, Yogesh K.

2017-02-01

Magnetic ordering temperatures in rare earth metal samarium (Sm) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to high-pressure up to 47 GPa and low-temperature to 10 K. The two magnetic transitions at 106 K and 14 K in the α-Sm phase, attributed to antiferromagnetic ordering on hexagonal and cubic layers respectively, collapse in to one magnetic transition near 10 GPa when Sm assumes a double hexagonal close packed (dhcp) phase. On further increase in pressure above 34 GPa, the magnetic transitions split again as Sm adopts a hexagonal-hP3 structure indicating different magnetic transition temperatures for different crystallographic sites. A model for magnetic ordering for the hexagonal-hP3 phase in samarium has been proposed based on the experimental data. The magnetic transition temperatures closely follow the crystallographic symmetry during α-Sm  →  dhcp  →  fcc/dist.fcc  →  hP3 structure sequence at high-pressures and low-temperatures.

Magnetic transition temperatures follow crystallographic symmetry in samarium under high-pressures and low-temperatures.

PubMed

Johnson, Craig R; Tsoi, Georgiy M; Vohra, Yogesh K

2017-02-15

Magnetic ordering temperatures in rare earth metal samarium (Sm) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to high-pressure up to 47 GPa and low-temperature to 10 K. The two magnetic transitions at 106 K and 14 K in the α-Sm phase, attributed to antiferromagnetic ordering on hexagonal and cubic layers respectively, collapse in to one magnetic transition near 10 GPa when Sm assumes a double hexagonal close packed (dhcp) phase. On further increase in pressure above 34 GPa, the magnetic transitions split again as Sm adopts a hexagonal-hP3 structure indicating different magnetic transition temperatures for different crystallographic sites. A model for magnetic ordering for the hexagonal-hP3 phase in samarium has been proposed based on the experimental data. The magnetic transition temperatures closely follow the crystallographic symmetry during α-Sm  →  dhcp  →  fcc/dist.fcc  →  hP3 structure sequence at high-pressures and low-temperatures.

Toxicological and pharmacological effects of gadolinium and samarium chlorides

PubMed Central

Haley, T. J.; Raymond, K.; Komesu, N.; Upham, H. C.

1961-01-01

A study has been made of the toxicology and pharmacology of gadolinium and samarium chlorides. The symptoms of acute toxicity following intraperitoneal injection are described. The chronic oral ingestion of both chemicals for 12 weeks produced no effects on growth or the blood picture, and only the male rats receiving gadolinium chloride showed liver damage. The pharmacological responses to both chemicals were mainly depressant on all systems studied, and death was associated with cardiovascular collapse coupled with respiratory paralysis. The greatest damage seen was on abraded skin, where non-healing ulcers were produced by both chemicals, whereas irritation of intact skin and ocular tissues was only transient in nature. PMID:13903826

Moringa oleifera extract (Lam) attenuates Aluminium phosphide-induced acute cardiac toxicity in rats.

PubMed

Gouda, Ahmed S; El-Nabarawy, Nagla A; Ibrahim, Samah F

2018-01-01

Moringa oleifera extract (Lam) has many antioxidant and protective properties. Objective: to investigate the antioxidant activities of Lam in counteracting the high oxidative stress caused by acute sub-lethal aluminium phosphide (AlP) intoxication in rat heart. These activities will be detected by histopathological examination and some oxidative stress biomarkers. a single sub-lethal dose of Alp (2 mg/kg body weight) was administered orally, and Lam was given orally at a dose (100 mg/kg body weight) one hour after receiving AlP to rats. aluminium phosphide caused significant cardiac histopathological changes with a significant increase in malondialdehyde (MDA); lipid peroxidation marker; and a significant depletion of antioxidant enzymes (catalase and glutathione reductase). However, treatment with Lam protected efficiently the cardiac tissue of intoxicated rats by increasing antioxidants levels with slight decreasing in MDA production compared to untreated group. This study suggested that Moringa oleifera extract could possibly restore the altered cardiac histopathology and some antioxidant power in AlP intoxicated rats, and it could even be used as adjuvant therapy against AlP-induced cardiotoxicity.

Novel, high-activity hydroprocessing catalysts: Iron group phosphides

NASA Astrophysics Data System (ADS)

Wang, Xianqin

A series of iron, cobalt and nickel transition metal phosphides was synthesized by means of temperature-programmed reduction (TPR) of the corresponding phosphates. The same materials, Fe2P, CoP and NO, were also prepared on a silica (SiO2) support. The phase purity of these catalysts was established by x-ray diffraction (XRD), and the surface properties were determined by N2 BET specific surface area (Sg) measurements and CO chemisorption. The activities of the silica-supported catalysts were tested in a three-phase trickle bed reactor for the simultaneous hydrodenitrogenation (HDN) of quinoline and hydrodesulfurization (HDS) of dibenzothiophene using a model liquid feed at realistic conditions (30 atm, 370°C). The reactivity studies showed that the nickel phosphide (Ni2P/SiO2) was the most active of the catalysts. Compared with a commercial Ni-Mo-S/gamma-Al 2O3 catalyst at the same conditions, Ni2P/silica had a substantially higher HDS activity (100% vs. 76%) and HDN activity (82% vs. 38%). Because of their good hydrotreating activity, an extensive study of the preparation of silica supported nickel phosphides, Ni2P/SiO 2, was carried out. The parameters investigated were the phosphorus content and the weight loading of the active phase. The most active composition was found to have a starting synthesis Ni/P ratio close to 1/2, and the best loading of this sample on silica was observed to be 18 wt.%. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) measurements were employed to determine the structures of the supported samples. The main phase before and after reaction was found to be Ni2P, but some sulfur was found to be retained after reaction. A comprehensive scrutiny of the HDN reaction mechanism was also made over the Ni2P/SiO2 sample (Ni/P = 1/2) by comparing the HDN activity of a series of piperidine derivatives of different structure. It was found that piperidine adsorption involved an alpha-H activation

Electronic properties of hexagonal gallium phosphide: A DFT investigation

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

Kumar, Vipin; Shah, Esha V.; Roy, Debesh R., E-mail: drr@ashd.svnit.ac.in

2016-05-23

A detail density functional investigation is performed to develop hexagonal 2D gallium phosphide material. The geometry, band structure and density of states (total and projected) of 2D hexagonal GaP are reported in detail. It is heartening to note that the developed material is identified as an indirect band gap semiconductor. The indirect gap for this material is predicted as 1.97 eV at K-Γ, and a direct gap of 2.28 eV at K point is achieved, which is very close to the reported direct band gap for zinc blende and buckled structures of GaP.

Isoelectronic Traps in Gallium Phosphide

NASA Astrophysics Data System (ADS)

Christian, Theresa; Alberi, Kirstin; Beaton, Daniel; Fluegel, Brian; Mascarenhas, Angelo

2015-03-01

Isoelectronic substitutional dopants can result in strongly localized exciton traps within a host bandstructure such as gallium arsenide (GaAs) or gallium phosphide (GaP). These traps have received great attention for their role in the anomalous bandgap bowing of nitrogen or bismuth-doped GaAs, creating the dramatic bandgap tunability of these unusual dilute alloys. In the wider, indirect-bandgap host material GaP, these same isoelectronic dopants create bound states within the gap that can have very high radiative efficiency and a wealth of discrete spectral transitions illuminating the symmetry of the localized excitonic trap state. We will present a comparative study of nitrogen and bismuth isoelectronic traps in GaP. Research was supported by the U. S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division under contract DE-AC36-08GO28308 and by the Department of Energy Office of Science Graduate Fellowship Program (DOE SCGF), made possible in part by the American Recovery and Reinvestment Act of 2009, administered by ORISE-ORAU under contract no. DE-AC05-06OR23100.

Photoluminescence of samarium-doped TiO{sub 2} nanotubes

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

Park, Dong Jin; Sekino, Tohru, E-mail: sekino@tagen.tohoku.ac.jp; Tsukuda, Satoshi

2011-10-15

Samarium (Sm)-modified TiO{sub 2} nanotubes (TNTs) were synthesized by low-temperature soft chemical processing. X-ray powder diffraction analyses of the synthesized Sm-doped and non-doped TNTs show a broad peak near 2{theta}=10{sup o}, which is typical of TNTs. The binding energy of Sm {sup 3}d{sub 5/2} for 10 mol% Sm-doped TNT (1088.3 eV) was chemically shifted from that of Sm{sub 2}O{sub 3} (1087.5 eV), showing that Sm existed in the TiO{sub 2} lattice. Sm-doped TNTs clearly exhibited red fluorescence, corresponding to the doped Sm{sup 3+} ion in the TNT lattice. The Sm-doped TNT excitation spectrum exhibited a broad curve, which was similarmore » to the UV-vis optical absorption spectrum. Thus, it was considered that the photoluminescence emission of Sm{sup 3+}-doped TNT with UV-light irradiation was caused by the energy transfer from the TNT matrix via the band-to-band excitation of TiO{sub 2} to the Sm{sup 3+} ion. - Graphical Abstract: Samarium-doped TiO{sub 2} nanotubes (TNTs) having a nanotubular structure were synthesized by soft chemical route. It was revealed that the energy associated by the band-to-band excitation of TNT matrix transferred to the doped Sm{sup 3+} ions in the lattice, resulting in emission of strong and visible red fluorescence. Highlights: > Sm-doped TiO{sub 2} nanotubes synthesized by low-temperature soft chemical processing. > Sm{sup 3+} substitutes Ti{sup 4+} ions in the nanotube lattice. > Clear fluorescent emission due to the f-f transition at the Sm{sup 3+} in a crystal field environment. > Band-to-band excitation of TiO{sub 2} and followed energy transfer to Sm{sup 3+} causes the luminescence.« less

Fabrication of hierarchical CoP nanosheet@microwire arrays via space-confined phosphidation toward high-efficiency water oxidation electrocatalysis under alkaline conditions.

PubMed

Ji, Xuqiang; Zhang, Rong; Shi, Xifeng; Asiri, Abdullah M; Zheng, Baozhan; Sun, Xuping

2018-05-03

In spite of recent advances in the synthesis of transition metal phosphide nanostructures, the simple fabrication of hierarchical arrays with more accessible active sites still remains a great challenge. In this Communication, we report a space-confined phosphidation strategy toward developing hierarchical CoP nanosheet@microwire arrays on nickel foam (CoP NS@MW/NF) using a Co(H2PO4)2·2H3PO4 microwire array as the precursor. The thermally stable nature of the anion in the precursor is key to hierarchical nanostructure formation. When used as a 3D electrode for water oxidation electrocatalysis, such CoP NS@MW/NF needs an overpotential as low as 296 mV to drive a geometrical catalytic current density of 100 mA cm-2 in 1.0 M KOH, outperforming all reported Co phosphide catalysts in alkaline media. This catalyst also shows superior long-term electrochemical durability, maintaining its activity for at least 65 h. This study offers us a general method for facile preparation of hierarchical arrays for applications.

Electrical properties of samarium cobaltite nanoparticles synthesized using Sol–Gel autocombustion route

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

Sathyamoorthy, B.; Md Gazzali, P.M.; Murugesan, C.

2014-05-01

Highlights: • The structural evolution and its electrical properties of samarium cobaltite nanograins are discussed. • Optimization of SmCoO{sub 3} nanograins is achieved by post sintering as-prepared gel at 800 °C. • The impedance spectra indicate the semiconducting behavior SmCoO{sub 3} nanograins. - Abstract: Nanograins of SmCoO{sub 3} are prepared by citric acid assisted Sol–Gel autocombustion route. The characterizations of crystal structure, surface morphology and electrical properties of SmCoO{sub 3} powder are done using XRD, HRSEM, FTIR and BDS. The structural evolution of SmCoO{sub 3} upon increasing the annealing temperature is followed using XRD and FTIR analyses. The powder samplemore » contains polycrystalline grains with average size equal to 35 nm and orthorhombic perovskite structure with Pbnm space group. The vibrational bands observed in FTIR spectrum at 545 cm{sup −1} and 439 cm{sup −1} correspond to Co-O stretching modes in cobaltite system. HRSEM images of the sample show the formation of hexagonal shaped grains of samarium cobaltite. The AC electrical conductivity of 4.914 × 10{sup −5} S cm{sup −1} at 295 K is measured for SmCoO{sub 3} nanoparticles. The impedance spectra bring out the semiconducting behavior of the material.« less

Application of a Boson Expansion Formalism Based on the Random Phase Approximation to Samarium Isotopes

NASA Astrophysics Data System (ADS)

Jamaluddin, Muzhar Bin

The Boson Expansion Theory of Kishimoto and Tamura has proved to be very successful in describing quadrupole collective motions in even-even nuclei. This theory, however, involves a complicated transformation from the Tamm-Dancoff phonons to the phonons of the Random Phase Approximation. In this thesis a Boson Expansion formalism, derived directly from the Random Phase Approximation and set forth by Pedracchi and Tamura, is used to derive the boson forms of the nuclear Hamiltonian and the electromagnetic transition operator. Detailed discussions of the formalism of Pedrocchi and Tamura and its extension needed to perform realistic calculations are presented. The technique used to deriving the boson forms and the formulae used in the calculations are also given a thorough treatment to demonstrate the simplicity of this approach. Finally, the theory is tested by applying it to calculate the energy levels and some electromagnetic properties of the Samarium isotopes. The results show that the present theory is capable of describing the range of behavior from a vibrational to a rotational character of the Samarium isotopes as good as the previous theory.

New reactions involving the oxidative O-, N-, and C-phosphorylation of organic compounds by phosphorus and phosphides in the presence of metal complexes

NASA Astrophysics Data System (ADS)

Dorfman, Ya A.; Aleshkova, M. M.; Polimbetova, G. S.; Levina, L. V.; Petrova, T. V.; Abdreimova, R. R.; Doroshkevich, D. M.

1993-09-01

The mechanisms of new catalytic reactions leading to the formation of di-, and tri-alkyl phosphates, di- and tri-alkyl phosphites, phosphoramidites, phosphazenes, phosphines, and phosphine oxides from hydrogen, copper, and zinc phosphides and white and red phosphorus are analysed. The mechanisms of the activation of the reactants by metal complexes and of the reactions involving the oxidative P-O, P-N, and P-C coupling of organic compounds to phosphorus and phosphides are considered. The bibliography includes 124 references.

Synthesis of samarium doped gadolinium oxide nanorods, its spectroscopic and physical properties

NASA Astrophysics Data System (ADS)

Boopathi, G.; Gokul Raj, S.; Ramesh Kumar, G.; Mohan, R.; Mohan, S.

2018-06-01

One-dimensional samarium doped gadolinium oxide [Sm:Gd2O3] nanorods have been synthesized successfully through co-precipitation technique in aqueous solution. The as-synthesized and calcined products were characterized by using powder X-ray diffraction pattern, Fourier transform Raman spectroscopy, thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-Visible spectrometry, photoluminescence spectrophotometer and X-ray photoelectron spectroscopy techniques. The obtained results are discussed in detailed manner.

Scalable Indium Phosphide Thin-Film Nanophotonics Platform for Photovoltaic and Photoelectrochemical Devices.

PubMed

Lin, Qingfeng; Sarkar, Debarghya; Lin, Yuanjing; Yeung, Matthew; Blankemeier, Louis; Hazra, Jubin; Wang, Wei; Niu, Shanyuan; Ravichandran, Jayakanth; Fan, Zhiyong; Kapadia, Rehan

2017-05-23

Recent developments in nanophotonics have provided a clear roadmap for improving the efficiency of photonic devices through control over absorption and emission of devices. These advances could prove transformative for a wide variety of devices, such as photovoltaics, photoelectrochemical devices, photodetectors, and light-emitting diodes. However, it is often challenging to physically create the nanophotonic designs required to engineer the optical properties of devices. Here, we present a platform based on crystalline indium phosphide that enables thin-film nanophotonic structures with physical morphologies that are impossible to achieve through conventional state-of-the-art material growth techniques. Here, nanostructured InP thin films have been demonstrated on non-epitaxial alumina inverted nanocone (i-cone) substrates via a low-cost and scalable thin-film vapor-liquid-solid growth technique. In this process, indium films are first evaporated onto the i-cone structures in the desired morphology, followed by a high-temperature step that causes a phase transformation of the indium into indium phosphide, preserving the original morphology of the deposited indium. Through this approach, a wide variety of nanostructured film morphologies are accessible using only control over evaporation process variables. Critically, the as-grown nanotextured InP thin films demonstrate excellent optoelectronic properties, suggesting this platform is promising for future high-performance nanophotonic devices.

Characterization of Gallium Indium Phosphide and Progress of Aluminum Gallium Indium Phosphide System Quantum-Well Laser Diode.

PubMed

Hamada, Hiroki

2017-07-28

Highly ordered gallium indium phosphide layers with the low bandgap have been successfully grown on the (100) GaAs substrates, the misorientation toward [01-1] direction, using the low-pressure metal organic chemical vapor deposition method. It is found that the optical properties of the layers are same as those of the disordered ones, essentially different from the ordered ones having two orientations towards [1-11] and [11-1] directions grown on (100) gallium arsenide substrates, which were previously reported. The bandgap at 300 K is 1.791 eV. The value is the smallest ever reported, to our knowledge. The high performance transverse stabilized AlGaInP laser diodes with strain compensated quantum well structure, which is developed in 1992, have been successfully obtained by controlling the misorientation angle and directions of GaAs substrates. The structure is applied to quantum dots laser diodes. This paper also describes the development history of the quantum well and the quantum dots laser diodes, and their future prospects.

Deoxygenation of Palmitic Acid on Unsupported Transition-Metal Phosphides

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

Peroni, Marco; Lee, Insu; Huang, Xiaoyang

Abstract Highly active bulk transition metal phosphides (WP, MoP, and Ni2P) were synthesized for the catalytic hydrodeoxygenation of palmitic acid, hexadecanol, hexadecanal, and microalgae oil. The specific activities positively correlated with the concentration of exposed metal sites, although the relative rates changed with temperature due to activation energies varying from 57 kJ·mol-1 for MoP to 142 kJ·mol-1 for WP. The reduction of the fatty acid to the aldehyde occurs through a Langmuir-Hinshelwood mechanism, where the rate-determining step is the addition of the second H to the hydrocarbon. On WP, the conversion of palmitic acid proceeds via R-CH2COOH R-CH2CHO R-CH2CH2OH R-CHCH2more » R-CH2CH3 (hydrodeoxygenation). Decarbonylation of the intermittently formed aldehyde (R-CH2COOH R-CH2CHO R-CH3) was an important pathway on MoP and Ni2P. Conversion via dehydration to a ketene, followed by its decarbonylation occurred only on Ni2P. The rates of alcohol dehydration (R-CH2CH2OH R-CHCH2) correlate with the concentration of Lewis acid sites of the phosphides. Acknowledgements The authors would like to thank Roel Prins for the critical discussion of the results. We are also grateful to Xaver Hecht for technical support. Funding by the German Federal Ministry of Food and Agriculture in the framework of the Advanced Biomass Value project (03SF0446A) is gratefully acknowledged. J.A.L. acknowledges support for his contribution by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences for exploring non-oxidic supports for deoxygenation reactions.« less

Studies on effective atomic numbers, electron densities from mass attenuation coefficients near the K edge in some samarium compounds.

PubMed

Akman, F; Durak, R; Turhan, M F; Kaçal, M R

2015-07-01

The effective atomic numbers and electron densities of some samarium compounds were determined using the experimental total mass attenuation coefficient values near the K edge in the X-ray energy range from 36.847 up to 57.142 keV. The measurements, in the region from 36.847 to 57.142 keV, were done in a transmission geometry utilizing the Kα2, Kα1, Kβ1 and Kβ2 X-rays from different secondary source targets excited by the 59.54 keV gamma-photons from an Am-241 annular source. This paper presents the first measurement of the effective atomic numbers and electron densities for some samarium compounds near the K edge. The results of the study showed that the measured values were in good agreement with the theoretically calculated ones. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study of structural, spectroscopic and dielectric properties of multiferroic cadmium doped Samarium manganite synthesized by solid state reaction method

NASA Astrophysics Data System (ADS)

Gupta, Vandana; Raina, Bindu; Verma, Seema; Bamzai, K. K.

2018-05-01

Samarium manganite doped with cadmium having general formula Sm1-xCdxMnO3 for x = 0.05, 0.15 were synthesized by solid state reaction technique. These compositions were characterized by various techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and dielectric. XRD analysis confirms the single phase formation with pervoskites structure having orthorhombic phase. Densities were determined and compared with the results obtained by Archimedes principle. The scanning electron micrograph shows that the particle size distribution is almost homogeneous and spherical in shape. FTIR analysis confirms the presence of various atomic bonds within a molecule. A very large value of dielectric constant was observed at low frequencies due to the presence of grains and interfaces. The dielectric constant value decreases with increase in cadmium doping at samarium site.

Application of a Boson Expansion formalism based on the Random Phase Approximation to samarium isotopes

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

Jamaluddin, M.B.

1986-01-01

The Boson Expansion Theory of Kishimoto and Tamura has proved to be very successful in describing quadrupole collective motions in even-even nuclei. This theory, however, involves a complicated transformation from the Tamm-Dancoff phonons to the phonons of the random Phase Approximation. In this thesis a Boson Expansion formalism, derived directly from the Random Phase Approximation and set forth by Pedracchi and Tamura, is used to derive the boson forms of the nuclear Hamiltonian and the electromagnetic transition operator. Detailed discussions of the formalism of Pedrocchi and Tamura and its extension needed to perform realistic calculations are presented. The technique usedmore » to deriving the boson forms and the formulae used in the calculations are also given a thorough treatment to demonstrate the simplicity of this approach. Finally, the theory is tested by applying it to calculate the energy levels and some electromagnetic properties of the Samarium isotopes. The results show that the present theory is capable of describing the range of behavior from a vibrational to a rotational character of the Samarium isotopes as well as the previous theory.« less

Direct Band Gap Wurtzite Gallium Phosphide Nanowires

PubMed Central

2013-01-01

The main challenge for light-emitting diodes is to increase the efficiency in the green part of the spectrum. Gallium phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the green emission efficiency. Band structure calculations have predicted a direct band gap for wurtzite GaP. Here, we report the fabrication of GaP nanowires with pure hexagonal crystal structure and demonstrate the direct nature of the band gap. We observe strong photoluminescence at a wavelength of 594 nm with short lifetime, typical for a direct band gap. Furthermore, by incorporation of aluminum or arsenic in the GaP nanowires, the emitted wavelength is tuned across an important range of the visible light spectrum (555–690 nm). This approach of crystal structure engineering enables new pathways to tailor materials properties enhancing the functionality. PMID:23464761

Vertically Emitting Indium Phosphide Nanowire Lasers.

PubMed

Xu, Wei-Zong; Ren, Fang-Fang; Jevtics, Dimitars; Hurtado, Antonio; Li, Li; Gao, Qian; Ye, Jiandong; Wang, Fan; Guilhabert, Benoit; Fu, Lan; Lu, Hai; Zhang, Rong; Tan, Hark Hoe; Dawson, Martin D; Jagadish, Chennupati

2018-06-13

Semiconductor nanowire (NW) lasers have attracted considerable research effort given their excellent promise for nanoscale photonic sources. However, NW lasers currently exhibit poor directionality and high threshold gain, issues critically limiting their prospects for on-chip light sources with extremely reduced footprint and efficient power consumption. Here, we propose a new design and experimentally demonstrate a vertically emitting indium phosphide (InP) NW laser structure showing high emission directionality and reduced energy requirements for operation. The structure of the laser combines an InP NW integrated in a cat's eye (CE) antenna. Thanks to the antenna guidance with broken asymmetry, strong focusing ability, and high Q-factor, the designed InP CE-NW lasers exhibit a higher degree of polarization, narrower emission angle, enhanced internal quantum efficiency, and reduced lasing threshold. Hence, this NW laser-antenna system provides a very promising approach toward the achievement of high-performance nanoscale lasers, with excellent prospects for use as highly localized light sources in present and future integrated nanophotonics systems for applications in advanced sensing, high-resolution imaging, and quantum communications.

Preparation and Quality Control of the [153Sm]-Samarium Maltolate Complex as a Lanthanide Mobilization Product in Rats

PubMed Central

Naseri, Zohreh; Hakimi, Amir; Jalilian, Amir R.; Nemati Kharat, Ali; Bahrami-Samani, Ali; Ghannadi-Maragheh, Mohammad

2011-01-01

Development of lanthanide detoxification agents and protocols is of great importance in management of overdoses. Due to safety of maltol as a detoxifying agent in metal overloads, it can be used as a lanthanide detoxifying agent. In order to demonstrate the biodistribution of final complex, [153Sm]-samarium maltolate was prepared using Sm-153 chloride (radiochemical purity >99.9%; ITLC and specific activity). The stability of the labeled compound was determined in the final solution up to 24h as well as the partition coefficient. Biodistribution studies of Sm-153 chloride, [153Sm]-samarium maltolate were carried out in wild-type rats comparing the critical organ uptakes. Comparative study for Sm3+ cation and the labeled compound was conducted up to 48 h, demonstrating a more rapid wash out for the labeled compound. The effective and biological half lives of 2.3 h and 2.46h were calculated for the complex. The data suggest the detoxification property of maltol formulation for lanthanide overdoses. PMID:21773065

Thorium Copper Phosphides: More Diverse Metal-Phosphorus and Phosphorus-Phosphorus Interactions than U analogues

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

Jin, Geng Bang; Malliakas, Christos D.; Lin, Jian

To explore the chemical analogy between thorium and heavier actinides in soft anionic environments, three new thorium phosphides (ThCuP 2, beta-ThCu 2P 2, and ThCu 5P 3) have been prepared through solid-state reactions using CuI as a reaction promoter. The structure of ThCuP 2 can be described as a filled UTe 2-type with both dimeric P 2 4- and monomeric P 3- anions, in which Th is coordinated by eight P atoms in a bicapped trigonal prismatic arrangement and Cu is tetrahedrally coordinated by four P atoms. β-ThCu 2P 2 contains only P 3- anions and is isostructural with BaCumore » 2S 2. In this structure, Th is coordinated by seven P atoms in monocapped trigonal prismatic geometry and Cu is tetrahedrally coordinated by four P atoms. ThCu 5P 3 adopts the YCo 5P 3-type structure consisting of P 3- anions. This structure contains Th atoms coordinated by six P atoms in a trigonal prismatic arrangement and Cu atoms that are either tetrahedrally coordinated by four P atoms or square pyramidally coordinated by five P atoms. Electric resistivity measurements and electronic structure calculations on β-ThCu 2P 2 indicate a metal. These new compounds may be charge-balanced and formulated as Th 4+Cu +(P 2 4-) 1/2P 3-, Th 4+(Cu +) 2(P 3-) 2, and Th 4+(Cu +) 5(P 3-) 3, respectively. The structural, bonding, and property relationships between these Th compounds and related actinide and rare-earth phases are discussed. In conclusion, titled compounds display more diverse ion-ion interactions and different electronic structures from those in UCuP 2 and UCu 2P 2 that were synthesized under similar experimental conditions, suggesting divergence of thorium-phosphide chemistry from uranium-phosphide chemistry.« less

Thorium Copper Phosphides: More Diverse Metal-Phosphorus and Phosphorus-Phosphorus Interactions than U analogues

DOE PAGES

Jin, Geng Bang; Malliakas, Christos D.; Lin, Jian

2017-09-28

To explore the chemical analogy between thorium and heavier actinides in soft anionic environments, three new thorium phosphides (ThCuP 2, beta-ThCu 2P 2, and ThCu 5P 3) have been prepared through solid-state reactions using CuI as a reaction promoter. The structure of ThCuP 2 can be described as a filled UTe 2-type with both dimeric P 2 4- and monomeric P 3- anions, in which Th is coordinated by eight P atoms in a bicapped trigonal prismatic arrangement and Cu is tetrahedrally coordinated by four P atoms. β-ThCu 2P 2 contains only P 3- anions and is isostructural with BaCumore » 2S 2. In this structure, Th is coordinated by seven P atoms in monocapped trigonal prismatic geometry and Cu is tetrahedrally coordinated by four P atoms. ThCu 5P 3 adopts the YCo 5P 3-type structure consisting of P 3- anions. This structure contains Th atoms coordinated by six P atoms in a trigonal prismatic arrangement and Cu atoms that are either tetrahedrally coordinated by four P atoms or square pyramidally coordinated by five P atoms. Electric resistivity measurements and electronic structure calculations on β-ThCu 2P 2 indicate a metal. These new compounds may be charge-balanced and formulated as Th 4+Cu +(P 2 4-) 1/2P 3-, Th 4+(Cu +) 2(P 3-) 2, and Th 4+(Cu +) 5(P 3-) 3, respectively. The structural, bonding, and property relationships between these Th compounds and related actinide and rare-earth phases are discussed. In conclusion, titled compounds display more diverse ion-ion interactions and different electronic structures from those in UCuP 2 and UCu 2P 2 that were synthesized under similar experimental conditions, suggesting divergence of thorium-phosphide chemistry from uranium-phosphide chemistry.« less

Characterization of Gallium Indium Phosphide and Progress of Aluminum Gallium Indium Phosphide System Quantum-Well Laser Diode

PubMed Central

Hamada, Hiroki

2017-01-01

Highly ordered gallium indium phosphide layers with the low bandgap have been successfully grown on the (100) GaAs substrates, the misorientation toward [01−1] direction, using the low-pressure metal organic chemical vapor deposition method. It is found that the optical properties of the layers are same as those of the disordered ones, essentially different from the ordered ones having two orientations towards [1−11] and [11−1] directions grown on (100) gallium arsenide substrates, which were previously reported. The bandgap at 300 K is 1.791 eV. The value is the smallest ever reported, to our knowledge. The high performance transverse stabilized AlGaInP laser diodes with strain compensated quantum well structure, which is developed in 1992, have been successfully obtained by controlling the misorientation angle and directions of GaAs substrates. The structure is applied to quantum dots laser diodes. This paper also describes the development history of the quantum well and the quantum dots laser diodes, and their future prospects. PMID:28773227

Solar cells with gallium phosphide/silicon heterojunction

NASA Astrophysics Data System (ADS)

Darnon, Maxime; Varache, Renaud; Descazeaux, Médéric; Quinci, Thomas; Martin, Mickaël; Baron, Thierry; Muñoz, Delfina

2015-09-01

One of the limitations of current amorphous silicon/crystalline silicon heterojunction solar cells is electrical and optical losses in the front transparent conductive oxide and amorphous silicon layers that limit the short circuit current. We propose to grow a thin (5 to 20 nm) crystalline Gallium Phosphide (GaP) by epitaxy on silicon to form a more transparent and more conducting emitter in place of the front amorphous silicon layers. We show that a transparent conducting oxide (TCO) is still necessary to laterally collect the current with thin GaP emitter. Larger contact resistance of GaP/TCO increases the series resistance compared to amorphous silicon. With the current process, losses in the IR region associated with silicon degradation during the surface preparation preceding GaP deposition counterbalance the gain from the UV region. A first cell efficiency of 9% has been obtained on ˜5×5 cm2 polished samples.

High-efficiency indium tin oxide/indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

1989-01-01

Improvements in the performance of indium tin oxide (ITO)/indium phosphide solar cells have been realized by the dc magnetron sputter deposition of n-ITO onto an epitaxial p/p(+) structure grown on commercial p(+) bulk substrates. The highest efficiency cells were achieved when the surface of the epilayer was exposed to an Ar/H2 plasma before depositing the bulk of the ITO in a more typical Ar/O2 plasma. With H2 processing, global efficiencies of 18.9 percent were achieved. It is suggested that the excellent performance of these solar cells results from the optimization of the doping, thickness, transport, and surface properties of the p-type base, as well as from better control over the ITO deposition procedure.

Managing aluminum phosphide poisonings

PubMed Central

Gurjar, Mohan; Baronia, Arvind K; Azim, Afzal; Sharma, Kalpana

2011-01-01

Aluminum phosphide (AlP) is a cheap, effective and commonly used pesticide. However, unfortunately, it is now one of the most common causes of poisoning among agricultural pesticides. It liberates lethal phosphine gas when it comes in contact either with atmospheric moisture or with hydrochloric acid in the stomach. The mechanism of toxicity includes cellular hypoxia due to the effect on mitochondria, inhibition of cytochrome C oxidase and formation of highly reactive hydroxyl radicals. The signs and symptoms are nonspecific and instantaneous. The toxicity of AlP particularly affects the cardiac and vascular tissues, which manifest as profound and refractory hypotension, congestive heart failure and electrocardiographic abnormalities. The diagnosis of AlP usually depends on clinical suspicion or history, but can be made easily by the simple silver nitrate test on gastric content or on breath. Due to no known specific antidote, management remains primarily supportive care. Early arrival, resuscitation, diagnosis, decrease the exposure of poison (by gastric lavage with KMnO4, coconut oil), intensive monitoring and supportive therapy may result in good outcome. Prompt and adequate cardiovascular support is important and core in the management to attain adequate tissue perfusion, oxygenation and physiologic metabolic milieu compatible with life until the tissue poison levels are reduced and spontaneous circulation is restored. In most of the studies, poor prognostic factors were presence of acidosis and shock. The overall outcome improved in the last decade due to better and advanced intensive care management. PMID:21887030

Aqueous corrosion of phosphide minerals from iron meteorites: a highly reactive source of prebiotic phosphorus on the surface of the early Earth.

PubMed

Pasek, Matthew A; Lauretta, Dante S

2005-08-01

We present the results of an experimental study of aqueous corrosion of Fe-phosphide under conditions relevant to the early Earth. The results strongly suggest that iron meteorites were an important source of reactive phosphorus (P), a requirement for the formation of P-based life. We further demonstrate that iron meteorites were an abundant source of phosphide minerals early in Earth history. Phosphide corrosion was studied in five different solutions: deionized water, deionized water buffered with sodium bicarbonate, deionized water with dissolved magnesium and calcium chlorides, deionized water containing ethanol and acetic acid, and deionized water containing the chlorides, ethanol, and acetic acid. Experiments were performed in the presence of both air and pure Ar gas to evaluate the effect of atmospheric chemistry. Phosphide corrosion in deionized water results in a metastable mixture of mixed-valence, P-bearing ions including pyrophosphate and triphosphate, key components for metabolism in modern life. In a pH-buffered solution of NaHCO(3), the condensed and reduced species diphosphonate is an abundant corrosion product. Corrosion in ethanol- and acetic acid-containing solutions yields additional P-bearing organic molecules, including acetyl phosphonate and a cyclic triphosphorus molecule. Phosphonate is a major corrosion product of all experiments and is the only P-bearing molecule that persists in solutions with high concentrations of magnesium and calcium chlorides, which suggests that phosphonate may have been a primitive oceanic source of P. The stability and reactivity of phosphonate and hypophosphite in solution were investigated to elucidate reaction mechanisms and the role of mineral catalysts on P-solution chemistry. Phosphonate oxidation is rapid in the presence of Fe metal but negligible in the presence of magnetite and in the control sample. The rate of hypophosphite oxidation is independent of reaction substrate.

Andreyivanovite: A Second New Phosphide from the Kaidun Meteorite

NASA Technical Reports Server (NTRS)

Zolensky, Michael

2008-01-01

Andreyivanovite (ideally FeCrP) is another new phosphide species from the Kaidun meteorite, which fell in South Yemen in 1980. Kaidun is a unique breccia containing an unprecedented variety of fragments of different chondritic as well as achondritic lithologies. Andreyivanovite was found as individual grains and linear arrays of grains with a maximum dimension of 8 m within two masses of Fe-rich serpentine. In one sample it is associated with Fe-Ni-Cr sulfides and florenskyite (FeTiP). Andreyivanovite is creamy white in reflected light, and its luster is metallic. The average of nine electron microprobe analyses yielded the formula Fe(Cr0.587 Fe0.150 V0.109 Ti0.081 Ni0.060 Co0.002)P. Examination of single grains of andreyivanovite using Laue patterns collected by in-situ synchrotron X-ray diffraction (XRD), and by electron backscattered diffraction revealed that it is isostructural with florenskyite; we were unable to find single crystals of sufficient quality to perform a complete structure analysis. Andreyivanovite crystallizes in the space group Pnma, and has the anti-PbCl2 structure. Previously-determined cell constants of synthetic material [a = 5.833(1), b = 3.569(1), c = 6.658(1) A] were consistent with our XRD work. We used the XPOW program to calculate a powder XRD pattern; the 5 most intense reflections are d = 2.247 (I = 100), 2.074 (81), 2.258 (46), 1.785 (43), and 1.885 A (34). Andreyivanovite is the second new phosphide to be described from the Kaidun meteorite. Andreyivanovite could have formed as a result of cooling and crystallization of a melted precursor consisting mainly of Fe-Ni metal enriched in P, Ti, and Cr. Serpentine associated with andreyivanovite would then have formed during aqueous alteration on the parent asteroid. It is also possible that the andreyivanovite could have formed during aqueous alteration, however, artificial FeTiP has been synthesized only during melting experiments, at low oxygen fugacity, and there is no evidence that

A novel and efficient samarium iodide-mediated synthesis of neoflavonoids (4-arycloumarins)

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

Nagasawa, Kazuo; Ryohke, Hirosi; Ohnishi, Makoto

1995-12-31

Bioactive 4-arylcoumarins (4-aryl-2H-1-benzopyran-2-ones) have been recently isolated from the plants belonging to the families like Leguminosae, Guttiferae, and Compositae, some of which are still used as the traditional folk medicine. Despite many methods reported so far, there appears to be of limited success or of no success in some cases (II{sub b-g}) and, therefore, a simpler and more reliable one remains to be highly desired. Thus, a new and sterling protocol is now presented for the synthesis of neoflavonoids, which involves the intramolecular Reformatsky-type reaction via a one electron transfer process with samarium diiodide as a key step.

MOF-Derived Ultrathin Cobalt Phosphide Nanosheets as Efficient Bifunctional Hydrogen Evolution Reaction and Oxygen Evolution Reaction Electrocatalysts

PubMed Central

Li, Hong; Ke, Fei; Zhu, Junfa

2018-01-01

The development of a highly efficient and stable bifunctional electrocatalyst for water splitting is still a challenging issue in obtaining clean and sustainable chemical fuels. Herein, a novel bifunctional catalyst consisting of 2D transition-metal phosphide nanosheets with abundant reactive sites templated by Co-centered metal−organic framework nanosheets, denoted as CoP-NS/C, has been developed through a facile one-step low-temperature phosphidation process. The as-prepared CoP-NS/C has large specific surface area and ultrathin nanosheets morphology providing rich catalytic active sites. It shows excellent electrocatalytic performances for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic and alkaline media, with the Tafel slopes of 59 and 64 mV/dec and a current density of 10 mA/cm2 at the overpotentials of 140 and 292 mV, respectively, which are remarkably superior to those of CoP/C, CoP particles, and comparable to those of commercial noble-metal catalysts. In addition, the CoP-NS/C also shows good durability after a long-term test. PMID:29414838

Surface-oxidized cobalt phosphide used as high efficient electrocatalyst in activated carbon air-cathode microbial fuel cell

NASA Astrophysics Data System (ADS)

Yang, Tingting; Wang, Zhong; Li, Kexun; Liu, Yi; Liu, Di; Wang, Junjie

2017-09-01

Herein, we report a simplistic method to fabricate the surface-oxidized cobalt phosphide (CoP) nanocrystals (NCs), which is used as electrocatalyst for oxygen reduction reaction (ORR) in microbial fuel cell (MFC) for the first time. The corallite-like CoP NCs are successfully prepared by a hydrothermal reaction following a phosphating treatment in N2 atmosphere. When used as an ORR catalyst, cobalt phosphide shows comparable onset potential, inferior resistance, as well as a small Tafel slope with long-term stability in neutral media. The maximum power density of MFC embellished with 10% CoP reached 1914.4 ± 59.7 mW m-2, which is 108.5% higher than the control. The four-electron pathway, observed by the RDE, plays a crucial role in electrochemical catalytic activity. In addition, material characterizations indicate that the surface oxide layer (CoOx) around the metallic CoP core is important and beneficial for ORR. Accordingly, it can be expected that the as-synthesized CoP will be a promising candidate of the non-precious metal ORR electrocatalysts for electrochemical energy applications.

Phase Composition of Samarium Niobate and Tantalate Thin Films Prepared by Sol-Gel Method

NASA Astrophysics Data System (ADS)

Bruncková, H.; Medvecký, Ľ.; Múdra, E.; Kovalčiková, A.; Ďurišin, J.; Šebek, M.; Girman, V.

2017-12-01

Samarium niobate SmNbO4 (SNO) and tantalate SmTaO4 (STO) thin films ( 100 nm) were prepared by sol-gel/spin-coating process on alumina substrates with PZT interlayer and annealing at 1000°C. The precursors of films were synthesized using Nb or Ta tartrate complexes. The improvement of the crystallinity of monoclinic M'-SmTaO4 phase via heating was observed through the coexistence of small amounts of tetragonal T-SmTa7O19 phase in STO precursor at 1000°C. The XRD results of SNO and STO films confirmed monoclinic M-SmNbO4 and M'-SmTaO4 phases, respectively, with traces of orthorhombic O-SmNbO4 (in SNO). In STO film, the single monoclinic M'-SmTaO4 phase was revealed. The surface morphology and topography of thin films were investigated by SEM and AFM analysis. STO film was smoother with roughness 3.2 nm in comparison with SNO (6.3 nm). In the microstructure of SNO film, small spherical ( 50 nm) and larger cuboidal particles ( 100 nm) of the SmNbO4 phase were observed. In STO, compact clusters composed of fine spherical SmTaO4 particles ( 20-50 nm) were found. Effect of samarium can contribute to the formation different polymorphs of these films for the application to environmental electrolytic thin film devices.

Efficient telecom to visible wavelength conversion in doubly resonant gallium phosphide microdisks

NASA Astrophysics Data System (ADS)

Lake, David P.; Mitchell, Matthew; Jayakumar, Harishankar; dos Santos, Laís Fujii; Curic, Davor; Barclay, Paul E.

2016-01-01

Resonant second harmonic generation between 1550 nm and 775 nm with normalized outside efficiency > 3.8 × 10 - 4 mW - 1 is demonstrated in a gallium phosphide microdisk supporting high-Q modes at visible ( Q ˜ 10 4 ) and infrared ( Q ˜ 10 5 ) wavelengths. The double resonance condition is satisfied for a specific pump power through intracavity photothermal temperature tuning using ˜ 360 μ W of 1550 nm light input to a fiber taper and coupled to a microdisk resonance. Power dependent efficiency consistent with a simple model for thermal tuning of the double resonance condition is observed.

Incommensurate structure of a lillianite-type samarium chromium sulfide Sm{sub 2/3}Cr{sub 2}S{sub 4}

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

Lafond, A.; Cario, L.; Meerschaut, A.

1996-12-01

The structure of Sm{sub 2/3}Cr{sub 2}S{sub 4} has been solved from single-crystal X-ray diffraction data. This compound presents a 3 X a superstructure along a and an incommensurate superstructure along b close to 3 x b. The basic structure is described in the space group Pmnb with a = 3.5030(3) {Angstrom}, b = 10.9199(8) {Angstrom}, c = 12.7987(8) {Angstrom}, Z = 4, R = 0.046 for 916 observed reflections. The modulated structure refinement, taking into account the two superstructures, was carried out in a (3 + 2)D superspace group and leads to R = 0.063 for 1706 reflections. This structuremore » consists of staggered double columns of [CrS{sub 6}] octahedra connected by samarium atoms in a trigonal prismatic bicapped environment. This structure is reminiscent of that found in the lillianite mineral family. The statistical occupancy of samarium atoms (1/3), in agreement with the charge equilibrium (Sm{sup 3+}, Cr{sup 3+}, S{sup 2-}), is related to the superstructure.« less

Magnetic behavior study of samarium nitride using density functional theory

NASA Astrophysics Data System (ADS)

Som, Narayan N.; Mankad, Venu H.; Dabhi, Shweta D.; Patel, Anjali; Jha, Prafulla K.

2018-02-01

In this work, the state-of-art density functional theory is employed to study the structural, electronic and magnetic properties of samarium nitride (SmN). We have performed calculation for both ferromagnetic and antiferromagnetic states in rock-salt phase. The calculated results of optimized lattice parameter and magnetic moment agree well with the available experimental and theoretical values. From energy band diagram and electronic density of states, we observe a half-metallic behaviour in FM phase of rock salt SmN in while metallicity in AFM I and AFM III phases. We present and discuss our current understanding of the possible half-metallicity together with the magnetic ordering in SmN. The calculated phonon dispersion curves shows dynamical stability of the considered structures. The phonon density of states and Eliashberg functional have also been analysed to understand the superconductivity in SmN.

Gallium Phosphide Integrated with Silicon Heterojunction Solar Cells

NASA Astrophysics Data System (ADS)

Zhang, Chaomin

It has been a long-standing goal to epitaxially integrate III-V alloys with Si substrates which can enable low-cost microelectronic and optoelectronic systems. Among the III-V alloys, gallium phosphide (GaP) is a strong candidate, especially for solar cells applications. Gallium phosphide with small lattice mismatch ( 0.4%) to Si enables coherent/pseudomorphic epitaxial growth with little crystalline defect creation. The band offset between Si and GaP suggests that GaP can function as an electron-selective contact, and it has been theoretically shown that GaP/Si integrated solar cells have the potential to overcome the limitations of common a-Si based heterojunction (SHJ) solar cells. Despite the promising potential of GaP/Si heterojunction solar cells, there are two main obstacles to realize high performance photovoltaic devices from this structure. First, the growth of the polar material (GaP) on the non-polar material (Si) is a challenge in how to suppress the formation of structural defects, such as anti-phase domains (APD). Further, it is widely observed that the minority-carrier lifetime of the Si substrates is significantly decreased during epitaxially growth of GaP on Si. In this dissertation, two different GaP growth methods were compared and analyzed, including migration-enhanced epitaxy (MEE) and traditional molecular beam epitaxy (MBE). High quality GaP can be realized on precisely oriented (001) Si substrates by MBE growth, and the investigation of structural defect creation in the GaP/Si epitaxial structures was conducted using high resolution X-ray diffraction (HRXRD) and high resolution transmission electron microscopy (HRTEM). The mechanisms responsible for lifetime degradation were further investigated, and it was found that external fast diffusors are the origin for the degradation. Two practical approaches including the use of both a SiNx diffusion barrier layer and P-diffused layers, to suppress the Si minority-carrier lifetime degradation

Comparative radiation resistance, temperature dependence and performance of diffused junction indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.; Ghandhi, S. K.; Borrego, J. M.

1987-01-01

Indium phosphide solar cells whose p-n junctions were processed by the open tube capped diffusion and by the closed tube uncapped diffusion of sulfur into Czochralski-grown p-type substrates are compared. Differences found in radiation resistance were attributed to the effects of increased base dopant concentration. Both sets of cells showed superior radiation resistance to that of gallium arsenide cells, in agreement with previous results. No correlation was, however, found between the open-circuit voltage and the temperature dependence of the maximum power.

Second harmonic generation in gallium phosphide photonic crystal nanocavities with ultralow continuous wave pump power.

PubMed

Rivoire, Kelley; Lin, Ziliang; Hatami, Fariba; Masselink, W Ted; Vucković, Jelena

2009-12-07

We demonstrate second harmonic generation in photonic crystal nanocavities fabricated in the semiconductor gallium phosphide. We observe second harmonic radiation at 750 nm with input powers of only nanowatts coupled to the cavity and conversion effciency P(out)/P(2)(in,coupled)=430%/W. The large electronic band gap of GaP minimizes absorption loss, allowing effcient conversion. Our results are promising for integrated, low-power light sources and on-chip reduction of input power in other nonlinear processes.

Fabrication and properties of gallium phosphide variable colour displays

NASA Technical Reports Server (NTRS)

Effer, D.; Macdonald, R. A.; Macgregor, G. M.; Webb, W. A.; Kennedy, D. I.

1973-01-01

The unique properties of single-junction gallium phosphide devices incorporating both red and green radiative recombination centers were investigated in application to the fabrication of monolithic 5 x 7 displays capable of displaying symbolic and alphanumeric information in a multicolor format. A number of potentially suitable material preparation techniques were evaluated in terms of both material properties and device performance. Optimum results were obtained for double liquid-phase-epitaxial process in which an open-tube dipping technique was used for n-layer growth and a sealed tipping procedure for subsequent p-layer growth. It was demonstrated that to prepare devices exhibiting a satisfactory range of dominant wavelengths which can be perceived as distinct emission colors extending from the red through green region of the visible spectrum involves a compromise between the material properties necessary for efficient red emission and those considered optimum for efficient green emission.

ANALYSIS OF THE WATER-SPLITTING CAPABILITIES OF GALLIUM INDIUM PHOSPHIDE NITRIDE (GaInPN)

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

Head, J.; Turner, J.

2007-01-01

With increasing demand for oil, the fossil fuels used to power society’s vehicles and homes are becoming harder to obtain, creating pollution problems and posing hazard’s to people’s health. Hydrogen, a clean and effi cient energy carrier, is one alternative to fossil fuels. Certain semiconductors are able to harness the energy of solar photons and direct it into water electrolysis in a process known as photoelectrochemical water-splitting. P-type gallium indium phosphide (p-GaInP2) in tandem with GaAs is a semiconductor system that exhibits water-splitting capabilities with a solar-tohydrogen effi ciency of 12.4%. Although this material is effi cient at producing hydrogenmore » through photoelectrolysis it has been shown to be unstable in solution. By introducing nitrogen into this material, there is great potential for enhanced stability. In this study, gallium indium phosphide nitride Ga1-yInyP1-xNx samples were grown using metal-organic chemical vapor deposition in an atmospheric-pressure vertical reactor. Photocurrent spectroscopy determined these materials to have a direct band gap around 2.0eV. Mott-Schottky analysis indicated p-type behavior with variation in fl atband potentials with varied frequencies and pH’s of solutions. Photocurrent onset and illuminated open circuit potential measurements correlated to fl atband potentials determined from previous studies. Durability analysis suggested improved stability over the GaInP2 system.« less

Hot charcoal vomitus in aluminum phosphide poisoning - A case report of internal thermal reaction in aluminum phosphide poisoning and review of literature

PubMed Central

Mirakbari, Seyed Mostafa

2015-01-01

Aluminium phosphide (ALP) poisoning is a commonly encountered poisoning in emergency departments in most developing countries. Many papers have revealed metabolic derangements in this poisoning and also examined contributing factors leading to death, but only few have reported physical damage. Some case reports have described a complication that has been frequently termed ‘ignition’. The exact mechanism of this phenomenon has not been fully elucidated. An exothermic reaction during therapeutic administration of chemicals may contribute to this problem, but the incidence has occurred in the absence of treatment or drug administration. Here, we report a 34-year-old woman with ALP poisoning who presented with hot charcoal vomitus, a sign of internal thermal event, leading to the thermal burning of the patient's face and internal damage resulting in death. We reviewed all reported cases with similar complication to demonstrate varied characteristics of patients and to propose the possible mechanisms leading to this event. PMID:26257417

Morphological, spectroscopic and thermal studies of samarium chloride coordinated single crystal grown by slow evaporation method

NASA Astrophysics Data System (ADS)

Slathia, Goldy; Raina, Bindu; Gupta, Rashmi; Bamzai, K. K.

2018-05-01

The synthesis of samarium chloride coordinated single crystal was carried out at room temperature by slow evaporation method. The crystal possesses a well defined hexagonal morphology with six symmetrically equivalent growth sectors separated by growth boundaries. The theoretical morphology has been established by structural approach using Bravaise-Friedele-Donnaye-Harker (BFDH) law. Fourier transform infra red spectroscopy was carried in order to study the geometry and structure of the crystal. The detailed thermogravimetric analysis elucidates the thermal stability of the complex.

Process Development of Gallium Nitride Phosphide Core-Shell Nanowire Array Solar Cell

NASA Astrophysics Data System (ADS)

Chuang, Chen

Dilute Nitride GaNP is a promising materials for opto-electronic applications due to its band gap tunability. The efficiency of GaNxP1-x /GaNyP1-y core-shell nanowire solar cell (NWSC) is expected to reach as high as 44% by 1% N and 9% N in the core and shell, respectively. By developing such high efficiency NWSCs on silicon substrate, a further reduction of the cost of solar photovoltaic can be further reduced to 61$/MWh, which is competitive to levelized cost of electricity (LCOE) of fossil fuels. Therefore, a suitable NWSC structure and fabrication process need to be developed to achieve this promising NWSC. This thesis is devoted to the study on the development of fabrication process of GaNxP 1-x/GaNyP1-y core-shell Nanowire solar cell. The thesis is divided into two major parts. In the first parts, previously grown GaP/GaNyP1-y core-shell nanowire samples are used to develop the fabrication process of Gallium Nitride Phosphide nanowire solar cell. The design for nanowire arrays, passivation layer, polymeric filler spacer, transparent col- lecting layer and metal contact are discussed and fabricated. The property of these NWSCs are also characterized to point out the future development of Gal- lium Nitride Phosphide NWSC. In the second part, a nano-hole template made by nanosphere lithography is studied for selective area growth of nanowires to improve the structure of core-shell NWSC. The fabrication process of nano-hole templates and the results are presented. To have a consistent features of nano-hole tem- plate, the Taguchi Method is used to optimize the fabrication process of nano-hole templates.

Gamma spectrometry and chemical characterization of ceramic seeds with samarium-153 and holmium-166 for brachytherapy proposal.

PubMed

Valente, Eduardo S; Campos, Tarcísio P R

2010-12-01

Ceramic seeds were synthesized by the sol-gel technique with Si:Sm:Ca and Si:Ho:Ca. One set of seeds was irradiated in the TRIGA type nuclear reactor IPR-R1 and submitted to instrumental neutron activation analysis (INAA), K(0) method, to determine mass percentage concentration of natural samarium and holmium in the seed as well as to determine all existing radionuclides and their activities. Attention was paid to discrimination of Si-31, Ca-40, Ca-45, Ca-47, Ca-49, Sm-145, Sm-155, Sm-153 and Ho-166. A second sample was submitted to atomic emission spectrometry (ICP-AES) also to determine samarium and holmium concentrations in weight. A third sample was submitted to X-ray fluorescence spectrometry to qualitatively determine chemical composition. The measured activity was due to Sm-153 and Ho-166 with a well-characterized gamma spectrum. The X-ray fluorescence spectrum demonstrated that there is no discrepancy in seed composition. The maximum ranges in the water of beta particles from Sm-153 and Ho-166 decay were evaluated, as well as the dose rate and total dose delivered within the volume delimited by the range of the beta particles. The results are relevant for investigation of the viability of producing Sm-153 and Ho-166 radioactive seeds for use in brachytherapy. Copyright 2010 Elsevier Ltd. All rights reserved.

Theoretical prediction of sandwiched two-dimensional phosphide binary compound sheets with tunable bandgaps and anisotropic physical properties

NASA Astrophysics Data System (ADS)

Zhang, C. Y.; Yu, M.

2018-03-01

Atomic layers of GaP and InP binary compounds with unique anisotropic structural, electronic and mechanical properties have been predicted from first-principle molecular dynamics simulations. These new members of the phosphide binary compound family stabilize to a sandwiched two-dimensional (2D) crystalline structure with orthorhombic lattice symmetry and high buckling of 2.14 Å-2.46 Å. Their vibration modes are similar to those of phosphorene with six Raman active modes ranging from ˜80 cm-1 to 400 cm-1. The speeds of sound in their phonon dispersions reflect anisotropy in their elastic constants, which was further confirmed by their strong directional dependence of Young’s moduli and effective nonlinear elastic moduli. They show wide bandgap semiconductor behavior with fundamental bandgaps of 2.89 eV for GaP and 2.59 eV for InP, respectively, even wider than their bulk counterparts. Such bandgaps were found to be tunable under strain. In particular, a direct-indirect bandgap transition was found under certain strains along zigzag or biaxial orientations, reflecting their promising applications in strain-induced bandgap engineering in nanoelectronics and photovoltaics. Feasible pathways to realize these novel 2D phosphide compounds are also proposed.

Indium phosphide solar cells - Status and prospects for use in space

NASA Technical Reports Server (NTRS)

Weinberg, I.; Brinker, D. J.

1986-01-01

The current status of indium phosphide cell research is reviewed and state of the art efficiencies compared to those of GaAs and Si. It is shown that the radiation resistance of InP cells is superior to that of either GaAs or Si under 1 MeV electron and 10 MeV proton irradiation. Using lightweight blanket technology, a SEP array structure and projected cell efficiencies, array specific powers are obtained for all three cell types. Array performance is calculated as a function of time in orbit. The results indicate that arrays using InP cells can outperform those using GaAs or Si in orbits where radiation is a significant cell degradation factor. It is concluded that InP solar cells are excellent prospects for future use in the space radiation environment.

Indium phosphide solar cells: status and prospects for use in space

NASA Technical Reports Server (NTRS)

Weinberg, I.; Brinker, D. J.

1986-01-01

The current status of indium phosphide cell research is reviewed and state of the art efficiencies compared to those of GaAs and Si. It is shown that the radiation resistance of InP cells is superior to that of either GaAs or Si under 1 MeV electron and 10 MeV proton irradiation. Using lightweight blanket technology, a SEP array structure and projected cell efficiencies, array specific powers are obtained for all three cell types. Array performance is calculated as a function of time in orbit. The results indicate that arrays using InP cells can outperform those using GaAs or Si in orbits where radiation is a significant cell degradation factor. It is concluded that InP solar cells are excellent prospects for future use in the space radiation environment.

Influence of Samarium Substitution on Dielectric Properties of Barium Titanate Based Ceramics

NASA Astrophysics Data System (ADS)

Kumar, Parveen; Singh, Sangeeta; Juneja, J. K.; Prakash, Chandra; Raina, K. K.

In this paper we report samarium substituted Ba0.80Pb0.20Ti0.90Zr0.10O3 (BPZT) ceramics. The material series with compositional formula Ba0.80-xSmxPb0.20Ti0.90Zr0.10O3 with x varying from 0 to 0.01 in the steps of 0.0025 was chosen for investigations. The material was synthesized by solid state reaction method. Reacted powders compacted in the form of circular discs were sintered at 1325°C. All the samples were subjected to X-ray analysis and found to be single phase. Dielectric behavior was studied as a function of frequency and temperature and Curie temperature (Tc) was determined. Tc was found to decrease with increasing x. The details are discussed and presented here.

Structural and luminescence properties of samarium doped lead alumino borate glasses

NASA Astrophysics Data System (ADS)

Mohan, Shaweta; Kaur, Simranpreet; Singh, D. P.; Kaur, Puneet

2017-11-01

The study reports the effect of samarium concentration on the physical, structural and spectroscopic characteristics of samarium doped lead alumino borate glasses having composition 20PbO-(10-x)Al2O3-70B2O3-xSm2O3; x = 0.1, 0.5, 1.0 and 2.0 mol %. The glasses were fabricated by conventional melt-quenching technique and then characterized by XRD, FTIR, optical absorption and fluorescence spectra. X-ray diffraction studies confirmed the amorphous nature of the prepared glasses. FTIR spectra indicate the presence of BO3, BO4, AlO6 and a few other structural groups. Various physical properties such as density, molar volume, refractive index, rare earth ion concentration, boron-boron distance and polarizability etc. were determined using conventional methods and standard formulae. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. The value of Ω2 was found to be highest for glass with 1 mol% Sm2O3 and attributed to the asymmetry of the ligand field at the rare earth ion site and the rare earth oxygen (Sm-O) covalency. The calculated intensity parameters and fluorescence spectra were further used to predict the radiative transition probability (A), radiative lifetime (τR), branching ratio (βR), peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σ) for the characteristic 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 transitions of the Sm3+ ion. Concentration quenching was observed for 2 mol% concentration of Sm2O3 and ascribed to energy transfer through various cross-relaxation channels between Sm3+ ions. Reasonably high values of branching ratios and stimulated emission cross-section for the prepared glasses points towards their utility in the development of visible lasers emitting in the reddish-orange spectral region. However, the glass with 1 mol% Sm2O3 was found to show better radiative properties.

Effectiveness of Radiation Synovectomy with Samarium-153 Particulate Hydroxyapatite in Rheumatoid Arthritis Patients with Knee Synovitis: A Controlled Randomized Double-Blind Trial

PubMed Central

dos Santos, Marla Francisca; Furtado, Rita Nely Vilar; Konai, Monique Sayuri; Castiglioni, Mario Luiz Vieira; Marchetti, Renata Rosa; Natour, Jamil

2009-01-01

OBJECTIVES: The aim of the present study was to investigate the effectiveness of Samarium153-particulate hydroxyapatite radiation synovectomy in rheumatoid arthritis patients with chronic knee synovitis. METHODS: Fifty-eight rheumatoid arthritis patients (60 knees) with chronic knee synovitis participated in a controlled double-blinded trial. Patients were randomized to receive either an intra-articular injection with 40 mg triamcinolone hexacetonide alone (TH group) or 40 mg triamcinolone hexacetonide combined with 15 mCi Samarium153-particulate hydroxyapatite (Sm/TH group). Blinded examination at baseline (T0) and at 1 (T1), 4 (T4), 12 (T12), 32 (T32), and 48 (T48) weeks post-intervention were performed on all patients and included a visual analog scale for joint pain and swelling as well as data on morning stiffness, flexion, extension, knee circumference, Likert scale of improvement, percentage of improvement, SF-36 generic quality of life questionnaire, Stanford Health Assessment Questionnaire (HAQ), Lequesne index, use of non-steroidal anti-inflammatory drugs or oral corticosteroids, events and adverse effects, calls to the physician, and hospital visits. RESULTS: The sample was homogeneous at baseline, and there were no withdrawals. Improvement was observed in both groups in relation to T0, but no statistically significant differences between groups were observed regarding all variables at the time points studied. The Sm/TH group exhibited more adverse effects at T1 (p<0.05), but these were mild and transitory. No severe adverse effects were reported during follow-up. CONCLUSION: Intra-articular injection of Samarium153-particulate hydroxyapatite (15 mCi) with 40 mg of triamcinolone hexacetonide is not superior to triamcinolone hexacetonide alone for the treatment of knee synovitis in patients with rheumatoid arthritis at 1 y of follow-up. PMID:20037706

Effectiveness of radiation synovectomy with samarium-153 particulate hydroxyapatite in rheumatoid arthritis patients with knee synovitis: a controlled randomized double-blind trial.

PubMed

Santos, Marla Francisca dos; Furtado, Rita Nely Vilar; Konai, Monique Sayuri; Castiglioni, Mario Luiz Vieira; Marchetti, Renata Rosa; Natour, Jamil

2009-01-01

The aim of the present study was to investigate the effectiveness of Samarium(153)-particulate hydroxyapatite radiation synovectomy in rheumatoid arthritis patients with chronic knee synovitis. Fifty-eight rheumatoid arthritis patients (60 knees) with chronic knee synovitis participated in a controlled double-blinded trial. Patients were randomized to receive either an intra-articular injection with 40 mg triamcinolone hexacetonide alone (TH group) or 40 mg triamcinolone hexacetonide combined with 15 mCi Samarium(153)-particulate hydroxyapatite (Sm/TH group). Blinded examination at baseline (T0) and at 1 (T1), 4 (T4), 12 (T12), 32 (T32), and 48 (T48) weeks post-intervention were performed on all patients and included a visual analog scale for joint pain and swelling as well as data on morning stiffness, flexion, extension, knee circumference, Likert scale of improvement, percentage of improvement, SF-36 generic quality of life questionnaire, Stanford Health Assessment Questionnaire (HAQ), Lequesne index, use of non-steroidal anti-inflammatory drugs or oral corticosteroids, events and adverse effects, calls to the physician, and hospital visits. The sample was homogeneous at baseline, and there were no withdrawals. Improvement was observed in both groups in relation to T0, but no statistically significant differences between groups were observed regarding all variables at the time points studied. The Sm/TH group exhibited more adverse effects at T1 (p<0.05), but these were mild and transitory. No severe adverse effects were reported during follow-up. Intra-articular injection of Samarium(153)-particulate hydroxyapatite (15 mCi) with 40 mg of triamcinolone hexacetonide is not superior to triamcinolone hexacetonide alone for the treatment of knee synovitis in patients with rheumatoid arthritis at 1 y of follow-up.

Samarium Monosulfide (SmS): Reviewing Properties and Applications

PubMed Central

Sousanis, Andreas

2017-01-01

In this review, we give an overview of the properties and applications of samarium monosulfide, SmS, which has gained considerable interest as a switchable material. It shows a pressure-induced phase transition from the semiconducting to the metallic state by polishing, and it switches back to the semiconducting state by heating. The material also shows a magnetic transition, from the paramagnetic state to an antiferromagnetically ordered state. The switching behavior between the semiconducting and metallic states could be exploited in several applications, such as high density optical storage and memory materials, thermovoltaic devices, infrared sensors and more. We discuss the electronic, optical and magnetic properties of SmS, its switching behavior, as well as the thin film deposition techniques which have been used, such as e-beam evaporation and sputtering. Moreover, applications and possible ideas for future work on this material are presented. Our scope is to present the properties of SmS, which were mainly measured in bulk crystals, while at the same time we describe the possible deposition methods that will push the study of SmS to nanoscale dimensions, opening an intriguing range of applications for low-dimensional, pressure-induced semiconductor–metal transition compounds. PMID:28813006

Carbon phosphide monolayers with superior carrier mobility

NASA Astrophysics Data System (ADS)

Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

2016-04-01

Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics.Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great

Phosphorus-Rich Copper Phosphide Nanowires for Field-Effect Transistors and Lithium-Ion Batteries.

PubMed

Li, Guo-An; Wang, Chiu-Yen; Chang, Wei-Chung; Tuan, Hsing-Yu

2016-09-27

Phosphorus-rich transition metal phosphide CuP2 nanowires were synthesized with high quality and high yield (∼60%) via the supercritical fluid-liquid-solid (SFLS) growth at 410 °C and 10.2 MPa. The obtained CuP2 nanowires have a high aspect ratio and exhibit a single crystal structure of monoclinic CuP2 without any impurity phase. CuP2 nanowires have progressive improvement for semiconductors and energy storages compared with bulk CuP2. Being utilized for back-gate field effect transistor (FET) measurement, CuP2 nanowires possess a p-type behavior intrinsically with an on/off ratio larger than 10(4) and its single nanowire electrical transport property exhibits a hole mobility of 147 cm(2) V(-1) s(-1), representing the example of a CuP2 transistor. In addition, CuP2 nanowires can serve as an appealing anode material for a lithium-ion battery electrode. The discharge capacity remained at 945 mA h g(-1) after 100 cycles, showing a good capacity retention of 88% based on the first discharge capacity. Even at a high rate of 6 C, the electrode still exhibited an outstanding result with a capacity of ∼600 mA h g(-1). Ex-situ transmission electron microscopy and CV tests demonstrate that the stability of capacity retention and remarkable rate capability of the CuP2 nanowires electrode are attributed to the role of the metal phosphide conversion-type lithium storage mechanism. Finally, CuP2 nanowire anodes and LiFePO4 cathodes were assembled into pouch-type lithium batteries offering a capacity over 60 mA h. The full cell shows high capacity and stable capacity retention and can be used as an energy supply to operate electronic devices such as mobile phones and mini 4WD cars.

Colloidal Cobalt Phosphide Nanocrystals as Trifunctional Electrocatalysts for Overall Water Splitting Powered by a Zinc–Air Battery

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

Li, Hui; Li, Qi; Wen, Peng

Highly efficient and stable electrocatalysts, particularly those that are capable of multifunctionality in the same electrolyte, are in high demand for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). In this paper, highly monodisperse CoP and Co 2P nanocrystals (NCs) are synthesized using a robust solution-phase method. The highly exposed (211) crystal plane and abundant surface phosphide atoms make the CoP NCs efficient catalysts toward ORR and HER, while metal-rich Co 2P NCs show higher OER performance owing to easier formation of plentiful Co 2P@COOH heterojunctions. Density functional theory calculation results indicate that themore » desorption of OH* from cobalt sites is the rate-limiting step for both CoP and Co 2P in ORR and that the high content of phosphide can lower the reaction barrier. A water electrolyzer constructed with a CoP NC cathode and a Co 2P NC anode can achieve a current density of 10 mA cm -2 at 1.56 V, comparable even to the noble metal-based Pt/C and RuO 2/C pair. Finally and furthermore, the CoP NCs are employed as an air cathode in a primary zinc–air battery, exhibiting a high power density of 62 mW cm -2 and good stability.« less

Colloidal Cobalt Phosphide Nanocrystals as Trifunctional Electrocatalysts for Overall Water Splitting Powered by a Zinc–Air Battery

DOE PAGES

Li, Hui; Li, Qi; Wen, Peng; ...

2018-01-15

Highly efficient and stable electrocatalysts, particularly those that are capable of multifunctionality in the same electrolyte, are in high demand for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). In this paper, highly monodisperse CoP and Co 2P nanocrystals (NCs) are synthesized using a robust solution-phase method. The highly exposed (211) crystal plane and abundant surface phosphide atoms make the CoP NCs efficient catalysts toward ORR and HER, while metal-rich Co 2P NCs show higher OER performance owing to easier formation of plentiful Co 2P@COOH heterojunctions. Density functional theory calculation results indicate that themore » desorption of OH* from cobalt sites is the rate-limiting step for both CoP and Co 2P in ORR and that the high content of phosphide can lower the reaction barrier. A water electrolyzer constructed with a CoP NC cathode and a Co 2P NC anode can achieve a current density of 10 mA cm -2 at 1.56 V, comparable even to the noble metal-based Pt/C and RuO 2/C pair. Finally and furthermore, the CoP NCs are employed as an air cathode in a primary zinc–air battery, exhibiting a high power density of 62 mW cm -2 and good stability.« less

Scaling Relations for Adsorption Energies on Doped Molybdenum Phosphide Surfaces

DOE PAGES

Fields, Meredith; Tsai, Charlie; Chen, Leanne D.; ...

2017-03-10

Molybdenum phosphide (MoP), a well-documented catalyst for applications ranging from hydrotreating reactions to electrochemical hydrogen evolution, has yet to be mapped from a more fundamental perspective, particularly in the context of transition-metal scaling relations. In this work, we use periodic density functional theory to extend linear scaling arguments to doped MoP surfaces and understand the behavior of the phosphorus active site. The derived linear relationships for hydrogenated C, N, and O species on a variety of doped surfaces suggest that phosphorus experiences a shift in preferred bond order depending on the degree of hydrogen substitution on the adsorbate molecule. Thismore » shift in phosphorus hybridization, dependent on the bond order of the adsorbate to the surface, can result in selective bond weakening or strengthening of chemically similar species. As a result, we discuss how this behavior deviates from transition-metal, sulfide, carbide, and nitride scaling relations, and we discuss potential applications in the context of electrochemical reduction reactions.« less

Samarium (III) Selective Membrane Sensor Based on Tin (IV) Boratophosphate

PubMed Central

Mittal, Susheel K.; Sharma, Harish Kumar; Kumar, Ashok S. K.

2004-01-01

A number of Sm (III) selective membranes of varying compositions using tin (IV) boratophosphate as electroactive material were prepared. Polyvinyl chloride, polystyrene and epoxy resin were used as binding materials. Membrane having composition of 40% exchanger and 60% epoxy resin exhibited best performance. This membrane worked well over a wide concentration range of 1×10-5M to 1×10-1 M of samarium ions with a Super-Nernstian slope of 40 mV/decade. It has a fast response time of less than 10 seconds and can be used for at least six months without any considerable divergence in potentials. The proposed sensor revealed good selectivities with respect to alkali, alkaline earth, some transition and rare earth metal ions and can be used in the pH range of 4.0-10.0. It was used as an indicator electrode in the potentiometric titration of Sm (III) ions against EDTA. Effect of internal solution was studied and the electrode was successfully used in non-aqueous media, too.

Thermochemistry of the gaseous fluorides of samarium, europium, and thulium

NASA Astrophysics Data System (ADS)

Kleinschmidt, P. D.; Lau, K. H.; Hildenbrand, D. L.

1981-01-01

The gaseous mono-, di-, and trifluorides of the lanthanide metals samarium, europium, and thulium were characterized thermochemically from high temperature equilibrium studies carried out by mass spectrometry. Reaction enthalpies and entropies were derived using second-law analysis throughout, and the results were used to evaluate the enthalpies of formation and bond dissociation energies (BDE) of the gaseous fluorides, and to obtain approximate values for the electronic entropies of the MF and MF2 species. The dissociation energies of the monofluorides D°0(SmF)=134 kcal/mole, D°0(EuF)=129 kcal/mole, and D°0(TmF)=121 kcal/mole, all ±2 kcal/mole, are in good agreement with values predicted by the Rittner electrostatic model, whereas values in the polyatomic fluorides show considerable variation and do not seem to follow any clear trends. Although the BDE values in some instances differ from previous estimates, their sums yield trifluoride heats of atomization that are in close accord with values derived from the vaporization thermodynamics of the solid trifluorides.

General One-Pot Synthesis of Transition-Metal Phosphide/Nitrogen-Doped Carbon Hybrid Nanosheets as Ultrastable Anodes for Sodium-Ion Batteries.

PubMed

Li, Jingjing; Shi, Liang; Gao, Jingyu; Zhang, Genqiang

2018-01-26

Sodium-ion batteries (SIBs) have been considered as promising energy storage devices in grid-level applications, owing to their largely reduced cost compared with that of lithium-ion batteries. However, the practical application of SIBs has been seriously hindered because of the lack of appropriate anode materials, limited by the thermodynamics perspective, which is one of the central task at current stage. Herein, we have developed a general one-pot strategy for the synthesis of transition-metal phosphide (TMP) based hybrid nanosheets composed of carbon-coated TMP nanoparticles anchored to the surface of nitrogen-doped carbon nanosheets. This facile and cost-effective method is quite universal and holds potential to be further extended to other metal phosphide materials. Significantly, the hybrid nanosheet electrode possesses excellent sodium storage properties as anodes for SIBs, including high specific capacity, an ultra-long cycle life and a remarkable rate performance. This work makes a significant contribution to not only the synthetic methodology of TMP-carbon two-dimensional hybrid nanostructures, but also the application of TMP-based anodes for high-energy SIBs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel tungsten phosphide embedded nitrogen-doped carbon nanotubes: A portable and renewable monitoring platform for anticancer drug in whole blood.

PubMed

Zhou, Haifeng; Ran, Guoxia; Masson, Jean-Francois; Wang, Chan; Zhao, Yuan; Song, Qijun

2018-05-15

Biosensors based on converting the concentration of analytes in complex samples into single electrochemical signals are attractive candidates as low cost, high-throughput, portable and renewable sensor platforms. Here, we describe a simple but practical analytical device for sensing an anticancer drug in whole blood, using the detection of methotrexate (MTX) as a model system. In this biosensor, a novel carbon-based composite, tungsten phosphide embedded nitrogen-doped carbon nanotubes (WP/N-CNT), was fixed to the electrode surface that supported redox cycling. The electronic transmission channel in nitrogen doped carbon nanotubes (N-CNT) and the synergistic effect of uniform distribution tungsten phosphide (WP) ensured that the electrode materials have outstanding electrical conductivity and catalytic performance. Meanwhile, the surface electronic structure also endows its surprisingly reproducible performance. To demonstrate portable operation for MTX sensing, screen printing electrodes (SPE) was modified with WP/N-CNT. The sensor exhibited low detection limits (45 nM), wide detection range (0.01-540 μM), good selectivity and long-term stability for the determination of MTX. In addition, the technique was successfully applied for the determination of MTX in whole blood. Copyright © 2018 Elsevier B.V. All rights reserved.

The 23 to 300 C demagnetization resistance of samarium-cobalt permanent magnets

NASA Technical Reports Server (NTRS)

Niedra, Janis M.; Overton, Eric

1991-01-01

The influence of temperature on knee point and squareness of the M-H demagnetization characteristic of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperature in demagnetization resistent permanent magnet devices. Composite plots of the knee field and the demagnetizing field required to produce a given magnetic induction swing below remanence were obtained for several commercial Sm2Co17 type magnet samples in the temperature range of 23 to 300 C. Using the knee point to define the limits of operation safe against irreversible demagnetization, such plots are shown to provide an effective overview of the useable regions in the space of temperature-induction swing parameters. The observed second quadrant M-H characteristic squareness is shown, by two measures, to increase gradually with temperature, reaching a peak in the interval 200 to 300 C.

Potential for use of indium phosphide solar cells in the space radiation environment

NASA Technical Reports Server (NTRS)

Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

1985-01-01

Indium phosphide solar cells were observed to have significantly higher radiation resistance than either GaAs or Si after exposure to 10 MeV proton irradiation data and previous 1 MeV electron data together with projected efficiencies for InP, it was found that these latter cells produced more output power than either GaAs or Si after specified fluences of 10 MeV protons and 1 MeV electrons. Estimates of expected performance in a proton dominated space orbit yielded much less degradation for InP when compared to the remaining two cell types. It was concluded that, with additional development to increase efficiency, InP solar cells would perform significantly better than either GaAs or Si in the space radiation environment.

Redox properties of samarium, europium and ytterbium in molten eutectic mixture of sodium, potassium and cesium chlorides

NASA Astrophysics Data System (ADS)

Golovanova, O. A.; Tropin, O. A.; Volkovich, V. A.

2017-09-01

The redox behavior of samarium, europium and ytterbium ions was investigated in the ternary 6NaCl-9KCl- 5CsCl eutectic based melts between 823 and 1073 K employing cyclic voltammetry on a tungsten working electrode. Ln(II)/Ln(III) (Ln=Sm, Eu, Yb) reduction-oxidation is reversible and controlled by diffusion of the electroactive species at the potential scan rates up to 0.1 V/s. Formal standard redox potentials E*Ln(II)/Ln(III) were determined, and the thermodynamic and transport properties of the corresponding Ln(III) and Ln(II) ions were estimated.

Effects of Polyethylene Glycol and Citric Acid on Preparation and Hydrodechlorination Activity of Molybdenum Phosphide

NASA Astrophysics Data System (ADS)

Liu, Xiaomeng; Lu, Shaoxiang; Xu, Hanghui; Ren, Lili

2018-07-01

Molybdenum phosphide (MoP), modified by polyethylene glycol (PEG) and citric acid (CA), exhibited 2 to 3 times superior activity than the MoP modified by CA alone. And the optimal activity temperature was reduced from 500 to 450oC. The catalyst was fully characterized by a variety of techniques including X-ray diffraction (XRD), N2 adsorption-desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The results showed that the addition of PEG and CA increased the surface area of MoP and decreased the particle size of MoP. Furthermore, the reaction mechanism also has been discussed by combining the activity data and characterization results.

Elastic, magnetic and electronic properties of iridium phosphide Ir 2P

DOE PAGES

Wang, Pei; Wang, Yonggang; Wang, Liping; ...

2016-02-24

Cubic (space group: Fm3¯m) iridium phosphide, Ir 2P, has been synthesized at high pressure and high temperature. Angle-dispersive synchrotron X-ray diffraction measurements on Ir 2P powder using a diamond-anvil cell at room temperature and high pressures (up to 40.6 GPa) yielded a bulk modulus of B 0 = 306(6) GPa and its pressure derivative B 0'= 6.4(5). Such a high bulk modulus attributed to the short and strongly covalent Ir-P bonds as revealed by first – principles calculations and three-dimensionally distributed [IrP 4] tetrahedron network. Indentation testing on a well–sintered polycrystalline sample yielded the hardness of 11.8(4) GPa. Relatively lowmore » shear modulus of ~64 GPa from theoretical calculations suggests a complicated overall bonding in Ir 2P with metallic, ionic, and covalent characteristics. Additionally, a spin glass behavior is indicated by magnetic susceptibility measurements.« less

Tailored surface structure of LiFePO4/C nanofibers by phosphidation and their electrochemical superiority for lithium rechargeable batteries.

PubMed

Lee, Yoon Cheol; Han, Dong-Wook; Park, Mihui; Jo, Mi Ru; Kang, Seung Ho; Lee, Ju Kyung; Kang, Yong-Mook

2014-06-25

We offer a brand new strategy for enhancing Li ion transport at the surface of LiFePO4/C nanofibers through noble Li ion conducting pathways built along reduced carbon webs by phosphorus. Pristine LiFePO4/C nanofibers composed of 1-dimensional (1D) LiFePO4 nanofibers with thick carbon coating layers on the surfaces of the nanofibers were prepared by the electrospinning technique. These dense and thick carbon layers prevented not only electrolyte penetration into the inner LiFePO4 nanofibers but also facile Li ion transport at the electrode/electrolyte interface. In contrast, the existing strong interactions between the carbon and oxygen atoms on the surface of the pristine LiFePO4/C nanofibers were weakened or partly broken by the adhesion of phosphorus, thereby improving Li ion migration through the thick carbon layers on the surfaces of the LiFePO4 nanofibers. As a result, the phosphidated LiFePO4/C nanofibers have a higher initial discharge capacity and a greatly improved rate capability when compared with pristine LiFePO4/C nanofibers. Our findings of high Li ion transport induced by phosphidation can be widely applied to other carbon-coated electrode materials.

Effectiveness of radiation synovectomy with Yttrium-90 and Samarium-153 particulate hydroxyapatite in rheumatoid arthritis patients with knee synovitis: a controlled, randomized, double-blinded trial.

PubMed

Dos Santos, Marla Francisca; Furtado, Rita Nely Vilar; Konai, Monique Sayuri; Castiglioni, Mario Luiz Vieira; Marchetti, Renata Rosa; Silva, Constancia Pagano Gonçalves; Natour, Jamil

2011-01-01

The aim of the present study was to investigate the long-term effectiveness of and tolerance to Yttrium-90 and Samarium-153-particulate hydroxyapatite radiation synovectomy in patients with rheumatoid arthritis (RA) and chronic knee synovitis. Eight-four patients (90 knees) with chronic knee synovitis and RA (according to the American College of Rheumatology criteria) participated in a controlled, double-blinded trial. Patients were randomized to receive an intra-articular injection with either 5 mCi Yttrium-90 plus 40 mg of triamcinolone hexacetonide (Y/TH Group), 15 mCi Samarium-153 hydroxyapatite plus 40 mg of triamcinolone hexacetonide (Sm/TH Group), or 40 mg triamcinolone hexacetonide alone (Control Group). Blinded examination at baseline, 1, 4, 12, 32, and 48 weeks post-intervention included a visual analog scale for joint pain and swelling, morning stiffness, range of motion, knee circumference, Likert scale, percentage of improvement, Stanford Health Assessment Questionnaire, Lequesne index, use of non-steroidal anti-inflammatory drugs and corticosteroids, events and adverse effects, calls to the physician, and hospital visits. There were three withdrawals prior to the injections. Regarding the pain, there was a significantly better response in the Y/TH Group versus the Sm/TH Group at T1 (p = 0.025) and versus TH alone at T48 (p = 0.026). The Sm/TH group had more adverse effects (p = 0.042), but these were mild and transitory. For the pain parameter alone, Yttrium-90 radiosynovectomy associated to TH proved superior to Samarium-153 hydroxyapatite radiosynovectomy associated to TH at T1 and to synovectomy with TH at T48. No other statistically significant inter-group differences were detected.

Dispersion of the refractive index of a samarium-doped Se{sup 95}Te{sup 5} chalcogenide glassy semiconductor

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

Atayeva, S. U., E-mail: seva-atayeva@mail.ru; Mekhtiyeva, S. I.; Isayev, A. I.

2015-07-15

The transmission spectrum of a Se{sup 95}Te{sup 5} chalcogenide glassy semiconductor doped with samarium (0.05, 0.1, 0.25, 0.5, and 1 at %) is studied; the Swanepoel method and the single-oscillator model are used to determine the oscillator energy E{sup 0}, dispersion energy E{sup d}, optical width of the band gap E{sup g}, and linear (n) and nonlinear (n{sup 2}) refractive indices. The changes in the values of these parameters as a result of doping are attributed to modification of the local structure and to a change in the concentration of defect states.

Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.; Weinberg, Irving; Flood, Dennis J.

1993-01-01

Indium phosphide (InP) solar cells are more radiation resistant than gallium arsenide (GaAs) and silicon (Si) solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of light weight, mechanically strong, and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5- and 3-MeV proton irradiations have been explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence was calculated by simulating the cell performance. The diffusion length damage coefficient, K(sub L), was also plotted as a function of proton fluence.

Hierarchical cobalt poly-phosphide hollow spheres as highly active and stable electrocatalysts for hydrogen evolution over a wide pH range

NASA Astrophysics Data System (ADS)

Wu, Tianli; Pi, Mingyu; Wang, Xiaodeng; Guo, Weimeng; Zhang, Dingke; Chen, Shijian

2018-01-01

Exploring highly-efficient and low-cost non-noble metal electrocatalyst toward the hydrogen evolution reaction (HER) is highly desired for renewable energy system but remains challenging. In this work, three dimensional hierarchical porous cobalt poly-phosphide hollow spheres (CoP3 HSs) were prepared by topotactic phosphidation of the cobalt-based precursor via vacuum encapsulation technique. As a porous HER cathode, the CoP3 HSs delivers remarkable electrocatalytic performance over the wide pH range. It needs overpotentials of -69 mV and -118 mV with a small Tafel slope of 51 mV dec-1 to obtain current densities of 10 mA cm-2 and 50 mA cm-2, respectively, and maintains its electrocatalytic performance over 30 h in acidic solution. In addition, CoP3 also exhibit superior electrocatalytic performance and stability under neutral and alkaline conditions for the HER. Both experimental measurements and density functional theory (DFT) calculations are performed to explore the mechanism behind the excellent HER performance. The results of our study make the porous CoP3 HSs as a promising electrocatalyst for practical applications toward energy conversion system and present a new way for designing and fabricating HER electrodes through high degree of phosphorization and nano-porous architecture.

Magneto-optical far-infrared absorption spectroscopy of the hole states of indium phosphide

NASA Astrophysics Data System (ADS)

Lewis, R. A.; Wang, Y.-J.

2005-03-01

Far-infrared absorption spectroscopy in magnetic fields of up to 30 T of the zinc acceptor impurity in indium phosphide has revealed for the first time a series of free-hole transitions (Landau-related series) in addition to the familiar bound-hole transitions (Lyman series) as well as hitherto unobserved phonon replicas of both series. Analysis of these data permits the simultaneous direct experimental determination of (i) the hole effective mass, (ii) the species-specific binding energy of the acceptor impurity, (iii) the absolute energy levels of the acceptor excited states of both odd and even parity, (iv) more reliable, and in some cases the only, g factors for acceptor states, through relaxation of the selection rules for phonon replicas, and (v) the LO phonon energy. The method is applicable to other semiconductors and may lead to the reappraisal of their physical parameters.

Optical and physical properties of samarium doped lithium diborate glasses

NASA Astrophysics Data System (ADS)

Hanumantharaju, N.; Sardarpasha, K. R.; Gowda, V. C. Veeranna

2018-05-01

Sm3+ doped lithium di-borate glasses with composition 30Li2O-60B2O3-(10-x) PbO, (where 0 < x < 2 mole. %) were prepared by melt quenching method. The addition of modifier oxide to vitreous B2O3 modifies the glass network by converting three coordinated trigonal boron units (BO3) to weaker anionic four coordinated tetrahedral borons (BO4). The decrease in density and increase in molar volume with samarium ion content indicates the openness of the glass structure. The gradual increase in average separation of boron-boron atoms with VmB clearly indicates deterioration of borate glass network, which in turn leads to decrease in the oxygen packing density. The replacements of Sm2O3 for PbO depolymerise the chain structure and that would increase the concentration of non-bridging oxygens. The marginal increase of optical band gap energy after 1.0 mol.% of Sm2O3 is explained by considering the structural modification in lead-borate. The influence of Sm3+ ion on physical and optical properties in lithium-lead-borate glasses is investigated and the results were discussed in view of the structure of borate glass network.

Study of samarium modified lead zirconate titanate and nickel zinc ferrite composite system

NASA Astrophysics Data System (ADS)

Rani, Rekha; Juneja, J. K.; Singh, Sangeeta; Raina, K. K.; Prakash, Chandra

2015-03-01

In the present work, composites of samarium substituted lead zirconate titanate and nickel zinc ferrite with compositional formula 0.95Pb1-3x/2 SmxZr0.65Ti0.35O3-0.05Ni0.8Zn0.2Fe2O4 (x=0, 0.01, 0.02 and 0.03) were prepared by the conventional solid state route. X-ray diffraction analysis was carried out to confirm the coexistence of individual phases. Microstructural study was done by using scanning electron microscope. Dielectric constant and loss were studied as a function of temperature and frequency. To study ferroelectric and magnetic properties of the composite samples, corresponding P-E and M-H hysteresis loops were recorded. Change in magnetic properties of electrically poled composite sample (x=0.02) was studied to confirm the magnetoelectric (ME) coupling. ME coefficient (dE/dH) of the samples (x=0 and 0.02) was measured as a function of DC magnetic field.

Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

NASA Astrophysics Data System (ADS)

Zhang, Qi-Xian; Wei, Wen-Sheng; Ruan, Fang-Ping

2011-04-01

Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO2 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells.

Ab-initio calculations of electronic, transport, and structural properties of boron phosphide

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

Ejembi, J. I.; Nwigboji, I. H.; Franklin, L.

2014-09-14

We present results from ab-initio, self-consistent density functional theory calculations of electronic and related properties of zinc blende boron phosphide (zb-BP). We employed a local density approximation potential and implemented the linear combination of atomic orbitals formalism. This technique follows the Bagayoko, Zhao, and Williams method, as enhanced by the work of Ekuma and Franklin. The results include electronic energy bands, densities of states, and effective masses. The calculated band gap of 2.02 eV, for the room temperature lattice constant of a=4.5383 Å, is in excellent agreement with the experimental value of 2.02±0.05 eV. Our result for the bulk modulus,more » 155.7 GPa, agrees with experiment (152–155 GPa). Our predictions for the equilibrium lattice constant and the corresponding band gap, for very low temperatures, are 4.5269 Å and 2.01 eV, respectively.« less

Dilute phosphide nitride materials as photocathodes for electrochemical solar energy conversion

NASA Astrophysics Data System (ADS)

Parameshwaran, Vijay; Xu, Xiaoqing; Kang, Yangsen; Harris, James; Wong, H.-S. Philip; Clemens, Bruce

2013-03-01

Dilute nitride materials have been used in a variety of III-V photonic devices, but have not been significantly explored in photoelectrochemical applications. This work focuses on using dilute phosphide nitride materials of the form (Al,In)P1-xNx as photocathodes for the generation of hydrogen fuel from solar energy. Heteroepitaxial MOCVD growth of AlPN thin films on GaP yields high quality material with a direct bandgap energy of 2.218 eV. Aligned epitaxial growth of InP and GaP nanowires on InP and Si substrates, respectively, provides a template for designing nanostructured photocathodes over a large area. Electrochemical testing of a AlPN/GaP heterostructure electrode yields up to a sixfold increase in photocurrent enhancement under blue light illumination as compared to a GaP electrode. Additionally, the AlPN/GaP electrodes exhibit no degradation in performance after galvanostatic biasing over time. These results show that (Al,In)P1-xNx is a promising materials system for use in nanoscale photocathode structures.

Novel elastic, lattice dynamics and thermodynamic properties of metallic single-layer transition metal phosphides: 2H-M 2P (Mo2P, W2P, Nb2P and Ta2P)

NASA Astrophysics Data System (ADS)

Yin, Jiuren; Wu, Bozhao; Wang, Yanggang; Li, Zhimi; Yao, Yuanpeng; Jiang, Yong; Ding, Yanhuai; Xu, Fu; Zhang, Ping

2018-04-01

Recently, there has been a surge of interest in the research of two-dimensional (2D) phosphides due to their unique physical properties and wide applications. Transition metal phosphides 2H-M 2Ps (Mo2P, W2P, Nb2P and Ta2P) show considerable catalytic activity and energy storage potential. However, the electronic structure and mechanical properties of 2D 2H-M 2Ps are still unrevealed. Here, first-principles calculations are employed to investigate the lattice dynamics, elasticity and thermodynamic properties of 2H-M 2Ps. Results show that M 2Ps with lower stiffness exhibit remarkable lateral deformation under unidirectional loads. Due to the largest average Grüneisen parameter, single-layer Nb2P has the strongest anharmonic vibrations, resulting in the highest thermal expansion coefficient. The lattice thermal conductivities of Ta2P, W2P and Nb2P contradict classical theory, which would predict a smaller thermal conductivity due to the much heavier atom mass. Moreover, the calculations also demonstrate that the thermal conductivity of Ta2P is the highest as well as the lowest thermal expansion, owing to its weak anharmonic phonon scattering and the lowest average Grüneisen parameter. The insight provided by this study may be useful for future experimental and theoretical studies concerning 2D transition metal phosphide materials.

Engineering a nanotubular mesoporous cobalt phosphide electrocatalyst by the Kirkendall effect towards highly efficient hydrogen evolution reactions.

PubMed

Miao, Yue-E; Li, Fei; Zhou, Yu; Lai, Feili; Lu, Hengyi; Liu, Tianxi

2017-11-02

Tailoring the size and controlling the morphology of particular nano-architectures are considered as two promising strategies to improve the catalytic performance of metal nanocrystals towards hydrogen evolution reactions (HERs). Herein, mesoporous cobalt phosphide nanotubes (CoP-NTs) with a three-dimensional network structure have been obtained through a facile and efficient electrospinning technique combined with thermal stabilization and phosphorization treatments. The thermal stabilization process has been demonstrated to play a key role in the morphological tailoring of Co 3 O 4 nanotubes (Co 3 O 4 -NTs). As a result, the CoP-NTs show one-dimensional hollow tubular architecture instead of forming a worm-like tubular CoP structure (W-CoP-NTs) or severely aggregated CoP powder (CoP-NPs) which originate from the Co 3 O 4 nanotubes without thermal stabilization treatment and Co 3 O 4 nanoparticles, respectively. Satisfyingly, under an optimized phosphorization degree, the CoP-NT electrode exhibits a low onset overpotential of 53 mV with a low Tafel slope of 50 mV dec -1 during the HER process. Furthermore, the CoP-NT electrode is capable of driving a large cathodic current density of 10 mA cm -2 at an overpotential of 152 mV, which is much lower than those of its contrast samples, i.e. CoP-NPs (211 mV) and W-CoP-NTs (230 mV). Therefore, this work provides a feasible and general strategy for constructing three-dimensionally organized mesoporous non-noble metal phosphide nanotubes as promising alternative high-performance electrocatalysts for the commercial platinum ones.

Molecular fingerprint-region spectroscopy from 5 to 12  μm using an orientation-patterned gallium phosphide optical parametric oscillator.

PubMed

Maidment, Luke; Schunemann, Peter G; Reid, Derryck T

2016-09-15

We report a femtosecond optical parametric oscillator (OPO) based on the new semiconductor gain material orientation-patterned gallium phosphide (OP-GaP), which enables the production of high-repetition-rate femtosecond pulses spanning 5-12 μm with average powers in the few to tens of milliwatts range. This is the first example of a broadband OPO operating across the molecular fingerprint region, and we demonstrate its potential by conducting broadband Fourier-transform spectroscopy using water vapor and a polystyrene reference standard.

Chemical nature of silicon nitride-indium phosphide interface and rapid thermal annealing for InP MISFETs

NASA Technical Reports Server (NTRS)

Biedenbender, M. D.; Kapoor, V. J.

1990-01-01

A rapid thermal annealing (RTA) process in pure N2 or pure H2 was developed for ion-implanted and encapsulated indium phosphide compound semiconductors, and the chemical nature at the silicon nitride-InP interface before and after RTA was examined using XPS. Results obtained from SIMS on the atomic concentration profiles of the implanted silicon in InP before and after RTA are presented, together with electrical characteristics of the annealed implants. Using the RTA process developed, InP metal-insulator semiconductor FETs (MISFETS) were fabricated. The MISFETS prepared had threshold voltages of +1 V, transconductance of 27 mS/mm, peak channel mobility of 1200 sq cm/V per sec, and drain current drift of only 7 percent.

Synthesis and x-ray characterization of cobalt phosphide (Co₂P) nanorods for the oxygen reduction reaction

DOE PAGES

Doan-Nguyen, Vicky V.T.; Su, Dong; Zhang, Sen; ...

2015-07-14

Low temperature fuel cells are clean, effective alternative fuel conversion technology. Oxygen reduction reaction (ORR) at the fuel cell cathode has required Pt as the electrocatalyst for high activity and selectivity of the four-electron reaction pathway. Targeting a less expensive, earth abundant alternative, we have developed the synthesis of cobalt phosphide (Co₂P) nanorods for ORR. Characterization techniques that include total X-ray scattering and extended X-ray absorption fine structure revealed a deviation of the nanorods from bulk crystal structure with a contraction along the b orthorhombic lattice parameter. The carbon supported nanorods have comparable activity but are remarkably more stable thanmore » conventional Pt catalysts for the oxygen reduction reaction in alkaline environments.« less

A review of aluminium phosphide poisoning and a flowchart to treat it.

PubMed

Hashemi-Domeneh, Behrooz; Zamani, Nasim; Hassanian-Moghaddam, Hossein; Rahimi, Mitra; Shadnia, Shahin; Erfantalab, Peyman; Ostadi, Ali

2016-09-01

The use of pesticides such as aluminium phosphide (AlP) has increased in the recent years and improved the quantity and quality of agricultural products in a number of developing countries. The downside is that AlP causes severe chronic and acute health effects that have reached major proportions in countries such as India, Iran, Bangladesh, and Jordan. Nearly 300,000 people die due to pesticide poisoning in the world every year. Poisoning with AlP accounts for many of these deaths. Unfortunately, at the same time, there is no standard treatment for it. The aim of this article is to give a brief review of AlP poisoning and propose a treatment flowchart based on the knowledge gained so far. For this purpose we reviewed all articles on the management of AlP poisoning published from 2000 till now. Using a modified Delphi design, we have designed a handy flowchart that could be used as a guide for AlP poisoning management of patients in emergency centres.

Studies on the structural, optical and dielectric properties of samarium coordinated with salicylic acid single crystal

NASA Astrophysics Data System (ADS)

Singh, Harjinder; Slathia, Goldy; Gupta, Rashmi; Bamzai, K. K.

2018-04-01

Samarium coordinated with salicylic acid was successfully grown as a single crystal by low temperature solution technique using mixed solvent of methanol and water in equal ratio. Structural characterization was carried out by single crystal X-ray diffraction analysis and it crystallizes in centrosymmetric space group P121/c1. FTIR and UV-Vis-NIR spectroscopy confirmed the compound formation and help to determine the mode of binding of the ligand to the rare earth-metal ion. Dielectric constant and dielectric loss have been measured over the frequency range 100 Hz - 30MHz. The decrease in dielectric constant with increases in frequency is due to the transition from interfacial polarization to dipolar polarization. The small value of dielectric constant at higher frequency ensures that the crystal is good candidate for NLO devices. Dielectric loss represents the resistive nature of the material.

Protonation of a lanthanum phosphide-alkyl occurs at the P-La not the C-La bond: isolation of a cationic lanthanum alkyl complex.

PubMed

Izod, Keith; Liddle, Stephen T; Clegg, William

2004-08-07

Protonation of the heteroleptic, cyclometalated lanthanum phosphide complex [((Me3Si)2CH)(C6H4-2-CH2NMe2)P]La(THF)[P(C6H4-2-CH2NMe2)(CH(SiMe3)(SiMe2CH2))] with [Et3NH][BPh4] yields the cationic alkyllanthanum complex [(THF)4La[P(C6H4-2-CH2NMe2)(CH(SiMe3)(SiMe2CH2))

Effects of P/Ni ratio and Ni content on performance of γ-Al2O3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

NASA Astrophysics Data System (ADS)

Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

2016-01-01

γ-Al2O3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0-2.5) and Ni content (m = 5-15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al2O3 was also studied for comparison. It was found that the formation of AlPO4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni3P, Ni12P5 and Ni2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al2O3, the mNi-Pn catalysts showed much lower activities for decarbonylation, Csbnd C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl laurate was promoted with increasing P/Ni ratio and Ni content, ascribed to the phase change in the order of Ni, Ni3P, Ni12P5 and Ni2P in the prepared catalysts.

Detonation nanodiamond introduced into samarium doped ceria electrolyte improving performance of solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Pei, Kai; Li, Hongdong; Zou, Guangtian; Yu, Richeng; Zhao, Haofei; Shen, Xi; Wang, Liying; Song, Yanpeng; Qiu, Dongchao

2017-02-01

A novel electrolyte materials of introducing detonation nanodiamond (DNDs) into samarium doped ceria (SDC) is reported here. 1%wt. DNDs doping SDC (named SDC/ND) can enlarge the electrotyle grain size and change the valence of partial ceria. DNDs provide the widen channel to accelerate the mobility of oxygen ions in electrolyte. Larger grain size means that oxygen ions move easier in electrolyte, it can also reduce the alternating current (AC) impedance spectra of internal grains. The lower valence of partial Ce provides more oxygen vacancies to enhance mobility rate of oxygen ions. Hence all of them enhance the transportation of oxygen ions in SDC/ND electrolyte and the OCV. Ultimately the power density of SOFC can reach 762 mw cm-2 at 800 °C (twice higher than pure SDC, which is 319 mw cm-2 at 800 °C), and it remains high power density in the intermediate temperature (600-800 °C). It is relatively high for the electrolyte supported (300 μm) cells.

M-H characteristics and demagnetization resistance of samarium-cobalt permanent magnets to 300 C

NASA Technical Reports Server (NTRS)

Niedra, J. M.

1992-01-01

The influence of temperature on the M-H demagnetization characteristics of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperatures in demagnetization-resistant permanent magnet devices. In high temperature space power converters, such as free-piston Stirling engine driven linear alternators, magnet demagnetization can occur as long-term consequence of thermal agitation of domains and of metallurgical change, and also as an immediate consequence of too large an applied field. Investigated here is the short-term demagnetization resistance to applied fields derived from basic M-H data. These quasistatic demagnetization data were obtained for commercial, high-intrinsic-coercivity, Sm2Co17-type magnets from 5 sources, in the temperature range 23 to 300 C. An electromagnet driven, electronic hysteresigraph was used to test the 1-cm cubic samples. The observed variation of the 2nd quadrant M-H characteristics was a typical rapid loss of M-coercivity and a relatively lesser loss of remanence with increasing temperature.

Synthesis of indium phosphide nanocrystals by sonochemical method and survey of optical properties

NASA Astrophysics Data System (ADS)

Trung, Ho Minh; Duy Thien, Nguyen; Van Vu, Le; Long, Nguyen Ngoc; Hieu, Truong Kim

2013-10-01

Indium phosphide semiconductor materials (InP) have various applications in the field of semiconductor optoelectronics because of its advantages. But the making of this material is difficult due to the very weak chemical activity of In element. In this report we present a simple method to synthesize InP nanocrystals from inorganic precursors such as indium chloride (InCl3), yellow phosphorus (P4), reduction agent NaBH4 at low temperature with the aid of ultrasound. Structural, morphological and optical properties of the formed InP nanocrystals were examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersed X-ray analysis (EDS), Raman scattering, absorption and photoluminscence (PL) spectroscopy. After the surface treatment of InP nanocrystals with liquid hydrofluoric (HF) acid, the luminescence spectra have an enhanced intensity and consist of the peaks in the region from 500 nm to 700 nm. The intensity of these peaks strongly depends on the concentration and etching time of HF. International Workshop on Advanced Materials and Nanotechnology 2012 (IWAMN 2012).

Heterogeneous Bimetallic Phosphide/Sulfide Nanocomposite for Efficient Solar-Energy-Driven Overall Water Splitting.

PubMed

Xin, Yanmei; Kan, Xiang; Gan, Li-Yong; Zhang, Zhonghai

2017-10-24

Solar-driven overall water splitting is highly desirable for hydrogen generation with sustainable energy sources, which need efficient, earth-abundant, robust, and bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we propose a heterogeneous bimetallic phosphide/sulfide nanocomposite electrocatalyst of NiFeSP on nickel foam (NiFeSP/NF), which shows superior electrocatalytic activity of low overpotentials of 91 mV at -10 mA cm -2 for HER and of 240 mV at 50 mA cm -2 for OER in 1 M KOH solution. In addition, the NiFeSP/NF presents excellent overall water splitting performance with a cell voltage as low as 1.58 V at a current density of 10 mA cm -2 . Combining with a photovoltaic device of a Si solar cell or integrating into photoelectrochemical (PEC) systems, the bifunctional NiFeSP/NF electrocatalyst implements unassisted solar-driven water splitting with a solar-to-hydrogen conversion efficiency of ∼9.2% and significantly enhanced PEC performance, respectively.

Submillimeter sources for radiometry using high power Indium Phosphide Gunn diode oscillators

NASA Technical Reports Server (NTRS)

Deo, Naresh C.

1990-01-01

A study aimed at developing high frequency millimeter wave and submillimeter wave local oscillator sources in the 60-600 GHz range was conducted. Sources involved both fundamental and harmonic-extraction type Indium Phosphide Gunn diode oscillators as well as varactor multipliers. In particular, a high power balanced-doubler using varactor diodes was developed for 166 GHz. It is capable of handling 100 mW input power, and typically produced 25 mW output power. A high frequency tripler operating at 500 GHz output frequency was also developed and cascaded with the balanced-doubler. A dual-diode InP Gunn diode combiner was used to pump this cascaded multiplier to produce on the order of 0.5 mW at 500 GHz. In addition, considerable development and characterization work on InP Gunn diode oscillators was carried out. Design data and operating characteristics were documented for a very wide range of oscillators. The reliability of InP devices was examined, and packaging techniques to enhance the performance were analyzed. A theoretical study of a new class of high power multipliers was conducted for future applications. The sources developed here find many commercial applications for radio astronomy and remote sensing.

Interaction potential for indium phosphide: a molecular dynamics and first-principles study of the elastic constants, generalized stacking fault and surface energies.

PubMed

Branicio, Paulo Sergio; Rino, José Pedro; Gan, Chee Kwan; Tsuzuki, Hélio

2009-03-04

Indium phosphide is investigated using molecular dynamics (MD) simulations and density-functional theory calculations. MD simulations use a proposed effective interaction potential for InP fitted to a selected experimental dataset of properties. The potential consists of two- and three-body terms that represent atomic-size effects, charge-charge, charge-dipole and dipole-dipole interactions as well as covalent bond bending and stretching. Predictions are made for the elastic constants as a function of density and temperature, the generalized stacking fault energy and the low-index surface energies.

Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

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

Marking, Gregory Allen

1994-01-04

Investigations of ternary mixed early transition metal-rich sulfide and phosphide systems resulted in the discovery of new structures and new phases. A new series of Zr and Hf - group V transition metal - sulfur K-phases was synthesized and crystallographically characterized. When the group V transition metal was Nb or Ta, the unit cell volume was larger than any previously reported K-phase. The presence of adventitious oxygen was determined in two K-phases through a combination of neutron scattering and X-ray diffraction experiments. A compound Hf 10Ta 3S 3 was found to crystallize in a new-structure type similar to the knownmore » gamma brasses. This structure is unique in that it is the only reported "stuffed" gamma-brass type structure. The metal components, Hf and Ta, are larger in size and more electropositive than the metals found in normal gamma brasses (e.g. Cu and Zn) and because of the larger metallic radii, sulfur can be incorporated into the structure where it plays an integral role in stabilizing this phase relative to others. X-ray single-crystal, X-ray powder and neutron powder refinements were performed on this structure. A new structure was found in the ternary Nb-Zr-P system which has characteristics in common with many known early transition metal-rich sulfides, selenides, and phosphides. This structure has the simplest known interconnection of the basic building blocks known for this structural class. Anomalous scattering was a powerful tool for differentiating between Zr and Nb when using Mo Kα X-radiation. The compounds ZrNbP and HfNbP formed in the space group Prima with the simple Co 2Si structure which is among the most common structures found for crystalline solid materials. Solid solution compounds in the Ta-Nb-P, Ta-Zr-P, Nb-Zr-P, Hf-Nb-P, and Hf-Zr-S systems were crystallographically characterized. The structural information corroborated ideas about bonding in metal-rich compounds.« less

Laser ablation synthesis of arsenic-phosphide Asm Pn clusters from As-P mixtures. Laser desorption ionisation with quadrupole ion trap time-of-flight mass spectrometry: The mass spectrometer as a synthesizer.

PubMed

Kubáček, Pavel; Prokeš, Lubomír; Pamreddy, Annapurna; Peña-Méndez, Eladia María; Conde, José Elias; Alberti, Milan; Havel, Josef

2018-05-30

Only a few arsenic phosphides are known. A high potential for the generation of new compounds is offered by Laser Ablation Synthesis (LAS) and when Laser Desorption Ionization (LDI) is coupled with simultaneous Time-Of-Flight Mass Spectrometry (TOFMS), immediate identification of the clusters can be achieved. LAS was used for the generation of arsenic phosphides via laser ablation of phosphorus-arsenic mixtures while quadrupole ion trap time-of-flight mass spectrometry (QIT-TOFMS) was used to acquire the mass spectra. Many new As m P n ± clusters (479 binary and 369 mono-elemental) not yet described in the literature were generated in the gas phase and their stoichiometry determined. The likely structures for some of the observed clusters arbitrary selected (20) were computed by density functional theory (DFT) optimization. LAS is an advantageous approach for the generation of new As m P n clusters, while mass spectrometry was found to be an efficient technique for the determination of cluster stoichiometry. The results achieved might inspire the synthesis of new materials. Copyright © 2018 John Wiley & Sons, Ltd.

Evaluation of Silica-Supported Metal and Metal Phosphide Nanoparticle Catalysts for the Hydrodeoxygenation of Guaiacol Under Ex Situ Catalytic Fast Pyrolysis Conditions

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

Griffin, Michael B.; Baddour, Frederick G.; Habas, Susan E.

A series of metal and metal phosphide catalysts were investigated for the hydrodeoxygenation of guaiacol under ex situ catalytic fast pyrolysis (CFP) conditions (350 °C, 0.5 MPa, 12 H 2:1 guaiacol, weight hourly space velocity 5 h $-$1). Ligand-capped Ni, Pt, Rh, Ni 2P, and Rh 2P nanoparticles (NPs) were prepared using solution-phase synthesis techniques and dispersed on a silica support. For the metal phosphide NP-catalysts, a synthetic route that relies on the decomposition of a single molecular precursor was employed. The reactivity of the NP-catalysts was compared to a series of reference materials including Ni/SiO 2 and Pt/SiO 2more » prepared using incipient wetness (IW) impregnation and a commercial (com) Pt/SiO 2 catalyst. The NP-Ni/SiO 2 catalyst exhibited the largest reduction in the oxygen mol% of the organic phase and outperformed the IW-Ni/SiO 2 material. Although it was less active for guaiacol conversion than NP-Ni/SiO 2, NP-Rh2P/SiO 2 demonstrated the largest production of completely deoxygenated products and the highest selectivity to anisole, benzene, and cyclohexane, suggesting that it is a promising catalyst for deoxygenation of aryl-OH bonds. Finally, the com-Pt/SiO 2 and IW-Pt/SiO 2 catalyst exhibited the highest normalized rate of guaiacol conversion per m 2 and per gram of active phase, respectively, but did not produce any completely deoxygenated products.« less

Evaluation of Silica-Supported Metal and Metal Phosphide Nanoparticle Catalysts for the Hydrodeoxygenation of Guaiacol Under Ex Situ Catalytic Fast Pyrolysis Conditions

DOE PAGES

Griffin, Michael B.; Baddour, Frederick G.; Habas, Susan E.; ...

2015-09-30

A series of metal and metal phosphide catalysts were investigated for the hydrodeoxygenation of guaiacol under ex situ catalytic fast pyrolysis (CFP) conditions (350 °C, 0.5 MPa, 12 H 2:1 guaiacol, weight hourly space velocity 5 h $-$1). Ligand-capped Ni, Pt, Rh, Ni 2P, and Rh 2P nanoparticles (NPs) were prepared using solution-phase synthesis techniques and dispersed on a silica support. For the metal phosphide NP-catalysts, a synthetic route that relies on the decomposition of a single molecular precursor was employed. The reactivity of the NP-catalysts was compared to a series of reference materials including Ni/SiO 2 and Pt/SiO 2more » prepared using incipient wetness (IW) impregnation and a commercial (com) Pt/SiO 2 catalyst. The NP-Ni/SiO 2 catalyst exhibited the largest reduction in the oxygen mol% of the organic phase and outperformed the IW-Ni/SiO 2 material. Although it was less active for guaiacol conversion than NP-Ni/SiO 2, NP-Rh2P/SiO 2 demonstrated the largest production of completely deoxygenated products and the highest selectivity to anisole, benzene, and cyclohexane, suggesting that it is a promising catalyst for deoxygenation of aryl-OH bonds. Finally, the com-Pt/SiO 2 and IW-Pt/SiO 2 catalyst exhibited the highest normalized rate of guaiacol conversion per m 2 and per gram of active phase, respectively, but did not produce any completely deoxygenated products.« less

Ultimate intrinsic-coercivity samarium-cobalt magnet: An Earth-based feasibility study for space-shuttle missions. [containerless melts

NASA Technical Reports Server (NTRS)

Das, D. K.; Kumar, K.; Frost, R. T.; Chang, C. W.

1980-01-01

Techniques for containerless melting and solidification of the samarium-cobalt alloy without excessive oxidation were developed. The rationale for extending these experiments in a weightless environment is also discussed. The effect of oxygen content from 0.15 to 0.63 weight percent and grain size in the range of 2 to 10 micrometers has been examined on arc-plasma-sprayed SmCo5 magnets. Contrary to expectations, the larger grain sizes tended to improve the coercivities. This was attributed to an increase in homogeneity resulting from higher temperature treatments used to produce larger grain size. No significant differences in coercivity were observed on the basis of oxygen content in the range examined. It is expected that more meaningful data on the relationship between oxygen content and coercivity will be seen when the oxygen content can be lowered to less than 0.1 weight percent.

Effect of Zinc Oxide Doping on Electroluminescence and Electrical Behavior of Metalloporphyrins-Doped Samarium Complex

NASA Astrophysics Data System (ADS)

Janghouri, Mohammad; Amini, Mostafa M.

2018-02-01

Samarium complex [(Sm(III)] as a new host material was used for preparation of red organic light-emitting diodes (OLEDs). Devices with configurations of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):(poly(styrenesulfonate) (PEDOT:PSS (50 nm)/polyvinyl carbazole (PVK):[zinc oxide (ZnO)] (50 nm)/[(Sm(III)]:[zinc(II) 2,3-tetrakis(dihydroxyphenyl)-porphyrin and Pt(II) 2,3-dimethoxyporphyrin] (60 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (15 nm)/Al (150 nm) have been fabricated and investigated. An electroplex occurring at the (PVK/Sm: Pt(II) 2,3-dimethoxyporphyrin) interface has been suggested when ZnO nanoparticles were doped in PVK. OLED studies have revealed that the photophysical characteristics and electrical behavior of devices with ZnO nanoparticles are much better than those of devices with pure PVK. The efficiency of devices based on [(Sm(III)] was superior than that of known aluminum tris(8-hydroxyquinoline) (Alq3) and also our earlier reports on red OLEDs under the same conditions.

Molybdenum Disulfide as a Protection Layer and Catalyst for Gallium Indium Phosphide Solar Water Splitting Photocathodes

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

Britto, Reuben J.; Benck, Jesse D.; Young, James L.

2016-06-02

Gallium indium phosphide (GaInP2) is a semiconductor with promising optical and electronic properties for solar water splitting, but its surface stability is problematic as it undergoes significant chemical and electrochemical corrosion in aqueous electrolytes. Molybdenum disulfide (MoS2) nanomaterials are promising to both protect GaInP2 and to improve catalysis since MoS2 is resistant to corrosion and also possesses high activity for the hydrogen evolution reaction (HER). In this work, we demonstrate that GaInP2 photocathodes coated with thin MoS2 surface protecting layers exhibit excellent activity and stability for solar hydrogen production, with no loss in performance (photocurrent onset potential, fill factor, andmore » light limited current density) after 60 hours of operation. This represents a five-hundred fold increase in stability compared to bare p-GaInP2 samples tested in identical conditions.« less

Hydrazine-Assisted Formation of Indium Phosphide (InP)-Based Nanowires and Core-Shell Composites.

PubMed

Patzke, Greta R; Kontic, Roman; Shiolashvili, Zeinab; Makhatadze, Nino; Jishiashvili, David

2012-12-27

Indium phosphide nanowires (InP NWs) are accessible at 440 °C from a novel vapor phase deposition approach from crystalline InP sources in hydrazine atmospheres containing 3 mol % H₂O. Uniform zinc blende (ZB) InP NWs with diameters around 20 nm and lengths up to several tens of micrometers are preferably deposited on Si substrates. InP particle sizes further increase with the deposition temperature. The straightforward protocol was extended on the one-step formation of new core-shell InP-Ga NWs from mixed InP/Ga source materials. Composite nanocables with diameters below 20 nm and shells of amorphous gallium oxide are obtained at low deposition temperatures around 350 °C. Furthermore, InP/Zn sources afford InP NWs with amorphous Zn/P/O-coatings at slightly higher temperatures (400 °C) from analogous setups. At 450 °C, the smooth outer layer of InP-Zn NWs is transformed into bead-shaped coatings. The novel combinations of the key semiconductor InP with isotropic insulator shell materials open up interesting application perspectives in nanoelectronics.

Laser ablation synthesis of new gold phosphides using red phosphorus and nanogold as precursors. Laser desorption ionisation time-of-flight mass spectrometry.

PubMed

Panyala, Nagender Reddy; Peña-Méndez, Eladia María; Havel, Josef

2012-05-15

Gold phosphides show unique optical or semiconductor properties and there are extensive high technology applications, e.g. in laser diodes, etc. In spite of the various AuP structures known, the search for new materials is wide. Laser ablation synthesis is a promising screening and synthetic method. Generation of gold phosphides via laser ablation of red phosphorus and nanogold mixtures was studied using laser desorption ionisation time-of-flight mass spectrometry (LDI TOFMS). Gold clusters Au(m)(+) (m = 1 to ~35) were observed with a difference of one gold atom and their intensities were in decreasing order with respect to m. For P(n)(+) (n = 2 to ~111) clusters, the intensities of odd-numbered phosphorus clusters are much higher than those for even-numbered phosphorus clusters. During ablation of P-nanogold mixtures, clusters Au(m)(+) (m = 1-12), P(n)(+) (n = 2-7, 9, 11, 13-33, 35-95 (odd numbers)), AuP(n)(+) (n = 1, 2-88 (even numbers)), Au(2)P(n)(+) (n = 1-7, 14-16, 21-51 (odd numbers)), Au(3)P(n)(+) (n = 1-6, 8, 9, 14), Au(4)P(n)(+) (n = 1-9, 14-16), Au(5)P(n)(+) (n = 1-6, 14, 16), Au(6)P(n)(+) (n = 1-6), Au(7)P(n)(+) (n = 1-7), Au(8)P(n)(+) (n = 1-6, 8), Au(9)P(n)(+) (n = 1-10), Au(10)P(n)(+) (n = 1-8, 15), Au(11)P(n)(+) (n = 1-6), and Au(12)P(n)(+) (n = 1, 2, 4) were detected in positive ion mode. In negative ion mode, Au(m)(-) (m = 1-5), P(n)(-) (n = 2, 3, 5-11, 13-19, 21-35, 39, 41, 47, 49, 55 (odd numbers)), AuP(n)(-) (n = 4-6, 8-26, 30-36 (even numbers), 48), Au(2)P(n)(-) (n = 2-5, 8, 11, 13, 15, 17), A(3) P(n)(-) (n = 6-11, 32), Au(4)P(n)(-) (n = 1, 2, 4, 6, 10), Au(6)P(5)(-), and Au(7)P(8)(-) clusters were observed. In both modes, phosphorus-rich Au(m)P(n) clusters prevailed. The first experimental evidence for formation of AuP(60) and gold-covered phosphorus Au(12)P(n) (n = 1, 2, 4) clusters is given. The new gold phosphides generated might inspire synthesis of

Bimetallic Cobalt-Based Phosphide Zeolitic Imidazolate Framework: CoP x Phase-Dependent Electrical Conductivity and Hydrogen Atom Adsorption Energy for Efficient Overall Water Splitting

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

Song, Junhua; Zhu, Chengzhou; Xu, Bo Z.

Cobalt-based bimetallic phosphide encapsulated in carbonized zeolitic imadazolate frameworks has been successfully synthesized and showed excellent activities toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Density functional theory calculation and electrochemical measurements reveal that the electrical conductivity and electrochemical activity are closely associated with the Co2P/CoP mixed phase behaviors upon Cu metal doping. This relationship is found to be the decisive factor for enhanced electrocatalytic performance. Moreover, the precise control of Cu content in Co-host lattice effectively alters the Gibbs free energy for H* adsorption, which is favorable for facilitating reaction kinetics. Impressively, an optimized performance hasmore » been achieved with mild Cu doping in Cu0.3Co2.7P/nitrogen-doped carbon (NC) which exhibits an ultralow overpotential of 0.19 V at 10 mA cm–2 and satisfying stability for OER. Cu0.3Co2.7P/NC also shows excellent HER activity, affording a current density of 10 mA cm–2 at a low overpotential of 0.22 V. In addition, a homemade electrolyzer with Cu0.3Co2.7P/NC paired electrodes shows 60% larger current density than Pt/ RuO2 couple at 1.74 V, along with negligible catalytic deactivation after 50 h operation. The manipulation of electronic structure by controlled incorporation of second metal sheds light on understanding and synthesizing bimetallic transition metal phosphides for electrolysis-based energy conversion.« less

Intense Femtosecond Laser-Mediated Electrical Discharge Enables Preparation of Amorphous Nickel Phosphide Nanoparticles.

PubMed

Ma, Zhuo-Chen; Chen, Qi-Dai; Han, Bing; Li, He-Long; Wang, Lei; Zhang, Yong-Lai; Sun, Hong-Bo

2018-05-09

Reported here is a high-efficiency preparation method of amorphous nickel phosphide (Ni-P) nanoparticles by intense femtosecond laser irradiation of nickel sulfate and sodium hypophosphite aqueous solution. The underlying mechanism of the laser-assisted preparation was discussed in terms of the breaking of chemical bond in reactants via highly intense electric field discharge generated by the intense femtosecond laser. The morphology and size of the nanoparticles can be tuned by varying the reaction parameters such as ion concentration, ion molar ratio, laser power, and irradiation time. X-ray diffraction and transmission electron microscopy results demonstrated that the nanoparticles were amorphous. Finally, the thermogravimetric-differential thermal analysis experiment verified that the as-synthesized noncrystalline Ni-P nanoparticles had an excellent catalytic capability toward thermal decomposition of ammonium perchlorate. This strategy of laser-mediated electrical discharge under such an extremely intense field may create new opportunities for the decomposition of molecules or chemical bonds that could further facilitate the recombination of new atoms or chemical groups, thus bringing about new possibilities for chemical reaction initiation and nanomaterial synthesis that may not be realized under normal conditions.

Electronic Structures of Free-Standing Nanowires made from Indirect Bandgap Semiconductor Gallium Phosphide

PubMed Central

Liao, Gaohua; Luo, Ning; Chen, Ke-Qiu; Xu, H. Q.

2016-01-01

We present a theoretical study of the electronic structures of freestanding nanowires made from gallium phosphide (GaP)—a III-V semiconductor with an indirect bulk bandgap. We consider [001]-oriented GaP nanowires with square and rectangular cross sections, and [111]-oriented GaP nanowires with hexagonal cross sections. Based on tight binding models, both the band structures and wave functions of the nanowires are calculated. For the [001]-oriented GaP nanowires, the bands show anti-crossing structures, while the bands of the [111]-oriented nanowires display crossing structures. Two minima are observed in the conduction bands, while the maximum of the valence bands is always at the Γ-point. Using double group theory, we analyze the symmetry properties of the lowest conduction band states and highest valence band states of GaP nanowires with different sizes and directions. The band state wave functions of the lowest conduction bands and the highest valence bands of the nanowires are evaluated by spatial probability distributions. For practical use, we fit the confinement energies of the electrons and holes in the nanowires to obtain an empirical formula. PMID:27307081

Comparative studies on mitochondrial electron transport chain complexes of Sitophilus zeamais treated with allyl isothiocyanate and calcium phosphide.

PubMed

Zhang, Chao; Wu, Hua; Zhao, Yuan; Ma, Zhiqing; Zhang, Xing

2016-01-01

With Sitophilus zeamais as the target organism, the present study for the first time attempted to elucidate the comparative effects between allyl isothiocyanate (AITC) and calcium phosphide (Ca3P2), exposure on mitochondrial electron transport chain (ETC.) complex I & IV and their downstream effects on enzymes relevant to reactive oxygen species (ROS). In vivo, both AITC and Ca3P2 inhibited complex I and IV with similar downstream effects. In contrast with Ca3P2, the inhibition of complex I caused by AITC was dependent on time and dose. In vitro, AITC inhibited complex IV more significantly than complex I. These results indicate that mitochondrial complex IV is the primary target of AITC, and that complex I is another potential target. Copyright © 2015 Elsevier B.V. All rights reserved.

Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.

2005-01-01

Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

Rational Design of Zinc Phosphide Heterojunction Photovoltaics

NASA Astrophysics Data System (ADS)

Bosco, Jeffrey Paul

The prospect of terawatt-scale electricity generation using a photovoltaic (PV) device places strict requirements on the active semiconductor optoelectronic properties and elemental abundance. After reviewing the constraints placed on an ``earth-abundant'' solar absorber, we find zinc phosphide (α-Zn 3P2) to be an ideal candidate. In addition to its near-optimal direct band gap of 1.5 eV, high visible-light absorption coefficient (>10. 4cm-1), and long minority-carrier diffusion length (>5 μm), Zn3P 2 is composed of abundant Zn and P elements and has excellent physical properties for scalable thin-film deposition. However, to date, a Zn 3P2 device of sufficient efficiency for commercial applications has not been demonstrated. Record efficiencies of 6.0% for multicrystalline and 4.3% for thin-film cells have been reported, respectively. Performance has been limited by the intrinsic p-type conductivity of Zn3P 2 which restricts us to Schottky and heterojunction device designs. Due to our poor understanding of Zn3P2 interfaces, an ideal heterojunction partner has not yet been found. The goal of this thesis is to explore the upper limit of solar conversion efficiency achievable with a Zn3P2 absorber through the design of an optimal heterojunction PV device. To do so, we investigate three key aspects of material growth, interface energetics, and device design. First, the growth of Zn3P2 on GaAs(001) is studied using compound-source molecular-beam epitaxy (MBE). We successfully demonstrate the pseudomorphic growth of Zn3P2 epilayers of controlled orientation and optoelectronic properties. Next, the energy-band alignments of epitaxial Zn3P2 and II-VI and III-V semiconductor interfaces are measured via high-resolution x-ray photoelectron spectroscopy in order to determine the most appropriate heterojunction partner. From this work, we identify ZnSe as a nearly ideal n-type emitter for a Zn3P 2 PV device. Finally, various II-VI/Zn3P2 heterojunction solar cells designs are

Orientation dependent ferroelectric properties in samarium doped bismuth titanate thin films grown by the pulsed-laser-ablation method

NASA Astrophysics Data System (ADS)

Cheng, Zhenxiang; Kannan, Chinna Venkatasamy; Ozawa, Kiyoshi; Kimura, Hideo; Wang, Xiaolin

2006-07-01

Samarium doped bismuth titanate thin films with the composition of Bi3.25Sm0.75Ti3O12 and with strong preferred orientations along the c axis and the (117) direction were fabricated on Pt /TiO2/SiO2/Si substrate by pulsed laser ablation. Measurements on Pt /BSmT/Pt capacitors showed that the c-axis oriented film had a small remanent polarization (2Pr) of 5μC/cm2, while the highly (117) oriented film showed a 2Pr value of 54μC/cm2 at an electrical field of 268kV/cm and a coercive field Ec of 89kV/cm. This is different from the sol-gel derived c-axis oriented Bi3.15Sm0.85Ti3O12 film showing a 2Pr value of 49μC/cm2.

Evolution of a short route to strychnine by using the samarium-diiodide-induced cascade cyclization as a key step.

PubMed

Beemelmanns, Christine; Reissig, Hans-Ulrich

2015-06-01

This comprehensive report accounts the development of a highly diastereoselective samarium diiodide-induced cascade reaction of substituted indolyl ketones. The complexity-generating transformation with SmI2 allows the diastereoselective generation of three stereogenic centers including one quaternary center in one step. The obtained tetra- or pentacyclic dihydroindole derivatives are structural motifs of many monoterpene indole alkaloids, and their subsequent transformations gave way to one of the shortest approaches towards strychnine (14 % overall yield in ten steps, or 10 % overall yield in eight steps). During the course of this report we discuss the influence of substituents on the cyclization step, plausible mechanistic scenarios for the SmI2 -induced cascade reaction, diastereoselective reductive amination, and regioselective dehydratization protocols towards the pentacyclic core structure of strychnos alkaloids. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Observation of three-component fermions in the topological semimetal molybdenum phosphide.

PubMed

Lv, B Q; Feng, Z-L; Xu, Q-N; Gao, X; Ma, J-Z; Kong, L-Y; Richard, P; Huang, Y-B; Strocov, V N; Fang, C; Weng, H-M; Shi, Y-G; Qian, T; Ding, H

2017-06-29

In quantum field theory, Lorentz invariance leads to three types of fermion-Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

Observation of three-component fermions in the topological semimetal molybdenum phosphide

NASA Astrophysics Data System (ADS)

Lv, B. Q.; Feng, Z.-L.; Xu, Q.-N.; Gao, X.; Ma, J.-Z.; Kong, L.-Y.; Richard, P.; Huang, Y.-B.; Strocov, V. N.; Fang, C.; Weng, H.-M.; Shi, Y.-G.; Qian, T.; Ding, H.

2017-06-01

In quantum field theory, Lorentz invariance leads to three types of fermion—Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

Electrostatically driven resonance energy transfer in "cationic" biocompatible indium phosphide quantum dots.

PubMed

Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta; Pillai, Pramod P

2017-05-01

Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent positive charge and stability to InP/ZnS QDs in biofluids. The two important properties of QDs, namely bioimaging and light induced resonance energy transfer, are successfully demonstrated in cationic InP/ZnS QDs. The low cytotoxicity and stable photoluminescence of cationic InP/ZnS QDs inside cells make them ideal candidates as optical probes for cellular imaging. An efficient resonance energy transfer ( E ∼ 60%) is observed, under physiological conditions, between the cationic InP/ZnS QD donor and anionic dye acceptor. A large bimolecular quenching constant along with a linear Stern-Volmer plot confirms the formation of a strong ground state complex between the cationic InP/ZnS QDs and the anionic dye. Control experiments prove the role of electrostatic attraction in driving the light induced interactions, which can rightfully form the basis for future nano-bio studies between cationic InP/ZnS QDs and anionic biomolecules.

Hydrazine-Assisted Formation of Indium Phosphide (InP)-Based Nanowires and Core-Shell Composites

PubMed Central

Patzke, Greta R.; Kontic, Roman; Shiolashvili, Zeinab; Makhatadze, Nino; Jishiashvili, David

2012-01-01

Indium phosphide nanowires (InP NWs) are accessible at 440 °C from a novel vapor phase deposition approach from crystalline InP sources in hydrazine atmospheres containing 3 mol % H2O. Uniform zinc blende (ZB) InP NWs with diameters around 20 nm and lengths up to several tens of micrometers are preferably deposited on Si substrates. InP particle sizes further increase with the deposition temperature. The straightforward protocol was extended on the one-step formation of new core-shell InP–Ga NWs from mixed InP/Ga source materials. Composite nanocables with diameters below 20 nm and shells of amorphous gallium oxide are obtained at low deposition temperatures around 350 °C. Furthermore, InP/Zn sources afford InP NWs with amorphous Zn/P/O-coatings at slightly higher temperatures (400 °C) from analogous setups. At 450 °C, the smooth outer layer of InP-Zn NWs is transformed into bead-shaped coatings. The novel combinations of the key semiconductor InP with isotropic insulator shell materials open up interesting application perspectives in nanoelectronics. PMID:28809296

Forward-biased current annealing of radiation degraded indium phosphide and gallium arsenide solar cells

NASA Technical Reports Server (NTRS)

Michael, Sherif; Cypranowski, Corinne; Anspaugh, Bruce

1990-01-01

The preliminary results of a novel approach to low-temperature annealing of previously irradiated indium phosphide and gallium arsenide solar cells are reported. The technique is based on forward-biased current annealing. The two types of III-V solar cells were irradiated with 1-MeV electrons to a fluence level of (1-10) x 10 to the 14th electrons/sq cm. Several annealing attempts were made, varying all conditions. Optimum annealing was achieved when cells were injected with minority currents at a constant 90 C. The current density for each type of cell was also determined. Significant recovery of degraded parameters was achieved in both cases. However, the InP cell recovery notably exceeded the recovery in GaAs cells. The recovery is thought to be caused by current-stimulated reordering of the radiator-induced displacement damage. Both types of cell were then subjected to several cycles of irradiation and annealing. The results were also very promising. The significant recovery of degraded cell parameters at low temperature might play a major role in considerably extending the end of life of future spacecraft.

Direct Band Gap Gallium Antimony Phosphide (GaSbxP1−x) Alloys

PubMed Central

Russell, H. B.; Andriotis, A. N.; Menon, M.; Jasinski, J. B.; Martinez-Garcia, A.; Sunkara, M. K.

2016-01-01

Here, we report direct band gap transition for Gallium Phosphide (GaP) when alloyed with just 1–2 at% antimony (Sb) utilizing both density functional theory based computations and experiments. First principles density functional theory calculations of GaSbxP1−x alloys in a 216 atom supercell configuration indicate that an indirect to direct band gap transition occurs at x = 0.0092 or higher Sb incorporation into GaSbxP1−x. Furthermore, these calculations indicate band edge straddling of the hydrogen evolution and oxygen evolution reactions for compositions ranging from x = 0.0092 Sb up to at least x = 0.065 Sb making it a candidate for use in a Schottky type photoelectrochemical water splitting device. GaSbxP1−x nanowires were synthesized by reactive transport utilizing a microwave plasma discharge with average compositions ranging from x = 0.06 to x = 0.12 Sb and direct band gaps between 2.21 eV and 1.33 eV. Photoelectrochemical experiments show that the material is photoactive with p-type conductivity. This study brings attention to a relatively uninvestigated, tunable band gap semiconductor system with tremendous potential in many fields. PMID:26860470

Highly Efficient and Robust Nickel Phosphides as Bifunctional Electrocatalysts for Overall Water-Splitting.

PubMed

Li, Jiayuan; Li, Jing; Zhou, Xuemei; Xia, Zhaoming; Gao, Wei; Ma, Yuanyuan; Qu, Yongquan

2016-05-04

To search for the efficient non-noble metal based and/or earth-abundant electrocatalysts for overall water-splitting is critical to promote the clean-energy technologies for hydrogen economy. Herein, we report nickel phosphide (NixPy) catalysts with the controllable phases as the efficient bifunctional catalysts for water electrolysis. The phases of NixPy were determined by the temperatures of the solid-phase reaction between the ultrathin Ni(OH)2 plates and NaH2PO2·H2O. The NixPy with the richest Ni5P4 phase synthesized at 325 °C (NixPy-325) delivered efficient and robust catalytic performance for hydrogen evolution reaction (HER) in the electrolytes with a wide pH range. The NixPy-325 catalysts also exhibited a remarkable performance for oxygen evolution reaction (OER) in a strong alkaline electrolyte (1.0 M KOH) due to the formation of surface NiOOH species. Furthermore, the bifunctional NixPy-325 catalysts enabled a highly performed overall water-splitting with ∼100% Faradaic efficiency in 1.0 M KOH electrolyte, in which a low applied external potential of 1.57 V led to a stabilized catalytic current density of 10 mA/cm(2) over 60 h.

Byproduct-free mass production of compound semiconductor nanowires: zinc phosphide

NASA Astrophysics Data System (ADS)

Chen, Yixi; Polinnaya, Rakesh; Vaddiraju, Sreeram

2018-05-01

A method for the mass production of compound semiconductor nanowires that involves the direct reaction of component elements in a chemical vapor deposition chamber (CVD) is presented. This method results in nanowires, without the associated production of any other byproducts such as nanoparticles or three-dimensional (3D) bulk crystals. Furthermore, no unreacted reactants remain mixed with the nanowire product in this method. This byproduct-free nanowire production thus circumvents the need to tediously purify and collect nanowires from a mixture of products/reactants after their synthesis. Demonstration made using zinc phosphide (Zn3P2) material system as an example indicated that the direct reaction of zinc microparticles with phosphorus supplied via the vapor phase results in the production of gram quantities of nanowires. To enhance thermal transport and achieve the complete reaction of zinc microparticles, while simultaneously ensuring that the microparticles do not agglomerate into macroscale zinc particles and partly remain unreacted (owing to diffusion limitations), pellets composed of mixtures of zinc and a sacrificial salt, NH4Cl, were employed as the starting material. The sublimation by decomposition of NH4Cl in the early stages of the reaction leaves a highly porous pellet of zinc composed of only zinc microparticles, which allows for inward diffusion of phosphorus/outward diffusion of zinc and the complete conversion of zinc into Zn3P2 nanowires. NH4Cl also aids in removal of any native oxide layer present on the zinc microparticles that may prevent their reaction with phosphorus. This method may be used to mass produce many other nanowires in a byproduct-free manner, besides Zn3P2.

Cobalt Phosphide Hollow Polyhedron as Efficient Bifunctional Electrocatalysts for the Evolution Reaction of Hydrogen and Oxygen.

PubMed

Liu, Mengjia; Li, Jinghong

2016-01-27

The development of efficient and low-cost hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts for renewable-energy conversion techniques is highly desired. A kind of hollow polyhedral cobalt phosphide (CoP hollow polyhedron) is developed as efficient bifunctional electrocatalysts for HER and OER templated by Co-centered metal-organic frameworks. The as-prepared CoP hollow polyhedron, which have large specific surface area and high porosity providing rich catalytic active sites, show excellent electrocatalytic performances for both HER and OER in acidic and alkaline media, respectively, with onset overpotentials of 35 and 300 mV, Tafel slopes of 59 and 57 mV dec(-1), and a current density of 10 mA cm(-2) at overpotentials of 159 and 400 mV for HER and OER, respectively, which are remarkably superior to those of particulate CoP (CoP particles) and comparable to those of commercial noble-metal catalysts. In addition, the CoP hollow polyhedron also show good durability after long-term operations.

Assembly of phosphide nanocrystals into porous networks: formation of InP gels and aerogels.

PubMed

Hitihami-Mudiyanselage, Asha; Senevirathne, Keerthi; Brock, Stephanie L

2013-02-26

The applicability of sol-gel nanoparticle assembly routes, previously employed for metal chalcogenides, to phosphides is reported for the case of InP. Two different sizes (3.5 and 6.0 nm) of InP nanoparticles were synthesized by solution-phase arrested precipitation, capped with thiolate ligands, and oxidized with H₂O₂ or O₂/light to induce gel formation. The gels were aged, solvent-exchanged, and then supercritically dried to obtain aerogels with both meso- (2-50 nm) and macropores (>50 nm) and accessible surface areas of ∼200 m²/g. Aerogels showed higher band gap values relative to precursor nanoparticles, suggesting that during the process of assembling nanoparticles into 3D architectures, particle size reduction may have taken place. In contrast to metal chalcogenide gelation, InP gels did not form using tetranitromethane, a non-oxygen-transferring oxidant. The requirement of an oxygen-transferring oxidant, combined with X-ray photoelectron spectroscopy data showing oxidized phosphorus, suggests gelation is occurring due to condensation of phosphorus oxoanionic moieties generated at the interfaces. The ability to link discrete InP nanoparticles into a 3D porous network while maintaining quantum confinement is expected to facilitate exploitation of nanostructured InP in solid-state devices.

Pushing indium phosphide quantum dot emission deeper into the near infrared

NASA Astrophysics Data System (ADS)

Saeboe, A. M.; Kays, J.; Mahler, A. H.; Dennis, A. M.

2018-02-01

Cadmium-free near infrared (NIR) emitting quantum dots (QDs) have significant potential for multiplexed tissue-depth imaging applications in the first optical tissue window (i.e., 650 - 900 nm). Indium phosphide (InP) chemistry provides one of the more promising cadmium-free options for biomedical imaging, but the full tunability of this material has not yet been achieved. Specifically, InP QD emission has been tuned from 480 - 730 nm in previous literature reports, but examples of samples emitting from 730 nm to the InP bulk bandgap limit of 925 nm are lacking. We hypothesize that by generating inverted structures comprising ZnSe/InP/ZnS in a core/shell/shell heterostructure, optical emission from the InP shell can be tuned by changing the InP shell thickness, including pushing deeper into the NIR than current InP QDs. Colloidal synthesis methods including hot injection precipitation of the ZnSe core and a modified successive ion layer adsorption and reaction (SILAR) method for stepwise shell deposition were used to promote growth of core/shell/shell materials with varying thicknesses of the InP shell. By controlling the number of injections of indium and phosphorous precursor material, the emission peak was tuned from 515 nm to 845 nm (2.41 - 1.47 eV) with consistent full width half maximum (FWHM) values of the emission peak 0.32 eV. To confer water solubility, the nanoparticles were encapsulated in PEGylated phospholipid micelles, and multiplexing of NIR-emitting InP QDs was demonstrated using an IVIS imaging system. These materials show potential for multiplexed imaging of targeted QD contrast agents in the first optical tissue window.

Trends in activity for the oxygen evolution reaction on transition metal (M = Fe, Co, Ni) phosphide pre-catalysts† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc05033j

PubMed Central

Xu, Junyuan; Li, Junjie; Xiong, Dehua; Zhang, Bingsen; Liu, Yuefeng; Wu, Kuang-Hsu; Amorim, Isilda; Li, Wei

2018-01-01

Transition metal phosphides (TMPs) have recently emerged as a new class of pre-catalysts that can efficiently catalyze the oxygen evolution reaction (OER). However, how the OER activity of TMPs varies with the catalyst composition has not been systematically explored. Here, we report the alkaline OER electrolysis of a series of nanoparticulate phosphides containing different equimolar metal (M = Fe, Co, Ni) components. Notable trends in OER activity are observed, following the order of FeP < NiP < CoP < FeNiP < FeCoP < CoNiP < FeCoNiP, which indicate that the introduction of a secondary metal(s) to a mono-metallic TMP substantially boosts the OER performance. We ascribe the promotional effect to the enhanced oxidizing power of bi- and tri-metallic TMPs that can facilitate the formation of MOH and chemical adsorption of OH– groups, which are the rate-limiting steps for these catalysts according to our Tafel analysis. Remarkably, the tri-metallic FeCoNiP pre-catalyst exhibits exceptionally high apparent and intrinsic OER activities, requiring only 200 mV to deliver 10 mA cm–2 and showing a high turnover frequency (TOF) of ≥0.94 s–1 at the overpotential of 350 mV. PMID:29780476

CVD growth and properties of boron phosphide on 3C-SiC

NASA Astrophysics Data System (ADS)

Padavala, Balabalaji; Frye, C. D.; Wang, Xuejing; Raghothamachar, Balaji; Edgar, J. H.

2016-09-01

Improving the crystalline quality of boron phosphide (BP) is essential for realizing its full potential in semiconductor device applications. In this study, 3C-SiC was tested as a substrate for BP epitaxy. BP films were grown on 3C-SiC(100)/Si, 3C-SiC(111)/Si, and 3C-SiC(111)/4H-SiC(0001) substrates in a horizontal chemical vapor deposition (CVD) system. Films were produced with good crystalline orientation and morphological features in the temperature range of 1000-1200 °C using a PH3+B2H6+H2 mixture. Rotational twinning was absent in the BP due to the crystal symmetry-matching with 3C-SiC. Confocal 3D Raman imaging of BP films revealed primarily uniform peak shift and peak widths across the scanned area, except at defects on the surface. Synchrotron white beam X-ray topography showed the epitaxial relationship between BP and 3C-SiC was (100) 〈 011 〉 BP||(100) 〈 011 〉 3C-SiC and (111) 〈 11 2 ̅ 〉 BP||(111) 〈 11 2 ̅ 〉 3C-SiC. Scanning electron microscopy, Raman spectroscopy and X-ray diffraction analysis indicated residual tensile strain in the films and improved crystalline quality at temperatures below 1200 °C. These results indicated that BP properties could be further enhanced by employing high quality bulk 3C-SiC or 3C-SiC epilayers on 4H-SiC substrates.

CVD growth and properties of boron phosphide on 3C-SiC

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

Padavala, Balabalaji; Frye, C. D.; Wang, Xuejing

Improving the crystalline quality of boron phosphide (BP) is essential for realizing its full potential in semiconductor device applications. In this study, 3C-SiC was tested as a substrate for BP epitaxy. BP films were grown on 3C-SiC(100)/Si, 3C-SiC(111)/Si, and 3C-SiC(111)/4H-SiC(0001) substrates in a horizontal chemical vapor deposition (CVD) system. Films were produced with good crystalline orientation and morphological features in the temperature range of 1000–1200 °C using a PH3+B2H6+H2 mixture. Rotational twinning was absent in the BP due to the crystal symmetry-matching with 3C-SiC. Confocal 3D Raman imaging of BP films revealed primarily uniform peak shift and peak widths acrossmore » the scanned area, except at defects on the surface. Synchrotron white beam X-ray topography showed the epitaxial relationship between BP and 3C-SiC was (100) <011>BP||(100) <011>3C-SiC and (111)View the MathML sourceBP||(111)View the MathML source3C-SiC. Scanning electron microscopy, Raman spectroscopy and X-ray diffraction analysis indicated residual tensile strain in the films and improved crystalline quality at temperatures below 1200 °C. These results indicated that BP properties could be further enhanced by employing high quality bulk 3C-SiC or 3C-SiC epilayers on 4H-SiC substrates.« less

Integration of Indium Phosphide Based Devices with Flexible Substrates

NASA Astrophysics Data System (ADS)

Chen, Wayne Huai

2011-12-01

Flexible substrates have many advantages in applications where bendability, space, or weight play important roles or where rigid circuits are undesirable. However, conventional flexible thin film transistors are typically characterized as having low carrier mobility as compared to devices used in the electronics industry. This is in part due to the limited temperature tolerance of plastic flexible substrates, which commonly reduces the highest processing temperature to below 200°C. Common approaches of implementation include low temperature deposition of organic, amorphous, or polycrystalline semiconductors, all of which result in carrier mobility well below 100 cm2V -1s-1. High quality, single crystalline III-V semiconductors such as indium phosphide (InP), on the other hand, have carrier mobility well over 1000 cm 2V-1s-1 at room temperature, depending on carrier concentration. Recently, the ion-cut process has been used in conjunction with wafer bonding to integrate thin layers of III-V material onto silicon for optoelectronic applications. This approach has the advantage of high scalability, reusability of the initial III-V substrate, and the ability to tailor the location (depth) of the layer splitting. However, the transferred substrate usually suffers from hydrogen implantation damage. This dissertation demonstrates a new approach to enable integration of InP with various substrates, called the double-flip transfer process. The process combines ion-cutting with adhesive bonding. The problem of hydrogen implantation was overcome by patterned ion-cut transfer. In this type of transfer, areas of interest are shielded from implantation but still transferred by surrounding implanted regions. We found that patterned ion-cut transfer is strongly dependent upon crystal orientation and that using cleavage-plane oriented donors can be beneficial in transferring large areas of high quality semiconductor material. InP-based devices were fabricated to demonstrate the

A review of episodes of zinc phosphide toxicosis in wild geese (Branta spp.) in Oregon (2004−2011)

USGS Publications Warehouse

Bildfell, Rob J.; Rumbeiha, Wilson K.; Schuler, Krysten L.; Meteyer, Carol U.; Wolff, Peregrine L.; Gillin, Colin M.

2013-01-01

Epizootic mortality in several geese species, including cackling geese (Branta hutchinsii) and Canada geese (Branta canadensis), has been recognized in the Willamette Valley of Oregon for over a decade. Birds are generally found dead on a body of water or are occasionally observed displaying neurologic clinical signs such as an inability to raise or control the head prior to death. Investigation of these epizootic mortality events has revealed the etiology to be accidental poisoning with the rodenticide zinc phosphide (Zn3P2). Gross and histologic changes are restricted to acute pulmonary congestion and edema, sometimes accompanied by distension of the upper alimentary tract by fresh grass. Geese are unusually susceptible to this pesticide; when combined with an epidemiologic confluence of depredation of specific agricultural crops by rodents and seasonal avian migration pathways, epizootic toxicosis may occur. Diagnosis requires a high index of suspicion, appropriate sample collection and handling, plus specific test calibration for this toxicant. Interagency cooperation, education of farmers regarding pesticide use, and enforcement of regulations has been successful in greatly decreasing these mortality events since 2009.

Effect of gas flow ratio on the microstructure and mechanical properties of boron phosphide films prepared by reactive magnetron sputtering

NASA Astrophysics Data System (ADS)

Jia, Z. C.; Zhu, J. Q.; Jiang, C. Z.; Shen, W. X.; Han, J. C.; Chen, R. R.

2011-10-01

Boron phosphide films were grown on silicon substrate by radio frequency reactive magnetron sputtering using boron target and hydrogen phosphine at different gas flow ratios (PH 3/Ar) at lower temperature. The chemical composition, microstructure and mechanical properties were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectrum, FTIR spectrum, surface profilometer and nano-indenter. The results indicate that the atomic ratio (P/B) rises from 1.06 up to 1.52 with the gas flow ratio increasing from 3/50 to 15/50. Simultaneously, the hardness and Young's modulus decrease from 25.4 GPa to 22.5 GPa, and 250.4 GPa to 238.4 GPa, respectively. Microstructure transforms from microcrystalline state to amorphous state along with the gas flow ratio increasing. Furthermore higher gas flow ratio leads to lower stress. The BP film prepared at the gas flow ratio of 3/50 can be contributed with the best properties.

Samarium oxide as a radiotracer to evaluate the in vivo biodistribution of PLGA nanoparticles

NASA Astrophysics Data System (ADS)

Mandiwana, Vusani; Kalombo, Lonji; Venter, Kobus; Sathekge, Mike; Grobler, Anne; Zeevaart, Jan Rijn

2015-09-01

Developing nanoparticulate delivery systems that will allow easy movement and localization of a drug to the target tissue and provide more controlled release of the drug in vivo is a challenge in nanomedicine. The aim of this study was to evaluate the biodistribution of poly( d, l-lactide- co-glycolide) (PLGA) nanoparticles containing samarium-153 oxide ([153Sm]Sm2O3) in vivo to prove that orally administered nanoparticles alter the biodistribution of a drug. These were then activated in a nuclear reactor to produce radioactive 153Sm-loaded-PLGA nanoparticles. The nanoparticles were characterized for size, zeta potential, and morphology. The nanoparticles were orally and intravenously (IV) administered to rats in order to trace their uptake through imaging and biodistribution studies. The 153Sm-loaded-PLGA nanoparticles had an average size of 281 ± 6.3 nm and a PDI average of 0.22. The zeta potential ranged between 5 and 20 mV. The [153Sm]Sm2O3 loaded PLGA nanoparticles, orally administered were distributed to most organs at low levels, indicating that there was absorption of nanoparticles. While the IV injected [153Sm]Sm2O3-loaded PLGA nanoparticles exhibited the highest localization of nanoparticles in the spleen (8.63 %ID/g) and liver (3.07 %ID/g), confirming that nanoparticles are rapidly removed from the blood by the RES, leading to rapid uptake in the liver and spleen. From the biodistribution data obtained, it is clear that polymeric nanoscale delivery systems would be suitable for improving permeability and thus the bioavailability of therapeutic compounds.

M-H characteristics and demagnetization resistance of samarium-cobalt permanent magnets to 300 C

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1992-01-01

The influence of temperature on the M-H demagnetization characteristics of permanent magnets is important information for the full utilization of the capabilities of samarium-cobalt magnets at high temperatures in demagnetization-resistant permanent magnet devices. In high temperature space power converters, such as free-piston Stirling engine driven linear alternators, magnet demagnetization can occur as a long-term consequence of thermal agitation of domains and of metallurgical change, and also as an immediate consequence of too large an applied field. Investigated here is the short-term demagnetization resistance to applied fields derived from basic M-H data. This quasistatic demagnetization data was obtained for commercial, high-intrinsic-coercivity, Sm2Co17-type magnets from 5 sources, in the temperature range 23 to 300 C. An electromagnet driven, electronic hysteresigraph was used to test the 1-cm cubic samples. The observed variation of the 2nd quadrant M-H characteristics was a typical rapid loss of M-coercivity and a relatively lesser loss of remanence with increasing temperature. The 2nd quadrant M-H curve knee point is used to define the limits of operation safe against irreversible demagnetization due to an excessive bucking field for a given flux density swing at temperature. Such safe operating area plots are shown to differentiate the high temperature capabilities of the samples from different sources. For most of the samples, their 2nd quadrant M-H loop squareness increased with temperature, reaching a peak or a plateau above 250 C.

Atomistic investigations on the mechanical properties and fracture mechanisms of indium phosphide nanowires.

PubMed

Pial, Turash Haque; Rakib, Tawfiqur; Mojumder, Satyajit; Motalab, Mohammad; Akanda, M A Salam

2018-03-28

The mechanical properties of indium phosphide (InP) nanowires are an emerging issue due to the promising applications of these nanowires in nanoelectromechanical and microelectromechanical devices. In this study, molecular dynamics simulations of zincblende (ZB) and wurtzite (WZ) crystal structured InP nanowires (NWs) are presented under uniaxial tension at varying sizes and temperatures. It is observed that the tensile strengths of both types of NWs show inverse relationships with temperature, but are independent of the size of the nanowires. Moreover, applied load causes brittle fracture by nucleating cleavage on ZB and WZ NWs. When the tensile load is applied along the [001] direction, the direction of the cleavage planes of ZB NWs changes with temperature. It is found that the {111} planes are the cleavage planes at lower temperatures; on the other hand, the {110} cleavage planes are activated at elevated temperatures. In the case of WZ NWs, fracture of the material is observed to occur by cleaving along the (0001) plane irrespective of temperature when the tensile load is applied along the [0001] direction. Furthermore, the WZ NWs of InP show considerably higher strength than their ZB counterparts. Finally, the impact of strain rate on the failure behavior of InP NWs is also studied, and higher fracture strengths and strains at higher strain rates are found. With increasing strain rate, the number of cleavages also increases in the NWs. This paper also provides in-depth understanding of the failure behavior of InP NWs, which will aid the design of efficient InP NWs-based devices.

Investigation of Characteristics and Predictive Factors Affecting Mortality from Aluminum Phosphide Poisoning, Iran.

PubMed

Navabi, Seyed Mohammad Navabi; Navabi, Seyed Jafar; Aghaei, Abbas; Shaahmadi, Zahra; Heydari, Ruhollah

2018-05-27

Aluminum phosphide (ALP) or rice tablet is one of the most effective rodenticides used for the protection of grain storages from animals and rodents. ALP poisoning annually leads to mortality in human beings. The aim of this study was to evaluate the characteristics and predictive factors affecting mortality from ALP poisoning. This study evaluated patients with ALP poisoning referred to Imam Khomeini hospital in Kermanshah from 2014 to 2015. There are several data gathered from patient such as age, sex, number of consumed tablets, the number of attempts to commit suicide, elapsed time from consuming till treatment, blood pressure, PH, HCO3 and PCO2. Survivors (recovery) and non-survivors (death) from ALP poisoning are also evaluated in this study. Univariate logistic regression and multivariate analysis have been applied for data analysis. In this study, 48 patients were male and 29 patients were female, respectively (total 77 patient). The average age of survivors and non-survivors were 28.69 and 31.34 years, respectively. All cases (100%) of ALP poisoning were tried to commit suicide. The results showed that the main predictive variables of mortality from ALP poisoning were blood pressure, PH and elapsed time from consuming till treatment. The prognosis of death for patients with ALP poisoning can be determined by awareness of some of the main characteristics or factors such as blood pressure, PH and elapsed time from consuming till treatment. This can give a possibility for healthcare groups to consider more measures in patients with ALP poisoning.

Synthesis and characterization of the divalent samarium Zintl-phases SmMg 2Bi 2 and SmMg 2Sb 2

DOE PAGES

Ramirez, D.; Gallagher, A.; Baumbach, R.; ...

2015-08-29

Here, single crystals of LnMg 2Bi 2 (Ln = Yb, Eu, Sm) and SmMg 2Sb 2 were synthesized using Mg-Bi metal and Mg-Sb metal fluxes, respectively. The crystal structures are of the CaAl 2Si 2 type with space group P3 m1 (#164, Z = 1): SmMg 2Bi 2 ( a = 4.7745(1)Å, c = 7.8490(2)Å), EuMg 2Bi 2 ( a = 4.7702(1)Å, c = 7.8457(2) Å), YbMg 2Bi 2 ( a = 4.7317(2)Å, c = 7.6524(3) Å), and SmMg 2Sb 2 ( a = 4.6861(1) Å, c = 7.7192(2) Å). Heat capacity, electrical transport, and magnetization of all bismuth containingmore » phases were measured. The materials behave as “poor metals” with resistivity between 2 and 10 mΩ·cm. Temperature independent Van Vleck paramagnetism is observed in SmMg 2Bi 2 indicative of divalent samarium (Sm 2+) ions.« less

The achievement of low contact resistance to indium phosphide: The roles of Ni, Au, Ge, and combinations thereof

NASA Technical Reports Server (NTRS)

Fatemi, Navid S.; Weizer, Victor G.

1992-01-01

We have investigated the electrical and metallurgical behavior of Ni, Au-Ni, and Au-Ge-Ni contacts on n-InP. We have found that very low values of contact resistivity rho(sub c) in the E-7 omega-sq cm range are obtained with Ni-only contacts. We show that the addition of Au to Ni contact metallization effects an additional order of magnitude reduction in rho(sub c). Ultra-low contact resistivities in the E-8 omega-sq cm range are obtained with both the Au-Ni and the Au-Ge-Ni systems, effectively eliminating the need for the presence of Ge in the Au-Ge-Ni system. The formation of various nickel phosphides at the metal-InP interface is shown to be responsible for the observed rho(sub c) values in the Ni and Au-Ni systems. We show, finally, that the order in which the constituents of Au-Ni and Au-Ge-Ni contacts are deposited has a significant bearing on the composition of the reaction products formed at the metal-InP interface and therefore on the contact resistivity at that interface.

Selective gas adsorption and I-V response of monolayer boron phosphide introduced by dopants: A first-principle study

NASA Astrophysics Data System (ADS)

Cheng, Yongfa; Meng, Ruishen; Tan, Chunjian; Chen, Xianping; Xiao, Jing

2018-01-01

Two-dimensional (2D) materials have gained tremendous research interests for gas sensing applications because of their ultrahigh theoretical specific surface areas and unique electronic properties. Here, we investigate the adsorption of CO, SO2, NH3, O2, NO and NO2 gas molecules on pure and doped boron phosphide (BP) systems using first-principles calculations to exploit their potential in gas sensing. Our results predict that all six gas molecules show stronger adsorption interactions on impurities-doped BP over the pristine monolayer BP. Al-doped BP shows the highest sensitivity to all gas molecules, but N-doped BP is more suitable as a sensing material for SO2, NO and NO2 due to the feasibility of desorption. We further calculated the current-voltage (I-V) relation by mean of nonequilibrium Green's function (NEGF) formalism. The I-V curves indicate that the electronic properties of the doping systems change significantly with gas adsorption by studying the nonparamagnetic molecules NH3 and the paramagnetic molecules NO, which can be more likely to be measured experimentally compared to graphene and phosphorene. This work explores the possibility of BP as a superior sensor through introducing the appropriate dopants.

Performance characterization of mid-infrared difference frequency generation in orientation-patterned gallium phosphide

NASA Astrophysics Data System (ADS)

Wei, Junxiong; Chaitanya Kumar, S.; Ye, Hanyu; Schunemann, Peter G.; Ebrahim-Zadeh, M.

2018-02-01

Orientation-patterned gallium phosphide (OP-GaP) is a recently developed nonlinear material with wide transparency across 0.8-12 μm and high nonlinearity (d14 70 pm/V), which is a promising candidate material for mid-infrared generation. Here we report the full performance characterization of a tunable single-pass nanosecond difference frequency generation (DFG) source based on OP-GaP by mixing the output of a Q-switched Nd:YAG laser at 1.064 μm with the signal from a pulsed MgO:PPLN OPO pumped by the same laser. Using the longest OP-GaP crystal (40 mm) deployed to date, the DFG source provides up to 14 mW of average output power at 2719 nm at 80 kHz repetition rate, with >6 mW across 2492-2782 nm, in TEM00 spatial profile. By performing relevant measurements, detrimental issues such as residual absorption and thermal effects have been studied and confirmed. The temperature and spectral acceptance bandwidths for DFG in the 40-mm-log OP-GaP are measured to be 18 °C and 17 nm, respectively, at 1766 nm. The DFG beam exhibits passive power stability better than 1.7% rms over 1.4 hours at 2774 nm, compared to 1.6% and 0.1% rms for the signal and pump, respectively. The polarization dependence of the input beams on the DFG power has also been systematically investigated, for the first time to our knowledge. Further, we have measured the damage threshold of the OP-GaP crystal to be 0.8 J/cm2 at 1064 nm.

Indium phosphide all air-gap Fabry-Pérot filters for near-infrared spectroscopic applications

NASA Astrophysics Data System (ADS)

Ullah, A.; Butt, M. A.; Fomchenkov, S. A.; Khonina, S. N.

2016-08-01

Food quality can be characterized by noninvasive techniques such as spectroscopy in the Near Infrared wavelength range. For example, 930 -1450 nm wavelength range can be used to detect diseases and differentiate between meat samples. Miniaturization of such NIR spectrometers is useful for quick and mobile characterization of food samples. Spectrometers can be miniaturized, without compromising the spectral resolution, using Fabry-Pérot (FP) filters consisting of two highly reflecting mirrors with a central cavity in between. The most commonly used mirrors in the design of FP filters are Distributed Bragg Reflections (DBRs) consisting of alternating high and low refractive index material pairs, due to their high reflectivity compared to metal mirrors. However, DBRs have high reflectivity for a selected range of wavelengths known as the stopband of the DBR. This range is usually much smaller than the sensitivity range of the spectrometer detector. Therefore, a bandpass filter is usually required to restrict wavelengths outside the stopband of the FP DBRs. Such bandpass filters are difficult to design and implement. Alternatively, high index contrast materials must be can be used to broaden the stopband width of the FP DBRs. In this work, Indium phosphide all air-gap filters are proposed in conjunction with InGaAs based detectors. The designed filter has a wide stopband covering the entire InGaAs detector sensitivity range. The filter can be tuned in the 950-1450 nm with single mode operation. The designed filter can hence be used for noninvasive meat quality control.

New Intermetallic Ternary Phosphide Chalcogenide AP2-xXx (A = Zr, Hf; X = S, Se) Superconductors with PbFCl-Type Crystal Structure

NASA Astrophysics Data System (ADS)

Kitô, Hijiri; Yanagi, Yousuke; Ishida, Shigeyuki; Oka, Kunihiko; Gotoh, Yoshito; Fujihisa, Hiroshi; Yoshida, Yoshiyuki; Iyo, Akira; Eisaki, Hiroshi

2014-07-01

We have synthesized a series of intermetallic ternary phosphide chalcogenide superconductors, AP2-xXx (A = Zr, Hf; X = S, Se), using the high-pressure synthesis technique. These materials have a PbFCl-type crystal structure (space group P4/nmm) when x is greater than 0.3. The superconducting transition temperature Tc changes systematically with x, yielding dome-like phase diagrams. The maximum Tc is achieved at approximately x = 0.7, at which point the Tc is 6.3 K for ZrP2-xSex (x = 0.75), 5.5 K for HfP2-xSex (x = 0.7), 5.0 K for ZrP2-xSx (x = 0.675), and 4.6 K for Hfp2-xSx (x = 0.5). They are typical type-II superconductors and the upper and lower critical fields are estimated to be 2.92 T at 0 K and 0.021 T at 2 K for ZrP2-xSex (x = 0.75), respectively.

Patents and Licenses Through 1994,

DTIC Science & Technology

1994-01-01

Chiang was employed at Honeywell Radiation Center, where she worked on mercury cadmium telluride (HgCdTe) and gallium phosphide photoconductive...5,251,225 Gallium Indium Arsenide Phosphide 4,258,375; 4,372,791; 4,718,070;4,722,092 Gallium Indium Arsenide Phosphide /Indium Phosphide ...Indirect-Gap Semiconductor 3,636,471 Indium Arsenide 2,990,259 Indium Gallium Arsenide 4,746,620 Indium Phosphide 2,990,259; 4,376,285

Occupational phosphine gas poisoning at veterinary hospitals from dogs that ingested zinc phosphide--Michigan, Iowa, and Washington, 2006-2011.

PubMed

2012-04-27

Zinc phosphide (Zn3P2) is a readily available rodenticide that, on contact with stomach acid and water, produces phosphine (PH3), a highly toxic gas. Household pets that ingest Zn3P2 often will regurgitate, releasing PH3 into the air. Veterinary hospital staff members treating such animals can be poisoned from PH3 exposure. During 2006-2011, CDC's National Institute for Occupational Safety and Health (NIOSH) received reports of PH3 poisonings at four different veterinary hospitals: two in Michigan, one in Iowa, and one in Washington. Each of the four veterinary hospitals had treated a dog that ingested Zn3P2. Among hospital workers, eight poisoning victims were identified, all of whom experienced transient symptoms related to PH3 inhalation. All four dogs recovered fully. Exposure of veterinary staff members to PH3 can be minimized by following phosphine product precautions developed by the American Veterinary Medical Association (AVMA). Exposure of pets, pet owners, and veterinary staff members to PH3 can be minimized by proper storage, handling, and use of Zn3P2 and by using alternative methods for gopher and mole control, such as snap traps.

General Strategy for the Synthesis of Transition-Metal Phosphide/N-Doped Carbon Frameworks for Hydrogen and Oxygen Evolution.

PubMed

Pu, Zonghua; Zhang, Chengtian; Amiinu, Ibrahim Saana; Li, Wenqiang; Wu, Lin; Mu, Shichun

2017-05-17

Transition metal phosphides (TMPs) have been identified as promising nonprecious metal electrocatalyst for hydrogen evolution reaction (HER) and other energy conversion reactions. Herein, we reported a general strategy for synthesis of a series of TMPs (Fe 2 P, FeP, Co 2 P, CoP, Ni 2 P, and Ni 12 P 5 ) nanoparticles (NPs) with different metal phases embedded in a N-doped carbon (NC) matrix using metal salt, ammonium dihydrogen phosphate, and melamine as precursor with varying molar ratios and thermolysis temperatures. The resultant TMPs can serve as highly active and durable bifunctional electrocatalyst toward HER and oxygen evolution reaction (OER). In particular, the Ni 2 P@NC phase only requires an overpotential of ∼138 mV to derive HER in 0.5 M H 2 SO 4, and ∼320 mV for OER in 1.0 M KOH at the current density of 10 mA cm -2 . Because of the encapsulation of NC that can effectively prevent corrosion of embedded TMP NPs, Ni 2 P@NC exhibits almost unfading catalytic performance even after 10 h under both acidic and alkaline solutions. This synthesis strategy provides a new avenue to exploring TMPs as highly active and stable electrocatalyst for the HER, OER, and other electrochemical applications.

Determination of the speciation and bioavailability of samarium to Chlamydomonas reinhardtii in the presence of natural organic matter.

PubMed

Rowell, Justine-Anne; Fillion, Marc-Alexandre; Smith, Scott; Wilkinson, Kevin J

2018-06-01

As technological interest and environmental emissions of the rare earth elements increase, it is becoming more important to assess their potential environmental impact. Samarium (Sm) is a lanthanide of intermediate molar mass that is used in numerous high-technology applications including wind turbines, solar panels, and electric vehicles. The present study relates the speciation of Sm determined in the presence of natural organic matter (NOM) to its bioavailability to the unicellular green alga Chlamydomonas reinhardtii. The free ion concentration was determined using a cation exchange resin (ion exchange technique) in dynamic mode and compared with thermodynamic modeling. Short-term biouptake experiments were performed in the presence of 4 types of NOM: Suwannee River fulvic acids, Pahokee Peat fulvic acids, Suwannee River humic acids, and a Luther Marsh dissolved organic matter isolate (90-95% humic acids). It was clearly shown that even a small amount of NOM (0.5 mg C L -1 ) resulted in a significant decrease (10 times) in the Sm internalization fluxes. Furthermore, complexation with humic acids (and the corresponding reduction in Sm bioavailability) was stronger than that with fulvic acids. The results showed that the experimentally measured (free) Sm was a better predictor of Sm internalization than either the total concentrations or the free ion concentrations obtained using thermodynamic modeling. Environ Toxicol Chem 2018;37:1623-1631. © 2018 SETAC. © 2018 SETAC.

Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning.

PubMed

Soltani, Motahareh; Shetab-Boushehri, Seyed F; Shetab-Boushehri, Seyed V

2016-08-01

Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Activated charcoal significantly reduced the volume of released gas (P <0.01). Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01). A gaseous adduct was formed in the reaction between pure AlP and boric acid. These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

Highly CO2-Tolerant Cathode for Intermediate-Temperature Solid Oxide Fuel Cells: Samarium-Doped Ceria-Protected SrCo0.85Ta0.15O3-δ Hybrid.

PubMed

Li, Mengran; Zhou, Wei; Zhu, Zhonghua

2017-01-25

Susceptibility to CO 2 is one of the major challenges for the long-term stability of the alkaline-earth-containing cathodes for intermediate-temperature solid oxide fuel cells. To alleviate the adverse effects from CO 2 , we incorporated samarium-stabilized ceria (SDC) into a SrCo 0.85 Ta 0.15 O 3-δ (SCT15) cathode by either mechanical mixing or a wet impregnation method and evaluated their cathode performance stability in the presence of a gas mixture of 10% CO 2 , 21% O 2 , and 69% N 2 . We observed that the CO 2 tolerance of the hybrid cathode outperforms the pure SCT15 cathode by over 5 times at 550 °C. This significant enhancement is likely attributable to the low CO 2 adsorption and reactivity of the SDC protective layer, which are demonstrated through thermogravimetric analysis, energy-dispersive spectroscopy, and electrical conductivity study.

Elevated Carboxyhaemoglobin Concentrations by Pulse CO-Oximetry is Associated with Severe Aluminium Phosphide Poisoning.

PubMed

Mashayekhian, Mohammad; Hassanian-Moghaddam, Hossein; Rahimi, Mitra; Zamani, Nasim; Aghabiklooei, Abbas; Shadnia, Shahin

2016-09-01

In pulse CO-oximetry of aluminium phosphide (ALP)-poisoned patients, we discovered that carboxyhaemoglobin (CO-Hb) level was elevated. We aimed to determine whether a higher CO level was detected in patients with severe ALP poisoning and if this could be used as a prognostic factor in these patients. In a prospective case-control study, 96 suspected cases of ALP poisoning were evaluated. In the ALP-poisoned group, demographic characteristics, gastric and exhalation silver nitrate test results, average CO-Hb saturation, methaemoglobin saturation, and blood pressure and blood gas analysis until death/discharge were recorded. Severely poisoned patients were defined as those with systolic blood pressure ≤80 mmHg, pH ≤7.2, or HCO3 ≤15 meq/L or those who died, while patients with minor poisoning were those without any of these signs/symptoms. A control group (37 patients) was taken from other medically ill patients to detect probable effects of hypotension and metabolic acidosis on CO-Hb and methaemoglobin saturations. Of 96 patients, 27 died and 37 fulfilled the criteria for severe poisoning. All patients with carbon monoxide saturation >18% met the criteria to be included in the severe poisoning group and all with a SpCO >25% died. Concerning all significant variables in univariate analysis of severe ALP toxicity, the only significant variable which could independently predict death was carbon monoxide saturation. Due to high mortality rate and need for intensive care support, early prediction of outcome is vital for choosing an appropriate setting (ICU or ordinary ward). CO-oximetry is a good diagnostic and prognostic factor in patients with ALP poisoning even before any clinical evidence of toxicity will develop. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

PLEURAL EFFECTS OF INDIUM PHOSPHIDE IN B6C3F1 MICE: NONFIBROUS PARTICULATE INDUCED PLEURAL FIBROSIS

PubMed Central

Kirby, Patrick J.; Shines, Cassandra J.; Taylor, Genie J.; Bousquet, Ronald W.; Price, Herman C.; Everitt, Jeffrey I.; Morgan, Daniel L.

2010-01-01

The mechanism(s) by which chronic inhalation of indium phosphide (InP) particles causes pleural fibrosis is not known. Few studies of InP pleural toxicity have been conducted because of the challenges in conducting particulate inhalation exposures, and because the pleural lesions developed slowly over the 2-year inhalation study. The authors investigated whether InP (1 mg/kg) administered by a single oropharyngeal aspiration would cause pleural fibrosis in male B6C3F1 mice. By 28 days after treatment, protein and lactate dehydrogenase (LDH) were significantly increased in bronchoalveolar lavage fluid (BALF), but were unchanged in pleural lavage fluid (PLF). A pronounced pleural effusion characterized by significant increases in cytokines and a 3.7-fold increase in cell number was detected 28 days after InP treatment. Aspiration of soluble InCl3 caused a similar delayed pleural effusion; however, other soluble metals, insoluble particles, and fibers did not. The effusion caused by InP was accompanied by areas of pleural thickening and inflammation at day 28, and by pleural fibrosis at day 98. Aspiration of InP produced pleural fibrosis that was histologically similar to lesions caused by chronic inhalation exposure, and in a shorter time period. This oropharyngeal aspiration model was used to provide an initial characterization of the progression of pleural lesions caused by InP. PMID:19995279

Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

PubMed Central

Soltani, Motahareh; Shetab-Boushehri, Seyed F.; Shetab-Boushehri, Seyed V.

2016-01-01

Objectives: Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01). Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01). A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning. PMID:27606109

Advanced transition metal phosphide materials from single-source molecular precursors

NASA Astrophysics Data System (ADS)

Colson, Adam Caleb

In this thesis, the feasibility of employing organometallic single-source precursors in the preparation of advanced transition metal pnictide materials such as colloidal nanoparticles and films has been investigated. In particular, the ternary FeMnP phase was targeted as a model for preparing advanced heterobimetallic phosphide materials, and the iron-rich Fe3P phase was targeted due to its favorable ferromagnetic properties as well as the fact that the preparation of advanced Fe3P materials has been elusive by commonly used methods. Progress towards the synthesis of advanced Fe2--xMn xP nanomaterials and films was facilitated by the synthesis of the novel heterobimetallic complexes FeMn(CO)8(mu-PR1R 2) (R1 = H, R2 = H or R1 = H, R2 = Ph), which contain the relatively rare mu-PH2 and mu-PPhH functionalities. Iron rich Fe2--xMnxP nanoparticles were obtained by thermal decomposition of FeMn(CO)8(mu-PH 2) using solution-based synthetic methods, and empirical evidence suggested that oleic acid was responsible for manganese depletion. Films containing Fe, Mn, and P with the desired stoichiometric ratio of 1:1:1 were prepared using FeMn(CO)8(mu-PH2) in a simple low-pressure metal-organic chemical vapor deposition (MOCVD) apparatus. Although the elemental composition of the precursor was conserved in the deposited film material, spectroscopic evidence indicated that the films were not composed of pure-phase FeMnP, but were actually mixtures of crystalline FeMnP and amorphous FeP and Mn xOy. A new method for the preparation of phase-pure ferromagnetic Fe 3P films on quartz substrates has also been developed. This approach involved the thermal decomposition of the single-source precursors H 2Fe3(CO)9PR (R = tBu or Ph) at 400 °C. The films were deposited using a simple home-built MOCVD apparatus and were characterized using a variety of analytical methods. The films exhibited excellent phase purity, as evidenced by X-ray diffraction, X-ray photoelectron spectroscopy, and

A comparative study on carbon, boron-nitride, boron-phosphide and silicon-carbide nanotubes based on surface electrostatic potentials and average local ionization energies.

PubMed

Esrafili, Mehdi D; Behzadi, Hadi

2013-06-01

A density functional theory study was carried out to predict the electrostatic potentials as well as average local ionization energies on both the outer and the inner surfaces of carbon, boron-nitride (BN), boron-phosphide (BP) and silicon-carbide (SiC) single-walled nanotubes. For each nanotube, the effect of tube radius on the surface potentials and calculated average local ionization energies was investigated. It is found that SiC and BN nanotubes have much stronger and more variable surface potentials than do carbon and BP nanotubes. For the SiC, BN and BP nanotubes, there are characteristic patterns of positive and negative sites on the outer lateral surfaces. On the other hand, a general feature of all of the systems studied is that stronger potentials are associated with regions of higher curvature. According to the evaluated surface electrostatic potentials, it is concluded that, for the narrowest tubes, the water solubility of BN tubes is slightly greater than that of SiC followed by carbon and BP nanotubes.

Neutron Activated Samarium-153 Microparticles for Transarterial Radioembolization of Liver Tumour with Post-Procedure Imaging Capabilities

PubMed Central

Hashikin, Nurul Ab. Aziz; Yeong, Chai-Hong; Abdullah, Basri Johan Jeet; Ng, Kwan-Hoong; Chung, Lip-Yong; Dahalan, Rehir; Perkins, Alan Christopher

2015-01-01

Introduction Samarium-153 (153Sm) styrene divinylbenzene microparticles were developed as a surrogate for Yttrium-90 (90Y) microspheres in liver radioembolization therapy. Unlike the pure beta emitter 90Y, 153Sm possess both therapeutic beta and diagnostic gamma radiations, making it possible for post-procedure imaging following therapy. Methods The microparticles were prepared using commercially available cation exchange resin, Amberlite IR-120 H+ (620–830 μm), which were reduced to 20–40 μm via ball mill grinding and sieve separation. The microparticles were labelled with 152Sm via ion exchange process with 152SmCl3, prior to neutron activation to produce radioactive 153Sm through 152Sm(n,γ)153Sm reaction. Therapeutic activity of 3 GBq was referred based on the recommended activity used in 90Y-microspheres therapy. The samples were irradiated in 1.494 x 1012 n.cm-2.s-1 neutron flux for 6 h to achieve the nominal activity of 3.1 GBq.g-1. Physicochemical characterisation of the microparticles, gamma spectrometry, and in vitro radiolabelling studies were carried out to study the performance and stability of the microparticles. Results Fourier Transform Infrared (FTIR) spectroscopy of the Amberlite IR-120 resins showed unaffected functional groups, following size reduction of the beads. However, as shown by the electron microscope, the microparticles were irregular in shape. The radioactivity achieved after 6 h neutron activation was 3.104 ± 0.029 GBq. The specific activity per microparticle was 53.855 ± 0.503 Bq. Gamma spectrometry and elemental analysis showed no radioactive impurities in the samples. Radiolabelling efficiencies of 153Sm-Amberlite in distilled water and blood plasma over 48 h were excellent and higher than 95%. Conclusion The laboratory work revealed that the 153Sm-Amberlite microparticles demonstrated superior characteristics for potential use in hepatic radioembolization. PMID:26382059

Double blind glucocorticoid controlled trial of samarium-153 particulate hydroxyapatite radiation synovectomy for chronic knee synovitis.

PubMed

O'Duffy, E K; Clunie, G P; Lui, D; Edwards, J C; Ell, P J

1999-09-01

Samarium-153 particulate hydroxyapatite (Sm-153 PHYP) is a relatively new radiation synovectomy agent developed for the treatment of chronic synovitis. Although it has been shown that the levels of unwanted extra-articular radiation are lower after intra-articular injection of Sm-153 PHYP than yttrium-90 colloid, its clinical efficacy has not been rigorously studied. To establish whether Sm-153 PHYP radiation synovectomy results in a clinically useful benefit sustained at one year. In a randomised double blind study, patients received either intra-articular 40 mg triamcinolone hexacetonide alone or 40 mg triamcinolone hexacetonide combined with Sm-153 PHYP in an outpatient clinic. Sixty patients (28 male, 32 female), median age 51 (18-75) with chronic knee synovitis were studied. Diagnoses included: rheumatoid arthritis (n=29); psoriatic arthritis (n=9); ankylosing spondylitis (n=3); reactive arthritis (n=2); undifferentiated seronegative oligoarthritis (n=13) and miscellaneous inflammatory conditions (n=4). More patients who received Sm-153 PHYP/triamcinolone hexacetonide sustained clinical benefit a year after treatment compared with patients who received corticosteroid alone (12 of 31 (39%) v 6 of 29 (21%), a difference of 18% more patients (95% CI -5% to 41%)) though the difference was not significant (chi(2)=2.31, 0.2>p>0.1, n=60). Despite the variation in injected activity (median 563 MBq, range 218-840 MBq), there was no obvious relation between low levels of injected activity (<555 MBq) and relapse within 12 months of treatment (chi(2) =2.61, 0.2>p>0.1, n=31). There was no clear beneficial clinical effect of combined Sm-153 PHYP/triamcinolone hexacetonide injection over triamcinolone hexacetonide alone a year after treatment for chronic knee synovitis.

Double blind glucocorticoid controlled trial of samarium-153 particulate hydroxyapatite radiation synovectomy for chronic knee synovitis

PubMed Central

O'Duffy, E; Clunie, G; Lui, D; Edwards, J; Ell, P

1999-01-01

BACKGROUND—Samarium-153 particulate hydroxyapatite (Sm-153 PHYP) is a relatively new radiation synovectomy agent developed for the treatment of chronic synovitis. Although it has been shown that the levels of unwanted extra-articular radiation are lower after intra-articular injection of Sm-153 PHYP than yttrium-90 colloid, its clinical efficacy has not been rigorously studied.
OBJECTIVES—To establish whether Sm-153 PHYP radiation synovectomy results in a clinically useful benefit sustained at one year.
METHODS—In a randomised double blind study, patients received either intra-articular 40 mg triamcinolone hexacetonide alone or 40 mg triamcinolone hexacetonide combined with Sm-153 PHYP in an outpatient clinic.
RESULTS—Sixty patients (28 male, 32 female), median age 51 (18-75) with chronic knee synovitis were studied. Diagnoses included: rheumatoid arthritis (n=29); psoriatic arthritis (n=9); ankylosing spondylitis (n=3); reactive arthritis (n=2); undifferentiated seronegative oligoarthritis (n=13) and miscellaneous inflammatory conditions (n=4). More patients who received Sm-153 PHYP/triamcinolone hexacetonide sustained clinical benefit a year after treatment compared with patients who received corticosteroid alone (12 of 31 (39%) v 6 of 29 (21%), a difference of 18% more patients (95% CI −5% to 41%)) though the difference was not significant (χ2=2.31, 0.2>p>0.1, n=60). Despite the variation in injected activity (median 563 MBq, range 218-840 MBq), there was no obvious relation between low levels of injected activity (<555 MBq) and relapse within 12 months of treatment (χ2 =2.61, 0.2>p>0.1, n=31).
CONCLUSIONS—There was no clear beneficial clinical effect of combined Sm-153 PHYP/triamcinolone hexacetonide injection over triamcinolone hexacetonide alone a year after treatment for chronic knee synovitis.

 PMID:10460188

N-acetylcysteine, Ascorbic Acid, and Methylene Blue for the Treatment of Aluminium Phosphide Poisoning: Still Beneficial?

PubMed Central

Gheshlaghi, Farzad; Lavasanijou, Mohamad Reza; Moghaddam, Noushin Afshar; Khazaei, Majid; Behjati, Mohaddeseh; Farajzadegan, Ziba; Sabzghabaee, Ali Mohammad

2015-01-01

Objectives: Intentional and accidental intoxication with aluminium phosphide (ALP) remains a clinical problem, especially in the Middle East region. Considering the high mortality rate besides lack of any recommended first option drug for its treatment, this study was aimed to compare the therapeutic effects of N-acetylcysteine (NAC), vitamin C (Vit C), and methylene blue; both in isolate and also in combination, for the treatment of ALP intoxication in a rat model. Materials and Methods: In this experimental animal study, 80 male Wistar rats in eight groups were intoxicated with ALP (12.5 mg/kg) and treated with a single dose of NAC (100 mg/kg) or Vit C (500–1,000 mg/kg) or methylene blue (1 mg/kg/5 min, 0.1%) or two of these agents or all three of them (controls were not treated). Rats were monitored regarding the parameters of drug efficacy as increased survival time and reduced morbidity and mortality rate for 3 consecutive days to ensure toxin neutralization. Macroscopic changes were recorded and biopsy sections were taken from brain, cerebellum, kidney, liver, and heart for microscopic evaluation regarding cellular hypoxia. Results: The mean survival times of rats exposed to ALP and treated with VitC + NAC was 210.55±236.22 minutes. In analysis of survival times, there was a significant difference between Group 5 which received VitC + NAC and the other groups (P < 0.01). Serum magnesium levels after death were higher than normal (P = 0.01). Conclusions: Despite the higher survival rate of antioxidant-treated rats compared with controls, this difference was not statistically significant. PMID:26862259

A Mechanistic Study of CO 2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy

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

Flynn, Kristen

2015-08-18

Carbon dioxide (CO 2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO 2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO 2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played duringmore » the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO 2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO 2 catalysis.« less

Preparation and photocatalytic activity of magnetic samarium-doped mesoporous titanium dioxide at the decomposition of methylene blue under visible light

NASA Astrophysics Data System (ADS)

Shi, Zhongliang; Lai, Hong; Yao, Shuhua

2012-08-01

Preparation of samarium-doped mesoporous titanium dioxide (Sm/MTiO2) coated magnetite (Fe3O4) photocatalysts (Sm/MTiO2/Fe3O4) and their activities under visible light were reported. The catalysts with Sm/MTiO2 shell and a Fe3O4 core were prepared by coating photoactive Sm/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate (Ti(OBu)4, TBT) with precursors of Sm(NO3)3 and TBT in the presence of Fe3O4 nanoparticles. The morphological, structural and optical properties of the prepared samples were characterized by BET surface area, transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy. The effect of Sm ion content on the photocatalytic activity was studied. The photocatalytic activities of obtained photocatalysts under visible light were estimated by measuring the decomposition rate of methylene blue (MB, 50 mg/L) in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxidation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Sm/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by a simple magnetic process. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.

Pyrolysis result of polyethylene waste as fuel for solid oxide fuel cell with samarium doped-ceria (SDC)-carbonate as electrolyte

NASA Astrophysics Data System (ADS)

Syahputra, R. J. E.; Rahmawati, F.; Prameswari, A. P.; Saktian, R.

2017-02-01

In this research, the result of pyrolysis on polyethylene was used as fuel for a solid oxide fuel cell (SOFC). The pyrolysis result is a liquid which consists of hydrocarbon chains. According to GC-MS analysis, the hydrocarbons mainly consist of C7 to C20 hydrocarbon chain. Then, the liquid was applied to a single cell of NSDC-L | NSDC | NSDC-L. NSDC is a composite SDC (samarium doped-ceria) with sodium carbonate. Meanwhile, NSDC-L is a composite of NSDC with LiNiCuO (LNC). NSDC and LNC were analyzed by X-ray diffraction to understand their crystal structure. The result shows that presence of carbonate did not change the crystal structure of SDC. SEM EDX analysis for fuel cell before and after being loaded with polyethylene oil to get information of element diffusion to the electrolyte. Meanwhile, the conductivity properties were investigated through impedance measurement. The presence of carbonate even increases the electrical conductivity. The single cell test with the pyrolysis result of polyethylene at 300 - 600 °C, found that the highest power density is at 600 °C with the maximum power density of 0.14 mW/cm2 and open circuit voltage of 0.4 Volt. Elemental analysis at three point spots of single cell NDSC-L |NSDC|NSDC-L found that a migration of ions was occurred during fuel operation at 300 - 600 °C.

Effect of multilayer structure, stacking order and external electric field on the electrical properties of few-layer boron-phosphide.

PubMed

Chen, Xianping; Tan, Chunjian; Yang, Qun; Meng, Ruishen; Liang, Qiuhua; Jiang, Junke; Sun, Xiang; Yang, D Q; Ren, Tianling

2016-06-28

Development of nanoelectronics requires two-dimensional (2D) systems with both direct-bandgap and tunable electronic properties as they act in response to the external electric field (E-field). Here, we present a detailed theoretical investigation to predict the effect of atomic structure, stacking order and external electric field on the electrical properties of few-layer boron-phosphide (BP). We demonstrate that the splitting of bands and bandgap of BP depends on the number of layers and the stacking order. The values for the bandgap show a monotonically decreasing relationship with increasing layer number. We also show that AB-stacking BP has a direct-bandgap, while ABA-stacking BP has an indirect-bandgap when the number of layers n > 2. In addition, for a bilayer and a trilayer, the bandgap increases (decreases) as the electric field increases along the positive direction of the external electric field (E-field) (negative direction). In the case of four-layer BP, the bandgap exhibits a nonlinearly decreasing behavior as the increase in the electric field is independent of the electric field direction. The tunable mechanism of the bandgap can be attributed to a giant Stark effect. Interestingly, the investigation also shows that a semiconductor-to-metal transition may occur for the four-layer case or more layers beyond the critical electric field. Our findings may inspire more efforts in fabricating new nanoelectronics devices based on few-layer BP.

High-pressure behavior of iron-nickel-cobalt phosphides and its implications for meteorites and planetary cores

NASA Astrophysics Data System (ADS)

Dera, P.; Lavina, B.; Borkowski, L. A.; Downs, R. T.; Prewitt, C. T.; Prakapenka, V.; Rivers, M. L.; Sutton, S.; Boctor, N.

2008-12-01

Minerals with composition (Fe,Ni)xP, are rare, but important accessory phases present in iron and chondrite meteorites. The occurrence of these minerals in meteoritic samples is believed to originate either from the equilibrium condensation of protoplanetary materials taking place in solar nebulae or from crystallization processes in the cores of parent bodies. Fe-Ni phosphides are considered an important candidate for a minor phase present in Earth's core, and at least partially responsible for the observed core density deficit with respect to pure Fe. We report results of high-pressure high-temperature single-crystal X- ray diffraction experiments with end-members belonging to the (Fe,Ni,Co)2P family, including Fe2P, Ni2P and Co2P. A new phase transition to the Co2Si-type structure (allabogdanite) has been found in Fe2P barringerite at 8.0 GPa, upon heating. The high-pressure phase can be quenched metastably to ambient conditions and then, if heated again, it transforms back to barringerite. Ni2P barringerite does not undergo transformation to allabogdanite structure up to 50 GPa, but instead exhibits incongruent melting with formation of pyrite-type NiP2 and Ni-P glass. Our results indicate that the presence of allabogdanite in meteoritic samples places two important constraints on the thermodynamic history of the meteorite. First, it imposes a minimum pressure and temperature for the formation of the Fe2P, and additionally rules out any higher temperature low pressure alterations. If present in the Earth's core, Fe2P will have the allabogdanite rather than the barringerite structure. Crystal chemical trends in the compressibility of (Fe,Ni,Co)2P minerals, as well as polymorphic transition paths are analyzed in the context of Earth and planetary core composition and properties.

Two-Dimensional Phosphorene-Derived Protective Layers on a Lithium Metal Anode for Lithium-Oxygen Batteries.

PubMed

Kim, Youngjin; Koo, Dongho; Ha, Seongmin; Jung, Sung Chul; Yim, Taeeun; Kim, Hanseul; Oh, Seung Kyo; Kim, Dong-Min; Choi, Aram; Kang, Yongku; Ryu, Kyoung Han; Jang, Minchul; Han, Young-Kyu; Oh, Seung M; Lee, Kyu Tae

2018-05-04

Lithium-oxygen (Li-O 2 ) batteries are desirable for electric vehicles because of their high energy density. Li dendrite growth and severe electrolyte decomposition on Li metal are, however, challenging issues for the practical application of these batteries. In this connection, an electrochemically active two-dimensional phosphorene-derived lithium phosphide is introduced as a Li metal protective layer, where the nanosized protective layer on Li metal suppresses electrolyte decomposition and Li dendrite growth. This suppression is attributed to thermodynamic properties of the electrochemically active lithium phosphide protective layer. The electrolyte decomposition is suppressed on the protective layer because the redox potential of lithium phosphide layer is higher than that of electrolyte decomposition. Li plating is thermodynamically unfavorable on lithium phosphide layers, which hinders Li dendrite growth during cycling. As a result, the nanosized lithium phosphide protective layer improves the cycle performance of Li symmetric cells and Li-O 2 batteries with various electrolytes including lithium bis(trifluoromethanesulfonyl)imide in N,N-dimethylacetamide. A variety of ex situ analyses and theoretical calculations support these behaviors of the phosphorene-derived lithium phosphide protective layer.

Future Directions for Selected Topics in Physics and Materials Science

DTIC Science & Technology

2012-07-12

referred to as lightides (e.g. borides , nitrides, phosphides) • Materials for energy conversion, energy storage, energy transport and energy production...Distributed nanosystems and sensors • Strategy for multilayered combinatorics • lightides ( borides , nitrides, phosphides, • New applications for...Strategy for multilayered combinatorics Lightides ( borides , nitrides, phosphides) • Energy conversion, .storage and production • Precision control

Catalytic decomposition of toxic chemicals over iron group metals supported on carbon nanotubes.

PubMed

Li, Lili; Chen, Can; Chen, Long; Zhu, Zixue; Hu, Jianli

2014-03-18

This study explores catalytic decomposition of phosphine (PH3) using iron group metals (Co, Ni) and metal oxides (Fe2O3, Co(3)O4, NiO) supported on carbon nanotubes (CNTs). The catalysts are synthesized by means of a deposition-precipitation method. The morphology, structure, and composition of the catalysts are characterized using a number of analytical instrumentations, including high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, BET surface area measurement, and inductively coupled plasma. The activity of the catalysts in the PH3 decomposition reaction is measured and correlated with their surface and structural properties. The characterization results show that phosphidation occurs on the catalyst surface, and the resulting metal phosphides act as an active phase in the PH3 decomposition reaction. Cobalt phosphide, CoP, is formed on Co/CNTs and Co(3)O4/CNTs, whereas iron phosphide, FeP, is formed on Fe2O3/CNTs. In contrast, phosphorus-rich phosphide NiP2 is formed on Ni/CNTs and NiO/CNTs. The initial activities of the catalysts are shown in the following sequence: Ni/CNTs > Co/CNTs > Co(3)O4/CNTs >NiO/CNTs > Fe2O3/CNTs, whereas activities of metal phosphides are shown in the following order: CoP > NiP2 > FeP. The catalytic activity of metal phosphides is attributed to their electronic properties. Cobalt phosphide formed on Co/CNTs and Co(3)O4/CNTs exhibits not only the highest activity, but also long-term stability in the PH3 decomposition reaction.

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

Electron emitting device and method of making the same

DOEpatents

Olsen, Gregory Hammond; Martinelli, Ramon Ubaldo; Ettenberg, Michael

1977-04-19

A substrate of single crystalline gallium arsenide has on a surface thereof a layer of single crystalline indium gallium phosphide. A layer of single crystalline gallium arsenide is on the indium gallium phosphide layer and a work function reducing material is on the gallium arsenide layer. The substrate has an opening therethrough exposing a portion of the indium gallium phosphide layer.

An electrocardiographic, molecular and biochemical approach to explore the cardioprotective effect of vasopressin and milrinone against phosphide toxicity in rats.

PubMed

Jafari, Abbas; Baghaei, Amir; Solgi, Reza; Baeeri, Maryam; Chamanara, Mohsen; Hassani, Shokoufeh; Gholami, Mahdi; Ostad, Seyed Nasser; Sharifzadeh, Moahmmad; Abdollahi, Mohammad

2015-06-01

The present study was conducted to identify the protective effect of vasopressin (AVP) and milrinone on cardiovascular function, mitochondrial complex activities, cellular ATP reserve, oxidative stress, and apoptosis in rats poisoned by aluminum phosphide (AlP). Rats were divided into five groups (n = 12) including control, AlP (12.5 mg/kg), AlP + AVP (2.0 Units/kg), AlP + milrinone (0.25 mg/kg) and AlP + AVP + milrinone. After treatment, the animals were connected to an electronic cardiovascular monitoring device to monitor electrocardiographic (ECG) parameter. Finally, oxidative stress biomarkers, mitochondrial complex activities, ADP/ATP ratio and apoptosis were evaluated on the heart tissues. Results indicated that AlP administration induced ECG abnormalities along with a decline in blood pressure and heart rate. AVP and milrinone significantly ameliorated these changes in all treated groups. Considerable protective effects on oxidative stress biomarkers, complex IV activity, ADP/ATP ratio and caspase-3 and -9 activities in treated groups were also found. These findings were supported by flow cytometry assay of cardiomyocytes. In conclusion, administration of AVP and milrinone, not only improve cardiovascular functions in AlP poisoned rats in the short time, but after a long time can also restore mitochondrial function and ATP level and reduce the oxidative damage, which prevent cardiomyocytes from entering the apoptotic phase. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Mechanistic Study of CO 2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy - Oral Presentation

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

Flynn, Kristen

2015-08-19

Carbon dioxide (CO 2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO 2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO 2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played duringmore » the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO 2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO 2 catalysis.« less

Growth and Performance of GaInP/A1GaInP Visible Light Emitting Laser-Diodes,

DTIC Science & Technology

SEMICONDUCTOR LASERS, *EPITAXIAL GROWTH, ALLOYS, LAYERS, LOW PRESSURE, PRESSURE, QUALITY, ROOM TEMPERATURE, SUBSTRATES, GALLIUM PHOSPHIDES, INDIUM PHOSPHIDES, THERMAL PROPERTIES, ENERGY GAPS, ENERGY BANDS, VAPOR PHASES.

Samarium-153-EDTMP (Quadramet®) with or without vaccine in metastatic castration-resistant prostate cancer: A randomized Phase 2 trial.

PubMed

Heery, Christopher R; Madan, Ravi A; Stein, Mark N; Stadler, Walter M; Di Paola, Robert S; Rauckhorst, Myrna; Steinberg, Seth M; Marté, Jennifer L; Chen, Clara C; Grenga, Italia; Donahue, Renee N; Jochems, Caroline; Dahut, William L; Schlom, Jeffrey; Gulley, James L

2016-10-18

PSA-TRICOM is a therapeutic vaccine in late stage clinical testing in metastatic castration-resistant prostate cancer (mCRPC). Samarium-153-ethylene diamine tetramethylene phosphonate (Sm-153-EDTMP; Quadramet®), a radiopharmaceutical, binds osteoblastic bone lesions and emits beta particles causing local tumor cell destruction. Preclinically, Sm-153-EDTMP alters tumor cell phenotype facilitating immune-mediated killing. This phase 2 multi-center trial randomized patients to Sm-153-EDTMP alone or with PSA-TRICOM vaccine. Eligibility required mCRPC, bone metastases, prior docetaxel and no visceral disease. The primary endpoint was the proportion of patients without radiographic disease progression at 4 months. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and immune responses. Forty-four patients enrolled. Eighteen and 21 patients were evaluable for the primary endpoint in Sm-153-EDTMP alone and combination arms, respectively. There was no statistical difference in the primary endpoint, with two of 18 (11.1%) and five of 21 (23.8%) in Sm-153-EDTMP alone and combination arms, respectively, having stable disease at approximately the 4-month evaluation time point (P = 0.27). Median PFS was 1.7 vs. 3.7 months in the Sm-153-EDTMP alone and combination arms (P = 0.041, HR = 0.51, P = 0.046). No patient in the Sm-153-EDTMP alone arm achieved prostate-specific antigen (PSA) decline > 30% compared with four patients (of 21) in the combination arm, including three with PSA decline > 50%. Toxicities were similar between arms and related to number of Sm-153-EDTMP doses administered. These results provide the rationale for clinical evaluation of new radiopharmaceuticals, such as Ra-223, in combination with PSA-TRICOM.

Samarium-153-EDTMP (Quadramet®) with or without vaccine in metastatic castration-resistant prostate cancer: A randomized Phase 2 trial

PubMed Central

Heery, Christopher R.; Madan, Ravi A.; Stein, Mark N.; Stadler, Walter M.; Di Paola, Robert S.; Rauckhorst, Myrna; Steinberg, Seth M.; Marté, Jennifer L.; Chen, Clara C.; Grenga, Italia; Donahue, Renee N.; Jochems, Caroline; Dahut, William L.; Schlom, Jeffrey; Gulley, James L.

2016-01-01

PSA-TRICOM is a therapeutic vaccine in late stage clinical testing in metastatic castration-resistant prostate cancer (mCRPC). Samarium-153-ethylene diamine tetramethylene phosphonate (Sm-153-EDTMP; Quadramet®), a radiopharmaceutical, binds osteoblastic bone lesions and emits beta particles causing local tumor cell destruction. Preclinically, Sm-153-EDTMP alters tumor cell phenotype facilitating immune-mediated killing. This phase 2 multi-center trial randomized patients to Sm-153-EDTMP alone or with PSA-TRICOM vaccine. Eligibility required mCRPC, bone metastases, prior docetaxel and no visceral disease. The primary endpoint was the proportion of patients without radiographic disease progression at 4 months. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and immune responses. Forty-four patients enrolled. Eighteen and 21 patients were evaluable for the primary endpoint in Sm-153-EDTMP alone and combination arms, respectively. There was no statistical difference in the primary endpoint, with two of 18 (11.1%) and five of 21 (23.8%) in Sm-153-EDTMP alone and combination arms, respectively, having stable disease at approximately the 4-month evaluation time point (P = 0.27). Median PFS was 1.7 vs. 3.7 months in the Sm-153-EDTMP alone and combination arms (P = 0.041, HR = 0.51, P = 0.046). No patient in the Sm-153-EDTMP alone arm achieved prostate-specific antigen (PSA) decline > 30% compared with four patients (of 21) in the combination arm, including three with PSA decline > 50%. Toxicities were similar between arms and related to number of Sm-153-EDTMP doses administered. These results provide the rationale for clinical evaluation of new radiopharmaceuticals, such as Ra-223, in combination with PSA-TRICOM. PMID:27486817

Concept Definition for the Pest Management Component of the Pollution Abatement Management System (PAMS).

DTIC Science & Technology

1982-01-01

able to obtain * Aluminum phosphide, Bromacil, Carbaryl (Sevin), Chlordane, Chlorpyrifos (Oursban), Diazinon, Dichlorovos (DODYP), Malathion, Paraquat...Pentachloro- phenol (PCP), Propoxur (Baygon), Thiram, strychnine/strychnine sulfate, zinc phosphide, and 2,4-D. 10 sufficient data to respond to

Yellow phosphorus-induced Brugada phenocopy.

PubMed

Dharanipradab, Mayakrishnan; Viswanathan, Stalin; Kumar, Gokula Raman; Krishnamurthy, Vijayalatchumy; Stanley, Daphene Divya

Metallic phosphides (of aluminum and phosphide) and yellow phosphorus are commonly used rodenticide compounds in developing countries. Toxicity of yellow phosphorus mostly pertains to the liver, kidney, heart, pancreas and the brain. Cardiotoxicity with associated Brugada ECG pattern has been reported only in poisoning with metallic phosphides. Brugada phenocopy and hepatic dysfunction were observed in a 29-year-old male following yellow phosphorus consumption. He had both type 1 (day1) and type 2 (day2) Brugada patterns in the electrocardiogram, which resolved spontaneously by the third day without hemodynamic compromise. Toxins such as aluminum and zinc phosphide have been reported to induce Brugada ECG patterns due to the generation of phosphine. We report the first case of yellow phosphorus-related Brugada phenocopy, without hemodynamic compromise or malignant arrhythmia. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of N-acetyl cysteine (NAC) on aluminum phosphide poisoning inducing cardiovascular toxicity: a case-control study.

PubMed

Taghaddosinejad, Fakhreddin; Farzaneh, Esmaeil; Ghazanfari-Nasrabad, Mahdi; Eizadi-Mood, Nastaran; Hajihosseini, Morteza; Mehrpour, Omid

2016-01-01

Aluminum phosphide (AlP) is a very effective indoor and outdoor pesticide. We investigated the effects of N-acetyl cysteine (NAC) on the survival time, hemodynamics, and cardiac biochemical parameters at various time intervals in some cases of AlP poisoning. This research was a case-control study to evaluate 63 AlP poisoned patients during 2010-2012. Patients with cardiovascular complications of AlP to be treated with intravenous NAC plus conventional treatment were considered as the case group and compared with patients who did not receive NAC. NAC infusion was administered to the case group at 300 mg/kg for 20 h. The data gathered included age, sex, heart rate, Systolic blood pressure (SBP), creatine phosphokinase (CPK), creatine kinase MB (CK-MB), and ECG at the admission time and 12, 18, and 24 h after admission. Analysis of repeated measures was performed to check the variability of parameters over time. The mean ages in the case and control groups were 26.65 ± 1.06 (19-37 years) and 28.39 ± 1.11 (18-37 years), respectively (P = 0.266). Most of the patients were female (56.5%). CK-MB means were significantly different between the two groups, but no differences between the other variables were observed. Also, CK-MB, CPK, heart rate, and systolic blood pressure means became significantly different over time (0, 12, 18, and 24 h) in both groups (P < 0.001). NAC prevented sharp heart rate fluctuations in AlP patients in the case group. Regarding the outcomes, 17 patients died (10 patients in the control and 7 patients in the case groups). No side-effects of NAC were observed. Our patients could be managed by the positive role of NAC as the biochemical index of cardiotoxicity was found to elevate in both the case and control groups. Therefore, for the management protocol optimization, NAC evaluation should be done in further cases.

Black-tailed prairie dog populations one year after treatment with rodenticides

Treesearch

Anthony D. Apa; Daniel W. Uresk; Raymond L. Linder

1990-01-01

Three rodenticide treatments, zinc phosphide with prebait, strychnine with prebait, and strychnine without prebait, were applied to black-tailed prairie dog (Cynomys ludovicianus) colonies in west central South Dakota. Results were compared immediately posttreatment and for one year after application. Zinc phosphide was the most effective for...

Strained quantum well photovoltaic energy converter

NASA Technical Reports Server (NTRS)

Freundlich, Alexandre (Inventor); Renaud, Philippe (Inventor); Vilela, Mauro Francisco (Inventor); Bensaoula, Abdelhak (Inventor)

1998-01-01

An indium phosphide photovoltaic cell is provided where one or more quantum wells are introduced between the conventional p-conductivity and n-conductivity indium phosphide layer. The approach allows the cell to convert the light over a wider range of wavelengths than a conventional single junction cell and in particular convert efficiently transparency losses of the indium phosphide conventional cell. The approach hence may be used to increase the cell current output. A method of fabrication of photovoltaic devices is provided where ternary InAsP and InGaAs alloys are used as well material in the quantum well region and results in an increase of the cell current output.

Sinterless Fabrication Of Contact Pads On InP Devices

NASA Technical Reports Server (NTRS)

Weizer, Victor G.; Fatemi, Navid S.; Korenyi-Both, Andras L.

1995-01-01

Research has shown that with proper choice of material, low-resistance contact pads deposited on solar cells and other devices by improved technique that does not involve sintering. Research directed at understanding mechanisms involved in contact-sintering process has resulted in identification of special group of materials that includes phosphides of gold, silver, and nickel; specifically, Au(2)P(3), AgP(2), and Ni(3)P. Incorporation of phosphide interlayer substantially reduces resistivity between gold current-carrying layer and indium phosphide substrate. Further research indicated only very thin interlayer of any of these compounds needed to obtain low contact resistance, without subjecting contact to destructive sintering process.

Eastern Indian 3800-million-year-old crust and early mantle differentiation

USGS Publications Warehouse

Basu, A.R.; Ray, S.L.; Saha, A.K.; Sarkar, S.N.

1981-01-01

Samarium-neodymium data for nine granitic and tonalite gneisses occurring as remnants within the Singhbhum granite batholith in eastern India define an isochron of age 3775 ?? 89 ?? 106 years with an initial 143Nd/144Nd ratio of 0.50798 ?? 0.00007. This age contrasts with the rubidium-strontium age of 3200 ?? 106 years for the same suite of rocks. On the basis of the new samarium-neodynium data, field data, and petrologic data, a scheme of evolution is proposed for the Archean crust in eastern India. The isotopic data provide evidence that parts of the earth's mantle were already differentiated with respect to the chondritic samarium-neodymium ratio 3800 ?? 106 years ago.

Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid: facile synthesis of (Z)-allyl iodides*

PubMed Central

Liu, Yun-Kui; Zheng, Hui; Xu, Dan-Qian; Xu, Zhen-Yuan; Zhang, Yong-Min

2006-01-01

Stereoselective transformation of Baylis-Hillman acetates 1 into corresponding (Z)-allyl iodides 2 has been achieved by treatment of 1 with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF4) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 °C within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2. PMID:16502505

Susan Habas | NREL

Science.gov Websites

chemical transformations Scalable methods for solution-phase nanomaterials synthesis Production of premium Patents "Metal Phosphide Catalysts and Methods for Making the Same and Uses Thereof," U.S . Patent No. 9,636,664 B1 (2017) "Metal Phosphide Catalysts and Methods for Making the Same and Uses

Gap/silicon Tandem Solar Cell with Extended Temperature Range

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2006-01-01

A two-junction solar cell has a bottom solar cell junction of crystalline silicon, and a top solar cell junction of gallium phosphide. A three (or more) junction solar cell has bottom solar cell junctions of silicon, and a top solar cell junction of gallium phosphide. The resulting solar cells exhibit improved extended temperature operation.

Wavelength-scale Microlasers based on VCSEL-Photonic Crystal Architecture

DTIC Science & Technology

2015-01-20

molecular beam epitaxy , MBE). We will also assume the triangular lattice of air...Abbreviations, and Acronyms InP: indium phosphide InGaAsP: indium gallium arsenide phosphide MBE: molecular beam epiitaxy VCSEL : vertical cavity...substrates and were grown by MBE. Electron beam lithography and reactive ion etching was used to deep‐etch the holes of the PhC‐ VCSELS ,

Zinc phosphide

Integrated Risk Information System (IRIS)

Zinc phoshide ; CASRN 1314 - 84 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

Hydrogen sensor based on Sm-doped SnO{sub 2} nanostructures

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

Singh, Gurpreet; Hastir, Anita; Singh, Ravi Chand, E-mail: ravichand.singh@gmail.com

2016-05-23

In this paper the effect of samarium doping on the structural and hydrogen gas sensing properties of SnO{sub 2} nanoparticles has been reported. X-ray Diffraction (XRD) results revealed tetragonal rutile structure of both undoped and Sm-doped SnO{sub 2} nanoparticles. It has been observed that doping with samarium led to reduction in crystallite size of SnO{sub 2} nanoparticles which was confirmed from XRD analysis. Shifting and broadening of Raman peaks in case of doped nanoparticles has been explained by well-known phonon confinement model. The optimum operable temperature of both the sensors was found to 400 °C and the sensor response towardsmore » hydrogen gas has been improved after doping with samarium which was attributed to increase in sensing sites for the gas adsorption.« less

The Mechanism of Anaerobic (Microbial) Corrosion.

DTIC Science & Technology

1982-12-01

hydrogen sulfide reacts with hypophosphite (as well as phosphate and phosphite ) .to form, in the presence of mild steel, iron phosphide, simulating the...of phosphate and phosphite , but not hypophosphite, were observed to have become yellow in 24 hours. The yellow color disap- peared upon exposure to... product is an amorphous type of iron phosphide which can be !- detected b the formation of phos hine upon its acidification. Phosphine( in M IFO, 1473

A Phase I Trial of Samarium-153-Lexidronam Complex for Treatment of Clinically Nonmetastatic High-Risk Prostate Cancer: First Report of a Completed Study

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

Valicenti, Richard K., E-mail: richard.valicenti@ucdmc.ucdavis.ed; Trabulsi, Edouard; Intenzo, Charles

Purpose: We completed a Phase I trial to determine the maximum tolerated dose of samarium-153 EDTMP ({sup 153}Sm) with hormonal therapy (HT) and radiation therapy (RT) in high-risk clinically nonmetastatic prostate cancer. Methods and Materials: High-risk M0 prostate cancer patients (prostate-specific antigen >20 ng/mL, Gleason score >7, or >T3) were eligible for this prospective trial of dose-escalated radioactive {sup 153}Sm-EDTMP (.25-2.0 mCi/kg) as primary or postoperative therapy. After 1 month of HT, we administered {sup 153}Sm-EDTMP followed by 4 more months of HT, 46.8 Gy to the pelvic region and 23.4 Gy to the prostate target (TD = 70.2 Gy).more » The primary endpoint was Grade III toxicity or higher by the National Cancer Institute Common Toxicity Criteria. Results: Twenty-nine patients enrolled (median prostate-specific antigen = 8.2 ng/mL, 27/29 (93%) T stage {>=}T2b, 24/29 (83%) had Gleason >7) and received {sup 153}Sm-EDTMP (.25 mCi/kg, 4 patients; 0.5 mCi/kg, 4 patients; 0.75 mCi/kg, 6 patients; 1.0 mCi/kg, 6 patients; 1.5 mCi/kg, 5 patients; 2.0mCi/kg, 4 patients). Twenty-eight patients underwent all planned therapy without delays (1 patient required surgery before the start of RT). With a median follow-up time of 23 months, there were 2 patients (7 %) experiencing Grade III hematologic toxicity. There were no other Grade III or IV side effects. Conclusions: Our trial demonstrates that 2 mCi/kg {sup 153}Sm -EDTMP with HT and RT was safe and feasible in men with high-risk M0 prostate cancer. A Phase II study to test this treatment is currently underway by the Radiation Therapy Oncology Group.« less

Development of diamond-lanthanide metal oxide affinity composites for the selective capture of endogenous serum phosphopeptides.

PubMed

Hussain, Dilshad; Musharraf, Syed Ghulam; Najam-ul-Haq, Muhammad

2016-02-01

Development of affinity materials for the selective enrichment of phosphopeptides has attracted attention during the last decade. In this work, diamond-lanthanum oxide and diamond-samarium oxide composites have been fabricated via the hydrothermal method. The composites are characterized by scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDAX), and atomic force microscopy (AFM). The analyses confirm the size and composition of the nanocomposites. They have been applied to selectively capture phosphorylated peptides from standard proteins (β-casein and BSA). Selectivity is calculated as 1:3000 and 1:1500 while sensitivity down to 1 and 20 fmol for diamond-lanthanum oxide and diamond-samarium oxide nanocomposites, respectively. Enrichment efficiency has also been evaluated for non-fat milk digest where 18 phosphopeptides are enriched. Total of 213 and 187 phosphopeptides are captured from tryptic digest of HeLa cells extracted proteins by diamond-lanthanum oxide and diamond-samarium oxide, respectively. Finally, human serum, without any pre-treatment, is applied and nanocomposites capture the endogenous serum phosphopeptides.

Synthesis and magnetic properties of NiFe2-xSmxO4 nanopowder

NASA Astrophysics Data System (ADS)

Hassanzadeh-Tabrizi, S. A.; Behbahanian, Shahrzad; Amighian, Jamshid

2016-07-01

NiFe2-xSmxO4 (x=0.00, 0.05, 0.10 and 0.15) nanopowders were synthesized via a sol-gel combustion route. The structural studies were carried out by X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The XRD results confirmed the formation of single-phase spinel cubic structure. The crystallite size decreased with an increase of samarium ion concentration, while lattice parameter and lattice strain increased with samarium substitution. TEM micrographs showed that agglomerated nanoparticles with particle sizes ranging from 35 to 90 nm were obtained. The magnetic studies were carried out using vibrating sample magnetometer. Magnetic measurements revealed that the saturation magnetization (Ms) of NiFe2-xSmxO4 nanoparticles decreases with increasing Sm3+substitution. The reduction of saturation magnetization is attributed to the dilution of the magnetic interaction. The coercivity (Hc) of samples increases by adding samarium.

SU-C-201-06: Utility of Quantitative 3D SPECT/CT Imaging in Patient Specific Internal Dosimetry of 153-Samarium with GATE Monte Carlo Package

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

Fallahpoor, M; Abbasi, M; Sen, A

Purpose: Patient-specific 3-dimensional (3D) internal dosimetry in targeted radionuclide therapy is essential for efficient treatment. Two major steps to achieve reliable results are: 1) generating quantitative 3D images of radionuclide distribution and attenuation coefficients and 2) using a reliable method for dose calculation based on activity and attenuation map. In this research, internal dosimetry for 153-Samarium (153-Sm) was done by SPECT-CT images coupled GATE Monte Carlo package for internal dosimetry. Methods: A 50 years old woman with bone metastases from breast cancer was prescribed 153-Sm treatment (Gamma: 103keV and beta: 0.81MeV). A SPECT/CT scan was performed with the Siemens Simbia-Tmore » scanner. SPECT and CT images were registered using default registration software. SPECT quantification was achieved by compensating for all image degrading factors including body attenuation, Compton scattering and collimator-detector response (CDR). Triple energy window method was used to estimate and eliminate the scattered photons. Iterative ordered-subsets expectation maximization (OSEM) with correction for attenuation and distance-dependent CDR was used for image reconstruction. Bilinear energy mapping is used to convert Hounsfield units in CT image to attenuation map. Organ borders were defined by the itk-SNAP toolkit segmentation on CT image. GATE was then used for internal dose calculation. The Specific Absorbed Fractions (SAFs) and S-values were reported as MIRD schema. Results: The results showed that the largest SAFs and S-values are in osseous organs as expected. S-value for lung is the highest after spine that can be important in 153-Sm therapy. Conclusion: We presented the utility of SPECT-CT images and Monte Carlo for patient-specific dosimetry as a reliable and accurate method. It has several advantages over template-based methods or simplified dose estimation methods. With advent of high speed computers, Monte Carlo can be used for treatment

In-depth survey report of Early and Daniel Co. , Inc. , Louisville, Kentucky

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

Zaebst, D.D.

1986-09-01

An in-depth industrial hygiene survey was conducted to evaluate worker exposures to phosphine during fumigation of grain at the Early and Daniel Co. grain elevator in Louisville, Kentucky. Stored grain was fumigated using aluminum phosphide. Aluminum-phosphide pellets were also added directly to the grain by the blender as it was poured into the storage containers. Local exhaust ventilation was used at points in the grain-moving system where grain dust was generated. Air samples were taken during full-shift periods at the breathing zone of the weighmaster, two bin floormen, and the blender. Area monitoring samples were also taken. If the operatorsmore » spend considerable time in the vicinity of a bin which is being filled with grain, there is a likelihood of far greater exposure levels being noted. According to the author, further studies of the use of phosphide products at other elevators should be conducted to determine the effect of environmental and process parameters on phosphine exposures.« less

High altitude chemical release systems for project BIME (Brazilian Ionospheric Modification Experiments) project IMS (Ionospheric Modification Studies) project PIIE (Polar Ionospheric Irregularities Experiment) project polar arcs

NASA Astrophysics Data System (ADS)

Stokes, Charles S.; Murphy, William J.

1987-07-01

Project BIME, a Spread F observation program involved the launching of two Nike-Black Brant rockets each containing a payload of Ammonium Nitrate Fuel Oil (ANFO). The rockets were launched from Barriera Do Inferno Launch Site in Natal, Brazil in August of 1982. Project IMS, an F-layer modification experiment involved three launch vehicles, a Nike-Tomahawk and two Sonda III rockets. The Nike-Tomahawk carried a sulfur hexafluoride (SF6) payload. One of the Sonda III rockets carried a payload that consisted of an SF6 canister and a samarium/strontium thermite canister. The remaining Sonda III carried a trifluorobromo methane (CF3Br) canister and a samarium thermite canister. The rockets were launched from Wallops Island Launch Facility, Virginia in November of 1984. Project PIIE and Polar Arcs, a program to investigate polar ionospheric irregularities, involved a Nike-Black Brant rocket carrying one samarium thermite canister and six barium canisters. An attempted launch failed when launch criteria could not be met. The rocket was launched successfully from Sondrestrom Air Base, Greenland in March 1987.

Barringerite Fe2P from Pyrometamorphic Rocks of the Hatrurim Formation, Israel

NASA Astrophysics Data System (ADS)

Britvin, S. N.; Murashko, M. N.; Vapnik, E.; Polekhovsky, Yu. S.; Krivovichev, S. V.

2017-12-01

The article provides a detailed mineralogical and crystallochemical description (including refinement of the crystal structure) of the first finding of the phosphide class mineral barringerite, Fe2P, from terrestrial pyrometamorphic rocks of the Hatrurim Formation in Israel. The mineral occurs in the association of the so-called paralavas—initially silicate—carbonate sedimentary rocks that remelted during pyrometamorphic processes at a temperature above 1000°C and at a low pressure. Questions on the genesis and crystal chemistry of barringerite are discussed in connection with another polymorphic iron phosphide, allabogdanite (Fe,Ni)2P.

Nd and Sm isotopic composition of spent nuclear fuels from three material test reactors

DOE PAGES

Sharp, Nicholas; Ticknor, Brian W.; Bronikowski, Michael; ...

2016-11-17

Rare earth elements such as neodymium and samarium are ideal for probing the neutron environment that spent nuclear fuels are exposed to in nuclear reactors. The large number of stable isotopes can provide distinct isotopic signatures for differentiating the source material for nuclear forensic investigations. The rare-earth elements were isolated from the high activity fuel matrix via ion exchange chromatography in a shielded cell. The individual elements were then separated using cation exchange chromatography. In conclusion, the neodymium and samarium aliquots were analyzed via MC–ICP–MS, resulting in isotopic compositions with a precision of 0.01–0.3%.

Nd and Sm isotopic composition of spent nuclear fuels from three material test reactors

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

Sharp, Nicholas; Ticknor, Brian W.; Bronikowski, Michael

Rare earth elements such as neodymium and samarium are ideal for probing the neutron environment that spent nuclear fuels are exposed to in nuclear reactors. The large number of stable isotopes can provide distinct isotopic signatures for differentiating the source material for nuclear forensic investigations. The rare-earth elements were isolated from the high activity fuel matrix via ion exchange chromatography in a shielded cell. The individual elements were then separated using cation exchange chromatography. In conclusion, the neodymium and samarium aliquots were analyzed via MC–ICP–MS, resulting in isotopic compositions with a precision of 0.01–0.3%.

Epitaxy of boron phosphide on AlN, 4H-SiC, 3C-SiC and ZrB2 substrates

NASA Astrophysics Data System (ADS)

Padavala, Balabalaji

The semiconductor boron phosphide (BP) has many outstanding features making it attractive for developing various electronic devices, including neutron detectors. In order to improve the efficiency of these devices, BP must have high crystal quality along with the best possible electrical properties. This research is focused on growing high quality crystalline BP films on a variety of superior substrates like AlN, 4H-SiC, 3C-SiC and ZrB2 by chemical vapor deposition. In particular, the influence of various parameters such as temperature, reactant flow rates, and substrate type and its crystalline orientation on the properties of BP films were studied in detail. Twin-free BP films were produced by depositing on off-axis 4H-SiC(0001) substrate tilted 4° toward [11¯00] and crystal symmetry matched zincblende 3C-SiC. BP crystalline quality improved at higher deposition temperature (1200°C) when deposited on AlN, 4H-SiC, whereas increased strain in 3C-SiC and increased boron segregation in ZrB2 at higher temperatures limited the best deposition temperature to below 1200°C. In addition, higher flow ratios of PH 3 to B2H6 resulted in smoother films and improved quality of BP on all substrates. The FWHM of the Raman peak (6.1 cm -1), XRD BP(111) peak FWHM (0.18°) and peak ratios of BP(111)/(200) = 5157 and BP(111)/(220) = 7226 measured on AlN/sapphire were the best values reported in the literature for BP epitaxial films. The undoped films on AlN/sapphire were n-type with a highest electron mobility of 37.8 cm2/V˙s and a lowest carrier concentration of 3.15x1018 cm -3. Raman imaging had lower values of FWHM (4.8 cm-1 ) and a standard deviation (0.56 cm-1) for BP films on AlN/sapphire compared to 4H-SiC, 3C-SiC substrates. X-ray diffraction and Raman spectroscopy revealed residual tensile strain in BP on 4H-SiC, 3C-SiC, ZrB2/4H-SiC, bulk AlN substrates while compressive strain was evident on AlN/sapphire and bulk ZrB2 substrates. Among the substrates studied, Al

Preparation and characterization of a supported system of Ni2P/Ni12P5 nanoparticles and their use as the active phase in chemoselective hydrogenation of acetophenone

NASA Astrophysics Data System (ADS)

Costa, Dolly C.; Soldati, Analía L.; Pecchi, Gina; Bengoa, José Fernando; Marchetti, Sergio Gustavo; Vetere, Virginia

2018-05-01

Ni2P/Ni12P5 nanoparticles were obtained by thermal decomposition of nickel organometallic salt at low temperature. The use of different characterization techniques allowed us to determine that this process produced a mixture of two nickel phosphide phases: Ni2P and Ni12P5. These nickel phosphides nanoparticles, supported on mesoporous silica, showed activity and high selectivity for producing the hydrogenation of the acetophenone carbonyl group to obtain 1-phenylethanol. This is a first report that demonstrates the ability of supported Ni2P/Ni12P5 nanoparticles to produce the chemoselective hydrogenation of acetophenone. We attribute these special catalytic properties to the particular geometry of the Ni–P sites on the surface of the nanoparticles. This is an interesting result because the nickel phosphides have a wide composition range (from Ni3P to NiP3), with different crystallographic structures, therefore we think that different phases could be active and selective to hydrogenate many important molecules with more than one functional group.

Phosphorization boosts the capacitance of mixed metal nanosheet arrays for high performance supercapacitor electrodes.

PubMed

Lan, Yingying; Zhao, Hongyang; Zong, Yan; Li, Xinghua; Sun, Yong; Feng, Juan; Wang, Yan; Zheng, Xinliang; Du, Yaping

2018-05-01

Binary transition metal phosphides hold immense potential as innovative electrode materials for constructing high-performance energy storage devices. Herein, porous binary nickel-cobalt phosphide (NiCoP) nanosheet arrays anchored on nickel foam (NF) were rationally designed as self-supported binder-free electrodes with high supercapacitance performance. Taking the combined advantages of compositional features and array architectures, the nickel foam supported NiCoP nanosheet array (NiCoP@NF) electrode possesses superior electrochemical performance in comparison with Ni-Co LDH@NF and NiCoO2@NF electrodes. The NiCoP@NF electrode shows an ultrahigh specific capacitance of 2143 F g-1 at 1 A g-1 and retained 1615 F g-1 even at 20 A g-1, showing excellent rate performance. Furthermore, a binder-free all-solid-state asymmetric supercapacitor device is designed, which exhibits a high energy density of 27 W h kg-1 at a power density of 647 W kg-1. The hierarchical binary nickel-cobalt phosphide nanosheet arrays hold great promise as advanced electrode materials for supercapacitors with high electrochemical performance.

Thin film photovoltaic device

DOEpatents

Catalano, Anthony W.; Bhushan, Manjul

1982-01-01

A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

Thin film photovoltaic device

DOEpatents

Catalano, A.W.; Bhushan, M.

1982-08-03

A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids. 5 figs.

Low resistance contacts for shallow junction semiconductors

NASA Technical Reports Server (NTRS)

Fatemi, Navid S. (Inventor); Weizer, Victor G. (Inventor)

1994-01-01

A method of enhancing the specific contact resistivity in InP semiconductor devices and improved devices produced thereby are disclosed. Low resistivity values are obtained by using gold ohmic contacts that contain small amounts of gallium or indium and by depositing a thin gold phosphide interlayer between the surface of the InP device and the ohmic contact. When both the thin interlayer and the gold-gallium or gold-indium contact metallizations are used, ultra low specific contact resistivities are achieved. Thermal stability with good contact resistivity is achieved by depositing a layer of refractory metal over the gold phosphide interlayer.

Magnetocrystalline Anisotropy in the Systems Samarium-Cobalt-Iron and Samarium-Manganese-Cobalt-Iron.

DTIC Science & Technology

1981-09-01

100 k0e) were measured by means of a magnetometer employing an O.S. Walker Co. integratinv flux- meter and American Magnetics superconducting magnet ...part of an ongoing effort in our laboratory to develop high- energy-product permanent magnet materials for use in advanced millimeter- wave/microwave...Saturation Magnetization 20. AiTUACT (CantI- m e~Cvem=a -- q ’,end Identify by block mnbThe anisotropy fields (HA) and saturation magnetizations (4rM

An experimental method for directly determining the interconnectivity of melt in a partially molten system

NASA Technical Reports Server (NTRS)

Daines, Martha J.; Richter, Frank M.

1988-01-01

An experimental method for directly determining the degree of interconnectivity of melt in a partially molten system is discussed using an olivine-basalt system as an example. Samarium 151 is allowed time to diffuse through mixtures of olivine and basalt powder which have texturally equilibrated at 1350 C and 13 to 15 kbars. The final distribution of samarium is determined through examination of developed radiographs of the samples. Results suggest an interconnected melt network is established at melt fractions at least as low as 1 wt pct and all melt is completely interconnected at melt fractions at least as low as 2 wt pct for the system examined.

MXP(M = Co/Ni)@carbon core-shell nanoparticles embedded in 3D cross-linked graphene aerogel derived from seaweed biomass for hydrogen evolution reaction.

PubMed

Zhao, Wentong; Lu, Xiaoqing; Selvaraj, Manickam; Wei, Wei; Jiang, Zhifeng; Ullah, Nabi; Liu, Jie; Xie, Jimin

2018-05-24

Low-cost electrocatalysts play an important role in the hydrogen evolution reaction (HER). Particularly, transition metal phosphides (TMPs) are widely applied in the development of HER electrocatalysts. To improve the poor electrochemical reaction kinetics of HER, we introduce a facile way to synthesize carbon core-shell materials containing cobalt phosphide nanoparticles embedded in different graphene aerogels (GAs) (CoP@C-NPs/GA-x (x = 5, 10 and 20)) using seaweed biomass as precursors. The synthesized CoP@C-NPs/GA-5 exhibits efficient catalytic activity with small overpotentials of 120 and 225 mV at current densities of 10 mA cm-2, along with the low Tafel slopes of 57 and 66 mV dec-1, for HER in acidic and alkaline electrolytes, respectively. Compared with carbon aerogel (CA) containing cobalt phosphide nanoparticles (CoP-NPs@CA), the stability of CoP@C-NPs/GA-5 coated with carbon-shells (∼0.8 nm) was significantly improved in acidic electrolytes. We also prepared carbon core-shell materials containing nickel phosphide nanoparticles embedded in GA (Ni2P@C-NPs/GA) to further expand this synthetic route. The graphene-Ni2P@C aerogel shows a similar morphology and better catalytic activity for HER in acidic and alkaline electrolytes. In this work, the robust three-dimensional (3D) GA matrix with abundant open pores and large surface area provides unblocked channels for electrolyte contact and electronic transfer and enables very close contact between the catalyst and electrolyte. The MxP@C core-shell structure prevents the inactivation of MxP NPs during HER processes, and the thin graphene oxide (GO) layers and 3D CA together build up a 3D conductive matrix, which not only adjusts the volume expansion of MxP NPs as well as preventing their aggregation, but also provides a 3D conductive pathway for rapid charge transfer processes. The present synthetic strategy for phosphides via in situ phosphorization with 3D GA can be extended to other novel high

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

Yu, Zhiquan; Wang, Anjie; Liu, Shan

SiO 2, HZSM-5 and Al 2O 3 were used to support nickel phosphides to prepare hydrodeoxygenation (HDO) catalysts. The nickel loading was kept at 20 wt% while the Ni/P molar ratio was varied among 3, 2, and 1 in the preparation by incipient wetness impregnation. XRD characterization revealed that Ni 3P, Ni 12P 5, and Ni 2P as the major crystal phases were obtained at Ni/P ratio of 3, 2, and 1, respectively, on SiO 2 and HZSM-5. When Al 2O 3 was used as the support, nickel metal rather than nickel phosphides was generated. Among SiO 2-supported nickel phosphides,more » Ni 3P exhibited highest hydrogenation activity and catalytic performance in phenol HDO. Ni 3P/HZSM-5 showed the high catalytic performance in HDO of phenol as well as catechol and o-cresol, with Ni 3P as the hydrogenation site and the acid sites in HZSM-5 zeolite as the dehydration site. In conclusion, the strong acidity in HZSM-5 also facilitated the isomerization of cycloalkanes at elevated temperatures.« less

Uranium distribution in pseudowollastonite slag from a phosphorus furnace

USGS Publications Warehouse

Young, Edward; Altschuler, Zalman S.

1956-01-01

Silicate slag from the Victor Chemical Company phosphorus furnace at Tarpon Springs, Fla., has been found to consist essentially of pseudowollastonite, α-CaSiO3. The first-formed crystals are euhedral laths which form a mesh making up most of the slag. As the slag continues to solidify, its composition changes slightly and more equant, subhedral crystals of pseudowollastonite are deposited within the framework of the earlier material. Finally, anherdral masses of fibrous, poorly crystallized material are deposited in the remaining pore spaces which are not always completely filled. Spherules of iron phosphide, Fe2P, occur very sparsely in the slag as inclusions from the immiscible iron phosphide melt. Uranium content increases in the later crystal products of the slag, and by heavy-liquid fractionation it has been possible to segregate partially the phases and to obtain a fourfold concentration of uranium in 5 percent of the material and a twofold concentration in 30 percent of the material. Nuclear-emulsion studies indicate that the last phases of the silicate slag are actually eight times as radioactive as the early phases. In addition, the iron phosphide spherules are comparably enriches in uranium.

The relation of the yield stress of high-pressure anvils to the pressure attained at yielding and the ultimate attainable pressure

NASA Technical Reports Server (NTRS)

Panda, P. C.; Ruoff, A. L.

1979-01-01

A sensitive microprofilometer was used to determine the onset of yielding in the anvils of a supported opposed anvil device for the case of 3% cobalt-cemented tungsten carbide as the anvil material. In addition, it is shown how the commencement of yielding in boron carbide pistons, the yield strength being known, can be used to obtain the transition pressure to a conducting phase in gallium phosphide. The transition pressures of bismuth and gallium phosphide are obtained and it is found that these transitions are extremely close to the maximum attainable pressure in, respectively, a maraging steel and a 3% cobalt-cemented tungsten carbide.

Vapor phase growth technique of III-V compounds utilizing a preheating step

NASA Technical Reports Server (NTRS)

Olsen, Gregory Hammond (Inventor); Zamerowski, Thomas Joseph (Inventor); Buiocchi, Charles Joseph (Inventor)

1978-01-01

In the vapor phase epitaxy fabrication of semiconductor devices and in particular semiconductor lasers, the deposition body on which a particular layer of the laser is to be grown is preheated to a temperature about 40.degree. to 60.degree. C. lower than the temperature at which deposition occurs. It has been discovered that by preheating at this lower temperature there is reduced thermal decomposition at the deposition surface, especially for semiconductor materials such as indium gallium phosphide and gallium arsenide phosphide. A reduction in thermal decomposition reduces imperfections in the deposition body in the vicinity of the deposition surface, thereby providing a device with higher efficiency and longer lifetime.

Synthesis, structural, photophysical and thermal studies of benzoate bridged Sm(III) complexes

NASA Astrophysics Data System (ADS)

Singh, Udai P.; Kumar, Rajeev; Upreti, Shailesh

2007-04-01

One samarium coordination polymer (chain like) 1 with composition [{Sm(OBz) 3(MeO) 2} 2] n has been prepared from the reaction of SmCl 3 and sodium benzoate in 1:3 ratio whereas four binuclear samarium complexes with chemical composition [{(tp)Sm(μ- p-X-OBz) 2} 2] have been prepared by the reaction of SmCl 3, potassium hydrotris(pyrazol-1-yl)borate [K(tp)] and sodium p-X-benzoate (where X = H, Cl, F, NO 2) in 1:1:2 ratio. These complexes have been characterized by elemental analysis, IR spectroscopy, thermogravimetry, optical properties, X-ray and magnetic measurement studies. The X-ray structure shows that the complexes 2- 5 are isostructural whereas the structure of 1 is different. The coordination number around metal center in 1 is eight whereas in complexes 2- 5, each samarium is seven coordinate. The X-ray studies indicate that the complex 1 crystallizes in monoclinic space group P2(1)/ c with the cell dimensions a = 9.75(7), b = 21.83(15), c = 22.28(15) Å, whereas the complexes 2 and 3 crystallizes isostructurally in the triclinic space group P1¯ with the cell dimension a = 11.77(10), b = 12.60(10), c = 17.57(13) Å and a = 9.55(3), b = 12.80(4), c = 14.47(5) Å, respectively. The samarium ions in 2 and 3 are coordinated by three N atoms of pyrazolylborate ligand and four O atoms from benzoate groups. The photophysical properties of above complexes have been studied with ultraviolet absorption, excitation and emission spectral studies. The complexes 1- 5 excited at 240 nm wavelength produced characteristic luminescence features, arising mostly due to the f-f transitions.

Properties of GaP Schottky barrier diodes at elevated temperatures.

NASA Technical Reports Server (NTRS)

Nannichi, Y.; Pearson, G. L.

1969-01-01

Gallium phosphide Schottky barrier diodes, discussing construction and metals used, barrier height relationships to impurity concentration and temperature, rectifying characteristics and internal quantum efficiency

Structural Characterization of Sm(III)(EDTMP).

PubMed

Yang, Y; Pushie, M J; Cooper, D M L; Doschak, M R

2015-11-02

Samarium-153 ethylenediamine-N,N,N',N'-tetrakis(methylenephosphonic acid) ((153)Sm-EDTMP, or samarium lexidronam), also known by its registered trademark name Quadramet, is an approved therapeutic radiopharmaceutical used in the palliative treatment of painful bone metastases. Typically, patients with prostate, breast, or lung cancer are most likely to go on to require bone pain palliation treatment due to bone metastases. Sm(EDTMP) is a bone-seeking drug which accumulates on rapidly growing bone, thereby delivering a highly region-specific dose of radiation, chiefly through β particle emission. Even with its widespread clinical use, the structure of Sm(EDTMP) has not yet been characterized at atomic resolution, despite attempts to crystallize the complex. Herein, we prepared a 1:1 complex of the cold (stable isotope) of Sm(EDTMP) under alkaline conditions and then isolated and characterized the complex using conventional spectroscopic techniques, as well as with extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional structure calculations, using natural abundance Sm. We present the atomic resolution structure of [Sm(III)(EDTMP)-8H](5-) for the first time, supported by the EXAFS data and complementary spectroscopic techniques, which demonstrate that the samarium coordination environment in solution is in agreement with the structure that has long been conjectured.

Magnetically adjustable intraocular lens.

PubMed

Matthews, Michael Wayne; Eggleston, Harry Conrad; Pekarek, Steven D; Hilmas, Greg Eugene

2003-11-01

To provide a noninvasive, magnetic adjustment mechanism to the repeatedly and reversibly adjustable, variable-focus intraocular lens (IOL). University of Missouri-Rolla, Rolla, and Eggleston Adjustable Lens, St. Louis, Missouri, USA. Mechanically adjustable IOLs have been fabricated and tested. Samarium and cobalt rare-earth magnets have been incorporated into the poly(methyl methacrylate) (PMMA) optic of these adjustable lenses. The stability of samarium and cobalt in the PMMA matrix was examined with leaching studies. Operational force testing of the magnetic optics with emphasis on the rotational forces of adjustment was done. Prototype optics incorporating rare-earth magnetic inserts were consistently produced. After 32 days in solution, samarium and cobalt concentration reached a maximum of 5 ppm. Operational force measurements indicate that successful adjustments of this lens can be made using external magnetic fields with rotational torques in excess of 0.6 ounce inch produced. Actual lenses were remotely adjusted using magnetic fields. The magnetically adjustable version of this IOL is a viable and promising means of handling the common issues of postoperative refractive errors without the requirement of additional surgery. The repeatedly adjustable mechanism of this lens also holds promise for the developing eyes of pediatric patients and the changing needs of all patients.

Impact Chemistry and the Origin of Life

NASA Astrophysics Data System (ADS)

Melosh, H. J.; Pasek, M.

2012-12-01

Most discussions of global environmental effects of large impacts focus on changes deleterious to extant life. However, impacts may also produce changes that enhance or even create conditions beneficial to the origin of life. Many other authors have discussed impact delivery of organic molecules, and some have shown the shock synthesis of prebiotic molecules such as amino acids during impact. Our past work on the chemistry of impacts demonstrated that strong chemical reduction occurs in impact melt ejecta (spherules and melt droplets; tektites). Here we focus on the element phosphorus (P), whose role is crucial in biology as the backbone of DNA and RNA, and in metabolic biochemical energy transfer. Pasek previously showed that reduced P readily enters into interesting biological compounds with organic molecules in aqueous solution, and that these reduced P compounds may generate structures similar to sugar phosphates, which are critical to life as we know it. In this talk we argue that impact reduction of P transforms terrestrial and meteoritic phosphates bearing an oxidation state of +5 to the lower redox states of +3 (phosphites) and 0 as an alloy with metal (phosphides). We base this argument on studies of fulgurites—glasses formed by cloud-to-ground lightning—that bear phosphides and phosphites as major carriers of P. Fulgurite chemistry frequently parallels that of impact glasses. Additionally, thermodynamic calculations show that separation of an O-rich vapor from a melt readily results in the transformation of phosphate to phosphites and metal phosphides. These results are confirmed by the presence of metal phosphides within tektites. The impact reduction of phosphates followed by global dispersal of reduced P in the form of glassy droplets likely played a major role in the origin of life on Earth and perhaps on other young planets.

Pesticide poisoning.

PubMed

Goel, Ashish; Aggarwal, Praveen

2007-01-01

Acute poisoning with pesticides is a global public health problem and accounts for as many as 300,000 deaths worldwide every year. The majority of deaths occur due to exposure to organophosphates, organochlorines and aluminium phosphide. Organophosphate compounds inhibit acetylcholinesterase resulting in acute toxicity. Intermediate syndrome can develop in a number of patients and may lead to respiratory paralysis and death. Management consists of proper oxygenation, atropine in escalating doses and pralidoxime in high doses. It is Important to decontaminate the skin while taking precautions to avoid secondary contamination of health personnel. Organochlorine pesticides are toxic to the central nervous system and sensitize the myocardium to catecholamines. Treatment involves supportive care and avoiding exogenous sympathomimetic agents. Ingestion of paraquat causes severe inflammation of the throat, corrosive injury to the gastrointestinal tract, renal tubular necrosis, hepatic necrosis and pulmonary fibrosis. Administration of oxygen should be avoided as it produces more fibrosis. Use of immunosuppressive agents have improved outcome in patients with paraquat poisoning. Rodenticides include thallium, superwarfarins, barium carbonate and phosphides (aluminium and zinc phosphide). Alopecia is an atypical feature of thallium toxicity. Most exposures to superwarfarins are harmless but prolonged bleeding may occur. Barium carbonate Ingestion can cause severe hypokalaemia and respiratory muscle paralysis. Aluminium phosphide is a highly toxic agent with mortality ranging from 37% to 100%. It inhibits mitochondrial cytochrome c oxidase and leads to pulmonary and cardiac toxicity. Treatment is supportive with some studies suggesting a beneficial effect of magnesium sulphate. Pyrethroids and insect repellants (e.g. diethyltoluamide) are relatively harmless but can cause toxic effects to pulmonary and central nervous systems. Ethylene dibromide-a highly toxic, fumigant

SEM-EDX analysis of an unknown "known" white powder found in a shipping container from Peru

NASA Astrophysics Data System (ADS)

Albright, Douglas C.

2009-05-01

In 2008, an unknown white powder was discovered spilled inside of a shipping container of whole kernel corn during an inspection by federal inspectors in the port of Baltimore, Maryland. The container was detained and quarantined while a sample of the powder was collected and sent to a federal laboratory where it was screened using chromatography for the presence of specific poisons and pesticides with negative results. Samples of the corn kernels and the white powder were forwarded to the Food and Drug Administration, Forensic Chemistry Center for further analysis. Stereoscopic Light Microscopy (SLM), Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDX), and Polarized Light Microscopy/Infrared Spectroscopy (PLM-IR) were used in the analysis of the kernels and the unknown powder. Based on the unique particle analysis by SLM and SEM as well as the detection of the presence of aluminum and phosphorous by EDX, the unknown was determined to be consistent with reacted aluminum phosphide (AlP). While commonly known in the agricultural industry, aluminum phosphide is relatively unknown in the forensic community. A history of the use and acute toxicity of this compound along with some very unique SEM/EDX analysis characteristics of aluminum phosphide will be discussed.

On the Chemistry and Physical Properties of Flux and Floating Zone Grown SmB6 Single Crystals

PubMed Central

Phelan, W. A.; Koohpayeh, S. M.; Cottingham, P.; Tutmaher, J. A.; Leiner, J. C.; Lumsden, M. D.; Lavelle, C. M.; Wang, X. P.; Hoffmann, C.; Siegler, M. A.; Haldolaarachchige, N.; Young, D. P.; McQueen, T. M.

2016-01-01

Recent theoretical and experimental findings suggest the long-known but not well understood low temperature resistance plateau of SmB6 may originate from protected surface states arising from a topologically non-trivial bulk band structure having strong Kondo hybridization. Yet others have ascribed this feature to impurities, vacancies, and surface reconstructions. Given the typical methods used to prepare SmB6 single crystals, flux and floating-zone procedures, such ascriptions should not be taken lightly. We demonstrate how compositional variations and/or observable amounts of impurities in SmB6 crystals grown using both procedures affect the physical properties. From X-ray diffraction, neutron diffraction, and X-ray computed tomography experiments we observe that natural isotope containing (SmB6) and doubly isotope enriched (154Sm11B6) crystals prepared using aluminum flux contain co-crystallized, epitaxial aluminum. Further, a large, nearly stoichiometric crystal of SmB6 was successfully grown using the float-zone technique; upon continuing the zone melting, samarium vacancies were introduced. These samarium vacancies drastically alter the resistance and plateauing magnitude of the low temperature resistance compared to stoichiometric SmB6. These results highlight that impurities and compositional variations, even at low concentrations, must be considered when collecting/analyzing physical property data of SmB6. Finally, a more accurate samarium-154 coherent neutron scattering length, 8.9(1) fm, is reported. PMID:26892648

Highly selective dry etching of GaP in the presence of AlxGa1–xP with a SiCl4/SF6 plasma

NASA Astrophysics Data System (ADS)

Hönl, Simon; Hahn, Herwig; Baumgartner, Yannick; Czornomaz, Lukas; Seidler, Paul

2018-05-01

We present an inductively coupled-plasma reactive-ion etching process that simultaneously provides both a high etch rate and unprecedented selectivity for gallium phosphide (GaP) in the presence of aluminum gallium phosphide (AlxGa1–xP). Utilizing mixtures of silicon tetrachloride (SiCl4) and sulfur hexafluoride (SF6), selectivities exceeding 2700:1 are achieved at GaP etch rates above 3000 nm min‑1. A design of experiments has been employed to investigate the influence of the inductively coupled-plasma power, the chamber pressure, the DC bias and the ratio of SiCl4 to SF6. The process enables the use of thin AlxGa1–xP stop layers even at aluminum contents of a few percent.

Growth of indium gallium arsenide thin film on silicon substrate by MOCVD technique

NASA Astrophysics Data System (ADS)

Chowdhury, Sisir; Das, Anish; Banerji, Pallab

2018-05-01

Indium gallium arsenide (InGaAs) thin film with indium phosphide (InP) buffer has been grown on p-type silicon (100) by Metal Organic Chemical Vapor Deposition (MOCVD) technique. To get a lattice matched substrate an Indium Phosphide buffer thin film is deposited onto Si substrate prior to InGaAs growth. The grown films have been investigated by UV-Vis-NIR reflectance spectroscopy. The band gap energy of the grown InGaAs thin films determined to be 0.82 eV from reflectance spectrum and the films are found to have same thickness for growth between 600 °C and 650 °C. Crystalline quality of the grown films has been studied by grazing incidence X-ray diffractometry (GIXRD).

New intermetallic MIrP (M=Ti, Zr, Nb, Mo) and MgRuP compounds related with MoM'P (M'=Ni and Ru) superconductor

NASA Astrophysics Data System (ADS)

Kito, Hijiri; Iyo, Akira; Wada, Toshimi

2011-01-01

Using a cubic-anvil high-pressure apparatus, ternary iridium phosphides MIrP (M=Ti, Zr, Nb, Mo) and MgRuP have been prepared by reaction of stoichiometric amounts of each metal and phosphide powders at around 2 Gpa and above 1523 K for the first time. The structure of these compounds prepared at high-pressure has been characterized by X-ray powder diffraction. Diffraction lines of these compounds are assigned by the index of the Co2Si-type structure. The electrical resistivity and the d.c magnetic susceptibility of MIrP (M=Ti, Zr, Nb, Mo) have measured at low temperatures. Unfortunately, no superconducting transition for MIrP (M=Ti, Zr, Nb, Mo) and MgRuP are observed down to 2 K.

Strongly-guided indium phosphide/indium gallium arsenic phosphide Mach-Zehnder modulator for optical communications

NASA Astrophysics Data System (ADS)

Betty, Ian Brian

2006-12-01

The development of strongly-guided InP/In1-x GaxAsyP 1-y based Mach-Zehnder optical modulators for 10Gb/s telecommunications is detailed. The modulators have insertion losses including coupling as low as 4.5dB, due to the incorporation of monolithically integrated optical mode spot-size converters (SSC's). The modulators are optimized to produce system performance that is independent of optical coupling alignment and for wavelength operation between 1525nm and 1565nm. A negatively chirped Mach-Zehnder modulator design is demonstrated, giving optimal dispersion-limited reach for 10Gb/s ON/OFF-keying modulation. It is shown that the optical system performance for this design can be determined from purely DC based optical measurements. A Mach-Zehnder modulator design invoking nearly no transient frequency shifts under intensity modulation is also presented, for the first time, using phase-shifter implementations based on the Quantum-Confined-Stark-Effect (QCSE). The performance impact on the modulator from the higher-order vertical and lateral waveguide modes found in strongly-guided waveguides has been determined. The impact of these higher-order modes has been minimized using the design of the waveguide bends, MMI structures, and doping profiles. The fabrication process and optical design for the spot-size mode converters are also thoroughly explored. The SSC structures are based on butt-joined vertically tapered passive waveguide cores within laterally flared strongly-guided ridges, making them compatible with any strong-guiding waveguide structure. The flexibility of the SSC process is demonstrated by the superior performance it has also enabled in a 40Gb/s electro-absorption modulator. The presented electro-absorption modulator has 3.6dB fiber-to-fiber insertion loss, polarization dependent loss (PDL) of only 0.3dB over 15dB extinction, and low absolute chirp (|alpha H| < 0.6) over the full dynamic range.

Window structure for passivating solar cells based on gallium arsenide

NASA Technical Reports Server (NTRS)

Barnett, Allen M. (Inventor)

1985-01-01

Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

Chemical shielding properties for BN, BP, AlN, and AlP nanocones: DFT studies

NASA Astrophysics Data System (ADS)

Mirzaei, Mahmoud; Yousefi, Mohammad; Meskinfam, Masoumeh

2012-06-01

The properties of boron nitride (BN), boron phosphide (BP), aluminum nitride (AlN), and aluminum phosphide (AlP) nanocones were investigated by density functional theory (DFT) calculations. The investigated structures were optimized and chemical shielding (CS) properties including isotropic and anisotropic CS parameters were calculated for the atoms of the optimized structures. The magnitudes of CS parameters were observed to be mainly dependent on the bond lengths of considered atoms. The results indicated that the atoms could be divided into atomic layers due to the similarities of their CS properties for the atoms of each layer. The trend means that the atoms of each layer detect almost similar electronic environments. Moreover, the atoms at the apex and mouth of nanocones exhibit different properties with respect to the other atomic layers.

GaAsP on GaP top solar cells

NASA Technical Reports Server (NTRS)

Mcneely, J. B.; Negley, G. H.; Barnett, A. M.

1985-01-01

GaAsP on GaP top solar cells as an attachment to silicon bottom solar cells are being developed. The GaAsP on GaP system offers several advantages for this top solar cell. The most important is that the gallium phosphide substrate provides a rugged, transparent mechanical substrate which does not have to be removed or thinned during processing. Additional advantages are that: (1) gallium phosphide is more oxidation resistant than the III-V aluminum compounds, (2) a range of energy band gaps higher than 1.75 eV is readily available for system efficiency optimization, (3) reliable ohmic contact technology is available from the light-emitting diode industry, and (4) the system readily lends itself to graded band gap structures for additional increases in efficiency.

A combined kick-out and dissociative diffusion mechanism of grown-in Be in InGaAs and InGaAsP. A new finite difference-Bairstow method for solution of the diffusion equations

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

Koumetz, Serge D., E-mail: Serge.Koumetz@univ-rouen.fr; Martin, Patrick; Murray, Hugues

Experimental results on the diffusion of grown-in beryllium (Be) in indium gallium arsenide (In{sub 0.53}Ga{sub 0.47}As) and indium gallium arsenide phosphide (In{sub 0.73}Ga{sub 0.27}As{sub 0.58}P{sub 0.42}) gas source molecular beam epitaxy alloys lattice-matched to indium phosphide (InP) can be successfully explained in terms of a combined kick-out and dissociative diffusion mechanism, involving neutral Be interstitials (Be{sub i}{sup 0}), singly positively charged gallium (Ga), indium (In) self-interstitials (I{sub III}{sup +}) and singly positively charged Ga, In vacancies (V{sub III}{sup +}). A new numerical method of solution to the system of diffusion equations, based on the finite difference approximations and Bairstow's method,more » is proposed.« less

Gallium phosphide high temperature diodes

NASA Technical Reports Server (NTRS)

Chaffin, R. J.; Dawson, L. R.

1981-01-01

High temperature (300 C) diodes for geothermal and other energy applications were developed. A comparison of reverse leakage currents of Si, GaAs, and GaP was made. Diodes made from GaP should be usable to 500 C. A Liquid Phase Epitaxy (LPE) process for producing high quality, grown junction GaP diodes is described. This process uses low vapor pressure Mg as a dopant which allows multiple boat growth in the same LPE run. These LPE wafers were cut into die and metallized to make the diodes. These diodes produce leakage currents below ten to the -9th power A/sq cm at 400 C while exhibiting good high temperature rectification characteristics. High temperature life test data is presented which shows exceptional stability of the V-I characteristics.

On the Chemistry and Physical Properties of Flux and Floating Zone Grown SmB 6 Single Crystals

DOE PAGES

Phelan, W. A.; Koohpayeh, S. M.; Cottingham, P.; ...

2016-02-19

Recent theoretical and experimental findings suggest the long-known but not well understood low temperature resistance plateau of SmB 6 may originate from protected surface states arising from a topologically non-trivial bulk band structure having strong Kondo hybridization. Yet others have ascribed this feature to impurities, vacancies, and surface reconstructions. Given the typical methods used to prepare SmB 6 single crystals, flux and floating-zone procedures, such ascriptions should not be taken lightly. We demonstrate how compositional variations and/or observable amounts of impurities in SmB 6 crystals grown using both procedures affect the physical properties. From X-ray diffraction, neutron diffraction, and X-raymore » computed tomography experiments we observe that natural isotope containing (SmB 6) and doubly isotope enriched ( 154Sm 11B 6) crystals prepared using aluminum flux contain co-crystallized, epitaxial aluminum. Further, a large, nearly stoichiometric crystal of SmB 6 was successfully grown using the float-zone technique; upon continuing the zone melting, samarium vacancies were introduced. These samarium vacancies drastically alter the resistance and plateauing magnitude of the low temperature resistance compared to stoichiometric SmB 6. Finally, these results highlight that impurities and compositional variations, even at low concentrations, must be considered when collecting/analyzing physical property data of SmB 6. Finally, a more accurate samarium-154 coherent neutron scattering length, 8.9(1) fm, is reported.« less

Phosphide oxides RE2AuP2O (RE = La, Ce, Pr, Nd): synthesis, structure, chemical bonding, magnetism, and 31P and 139La solid state NMR.

PubMed

Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer

2013-02-18

Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

Coated conductors

DOEpatents

Arendt, Paul N.; Foltyn, Stephen R.; Stan, Liliana; Usov, Igor O.; Wang, Haiyan

2010-06-15

Articles are provided including a base substrate having a layer of an IBAD oriented material thereon, and, a layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the layer of an IBAD oriented material. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates.

Thermophysical and Electronic Properties Information Analysis Center (TEPIAC): A Continuing Systematic Program on Tables of Thermophysical and Electronic Properties of Materials.

DTIC Science & Technology

1977-02-01

oxides and their mixtures, arsenides, borides, bromides , carbides , chlorides , fluoride s, nitride s, phosphides, silicides , sulfides , tellurides...ivity of alkali elements (lithium , sodium , potassium , rubi- dium , ces ium , and francium) and contains recomme nded reference values generated

Multiple quarantine treatment using bale compression and a three-day fumigation to control Hessian fly (Diptera: Cecidomyiidae) in exported hay.

PubMed

Yokoyama, Victoria Y

2014-06-01

A multiple quarantine treatment was developed to control Hessian fly puparia, Mayetiola destructor (Say), the stage of regulatory concern in exported hay. In a commercial test using 51.589 puparia, no insects survived to the adult stage after exposure to bale compression at 137 kg/cm2 and fumigation with 61 g/28.3 m3 hydrogen phosphide for 3d. The puparia were fumigated in infested wheat seedlings in cloth bags inside compressed timothy bales placed in different locations in three replicate freight containers in a heated building. Fumigant concentrations were 345-522 ppm on day 1; 580-824 ppm on day 2; and 680-861 ppm on day 3. Monitored temperatures were < 20 degrees C in all locations allowing the fumigation temperature to be established at > or = 20 degrees C. Copper detection plate corrosion values were severe inside the freight container doors, and moderate in the middle of bales in all locations, providing visual confirmation of exposure to hydrogen phosphide. Hydrogen phosphide residues in exposed hay bales were found in trace amounts, below the U.S. Environmental Protection Agency tolerance of 0.1 ppm for animal feeds. Timothy hay used in the commercial test is the representative species for all previously exported hay and straw species. The new multiple quarantine treatment is proposed for use with all previously tested bale sizes and wrapper styles for which 3-d fumigation data has been reported, and for bales and wrappers derived from those tested.

High-Performance Rh 2 P Electrocatalyst for Efficient Water Splitting

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

Duan, Haohong; Li, Dongguo; Tang, Yan

2017-04-05

Search for active, stable and cost-efficient electrocatalysts for hydrogen production via water splitting could make substantial impact to the energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high surface area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C NCs exhibit remarkable performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) compared to Rh/C and Pt/C catalysts. The atomic structure of the rhodium phosphide nanocubes was directly observed by annular dark-field scanning transmission electron microscopy (ADF-STEM),more » which revealed phosphorous-rich outermost atomic layer. Combined experimental and computational studies suggest that surface phosphorous plays crucial role in determining the robust catalyst properties.« less

Nucleation of intragranular ferrite in Fe-Ni-P alloys

NASA Astrophysics Data System (ADS)

Narayan, C.; Goldstein, J. I.

1984-05-01

The nucleation of intragranular ferrite from austenite in Fe-Ni-P alloys was investigated in order to understand the development of the Widmanstätten pattern in iron meteorites. Alloys containing 5 to 10 wt pct Ni and 0 to 1 wt pct P were used to simulate iron meteorite compositions. In the isothermal and controlled cooling experiments the reaction path γ → α + γ serves only to nucleate ferrite along austenite grain boundaries. It is necessary for (FeNi)3P to be present within y grains in order to nucleate intragranular ferrite. The reaction path γ → γ + phosphide → α + γ + phosphide yields rod shaped ferrite nuclei that bear a near Kurdjumov-Sachs orientation relationship with the surrounding matrix. The precipitation of ferrite, both along grain boundaries and within the austenite grains, is suppressed in the absence of P.

Investigation of optimal route to fabricate submicron-sized Sm{sub 2}Fe{sub 17} particles with reduction-diffusion method

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

Okada, Shusuke, E-mail: shusuke-okada@aist.go.jp; Takagi, Kenta; Ozaki, Kimihiro

Submicron-sized Sm{sub 2}Fe{sub 17} powder samples were fabricated by a non-pulverizing process through reduction-diffusion of precursors prepared by a wet-chemical technique. Three precursors having different morphologies, which were micron-sized porous Sm-Fe oxide-impregnated iron nitrate, acicular goethite impregnated-samarium nitrate, and a conventional Sm-Fe coprecipitate, were prepared and subjected to hydrogen reduction and reduction-diffusion treatment to clarify whether these precursors could be convert to Sm{sub 2}Fe{sub 17} without impurity phases and which precursor is the most attractive for producing submicron-sized Sm{sub 2}Fe{sub 17} powder. As a result, all three precursors were successfully converted to Sm{sub 2}Fe{sub 17} powders without impurity phases, andmore » the synthesis route using iron-oxide particle-impregnated samarium oxide was revealed to have the greatest potential among the three routes.« less

Interactions between exogenous rare earth elements and phosphorus leaching in packed soil columns

USDA-ARS?s Scientific Manuscript database

Rare earth elements (REEs) increasingly used in agriculture as an amendment for crop growth may help to lessen environmental losses of phosphorus (P) from heavily fertilized soils. The vertical transport characteristics of P and REEs, lanthanum (La), neodymium (Nd), samarium (Sm), and cerium (Ce), w...

Corrosion of Cellular Metals in Marine Environments

DTIC Science & Technology

2006-09-30

phosphides and silicides during the brazing process. Phosphorus, particularly, which is very proficient at depressing the filler alloy melting point...theories of corrosion were constructed for isolated AL-6XN in neutral sodium chloride solutions. This also demonstrated the intrinsic resistance of AL

49 CFR 173.52 - Classification codes and compatibility groups of explosives.

Code of Federal Regulations, 2011 CFR

2011-10-01

... one containing white phosphorus, phosphide or flammable liquid or gel or hypergolic liquid) G 1.1G1.2G 1.3G 1.4G Article containing both an explosive substance and white phosphorus H 1.2H1.3H Article...

49 CFR 173.52 - Classification codes and compatibility groups of explosives.

Code of Federal Regulations, 2010 CFR

2010-10-01

... one containing white phosphorus, phosphide or flammable liquid or gel or hypergolic liquid) G 1.1G1.2G 1.3G 1.4G Article containing both an explosive substance and white phosphorus H 1.2H1.3H Article...

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

Mendoza-Garcia, Adriana; Zhu, Huiyuan; Yu, Yongsheng

Presented here is a facile approach to bimetallic phosphides, Co-Fe-P, via high-temperature (300°C) reaction between Co-Fe-O nanoparticles and trioctylphosphine. The growth of Co-Fe-P from the Co-Fe-O is anisotropic. As a result, Co-Fe-P nanorods (from the polyhedral Co-Fe-O nanoparticles) and sea-urchin-like Co-Fe-P (from the cubic Co-Fe-O nanoparticles) are synthesized with both nanorod and the sea-urchin-arm dimensions controlled by Co/Fe ratios. The Co-Fe-P structure, especially the sea-urchin-like (Co 0.54Fe 0.46) 2P, shows enhanced catalysis for oxygen evolution reaction in KOH with its catalytic efficiency surpassing Ir catalyst. Our synthesis is simple and may be readily extended to the preparation of other multimetallicmore » phosphides for important catalysis and energy storage applications.« less

An in-situ phosphorus source for the synthesis of Cu 3P and the subsequent conversion to Cu 3PS 4 nanoparticle clusters

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

Sheets, Erik J.; Stach, Eric A.; Yang, Wei -Chang

2015-09-20

The search for alternative earth abundant semiconducting nanocrystals for sustainable energy applications has brought forth the need for nanoscale syntheses beyond bulk synthesis routes. Of particular interest are metal phosphides and derivative I-V-VI chalcogenides including copper phosphide (Cu 3P) and copper thiophosphate (Cu 3PS 4). Herein, we report a one-pot, solution-based synthesis of Cu 3P nanocrystals utilizing an in-situ phosphorus source: phosphorus pentasulfide (P 2S 5) in trioctylphosphine (TOP). By injecting this phosphorus source into a copper solution in oleylamine (OLA), uniform and size controlled Cu 3P nanocrystals with a phosphorous-rich surface are synthesized. The subsequent reaction of the Cumore » 3P nanocrystals with decomposing thiourea forms nanoscale Cu 3PS 4 particles having p-type conductivity and an effective optical band gap of 2.36 eV.« less

Ironless-armature brushless motor

NASA Technical Reports Server (NTRS)

Fisher, R. L.

1977-01-01

Device uses 12-pole samarium cobalt permanent-magnet rotor and three Hall-effect sensors for commutation. In prototype motor, torque constant (3-phase delta) is 65 oz-in/amp; electrical time constant (L/R) is 0.2 x 0.001 sec, and armature resistance is 20 ohms.

Ultimate intrinsic coercivity samarian-cobalt magnet. An Earth based feasibility study for Space Shuttle missions

NASA Technical Reports Server (NTRS)

Das, D.; Kumar, K.; Frost, R. T.; Chang, C. W.

1982-01-01

Techniques for the electromagnetic containerless reaction of samarium with cobalt for the formation of samarium-cobalt alloys are summarized. The effort expended to reduce and instrument the oxygen partial pressure in the reaction chamber and coolant gas system are described as well as the experiments in which these improvements were shown to be partially effective. A stainless steel glove box capable of being evacuated to low 10 to the -6th torr pressure and refilled with ultra-pure argon was built and installed. Necessary accessories to perform SmCo5 powder preparation, compaction and subsequent encapsulation of the powder inside a hot isostatic pressing cannister were designed, built, and incorporated into the chamber. All accessories were tested for proper functioning inside the chamber. Using the facility, the first batch of densified SmCo5 powder was fabricated to near total density. Analysis of the densified compacts shows that oxygen contamination during fabrication was near zero.

Alkaline and alkaline earth metal phosphate halides and phosphors

DOEpatents

Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

2012-11-13

Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

Advanced neutron absorber materials

DOEpatents

Branagan, Daniel J.; Smolik, Galen R.

2000-01-01

A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

Effects of prairie dog rodenticides on deer mice in western South Dakota

Treesearch

Michele S. Deisch; Daniel W. Uresk; Raymond L. Linder

1990-01-01

Mortality of nontarget small mammals was determined after application of three black-tailed prairie dog (Cynomys Zudovicianus) rodenticide treatments (prebaited zinc phosphide, prebaited strychnine, and strychnine alone) in western South Dakota. Immediate (September 1983) and long-term (September 1983 through August 1984) impacts on deer mouse (...

Static photoelasticity of gallium phosphide crystals

NASA Astrophysics Data System (ADS)

Mytsyk, B. G.; Andrushchak, A. S.; Kost', Ya. P.

2012-01-01

The piezo-optic effect (POE) in cubic GaP crystals (symmetry class bar 43 m) is studied in detail by interferometry. The relations for determining the absolute piezo-optic coefficients (POCs) π im or their combinations on a sample of X/45° cut at all allowable geometries of the experiment are recorded. The determination of a specific coefficient π im at different experimental geometries on samples of right cuts and a X/45° cut made it possible to find the π im values with a high accuracy and reliability.

Precipitation behavior in austenitic and ferritic steels during fast neutron irradiation and thermal aging*1

NASA Astrophysics Data System (ADS)

Kawanishi, H.; Hajima, R.; Sekimura, N.; Arai, Y.; Ishino, S.

1988-07-01

Precipitation behavior has been studied using a carbon extraction replica technique in Ti-modified Type 316 stainless steels (JPCA-2) and 9Cr-2Mo ferritic/martensitic steels (JFMS) irradiated to 8.1 × 10 24 n/m 2 at 873 and 673 K, respectively, in the experimental fast breeder reactor JOYO. Precipitate identification and compositional analysis were carried out on extracted replicas. The results were compared to those from the as-received steel and a control which had been given the same thermal as-treatment as the specimens received during irradiations. Carbides, Ti-sulphides and phosphides were precipitated in JPCA-2. Precipitate observed in JFMS included carbides, Laves-phases and phosphides. The precipitates in both steels were concluded to be stable under irradiation except for MC and M 6C in JPCA-2. Small MC particles were found precipitated in JPCA-2 during both irradiation and aging. Irradiation proved to promote the precipitation of M 6C in JPCA-2.

CoP/WS2 nanoflake heterostructures as efficient electrocatalysts for significant improvement in hydrogen evolution activity

NASA Astrophysics Data System (ADS)

Chen, Yajie; Kang, Chuanhong; Wang, Ruihong; Ren, Zhiyu; Fu, Huiying; Xiao, Yuting; Tian, Guohui

2018-06-01

The CoP/WS2 nanoflake composites were synthesized via the sulfuration and subsequent phosphidation using the pre-prepared WO2.72 nanowires as precursors. Originally, WO2.72 nanowires were prepared and followed by sulfuration to obtain WS2 nanoflakes. The as-prepared WS2 nanoflakes were used as substrates, on which the Co3O4 nanoparticles were uniformly anchored to construct the Co3O4/WS2 nanoflakes. Finally, the Co3O4/WS2 composites were subjected to phosphidation and in-situ converted into CoP/WS2 nanoflakes. Because of the dual functionalities of both CoP and WS2, the abundant interfaces as well as their synergy, the CoP/WS2 nanoflakes exhibited much higher electrocatalytic activity, smaller overpotential (-81 mV), lower Tafel slope (62 mV decade-1), and higher stability toward hydrogen-evolution reaction than those for the single CoP and WS2.

First principle study of electronic nanoscale structure of In x Ga1- x P with variable size, shape and alloying percentage

NASA Astrophysics Data System (ADS)

Hussein, M. T.; Kasim, T.; Abdulsattar, M. A.

2013-11-01

In present work, we investigate electronic properties of alloying percentage of In x Ga1- x P compound with different sizes of superlattice large unit cell (LUC) method with 8, 16, 54, and 64 nanocrystals core atoms. The size and type of alloying compound are varied so that it can be tuned to a required application. To determine properties of indium gallium phosphide nanocrystals density functional theory at the generalized-gradient approximation level coupled with LUC method is used to simulate electronic structure of zinc blende indium gallium phosphide nanocrystals that have dimensions around 2-2.8 nm. The calculated properties include lattice constant, energy gap, valence band width, cohesive energy, density of states (DOS) etc. Results show that laws that are applied at microscale alloying percentage are no more applicable at the present nanoscale. Results also show that size, shape and quantum effects are strong. Many properties fluctuate at nanoscale while others converge to definite values. DOS summarizes many of the above quantities.

Ternary rare earth-lanthanide sulfides

DOEpatents

Takeshita, Takuo; Gschneidner JR., Karl A.; Beaudry, Bernard J.

1987-01-06

A new ternary rare earth sulfur compound having the formula: where M is a rare earth element selected from the group europium, samarium and ytterbium and x=0.15 to 0.8. The compound has good high-temperature thermoelectric properties and exhibits long-term structural stability up to 1000.degree. C.

Perovskite catalysts for oxidative coupling

DOEpatents

Campbell, K.D.

1991-06-25

Perovskites of the structure A[sub 2]B[sub 2]C[sub 3]O[sub 10] are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

Perovskite catalysts for oxidative coupling

DOEpatents

Campbell, Kenneth D.

1991-01-01

Perovskites of the structure A.sub.2 B.sub.2 C.sub.3 O.sub.10 are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

Impacts of black-tailed prairie dog rodenticides on nontarget passerines

Treesearch

Anthony D. Apa; Daniel W. Uresk; Raymond L. Linder

1991-01-01

In 1983 zinc phosphide, strychnine with prebait, and strychnine without prebait were applied to black-tailed prairie dog (Cynomys Zudovicianus) colonies in west central South Dakota. Short-term (four days later) and long-term (one year later) impacts of the rodenticides on Horned Larks (Eremophila alpestris) and other...

48 CFR 252.225-7009 - Restriction on Acquisition of Certain Articles Containing Specialty Metals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... metal (by mass). (ii) If two metals are specified in the name (e.g., nickel-iron alloy), those metals... alloy (by mass). Assembly means an item forming a portion of a system or subsystem that— (i) Can be... its magnetic properties from rare earth metals (such as samarium). Produce means— (i) Atomization; (ii...

48 CFR 252.225-7009 - Restriction on Acquisition of Certain Articles Containing Specialty Metals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... metal (by mass). (ii) If two metals are specified in the name (e.g., nickel-iron alloy), those metals... alloy (by mass). Assembly means an item forming a portion of a system or subsystem that— (i) Can be... its magnetic properties from rare earth metals (such as samarium). Produce means— (i) Atomization; (ii...

Chemistry of the oxophosphinidene ligand. 2. Reactivity of the anionic complexes [MCp{P(O)R*}(CO)(2)](-) (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3)) toward electrophiles based on elements different from carbon.

PubMed

Alonso, María; Alvarez, M Angeles; García, M Esther; Ruiz, Miguel A; Hamidov, Hayrullo; Jeffery, John C

2010-12-20

The anionic oxophosphinidene complexes (H-DBU)[MCp{P(O)R*}(CO)(2)] (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3); Cp = η(5)-C(5)H(5), DBU = 1,8-diazabicyclo [5.4.0] undec-7-ene) displayed multisite reactivity when faced with different electrophilic reagents. The reactions with the group 14 organochloride compounds ER(4-x)Cl(x) (E = Si, Ge, Sn, Pb) led to either phosphide-like, oxophosphinidene-bridged derivatives [MCp{P(OE')R*}(CO)(2)] (E' = SiMe(3), SiPh(3), GePh(3), GeMe(2)Cl) or to terminal oxophosphinidene complexes [MCp{P(O)R*}(CO)(2)(E')] (E' = SnPh(3), SnPh(2)Cl, PbPh(3); Mo-Pb = 2.8845(4) Å for the MoPb compound). A particular situation was found in the reaction with SnMe(3)Cl, this giving a product existing in both tautomeric forms, with the phosphide-like complex [MCp{P(OSnMe(3))R*}(CO)(2)] prevailing at room temperature and the tautomer [MCp{P(O)R*}(CO)(2)(SnMe(3))] being the unique species present below 203 K in dichloromethane solution. The title anions also showed a multisite behavior when reacting with transition-metal based electrophiles. Thus, the reactions with the complexes [M'Cp(2)Cl(2)] (M' = Ti, Zr) gave phosphide-like derivatives [MCp{P(OM')R*}(CO)(2)] (M = Mo, M' = TiCp(2)Cl, ZrCp(2)Cl; M = W, M' = ZrCp(2)Cl), displaying a bridging κ(1),κ(1)-P,O- oxophosphinidene ligand connecting MCp(CO)(2) and M'Cp(2)Cl metal fragments (W-P = 2.233(1) Å, O-Zr = 2.016(4) Å for the WZr compound]. In contrast, the reactions with the complex [AuCl{P(p-tol)(3)}] gave the metal-metal bonded derivatives trans-[MCp{P(O)R*}(CO)(2){AuP(p-tol)(3)}] (M = Mo, W; Mo-Au = 2.7071(7) Å). From all the above results it was concluded that the terminal oxophosphinidene complexes are preferentially formed under conditions of orbital control, while charge-controlled reactions tend to give derivatives with the electrophilic fragment bound to the oxygen atom of the oxophosphinidene ligand (phosphide-like, oxophosphinidene-bridged derivatives).

Synthesis and thermoelectric properties of CoP(sub 3)

NASA Technical Reports Server (NTRS)

Shields, V. B.; Caillet, T.

2002-01-01

In an effort to expand the range of operation for highly efficient, segmented thermoelectric unicouples currently being developed at JPL, skutterudite phosphides are being investigated as potential high temperature segments to supplement antimonide segments that limit the use of these unicouples at a hot-side temperature of about 873-973 K.

Petrology and Geochemistry of Lunar Regolith Particle 65903,16-7: Evidence for Extreme Reduction and Oxidation

NASA Technical Reports Server (NTRS)

Zeigler, R. A.; Jolliff, B. L.; Korotev, R. L.; Kremser, D. T.; Haskin, L. A.

2001-01-01

Apollo 16 particle 65903,16-7 is a magnesian, alkali-rich impact melt breccia. Low Fe/Mn and high phosphide/phosphate ratios are evidence of severe reduction during impact-melt cooling. Presence of carbonate and FeOOH is evidence for later oxidation. Additional information is contained in the original extended abstract.

Pesticide Spill Prevention and Management

DTIC Science & Technology

2009-08-01

Gentrol IGR) Strong oxidizers. Imidacloprid Oxidizing agents. Lambda-cyhalothrin Oxidizing agents, alkalis, calcium hypochlorite. Malathion... Imidacloprid Sodium salt of diphacinone Methyl Azoxystrobin Use Hard Water Detergent for: Diquat Aluminum phosphide – NOTE: See special...Hydroprene, 9.0%, emulsifiable concentrate (Gentrol IGR) Imidacloprid (Maxforce Granular Fly Bait) Imidacloprid (Maxforce Fly Spot Bait

Demography of black-tailed prairie dog populations reoccupying sites treated with rodenticide

Treesearch

R. P. Cincotta; Daniel W. Uresk; R. M. Hansen

1987-01-01

A rodenticide, zinc phosphide, was applied to remove black-tailed prairie dogs (Cynomys ludovicianus) from 6 haofa prairie dog colony in southwestern South Dakota. Another adjacent 6 ha was left untreated. The removal experiment was repeated two consecutive years. Contingency table analysis showed that the resultant population was not homogeneous;...

An economic analysis of black-tailed prairie dog (Cynomys ludovicianus) control

Treesearch

Alan R. Collins; John P. Workman; Daniel W. Uresk

1984-01-01

Black-tailed prairie dog (Cynomys ludovicianus) control by poisoning with zinc phosphide was not economically feasible in the Conata Basin of South Dakota. Economic analyses were conducted from U.S. Forest Service and rancher viewpoints. Control programs were analyzed with annual maintenance or complete retreatment of initially treated areas to...

Producing Low-Oxygen Samarium/Cobalt Magnet Alloy

NASA Technical Reports Server (NTRS)

Das, Dilip K.; Kumar, Kaplesh; Frost, Robert T.; Chang, C. W.

1987-01-01

Experiments aimed at producing SmCo5 alloy with low oxygen contamination described in report. Two methods of alloying by melting without contact with crucible walls tested. Lowest oxygen contamination, 70 parts per million achieved by dc arc melting on water-cooled, tantalum-clad copper hearth in purified quiescent argon atmosphere. Report includes photographs of equipment, photomicrographs of alloy samples, detailed descriptions of procedures tried, and tables of oxygen contamination and intrinsic coercivities of samples produced.

Phase transitions in samarium at high pressures

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

Dong, W.Y.; Lin, T.H.; Dunn, K.J.

1987-01-15

The electrical behavior of Sm was studied for pressures up to 43 GPa and temperatures from 430 down to 2 K. The two Neel temperatures at ambient pressure are found to move toward each other as the pressure increases and finally merge into one at the dhcp phase. At room temperature, we found that Sm transforms to a new phase, presumably fcc, at about 12 GPa. The phase line between the dhcp and the new phase appears to tie with the cusp of the bcc phase line.

Reactive Materials for Evaporating Samarium (Pre-Print)

DTIC Science & Technology

2016-04-15

Nanocomposites  Titanium powder,   ‐325 mesh  Ti  Alfa  Aesar 99% 2B‐Ti, Ti‐C  Amorphous boron  powder, < 1 µm  B  SB Boron 93‐96% 2B‐Ti, 2B‐Zr  Carbon black powder...FE‐603, 1‐5 µm  C  Atlantic Equipment  Engineers  99.9% Ti‐C  Zirconium powder,  APS, 2‐3 µm  Zr  Alfa  Aesar 97.2% 2B‐Zr, Zr‐C  Magnesium powder...Mg  Alfa  Aesar 99.8% Mg‐S  Sulfur, powder,   ‐100 mesh  S  Sigma‐Aldrich Reagent  Grade  Mg‐S  Aluminum powder,   ‐325 mesh  Al  Atlantic Equipment

Coupled IVPs to Investigate a Nuclear Reactor Poison Burn Up

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

Faghihi, F.

2009-09-09

A set of coupled IVPs that describe the change rate of an important poison, in a nuclear reactor, has been written herein. Specifically, in this article, we have focused on the samarium-149 (as a poison) burnup in a desired pressurized water nuclear reactor and its concentration are given using our MATLAB-linked 'solver'.

CADMIUM-RARE EARTH BORATE GLASS AS REACTOR CONTROL MATERIAL

DOEpatents

Ploetz, G.L.; Ray, W.E.

1958-11-01

A reactor control rod fabricated from a cadmiumrare earth-borate glass is presented. The rare earth component of this glass is selected from among those rare earths having large neutron capture cross sections, such as samarium, gadolinium or europium. Partlcles of this glass are then dispersed in a metal matrix by standard powder metallurgy techniques.

Asymmetric NHC-catalyzed redox α-amination of α-aroyloxyaldehydes.

PubMed

Taylor, James E; Daniels, David S B; Smith, Andrew D

2013-12-06

Asymmetric α-amination through an N-heterocyclic carbene (NHC)-catalyzed redox reaction of α-aroyloxyaldehydes with N-aryl-N-aroyldiazenes to form α-hydrazino esters with high enantioselectivity (up to 99% ee) is reported. The hydrazide products are readily converted into enantioenriched N-aryl amino esters through samarium(II) iodide mediated N-N bond cleavage.

Coupled IVPs to Investigate a Nuclear Reactor Poison Burn Up

NASA Astrophysics Data System (ADS)

Faghihi, F.; Saidi-Nezhad, M.

2009-09-01

A set of coupled IVPs that describe the change rate of an important poison, in a nuclear reactor, has been written herein. Specifically, in this article, we have focused on the samarium-149 (as a poison) burnup in a desired pressurized water nuclear reactor and its concentration are given using our MATLAB-linked "solver."

Topological phase transition of decoupling quasi-two-dimensional vortex pairs in La1- y Sm y MnO3 + δ ( y = 0.85, 1.0)

NASA Astrophysics Data System (ADS)

Bukhanko, F. N.; Bukhanko, A. F.

2016-10-01

Characteristic signs of the universal Nelson-Kosterlitz jump of the superconducting liquid density in the temperature dependences of the magnetization of La1- y Sm y MnO3 + δ samples with samarium concentrations y = 0.85 and 1.0, which are measured in magnetic fields 100 Oe ≤ H ≤ 3.5 kOe, are detected. As the temperature increases, the sample with y = 0.85 exhibits a crescent-shaped singularity in the dc magnetization curve near the critical temperature of decoupling vortex-antivortex pairs ( T KT ≡ T c ≈ 43 K), which is independent of measuring magnetic field H and is characteristic of the dissociation of 2D vortex pairs. A similar singularity is also detected in the sample with a samarium concentration y = 1.0 at a significantly lower temperature ( T KT ≈ 12 K). The obtained experimental results are explained in terms of the topological Kosterlitz-Thouless phase transition of dissociation of 2D vortex pairs in a quasi-two-dimensional weak Josephson coupling network.

Structural and Spectroscopic Studies of Sm3+/CdS Nanocrystallites in Sol-Gel TiO2-ZrO2 Matrix

NASA Astrophysics Data System (ADS)

Karthika, S.; Prathibha, Vasudevan; Ann, Mary K. A.; Viji, Vidyadharan; Biju, P. R.; Unnikrishnan, N. V.

2014-02-01

A sol-gel method was used to prepare titania-zirconia matrices doped with Sm3+/CdS nanocrystallites. The structural properties of the matrices were characterized using transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Fourier-transform infrared spectroscopy studies. The thermal stability of the material was determined by TGA/DTA analysis. The absorption spectrum shows the characteristic peaks of the Sm3+ ions and the absorption peak corresponding to the CdS nanocrystallites. The optical bandgap and size of the CdS nanoparticles were calculated from the absorption spectrum. From TEM, the interplanar distance ( d) was estimated to be 3.533 Å, which matches with the (1 0 0) plane of bulk CdS. The measurements yield a nanocrystallite size of around 7.8 nm. The optical absorption and emission spectra confirmed the formation of CdS nanoparticles along with samarium ions in the titania-zirconia matrices. The fluorescence intensity of the samarium ions was found to be greatly enhanced by codoping with CdS nanocrystallites.

Investigation of doped Perovskite systems RAIO3 using density functional theory based electronic structure and thermoelectric studies

NASA Astrophysics Data System (ADS)

Sandeep; Rai, D. P.; Shankar, A.; Ghimire, M. P.; Thapa, R. K.

2016-10-01

Samarium doping effects on the thermoelectric properties in Eu1-xSmxAlO3 (x=0%, 50%, and 100%) were studied using first principles calculations based thermal transport property measurement. The result indicate that the compound is an intrinsic n-type material. Samarium doping has a positive effect on the overall thermoelectric performance of the Eu1-xSmxAlO3 system, with sharp increase in figure of merit (ZT) observed when x=0, 50 and 100% up to 150K. Compared to x=0 and 100%, the case of x=50% was found to have more positive increment in ZT value suggesting that the doing to have positive effect on figure of merit in Eu1-xSmxAlO3. Furthermore, all the samples show stable thermoelectric compatibility factors over a broad temperature range from 700 to 1000 K, which could have great benefits for their practical applications. It is concluded that the overall thermoelectric performance of the Eu1-xSmxAlO3 could be highly enhanced using doping techniques.

Effects of two prairie dog rodenticides on ground-dwelling invertebrates in western South Dakota

Treesearch

Michele S. Deisch; Daniel W. Uresk; Raymond L. Linder

1989-01-01

Immediate and long-term effects of 3 rodenticide treatments on nontarget invertebrates were evaluated on prairie dog colonies. Immediate impacts indicated zinc phosphide reduced ants, strychnine alone reduced wolf spiders, and prebaited strychnine had no impacts. Long-term changes showed increases in wolf spiders and ground beetles and densities were contributed to...

Ternary rare earth-lanthanide sulfides. [Re = Eu, Sm or Yb

DOEpatents

Takeshita, Takuo; Gschneidner, K.A. Jr.; Beaudry, B.J.

1986-03-06

Disclosed is a new ternary rare earth sulfur compound having the formula La/sub 3-x/M/sub x/S/sub 4/, where M is europium, samarium, or ytterbium, with x = 0.15 to 0.8. The compound has good high-temperature thermoelectric properties and exhibits long-term structural stability up to 1000/sup 0/C.

48 CFR 252.225-7009 - Restriction on Acquisition of Certain Articles Containing Specialty Metals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... metal (by mass). (ii) If two metals are specified in the name (e.g., nickel-iron alloy), those metals... alloy (by mass). (2) Assembly means an item forming a portion of a system or subsystem that— (i) Can be... obtains a majority of its magnetic properties from rare earth metals (such as samarium). (9) Produce means...

Rare Earths; The Fraternal Fifteen (Rev.)

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

Gschneidner, Jr., Karl A.

1966-01-01

Rare earths are a set of 15 elements: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. They are not rare and not earths; they are metals and quite abundant. They are studied to develop commercial products which are beneficial to mankind, and because some rare earths are important to fission products.

CYTOGENETIC EFFECTS OF PHOSPHINE INHALATION BY RODENTS

EPA Science Inventory

Phosphine (PH3) is a highly toxic grain fumigant that can be produced from the reaction of metal phosphides with water. o determine the in vivo cytogenetic effects of inhalation of PH3, male CD-1 mice were exposed to either 0, 5, 10, or 15 ppm target concentrations of PH3 for 6 h...

40 CFR Appendix Vii to Part 266 - Health-Based Limits for Exclusion of Waste-Derived Residues*

Code of Federal Regulations, 2013 CFR

2013-07-01

... Constituent CAS No. Concentration limits (mg/L) Antimony 7440-36-0 1xE+00 Arsenic 7440-38-2 5xE+00 Barium 7440... alcohol 107-18-6 2xE−01 Aluminum phosphide 20859-73-8 1xE−02 Aniline 62-53-3 6xE−02 Barium cyanide 542-62...

Field trials of the rodenticide gophacide against wild house mice (Mus musculus L.).

PubMed Central

Rowe, F. P.; Swinney, T.; Bradfield, A.

1975-01-01

The acute rodenticide gophacide was tested against urban infestations of the house mouse (Mus musculus L.) and treatment success was assessed from the results of census baitings conducted before and after each treatment. Seven of eight populations of mice living in premises where alternative food supplies were limited were successfully controlled when medium oatmeal bait containing gophacide at 0.1% was laid directly for 4 days. In further treatments against mice inhabiting more complex environments and having greater access to other foods, the performance of gophacide at 0.1% and at 0.25% in a wholemeal flour/pinhead oatmeal/corn oil bait was compared with that of zinc phosphide at 3.0% in the same bait-base. The poison treatments were conducted for 1 or 4 days and always after 3 days pre-baiting. Treatment success varied considerably irrespective of the type of treatment or of the poison used. In general, however, gophacide proved to be as effective as zinc phosphide for the control of mice. PMID:1054056

Optical Computing, 1991, Technical Digest Series, Vol. 6

DTIC Science & Technology

1992-05-22

lasers). Compound semiconductors may satisfy these requirements. For example, optical signal amplification by two-beam coupling and amplified phase... compound semiconductors can provide this type of implementationi. This paper presents results from a detailed investigation on potentials of the...conductivity to achieve high multichannel cell performance. We describe several high performance Gallium Phosphide multichannel Bragg cells which employ these

Sustainable Phosphorus Chemistry: A Silylphosphide Synthon for the Generation of Value-Added Phosphorus Chemicals.

PubMed

Slootweg, J Chris

2018-05-07

Avoiding white phosphorus: Cummins and Geeson have recently described the conversion of phosphoric acid into the novel bis(trichlorosilyl)phosphide anion, which serves as a key intermediate in the synthesis of organophosphines, hexafluorophosphate, and phosphine gas in a reaction sequence that does not rely on white phosphorus. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An experimental analysis of a doped lithium fluoride direct absorption solar receiver

NASA Technical Reports Server (NTRS)

Kesseli, James; Pollak, Tom; Lacy, Dovie

1988-01-01

An experimental analysis of two key elements of a direct absorption solar receiver for use with Brayton solar dynamic systems was conducted. Experimental data are presented on LiF crystals doped with dysprosium, samarium, and cobalt fluorides. In addition, a simulation of the cavity/window environment was performed and a posttest inspection was conducted to evaluate chemical reactivity, transmissivity, and condensation rate.

Rare Earth Element Concentrations in Geothermal Wells at the Puna Geothermal Field, Hawaii

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

Fowler, Andrew; Zierenberg, Robert

Rare earth element concentrations in the geothermal wells at the Puna geothermal field, Hawaii. Samples taken from geothermal wells KS-5, KS-6W, KS-9W, KS-14E, and KS-16N. Includes pH and concentrations for Cerium, Dysprosium, Erbium, Europium, Gadolinium, Holmium, Lanthanum, Lutetium, Neodymium, Praseodymium, Samarium, Terbium, Thulium, Yttrium, and Ytterbium. Samples collected on November 11-17, 2016.

Total Synthesis of Jiadifenolide**

PubMed Central

Paterson, Ian; Xuan, Mengyang; Dalby, Stephen M

2014-01-01

As a potent neurotrophic agent, the sesquiterpenoid jiadifenolide represents a valuable small-molecule lead for the potential therapeutic treatment of neurodegenerative diseases. A stereocontrolled total synthesis of this densely functionalized natural product is reported, central to which is an adventurous samarium-mediated cyclization reaction to establish the tricyclic core and the adjacent C5 and C6 quaternary stereocenters. PMID:24861364

Ternary rare earth-lanthanide sulfides

DOEpatents

Takeshita, Takuo; Gschneidner, Jr., Karl A.; Beaudry, Bernard J.

1987-01-06

A new ternary rare earth sulfur compound having the formula: La.sub.3-x M.sub.x S.sub.4 where M is a rare earth element selected from the group europium, samarium and ytterbium and x=0.15 to 0.8. The compound has good high-temperature thermoelectric properties and exhibits long-term structural stability up to 1000.degree. C.

Protonation at the aromatic ring of samarium benzophenone dianion species. Isolation and structural characterization of a samarium(III) enolate complex

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

Hou, Z.; Yoshimura, Takashi; Wakatsuki, Yasuo

1994-11-30

The reduction of aromatic compounds into their dihydro derivatives by dissolving metal/alcohol systems (the Birch reduction) is a useful methodology in organic synthesis. Of particular importance is the reduction of aromatic carbonyl compounds such as aromatic acids, esters, amides, and monoaryl ketones, which usually generates in situ useful metal enolate intermediates that upon further reaction with electrophiles yield a variety of cyclohexadiene derivatives. One of the possible processes to generate these metal enolate intermediates is thought to be the monoprotonation of dianionic species at the para position of the aromatic rings. On the other hand, the reduction of diaryl ketonesmore » by alkali metals in liquid ammonia or by lanthanide metals in THF/HMPA or DME has been well known to afford the corresponding ketone dianions. The first X-ray structure of metal ketone dianion complexes, [Yb([mu]-[eta][sup 1],[eta][sup 2]-OCPh[sub 2]) (HMPA)[sub 2

Hybrid indium phosphide-on-silicon nanolaser diode

NASA Astrophysics Data System (ADS)

Crosnier, Guillaume; Sanchez, Dorian; Bouchoule, Sophie; Monnier, Paul; Beaudoin, Gregoire; Sagnes, Isabelle; Raj, Rama; Raineri, Fabrice

2017-04-01

The most-awaited convergence of microelectronics and photonics promises to bring about a revolution for on-chip data communications and processing. Among all the optoelectronic devices to be developed, power-efficient nanolaser diodes able to be integrated densely with silicon photonics and electronics are essential to convert electrical data into the optical domain. Here, we report a demonstration of ultracompact laser diodes based on one-dimensional (1D) photonic crystal (PhC) nanocavities made in InP nanoribs heterogeneously integrated on a silicon-waveguide circuitry. The specific nanorib design enables an efficient electrical injection of carriers in the nanocavity without spoiling its optical properties. Room-temperature continuous-wave (CW) single-mode operation is obtained with a low current threshold of 100 µA. Laser emission at 1.56 µm in the silicon waveguides is obtained with wall-plug efficiencies greater than 10%. This result opens up exciting avenues for constructing optical networks at the submillimetre scale for on-chip interconnects and signal processing.

1/F Noise in Indium Phosphide Transistors

DTIC Science & Technology

1992-04-01

Zn/5 nm Au. The gate length and width were 1 Pm and 400 gm, respectively. The device was annealed at 375"C in argon for 1 minute to simultaneously...evaporation, defined by lift-off, and annealed at 375°C for 10 minutes. The gate region was recessed until a source-drain current of 35 mA was obtained...considerations for the signal Sn V,2/R, at the network input from the amplifier output show that vo2 4RoR,, s - 4 nR 2 = So •Mo. (6) 4Ro (Ro + R,) 2

Development of high temperature gallium phosphide rectifiers

NASA Technical Reports Server (NTRS)

Craford, M. G.; Keune, D. L.

1972-01-01

Large area high performance, GaP rectifiers were fabricated by means of Zn diffusion into vapor phase epitaxial GaP. Devices with an active area of 0.01 sq cm typically exhibit forward voltages of 3 volts for a bias current of 1 ampere and have reverse breakdown voltages of 300 volts for temperatures from 27 C to 400 C. Typical device reverse saturation current at a reverse bias of 150 volts is less than 10 to the minus 9th power amp at 27 C and less than 0.000050 amp at 400 C.

Changing trends and predictors of outcome in patients with acute poisoning admitted to the intensive care.

PubMed

Jayashree, M; Singhi, S

2011-10-01

Acute poisoning in children is a medical emergency and preventable cause of morbidity and mortality. Knowledge about the nature, magnitude, outcome and predictors of outcome is necessary for management and allocation of scant resources. This is a retrospective study conducted in the Pediatric Intensive Care Unit (PICU) of an urban multi speciality teaching and referral hospital in North India from January 1993 to June 2008 to determine the epidemiology, clinical profile, outcome and predictors of outcome in children with acute poisoning. Data of 225 children with acute poisoning was retrieved from case records with respect to demographic profile, time to presentation, PRISM score, clinical features, investigations, therapeutic measures, complications and outcome in terms of survival or death. Survivors and non-survivors were compared to determine the predictors of mortality. Acute poisoning constituted 3.9% of total PICU admissions; almost all (96.9%) were accidental. The mean age of study patient's was 3.3 ± 3.1 (range 0.10-12) years with majority (61.3%) being toddlers (1-3 years). In the overall cohort, kerosene (27.1%) and prescription drugs (26.7%) were the most common causative agents followed by organophosphates (16.0%), corrosives (7.6%), carbamates (4.9%) and aluminum phosphide (4.9%). However the trends of the three 5-year interval (1993 till the end of 1997, 1998 till the end of 2002 and 2003 till the end of June 2008) revealed a significant decrease in kerosene, aluminum phosphide and iron with increase in organophosphate compound poisoning. Ninety nine (44%) patients required supplemental oxygen, of which nearly half (n = 42; 42.4%) needed mechanical ventilation. Twenty (8.9%) died; cause of death being iron poisoning in five; aluminum phosphide in four; organophosphates in three and one each because of kerosene, diesel, carbamate, corrosive, sewing machine lubricant, isoniazid, salicylate and maduramycin poisoning. There has been a significant

Preparation and Luminescent Properties of the antibacterial materials of the La3+ Doped Sm3+-Hydroxyapatite

NASA Astrophysics Data System (ADS)

Lv, Yuguang; Shi, Qi; Jin, Yuling; Ren, Hengxin; Qin, Yushan; Wang, Bo; Song, Shanshan

2018-03-01

In this paper, the La3+-doped Sm3+ hydroxyapatite (La/Sm/HAP) complexes were prepared by a precipitation method. The sample was defined by IR spectra, fluorescence spectra and X ray diffraction analysis et al. The structure of complexes were discussed. The emission wavelength of heat treatment of Sm3+ do not change, but will affect the intensity of the peak Sm3+ luminescence properties and the occupy hydroxyapatite in the lattice Ca( II )and Ca( I ) loci with Sm3+ doped concentration and the proportion of the sintering temperature change and change: The nano hydroxyapatite complex of the La3+ doped samarium obtain the good fluorescence intensity, by La3+ doping content of Sm3+ were hydroxyapatite 6% (La3+, Sm3+ mole ratio) device. The complex of La3+ doped samarium HAP have Stable chemical property, fluorescence property and excellent biological activity. The ligand HAP absorbs energy or captures an electron-hole pair and then transfers it to the lanthanide ions. The catalytic activity influence of the La3+-doped Sm3+hydroxyapatite was discussed, the La/Sm/HAP had excellent antibacterial property, which used as potential biological antibacterial material.

Observation of a well-defined hybridization gap and in-gap states on the SmB6 (001) surface

NASA Astrophysics Data System (ADS)

Sun, Zhixiang; Maldonado, Ana; Paz, Wendel S.; Inosov, Dmytro S.; Schnyder, Andreas P.; Palacios, J. J.; Shitsevalova, Natalya Yu.; Filipov, Vladimir B.; Wahl, Peter

2018-06-01

The rise of topology in condensed-matter physics has generated strong interest in identifying novel quantum materials in which topological protection is driven by electronic correlations. Samarium hexaboride is a Kondo insulator for which it has been proposed that a band inversion between 5 d and 4 f bands gives rise to topologically protected surface states. However, unambiguous proof of the existence and topological nature of these surface states is still missing, and its low-energy electronic structure is still not fully established. Here we present a study of samarium hexaboride by ultralow-temperature scanning tunneling microscopy and spectroscopy. We obtain clear atomically resolved topographic images of the sample surface. Our tunneling spectra reveal signatures of a hybridization gap with a size of about 8 meV and with a reduction of the differential conductance inside the gap by almost half, and surprisingly, several strong resonances below the Fermi level. The spatial variations of the energy of the resonances point toward a microscopic variation of the electronic states by the different surface terminations. High-resolution tunneling spectra acquired at 100 mK reveal a splitting of the Kondo resonance, possibly due to the crystal electric field.

Measuring the Dispersion in Laser Cavity Mirrors using White-Light Interferometry

DTIC Science & Technology

2008-03-01

mirrors. Two AlGaInP (aluminum gallium indium phosphide ) diode lasers are aligned such that one is polarized vertically while one is polarized...linear crystals, where the index of refraction depends on beam intensity. Short pulses with high peak intensities are well 14 suited to induce the...MEASURING THE DISPERSION OF LASER CAVITY MIRRORS USING WHITE-LIGHT INTERFEROMETRY THESIS Allison S

Nonequilibrium Floquet States in Topological Kondo Insulators

DTIC Science & Technology

2016-02-04

increase in an insulating crystal of SmB6. However, extrinsic heating effects are a potential source of the observation, which would act to reduce...the first known topological Kondo insulator , Samarium Hexaboride, we investigated the possibility of realizing a moving cascade of topological... insulator -to-metal transitions to obtain bulk-like conduction through the Kondo insulator . Experiments in collaboration with Prof. T. Yanagisawa at

European Conference on Thermophysical Properties (11th) Held on 13-16 June 1988, University of Umea, Sweden. Abstracts

DTIC Science & Technology

1988-06-16

University of Urnea 901 87 UMEA SWEDEN E Karawacki Dept of Physics 48 Chalmers Tekniska Hogskola 412 96 GOTEBORG SWEDEN S Klarsfeld Glass Properties...Saunders, Electrical Conductivity and Dielectric Constant of Samarium Phosphate Glasses © 0 Andersson, P Andersson, R G Ross & G Backstrcm. Thermophysical...delivers extinction coefficients of about 50 m-/kg for pure (conventional) glass fiber insulations. We have thoroughly studied the potentials for a

Electrostatically driven resonance energy transfer in “cationic” biocompatible indium phosphide quantum dots† †Electronic supplementary information (ESI) available: Detailed experimental methods, the synthesis and characterization of QDs, bioimaging, stability studies, control experiments, and the calculation of various parameters involved in the resonance energy transfer process etc. See DOI: 10.1039/c7sc00592j Click here for additional data file.

PubMed Central

Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta

2017-01-01

Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent positive charge and stability to InP/ZnS QDs in biofluids. The two important properties of QDs, namely bioimaging and light induced resonance energy transfer, are successfully demonstrated in cationic InP/ZnS QDs. The low cytotoxicity and stable photoluminescence of cationic InP/ZnS QDs inside cells make them ideal candidates as optical probes for cellular imaging. An efficient resonance energy transfer (E ∼ 60%) is observed, under physiological conditions, between the cationic InP/ZnS QD donor and anionic dye acceptor. A large bimolecular quenching constant along with a linear Stern–Volmer plot confirms the formation of a strong ground state complex between the cationic InP/ZnS QDs and the anionic dye. Control experiments prove the role of electrostatic attraction in driving the light induced interactions, which can rightfully form the basis for future nano-bio studies between cationic InP/ZnS QDs and anionic biomolecules. PMID:28626557

Superconductivity theory applied to the periodic table of the elements

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

Elifritz, T.L.

1994-12-31

The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition, is applied to the periodic table of the elements, in order to isolate the essential features of high temperature superconductivity and to predict its occurrence within the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity.

Superconductivity theory applied to the periodic table of the elements

NASA Technical Reports Server (NTRS)

Elifritz, Thomas Lee

1995-01-01

The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition is applied to the periodic table of the elements, in order to isolate the essential features of of high temperature superconductivity and to predict its occurrence with the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity.

Europe/Latin America Report, Science and Technology

DTIC Science & Technology

1997-01-16

Space Accord 3 AUTOMOBILE INDUSTRY Volvo Chief Attacks Japanese Car Manufacturers’ Tactics in Sweden (SVENSKA DAGBLADET, 21 Nov 86) 4...Great Britain (BIOTEC, Apr 86) 10 EEC’s 1982-86 Biotechnology Programs (BIOTEC, Apr 86) 11 - a Industry , Universities Meet in Italy on...Epitaxy Devices (S. Dumontet; ELECTRONIQUE ACTUALITES, 19 Sep 86) 23 Briefs French Indium Phosphide Production 25 SCIENTIFIC AND INDUSTRIAL POLICY

Sarah Kurtz | NREL

Science.gov Websites

next stage of growth for the PV industry. Participated in the demonstration of the GaInP/GaAs solar photovoltaics (PV), concentrator PV, and PV reliability. Kurtz and NREL colleague Jerry Olson championed the early use of multi-junction solar cells by showing that a top cell of gallium indium phosphide (GaInP

Free-space coherent optical communication receivers implemented with photorefractive optical beam combiners

NASA Technical Reports Server (NTRS)

Davidson, Frederic M.

1992-01-01

Performance measurements are reported concerning a coherent optical communication receiver that contained an iron doped indium phosphide photorefractive beam combiner, rather than a conventional optical beam splitter. The system obtained a bit error probability of 10(exp -6) at received signal powers corresponding to less than 100 detected photons per bit. The system used phase modulated Nd:YAG laser light at a wavelength of 1.06 microns.

Implications of extraterrestrial material on the origin of life

NASA Astrophysics Data System (ADS)

Pasek, Matthew A.

Meteoritic organic material may provide the best perspective on prebiotic chemistry. Meteorites have also been invoked as a source of prebiotic material. This study suggests a caveat to extraterrestrial organic delivery: that prebiotic meteoritic organics were too dilute to promote prebiotic reactions. However, meteoritic material provides building material for endogenous synthesis of prebiotic molecules, such as by hydrolysis of extraterrestrial organic tars, and corrosion of phosphide minerals.

Quantum Enhanced Imaging by Entangled States

DTIC Science & Technology

2009-07-01

classes of entangled states. In tripartite systems two classes of genuine tripartite entanglement have been discovered, namely, the Greenberger -Horne...D. M. Greenberger , M. Horne and A. Zeilinger, in Bell’s Theorem, Quantum Theory, and Concepts of the Universe, ed. M. Kafatos (Kluwer, Dordrecht 1989...Gallium Indium Arsenide Phosphide (a III-V compound semiconductor) GHZ: Greenberger -Horne-Zeilinger (a class of entangled states) GLAD: General

Investigation of the thermophysical properties of high-melting materials with the aid of a complex of instruments

NASA Technical Reports Server (NTRS)

Bolgar, A. S.; Gordiyenko, S. P.; Guseva, Y. A.; Turchanin, A. G.; Fenochka, B. V.; Fesenko, V. V.

1984-01-01

The evaporation rate, vapor pressure, heats of evaporation reaction (sublimation, dissociation), enthalpy, electrical resistance, heat capacity, emissivity, and heat conductivity of various carbides, borides, sulfides, nitrides, selenides, and phosphides were investigated. A set of high temperature high vacuum devices, calorimeters (designed for operation at 400 to 1300 K and from 1200 K), and mass spectrometers, most of which were specially developed for these studies, is described.

Strongly luminescent InP/ZnS core-shell nanoparticles.

PubMed

Haubold, S; Haase, M; Kornowski, A; Weller, H

2001-05-18

The wide-bandgap semiconducting material, zinc sulfide, has been coated on indium phosphide nanoclusters to a 1-2-Å thickness. The resulting InP-ZnS core-shell particle (as shown in the TEM image; scale 1 cm=5 nm) exhibits bright luminescence at room temperature with quantum efficiencies as high as 23 %. © 2001 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

Monodispersed Carbon-Coated Cubic NiP2 Nanoparticles Anchored on Carbon Nanotubes as Ultra-Long-Life Anodes for Reversible Lithium Storage.

PubMed

Lou, Peili; Cui, Zhonghui; Jia, Zhiqing; Sun, Jiyang; Tan, Yingbin; Guo, Xiangxin

2017-04-25

In search of new electrode materials for lithium-ion batteries, metal phosphides that exhibit desirable properties such as high theoretical capacity, moderate discharge plateau, and relatively low polarization recently have attracted a great deal of attention as anode materials. However, the large volume changes and thus resulting collapse of electrode structure during long-term cycling are still challenges for metal-phosphide-based anodes. Here we report an electrode design strategy to solve these problems. The key to this strategy is to confine the electroactive nanoparticles into flexible conductive hosts (like carbon materials) and meanwhile maintain a monodispersed nature of the electroactive particles within the hosts. Monodispersed carbon-coated cubic NiP 2 nanoparticles anchored on carbon nanotubes (NiP 2 @C-CNTs) as a proof-of-concept were designed and synthesized. Excellent cyclability (more than 1000 cycles) and capacity retention (high capacities of 816 mAh g -1 after 1200 cycles at 1300 mA g -1 and 654.5 mAh g -1 after 1500 cycles at 5000 mA g -1 ) are characterized, which is among the best performance of the NiP 2 anodes and even most of the phosphide-based anodes reported so far. The impressive performance is attributed to the superior structure stability and the enhanced reaction kinetics incurred by our design. Furthermore, a full cell consisting of a NiP 2 @C-CNTs anode and a LiFePO 4 cathode is investigated. It delivers an average discharge capacity of 827 mAh g -1 based on the mass of the NiP 2 anode and exhibits a capacity retention of 80.7% over 200 cycles, with an average output of ∼2.32 V. As a proof-of-concept, these results demonstrate the effectiveness of our strategy on improving the electrode performance. We believe that this strategy for construction of high-performance anodes can be extended to other phase-transformation-type materials, which suffer a large volume change upon lithium insertion/extraction.

Development of a YAG laser system for the edge Thomson scattering system in ITER.

PubMed

Hatae, T; Yatsuka, E; Hayashi, T; Yoshida, H; Ono, T; Kusama, Y

2012-10-01

A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).

Rare Earth Element Concentrations from Wells at the Don A. Campbell Geothermal Plant, Nevada

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

Fowler, Andrew; Zierenberg, Robert

* Requires permission of originators for use. Rare earth element concentrations in thermal springs from the wells at the Don A. Campbell geothermal plant, Nevada. Samples taken from geothermal wells 85-11, 65-11, 54-11, and 64-11. Includes pH and concentrations for Cerium, Dysprosium, Erbium, Europium, Gadolinium, Holmium, Lanthanum, Lutetium, Neodymium, Praseodymium, Samarium, Terbium, Thulium, Yttrium, and Ytterbium. Samples from Don A. Campbell, Nevada collected on October 14, 2016.

Ultrasound-assisted synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydropyrimidin-(1H)-(thio)ones catalyzed by Sm(ClO(4))(3).

PubMed

Liu, Chen-Jiang; Wang, Ji-De

2010-03-24

An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydro-pyrimidin-2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4-carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter reaction times and higher yields.

XPOSE: the Exxon Nuclear revised LEOPARD

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

Skogen, F.B.

1975-04-01

Main differences between XPOSE and LEOPARD codes used to generate fast and thermal neutron spectra and cross sections are presented. Models used for fast and thermal spectrum calculations as well as the depletion calculations considering U-238 chain, U-235 chain, xenon and samarium, fission products and boron-10 are described. A detailed description of the input required to run XPOSE and a description of the output are included. (FS)

Synergistic Effects of Sm and C Co-Doped Mixed Phase Crystalline TiO2 for Visible Light Photocatalytic Activity

PubMed Central

Peng, Fuchang; Gao, Honglin; Zhang, Genlin; Zhu, Zhongqi; Zhang, Jin; Liu, Qingju

2017-01-01

Mixed phase TiO2 nanoparticles with element doping by Sm and C were prepared via a facile sol-gel procedure. The UV-Vis light-diffuse reflectance spectroscopy analysis showed that the absorption region of co-doped TiO2 was shifted to the visible-light region, which was attributed to incorporation of samarium and carbon into the TiO2 lattice during high-temperature reaction. Samarium effectively decreased the anatase-rutile phase transformation. The grain size can be controlled by Sm doping to achieve a large specific surface area useful for the enhancement of photocatalytic activity. The photocatalytic activities under visible light irradiation were evaluated by photocatalytic degradation of methylene blue (MB). The degradation rate of MB over the Sm-C co-doped TiO2 sample was the best. Additionally, first-order apparent rate constants increased by about 4.3 times compared to that of commercial Degusssa P25 under the same experimental conditions. Using different types of scavengers, the results indicated that the electrons, holes, and •OH radicals are the main active species for the MB degradation. The high visible-light photocatalytic activity was attributed to low recombination of the photo-generated electrons and holes which originated from the synergistic effect of the co-doped ions and the heterostructure. PMID:28772569

Screening-Engineered Field-Effect Solar Cells

DTIC Science & Technology

2012-01-01

virtually any semiconductor, including the promising but hard-to- dope metal oxides, sulfides, and phosphides.3 Prototype SFPV devices have been...MIS interface. Unfortu- nately, MIS cells, though sporting impressive efficiencies,4−6 typically have short operating lifetimes due to surface state...instability at the MIS interface.7 Methods aimed at direct field- effect “ doping ” of semiconductors, in which the voltage is externally applied to a gate

Crystal growth of device quality GaAs in space

NASA Technical Reports Server (NTRS)

Gatos, H. C.; Lagowski, J.

1980-01-01

The apparatus and techniques used in effort to determine the relationships between crystal growth and electronic properties are described with emphasis on electroepitaxy and melt-grown gallium aresenide crystal. Applications of deep level transient spectroscopy, derivative photocapitance spectroscopy, and SEM-cathodoluminescene in characterizing wide bandgap semiconductors; determining photoionization in MOS, Schottky barriers, and p-n junctions; and for identifying inhomogeneities are examined, as well as the compensation of indium phosphide.

Bibliography of Soviet Laser Developments. Number 71, May - June 1984.

DTIC Science & Technology

1985-08-01

d * Coumarin *o..*....... .. o... -- e. Phthalimide ...... o..... o. .. ... --- f . Cyanine .. ... .o o . .. .. .. see. --- go Xanthene...Barinova, E.Yu. (MGU). Determining the concentration of nitrogen in gallium phosphide from its photoluminescence spectrum. VMUFA, no. 3, 1984, 59-62. 23...characteristics for lasing in solutions of rhodamine 6G in a small-base resonator. OPSPA, v.56, no.5, 1984, 884-888. 5 a’ F, c. Polymethine d. Coumarin e

Synthesis of actinide nitrides, phosphides, sulfides and oxides

DOEpatents

Van Der Sluys, William G.; Burns, Carol J.; Smith, David C.

1992-01-01

A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g., uranium mononitride, by subliming an actinide organometallic precursor, e.g., a uranium amide precursor, in the presence of an effectgive amount of a protic Lewis base, e.g., ammonia, within a reactor at temperatures and for time sufficient to form a thin film of the actinide compound, are disclosed.

Broadband arrayed waveguide grating multiplexers on indium phosphide

NASA Astrophysics Data System (ADS)

Rausch, Kameron

2005-11-01

Coarse Wavelength Division Multiplexing (CWDM) is becoming a popular way to increase the optical throughput of fibers for short to medium haul networks at a reduced cost. The International Telecommunications Union (ITU) has defined the CWDM network to consist of eighteen channels with channel spacings of 20 nm starting at 1270 nm and ending at 1610 nm. Four and eight channel AWGs suitable for CWDM were fabricated using a versatile S-shape design novel to InP. The standard horseshoe layout will not work on semiconductor for AWGs with a free spectral range (FSR) larger than 30 nm. The AWG design provides operation insensitive to thermal and polarization fluctuations; which is key for low cost operation and packaging. It will be shown that, refractive index changes over the large operating wavelength band produced negligible effects in the transmission spectrum. Standard AWG design assumes refractive index is a constant over the operating wavelength band. As a result, the output waveguide separations are held constant on the second star coupler. As the channel number increases, secondary focal dispersion caused from a changing refractive index can have detrimental effects on performance. A new design method will be introduced which includes refractive index dispersion by allowing the output waveguide separations to vary. The new design is consistent with standard design but is applicable in materials with a linear index dispersion over an arbitrarily large wavelength band. Lastly, a method for increasing the transmission using multimode waveguides is discussed. Traditionally, single mode waveguides are required in order to prevent higher order waveguide modes creating ghost images in the output spectrum. Using bend loss and waveguide junction offsets, higher order modes can be filtered from the output, thereby eliminating ghost images and at the same time, increase transmission.

Radiation-acoustic treatment of gallium phosphide light diodes

NASA Astrophysics Data System (ADS)

Tartachnik, Volodimir P.; Gontaruk, Olexsandr M.; Vernydub, Roman M.; Kryvutenko, Anatoly M.; Olikh, Yaroslav M.; Opilat, Vitalij Y.; Petrenko, Igor V.; Pinkovska, Myroslava B.

1999-11-01

The ultrasound influence on the defects of technological and radiation origin of GaP light diodes has been investigated. GaP light diodes were treated by ultrasound wave in different operating modes. Electroluminescence spectra were measured at room and low temperatures, integrated luminosity of devices was checked by solar cell. In order to find out the radiation field influence on non-equilibrium defects of acoustic origin samples were irradiated at room temperature by gamma rays of Co60. It has been discovered that in GaP light diodes treated by ultrasound unstable at room temperature dislocation networks occur at the volume of crystal. Ultrasound dose increase causes the creation of complex defects with high relaxation time and appearing of a part of more mobile defect,s which relax quicker. The nature of effects discovered has been discussed. The method of the emissive capacity restoring of samples degraded after irradiation have been proposed.

CSMP (Continuous System Modeling Program) Modeling of Brushless DC Motors.

DTIC Science & Technology

1984-09-01

Characteristics of Fifteen HP Samarium Cobalt and Ferrite Based brushless DC Ictcrs j. Operated by the Same Power Conditioner ," IEEE Transactions on Pcwer stenM...paratus and Systeis, v. P -Ii-- -ry Demerdash, N.A. and Nehl.T.W., Dynamic Modeling cf Brushless DC Motor-Power Conditioner U if-- fo -- Iec tro me...III _J- _ o 0 NAVAL POSTGRADUATE SCHOOL Monterey, California •S THETIS CSMP MODEL{ING OF BRUSHLESS DC MOTORS by DTIC

Thermophysical Properties of Matter - The TPRC Data Series. Volume 4. Specific Heat - Metallic Elements and Alloys

DTIC Science & Technology

1971-01-01

alloys— sodium — sodium alloya— solder—carbon ateels—chromium steels—silicon steels—tantalum—tantalum alloys—terbium—thallium—thallium alloys—thorium...Praseodymium 45 Rhenium 46 Rhodium 47 Rubidium 48 Ruthenium 4» Samarium 50 Scandium 51 Selenium 52 Silicon 5:i Silver 54 Sodium 55 Strontium 56...Potassium ♦ Sodium 111 Sodium * Potassium 112 Tantalum ♦ Tungsten 113 Thallium + Lead, PbTl| 114 Tin ♦ Bismuth 115 Tin ♦ Indium 116 Tin+ Lead 117

Two-Piece Extraoral Prosthetic Rehabilitation to a Perineural Invasion Lip Cancer.

PubMed

Şahan, Makbule Heval; Eskiizmir, Görkem; Ateş, Pınar

2018-03-01

Lip cancers can severely affect a person in terms of function, esthetics, and psychological trauma. After surgical resection, lip defects require special rehabilitation. This clinical report describes a neck prosthesis of a male patient diagnosed with lower lip squamous cell carcinoma with perineural involvement. The neck prosthesis was connected to the mandibular complete denture with cobalt samarium magnets. Both prostheses improved the patient's mastication, deglutition, and esthetics. © 2016 by the American College of Prosthodontists.

Reductive Bis-addition of Aromatic Aldehydes to α,β-Unsaturated Esters via the Use of Sm/Cu(I) in Air: A Route to the Construction of Furofuran Lignans.

PubMed

Liu, Yongjun; Tian, Guang; Li, Jingjing; Qi, Yan; Wen, Yonghong; Du, Feng

2017-06-02

The novel bis-addition of benzaldehydes to acrylates or maleates was achieved by the direct use of samarium metal with the assistance of CuI under mild conditions under dry air, and the useful 2-hydroxylalkyl-γ-butyrolactons and lignan derivatives were thus constructed with high efficiency. The key factors that influence the reaction efficiency were investigated. The use of potassium iodide and molecular sieves as additives can improve the reaction efficiency remarkably.

Obsidian sources characterized by neutron-activation analysis.

PubMed

Gordus, A A; Wright, G A; Griffin, J B

1968-07-26

Concentrations of elements such as manganese, scandium, lanthanum, rubidium, samarium, barium, and zirconium in obsidian samples from different flows show ranges of 1000 percent or more, whereas the variation in element content in obsidian samples from a single flow appears to be less than 40 percent. Neutron-activation analysis of these elements, as well as of sodium and iron, provides a means of identifying the geologic source of an archeological artifact of obsidian.

Development of a satellite flywheel family operating on one active axis magnetic bearings

NASA Technical Reports Server (NTRS)

Poubeau, P. C.

1977-01-01

Since the samarium-cobalt magnets were available at industrial level, new possibilities appeared in the area of magnetic bearings with the radial passive centering and axial control of the rotor position. Magnetic bearings of this type on which a wide effort was made towards the optimization for satellite flywheel applications are described. Also, the momentum and reaction wheels were considered. This work was extended to the kinetic storage of energy for satellites.

Implications of convection in the Moon and the terrestrial planets

NASA Technical Reports Server (NTRS)

Turcotte, Donald L.

1987-01-01

The early thermal and chemical evolution of the Moon is discussed. The rubidium-strontium, neodymium-samarium, and uranium-thorium-lead systems were studied. The relation of source region heterogeneity to the mixing associated with mantle convection is considered. Work on the application of fractal concepts to planetary geology and geophysics is also discussed. The fractal concept was applied to fragmentation, including the frequency-size distribution of meteorites, asteroids and particulate matter produced by impacts.

Sm and Y radiolabeled magnetic fluids: magnetic and magneto-optical characterization

NASA Astrophysics Data System (ADS)

Aquino, R.; Gomes, J. A.; Tourinho, F. A.; Dubois, E.; Perzynski, R.; da Silva, G. J.; Depeyrot, J.

2005-03-01

We report on magnetic fluids based on samarium and ytrium-doped nanoparticles. The nanostructures chemical composition is checked and X-ray diffraction provides both their mean size and a structural characterization. Magnetization and magneto-optical birefringence results are presented and well agree with the pure maghemite behavior. Since these particles can become radioactive after neutron activation, they could therefore represent a new perspective for biomedical applications in the radiation therapy of cancer.

Investigation of 2D photonic crystal structure based channel drop filter using quad shaped photonic crystal ring resonator for CWDM system

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

Chhipa, Mayur Kumar, E-mail: mayurchhipa1@gmail.com; Dusad, Lalit Kumar; Rajasthan Technical University, Kota, Rajasthan

In this paper, the design & performance of two dimensional (2-D) photonic crystal structure based channel drop filter is investigated using quad shaped photonic crystal ring resonator. In this paper, Photonic Crystal (PhC) based on square lattice periodic arrays of Gallium Indium Phosphide (GaInP) rods in air structure have been investigated using Finite Difference Time Domain (FDTD) method and photonic band gap is being calculated using Plane Wave Expansion (PWE) method. The PhC designs have been optimized for telecommunication wavelength λ= 1571 nm by varying the rods lattice constant. The number of rods in Z and X directions is 21 andmore » 20, with lattice constant 0.540 nm it illustrates that the arrangement of Gallium Indium Phosphide (GaInP) rods in the structure which gives the overall size of the device around 11.4 µm × 10.8 µm. The designed filter gives good dropping efficiency using 3.298, refractive index. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm{sup 2}.« less

Conceptual design of a lunar base solar power plant lunar base systems study task 3.3

NASA Technical Reports Server (NTRS)

1988-01-01

The best available concepts for a 100 kW Solar Lunar Power Plant based on static and dynamic conversion concepts have been examined. The two concepts which emerged for direct comparison yielded a difference in delivered mass of 35 MT, the mass equivalent of 1.4 lander payloads, in favor of the static concept. The technologies considered for the various elements are either state-of-the-art or near-term. Two photovoltaic cell concepts should receive high priority for development: i.e., amorphous silicon and indium phosphide cells. The amorphous silicon, because it can be made so light weight and rugged; and the indium phosphide, because it shows very high efficiency potential and is reportedly not degraded by radiation. Also the amorphous silicon cells may be mounted on flexible backing that may roll up much like a carpet for compact storage, delivery, and ease of deployment at the base. The fuel cell and electrolysis cell technology is quite well along for lunar base applications, and because both the Shuttle and the forthcoming Space Station incorporate these devices, the status quo will be maintained. Early development of emerging improvements should be implemented so that essential life verification test programs may commence.

Development of advanced thermoelectric materials

NASA Technical Reports Server (NTRS)

1984-01-01

The development of an advanced thermoelectric material for radioisotope thermoelectric generator (RTG) applications is reported. A number of materials were explored. The bulk of the effort, however, was devoted to improving silicon germanium alloys by the addition of gallium phosphide, the synthesis and evaluation of lanthanum chrome sulfide and the formulation of various mixtures of lanthanum sulfide and chrome sulfide. It is found that each of these materials exhibits promise as a thermoelectric material.

Low-Resistivity Zinc Selenide for Heterojunctions

NASA Technical Reports Server (NTRS)

Stirn, R. J.

1986-01-01

Magnetron reactive sputtering enables doping of this semiconductor. Proposed method of reactive sputtering combined with doping shows potential for yielding low-resistivity zinc selenide films. Zinc selenide attractive material for forming heterojunctions with other semiconductor compounds as zinc phosphide, cadmium telluride, and gallium arsenide. Semiconductor junctions promising for future optoelectronic devices, including solar cells and electroluminescent displays. Resistivities of zinc selenide layers deposited by evaporation or chemical vapor deposition too high to form practical heterojunctions.

Microwave Semiconductor Research-Materials, Devices and Circuits.

DTIC Science & Technology

1987-10-01

Quantum Well and Graded Refractive Index Separate Confinement Heterostructure Quantum Well Lasers Grown Via Molecular Beam Epitaxy" JSEP PUBLICATIONS...J.M. Ballantyne and A.J. Sievers, J. Appl. Phys., 58, 3145 (1985). 6. "Epitaxial Growth and Characterization of Indian Phosphide and Gallium Indian...Approach to Dispersion Analysis in Graded Index Optical Fiber", by H.J. Carlin and Henry Zmuda. DEGREES 1. Henry Zmuda, Ph.D., July 1984 "A New Approach

Enantioselective cyclizations and cyclization cascades of samarium ketyl radicals

NASA Astrophysics Data System (ADS)

Kern, Nicolas; Plesniak, Mateusz P.; McDouall, Joseph J. W.; Procter, David J.

2017-12-01

The rapid generation of molecular complexity from simple starting materials is a key challenge in synthesis. Enantioselective radical cyclization cascades have the potential to deliver complex, densely packed, polycyclic architectures, with control of three-dimensional shape, in one step. Unfortunately, carrying out reactions with radicals in an enantiocontrolled fashion remains challenging due to their high reactivity. This is particularly the case for reactions of radicals generated using the classical reagent, SmI2. Here, we demonstrate that enantioselective SmI2-mediated radical cyclizations and cascades that exploit a simple, recyclable chiral ligand can convert symmetrical ketoesters to complex carbocyclic products bearing multiple stereocentres with high enantio- and diastereocontrol. A computational study has been used to probe the origin of the enantioselectivity. Our studies suggest that many processes that rely on SmI2 can be rendered enantioselective by the design of suitable ligands.

Cosmogenic Samarium-150 and Calcium-41 in Norton County

NASA Technical Reports Server (NTRS)

Fink, D.; Klein, J.; Middleton, R.; Albrecht, A.; Ma, P.; Herzog, G. F.; Bogard, D. D.; Nyquist, L. E.; Shih, C.-Y.; Reese, Y.;

Lattice dynamics of the lanthanides: Samarium at high pressure

NASA Astrophysics Data System (ADS)

Olijnyk, H.; Jephcoat, A. P.

2005-02-01

Sm was studied by Raman spectroscopy at pressures up to 20 GPa. The Raman-active phonon modes, both of the Sm-type phase and the dhcp phase, show a frequency decrease as pressure increases. There is evidence that the entire structural sequence hcp → Sm-type → dhcp → fcc under pressure for the individual regular lanthanides is associated with softening of certain acoustic and optical-phonon modes as well as elastic anomalies. Comparison is made to corresponding transitions between close-packed lattices in other metals and possible relations to the lanthanide's electronic structure are addressed.

Samarium Hexaboride: The First True 3D Topological Insulator?

NASA Astrophysics Data System (ADS)

Wolgast, Steven G.

The recent theoretical prediction of a topologically protected surface state in the mixed-valent insulator SmB6 has motivated a series of charge transport studies, which are presented here. It is first studied using a specialized configuration designed to distinguish bulk-dominated conduction from surface-dominated conduction. As the material is cooled below 4 K, it exhibits a crossover from thermally activated bulk transport to metallic surface conduction with a fully insulating bulk. The robustness and magnitude of the surface conductivity, as is manifest in the literature of SmB6, is strong evidence for the topological insulator (TI) metallic surface states predicted for this material. This resolves a decades-old puzzle surrounding the low-temperature behavior of SmB6. Next, the magnetotransport properties of the surface are investigated using a Corbino disk geometry, which can directly measure the conductivity of individual surfaces. Both (011) and (001) crystal surfaces show a strong negative magnetoresistance at all magnetic field angles, due primarily to changes in the carrier density. The low mobility value accounts for the failure so far to observe Shubnikov-de Haas oscillations below 95 T. Small variations in the mobility and temperature dependence suggest a suppression of Kondo scattering from native oxide-layer magnetic moments. At low fields, a dynamical field-sweep-rate-dependent hysteretic behavior is observed. It persists at the slowest sweep rates, and cannot be explained by quantum interference corrections; it is likely due to extrinsic effects such as the magnetocaloric effect or glassy ordering of the native oxide moments. Pulsed magnetic field measurements up to 60 T at temperatures throughout the crossover regime clearly distinguish the surface magnetoresistance from the bulk magnetoresistance. The bulk magnetoresistance is due to a reduction in the bulk gap with increasing magnetic field. Finally, small subsurface cracks formed in SmB6 via systematic scratching or sanding results in a counter-intuitive increase in the electrical conduction due to the unique surface-conducting property of TIs, strengthening the building case for SmB 6's topological nature. This material is attractive as a TI because its bulk is fully insulating at a readily achieved 2 K, but it presents a large number of scientific mysteries and experimental challenges for future research.

150 KVA Samarium Cobalt VSCF Starter Generator Electrical System

DTIC Science & Technology

1978-12-01

also has protective circuits to limit damage to the system in evpnt tif failure. During normal operation , the system either starts up automatically when...determined during operation due to the external til loop . 4.2. 1. 1. 11 Temperature Sensor Four copper constantan thermocouples are located in stator...design and part of the vibration problem being experienced can be attributed to the shaft critical being too close to the top operating ,)eed range

Petrography of the carbonaceous, diamond-bearing stone "Hypatia" from southwest Egypt: A contribution to the debate on its origin

NASA Astrophysics Data System (ADS)

Belyanin, Georgy A.; Kramers, Jan D.; Andreoli, Marco A. G.; Greco, Francesco; Gucsik, Arnold; Makhubela, Tebogo V.; Przybylowicz, Wojciech J.; Wiedenbeck, Michael

2018-02-01

The stone named "Hypatia" found in the Libyan Desert Glass area of southwest Egypt is carbon-dominated and rich in microdiamonds. Previous noble gas and nitrogen isotope studies suggest an extraterrestrial origin. We report on a reconnaissance study of the carbonaceous matrix of this stone and the phases enclosed in it. This focused on areas not affected by numerous transecting fractures mostly filled with secondary minerals. The work employed scanning electron microscopy (SEM) with energy-dispersive (EDS) and wavelength-dispersive (WDS) electron microprobe (EMPA) analysis, Proton Induced X-ray Emission (PIXE) spectrometry and micro-Raman spectroscopy. We found that carbonaceous matrices of two types occur irregularly intermingled on the 50-500 μm scale: Matrix-1, consisting of almost pure carbonaceous matter, and Matrix-2, containing Fe, Ni, P and S at abundances analyzable by microprobe. Matrix-2 contains the following phases as inclusions: (i) (Fe,Ni) sulphide occurring in cloud-like concentrations of sub-μm grains, in domains of the matrix that are enriched in Fe and S. These domains have (Fe + Ni)/S (atomic) = 1.51 ± 0.24 and Ni/Fe = 0.086 ± 0.061 (both 1SD); (ii) grains up to ∼5 μm in size of moissanite (SiC); (iii) Ni-phosphide compound grains up to 60 μm across that appear cryptocrystalline or amorphous and have (Ni + Fe)/P (atomic) = 5.6. ± 1.7 and Ni/Fe = 74 ± 29 (both 1SD), where both these ratios are much higher than any known Ni-phosphide minerals; (iv) rare grains (observed only once) of graphite, metallic Al, Fe and Ag, and a phase consisting of Ag, P and I. In Matrix-2, Raman spectroscopy shows a prominent narrow diamond band at 1340 cm-1. In Matrix-1 the D and G bands of disordered carbon are dominant, but a minor diamond band is ubiquitous, accounting for the uniform hardness of the material. The D and G bands have average full width at half maximum (FWHM) values of 295 ± 19 and 115 ± 19 cm-1, respectively, and the D/G intensity ratio

Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

NASA Astrophysics Data System (ADS)

Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Yeong-Shyung; Cramer, Carolyn N.

Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below ∼800 °C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing ≤2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co) 3O 4 protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr) 3O 4 passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr 2O 3. On SS 441, reaction of phosphorus with (Mn,Cr) 3O 4 led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe 3P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co) 3O 4 spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn 3(PO 4) 2 and Co 2P. A thin Cr 2O 3 passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr 2O 3 was apparent. On alumel, an Al 2O 3 passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al 2O 3 occurred. This work shows that unprotected metallic components of an SOFC stack and system can provide a sink for P, As and Sb impurities that may be present in fuel gases, and thus complicate

Improved transistor-controlled and commutated brushless DC motors for electric vehicle propulsion

NASA Technical Reports Server (NTRS)

Demerdash, N. A.; Miller, R. H.; Nehl, T. W.; Nyamusa, T. A.

1983-01-01

The development, design, construction, and testing processes of two electronically (transistor) controlled and commutated permanent magnet brushless dc machine systems, for propulsion of electric vehicles are detailed. One machine system was designed and constructed using samarium cobalt for permanent magnets, which supply the rotor (field) excitation. Meanwhile, the other machine system was designed and constructed with strontium ferrite permanent magnets as the source of rotor (field) excitation. These machine systems were designed for continuous rated power output of 15 hp (11.2 kw), and a peak one minute rated power output of 35 hp (26.1 kw). Both power ratings are for a rated voltage of 115 volts dc, assuming a voltage drop in the source (battery) of about 5 volts. That is, an internal source voltage of 120 volts dc. Machine-power conditioner system computer-aided simulations were used extensively in the design process. These simulations relied heavily on the magnetic field analysis in these machines using the method of finite elements, as well as methods of modeling of the machine power conditioner system dynamic interaction. These simulation processes are detailed. Testing revealed that typical machine system efficiencies at 15 hp (11.2 kw) were about 88% and 84% for the samarium cobalt and strontium ferrite based machine systems, respectively. Both systems met the peak one minute rating of 35 hp.

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b

DOE PAGES

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A.; ...

2016-05-12

It is well-known that M. trichosporium OB3b has two forms of methane monooxygenase responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase (sMMO) and a membrane-associated (particulate) methane monooxygenase (pMMO) and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-MeDH and Xox-MeDH, and the expression of these two forms is regulated by the availability of the rare earth element, cerium. Here we extend these studies and show that lanthanum, praseodymium, neodymium andmore » samarium also regulate expression of alternative forms of MeDH. The effect of these rare earth elements on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b where the Mxa-MeDH was knocked out was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. In conclusion, collectively these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b but that copper overrides the effect of other metals by an as yet unknown mechanism.« less

Scanning Electron Microscope-Cathodoluminescence Analysis of Rare-Earth Elements in Magnets.

PubMed

Imashuku, Susumu; Wagatsuma, Kazuaki; Kawai, Jun

2016-02-01

Scanning electron microscope-cathodoluminescence (SEM-CL) analysis was performed for neodymium-iron-boron (NdFeB) and samarium-cobalt (Sm-Co) magnets to analyze the rare-earth elements present in the magnets. We examined the advantages of SEM-CL analysis over conventional analytical methods such as SEM-energy-dispersive X-ray (EDX) spectroscopy and SEM-wavelength-dispersive X-ray (WDX) spectroscopy for elemental analysis of rare-earth elements in NdFeB magnets. Luminescence spectra of chloride compounds of elements in the magnets were measured by the SEM-CL method. Chloride compounds were obtained by the dropwise addition of hydrochloric acid on the magnets followed by drying in vacuum. Neodymium, praseodymium, terbium, and dysprosium were separately detected in the NdFeB magnets, and samarium was detected in the Sm-Co magnet by the SEM-CL method. In contrast, it was difficult to distinguish terbium and dysprosium in the NdFeB magnet with a dysprosium concentration of 1.05 wt% by conventional SEM-EDX analysis. Terbium with a concentration of 0.02 wt% in an NdFeB magnet was detected by SEM-CL analysis, but not by conventional SEM-WDX analysis. SEM-CL analysis is advantageous over conventional SEM-EDX and SEM-WDX analyses for detecting trace rare-earth elements in NdFeB magnets, particularly dysprosium and terbium.

Opto-EM and Devices Investigation

DTIC Science & Technology

1989-06-01

value of bandwidth is used the signal to noise ratio of the UAM system becomes ( SNP )u z exp ’cr. 2P,\\ 3 .V N._ W/ 3.3 GAUSSIAN SHAPED MESSAGE SPECTRA...Unclassified N/A 2a. SECURITY CLASSIFICATION AUTHORITY 3 . DISTRIBUTION/AVAILABILITY OF REPORT N/A Approved for public release; 2b. DECLASSIFICATION...Synthesis, Single Crystal Growth, Purification and Characterization of Indium Phosphide 2. Deposition of Select Silicides Under High Vacuum Conditions 3 . Use

Pulsed Plasma Preparation for LWIR Materials

DTIC Science & Technology

1990-06-18

Reported Data: AlP is normally considered chemically unstable with respect to hydrolysis and formation of PH3 as a result of the exceptional stability of...A1203 (and consequently it is often used as a fumigant ). Its stability is thought to increase with purity. The thermal conductivity of crystalline...AlP is high (-1.3 Wcm’Kŕ at room temperature). Experimental Data: Initial films of aluminium phosphide, deposited from trimethylaluminium (TMA) and PH3

Accumulation of rare earth elements by siderophore-forming Arthrobacter luteolus isolated from rare earth environment of Chavara, India.

PubMed

Emmanuel, E S Challaraj; Ananthi, T; Anandkumar, B; Maruthamuthu, S

2012-03-01

In this study, Arthrobacter luteolus, isolated from rare earth environment of Chavara (Quilon district, Kerala, India), were found to produce catechol-type siderophores. The bacterial strain accumulated rare earth elements such as samarium and scandium. The siderophores may play a role in the accumulation of rare earth elements. Catecholate siderophore and low-molecular-weight organic acids were found to be present in experiments with Arthrobacter luteolus. The influence of siderophore on the accumulation of rare earth elements by bacteria has been extensively discussed.

Physical and structural properties of Sm3+ ions doped heavy metal oxide containing lanthanum-boro-telluirte glass

NASA Astrophysics Data System (ADS)

Madhu, A.; Eraiah, B.

2018-05-01

The structural studies of Tellurium oxide substituted by samarium oxide in lathanum-lead-boro-tellurite glass are successfully prepared with physical and optical parameters are determined. Due to the effect of increased number of non-bridging oxygen's in the glass samples few physical parameters are observed to be decreased. For the better structural analysis FTIR was carried out and transformation of BO3 → BO4 is observed. Most effective absorption coefficient OH- group was attained in the present work.

Experimental discovery of a topological Weyl semimetal state in TaP

DOE PAGES

Xu, Su -Yang; Belopolski, Ilya; Sanchez, Daniel S.; ...

2015-11-13

Here, Weyl semimetals are expected to open up new horizons in physics and materials science because they provide the first realization of Weyl fermions and exhibit protected Fermi arc surface states. However, they had been found to be extremely rare in nature. Recently, a family of compounds, consisting of tantalum arsenide, tantalum phosphide (TaP), niobium arsenide, and niobium phosphide, was predicted as a Weyl semimetal candidates. We experimentally realize a Weyl semimetal state in TaP. Using photoemission spectroscopy, we directly observe the Weyl fermion cones and nodes in the bulk, and the Fermi arcs on the surface. Moreover, we findmore » that the surface states show an unexpectedly rich structure, including both topological Fermi arcs and several topologically trivial closed contours in the vicinity of the Weyl points, which provides a promising platform to study the interplay between topological and trivial surface states on a Weyl semimetal’s surface. We directly demonstrate the bulk-boundary correspondence and establish the topologically nontrivial nature of the Weyl semimetal state in TaP, by resolving the net number of chiral edge modes on a closed path that encloses the Weyl node. This also provides, for the first time, an experimentally practical approach to demonstrating a bulk Weyl fermion from a surface state dispersion measured in photoemission.« less

180-GHz I-Q Second Harmonic Resistive Mixer MMIC

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka P.; Lai, Richard; Mei, Xiaobing

2010-01-01

An indium phosphide MMIC (monolithic microwave integrated circuit) mixer was developed, processed, and tested in the NGC 35-nm-gate-length HEMT (high electron mobility transistor) process. This innovation is very compact in size and operates with very low LO power. Because it is a resistive mixer, this innovation does not require DC power. This is an enabling technology for the miniature receiver modules for the GeoSTAR instrument, which is the only viable option for the NRC decadal study mission PATH.

Gas Phase Ion-Molecule Chemistry of Carbon, Nitrogen and Oxygen Compounds.

DTIC Science & Technology

1985-01-29

silyl anions aza allyl anion) phosphide anion sulfides) Reactivity; nitrite estersj electron affinityMechanism’, sulfur dioxidej. (cont’d) M L..J A6*rAcr...use of silane chemistry to attack a problem of fundamental importance to all organic chemistry, the relative acidity of the alkanes.20 While it is well...alkane lost are a measure of the relative acidity of RH. For example, because ethane is lost less easily than methane, we believe that the ethyl anion

Laboratory trials of seven rodenticides for use against the cotton rat (Sigmodon hispidus).

PubMed Central

Gill, J. E.; Redfern, R.

1980-01-01

The efficacy of seven rodenticides for use against Sigmodon hispidus was investigated in the laboratory. The poisons (warfarin, coumatetralyl, difenacoum, brodifacoum, bromadiolone, calciferol and zinc phosphide) were all toxic at the concentrations normally used against Rattus rattus and R. norvegicus and all were palatable. Trials are now needed to confirm the efficacy of these poisons in the field, but it seems likely that, if used in suitable bait formulations, they would all be useful for the practical control of S. hispidus. PMID:7462594

Electrochemical Characterization of InP and GaAs Based Structures for Space Solar Cell Applications.

NASA Technical Reports Server (NTRS)

Faur, Maria; Faur, Mircea; Jenkins, Philip P.; Goradia, Manju; Wilt, David M.

1994-01-01

In this paper the emphasis is on accurate majority carrier concentration EC-V profiling of structures based on Indium Phosphide and Gallium Arsenide, using a newly developed electrolyte based on Hydrogen Flouride, Acetic Acid, Phosphoric Acid, 1-phenyl-2-propanamine and Ammonia Diflouride. Some preliminary data on the use of this electrolyte for determining the energy distribution of surface and deep states of these structures, applicable to fabrication process optimization and radiation induced defects studies of solar cells, are also provided.

40 CFR 180.284 - Zinc phosphide; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... agricultural commodities as follows: Commodity Parts per million Alfalfa, forage 0.2 Alfalfa, hay 0.2 Barley... Expiration/Revocation Date Alfalfa, forage 1.0 12/31/05 Alfalfa, hay 1.0 12/31/05 Clover, forage 0.1 12/31/05...

Technology and Application of Indium Phosphide and Related Semiconductors

DTIC Science & Technology

1989-03-01

Application and Insertion, GED-L 80/84-9, Oct 1984 1.2: M. Y. Yen , B. F. Levine, C. G. Bethea, K. K. Choi, and A. Y. Cho, Appl. Phys. Lett. 50 (1987) 927...Schlachetzki, Solid-State Electron. 28 (1985) 299 40 IV,A,5: F. B. Fank, J. D. Crowley, and J. J. Berenz, Microwave Journal, June 1979, p. 86 IV,A.6...Ser. 79 (1986) 703 IV,CIb.6: N. K. Dutta, S. G. Napholtz, R. Yen , R. L. Brown, T. M. Shen, N. A. Olsson, and D. C. Craft, Appl. Phys. Lett. 46 (1985

Femtosecond Nonlinearities in Indium Gallium Arsenic Phosphide Diode Lasers

NASA Astrophysics Data System (ADS)

Hall, Katherine Lavin

Semiconductor optical amplifiers are receiving increasing attention for possible applications to broadband optical communication and switching systems. In this thesis we report the results of an extensive experimental study of the ultrafast gain and refractive index nonlinearities in 1.5 μm InGaAsP laser diode amplifiers. The temporal resolution afforded by the femtosecond optical pulses used in these experiments allows us to study carrier interactions with other carriers as well as carrier interactions with the lattice. The 100-200 fs optical pulses used in the pump -probe experiments are generated by an Additive Pulse Modelocked color center laser. The measured group velocity dispersion in the diodes ranged from -0.6 to -0.95 mu m^{-1 }. Differences in the group velocity for TE - and TM-polarized pulses suggested that cross-polarized pump-probe pulses walk off from each other in the diode. This walk-off can diminish the time resolution of some experiments. A novel heterodyne pump-probe technique was developed to distinguish collinear, copolarized, pump and probe pulses that were nominally at the same wavelength. Comparing cross-polarized and copolarized pump-probe results yielded new information about the physical mechanisms responsible for nonlinear gain in the diodes. We observed a gain compression across the entire bandwidth of the diode, associated with carrier heating. The hot carrier distribution cooled back to the lattice temperature with a 0.6 to 1.0 ps time constant, depending on the device structure. In addition, we observed a 0.1 to 0.25 ps delay in onset of carrier heating. Large gain compression due to two photon absorption was also observed. A small portion of the nonlinear gain is attributed to spectral hole burning. Pulsewidth-dependent output saturation energies were explained by a rate equation model that included the effect of carrier heating. Measurements of pump-induced probe phase changes revealed index nonlinearities due to delayed carrier heating and an instantaneous electronic, or virtual process. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).

Evidence for extreme mantle fractionation in early Archaean ultramafic rocks from northern Labrador

NASA Technical Reports Server (NTRS)

Collerson, Kenneth D.; Campbell, Lisa M.; Weaver, Barry L.; Palacz, Zenon A.

1991-01-01

Samarium-neodymium isotope data for tectonically interleaved fragments of lithospheric mantle and meta-komatiite from the North Atlantic craton provide the first direct record of mantle differentiation before 3,800 Myr ago. The results confirm the magnitude of light-rare-earth-element depletion in the early mantle, and also its depleted neodymium isotope composition. The mantle fragments were able to retain these ancient geochemical signatures by virtue of having been tectonically incorporated in buoyant felsic crust, thus escaping recycling and homogenization by mantle convection.

Advanced AN/TPQ-37 transmitter tube

NASA Astrophysics Data System (ADS)

Giebeler, R. H.

1980-08-01

The purpose of this program is to improve the performance and reliability of the AN/TPQ-37 transmitter tube. The task is to build and test two high power, PPM focused, grid pulsed Traveling Wave Tubes (TWT) that meet the requirements of Technical Guidelines MW-119B. The TWT will employ a M-type cathode for reduced temperature operation and extended life. Gain variations will be minimized by use of in band loss techniques and weight will be reduced by using samarium cobalt magnets.

Experimental radiation cooled magnetrons for space

NASA Astrophysics Data System (ADS)

Brown, W. C.; Pollock, M.

The heat disposal problem that occurs in the microwave generator of the Solar Power Satellite when it converts dc power from solar photovoltaic arrays into microwave power for transmission to earth is examined. A theoretical study is made of the radiation cooling of a magnetron directional amplifier, and some experimental data obtained from the QKH 2244 magnetron are presented. This instrument is an unpackaged microwave oven magnetron to which an anodized aluminum radiator has been attached and whose magnetic field is supplied by special samarium cobalt magnets.

MM&T for Linear Resonant Cooler. Volume 1

DTIC Science & Technology

1988-02-16

Tesla *Magnet Material Samarium Cobalt Radially Magnetized Inner Diameter = 1.25" Length = 0.79" Coil Assembly Number of Turns/Section = 90 Outside...Diameter = 1.22" Inside Diameter = 0.86" Inner Iron Material 2 V Permendur Inside Diameter = 0.38" Length 1.84" Design Max. Flux Density = 2.4 Tesla 0 3-12...suspended with rubber bands 60 inches above the floor of the semi -anechoic room. A six foot square piece of 2 inch thick foam was centered on the floor

Effect of silver nanoparticles on the fluorescence of Pb2+ and compositional dependence of Sm3+ fluorescence in borate glasses

NASA Astrophysics Data System (ADS)

Olumoroti, Akinloluwa T.

Borate glasses have been widely studied due to their good optical and mechanical properties. Lead and bismuth (PbO/Bi2O 3:B2O3) borate glasses belong to a family of heavy metal oxide (HMO) glasses which are well known to be chemically durable, stable against atmospheric moisture, have low melting temperatures and good corrosion resistance. The first part of this work deals with lead borate glasses with silver nanoparticles (NPs) introduced into the glass matrix. Transmission electron microscopy characterization is done to verify the nucleation of NPs. Fluorescence and optical absorption experiments are then carried out after different heat treatment duration to investigate the influence of silver NPs on the optical properties of lead (Pb2+) by comparing with a glass sample without silver NPs. Optical absorption experiments show that a well-defined surface plasmon resonance (SPR) peak due to Ag NPs can be observed only for samples that were annealed for 36 hrs. Pb2+ fluorescence spectra reveal that the presence of silver NPs creates new emission centers for Pb2+ ions by altering their chemical environment. The second part of the work involves the use of samarium (a rare earth ion) as a dopant in lead and bismuth borate glasses. The concentration of samarium (Sm3+) is fixed and the base glass composition is varied. The goal is to investigate the compositional dependence of optical properties of samarium in the base glass (PbO/Bi2O3:B 2O3). Optical absorption spectra have been collected and the oscillator strength of each transition - including the hypersensitive - is obtained. The Optical absorption edge is found to shift toward lower energies with increasing PbO/Bi2O3 concentration. Both the oscillator strength and the peak position of the hypersensitive transition show significant variation with glass composition. Strong interaction between Sm3+ ions and Pb2+/Bi3+ ions can also be seen from the variations in the fluorescence emission properties of Sm3+ as a

Effect of polyoxyethylene n-alkyl ethers on carrier-mediated transport of lanthanide ions through cellulose triacetate membranes

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

Sugiura, Masaaki

1992-02-01

Fluxes of 14 kinds of lanthanides across cellulose triacetate membranes were determined by using mixtures of o-nitrophenyl n-octyl ether and a series of polyoxythylene n-alkyl ethers (POE ethers) as plasticizers, and hinokitiol as carrier. Effects of alkyl and polyoxyethylene (POE) chains of POE ether on the flux were demonstrated. The transport of the lanthanides was coupled to a flow of hydrogen ions. The POE ethers used (C{sub n}H{sub 2n+1}(OCH{sub 2}CH{sub 2}){sub x}OH, referred to as C{sub n}E{sub x}) were C{sub 10}E{sub 3}, C{sub 12}E{sub 3}, C{sub 14}E{sub 3}, C{sub 16}E{sub 3}, C{sub 12}E{sub 2}, C{sub 12}E{sub 4}, C{sub 12}E{sub 6}more » and C{sub 12}E{sub 8}, In all cases, high fluxes were observed for the lanthanides from samarium to lutetium. On the contrary, the fluxes for lanthanum to neodymium were extremely low. In experiments testing the effect of the alkyl chain, the order of the POE ethers in the lanthanide flux for samarium to lutetium was C{sub 12}E{sub 3} > C{sub 10}E{sub 3} > C{sub 14}E{sub 3} >C{sub 16}E{sub 3}. In experiments testing the effect of the POE chain, the flux decreased with an increase in the chain length.« less

HF Propagation Effects Caused by an Artificial Plasma Cloud in the Ionosphere

NASA Astrophysics Data System (ADS)

Joshi, D. R.; Groves, K. M.; McNeil, W. J.; Caton, R. G.; Parris, R. T.; Pedersen, T. R.; Cannon, P. S.; Angling, M. J.; Jackson-Booth, N. K.

2014-12-01

In a campaign carried out by the NASA sounding rocket team, the Air Force Research Laboratory (AFRL) launched two sounding rockets in the Kwajalein Atoll, Marshall Islands, in May 2013 known as the Metal Oxide Space Cloud (MOSC) experiment to study the interactions of artificial ionization and the background plasma and measure the effects on high frequency (HF) radio wave propagation. The rockets released samarium metal vapor in the lower F-region of the ionosphere that ionized forming a plasma cloud that persisted for tens of minutes to hours in the post-sunset period. Data from the experiments has been analyzed to understand the impacts of the artificial ionization on HF radio wave propagation. Swept frequency HF links transiting the artificial ionization region were employed to produce oblique ionograms that clearly showed the effects of the samarium cloud. Ray tracing has been used to successfully model the effects of the ionized cloud. Comparisons between observations and modeled results will be presented, including model output using the International Reference Ionosphere (IRI), the Parameterized Ionospheric Model (PIM) and PIM constrained by electron density profiles measured with the ALTAIR radar at Kwajalein. Observations and modeling confirm that the cloud acted as a divergent lens refracting energy away from direct propagation paths and scattering energy at large angles relative to the initial propagation direction. The results confirm that even small amounts of ionized material injected in the upper atmosphere can result in significant changes to the natural propagation environment.

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b.

PubMed

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A; Semrau, Jeremy D

2016-07-01

It is well known that Methylosinus trichosporium OB3b has two forms of methane monooxygenase (MMO) responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase and a membrane-associated (particulate) methane monooxygenase, and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-type MeDH (Mxa-MeDH) and Xox-type MeDH (Xox-MeDH), and the expression of these two forms is regulated by the availability of the rare earth element (REE), cerium. Here, we extend these studies and show that lanthanum, praseodymium, neodymium and samarium also regulate expression of alternative forms of MeDH. The effect of these REEs on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b, where the Mxa-MeDH was knocked out, was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. Collectively, these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b, but that copper overrides the effect of other metals by an as yet unknown mechanism. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Spectroscopy of samarium isotopes in the sdg interacting boson model

NASA Astrophysics Data System (ADS)

Devi, Y. D.; Kota, V. K. B.

1992-05-01

Successful spectroscopic calculations for the 0+1, 2+1, and 4+1 levels in 146-158Sm are carried out in sdg boson space with the restriction that the s-boson number ns>=2 and the g-boson number ng<=2. Observed energies, quadrupole and magnetic moments, E2 and E4 transition strengths, nuclear radii, and two-nucleon transfer intensities are reproduced with a simple two-parameter Hamiltonian. For a good simultaneous description of ground, β, and γ bands, a Hamiltonian interpolating the dynamical symmetries in the sdg model is employed. Using the resulting wave functions, in 152,154Sm, the observed B(E40+1-->4+γ) values are well reproduced and E4 strength distributions are predicted. Moreover, a particular ratio scrR involving two-nucleon transfer strengths showing a peak at neutron number 90 is well described by the calculations.

Isotopic Ratios of Samarium by TIMS for Nuclear Forensic Application

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

Louis Jean, James; Inglis, Jeremy David

The isotopic ratio of Nd, Sm, and Gd can provide important information regarding fissile material (nuclear devices, reactors), neutron environment, and device yield. These studies require precise measurement of Sm isotope ratios, by either TIMS or MC-ICP-MS. There has been an increasing trend to measure smaller and smaller quantities of Sm bearing samples. In nuclear forensics 10-100 ng of Sm are needed for precise measurement. To measure sub-ng Sm samples using TIMS for nuclear forensic analysis.

Strychnine as Target, Samarium Diiodide as Tool: A Personal Story.

PubMed

Beemelmanns, Christine; Reissig, Hans-Ulrich

2015-10-01

Strychnine stands out from the group of classical natural products as one of the first complex compounds to be isolated in pure form and an extreme challenge to be structurally characterized. It has played a central role in natural product total syntheses and the surge in the development of innovative synthetic methods for many decades. Recently, we have accomplished one of the shortest formal total syntheses of strychnine (in ten steps and 14% overall yield or even shorter in eight steps and 10% overall yield). The evolution of a productive synthetic strategy, as well as the synthetic challenges tackled, are described here in detail, including examples of related transformations. The successful synthetic strategy was inspired by the premise that the core structure could be derived from simple aromatic indole precursors by a reductive SmI2 -induced ketyl-aryl coupling. Other key reactions included a diastereoselective reduction and a regioselective elimination protocol. Altogether one of the shortest syntheses of iso-strychnine and hence of strychnine was established. Copyright © 2015 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental control of steady state photorefractive self-focusing in InP:Fe at infrared wavelengths

NASA Astrophysics Data System (ADS)

Dan, C.; Wolfersberger, D.; Fressengeas, N.

2011-09-01

This paper reports an experimental study of the self-focusing process in iron doped indium phosphide at an 1.06 micron wavelength, identifying the influence of temperature, beam intensity and background illumination for two different iron dopings. We point out that the iron ionization ratio is at the origin of different qualitative behavior previously reported and we show that it is possible to reproduce the said behaviors in the same crystal by applying a uniform illumination, allowing their eventual control for dynamic wave-guiding.

Modeling Laser Effects on Multi-Junction Solar Cells Using Silvaco ATLAS Software for Spacecraft Power Beaming Applications

DTIC Science & Technology

2010-06-01

could not. Figure 11 shows the Indium Gallium Phosphide (InGaP)- Gallium Arsenide (GaAs)- Germanium (Ge) solar cell utilization of the solar spectrum...2 opcv nL  (4.4) p = 1, 2, 3, … nr = index of refraction of the cavity co = speed of light in a vacuum (m/s) L = cavity length (meters...illumination – ηsolar  Efficiency under solar illumination – n Number of electrons – nr Index of refraction –  Photon frequency Hz ΔFSR

99 W mid-IR operation of a ZGP OPO at 25% duty cycle.

PubMed

Hemming, Alexander; Richards, Jim; Davidson, Alan; Carmody, Neil; Bennetts, Shayne; Simakov, Nikita; Haub, John

2013-04-22

We have demonstrated the highest reported output power from a mid-IR ZGP OPO. The laser is a cascaded hybrid system consisting of a thulium fibre laser, Ho:YAG solid state laser and a Zinc Germanium Phosphide parametric oscillator. The system produces 27 W of output power in the 3-5 μm wavelength range with an M(2) = 4.0 when operating in a repetitively q-switched mode, and a modulated peak output power of 99 W at a reduced duty cycle of 25%.

Space Photovoltaic Research and Technology, 1989

NASA Technical Reports Server (NTRS)

1991-01-01

Remarkable progress on a wide variety of approaches in space photovoltaics, for both near and far term applications is reported. Papers were presented in a variety of technical areas, including multi-junction cell technology, GaAs and InP cells, system studies, cell and array development, and non-solar direct conversion. Five workshops were held to discuss the following topics: mechanical versus monolithic multi-junction cells; strategy in space flight experiments; non-solar direct conversion; indium phosphide cells; and space cell theory and modeling.

Magnetically suspended miniature fluid pump and method of designing the same

NASA Technical Reports Server (NTRS)

Antaki, James F. (Inventor); Paden, Bradley (Inventor); Burgreen, Gregory (Inventor); Groom, Nelson (Inventor)

2000-01-01

A rotary pump for pumping fluids through a patient having a housing with an internal region, a stator member and an impeller positioned within the housing and having impeller blades, wherein the impeller is magnetically suspended and rotated, and wherein the geometric configuration of the rotary pump is sized and proportioned to minimize stagnant and traumatic fluid flow within the rotary pump. The plurality of magnetic impeller blades are preferably rare earth, high-energy-density magnets selected from the group consisting of samarium cobalt and neodymium-iron-boron alloy.

Origin of the Sudbury Complex by meteoritic impact: Neodymium isotopic evidence

USGS Publications Warehouse

Faggart, B.E.; Basu, A.R.; Tatsumoto, M.

1985-01-01

Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 ?? 21 ?? 106 years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration patterns of Sudbury rocks are also similar to upper crustal averages. These data suggest that the Sudbury Complex formed from melts generated in the upper crust and are consistent with a meteoritic impact.

Dielectric properties of rare earth (Sm and La) substituted lead zirconate titanate (PZT) ceramics

NASA Astrophysics Data System (ADS)

Dipti, Singh, Sangeeta; Juneja, J. K.; Raina, K. K.; Prakash, Chandra

2013-06-01

In the present paper, we are reporting the studies on dielectric properties of Lanthanum (La) and Samarium (Sm) substituted Lead Zirconate Titanate with compositional formula Pb(1.02-x)SmxZr0.55Ti0.45O3 and Pb(1.02-x)LaxZr0.55Ti0.45O3 with x = 0.00, 0.01, 0.02, 0.03. The materials were synthesized by solid state reaction route. XRD analysis shows that all the samples be in single phase with tetragonal structure. Dielectric properties were studied as a function of temperature.

Sm 3+-doped polymer optical waveguide amplifiers

NASA Astrophysics Data System (ADS)

Huang, Lihui; Tsang, Kwokchu; Pun, Edwin Yue-Bun; Xu, Shiqing

2010-04-01

Trivalent samarium ion (Sm 3+) doped SU8 polymer materials were synthesized and characterized. Intense red emission at 645 nm was observed under UV laser light excitation. Spectroscopic investigations show that the doped materials are suitable for realizing planar optical waveguide amplifiers. About 100 μm wide multimode Sm 3+-doped SU8 channel waveguides were fabricated using a simple UV exposure process. At 250 mW, 351 nm UV pump power, a signal enhancement of ˜7.4 dB at 645 nm was obtained for a 15 mm long channel waveguide.

Liver histopathology of fatal phosphine poisoning.

PubMed

Saleki, Sepideh; Ardalan, Farid Azmoudeh; Javidan-Nejad, Abdullah

2007-03-02

Two commonly used pesticides in agriculture are phosphides of aluminium and zinc. Both of these metal phosphides act through elaboration of toxic phosphine gas. The poisoning in Iran is mostly oral and suicidal. Phosphine is rapidly absorbed throughout the gastrointestinal tract after ingestion and it is partly carried to the liver by the portal vein. In this study the liver histopathology of fatal poisoning is scrutinized. A descriptive, retrospective study was performed on 38 fatal phosphine poisonings. The slides of liver specimens of the cases were retrieved and studied separately by two pathologists. The poisoning was suicidal in 33 (86.5%) of cases. Portal inflammation was negligible in 37 cases and only in one of the cases, a moderate degree of chronic inflammation accompanied by granuloma formation was observed. Major histopathologic findings were as follows: mild sinusoidal congestion; 12 cases (31.6%), severe sinusoidal congestion; 25 cases (45.8%), central vein congestion; 23 cases (60.5%), centrilobular necrosis; 3 cases (7.9%), hepatocytes nuclear fragmentation; 6 cases (15.8%), sinusoidal clusters of polymorphonuclear leukocytes; 12 cases (31.6%), and mild macrovesicular steatosis; 5 cases (13.2%). Fine isomorphic cytoplasmic vacuoles were observed in 36 cases (94.7%). These vacuoles were distributed uniformly in all hepatic zones in the majority (75%) of cases. This study reveals that the main histopathologic findings of fatal phosphine poisoning in the liver are fine cytoplasmic vacuolization of hepatocytes and sinusoidal congestion.

Cobalt-Doped Nickel Phosphite for High Performance of Electrochemical Energy Storage.

PubMed

Li, Bing; Shi, Yuxin; Huang, Kesheng; Zhao, Mingming; Qiu, Jiaqing; Xue, Huaiguo; Pang, Huan

2018-03-01

Compared to single metallic Ni or Co phosphides, bimetallic Ni-Co phosphides own ameliorative properties, such as high electrical conductivity, remarkable rate capability, upper specific capacity, and excellent cycle performance. Here, a simple one-step solvothermal process is proposed for the synthesis of bouquet-like cobalt-doped nickel phosphite (Ni 11 (HPO 3 ) 8 (OH) 6 ), and the effect of the structure on the pseudocapacitive performance is investigated via a series of electrochemical measurements. It is found that when the cobalt content is low, the glycol/deionized water ratio is 1, and the reaction is under 200 °C for 20 h, the morphology of the sample is uniform and has the highest specific surface area. The cobalt-doped Ni 11 (HPO 3 ) 8 (OH) 6 electrode presents a maximum specific capacitance of 714.8 F g -1 . More significantly, aqueous and solid-state flexible electrochemical energy storage devices are successfully assembled. The aqueous device shows a high energy density of 15.48 mWh cm -2 at the power density of 0.6 KW cm -2 . The solid-state device shows a high energy density of 14.72 mWh cm -2 at the power density of 0.6 KW cm -2 . These excellent performances confirm that the cobalt-doped Ni 11 (HPO 3 ) 8 (OH) 6 are promising materials for applications in electrochemical energy storage devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Porous Structured Ni–Fe–P Nanocubes Derived from a Prussian Blue Analogue as an Electrocatalyst for Efficient Overall Water Splitting

DOE PAGES

Xuan, Cuijuan; Wang, Jie; Xia, Weiwei; ...

2017-07-18

Exploring nonprecious metal electrocatalysts to replace the noble metal-based catalysts for full water electrocatalysis is still an ongoing challenge. In this work, porous structured ternary nickel–iron–phosphide (Ni–Fe–P) nanocubes were synthesized through one-step phosphidation of a Ni–Fe-based Prussian blue analogue. The Ni–Fe–P nanocubes exhibit a rough and loose porous structure on their surface under suitable phosphating temperature, which is favorable for the mass transfer and oxygen diffusion during the electrocatalysis process. As a result, Ni–Fe–P obtained at 350 °C with poorer crystallinity offers more unsaturated atoms as active sites to expedite the absorption of reactants. Additionally, the introduction of nickel improvedmore » the electronic structure and then reduced the charge-transfer resistance, which would result in a faster electron transport and an enhancement of the intrinsic electrocatalytic activities. Benefiting from the unique porous nanocubes and the chemical composition, the Ni–Fe–P nanocubes exhibit excellent hydrogen evolution reaction and oxygen evolution reaction activities in alkaline medium, with low overpotentials of 182 and 271 mV for delivering a current density of 10 mA cm–2, respectively. Moreover, the Ni–Fe–P nanocubes show outstanding stability for sustained water splitting in the two-electrode alkaline electrolyzer. Furthermore, this work not only provides a facile approach for designing bifunctional electrocatalysts but also further extends the application of metal–organic frameworks in overall water splitting.« less

Porous Structured Ni–Fe–P Nanocubes Derived from a Prussian Blue Analogue as an Electrocatalyst for Efficient Overall Water Splitting

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

Xuan, Cuijuan; Wang, Jie; Xia, Weiwei

Exploring nonprecious metal electrocatalysts to replace the noble metal-based catalysts for full water electrocatalysis is still an ongoing challenge. In this work, porous structured ternary nickel–iron–phosphide (Ni–Fe–P) nanocubes were synthesized through one-step phosphidation of a Ni–Fe-based Prussian blue analogue. The Ni–Fe–P nanocubes exhibit a rough and loose porous structure on their surface under suitable phosphating temperature, which is favorable for the mass transfer and oxygen diffusion during the electrocatalysis process. As a result, Ni–Fe–P obtained at 350 °C with poorer crystallinity offers more unsaturated atoms as active sites to expedite the absorption of reactants. Additionally, the introduction of nickel improvedmore » the electronic structure and then reduced the charge-transfer resistance, which would result in a faster electron transport and an enhancement of the intrinsic electrocatalytic activities. Benefiting from the unique porous nanocubes and the chemical composition, the Ni–Fe–P nanocubes exhibit excellent hydrogen evolution reaction and oxygen evolution reaction activities in alkaline medium, with low overpotentials of 182 and 271 mV for delivering a current density of 10 mA cm–2, respectively. Moreover, the Ni–Fe–P nanocubes show outstanding stability for sustained water splitting in the two-electrode alkaline electrolyzer. Furthermore, this work not only provides a facile approach for designing bifunctional electrocatalysts but also further extends the application of metal–organic frameworks in overall water splitting.« less

High-Efficiency Thin-Film Silicon-on-GaP Solar Cell for Improved Radiation Resistance.

DTIC Science & Technology

1987-09-01

UNCLASSIFIED MyUM 21 LIX E / 82H M D 132 11111_Lt5l1. t FILE UPI" AD-A190 268 AFWAL-TR-87-2070 HIGH-EFFICIENCY THIN- FILM SILICON-ON-GaP SOLAR CELL...EFFICIENCY THIN- FILM SILICON-ON-GaP SOLAR CELL FOR IMPROVED RADIATION RESISTANCE 12. PERSONAL AUTHOR(S) JEROME S. CULIK 13a. TYPE OF REPORT 13b. TIME...C tinue on reverse if necessary and identify by block number) 10 01 SILICONs THIN* FILM , . HETEROEPITAXIAL, RADIATION, 10 01 i GALLIUM PHOSPHIDE 19

Label swapper device for spectral amplitude coded optical packet networks monolithically integrated on InP.

PubMed

Muñoz, P; García-Olcina, R; Habib, C; Chen, L R; Leijtens, X J M; de Vries, T; Robbins, D; Capmany, J

2011-07-04

In this paper the design, fabrication and experimental characterization of an spectral amplitude coded (SAC) optical label swapper monolithically integrated on Indium Phosphide (InP) is presented. The device has a footprint of 4.8x1.5 mm2 and is able to perform label swapping operations required in SAC at a speed of 155 Mbps. The device was manufactured in InP using a multiple purpose generic integration scheme. Compared to previous SAC label swapper demonstrations, using discrete component assembly, this label swapper chip operates two order of magnitudes faster.

The Kaidun Meteorite: Where Did It Come From?

NASA Technical Reports Server (NTRS)

Ivanov, Andrei; Zolensky, Michael

2003-01-01

The Kaidun meteorite, which fell on 3.12.1980 at lat. 15 deg N, long. 48.3 deg E, holds a special place in the world meteorite collection. Kaidun is characterized by an unprecedentedly wide variety of meteorite material in its makeup. The high degree of variability in this meteorite s material is evidenced by the richness of its mineral composition - nearly 60 minerals and mineral phases have been identified in Kaidun, including several never before found in nature, such as florenskiite FeTiP, the first known phosphide of a lithophilic element.

Diffusion length variation and proton damage coefficients for InP/In(x)Ga(1-x)As/GaAs solar cells

NASA Technical Reports Server (NTRS)

Jain, R. K.; Weinberg, I.; Flood, D. J.

1993-01-01

Indium phosphide solar cells are more radiation resistant than gallium arsenide and silicon solar cells, and their growth by heteroepitaxy offers additional advantages leading to the development of lighter, mechanically strong and cost-effective cells. Changes in heteroepitaxial InP cell efficiency under 0.5 and 3 MeV proton irradiations are explained by the variation in the minority-carrier diffusion length. The base diffusion length versus proton fluence is calculated by simulating the cell performance. The diffusion length damage coefficient K(L) is plotted as a function of proton fluence.

Influence of Natural Convection and Thermal Radiation Multi-Component Transport in MOCVD Reactors

NASA Technical Reports Server (NTRS)

Lowry, S.; Krishnan, A.; Clark, I.

1999-01-01

The influence of Grashof and Reynolds number in Metal Organic Chemical Vapor (MOCVD) reactors is being investigated under a combined empirical/numerical study. As part of that research, the deposition of Indium Phosphide in an MOCVD reactor is modeled using the computational code CFD-ACE. The model includes the effects of convection, conduction, and radiation as well as multi-component diffusion and multi-step surface/gas phase chemistry. The results of the prediction are compared with experimental data for a commercial reactor and analyzed with respect to the model accuracy.

Method for the preparation of inorganic single crystal and polycrystalline electronic materials

NASA Technical Reports Server (NTRS)

Groves, W. O. (Inventor)

1969-01-01

Large area, semiconductor crystals selected from group 3-5 compounds and alloys are provided for semiconductor device fabrication by the use of a selective etching operation which completely removes the substrate on which the desired crystal was deposited. The substrate, selected from the same group as the single crystal, has a higher solution rate than the epitaxial single crystal which is essentially unaffected by the etching solution. The preparation of gallium phosphide single crystals using a gallium arsenide substrate and a concentrated nitric acid etching solution is described.

Photovoltaic options for solar electric propulsion

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Flood, Dennis J.

1990-01-01

This paper discusses both state-of-the-art and advanced development cell and array technology. Present technology includes rigid, roll-out, and foldout flexible substrate designs, with silicon and GaAs solar cells. The use of concentrator array systems is discussed based on both DOD efforts and NASA work. The benefits of advanced lightweight array technology, for both near term and far term utilization, and of advanced high efficiency thin radiation resistant cells is examined. This includes gallium arsenide/germanium, indium phosphide, and thin film devices such as copper indium disclenide.

Probing near-normally propagating bulk acoustic waves using pseudo-reflection geometry Brillouin spectroscopy

NASA Astrophysics Data System (ADS)

Parsons, L. C.; Andrews, G. T.

2012-09-01

Pseudo-reflection geometry Brillouin spectroscopy can be used to probe acoustic wave dispersion approximately along the surface normal of a material system while avoiding the difficulties associated with specularly reflected light encountered in an ideal reflection configuration. As an example of its application, we show analytically that it can be used to determine both the refractive index and bulk acoustic mode velocities of optically-isotropic non-metallic materials and confirm the utility of the approach via a series of experiments on fused quartz, gallium phosphide, water, and porous silicon films.

Nanostructured Semiconductor Electrodes for Solar Energy Conversion and Innovations in Undergraduate Chemical Lab Curriculum

NASA Astrophysics Data System (ADS)

Lee, Sudarat

This dissertation presents the methodology and discussion of preparing nanostructured, high aspect ratio p-type phosphide-based binary and ternary semiconductors via "top-down" anodic etching, a process which creates nanostructures from a large parent entity, and "bottom-up" vapor-liquid-solid growth, a mechanism which builds up small clusters of molecules block-by-block. Such architecture is particularly useful for semiconducting materials with incompatible optical absorption depth and charge carrier diffusion length, as it not only relaxes the requirement for high-grade crystalline materials, but also increases the carrier collection efficiencies for photons with energy greater than or equal to the band gap. The main focus of this dissertation is to obtain nanostructured p-type phosphide semiconductors for photoelectrochemical (PEC) cell applications. Chapter II in the thesis describes a methodology for creating high-aspect ratio p-GaP that function as a photocathode under white light illumination. Gallium phosphide (GaP, band gap: 2.26 eV) is a suitable candidate for solar conversion and energy storage due to its ability to generate large photocurrent and photovoltage to drive fuel-forming reactions. Furthermore, the band edge positions of GaP can provide sufficient kinetics for the reduction of protons and carbon dioxide. The structure is prepared by anodic etching, and the resulting macroporous structures are subsequently doped with Zn by thermally driving in Zn from conformal ZnO films prepared by atomic layer deposition (ALD). The key finding of this work is a viable doping strategy involving ALD ZnO films for making functioning p-type GaP nanostructures. Chapter III compares the GaP nanowires grown from gold (Au) and tin (Sn) VLS catalysts in a benign solid sublimation growth scheme in terms of crystal structure and photoactivity. Sn is less noble than Au, allowing complete removal of Sn metal catalysts from the nanowires through wet chemical etching which

Humidity-induced room-temperature decomposition of Au contacted indium phosphide

NASA Technical Reports Server (NTRS)

Fatemi, Navid S.; Weizer, Victor G.

1990-01-01

It has been found that Au-contacted InP is chemically unstable at room temperature in a humid ambient due to the leaching action of indium nitrate islands that continually remove In from the contact metallization and thus, in effect, from the Inp substrate. While similar appearing islands form on Au-contacted GaAs, that system appears to be stable since leaching of the group III element does not take place.

Junction characteristics of indium tin oxide/indium phosphide solar cells

NASA Astrophysics Data System (ADS)

Sheldon, P.; Ahrenkiel, R. K.; Hayes, R. E.; Russell, P. E.; Nottenburg, R. N.; Kazmerski, L. L.

Efficient indium tin oxide (ITO)/p-InP solar cells have been fabricated. Typical uncorrected efficiencies range from 9-12 percent at AM1 intensities. It is shown that deposition of ITO causes a semi-insulating layer at the InP surface as determined by C-V measurements. The thickness of this layer is approximately 750 A. We believe that this high resistivity region is due to surface accumulation of Fe at the ITO/InP interface.

High-performance indium gallium phosphide/gallium arsenide heterojunction bipolar transistors

NASA Astrophysics Data System (ADS)

Ahmari, David Abbas

Heterojunction bipolar transistors (HBTs) have demonstrated the high-frequency characteristics as well as the high linearity, gain, and power efficiency necessary to make them attractive for a variety of applications. Specific applications for which HBTs are well suited include amplifiers, analog-to-digital converters, current sources, and optoelectronic integrated circuits. Currently, most commercially available HBT-based integrated circuits employ the AlGaAs/GaAs material system in applications such as a 4-GHz gain block used in wireless phones. As modern systems require higher-performance and lower-cost devices, HBTs utilizing the newer, InGaP/GaAs and InP/InGaAs material systems will begin to dominate the HBT market. To enable the widespread use of InGaP/GaAs HBTs, much research on the fabrication, performance, and characterization of these devices is required. This dissertation will discuss the design and implementation of high-performance InGaP/GaAs HBTs as well as study HBT device physics and characterization.

A review of indium phosphide space solar cell fabrication technology

NASA Technical Reports Server (NTRS)

Spitzer, M. B.; Dingle, B.; Dingle, J.; Morrison, R.

1990-01-01

A review of the status of InP cell efficiency and of approaches to the reduction of cell cost is presented. The use of heteroepitaxial techniques such as InP-on-GaAs and InP-on-Si is discussed along with the use of chemical and mechanical techniques for removal and recovery of the substrate. The efficiency ultimately obtainable with designs made possible by such an approach is calculated.

Design and test of a four channel motor for electromechanical flight control actuation

NASA Technical Reports Server (NTRS)

1984-01-01

To provide a suitable electromagnetic torque summing approach to flight control system redundancy, a four channel motor capable of sustaining full performance after any two credible failures was designed, fabricated, and tested. The design consists of a single samarium cobalt permanent magnet rotor with four separate three phase windings arrayed in individual stator quadrants around the periphery. Trade studies established the sensitivities of weight and performance to such parameters as design speed, winding pattern, number of poles, magnet configuration, and strength. The motor electromagnetically sums the torque of the individual channels on a single rotor and eliminate complex mechanical gearing arrangements.

Development of a magnetically suspended momentum wheel

NASA Technical Reports Server (NTRS)

Hamilton, S. B.

1973-01-01

An engineering model of a magnetically suspended momentum wheel was designed, fabricated, and tested under laboratory conditions. The basic unit consisted of two magnet bearings, a sculptured aluminum rotor, brushless dc spin motor, and electronics. The magnet bearings, utilizing rare-earth cobltrat-samarium magnets were active radially and passive axially. The results of the program showed that momentum wheels with magnetic bearings are feasible and operable, and that magnetic bearings of this type are capable of being used for applications where high capacity, high stiffness, and low power consumption are required. The tests performed developed criteria for improved performance for future designs.

Voltage color tunable OLED with (Sm,Eu)-β-diketonate complex blend

NASA Astrophysics Data System (ADS)

Reyes, R.; Cremona, M.; Teotonio, E. E. S.; Brito, H. F.; Malta, O. L.

2004-09-01

Light emission from organic electroluminescent diodes (OLEDs) in which mixed samarium and europium β-diketonate complexes, [Sm 0.7Eu 0.3(TTA) 3(TPPO) 2], was used as the emitting layer is described. The electroluminescence spectra exhibit narrow peaks arising from 4f-intraconfigurational transitions of the Sm 3+ and Eu 3+ ions and a broad emission band attributed to the electrophosphorescence of the TTA ligand. The intensity ratio of the peaks determined by the bias voltage applied to the OLED, together with the ligand electrophosphorescence, allows to obtain a voltage-tunable color light source.

Visible properties of Sm{sup 3+} ions in chloro-fluoro-borate glasses for reddish - orange emission

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

Rao, K. Venkata, E-mail: drvenkataraok@gmail.com; Babu, S.; Ratnakaram, Y. C.

2016-05-23

Optical properties of different concentration (0.2, 0.4, 0.6, 0.8 and 1.0 mol %) of Sm{sup 3+} doped chloro-fluoro-borate glasses have been synthesized and discussed. Structural characterizations have been studied through XRD analysis. Spectroscopic analysis has done from absorption spectra, luminescence spectra and decay lifetime profiles. From the emission spectra, concentration quenching is observed, with increase of samarium concentration and discussed behind the phenomena. The nature of decay curve analysis was performed for the {sup 4}G{sub 5/2} level. These glasses are expected to give interesting application in the field of optics.

Understanding the photoluminescence characteristics of Eu{sup 3+}-doped double-perovskite by electronic structure calculation

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

Ghosh, Binita; Halder, Saswata; Sinha, T. P.

2016-05-23

Europium-doped luminescent barium samarium tantalum oxide Ba{sub 2}SmTaO{sub 6} (BST) has been investigated by first-principles calculation, and the crystal structure, electronic structure, and optical properties of pure BST and Eu-doped BST have been examined and compared. Based on the calculated results, the luminescence properties and mechanism of Eu-doped BST has been discussed. In the case of Eu-doped BST, there is an impurity energy band at the Fermi level, which is formed by seven spin up energy levels of Eu and act as the luminescent centre, which is evident from the band structure calculations.

Synthesis and application of a new fluorous-tagged ammonia equivalent.

PubMed

Nielsen, Simon D; Smith, Garrick; Begtrup, Mikael; Kristensen, Jesper L

2010-04-19

A novel fluorous-tagged ammonia equivalent has been developed. It is based on a nitrogen-oxygen bond, which can be cleaved in a traceless manner by a molybdenum complex or samarium diiodide. The application in the synthesis of ureas, amides, sulfonamides, and carbamates is described. The scope of the fluorous N-O linker is exemplified by the synthesis of itopride, a drug used for the treatment of functional dyspepsia. Itopride was synthesized with the aid of fluorous purification methods and the product was isolated in good overall yield, with high purity. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High efficiency GaP power conversion for Betavoltaic applications

NASA Astrophysics Data System (ADS)

Sims, Paul E.; Dinetta, Louis C.; Barnett, Allen M.

1994-09-01

AstroPower is developing a gallium phosphide (GaP) based energy converter optimized for radio luminescent light-based power supplies. A 'two-step' or 'indirect' process is used where a phosphor is excited by radioactive decay products to produce light that is then converted to electricity by a photovoltaic energy converter. This indirect conversion of beta-radiation to electrical energy can be realized by applying recent developments in tritium based radio luminescent (RL) light sources in combination with the high conversion efficiencies that can be achieved under low illumination with low leakage, gallium phosphide based devices. This tritium to light approach is inherently safer than battery designs that incorporate high activity radionuclides because the beta particles emitted by tritium are of low average energy and are easily stopped by a thin layer of glass. GaP layers were grown by liquid phase epitaxy and p/n junction devices were fabricated and characterized for low light intensity power conversion. AstroPower has demonstrated the feasibility of the GaP based energy converter with the following key results: 23.54 percent conversion efficiency under 968 muW/sq cm 440 nm blue light, 14.59 percent conversion efficiency for 2.85 muW/sq cm 440 nm blue light, and fabrication of working 5 V array. We have also determined that at least 20 muW/sq cm optical power is available for betavoltaic power systems. Successful developments of this device is an enabling technology for low volume, safe, high voltage, milliwatt power supplies with service lifetimes in excess of 12 years.

Acute pesticide poisoning related deaths in Tehran during the period 2003-2004.

PubMed

Soltaninejad, Kambiz; Faryadi, Mansoor; Sardari, Fariba

2007-08-01

Acute pesticide poisoning is an important cause of morbidity and mortality in Iran and worldwide. Determination of inducing factors in pesticide poisoning is very important parameter for planning of preventive and controlling programs. The aim of present study is assessing of effects of epidemiological variables on fatal pesticide poisoning. Data was obtained from autopsies on suspected pesticide poisoning deaths were performed in the Tehran Legal Medicine Center between 2003 and 2004. Among these medicolegal autopsies, fatal poisoning cases were evaluated retrospectively by reports of toxicological analysis. The variables such as age, sex, job, residential location, educational level, type of pesticide and cause of poisoning were reviewed. From total of 3885 autopsies referred to forensic toxicology laboratory for pesticide toxicology analysis, 51 (1.31%) deaths were due to pesticide poisoning. The age of cases was 32+/-17 years old. 63.3% of cases were male and 36.7% of them were female. The majority of cases (31.4%) were housekeeper and 23.5% were student. 66.7% of cases were lived in urban and 33.3% were lived in rural area. The most common type of poisoning was suicide (52.9%). 33.3% of cases had primary education. The common type of pesticide in this study was aluminum phosphide 18 (35.8%) and organophosphates 17 (33.3%). According to fatal aluminum phosphide poisoning, more stringent legislation and enforcement regarding the sale and distribution of this toxic substance is needed. Thus substitution of this pesticide with safer agents is necessary.

Strain-Compensated InGaAsP Superlattices for Defect Reduction of InP Grown on Exact-Oriented (001) Patterned Si Substrates by Metal Organic Chemical Vapor Deposition.

PubMed

Megalini, Ludovico; Šuran Brunelli, Simone Tommaso; Charles, William O; Taylor, Aidan; Isaac, Brandon; Bowers, John E; Klamkin, Jonathan

2018-02-26

We report on the use of InGaAsP strain-compensated superlattices (SC-SLs) as a technique to reduce the defect density of Indium Phosphide (InP) grown on silicon (InP-on-Si) by Metal Organic Chemical Vapor Deposition (MOCVD). Initially, a 2 μm thick gallium arsenide (GaAs) layer was grown with very high uniformity on exact oriented (001) 300 mm Si wafers; which had been patterned in 90 nm V-grooved trenches separated by silicon dioxide (SiO₂) stripes and oriented along the [110] direction. Undercut at the Si/SiO₂ interface was used to reduce the propagation of defects into the III-V layers. Following wafer dicing; 2.6 μm of indium phosphide (InP) was grown on such GaAs-on-Si templates. InGaAsP SC-SLs and thermal annealing were used to achieve a high-quality and smooth InP pseudo-substrate with a reduced defect density. Both the GaAs-on-Si and the subsequently grown InP layers were characterized using a variety of techniques including X-ray diffraction (XRD); atomic force microscopy (AFM); transmission electron microscopy (TEM); and electron channeling contrast imaging (ECCI); which indicate high-quality of the epitaxial films. The threading dislocation density and RMS surface roughness of the final InP layer were 5 × 10⁸/cm² and 1.2 nm; respectively and 7.8 × 10⁷/cm² and 10.8 nm for the GaAs-on-Si layer.

High efficiency GaP power conversion for Betavoltaic applications

NASA Technical Reports Server (NTRS)

Sims, Paul E.; Dinetta, Louis C.; Barnett, Allen M.

1994-01-01

AstroPower is developing a gallium phosphide (GaP) based energy converter optimized for radio luminescent light-based power supplies. A 'two-step' or 'indirect' process is used where a phosphor is excited by radioactive decay products to produce light that is then converted to electricity by a photovoltaic energy converter. This indirect conversion of beta-radiation to electrical energy can be realized by applying recent developments in tritium based radio luminescent (RL) light sources in combination with the high conversion efficiencies that can be achieved under low illumination with low leakage, gallium phosphide based devices. This tritium to light approach is inherently safer than battery designs that incorporate high activity radionuclides because the beta particles emitted by tritium are of low average energy and are easily stopped by a thin layer of glass. GaP layers were grown by liquid phase epitaxy and p/n junction devices were fabricated and characterized for low light intensity power conversion. AstroPower has demonstrated the feasibility of the GaP based energy converter with the following key results: 23.54 percent conversion efficiency under 968 muW/sq cm 440 nm blue light, 14.59 percent conversion efficiency for 2.85 muW/sq cm 440 nm blue light, and fabrication of working 5 V array. We have also determined that at least 20 muW/sq cm optical power is available for betavoltaic power systems. Successful developments of this device is an enabling technology for low volume, safe, high voltage, milliwatt power supplies with service lifetimes in excess of 12 years.

Strain-Compensated InGaAsP Superlattices for Defect Reduction of InP Grown on Exact-Oriented (001) Patterned Si Substrates by Metal Organic Chemical Vapor Deposition

PubMed Central

Megalini, Ludovico; Šuran Brunelli, Simone Tommaso; Charles, William O.; Taylor, Aidan; Isaac, Brandon; Klamkin, Jonathan

2018-01-01

We report on the use of InGaAsP strain-compensated superlattices (SC-SLs) as a technique to reduce the defect density of Indium Phosphide (InP) grown on silicon (InP-on-Si) by Metal Organic Chemical Vapor Deposition (MOCVD). Initially, a 2 μm thick gallium arsenide (GaAs) layer was grown with very high uniformity on exact oriented (001) 300 mm Si wafers; which had been patterned in 90 nm V-grooved trenches separated by silicon dioxide (SiO2) stripes and oriented along the [110] direction. Undercut at the Si/SiO2 interface was used to reduce the propagation of defects into the III–V layers. Following wafer dicing; 2.6 μm of indium phosphide (InP) was grown on such GaAs-on-Si templates. InGaAsP SC-SLs and thermal annealing were used to achieve a high-quality and smooth InP pseudo-substrate with a reduced defect density. Both the GaAs-on-Si and the subsequently grown InP layers were characterized using a variety of techniques including X-ray diffraction (XRD); atomic force microscopy (AFM); transmission electron microscopy (TEM); and electron channeling contrast imaging (ECCI); which indicate high-quality of the epitaxial films. The threading dislocation density and RMS surface roughness of the final InP layer were 5 × 108/cm2 and 1.2 nm; respectively and 7.8 × 107/cm2 and 10.8 nm for the GaAs-on-Si layer. PMID:29495381

Alkaline earth metal and samarium co-doped ceria as efficient electrolytes

NASA Astrophysics Data System (ADS)

Ali, Amjad; Raza, Rizwan; Kaleem Ullah, M.; Rafique, Asia; Wang, Baoyuan; Zhu, Bin

2018-01-01

Co-doped ceramic electrolytes M0.1Sm0.1Ce0.8O2-δ (M = Ba, Ca, Mg, and Sr) were synthesized via co-precipitation. The focus of this study was to highlight the effects of alkaline earth metals in doped ceria on the microstructure, densification, conductivity, and performance. The ionic conductivity comparisons of prepared electrolytes in the air atmosphere were studied. It has been observed that Ca0.1Sm0.1Ce0.8O2-δ shows the highest conductivity of 0.124 Scm-1 at 650 °C and a lower activation energy of 0.48 eV. The cell shows a maximum power density of 630 mW cm-2 at 650 °C using hydrogen fuel. The enhancement in conductivity and performance was due to increasing the oxygen vacancies in the ceria lattice with the increasing dopant concentration. The bandgap was calculated from UV-Vis data, which shows a red shift when compared with pure ceria. The average crystallite size is in the range of 37-49 nm. DFT was used to analyze the co-doping structure, and the calculated lattice parameter was compared with the experimental lattice parameter.

Fundamental properties of a new samarium compound SmPtSi2

NASA Astrophysics Data System (ADS)

Yamaguchi, Shuto; Takahashi, Eisuke; Kase, Naoki; Nakano, Tomohito; Takeda, Naoya; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya

2018-05-01

We have discovered a new orthorhombic ternary compound SmPtSi2. We succeeded in growing a single crystal of SmPtSi2; prepared a polycrystalline sample of this compound, and measured their　susceptibility, specific heat, and resistivity. The temperature dependence of susceptibility of the polycrystalline sample is close to that of Sm3+ at high temperatures, and its specific heat shows anomalies at TH = 8.6 K and TL = 5.6 K. The resistivity of a single crystal of SmPtSi2 shows a hump-type anomaly just below TH and a sudden decrease at TL, indicating that these anomalies are intrinsic and that SmPtSi2 exhibits a two-step transition.

Rhenium-osmium and samarium-neodymium isotopic systematics of the Stillwater complex

NASA Technical Reports Server (NTRS)

Lambert, David D.; Shirey, Steven B.; Carlson, Richard W.; Morgan, John W.; Walker, Richard J.

1989-01-01

The role of magma mixing in the formation of strategic platinum-group element ore deposits is examined using isotopic data from the Stillwater Complex, Montana. Nd and Os isotopic data show that the intrusion formed from at least two distinct magmas: ultramafic (U-type) affinity magmas and anorthositic (A-type) affinity magmas. The U-type magmas formed from a lithospheric mantle source containing recycled crustal materials and the A-type magmas originated either by crustal contamination of basaltic magmas or by partial melting of basalt in the lower crust. The results also suggest that the platinum-group element ore deposits were derived from A-type magmas which were injected into the U-type magma chamber at several stages during the development of the ultramafic series.

Rhenium-osmium and samarium-neodymium isotopic systematics of the stillwater complex

USGS Publications Warehouse

Lambert, D.D.; Morgan, J.W.; Walker, R.J.; Shirey, S.B.; Carlson, R.W.; Zientek, M.L.; Koski, M.S.

1989-01-01

Isotopic data for the Stillwater Complex, Montana , which formed about 2700 Ma (million years ago), were obtained to evaluate the role of magma mixing in the formation of strategic platinum-group element (PGE) ore deposits. Neodymium and osmium isotopic data indicate that the intrusion formed from at least two geochemically distinct magmas. Ultramafic affinity (U-type) magmas had initial ??Nd of -0.8 to -3.2 and a chondritic initial 187Os/186Os ratio of ???0.88, whereas anorthositic affinity (A-type) magmas had ??Nd of -0.7 to +1.7 and an initial 187Os/186Os ratio of ???1.13. These data suggest that U-type magmas were derived from a lithospheric mantle source containing recycled crustal materials whereas A-type magmas originated either by crustal contamination of basaltic magmas or by partial melting of basalt in the lower crust. The Nd and Os isotopic data also suggest that Os, and probably the other PGEs in ore horizons such as the J-M Reef, was derived from A-type magmas. The Nd and Os isotopic heterogeneity observed in rocks below the J-M Reef also suggests that A-type magmas were injected into the Stillwater U-type magma chamber at several stages during the development of the Ultramafic series.

Comparative modeling of InP solar cell structures

NASA Technical Reports Server (NTRS)

Jain, R. K.; Weinberg, I.; Flood, D. J.

1991-01-01

The comparative modeling of p(+)n and n(+)p indium phosphide solar cell structures is studied using a numerical program PC-1D. The optimal design study has predicted that the p(+)n structure offers improved cell efficiencies as compared to n(+)p structure, due to higher open-circuit voltage. The various cell material and process parameters to achieve the maximum cell efficiencies are reported. The effect of some of the cell parameters on InP cell I-V characteristics was studied. The available radiation resistance data on n(+)p and p(+)p InP solar cells are also critically discussed.

Solar cells based on InP/GaP/Si structure

NASA Astrophysics Data System (ADS)

Kvitsiani, O.; Laperashvil, D.; Laperashvili, T.; Mikelashvili, V.

2016-10-01

Solar cells (SCs) based on III-V semiconductors are reviewed. Presented work emphases on the Solar Cells containing Quantum Dots (QDs) for next-generation photovoltaics. In this work the method of fabrication of InP QDs on III-V semiconductors is investigated. The original method of electrochemical deposition of metals: indium (In), gallium (Ga) and of alloys (InGa) on the surface of gallium phosphide (GaP), and mechanism of formation of InP QDs on GaP surface is presented. The possibilities of application of InP/GaP/Si structure as SC are discussed, and the challenges arising is also considered.

Clarifying coverages on the basis of tapes SnO2, SiO2, Si3N4 for photodiodes of ultraviolet and visible range

NASA Astrophysics Data System (ADS)

Dobrovolsciy, Yu. George; Perevertaylo, Vladimir L.; Shabashcevich, Boris G.; Pidkamin, Leonid J.

2009-10-01

It is shown, what coverage of dioxide of tin is instrumental in the rise of sensitiveness of photodiodes sensible in the ultraviolet region of spectrum on the basis of selenid zinc and phosphide of gallium to 0,12 A/W and 0,2 A/W accordingly in the maximum of spectral description of sensitiveness. All so it is shown, that tape of nitrid silicon - dioxide of silicon a bit better clarifies silicon photodiode, especially on a wave-length 700 nm. Gluing composition, in general, worsens admission of tapes, and in a greater degree the admission of tape of nitrid silicon - dioxide of silicon.