An instrument for in situ coherent x-ray studies of metal-organic vapor phase epitaxy of III-nitrides

NASA Astrophysics Data System (ADS)

Ju, Guangxu; Highland, Matthew J.; Yanguas-Gil, Angel; Thompson, Carol; Eastman, Jeffrey A.; Zhou, Hua; Brennan, Sean M.; Stephenson, G. Brian; Fuoss, Paul H.

2017-03-01

We describe an instrument that exploits the ongoing revolution in synchrotron sources, optics, and detectors to enable in situ studies of metal-organic vapor phase epitaxy (MOVPE) growth of III-nitride materials using coherent x-ray methods. The system includes high-resolution positioning of the sample and detector including full rotations, an x-ray transparent chamber wall for incident and diffracted beam access over a wide angular range, and minimal thermal sample motion, giving the sub-micron positional stability and reproducibility needed for coherent x-ray studies. The instrument enables surface x-ray photon correlation spectroscopy, microbeam diffraction, and coherent diffraction imaging of atomic-scale surface and film structure and dynamics during growth, to provide fundamental understanding of MOVPE processes.

Study of thermal stability of spontaneously grown superlattice structures by metalorganic vapor phase epitaxy in AlxGa1-xAs/GaAs heterostructure

NASA Astrophysics Data System (ADS)

Pradhan, A.; Maitra, T.; Mukherjee, S.; Mukherjee, S.; Satpati, B.; Nayak, A.; Bhunia, S.

2018-04-01

Spontaneous superlattice ordering in a length scale larger than an atomic layer has been observed in AlxGa1-xAs layers grown on (100) GaAs substrates by metalorganic vapor phase epitaxy. Transmission electron microscopic image clearly revealed superlattice structures and the selected area electron diffraction showed closely spaced superlattice spots around the main diffraction pattern. High resolution x-ray diffraction showed distinct and sharp superlattice peaks symmetrically positioned around the central (004) Bragg peak and the similar measurement for (002) planes, which is quasi-forbidden for Bragg reflections showed only superlattice peaks. Thermal annealing studies showed the superlattice structure was stable up to 800 °C and disappeared after annealing at 900 °C retaining the crystallinity of the epilayer. Study of inter-diffusivitiesin such superlattice structures has been carried out using high temperaturex-ray diffraction results. Here we present (004) x-ray θ-2θ scans of the AlGaAs/GaAs (100) sample with annealing time for different temperatures. Conclusions regarding interdiffusion in such superlattice structures are drawn from high temperature X-ray measurements.

Using Variable Temperature Powder X-Ray Diffraction to Determine the Thermal Expansion Coefficient of Solid MgO

ERIC Educational Resources Information Center

Corsepius, Nicholas C.; DeVore, Thomas C.; Reisner, Barbara A.; Warnaar, Deborah L.

2007-01-01

A laboratory exercise was developed by using variable temperature powder X-ray diffraction (XRD) to determine [alpha] for MgO (periclase)and was tested in the Applied Physical Chemistry and Materials Characterization Laboratories at James Madison University. The experiment which was originally designed to provide undergraduate students with a…

An instrument for in situ coherent x-ray studies of metal-organic vapor phase epitaxy of III-nitrides

DOE PAGES

Ju, Guangxu; Highland, Matthew J.; Yanguas-Gil, Angel; ...

2017-03-21

Here, we describe an instrument that exploits the ongoing revolution in synchrotron sources, optics, and detectors to enable in situ studies of metal-organic vapor phase epitaxy (MOVPE) growth of III-nitride materials using coherent x-ray methods. The system includes high-resolution positioning of the sample and detector including full rotations, an x-ray transparent chamber wall for incident and diffracted beam access over a wide angular range, and minimal thermal sample motion, giving the sub-micron positional stability and reproducibility needed for coherent x-ray studies. The instrument enables surface x-ray photon correlation spectroscopy, microbeam diffraction, and coherent diffraction imaging of atomic-scale surface and filmmore » structure and dynamics during growth, to provide fundamental understanding of MOVPE processes.« less

Mechanical properties and negative thermal expansion of a dense rare earth formate framework

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

Zhang, Zhanrui; Jiang, Xingxing; Feng, Guoqiang

The fundamental mechanical properties of a dense metal–organic framework material, [NH{sub 2}CHNH{sub 2}][Er(HCOO){sub 4}] (1), have been studied using nanoindentation technique. The results demonstrate that the elastic moduli, hardnesses, and yield stresses on the (021)/(02−1) facets are 29.8/30.2, 1.80/1.83 and 0.93/1.01 GPa, respectively. Moreover, variable-temperature powder and single-crystal X-ray diffraction experiments reveal that framework 1 shows significant negative thermal expansion along its b axis, which can be explained by using a hinge–strut structural motif. - Graphical abstract: The structure of framework, [NH{sub 2}CHNH{sub 2}][Er(HCOO){sub 4}], and its indicatrix of thermal expansion. - Highlights: • The elastic modulus, hardness, and yieldmore » stress properties of a rare earth metal–organic framework material were studied via nanoindentation technique. • Variable-temperature powder X-ray diffraction experiments reveal that this framework shows significant negative thermal expansion along its b axis. • Based on variable-temperature single-crystal X-ray diffraction experiments, the mechanism of negative thermal expansion can be explained by a hinge–strut structural motif.« less

Search for life on Mars: Evaluation of techniques

NASA Technical Reports Server (NTRS)

Schwartz, D. E.; Mancinelli, R. L.; White, M. R.

1995-01-01

An important question for exobiology is, did life evolve on Mars? To answer this question, experiments must be conducted on the martian surface. Given current mission constraints on mass, power, and volume, these experiments can only be performed using proposed analytical techniques such as: electron microscopy, X-ray fluorescence, X-ray diffraction, a-proton backscatter, g-ray spectrometry, differential thermal analysis, differential scanning calorimetry, pyrolysis gas chromatography, mass spectrometry, and specific element detectors. Using prepared test samples consisting of 1% organic matter (bovine serum albumin) in palagonite and a mixture of palagonite, clays, iron oxides, and evaporites, it was determined that a combination of X-ray diffraction and differential thermal analysis coupled with gas chromatography provides the best insight into the chemistry, mineralogy, and geological history of the samples.

Search for life on Mars: evaluation of techniques.

PubMed

Schwartz, D E; Mancinelli, R L; White, M R

1995-03-01

An important question for exobiology is, did life evolve on Mars? To answer this question, experiments must be conducted on the martian surface. Given current mission constraints on mass, power, and volume, these experiments can only be performed using proposed analytical techniques such as: electron microscopy, X-ray fluorescence, X-ray diffraction, alpha-proton backscatter, gamma-ray spectrometry, differential thermal analysis, differential scanning calorimetry, pyrolysis gas chromatography, mass spectrometry, and specific element detectors. Using prepared test samples consisting of 1% organic matter (bovine serum albumin) in palagonite and a mixture of palagonite, clays, iron oxides, and evaporites, it was determined that a combination of X-ray diffraction and differential thermal analysis coupled with gas chromatography provides the best insight into the chemistry, mineralogy, and geological history of the samples.

Synthesis and Characterization of Single-Source Molecular Precursors to Binary Metal Sulphides: Bis(Diethyldithiocarbamato) M(II)Trialkylphosphine (M=Zn and Cd) Adducts

DTIC Science & Technology

1994-05-06

while the heterobimetallic species, 7, thermally decomposed to give00 crystalline ZnO.5S according to X-ray powder diffraction data. A. SUBJECT TERMS 15... heterobimetallic species, 7, thermally decomposed to give crystalline ZnO.5CdO.5S according to X-ray powder diffraction data. LaGOSSIOn "or OTIS RA&I VT-iC TAB EU...on the NMR timescale, and a single heterobimetallic species. Attempts to distinguish these possibilities are described later. The variable temperature

Luminescent properties under X-ray excitation of Ba(1-x)PbxWO4 disordered solid solution

NASA Astrophysics Data System (ADS)

Bakiz, B.; Hallaoui, A.; Taoufyq, A.; Benlhachemi, A.; Guinneton, F.; Villain, S.; Ezahri, M.; Valmalette, J.-C.; Arab, M.; Gavarri, J.-R.

2018-02-01

A series of polycrystalline barium-lead tungstate Ba1-xPbxWO4 with 0 ≤ x ≤ 1 was synthesized using a classical solid-state method with thermal treatment at 1000 °C. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Raman (FT-Raman) spectroscopy. X-ray diffraction profile analyses were performed using Rietveld method. These materials crystallized in the scheelite tetragonal structure and behaved as quasi ideal solid solution. Raman spectroscopy confirmed the formation of the solid solution. Structural distortions were evidenced in X-ray diffraction profiles and in vibration Raman spectra. The scanning electron microscopy experiments showed large and rounded irregular grains. Luminescence experiments were performed under X-ray excitation. The luminescence emission profiles have been interpreted in terms of four Gaussian components, with a major contribution of blue emission. The integrated intensity of luminescence reached a maximum value in the composition range x = 0.3-0.6, in relation with distortions of crystal lattice.

Thermal oxidation and nitridation of Si nanowalls prepared by metal assisted chemical etching

NASA Astrophysics Data System (ADS)

Behera, Anil K.; Viswanath, R. N.; Lakshmanan, C.; Polaki, S. R.; Sarguna, R. M.; Mathews, Tom

2018-04-01

Silicon nanowalls with controlled orientation have been prepared using metal assisted chemical etching process. Thermal oxidation and nitridation processes have been carried out on the prepared silicon nanowalls under a control flow of oxygen/nitrogen gases independently at 1050°C for 900s. The morphology and structural properties of the as-prepared, oxidized and nitridated silicon nanowalls have been studied using the scanning electron microscopy and the Grazing incident X-ray diffraction techniques. The results obtained from the analysis of X-ray diffraction patterns and the microscopy images are discussed.

Growth and characterization of organic NLO material: Clobetasol propionate

NASA Astrophysics Data System (ADS)

Purusothaman, R.; Rajesh, P.; Ramasamy, P.

2015-06-01

Single crystals of clobetasol propionate (CP) have been grown by slow evaporation solution technique using mixed solvent of methanol-acetone. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their lattice parameter and space group. The powder X-ray diffraction pattern of the grown CP has been indexed. Thermal analysis was performed to study the thermal stability of the grown crystals. Photoluminescence spectrum shows broad emission peak observed at 421 nm. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found in the crystal.

Characterization of nanodimensional Ni-Zn ferrite prepared by mechanochemical and thermal methods

NASA Astrophysics Data System (ADS)

Manova, E.; Paneva, D.; Kunev, B.; Rivière, E.; Estournès, C.; Mitov, I.

2010-03-01

Nickel zinc ferrite nanoparticles, Ni1-xZnxFe2O4 (x = 0, 0.2, 0.5, 0.8, 1.0), with dimensions below 10 nm have been prepared by combining chemical precipitation with high-energy ball milling. For comparison, their analogues obtained by thermal synthesis have also been studied. Mössbauer spectroscopy, X-ray diffraction, and magnetic measurements are used for the characterization of the obtained materials. X-ray diffraction shows that after 3h of mechanical treatment ferrites containing zinc are formed, while 6h of treatment is needed to obtain NiFe2O4. The magnetic properties of the samples exhibit a strong dependence on the phase composition, particle size and preparation method.

Investigation of ZrO x /ZrC-ZrN/Zr thin-film structural evolution and their degradation using X-ray diffraction and Raman spectrometry

NASA Astrophysics Data System (ADS)

Usmani, B.; Vijay, V.; Chhibber, R.; Dixit, A.

2016-11-01

The thin-film structures of DC/FR magnetron-sputtered ZrO x /ZrC-ZrN/Zr tandem solar-selective coatings are investigated using X-ray diffraction and room-temperature Raman spectroscopic measurements. These studies suggest that the major contribution is coming from h-ZrN0.28, c-ZrC, h-Zr3C2 crystallographic phases in ZrN-ZrC absorber layer, in conjunction with mixed ZrO x crystallographic phases. The change in structure for thermally annealed samples has been examined and observed that cubic and hexagonal ZrO x phase converted partially into tetragonal and monoclinic ZrO x phases, whereas hexagonal and cubic ZrN phases, from absorber layer, have not been observed for these thermally treated samples in air. These studies suggest that thermal treatment may lead to the loss of ZrN phase in absorber, degrading the thermal response for the desired wavelength range in open ambient conditions in contrast to vacuum conditions.

Formation of nanostructures in Eu3+ doped glass-ceramics: an XAS study.

PubMed

Pellicer-Porres, J; Segura, A; Martínez-Criado, G; Rodríguez-Mendoza, U R; Lavín, V

2013-01-16

We describe the results of x-ray absorption experiments carried out to deduce structural and chemical information in Eu(3+) doped, transparent, oxyfluoride glass and nanostructured glass-ceramic samples. The spectra were measured at the Pb and Eu-L(III) edges. The Eu environment in the glass samples is observed to be similar to that of EuF(3). Complementary x-ray diffraction experiments show that thermal annealing creates β-PbF(2) type nanocrystals. X-ray absorption indicates that Eu ions act as seeds in the nanocrystal formation. There is evidence of interstitial fluorine atoms around Eu ions as well as Eu dimers. X-ray absorption at the Pb-L(III) edge shows that after the thermal treatment most lead atoms form a PbO amorphous phase and that only 10% of the lead atoms remain available to form β-PbF(2) type nanocrystals. Both x-ray diffraction and absorption point to a high Eu content in the nanocrystals. Our study suggests new approaches to the oxyfluoride glass-ceramic synthesis in order to further improve their properties.

Investigation and Characterization of Water-Recrystallized Croconic Acid

DTIC Science & Technology

2016-12-01

high- pressure synthesis. Thermal analysis, bomb calorimetry, X-ray diffraction, and Raman spectroscopy were performed on water- recrystallized...3.2.3 Raman Spectroscopy and X-ray Diffraction 12 3.2.4 Bomb Calorimetry 13 4. Conclusions 15 5. References 16 List of Symbols, Abbreviations, and...and is called the β-phase (the as-received [AR] material is also known as the α-phase). Bomb calorimeter testing of the β-CA indicated a heat of

Effect of gamma-irradiation on thermal decomposition kinetics, X-ray diffraction pattern and spectral properties of tris(1,2-diaminoethane)nickel(II)sulphate

NASA Astrophysics Data System (ADS)

Jayashri, T. A.; Krishnan, G.; Rema Rani, N.

2014-12-01

Tris(1,2-diaminoethane)nickel(II)sulphate was prepared, and characterised by various chemical and spectral techniques. The sample was irradiated with 60Co gamma rays for varying doses. Sulphite ion and ammonia were detected and estimated in the irradiated samples. Non-isothermal decomposition kinetics, X-ray diffraction pattern, Fourier transform infrared spectroscopy, electronic, fast atom bombardment mass spectra, and surface morphology of the complex were studied before and after irradiation. Kinetic parameters were evaluated by integral, differential, and approximation methods. Irradiation enhanced thermal decomposition, lowering thermal and kinetic parameters. The mechanism of decomposition is controlled by R3 function. From X-ray diffraction studies, change in lattice parameters and subsequent changes in unit cell volume and average crystallite size were observed. Both unirradiated and irradiated samples of the complex belong to trigonal crystal system. Decrease in the intensity of the peaks was observed in the infrared spectra of irradiated samples. Electronic spectral studies revealed that the M-L interaction is unaffected by irradiation. Mass spectral studies showed that the fragmentation patterns of the unirradiated and irradiated samples are similar. The additional fragment with m/z 256 found in the irradiated sample is attributed to S8+. Surface morphology of the complex changed upon irradiation.

Applications of thermal-gradients method for the optimization of α-amylase crystallization conditions based on dynamic and static light scattering data

NASA Astrophysics Data System (ADS)

Delboni, L. F.; Iulek, J.; Burger, R.; da Silva, A. C. R.; Moreno, A.

2002-02-01

The expression, purification, crystallization, and characterization by X-ray diffraction of α-amylase are described here. Dynamic and static light scattering methods with a temperature controller was used to optimize the crystallization conditions of α-amylase from Bacillus stearothermophilus an important enzyme in many fields of industrial activity. After applying thermal gradients for growing crystals, X-ray cryo-crystallographic methods were employed for the data collection. Crystals grown by these thermal-gradients diffracted up to a maximum resolution of 3.8 Å, which allowed the determination of the unit cell constants as follows: a=61.7 Å, b=86.7 Å, c=92.2 Å and space group C222 (or C222 1).

Thermal effects on domain orientation of tetragonal piezoelectrics studied by in situ x-ray diffraction

NASA Astrophysics Data System (ADS)

Chang, Wonyoung; King, Alexander H.; Bowman, Keith J.

2006-06-01

Thermal effects on domain orientation in tetragonal lead zirconate titanate (PZT) and lead titanate (PT) have been investigated by using in situ x-ray diffraction with an area detector. In the case of a soft PZT, it is found that the texture parameter called multiples of a random distribution (MRD) initially increases with temperature up to approximately 100°C and then falls to unity at temperatures approaching the Curie temperature, whereas the MRD of hard PZT and PT initially undergoes a smaller increase or no change. The relationship between the mechanical strain energy and domain wall mobility with temperature is discussed.

Probing the thermal stability and the decomposition mechanism of a magnesium-fullerene polymer via X-ray Raman spectroscopy, X-ray diffraction and molecular dynamics simulations.

PubMed

Aramini, Matteo; Niskanen, Johannes; Cavallari, Chiara; Pontiroli, Daniele; Musazay, Abdurrahman; Krisch, Michael; Hakala, Mikko; Huotari, Simo

2016-02-21

We report the microscopic view of the thermal structural stability of the magnesium intercalated fullerene polymer Mg2C60. With the application of X-ray Raman spectroscopy and X-ray diffraction, we study in detail the decomposition pathways of the polymer system upon annealing at temperatures between 300 and 700 °C. We show that there are at least two energy scales involved in the decomposition reaction. Intermolecular carbon bonds, which are responsible for the formation of a 2D fullerene polymer, are broken with a relatively modest thermal energy, while the long-range order of the original polymer remains intact. With an increased thermal energy, the crystal structure in turn is found to undergo a transition to a novel intercalated cubic phase that is stable up to the highest temperature studied here. The local structure surrounding magnesium ions gets severely modified close to, possibly at, the phase transition. We used density functional theory based calculations to study the thermodynamic and kinetic aspects of the collapse of the fullerene network, and to explain the intermediate steps as well as the reaction pathways in the break-up of this peculiar C60 intermolecular bonding architecture.

In situ x-ray diffraction studies of a new LiMg{sub 0.125}Ni{sub 0.75}O{sub 2} cathode material

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

Yang, X.Q.; Sun, X.; McBreen, J.

A Synchrotron x-ray source was used for In Situ x-ray diffraction studies during charge on a new LiMg{sub 0.125}Ti{sub 0.125}Ni{sub 0.75} cathode material synthesized by FMC Corp. It had been demonstrated by Gao that this new material has superior thermal stability than LiNiO{sub 2} and LiCo{sub 0.2}Ni{sub 0.8}O{sub 2} at over-charged state. In this current paper, studies on the relationship between the structural changes and thermal stability at over-charged state for these materials are presented. For the first time, the thermal stability of these materials are related to their structural changes during charge, especially to the formation and lattice constantmore » change of a hexagonal phase (H3). The spectral evidence support the hypothesis that the improvement of thermal stability is obtained by suppressing the formation of H3 phase and reducing the shrinkage of its lattice constant c when charged above 4.3 V.« less

Thermoluminescence and X-ray diffraction studies on sliced ancient porcelain samples

NASA Astrophysics Data System (ADS)

Leung, P. L.; Yang, B.

1999-09-01

The thermal activation characteristics (TACs) of the sensitivity of the '110°C' peak in 14 sliced ancient Chinese porcelain samples are studied. Comparing with the TACs of natural quartz and synthetic mullite, the relation between the TACs and the composition of the sample is discussed with reference to the X-ray diffraction (XRD) spectra. It is suggested that in some cases, contribution of the porcelain components other than quartz to the TACs is not negligible.

X-ray diffraction study of the caged magnetic compound DyFe 2 Zn 20 at low temperatures

NASA Astrophysics Data System (ADS)

Ohashi, M.; Ohashi, K.; Sawabu, M.; Miyagawa, M.; Maeta, K.; Isikawa, Y.

2018-05-01

We have carried out high-angle X-ray powder diffraction measurements of the caged magnetic compound DyFe2Zn20 at low temperature between 14 and 300 K. Even though a strong magnetic anisotropy exists in the magnetization and magnetic susceptibility due to strong exchange interaction between Fe and Dy, almost all X-ray powder diffraction peaks correspond to Bragg reflections of the cubic structural models not only at room temperature paramagnetic state but also at low temperature magnetic ordering state. The Debye temperature is obtained to be 227 K from the results of the volumetric thermal expansion coefficient, which is approximately coincident with that of CeRu2Zn20 (245 K) and that of pure Zn metal (235 K).

Room temperature synthesis of Cu₂O nanospheres: optical properties and thermal behavior.

PubMed

Nunes, Daniela; Santos, Lídia; Duarte, Paulo; Pimentel, Ana; Pinto, Joana V; Barquinha, Pedro; Carvalho, Patrícia A; Fortunato, Elvira; Martins, Rodrigo

2015-02-01

The present work reports a simple and easy wet chemistry synthesis of cuprous oxide (Cu2O) nanospheres at room temperature without surfactants and using different precursors. Structural characterization was carried out by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy coupled with focused ion beam and energy-dispersive X-ray spectroscopy. The optical band gaps were determined from diffuse reflectance spectroscopy. The photoluminescence behavior of the as-synthesized nanospheres showed significant differences depending on the precursors used. The Cu2O nanospheres were constituted by aggregates of nanocrystals, in which an on/off emission behavior of each individual nanocrystal was identified during transmission electron microscopy observations. The thermal behavior of the Cu2O nanospheres was investigated with in situ X-ray diffraction and differential scanning calorimetry experiments. Remarkable structural differences were observed for the nanospheres annealed in air, which turned into hollow spherical structures surrounded by outsized nanocrystals.

Solid state parameters, structure elucidation, High Resolution X-Ray Diffraction (HRXRD), phase matching, thermal and impedance analysis on L-Proline trichloroacetate (L-PTCA) NLO single crystals.

PubMed

Kalaiselvi, P; Raj, S Alfred Cecil; Jagannathan, K; Vijayan, N; Bhagavannarayana, G; Kalainathan, S

2014-11-11

Nonlinear optical single crystal of L-Proline trichloroacetate (L-PTCA) was successfully grown by Slow Evaporation Solution Technique (SEST). The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm the structure. From the single crystal XRD data, solid state parameters were determined for the grown crystal. The crystalline perfection has been evaluated using high resolution X-ray diffractometer. The frequencies of various functional groups were identified from FTIR spectral analysis. The percentage of transmittance was obtained from UV Visible spectral analysis. TGA-DSC measurements indicate the thermal stability of the crystal. The dielectric constant, dielectric loss and ac conductivity were measured by the impedance analyzer. The DC conductivity was calculated by the cole-cole plot method. Copyright © 2014 Elsevier B.V. All rights reserved.

A novel coordination polymer of Ni(II) based on 1,3,5-benzenetricarboxylic acid synthesis, characterization, crystal structure, thermal study, and luminescent properties

NASA Astrophysics Data System (ADS)

Saheli, Sania; Rezvani, Alireza

2017-01-01

A new metal-organic framework (MOF) formulated as [Ni(H2btc)(OH)(H2O)2] (1) (H3btc = 1,3,5-benzenetricarboxylic acid) was synthesized using the hydrothermal technique. The complex 1 was characterized by elemental analysis, infrared spectroscopy, and powder X-ray diffraction in addition to single crystal X-ray diffraction. X-ray crystal structural analysis displayed that the compound belonged to the monoclinic space group P21/n with cell parameters a = 6.8658(14) Å, b = 18.849(4) Å, c = 8.5608(17) Å. In the title complex, ligand is linked to metal centers through two μ-oxo bridges and forming a 2D layer which is led to form an interesting geometry. The thermal stability and fluorescence property of 1 have also been investigated.

Development of a Grazing Incidence X-Ray Interferometer

NASA Technical Reports Server (NTRS)

Shipley, Ann; Cash, Webster; Osterman, Steve; Joy, Marshall; Carter, James

1999-01-01

A grazing incidence x-ray interferometer design capable of micro-arcsecond level resolution is discussed. This practical design employs a Michelson Stellar interferometer approach to create x-ray interference fringes without the use of Wolter style optics or diffraction crystals. Design solutions accommodating alignment, vibration, and thermal constraints are reviewed. We present the development and demonstration of a working experiment along with tolerance studies, data analysis, and results.

FT-IR and Zeta potential measurements on TiO nanoparticles

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

Singh, Jaiveer; Rathore, Ravi; Kaurav, Netram, E-mail: netramkaurav@yahoo.co.uk

2016-05-23

In the present investigation, ultrafine TiO particles have been synthesized successfully by thermal decomposition method. The sample was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. As-synthesized TiO nanoparticles have a cubic structure as characterized by power X-ray diffraction (XRD), which shows that TiO nanoparticles have narrow size distribution with particle size 11.5 nm. FTIR data shows a strong peak at 1300 cm{sup −1}, assignable to the Ti-O stretching vibrations mode.

Increasing dissolution of trospium chloride by co-crystallization with urea

NASA Astrophysics Data System (ADS)

Skořepová, Eliška; Hušák, Michal; Čejka, Jan; Zámostný, Petr; Kratochvíl, Bohumil

2014-08-01

The search for various solid forms of an active pharmaceutical ingredient (API) is an important step in drug development. Our aim was to prepare co-crystals of trospium chloride, an anticholinergic drug used for the treatment of incontinence, and to investigate if they have advantageous properties for drug formulation. Phase identification was done by powder X-ray diffraction and single-crystal X-ray diffraction. The chemical composition was verified by solution NMR and the dissolution rate of the prepared phases was studied by IDR (intrinsic dissolution rate). For further analysis of phase stability and transitions, combined thermal analysis and temperature-resolved X-ray powder diffraction were used. Urea was selected as a co-crystallization partner. Trospium chloride urea (1:1) co-crystal was prepared by a solvent evaporation. From single-crystal data, the co-crystal structure was solved in a space group P21/c and compared to previously published structures of trospium chloride. Intrinsic dissolution rate revealed that the co-crystal dissolves 32% faster than pure API. However, its low thermal and pressure stability makes it a challenging choice for the final drug formulation.

Ba(1-x)Sr(x)Zn2Si2O7--A new family of materials with negative and very high thermal expansion.

PubMed

Thieme, Christian; Görls, Helmar; Rüssel, Christian

2015-12-15

The compound BaZn2Si2O7 shows a high coefficient of thermal expansion up to a temperature of 280 °C, then a transition to a high temperature phase is observed. This high temperature phase exhibits negative thermal expansion. If Ba(2+) is successively replaced by Sr(2+), a new phase with a structure, similar to that of the high temperature phase of BaZn2Si2O7, forms. At the composition Ba0.8Sr0.2Zn2Si2O7, this new phase is completely stabilized. The crystal structure was determined with single crystal X-ray diffraction using the composition Ba0.6Sr0.4Zn2Si2O7, which crystallizes in the orthorhombic space group Cmcm. The negative thermal expansion is a result of motions and distortions inside the crystal lattice, especially inside the chains of ZnO4 tetrahedra. Dilatometry and high temperature X-ray powder diffraction were used to verify the negative thermal expansion. Coefficients of thermal expansion partially smaller than -10·10(-6) K(-1) were measured.

The syntheses, molecular structure analyses and DFT studies on new benzil monohydrazone based Schiff bases

NASA Astrophysics Data System (ADS)

Elmacı, Gökhan; Duyar, Halil; Aydıner, Burcu; Seferoğlu, Nurgül; Naziri, Mir Abolfazl; Şahin, Ertan; Seferoğlu, Zeynel

2018-06-01

Benzil monohydrazone based Schiff bases were synthesized and characterized by 1H NMR, 13C NMR, HRMS as well as by single crystal X-ray diffraction. The geometries of the compounds was optimized by the DFT method and the results were compared with the X-ray diffraction data. The HOMO and LUMO energy gap and also related parameters (electronic chemical potential (μ) and global hardness (η), global electrophilicity index (ω) and softness (s)) were obtained from ground state calculations. In addition, the thermal properties of the compounds were investigated by DTA-TGA. The results showed that the compounds have good thermal properties for practical applications as optic dye.

Thermal stability of the Mobil Five type metallosilicate molecular sieves-An in situ high temperature X-ray diffraction study

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

Bhange, D.S.; Ramaswamy, Veda

2007-05-03

We have carried out in situ high temperature X-ray diffraction (HTXRD) studies of silicalite-1 (S-1) and metallosilicate molecular sieves containing iron, titanium and zirconium having Mobil Five (MFI) structure (iron silicalite-1 (FeS-1), titanium silicalite-1 (TS-1) and zirconium silicalite-1 (ZrS-1), respectively) in order to study the thermal stability of these materials. Isomorphous substitution of Si{sup 4+} by metal atoms is confirmed by the expansion of unit cell volume by X-ray diffraction (XRD) and the presence of Si-O-M stretching band at {approx}960 cm{sup -1} by Fourier transform infrared (FTIR) spectroscopy. Appearance of cristobalite phase is seen at 1023 and 1173 K inmore » S-1 and FeS-1 samples. While the samples S-1 and FeS-1 decompose completely to cristobalite at 1173 and 1323 K, respectively, the other two samples are thermally stable upto 1623 K. This transformation is irreversible. Although all materials show a negative lattice thermal expansion, their lattice thermal expansion coefficients vary. The thermal expansion behavior in all samples is anisotropic with relative strength of contraction along 'a' axes is more than along 'b' and 'c' axes in S-1, TS-1, ZrS-1 and vice versa in FeS-1. Lattice thermal expansion coefficients ({alpha} {sub v}) in the temperature range 298-1023 K were -6.75 x 10{sup -6} K{sup -1} for S-1, -12.91 x 10{sup -6} K{sup -1} for FeS-1, -16.02 x 10{sup -6} K{sup -1} for TS-1 and -17.92 x 10{sup -6} K{sup -1} for ZrS-1. The highest lattice thermal expansion coefficients ({alpha} {sub v}) obtained were -11.53 x 10{sup -6} K{sup -1} for FeS-1 in temperature range 298-1173 K, -20.86 x 10{sup -6} K{sup -1} for TS-1 and -25.54 x 10{sup -6} K{sup -1} for ZrS-1, respectively, in the temperature range 298-1623 K. Tetravalent cation substitution for Si{sup 4+} in the lattice leads to a high thermal stability as compared to substitution by trivalent cations.« less

Nano-Crystalline Thermally Evaporated Bi2Se3 Thin Films Synthesized from Mechanically Milled Powder

NASA Astrophysics Data System (ADS)

Amara, A.; Abdennouri, N.; Drici, A.; Abdelkader, D.; Bououdina, M.; Chaffar Akkari, F.; Khemiri, N.; Kanzari, M.; Bernède, J. C.

2017-08-01

Bi2Se3 powder has been successfully synthesized via mechanical ball milling of bismuth and selenium as starting materials. X-ray diffraction characterization revealed the formation of the rhombohedral and orthorhombic phases of Bi2Se3 material belonging to systems with space groups R\\bar{3}m and Pbnm, respectively. The advantageous last finding is confirmed by the Rietveld refinement of the x-ray diffraction data. Furthermore, the analysis of the x-ray data of thermally deposited thin films revealed that both orthorhombic and rhombohedral phases are coexisting in the layer. The morphology of the ball milled powder was studied by scanning electron microscopy. The phase formation of the material is confirmed by Raman spectroscopy. M-H (Magnetization versus Magnetic field) curve indicates that Bi2Se3 powder has a ferromagnetic behavior. Additionally, absorbance and transmittance measurements were carried out on the obtained thermally evaporated thin films and yielded a band gap of 1.33 eV supporting the potential application of the heterogeneous rhombohedral/orthorhombic Bi2Se3 material in photovoltaics.

X-ray diffraction, Raman, and photoacoustic studies of ZnTe nanocrystals

NASA Astrophysics Data System (ADS)

Ersching, K.; Campos, C. E. M.; de Lima, J. C.; Grandi, T. A.; Souza, S. M.; da Silva, D. L.; Pizani, P. S.

2009-06-01

Nanocrystalline ZnTe was prepared by mechanical alloying. X-ray diffraction (XRD), energy dispersive spectroscopy, Raman spectroscopy, and photoacoustic absorption spectroscopy techniques were used to study the structural, chemical, optical, and thermal properties of the as-milled powder. An annealing of the mechanical alloyed sample at 590 °C for 6 h was done to investigate the optical properties in a defect-free sample (close to bulk form). The main crystalline phase formed was the zinc-blende ZnTe, but residual trigonal tellurium and hexagonal ZnO phases were also observed for both as-milled and annealed samples. The structural parameters, phase fractions, average crystallite sizes, and microstrains of all crystalline phases were obtained from Rietveld analyses of the X-ray patterns. Raman results corroborate the XRD results, showing the longitudinal optical phonons of ZnTe (even at third order) and those modes of trigonal Te. Nonradiative surface recombination and thermal bending heat transfer mechanisms were proposed from photoacoustic analysis. An increase in effective thermal diffusivity coefficient was observed after annealing and the carrier diffusion coefficient, the surface recombination velocity, and the recombination time parameters remained the same.

Thermally exfoliated graphite oxide

NASA Technical Reports Server (NTRS)

Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor); Abdala, Ahmed (Inventor)

2011-01-01

A modified graphite oxide material contains a thermally exfoliated graphite oxide with a surface area of from about 300 sq m/g to 2600 sq m/g, wherein the thermally exfoliated graphite oxide displays no signature of the original graphite and/or graphite oxide, as determined by X-ray diffraction.

Effect of powder compaction on radiation-thermal synthesis of lithium-titanium ferrites

NASA Astrophysics Data System (ADS)

Surzhikov, A. P.; Lysenko, E. N.; Vlasov, V. A.; Malyshev, A. V.; Korobeynikov, M. V.; Mikhailenko, M. A.

2017-01-01

Effect of powder compaction on the efficiency of thermal and radiation-thermal synthesis of lithium-substituted ferrites was investigated by X-Ray diffraction and specific magnetization analysis. It was shown that the radiation-thermal heating of compacted powder reagents mixture leads to an increase in efficiency of lithium-titanium ferrites synthesis.

Neutron and X-ray diffraction of plasma-sprayed zirconia-yttria thermal barrier coatings

NASA Technical Reports Server (NTRS)

Shankar, N. R.; Herman, H.; Singhal, S. P.; Berndt, C. C.

1984-01-01

ZrO2-7.8mol. pct. YO1.5, a fused powder, and ZrO2-8.7mol. pct. YO1.5, a prereacted powder, were plasma-sprayed onto steel substrates. Neutron diffraction and X-ray diffraction of the as-received powder, the powder plasma sprayed into water, as-sprayed coatings, and coatings heat-treated for 10 and 100 h were carried out to study phase transformations and ordering of the oxygen ions on the oxygen sublattice. The as-received fused powder has a much lower monoclinic percentage than does the pre-reacted powder, this resulting in a much lower monoclinic percentage in the coating. Heat treatment increases the percentages of the cubic and monoclinic phases, while decreasing the tetragonal content. An ordered tetragonal phase is detected by the presence of extra neutron diffraction peaks. These phase transformations and ordering will result in volume changes. The implications of these transformations on the performance of partially stabilized zirconia thermal barrier coatings is discussed.

Synthesis, crystal structure and characterization of a new organic-inorganic hybrid material 4-(ammonium methyl) pipyridinium hexachloro stanate (II) trihydrate

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-03-01

The present paper undertakes the study of (C6H16N2) SnCl6·3H2O which is a new hybrid compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. The single crystal X-ray diffraction studies revealed that the compound crystallizes in monoclinic Cc space group with cell parameters a = 8.3309(9) Å, b = 22.956(2) Å, c = 9.8381(9) Å, β = 101.334(9) ° and Z = 4. The atomic arrangement shows an alternation of organic and inorganic entities. The cohesion between these entities is performed via Nsbnd H⋯Cl, Nsbnd H⋯O, Osbnd H⋯Cl and Osbnd H⋯O hydrogen bonding to form a three-dimensional network. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electron microscope (SEM) was carried out. Furthermore, the room temperature infrared (IR) spectrum of the title compound was recorded and analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows four signals, confirming the solid state structure determined by X-ray diffraction. Besides, the thermal analysis studies were performed, but no phase transition was found in the temperature range between 30 and 450 °C. The optical and PL properties of the compound were investigated in the solid state at room temperature and exhibited three bands at 348 and 401 cm-1 and a strong fluorescence at 480 nm.

Phase Composition and the Effect of Thermal Cycling for VH(sub x) V(sub 0.995) C(sub 0.005)H(sub x) and V(sub 0.975)Zr(sub 0.020)C(sub 0.005)H(sub x)

NASA Technical Reports Server (NTRS)

Cantrell, J.; Bowman, R.

1999-01-01

X-ray diffraction (XRD) studies were performed on hydride phases formed by vanadium and its carbon substituted alloys. It was previously found that thermal cycling of VHx across the B-y mixed phase region changed the reversible hydrogen storage capacity and other properties.

Tungsten tetraboride, an inexpensive superhard material

PubMed Central

Mohammadi, Reza; Lech, Andrew T.; Xie, Miao; Weaver, Beth E.; Yeung, Michael T.; Tolbert, Sarah H.; Kaner, Richard B.

2011-01-01

Tungsten tetraboride (WB4) is an interesting candidate as a less expensive member of the growing group of superhard transition metal borides. WB4 was successfully synthesized by arc melting from the elements. Characterization using powder X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) indicates that the as-synthesized material is phase pure. The zero-pressure bulk modulus, as measured by high-pressure X-ray diffraction for WB4, is 339 GPa. Mechanical testing using microindentation gives a Vickers hardness of 43.3 ± 2.9 GPa under an applied load of 0.49 N. Various ratios of rhenium were added to WB4 in an attempt to increase hardness. With the addition of 1 at.% Re, the Vickers hardness increased to approximately 50 GPa at 0.49 N. Powders of tungsten tetraboride with and without 1 at.% Re addition are thermally stable up to approximately 400 °C in air as measured by thermal gravimetric analysis. PMID:21690363

Inorganic pyrophosphatase crystals from Thermococcus thioreducens for X-ray and neutron diffraction.

PubMed

Hughes, Ronny C; Coates, Leighton; Blakeley, Matthew P; Tomanicek, Steve J; Langan, Paul; Kovalevsky, Andrey Y; García-Ruiz, Juan M; Ng, Joseph D

2012-12-01

Inorganic pyrophosphatase (IPPase) from the archaeon Thermococcus thioreducens was cloned, overexpressed in Escherichia coli, purified and crystallized in restricted geometry, resulting in large crystal volumes exceeding 5 mm3. IPPase is thermally stable and is able to resist denaturation at temperatures above 348 K. Owing to the high temperature tolerance of the enzyme, the protein was amenable to room-temperature manipulation at the level of protein preparation, crystallization and X-ray and neutron diffraction analyses. A complete synchrotron X-ray diffraction data set to 1.85 Å resolution was collected at room temperature from a single crystal of IPPase (monoclinic space group C2, unit-cell parameters a=106.11, b=95.46, c=113.68 Å, α=γ=90.0, β=98.12°). As large-volume crystals of IPPase can be obtained, preliminary neutron diffraction tests were undertaken. Consequently, Laue diffraction images were obtained, with reflections observed to 2.1 Å resolution with I/σ(I) greater than 2.5. The preliminary crystallographic results reported here set in place future structure-function and mechanism studies of IPPase.

Effect of different conventional melt quenching technique on purity of lithium niobate (LiNbO3) nano crystal phase formed in lithium borate glass

NASA Astrophysics Data System (ADS)

Kashif, Ismail; Soliman, Ashia A.; Sakr, Elham M.; Ratep, Asmaa

2012-01-01

The glass system (45Li2O + 45B2O3 + 10Nb2O5) was fabricated by the conventional melt quenching technique poured in water, at air, between two hot plates and droplets at the cooled surface. The glass and glass ceramics were studied by differential thermal analysis (DTA) and X-ray diffraction (XRD). The as quenched samples poured in water and between two hot plates were amorphous. The samples poured at air and on cooled surface were crystalline as established via X-ray powder diffraction (XRD) studies. Differential thermal analysis was measured. The glass transition temperature (Tg) and the crystallization temperatures were calculated. Lithium niobate (LiNbO3) was the main phase in glass ceramic poured at air, droplets at the cooled surface and the heat treated glass sample at 500, 540 and 580 °C in addition to traces from LiNb3O8. Crystallite size of the main phases determined from the X-ray diffraction peaks is in the range of <100 nm. The fraction of crystalline (LiNbO3) phase decreases with increase in the heat treatment temperature.

Structural studies of crystalline forms of triamterene with carboxylic acid, GRAS and API molecules

PubMed Central

Rehman, Abida

2018-01-01

Pharmaceutical salt solvates (dimethyl sulfoxide, DMSO) of the drug triamterene with the coformers acetic, succinic, adipic, pimelic, azelaic and nicotinic acid and ibuprofen are prepared by liquid-assisted grinding and solvent-evaporative crystallization. The modified ΔpK a rule as proposed by Cruz-Cabeza [(2012 ▸). CrystEngComm, 14, 6362–6365] is in close agreement with the results of this study. All adducts were characterized by X-ray diffraction and thermal analytical techniques, including single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry and thermal gravimetric analysis. Hydrogen-bonded motifs combined to form a variety of extended tapes and sheets. Analysis of the crystal structures showed that all adducts existed as salt solvates and contained the amino­pyridinium–carboxyl­ate heterodimer, except for the solvate containing triamterene, ibuprofen and DMSO, as a result of the presence of a strong and stable hemitriamterenium duplex. A search of the Cambridge Structural Database (CSD 5.36, Version 1.18) to determine the frequency of occurrence of the putative supramolecular synthons found in this study showed good agreement with previous work. PMID:29755747

Dicoumarol complexes of Cu(II) based on 1,10-phenanthroline: Synthesis, X-ray diffraction studies, thermal behavior and biological evaluation

NASA Astrophysics Data System (ADS)

Dholariya, Hitesh R.; Patel, Ketan S.; Patel, Jiten C.; Patel, Kanuprasad D.

2013-05-01

A series of Cu(II) complexes containing dicoumarol derivatives and 1, 10-phenanthroline have been synthesized. Structural and spectroscopic properties of ligands were studied on the basis of mass spectra, NMR (1H and 13C) spectra, FT-IR spectrophotometry and elemental analysis, while physico-chemical, spectroscopic and thermal properties of mixed ligand complexes have been studied on the basis of infrared spectra, mass spectra, electronic spectra, powder X-ray diffraction, elemental analysis and thermogravimetric analysis. X-ray diffraction study suggested the suitable octahedral geometry for hexa-coordinated state. The kinetic parameters such as order of reaction (n), energy of activation (Ea), entropy (S*), pre-exponential factor (A), enthalpy (H*) and Gibbs free energy (G*) have been calculated using Freeman-Carroll method. Ferric-reducing antioxidant power (FRAP) of all complexes were measured. All the compounds were screened for their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes and Bacillus subtilis, while antifungal activity against Candida albicans and Aspergillus niger have been carried out. Also compounds against Mycobacterium tuberculosis shows clear enhancement in the anti-tubercular activity upon copper complexation.

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.

Thermal equation of state of Molybdenum determined from in situ synchrotron X-ray diffraction with laser-heated diamond anvil cells

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

Huang, Xiaoli; Li, Fangfei; Zhou, Qiang

Here we report that the equation of state (EOS) of Mo is obtained by an integrated technique of laser-heated DAC and synchrotron X-ray diffraction. The cold compression and thermal expansion of Mo have been measured up to 80 GPa at 300 K, and 92 GPa at 3470 K, respectively. The P-V-T data have been treated with both thermodynamic and Mie–Gruneisen-Debye methods for the thermal EOS inversion. The results are self-consistent and in agreement with the static multi-anvil compression data of Litasov et al. (J. Appl. Phys. 113, 093507 (2013)) and the theoretical data of Zeng et al. (J. Phys. Chem.more » B 114, 298 (2010)). Furthermore, these high pressure and high temperature (HPHT) data with high precision firstly complement and close the gap between the resistive heating and the shock compression experiment.« less

Thermal equation of state of Molybdenum determined from in situ synchrotron X-ray diffraction with laser-heated diamond anvil cells

DOE PAGES

Huang, Xiaoli; Li, Fangfei; Zhou, Qiang; ...

2016-02-17

Here we report that the equation of state (EOS) of Mo is obtained by an integrated technique of laser-heated DAC and synchrotron X-ray diffraction. The cold compression and thermal expansion of Mo have been measured up to 80 GPa at 300 K, and 92 GPa at 3470 K, respectively. The P-V-T data have been treated with both thermodynamic and Mie–Gruneisen-Debye methods for the thermal EOS inversion. The results are self-consistent and in agreement with the static multi-anvil compression data of Litasov et al. (J. Appl. Phys. 113, 093507 (2013)) and the theoretical data of Zeng et al. (J. Phys. Chem.more » B 114, 298 (2010)). Furthermore, these high pressure and high temperature (HPHT) data with high precision firstly complement and close the gap between the resistive heating and the shock compression experiment.« less

X-ray diffraction, IR spectroscopy and thermal characterization of partially hydrolyzed guar gum.

PubMed

Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

2012-05-01

Guar gum was hydrolyzed using cellulase from Aspergillus niger at 5.6 pH and 50°C temperature. Hydrolyzed guar gum sample was characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, dilute solution viscometry and rotational viscometry. Viscometry analysis of native guar gum showed a molecular weight of 889742.06, whereas, after enzymatic hydrolysis, the resultant product had a molecular weight of 7936.5. IR spectral analysis suggests that after enzymatic hydrolysis of guar gum there was no major transformation of functional group. Thermal analysis revealed no major change in thermal behavior of hydrolyzed guar gum. It was shown that partial hydrolysis of guar gum could be achieved by inexpensive and food grade cellulase (Aspergillus niger) having commercial importance and utilization as a functional soluble dietary fiber for food industry. Copyright © 2012 Elsevier B.V. All rights reserved.

On the influence of monochromator thermal deformations on X-ray focusing

DOE PAGES

Antimonov, M. A.; Khounsary, A. M.; Sandy, A. R.; ...

2016-03-02

A cooled double crystal monochromator system is used on many high heat load X-ray synchrotron radiation beamlines in order to select, by diffraction, a narrow spectrum of the beam. Thermal deformation of the first crystal monochromator – and the potential loss of beam brightness – is often a concern. However, if downstream beam focusing is planned, the lensing effect of the monochromator must be considered even if thermal deformations are small. In this paper we report on recent experiments at an Advanced Photon Source (APS) beamline that focuses the X-ray beam using compound refractive lenses downstream of an X-ray monochromatormore » system. Increasing the X-ray beam power by increasing the storage ring current from 100 mA to 130 mA resulted in an effective doubling of the focal distance. We show quantitatively that this is due to a lensing effect of the distorted monochromator that results in the creation of a virtual source downstream of the actual source. Lastly, an analysis of the defocusing and options to mitigate this effect are explored.« less

Order-disorder-reorder process in thermally treated dolomite samples: a combined powder and single-crystal X-ray diffraction study

NASA Astrophysics Data System (ADS)

Zucchini, A.; Comodi, P.; Katerinopoulou, A.; Balic-Zunic, T.; McCammon, C.; Frondini, F.

2012-04-01

A combined powder and single-crystal X-ray diffraction analysis of dolomite [CaMg(CO3)2] heated to 1,200°C at 3 GPa was made to study the order-disorder-reorder process. The order/disorder transition is inferred to start below 1,100°C, and complete disorder is attained at approximately 1,200°C. Twinned crystals characterized by high internal order were found in samples annealed over 1,100°C, and their fraction was found to increase with temperature. Evidences of twinning domains combined with probable remaining disordered portions of the structure imply that reordering processes occur during the quench. Twin domains are hereby proposed as a witness to thermally induced intra-layer-type cation disordering.

Unambiguous determination of H-atom positions: comparing results from neutron and high-resolution X-ray crystallography.

PubMed

Gardberg, Anna S; Del Castillo, Alexis Rae; Weiss, Kevin L; Meilleur, Flora; Blakeley, Matthew P; Myles, Dean A A

2010-05-01

The locations of H atoms in biological structures can be difficult to determine using X-ray diffraction methods. Neutron diffraction offers a relatively greater scattering magnitude from H and D atoms. Here, 1.65 A resolution neutron diffraction studies of fully perdeuterated and selectively CH(3)-protonated perdeuterated crystals of Pyrococcus furiosus rubredoxin (D-rubredoxin and HD-rubredoxin, respectively) at room temperature (RT) are described, as well as 1.1 A resolution X-ray diffraction studies of the same protein at both RT and 100 K. The two techniques are quantitatively compared in terms of their power to directly provide atomic positions for D atoms and analyze the role played by atomic thermal motion by computing the sigma level at the D-atom coordinate in simulated-annealing composite D-OMIT maps. It is shown that 1.65 A resolution RT neutron data for perdeuterated rubredoxin are approximately 8 times more likely overall to provide high-confidence positions for D atoms than 1.1 A resolution X-ray data at 100 K or RT. At or above the 1.0sigma level, the joint X-ray/neutron (XN) structures define 342/378 (90%) and 291/365 (80%) of the D-atom positions for D-rubredoxin and HD-rubredoxin, respectively. The X-ray-only 1.1 A resolution 100 K structures determine only 19/388 (5%) and 8/388 (2%) of the D-atom positions above the 1.0sigma level for D-rubredoxin and HD-rubredoxin, respectively. Furthermore, the improved model obtained from joint XN refinement yielded improved electron-density maps, permitting the location of more D atoms than electron-density maps from models refined against X-ray data only.

Projection of the Liquidus Surface of the Co - Sn - Bi System

NASA Astrophysics Data System (ADS)

Abilov, Ch. I.; Allazov, M. R.; Sadygova, S. G.

2016-11-01

The crystallization behavior of phases in alloys of the Co - Sn - Bi system is studied by the methods of differential thermal (DTA), x-ray phase (XRP) and x-ray diffraction (XRD) analyses and hardness measurement. The projection of the liquidus surface is plotted. The boundaries of layering, the development of the monovariant processes, and the coordinates of the nonvariant equilibrium compositions are determined. Compositions of (Co3Sn2)1 - x Bi x solid solutions suitable for the production of antifriction materials are suggested.

Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

DOEpatents

Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

2016-08-09

A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

Lunar sample contracts

NASA Technical Reports Server (NTRS)

Walker, R. M.

1974-01-01

The major scientific accomplishments through 1971 are reported for the particle track studies of lunar samples. Results are discussed of nuclear track measurements by optical and electron microscopy, thermoluminescence, X-ray diffraction, and differential thermal analysis.

Growth, crystalline perfection, spectral, thermal and theoretical studies on imidazolium L-tartrate crystals.

PubMed

Meena, K; Muthu, K; Meenatchi, V; Rajasekar, M; Bhagavannarayana, G; Meenakshisundaram, S P

2014-04-24

Transparent optical quality single crystals of imidazolium L-tartrate (IMLT) were grown by conventional slow evaporation solution growth technique. Crystal structure of the as-grown IMLT was determined by single crystal X-ray diffraction analysis. Thermal analysis reveals the purity of the crystal and the sample is stable up to the melting point. Good transmittance in the visible region is observed and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka-Munk algorithm. The powder X-ray diffraction study reveals the crystallinity of the as-grown crystal and it is compared with that of the experimental one. An additional peak in high resolution X-ray diffraction (HRXRD) indicates the presence of an internal structural low angle boundary. Second harmonic generation (SHG) activity of IMLT is significant as estimated by Kurtz and Perry powder technique. HOMO-LUMO energies and first-order molecular hyperpolarizability of IMLT have been evaluated using density functional theory (DFT) employing B3LYP functional and 6-31G(d,p) basis set. The optimized geometry closely resembles the ORTEP. The vibrational patterns present in the molecule are confirmed by FT-IR coinciding with theoretical patterns. Copyright © 2014 Elsevier B.V. All rights reserved.

Yes, one can obtain better quality structures from routine X-ray data collection.

PubMed

Sanjuan-Szklarz, W Fabiola; Hoser, Anna A; Gutmann, Matthias; Madsen, Anders Østergaard; Woźniak, Krzysztof

2016-01-01

Single-crystal X-ray diffraction structural results for benzidine dihydrochloride, hydrated and protonated N,N,N,N-peri(dimethylamino)naphthalene chloride, triptycene, dichlorodimethyltriptycene and decamethylferrocene have been analysed. A critical discussion of the dependence of structural and thermal parameters on resolution for these compounds is presented. Results of refinements against X-ray data, cut off to different resolutions from the high-resolution data files, are compared to structural models derived from neutron diffraction experiments. The Independent Atom Model (IAM) and the Transferable Aspherical Atom Model (TAAM) are tested. The average differences between the X-ray and neutron structural parameters (with the exception of valence angles defined by H atoms) decrease with the increasing 2θmax angle. The scale of differences between X-ray and neutron geometrical parameters can be significantly reduced when data are collected to the higher, than commonly used, 2θmax diffraction angles (for Mo Kα 2θmax > 65°). The final structural and thermal parameters obtained for the studied compounds using TAAM refinement are in better agreement with the neutron values than the IAM results for all resolutions and all compounds. By using TAAM, it is still possible to obtain accurate results even from low-resolution X-ray data. This is particularly important as TAAM is easy to apply and can routinely be used to improve the quality of structural investigations [Dominiak (2015 ▸). LSDB from UBDB. University of Buffalo, USA]. We can recommend that, in order to obtain more adequate (more accurate and precise) structural and displacement parameters during the IAM model refinement, data should be collected up to the larger diffraction angles, at least, for Mo Kα radiation to 2θmax = 65° (sin θmax/λ < 0.75 Å(-1)). The TAAM approach is a very good option to obtain more adequate results even using data collected to the lower 2θmax angles. Also the results of translation-libration-screw (TLS) analysis and vibrational entropy values are more reliable for 2θmax > 65°.

Studies on the growth, structural, spectral and third-order nonlinear optical properties of ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate single crystal.

PubMed

Silambarasan, A; Krishna Kumar, M; Thirunavukkarasu, A; Mohan Kumar, R; Umarani, P R

2015-01-25

An organic nonlinear optical bulk single crystal, Ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate (ACHBS) was successfully grown by solution growth technique. Single crystal X-ray diffraction study confirms that, the grown crystal belongs to P21/c space group. Powder X-ray diffraction and high resolution X-ray diffraction analyses revealed the crystallinity of the grown crystal. Infrared spectral analysis showed the vibrational behavior of chemical bonds and its functional groups. The thermal stability and decomposition stages of the grown crystal were studied by TG-DTA analysis. UV-Visible transmittance studies showed the transparency region and cut-off wavelength of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was estimated by Z-scan technique using He-Ne laser source. The mechanical property of the grown crystal was studied by using Vicker's microhardness test. Copyright © 2014 Elsevier B.V. All rights reserved.

Crystallization and preliminary X-ray diffraction analysis of recombinant phosphoribosylpyrophosphate synthetase from the Thermophilic thermus thermophilus strain HB27

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

Abramchik, Yu. A.; Timofeev, V. I., E-mail: tostars@mail.ru; Muravieva, T. I.

2017-01-15

Phosphoribosylpyrophosphate synthetases (PRPP synthetases) are among the key enzymes essential for vital functions of organisms and are involved in the biosynthesis of purine and pyrimidine nucleotides, coenzymes, and the amino acids histidine and tryptophan. These enzymes are used in biotechnology for the combined chemoenzymatic synthesis of natural nucleotide analogs. Recombinant phosphoribosylpyrophosphate synthetase I from the thermophilic strain HB27 of the bacterium Thermus thermophilus (T. th HB27) has high thermal stability and shows maximum activity at 75°Ð¡, due to which this enzyme holds promise for biotechnological applications. In order to grow crystals and study them by X-ray crystallography, an enzyme sample,more » which was produced using a highly efficient producer strain, was purified by affinity and gel-filtration chromatography. The screening of crystallization conditions was performed by the vapor-diffusion technique. The crystals of the enzyme suitable for X-ray diffraction were grown by the counter-diffusion method through a gel layer. These crystals were used to collect the X-ray diffraction data set at the SPring-8 synchrotron radiation facility (Japan) to 3-Å resolution. The crystals belong to sp. gr. P2{sub 1} and have the following unitcell parameters: a = 107.7 Å, b = 112.6 Å, c = 110.2 Å, α = γ = 90°, β = 116.6°. The X-ray diffraction data set is suitable for determining the three-dimensional structure of the enzyme at 3.0-Å resolution.« less

Crystallization and preliminary X-ray diffraction analysis of recombinant phosphoribosylpyrophosphate synthetase from the Thermophilic thermus thermophilus strain HB27

NASA Astrophysics Data System (ADS)

Abramchik, Yu. A.; Timofeev, V. I.; Muravieva, T. I.; Sinitsyna, E. V.; Esipov, R. S.; Kuranova, I. P.

2017-01-01

Phosphoribosylpyrophosphate synthetases (PRPP synthetases) are among the key enzymes essential for vital functions of organisms and are involved in the biosynthesis of purine and pyrimidine nucleotides, coenzymes, and the amino acids histidine and tryptophan. These enzymes are used in biotechnology for the combined chemoenzymatic synthesis of natural nucleotide analogs. Recombinant phosphoribosylpyrophosphate synthetase I from the thermophilic strain HB27 of the bacterium Thermus thermophilus ( T. th HB27) has high thermal stability and shows maximum activity at 75°C, due to which this enzyme holds promise for biotechnological applications. In order to grow crystals and study them by X-ray crystallography, an enzyme sample, which was produced using a highly efficient producer strain, was purified by affinity and gel-filtration chromatography. The screening of crystallization conditions was performed by the vapor-diffusion technique. The crystals of the enzyme suitable for X-ray diffraction were grown by the counter-diffusion method through a gel layer. These crystals were used to collect the X-ray diffraction data set at the SPring-8 synchrotron radiation facility (Japan) to 3-Å resolution. The crystals belong to sp. gr. P21 and have the following unitcell parameters: a = 107.7 Å, b = 112.6 Å, c = 110.2 Å, α = γ = 90°, β = 116.6°. The X-ray diffraction data set is suitable for determining the three-dimensional structure of the enzyme at 3.0-Å resolution.

Crystal growth, structural, thermal and mechanical behavior of l-arginine 4-nitrophenolate 4-nitrophenol dihydrate (LAPP) single crystals.

PubMed

Mahadevan, M; Ramachandran, K; Anandan, P; Arivanandhan, M; Bhagavannarayana, G; Hayakawa, Y

2014-12-10

Single crystals of l-arginine 4-nitrophenolate 4-nitrophenol dihydrate (LAPP) have been grown successfully from the solution of l-arginine and 4-nitrophenol. Slow evaporation of solvent technique was adopted to grow the bulk single crystals. Single crystal X-ray diffraction analysis confirms the grown crystal has monoclinic crystal system with space group of P21. Powder X-ray diffraction analysis shows the good crystalline nature. The crystalline perfection of the grown single crystals was analyzed by HRXRD by employing a multicrystal X-ray diffractometer. The functional groups were identified from proton NMR spectroscopic analysis. Linear and nonlinear optical properties were determined by UV-Vis spectrophotometer and Kurtz powder technique respectively. It is found that the grown crystal has no absorption in the green wavelength region and the SHG efficiency was found to be 2.66 times that of the standard KDP. The Thermal stability of the crystal was found by obtaining TG/DTA curve. The mechanical behavior of the grown crystal has been studied by Vicker's microhardness method. Copyright © 2014 Elsevier B.V. All rights reserved.

Crystal chemistry and thermal behavior of La doped (U, Th)O2

NASA Astrophysics Data System (ADS)

Keskar, Meera; Shelke, Geeta P.; Shafeeq, Muhammed; Krishnan, K.; Sali, S. K.; Kannan, S.

2017-12-01

X-ray diffraction, chemical and thermal studies of [(U0.2Th0.8)1-yLay]O2+x (LUTL) and [(U0.3Th0.7)1-yLay]O2+x (UTL); compounds (where y ≤ 0.4) were carried out. These compounds were synthesized by gel combustion method followed by heating in reduced atmospheres at 1673 K. To co-relate lattice parameters with metal and oxygen concentrations, reduced oxides were heated in Ar, CO2 and air atmospheres. Retention of FCC phase was confirmed in all mixed oxides with y ≤ 0.4. The cubic lattice parameters could be expressed in a linear equation of x and y as: a (Ǻ) = 5.5709 - 0.187 x + 0.032 y; [x < 0 and 0 ≤ y ≤ 0.40] for LUTL and a (Ǻ) = 5.5580 - 0.26 x + 0.015 y; [x < 0 and 0 ≤ y ≤ 0.36] for UTL. Oxidation studies and simple ionic model calculations suggested that uranium is predominantly present as a mixture of +5 and + 6 states when La/U ratio ∼2. Oxidation kinetics of mixed oxides was studied by non-isothermal method using thermogravimetry and was found to be a diffusion controlled reaction. High temperature X-ray diffraction studies of LUTL and UTL mixed oxides showed positive thermal expansion in the temperature range of 298-1273 K and % expansion increases with La concentration.

Low Temperature X-Ray Diffraction Study on CaFe2As2

NASA Astrophysics Data System (ADS)

Huyan, Shuyuan; Deng, Liangzi; Wu, Zheng; Zhao, Kui; Lv, Bing; Xue, Yiyu; Chu, Ching-Wu; B. Lv Collaboration; HPLT (Paul C. W. Chu) Team

For undoped CaFe2As2 single crystals, we observed that utilizing thermal treatments could stabilize two pure tetragonal phases PI and PII. Both phases are non-superconducting, while the superconductivity with a Tc up to 25 K can be induced through proper thermal treatment. Room temperature X-ray studies suggest that the origin of superconductivity arises from the interface of the mesoscopically stacked layers of PI and PII. To further investigate, a systematic low temperature X-ray study was conducted over a series of thermal treated CaFe2As2 single crystals. From which, we observed the phase aggregation of PI and PII upon cooling, more importantly, an ordered stacking structure exists at low temperature, which closely related to superconducting volume fraction and the ratio of PI and PII. These results further support the proposal of interface-enhanced superconductivity in undoped CaFe2As2. UT Dallas

Thermal decomposition of ammonium hexachloroosmate.

PubMed

Asanova, T I; Kantor, I; Asanov, I P; Korenev, S V; Yusenko, K V

2016-12-07

Structural changes of (NH 4 ) 2 [OsCl 6 ] occurring during thermal decomposition in a reduction atmosphere have been studied in situ using combined energy-dispersive X-ray absorption spectroscopy (ED-XAFS) and powder X-ray diffraction (PXRD). According to PXRD, (NH 4 ) 2 [OsCl 6 ] transforms directly to metallic Os without the formation of any crystalline intermediates but through a plateau where no reactions occur. XANES and EXAFS data by means of Multivariate Curve Resolution (MCR) analysis show that thermal decomposition occurs with the formation of an amorphous intermediate {OsCl 4 } x with a possible polymeric structure. Being revealed for the first time the intermediate was subjected to determine the local atomic structure around osmium. The thermal decomposition of hexachloroosmate is much more complex and occurs within a minimum two-step process, which has never been observed before.

Thermoelectric properties and thermal stability of Bi-doped PbTe single crystal

NASA Astrophysics Data System (ADS)

Chen, Zhong; Li, Decong; Deng, Shuping; Tang, Yu; Sun, Luqi; Liu, Wenting; Shen, Lanxian; Yang, Peizhi; Deng, Shukang

2018-06-01

In this study, n-type Bi-doped single-crystal PbTe thermoelectric materials were prepared by melting and slow cooling method according to the stoichiometric ratio of Pb:Bi:Te = 1-x:x:1 (x = 0, 0.1, 0.15, 0.2, 0.25). The X-ray diffraction patterns of Pb1-xBixTe samples show that all main diffraction peaks are well matched with the PbTe matrix, which has a face-centered cubic structure with the space group Fm 3 bar m . Electron probe microanalysis reveals that Pb content decreases gradually, and Te content remains invariant basically with the increase of Bi content, indicating that Bi atoms are more likely to replace Pb atoms. Thermal analysis shows that the prepared samples possess relatively high thermal stability. Simultaneously, transmission electron microscopy and selected area electron diffraction pattern indicate that the prepared samples have typical single-crystal structures with good mechanical properties. Moreover, the electrical conductivity of the prepared samples improved significantly compared with that of the pure sample, and the maximum ZT value of 0.84 was obtained at 600 K by the sample with x = 0.2.

Fe-catalyzed thermal conversion of sodium lignosulfonate to graphene

Treesearch

Sung Phil Mun; Zhiyong Cai; Jilei Zhang

2013-01-01

Sodium lignosulfonate (LS) from sulfite pulping processing was used as a carbon source to synthesize graphene. LS was mixed with Fe nanoparticles (FeNPs) as a catalyst and thermally treated at 1000 °C for 1 h. The Raman spectrum and X-ray diffraction pattern suggested that graphene sheets were formed in LS thermally treated with FeNPs (Fe-HTLS). Scanning...

The structure, thermal expansion and phase transition properties of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0, 1.0, 2.0) solid solutions

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

Liu, X.Z.; Hao, L.J.; Wu, M.M.

Graphical abstract: A polymorph with Gd{sub 2}Mo{sub 3}O{sub 12}-type structure (space group: Pba2) for negative thermal expansion material Ho{sub 2}Mo{sub 3}O{sub 12} is observed above 700 °C, this polymorphism could be effectively supressed by W-substiution for Mo, the give the temperature dependence of Pba2 phase contents for Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0.0, 1.0, 2.0). - Highlights: • The solid solution Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} was investigated by in situ X-ray diffraction. • It is found that the substitution slightly influence thermal expansion property. • A polymorph of Ho{sub 2}Mo{sub 3}O{sub 12} with Pba2 space group wasmore » observed above 700 °C. • The W-substitution for Mo effectively suppresses this transformation. - Abstract: Three solid solutions of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12}(x = 0, 1.0, 2.0) were prepared by solid state reaction method, the temperature dependent in-situ X-ray diffraction and thermal analysis were performed to investigate their structure and thermal expansion. All samples have orthorhombic structure(space group Pbcn# 60) with negative thermal expansion at the room temperature. the substitution of W for Mo enlarges the lattice constant and slightly influences the negative thermal expansion. An irreversible phase transformation to the Pba2 phase(Tb{sub 2}Mo{sub 3}O{sub 12} structure) was observed at high temperature for Mo-rich samples. This ploymorphism could be effectively suppressed by the W-substitution for Mo, this phenomenon could be explained by the lower electronegativity of W{sup 6+} than Mo{sup 6+}.« less

Growth, structural, optical, thermal and mechanical properties of ammonium pentaborate single crystal.

PubMed

Balakrishnan, T; Bhagavannarayana, G; Ramamurthi, K

2008-11-15

Nonlinear optical single crystals of ammonium pentaborate (APB) were grown by the slow cooling method from aqueous solution. Grown crystal was characterized by powder X-ray diffraction (PXRD) and FT-IR spectral analysis. Perfection of the grown crystal was evaluated by high-resolution X-ray diffractometry (HRXRD). The effect of nylon threading on the perfection of the grown bigger crystal was also studied by HRXRD. The range and percentage of optical transmission was ascertained by recording UV-vis-NIR spectrum. Thermal properties were investigated by TG-DTA and DSC analyses. Its mechanical hardness was estimated by Vickers microhardness tester.

Study of the Decomposition and Phase Transition of Uranium Nitride under UHV Conditions via TDS, XRD, SEM, and XPS.

PubMed

Wang, Xiaofang; Long, Zhong; Bin, Ren; Yang, Ruilong; Pan, Qifa; Li, Fangfang; Luo, Lizhu; Hu, Yin; Liu, Kezhao

2016-11-07

Uranium nitrides are among the most promising fuels for Generation IV nuclear reactors, but until now, very little has been known about their thermal stability properties under nonequilibrium conditions. In this work, thermal decomposition of nitrogen-rich uranium nitride (denoted as UN 2-x ) under ultrahigh-vacuum (UHV) conditions was investigated by thermal desorption spectroscopy (TDS). It has been shown that the nitrogen TDS spectrum consists of two peaks at about 723 and 1038 K. The X-ray diffraction, scanning electron microscopy, and X-ray photoelectron microscopy results indicate that UN 2-x (UN 2 phase) decomposed into the α-U 2 N 3 phase in the first step and the α-U 2 N 3 phase decomposed into the UN phase in the second step.

In situ X-ray and neutron diffraction of the Ruddlesden–Popper compounds (RE 2–xSr x)₀.₉₈(Fe₀.₈Co₀.₂) 1–yMg yO 4–δ (RE=La, Pr): Structure and CO₂ stability

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

Chatzichristodoulou, C., E-mail: ccha@dtu.dk; Hauback, B.C.; Hendriksen, P.V.

2013-05-01

The crystal structure of the Ruddlesden–Popper compounds (La₁.₀Sr₁.₀)₀.₈Fe₁.₀Co₀.₂O 4–δ and (La₁.₂Sr₀.₈)₀.₉₈(Fe₀.₈Co₀.₂)₀.₈Mg₀.₂O 4–δ was investigated at 1000 °C in N₂ (a O₂=1×10₋₄ by in-situ powder neutron diffraction. In-situ powder X-ray diffraction (PXD) was also employed to investigate the temperature dependence of the lattice parameters of the compounds in air and the oxygen activity dependence of the lattice parameters at 800 °C and 1000 °C. The thermal and chemical expansion coefficients, determined along the two crystallographic directions of the tetragonal unit cell, are highly anisotropic. The equivalent pseudo-cubic thermal and chemical expansion coefficients are in agreement with values determined by dilatometry. Themore » chemical stability in CO₂ containing environments of various Ruddlesden–Popper compounds with chemical formula (RE 2-xSr x)₀.₉₈(Fe₀.₈Co₀.₂) 1-yMg yO 4–δ (RE=La, Pr), as well as their stability limit in H₂/H₂O=4.5 were also determined by in-situ PXD for x=0.9, 1.0 and y=0, 0.2. - Graphical abstract: Influence of electronic configuration on bond length, lattice parameters and anisotropic thermal and chemical expansion. Highlights: • The thermal and chemical expansion coefficients are largely anisotropic. • The expansion of the perovskite layers is constrained along the a direction. • The studied compositions show remarkable thermodynamic stability upon reduction. • The thermal and chemical expansion coefficients are lower than related perovskites. • The investigated materials decompose in CO₂ containing atmospheres.« less

Characterization of low thermal conductivity PAN-based carbon fibers

NASA Technical Reports Server (NTRS)

Katzman, Howard A.; Adams, P. M.; Le, T. D.; Hemminger, Carl S.

1992-01-01

The microstructure and surface chemistry of eight low thermal conductivity (LTC) PAN-based carbon fibers were determined and compared with PAN-based fibers heat treated to higher temperatures. Based on wide-angle x ray diffraction, the LTC PAN fibers all appear to have a similar turbostratic structure with large 002 d-spacings, small crystallite sizes, and moderate preferred orientation. Limited small-angle x ray scattering (SAXS) results indicate that, with the exception of LTC fibers made by BASF, the LTC fibers do not have well developed pores. Transmission electron microscopy shows that the texture of the two LTC PAN-based fibers studied (Amoco T350/23X and /25X) consists of multiple sets of parallel, wavy, bent layers that interweave with each other forming a complex three dimensional network oriented randomly around the fiber axis. X ray photoelectron spectroscopy (XPS) analysis finds correlations between heat treated temperatures and the surface composition chemistry of the carbon fiber samples.

Thermal equation of state of TiC: A synchrotron x-ray diffraction study

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

Yu Xiaohui; National Lab for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080; Department of Physics, University of Science and Technology of China, Hefei 230026

2010-06-15

The pressure-volume-temperature measurements were carried out for titanium carbide (TiC) at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal pressure approach. With the pressure derivative of the bulk modulus, K{sub 0}{sup '}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0}=268(6) GPa, which is comparable to previously reported value; temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub P}=-0.026(9) GPa K{sup -1}, volumetric thermal expansivity {alpha}{sub T}(K{sup -1})=a+bT with a=1.62(12)x10{sup -5} K{supmore » -1} and b=1.07(17)x10{sup -8} K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}{alpha}/{partial_derivative}P){sub T}=(-3.62{+-}1.14)x10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub V}=-0.015(8) GPa K{sup -1}. These results provide fundamental thermophysical properties for TiC for the first time and are important to theoretical and computational modeling of transition metal carbides.« less

Thermal equation-of-state of TiC: a synchrotron x-ray diffraction study

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

Yu, Xiaohui; Lin, Zhijun; Zhang, Jianzhong

2009-01-01

The pressure (P)-volume (V)-temperature (T) measurements were carried out for titanium carbide at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal-pressure approach. With the pressure derivative of the bulk modulus, K'{sub 0}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0} = 268(6) GPa, temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub p} = -0.026(9) GPa K{sup -1}, volumetric thermal expansivity a{sub T}(K{sup -1}) = a + bT with a =more » 1.62(12) x 10{sup -5} K{sup -1} and b = 1.07(17) x 10{sup -8} K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}a/{partial_derivative}P){sub T} = (-3.62 {+-} 1.14) x 10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub v} = -0.015 (8) GPa K{sup -1}. These results provide fundamental thermo physical properties for TiC and are important to theoretical and computational modeling of transition metal carbides.« less

Linear thermal expansion coefficient determination using in situ curvature and temperature dependent X-ray diffraction measurements applied to metalorganic vapor phase epitaxy-grown AlGaAs

NASA Astrophysics Data System (ADS)

Maaßdorf, A.; Zeimer, U.; Grenzer, J.; Weyers, M.

2013-07-01

AlxGa1-xAs grown on GaAs is known to be almost perfectly lattice matched with a maximum lattice mismatch of 0.14% at room temperature and even less at temperatures of 700 °C-800 °C. However, as layer structures for edge-emitting diode lasers exhibit an increasing overall thickness of several microns of AlxGa1-xAs, e.g., diode lasers comprising a super-large optical cavity, the accumulated elastic strain energy increases as well. Depending on the growth temperature the formation energy of dislocations can be reached, which is limiting the pseudomorphic growth. In this regard, the thermal expansion coefficient difference between layer and substrate is an important parameter. We utilize in situ curvature measurements during growth of AlxGa1-xAs by metal-organic vapour phase epitaxy to determine the thermal expansion coefficient α. The curvature change with increasing layer thickness, as well as with wafer temperature at constant layer thickness is used to assess α. This is compared to ex situ temperature dependent X-ray diffraction measurements to obtain α. All determined values for α are in good agreement, yielding αAlAs=4.1×10-6 K-1 for a given GaAs linear thermal expansion coefficient of αGaAs=5.73×10-6 K-1.

Lattice thermal expansion of the solid solutions (La{sub 1−x}Sm{sub x}){sub 2}Ce{sub 2}O{sub 7}

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

Wu, Hongdan; Lei, Xinrong; Zhang, Jinhua, E-mail: jhzhang1212@126.com

2014-09-15

Highlights: • Sm-doped La{sub 2}Ce{sub 2}O{sub 7} was prepared by the coprecipitation–calcination method. • In situ HT-XRD measurements revealed that is much stable than 8YSZ. • Its thermal expansion is better than 8YSZ. - Abstract: A series of solid solutions with the general formula (La{sub 1−x}Sm{sub x}){sub 2}Ce{sub 2}O{sub 7} (0.0 ≤ x ≤ 1.0) were prepared by the coprecipitation–calcination method. The products obtained were characterized by powder X-ray diffraction for phase purity. It was observed that La{sup 3+} and Sm{sup 3+} can form complete solid solution in (La,Sm){sub 2}Ce{sub 2}O{sub 7} with defect-fluorite-type phase. The unit cell parameters ofmore » these solutions were calculated by a least squares method and the lattice parameters decreased linearly as x increased. The lattice thermal expansion behavior of (La{sub 1−x}Sm{sub x}){sub 2}Ce{sub 2}O{sub 7} (0.0 ≤ x ≤ 1.0) was investigated by high-temperature X-ray diffraction in the temperature range 298–1623 K. The lattice parameters a{sub T} of all the solutions at different temperature can be expressed as a{sub T} = a + bT + cT{sup 2}. As x < 1, the thermal expansion has a sudden decrease at ca. 473 K. The coefficients of lattice thermal expansion of Sm{sub 2}Ce{sub 2}O{sub 7} were 10.2–13.6 × 10{sup −6} K{sup −1} from 298 to 1623 K, and without the thermal contraction at low temperature. The materials show positive or negative thermal expansion due to the asymmetric anharmonic vibration.« less

Antibacterial Carbon Nanotubes by Impregnation with Copper Nanostructures

NASA Astrophysics Data System (ADS)

Palza, Humberto; Saldias, Natalia; Arriagada, Paulo; Palma, Patricia; Sanchez, Jorge

2017-08-01

The addition of metal-based nanoparticles on carbon nanotubes (CNT) is a relevant method producing multifunctional materials. In this context, CNT were dispersed in an ethanol/water solution containing copper acetate for their impregnation with different copper nanostructures by either a non-thermal or a thermal post-synthesis treatment. Our simple method is based on pure CNT in an air atmosphere without any other reagents. Particles without thermal treatment were present as a well-dispersed layered copper hydroxide acetate nanostructures on CNT, as confirmed by scanning and transmission (TEM) electron microscopies, and showing a characteristic x-ray diffraction peak at 6.6°. On the other hand, by thermal post-synthesis treatment at 300°C, these layered nanostructures became Cu2O nanoparticles of around 20 nm supported on CNT, as confirmed by TEM images and x-ray diffraction peaks. These copper nanostructures present on the CNT surface rendered antibacterial behavior to the resulting hybrid materials against both Staphylococcus aureus and Escherichia coli. These findings present for the first time a simple method for producing antibacterial CNT by direct impregnation of copper nanostructures.

FTIR spectroscopic, thermal and XRD characterization of hydroxyapatite from new natural sources

NASA Astrophysics Data System (ADS)

Shaltout, Abdallah A.; Allam, Moussa A.; Moharram, Mohamed A.

2011-12-01

The inorganic constituents of 5 different plants (leaves and stalks) were investigated by using Fourier transformer infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal analysis including thermal gravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). These plants are Catha edulis (Khat), basil, mint, green tea and trifolium. The absorption bands of carbonate ions CO 32- was exhibited at 1446 cm -1, and the phosphate ions PO 43- was assigned at 1105 and 1035 cm -1. At high temperatures (600, 700 and 600 °C) further absorption bands of the phosphate ions PO 43- was assigned at the frequencies 572, 617, 962, 1043 and 1110 cm -1 and the vibrational absorption band of the carbonate ions CO 32- was assigned at 871, 1416 and 1461 cm -1. X-ray diffraction and thermal analysis confirm the obtained results of FITR. Results showed that the main inorganic constituents of C. edulis and basil leaves are hydroxyapatite whereas the hydroxyapatite content in the other plant samples is less than that in case of C. edulis and basil plant leaves.

Scanning electron microscopy, X-ray diffraction and thermal analysis study of the TiH{sub 2} foaming agent

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

Mandrino, Djordje, E-mail: djordje.mandrino@imt.si; Paulin, Irena; Skapin, Sreco D.

2012-10-15

The decomposition of commercially available TiH{sub 2} was investigated while performing different thermal treatments. TiH{sub 2} powder, which is widely used as a foaming agent, was heat treated at 450 Degree-Sign C for various times, from 15 min to 120 min. Scanning electron microscopy (SEM) images of the surfaces at different magnifications were obtained and interpreted. A Bragg-Brentano X-ray diffractometer was used to measure the X-ray diffraction (XRD) spectra on all five samples. A close examination of the diffraction spectra showed that for an as-received sample and samples undergoing the longest thermal treatment (1 and 2 h) these spectra canmore » be explained as deriving from cubic TiH{sub 1.924}, while for the other two samples they can be explained as deriving from tetragonal TiH{sub 1.924}. A constant-unit-cell-volume phase transition between the cubic and tetragonal phases in TiH{sub 2-y}-type compounds had been described in the literature. The unit-cell parameters obtained from measured spectra confirm that within the measurement uncertainty the unit-cell volume is indeed constant in all five samples. Thermo-gravimetry (TG) and differential thermal analysis (DTA) measurements were performed on all the samples, showing that the intensity of the dehydrogenation depends on the previous treatment of the TiH{sub 2}. After the thermal analysis XRD of the samples was performed again and the material was found to exhibit a Ti-like unit cell, but slightly enlarged due to the unreleased hydrogen. - Highlights: Black-Right-Pointing-Pointer TiH{sub 2} samples were cubic or tetragonal TiH{sub 1.924} Black-Right-Pointing-Pointer Onset of the hydrogen release temperature increases with the pre-treatment time. Black-Right-Pointing-Pointer Thermal dehydrogenation for the as-prepared TiH{sub 2} is a three-step process. Black-Right-Pointing-Pointer After thermal analysis 2 residual hydrogen TiH{sub x} phases, close to {alpha}Ti, appeared.« less

Controlled nucleation and growth of CdS nanoparticles in a polymer matrix.

PubMed

Di Luccio, Tiziana; Laera, Anna Maria; Tapfer, Leander; Kempter, Susanne; Kraus, Robert; Nickel, Bert

2006-06-29

In-situ synchrotron X-ray diffraction (XRD) was used to monitor the thermal decomposition (thermolysis) of Cd thiolates precursors embedded in a polymer matrix and the nucleation of CdS nanoparticles. A thiolate precursor/polymer solid foil was heated to 300 degrees C in the X-ray diffraction setup of beamline W1.1 at Hasylab, and the diffraction curves were each recorded at 10 degrees C. At temperatures above 240 degrees C, the precursor decomposition is complete and CdS nanoparticles grow within the polymer matrix forming a nanocomposite with interesting optical properties. The nanoparticle structural properties (size and crystal structure) depend on the annealing temperature. Transmission electron microscopy (TEM) and photoluminescence (PL) analyses were used to characterize the nanoparticles. A possible mechanism driving the structural transformation of the precursor is inferred from the diffraction features arising at the different temperatures.

X-ray absorption fine structure and x-ray diffraction studies of crystallographic grains in nanocrystalline FePd:Cu thin films

NASA Astrophysics Data System (ADS)

Krupinski, M.; Perzanowski, M.; Polit, A.; Zabila, Y.; Zarzycki, A.; Dobrowolska, A.; Marszalek, M.

2011-03-01

FePd alloys have recently attracted considerable attention as candidates for ultrahigh density magnetic storage media. In this paper we investigate FePd thin alloy film with a copper admixture composed of nanometer-sized grains. [Fe(0.9 nm)/Pd(1.1 nm)/Cu(d nm)]×5 multilayers were prepared by thermal deposition at room temperature in UHV conditions on Si(100) substrates covered by 100 nm SiO2. The thickness of the copper layer has been changed from 0 to 0.4 nm. After deposition, the multilayers were rapidly annealed at 600 °C in a nitrogen atmosphere, which resulted in the creation of the FePd:Cu alloy. The structure of alloy films obtained this way was determined by x-ray diffraction (XRD), glancing angle x-ray diffraction, and x-ray absorption fine structure (EXAFS). The measurements clearly showed that the L10 FePd:Cu nanocrystalline phase has been formed during the annealing process for all investigated copper compositions. This paper concentrates on the crystallographic grain features of FePd:Cu alloys and illustrates that the EXAFS technique, supported by XRD measurements, can help to extend the information about grain size and grain shape of poorly crystallized materials. We show that, using an appropriate model of the FePd:Cu grains, the comparison of EXAFS and XRD results gives a reasonable agreement.

Simple glucose reduction route for one-step synthesis of copper nanofluids

NASA Astrophysics Data System (ADS)

Shenoy, U. Sandhya; Shetty, A. Nityananda

2014-01-01

One-step method has been employed in the synthesis of copper nanofluids. Copper nitrate is reduced by glucose in the presence of sodium lauryl sulfate. The synthesized particles are characterized by X-ray diffraction technique for the phase structure; electron diffraction X-ray analysis for chemical composition; transmission electron microscopy and field emission scanning electron microscopy for the morphology; Fourier-transform infrared spectroscopy and ultraviolet-visible spectroscopy for the analysis of ingredients of the solution. Thermal conductivity, sedimentation and rheological measurements have also been carried out. It is found that the reaction parameters have considerable effect on the size of the particle formed and rate of the reaction. The techniques confirm that the synthesized particles are copper. The reported method showed promising increase in the thermal conductivity of the base fluid and is found to be reliable, simple and cost-effective method for preparing heat transfer fluids with higher stability.

Crystal Structure of the Caged Magnetic Compound DyFe2Zn20 at Low Temperature Magnetic Ordering State

NASA Astrophysics Data System (ADS)

Kishii, Nobuya; Tateno, Shota; Ohashi, Masashi; Isikawa, Yosikazu

We have carried out X-ray powder diffraction and thermal expansion measurements of the caged magnetic compound DyFe2Zn20. Even though a strong magnetic anisotropy exists in the magnetization and magnetic susceptibility due to strong exchange interaction between Fe and Dy, almost all X-ray powder diffraction peaks at 14 K correspond to Bragg reflections of the cubic structural models not only at room temperature paramagnetic state but also at low temperature magnetic ordering state. Although the temperature change of the lattice constant is isotropic, an anomalous behavior was observed in the thermal expansion coefficient around 15 K, while the anomaly around TC = 53 K is not clear. The results indicate that the volume change is not caused by the ferromagnetic interaction between Fe and Dy but by the exchange interaction between two Dy ions.

Crystal structure, thermal and optical properties of Benzimidazole benzimidazolium picrate crystal

NASA Astrophysics Data System (ADS)

Jagadesan, A.; Peramaiyan, G.; Srinivasan, T.; Kumar, R. Mohan; Arjunan, S.

2016-02-01

A new organic framework of benzimidazole with picric acid has been synthesized. A single crystal with a size of 38×10×4 mm3 was grown by a slow evaporation solution growth technique. X-ray diffraction study revealed that the BZP crystal belongs to triclinic system with space group P-1. High resolution X-ray diffraction study shows the absence of grain boundaries without any defects. The thermal stability and specific heat capacity of BZP were investigated by TG/DT and TG/DSC analyses. From the UV-vis-NIR spectral study, optical transmission window and band gap of BZP were found out. The nonlinear refractive index (n2) and third order susceptibility Re(χ(3)) values of BZP crystal are estimated to be 1.73×10-7 cm2/W and 1.26×10-5 esu, respectively using a Z-scan technique.

Micro X-ray diffraction analysis of thin films using grazing-exit conditions.

PubMed

Noma, T; Iida, A

1998-05-01

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick-Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 x 10 micro m. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.

Effects of alkyl chain length and anion size on thermal and structural properties for 1-alkyl-3-methylimidazolium hexafluorocomplex salts (C(x)MImAF6, x = 14, 16 and 18; A = P, As, Sb, Nb and Ta).

PubMed

Xu, Fei; Matsumoto, Kazuhiko; Hagiwara, Rika

2012-03-28

A series of 1-alkyl-3-methylimidazolium hexafluorocomplex salts (C(x)MImAF(6), x = 14, 16 and 18, A = P, As, Sb, Nb and Ta) have been characterized by thermal analysis, X-ray diffraction and polarized optical microscopy. A liquid crystalline mesophase is observed for all the C(16)MIm and C(18)MIm salts. The C(14)MIm(+) cation gives a liquid crystalline mesophase only with PF(6)(-). The temperature range of the liquid crystalline mesophase increases with an increase in alkyl chain length or with decrease in anion size. Single-crystal X-ray diffraction revealed that all the C(18)MImAF(6) salts (A = P, As, Sb, Nb and Ta) are isostructural with each other in the crystalline phase and have a layered structure. The interdigitated alkyl chain of the cation has a bent shape like a spoon near the imidazolium ring in the crystalline phase at -100 °C and is tilted with respect to the sheets of the imidazolium headgroups and anions. An increase of temperature increases the ratio of an all-trans conformation to the bent conformation in the crystalline phase. X-ray diffraction and polarized optical microscopy suggested that the liquid crystalline mesophase has a smectic A(2) structure. The interlayer distance increases with a decrease in the anion size since the smaller anion has a stronger coulombic interaction with the imidazolium headgroup, resulting in the decrease of the interdigitated part to give a larger layer spacing.

The Investigation of Strain-Induced Martensite Reverse Transformation in AISI 304 Austenitic Stainless Steel

NASA Astrophysics Data System (ADS)

Cios, G.; Tokarski, T.; Żywczak, A.; Dziurka, R.; Stępień, M.; Gondek, Ł.; Marciszko, M.; Pawłowski, B.; Wieczerzak, K.; Bała, P.

2017-10-01

This paper presents a comprehensive study on the strain-induced martensitic transformation and reversion transformation of the strain-induced martensite in AISI 304 stainless steel using a number of complementary techniques such as dilatometry, calorimetry, magnetometry, and in-situ X-ray diffraction, coupled with high-resolution microstructural transmission Kikuchi diffraction analysis. Tensile deformation was applied at temperatures between room temperature and 213 K (-60 °C) in order to obtain a different volume fraction of strain-induced martensite (up to 70 pct). The volume fraction of the strain-induced martensite, measured by the magnetometric method, was correlated with the total elongation, hardness, and linear thermal expansion coefficient. The thermal expansion coefficient, as well as the hardness of the strain-induced martensitic phase was evaluated. The in-situ thermal treatment experiments showed unusual changes in the kinetics of the reverse transformation (α' → γ). The X-ray diffraction analysis revealed that the reverse transformation may be stress assisted—strains inherited from the martensitic transformation may increase its kinetics at the lower annealing temperature range. More importantly, the transmission Kikuchi diffraction measurements showed that the reverse transformation of the strain-induced martensite proceeds through a displacive, diffusionless mechanism, maintaining the Kurdjumov-Sachs crystallographic relationship between the martensite and the reverted austenite. This finding is in contradiction to the results reported by other researchers for a similar alloy composition.

Improving the dissolution and bioavailability of 6-mercaptopurine via co-crystallization with isonicotinamide.

PubMed

Wang, Jian-Rong; Yu, Xueping; Zhou, Chun; Lin, Yunfei; Chen, Chen; Pan, Guoyu; Mei, Xuefeng

2015-03-01

6-Mercaptopurine (6-MP) is a clinically important antitumor drug. The commercially available form was provided as monohydrate and belongs to BCS class II category. Co-crystallization screening by reaction crystallization method (RCM) and monitored by powder X-ray diffraction led to the discovery of a new co-crystal formed between 6-MP and isonicotinamide (co-crystal 1). Co-crystal 1 was thoroughly characterized by X-ray diffraction, FT-IR and Raman spectroscopy, and thermal analysis. Noticeably, the in vitro and in vivo studies revealed that co-crystal 1 possesses improved dissolution rate and superior bioavailability on animal model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transmission in situ and operando high temperature X-ray powder diffraction in variable gaseous environments

NASA Astrophysics Data System (ADS)

Schlicker, Lukas; Doran, Andrew; Schneppmüller, Peter; Gili, Albert; Czasny, Mathias; Penner, Simon; Gurlo, Aleksander

2018-03-01

This work describes a device for time-resolved synchrotron-based in situ and operando X-ray powder diffraction measurements at elevated temperatures under controllable gaseous environments. The respective gaseous sample environment is realized via a gas-tight capillary-in-capillary design, where the gas flow is achieved through an open-end 0.5 mm capillary located inside a 0.7 mm capillary filled with a sample powder. Thermal mass flow controllers provide appropriate gas flows and computer-controlled on-the-fly gas mixing capabilities. The capillary system is centered inside an infrared heated, proportional integral differential-controlled capillary furnace allowing access to temperatures up to 1000 °C.

Investigations on synthesis, growth and physicochemical properties of semi-organic NLO crystal bis(thiourea) ammonium nitrate for nonlinear frequency conversion

NASA Astrophysics Data System (ADS)

Anbarasi, A.; Ravi Kumar, S. M.; Sundar, G. J. Shanmuga; Mosses, M. Allen; Raj, M. Packiya; Prabhakaran, M.; Ravisankar, R.; Gunaseelan, R.

2017-10-01

Bis(thiourea) ammonium nitrate (BTAN), a new nonlinear optical crystal was grown successfully by slow evaporation technique using water as solvent at room temperature. The grown crystals were optically good quality with dimensions upto 10 × 6 × 3 mm3. Single crystal X-Ray diffraction analysis reveals that the crystal lattice is orthorhombic. From Powder X-ray diffraction analysis the diffraction planes have been indexed. The presence of the various functional groups of BTAN was identified through FTIR spectroscopic analysis. UV cut-off wavelength was observed from optical absorbance spectrum and it was found to be 240 nm. Second harmonic efficiency was determined using Kurtz powder method in comparison with KDP to confirm the nonlinearity of the material. Thermal analysis confirmed that grown crystal is thermally stable upto 184 °C. Microhardness studies show that hardness number (Hv) increases with load. Conductivity measurements such as dielectric, ac and photoconductivity were studied. Growth mechanism and surface features of the as grown single crystal was analysed by chemical etching analysis.

Two-dimensional single crystal diamond refractive x-ray lens

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

Antipov, S., E-mail: s.antipov@euclidtechlabs.com; Baryshev, S. V.; Butler, J. E.

2016-07-27

The next generation light sources such as diffraction-limited storage rings and high repetition rate x-ray free-electron lasers will generate x-ray beams with significantly increased brilliance. These future machines will require X-ray optical components that are capable of handling higher instantaneous and average power densities while tailoring the properties of the x-ray beams for a variety of scientific experiments. Single crystal diamond is one of the best bulk materials for this application, because it is radiation hard, has a suitable uniform index of refraction and the best available thermal properties. In this paper we report on fabrication and experimental testing ofmore » a two-dimensional (2D) single crystal diamond compound refractive X-ray lenses (CRL). These lenses were manufactured using femto-second laser cutting and tested at the Advanced Photon Source of Argonne National Laboratory.« less

Effects of limestone petrography and calcite microstructure on OPC clinker raw meals burnability

NASA Astrophysics Data System (ADS)

Galimberti, Matteo; Marinoni, Nicoletta; Della Porta, Giovanna; Marchi, Maurizio; Dapiaggi, Monica

2017-10-01

Limestone represents the main raw material for ordinary Portland cement clinker production. In this study eight natural limestones from different geological environments were chosen to prepare raw meals for clinker manufacturing, aiming to define a parameter controlling the burnability. First, limestones were characterized by X-Ray Fluorescence, X-Ray Powder Diffraction and Optical Microscopy to assess their suitability for clinker production and their petrographic features. The average domains size and the microstrain of calcite were also determined by X-Ray Powder Diffraction line profile analysis. Then, each limestone was admixed with clay minerals to achieve the adequate chemical composition for clinker production. Raw meals were thermally threated at seven different temperatures, from 1000 to 1450 °C, to evaluate their behaviour on heating by ex situ X-Ray Powder Diffraction and to observe the final clinker morphology by Scanning Electron Microscopy. Results indicate the calcite microstrain is a reliable parameter to predict the burnability of the raw meals, in terms of calcium silicates growth and lime consumption. In particular, mixtures prepared starting from high-strained calcite exhibit a better burnability. Later, when the melt appears this correlation vanishes; however differences in the early burnability still reflect on the final clinker composition and texture.

Low thermal conductivity and improved thermoelectric performance of nanocrystalline silicon germanium films by sputtering

NASA Astrophysics Data System (ADS)

Perez Taborda, J. A.; Romero, J. J.; Abad, B.; Muñoz-Rojo, M.; Mello, A.; Briones, F.; Gonzalez, M. S. Martin

2016-04-01

Si x Ge1-x alloys are well-known thermoelectric materials with a high figure of merit at high temperatures. In this work, metal-induced crystallization (MIC) has been used to grow Si0.8Ge0.2 films that present improved thermoelectric performance (zT = 5.6 × 10-4 at room temperature)—according to previously reported values on films—with a relatively large power factor (σ · S 2 = 16 μW · m-1 · K-2). More importantly, a reduction in the thermal conductivity at room temperature (κ = 1.13 ± 0.12 W · m-1 · K-1) compared to other Si-Ge films (˜3 W · m-1 · K-1) has been found. Whereas the usual crystallization of amorphous SiGe (a-SiGe) is achieved at high temperatures and for long times, which triggers dopant loss, MIC reduces the crystallization temperature and the heating time. The associated dopant loss is thus avoided, resulting in a nanostructuration of the film. Using this method, we obtained Si0.8Ge0.2 films (grown by DC plasma sputtering) with appropriate compositional and structural properties. Different thermal treatments were tested in situ (by heating the sample inside the deposition chamber) and ex situ (annealed in an external furnace with controlled conditions). From the studies of the films by: x-ray diffraction (XRD), synchrotron radiation grazing incidence x-ray diffraction (SR-GIXRD), micro Raman, scanning electron microscopy (SEM), x-ray photoemission spectroscopy (XPS), Hall effect, Seebeck coefficient, electrical and thermal conductivity measurements, we observed that the in situ films at 500 °C presented the best zT values with no gold contamination.

Tuning Thermoelectric Properties of Type I Clathrate K 8–x Ba x Al 8+x Si 38–x through Barium Substitution

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

Sui, Fan; Kauzlarich, Susan M.

2016-05-10

The thermal stability and thermoelectric properties of type I clathrate K8Al8Si38 up to 873 K are reported. K8Al8Si38 possesses a high absolute Seebeck coefficient value and high electrical resistivity in the temperature range of 323 to 873 K, which is consistent with previously reported low temperature thermoelectric properties. Samples with Ba partial substitution at the K guest atom sites were synthesized from metal hydride precursors. The samples with the nominal chemical formula of K8–xBaxAl8+xSi38–x (x = 1, 1.5, 2) possess type I clathrate structure (cubic, Pm3n), confirmed by X-ray diffraction. The guest atom site occupancies and thermal motions were investigatedmore » with Rietveld refinement of synchrotron powder X-ray diffraction. Transport properties of Ba-containing samples were characterized from 2 to 300 K. The K–Ba alloy phases showed low thermal conductivity and improved electrical conductivity compared to K8Al8Si38. Electrical resistivity and Seebeck coefficients were measured over the temperature range of 323 to 873 K. Thermal conductivity from 323 to 873 K was estimated from the Wiedemann–Franz relation and lattice thermal conductivity extrapolation from 300 to 873 K. K8–xBaxAl8+xSi38–x (x = 1, 1.5) synthesized with Al deficiency showed enhanced electrical conductivity, and the absolute Seebeck coefficients decrease with the increased carrier concentration. When x = 2, the Al content increases toward the electron balanced composition, and the electrical resistivity increases with the decreasing charge carrier concentration. Overall, K6.5Ba1.5Al9Si37 achieves an enhanced zT of 0.4 at 873 K.« less

Self catalytic growth of indium oxide (In2O3) nanowires by resistive thermal evaporation.

PubMed

Kumar, R Rakesh; Rao, K Narasimha; Rajanna, K; Phani, A R

2014-07-01

Self catalytic growth of Indium Oxide (In2O3) nanowires (NWs) have been grown by resistive thermal evaporation of Indium (In) in the presence of oxygen without use of any additional metal catalyst. Nanowires growth took place at low substrate temperature of 370-420 degrees C at an applied current of 180-200 A to the evaporation boat. Morphology, microstructures, and compositional studies of the grown nanowires were performed by employing field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) respectively. Nanowires were uniformly grown over the entire Si substrate and each of the nanowire is capped with a catalyst particle at their end. X-ray diffraction study reveals the crystalline nature of the grown nanowires. Transmission electron microscopy study on the nanowires further confirmed the single crystalline nature of the nanowires. Energy dispersive X-ray analysis on the nanowires and capped nanoparticle confirmed that Indium act as catalyst for In2O3 nanowires growth. A self catalytic Vapor-Liquid-Solid (VLS) growth mechanism was responsible for the growth of In2O3 nanowires. Effect of oxygen partial pressure variation and variation of applied currents to the evaporation boat on the nanowires growth was systematically studied. These studies concluded that at oxygen partial pressure in the range of 4 x 10(-4), 6 x 10(-4) mbar at applied currents to the evaporation boat of 180-200 A were the best conditions for good nanowires growth. Finally, we observed another mode of VLS growth along with the standard VLS growth mode for In2O3 nanowires similar to the growth mechanism reported for GaAs nanowires.

In situ X-ray measurements of MOVPE growth of InxGa1-xN single quantum wells

NASA Astrophysics Data System (ADS)

Ju, Guangxu; Fuchi, Shingo; Tabuchi, Masao; Takeda, Yoshikazu

2013-05-01

GaN/InxGa1-xN/GaN single quantum wells (SQWs) have been grown on c-plane GaN/sapphire substrates using MOVPE system. PL (photoluminescence) and AFM (atomic force microscope) measurements demonstrate good quality of after-growth thermal-annealed SQWs. In situ XRD (X-ray diffraction), XRR (X-ray reflectivity), and X-ray CTR (crystal truncation rod) scattering measurements were successfully conducted on the SQWs under the NH3+N2 ambient at 1103 K. The analysis results of the XRR and the X-ray CTR spectra at 1103 K and at 300 K on the same sample matched well. It demonstrated that In0.09Ga0.91N SQW structure with several ML (monolayer) InGaN thicknesses was successfully investigated using the XRR and CTR scattering measurements at 1103 K.

X-ray diffraction from shock-loaded polycrystals.

PubMed

Swift, Damian C

2008-01-01

X-ray diffraction was demonstrated from shock-compressed polycrystalline metals on nanosecond time scales. Laser ablation was used to induce shock waves in polycrystalline foils of Be, 25-125 microm thick. A second laser pulse was used to generate a plasma x-ray source by irradiation of a Ti foil. The x-ray source was collimated to produce a beam of controllable diameter, which was directed at the Be sample. X-rays were diffracted from the sample, and detected using films and x-ray streak cameras. The diffraction angle was observed to change with shock pressure. The diffraction angles were consistent with the uniaxial (elastic) and isotropic (plastic) compressions expected for the loading conditions used. Polycrystalline diffraction will be used to measure the response of the crystal lattice to high shock pressures and through phase changes.

Determining and Controlling the Magnesium Composition in CdTe/CdMgTe Heterostructures

DOE PAGES

LeBlanc, E. G.; Edirisooriya, M.; Ogedengbe, O. S.; ...

2017-06-05

The relationships between Mg composition, band gap, and lattice characteristics are investigated for Cd 1-xMg xTe barrier layers using a combination of cathodoluminescence, energy dispersive x-ray spectroscopy, variable angle spectral ellipsometry, and atom probe tomography. The use of a simplified, yet accurate, variable angle spectral ellipsometry analysis is shown to be appropriate for fast determination of composition in thin Cd 1-xMg xTe layers. The validity of using high-resolution x-ray diffraction for CdTe/Cd 1-xMg xTe double heterostructures is discussed. Furthermore, the stability of CdTe/Cd 1-xMg xTe heterostructures are investigated with respect to thermal processing.

Determining and Controlling the Magnesium Composition in CdTe/CdMgTe Heterostructures

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

LeBlanc, E. G.; Edirisooriya, M.; Ogedengbe, O. S.

The relationships between Mg composition, band gap, and lattice characteristics are investigated for Cd 1-xMg xTe barrier layers using a combination of cathodoluminescence, energy dispersive x-ray spectroscopy, variable angle spectral ellipsometry, and atom probe tomography. The use of a simplified, yet accurate, variable angle spectral ellipsometry analysis is shown to be appropriate for fast determination of composition in thin Cd 1-xMg xTe layers. The validity of using high-resolution x-ray diffraction for CdTe/Cd 1-xMg xTe double heterostructures is discussed. Furthermore, the stability of CdTe/Cd 1-xMg xTe heterostructures are investigated with respect to thermal processing.

Unusual thermal expansion of Sr{sub 2}IrO{sub 4}: A variable temperature synchrotron X-ray diffraction study

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

Ranjbar, Ben; Kennedy, Brendan J.

The structure of Sr{sub 2}IrO{sub 4} has been studied between 20 and 1273 K using synchrotron X-ray diffraction. Sr{sub 2}IrO{sub 4} undergoes an apparently continuous transition from I4{sub 1}/acd to I4/mmm near 1123 K. The cooperative tilting of the corner sharing IrO{sub 6} octahedra in I4{sub 1}/acd results in highly anisotropic and unusual thermal expansion behavior with negative thermal expansion along the c-axis. - Graphical abstract: The progressive reduction in the magnitude of the tilting of the corner sharing IrO{sub 6} octahedra in Sr{sub 2}IrO{sub 4} results in negative thermal expansion along the c-axis before undergoing an apparently continuous transitionmore » from I4{sub 1}/acd to I4/mmm near 1123 K. - Highlights: • Thermal expansion of Sr{sub 2}IrO{sub 4} was studied using Synchrotron-XRD. • Unusual negative thermal expansion along c-axis observed. • I4{sub 1}/acd→I4/mmm phase transition detected near 1120 K. • Tilting of the corner sharing IrO{sub 6} octahedra related to the observed NTE.« less

Thermal Equation of State of TiC: A Synchrotron X-ray Diffraction

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

Yu, X.; Lin, Z; Zhang, J

2010-01-01

The pressure-volume-temperature measurements were carried out for titanium carbide (TiC) at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal pressure approach. With the pressure derivative of the bulk modulus, K{prime}{sub 0}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0} = 268(6) GPa, which is comparable to previously reported value; temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub P} = -0.026(9) GPa K{sup -1}, volumetric thermal expansivity {alpha}{sub T}(K{sup -1}) =more » a+b T with a = 1.62(12) x 10{sup -5} K{sup -1} and b = 1.07(17) x 10{sup -8}K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}{sub {alpha}}/{partial_derivative}{sub P}){sub T} = (-3.62 {+-} 1.14) x 10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub V} = -0.015(8) GPa K{sup -1}. These results provide fundamental thermophysical properties for TiC for the first time and are important to theoretical and computational modeling of transition metal carbides.« less

Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

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

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.

2016-08-15

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from themore » sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.« less

Coherence Length and Vibrations of the Coherence Beamline I13 at the Diamond Light Source

NASA Astrophysics Data System (ADS)

Wagner, U. H.; Parson, A.; Rau, C.

2017-06-01

I13 is a 250 m long hard x-ray beamline for imaging and coherent diffraction at the Diamond Light Source. The beamline (6 keV to 35 keV) comprises two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques [1]. In particular the coherence experiments pose very high demands on the performance on the beamline instrumentation, requiring extensive testing and optimisation of each component, even during the assembly phase. Various aspects like the quality of optical components, the mechanical design concept, vibrations, drifts, thermal influences and the performance of motion systems are of particular importance. In this paper we study the impact of the front-end slit size (FE slit size), which determines the horizontal source size, onto the coherence length and the detrimental impact of monochromator vibrations using in-situ x-ray metrology in conjunction with fringe visibility measurements and vibration measurements, based on centroid tracking of an x-ray pencil beam with a photon-counting detector.

Synthesis, crystal structure, vibrational spectroscopy and photoluminescence of new hybrid compound containing chlorate anions of stanate (II)

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Meroño, Rafael Mendoza; Gadri, Abdellatif; Ammar, Salah; Ben Salah, Abdelhamid; García-Granda, Santiago

2017-08-01

The present work aimed at studying a new organic-inorganic bis (4-amino quinolinium) hexachloro stanate (II) dihydrate compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. It was found to crystallize in the monoclinic system (P21/c space group) with the following lattice parameters: a = 7.2558(6) Å, b = 13.4876(5) Å, c = 17.2107(13) Å, β = 102.028 (12)°. Its crystal structure was determined and refined down to an R value of 0.06 and a wR value of 0.087. The structure consisted of two different alternating organic-inorganic layers. The crystal packing was stabilized by Nsbnd H⋯Cl and Osbnd H⋯Cl hydrogen bonds and π-π interactions. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electronic microscopy (SEM) was carried out. Furthermore, the room temperature Infra Red (IR) spectrum of the title compound was analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows ten signals, confirming the solid state structure determined by X-ray diffraction. Thermal analysis shows two anomalies at 380 and 610 °C. The optical properties of the crystal were studied using optical absorption UV-visible and photoluminescence (PL) spectroscopy, which were investigated at room temperature.

Structures and standard molar enthalpies of formation of a series of Ln(III)–Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid

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

Yang, Qi; Xie, Gang; Wei, Qing

2014-07-01

Fifteen lanthanide–copper heteronuclear compounds, formulated as [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 6}]·xH{sub 2}O (1–6(x=2), 8(x=3), 9–10(x=4)); [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 4}]·xH{sub 2}O (7, 12–13, 15(x=4), 14(x=5), 11(x=8)) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H{sub 2}pzdc (C{sub 6}H{sub 4}N{sub 2}O{sub 4})=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with (4.6{sup 2}){sub 2}(4{sup 2}.6{sup 2}.8{sup 2})(6{sup 3}){sup 2}(6{sup 5}.8){sub 2} topology. Using 1 mol cm{supmore » −3} HCl(aq) as calorimetric solvent, with an isoperibol solution–reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state. - Graphical abstract: According to Hess' rule, the standard molar enthalpies of formation of Ln–Cu heterometallic coordination compounds were determined by a designed thermochemical cycle. - Highlights: • Fifteen lanthanide–copper heteronuclear isostructural compounds. • Structurally characterization by IR, X-ray diffraction and thermal analysis. • The standard molar enthalpy of formation. • Isoperibol solution–reaction calorimetry.« less

Valence band offset of β-Ga2O3/wurtzite GaN heterostructure measured by X-ray photoelectron spectroscopy.

PubMed

Wei, Wei; Qin, Zhixin; Fan, Shunfei; Li, Zhiwei; Shi, Kai; Zhu, Qinsheng; Zhang, Guoyi

2012-10-10

A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN structure is 1.40 ± 0.08 eV.

Valence band offset of β-Ga2O3/wurtzite GaN heterostructure measured by X-ray photoelectron spectroscopy

PubMed Central

2012-01-01

A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN structure is 1.40 ± 0.08 eV. PMID:23046910

Fabrication of Three-Dimensional Nanostructures for Thermal Study

DTIC Science & Technology

2013-01-01

Cu2O Inverse Opal …………………………………24 3.4 X - ray Analysis of the Structure …………………………………………………….26 3.5 Discussion and Future Direction...2.3 Characterization of Silicon Inverse Opal The 80 nm and 40 nm silicon inverse opal material properties were characterized by x - ray diffraction... x - ray beam of 1 ° relative to the surface of the sample was used due to the low amounts silicon present in the thin porous structure to enhance the

Structural and optical properties of CuS thin films deposited by Thermal co-evaporation

NASA Astrophysics Data System (ADS)

Sahoo, A. K.; Mohanta, P.; Bhattacharyya, A. S.

2015-02-01

Copper sulfide (CuS) thin films with thickness 100, 150 and 200 nm have been deposited on glass substrates by thermal co-evaporation of Copper and Sulphur. The effect of CuS film thickness on the structural and optical properties have investigated and discussed. Structural and optical investigations of the films were carried out by X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy and UV spectroscopy. XRD and selected area electron diffraction conforms that polycrystalline in nature with hexagonal crystal structure. AFM studies revealed a smooth surface morphology with root mean-square roughness values increases from 24 nm to 42 nm as the film thickness increase from 100 nm to 200 nm. AFM image showed that grain size increases with thickness of film increases and good agreement with the calculated from full width half maximum of the X-ray diffraction peak using Scherrer's formula and Williamson-Hall plot. The absorbance of the thin films were absorbed decreases with wavelength through UV-visible regions but showed a increasing in the near-infrared regions. The reflectance spectra also showed lower reflectance peak (25% to 32%) in visible region and high reflectance peak (49 % to 54 %) in near-infrared region. These high absorbance films made them for photo-thermal conversion of solar energy.

Anomalous Thermal Expansion of HoCo0.5Cr0.5O3 Probed by X-ray Synchrotron Powder Diffraction.

PubMed

Hreb, Vasyl; Vasylechko, Leonid; Mykhalichko, Vitaliya; Prots, Yurii

2017-12-01

Mixed holmium cobaltite-chromite HoCo 0.5 Cr 0.5 O 3 with orthorhombic perovskite structure (structure type GdFeO 3 , space group Pbnm) was obtained by solid state reaction of corresponding oxides in air at 1373 K. Room- and high-temperature structural parameters were derived from high-resolution X-ray synchrotron powder diffraction data collected in situ in the temperature range of 300-1140 K. Analysis of the results obtained revealed anomalous thermal expansion of HoCo 0.5 Cr 0.5 O 3 , which is reflected in a sigmoidal temperature dependence of the unit cell parameters and in abnormal increase of the thermal expansion coefficients with a broad maxima near 900 K. Pronounced anomalies are also observed for interatomic distances and angles within Co/CrO 6 octahedra, tilt angles of octahedra and atomic displacement parameters. The observed anomalies are associated with the changes of spin state of Co 3+ ions and insulator-metal transition occurring in HoCo 0.5 Cr 0.5 O 3 .

Atomically designed precursors in optical fiber amplifiers: The thermal stability of the heterobimetallic ErAl3(OPri)12 in a solution-coated silica soot

NASA Astrophysics Data System (ADS)

Engholm, M.; Lashgari, K.; Edvardsson, S.; Westin, G.; Norin, L.

2005-06-01

The thermal stability of the bimetallic alkoxide ErAl3(OPri)12 doped in an unsintered silica (soot) has been investigated. Samples have been heated to different temperatures (up to 1500°C and analyzed by using ultraviolet-visible-near infrared absorption spectroscopy, infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, thermal gravimetric analysis, and powder x-ray diffraction. It is seen that the doped samples heated up to 1000°C show broad glasslike absorption spectra, indicating an amorphous structure, while the high-temperature sample shows an ordered crystallinelike structure with sharp characteristic absorption peaks. X-ray diffraction measurements indicate the formation of an ordered structure at temperatures of 1500°C, revealing a crystal phase of silica and phases of erbium and aluminosilicate. A comparison is also made with a sample doped with aqueous ErCl3 and Al(NO3)3. It is concluded that the local structure of the ErAl3 precursor is not preserved at temperatures above 1000°C. Alternative doping procedures are discussed.

Anomalous Thermal Expansion of HoCo0.5Cr0.5O3 Probed by X-ray Synchrotron Powder Diffraction

NASA Astrophysics Data System (ADS)

Hreb, Vasyl; Vasylechko, Leonid; Mykhalichko, Vitaliya; Prots, Yurii

2017-07-01

Mixed holmium cobaltite-chromite HoCo0.5Cr0.5O3 with orthorhombic perovskite structure (structure type GdFeO3, space group Pbnm) was obtained by solid state reaction of corresponding oxides in air at 1373 K. Room- and high-temperature structural parameters were derived from high-resolution X-ray synchrotron powder diffraction data collected in situ in the temperature range of 300-1140 K. Analysis of the results obtained revealed anomalous thermal expansion of HoCo0.5Cr0.5O3, which is reflected in a sigmoidal temperature dependence of the unit cell parameters and in abnormal increase of the thermal expansion coefficients with a broad maxima near 900 K. Pronounced anomalies are also observed for interatomic distances and angles within Co/CrO6 octahedra, tilt angles of octahedra and atomic displacement parameters. The observed anomalies are associated with the changes of spin state of Co3+ ions and insulator-metal transition occurring in HoCo0.5Cr0.5O3.

Identification of New Cocrystal Systems with Stoichiometric Diversity of Salicylic Acid Using Thermal Methods.

PubMed

Zhou, Zhengzheng; Chan, Hok Man; Sung, Herman H-Y; Tong, Henry H Y; Zheng, Ying

2016-04-01

The purpose of this work was to develop thermal methods to identify cocrystal systems with stoichiometric diversity. Differential scanning calorimetry (DSC) and hot stage microscopy (HSM) have been applied to study the stoichiometric diversity phenomenon on cocrystal systems of the model compound salicylic acid (SA) with different coformers (CCFs). The DSC method was particularly useful in the identification of cocrystal re-crystallization, especially to improve the temperature resolution using a slower heating rate. HSM was implemented as a complementary protocol to confirm the DSC results. The crystal structures were elucidated by single-crystal X-ray diffraction (SXRD). Two new cocrystal systems consisting of salicylic acid-benzamide (SA-BZD, 1:1, 1:2) and salicylic acid-isonicotinamide (SA-ISN, 1:1, 2:1) have been identified in the present work. The chemical structures of the newly discovered cocrystals SA-BZD (1:2) and SA-ISN (2:1) have been elucidated using X-ray single crystal and powder diffraction methods. The developed thermal methods could rapidly identify cocrystal systems with stoichiometric diversity, with the potential to discover new pharmaceutical cocrystals in the future.

Crystal structure and thermal expansion of a CsCe 2Cl 7 scintillator

DOE PAGES

Zhuravleva, M.; Lindsey, A.; Chakoumakos, B. C.; ...

2015-04-06

Here we used single-crystal X-ray diffraction data to determine crystal structure of CsCe 2Cl 7. It crystallizes in a P112 1/b space group with a = 19.352(1) Å, b = 19.352(1) Å, c = 14.838(1) Å, γ = 119.87(2) ° , and V = 4818.6(5) Å 3. Differential scanning calorimetry measurements combined with the structural evolution of CsCe 2Cl 7 via X-ray diffractometry over a temperature range from room temperature to the melting point indicates no obvious intermediate solid-solid phase transitions. The anisotropy in the average linear coefficient of thermal expansion of the a axis (21.3 10 -6/ °C) withmore » respect to the b and c axes (27.0 10 -6/ °C) was determined through lattice parameter refinement of the temperature dependent diffraction patterns. Lastly, these findings suggest that the reported cracking behavior during melt growth of CsCe 2Cl 7 bulk crystals using conventional Bridgman and Czochralski techniques may be largely attributed to the anisotropy in thermal expansion.« less

Crystal growth, structural, optical, spectral and thermal studies of tris( L-phenylalanine) L-phenylalaninium nitrate: A new organic nonlinear optical material

NASA Astrophysics Data System (ADS)

Prakash, M.; Geetha, D.; Lydia Caroline, M.

2011-10-01

Tris( L-phenylalanine) L-phenylalaninium nitrate, C 9H 12NO 2+·NO 3-·3C 9H 11NO 2 (TPLPN), a new organic nonlinear optical material was grown from aqueous solution by slow evaporation solution growth at room temperature. The grown crystals were subjected to powder X-ray diffraction and single crystal X-ray diffraction studies to confirm the crystalline nature and crystal structure. The modes of vibration of different molecular groups present in TPLPN have been identified by FTIR spectral analysis. The presence of hydrogen and carbon in the grown crystal were confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. The optical transmission spectral study establishes good transmitting ability of the crystal in the entire visible region. The thermogravimetric (TG) and differential thermal analyses (DTA) were carried out to understand the thermal stability of the sample. The nonlinear optical property of the compound observed using Kurtz powder second harmonic generation test assets the suitability of the grown material for the frequency conversion of laser radiation of Nd:YAG.

Synthesis and characterization of nano TiO2-SiO2: PVA composite - a novel route

NASA Astrophysics Data System (ADS)

Venckatesh, Rajendran; Balachandaran, Kartha; Sivaraj, Rajeshwari

2012-07-01

A novel, simple, less time consuming and cost-effective sol-gel method has been developed to synthesize nano titania-silica with polyvinyl alcohol (PVA) composite relatively at low temperature in acidic pH. Titania sol is prepared by hydrolysis of titanium tetrachloride and was mixed with silicic acid and tetrahydrofuran mixture. The reaction was carried out under vigorous stirring for 6 h and dried at room temperature with the addition of PVA solution. The resulting powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FT-IR), UV-visible spectroscopy and thermal techniques. The grain size of the particles was calculated by X-ray diffraction; surface morphology and chemical composition were determined from scanning electron microscopy-energy dispersive spectroscopy; metal oxide stretching was confirmed from FT-IR spectroscopy; bandgap was calculated using UV-visible spectroscopy, and thermal stability of the prepared composite was determined by thermogravimetric/differential thermal analysis. Since TiO2 got agglomerated on the surface of SiO2, effective absorptive sites increase which in turn increase the photocatalytic efficiency of the resulting composite.

Effects of X-ray irradiation on the Eu3+ → Eu2+ conversion in CaAl2O4 phosphors

NASA Astrophysics Data System (ADS)

Gomes, Manassés A.; Carvalho, Jéssica C.; Andrade, Adriano B.; Rezende, Marcos V.; Macedo, Zélia S.; Valerio, Mário E. G.

2018-01-01

This paper reports structural and luminescence properties of Eu-doped CaAl2O4 produced by an alternative sol-gel method using coconut water. Results of differential thermal analysis (DTA), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) allowed us to identify the best synthesis conditions for sample preparation. Simultaneous measurements of X-ray absorption spectroscopy (XAS) and X-ray excited optical luminescence (XEOL) were also performed in the X-ray energy range of the Eu LIII edge. Results from photoluminescence (PL) showed only the characteristic Eu3+ emission. However, radioluminescence emission spectra from Eu-doped CaAl2O4 shows a process of conversion of Eu3+ to Eu2+, which is induced by X-ray irradiation and is dependent on the radiation dose energy. X-ray absorption near edge structure (XANES) measurements corroborate Eu reduction due to irradiation, showing that only the Eu3+ ion is present in stable form in the CaAl2O4.

Enhanced saturation of sputtered amorphous SiN film frameworks using He- and Ne-Penning effects

NASA Astrophysics Data System (ADS)

Sugimoto, Iwao; Nakano, Satoko; Kuwano, Hiroki

1994-06-01

Optical emission spectroscopy reveals that helium and neon gases enhance the nitridation reactivity of the nitrogen plasma by Penning effects during magnetron sputtering of the silicon target. These excited nitrogen plasmas promote the saturation of frameworks of the resultant silicon nitride films. X-ray photoelectron spectroscopy, electron spin resonance, and x-ray diffraction analyses provide insight into the structure of these films, and thermal desorption mass spectroscopy reveals the behavior of volatile species in these films.

Study of microstructure and electroluminescence of zinc sulfide thin film

NASA Astrophysics Data System (ADS)

Zhao-hong, Liu; Yu-jiang, Wang; Mou-zhi, Chen; Zhen-xiang, Chen; Shu-nong, Sun; Mei-chun, Huang

1998-03-01

The electroluminscent zinc sulfide thin film doped with erbium, fabricated by thermal evaporation with two boats, are examined. The surface and internal electronic states of ZnS thin film are measured by means of x-ray diffraction and x-ray photoemission spectroscopy. The information on the relations between electroluminescent characteristics and internal electronic states of the film is obtained. And the effects of the microstructure of thin film doped with rare earth erbium on electroluminescence are discussed as well.

New chemical hydrogen storage materials exploiting the self-sustaining thermal decomposition of guanidinium borohydride.

PubMed

Groshens, Thomas J; Hollins, Richard A

2009-06-07

Guanidinium borohydride (GBH) was structurally characterized by single-crystal X-ray diffraction and found to release more than 10 wt% H(2) as a fairly pure stream during a self-sustaining thermal decomposition reaction both with and without additives that were identified to reduce the concentration of the main ammonia impurity and control the reaction sustainability.

X-Ray Diffraction Apparatus

NASA Technical Reports Server (NTRS)

Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

1996-01-01

An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

Investigation on synthesis, growth and characterization of CdIn2S2Se2 single crystal grown by vertical Bridgman method

NASA Astrophysics Data System (ADS)

Vijayakumar, P.; Ramasamy, P.

2017-06-01

CdIn2S2Se2 polycrystalline material has been synthesized by melt oscillation method. Vertical Bridgman method was used to grow a good quality CdIn2S2Se2 single crystal. The crystalline phase and growth orientation were confirmed by powder X-ray diffraction pattern and unit cell parameters were determined by single crystal X-ray diffraction analysis. The structural uniformity of CdIn2S2Se2 was studied using Raman scattering spectroscopy at room temperature. The stoichiometric composition variation along the CdIn2S2Se2 was measured using energy dispersive spectrometry. The transmission spectra of CdIn2S2Se2 single crystal gave 42% transmission in the NIR region. Thermal property of CdIn2S2Se2 has been studied using differential thermal analysis. Thermal diffusivity, specific heat capacity and thermal conductivity were also measured. Electrical property was measured using Hall Effect measurement and it confirms the n-type semiconducting nature. The hardness behavior has been measured using Vickers micro hardness measurement and the indentation size effect has been observed.

Practical Problems in the Cement Industry Solved by Modern Research Techniques

ERIC Educational Resources Information Center

Daugherty, Kenneth E.; Robertson, Les D.

1972-01-01

Practical chemical problems in the cement industry are being solved by such techniques as infrared spectroscopy, gas chromatography-mass spectrometry, X-ray diffraction, atomic absorption and arc spectroscopy, thermally evolved gas analysis, Mossbauer spectroscopy, transmission and scanning electron microscopy. (CP)

Microcellular poly(hydroxybutyrate-co-hydroxyvalerate)-hyperbranched polymer-nanoclay nanocomposites

Treesearch

Alireza Javadi; Yottha Srithep; Srikanth Pilla; Craig C. Clemons; Shaoqin Gong; Lih-Sheng Turng

2012-01-01

The effects of incorporating hyperbranched polymers (HBPs) and different nanoclays [Cloisite® 30B and halloysite nanotubes (HNT)] on the mechanical, morphological, and thermal properties of solid and microcellular poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were investigated. According to the X-ray diffraction (...

Complex compound polyvinyl alcohol-titanic acid/titanium dioxide

NASA Astrophysics Data System (ADS)

Prosanov, I. Yu.

2013-02-01

A complex compound polyvinyl alcohol-titanic acid has been produced and investigated by means of IR and Raman spectroscopy, X-ray diffraction, and synchronous thermal analysis. It is claimed that it represents an interpolymeric complex of polyvinyl alcohol and hydrated titanium oxide.

Real-time X-ray Diffraction: Applications to Materials Characterization

NASA Technical Reports Server (NTRS)

Rosemeier, R. G.

1984-01-01

With the high speed growth of materials it becomes necessary to develop measuring systems which also have the capabilities of characterizing these materials at high speeds. One of the conventional techniques of characterizing materials was X-ray diffraction. Film, which is the oldest method of recording the X-ray diffraction phenomenon, is not quite adequate in most circumstances to record fast changing events. Even though conventional proportional counters and scintillation counters can provide the speed necessary to record these changing events, they lack the ability to provide image information which may be important in some types of experiment or production arrangements. A selected number of novel applications of using X-ray diffraction to characterize materials in real-time are discussed. Also, device characteristics of some X-ray intensifiers useful in instantaneous X-ray diffraction applications briefly presented. Real-time X-ray diffraction experiments with the incorporation of image X-ray intensification add a new dimension in the characterization of materials. The uses of real-time image intensification in laboratory and production arrangements are quite unlimited and their application depends more upon the ingenuity of the scientist or engineer.

Radiation damage free ghost diffraction with atomic resolution

DOE PAGES

Li, Zheng; Medvedev, Nikita; Chapman, Henry N.; ...

2017-12-21

The x-ray free electron lasers can enable diffractive structural determination of protein nanocrystals and single molecules that are too small and radiation-sensitive for conventional x-ray diffraction. However the electronic form factor may be modified during the ultrashort x-ray pulse due to photoionization and electron cascade caused by the intense x-ray pulse. For general x-ray imaging techniques, the minimization of the effects of radiation damage is of major concern to ensure reliable reconstruction of molecular structure. Here in this paper, we show that radiation damage free diffraction can be achieved with atomic spatial resolution by using x-ray parametric down-conversion and ghostmore » diffraction with entangled photons of x-ray and optical frequencies. We show that the formation of the diffraction patterns satisfies a condition analogous to the Bragg equation, with a resolution that can be as fine as the crystal lattice length scale of several Ångstrom. Since the samples are illuminated by low energy optical photons, they can be free of radiation damage.« less

Radiation damage free ghost diffraction with atomic resolution

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

Li, Zheng; Medvedev, Nikita; Chapman, Henry N.

The x-ray free electron lasers can enable diffractive structural determination of protein nanocrystals and single molecules that are too small and radiation-sensitive for conventional x-ray diffraction. However the electronic form factor may be modified during the ultrashort x-ray pulse due to photoionization and electron cascade caused by the intense x-ray pulse. For general x-ray imaging techniques, the minimization of the effects of radiation damage is of major concern to ensure reliable reconstruction of molecular structure. Here in this paper, we show that radiation damage free diffraction can be achieved with atomic spatial resolution by using x-ray parametric down-conversion and ghostmore » diffraction with entangled photons of x-ray and optical frequencies. We show that the formation of the diffraction patterns satisfies a condition analogous to the Bragg equation, with a resolution that can be as fine as the crystal lattice length scale of several Ångstrom. Since the samples are illuminated by low energy optical photons, they can be free of radiation damage.« less

Synchrotron Radiation X-ray Diffraction Techniques Applied to Insect Flight Muscle.

PubMed

Iwamoto, Hiroyuki

2018-06-13

X-ray fiber diffraction is a powerful tool used for investigating the molecular structure of muscle and its dynamics during contraction. This technique has been successfully applied not only to skeletal and cardiac muscles of vertebrates but also to insect flight muscle. Generally, insect flight muscle has a highly ordered structure and is often capable of high-frequency oscillations. The X-ray diffraction studies on muscle have been accelerated by the advent of 3rd-generation synchrotron radiation facilities, which can generate brilliant and highly oriented X-ray beams. This review focuses on some of the novel experiments done on insect flight muscle by using synchrotron radiation X-rays. These include diffraction recordings from single myofibrils within a flight muscle fiber by using X-ray microbeams and high-speed diffraction recordings from the flight muscle during the wing-beat of live insects. These experiments have provided information about the molecular structure and dynamic function of flight muscle in unprecedented detail. Future directions of X-ray diffraction studies on muscle are also discussed.

A hydrous Ca-bearing magnesium carbonate from playa lake sediments, Salines Lake, Spain

USGS Publications Warehouse

Queralt, I.; Julia, R.; Plana, F.; Bischoff, J.L.

1997-01-01

Sediments of playa Lake Salines, SE, Spain, contain a carbonate mineral characterized by X-ray diffraction peaks very similar to, but systematically shifted from those of pure magnesite. Analyses (SEM, IR and Raman spectroscopy, DTA, TGA, and ICP) indicate the mineral is a hydrous Ca-bearing magnesium carbonate with the chemical formula (Mg0.92,Ca0.08)CO3??3H2O. Thermal characteristics of the mineral are similar to those of other known hydrated magnesium carbonates. X-ray and electron diffraction data suggests a monoclinic system (P21/n space group) with unit-cell parameters of a = 6.063(6), b = 10.668(5), and c = 6.014(4) A?? and ?? = 107.28??.

A recommended procedure for the preparation of oriented clay-mineral specimens for X-ray diffraction analysis; modifications to Drever's filter-membrane peel technique

USGS Publications Warehouse

Pollastro, R.M.

1982-01-01

Extremely well-oriented clay mineral mounts for X-ray diffraction analysis can be prepared quickly and without introducing segregation using the filter-membrane peel technique. Mounting problems encountered with smectite-rich samples can be resolved by using minimal sample and partial air-drying of the clay film before transfer to a glass slide. Samples containing small quantities of clay can produce useful oriented specimens if Teflon masks having more restrictive areas are inserted above the membrane filter during clay deposition. War]page and thermal shock of glass slides can be controlled by using a flat, porous, ceramic plate as a holding surface during heat treatments.

Synthesis of a 3D lanthanum(III) MOFs as a multi-chemosensor to Cr(VI)-containing anion and Fe(III) cation based on a flexible ligand

NASA Astrophysics Data System (ADS)

Ma, Yang-Min; Liu, Tong; Huang, Wen-Huan

2018-02-01

Based on La(NO3)3·6H2O and 4,4‧-((5-carboxy-1,3-phenylene)bis(oxy))dibenzoic acid (H3cpbda), a 3D porous MOFs, [La(cpbda)(H2O)1.5]n (1), was synthesized by hydrothermal method and further characterized by single-crystal X-ray diffraction, power X-ray diffraction, IR spectroscopy, thermal-gravimetric analysis and fluorescence spectroscopy. Owing to its good stabilities and fluorescence property, the sensing experiments on sixteen cations and eleven anions were implemented. Moreover, the further titration processes show 1 can sensitively detect the Fe(III) cation and Cr(VI)-containing anions by quenching responses.

Structural and optical properties of nanostructured nickel

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

Singh, J., E-mail: jaiveer24singh@gmail.com; Pandey, J.; Gupta, R.

2016-05-06

Metal nanoparticles are attractive because of their special structure and better optical properties. Nickel nanoparticles (Ni-Np) have been synthesized successfully by thermal decomposition method in the presence of trioctyl phosphine (TOP) and oleylamine (OAm). The samples were characterized by X-ray diffraction (XRD), Zetapotential measurement and Fourier transforms infrared (FTIR) spectroscopy. The size of Ni nanoparticles can be readily tuned from 13.86 nm. As-synthesized Ni nanoparticles have hexagonal closed pack (hcp) cubic structure as characterized by power X-ray diffraction (XRD) prepared at 280°C. The possible formation mechanism has also been phenomenological proposed for as synthesized Ni-Np. The value of Zeta potential wasmore » found 12.25 mV.« less

Synthesis of In2O3nanoparticles by thermal decomposition of a citrate gel precursor

NASA Astrophysics Data System (ADS)

Rey, J. F. Q.; Plivelic, T. S.; Rocha, R. A.; Tadokoro, S. K.; Torriani, I.; Muccillo, E. N. S.

2005-06-01

This paper describes the synthesis of indium oxide by a modified sol-gel method, and the study of thermal decomposition of the metal complex in air. The characterization of the intermediate as well as the final compounds was carried out by thermogravimetry, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and small angle X-ray scattering. The results show that the indium complex decomposes to In2O3 with the formation of an intermediate compound. Nanoparticles of cubic In2O3 with crystallite sizes in the nanosize range were formed after calcination at temperatures up to 900°C. Calcined materials are characterized by a polydisperse distribution of spherical particles with sharp and smooth surfaces.

Time Resolved X-Ray Diffraction Study of Acoustoelectrically Amplified Phonons.

NASA Astrophysics Data System (ADS)

Chapman, Leroy Dean

X-rays diffracted by nearly perfect crystals of n-type InSb have been investigated in the presence of intense acoustoelectrically (A.E.) amplified phonons. The fact that these phonons are nearly monochromatic and have a well defined propagation and polarization direction presents an excellent opportunity to investigate the nature of x -ray photon-phonon scattering in a diffracting crystal. The Debye-Waller factor which accounts for the attenuation of diffracted x-ray intensities due to thermal phonons is reflection dependent owing to its sin (theta)/(lamda) dependence. We have performed experiments comparing the (004) and (008) anomalously transmitted intensities as a function of A.E. amplified flux. The attenuation of both reflections due to the amplified phonons was the same in direct contradiction to an expected sin (theta)/(lamda) dependence. Some possible reasons for this failure are discussed. In a Bragg reflection scattering geometry, the intense monochromatic amplified phonons give rise to satellite peaks symmetrically located about the central elastic Brag peak in a rocking profile. We report in this thesis on the first observation of satellites in a thin crystal Laue transmission geometry. We have theoretically simulated the rocking profiles with some success. The A.E. amplification process in InSb is strongly favored for {110} propagation fast transverse (FT) phonons. In earlier experiments it was found that non-{110} FT phonons were also produced during the amplification process. We have developed a time resolved x-ray counting system which, in conjunction with a spatially resolved x-ray beam and a localized, traveling A.E. phonon distribution, allow the time evolution of the amplified distribution to be followed. We report on time resolved measurements for both the symmetric Bragg and Laue geometries from which we can determine when and where non-{110 } FT flux is generated and restrict the possible mechanisms for its generation.

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

Yin, Fei; Chen, Jing; Liang, Yongfeng

Two coordination polymers [Co(dnbab){sub 2}(bimb)](H{sub 2}O){sub 4} (1) and [Zn(dnbab){sub 2}(bimb)](H{sub 2}O){sub 5} (2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been solvothermally synthesized. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complexes 1 and 2 are isostructures and each displays an one-dimensional (1D) zigzag chain, which further forms a 3D supramolecular architecture with 1-D channels via inter-chain π–π interactions and hydrogen bonds. Moreover, the magnetic properties of 1 and fluorescent properties of 2 have been investigated. - Graphical abstract: Two coordination supramolecular frameworks [Co(dnbab){sub 2}(bimb)](H{sub 2}O){sub 4}(1)more » and [Zn(dnbab){sub 2}(bimb)](H{sub 2}O){sub 5}(2) (Hdnbab=4-[(3,5-dinitrobenzoyl)amino]benzoic acid, bimb=1,4-bis(1-imidazolyl) benzene) have been synthesized and characterized by X-ray single-crystal diffraction. Their thermal, magnetic and fluorescent properties have also been studied. - Highlights: • Two isomorphic Co(II)/Zn(II) complexes with the mixed-ligands have been synthesized. • Hydrogen bonds and π–π stacking interactions directed the final 3-D architecture assembly. • Both Co(II) and Zn(II) complexes show good thermal stability. • Co complex exhibits antiferromagnetic interaction. • The fluorescent property of Zn(II) complex has been investigated in the solid state.« less

Combining experiment and optical simulation in coherent X-ray nanobeam characterization of Si/SiGe semiconductor heterostructures

DOE PAGES

Tilka, J. A.; Park, J.; Ahn, Y.; ...

2016-07-06

Here, the highly coherent and tightly focused x-ray beams produced by hard x-ray light sources enable the nanoscale characterization of the structure of electronic materials but are accompanied by significant challenges in the interpretation of diffraction and scattering patterns. X-ray nanobeams exhibit optical coherence combined with a large angular divergence introduced by the x-ray focusing optics. The scattering of nanofocused x-ray beams from intricate semiconductor heterostructures produces a complex distribution of scattered intensity. We report here an extension of coherent xray optical simulations of convergent x-ray beam diffraction patterns to arbitrary x-ray incident angles to allow the nanobeam diffraction patternsmore » of complex heterostructures to be simulated faithfully. These methods are used to extract the misorientation of lattice planes and the strain of individual layers from synchrotron x-ray nanobeam diffraction patterns of Si/SiGe heterostructures relevant to applications in quantum electronic devices. The systematic interpretation of nanobeam diffraction patterns from semiconductor heterostructures presents a new opportunity in characterizing and ultimately designing electronic materials.« less

Large-area soft x-ray projection lithography using multilayer mirrors structured by RIE

NASA Astrophysics Data System (ADS)

Rahn, Steffen; Kloidt, Andreas; Kleineberg, Ulf; Schmiedeskamp, Bernt; Kadel, Klaus; Schomburg, Werner K.; Hormes, F. J.; Heinzmann, Ulrich

1993-01-01

SXPL (soft X-ray projection lithography) is one of the most promising applications of X-ray reflecting optics using multilayer mirrors. Within our collaboration, such multilayer mirrors were fabricated, characterized, laterally structured and then used as reflection masks in a projecting lithography procedure. Mo/Si-multilayer mirrors were produced by electron beam evaporation in UHV under thermal treatment with an in-situ X-ray controlled thickness in the region of 2d equals 14 nm. The reflectivities measured at normal incidence reached up to 54%. Various surface analysis techniques have been applied in order to characterize and optimize the X-ray mirrors. The multilayers were patterned by reactive ion etching (RIE) with CF(subscript 4), using a photoresist as the etch mask, thus producing X-ray reflection masks. The masks were tested in the synchrotron radiation laboratory of the electron accelerator ELSA at the Physikalisches Institut of Bonn University. A double crystal X-ray monochromator was modified so as to allow about 0.5 cm(superscript 2) of the reflection mask to be illuminated by white synchrotron radiation. The reflected patterns were projected (with an energy of 100 eV) onto the resist (Hoechst AZ PF 514), which was mounted at an average distance of about 7 mm. In the first test-experiments, structure sizes down to 8 micrometers were nicely reproduced over the whole of the exposed area. Smaller structures were distorted by Fresnel-diffraction. The theoretically calculated diffraction images agree very well with the observed images.

The crystal structure of paramagnetic copper(II) oxalate (CuC₂O₄): formation and thermal decomposition of randomly stacked anisotropic nano-sized crystallites.

PubMed

Christensen, Axel Nørlund; Lebech, Bente; Andersen, Niels Hessel; Grivel, Jean-Claude

2014-11-28

Synthetic copper(II) oxalate, CuC2O4, was obtained in a precipitation reaction between a copper(II) solution and an aqueous solution of oxalic acid. The product was identified from its conventional X-ray powder patterns which match that of the copper mineral Moolooite reported to have the composition CuC2O4·0.44H2O. Time resolved in situ investigations of the thermal decomposition of copper(II) oxalate using synchrotron X-ray powder diffraction showed that in air the compound converts to Cu2O at 215 °C and oxidizes to CuO at 345 °C. Thermo gravimetric analysis performed in an inert Ar-gas reveals that the material contains no crystal water and reduces to pure Cu at 295 °C. Magnetic susceptibility measurements in the temperature range from 2 K to 300 K show intriguing paramagnetic behaviour with no sign of magnetic order down to 2 K. A crystal structure investigation is made based on powder diffraction data using one neutron diffraction pattern obtained at 5 K (λ = 1.5949(1) Å) combined with one conventional and two synchrotron X-ray diffraction patterns obtained at ambient temperature using λ = 1.54056, 1.0981 and λ = 0.50483(1) Å, respectively. Based on the X-ray synchrotron data the resulting crystal structure is described in the monoclinic space group P2₁/c (#14) in the P12₁/n1 setting with unit cell parameters a = 5.9598(1) Å, b = 5.6089(1) Å, c = 5.1138 (1) Å, β = 115.320(1)°. The composition is CuC2O4 with atomic coordinates determined by FullProf refinement of the neutron diffraction data. The crystal structure consists of a random stacking of CuC2O4 micro-crystallites where half the Cu-atoms are placed at (2a) and the other half at (2b) positions with the corresponding oxalate molecules centred around the corresponding (2b) and (2a) site positions, respectively. The diffraction patterns obtained for both kinds of radiation show considerable broadening of several Bragg peaks caused by highly anisotropic microstructural size and strain effects. In contrast to the water reported to be present in Moolooite, neither thermogravimetric nor the in situ thermal decomposition investigations and crystal structure analysis of the neutron diffraction data revealed any trace of water. An appendix contains details about the profile parameters for the diffractometers used at the European Synchrotron Radiation Facility and the Institute Max von Laue-Paul Langevin.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Sequestration and disposal of dissolved Cs+ using zeolite 13X

NASA Astrophysics Data System (ADS)

Park, M.; Park, J.; Jeong, H. Y.

2017-12-01

Low-to-intermediate level liquid radioactive wastes (LILLW) typically contain high levels of radioactive 137Cs. Due to the great radiational and thermal stability as well as the high selectivity, zeolite has been commonly utilized to sequester radioactive isotopes from nuclear wastewater effluents. In this study, an Al-rich synthetic zeolite 13X was evaluated for the sorption capacity of Cs+ as a function of pH (4.0-10.5), ionic strength (0.05 and 0.2 M), and initial Cs+ concentration (1×10-6-5×10-3 M). For safe disposal, Cs+-exchanged 13X was both thermally and hydrothermally treated under different temperature and pressure. Subsequently, the resultant materials were examined for the phase transition by X-ray diffraction (XRD) and the local coordination chemistry by X-ray absorption spectroscopy (XAS). Our experimental results will detail the Cs+ sorption behavior by 13X under varying solution compositions. Also, the structural changes of Cs+-exchanged 13X upon thermal and hydrothermal treatment will be delineated to assess the stability of Cs+ in the treated materials.

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

Singh, Paviter; Kaur, Manpreet; Singh, Bikramjeet

Boron-carbon core shell structures have been synthesized by solvo-thermal synthesis route. The synthesized material is highly pure. X-ray diffraction analysis confirms the reduction of reactants in to boron and carbon. Scanning Electron Microscopy (SEM) analysis showed that the shell is uniform with average thickness of 340 nm. Photo luminescence studies showed that the material is blue light emitting with CIE color coordinates: x=0.16085, y=0.07554.

The Composition of Intermediate Products of the Thermal Decomposition of (NH4)2ZrF6 to ZrO2 from Vibrational-Spectroscopy Data

NASA Astrophysics Data System (ADS)

Voit, E. I.; Didenko, N. A.; Gaivoronskaya, K. A.

2018-03-01

Thermal decomposition of (NH4)2ZrF6 resulting in ZrO2 formation within the temperature range of 20°-750°C has been investigated by means of thermal and X-ray diffraction analysis and IR and Raman spectroscopy. It has been established that thermolysis proceeds in six stages. The vibrational-spectroscopy data for the intermediate products of thermal decomposition have been obtained, systematized, and summarized.

Probing multi-scale mechanical damage in connective tissues using X-ray diffraction.

PubMed

Bianchi, Fabio; Hofmann, Felix; Smith, Andrew J; Thompson, Mark S

2016-11-01

The accumulation of microstructural collagen damage following repetitive loading is linked to painful and debilitating tendon injuries. As a hierarchical, semi-crystalline material, collagen mechanics can be studied using X-ray diffraction. The aim of the study was to describe multi-structural changes in tendon collagen following controlled plastic damage (5% permanent strain). We used small angle X-ray scattering (SAXS) to interrogate the spacing of collagen molecules within a fibril, and wide angle X-ray scattering (WAXS) to measure molecular strains under macroscopic loading. Simultaneous recordings of SAXS and WAXS patterns, together with whole-tissue strain in physiologically hydrated rat-tail tendons were made during increments of in situ tensile loading. Results showed that while tissue level modulus was unchanged, fibril modulus decreased significantly, and molecular modulus significantly increased. Further, analysis of higher order SAXS peaks suggested structural changes in the gap and overlap regions, possibly localising the damage to molecular cross-links. Our results provide new insight into the fundamental damage processes at work in collagenous tissues and point to new directions for their mitigation and repair. This article reports the first in situ loading synchrotron studies on mechanical damage in collagenous tissues. We provide new insight into the nano- and micro-structural mechanisms of damage processes. Pre-damaged tendons showed differential alteration of moduli at macro, micro and nano-scales as measured using X-ray scattering techniques. Detailed analysis of higher order diffraction peaks suggested damage is localised to molecular cross-links. The results are consistent with previous X-ray scattering studies of tendons and also with recent thermal stability studies on damaged material. Detailed understanding of damage mechanisms is essential in the development of new therapies promoting tissue repair. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Studies on synthesis, growth, structural, thermal, linear and nonlinear optical properties of organic picolinium maleate single crystals.

PubMed

Pandi, P; Peramaiyan, G; Sudhahar, S; Chakkaravarthi, G; Mohan Kumar, R; Bhagavannarayana, G; Jayavel, R

2012-12-01

Picolinium maleate (PM), an organic material has been synthesised and single crystals were grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction analysis. PM crystal belongs to the monoclinic crystallographic system with space group P2(1)/c. The crystalline perfection of the grown crystals was analyzed by high-resolution X-ray diffraction rocking curve measurements. The presence of functional groups in PM was identified by FTIR and FT-NMR spectral analyses. Thermal behaviour and stability of picolinium maleate were studied by TGA/DTA analyses. UV-Vis spectral studies reveal that PM crystals are transparent in the wavelength region 327-1100 nm. The laser damage threshold value of PM crystal was found to be 4.3 GW/cm(2) using Nd:YAG laser. The Kurtz and Perry powder second harmonic generation technique confirms the nonlinear optical property of the grown crystal. Copyright © 2012 Elsevier B.V. All rights reserved.

Growth and characterization of barium complex of 1,3,5-triazinane-2,4,6-trione in gel: a corrosion inhibiting material

NASA Astrophysics Data System (ADS)

Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Babu, K. Rajendra

2018-05-01

Good quality prismatic crystals of industrially applicable corrosion inhibiting barium complex of 1,3,5-triazinane-2,4,6-trione have been grown by conventional gel method. The crystal structure, packing, and nature of bonds are revealed in the single crystal X-ray diffraction analysis. The crystal has a three-dimensional polymeric structure having a triclinic crystal system with the space group P-1. The powder X-ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal are identified by Fourier transform infrared spectroscopy. Elemental analysis confirms the stoichiometry of the elements present in the complex. Thermogravimetric analysis and differential thermal analysis reveal its good thermal stability. The optical properties like band gap, refractive index and extinction coefficient are evaluated from the UV-visible spectral analysis. The singular property of the material, corrosion inhibition efficiency achieved by the adsorption of the sample molecules is determined by the weight loss method.

In-situ X-ray diffraction studies of the phase transformations and structural states of B2, R and B19′ phases in Ti{sub 49.5}Ni{sub 50.5} alloy

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

Ostapenko, Marina G., E-mail: artifakt@ispms.tsc.ru; National Research Tomsk Polytechnic University, Tomsk, 634050; Meisner, Ludmila L., E-mail: llm@ispms.tsc.ru

2015-10-27

The martensitic transformation, Debye–Waller factor, mean-square atomic displacements and the coefficient of thermal expansion on cooling of the Ti{sub 49.5}Ni{sub 50.5} shape memory alloy were examined using in-situ X-ray diffraction. It was revealed B2→R (T{sub R} ≡ T = 273 ± 10 K) along with B2→B19’ (M{sub s} ≡ T = 273 ± 10 K) transitions occur. It was found that Debye–Waller factor and mean-square displacement of B2 phase undergo significant increase as functions of temperature when phase transition B2→R and B2→B19’ take place. The analysis of the thermal expansion coefficient of the B2 phase indicates that the value of a increasesmore » almost linearly while cooling.« less

The first 3-D LaIII-SrII heterometallic complex: Synthesis, structure and luminescent properties

NASA Astrophysics Data System (ADS)

Hong, Zhiwei; Ran, Jingwen; Li, Tao; Chen, Yanmei

2016-10-01

The first 3-D LaIII-SrII heterometallic complex, namely [La2Sr(pda)4(H2O)4]n·6nH2O (1, H2pda = pyridine-2,6-dicarboxylic acid), has been successfully synthesized under solvothermal conditions. Single crystal X-ray diffraction analysis reveals that complex 1 features a 3-D porous framework and displays a new topology. The crystal structure can be simplified to a 4,6-connected 3-D network with Schläfli symbol of {34·42·88·9}2{34·42}. The crystals also have been characterized by X-ray powder diffraction, elemental analysis, thermal analysis, and IR spectroscopy. The infrared spectral analysis indicates that complex 1 is a carboxylate coordinated compound, several water molecules exist in the compound. The thermal study shows that there are ten water molecules in the crystal structure. The luminescent property has also been investigated. It shows a blue-purple fluorescence emission.

Synthesis of boron nitride nanostructures from catalyst of iron compounds via thermal chemical vapor deposition technique

NASA Astrophysics Data System (ADS)

da Silva, Wellington M.; Ribeiro, Hélio; Ferreira, Tiago H.; Ladeira, Luiz O.; Sousa, Edésia M. B.

2017-05-01

For the first time, patterned growth of boron nitride nanostructures (BNNs) is achieved by thermal chemical vapor deposition (TCVD) technique at 1150 °C using a mixture of FeS/Fe2O3 catalyst supported in alumina nanostructured, boron amorphous and ammonia (NH3) as reagent gas. This innovative catalyst was synthesized in our laboratory and systematically characterized. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The X-ray diffraction profile of the synthesized catalyst indicates the coexistence of three different crystal structures showing the presence of a cubic structure of iron oxide and iron sulfide besides the gamma alumina (γ) phase. The results show that boron nitride bamboo-like nanotubes (BNNTs) and hexagonal boron nitride (h-BN) nanosheets were successfully synthesized. Furthermore, the important contribution of this work is the manufacture of BNNs from FeS/Fe2O3 mixture.

Dynamical scattering in coherent hard x-ray nanobeam Bragg diffraction

NASA Astrophysics Data System (ADS)

Pateras, A.; Park, J.; Ahn, Y.; Tilka, J. A.; Holt, M. V.; Kim, H.; Mawst, L. J.; Evans, P. G.

2018-06-01

Unique intensity features arising from dynamical diffraction arise in coherent x-ray nanobeam diffraction patterns of crystals having thicknesses larger than the x-ray extinction depth or exhibiting combinations of nanoscale and mesoscale features. We demonstrate that dynamical scattering effects can be accurately predicted using an optical model combined with the Darwin theory of dynamical x-ray diffraction. The model includes the highly divergent coherent x-ray nanobeams produced by Fresnel zone plate focusing optics and accounts for primary extinction, multiple scattering, and absorption. The simulation accurately reproduces the dynamical scattering features of experimental diffraction patterns acquired from a GaAs/AlGaAs epitaxial heterostructure on a GaAs (001) substrate.

Coherent x-ray diffraction imaging with nanofocused illumination.

PubMed

Schroer, C G; Boye, P; Feldkamp, J M; Patommel, J; Schropp, A; Schwab, A; Stephan, S; Burghammer, M; Schöder, S; Riekel, C

2008-08-29

Coherent x-ray diffraction imaging is an x-ray microscopy technique with the potential of reaching spatial resolutions well beyond the diffraction limits of x-ray microscopes based on optics. However, the available coherent dose at modern x-ray sources is limited, setting practical bounds on the spatial resolution of the technique. By focusing the available coherent flux onto the sample, the spatial resolution can be improved for radiation-hard specimens. A small gold particle (size <100 nm) was illuminated with a hard x-ray nanobeam (E=15.25 keV, beam dimensions approximately 100 x 100 nm2) and is reconstructed from its coherent diffraction pattern. A resolution of about 5 nm is achieved in 600 s exposure time.

DynAMITe: a prototype large area CMOS APS for breast cancer diagnosis using x-ray diffraction measurements

NASA Astrophysics Data System (ADS)

Konstantinidis, A.; Anaxagoras, T.; Esposito, M.; Allinson, N.; Speller, R.

2012-03-01

X-ray diffraction studies are used to identify specific materials. Several laboratory-based x-ray diffraction studies were made for breast cancer diagnosis. Ideally a large area, low noise, linear and wide dynamic range digital x-ray detector is required to perform x-ray diffraction measurements. Recently, digital detectors based on Complementary Metal-Oxide- Semiconductor (CMOS) Active Pixel Sensor (APS) technology have been used in x-ray diffraction studies. Two APS detectors, namely Vanilla and Large Area Sensor (LAS), were developed by the Multidimensional Integrated Intelligent Imaging (MI-3) consortium to cover a range of scientific applications including x-ray diffraction. The MI-3 Plus consortium developed a novel large area APS, named as Dynamically Adjustable Medical Imaging Technology (DynAMITe), to combine the key characteristics of Vanilla and LAS with a number of extra features. The active area (12.8 × 13.1 cm2) of DynaMITe offers the ability of angle dispersive x-ray diffraction (ADXRD). The current study demonstrates the feasibility of using DynaMITe for breast cancer diagnosis by identifying six breast-equivalent plastics. Further work will be done to optimize the system in order to perform ADXRD for identification of suspicious areas of breast tissue following a conventional mammogram taken with the same sensor.

Resolution enhancement in coherent x-ray diffraction imaging by overcoming instrumental noise.

PubMed

Kim, Chan; Kim, Yoonhee; Song, Changyong; Kim, Sang Soo; Kim, Sunam; Kang, Hyon Chol; Hwu, Yeukuang; Tsuei, Ku-Ding; Liang, Keng San; Noh, Do Young

2014-11-17

We report that reference objects, strong scatterers neighboring weak phase objects, enhance the phase retrieval and spatial resolution in coherent x-ray diffraction imaging (CDI). A CDI experiment with Au nano-particles exhibited that the reference objects amplified the signal-to-noise ratio in the diffraction intensity at large diffraction angles, which significantly enhanced the image resolution. The interference between the diffracted x-ray from reference objects and a specimen also improved the retrieval of the phase of the diffraction signal. The enhancement was applied to image NiO nano-particles and a mitochondrion and confirmed in a simulation with a bacteria phantom. We expect that the proposed method will be of great help in imaging weakly scattering soft matters using coherent x-ray sources including x-ray free electron lasers.

Incorporation of Cadmium and Nickel into Ferrite Spinel Solid Solution: X-ray Diffraction and X-ray Absorption Fine Structure Analyses.

PubMed

Su, Minhua; Liao, Changzhong; Chan, Tingshan; Shih, Kaimin; Xiao, Tangfu; Chen, Diyun; Kong, Lingjun; Song, Gang

2018-01-16

The feasibility of incorporating Cd and Ni in hematite was studied by investigating the interaction mechanism for the formation of Cd x Ni 1-x Fe 2 O 4 solid solutions (CNFs) from CdO, NiO, and α-Fe 2 O 3 . X-ray diffraction results showed that the CNFs crystallized into spinel structures with increasing lattice parameters as the Cd content in the precursors was increased. Cd 2+ ions were found to occupy the tetrahedral sites, as evidenced by Rietveld refinement and extended X-ray absorption fine structure analyses. The incorporation of Cd and Ni into ferrite spinel solid solution strongly relied on the processing parameters. The incorporation of Cd and Ni into the CNFs was greater at high x values (0.7 < x ≤ 1.0) than at low x values (0.0 ≤ x ≤ 0.7). A feasible treatment technique based on the investigated mechanism of CNF formation was developed, involving thermal treatment of waste sludge containing Cd and Ni. Both of these metals in the waste sludge were successfully incorporated into a ferrite spinel solid solution, and the concentrations of leached Cd and Ni from this solid solution were substantially reduced, stabilizing at low levels. This research offers a highly promising approach for treating the Cd and Ni content frequently encountered in electronic waste and its treatment residues.

A synchrotron X-ray diffraction deconvolution method for the measurement of residual stress in thermal barrier coatings as a function of depth.

PubMed

Li, C; Jacques, S D M; Chen, Y; Daisenberger, D; Xiao, P; Markocsan, N; Nylen, P; Cernik, R J

2016-12-01

The average residual stress distribution as a function of depth in an air plasma-sprayed yttria stabilized zirconia top coat used in thermal barrier coating (TBC) systems was measured using synchrotron radiation X-ray diffraction in reflection geometry on station I15 at Diamond Light Source, UK, employing a series of incidence angles. The stress values were calculated from data deconvoluted from diffraction patterns collected at increasing depths. The stress was found to be compressive through the thickness of the TBC and a fluctuation in the trend of the stress profile was indicated in some samples. Typically this fluctuation was observed to increase from the surface to the middle of the coating, decrease a little and then increase again towards the interface. The stress at the interface region was observed to be around 300 MPa, which agrees well with the reported values. The trend of the observed residual stress was found to be related to the crack distribution in the samples, in particular a large crack propagating from the middle of the coating. The method shows promise for the development of a nondestructive test for as-manufactured samples.

Bragg Coherent Diffractive Imaging of Zinc Oxide Acoustic Phonons at Picosecond Timescales

DOE PAGES

Ulvestad, A.; Cherukara, M. J.; Harder, R.; ...

2017-08-29

Mesoscale thermal transport is of fundamental interest and practical importance in materials such as thermoelectrics. Coherent lattice vibrations (acoustic phonons) govern thermal transport in crystalline solids and are affected by the shape, size, and defect density in nanoscale materials. The advent of hard x-ray free electron lasers (XFELs) capable of producing ultrafast x-ray pulses has significantly impacted the understanding of acoustic phonons by enabling their direct study with x-rays. However, previous studies have reported ensemble-averaged results that cannot distinguish the impact of mesoscale heterogeneity on the phonon dynamics. Here we use Bragg coherent diffractive imaging (BCDI) to resolve the 4Dmore » evolution of the acoustic phonons in a single zinc oxide rod with a spatial resolution of 50 nm and a temporal resolution of 25 picoseconds. We observe homogeneous (lattice breathing/rotation) and inhomogeneous (shear) acoustic phonon modes, which are compared to finite element simulations. We investigate the possibility of changing phonon dynamics by altering the crystal through acid etching. Lastly, we find that the acid heterogeneously dissolves the crystal volume, which will significantly impact the phonon dynamics. In general, our results represent the first step towards understanding the effect of structural properties at the individual crystal level on phonon dynamics.« less

Bragg Coherent Diffractive Imaging of Zinc Oxide Acoustic Phonons at Picosecond Timescales

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

Ulvestad, A.; Cherukara, M. J.; Harder, R.

Mesoscale thermal transport is of fundamental interest and practical importance in materials such as thermoelectrics. Coherent lattice vibrations (acoustic phonons) govern thermal transport in crystalline solids and are affected by the shape, size, and defect density in nanoscale materials. The advent of hard x-ray free electron lasers (XFELs) capable of producing ultrafast x-ray pulses has significantly impacted the understanding of acoustic phonons by enabling their direct study with x-rays. However, previous studies have reported ensemble-averaged results that cannot distinguish the impact of mesoscale heterogeneity on the phonon dynamics. Here we use Bragg coherent diffractive imaging (BCDI) to resolve the 4Dmore » evolution of the acoustic phonons in a single zinc oxide rod with a spatial resolution of 50 nm and a temporal resolution of 25 picoseconds. We observe homogeneous (lattice breathing/rotation) and inhomogeneous (shear) acoustic phonon modes, which are compared to finite element simulations. We investigate the possibility of changing phonon dynamics by altering the crystal through acid etching. Lastly, we find that the acid heterogeneously dissolves the crystal volume, which will significantly impact the phonon dynamics. In general, our results represent the first step towards understanding the effect of structural properties at the individual crystal level on phonon dynamics.« less

Studies on densification, mechanical, micro-structural and structure–properties relationship of magnesium aluminate spinel refractory aggregates prepared from Indian magnesite

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

Ghosh, Chandrima; Ghosh, Arup; Haldar, Manas Kamal, E-mail: manashaldar@cgcri.res.in

The present work intends to study the development of magnesium aluminate spinel aggregates from Indian magnesite in a single firing stage. The raw magnesite has been evaluated in terms of chemical analysis, differential thermal analysis, thermogravimetric analysis, infrared spectroscopy, and X-ray diffraction. The experimental batch containing Indian magnesite and calcined alumina has been sintered in the temperature range of 1550 °C–1700 °C. The sintered material has been characterized in terms of physico-chemical properties like bulk density, apparent porosity, true density, relative density and thermo-mechanical/mechanical properties like hot modulus of rupture, thermal shock resistance, cold modulus of rupture and structural propertiesmore » by X-ray diffraction in terms of phase identification and evaluation of crystal structure parameters of corresponding phases by Rietveld analysis. The microstructures developed at different temperatures have been analyzed by field emission scanning electron microscope study and compositional analysis of the developed phase has been carried out by energy dispersive X-ray study. - Highlights: • The studies have been done to characterize the developed magnesium aluminate spinel. • The studies reveal correlation between refractory behavior of spinel and developed microstructures. • The studies show the values of lattice parameters of developed phases.« less

Modeling of Interface and Internal Disorder Applied to XRD Analysis of Ag-Based Nano-Multilayers.

PubMed

Ariosa, Daniel; Cancellieri, Claudia; Araullo-Peters, Vicente; Chiodi, Mirco; Klyatskina, Elizaveta; Janczak-Rusch, Jolanta; Jeurgens, Lars P H

2018-06-20

Multilayered structures are a promising route to tailor electronic, magnetic, optical, and/or mechanical properties and durability of functional materials. Sputter deposition at room temperature, being an out-of-equilibrium process, introduces structural defects and confers to these nanosystems an intrinsic thermodynamical instability. As-deposited materials exhibit a large amount of internal atomic displacements within each constituent block as well as severe interface roughness between different layers. To access and characterize the internal multilayer disorder and its thermal evolution, X-ray diffraction investigation and analysis are performed systematically at differently grown Ag-Ge/aluminum nitride (AlN) multilayers (co-deposited, sequentially deposited with and without radio frequency (RF) bias) samples and after high-temperature annealing treatment. We report here on model calculations based on a kinematic formalism describing the displacement disorder both within the multilayer blocks and at the interfaces to reproduce the experimental X-ray diffraction intensities. Mixing and displacements at the interface are found to be considerably reduced after thermal treatment for co- and sequentially deposited Ag-Ge/AlN samples. The application of a RF bias during the deposition causes the highest interface mixing and introduces random intercalates in the AlN layers. X-ray analysis is contrasted to transmission electron microscopy pictures to validate the approach.

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

Willey, Trevor M.; Lauderbach, Lisa; Gagliardi, Franco

HMX-based explosives LX-10 and PBX-9501 were heated through the β-δ phase transition. Ultra-small angle x-ray scattering (USAXS) and molecular diffraction were simultaneously recorded as the HMX was heated. Mesoscale voids and structure dramatically change promptly with the β-δ phase transition, rather than with other thermal effects. Also, x-ray induced damage, observed in the USAXS, occurs more readily at elevated temperatures; as such, the dose was reduced to mitigate this effect. Optical microscopy performed during a similar heating cycle gives an indication of changes on longer length scales, while x-ray microtomography, performed before and after heating, shows the character of extensivemore » microstructural damage resulting from the temperature cycle and solid-state phase transition.« less

Solid-state amorphization of rebamipide and investigation on solubility and stability of the amorphous form.

PubMed

Xiong, Xinnuo; Xu, Kailin; Li, Shanshan; Tang, Peixiao; Xiao, Ying; Li, Hui

2017-02-01

Solid-state amorphization of crystalline rebamipide (RBM) was realized by ball milling and spray drying. The amorphous content of samples milled for various time was quantified using X-ray powder diffraction. Crystalline RBM and three amorphous RBM obtained by milling and spray drying were characterized by morphological analysis, X-ray diffraction, thermal analysis and vibrational spectroscopy. The crystal structure of RBM was first determined by single-crystal X-ray diffraction. In addition, the solubility and dissolution rate of the RBM samples were investigated in different media. Results indicated that the solubility and the dissolution rates of spray-dried RBM-PVP in different media were highly improved compared with crystalline RBM. The physical stabilities of the three amorphous RBM were systematically investigated, and the stability orders under different storage temperatures and levels of relative humidity (RH) were both as follows: spray dried RBM < milled RBM < spray dried RBM-PVP. A direct glass-to-crystal transformation was induced under high RH, and the transformation rate rose with increasing RH. However, amorphous RBM could stay stable at RH levels lower than 57.6% (25 °C).

First X-Ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest Aeolian Bedform at Gale Crater

NASA Technical Reports Server (NTRS)

Bish, D. L.; Blake, D. F.; Vaniman, D. T.; Chipera, S. J.; Sarrazin, P.; Morris, R. V.; Ming, D. W.; Treiman, A. H.; Downs, R. T.; Morrison, S. M.;

CFA-4 - a fluorinated metal-organic framework with exchangeable interchannel cations.

PubMed

Fritzsche, J; Grzywa, M; Denysenko, D; Bon, V; Senkovska, I; Kaskel, S; Volkmer, D

2017-05-23

The syntheses and crystal structures of the fluorinated linker 1,4-bis(3,5-bis(trifluoromethyl)-1H-pyrazole-4-yl)benzene (H 2 -tfpb; 1) and the novel metal-organic framework family M[CFA-4] (Coordination Framework Augsburg University-4), M[Cu 5 (tfpb) 3 ] (M = Cu(i), K, Cs, Ca(0.5)), are described. The ligand 1 is fully characterized by single crystal X-ray diffraction, photoluminescence-, NMR-, IR spectroscopy, and mass spectrometry. The copper(i)-containing MOF crystallizes in the hexagonal crystal system within the chiral space group P6 3 22 (no. 182) and the unit cell parameters are as follows: a = 23.630(5) Å, c = 41.390(5) Å, V = 20 015(6) Å 3 . M[CFA-4] features a porous 3-D structure constructed from pentanuclear copper(i) secondary building units {Cu(pz) 6 } - (pz = pyrazolate). Cu(I)[CFA-4] is fully characterized by synchrotron single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence and gas sorption measurements. Moreover, thermal stability and gas sorption properties of K[CFA-4] and Cu(I)[CFA-4] are compared.

[Physicochemical properties of suplatast tosilate racemate and enantiomers].

PubMed

Ushio, T; Endo, K; Yamamoto, K

1996-11-01

The physicochemical properties of the enantiomer and racemates of suplatast tosilate (ST) were investigated by means of infrared spectroscopy, solid-state 13C CP/MAS NMR spectroscopy, thermal analysis, and X-ray diffraction analysis, and by measuring the solubility and hygroscopy. The infrared and NMR spectra and X-ray diffraction pattern of the enantiomer were distinctly different from those of the racemate. The melting point of the enantiomer was lower than that of the racemate by 5 degrees C, while the solubility of the enantiomer was 1.3 times higher than that of the racemate. The hygroscopic rate of the enantiomer was greater than that of the racemate. These results suggested that ST was classified into a racemic compound crystal. Furthermore, by comparing the relative peak intensity ratios on X-ray diffraction patterns of the crystals with various optical purities prepared by recrystallization, it was found that a mixture of racemic compound crystals and either of racemic mixture crystals or racemic solid solutions was obtained by recrystallization of ST in the content of 0 to 64%ee, while the recrystallization of ST in the content of more than 64%ee led to the formation of racemic mixture crystals or racemic solid solutions.

Study of the structural and thermal properties of plasma treated jute fibre

NASA Astrophysics Data System (ADS)

Sinha, E.; Rout, S. K.; Barhai, P. K.

2008-08-01

Jute fibres ( Corchorus olitorius), were treated with argon cold plasma for 5, 10 and 15 min. Structural macromolecular parameters of untreated and plasma treated fibres were investigated using small angle X-ray scattering (SAXS), and the crystallinity parameters of the same fibres were determined by using X-ray diffraction (XRD). Differential scanning calorimetry (DSC) was used to study the thermal behavior of the untreated and treated fibres. Comparison and analysis of the results confirmed the changes in the macromolecular structure after plasma treatment. This is due to the swelling of cellulosic particles constituting the fibres, caused by the bombardment of high energetic ions onto the fibre surface. Differential scanning calorimetry data demonstrated the thermal instability of the fibre after cold plasma treatment, as the thermal degradation temperature of hemicelluloses and cellulose was found lowered than that of raw fibre after plasma treatment.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

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

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Local terahertz field enhancement for time-resolved x-ray diffraction

DOE PAGES

Kozina, M.; Pancaldi, M.; Bernhard, C.; ...

2017-02-20

We report local field strength enhancement of single-cycle terahertz (THz) pulses in an ultrafast time-resolved x-ray diffraction experiment. We show that patterning the sample with gold microstructures increases the THz field without changing the THz pulse shape or drastically affecting the quality of the x-ray diffraction pattern. Lastly, we find a five-fold increase in THz-induced x-ray diffraction intensity change in the presence of microstructures on a SrTiO 3 thin-film sample.

Local terahertz field enhancement for time-resolved x-ray diffraction

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

Kozina, M.; Pancaldi, M.; Bernhard, C.

We report local field strength enhancement of single-cycle terahertz (THz) pulses in an ultrafast time-resolved x-ray diffraction experiment. We show that patterning the sample with gold microstructures increases the THz field without changing the THz pulse shape or drastically affecting the quality of the x-ray diffraction pattern. Lastly, we find a five-fold increase in THz-induced x-ray diffraction intensity change in the presence of microstructures on a SrTiO 3 thin-film sample.

X-ray diffraction analysis of residual stress in zirconia dental composites

NASA Astrophysics Data System (ADS)

Allahkarami, Masoud

Dental restoration ceramic is a complex system to be characterized. Beside its essential biocompatibility, and pleasant appearance, it requires being mechanically strong in a catastrophic loading environment. Any design is restricted with geometry boundary and material property limits. Inspired by natural teeth, a multilayer ceramic is a smart way of achieving an enhanced restoration. Bi-layers of zirconia core covered by porcelain are known as one of the best multilayer restorations. Residual stresses may be introduced into a bi-layer dental ceramic restoration during its entire manufacturing process due to thermal expansion and elastic property mismatch. It is impossible to achieve a free of residual stresses bi-layer zirconia-porcelain restoration. The idea is to take the advantage of residual stress in design in such a way to prevent the crack initiation and progression. The hypothesis is a compressive residual stress at external contact surface would be enabling the restoration to endure a greater tensile stress. Optimizing the layers thickness, manufacturing process, and validating 3D simulations require development of new techniques of thickness, residual stresses and phase transformation measurement. In the present work, a combined mirco-tomography and finite element based method were adapted for thickness measurement. Two new 2D X-ray diffraction based techniques were adapted for phase transformation area mapping and combined phase transformation and residual stress measurement. Concerning the complex geometry of crown, an efficient method for X-ray diffraction data collection mapping on a given curved surface was developed. Finally a novel method for 3D dimensional x-ray diffraction data collection and visualization were introduced.

An image focusing means by using an opaque object to diffract x-rays

DOEpatents

Sommargren, Gary E.; Weaver, H. Joseph

1991-01-01

The invention provides a method and apparatus for focusing and imaging x-rays. An opaque sphere is used as a diffractive imaging element to diffract x-rays from an object so that the divergent x-ray wavefronts are transformed into convergent wavefronts and are brought to focus to form an image of the object with a large depth of field.

Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell

DOE PAGES

Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; ...

2009-11-01

We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 °C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

Morphology and dispersion of FeCo alloy nanoparticles dispersed in a matrix of IR pyrolized polyvinyl alcohol

NASA Astrophysics Data System (ADS)

Vasilev, A. A.; Dzidziguri, E. L.; Muratov, D. G.; Zhilyaeva, N. A.; Efimov, M. N.; Karpacheva, G. P.

2018-04-01

Metal-carbon nanocomposites consisting of FeCo alloy nanoparticles dispersed in a carbon matrix were synthesized by the thermal decomposition method of a precursor based on polyvinyl alcohol and metals salts. The synthesized powders were investigated by X-ray diffraction (XRD), X-ray fluorescent spectrometry (XRFS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Surface characteristics of materials were measured by BET-method. The morphology and dispersity of metal nanoparticles were studied depending on the metals ratio in the composite.

Nanoscale interfacial mixing of Au/Bi layers using MeV ion beams

NASA Astrophysics Data System (ADS)

Prusty, Sudakshina; Siva, V.; Ojha, S.; Kabiraj, D.; Sahoo, P. K.

2017-05-01

We have studied nanoscale mixing of thermally deposited double bilayer films of Au/Bi after irradiating them by 1.5 MeV Au2+ ions. Post irradiation effects on the morphology and elemental identification in these films are studied by Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). Glancing angle X-ray diffraction (GAXRD) of the samples indicate marginal changes in the irradiated samples due to combined effect of nuclear and electronic energy loss. The interfacial mixing is studied by Rutherford backscattering (RBS).

Application of focused-beam flat-sample method to synchrotron powder X-ray diffraction with anomalous scattering effect

NASA Astrophysics Data System (ADS)

Tanaka, M.; Katsuya, Y.; Matsushita, Y.

2013-03-01

The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe2O4 and Fe3O4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe2+/Fe3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.

Rietveld analysis using powder diffraction data with anomalous scattering effect obtained by focused beam flat sample method

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

Tanaka, Masahiko, E-mail: masahiko@spring8.or.jp; Katsuya, Yoshio, E-mail: katsuya@spring8.or.jp; Sakata, Osami, E-mail: SAKATA.Osami@nims.go.jp

2016-07-27

Focused-beam flat-sample method (FFM) is a new trial for synchrotron powder diffraction method, which is a combination of beam focusing optics, flat shape powder sample and area detectors. The method has advantages for X-ray diffraction experiments applying anomalous scattering effect (anomalous diffraction), because of 1. Absorption correction without approximation, 2. High intensity X-rays of focused incident beams and high signal noise ratio of diffracted X-rays 3. Rapid data collection with area detectors. We applied the FFM to anomalous diffraction experiments and collected synchrotron X-ray powder diffraction data of CoFe{sub 2}O{sub 4} (inverse spinel structure) using X-rays near Fe K absorptionmore » edge, which can distinguish Co and Fe by anomalous scattering effect. We conducted Rietveld analyses with the obtained powder diffraction data and successfully determined the distribution of Co and Fe ions in CoFe{sub 2}O{sub 4} crystal structure.« less

U-PuO2, U-PuC, U-PuN cermet fuel for fast reactor

NASA Astrophysics Data System (ADS)

Mishra, Sudhir; Kaity, Santu; Banerjee, Joydipta; Nandi, Chiranjeet; Dey, G. K.; Khan, K. B.

2018-02-01

Cermet fuel combines beneficial properties of both ceramic and metal and attracts global interest for research as a candidate fuel for nuclear reactors. In the present study, U matrix PuC/PuN/PuO2 cermet for fast reactor have been fabricated on laboratory scale by the powder metallurgy route. Characterization of the fuel has been carried out using Dilatometer, Differential Thermal analysis (DTA), X-ray diffractometer and Optical microscope. X ray diffraction study of the fuel reveals presence of different phases. The PuN dispersed cermet was observed to have high solidus temperature as compared to PuC and PuO2 dispersed cermet. Swelling was observed in U matrix PuO2 cermet which also showed higher thermal expansion. Among the three cermets studied, U matrix PuC cermet showed maximum thermal conductivity.

Thermal behavior of potato starch and water-vaporization behavior of its paste controlled with amino acid and peptide-rich food materials.

PubMed

Sakauchi, Satoshi; Hattori, Makoto; Yoshida, Tadashi; Yagishita, Takahiro; Ito, Koichi; Akemitsu, Shin-Ichi; Takahashi, Koji

2010-03-01

The particular effect of 4 kinds of amino acid and peptide-rich food material (APRM) containing different charged amino acid contents on the gelatinization and retrogradation behavior of potato starch granules and on the water-vaporization behavior was analyzed by differential scanning calorimetry, rapid viscoanalysis, x-ray diffractometry, thermal gravimetry-differential thermal analysis, and pulsed NMR. APRM with a high-charged amino acid content produced unique gelatinization and retrogradation behavior in terms of an elevated gelatinization temperature, reduced viscosity, higher setback, and lower retrograded starch melting enthalpy. The recovered x-ray diffraction intensity decreased with increasing charged amino acid content. APRM with high-charged amino acid content could provide an improved paste having easy vaporization of external water in the swollen starch granules due to the reduced swelling.

Effect of niobium content on the microstructure and thermal properties of fluorapatite glass-ceramics.

PubMed

Denry, I L; Holloway, J A; Nakkula, R J; Walters, J D

2005-10-01

Niobium oxide has been shown to improve biocompatibility and promote bioactivity. The purpose of this study was to evaluate the effect of niobium oxide additions on the microstructure and thermal properties of fluorapatite glass-ceramics for biomedical applications. Four glass-ceramic compositions with increasing amounts of niobium oxide from 0 to 5 wt % were prepared. The glass compositions were melted at 1,525 degrees C for 3 h, quenched, ground, melted again at 1,525 degrees C for 3 h and furnace cooled. The coefficient of thermal expansion was measured by dilatometry. The crystallization behavior was evaluated by differential thermal analysis. The nature of the crystalline phases was investigated by X-ray diffraction. The microstructure was studied by SEM. In addition, the cytotoxicity of the ceramics was evaluated according to the ASTM standard F895--84. The results from X-ray diffraction analyses showed that fluorapatite was the major crystalline phase in all glass-ceramics. Differential thermal analyses revealed that fluorapatite crystallization occurred between 800 and 934 degrees C depending on the composition. The coefficient of thermal expansion varied from 7.6 to 9.4 x 10(-6)/ degrees C. The microstructure after heat treatment at 975 degrees C for 30 min consisted of submicroscopic fluorapatite crystals (200--300 nm) for all niobium-containing glass-ceramics, whereas the niobium-free glass-ceramic contained needle-shaped fluorapatite crystals, 2 microm in length. None of the glass-ceramics tested exhibited any cytotoxic activity as tested by ASTM standard F895--84. (c) 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005.

HPHT growth and x-ray characterization of high-quality type IIa diamond.

PubMed

Burns, R C; Chumakov, A I; Connell, S H; Dube, D; Godfried, H P; Hansen, J O; Härtwig, J; Hoszowska, J; Masiello, F; Mkhonza, L; Rebak, M; Rommevaux, A; Setshedi, R; Van Vaerenbergh, P

2009-09-09

The trend in synchrotron radiation (x-rays) is towards higher brilliance. This may lead to a very high power density, of the order of hundreds of watts per square millimetre at the x-ray optical elements. These elements are, typically, windows, polarizers, filters and monochromators. The preferred material for Bragg diffracting optical elements at present is silicon, which can be grown to a very high crystal perfection and workable size as well as rather easily processed to the required surface quality. This allows x-ray optical elements to be built with a sufficient degree of lattice perfection and crystal processing that they may preserve transversal coherence in the x-ray beam. This is important for the new techniques which include phase-sensitive imaging experiments like holo-tomography, x-ray photon correlation spectroscopy, coherent diffraction imaging and nanofocusing. Diamond has a lower absorption coefficient than silicon, a better thermal conductivity and lower thermal expansion coefficient which would make it the preferred material if the crystal perfection (bulk and surface) could be improved. Synthetic HPHT-grown (high pressure, high temperature) type Ib material can readily be produced in the necessary sizes of 4-8 mm square and with a nitrogen content of typically a few hundred parts per million. This material has applications in the less demanding roles such as phase plates: however, in a coherence-preserving beamline, where all elements must be of the same high quality, its quality is far from sufficient. Advances in HPHT synthesis methods have allowed the growth of type IIa diamond crystals of the same size as type Ib, but with substantially lower nitrogen content. Characterization of this high purity type IIa material has been carried out with the result that the crystalline (bulk) perfection of some of the HPHT-grown materials is approaching the quality required for the more demanding applications such as imaging applications and imaging applications with coherence preservation. The targets for further development of the type IIa diamond are size, crystal perfection, as measured by the techniques of white beam and monochromatic x-ray diffraction imaging (historically called x-ray topography), and also surface quality. Diamond plates extracted from the cubic growth sector furthest from the seed of the new low strain material produces no measurable broadening of the x-ray rocking curve width. One measures essentially the crystal reflectivity as defined by the intrinsic reflectivity curve (Darwin curve) width of a perfect crystal. In these cases the more sensitive technique of plane wave topography has been used to establish a local upper limit of the strain at the level of an 'effective misorientation' of 10(-7) rad.

Green synthesis of silver nanoparticles using green tea leaves: Experimental study on the morphological, rheological and antibacterial behaviour

NASA Astrophysics Data System (ADS)

Nakhjavani, Maryam; Nikkhah, V.; Sarafraz, M. M.; Shoja, Saeed; Sarafraz, Marzieh

2017-10-01

In this paper, silver nanoparticles are produced via green synthesis method using green tea leaves. The introduced method is cost-effective and available, which provides condition to manipulate and control the average nanoparticle size. The produced particles were characterized using x-ray diffraction, scanning electron microscopic images, UV visualization, digital light scattering, zeta potential measurement and thermal conductivity measurement. Results demonstrated that the produced samples of silver nanoparticles are pure in structure (based on the x-ray diffraction test), almost identical in terms of morphology (spherical and to some extent cubic) and show longer stability when dispersed in deionized water. The UV-visualization showed a peak in 450 nm, which is in accordance with the previous studies reported in the literature. Results also showed that small particles have higher thermal and antimicrobial performance. As green tea leaves are used for extracting the silver nanoparticles, the method is eco-friendly. The thermal behaviour of silver nanoparticle was also analysed by dispersing the nanoparticles inside the deionized water. Results showed that thermal conductivity of the silver nano-fluid is higher than that of obtained for the deionized water. Activity of Ag nanoparticles against some bacteria was also examined to find the suitable antibacterial application for the produced particles.

Synergistic effects of mica and wollastonite fillers on thermal performance of intumescent fire retardant coating

NASA Astrophysics Data System (ADS)

Zia-ul-Mustafa, M.; Ahmad, Faiz; Megat-Yusoff, Puteri S. M.; Aziz, Hammad

2015-07-01

In this study, intumescent fire retardant coatings (IFRC) were developed to investigate the synergistic effects of reinforced mica and wollastonite fillers based IFRC towards heat shielding, char expansion, char composition and char morphology. Ammonium poly-phosphate (APP) was used as acid source, expandable graphite (EG) as carbon source, melamine as blowing agent, boric acid as additive and Hardener H-2310 polyamide amine in bisphenol A epoxy resin BE-188(BPA) was used as curing agent. Bunsen burner fire test was used for thermal performance according to UL-94 for 1 h. Field Emission Scanning Electron Microscopy (FESEM) was used to observe char microstructure. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to analyse char composition. The results showed that addition of clay filler in IFRC enhanced the fire protection performance of intumescent coating. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of boron phosphate, silicon phosphate oxide, aluminium borate in the char that improved the thermal performance of intumescent fire retardant coating (IFRC). Resultantly, the presence of these developed compounds enhanced the Integrity of structural steel upto 500°C.

Crystal growth, structural, optical, spectral and thermal studies of tris(L-phenylalanine)L-phenylalaninium nitrate: a new organic nonlinear optical material.

PubMed

Prakash, M; Geetha, D; Lydia Caroline, M

2011-10-15

Tris(L-phenylalanine)L-phenylalaninium nitrate, C(9)H(12)NO(2)(+)·NO(3)(-)·3C(9)H(11)NO(2) (TPLPN), a new organic nonlinear optical material was grown from aqueous solution by slow evaporation solution growth at room temperature. The grown crystals were subjected to powder X-ray diffraction and single crystal X-ray diffraction studies to confirm the crystalline nature and crystal structure. The modes of vibration of different molecular groups present in TPLPN have been identified by FTIR spectral analysis. The presence of hydrogen and carbon in the grown crystal were confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. The optical transmission spectral study establishes good transmitting ability of the crystal in the entire visible region. The thermogravimetric (TG) and differential thermal analyses (DTA) were carried out to understand the thermal stability of the sample. The nonlinear optical property of the compound observed using Kurtz powder second harmonic generation test assets the suitability of the grown material for the frequency conversion of laser radiation of Nd:YAG. Copyright © 2011 Elsevier B.V. All rights reserved.

Impacts of excimer laser annealing on Ge epilayer on Si

NASA Astrophysics Data System (ADS)

Huang, Zhiwei; Mao, Yichen; Yi, Xiaohui; Lin, Guangyang; Li, Cheng; Chen, Songyan; Huang, Wei; Wang, Jianyuan

2017-02-01

The impacts of excimer laser annealing on the crystallinity of Ge epilayers on Si substrate grown by low- and high-temperature two-step approach in an ultra-high vacuum chemical vapor deposition system were investigated. The samples were treated by excimer laser annealing (ELA) at various laser power densities with the temperature above the melting point of Ge, while below that of Si, resulting in effective reduction of point defects and dislocations in the Ge layer with smooth surface. The full-width at half-maximum (FWHM) of X-ray diffraction patterns of the low-temperature Ge epilayer decreases with the increase in laser power density, indicating the crystalline improvement and negligible effect of Ge-Si intermixing during ELA processes. The short laser pulse time and large cooling rate cause quick melting and recrystallization of Ge epilayer on Si in the non-thermal equilibrium process, rendering tensile strain in Ge epilayer as calculated quantitatively with thermal mismatch between Si and Ge. The FWHM of X-ray diffraction patterns is significantly reduced for the two-step grown samples after treated by a combination of ELA and conventional furnace thermal annealing, indicating that the crystalline of Ge epilayer is improved more effectively with pre- annealing by excimer laser.

Dynamical effects in Bragg coherent x-ray diffraction imaging of finite crystals

NASA Astrophysics Data System (ADS)

Shabalin, A. G.; Yefanov, O. M.; Nosik, V. L.; Bushuev, V. A.; Vartanyants, I. A.

2017-08-01

We present simulations of Bragg coherent x-ray diffractive imaging (CXDI) data from finite crystals in the frame of the dynamical theory of x-ray diffraction. The developed approach is based on a numerical solution of modified Takagi-Taupin equations and can be applied for modeling of a broad range of x-ray diffraction experiments with finite three-dimensional crystals of arbitrary shape also in the presence of strain. We performed simulations for nanocrystals of a cubic and hemispherical shape of different sizes and provided a detailed analysis of artifacts in the Bragg CXDI reconstructions introduced by the dynamical diffraction. Based on our theoretical analysis we developed an analytical procedure to treat effects of refraction and absorption in the reconstruction. Our results elucidate limitations for the kinematical approach in the Bragg CXDI and suggest a natural criterion to distinguish between kinematical and dynamical cases in coherent x-ray diffraction on a finite crystal.

Thermal Expansion Behavior in TcO2. Toward Breaking the Tc-Tc Bond.

PubMed

Reynolds, Emily; Zhang, Zhaoming; Avdeev, Maxim; Thorogood, Gordon J; Poineau, Frederic; Czerwinski, Kenneth R; Kimpton, Justin A; Kennedy, Brendan J

2017-08-07

The structure of TcO 2 between 25 and 1000 °C has been determined in situ using X-ray powder diffraction methods and is found to remain monoclinic in space group P2 1 /c. Thermal expansion in TcO 2 is highly anisotropic, with negative thermal expansion of the b axis observed above 700 °C. This is the result of an anomalous expansion along the a axis that is a consequence of weakening of the Tc-Tc bonds.

The effect of Al intermediate layer on thermal resistance of EB-PVD yttria-stabilized zirconia coatings on titanium substrate

NASA Astrophysics Data System (ADS)

Panin, Alexey; Panin, Victor; Kazachenok, Marina; Shugurov, Artur; Sinyakova, Elena; Martynov, Sergey; Rusyaev, Andrey; Kasterov, Artur

2017-12-01

The yttria-stabilized zirconia coatings sprayed on titanium substrates by the electron beam physical vapor deposition were subjected to thermal annealing in air at 1000°C for 1, 30 and 60 min. The delamination and fracture of the coatings are studied by the scanning electron microscopy and X-ray diffraction. It is shown that a magnetron sputtered Al interlayer between the coating and the substrate considerably improves the thermal resistance of ceramic coatings.

Thermally induced phase transformation in multi-phase iron oxide nanoparticles on vacuum annealing

NASA Astrophysics Data System (ADS)

Anupama, A. V.; Keune, W.; Sahoo, B.

2017-10-01

The evolution of magnetic phases in multi-phase iron oxide nanoparticles, synthesized via the transferred arc plasma induced gas phase condensation method, was investigated by X-ray diffraction, vibrating sample magnetometry and 57Fe Mössbauer spectroscopy. The particles are proposed to be consisting of three different iron oxide phases: α-Fe2O3, γ-Fe2O3 and Fe3O4. These nanoparticles were exposed to high temperature (∼935 K) under vacuum (10-3 mbar He pressure), and the thermally induced phase transformations were investigated. The Rietveld refinement of the X-ray diffraction data corroborates the least-squares fitting of the transmission Mössbauer spectra in confirming the presence of Fe3O4, γ-Fe2O3 and α-Fe2O3 phases before the thermal treatment, while only Fe3O4 and α-Fe2O3 phases exist after thermal treatment. On thermal annealing in vacuum, conversion from γ-Fe2O3 to Fe3O4 and α-Fe2O3 was observed. Interestingly, we have observed a phase transformation occurring in the temperature range ∼498 K-538 K, which is strikingly lower than the phase transformation temperature of γ-Fe2O3 to α-Fe2O3 (573-623 K) in air. Combining the results of Rietveld refinement of X-ray diffraction patterns and Mössbauer spectroscopy, we have attributed this phase transformation to the phase conversion of a metastable "defected and strained" d-Fe3O4 phase, present in the as-prepared sample, to the α-Fe2O3 phase. Stabilization of the phases by controlling the phase transformations during the use of different iron-oxide nanoparticles is the key factor to select them for a particular application. Our investigation provides insight into the effect of temperature and chemical nature of the environment, which are the primary factors governing the phase stability, suitability and longevity of the iron oxide nanomaterials prepared by the gas-phase condensation method for various applications.

Synthesis of nanocrystalline zirconia by amorphous citrate route: structural and thermal (HTXRD) studies

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

Bhagwat, Mahesh; Ramaswamy, Veda

Nanocrystalline zirconia powder with a fairly narrow particle size distribution has been synthesized by the amorphous citrate route. The sample obtained has a high BET surface area of 89 m{sup 2} g{sup -1}. Rietveld refinement of the powder X-ray diffraction (XRD) profile of the zirconia sample confirms stabilization of zirconia in the tetragonal phase with around 8% monoclinic impurity. The data show the presence of both anionic as well as cationic vacancies in the lattice. Crystallite size determined from XRD is 8 nm and is in close agreement with the particle size determined by TEM. The in situ high temperature-X-raymore » diffraction (HTXRD) study revealed high thermal stability of the mixture till around 1023 K after which the transformation of tetragonal phase into the monoclinic phase has been seen as a function of temperature till 1473 K. This transformation is accompanied by an increase in the crystallite size of the sample from 8 to 55 nm. The thermal expansion coefficients are 9.14 x 10{sup -6} K{sup -1} along 'a'- and 15.8 x 10{sup -6} K{sup -1} along 'c'-axis. The lattice thermal expansion coefficient in the temperature range 298-1623 K is 34.6 x 10{sup -6} K{sup -1}.« less

Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

NASA Technical Reports Server (NTRS)

Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

2010-01-01

An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

Solution combustion synthesis and characterization of nanosized bismuth ferrite

NASA Astrophysics Data System (ADS)

Sai Kumar, V. Sesha; Rao, K. Venkateswara; Krishnaveni, T.; Kishore Goud, A. Shiva; Reddy, P. Ranjith

2012-06-01

The present paper describes a simple method of nanosized BiFeO3 by the solution combustion synthesis using bismuth and iron nitrates as oxidizers and the combination fuel of citric acid and ammonium hydroxide, with fuel to oxidizer ratio (Ψ = 1) one. The X-ray Diffraction results indicated rhombohedral phase (R3m) with JCPDS data card no: 72-2035. The ferroelectric transition of the sample at 8310C was detected by differential thermal analysis. Thermal analysis was done by Thermal gravimetric-Differential thermal analyzer and obtained results were presented in this paper.

Thermal stability characterization of SiC ceramic fibers. II. Fractography and structure

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

Sawyer, L.C.; Chen, R.T.; Haimbach, F.,IV

1986-08-01

SiC ceramic fibers (Nicalon) exhibit tensile strength reduction following thermal treatment in air, argon and nitrogen environments above 1200 C. Grain-size variations have been observed in the treated fibers by X-ray diffraction and electron microscopy. Fractography studies show that strength reduction occurs in all thermal treatments, although the mechanism of fiber failure varies depending upon the specific environment. Structure-property relations will be developed as mechanical testing and fractography of the thermally treated fibers are associated with tensile strength loss mechanisms. 16 references.

Nondestructive evaluation of plasma-sprayed thermal barrier coatings

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

Andrews, D.J.; Taylor, J.A.T.

Acoustic emission has been used as a nondestructive evaluation technique to examine the thermal shock response of thermal barrier coatings. In this study, samples of partially stabilized zirconia powder were sprayed and acoustic emission (AE) data were taken in a series of thermal shock tests in an effort to correlate AE with a given failure mechanism. Microstructural evidence was examined using parallel beam x-ray diffraction and optical microscopy. The AE data are discussed in terms of cumulative amplitude distributions and the use of this technique to characterize fracture events.

Influence of reagents mixture density on the radiation-thermal synthesis of lithium-zinc ferrites

NASA Astrophysics Data System (ADS)

Surzhikov, A. P.; Lysenko, E. N.; Vlasov, V. A.; Malyshev, A. V.; Korobeynikov, M. V.; Mikhailenko, M. A.

2017-01-01

Influence of Li2CO3-ZnO-Fe2O3 powder reagents mixture density on the synthesis efficiency of lithium-zinc ferrites in the conditions of thermal heating or pulsed electron beam heating was studied by X-Ray diffraction and magnetization analysis. The results showed that the including a compaction of powder reagents mixture in ferrite synthesis leads to an increase in concentration of the spinel phase and decrease in initial components content in lithium-substituted ferrites synthesized by thermal or radiation-thermal heating.

Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

NASA Astrophysics Data System (ADS)

Wang, Ji; Wei, Min; Rao, Guoying; Evans, David G.; Duan, Xue

2004-01-01

The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation.

Linking strain anisotropy and plasticity in copper metallization

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

Murray, Conal E., E-mail: conal@us.ibm.com; Jordan-Sweet, Jean; Priyadarshini, Deepika

2015-05-04

The elastic anisotropy of copper leads to significant variation in the x-ray elastic constants (XEC), which link diffraction-based strain measurements to stress. An accurate depiction of the mechanical response in copper thin films requires a determination of an appropriate grain interaction model that lies between Voigt and Reuss limits. It is shown that the associated XEC weighting fraction, x*, between these limits provides a metric by which strain anisotropy can be quantified. Experimental values of x*, as determined by a linear regression scheme of diffraction data collected from multiple reflections, reveal the degree of strain anisotropy and its dependence onmore » plastic deformation induced during in-situ and ex-situ thermal treatments.« less

Phase diagram and electrical behavior of silicon-rich iridium silicide compounds

NASA Technical Reports Server (NTRS)

Allevato, C. E.; Vining, Cronin B.

1992-01-01

The iridium-silicon phase diagram on the silicon-rich side was investigated by means of X-ray powder diffraction, density, differential thermal analysis, metalography, microprobe analysis, and electrical resistivity. Attempts were made to prepare eight previously reported silicon-rich iridium silicide compounds by arc melting and Bridgman-like growth. However, microprobe analysis identified only four distinct compositions: IrSi, Ir3Si4, Ir3Si5 and IrSi sub about 3. The existence of Ir4Si5 could not be confirmed in this study, even though the crystal structure has been previously reported. Differential thermal analysis (DTA) in conjunction with X-ray powder diffraction confirm polymorphism in IrSi sub about 3, determined to have orthorhombic and monoclinic unit cells in the high and low temperature forms. A eutectic composition alloy of 83 +/- 1 atomic percent silicon was observed between IrSi sub about 3 and silicon. Ir3Si4 exhibits distinct metallic behavior while Ir3Si5 is semiconducting. Both and IrSi and IrSi sub about 3 exhibit nearly temperature independent electrical resistivities on the order of 5-10 x 10 exp -6 ohms-m.

Philip A. Parilla | NREL

Science.gov Websites

atomic layer deposition for applications. He also manages the majority of X-ray characterization equipment at NREL, specifically X-ray diffraction and X-ray fluorescence instrumentation. Additionally, he for EERE's Hydrogen Storage program. He is also an expert in X-ray diffraction and X-ray fluorescence

Effect of ternary addition and gamma-irradiation on the characteristics of rapidly solidified Pb-base alloys

NASA Astrophysics Data System (ADS)

Abd El-Khalek, A. M.

The properties of a series of rapidly solidified Pb-Sb-3-Sn-x alloys ( x =0-2.5 wt.%) irradiated with gamma-rays were studied. Variations in the internal friction, Q(-1) , thermal diffusivity D th and dynamic Young's modulus Y were traced before and after irradiation by applying the resonance technique. Variations of specific heat C-p were obtained from DTA thermograms. Structure parameters were obtained from the X-rays diffraction patterns. A marked change in the behaviour of the measured parameters was observed at 1.5 wt.% Sn addition. Besides, irradiation induced defects increased the level of the measured hardening parameters.

Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources.

PubMed

Tang, M X; Zhang, Y Y; E, J C; Luo, S N

2018-05-01

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic-plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of the diffraction patterns is discussed.

Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources

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

Tang, M. X.; Zhang, Y. Y.; E, J. C.

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic–plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of themore » diffraction patterns is discussed.« less

Coherent X-ray diffraction imaging of nanoengineered polymeric capsules

NASA Astrophysics Data System (ADS)

Erokhina, S.; Pastorino, L.; Di Lisa, D.; Kiiamov, A. G.; Faizullina, A. R.; Tayurskii, D. A.; Iannotta, S.; Erokhin, V.

2017-10-01

For the first time, nanoengineered polymeric capsules and their architecture have been studied with coherent X-ray diffraction imaging technique. The use of coherent X-ray diffraction imaging technique allowed us to analyze the samples immersed in a liquid. We report about the significant difference between polymeric capsule architectures under dry and liquid conditions.

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

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

Murray, Thomas D.; Johns Hopkins University School of Medicine, Baltimore, MD 21205; Lyubimov, Artem Y.

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs. Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming themore » challenges intrinsic to microcrystal analysis is to pair so-called ‘fixed-target’ sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less

Thermodynamic studies of studtite thermal decomposition pathways via amorphous intermediates UO 3, U 2O 7, and UO 4

DOE PAGES

Guo, Xiaofeng; Wu, Di; Xu, Hongwu; ...

2016-09-01

The thermal decomposition of studtite (UO 2)O 2(H 2O) 2·2H 2O results in a series of intermediate X-ray amorphous materials with general composition UO 3+x (x = 0, 0.5, 1). As an extension of a structural study on U 2O 7, this work provides detailed calorimetric data on these amorphous oxygen-rich materials since their energetics and thermal stability are unknown. These were characterized in situ by thermogravimetry, and mass spectrometry. Ex situ X-ray diffraction and infrared spectroscopy characterized their chemical bonding and local structures. This detailed characterization formed the basis for obtaining formation enthalpies by high temperature oxide melt solutionmore » calorimetry. The thermodynamic data demonstrate the metastability of the amorphous UO 3+x materials, and explain their irreversible and spontaneous reactions to generate oxygen and form metaschoepite. Thus, formation of studtite in the nuclear fuel cycle, followed by heat treatment, can produce metastable amorphous UO 3+x materials that pose the risk of significant O 2 gas. Quantitative knowledge of the energy landscape of amorphous UO 3+x was provided for stability analysis and assessment of conditions for decomposition.« less

X-Ray Structure determination of the Glycine Cleavage System Protein H of Mycobacterium tuberculosis Using An Inverse Compton Synchrotron X-Ray Source

PubMed Central

Abendroth, Jan; McCormick, Michael S.; Edwards, Thomas E.; Staker, Bart; Loewen, Roderick; Gifford, Martin; Rifkin, Jeff; Mayer, Chad; Guo, Wenjin; Zhang, Yang; Myler, Peter; Kelley, Angela; Analau, Erwin; Hewitt, Stephen Nakazawa; Napuli, Alberto J.; Kuhn, Peter; Ruth, Ronald D.; Stewart, Lance J.

2010-01-01

Structural genomics discovery projects require ready access to both X-ray and NMR instrumentation which support the collection of experimental data needed to solve large numbers of novel protein structures. The most productive X-ray crystal structure determination laboratories make extensive frequent use of tunable synchrotron X-ray light to solve novel structures by anomalous diffraction methods. This requires that frozen cryo-protected crystals be shipped to large government-run synchrotron facilities for data collection. In an effort to eliminate the need to ship crystals for data collection, we have developed the first laboratory-scale synchrotron light source capable of performing many of the state-of-the-art synchrotron applications in X-ray science. This Compact Light Source is a first-in-class device that uses inverse Compton scattering to generate X-rays of sufficient flux, tunable wavelength and beam size to allow high-resolution X-ray diffraction data collection from protein crystals. We report on benchmarking tests of X-ray diffraction data collection with hen egg white lysozyme, and the successful high-resolution X-ray structure determination of the Glycine cleavage system protein H from Mycobacterium tuberculosis using diffraction data collected with the Compact Light Source X-ray beam. PMID:20364333

X-ray analyses of thermally grown and reactively sputtered tantalum oxide films on NiTi alloy

NASA Astrophysics Data System (ADS)

McNamara, Karrina; Tofail, Syed A. M.; Conroy, Derek; Butler, James; Gandhi, Abbasi A.; Redington, Wynette

2012-08-01

Sputter deposition of tantalum (Ta) on the surface of NiTi alloy is expected to improve the alloy's corrosion resistance and biocompatibility. Tantalum is a well-known biomaterial which is not affected by body fluids and is not irritating to human tissue. Here we compare the oxidation chemistry crystal structure evolution of tantalum oxide films grown on NiTi by reactive O2 sputtering and by thermal oxidation of sputter deposited Ta films. The effect of sputtering parameters and post-sputtering treatments on the morphology, oxidation state and crystal structure of the tantalum oxide layer have been investigated by field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The study has found that it may be better to avoid oxidation at and above 600 °C. The study establishes that reactive sputtering in presence of low oxygen mixture yields thicker film with better control of the film quality except that the surface oxidation state of Ta is slightly lower.

Prepared by Thermal Hydro-decomposition

NASA Astrophysics Data System (ADS)

Prasoetsopha, N.; Pinitsoontorn, S.; Kamwanna, T.; Kurosaki, K.; Ohishi, Y.; Muta, H.; Yamanaka, S.

2014-06-01

The polycrystalline samples of Ca3Co4- x Ga x O9+ δ (0 ≤ x ≤ 0.15) were prepared by a simple thermal hydro-decomposition method. The high density ceramics were fabricated using a spark plasma sintering technique. The crystal structure of calcined powders was characterized by x-ray diffraction. The single phase of Ca3Co4- x Ga x O9+ δ was obtained. The scanning electron micrograph illustrated the grain alignment perpendicular to the direction of the pressure in the sintering process. The evidence from x-ray absorption near edge spectra were used to confirm the oxidation state of the Ga dopant. The thermoelectric properties of the misfit-layered of Ca3Co4- x Ga x O9+ δ were investigated. Seebeck coefficient tended to decrease with increasing Ga content due to the hole-doping effect. The electrical resistivity and thermal conductivity were monotonically decreased with increasing Ga content. The Ga doping of x = 0.15 showed the highest power factor of 3.99 × 10-4 W/mK2 at 1,023 K and the lowest thermal conductivity of 1.45 W/mK at 1,073 K. This resulted in the highest ZT of 0.29 at 1,073 K. From the optical absorption spectra, the electronic structure near the Fermi level show no significant change with Ga doping.

Anti-contamination device for cryogenic soft X-ray diffraction microscopy

DOE PAGES

Huang, Xiaojing; Miao, Huijie; Nelson, Johanna; ...

2011-05-01

Cryogenic microscopy allows one to view frozen hydrated biological and soft matter specimens with good structural preservation and a high degree of stability against radiation damage. We describe a liquid nitrogen-cooled anti-contamination device for cryogenic X-ray diffraction microscopy. The anti-contaminator greatly reduces the buildup of ice layers on the specimen due to condensation of residual water vapor in the experimental vacuum chamber. We show by coherent X-ray diffraction measurements that this leads to fivefold reduction of background scattering, which is important for far-field X-ray diffraction microscopy of biological specimens.

Thermal annealing of natural, radiation-damaged pyrochlore

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

Zietlow, Peter; Beirau, Tobias; Mihailova, Boriana

Abstract Radiation damage in minerals is caused by the α-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400–1000 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia [6.4 wt% Th, 23.1·10

Structural and Thermal Diffusivity Studies of Polycrystalline (CuSe)1-XSeX Metal Chalcogenide Compound

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

Josephine, L. Y. C.; Talib, Z. A.; Yunus, W. M. M.

2007-05-09

This paper reports the preparation and the characterization of the (CuSe)1-xSex metal chalcogenide semiconductor compounds with different stoichiometric compositions of Se (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) in bulk form. The (CuSe)1-xSex compounds were prepared using the solid state reaction by varying the ratio of CuSe:Se in the reaction mixture. X-ray powder diffraction analysis is used to identify and measure the mass absorption coefficient of the (CuSe)1-xSex compounds to support the thermal diffusivity behaviour. The thermal diffusivity of the polycrystalline (CuSe)1-xSex compounds were measured and analyzed for the first time, using the photoflash technique. The thermal diffusivitymore » values were determined to be in the range of 2.524 x 10-3 cm2/s to 1.125 x 10-2 cm2/s. It was found that the thermal diffusivity value tends to decrease as the parameter x increases. The relationship between the thermal diffusivity, mass absorption coefficient and density of the (CuSe)1-xSex are discussed in detail.« less

Fabrication of VO2 thin film by rapid thermal annealing in oxygen atmosphere and its metal—insulator phase transition properties

NASA Astrophysics Data System (ADS)

Liang, Ji-Ran; Wu, Mai-Jun; Hu, Ming; Liu, Jian; Zhu, Nai-Wei; Xia, Xiao-Xu; Chen, Hong-Da

2014-07-01

Vanadium dioxide thin films have been fabricated through sputtering vanadium thin films and rapid thermal annealing in oxygen. The microstructure and the metal—insulator transition properties of the vanadium dioxide thin films were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and a spectrometer. It is found that the preferred orientation of the vanadium dioxide changes from (1¯11) to (011) with increasing thickness of the vanadium thin film after rapid thermal annealing. The vanadium dioxide thin films exhibit an obvious metal—insulator transition with increasing temperature, and the phase transition temperature decreases as the film thickness increases. The transition shows hysteretic behaviors, and the hysteresis width decreases as the film thickness increases due to the higher concentration carriers resulted from the uncompleted lattice. The fabrication of vanadium dioxide thin films with higher concentration carriers will facilitate the nature study of the metal—insulator transition.

Preparation and characteristics of epoxy/clay/B4C nanocomposite at high concentration of boron carbide for neutron shielding application

NASA Astrophysics Data System (ADS)

Kiani, Mohammad Amin; Ahmadi, Seyed Javad; Outokesh, Mohammad; Adeli, Ruhollah; Mohammadi, Aghil

2017-12-01

In this research, the characteristics of the prepared samples in epoxy matrix by means of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), as well as scanning electron microscope (SEM) are evaluated. Meanwhile, the obtained mechanical properties of the specimen are investigated. Thermogravimetric analysis (TGA) is also employed to evaluate the thermal degradation of manufactured nanocomposites. The thermal neutron absorption properties of nanocomposites containing 3 wt% of montmorillonite nanoclay (closite30B) have been studied experimentally, using an Am-Be point source. Mechanical tests reveal that the higher B4C concentrations, the more tensile strengths, but lower Young's modulus in all samples under consideration. TGA analysis also shows that thermal stability of the nanocomposite, increases in presence of B4C. Finally, neutron absorption analysis shows that increasing the B4C concentration leads to a nonlinearly build-up of neutron absorption cross section.

Note: application of a pixel-array area detector to simultaneous single crystal X-ray diffraction and X-ray absorption spectroscopy measurements.

PubMed

Sun, Cheng-Jun; Zhang, Bangmin; Brewe, Dale L; Chen, Jing-Sheng; Chow, G M; Venkatesan, T; Heald, Steve M

2014-04-01

X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr0.67Sr0.33MnO3 film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.

Three-energy focusing Laue monochromator for the diamond light source x-ray pair distribution function beamline I15-1

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

Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Chater, Philip A.; Hillman, Michael R.

2016-07-27

The I15-1 beamline, the new side station to I15 at the Diamond Light Source, will be dedicated to the collection of atomic pair distribution function data. A Laue monochromator will be used consisting of three silicon crystals diffracting X-rays at a common Bragg angle of 2.83°. The crystals use the (1 1 1), (2 2 0), and (3 1 1) planes to select 40, 65, and 76 keV X-rays, respectively, and will be bent meridionally to horizontally focus the selected X-rays onto the sample. All crystals will be cut to the same optimized asymmetry angle in order to eliminate imagemore » broadening from the crystal thickness. Finite element calculations show that the thermal distortion of the crystals will affect the image size and bandpass.« less

Synthesis of carbon-encapsulated metal nanoparticles from wood char

Treesearch

Yicheng Du; Chuji Wang; Hossein Toghiani; Zhiyong Cai; Xiaojian Liu; Jilei Zhang; Qiangu Yan

2010-01-01

Carbon-encapsulated metal nanoparticles were synthesized by thermal treatment of wood char, with or without transition metal ions pre-impregnated, at 900ºC to 1,100ºC. Nanoparticles with concentric multilayer shells were observed. The nanoparticles were analyzed by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction...

Laboratory plant study on the melting process of asbestos waste

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

Sakai, Shinichi; Terazono, Atsushi; Takatsuki, Hiroshi

The melting process was studied as a method of changing asbestos into non-hazardous waste and recovering it as a reusable resource. In an initial effort, the thermal behaviors of asbestos waste in terms of physical and chemical structure have been studied. Then, 10 kg/h-scale laboratory plant experiments were carried out. By X-ray diffraction analysis, the thermal behaviors of sprayed-on asbestos waste revealed that chrysotile asbestos waste change in crystal structure at around 800 C, and becomes melted slag, mainly composed of magnesium silicate, at around 1,500 C. Laboratory plant experiments on the melting process of sprayed-on asbestos have shown thatmore » melted slag can be obtained. X-ray diffraction analysis of the melted slag revealed crystal structure change, and SEM analysis showed the slag to have a non-fibrous form. And more, TEM analysis proved the very high treatment efficiency of the process, that is, reduction of the asbestos content to 1/10{sup 6} as a weight basis. These analytical results indicate the effectiveness of the melting process for asbestos waste treatment.« less

Ni@Fe2O3 heterodimers: controlled synthesis and magnetically recyclable catalytic application for dehalogenation reactions

NASA Astrophysics Data System (ADS)

Nakhjavan, Bahar; Tahir, Muhammad Nawaz; Natalio, Filipe; Panthöfer, Martin; Gao, Haitao; Dietzsch, Michael; Andre, Rute; Gasi, Teuta; Ksenofontov, Vadim; Branscheid, Robert; Kolb, Ute; Tremel, Wolfgang

2012-07-01

Ni@Fe2O3 heterodimer nanoparticles (NPs) were synthesized by thermal decomposition of organometallic reactants. After functionalization, these Ni@Fe2O3 heterodimers became water soluble. The pristine heterodimeric NPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy and magnetic susceptibility measurements. A special advantage of the heterodimers lies in the fact that nanodomains of different composition can be used as catalysts for the removal of environmentally hazardous halogenated pollutants.Ni@Fe2O3 heterodimer nanoparticles (NPs) were synthesized by thermal decomposition of organometallic reactants. After functionalization, these Ni@Fe2O3 heterodimers became water soluble. The pristine heterodimeric NPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy and magnetic susceptibility measurements. A special advantage of the heterodimers lies in the fact that nanodomains of different composition can be used as catalysts for the removal of environmentally hazardous halogenated pollutants. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr12121b

A novel structure of gel grown strontium cyanurate crystal and its structural, optical, electrical characterization

NASA Astrophysics Data System (ADS)

Divya, R.; Nair, Lekshmi P.; Bijini, B. R.; Nair, C. M. K.; Gopakumar, N.; Babu, K. Rajendra

2017-12-01

Strontium cyanurate crystals with novel structure and unique optical property like mechanoluminescence have been grown by conventional gel method. Transparent crystals were obtained. The single crystal X-ray diffraction analysis reveals the exquisite structure of the grown crystal. The crystal is centrosymmetric and has a three dimensional polymeric structure. The powder X ray diffraction analysis confirms its crystalline nature. The functional groups present in the crystal were identified by Fourier transform infrared spectroscopy. Elemental analysis confirmed the composition of the complex. A study of thermal properties was done by thermo gravimetric analysis and differential thermal analysis. The optical properties like band gap, refractive index and extinction coefficient were evaluated from the UV visible spectral analysis. The etching study was done to reveal the dislocations in the crystal which in turn explains mechanoluminescence emission. The mechanoluminescence property exhibited by the crystal makes it suitable for stress sensing applications. Besides being a centrosymmetric crystal, it also exhibits NLO behavior. Dielectric properties were studied and theoretical calculations of Fermi energy, valence electron plasma energy, penn gap and polarisability have been done.

Synthesis and luminescence properties of cinnamide based nanohybrid materials containing Eu (II) ions

NASA Astrophysics Data System (ADS)

Kiran Kumar, A. B. V.; Jayasimhadri, M.; Cha, Hyeongrae; Chen, Kuangcai; Lim, Jae-Min; Lee, Yong-Ill

2011-07-01

In the present work, the cinnamide based organic-inorganic hybrid luminescent materials were prepared by using sol-gel technique, in which both the components are covalently linked via Si-C bonds. The organic precursor N-(3-(triethoxysilyl)propyl)cinnamide (Cn-Si) was synthesized by (3-aminopropyl) triethoxysilane being reacted with cinnamoyal chloride. Finally, novel hybrid materials were prepared successfully through hydrolysis and polycondensation processes between the alkoxide groups of precursors Cn-Si and tetraethylorthosilane (TEOS) in the presence of europium nitrate. We have characterized thoroughly the prepared samples using FT-IR, thermal analysis (TGA/DTA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) and photoluminescence (PL) spectroscopy. The results indicate that these materials exhibit the excellent thermal stability up to 350 °C. The X-ray diffraction patterns confirmed the amorphous nature of the developed materials. The rare-earth doped hybrid materials have exhibited an intense green emission at 530 nm with CIE chromaticity coordinates (0.4801, 0.4669). Whereas, the un-doped one gives some remarkable blue emission properties under UV excitation.

A luminescent silver-saccharinato complex with S, S-diphenylsulfimide: Synthesis, spectroscopic, thermal, structural and DFT computational studies

NASA Astrophysics Data System (ADS)

Gumus, Sedat; Hamamci, Sevim; Yilmaz, V. T.; Kazak, Canan

2007-02-01

A new silver(I)-saccharinato (sac) complex with S, S-diphenylsulfimide, [Ag(sac)(Ph 2SNH)], has been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. X-ray diffraction analyses show that the title complex has a monomeric structure containing linearly coordinated silver(I) ion with an N-Ag-N angle of 173.80(10)°. The individual molecules are linked by strong N-H⋯O hydrogen bonds and aromatic stacking π⋯π interactions and packing of the molecules is further reinforced by C-H⋯π interactions. Ph 2SNH and [Ag(sac)(Ph 2SNH)] in solution at room temperature display intense blue luminescence with emission maxima at 380 and 408 nm, respectively. The photoluminescence properties have been investigated by DFT calculations, showing that the luminescence properties of the Ph 2SNH are due to intraligand transitions, while for the silver(I) complex, the luminescence was originated from several transitions including intraligand transitions and metal-to-ligand charge transfer (MLCT).

In Vitro Sustained Release Study of Gallic Acid Coated with Magnetite-PEG and Magnetite-PVA for Drug Delivery System

PubMed Central

Kura, Aminu Umar; Hussein-Al-Ali, Samer Hasan; Bin Hussein, Mohd Zobir; Fakurazi, Sharida; Shaari, Abdul Halim; Ahmad, Zalinah

2014-01-01

The efficacy of two nanocarriers polyethylene glycol and polyvinyl alcohol magnetic nanoparticles coated with gallic acid (GA) was accomplished via X-ray diffraction, infrared spectroscopy, magnetic measurements, thermal analysis, and TEM. X-ray diffraction and TEM results showed that Fe3O4 nanoparticles were pure iron oxide having spherical shape with the average diameter of 9 nm, compared with 31 nm and 35 nm after coating with polyethylene glycol-GA (FPEGG) and polyvinyl alcohol-GA (FPVAG), respectively. Thermogravimetric analyses proved that after coating the thermal stability was markedly enhanced. Magnetic measurements and Fourier transform infrared (FTIR) revealed that superparamagnetic iron oxide nanoparticles could be successfully coated with two polymers (PEG and PVA) and gallic acid as an active drug. Release behavior of gallic acid from two nanocomposites showed that FPEGG and FPVAG nanocomposites were found to be sustained and governed by pseudo-second-order kinetics. Anticancer activity of the two nanocomposites shows that the FPEGG demonstrated higher anticancer effect on the breast cancer cell lines in almost all concentrations tested compared to FPVAG. PMID:24737969

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

Zia-ul-Mustafa, M., E-mail: engr.ziamustafa@gmail.com; Ahmad, Faiz; Megat-Yusoff, Puteri S. M.

In this study, intumescent fire retardant coatings (IFRC) were developed to investigate the synergistic effects of reinforced mica and wollastonite fillers based IFRC towards heat shielding, char expansion, char composition and char morphology. Ammonium poly-phosphate (APP) was used as acid source, expandable graphite (EG) as carbon source, melamine as blowing agent, boric acid as additive and Hardener H-2310 polyamide amine in bisphenol A epoxy resin BE-188(BPA) was used as curing agent. Bunsen burner fire test was used for thermal performance according to UL-94 for 1 h. Field Emission Scanning Electron Microscopy (FESEM) was used to observe char microstructure. X-Ray Diffraction (XRD)more » and Fourier transform infrared spectroscopy (FTIR) were used to analyse char composition. The results showed that addition of clay filler in IFRC enhanced the fire protection performance of intumescent coating. X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results showed the presence of boron phosphate, silicon phosphate oxide, aluminium borate in the char that improved the thermal performance of intumescent fire retardant coating (IFRC). Resultantly, the presence of these developed compounds enhanced the Integrity of structural steel upto 500°C.« less

Thermal degradation behavior and X-ray diffraction studies of chitosan based polyurethane bio-nanocomposites using different diisocyanates.

PubMed

Javaid, Muhammad Asif; Rizwan, Muhammad; Khera, Rasheed Ahmad; Zia, Khalid Mahmood; Saito, Kei; Zuber, Muhammad; Iqbal, Javed; Langer, Peter

2018-05-29

Five different samples of chitosan based polyurethane bio-nanocomposites (PUBNCs) were synthesized by step growth polymerization technique. Five different diisocyanates were used by keeping hydroxyl terminated polybutadiene (HTPB)/1,4-butane diol (1,4-BDO)/chitosan (CS) and montmorillonite (MMT) clay ratios constant (PUR1-PUR5). For comparative studies, PUR-6 was prepared without CS and clay components. Molecular characterizations of polyurethane (PU) films were carried out by FTIR and NMR which was found to have confirmatory evidence of the proposed structures. X-ray diffraction angles (2θ), d-spacing and intensities of chitosan based samples (PUR1-PUR5) and PUR-6 indicated that crystalline behavior of PUBNCs is influenced by varying diisocyanate structures. TGA/DTA results revealed that chitosan increased thermal stability of PU samples; it also enhanced the mechanical strength and decreased the glass transition temperature (T g ) of all the samples. Based on the above mentioned facts this study suggests the best usage of PUs according to the operational and environmental conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Thermal Stability of NaxCrO2 for Rechargeable Sodium Batteries; Studies by High-Temperature Synchrotron X-ray Diffraction.

PubMed

Yabuuchi, Naoaki; Ikeuchi, Issei; Kubota, Kei; Komaba, Shinichi

2016-11-30

Thermal stability and phase transition processes of NaCrO 2 and Na 0.5 CrO 2 are carefully examined by high-temperature synchrotron X-ray diffraction method. O3-type NaCrO 2 shows anisotropic thermal expansion on heating, which is a common character as layered materials, without phase transition in the temperature range of 27-527 °C. In contrast, for the desodiated phase, in-plane distorted P3-type layered oxide (P'3 Na 0.5 CrO 2 ), phase transition occurs in the following order. Monoclinic distortion associated with Na/vacancy ordering is gradually lost on heating, and its symmetry increases and changes to a rhombohedral lattice at 207 °C. On further heating, phase segregation to two P3 layered metastable phases, which have different interlayer distances (17.0 and 13.5 Å, presumably sodium-rich and sodium-free P3 phases, respectively) are observed on heating to 287-477 °C, but oxygen loss is not observed. Oxygen loss is observed at temperatures only above 500 °C, resulting in the formation of corundum-type Cr 2 O 3 and O3 NaCrO 2 as thermodynamically stable phases. From these results, possibility of Na x CrO 2 as a positive electrode material for safe rechargeable sodium batteries is also discussed.

X-Ray Diffraction Wafer Mapping Method for Rhombohedral Super-Hetero-Epitaxy

NASA Technical Reports Server (NTRS)

Park, Yoonjoon; Choi, Sang Hyouk; King, Glen C.; Elliott, James R.; Dimarcantonio, Albert L.

2010-01-01

A new X-ray diffraction (XRD) method is provided to acquire XY mapping of the distribution of single crystals, poly-crystals, and twin defects across an entire wafer of rhombohedral super-hetero-epitaxial semiconductor material. In one embodiment, the method is performed with a point or line X-ray source with an X-ray incidence angle approximating a normal angle close to 90 deg, and in which the beam mask is preferably replaced with a crossed slit. While the wafer moves in the X and Y direction, a narrowly defined X-ray source illuminates the sample and the diffracted X-ray beam is monitored by the detector at a predefined angle. Preferably, the untilted, asymmetric scans are of {440} peaks, for twin defect characterization.

Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source

NASA Astrophysics Data System (ADS)

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.

Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source.

PubMed

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.

The synthesis and the spectroscopic, thermal, and structural properties of the M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) clathrate (M = Co, Ni, Cd and Hg)

NASA Astrophysics Data System (ADS)

Kartal, Zeki; Yavuz, Abdülkerim

2018-03-01

In this study, the clathrates of fumarate-tetracyanonickel-dioxane, given by the formula M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) (M = Co, Ni, Cd and Hg), have been obtained for the first time through chemical methods. These clathrates have been characterized by elemental, thermal, FT-IR, and FT-Raman spectroscopies. The parameters of structures of clathrates have been determined by X-ray powder diffraction. The thermal behaviors of these clathrates have been also investigated by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), and derivative thermal gravimetric analysis (DTG) in the range of 20-900 °C. X-ray powder diffraction data have been recorded at ambient temperature in the 2θ range 5-50°. The FT-IR and FT-Raman spectra of clathrates have been recorded in the region of 4000-400 cm-1 and 4000-100 cm-1, respectively. The results of the spectral and thermal analyses of the newly synthesized clathrates of fumarate-tetracyanonickel-dioxane suggest that these clathrates are new examples of the Hofmann-type dioxane clathrates. In our study, the Hofmann-type dioxane clathrates, which are formed by bounding electrons of oxygen-donor atoms of fumarate ion ligand molecule to transition metal atoms, consist of the corrugated |M-Ni(CN)4|∞ polymeric layers, which are held in parallel through the chain of (-M-fumarate-M-).

Gas gun shock experiments with single-pulse x-ray phase contrast imaging and diffraction at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Luo, S. N.; Jensen, B. J.; Hooks, D. E.; Fezzaa, K.; Ramos, K. J.; Yeager, J. D.; Kwiatkowski, K.; Shimada, T.

2012-07-01

The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for in situ, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources are advantageous for x-ray phase contrast imaging (PCI) and diffraction under dynamic loading, due to their high photon fluxes, high coherency, and high pulse repetition rates. The feasibility of bulk-scale gas gun shock experiments with dynamic x-ray PCI and diffraction measurements was investigated at the beamline 32ID-B of the Advanced Photon Source. The x-ray beam characteristics, experimental setup, x-ray diagnostics, and static and dynamic test results are described. We demonstrate ultrafast, multiframe, single-pulse PCI measurements with unprecedented temporal (<100 ps) and spatial (˜2 μm) resolutions for bulk-scale shock experiments, as well as single-pulse dynamic Laue diffraction. The results not only substantiate the potential of synchrotron-based experiments for addressing a variety of shock physics problems, but also allow us to identify the technical challenges related to image detection, x-ray source, and dynamic loading.

A porous Cd(II) metal-organic framework with high adsorption selectivity for CO2 over CH4

NASA Astrophysics Data System (ADS)

Zhu, Chunlan

2017-05-01

Metal-organic frameworks (MOFs) have attracted a lot of attention in recent decades. We applied a semi-rigid four-carboxylic acid linker to assemble with Cd(II) ions to generate a novel microporous Cd(II) MOF material. Single crystal X-ray diffraction study reveals the different two dimension (2D) layers can be further packed together with an AB fashion by hydrogen bonds (O4sbnd H4⋯O7 = 1.863 Å) to construct a three dimension (3D) supermolecular architecture. The resulting sample can be synthesized under solvothermal reactions successfully, which exhibits high selectivity adsorption of CO2 over CH4 at room temperature. In addition, the obtained sample was characterized by thermal gravimetric analyses (TGA), Fourier-transform infrared spectra (FT-IR), elemental analysis (CHN) and powder X-ray diffraction (PXRD).

Compact low power infrared tube furnace for in situ X-ray powder diffraction

NASA Astrophysics Data System (ADS)

Doran, A.; Schlicker, L.; Beavers, C. M.; Bhat, S.; Bekheet, M. F.; Gurlo, A.

2017-01-01

We describe the development and implementation of a compact, low power, infrared heated tube furnace for in situ powder X-ray diffraction experiments. Our silicon carbide (SiC) based furnace design exhibits outstanding thermal performance in terms of accuracy control and temperature ramping rates while simultaneously being easy to use, robust to abuse and, due to its small size and low power, producing minimal impact on surrounding equipment. Temperatures in air in excess of 1100 °C can be controlled at an accuracy of better than 1%, with temperature ramping rates up to 100 °C/s. The complete "add-in" device, minus power supply, fits in a cylindrical volume approximately 15 cm long and 6 cm in diameter and resides as close as 1 cm from other sensitive components of our experimental synchrotron endstation without adverse effects.

Thermal, spectroscopic and structural characterization of isostructural phase transition in 4-hydroxybenzaldehyde

NASA Astrophysics Data System (ADS)

Panicker, Lata

2018-05-01

Polycrystalline samples of 4-hydroxybenzaldehyde (4-HOBAL) were investigated using differential scanning calorimeter (DSC), Raman spectroscopy and X-ray powder diffraction. The DSC data indicated that 4-HOBAL on heating undergoes a polymorphic transformation from polymorph I to polymorph II. The polymorph II formed remains metastable at ambient condition and transforms to polymorph I when annealed at ambient temperature for more than seven days. The structural information of polymorphs I and II obtained using its X-ray powder diffraction patterns indicated that 4-HOBAL undergoes an isostructural phase transition from polymorph I (monoclinic, P21/c) to polymorph II (monoclinic, P21/c). Raman data suggest that this structural change is associated with some change in its molecular interactions. Thus, in 4-HOBAL the polymorphic phase transformation (II to I) even though energetically favoured is kinetically hindered.

Synthesis, characterization and dissolution of three pharmaceutical cocrystals based on deferiprone

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Tian, Yuyang; Jia, Jiangtao; Zhang, Tingting; Zhu, Guangshan

2016-03-01

In this paper we present three new cocrystals based on deferiprone which is the first oral medicine as iron chelator. Solitary deferiprone possesses some known problems due to its good solubility and frequent dosing side effects. For these three novel co crystals, deferiprone is the active pharmaceutical ingredient (API), p-hydroxybenzoic acid (1, C7H9NO2·C7H6O3), 2, 5-dihydroxybenzoic acid (2, C7H9NO2·C7H6O4) and maleic acid (3, C7H9NO2·C4H4O4) are used as cocrystal formers (CCFs), respectively. Their structures were characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) analysis, thermogravimetric analyses (TGA), differential thermal analysis (DTA), elemental analysis (EA) and infrared spectral analysis (IR). Single crystal X-ray diffraction demonstrates that all three cocrystals (1-3) possess strong hydrogen-bondings assembled through hydroxyl of API and carboxylic acids of CCFs. The PXRD results indicate their high purity of as-synthesized samples. TGA, DTA, EA, IR and dissolution study of API and cocrystals were also measured and discussed, respectively. The results suggest that the cocrystals exhibit low dissolution rates comparing with solitary deferiprone, which is very advantageous for the oral medicine with frequent dosing side effects.

Growth, structural, spectral, mechanical, thermal and dielectric characterization of phosphoric acid admixtured L-alanine (PLA) single crystals.

PubMed

Rose, A S J Lucia; Selvarajan, P; Perumal, S

2011-10-15

Phosphoric acid admixtured L-alanine (PLA) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 18 mm×12 mm×8 mm have been obtained in 28 days. The grown crystals were colorless and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV-visible transmittance spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied. Copyright © 2011 Elsevier B.V. All rights reserved.

Whisker growth of l-menthol in coexistence with various excipients.

PubMed

Yuasa, H; Ooi, M; Takashima, Y; Kanaya, Y

2000-08-10

The purpose of the present study was to clarify the mechanism for l-menthol whisker growth. l-Menthol was mixed with an excipient, and the interaction was examined by IR measurement, thermal analysis and powder X-ray diffraction. Then we examined the involvement of the capillary condensation using the pore size distribution measurement. By mixing l-menthol with an excipient with whisker growth, the hydroxyl group stretching band of l-menthol was shifted to the higher wavenumber in the IR spectrum, the melting point and heat of fusion of l-menthol became lower in the thermal analysis, and the diffraction intensity of l-menthol became lower in the powder X-ray diffraction. The excipients with whisker growth showed the tendency to have the meso-pore involved in the capillary condensation in the pore size distribution measurement. From the above results, the whisker growth mechanism is considered as follows. When l-menthol was mixed with an excipient with whisker growth, the crystallinity of l-menthol was lowered and the vapor pressure was increased by the interaction mainly consisting of the hydrogen bond. The generated l-menthol vapor entered meso-pore, the saturated vapor pressure was lowered by the capillary condensation, and the nucleation occurred. The vapor was further supplied, generating the growth of whisker.

Low-temperature synthesis of homogeneous solid solutions of scheelite-structured Ca 1-xSr xWO 4 and Sr 1-xBa xWO 4 nanocrystals

DOE PAGES

Culver, Sean P.; Greaney, Matthew J.; Tinoco, Antonio; ...

2015-07-24

Here, a series of compositionally complex scheelite-structured nanocrystals of the formula A 1-xA’ xWO 4 (A = Ca, Sr, Ba) have been prepared under benign synthesis conditions using the vapor diffusion sol–gel method. Discrete nanocrystals with sub-20 nm mean diameters were obtained after kinetically controlled hydro- lysis and polycondensation at room temperature, followed by composition-dependent thermal aging at or below 60 °C. Rietveld analysis of X-ray diffraction data and Raman spectroscopy verified the synthesis of continuous and phase-pure nanocrystal solid solutions across the entire composition space for A 1-xA’ xWO 4, where 0 ≤ x ≤ 1. Elemental analysis bymore » X-ray photoelectron and inductively coupled plasma- atomic emission spectroscopies demonstrated excellent agreement between the nominal and experi- mentally determined elemental stoichiometries, while energy dispersive X-ray spectroscopy illustrated good spatial elemental homogeneity within these nanocrystals synthesized under benign conditions.« less

Influence of Fe ions on structural, optical and thermal properties of SnO{sub 2} nanoparticles

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

Ahmed, Ateeq, E-mail: ateeqamu124@gmail.com; Tripathi, P.; Khan, Wasi

2016-05-23

In the present work, Fe doped SnO{sub 2} nanoparticles with the composition Sn{sub 1-x}Fe{sub x}O{sub 2} (x = 0, 0.02, 0.04 and 0.06) have been successfully synthesized using sol-gel auto combustion technique. The samples are characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDAX), Ultraviolet (UV-Visible) absorption spectroscopy and thermal gravimetric analysis (TGA). The XRD study shows that all the samples have been found in tetragonal rutile structure without any extra phase and average crystallite size which lies in the range of 6-17 nm. The EDAX spectrum confirmed the doping of Fe ion into tin oxidemore » nanomaterial. The optical band gap of doped SnO{sub 2} is found to decrease with increasing Fe ion concentration, which is due to the formation of donor energy levels in the actual band gap of SnO{sub 2}.« less

X-ray and neutron diffraction studies of crystallinity in hydroxyapatite coatings.

PubMed

Girardin, E; Millet, P; Lodini, A

2000-02-01

To standardize industrial implant production and make comparisons between different experimental results, we have to be able to quantify the crystallinity of hydroxyapatite. Methods of measuring crystallinity ratio were developed for various HA samples before and after plasma spraying. The first series of methods uses X-ray diffraction. The advantage of these methods is that X-ray diffraction equipment is used widely in science and industry. In the second series, a neutron diffraction method is developed and the results recorded are similar to those obtained by the modified X-ray diffraction methods. The advantage of neutron diffraction is the ability to obtain measurements deep inside a component. It is a nondestructive method, owing to the very low absorption of neutrons in most materials. Copyright 2000 John Wiley & Sons, Inc.

X-ray Diffraction Gratings for Astrophysics

NASA Astrophysics Data System (ADS)

Paerels, Frits

2010-12-01

Over the past year, we have celebrated the tenth anniversary of the Chandra and XMM-Newton X-ray observatories. Both carry powerful, novel diffraction grating spectrometers, which have opened true X-ray spectroscopy for astrophysics. I will describe the design and operation of these instruments, as the background to some of the beautiful results they have produced. But these designs do not exhaust the versatility and essential simplicity of diffraction grating spectrometers, and I will discuss applications for the International X-ray Observatory IXO.

Amorphous boron gasket in diamond anvil cell research

NASA Astrophysics Data System (ADS)

Lin, Jung-Fu; Shu, Jinfu; Mao, Ho-kwang; Hemley, Russell J.; Shen, Guoyin

2003-11-01

Recent advances in high-pressure diamond anvil cell experiments include high-energy synchrotron x-ray techniques as well as new cell designs and gasketing procedures. The success of high-pressure experiments usually depends on a well-prepared sample, in which the gasket plays an important role. Various gasket materials such as diamond, beryllium, rhenium, and stainless steel have been used. Here we introduce amorphous boron as another gasket material in high-pressure diamond anvil cell experiments. We have applied the boron gasket for laser-heating x-ray diffraction, radial x-ray diffraction, nuclear resonant inelastic x-ray scattering, and inelastic x-ray scattering. The high shear strength of the amorphous boron maximizes the thickness of the sample chamber and increases the pressure homogeneity, improving the quality of high-pressure data. Use of amorphous boron avoids unwanted x-ray diffraction peaks and reduces the absorption of incident and x rays exiting the gasket material. The high quality of the diffraction patterns makes it possible to refine the cell parameters with powder x-ray diffraction data under high pressure and high temperature. The reactivity of boron prevents its use at high temperatures, however. When heated, boron may also react with the specimen to produce unwanted phases. The relatively porous boron starting material at ambient conditions also poses some challenges for sample preparation.

X-Ray Sum Frequency Diffraction for Direct Imaging of Ultrafast Electron Dynamics

NASA Astrophysics Data System (ADS)

Rouxel, Jérémy R.; Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

2018-06-01

X-ray diffraction from molecules in the ground state produces an image of their charge density, and time-resolved x-ray diffraction can thus monitor the motion of the nuclei. However, the density change of excited valence electrons upon optical excitation can barely be monitored with regular diffraction techniques due to the overwhelming background contribution of the core electrons. We present a nonlinear x-ray technique made possible by novel free electron laser sources, which provides a spatial electron density image of valence electron excitations. The technique, sum frequency generation carried out with a visible pump and a broadband x-ray diffraction pulse, yields snapshots of the transition charge densities, which represent the electron density variations upon optical excitation. The technique is illustrated by ab initio simulations of transition charge density imaging for the optically induced electronic dynamics in a donor or acceptor substituted stilbene.

Using acoustic levitation in synchrotron based laser pump hard x-ray probe experiments

NASA Astrophysics Data System (ADS)

Hu, Bin; Lerch, Jason; Suthar, Kamlesh; Dichiara, Anthony

Acoustic levitation provides a platform to trap and hold a small amount of material by using standing pressure waves without a container. The technique has a potential to be used for laser pump x-ray probe experiments; x-ray scattering and laser distortion from the container can be avoided, sample consumption can be minimized, and unwanted chemistry that may occur at the container interface can be avoided. The method has been used at synchrotron sources for studying protein and pharmaceutical solutions using x-ray diffraction (XRD) and small angle x-ray scattering (SAXS). However, pump-probe experiments require homogeneously excited samples, smaller than the absorption depth of the material that must be held stably at the intersection of both the laser and x-ray beams. We discuss 1) the role of oscillations in acoustic levitation and the optimal acoustic trapping conditions for x-ray/laser experiments, 2) opportunities to automate acoustic levitation for fast sample loading and manipulation, and 3) our experimental results using SAXS to monitor laser induced thermal expansion in gold nanoparticles solution. We also performed Finite Element Analysis to optimize the trapping performance and stability of droplets ranging from 0.4 mm to 2 mm. Our early x-ray/laser demonstrated the potential of the technique for time-resolved X-ray science.

Kinetic products in coordination networks: ab initio X-ray powder diffraction analysis.

PubMed

Martí-Rujas, Javier; Kawano, Masaki

2013-02-19

Porous coordination networks are materials that maintain their crystal structure as molecular "guests" enter and exit their pores. They are of great research interest with applications in areas such as catalysis, gas adsorption, proton conductivity, and drug release. As with zeolite preparation, the kinetic states in coordination network preparation play a crucial role in determining the final products. Controlling the kinetic state during self-assembly of coordination networks is a fundamental aspect of developing further functionalization of this class of materials. However, unlike for zeolites, there are few structural studies reporting the kinetic products made during self-assembly of coordination networks. Synthetic routes that produce the necessary selectivity are complex. The structural knowledge obtained from X-ray crystallography has been crucial for developing rational strategies for design of organic-inorganic hybrid networks. However, despite the explosive progress in the solid-state study of coordination networks during the last 15 years, researchers still do not understand many chemical reaction processes because of the difficulties in growing single crystals suitable for X-ray diffraction: Fast precipitation can lead to kinetic (metastable) products, but in microcrystalline form, unsuitable for single crystal X-ray analysis. X-ray powder diffraction (XRPD) routinely is used to check phase purity, crystallinity, and to monitor the stability of frameworks upon guest removal/inclusion under various conditions, but rarely is used for structure elucidation. Recent advances in structure determination of microcrystalline solids from ab initio XRPD have allowed three-dimensional structure determination when single crystals are not available. Thus, ab initio XRPD structure determination is becoming a powerful method for structure determination of microcrystalline solids, including porous coordination networks. Because of the great interest across scientific disciplines in coordination networks, especially porous coordination networks, the ability to determine crystal structures when the crystals are not suitable for single crystal X-ray analysis is of paramount importance. In this Account, we report the potential of kinetic control to synthesize new coordination networks and we describe ab initio XRPD structure determination to characterize these networks' crystal structures. We describe our recent work on selective instant synthesis to yield kinetically controlled porous coordination networks. We demonstrate that instant synthesis can selectively produce metastable networks that are not possible to synthesize by conventional solution chemistry. Using kinetic products, we provide mechanistic insights into thermally induced (573-723 K) (i.e., annealing method) structural transformations in porous coordination networks as well as examples of guest exchange/inclusion reactions. Finally, we describe a memory effect that allows the transfer of structural information from kinetic precursor structures to thermally stable structures through amorphous intermediate phases. We believe that ab initio XRPD structure determination will soon be used to investigate chemical processes that lead intrinsically to microcrystalline solids, which up to now have not been fully understood due to the unavailability of single crystals. For example, only recently have researchers used single-crystal X-ray diffraction to elucidate crystal-to-crystal chemical reactions taking place in the crystalline scaffold of coordination networks. The potential of ab initio X-ray powder diffraction analysis goes beyond single-crystal-to-single-crystal processes, potentially allowing members of this field to study intriguing in situ reactions, such as reactions within pores.

Characterization of Graphite Oxide and Reduced Graphene Oxide Obtained from Different Graphite Precursors and Oxidized by Different Methods Using Raman Spectroscopy.

PubMed

Muzyka, Roksana; Drewniak, Sabina; Pustelny, Tadeusz; Chrubasik, Maciej; Gryglewicz, Grażyna

2018-06-21

In this paper, the influences of the graphite precursor and the oxidation method on the resulting reduced graphene oxide (especially its composition and morphology) are shown. Three types of graphite were used to prepare samples for analysis, and each of the precursors was oxidized by two different methods (all samples were reduced by the same method of thermal reduction). Each obtained graphite oxide and reduced graphene oxide was analysed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS).

Boehmite nanostructures preparation by hydrothermal method from anodic aluminium oxide membrane.

PubMed

Yang, X; Wang, J Y; Pan, H Y

2009-02-01

Boehmite nanostructures were successfully synthesized from porous anodic aluminium oxide (AAO) membrane by a simple and efficient hydro-thermal method. The experiment used high purity alumina as raw material, and the whole reaction process avoided superfluous impurities to be introduced. Thus, the purity of Boehmite products was ensured. The examinations of the morphology and structure were carried out by atomic force microscope (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Composition of the specimens was analyzed using energy dispersive X-ray spectroscope (EDX) and X-ray diffraction (XRD). Based on these observations the growth process was analyzed.

A New Star-shaped Carbazole Derivative with Polyhedral Oligomeric Silsesquioxane Core: Crystal Structure and Unique Photoluminescence Property.

PubMed

Xu, Zixuan; Yu, Tianzhi; Zhao, Yuling; Zhang, Hui; Zhao, Guoyun; Li, Jianfeng; Chai, Lanqin

2016-01-01

A new inorganic–organic hybrid material based on polyhedral oligomeric silsesquioxane (POSS) capped with carbazolyl substituents, octakis[3-(carbazol-9-yl)propyldimethylsiloxy]-silsesquioxane (POSS-8Cz), was successfully synthesized and characterized. The X-ray crystal structure of POSS-8Cz were described. The photophysical properties of POSS-8Cz were investigated by using UV–vis,photoluminescence spectroscopic analysis. The hybrid material exhibits blue emission in the solution and the solid film.The morphology and thermal stablity properties were measured by X-ray diffraction (XRD) and TG-DTA analysis.

Electron-Beam Deposition of Superconducting Molybdenum Thin Films for the Development of Mo/Au TES X-Ray Microcalorimeter

NASA Technical Reports Server (NTRS)

Finkbeiner, Fred Michael; Adams, Joseph S.; Bandler, Simon R.; Betancour-Martinez, Gabriele L.; Brown, Ari David; Chang, Meng-Ping; Chervenak, James A.; Chiao, Meng P.; Datesman, Aaron; Eckart, Megan E.;

Structure and giant magnetoresistance of granular Co-Cu nanolayers prepared by cross-beam pulsed laser deposition

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

Jesche, A.; Stoecker, H.; Levin, A. A.

2010-01-15

A series of Co{sub x}Cu{sub 100-x} (x=0, 40-75, 100) layers with thicknesses between 13 and 55 nm were prepared on silicon substrates using cross-beam pulsed laser deposition. Wide-angle x-ray diffraction (WAXRD), transmission electron microscopy (TEM), and electrical transport measurements revealed a structure consisting of decomposed cobalt and copper grains with grain sizes of about 10 nm. The influence of cobalt content and layer thickness on the grain size is discussed. Electron diffraction indicates the presence of an intermetallic Co-Cu phase of Cu{sub 3}Au structure type. Thermal treatment at temperatures between 525 and 750 K results in the progressive decomposition ofmore » Co and Cu, with an increase of the grain sizes up to about 100 nm. This is tunable by controlling the temperature and duration of the anneal, and is directly observable in WAXRD patterns and TEM images. A careful analysis of grain size and the coherence length of the radiation used allows for an accurate interpretation of the x-ray diffraction patterns, by taking into account coherent and noncoherent scattering. The alloy films show a giant magnetoresistance of 1%-2.3% with the maximum obtained after annealing at around 725 K.« less

Study of the specific features of single-crystal boron microstructure

NASA Astrophysics Data System (ADS)

Blagov, A. E.; Vasil'ev, A. L.; Dmitriev, V. P.; Ivanova, A. G.; Kulikov, A. G.; Marchenkov, N. V.; Popov, P. A.; Presnyakov, M. Yu.; Prosekov, P. A.; Pisarevskii, Yu. V.; Targonskii, A. V.; Chernaya, T. S.; Chernyshov, D. Yu.

2017-09-01

A complex study of the structure of β-boron single crystal grown by the floating-zone method, with sizes significantly exceeding the analogs known in the literature, has been performed. The study includes X-ray diffraction analysis and X-ray diffractometry (measurement of pole figures and rocking curves), performed on both laboratory and synchrotron sources; atomic-resolution scanning transmission electron microscopy with spherical aberration correction; and energy-dispersive microanalysis. X-ray diffraction analysis using synchrotron radiation has been used to refine the β-boron structure and find impurity Si atoms. The relative variations in the unit-cell parameters a and c for the crystal bulk are found to be δ a/ a ≈ 0.4 and δ c/ c ≈ 0.1%. X-ray diffractometry has revealed that the single-crystal growth axis coincides with the [2\\bar 2013] crystallographic axis and makes an angle of 21.12° with the [0001] threefold axis. Electron microscopy data have confirmed that the sample under study is a β-boron crystal, which may contain 0.3-0.4 at % Si as an impurity. Planar defects (stacking faults and dislocations) are found. The results of additional measurements of the temperature dependence of the thermal conductivity of the crystal in the range of 50-300 K are indicative of its high structural quality.

High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt

DOE PAGES

Ueland, B. G.; Saunders, S. M.; Bud'ko, S. L.; ...

2015-11-30

In this study, YbBiPt is a heavy-fermion compound possessing significant short-range antiferromagnetic correlations below a temperature of T*=0.7K, fragile antiferromagnetic order below T N = 0.4K, a Kondo temperature of T K ≈ 1K, and crystalline-electric-field splitting on the order of E/k B = 1 – 10K. Whereas the compound has a face-centered-cubic lattice at ambient temperature, certain experimental data, particularly those from studies aimed at determining its crystalline-electric-field scheme, suggest that the lattice distorts at lower temperature. Here, we present results from high-resolution, high-energy x-ray diffraction experiments which show that, within our experimental resolution of ≈ 6 – 10more » × 10 –5 Å, no structural phase transition occurs between T = 1.5 and 50 K. In combination with results from dilatometry measurements, we further show that the compound's thermal expansion has a minimum at ≈ 18 K and a region of negative thermal expansion for 9 ≲ T ≲ 18 K. Despite diffraction patterns taken at 1.6 K which indicate that the lattice is face-centered cubic and that the Yb resides on a crystallographic site with cubic point symmetry, we demonstrate that the linear thermal expansion may be modeled using crystalline-electric-field level schemes appropriate for Yb 3+ residing on a site with either cubic or less than cubic point symmetry.« less

Crystal structure and thermal expansion of CsCaI3:Eu and CsSrBr3:Eu scintillators

NASA Astrophysics Data System (ADS)

Loyd, Matthew; Lindsey, Adam; Patel, Maulik; Koschan, Merry; Melcher, Charles L.; Zhuravleva, Mariya

2018-01-01

The distorted-perovskite scintillator materials CsCaI3:Eu and CsSrBr3:Eu prepared as single crystals have shown promising potential for use in radiation detection applications requiring a high light yield and excellent energy resolution. We present a study using high temperature powder X-ray diffraction experiments to examine a deleterious high temperature phase transition. High temperature phases were identified through sequential diffraction pattern Rietveld refinement in GSAS II. We report the linear coefficients of thermal expansion for both high and low temperature phases of each compound. Thermal expansion for both compositions is greatest in the [0 0 1] direction. As a result, Bridgman growth utilizing a seed oriented with the [0 0 1] along the growth direction should be used to mitigate thermal stress.

Thermal behaviour and microanalysis of coal subbituminus

NASA Astrophysics Data System (ADS)

Heriyanti; Prendika, W.; Ashyar, R.; Sutrisno

2018-04-01

Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) is used to study the thermal behaviour of sub-bituminous coal. The DSC experiment was performed in air atmosphere up to 125 °C at a heating rate of 25 °C min1. The DSC curve showed that the distinct transitional stages in the coal samples studied. Thermal heating temperature intervals, peak and dissociation energy of the coal samples were also determined. The XRD analysis was used to evaluate the diffraction pattern and crystal structure of the compounds in the coal sample at various temperatures (25-350 °C). The XRD analysis of various temperatures obtained compounds from the coal sample, dominated by quartz (SiO2) and corundum (Al2O3). The increase in temperature of the thermal treatment showed a better crystal formation.

Synthesis, structural, thermal and optical properties of TeO2-Bi2O3-GeO2-Li2O glasses

NASA Astrophysics Data System (ADS)

Dimowa, Louiza; Piroeva, Iskra; Atanasova-Vladimirova, S.; Petrova, Nadia; Ganev, Valentin; Titorenkova, Rositsa; Yankov, Georgi; Petrov, Todor; Shivachev, Boris L.

2016-10-01

In this study, synthesis and characterization of novel quaternary tellurite glass system TeO2-Bi2O3-GeO2-Li2O is presented. The compositions include TeO2 and GeO2 as glass formers while different proportion of Bi2O3 and Li2O act as network modifiers. Differential thermal analysis, X-ray diffraction, scanning electron microscopy energy dispersive X-ray spectroscopy, laser ablation inductively coupled plasma mass spectrometry, UV-Vis and Raman spectroscopy are applied to study the structural, thermal and optical properties of the studied glasses. Obtained glasses possess a relatively low glass transition temperature (around 300 °C) if compared to other tellurite glasses, show good thermal transparency in the visible and near infra-red (from 2.4 to 0.4 μm) and can double the frequency of laser light from its original wavelength of 1064 nm to its second-harmonic at 532 nm (i.e. second harmonic generation).

Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens.

PubMed

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10(-2) Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.

Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens

NASA Astrophysics Data System (ADS)

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10-2 Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.

Thin Film Research. Volume 1

DTIC Science & Technology

1985-05-30

Order (FECO) ......... 23 3. X -Ray Diffraction ............................... 26 4. Transmission Electron Microscopy (TEM) ............... 26 5...remained amorphous after bombardment, as evidenced by X - ray diffraction, and showed no other changes. 0 (2) For Sb203, the crystallite size was reduced...main effect on MgF2 was the reduction in crystallite size. The films were too thir. for meaningful x - ray diffraction analysis. Durability and

X-Ray Diffraction and the Discovery of the Structure of DNA

ERIC Educational Resources Information Center

Crouse, David T.

2007-01-01

A method is described for teaching the analysis of X-ray diffraction of DNA through a series of steps utilizing the original methods used by James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin. The X-ray diffraction pattern led to the conclusion of the basic helical structure of DNA and its dimensions while basic chemical principles…

High Resolution X-Ray Diffraction of Macromolecules with Synchrotron Radiation

NASA Technical Reports Server (NTRS)

Stojanoff, Vivian; Boggon, Titus; Helliwell, John R.; Judge, Russell; Olczak, Alex; Snell, Edward H.; Siddons, D. Peter; Rose, M. Franklin (Technical Monitor)

2000-01-01

We recently combined synchrotron-based monochromatic X-ray diffraction topography methods with triple axis diffractometry and rocking curve measurements: high resolution X-ray diffraction imaging techniques, to better understand the quality of protein crystals. We discuss these methods in the light of results obtained on crystals grown under different conditions. These non destructive techniques are powerful tools in the characterization of the protein crystals and ultimately will allow to improve, develop, and understand protein crystal growth. High resolution X-ray diffraction imaging methods will be discussed in detail in light of recent results obtained on Hen Egg White Lysozyme crystals and other proteins.

Hard X-ray polarizer to enable simultaneous three-dimensional nanoscale imaging of magnetic structure and lattice strain

DOE PAGES

Logan, Jonathan; Harder, Ross; Li, Luxi; ...

2016-01-01

Recent progress in the development of dichroic Bragg coherent diffractive imaging, a new technique for simultaneous three-dimensional imaging of strain and magnetization at the nanoscale, is reported. This progress includes the installation of a diamond X-ray phase retarder at beamline 34-ID-C of the Advanced Photon Source. Here, the performance of the phase retarder for tuning X-ray polarization is demonstrated with temperature-dependent X-ray magnetic circular dichroism measurements on a gadolinium foil in transmission and on a Gd 5Si 2Ge 2crystal in diffraction geometry with a partially coherent, focused X-ray beam. Feasibility tests for dichroic Bragg coherent diffractive imaging are presented. Thesemore » tests include (1) using conventional Bragg coherent diffractive imaging to determine whether the phase retarder introduces aberrations using a nonmagnetic gold nanocrystal as a control sample, and (2) collecting coherent diffraction patterns of a magnetic Gd 5Si 2Ge 2nanocrystal with left- and right-circularly polarized X-rays. Future applications of dichroic Bragg coherent diffractive imaging for the correlation of strain and lattice defects with magnetic ordering and inhomogeneities are considered.« less

Synthesis of Mesoporous Nanocrystalline Zirconia by Surfactant-Assisted Hydrothermal Approach.

PubMed

Nath, Soumav; Biswas, Ashik; Kour, Prachi P; Sarma, Loka S; Sur, Ujjal Kumar; Ankamwar, Balaprasad G

2018-08-01

In this paper, we have reported the chemical synthesis of thermally stable mesoporous nanocrystalline zirconia with high surface area using a surfactant-assisted hydrothermal approach. We have employed different type of surfactants such as CTAB, SDS and Triton X-100 in our synthesis. The synthesized nanocrystalline zirconia multistructures exhibit various morphologies such as rod, mortar-pestle with different particle sizes. We have characterized the zirconia multistructures by X-ray diffraction study, Field emission scanning electron microscopy, Attenuated total refection infrared spectroscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The thermal stability of as synthesized zirconia multistructures was studied by thermo gravimetric analysis, which shows the high thermal stability of nanocrystalline zirconia around 900 °C temperature.

Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging

DOE PAGES

Cha, W.; Ulvestad, A.; Allain, M.; ...

2016-11-23

Here, we present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We also demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Furthermore, variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.

Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results

NASA Technical Reports Server (NTRS)

Treiman, A. H.; Lanzirotti, A.; Xirouchakis, D.

2004-01-01

X-ray diffraction is the pre-eminent technique for mineral identification and structure determination, but is difficult to apply to grains in thin section, the standard meteorite preparation. Bright focused X-ray beams from synchrotrons have been used extensively in mineralogy and have been applied to extraterrestrial particles. The intensity and small spot size achievable in synchrotron X-ray beams makes them useful for study of materials in thin sections. Here, we describe Synchrotron X-ray Diffraction (SXRD) in thin section as done at the National Synchrotron Light Source, and cite examples of its value for studies of meteorites in thin section.

Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging

NASA Astrophysics Data System (ADS)

Cha, W.; Ulvestad, A.; Allain, M.; Chamard, V.; Harder, R.; Leake, S. J.; Maser, J.; Fuoss, P. H.; Hruszkewycz, S. O.

2016-11-01

We present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.

Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging.

PubMed

Cha, W; Ulvestad, A; Allain, M; Chamard, V; Harder, R; Leake, S J; Maser, J; Fuoss, P H; Hruszkewycz, S O

2016-11-25

We present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.

X-ray induced chemical reaction revealed by in-situ X-ray diffraction and scanning X-ray microscopy in 15 nm resolution (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ge, Mingyuan; Liu, Wenjun; Bock, David; De Andrade, Vincent; Yan, Hanfei; Huang, Xiaojing; Marschilok, Amy; Takeuchi, Esther; Xin, Huolin; Chu, Yong S.

2016-09-01

The detection sensitivity of synchrotron-based X-ray techniques has been largely improved due to the ever increasing source brightness, which have significantly advanced ex-situ and in-situ research for energy materials, such as lithium-ion batteries. However, the strong beam-matter interaction arisen from the high beam flux can significantly modify the material structure. The parasitic beam-induced effect inevitably interferes with the intrinsic material property, which brings difficulties in interpreting experimental results, and therefore requires comprehensive evaluation. Here we present a quantitative in-situ study of the beam-effect on one electrode material Ag2VO2PO4 using four different X-ray probes with different radiation dose rate. The material system we reported exhibits interesting and reversible radiation-induced thermal and chemical reactions, which was further evaluated under electron microscopy to illustrate the underlying mechanism. The work we presented here will provide a guideline in using synchrotron X-rays to distinguish the materials' intrinsic behavior from extrinsic structure changed induced by X-rays, especially in the case of in-situ and operando study where the materials are under external field of either temperature or electric field.

Inorganic polymers from laterite using activation with phosphoric acid and alkaline sodium silicate solution: Mechanical and microstructural properties

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

Lassinantti Gualtieri, Magdalena, E-mail: magdalena.gualtieri@unimore.it; Romagnoli, Marcello; Pollastri, Simone

2015-01-15

Geopolymers from laterite, an iron-rich soil available in developing countries, have great potential as building materials. In this work, laterite from Togo (Africa) was used to prepare geopolymers using both phosphoric acid and alkaline sodium silicate solution. Microstructural properties were investigated by scanning electron microscopy, X-ray powder diffraction and mercury porosimetry, whereas thermal properties were evaluated by thermal analyses. The local environment of iron was studied by X-ray Absorption Spectroscopy (XANES region). The mechanical properties were determined. Modulus of Rupture and Young's modulus fell in the ranges 3.3–4.5 MPa and 12–33 GPa, respectively, rendering the materials good candidates for constructionmore » purposes. Heating above 900 °C results in weight-gain, presumably due to iron redox reactions. X-ray Absorption Spectroscopy data evidence changes in the chemical and structural environments of iron following thermal treatment of geopolymers. These changes indicate interaction between the geopolymer structure and iron during heating, possibly leading to redox properties. -- Highlights: •Geopolymerization of laterite is promising for fabrication of building materials. •Both phosphoric acid and alkaline sodium silicate solution can be used for activation. •Thermally activated redox properties of the inorganic polymers were observed.« less

In-situ X-ray diffraction system using sources and detectors at fixed angular positions

DOEpatents

Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

2007-06-26

An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients.

PubMed

Siddiqui, Sanna F; Knipe, Kevin; Manero, Albert; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M; Bartsch, Marion; Raghavan, Seetha

2013-08-01

Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.

Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients

NASA Astrophysics Data System (ADS)

Siddiqui, Sanna F.; Knipe, Kevin; Manero, Albert; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Bartsch, Marion; Raghavan, Seetha

2013-08-01

Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.

Misfit strain of oxygen precipitates in Czochralski silicon studied with energy-dispersive X-ray diffraction

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

Gröschel, A., E-mail: alexander.groeschel@fau.de; Will, J.; Bergmann, C.

Annealed Czochralski Silicon wafers containing SiO{sub x} precipitates have been studied by high energy X-ray diffraction in a defocused Laue setup using a laboratory tungsten tube. The energy dispersive evaluation of the diffracted Bragg intensity of the 220 reflection within the framework of the statistical dynamical theory yields the static Debye-Waller factor E of the crystal, which gives access to the strain induced by the SiO{sub x} precipitates. The results are correlated with precipitate densities and sizes determined from transmission electron microscopy measurements of equivalent wafers. This allows for the determination of the constrained linear misfit ε between precipitate andmore » crystal lattice. For samples with octahedral precipitates the values ranging from ε = 0.39 (+0.28/−0.12) to ε = 0.48 (+0.34/−0.16) indicate that self-interstitials emitted into the matrix during precipitate growth contribute to the lattice strain. In this case, the expected value calculated from literature values is ε = 0.26 ± 0.05. Further, the precise evaluation of Pendellösung oscillations in the diffracted Bragg intensity of as-grown wafers reveals a thermal Debye-Waller parameter for the 220 reflection B{sup 220}(293 K) of 0.5582 ± 0.0039 Å{sup 2} for a structure factor based on spherically symmetric scattering contributions.« less

The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions

NASA Astrophysics Data System (ADS)

Hruszkewycz, S. O.; Harder, R.; Xiao, X.; Fuoss, P. H.

2010-12-01

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.

The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions.

PubMed

Hruszkewycz, S O; Harder, R; Xiao, X; Fuoss, P H

2010-12-01

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.

Femtosecond X-ray Diffraction From Two-Dimensional Protein Crystals

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

Frank, Matthias; Carlson, David B.; Hunter, Mark

2014-02-28

Here we present femtosecond x-ray diffraction patterns from two-dimensional (2-D) protein crystals using an x-ray free electron laser (XFEL). To date it has not been possible to acquire x-ray diffraction from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permits a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy methodology at the Linac Coherent Light Source, we observed Bragg diffraction to better than 8.5 Å resolution for two different 2-D protein crystal samples that were maintained at room temperature. These proof-of-principle results show promisemore » for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.« less

Simulation and optimization of the SIRIUS IPE soft x-ray beamline

NASA Astrophysics Data System (ADS)

Meyer, Bernd C.; Rocha, Tulio C. R.; Luiz, Sergio A. L.; C. Pinto, Artur; Westfahl, Harry

2017-08-01

The soft X-ray beamline IPE is one of the first phase SIRIUS beamlines at the LNLS, Brazil. Divided into two branches, IPE is designed to perform ambient pressure X-ray photo-electron spectroscopy (AP-XPS) and high resolution resonant inelastic X-ray scattering (RIXS) for samples in operando/environmental conditions inside cells and liquid jets. The aim is to maximize the photon flux in the energy range 200-1400 eV generated by an elliptically polarizing undulator source (EPU) and focus it to a 1 μm vertical spot size at the RIXS station and 10 μm at the AP-XPS station. In order to achieve the required resolving power (40.000 at 930 eV) for RIXS both the dispersion properties of the plane grating monochromator (PGM) and the thermal deformation of the optical elements need special attention. The grating parameters were optimized with the REFLEC code to maximize the efficiency at the required resolution. Thermal deformation of the PGM plane mirror limits the possible range of cff parameters depending of the photon energy used. Hence, resolution of the PGM and thermal deformation effects define the boundary conditions of the optical concept and the simulations of the IPE beamline. We compare simulations performed by geometrical ray-tracing (SHADOW) and wave front propagation (SRW) and show that wave front diffraction effects (apertures, optical surface error profiles) has a small effect on the beam spot size and shape.

Influence of gamma ray irradiation on stoichiometry of hydrothermally synthesized bismuth telluride nanoparticles

NASA Astrophysics Data System (ADS)

Abishek, N. S.; Naik, K. Gopalakrishna

2018-05-01

Bismuth telluride (Bi2Te3) nanoparticles were synthesized by the hydrothermal method at 200 °C for 24 h. The synthesized Bi2Te3 nanoparticles were irradiated with gamma rays at doses of 50 kGy and 100 kGy. The structural characterization of the pre-irradiated and post-irradiated samples was carried out by X-ray diffraction technique and was found to have rhombohedral phase having R3 ¯m (166) space group. The X-ray diffraction peaks were found to shift towards lower diffraction angle with gamma ray irradiation. The morphologies and compositions of the grown Bi2Te3 nanoparticles were studied using Field Emission Scanning Electron Microscope and X-ray energy dispersive analysis, respectively. The possible cause for the shift in the X-ray diffraction peaks with gamma ray irradiation has been discussed in the present work.

High Power Optical Coatings by Atomic Layer Deposition and Signatures of Laser-Induced Damage

DTIC Science & Technology

2012-08-28

diffraction angle 0 into crystal lattice spacing d by the Bragg condition, mX = 2d sin 0. Here X is the x - ray wavelength... angle x - ray diffraction (GAXRD) measurements, which were made at a fixed shallow incidence angle of 0.5°. Detector scans were done to measure the...was finished with 200 hafnia cycles m the fmal half period rather than 400. Crystallinity was measured by x - ray diffraction (XRD) with

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

Shivananda, C. S.; Rao, B. Lakshmeesha; Madhukumar, R.

In this work silk fibroin/pullulan blend films have been prepared by solution casting method. The blend films were examined for structural, and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results indicate that with the introduction of pullulan, the interaction between SF and pullulan in the blend films induced the conformation transition of SF films and amorphous phase increases with increasing pullulan ratio. The thermal properties of the blend films were improved significantly in the blend films.

Anisotropic lattice thermal expansion of PbFeBO 4: A study by X-ray and neutron diffraction, Raman spectroscopy and DFT calculations

DOE PAGES

Murshed, M. Mangir; Mendive, Cecilia B.; Curti, Mariano; ...

2014-11-01

We present the lattice thermal expansion of mullite-type PbFeBO 4 in this study. The thermal expansion coefficients of the metric parameters were obtained from composite data collected from temperature-dependent neutron and X-ray powder diffraction between 10 K and 700 K. The volume thermal expansion was modeled using extended Grüneisen first-order approximation to the zero-pressure equation of state. The additive frame of the model includes harmonic, quasi-harmonic and intrinsic anharmonic potentials to describe the change of the internal energy as a function of temperature. Moreover, the unit-cell volume at zero-pressure and 0 K was optimized during the DFT simulations. Harmonic frequenciesmore » of the optical Raman modes at the Γ-point of the Brillouin zone at 0 K were also calculated by DFT, which help to assign and crosscheck the experimental frequencies. The low-temperature Raman spectra showed significant anomaly in the antiferromagnetic regions, leading to softening or hardening of some phonons. Selected modes were analyzed using a modified Klemens model. The shift of the frequencies and the broadening of the line-widths helped to understand the anharmonic vibrational behaviors of the PbO4, FeO6 and BO3 polyhedra as a function of temperature.« less

Materials identification using a small-scale pixellated x-ray diffraction system

NASA Astrophysics Data System (ADS)

O'Flynn, D.; Crews, C.; Drakos, I.; Christodoulou, C.; Wilson, M. D.; Veale, M. C.; Seller, P.; Speller, R. D.

2016-05-01

A transmission x-ray diffraction system has been developed using a pixellated, energy-resolving detector (HEXITEC) and a small-scale, mains operated x-ray source (Amptek Mini-X). HEXITEC enables diffraction to be measured without the requirement of incident spectrum filtration, or collimation of the scatter from the sample, preserving a large proportion of the useful signal compared with other diffraction techniques. Due to this efficiency, sufficient molecular information for material identification can be obtained within 5 s despite the relatively low x-ray source power. Diffraction data are presented from caffeine, hexamine, paracetamol, plastic explosives and narcotics. The capability to determine molecular information from aspirin tablets inside their packaging is demonstrated. Material selectivity and the potential for a sample classification model is shown with principal component analysis, through which each different material can be clearly resolved.

Dynamic X-ray diffraction sampling for protein crystal positioning

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

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less

Dynamic X-ray diffraction sampling for protein crystal positioning

DOE PAGES

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; ...

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less

Dynamic X-ray diffraction sampling for protein crystal positioning

PubMed Central

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; Kissick, David J.; Zhang, Shijie; Newman, Justin A.; Sheedlo, Michael J.; Chowdhury, Azhad U.; Fischetti, Robert F.; Das, Chittaranjan; Buzzard, Gregery T.; Bouman, Charles A.; Simpson, Garth J.

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations. PMID:28009558

Dynamic X-ray diffraction sampling for protein crystal positioning.

PubMed

Scarborough, Nicole M; Godaliyadda, G M Dilshan P; Ye, Dong Hye; Kissick, David J; Zhang, Shijie; Newman, Justin A; Sheedlo, Michael J; Chowdhury, Azhad U; Fischetti, Robert F; Das, Chittaranjan; Buzzard, Gregery T; Bouman, Charles A; Simpson, Garth J

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.

Diffraction imaging for in situ characterization of double-crystal X-ray monochromators

DOE PAGES

Stoupin, Stanislav; Liu, Zunping; Heald, Steve M.; ...

2015-10-30

In this paper, imaging of the Bragg-reflected X-ray beam is proposed and validated as an in situ method for characterization of the performance of double-crystal monochromators under the heat load of intense synchrotron radiation. A sequence of images is collected at different angular positions on the reflectivity curve of the second crystal and analyzed. The method provides rapid evaluation of the wavefront of the exit beam, which relates to local misorientation of the crystal planes along the beam footprint on the thermally distorted first crystal. The measured misorientation can be directly compared with the results of finite element analysis. Finally,more » the imaging method offers an additional insight into the local intrinsic crystal quality over the footprint of the incident X-ray beam.« less

Structural and thermal properties of silk fibroin - Silver nanoparticles composite films

NASA Astrophysics Data System (ADS)

Shivananda, C. S.; Rao B, B. Lakshmeesha; Shetty, G. Rajesh; Sangappa, Y.

2018-05-01

In this work, silk fibroin-silver nanoparticles (SF-AgNPs) composite films have been prepared by simple solution casting method. The composite films were examined for structural and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results showed that with the introduction of AgNPs in the silk fibroin matrix the amorphous nature of the silk fibroin decreases with increasing nanoparticles concentration. The silk fibroin films possess good thermal stability with the presence of AgNPs.

The thermal stability of the carbon-palladium films for hydrogen sensor applications

NASA Astrophysics Data System (ADS)

Rymarczyk, Joanna; Czerwosz, ElŻbieta; Diduszko, Ryszard; Kozłowski, Mirosław

2017-08-01

The thermal stability of two types of C-Pd films prepared in PVD process were studied. These films are composed of Pd nanograins embedded in a multiphase carbonaceous matrix. These films were distinguished by Pd content. These films were annealed in a range of temperatures 50÷1000°C. The structural, topographical and molecular changes were studied by scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods. The results show that investigated films are thermally stable up to 200°C.

Structural and thermal properties of γ - irradiated Bombyx mori silk fibroin films

NASA Astrophysics Data System (ADS)

Madhukumar, R.; Asha, S.; Sarojini, B. K.; Somashekar, R.; Rao, B. Lakshmeesha; Shivananda, C. S.; Harish, K. V.; Sangappa

2015-06-01

The gamma radiation-induced change in structural and thermal properties of Bombyx mori silk fibroin films were investigated and have been correlated with the applied radiation doses. Irradiation of samples were carried out in dry air at room temperature using Co-60 source, and radiation doses are in the range of 0 - 300 kGy. Structural and thermal properties of the irradiated silk films were studied using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA) and compared with unirradiated sample. Interesting results are discussed in this report.

Fixture for supporting and aligning a sample to be analyzed in an x-ray diffraction apparatus

DOEpatents

Green, L.A.; Heck, J.L. Jr.

1985-04-23

A fixture is provided for supporting and aligning small samples of material on a goniometer for x-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the x-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an x-ray diffraction apparatus previously limited to the analysis of much larger samples.

Fixture for supporting and aligning a sample to be analyzed in an X-ray diffraction apparatus

DOEpatents

Green, Lanny A.; Heck, Jr., Joaquim L.

1987-01-01

A fixture is provided for supporting and aligning small samples of material on a goniometer for X-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the X-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an X-ray diffraction apparatus previously limited to the analysis of much larger samples.

Structural insights into the thermal decomposition sequence of barium tetrahydrogenorthotellurate(VI), Ba[H{sub 4}TeO{sub 6}

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

Weil, Matthias, E-mail: Matthias.Weil@tuwien.ac.at; Stöger, Berthold; Gierl-Mayer, Christian

2016-09-15

The compounds Ba[H{sub 4}TeO{sub 6}] (I), Ba[H{sub 2}TeO{sub 5}] (II), Ba[Te{sub 2}O{sub 6}(OH){sub 2}] (III) and Ba[TeO{sub 4}] (IV) were prepared by application of a diffusion method (I), under hydrothermal conditions (II and III) and from solid state reactions (IV), respectively. Structure analysis on the basis of single crystal X-ray diffraction data revealed novel structure types for (I), (II) and (III) and isotypism of (IV) with PrSbO{sub 4} and LaSbO{sub 4}. Common feature of the four oxotellurate(VI) structures are [TeO{sub 6}] octahedra. Whereas in the crystal structure of (I) the octahedral units are isolated, they are condensed into chains viamore » corner-sharing in (II) and via edge-sharing in (III) and (IV). The coordination numbers of the barium cations in the four structures range from seven to ten. Although hydrogen atom positions could not be located for the structures of (I) and (II), short interpolyhedral O···O contacts are evident for strong hydrogen bonding. The temperature behaviour of (I), (II) and (IV) was monitored by simultaneous thermal analysis (STA) measurements and in situ powder X-ray diffraction, revealing the decomposition sequence Ba[H{sub 4}TeO{sub 6}] → Ba[H{sub 2}TeO{sub 5}] → Ba[TeO{sub 4}]→ Ba[TeO{sub 3}] upon heating to temperatures up to 900 °C. - Graphical abstract: The crystal structures of the four oxotellurates(VI) were determined from single crystal data. The thermal decomposition of Ba[H{sub 4}TeO{sub 6}], monitored by temperature-dependent X-ray powder diffraction and simultaneous thermal analysis measurements, involves two condensation reactions according to Ba[H{sub 4}TeO{sub 6}]→Ba[H{sub 2}TeO{sub 5}]+H{sub 2}O(↑)→Ba[TeO{sub 4}]+ H{sub 2}O(↑). Display Omitted.« less

The effect of heat treatment on structural and electronic properties of niobium nitride prepared by a thermal diffusion method

DOE PAGES

Farha, Ashraf Hassan; Ozkendir, Osman Murat; Elsayed-Ali, Hani E.; ...

2016-11-15

NbN coatings are prepared onto Nb substrate by thermal diffusion at high temperatures. The formation of NbN coating by thermal diffusion was studied in the range of 1250-1500 °C at constant nitrogen background gas pressure (1.3x10 -3 Pa) and processing time (180 min). The electronic and crystal structures of the NbN coatings were investigated. It was found that nitrogen diffuses into Nb forming the Nb-N solid solution (bcc) a-NbN phase that starts to appear above 1250 °C. Increasing the processing temperature gives richer a-phase concentration. Besides, X-ray absorption spectroscopy (XAS) was performed to study the electronic structure of the NbNmore » layer. The results of the electronic structural study corroborate the crystal structural analysis. The Nb M 3,2 edge X-ray absorption spectroscopy (XAS) spectrum shows strong temperature dependence. At the highest processing temperature (1500 °C), the number of d holes increased. Nitrogen diffusion into Nb is resulting to increase electrostatic interaction between d electron and core hole. Lastly, for the studied conditions, only the α-NbN was observed in the X-ray diffraction patterns.« less

The effect of heat treatment on structural and electronic properties of niobium nitride prepared by a thermal diffusion method

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

Farha, Ashraf Hassan; Ozkendir, Osman Murat; Elsayed-Ali, Hani E.

NbN coatings are prepared onto Nb substrate by thermal diffusion at high temperatures. The formation of NbN coating by thermal diffusion was studied in the range of 1250-1500 °C at constant nitrogen background gas pressure (1.3x10 -3 Pa) and processing time (180 min). The electronic and crystal structures of the NbN coatings were investigated. It was found that nitrogen diffuses into Nb forming the Nb-N solid solution (bcc) a-NbN phase that starts to appear above 1250 °C. Increasing the processing temperature gives richer a-phase concentration. Besides, X-ray absorption spectroscopy (XAS) was performed to study the electronic structure of the NbNmore » layer. The results of the electronic structural study corroborate the crystal structural analysis. The Nb M 3,2 edge X-ray absorption spectroscopy (XAS) spectrum shows strong temperature dependence. At the highest processing temperature (1500 °C), the number of d holes increased. Nitrogen diffusion into Nb is resulting to increase electrostatic interaction between d electron and core hole. Lastly, for the studied conditions, only the α-NbN was observed in the X-ray diffraction patterns.« less

Intrinsic ferromagnetism in nanocrystalline Mn-doped ZnO depending on Mn concentration.

PubMed

Subramanian, Munisamy; Tanemura, Masaki; Hihara, Takehiko; Soga, Tetsuo; Jimbo, Takashi

2011-04-01

The physical properties of Zn(1-x)Mn(x)O nanoparticles synthesized by thermal decomposition are extensively investigated by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman light scattering and Hysteresis measurements. XRD and XPS spectra reveal the absence of secondary phase in nanocrystalline ZnO doped with 5% or less Mn; and, later confirms that the valance state of Mn to be 2+ for all the samples. Raman spectra exhibit a peak at 660 cm(-1) which we attribute to the intrinsic lattice defects of ZnO with increasing Mn concentration. Overall, our results demonstrate that ferromagnetic properties can be realized while Mn-doped ZnO obtained in the nanocrystalline form.

Effects of gamma-ray irradiation on the optical properties of amorphous Se100-xHgx thin films

NASA Astrophysics Data System (ADS)

Ahmad, Shabir; Islam, Shama; Nasir, Mohd.; Asokan, K.; Zulfequar, M.

2018-06-01

In this study, the thermal quenching technique was employed to prepare bulk samples of Se100-xHgx (x = 0, 5, 10, 15). Thin films with a thickness of ∼250 nm were deposited on glass substrates using the thermal evaporation technique. These films were irradiated with gamma rays at doses of 25-100 kGy. The elemental compositions of the as-deposited thin films were confirmed by energy dispersive X-ray analysis and Rutherford backscattering spectrometry. X-ray diffraction analysis confirmed the crystalline nature of these thin films upto the dose of 75 kGy. Fourier transform-infrared spectroscopy showed that the concentration of defects decreased after gamma irradiation. Microstructural analysis by field emission scanning electron microscopy indicated that the grain size increases after irradiation. Optical study based on spectrophotometry showed that the optical band gap values of these films increase after the addition of Hg whereas they decrease after gamma irradiation. We found that the absorption coefficient increases with doses up to 75 kGy but decreases at higher doses. These remarkable shifts in the optical band gap and absorption coefficient values are interpreted in terms of the creation and annihilation of defects, which are the main effects produced by gamma irradiation.

Phase stability and lattice thermal conductivity reduction in CoSb{sub 3} skutterudites, doped with chalcogen atoms

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

Battabyal, M., E-mail: manjusha.battabyal@project.arci.res.in; Priyadarshini, B.; Gopalan, R.

We report a significant reduction in the lattice thermal conductivity of the CoSb{sub 3} skuttertudites, doped with chalcogen atoms. Te/Se chalcogen atoms doped CoSb{sub 3} skutterudite samples (Te{sub 0.1}Co{sub 4}Sb{sub 12}, Se{sub 0.1}Co{sub 4}Sb{sub 12}, Te{sub 0.05}Se{sub 0.05}Co{sub 4}Sb{sub 12}) are processed by ball milling and spark plasma sintering. X-ray diffraction data combined with energy dispersive X-ray spectra indicate the doping of Te/Se chalcogen atoms in the skutterudite. The temperature dependent X-ray diffraction confirms the stability of the Te/Se doped CoSb{sub 3} skutterudite phase and absence of any secondary phase in the temperature range starting from 300 K to 773more » K. The Raman spectroscopy reveals that different chalcogen dopant atoms cause different resonant optical vibrational modes between the dopant atom and the host CoSb{sub 3} skutterudite lattice. These optical vibrational modes do scatter heat carrying acoustic phonons in a different spectral range. It was found that among the Te/Se chalcogen atoms, Te atoms alter the host CoSb{sub 3} skutterudite lattice vibrations to a larger extent than Se atoms, and can potentially scatter more Sb related acoustic phonons. The Debye model of lattice thermal conductivity confirms that the resonant phonon scattering has important contributions to the reduction of lattice thermal conductivity in CoSb{sub 3} skutterudites doped with Te/Se chalcogen atoms. Lattice thermal conductivity ∼ 0.9 W/mK at 773 K is achieved in Te{sub 0.1}Co{sub 4}Sb{sub 12} skutterudites, which is the lowest value reported so far in CoSb{sub 3} skutterudites, doped with single Te chalcogen atom.« less

Synthetic hydroxyapatites doped with Zn(II) studied by X-ray diffraction, infrared, Raman and thermal analysis

NASA Astrophysics Data System (ADS)

Guerra-López, José R.; Echeverría, Gustavo A.; Güida, Jorge A.; Viña, Raúl; Punte, Graciela

2015-06-01

Calcium hydroxyapatite (CaHap) formation when different amounts of Zn(II) are present in the mother solution has been investigated by atomic absorption, infrared and Raman spectroscopies, X-ray diffraction and thermal analysis (DTA and TG). The studied samples have been synthesized at T=95 °C and pH 9 in air. The analysis of the results have shown that the pure CaHap sample crystallizes in the monoclinic form P21/b. Concentrations up to 20% of Zn(II) in the mother solution, equivalent to smaller concentrations in solid (up to 9.1% in wt), favor the formation of the hexagonal apatite, P63/m, while Zn(II) concentrations higher than 20% in solution help an amorphous phase development where vibrational spectra indicated coexistence of two phases: an apatite and ZnNH4PO4·H2O. Infrared data of thermal treated samples endorse that HPO42- ion had not been incorporated in Zn(II) doped samples during the synthesis process. Present results also allow to conclude that Zn(II) cation exhibits a preference to occupy the Ca2 site of the apatite structure and induces water adsorption and a small quantity of CO32- cation incorporation, leading to formation of a less crystalline Ca deficient apatite.

Phase transformation from cubic ZnS to hexagonal ZnO by thermal annealing

NASA Astrophysics Data System (ADS)

Mahmood, K.; Asghar, M.; Amin, N.; Ali, Adnan

2015-03-01

We have investigated the mechanism of phase transformation from ZnS to hexagonal ZnO by high-temperature thermal annealing. The ZnS thin films were grown on Si (001) substrate by thermal evaporation system using ZnS powder as source material. The grown films were annealed at different temperatures and characterized by X-ray diffraction (XRD), photoluminescence (PL), four-point probe, scanning electron microscope (SEM) and energy dispersive X-ray diffraction (EDX). The results demonstrated that as-deposited ZnS film has mixed phases but high-temperature annealing leads to transition from ZnS to ZnO. The observed result can be explained as a two-step process: (1) high-energy O atoms replaced S atoms in lattice during annealing process, and (2) S atoms diffused into substrate and/or diffused out of the sample. The dissociation energy of ZnS calculated from the Arrhenius plot of 1000/T versus log (resistivity) was found to be 3.1 eV. PL spectra of as-grown sample exhibits a characteristic green emission at 2.4 eV of ZnS but annealed samples consist of band-to-band and defect emission of ZnO at 3.29 eV and 2.5 eV respectively. SEM and EDX measurements were additionally performed to strengthen the argument.

Synthesis, DFT calculations of structure, vibrational and thermal decomposition studies of the metal complex Pb[Mn(C3H2O4)2(H2O)2].

PubMed

Gil, Diego M; Carbonio, Raúl E; Gómez, María Inés

2015-04-15

The metallo-organic complex Pb[Mn(C3H2O4)2(H2O)2] was synthesized and characterized by IR and Raman spectroscopy and powder X-ray diffraction methods. The cell parameters for the complex were determined from powder X-ray diffraction using the autoindexing program TREOR, and refined by the Le Bail method with the Fullprof program. A hexagonal unit cell was determined with a=b=13.8366(7)Å, c=9.1454(1)Å, γ=120°. The DFT calculated geometry of the complex anion [Mn(C3H2O4)2(H2O)2](2-) is very close to the experimental data reported for similar systems. The IR and Raman spectra and the thermal analysis of the complex indicate that only one type of water molecules is present in the structure. The thermal decomposition of Pb[Mn(C3H2O4)2(H2O)2] at 700 °C in air produces PbO and Pb2MnO4 as final products. The crystal structure of the mixed oxide is very similar to that reported for Pb3O4. Copyright © 2015 Elsevier B.V. All rights reserved.

Thermoelectric properties of Ge 1-xSn xTe crystals grown by vertical Bridgman method

NASA Astrophysics Data System (ADS)

Wu, C. C.; Ferng, N. J.; Gau, H. J.

2007-06-01

Single crystals of Ge 1-xSn xTe compounds with x=0, 0.8, 0.9 and 1.0 were grown by vertical Bridgman method. The crystalline phase and stochiometry for these crystals were investigated by X-ray diffraction, metallographic microscope as well as electron-probe microanalysis (EPMA). Electrical property of the as-grown samples was characterized using room temperature resistivity and Hall measurements. The thermoelectric behaviors for the Ge 1-xSn xTe crystals were studied by means of thermal and carrier transport measurements. Temperature dependences of resistivity, Seebeck coefficient and thermal conductivity for the various compositions of Ge 1-xSn xTe were analyzed. A two-valence band model was proposed to describe the temperature dependence of thermoelectric property of the Ge 1-xSn xTe crystals. The dimensionless thermoelectric figure of merit ZT for the alloys was evaluated and discussed.

JMFA2—a graphically interactive Java program that fits microfibril angle X-ray diffraction data

Treesearch

Steve P. Verrill; David E. Kretschmann; Victoria L. Herian

2006-01-01

X-ray diffraction techniques have the potential to decrease the time required to determine microfibril angles dramatically. In this paper, we discuss the latest version of a curve-fitting toll that permits us to reduce the time required to evaluate MFA X-ray diffraction patterns. Further, because this tool reflects the underlying physics more accurately than existing...

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

DOE PAGES

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.; ...

2015-08-11

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessarymore » to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. In addition, the features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

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

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessarymore » to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. In addition, the features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

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

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary tomore » fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15µm) loaded into the chips yielded a complete, high-resolution (<1.6Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

PubMed Central

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.; Vo, Huy; Uervirojnangkoorn, Monarin; Brunger, Axel T.; Berger, James M.

2015-01-01

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called ‘fixed-target’ sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs. PMID:26457423

Tropical sea snail shells: Possible exotic sources for ceramic biomaterial synthesis

NASA Astrophysics Data System (ADS)

Oktar, F. N.; Kiyici, I. A.; Gökçe, H.; Aǧaogulları, D.; Kayali, E. S.

2013-12-01

In this study, chemical and structural properties of sea snail shell based bioceramic materials (i.e. hydroxyapatite, whitlockite and other phases) are produced by using mechano-chemical (ultrasonic) conversion method. For this purpose, differential thermal and gravimetric analysis (DTA/TG), X-ray diffraction, infra-red (IR) and scanning electron microscope (SEM) studies are performed.

Nanomechanical study of amorphous and polycrystalline ALD HfO2 thin films

Treesearch

K. Tapily; J.E. Jakes; D. Gu; H. Baumgart; A.A. Elmustafa

2011-01-01

Thin films of hafnium oxide (HfO2) were deposited by atomic layer deposition (ALD). The structural properties of the deposited films were characterised by transmission electron microscopy (TEM) and X-ray diffraction (XRD). We investigated the effect of phase transformations induced by thermal treatments on the mechanical properties of ALD HfO

A Progress Report on X-Ray Diffraction Measurements on New Low-Thermal Conductivity Thermoelectric Materials

DTIC Science & Technology

1999-04-01

as the only moving parts and no environmentally unfriendly gases . Thermoelectric generators can also improve fuel efficiency by using the heat lost...Facolta di Chimica Industriale di Bologna, 24[4] (1966) 113-132. 11 — i at £ 73 U « ■ 2-Theta (deg) Figure 1. Calibration plot for SRM1976

Influence of solvents on the habit modification of alpha lactose monohydrate single crystals

NASA Astrophysics Data System (ADS)

Parimaladevi, P.; Srinivasan, K.

2013-02-01

Restricted evaporation of solvent method was adopted for the growth of alpha lactose monohydrate single crystals from different solvents. The crystal habits of grown crystals were analysed. The form of crystallization was confirmed by powder x-ray diffraction analysis. Thermal behaviour of the grown crystals was studied by using differential scanning calorimetry.

Rapid crystallization of WS2 films assisted by a thin nickel layer: An in situ energy-dispersive X-ray diffraction study

NASA Astrophysics Data System (ADS)

Ellmer, K.; Seeger, S.; Mientus, R.

2006-08-01

By rapid thermal crystallization of an amorphous WS3+x film, deposited by reactive magnetron sputtering at temperatures below 150 °C, layer-type semiconducting tungsten disulfide films (WS2) were grown. The rapid crystallization was monitored in real-time by in situ energy-dispersive X-ray diffraction. The films crystallize very fast (>40 nm/s), provided that a thin nickel film acts as nucleation seeds. Experiments on different substrates and the onset of the crystallization only at a temperature between 600 and 700 °C points to the decisive role of seeds for the textured growth of WS2, most probably liquid NiSx drops. The rapidly crystallized WS2 films exhibit a pronounced (001) texture with the van der Waals planes oriented parallel to the surface, leading to photoactive layers with a high hole mobility of about 80 cm2/Vs making such films suitable as absorbers for thin film solar cells.

High-resolution x-ray diffraction microscopy of specifically labeled yeast cells

PubMed Central

Nelson, Johanna; Huang, Xiaojing; Steinbrener, Jan; Shapiro, David; Kirz, Janos; Marchesini, Stefano; Neiman, Aaron M.; Turner, Joshua J.; Jacobsen, Chris

2010-01-01

X-ray diffraction microscopy complements other x-ray microscopy methods by being free of lens-imposed radiation dose and resolution limits, and it allows for high-resolution imaging of biological specimens too thick to be viewed by electron microscopy. We report here the highest resolution (11–13 nm) x-ray diffraction micrograph of biological specimens, and a demonstration of molecular-specific gold labeling at different depths within cells via through-focus propagation of the reconstructed wavefield. The lectin concanavalin A conjugated to colloidal gold particles was used to label the α-mannan sugar in the cell wall of the yeast Saccharomyces cerevisiae. Cells were plunge-frozen in liquid ethane and freeze-dried, after which they were imaged whole using x-ray diffraction microscopy at 750 eV photon energy. PMID:20368463

High-resolution x-ray diffraction microscopy of specifically labeled yeast cells

DOE PAGES

Nelson, Johanna; Huang, Xiaojing; Steinbrener, Jan; ...

2010-04-20

X-ray diffraction microscopy complements other x-ray microscopy methods by being free of lens-imposed radiation dose and resolution limits, and it allows for high-resolution imaging of biological specimens too thick to be viewed by electron microscopy. We report here the highest resolution (11-13 nm) x-ray diffraction micrograph of biological specimens, and a demonstration of molecular-specific gold labeling at different depths within cells via through-focus propagation of the reconstructed wavefield. The lectin concanavalin A conjugated to colloidal gold particles was used to label the α-mannan sugar in the cell wall of the yeast Saccharomyces cerevisiae. Cells were plunge-frozen in liquid ethane andmore » freeze-dried, after which they were imaged whole using x-ray diffraction microscopy at 750 eV photon energy.« less

Time-resolved x-ray diffraction and calorimetric studies at low scan rates

PubMed Central

Yao, Haruhiko; Hatta, Ichiro; Koynova, Rumiana; Tenchov, Boris

1992-01-01

The phase transitions of dipalmitoylphosphatidylethanolamine (DPPE) in excess water have been examined by low-angle time-resolved x-ray diffraction and calorimetry at low scan rates. The lamellar subgel/lamellar liquid-crystalline (Lc → Lα), lamellar gel/lamellar liquid-crystalline (Lβ → Lα), and lamellar liquid-crystalline/lamellar gel (Lα → Lβ) phase transitions proceed via coexistence of the initial and final phases with no detectable intermediates at scan rates 0.1 and 0.5°C/min. At constant temperature within the region of the Lβ → Lα transition the ratio of the two coexisting phases was found to be stable for over 30 min. The state of stable phase coexistence was preceded by a 150-s relaxation taking place at constant temperature after termination of the heating scan in the transition region. While no intermediate structures were present in the coexistence region, a well reproducible multipeak pattern, with at least four prominent heat capacity peaks separated in temperature by 0.4-0.5°C, has been observed in the cooling transition (Lα → Lβ) by calorimetry. The multipeak pattern became distinct with an increase of incubation time in the liquid-crystalline phase. It was also clearly resolved in the x-ray diffraction intensity versus temperature plots recorded at slow cooling rates. These data suggest that the equilibrium state of the Lα phase of hydrated DPPE is represented by a mixture of domains that differ in thermal behavior, but cannot be distinguished structurally by x-ray scattering. Imagesp689-aFIGURE 9 PMID:19431820

Coherent x-ray zoom condenser lens for diffractive and scanning microscopy.

PubMed

Kimura, Takashi; Matsuyama, Satoshi; Yamauchi, Kazuto; Nishino, Yoshinori

2013-04-22

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers.

Scanning force microscope for in situ nanofocused X-ray diffraction studies

PubMed Central

Ren, Zhe; Mastropietro, Francesca; Davydok, Anton; Langlais, Simon; Richard, Marie-Ingrid; Furter, Jean-Jacques; Thomas, Olivier; Dupraz, Maxime; Verdier, Marc; Beutier, Guillaume; Boesecke, Peter; Cornelius, Thomas W.

2014-01-01

A compact scanning force microscope has been developed for in situ combination with nanofocused X-ray diffraction techniques at third-generation synchrotron beamlines. Its capabilities are demonstrated on Au nano-islands grown on a sapphire substrate. The new in situ device allows for in situ imaging the sample topography and the crystallinity by recording simultaneously an atomic force microscope (AFM) image and a scanning X-ray diffraction map of the same area. Moreover, a selected Au island can be mechanically deformed using the AFM tip while monitoring the deformation of the atomic lattice by nanofocused X-ray diffraction. This in situ approach gives access to the mechanical behavior of nanomaterials. PMID:25178002

X-ray topography using the forward transmitted beam under multiple-beam diffraction conditions

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

Tsusaka, Y., E-mail: tsusaka@sci.u-hyogo.ac.jp; Takano, H.; Takeda, S.

2016-02-15

X-ray topographs are taken for a sapphire wafer with the [0001] surface normal, as an example, by forward transmitted synchrotron x-ray beams combined with two-dimensional electronic arrays in the x-ray detector having a spatial resolution of 1 μm. They exhibit no shape deformation and no position shift of the dislocation lines on the topographs. Since the topography is performed under multiple-beam diffraction conditions, the topographic images of a single diffraction (two-wave approximation condition) or plural diffractions (six-wave approximation condition) can be recorded without large specimen position changes. As usual Lang topographs, it is possible to determine the Burgers vector ofmore » each dislocation line. Because of high parallelism of the incoming x-rays and linear sensitivity of the electronic arrays to the incident x-rays, the present technique can be used to visualize individual dislocations in single crystals of the dislocation density as high as 1 × 10{sup 5} cm{sup −2}.« less

X-ray diffraction analysis of hydroxyapatite-coated in different plasma gas atmosphere on Ti and Ti-6Al-4V

PubMed Central

Kotian, Ravindra; Rao, P. Prasad; Madhyastha, Prashanthi

2017-01-01

Objective: The aim is to study the effect of plasma working gas on composition, crystallinity, and microstructure of hydroxyapatite (HA) coated on Ti and Ti-6Al-4V metal substrates. Materials and Methods: Ti and Ti-6Al-4V metal substrates were coated with HA by plasma spray using four plasma gas atmospheres of argon, argon/hydrogen, nitrogen, and nitrogen/hydrogen. The degree of crystallinity, the phases present, and microstructure of HA coating were characterized using X-ray diffraction and scanning electron microscopy. Results: Variation in crystallinity and the microstructure of HA coating on plasma gas atmosphere was observed. Micro-cracks due to thermal stresses and shift in the 2θ angle of HA compared to feedstock was seen. Conclusion: Plasma gas atmosphere has a significant influence on composition, crystallinity, and micro-cracks of HA-coated dental implants. PMID:29279668

In situ analysis of phase transformation in sol-gel cogelified nanopowder mixture of Al 2O 3 and TiO 2 using synchrotron X-ray radiation diffraction experiments

NASA Astrophysics Data System (ADS)

Jianu, A.; Stanciu, L.; Groza, J. R.; Lathe, Ch.; Burkel, E.

2003-01-01

Aluminium titanate (Al 2TiO 5) has been selected for study due to its high melting point and thermal shock resistance. In situ analysis of phase transformation and of transformation kinetics of sol-gel powder mixture of alumina and titania cogelified samples was performed using high-temperature synchrotron radiation X-ray diffraction experiments. The high reactivity and molecular mixing of sol-gel cogelified precursor powders contributed to the evolution of the reaction. The stability of the TiO 2-tetragonal structure (anatase) increases due to Al 2O 3 presence. The temperature of the aluminium titanate endothermic reaction decreases when heating rate increases. The results obtained by in situ analysis have been used to establish the sintering parameters in order to obtain fully transformed, dense aluminium titanate bulk ceramics.

A comparative study of heterostructured CuO/CuWO4 nanowires and thin films

NASA Astrophysics Data System (ADS)

Polyakov, Boris; Kuzmin, Alexei; Vlassov, Sergei; Butanovs, Edgars; Zideluns, Janis; Butikova, Jelena; Kalendarev, Robert; Zubkins, Martins

2017-12-01

A comparative study of heterostructured CuO/CuWO4 core/shell nanowires and double-layer thin films was performed through X-ray diffraction, confocal micro-Raman spectroscopy and electron (SEM and TEM) microscopies. The heterostructures were produced using a two-step process, starting from a deposition of amorphous WO3 layer on top of CuO nanowires and thin films by reactive DC magnetron sputtering and followed by annealing at 650 °C in air. The second step induced a solid-state reaction between CuO and WO3 oxides through a thermal diffusion process, revealed by SEM-EDX analysis. Morphology evolution of core/shell nanowires and double-layer thin films upon heating was studied by electron (SEM and TEM) microscopies. A formation of CuWO4 phase was confirmed by X-ray diffraction and confocal micro-Raman spectroscopy.

In situ synchrotron X-ray diffraction study of hydrides in Zircaloy-4 during thermomechanical cycling

DOE PAGES

Cinbiz, Mahmut N.; Koss, Donald A.; Motta, Arthur T.; ...

2017-02-20

The d-spacing evolution of both in-plane and out-of-plane hydrides has been studied using in situ synchrotron radiation X-ray diffraction during thermo-mechanical cycling of cold-worked stress-relieved Zircaloy-4. The structure of the hydride precipitates is such that the δ{111} d-spacing of the planes aligned with the hydride platelet face is greater than the d-spacing of the 111 planes aligned with the platelet edges. Upon heating from room temperature, the δ{111} planes aligned with hydride plate edges exhibit bi-linear thermally-induced expansion. In contrast, the d-spacing of the (111) plane aligned with the hydride plate face initially contracts upon heating. Furthermore, these experimental resultsmore » can be understood in terms of a reversal of stress state associated with precipitating or dissolving hydride platelets within the α-zirconium matrix.« less

Crystal structure, spectrum character and explosive property of a new cocrystal CL-20/DNT

NASA Astrophysics Data System (ADS)

Liu, Ke; Zhang, Gao; Luan, Jieyu; Chen, Zhiqun; Su, Pengfei; Shu, Yuanjie

2016-04-01

A new cocrystal explosive of 2,4,6,8,10,12-hexanitrohexaazaiso-wurtzitane(CL-20) and 2,5-dinitrotoluene(DNT) in a molar ratio of 1:2 has been prepared by slow solvent evaporation method. Crystal structure of the cocrystal characterized by single crystal X-ray diffraction (SXRD) reveals that the cocrystal is formed by intermolecular hydrogen bond interactions and belongs to the triclinic system with P-1 group. Moreover, the obivious differences of powder X-ray diffraction (PXRD) patterns, infrared spectroscopy and Raman spectroscopy confirm that the intermolecular interactions have great influence for the crystal structure and formation of cocrystal. The cocrystal exhibits a lower impact height of 44 cm, suggesting a substantial reduction of sensitivity in comparison with CL-20. And thermal test results showed cocrystal obtains a lower melting point than DNT, which means huge advantages in blasting engineering.

Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

NASA Astrophysics Data System (ADS)

Krasniqi, F. S.; Zhong, Y.; Epp, S. W.; Foucar, L.; Trigo, M.; Chen, J.; Reis, D. A.; Wang, H. L.; Zhao, J. H.; Lemke, H. T.; Zhu, D.; Chollet, M.; Fritz, D. M.; Hartmann, R.; Englert, L.; Strüder, L.; Schlichting, I.; Ullrich, J.

2018-03-01

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga0.91 Mn0.09 As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a single wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.

Single-crystal X-ray diffraction study of SrGeO3 high-pressure perovskite phase at 100 K

NASA Astrophysics Data System (ADS)

Nakatsuka, Akihiko; Arima, Hiroshi; Ohtaka, Osamu; Fujiwara, Keiko; Yoshiasa, Akira

2017-10-01

Single-crystal X-ray diffraction study of SrGeO3 perovskite (cubic; space group Pmɜ¯m) synthesized at 6 GPa and 1223 K was conducted at a low temperature of 100 K. The residual electron density revealed the presence of the bonding electron at the center of the Ge-O bond, in accordance with our previous conclusion that the Ge-O bond is strongly covalent. From comparison with our previous structure-refinement result at 296 K, the mean square displacement (MSD) of the O atom in the direction of the Ge-O bond is suggested to exhibit no significant temperature dependence, in contrast to that in the direction perpendicular to the bond. Thus, the strong covalency of the Ge-O bond can have a large influence on the temperature dependence of thermal vibration of the O atom.

Improving aluminum particle reactivity by annealing and quenching treatments: Synchrotron X-ray diffraction analysis of strain

DOE PAGES

McCollum, Jena; Pantoya, Michelle L.; Tamura, Nobumichi

2015-11-06

In bulk material processing, annealing and quenching metals such as aluminum (Al) can improve mechanical properties. On a single particle level, affecting mechanical properties may also affect Al particle reactivity. Our study examines the effect of annealing and quenching on the strain of Al particles and the corresponding reactivity of aluminum and copper oxide (CuO) composites. Micron-sized Al particles were annealed and quenched according to treatments designed to affect Al mechanical properties. Furthermore, synchrotron X-ray diffraction (XRD) analysis of the particles reveals that thermal treatment increased the dilatational strain of the aluminum-core, alumina-shell particles. Flame propagation experiments also show thermalmore » treatments effect reactivity when combined with CuO. An effective annealing and quenching treatment for increasing aluminum reactivity was identified. Our results show that altering the mechanical properties of Al particles affects their reactivity.« less

X-Ray diffraction, spectroscopy and thermochemical characterization of the pharmaceutical paroxetine nitrate salt

NASA Astrophysics Data System (ADS)

Carvalho, Paulo S.; de Melo, Cristiane C.; Ayala, Alejandro P.; Ellena, Javier

2016-08-01

A comprehensive solid state study of Paroxetine nitrate hydrate, (PRX+·NO3-)H2O, is reported. This salt was characterized by a combination of methods, including Single crystal X-ray diffraction, Thermal analysis, Fourier transform infrared spectroscopy (FTIR) and Solubility measurements. (PRX+·NO3-)H2O crystallizes in the monoclinic C2 space group (Z‧ = 1) and its packing was analyzed in details, showing that the main supramolecular motif consists in a C22(4) chain formed by charge-assisted N+-H⋯O- hydrogen bonds. The salt formation and conformation features were also accuracy established via FTIR spectra. In comparison with the pharmaceutical approved (PRX+ṡCl-)ṡ0.5H2O, (PRX+ṡNO3-)ṡH2O showed a decrease of 24 °C in the drug melting peak and a slight reduction in its water solubility value.

Conducting linear chains of sulphur inside carbon nanotubes

PubMed Central

Fujimori, Toshihiko; Morelos-Gómez, Aarón; Zhu, Zhen; Muramatsu, Hiroyuki; Futamura, Ryusuke; Urita, Koki; Terrones, Mauricio; Hayashi, Takuya; Endo, Morinobu; Young Hong, Sang; Chul Choi, Young; Tománek, David; Kaneko, Katsumi

2013-01-01

Despite extensive research for more than 200 years, the experimental isolation of monatomic sulphur chains, which are believed to exhibit a conducting character, has eluded scientists. Here we report the synthesis of a previously unobserved composite material of elemental sulphur, consisting of monatomic chains stabilized in the constraining volume of a carbon nanotube. This one-dimensional phase is confirmed by high-resolution transmission electron microscopy and synchrotron X-ray diffraction. Interestingly, these one-dimensional sulphur chains exhibit long domain sizes of up to 160 nm and high thermal stability (~800 K). Synchrotron X-ray diffraction shows a sharp structural transition of the one-dimensional sulphur occurring at ~450–650 K. Our observations, and corresponding electronic structure and quantum transport calculations, indicate the conducting character of the one-dimensional sulphur chains under ambient pressure. This is in stark contrast to bulk sulphur that needs ultrahigh pressures exceeding ~90 GPa to become metallic. PMID:23851903

Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

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

Riise, Ellen Kristin; Lorentzen, Marit Sjo; Helland, Ronny

2006-01-01

Monoclinic (P2{sub 1}) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å. Catalase (EC 1.11.1.6) catalyses the breakdown of hydrogen peroxide to water and molecular oxygen. Recombinant Vibrio salmonicida catalase (VSC) possesses typical cold-adapted features, with higher catalytic efficiency, lower thermal stability and a lower temperature optimum than its mesophilic counterpart from Proteus mirabilis. Crystals of VSC were produced by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 98.15, b = 217.76, c = 99.28 Å, βmore » = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit.« less

Substrate temperature effect on structural and optical properties of Bi2Te3 thin films

NASA Astrophysics Data System (ADS)

Jariwala, B. S.; Shah, D. V.; Kheraj, Vipul

2012-06-01

Structural and optical properties of Bi2Te3 thin films, thermally evaporated on well-cleaned glass substrates at different substrate temperatures, are reported here. X-ray diffraction was carried out for the structural characterization. XRD patterns of the films exhibit preferential orientation along the [0 1 5] direction for the films deposited at all the substrate temperatures together with other supported planes [2 0 5] & [1 1 0]. All other deposition conditions like thickness, deposition rate and pressure were maintained same throughout the experiment. X-ray diffraction lines confirm that the grown films are polycrystalline in nature with hexagonal crystal structure. The effect of substrate temperature on lattice constants, grain size, micro strain, number of crystallites and dislocation density have been investigated and reported in this paper. Also the substrate temperature effect on the optical property has been also investigated using the FTIR spectroscopy.

Application of vibrational spectroscopy, thermal analyses and X-ray diffraction in the rapid evaluation of the stability in solid-state of ranitidine, famotidine and cimetidine.

PubMed

Jamrógiewicz, Marzena; Ciesielski, Aleksander

2015-03-25

This paper reports the study on applicability of Fourier transform infrared (FTIR), near-infrared (NIR) and Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) for the estimation of the chemical stability and photostability of histamine H2-receptor antagonist substances. Ranitidine hydrochloride (RAN), famotidine (FAM) and cimetidine (CIM) were tested and differences in sensitivity were measured via soft independence modeling of class analogies (Simca) model. The low values of variations for FAM and CIM and high variations obtained for RAN using FTIR and NIR techniques indicated that these methods were suitable and applicable to classify the degradation of RAN. Examined methods are recommendable in the first technological stage of drug production, and the preclinical and clinical development of pharmaceuticals or their quality control. Copyright © 2015 Elsevier B.V. All rights reserved.

Multiple defocused coherent diffraction imaging: method for simultaneously reconstructing objects and probe using X-ray free-electron lasers.

PubMed

Hirose, Makoto; Shimomura, Kei; Suzuki, Akihiro; Burdet, Nicolas; Takahashi, Yukio

2016-05-30

The sample size must be less than the diffraction-limited focal spot size of the incident beam in single-shot coherent X-ray diffraction imaging (CXDI) based on a diffract-before-destruction scheme using X-ray free electron lasers (XFELs). This is currently a major limitation preventing its wider applications. We here propose multiple defocused CXDI, in which isolated objects are sequentially illuminated with a divergent beam larger than the objects and the coherent diffraction pattern of each object is recorded. This method can simultaneously reconstruct both objects and a probe from the coherent X-ray diffraction patterns without any a priori knowledge. We performed a computer simulation of the prposed method and then successfully demonstrated it in a proof-of-principle experiment at SPring-8. The prposed method allows us to not only observe broad samples but also characterize focused XFEL beams.

Angular rheology study of colloidal nanocrystals using Coherent X-ray Diffraction

NASA Astrophysics Data System (ADS)

Liang, Mengning; Harder, Ross; Robinson, Ian

2007-03-01

A new method using coherent x-ray diffraction provides a way to investigate the rotational motion of a colloidal suspension of crystals in real time. Coherent x-ray diffraction uses the long coherence lengths of synchrotron sources to illuminate a nanoscale particle coherently over its spatial dimensions. The penetration of high energy x-rays into various media allows for in-situ measurements making it ideal for suspensions. This technique has been used to image the structure of nanocrystals for some time but also has the capability of providing information about the orientation and dynamics of crystals. The particles are imaged in a specific diffraction condition allowing us to determine their orientation and observe how they rotate in real time with exceptional resolution. Such sensitivity allows for the study of rotational Brownian motion of nanocrystals in various suspensions and conditions. We present a study of the angular rheology of alumina and TiO2 colloidal nanocrystals in media using coherent x-ray diffraction.

Characterization of polycrystalline materials using synchrotron X-ray imaging and diffraction techniques

NASA Astrophysics Data System (ADS)

Ludwig, W.; King, A.; Herbig, M.; Reischig, P.; Marrow, J.; Babout, L.; Lauridsen, E. M.; Proudhon, H.; Buffière, J. Y.

2010-12-01

The combination of synchrotron radiation x-ray imaging and diffraction techniques offers new possibilities for in-situ observation of deformation and damage mechanisms in the bulk of polycrystalline materials. Minute changes in electron density (i.e., cracks, porosities) can be detected using propagation based phase contrast imaging, a 3-D imaging mode exploiting the coherence properties of third generation synchrotron beams. Furthermore, for some classes of polycrystalline materials, one may use a 3-D variant of x-ray diffraction imaging, termed x-ray diffraction contrast tomography. X-ray diffraction contrast tomography provides access to the 3-D shape, orientation, and elastic strain state of the individual grains from polycrystalline sample volumes containing up to thousand grains. Combining both imaging modalities, one obtains a comprehensive description of the materials microstructure at the micrometer length scale. Repeated observation during (interrupted) mechanical tests provide unprecedented insight into crystallographic and grain microstructure related aspects of polycrystalline deformation and degradation mechanisms.

Photo-thermal and cytotoxic properties of inkjet-printed copper sulfide films on biocompatible latex coated substrates

NASA Astrophysics Data System (ADS)

Sarfraz, Jawad; Borzenkov, Mykola; Niemelä, Erik; Weinberger, Christian; Törngren, Björn; Rosqvist, Emil; Collini, Maddalena; Pallavicini, Piersandro; Eriksson, John; Peltonen, Jouko; Ihalainen, Petri; Chirico, Giuseppe

2018-03-01

Inkjet-printing of metal nanoparticles is a particularly promising technique for the fabrication and modification of surfaces with a multifunctional nature. Recently copper sulfide nanoparticles (CuS NPs) have attracted wide interest due to a range of valuable properties including long term stability, photo-thermal activity, ease of synthesis and low cost. In the present study, printed CuS patterns were successfully fabricated on latex coated paper substrates and characterized by means of atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV-Vis-NIR spectroscopy, and grazing incidence X-ray diffraction (GID). The resulted patterns displayed pronounced photo-thermal effect under Near Infrared Irradiation (NIR) even with relatively low laser power. Finally, by utilizing an automated real-time imaging platform it was possible to verify that the CuS printed film was not cytotoxic to human dermal fibroblast cells (HDF). The pronounced photo-thermal properties and nontoxic nature of these printed low-cost flexible CuS films make them promising candidates for fabrication of devices with localized photo-thermal effect suitable for biomedical applications.

Quantitative analysis of thoria phase in Th-U alloys using diffraction studies

NASA Astrophysics Data System (ADS)

Thakur, Shital; Krishna, P. S. R.; Shinde, A. B.; Kumar, Raj; Roy, S. B.

2017-05-01

In the present study the quantitative phase analysis of Th-U alloys in bulk form namely Th-52 wt% U and Th-3wt%U has been performed over the data obtained from both X ray diffraction and neutron diffraction technique using Rietveld method of FULLPROF software. Quantifying thoria (ThO2) phase present in bulk of the sample is limited due to surface oxidation and low penetration of x rays in high Z material. Neutron diffraction study probing bulk of the samples has been presented in comparison with x-ray diffraction study.

Selenium single-wavelength anomalous diffraction de novo phasing using an X-ray-free electron laser

DOE PAGES

Hunter, Mark S.; Yoon, Chun Hong; DeMirci, Hasan; ...

2016-11-04

Structural information about biological macromolecules near the atomic scale provides important insight into the functions of these molecules. To date, X-ray crystallography has been the predominant method used for macromolecular structure determination. However, challenges exist when solving structures with X-rays, including the phase problem and radiation damage. X-ray-free electron lasers (X-ray FELs) have enabled collection of diffraction information before the onset of radiation damage, yet the majority of structures solved at X-ray FELs have been phased using external information via molecular replacement. De novo phasing at X-ray FELs has proven challenging due in part to per-pulse variations in intensity andmore » wavelength. Here we report the solution of a selenobiotinyl-streptavidin structure using phases obtained by the anomalous diffraction of selenium measured at a single wavelength (Se-SAD) at the Linac Coherent Light Source. Finally, our results demonstrate Se-SAD, routinely employed at synchrotrons for novel structure determination, is now possible at X-ray FELs.« less

Macromolecular structures probed by combining single-shot free-electron laser diffraction with synchrotron coherent X-ray imaging.

PubMed

Gallagher-Jones, Marcus; Bessho, Yoshitaka; Kim, Sunam; Park, Jaehyun; Kim, Sangsoo; Nam, Daewoong; Kim, Chan; Kim, Yoonhee; Noh, Do Young; Miyashita, Osamu; Tama, Florence; Joti, Yasumasa; Kameshima, Takashi; Hatsui, Takaki; Tono, Kensuke; Kohmura, Yoshiki; Yabashi, Makina; Hasnain, S Samar; Ishikawa, Tetsuya; Song, Changyong

2014-05-02

Nanostructures formed from biological macromolecular complexes utilizing the self-assembly properties of smaller building blocks such as DNA and RNA hold promise for many applications, including sensing and drug delivery. New tools are required for their structural characterization. Intense, femtosecond X-ray pulses from X-ray free-electron lasers enable single-shot imaging allowing for instantaneous views of nanostructures at ambient temperatures. When combined judiciously with synchrotron X-rays of a complimentary nature, suitable for observing steady-state features, it is possible to perform ab initio structural investigation. Here we demonstrate a successful combination of femtosecond X-ray single-shot diffraction with an X-ray free-electron laser and coherent diffraction imaging with synchrotron X-rays to provide an insight into the nanostructure formation of a biological macromolecular complex: RNA interference microsponges. This newly introduced multimodal analysis with coherent X-rays can be applied to unveil nano-scale structural motifs from functional nanomaterials or biological nanocomplexes, without requiring a priori knowledge.

Preparation, characterization and X-ray attenuation property of Gd2O3-based nanocomposites

NASA Astrophysics Data System (ADS)

Jayakumar, Sangeetha; Saravanan, T.; Philip, John

2017-11-01

In an attempt to develop an alternate to lead-based X-ray shielding material, we describe the X-ray attenuation property of nanocomposites containing Gd2O3 as nanofiller and silicone resin as matrix, prepared by a simple solution-casting technique. Gd2O3 nanoparticles of size 30 and 56 nm are used at concentrations of 25 and 2.5 wt%. The nanoparticles and the nanocomposites are characterized using X-ray diffraction (XRD) studies, small angle X-ray spectroscopy (SAXS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The X-ray attenuation property of nanocomposites, studied using an industrial X-ray unit, shows that nanocomposites containing nanoparticles of size 56 nm (G2) exhibit better attenuation than nanocomposites containing nanoparticles of size 30 nm (G1), which is attributed to the greater interfacial interaction between the G2 nanofillers and silicone matrix. In the case of nanocomposites containing G1 nanoparticles, the interfacial interaction between the nanofiller and the matrix is so weak that it results in pulling out of nanofillers, causing voids in the matrix, which act as X-ray transparent region, thereby reducing the overall X-ray attenuation property of G1 nanocomposites. This is further corroborated from the AFM images of the nanocomposites. The weight loss and heat flow curves of pure silicone matrix and the nanocomposites containing Gd2O3 nanoparticles of size 30 and 56 nm show the degradation of silicone resin, due to chain scission, between 403 and 622 °C. The same onset temperature (403 °C) of degradation of matrix with and without nanoparticles shows that the addition of nanofillers to the matrix does not deteriorate the thermal stability of the matrix. This confirms the thermal stability of nanocomposites. Therefore, our study shows that nanocomposites containing G2 nanoparticles are potential candidates for the development of X-ray opaque fabric material.

Exploration of New Principles in Spintronics Based on Topological Insulators (Option 1)

DTIC Science & Technology

2012-05-14

on the surface and found that our crystals are exceedingly homogeneous (Supplementary Information). The persistently narrow X - ray diffraction peaks...modified Bridgman method (see Supplementary Information for details). X - ray diffraction measurements indicated the monotonic shrinkage of a and c axis...and annealing at that temperature for 4 days. X - ray diffraction analyses confirmed that all the samples have the same crystal structure (R 3m

Efficient modeling of Bragg coherent x-ray nanobeam diffraction

DOE PAGES

Hruszkewycz, S. O.; Holt, M. V.; Allain, M.; ...

2015-07-02

X-ray Bragg diffraction experiments that utilize tightly focused coherent beams produce complicated Bragg diffraction patterns that depend on scattering geometry, characteristics of the sample, and properties of the x-ray focusing optic. In this paper, we use a Fourier-transform-based method of modeling the 2D intensity distribution of a Bragg peak and apply it to the case of thin films illuminated with a Fresnel zone plate in three different Bragg scattering geometries. Finally, the calculations agree well with experimental coherent diffraction patterns, demonstrating that nanodiffraction patterns can be modeled at nonsymmetric Bragg conditions with this approach—a capability critical for advancing nanofocused x-raymore » diffraction microscopy.« less

Synchrotron powder X-ray diffraction and structural analysis of Eu0.5La0.5FBiS2-x Se x

NASA Astrophysics Data System (ADS)

Nagasaka, K.; Jinno, G.; Miura, O.; Miura, A.; Moriyoshi, C.; Kuroiwa, Y.; Mizuguchi, Y.

2017-07-01

Eu0.5La0.5FBiS2-x Se x is a new BiS2-based superconductor system. In Eu0.5La0.5FBiS2-x Se x , electron carriers are doped to the BiS2 layer by the substitution of Eu by La. Bulk superconductivity in this system is induced by increasing the in-plane chemical pressure, which is controlled by the Se concentration (x). In this study, we have analysed the crystal structure of Eu0.5La0.5FBiS2-x Se x using synchrotron powder diffraction and the Rietveld refinement. The precise determination of the structural parameters and thermal factors suggest that the emergence of bulk superconductivity in Eu0.5La0.5FBiS2-x Se x is achieved by the enhanced in-plane chemical pressure and the decrease in in-plane disorder.

Instrument and method for focusing X-rays, gamma rays and neutrons

DOEpatents

Smither, Robert K.

1984-01-01

A crystal diffraction instrument or diffraction grating instrument with an improved crystalline structure or grating spacing structure having a face for receiving a beam of photons or neutrons and diffraction planar spacing or grating spacing along that face with the spacing increasing progressively along the face to provide a decreasing Bragg diffraction angle for a monochromatic radiation and thereby increasing the usable area and acceptance angle. The increased planar spacing for the diffraction crystal is provided by the use of a temperature differential across the crystalline structure, by assembling a plurality of crystalline structures with different compositions, by an individual crystalline structure with a varying composition and thereby a changing planar spacing along its face, and by combinations of these techniques. The increased diffraction grating element spacing is generated during the fabrication of the diffraction grating by controlling the cutting tool that is cutting the grooves or controlling the laser beam, electron beam or ion beam that is exposing the resist layer, etc. It is also possible to vary this variation in grating spacing by applying a thermal gradient to the diffraction grating in much the same manner as is done in the crystal diffraction case.

Instrument and method for focusing x rays, gamma rays, and neutrons

DOEpatents

Smither, R.K.

1982-03-25

A crystal-diffraction instrument or diffraction-grating instrument is described with an improved crystalline structure or grating spacing structure having a face for receiving a beam of photons or neutrons and diffraction planar spacing or grating spacing along that face with the spacing increasing progressively along the face to provide a decreasing Bragg diffraction angle for a monochromatic radiation and thereby increasing the usable area and acceptance angle. The increased planar spacing for the diffraction crystal is provided by the use of a temperature differential across the line structures with different compositions, by an individual crystalline structure with a varying composition and thereby a changing planar spacing along its face, and by combinations of these techniques. The increased diffraction grating element spacing is generated during the fabrication of the diffraction grating by controlling the cutting tool that is cutting the grooves or controlling the laser beam, electron beam, or ion beam that is exposing the resist layer, etc. It is also possible to vary this variation in grating spacing by applying a thermal gradient to the diffraction grating in much the same manner as is done in the crystal-diffraction case.

Synthesis of MnFe2O4 magnetic nano hollow spheres by a facile solvothermal route and its characterization

NASA Astrophysics Data System (ADS)

Dey, Chaitali; Chaudhuri, Arka; Goswami, Madhuri Mandal

2018-04-01

Herein, we report the synthesis of manganese ferrite (MnFe2O4) magnetic nano hollow sphere (NHS) by a solvothermal route. Crystalline phase was confirmed by X-ray diffraction (XRD), energy dispersive x-ray (EDX). Magnetic measurements were done in vibrating sample magnetometer (VSM) and morphological structure was analyzed by field emission high resolution scanning electron microscope (FESEM) and structural characterization was confirmed by Fourier transform infrared spectroscopy (FTIR), thermal analysis was performed by thermo-gravimetric analysis-differential thermal analysis (TGA-DTA). The size of the NHS was around 470 nm, this large size may show a potential applicability in industrial application, like dye adsorption, catalysis etc. In addition, because of its ferromagnetic character at room temperature, it can be easily separated by external magnetic field after the application is done.

Thermal phase transition behavior of lipid layers on a single human corneocyte cell.

PubMed

Imai, Tomohiro; Nakazawa, Hiromitsu; Kato, Satoru

2013-09-01

We have improved the selected area electron diffraction method to analyze the dynamic structural change in a single corneocyte cell non-invasively stripped off from human skin surface. The improved method made it possible to obtain reliable diffraction images to trace the structural change in the intercellular lipid layers on a single corneocyte cell during heating from 24°C to 100°C. Comparison of the results with those of synchrotron X-ray diffraction experiments on human stratum corneum sheets revealed that the intercellular lipid layers on a corneocyte cell exhibit essentially the same thermal phase transitions as those in a stratum corneum sheet. These results suggest that the structural features of the lipid layers are well preserved after the mechanical stripping of the corneocyte cell. Moreover, electron diffraction analyses of the thermal phase transition behaviors of the corneocyte cells that had the lipid layers with different distributions of orthorhombic and hexagonal domains at 24°C suggested that small orthorhombic domains interconnected with surrounding hexagonal domains transforms in a continuous manner into new hexagonal domains. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

HiSPoD: a program for high-speed polychromatic X-ray diffraction experiments and data analysis on polycrystalline samples

DOE PAGES

Sun, Tao; Fezzaa, Kamel

2016-06-17

Here, a high-speed X-ray diffraction technique was recently developed at the 32-ID-B beamline of the Advanced Photon Source for studying highly dynamic, yet non-repeatable and irreversible, materials processes. In experiments, the microstructure evolution in a single material event is probed by recording a series of diffraction patterns with extremely short exposure time and high frame rate. Owing to the limited flux in a short pulse and the polychromatic nature of the incident X-rays, analysis of the diffraction data is challenging. Here, HiSPoD, a stand-alone Matlab-based software for analyzing the polychromatic X-ray diffraction data from polycrystalline samples, is described. With HiSPoD,more » researchers are able to perform diffraction peak indexing, extraction of one-dimensional intensity profiles by integrating a two-dimensional diffraction pattern, and, more importantly, quantitative numerical simulations to obtain precise sample structure information.« less

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

Madhukumar, R.; Asha, S.; Rao, B. Lakshmeesha

The gamma radiation-induced change in structural and thermal properties of Bombyx mori silk fibroin films were investigated and have been correlated with the applied radiation doses. Irradiation of samples were carried out in dry air at room temperature using Co-60 source, and radiation doses are in the range of 0 - 300 kGy. Structural and thermal properties of the irradiated silk films were studied using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA) and compared with unirradiated sample. Interesting results are discussed in this report.

Structural, vibrational, thermal and optical studies of organic single crystal: Benzotriazolium p-toluene sulfonate (BTPTS)

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

Kumar, R. Ramesh; Sathya, P.; Gopalakrishnan, R., E-mail: krgkrishnan@yahoo.com

Benzotriazolium p-toluene sulfonate (BTPTS) was grown by solution growth technique. The powder X-ray diffraction analysis was carried out to evaluate crystal system of the compound. LeBail Profile fitting analysis was performed to extract the individual peak intensities. FTIR spectrum analysis was recorded to study vibration frequencies of the prepared organic salt. Thermal studies were carried out using TG-DSC analysis. Optical absorption and energy band gap of the title compound was evaluated by UV-Vis spectral study.

Low-Temperature Bainite: A Thermal Stability Study

NASA Astrophysics Data System (ADS)

Santajuana, Miguel A.; Rementeria, Rosalia; Kuntz, Matthias; Jimenez, Jose A.; Caballero, Francisca G.; Garcia-Mateo, Carlos

2018-06-01

The thermal stability of nanobainitic structures obtained by heat treating two different high-carbon high-silicon steels at temperatures between 200 °C and 600 °C has been investigated by means of three complementary techniques, i.e., field emission gun-scanning electron microscopy, X-ray diffraction, and high-resolution dilatometry. Three main stages have been established, each of them characterized by a distinctive microstructure. Furthermore, the nanocrystalline structure generated by the bainite reaction confers the steel with an extraordinary tempering resistance.

Growth and characterization of metal halide perovskite crystals: Benzyltributyl ammonium tetrachloro manganate(II) monohydrate

NASA Astrophysics Data System (ADS)

Dhandapani, M.; Sugandhi, K.; Nithya, S.; Muthuraja, P.; Balachandar, S.; Aranganayagam, K. R.

2018-05-01

The perovskite type organic-inorganic hybrid benzyltributyl ammoniumtetrachloro manganate (II) monohydrates (BTBA-Mn) are synthesized and the single crystals are grown by slow evaporation solution growth technique. The structure of the grown crystals are confirmed by using X-ray diffraction (XRD), unit cell parameter analysis, Fourier transform Infrared (FTIR), elemental analysis and 13C-NMR spectral studies. Thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning colorimetric (DSC) analysis were carried out to understand thermal stability and occurrence of phase transition.

Low-Temperature Bainite: A Thermal Stability Study

NASA Astrophysics Data System (ADS)

Santajuana, Miguel A.; Rementeria, Rosalia; Kuntz, Matthias; Jimenez, Jose A.; Caballero, Francisca G.; Garcia-Mateo, Carlos

2018-04-01

The thermal stability of nanobainitic structures obtained by heat treating two different high-carbon high-silicon steels at temperatures between 200 °C and 600 °C has been investigated by means of three complementary techniques, i.e., field emission gun-scanning electron microscopy, X-ray diffraction, and high-resolution dilatometry. Three main stages have been established, each of them characterized by a distinctive microstructure. Furthermore, the nanocrystalline structure generated by the bainite reaction confers the steel with an extraordinary tempering resistance.

Effects of ultraviolet radiation on lattice imperfections in pyrolytic boron nitride.

NASA Technical Reports Server (NTRS)

Buckley, J. D.; Cooley, J. A.

1971-01-01

Pyrolitic boron nitride was exposed to 310 equivalent sun hours of ultraviolet radiation in a space environment simulator with the objective to evaluate its applicability as a pigment for a thermal control coating and to identify radiation damage using X-ray diffraction techniques. Lattice parameter comparisons show a definite increase in lattice imperfections in the crystal structure resulting from the ultraviolet irradiation. This sensitivity to radiation damage makes pyrolitic boron nitride unsuitable as a pigment for thermal control coating.

Influence of electron irradiation on the structural and thermal properties of silk fibroin films

NASA Astrophysics Data System (ADS)

Asha, S.; Sangappa, Sanjeev, Ganesh

2015-06-01

Radiation-induced changes in Bombyx mori silk fibroin (SF) films under electron irradiation were investigated and correlated with dose. SF films were irradiated in air at room temperature using 8 MeV electron beam in the range 0-150 kGy. Various properties of the irradiated SF films were studied using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Electron irradiation was found to induce changes in the physical and thermal properties, depending on the radiation dose.

Editorial: Focus on X-ray Beams with High Coherence

NASA Astrophysics Data System (ADS)

Robinson, Ian; Gruebel, Gerhard; Mochrie, Simon

2010-03-01

This editorial serves as the preface to a special issue of New Journal of Physics, which collects together solicited papers on a common subject, x-ray beams with high coherence. We summarize the issue's content, and explain why there is so much current interest both in the sources themselves and in the applications to the study of the structure of matter and its fluctuations (both spontaneous and driven). As this collection demonstrates, the field brings together accelerator physics in the design of new sources, particle physics in the design of detectors, and chemical and materials scientists who make use of the coherent beams produced. Focus on X-ray Beams with High Coherence Contents Femtosecond pulse x-ray imaging with a large field of view B Pfau, C M Günther, S Schaffert, R Mitzner, B Siemer, S Roling, H Zacharias, O Kutz, I Rudolph, R Treusch and S Eisebitt The FERMI@Elettra free-electron-laser source for coherent x-ray physics: photon properties, beam transport system and applications E Allaria, C Callegari, D Cocco, W M Fawley, M Kiskinova, C Masciovecchio and F Parmigiani Beyond simple exponential correlation functions and equilibrium dynamics in x-ray photon correlation spectroscopy Anders Madsen, Robert L Leheny, Hongyu Guo, Michael Sprung and Orsolya Czakkel The Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) Sébastien Boutet and Garth J Williams Dynamics and rheology under continuous shear flow studied by x-ray photon correlation spectroscopy Andrei Fluerasu, Pawel Kwasniewski, Chiara Caronna, Fanny Destremaut, Jean-Baptiste Salmon and Anders Madsen Exploration of crystal strains using coherent x-ray diffraction Wonsuk Cha, Sanghoon Song, Nak Cheon Jeong, Ross Harder, Kyung Byung Yoon, Ian K Robinson and Hyunjung Kim Coherence properties of the European XFEL G Geloni, E Saldin, L Samoylova, E Schneidmiller, H Sinn, Th Tschentscher and M Yurkov Fresnel coherent diffractive imaging: treatment and analysis of data G J Williams, H M Quiney, A G Peele and K A Nugent Imaging of complex density in silver nanocubes by coherent x-ray diffraction R Harder, M Liang, Y Sun, Y Xia and I K Robinson Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction N Vaxelaire, H Proudhon, S Labat, C Kirchlechner, J Keckes, V Jacques, S Ravy, S Forest and O Thomas Ptychographic coherent diffractive imaging of weakly scattering specimens Martin Dierolf, Pierre Thibault, Andreas Menzel, Cameron M Kewish, Konstantins Jefimovs, Ilme Schlichting, Konstanze von König, Oliver Bunk and Franz Pfeiffer Dose requirements for resolving a given feature in an object by coherent x-ray diffraction imaging Andreas Schropp and Christian G Schroer FLASH: new opportunities for (time-resolved) coherent imaging of nanostructures R Treusch and J Feldhaus Structure of a single particle from scattering by many particles randomly oriented about an axis: toward structure solution without crystallization? D K Saldin, V L Shneerson, M R Howells, S Marchesini, H N Chapman, M Bogan, D Shapiro, R A Kirian, U Weierstall, K E Schmidt and J C H Spence Analysis of strain and stacking faults in single nanowires using Bragg coherent diffraction imaging V Favre-Nicolin, F Mastropietro, J Eymery, D Camacho, Y M Niquet, B M Borg, M E Messing, L-E Wernersson, R E Algra, E P A M Bakkers, T H Metzger, R Harder and I K Robinson Coherent science at the SwissFEL x-ray laser B D Patterson, R Abela, H-H Braun, U Flechsig, R Ganter, Y Kim, E Kirk, A Oppelt, M Pedrozzi, S Reiche, L Rivkin, Th Schmidt, B Schmitt, V N Strocov, S Tsujino and A F Wrulich Energy recovery linac (ERL) coherent hard x-ray sources Donald H Bilderback, Joel D Brock, Darren S Dale, Kenneth D Finkelstein, Mark A Pfeifer and Sol M Gruner Statistical and coherence properties of radiation from x-ray free-electron lasers E L Saldin, E A Schneidmiller and M V Yurkov Microscopic return point memory in Co/Pd multilayer films K A Seu, R Su, S Roy, D Parks, E Shipton, E E Fullerton and S D Kevan Holographic and diffractive x-ray imaging using waveguides as quasi-point sources K Giewekemeyer, H Neubauer, S Kalbfleisch, S P Krüger and T Salditt Mapping the conformations of biological assemblies P Schwander, R Fung, G N Phillips Jr and A Ourmazd Imaging the displacement field within epitaxial nanostructures by coherent diffraction: a feasibility study Ana Diaz, Virginie Chamard, Cristian Mocuta, Rogerio Magalhães-Paniago, Julian Stangl, Dina Carbone, Till H Metzger and Günther Bauer The potential for two-dimensional crystallography of membrane proteins at future x-ray free-electron laser sources Cameron M Kewish, Pierre Thibault, Oliver Bunk and Franz Pfeiffer Coherence properties of hard x-ray synchrotron sources and x-ray free-electron lasers I A Vartanyants and A Singer Coherent imaging of biological samples with femtosecond pulses at the free-electron laser FLASH A P Mancuso, Th Gorniak, F Staier, O M Yefanov, R Barth, C Christophis, B Reime, J Gulden, A Singer, M E Pettit, Th Nisius, Th Wilhein, C Gutt, G Grübel, N Guerassimova, R Treusch, J Feldhaus, S Eisebitt, E Weckert, M Grunze, A Rosenhahn and I A Vartanyants

X-ray diffraction and X-ray standing-wave study of the lead stearate film structure

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

Blagov, A. E.; Dyakova, Yu. A.; Kovalchuk, M. V.

2016-05-15

A new approach to the study of the structural quality of crystals is proposed. It is based on the use of X-ray standing-wave method without measuring secondary processes and considers the multiwave interaction of diffraction reflections corresponding to different harmonics of the same crystallographic reflection. A theory of multiwave X-ray diffraction is developed to calculate the rocking curves in the X-ray diffraction scheme under consideration for a long-period quasi-one-dimensional crystal. This phase-sensitive method is used to study the structure of a multilayer lead stearate film on a silicon substrate. Some specific structural features are revealed for the surface layer ofmore » the thin film, which are most likely due to the tilt of the upper layer molecules with respect to the external normal to the film surface.« less

Molybdenum cell for x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures

NASA Astrophysics Data System (ADS)

Matsuda, Kazuhiro; Tamura, Kozaburo; Katoh, Masahiro; Inui, Masanori

2004-03-01

We have developed a sample cell for x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures. All parts of the cell are made of molybdenum which is resistant to the chemical corrosion of alkali metals. Single crystalline molybdenum disks electrolytically thinned down to 40 μm were used as the walls of the cell through which x rays pass. The crystal orientation of the disks was controlled in order to reduce the background from the cell. All parts of the cell were assembled and brazed together using a high-temperature Ru-Mo alloy. Energy dispersive x-ray diffraction measurements have been successfully carried out for fluid rubidium up to 1973 K and 16.2 MPa. The obtained S(Q) demonstrates the applicability of the molybdenum cell to x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures.

High-resolution ab initio three-dimensional x-ray diffraction microscopy

DOE PAGES

Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; ...

2006-01-01

Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatialmore » resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.« less

Enhancing resolution in coherent x-ray diffraction imaging.

PubMed

Noh, Do Young; Kim, Chan; Kim, Yoonhee; Song, Changyong

2016-12-14

Achieving a resolution near 1 nm is a critical issue in coherent x-ray diffraction imaging (CDI) for applications in materials and biology. Albeit with various advantages of CDI based on synchrotrons and newly developed x-ray free electron lasers, its applications would be limited without improving resolution well below 10 nm. Here, we review the issues and efforts in improving CDI resolution including various methods for resolution determination. Enhancing diffraction signal at large diffraction angles, with the aid of interference between neighboring strong scatterers or templates, is reviewed and discussed in terms of increasing signal-to-noise ratio. In addition, we discuss errors in image reconstruction algorithms-caused by the discreteness of the Fourier transformations involved-which degrade the spatial resolution, and suggest ways to correct them. We expect this review to be useful for applications of CDI in imaging weakly scattering soft matters using coherent x-ray sources including x-ray free electron lasers.

A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

NASA Astrophysics Data System (ADS)

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-09-01

It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.

Synchrotron X-Ray Diffraction Studies of Olivine from Comet Wild 2

NASA Technical Reports Server (NTRS)

2008-01-01

We have analyzed a collection of the Comet Wild 2 coma grains returned by the NASA Stardust Mission, using micro-area Laue diffraction equipment. The purpose of the diffraction experiment is to permit the structure refinement of olivine including site occupancies. In addition to the intrinsic importance of the olivine structures for revealing the thermal history of Wild 2 materials, we wish to test reports that olivine recovered after hypervelocity capture in silica aerogel has undergone a basic structural change due to capture heating [1]. The diffraction equipment placed at beam line BL- 4B1 of PF, KEK was developed with a micropinhole and an imaging plate (Fuji Co. Ltd.) using the Laue method combined with polychromatic X-ray of synchrotron radiation operated at energy of 2.5 GeV. The incident beam is limited to 1.6 m in diameter by a micropinhole set just upstream of the sample [2, 3]. It is essential to apply a microbeam to obtain diffracted intensities with high signal to noise ratios. This equipment has been successfully applied to various extraterrestrial materials, including meteorites and interplanetary dust particles [4]. The Laue pattern of the sample C2067,1,111,4 (Fig. 1) was successfully taken on an imaging plate after a 120 minute exposure (Fig. 2).

Role of intensive milling in the processing of barium ferrite/magnetite/iron hybrid magnetic nano-composites via partial reduction of barium ferrite

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

Molaei, M.J., E-mail: mj.molaee@merc.ac.ir; Delft Chem Tech, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, 2628 BL Delft; Ataie, A.

2015-03-15

In this research a mixture of barium ferrite and graphite was milled for different periods of time and then heat treated at different temperatures. The effects of milling time and heat treatment temperature on the phase composition, thermal behavior, morphology and magnetic properties of the samples have been investigated using X-ray diffraction, differential thermal analysis, high resolution transmission electron microscopy and vibrating sample magnetometer techniques, respectively. X-ray diffraction results revealed that BaFe{sub 12}O{sub 19}/Fe{sub 3}O{sub 4} nanocomposites form after a 20 h milling due to the partial reduction of BaFe{sub 12}O{sub 19}. High resolution transmission electron microscope images of amore » 40 h milled sample showed agglomerated structure consisting of nanoparticles with a mean particle size of 30 nm. Thermal analysis of the samples via differential thermal analysis indicated that for un-milled samples, heat treatment up to 900 °C did not result in α-Fe formation, while for a 20 h milled sample heat treatment at 700 °C resulted in reduction process progress to the formation of α-Fe. Wustite was disappeared in an X-ray diffraction pattern of a heat treated sample at 850 °C, by increasing the milling time from 20 to 40 h. By increasing the milling time, the structure of heat treated samples becomes magnetically softer due to an increase in saturation magnetization and a decrease in coercivity. Saturation magnetization and coercivity of a sample milled for 20 h and heat treated at 850 °C were 126.3 emu/g and 149.5 Oe which by increasing the milling time to 40 h, alter to 169.1 emu/g and 24.3 Oe, respectively. High coercivity values of milled and heat treated samples were attributed to the nano-scale formed iron particles. - Graphical abstract: Display Omitted - Highlights: • Barium ferrite and graphite were treated mechano-thermally. • Increasing milling time increases reduction progress after heat treatment. • Composites including iron nano-crystals forms by milling and heat treatment. • Shorter milling time results in higher H{sub C} of the milled and heat treated samples.« less

X-ray fractography on fatigue fractured surface of austenitic stainless steel

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

Yajima, Zenjiro; Tokuyama, Hideki; Kibayashi, Yasuo

1995-12-31

X-ray diffraction observation of the material internal structure beneath fracture surfaces provide fracture analysis with useful information to investigate the conditions and mechanisms of fracture. X-ray fractography is a generic name given to this technique. In the present study, X-ray fractography was applied to fatigue fracture surfaces of austenitic stainless steel (AISI 304) which consisted of solution treatment. The fatigue tests were carried out on compact tension (CT) specimens. The plastic strain on the fracture surface was estimated from measuring the line broadening of X-ray diffraction profiles. The line broadening of X-ray diffraction profiles was measured on and beneath fatiguemore » fracture surfaces. The depth of the plastic zone left on fracture surfaces was evaluated from the line broadening. The results are discussed on the basis of fracture mechanics.« less

Toward in situ x-ray diffraction imaging at the nanometer scale

NASA Astrophysics Data System (ADS)

Zatsepin, Nadia A.; Dilanian, Ruben A.; Nikulin, Andrei Y.; Gable, Brian M.; Muddle, Barry C.; Sakata, Osami

2008-08-01

We present the results of preliminary investigations determining the sensitivity and applicability of a novel x-ray diffraction based nanoscale imaging technique, including simulations and experiments. The ultimate aim of this nascent technique is non-destructive, bulk-material characterization on the nanometer scale, involving three dimensional image reconstructions of embedded nanoparticles and in situ sample characterization. The approach is insensitive to x-ray coherence, making it applicable to synchrotron and laboratory hard x-ray sources, opening the possibility of unprecedented nanometer resolution with the latter. The technique is being developed with a focus on analyzing a technologically important light metal alloy, Al-xCu (where x is 2.0-5.0 %wt). The mono- and polycrystalline samples contain crystallographically oriented, weakly diffracting Al2Cu nanoprecipitates in a sparse, spatially random dispersion within the Al matrix. By employing a triple-axis diffractometer in the non-dispersive setup we collected two-dimensional reciprocal space maps of synchrotron x-rays diffracted from the Al2Cu nanoparticles. The intensity profiles of the diffraction peaks confirmed the sensitivity of the technique to the presence and orientation of the nanoparticles. This is a fundamental step towards in situ observation of such extremely sparse, weakly diffracting nanoprecipitates embedded in light metal alloys at early stages of their growth.

Diffraction and Imaging Study of Imperfections of Protein Crystals with Coherent X-rays

NASA Technical Reports Server (NTRS)

Hu, Z. W.; Thomas, B. R.; Chernov, A. A.; Chu, Y. S.; Lai, B.

2004-01-01

High angular-resolution x-ray diffraction and phase contrast x-ray imaging were combined to study defects and perfection of protein crystals. Imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of a uniformly grown lysozyme crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in diffraction images. X-ray imaging and diffraction characterization of the quality of apoferritin crystals will also be discussed in the presentation.

Synthesis and properties of nanocrystalline copper indium oxide thin films deposited by Rf magnetron sputtering.

PubMed

Singh, Mandeep; Singh, V N; Mehta, B R

2008-08-01

Nanocrystalline copper indium oxide (CuInO2) thin films with particle size ranging from 25 nm to 71 nm have been synthesized from a composite target using reactive Rf magnetron sputtering technique. X-ray photoelectron spectroscopy (XPS) combined with glancing angle X-ray diffraction (GAXRD) analysis confirmed the presence of delafossite CuInO2 phase in these films. The optical absorption studies show the presence of two direct band gaps at 3.3 and 4.3 eV, respectively. The resistance versus temperature measurements show thermally activated hopping with activation energy of 0.84 eV to be the conduction mechanism.

Thin films deposited by femtosecond pulsed laser ablation of tungsten carbide

NASA Astrophysics Data System (ADS)

De Bonis, A.; Teghil, R.; Santagata, A.; Galasso, A.; Rau, J. V.

2012-09-01

Ultra-short Pulsed Laser Deposition has been applied to the production of thin films from a tungsten carbide target. The gaseous phase obtained by the laser ablation shows a very weak primary plume, in contrast with a very strong secondary one. The deposited films, investigated by Scanning Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron Spectroscopy and X-Ray Diffraction, present a mixture of WC and other phases with lower carbon content. All films are amorphous, independently from the substrate temperature. The characteristics of the deposits have been explained in terms of thermal evaporation and cooling rate of molten particles ejected from the target.

THE EFFECT OF SATELLITE LINES FROM THE X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...

History and Solution of the Phase Problem in theTheory of Structure Determination of Crystals from X-ray Diffraction Experiments

ScienceCinema

Wolf, Emil [University of Rochester, Rochester, New York, United States

2017-12-09

Since the pioneering work of Max von Laue on interference and diffraction of x-rays, carried out almost 100 years ago, numerous attempts have been made to determine structures of crystalline media from x-ray diffraction experiments. The usefulness of all of them has been limited by the inability of measuring phases of the diffracted beams. In this talk, the most important research carried out in this field will be reviewed and a recently obtained solution of the phase problem will be presented.

Synthesis and characterization of new nanocomposites films using alanine-Cu-functionalized graphene oxide as nanofiller and PVA as polymeric matrix for improving of their properties

NASA Astrophysics Data System (ADS)

Abdolmaleki, Amir; Mallakpour, Shadpour; Karshenas, Azam

2017-09-01

In the synthesis of polymer-graphene nanocomposites, for improving properties of nanocomposites, two factors dispersion and strong interfacial interactions between graphene and the polymer, are essential. In the present work, poly(vinyl alcohol) PVA/GO-Cu-alanine nanocomposite films were manufactured using concentrations 0, 1, 3 and 5 wt% of GO-Cu-alanine in water solution. For this purpose, L-alanine amino acid was located on the surface and edges of GO through copper(II) ion as a coordinating function. Then, flexible PVA/GO-Cu-alanine nanocomposite films were fabricated using GO-Cu-alanine as filler and PVA as matrix. Due to the existence of affective interaction between GO-Cu-alanine and PVA matrix, the acquired PVA/GO-Cu-alanine nanocomposites demonstrated great thermal and mechanical properties. Properties of manufactured materials were characterized by Fourier transform infrared, X-ray photoelectron spectroscopies (XPS), X-ray diffraction (XRD), Thermal gravimetric analysis, elemental analysis, field emission scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX).

Characterization of thermally evaporated lead iodide films aimed for the detection of X-rays

NASA Astrophysics Data System (ADS)

Caldeira Filho, A. M.; Mulato, M.

2011-04-01

Some semiconductor materials such as lead iodide (PbI2) have applications in the detection of ionizing radiation at room temperature using the direct detection method. In this work we investigate lead iodide films deposited by thermal evaporation. The morphology, structure, and electric properties were investigated as a function of deposition height, i.e. the distance between evaporation-boat and substrates. The results show a morphology of vertical leaves and X-ray diffraction shows just one preferential orientation along the direction 110. Energy dispersive spectroscopy reveals that the films are not stoichiometric, with excess iodine atoms. Electrical resistivity of about 108 Ω cm was measured. This is smaller than for the bulk due to structural defects. The values of activation energy for electric transport increase from 0.52 up to 1.1 eV with decreasing deposition height, what indicates that the best film is the one deposited at the shortest distance. Exposure under X-ray mammographic energy shows a linear behavior up to 500 mR. No variation in sensibility was observed between 22 and 30 kVp.

Mesoscopic structural phase progression in photo-excited VO 2 revealed by time-resolved x-ray diffraction microscopy

DOE PAGES

Zhu, Yi; Cai, Zhonghou; Chen, Pice; ...

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase seperated regions. The ability to simultanousely track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of- the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO 2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation ismore » initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO 2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, which is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO 2. Lastly, the direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.« less

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy

NASA Astrophysics Data System (ADS)

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J.; Jung, Il Woong; Walko, Donald A.; Dufresne, Eric M.; Jeong, Jaewoo; Samant, Mahesh G.; Parkin, Stuart S. P.; Freeland, John W.; Evans, Paul G.; Wen, Haidan

2016-02-01

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy.

PubMed

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J; Jung, Il Woong; Walko, Donald A; Dufresne, Eric M; Jeong, Jaewoo; Samant, Mahesh G; Parkin, Stuart S P; Freeland, John W; Evans, Paul G; Wen, Haidan

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al0.15Ga0.85N

NASA Astrophysics Data System (ADS)

Magalhães, S.; Fialho, M.; Peres, M.; Lorenz, K.; Alves, E.

2016-04-01

In this work radial symmetric x-ray diffraction scans of Al0.15Ga0.85N thin films implanted with Tm ions were measured to determine the lattice deformation and crystal quality as functions of depth. The alloys were implanted with 300 keV Tm with 10° off-set to the sample normal to avoid channelling, with fluences varying between 1013 Tm cm-2 and 5  ×  1015 Tm cm-2. Simulations of the radial 2θ-ω scans were performed under the frame of the dynamical theory of x-ray diffraction assuming Gaussian distributions of the lattice strain induced by implantation defects. The structure factor of the individual layers is multiplied by a static Debye-Waller factor in order to take into account the effect of lattice disorder due to implantation. For higher fluences two asymmetric Gaussians are required to describe well the experimental diffractograms, although a single asymmetric Gaussian profile for the deformation is found in the sample implanted with 1013 Tm cm-2. After thermal treatment at 1200 °C, the crystal quality partially recovers as seen in a reduction of the amplitude of the deformation maximum as well as the total thickness of the deformed layer. Furthermore, no evidence of changes with respect to the virgin crystal mosaicity is found after implantation and annealing.

XRayView: a teaching aid for X-ray crystallography.

PubMed

Phillips, G N

1995-10-01

A software package, XRayView, has been developed that uses interactive computer graphics to introduce basic concepts of x-ray diffraction by crystals, including the reciprocal lattice, the Ewald sphere construction, Laue cones, the wavelength dependence of the reciprocal lattice, primitive and centered lattices and systematic extinctions, rotation photography. Laue photography, space group determination and Laue group symmetry, and the alignment of crystals by examination of reciprocal space. XRayView is designed with "user-friendliness" in mind, using pull-down menus to control the program. Many of the experiences of using real x-ray diffraction equipment to examine crystalline diffraction can be simulated. Exercises are available on-line to guide the users through many typical x-ray diffraction experiments.

Application of MEMS-based x-ray optics as tuneable nanosecond choppers

NASA Astrophysics Data System (ADS)

Chen, Pice; Walko, Donald A.; Jung, Il Woong; Li, Zhilong; Gao, Ya; Shenoy, Gopal K.; Lopez, Daniel; Wang, Jin

2017-08-01

Time-resolved synchrotron x-ray measurements often rely on using a mechanical chopper to isolate a set of x-ray pulses. We have started the development of micro electromechanical systems (MEMS)-based x-ray optics, as an alternate method to manipulate x-ray beams. In the application of x-ray pulse isolation, we recently achieved a pulse-picking time window of half a nanosecond, which is more than 100 times faster than mechanical choppers can achieve. The MEMS device consists of a comb-drive silicon micromirror, designed for efficiently diffracting an x-ray beam during oscillation. The MEMS devices were operated in Bragg geometry and their oscillation was synchronized to x-ray pulses, with a frequency matching subharmonics of the cycling frequency of x-ray pulses. The microscale structure of the silicon mirror in terms of the curvature and the quality of crystallinity ensures a narrow angular spread of the Bragg reflection. With the discussion of factors determining the diffractive time window, this report showed our approaches to narrow down the time window to half a nanosecond. The short diffractive time window will allow us to select single x-ray pulse out of a train of pulses from synchrotron radiation facilities.

Fabrication of high-resolution x-ray diffractive optics at King's College London

NASA Astrophysics Data System (ADS)

Charalambous, Pambos S.; Anastasi, Peter A. F.; Burge, Ronald E.; Popova, Katia

1995-09-01

The fabrication of high resolution x-ray diffractive optics, and Fresnel zone plates (ZPs) in particular, is a very demanding multifaceted technological task. The commissioning of more (and brighter) synchrotron radiation sources, has increased the number of x-ray imaging beam lines world wide. The availability of cheaper and more effective laboratory x-ray sources, has further increased the number of laboratories involved in x-ray imaging. The result is an ever increasing demand for x-ray optics with a very wide range of specifications, reflecting the particular type of x-ray imaging performed at different laboratories. We have been involved in all aspects of high resolution nanofabrication for a number of years, and we have explored many different methods of lithography, which, although unorthodox, open up possibilities, and increase our flexibility for the fabrication of different diffractive optical elements, as well as other types of nanostructures. The availability of brighter x-ray sources, means that the diffraction efficiency of the ZPs is becoming of secondary importance, a trend which will continue in the future. Resolution, however, is important and will always remain so. Resolution is directly related to the accuracy af pattern generation, as well as the ability to draw fine lines. This is the area towards which we have directed most of our efforts so far.

Melting-solidification transition of Zn nanoparticles embedded in SiO2: Observation by synchrotron x-ray and ultraviolet-visible-near-infrared light

NASA Astrophysics Data System (ADS)

Amekura, H.; Tanaka, M.; Katsuya, Y.; Yoshikawa, H.; Ohnuma, M.; Matsushita, Y.; Kobayashi, K.; Kishimoto, N.

2010-11-01

Melting-solidification transition of Zn nanoparticles (NPs) with the mean diameter of 11.5 nm, embedded in silica glass, was investigated by glancing incident x-ray diffraction (GIXRD) at high temperatures using synchrotron radiation (SR). With increasing temperature, 101Zn diffraction peak gradually decreases up to ˜360 °C and then steeply decreases. This is due to the melting of Zn NPs, which completes around 420 °C. With decreasing temperature, the solidification of the NPs begins around ˜310 °C. The temperature hysteresis with a width of ˜110 °C was observed. With temperature, the diffraction angle shows a shift without hysteresis, which is ascribed to thermal expansion of Zn NP lattice. Thermal expansion coefficient of Zn NPs was determined as 24.4×10-6 K-1 along the ⟨101⟩ direction. Optical absorption spectroscopy shows a broad ultraviolet (UV) peak which was observed at even higher temperatures than the melting temperature but shifts to the low-energy side with the melting. The energy shift in the UV peak also shows the temperature hysteresis which resembles with the melting-solidification hysteresis recorded by SR-GIXRD. The melting-solidification transition is also detectable by the optical absorption spectroscopy in the UV-visible-near-infrared region.

CaMn(1-x)Nb(x)O3 (x < or = 0.08) perovskite-type phases as promising new high-temperature n-type thermoelectric materials.

PubMed

Bocher, L; Aguirre, M H; Logvinovich, D; Shkabko, A; Robert, R; Trottmann, M; Weidenkaff, A

2008-09-15

Perovskite-type CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) compounds were synthesized by applying both a "chimie douce" (SC) synthesis and a classical solid state reaction (SSR) method. The crystallographic parameters of the resulting phases were determined from X-ray, electron, and neutron diffraction data. The manganese oxidations states (Mn(4+)/Mn(3+)) were investigated by X-ray photoemission spectroscopy. The orthorhombic CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) phases were studied in terms of their high-temperature thermoelectric properties (Seebeck coefficient, electrical resistivity, and thermal conductivity). Differences in electrical transport and thermal properties can be correlated with different microstructures obtained by the two synthesis methods. In the high-temperature range, the electron-doped manganate phases exhibit large absolute Seebeck coefficient and low electrical resistivity values, resulting in a high power factor, PF (e.g., for x = 0.05, S(1000K) = -180 microV K(-1), rho(1000K) = 16.8 mohms cm, and PF > 1.90 x 10(-4) W m(-1) K(-2) for 450 K < T < 1070 K). Furthermore, lower thermal conductivity values are achieved for the SC-derived phases (kappa < 1 W m(-1) K(-1)) compared to the SSR compounds. High power factors combined with low thermal conductivity (leading to ZT values > 0.3) make these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures.

Microstructural investigation of nickel silicide thin films and the silicide-silicon interface using transmission electron microscopy.

PubMed

Bhaskaran, M; Sriram, S; Mitchell, D R G; Short, K T; Holland, A S; Mitchell, A

2009-01-01

This article discusses the results of transmission electron microscopy (TEM)-based investigation of nickel silicide (NiSi) thin films grown on silicon. Nickel silicide is currently used as the CMOS technology standard for local interconnects and in electrical contacts. Films were characterized with a range of TEM-based techniques along with glancing angle X-ray diffraction. The nickel silicide thin films were formed by vacuum annealing thin films of nickel (50 nm) deposited on (100) silicon. The cross-sectional samples indicated a final silicide thickness of about 110 nm. This investigation studied and reports on three aspects of the thermally formed thin films: the uniformity in composition of the film using jump ratio maps; the nature of the interface using high resolution imaging; and the crystalline orientation of the thin films using selected-area electron diffraction (SAED). The analysis highlighted uniform composition in the thin films, which was also substantiated by spectroscopy techniques; an interface exhibiting the desired abrupt transition from silicide to silicon; and desired and preferential crystalline orientation corresponding to stoichiometric NiSi, supported by glancing angle X-ray diffraction results.

Transmission Grating and Optics Technology Development for the Arcus Explorer Mission

NASA Astrophysics Data System (ADS)

Heilmann, Ralf; Arcus Team

2018-01-01

Arcus is a high-resolution x-ray spectroscopy MIDEX mission selected for a Phase A concept study. It is designed to explore structure formation through measurements of hot baryon distributions, feedback from black holes, and the formation and evolution of stars, disks, and exoplanet atmospheres. The design provides unprecedented sensitivity in the 1.2-5 nm wavelength band with effective area above 450 sqcm and spectral resolution R > 2500. The Arcus technology is based on 12 m-focal length silicon pore optics (SPO) developed for the European Athena mission, and critical-angle transmission (CAT) x-ray diffraction gratings and x-ray CCDs developed at MIT. The modular design consists of four parallel channels, each channel holding an optics petal, followed by a grating petal. CAT gratings are lightweight, alignment insensitive, high-efficiency x-ray transmission gratings that blaze into high diffraction orders, leading to high spectral resolution. Each optics petal represents an azimuthal sub-aperture of a full Wolter optic. The sub-aperturing effect increases spectral resolving power further. Two CCD readout strips receive photons from each channel, including higher-energy photons in 0th order. Each optics petal holds 34 SPO modules. Each grating petal holds 34 grating windows, and each window holds 4-6 grating facets. A grating facet consists of a silicon grating membrane, bonded to a flexure frame that interfaces with the grating window. We report on a sequence of tests with increasing complexity that systematically increase the Technology Readiness Level (TRL) for the combination of CAT gratings and SPOs towards TLR 6. CAT gratings have been evaluated in x rays for diffraction efficiency (> 30% at 2.5 nm) and for resolving power (R> 10,000). A CAT grating/SPO combination was measured at R ~ 3100 at blaze angles smaller than design values, exceeding Arcus requirements. Efficiency and resolving power were not impacted by vibration and thermal testing of gratings. A pair of large (32 mm x 32 mm) gratings was aligned using laser metrology, and alignment was verified under x rays. We present results on simultaneous illumination of the aligned grating pair, and describe our progress towards further tests.

The preparation and hydrogen brittleness resistance of Pd71.5Cu12Si16.5 metallic glass ribbons

NASA Astrophysics Data System (ADS)

Du, Xiaoqing; Ye, Xiaoqiu; Ren, Qingbo

2017-12-01

Pd71.5Cu12Si16.5 metallic glass ribbons as wide as 10mm were prepared by splat quenching. Structure was identified with X-ray diffraction (XRD) spectrums from the conventional X-ray diffractometer and also short wavelength X-ray stress analyzer. The results confirm fully amorphous structure of the ribbons. Multiple H2 adsorption and desorption cycles under a pressure of 100kPa were carried out in the metallic glass ribbon and also pure palladium membrane for comparison. The former didn’t show any cracks after more than 10 cycles, and thermal desorption spectroscopy (TDS) measurement confirms that hydrogen was adsorbed abundantly in the metallic glass ribbon. Pd71.5Cu12Si16.5 metallic glass ribbons demonstrate excellent hydrogen brittleness resistance.

Agglomeration dynamics of germanium islands on a silicon oxide substrate: A grazing incidence small-angle x-ray scattering study

NASA Astrophysics Data System (ADS)

Cheynis, F.; Leroy, F.; Passanante, T.; Müller, P.

2013-04-01

Grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence X-ray diffraction techniques are used to characterise the thermally induced solid-state dewetting of Ge(001) thin films leading to the formation of 3D Ge islands. A quantitative analysis based on the Kolmogorov-Johnson-Mehl-Avrami model is derived. The main physical parameters controlling the dewetting (activation energy and kinetic pre-factors) are determined. Assuming that the dewetting is driven by surface/interface minimisation and limited by surface diffusion, the Ge surface self-diffusion reads as Ds ,0c0 e-Ea/(kBT) ˜3×1018 e-2.6±0.3eV/(kBT) nm2/s. GISAXS technique enables to reconstruct the mean Ge-island shape, including facets.

Mesoscale evolution of voids and microstructural changes in HMX-based explosives during heating through the β-δ phase transition

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

Willey, Trevor M., E-mail: willey1@llnl.gov; Lauderbach, Lisa; Gagliardi, Franco

HMX-based explosives LX-10 and PBX-9501 were heated through the β-δ phase transition. Ultra-small angle x-ray scattering (USAXS) and molecular diffraction were simultaneously recorded as the HMX was heated. Mesoscale voids and structure dramatically change promptly with the β-δ phase transition, rather than with other thermal effects. Also, x-ray induced damage, observed in the USAXS, occurs more readily at elevated temperatures; as such, the dose was reduced to mitigate this effect. Optical microscopy performed during a similar heating cycle gives an indication of changes on longer length scales, while x-ray microtomography, performed before and after heating, shows the character of extensivemore » microstructural damage resulting from the temperature cycle and solid-state phase transition.« less

Mesoscale evolution of voids and microstructural changes in HMX-based explosives during heating through the β-δ phase transition

DOE PAGES

Willey, Trevor M.; Lauderbach, Lisa; Gagliardi, Franco; ...

2015-08-07

HMX-based explosives LX-10 and PBX-9501 were heated through the β-δ phase transition. Ultra-small angle x-ray scattering (USAXS) and molecular diffraction were simultaneously recorded as the HMX was heated. Mesoscale voids and structure dramatically change promptly with the β-δ phase transition, rather than with other thermal effects. Also, x-ray induced damage, observed in the USAXS, occurs more readily at elevated temperatures; as such, the dose was reduced to mitigate this effect. Optical microscopy performed during a similar heating cycle gives an indication of changes on longer length scales, while x-ray microtomography, performed before and after heating, shows the character of extensivemore » microstructural damage resulting from the temperature cycle and solid-state phase transition.« less

Two-photon x-ray diffraction

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

Stohr, J.

The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a “source”, consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focused beyond the diffraction limit. Furthermore, the case of cloned photon pairs is compared to and distinguished from entangled photonmore » pairs or biphotons.« less

Two-photon x-ray diffraction

DOE PAGES

Stohr, J.

2017-01-11

The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a “source”, consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focused beyond the diffraction limit. Furthermore, the case of cloned photon pairs is compared to and distinguished from entangled photonmore » pairs or biphotons.« less

Characterization of X80 and X100 Microalloyed Pipeline Steel Using Quantitative X-ray Diffraction

NASA Astrophysics Data System (ADS)

Wiskel, J. B.; Li, X.; Ivey, D. G.; Henein, H.

2018-06-01

Quantitative X-ray diffraction characterization of four (4) X80 and three (3) X100 microalloyed steels was undertaken. The effect of through-thickness position, processing parameters, and composition on the measured crystallite size, microstrain, and J index (relative magnitude of crystallographic texture) was determined. Microstructure analysis using optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron-backscattered diffraction was also undertaken. The measured value of microstrain increased with increasing alloy content and decreasing cooling interrupt temperature. Microstructural features corresponding to crystallite size in the X80 steels were both above and below the detection limit for quantitative X-ray diffraction. The X100 steels consistently exhibited microstructure features below the crystallite size detection limit. The yield stress of each steel increased with increasing microstrain. The increase in microstrain from X80 to X100 is also associated with a change in microstructure from predominantly polygonal ferrite to bainitic ferrite.

Magnetic separation of carbon-encapsulated Fe nanoparticles from thermally-treated wood char

Treesearch

Sung Phil Mun; Zhiyong Cai; Jilei Zhang

2013-01-01

Wood char,a by-product from the fast-pyrolysis process of southern yellow pine wood for bio-oil production, was carbonized with Fenano particles (FeNPs) as a catalyst to prepare carbon-encapsulated Fe nanoparticles. A magnetic separation method was tested to isolate carbon-encapsulated Fe nano particles from the carbonized char. X-ray diffraction pattern clearly shows...

The fifth solvatomorph of gallic acid with a supramolecular channel structure: Structural complexity and phase transitions

NASA Astrophysics Data System (ADS)

Thomas, Sajesh P.; Kaur, Ramanpreet; Kaur, Jassjot; Sankolli, Ravish; Nayak, Susanta K.; Guru Row, Tayur N.

2013-01-01

A new solvatomorph of gallic acid was generated using chiral additive technique and characterized by single crystal and powder X-ray diffraction, C-13 NMR, IR spectroscopic techniques and thermal analysis. The supramolecular channels formed by hexameric motifs of gallic acid and solvent molecules contain highly disordered solvent molecules with fractional occupancies.

Thermal alteration of young kerogen in relation to petroleum genesis

NASA Technical Reports Server (NTRS)

Ishiwatari, R.; Ishiwatari, M.; Kaplan, I. R.; Rohrback, B. G.

1976-01-01

Kerogen, humic acid, and lipid material were separated from a young marine sediment and heated in sealed tubes in a nitrogen atmosphere at 150 and 410 C. Gaseous and liquid products generated during heating, and also the residual organic material, were characterized by gas-liquid chromatography, elemental analysis, infrared and electron spin resonance spectroscopy, and X-ray diffraction.

Influence of Annealing on the Depth Microstructure of the Shot Peened Duplex Stainless Steel at Elevated Temperature

NASA Astrophysics Data System (ADS)

Feng, Qiang; She, Jia; Xiang, Yong; Wu, Xianyun; Wang, Chengxi; Jiang, Chuanhai

The depth profiles of residual stresses and lattice parameters in the surface layers of shot peened duplex stainless steel at elevated temperature were investigated utilizing X-ray diffraction analysis. At each deformation depth, residual stress distributions in both ferrite and austenite were studied by X-ray diffraction stress analysis which is performed on the basis of the sin2ψ method and the lattice parameters were explored by Rietveld method. The results reveal that difference changes of depth residual compressive stress profiles between ferrite and austenite under the same annealing condition are resulted from the diverse coefficient of thermal expansion, dislocation density, etc. for different phases in duplex stainless steel. The relaxations of depth residual stresses in austenite are more obvious than those in ferrite. The lattice parameters decrease in the surface layer with the extending of annealing time, however, they increase along the depth after annealing for 16min. The change of the depth lattice parameters can be ascribed to both thermal expansion and the relaxation of residual stress. The different changes of microstructure at elevated temperature between ferrite and austenite are discussed.

Growth, structural, thermal, linear and nonlinear optical and laser damage threshold studies of picolinium tartrate monohydrate single crystals.

PubMed

Peramaiyan, G; Pandi, P; Sornamurthy, B M; Bhagavannarayana, G; Mohan Kumar, R

2012-09-01

Picolinium tartrate monohydrate (PTM), a novel organic nonlinear optical material was synthesized and bulk crystals were grown from aqueous solution by slow cooling technique. The cell parameters of the grown crystal were found by single and powder X-ray diffraction analyses. The crystalline perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The presence of functional groups in the grown crystal was identified by FTIR and FT-Raman spectral analyses. UV-Vis spectral studies reveal PTM crystals are transparent in the wavelength region of 295-1100 nm. The thermal characteristics of PTM were analyzed by TGA/DTA studies. The dielectric and mechanical behaviours of PTM crystals were investigated. Dislocation density was estimated to be 2.89 × 10(3) cm(-2) on the flat-surface of PTM crystals from the etching studies. The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser. Its second harmonic generation relative efficiency was measured by Kurtz and Perry powder technique and was observed to be comparable with KDP crystal. Copyright © 2012 Elsevier B.V. All rights reserved.

Growth, nonlinear optical, thermal, dielectric and laser damage threshold studies of semiorganic crystal: monohydrate piperazine hydrogen phosphate.

PubMed

Krishnan, P; Gayathri, K; Bhagavannarayana, G; Gunasekaran, S; Anbalagan, G

2013-02-01

Monohydrate piperazine hydrogen phosphate (MPHP), a semi organic nonlinear optical material has been synthesized and single crystals were grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction study on grown crystal reveals that they belong to monoclinic crystal system with space group P2(1)/c; (a=6.39Å; b=12.22Å; c=11.16Å; β=97.14°; V=864Å(3)). The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. FTIR spectrum confirms the presence of the functional groups in synthesized material. UV-Vis spectrum indicates that the crystal is transparent in the entire visible region with a lower cut off wavelength of 387 nm. The variation of dielectric properties of the grown crystal with respect to frequency has been investigated at different temperatures. Thermal analysis carried out on the MPHP crystal shows that the crystal is stable up to 135°C. Relative powder second harmonic generation efficiency tested by Kurtz-Perry powder technique, which was about 0.638 times that of Potassium dihydrogen phosphate. Copyright © 2012 Elsevier B.V. All rights reserved.

A novel conformation of gel grown biologically active cadmium nicotinate

NASA Astrophysics Data System (ADS)

Nair, Lekshmi P.; Bijini, B. R.; Divya, R.; Nair, Prabitha B.; Eapen, S. M.; Dileep Kumar, B. S.; Nishanth Kumar, S.; Nair, C. M. K.; Deepa, M.; Rajendra Babu, K.

2017-11-01

The elimination of toxic heavy metals by the formation of stable co-ordination compounds with biologically active ligands is applicable in drug designing. A new crystalline complex of cadmium with nicotinic acid is grown at ambient temperature using the single gel diffusion method in which the crystal structure is different from those already reported. Single crystal x-ray diffraction reveals the identity of crystal structure belonging to monoclinic system, P21/c space group with cell dimensions a = 17.220 (2) Å, b = 10.2480 (2) Å, c = 7.229(9) Å, β = 91.829(4)°. Powder x-ray diffraction analysis confirmed the crystallinity of the sample. The unidentate mode of co-ordination between the metal atom and the carboxylate group is supported by the Fourier Transform Infra Red spectral data. Thermal analysis ensures the thermal stability of the complex. Kinetic and thermodynamic parameters are also calculated. The stoichiometry of the complex is confirmed by the elemental analysis. The UV-visible spectral analysis shows the wide transparency window of the complex in the visible region. The band gap of the complex is found to be 3.92 eV. The complex shows excellent antibacterial and antifungal activity.

Different water clusters dependent on long-chain dicarboxylates in two Ag(I) coordination polymers: Synthesis, structure and thermal stability

NASA Astrophysics Data System (ADS)

Sun, Di; Liu, Fu-Jing; Hao, Hong-Jun; Huang, Rong-Bin; Zheng, Lan-Sun

2011-10-01

Two mixed-ligand Ag(I) coordination polymers (CPs), [Ag 2(bipy) 2(sub)·5H 2O] n ( 1), [Ag 2(bipy) 2(aze)·3H 2O] n ( 2), (bipy = 4,4'-bipyridine, H 2sub = suberic acid, H 2aze = azelaic acid) have been synthesized and structurally characterized by elemental analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis, and single crystal X-ray diffraction. Both 1 and 2 are two-dimensional (2D) sheets based on infinite [Ag(bipy)] n double chain incorporating Ag⋯Ag interactions. Interestingly, two different water clusters are encapsulated in the voids between the sheets of 1 and 2. For 1, one water decamer (H 2O) 10 based on a cyclic water tetramer was hydrogen-bonded with the host 2D sheet. While, one water hexamer (H 2O) 6 also based on a cyclic water tetramer was observed in 2. Comparing the experimental results, it is comprehensible that the dicarboxylates play a crucial role in the formation of the different water clusters. Moreover, the thermal stabilities of them were also discussed.

Growth and physicochemical properties of organometallic (DL)-trithioureatartrato-O1,O2,O3-cadmium(II) single crystals

NASA Astrophysics Data System (ADS)

Sathyamoorthy, K.; Vinothkumar, P.; Irshad Ahamed, J.; Murali Manohar, P.; Priya, M.; Liu, Jinghe

2018-04-01

Single crystals of organometallic (DL)-trithioureatartrato-O1,O2,O3-cadmium(II) (TUDLC) have been grown from methanol solution by using the slow evaporation of solvent growth technique. The lattice structure and crystalline perfection have been determined by carrying out single crystal X-ray diffraction and high resolution X-ray diffraction measurements. The grown crystal was characterized thermally and mechanically by carrying out thermo-gravimetric and micro hardness measurements. The linear and nonlinear optical characterizations were made by carrying out optical transmittance, surface laser damage threshold, particle size-dependent second harmonic generation (SHG) efficiency and photo conductivity measurements. The grown crystal was electrically characterized by carrying out frequency-dependent dielectric measurements. Chemical etching study was also carried out and the dislocation density was estimated. Results obtained in the present study indicate that the grown TUDLC crystal is optically transparent with lower cut-off wavelength 304 nm, mechanically soft, thermally stable up to 101 °C and NLO active with SHG efficiency 2.13 (in KDP unit). The grown crystal is found to have considerably large size, good crystalline perfection, large specific heat capacity, higher surface laser damage threshold and negative photoconductivity.

Preparation and Characterization of Cellulose Microcrystalline (MCC) from Fiber of Empty Fruit Bunch Palm Oil

NASA Astrophysics Data System (ADS)

Nasution, H.; Yurnaliza; Veronicha; Irmadani; Sitompul, S.

2017-03-01

Alpha cellulose which was isolated from cellulose of fiber empty fruit bunch palm oil was hidrolized with hydrochloric acid (2,5N) at 80°C to produce microcrystalline cellulose (MCC). Microcrystalline cellulose is an important additional ingredient in the pharmaceutical, food, cosmetics, and structural composites. In this study, MCC, alpha cellulose, and cellulose were characterized and thereafter were compared. Characterizations were made using some equipment such as x-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and thermogravimetry analyzer (TGA). X-ray diffraction and infrared spectroscopy were studied to determine crystallinity and molecular structure of MCC, where scanning electron microscopy images were conducted for information about morfology of MCC. Meanwhile, thermal resistance of MCC was determined using thermogravimetry analyzer (TGA). From XRD and FTIR, the obtained results showed that the crystalline part was traced on MCC, where the -OH and C-O groups tended to reduced as alpha cellulose has changed to MCC. From SEM the image showed the reduction of particle size of MCC, while the thermal resistance of MCC was found lower as compared with cellulose and alpha cellulose as well, which was attributed to the lower molecular weight of MCC.

X-ray powder diffraction, spectroscopic study, dielectric properties and thermal analysis of new doped compound TiGa0.67Te2.33O8

NASA Astrophysics Data System (ADS)

Smaoui, S.; Ben Aribia, W.; Kabadou, A.; Abdelmouleh, M.

2017-04-01

A novel mixed valence tellurium oxide, TiGa0.67Te2.33O8, was synthesized and its crystal structure determined using the X-ray powder diffraction technique. The obtained oxide was found to crystallize in a cubic unit-cell, Ia 3 bar space group, with the lattice parameter a = 10.9557(1) Å. Rietveld refinement of the structure led to ultimate confidence factors Rp = 7.63 and Rwp = 6.71. This structure was based on slabs containing groups of (Te/Ga)O4 joined by the metal cations Ti4+. The structure analysis showed a cation ordering of Te4+ and Te6+ yielding a TiGa2/3Te7/3O8 formula. The IR and RAMAN spectra confirmed the presence of the TiO6 and (Te/Ga)O4 groups. The dielectric anomalies observed at 500 K were attributed to the mixed valence structure, arising from the mixed-valence Te6+/Te4+. We detected only one peak in thermal behavior by the DTA/TG analysis; which implied a melting reaction.

Thermal equation of state of MgSiO4H2 phase H determined by in situ X-ray diffraction and a multianvil apparatus

NASA Astrophysics Data System (ADS)

Nishi, Masayuki; Tsuchiya, Jun; Arimoto, Takeshi; Kakizawa, Sho; Kunimoto, Takehiro; Tange, Yoshinori; Higo, Yuji; Irifune, Tetsuo

2018-06-01

Phase H (MgSiO4H2) is the high-pressure form of dense hydrous silicate that could deliver surface water into the lower mantle. In this study, we determined the thermal equations of the state of phase H using in situ X-ray diffraction measurements, under conditions ranging from 34 to 62 GPa and 300 and 1300 K, using a multianvil apparatus. Analysis of the data, based on the Mie-Grüneisen-Debye model using third-order Burch-Murnaghan equations at a reference pressure of 35 GPa, yielded the following results V ref = 49.61 ± 0.01 Å3, K ref = 344.6±4.1 GPa, K_{{{ref}}}^' } = 3.05 ± 0.32, θ ref = 974 ± 146 K, γ ref = 1.8 ± 0.1, and q = 1.79 ± 0.55. The compressibility of phase H observed in this study agrees well with that derived from theoretical calculations in pressure regions where hydrogen bond symmetrization is predicted. It was also found that the volume and compressibility of phase H and δ-AlOOH were similar.

Crystal structure and physicochemical characterization of ambazone monohydrate, anhydrous, and acetate salt solvate.

PubMed

Muresan-Pop, Marieta; Braga, Dario; Pop, Mihaela M; Borodi, Gheorghe; Kacso, Irina; Maini, Lucia

2014-11-01

The crystal structures of the monohydrate and anhydrous forms of ambazone were determined by single-crystal X-ray diffraction (SC-XRD). Ambazone monohydrate is characterized by an infinite three-dimensional network involving the water molecules, whereas anhydrous ambazone forms a two-dimensional network via hydrogen bonds. The reversible transformation between the monohydrate and anhydrous forms of ambazone was evidenced by thermal analysis, temperature-dependent X-ray powder diffraction and accelerated stability at elevated temperature, and relative humidity (RH). Additionally, a novel ambazone acetate salt solvate form was obtained and its nature was elucidated by SC-XRD. Powder dissolution measurements revealed a substantial solubility and dissolution rate improvement of acetate salt solvated form in water and physiological media compared with ambazone forms. Also, the acetate salt solvate displayed good thermal and solution stability but it transformed to the monohydrate on storage at elevated temperature and RH. Our study shows that despite the requirement for controlled storage conditions, the acetate salt solvated form could be an alternative to ambazone when solubility and bioavailability improvement is critical for the clinical efficacy of the drug product. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Investigation of the Thermal Stability of Nd(x)Sc(y)Zr(1-x-y)O(2-δ) Materials Proposed for Inert Matrix Fuel Applications.

PubMed

Hayes, John R; Grosvenor, Andrew P; Saoudi, Mouna

2016-02-01

Inert matrix fuels (IMF) consist of transuranic elements (i.e., Pu, Am, Np, Cm) embedded in a neutron transparent (inert) matrix and can be used to "burn up" (transmute) these elements in current or Generation IV nuclear reactors. Yttria-stabilized zirconia has been extensively studied for IMF applications, but the low thermal conductivity of this material limits its usefulness. Other elements can be used to stabilize the cubic zirconia structure, and the thermal conductivity of the fuel can be increased through the use of a lighter stabilizing element. To this end, a series of Nd(x)Sc(y)Zr(1-x-y)O(2-δ) materials has been synthesized via a co-precipitation reaction and characterized by multiple techniques (Nd was used as a surrogate for Am). The long-range and local structures of these materials were studied using powder X-ray diffraction, scanning electron microscopy, and X-ray absorption spectroscopy. Additionally, the stability of these materials over a range of temperatures has been studied by annealing the materials at 1100 and 1400 °C. It was shown that the Nd(x)Sc(y)Zr(1-x-y)O(2-δ) materials maintained a single cubic phase upon annealing at high temperatures only when both Nd and Sc were present with y ≥ 0.10 and x + y > 0.15.

Enhanced thermoelectric performance through grain boundary engineering in quaternary chalcogenide Cu2ZnSnSe4

NASA Astrophysics Data System (ADS)

Zhu, Yingcai; Liu, Yong; Tan, Xing; Ren, Guangkun; Yu, Meijuan; Hu, Tiandou; Marcelli, Augusto; Xu, Wei

2018-04-01

Quaternary chalcogenide Cu2ZnSnSe4 (CZTSe) is a promising wide band-gap p-type thermoelectric material. The structure and thermoelectric properties of lead substituted Cu2ZnSn1-xPbxSe4 are investigated. Lead primarily exists in the framework of PbSe as demonstrated by x-ray diffraction and calculation of x-ray absorption near-edge structure spectroscopy. The second phase distributes at the boundaries of CZTSe with thickness in several hundreds of nanometer. With appropriate grain boundary engineering, the enhancement of power factor and a decrease of thermal conductivity can be achieved simultaneously. As a result, a maximum figure of merit zT of 0.45 is obtained for the sample with x=0.02 at 723K.

Diffractive-refractive optics: (+,-,-,+) X-ray crystal monochromator with harmonics separation.

PubMed

Hrdý, Jaromír; Mikulík, Petr; Oberta, Peter

2011-03-01

A new kind of two channel-cut crystals X-ray monochromator in dispersive (+,-,-,+) position which spatially separates harmonics is proposed. The diffracting surfaces are oriented so that the diffraction is inclined. Owing to refraction the diffracted beam is sagittally deviated. The deviation depends on wavelength and is much higher for the first harmonics than for higher harmonics. This leads to spatial harmonics separation. The idea is supported by ray-tracing simulation.

Dye sensitized solar cell applications of CdTiO3-TiO2 composite thin films deposited from single molecular complex

NASA Astrophysics Data System (ADS)

Ehsan, Muhammad Ali; Khaledi, Hamid; Pandikumar, Alagarsamy; Huang, Nay Ming; Arifin, Zainudin; Mazhar, Muhammad

2015-10-01

A heterobimetallic complex [Cd2Ti4(μ-O)6(TFA)8(THF)6]·1.5THF (1) (TFA=trifluoroacetato, THF=tetrahydrofuran) comprising of Cd:Ti (1:2) ratio was synthesized by a chemical reaction of cadmium (II) acetate with titanium (IV) isopropoxide and triflouroacetic acid in THF. The stoichiometry of (1) was recognized by single crystal X-ray diffraction, spectroscopic and elemental analyses. Thermal studies revealed that (1) neatly decomposes at 450 °C to furnish 1:1 ratio of cadmium titanate:titania composite oxides material. The thin films of CdTiO3-TiO2 composite oxides were deposited at 550 °C on fluorine doped tin oxide coated conducting glass substrate in air ambient. The micro-structure, crystallinity, phase identification and chemical composition of microspherical architectured CdTiO3-TiO2 composite thin film have been determined by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analysis. The scope of composite thin film having band gap of 3.1 eV was explored as photoanode for dye-sensitized solar cell application.

Annealing of aromatic polyimide precursors

NASA Technical Reports Server (NTRS)

Wakelyn, N. T.

1975-01-01

A study has been made of the thermal behavior of polyimide precursors: an isomeric pair of crystals of the complex formed by p-phenylenediamine with the separated isomers of the di-isopropyl ester of pyromellitic acid. Specimens of this material were isothermally annealed in the temperature range 120 C to 170 C for periods of time up to 1 week. Although this temperature range is well below that customarily used for imidizations, the working hypothesis was that it would be more likely that a polymer embodying at least part of the precursor structure could be formed if the molecular motion was minimized to that actually required for the formation of the imide linkage. The progress of the annealing was followed by: infrared spectroscopy, differential thermal analysis, powder X-ray diffraction, and thermal gravimetric analysis. Single crystal X-ray analysis of the meta monomer yields a structure of chains of alternating acid and base and suggests that this monomer is amenable to polymerization with a minimum of geometrical disruption.

Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction

NASA Astrophysics Data System (ADS)

Knipe, Kevin; Manero, Albert; Siddiqui, Sanna F.; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Bartsch, Marion; Raghavan, Seetha

2014-07-01

The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

Acid-functionalized carbon nanofibers for high stability, thermoelectrical and electrochemical properties of nanofluids.

PubMed

Said, Zafar; Allagui, Anis; Abdelkareem, Mohammad Ali; Alawadhi, Hussain; Elsaid, Khaled

2018-06-15

Carbon-based nanofluids are viewed as promising thermal fluids for heat transfer applications. However, other properties, such as electrical conductivity and electrochemical behavior, are usually overlooked and rarely investigated despite their importance for the overall performance characterization of a given application. In this study, we synthesized PAN-based carbon nanofibers (CNF) by electrospinning, and characterized them using electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and thermogravimetric analysis. Thermoelectrical and electrochemical measurements were carried out on nanofluids. We found that, although CNF nanofluids exhibit good thermal and electrical properties with a negligible corrosive effect, the suspensions tend to sediment within a few days. However, acid treatment of CNF (F-CNF), which resulted in the shortening of the fibers and the appearance of surface-oxygenated species, made F-CNF-based nanofluids exhibit superior stability in water that extended for more than 90 days, with consistent and superior thermal and electrical properties. Copyright © 2018 Elsevier Inc. All rights reserved.

Influence of Thermal Annealing Treatment on Bipolar Switching Properties of Vanadium Oxide Thin-Film Resistance Random-Access Memory Devices

NASA Astrophysics Data System (ADS)

Chen, Kai-Huang; Cheng, Chien-Min; Kao, Ming-Cheng; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Wu, Sean; Su, Feng-Yi

2017-04-01

The bipolar switching properties and electrical conduction mechanism of vanadium oxide thin-film resistive random-access memory (RRAM) devices obtained using a rapid thermal annealing (RTA) process have been investigated in high-resistive status/low-resistive status (HRS/LRS) and are discussed herein. In addition, the resistance switching properties and quality improvement of the vanadium oxide thin-film RRAM devices were measured by x-ray diffraction (XRD) analysis, x-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and current-voltage ( I- V) measurements. The activation energy of the hopping conduction mechanism in the devices was investigated based on Arrhenius plots in HRS and LRS. The hopping conduction distance and activation energy barrier were obtained as 12 nm and 45 meV, respectively. The thermal annealing process is recognized as a candidate method for fabrication of thin-film RRAM devices, being compatible with integrated circuit technology for nonvolatile memory devices.

Design of Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle

NASA Technical Reports Server (NTRS)

Fuerstenau, D. W.; Ravikumar, R.

1997-01-01

In this report, thin film deposition of one of the model candidate materials for use as water repellent coating on the thermal protection systems (TPS) of an aerospace vehicle was investigated. The material tested was boron nitride (BN), the water-repellent properties of which was detailed in our other investigation. Two different methods, chemical vapor deposition (CVD) and pulsed laser deposition (PLD), were used to prepare the BN films on a fused quartz substrate (one of the components of thermal protection systems on aerospace vehicles). The deposited films were characterized by a variety of techniques including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The BN films were observed to be amorphous in nature, and a CVD-deposited film yielded a contact angle of 60 degrees with water, similar to the pellet BN samples investigated previously. This demonstrates that it is possible to use the bulk sample wetting properties as a guideline to determine the candidate waterproofing material for the TPS.

Applied Crystallography - Proceedings of the XVth Conference

NASA Astrophysics Data System (ADS)

Morawiec, H.; Ströż, D.

1993-06-01

The Table of Contents for the full book PDF is as follows: * Foreword * The International Centre for Diffraction Data and Its Future Developments * The Rietveld Method - A Historical Perspective * Real Structure in Quantitative Powder Diffraction Phase Analysis * Neutron Focusing Optics in Applied Crystallography * The Crystal Structures of Oxygen Deficient Rare Earth Oxides * Short-Range Order in Layer-Structured Ba1-xSrxBi2Nb2O9 Ferroelectrics * Radial Distribution Function as a Tool of Structural Studies on Noncrystalline Materials * Determination of Radial Distribution Function (RDF) of Electrodeposited Cu-Cd Alloys After Annealing * Spheres Packing as a Factor Describing the Local Environment and Structure Stability * X-Ray Stress Measurement of Samples Combined with Diffraction Line Analysis * Phase Stability and Martensitic Transformation in Cu-Zn and Cu-Zn-Al Single Crystals * Order, Defects, Precipitates and the Martensitic Transformation in β Cu-Zn-Al * Effect of γ Precipitates on the Martensitic Transformation in Cu-Zn-Al Alloys * Phase Transitions and Shape Memory Effect in a Thermomechanically Treated NiTi Alloy * Structure of Martensite and Bainite in CuAlMn Alloys * Glass-Ceramics * Mechanism of Texture Formation at the Rolling of Low Stacking Fault Energy Metals and Alloys * Shear Texture of Zinc and the Conditions of Its Occuring * The Development of Texture of ZnAlMg Sheets Depending on Deformation Geometry * Texture Stability of the D.S. NiAlMoCrTi Alloy After Heat Treatment * X-Ray Diffraction Method for Controlling of Texture Evolution in Layers * Texture and Lattice Imperfections Study of Some Low Alloyed Copper Alloys * Selected Examples of the Calculation of the Orientation Distribution Function for Low Crystal and Sample Symmetries * Automatical X-Ray Quantitative Phase Analysis * Application of a PC Computer for Crystallographic Calculations * Electron Diffraction Analysis using a Personal Computer * CA.R.INE Crystallography Version 2.1-1992 * PC-MINREF: The Computer Program Package for Neutron Refinement of Incommensurate Multiphase Crystal and Magnetic Structures on IBM PC Computers * Possibilities of Deflections from Stoichiometry Investigation for Phases of b1-b37 Structure by X-Ray Method * A Computer Program: “Measurement of Elastic Constants of Phases in Nontextured Polycrystalline Materials by X-Ray Method” * Crystallite Sizes and Lattice Strains of Hydrogenatid Tungsten Carbid Powder * The Bragg-Case Images of Dislocations at Different Absorption * Extended X-Ray Bremsstrahlung Isochromat of Molybdenum * Size Distribution Determination of Heterogeneity Regions in Electrodeposited Metals by Saxs Method * The Possibility of the Application of the CH2I2 - Paraffin Oil Mixture as a Masking Liquid for Metal/Carrier Systems in Saxs Investigations * Investigation on Mechanical Alloying and Amorphisation Processes by the Rietveld Method * Growth of β' Phase Single Crystals of Sn-Sb Alloy * Effect of Oxygen Agglomeration on Structure of Annealed Cz-Si Single Crystal * X-Ray Investigation of Non-Uniform Stress Fields * Problem of Polytype Structures Series for Martensitic Phases of Metals and Alloys * Structure of Strain-Induced Martensite in β-CuZnAl Alloy * The Effect of Heat Treatment on the Phase Transitions in NiTiCo Shape Memory Alloy * 9R → 18R Phase Transformation in Cu-13Zn-8Al Alloy * Effect of Austenite Thermal Instability on Characteristics of Martensitic Transformation in Fe-Ni Alloys * Vacuum Annealing Study of Thin Ti Layers on High Carbon Steel Substrates * Vacuum Annealing Study of Thin Ta Layers on High Carbon Steel Substrates * Investigation of Speed of Ionic Sputtering of NiTi Alloys in Sea 02 Auger Spectrometer * Effect of Precipitation Hardening on Thermal Stability of Austenite in Fe-Ni Alloys * Structure of 18Cr-25Ni-Nb L Steel After Two Years Operation in Catalytic Tubes * Influence of Magnetic Field on Mechanical Barkhausen Effect Stress Dependence in Steel * Precipitation Structure in High Strength Aluminium Alloys * Morphology of Laser Treated Al-Zn and Al-Fe Alloys * Structure of Rapidly Solidified AlFe and AlFeNi Ribbons After Continuous Heating * X-Ray Diffractometric Investigations of Anatase—Rutile Titanium Dioxide Forms Transformation in the Presence of Some Additives * Investigations on Phase Transformation of Coprecipitated Iron-Magnesium Hydroxides * Determination of the Crystallinity of Polymer Blends by X-Ray Diffraction Method * XPD Study of the Selected Magnesium Compounds with the Expected Pharmacological Activity * Supermolecular Structure of the Nylon 6.10 Crystallized from the Melt and Its Changes During Heating * The Analysis of Substructural Parameters of PZT-Type Ferroelectric Ceramics

Room Temperature Elastic Moduli and Vickers Hardness of Hot-Pressed LLZO Cubic Garnet

DTIC Science & Technology

2012-01-01

polishing compounds, Leco, St. Joseph, MI). X - ray diffraction and scanning electron microscopy (SEM) The microstructure of the hot-pressed specimens...was examined on uncoated fracture surfaces by SEM with an accelerating voltage of 1 and 3 kV. Phase purity was evaluated from X - ray diffraction data...the micro- structure appeared to be homogenous for the two hot- pressed LLZO specimens included in this study (Fig. 1). X - ray diffraction confirmed that

A facile thermal decomposition route to synthesise CoFe2O4 nanostructures

NASA Astrophysics Data System (ADS)

Kalpanadevi, K.; Sinduja, C. R.; Manimekalai, R.

2014-01-01

The synthesis of CoFe2O4 nanoparticles has been achieved by a simple thermal decomposition method from an inorganic precursor, cobalt ferrous cinnamate hydrazinate (CoFe2(cin)3(N2H4)3) which was obtained by a novel precipitation method from the corresponding metal salts, cinnamic acid and hydrazine hydrate. The precursor was characterized by hydrazine and metal analyses, infrared spectral analysis and thermo gravimetric analysis. Under appropriate annealing, CoFe2(cin)3(N2H4)3 yielded CoFe2O4 nanoparticles, which were characterized for their size and structure using X-Ray diffraction (XRD), high resolution transmission electron microscopic (HRTEM), selected area electron diffraction (SAED) and scanning electron microscopic (SEM) techniques.

Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

DOEpatents

Berman, Robert M.; Cohen, Isadore

1990-01-01

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

Effect of high intensity ultrasound on the mesostructure of hydrated zirconia

NASA Astrophysics Data System (ADS)

Kopitsa, G. P.; Baranchikov, A. E.; Ivanova, O. S.; Yapryntsev, A. D.; Grigoriev, S. V.; Pranzas, P. Klaus; Ivanov, V. K.

2012-02-01

We report structural changes in amorphous hydrated zirconia caused by high intensity ultrasonic treatment studied by means of small-angle neutron scattering (SANS) and X-ray diffraction (XRD). It was established that sonication affects the mesostructure of ZrO2×xH2O gels (i.e. decreases their homogeneity, increases surface fractal dimension and the size of monomer particles). Ultrasound induced structural changes in hydrated zirconia governs its thermal behaviour, namely decreases the rate of tetragonal to monoclinic zirconia phase transition.

Crystal structure and density of helium to 232 kbar

NASA Technical Reports Server (NTRS)

Mao, H. K.; Wu, Y.; Jephcoat, A. P.; Hemley, R. J.; Bell, P. M.; Bassett, W. A.

1988-01-01

The properties of helium and hydrogen at high pressure are topics of great interest to the understanding of planetary interiors. These materials constitute 95 percent of the entire solar system. A technique was presented for the measurement of X-ray diffraction from single-crystals of low-Z condenses gases in a diamond-anvil cell at high pressure. The first such single-crystal X-ray diffraction measurements on solid hydrogen to 26.5 GPa were presented. The application of this technique to the problem of the crystal structure, equation of state, and phase diagram of solid helium is reported. Crucial for X-ray diffraction studies of these materials is the use of a synchrotron radiation source which provides high brillance, narrow collimation of the incident and diffracted X-ray beams to reduce the background noise, and energy-dispersive diffraction techniques with polychromatic (white) radiation, which provides high detection efficiency.

Thermal expansion in the nickel-chromium-aluminum and cobalt-chromium-aluminum systems to 1200 degrees C

NASA Technical Reports Server (NTRS)

Lowell, C. E.; Garlick, R. G.; Henry, B.

1975-01-01

Thermal expansion data were obtained on 12 Ni-Cr-Al and 9 Co-Cr-Al alloys by high temperature X-ray diffraction. The data were computer fit to an empirical thermal expansion equation developed in the study. It is shown that the fit is excellent to good, and that the expansion constants depend on phase but not on composition. Phases for the Ni-Cr-Al system and Co-Cr-Al system are given. Results indicate that only alpha Cr has an expansion constant low enough to minimize oxide spalling or coating cracking induced by thermal expansion mismatch.

High temperature XRD of Cu2.1Zn0.9SnSe4

NASA Astrophysics Data System (ADS)

Chetty, Raju; Mallik, Ramesh Chandra

2014-04-01

Quaternary compound with chemical composition Cu2.1Zn0.9SnSe4 is prepared by solid state synthesis. High temperature XRD (X-Ray Diffraction) of this compound is used in studying the effect of temperature on lattice parameters and thermal expansion coefficients. Thermal expansion coefficient is one of the important quantities in evaluating the Grüneisen parameter which further useful in determining the lattice thermal conductivity of the material. The high temperature XRD of the material revealed that the lattice parameters as well as thermal expansion coefficients of the material increased with increase in temperature which confirms the presence of anharmonicty.

Effect of the microstructure on the thermoelectric properties of polycrystalline lanthanum chalcogenides

NASA Technical Reports Server (NTRS)

Lockwood, A.; Wood, C.; Vandersande, J.; Zoltan, A.; Parker, J.; Danielson, L.; Alexander, M.; Whittenberger, D.

1987-01-01

Small amounts of second phase materials can have important effects on the thermoelectric properties of polycrystalline gamma-La(3-x)X4 (X-S, Te; X in the range of 0 to 1/3). Microscopic examination by SEM of hot pressed La(3-x)Te4 samples has revealed from 1-5 vol. pct of La2O2Te, an amount which is not detected by X-ray powder diffraction measurements. This amount of La2O2Te resulting from oxygen contamination can reduce the concentration of electrons by as much as 10 to 75 percent below the electron concentration calculated for single phase La(3-x)Te4 in the composition range of greatest interest. Small amounts of second phase materials can also lower the lattice thermal conductivity by scattering low frequency phonons. These results indicate that microstructural effects should be considered when electrical and thermal properties of polycrystalline materials are analyzed.

X-Ray Diffraction Studies of 145 MeV proton-irradiated AlBeMet 162

DOE PAGES

Elbakhshwan, Mohamed; McDonald, Kirk T.; Ghose, Sanjit; ...

2016-08-03

AlBeMet 162 (Materion Co., formerly Brush Wellman) has been irradiated with 145 MeV protons up to 1.2x10 20 cm -2 fluence, with irradiation temperatures in the range of 100-220oC. Macroscopic postirradiation evaluation on the evolution of mechanical and thermal properties was integrated with a comprehensive X-ray- diffraction study using high-energy monochromatic and polychromatic X-ray beams, which offered a microscopic view of the irradiation damage effects on AlBeMet. The study confirmed the stability of the metal-matrix composite, its resistance to proton damage, and the continuing separation of the two distinct phases, fcc aluminum and hcp beryllium, following irradiation. Furthermore, based onmore » the absence of inter-planar distance change during proton irradiation, it was confirmed that the stacking faults and clusters on the Al (111) planes are stable, and thus can migrate from the cascade region and be absorbed at various sinks. XRD analysis of the unirradiated AlBeMet 162 showed clear change in the texture of the fcc phase with orientation especially in the Al (111) reflection which exhibits a “non-perfect” six-fold symmetry, implying lack of isotropy in the composite.« less

Structural investigation of porcine stomach mucin by X-ray fiber diffraction and homology modeling

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

Veluraja, K., E-mail: veluraja@msuniv.ac.in; Vennila, K.N.; Umamakeshvari, K.

Research highlights: {yields} Techniques to get oriented mucin fibre. {yields} X-ray fibre diffraction pattern for mucin. {yields} Molecular modeling of mucin based on X-ray fibre diffraction pattern. -- Abstract: The basic understanding of the three dimensional structure of mucin is essential to understand its physiological function. Technology has been developed to achieve orientated porcine stomach mucin molecules. X-ray fiber diffraction of partially orientated porcine stomach mucin molecules show d-spacing signals at 2.99, 4.06, 4.22, 4.7, 5.37 and 6.5 A. The high intense d-spacing signal at 4.22 A is attributed to the antiparallel {beta}-sheet structure identified in the fraction of themore » homology modeled mucin molecule (amino acid residues 800-980) using Nidogen-Laminin complex structure as a template. The X-ray fiber diffraction signal at 6.5 A reveals partial organization of oligosaccharides in porcine stomach mucin. This partial structure of mucin will be helpful in establishing a three dimensional structure for the whole mucin molecule.« less

Thermally stimulated nonlinear refraction in gelatin stabilized Cu-PVP nanocomposite thin films

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

Tamgadge, Y. S., E-mail: ystamgadge@gmail.com; Atkare, D. V.; Pahurkar, V. G.

2016-05-06

This article illustrates investigations on thermally stimulated third order nonlinear refraction of Cu-PVP nanocomposite thin films. Cu nanoparticles have been synthesized using chemical reduction method and thin films in PVP matrix have been obtained using spin coating technique. Thin films have been characterized by X-ray diffraction (XRD) and Ultraviolet-visible (UV-vis) spectroscopyfor structural and linear optical studies. Third order nonlinear refraction studies have been performed using closed aperture z-scan technique under continuous wave (CW) He-Ne laser. Cu-PVP nanocomposites are found to exhibit strong nonlinear refractive index stimulated by thermal lensing effect.

Thermal expansion of L-ascorbic acid

NASA Astrophysics Data System (ADS)

Nicolaï, B.; Barrio, M.; Tamarit, J.-Ll.; Céolin, R.; Rietveld, I. B.

2017-04-01

The specific volume of vitamin C has been investigated by X-ray powder diffraction as a function of temperature from 110 K up to complete degradation around 440 K. Its thermal expansion is relatively small in comparison with other organic compounds with an expansivity α v of 1.2(3) × 10-4 K-1. The structure consists of strongly bound molecules in the ac plane through a dense network of hydrogen bonds. The thermal expansion is anisotropic. Along the b axis, the expansion has most leeway and is about 10 times larger than in the other directions.

A nearly on-axis spectroscopic system for simultaneously measuring UV-visible absorption and X-ray diffraction in the SPring-8 structural genomics beamline.

PubMed

Sakaguchi, Miyuki; Kimura, Tetsunari; Nishida, Takuma; Tosha, Takehiko; Sugimoto, Hiroshi; Yamaguchi, Yoshihiro; Yanagisawa, Sachiko; Ueno, Go; Murakami, Hironori; Ago, Hideo; Yamamoto, Masaki; Ogura, Takashi; Shiro, Yoshitsugu; Kubo, Minoru

2016-01-01

UV-visible absorption spectroscopy is useful for probing the electronic and structural changes of protein active sites, and thus the on-line combination of X-ray diffraction and spectroscopic analysis is increasingly being applied. Herein, a novel absorption spectrometer was developed at SPring-8 BL26B2 with a nearly on-axis geometry between the X-ray and optical axes. A small prism mirror was placed near the X-ray beamstop to pass the light only 2° off the X-ray beam, enabling spectroscopic analysis of the X-ray-exposed volume of a crystal during X-ray diffraction data collection. The spectrometer was applied to NO reductase, a heme enzyme that catalyzes NO reduction to N2O. Radiation damage to the heme was monitored in real time during X-ray irradiation by evaluating the absorption spectral changes. Moreover, NO binding to the heme was probed via caged NO photolysis with UV light, demonstrating the extended capability of the spectrometer for intermediate analysis.

Investigating the Effects of Low Temperature Annealing of Amorphous Corrosion Resistant Alloys.

DTIC Science & Technology

1980-11-01

Ray Diffraction.................................................... 6 Differential Scanning Calorimetry....................................... 9...17 LIST OF FIGURES Figure 1. X- Ray Diffraction Results From Fe32Ni 36Cr 4P 2 B Annealed for One Hour at...Various Temperatures (Cr Ka Radiation) ................................. 7 Figure 2. X- Ray Diffraction Results From FeU2NiaeCr14SieB Annealed for One

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl(6) and other alloys are twinned cubic crystals.

PubMed

Pauling, L

1987-06-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl(6) and Mg(32)(Al,Zn)(49) and the neutron powder diffraction pattern of MnAl(6) are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 A (x-ray) and 23.416 A (neutron) for MnAl(6) and 24.313 A (x-ray) for Mg(32)(Al,Zn)(49).

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twinned cubic crystals

PubMed Central

Pauling, Linus

1987-01-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl6 and Mg32(Al,Zn)49 and the neutron powder diffraction pattern of MnAl6 are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 Å (x-ray) and 23.416 Å (neutron) for MnAl6 and 24.313 Å (x-ray) for Mg32(Al,Zn)49. PMID:16593841

High-energy X-ray diffraction using the Pixium 4700 flat-panel detector.

PubMed

Daniels, J E; Drakopoulos, M

2009-07-01

The Pixium 4700 detector represents a significant step forward in detector technology for high-energy X-ray diffraction. The detector design is based on digital flat-panel technology, combining an amorphous Si panel with a CsI scintillator. The detector has a useful pixel array of 1910 x 2480 pixels with a pixel size of 154 microm x 154 microm, and thus it covers an effective area of 294 mm x 379 mm. Designed for medical imaging, the detector has good efficiency at high X-ray energies. Furthermore, it is capable of acquiring sequences of images at 7.5 frames per second in full image mode, and up to 60 frames per second in binned region of interest modes. Here, the basic properties of this detector applied to high-energy X-ray diffraction are presented. Quantitative comparisons with a widespread high-energy detector, the MAR345 image plate scanner, are shown. Other properties of the Pixium 4700 detector, including a narrow point-spread function and distortion-free image, allows for the acquisition of high-quality diffraction data at high X-ray energies. In addition, high frame rates and shutterless operation open new experimental possibilities. Also provided are the necessary data for the correction of images collected using the Pixium 4700 for diffraction purposes.

Crystallization and preliminary X-ray diffraction analysis of a chitin-binding domain of hyperthermophilic chitinase from Pyrococcus furiosus

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

Nakamura, Tsutomu; Ishikawa, Kazuhiko; Hagihara, Yoshihisa

The expression, purification and preliminary X-ray diffraction studies of a chitin-binding domain of the chitinase from P. furiosus are reported. The crystallization and preliminary X-ray diffraction analysis of the chitin-binding domain of chitinase from a hyperthermophilic archaeon, Pyrococcus furiosus, are reported. The recombinant protein was prepared using an Escherichia coli overexpression system and was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected to 1.70 Å resolution. The crystal belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2. The unit-cell parameters were determined to be a = b = 48.8, c = 85.0 Å.

Long-Wavelength X-Ray Diffraction and Its Applications in Macromolecular Crystallography.

PubMed

Weiss, Manfred S

2017-01-01

For many years, diffraction experiments in macromolecular crystallography at X-ray wavelengths longer than that of Cu-K α (1.54 Å) have been largely underappreciated. Effects caused by increased X-ray absorption result in the fact that these experiments are more difficult than the standard diffraction experiments at short wavelengths. However, due to the also increased anomalous scattering of many biologically relevant atoms, important additional structural information can be obtained. This information, in turn, can be used for phase determination, for substructure identification, in molecular replacement approaches, as well as in structure refinement. This chapter reviews the possibilities and the difficulties associated with such experiments, and it provides a short description of two macromolecular crystallography synchrotron beam lines dedicated to long-wavelength X-ray diffraction experiments.

Micro/nanostructured surface modification using femtosecond laser pulses on minimally invasive electrosurgical devices.

PubMed

Lin, Chia-Cheng; Lin, Hao-Jan; Lin, Yun-Ho; Sugiatno, Erwan; Ruslin, Muhammad; Su, Chen-Yao; Ou, Keng-Liang; Cheng, Han-Yi

2017-05-01

The purpose of the present study was to examine thermal damage and a sticking problem in the tissue after the use of a minimally invasive electrosurgical device with a nanostructured surface treatment that uses a femtosecond laser pulse (FLP) technique. To safely use an electrosurgical device in clinical surgery, it is important to decrease thermal damage to surrounding tissues. The surface characteristics and morphology of the FLP layer were evaluated using optical microscopy, scanning electron microscopy, and transmission electron microscopy; element analysis was performed using energy-dispersive X-ray spectroscopy, grazing incidence X-ray diffraction, and X-ray photoelectron spectroscopy. In the animal model, monopolar electrosurgical devices were used to create lesions in the legs of 30 adult rats. Animals were sacrificed for investigations at 0, 3, 7, 14, and 28 days postoperatively. Results indicated that the thermal damage and sticking situations were reduced significantly when a minimally invasive electrosurgical instrument with an FLP layer was used. Temperatures decreased while film thickness increased. Thermographic data revealed that surgical temperatures in an animal model were significantly lower in the FLP electrosurgical device compared with that in the untreated one. Furthermore, the FLP device created a relatively small area of thermal damage. As already mentioned, the biomedical nanostructured layer reduced thermal damage and promoted the antisticking property with the use of a minimally invasive electrosurgical device. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 865-873, 2017. © 2016 Wiley Periodicals, Inc.

Titanium doped LSCM anode for hydrocarbon fuelled SOFCs

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

Azad, Abul K.; Hakem, Afizul; Petra, Pg. M. Iskandar

2015-05-15

La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5-x}Mn{sub 0.5}Ti{sub x}O{sub 3} (x = 0.1, 0.2) has been synthesized in solid state reaction method and tested as a potential anode material for solid oxide fuel cells. Rietveld refinement of X-ray powder diffraction data using Fullprof software shows that the materials crystallize in the rhombohedral symmetry in the R-3C space group. The cell parameters are: a = b = 5.5286 (4) Å, c = 13.408(1) Å, α = β = 90°, γ = 120°. Particle size distribution measurements show that the average particle size for x = 0.1 and 0.2 was 232.66 nm and 176.63 nm, respectively. Themore » potential on particles were found to be −22.86 mV and −27.73 mV, for x = 0.1 and x = 0.2, respectively. Thermal expansion measurement using thermo-mechanical analyzer shows that the thermal expansion coefficient is 13.96 × 10{sup −6}/°C which is close to the thermal expansion of the state-of–the art YSZ electrolyte. Microstructure has been observed from scanning electron microscopy which shows a porous structure. Energy dispersive X-ray shows that the percentage of the different cations and anions in the structure are close to the chemical occupancies.« less

Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA.

PubMed

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-05-01

Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the `diffraction before destruction' scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles.

Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA

PubMed Central

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-01-01

Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the ‘diffraction before destruction’ scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles. PMID:24763651

Effects of copper on the preparation and characterization of Na-Ca-P borate glasses.

PubMed

Shailajha, S; Geetha, K; Vasantharani, P; Sheik Abdul Kadhar, S P

2015-03-05

Glasses in the system Na2O-CaO-B2O3-P2O5: CuO have been prepared by melt quenching at 1200°C and rapidly cooling at room temperature. The structural, optical and thermal properties have been investigated using X-ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform infrared (FTIR) spectroscopy, high resolution scanning electron microscopy (HRSEM) with energy dispersive X-ray (EDX) spectroscopy and high resolution transmission electron microscope (HRTEM) with energy dispersive X-ray (EDAX). The amorphous and crystalline nature of these samples was verified by XRD. Glass transition, crystallization and thermal stability were determined by TG-DTA investigations. Direct optical energy band gaps before and after doping with different percents of copper oxide were evaluated from 4.81eV to 2.99eV indicated the role of copper in the glassy matrix by UV spectra. FTIR spectrum reveals characteristic absorption bands due to various groups of triangular and tetrahedral borate network. Due to the amorphous nature, the particles like agglomerates on the glass surface were investigated by the HRSEM analysis. The crystalline nature of the samples in XRD is confirmed by SAED pattern using HRTEM. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

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

Not Available

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimentalmore » fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.« less

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

NASA Astrophysics Data System (ADS)

Parrot, I. M.; Urban, V.; Gardner, K. H.; Forsyth, V. T.

2005-08-01

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar® or Twaron®.

Conceptual Design for Time-Resolved X-ray Diffraction in a Single Laser-Driven Compression Experiment

NASA Astrophysics Data System (ADS)

Benedetti, Laura Robin; Eggert, J. H.; Kilkenny, J. D.; Bradley, D. K.; Bell, P. M.; Palmer, N. E.; Rygg, J. R.; Boehly, T. R.; Collins, G. W.; Sorce, C.

2017-06-01

Since X-ray diffraction is the most definitive method for identifying crystalline phases of a material, it is an important technique for probing high-energy-density materials during laser-driven compression experiments. We are developing a design for collecting several x-ray diffraction datasets during a single laser-driven experiment, with a goal of achieving temporal resolution better than 1ns. The design combines x-ray streak cameras, for a continuous temporal record of diffraction, with fast x-ray imagers, to collect several diffraction patterns with sufficient solid angle range and resolution to identify crystalline texture. Preliminary experiments will be conducted at the Omega laser and then implemented at the National Ignition Facility. We will describe the status of the conceptual design, highlighting tradeoffs in the design process. We will also discuss the technical issues that must be addressed in order to develop a successful experimental platform. These include: Facility-specific geometric constraints such as unconverted laser light and target alignment; EMP issues when electronic diagnostics are close to the target; X-ray source requirements; and detector capabilities. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, LLNL-ABS-725146.

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite.

PubMed

Yao, Guangyuan; Lei, Jingjing; Zhang, Xiaoyu; Sun, Zhiming; Zheng, Shuilin

2018-05-28

Zeolite X powder was synthesized using natural low-grade diatomite as the main source of Si but only as a partial source of Al via a simple and green hydrothermal method. The microstructure and surface properties of the obtained samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), wavelength dispersive X-ray fluorescence (XRF), calcium ion exchange capacity (CEC), thermogravimetric-differential thermal (TG-DTA) analysis, and N₂ adsorption-desorption technique. The influence of various synthesis factors, including aging time and temperature, crystallization time and temperature, Na₂O/SiO₂ and H₂O/Na₂O ratio on the CEC of zeolite, were systematically investigated. The as-synthesized zeolite X with binary meso-microporous structure possessed remarkable thermal stability, high calcium ion exchange capacity of 248 mg/g and large surface area of 453 m²/g. In addition, the calcium ion exchange capacity of zeolite X was found to be mainly determined by the crystallization degree. In conclusion, the synthesized zeolite X using diatomite as a cost-effective raw material in this study has great potential for industrial application such as catalyst support and adsorbent.

IDATEN and G-SITENNO: GUI-assisted software for coherent X-ray diffraction imaging experiments and data analyses at SACLA.

PubMed

Sekiguchi, Yuki; Yamamoto, Masaki; Oroguchi, Tomotaka; Takayama, Yuki; Suzuki, Shigeyuki; Nakasako, Masayoshi

2014-11-01

Using our custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors, cryogenic coherent X-ray diffraction imaging experiments have been undertaken at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility. To efficiently perform experiments and data processing, two software suites with user-friendly graphical user interfaces have been developed. The first is a program suite named IDATEN, which was developed to easily conduct four procedures during experiments: aligning KOTOBUKI-1, loading a flash-cooled sample into the cryogenic goniometer stage inside the vacuum chamber of KOTOBUKI-1, adjusting the sample position with respect to the X-ray beam using a pair of telescopes, and collecting diffraction data by raster scanning the sample with X-ray pulses. Named G-SITENNO, the other suite is an automated version of the original SITENNO suite, which was designed for processing diffraction data. These user-friendly software suites are now indispensable for collecting a large number of diffraction patterns and for processing the diffraction patterns immediately after collecting data within a limited beam time.

Dynamical diffraction imaging (topography) with X-ray synchrotron radiation

NASA Technical Reports Server (NTRS)

Kuriyama, M.; Steiner, B. W.; Dobbyn, R. C.

1989-01-01

By contrast to electron microscopy, which yields information on the location of features in small regions of materials, X-ray diffraction imaging can portray minute deviations from perfect crystalline order over larger areas. Synchrotron radiation-based X-ray optics technology uses a highly parallel incident beam to eliminate ambiguities in the interpretation of image details; scattering phenomena previously unobserved are now readily detected. Synchrotron diffraction imaging renders high-resolution, real-time, in situ observations of materials under pertinent environmental conditions possible.

Development of Thin Films as Potential Structural Cathodes to Enable Multifunctional Energy-Storage Structural Composite Batteries for the U.S. Army’s Future Force

DTIC Science & Technology

2011-09-01

glancing angle X - ray diffraction (GAXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and electrochemical...Emission SEM FWHM full width at half maximum GAXRD glancing angle X - ray diffraction H3COCH2CH2OH 2-methoxyethanol LiMn2O4 lithium manganese oxide...were characterized by scanning electron microscopy (SEM), X - ray diffraction (XRD), and atomic force microscopy (AFM). In addition,

Diffuse x-ray scattering and transmission electron microscopy study of defects in antimony-implanted silicon

NASA Astrophysics Data System (ADS)

Takamura, Y.; Marshall, A. F.; Mehta, A.; Arthur, J.; Griffin, P. B.; Plummer, J. D.; Patel, J. R.

2004-04-01

Ion implantation followed by laser annealing has been used to create supersaturated and electrically active concentrations of antimony in silicon. Upon subsequent thermal annealing, however, these metastable dopants deactivate towards the equilibrium solubility limit. In this work, the formation of inactive antimony structures has been studied with grazing incidence diffuse x-ray scattering, and transmission electron microscopy, and the results are correlated to previous high-resolution x-ray diffraction data. We find that at a concentration of 6.0×1020 cm-3, small, incoherent clusters of radius 3-4 Å form during annealing at 900 °C. At a higher concentration of 2.2×1021 cm-3, deactivation at 600 °C occurs through the formation of small, antimony aggregates and antimony precipitates. The size of these precipitates from diffuse x-ray scattering is roughly 15 Å in radius for anneal times from 15 to 180 seconds. This value is consistent with the features observed in high-resolution and mass contrast transmission electron microscopy images. The coherent nature of the aggregates and precipitates causes the expansion of the surrounding silicon matrix as the deactivation progresses. In addition, the sensitivity of the diffuse x-ray scattering technique has allowed us to detect the presence of small clusters of radius ˜2 Å in unprocessed Czochralski silicon wafers. These defects are not observed in floating zone silicon wafers, and are tentatively attributed to thermal donors.

Effect of basalt fibres reinforcement and aluminum trihydrate on the thermal properties of intumescent fire retardant coatings

NASA Astrophysics Data System (ADS)

Yasir, Muhammad; Amir, Norlaili Binti; Ahmad, Faiz; Syahirah Rodzhan, N.

2017-08-01

This research is carried out in order to study the synergistic effect of aluminium trihydrate and basalt fibres on the properties of fire resistant intumescent coatings. Intumescent fire retardant coatings were developed using different flame retardants such as ammonium polyphosphate, expandable graphite, melamine and boric acid. These flame retardants were bound together with the help of epoxy binder along with curing agent. Furthermore, individual and combinations of aluminium trihydrate and basalt fibres was incorporated in the formulations to analyse mechanical and chemical properties of the coatings. Char expansion was observed using furnace test, thermogravimetric analysis was used to determine residual weight, X-Ray Diffraction was performed to investigate compounds present in the char, shear test was conducted to determine char strength and scanning electron microscopy analysis was performed to observe morphology of the burnt char. From the microscopic investigation it was concluded that the dense structure of the char increased the char integrity by adding basalt and aluminium trihydrate as fillers. X-Ray Diffraction results shows the presence boron phosphate, and boric acid which enhanced the thermal performance of the coating up to 800°C. From the Thermogravimetric analysis it was concluded that the residual weight of the char was increased up to 34.9 % for IC-B2A4 which enhanced thermal performance of intumescent coating.

Growth, spectral, thermal, dielectric, mechanical, linear and nonlinear optical, birefringence, laser damage threshold studies of semi-organic crystal: dibrucinium sulfate heptahydrate.

PubMed

Krishnan, P; Gayathri, K; Bhagavannarayana, G; Jayaramakrishnan, V; Gunasekaran, S; Anbalagan, G

2013-08-01

Dibrucinium sulfate heptahydrate (DBSH), a semi-organic nonlinear optical material, has been synthesized and single crystals were grown from water-ethanol solution at room temperature up to dimensions of 10×7×2 mm(3). The unit cell parameters were determined from single crystal and powder X-ray diffraction studies. The structural perfection of the grown crystal has been analyzed by high-resolution X-ray diffraction (HRXRD) study. FTIR and Raman studies were performed to identify the functional groups present in the title compound. The activation energy (E), entropy (ΔS), enthalpy (ΔH) and Gibbs free energy (ΔG), of the thermal decomposition reaction have been derived from thermo gravimetric (TGA) and differential thermal (DTA) analysis curves, using Coats-Redfern method. The variation of dielectric properties of the grown crystal with respect to frequency has been investigated at different temperatures. Microhardness measurements revealed the mechanical strength of grown crystal. The optical parameters, the optical band gap E(g) and width of localized states Eu were determined using the transmittance data in the spectral range 200-800 nm. The relative second harmonic efficiency of the compound is found to be 1.4 times greater than that of KDP. Birefringence and Laser damage threshold studies were carried out for the grown crystal. Copyright © 2013 Elsevier B.V. All rights reserved.

Thermal expansion of coesite determined by synchrotron powder X-ray diffraction

NASA Astrophysics Data System (ADS)

Kulik, Eleonora; Murzin, Vadim; Kawaguchi, Shogo; Nishiyama, Norimasa; Katsura, Tomoo

2018-05-01

Thermal expansion of synthetic coesite was studied with synchrotron powder X-ray diffraction in the temperature range of 100-1000 K. We determined the unit cell parameters of monoclinic coesite (a, b, c, and β) every 50 K in this temperature range. We observed that a and b parameters increase with increasing temperature, while c decreases. The β angle also decreases with temperature and approaches 120°. As a result, the unit cell volume expands by only 0.7% in this temperature range. Our measurements provide thermal expansion coefficients of coesite as a function of temperature: it increases from 3.4 × 10-6 K-1 at 100 K to 9.3 × 10-6 K-1 at 600 K and remains nearly constant above this temperature. The Suzuki model based on the zero-pressure Mie-Grüneisen equation of state was implemented to fit the unit cell volume data. The refined parameters are {V_0} = 546.30(2) Å3, Q = 7.20(12) × 106 J/mol and {θ D} = 1018(43) K, where {θ D} is the Debye temperature and {V_0} is the unit cell volume at 0 K with an assumption that {K^' } is equal to 1.8. The obtained Debye temperature is consistent with that determined in a previous study for heat capacity measurements.

Simultaneous X-ray fluorescence and scanning X-ray diffraction microscopy at the Australian Synchrotron XFM beamline

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

Jones, Michael W. M.; Phillips, Nicholas W.; van Riessen, Grant A.

2016-08-11

Owing to its extreme sensitivity, quantitative mapping of elemental distributionsviaX-ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X-ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super-resolved ultra-structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step- and fly-scanning modes, robust, simultaneous XFM-SXDM is demonstrated.

Mössbauer study of Cu1-xZnxFe2O4 catalytic materials

NASA Astrophysics Data System (ADS)

Koleva, K.; Velinov, N.; Tsoncheva, T.; Mitov, I.

2014-04-01

Copper zinc ferrites (Cu1-xZnxFe2O4) with different composition (x = 1; 0.2; 0.5; 0.8) were prepared by conventional thermal method. Formation of well crystallized ferrite phase with cubic structure and crystallites size of about 19.08-24.39 nm was observed by Powder X-ray diffraction and Mössbauer spectroscopy. The ferrite materials were tested as catalysts in methanol decomposition to CO and H2. A strong dependence of the catalytic behaviour of Cu1-xZnxFe2O4 ferrites of their composition and the phase transformations which occurred under the reaction medium was established.

An Excel Spreadsheet for a One-Dimensional Fourier Map in X-ray Crystallography

ERIC Educational Resources Information Center

Clegg, William

2004-01-01

The teaching of crystal structure determination with single-crystal X-ray diffraction at undergraduate level faces numerous challenges. Single-crystal X-ray diffraction is used in a vast range of chemical research projects and forms the basis for a high proportion of structural results that are presented to high-school, undergraduate, and graduate…

Laser-induced Multi-energy Processing in Diamond Growth

DTIC Science & Technology

2012-05-01

microscopy (SEM) and energy dispersive X - ray (EDX) measurements, Drs. Yi Liu and Shah Valloppilly from Nebraska Center for Materials and Nanoscience...NCMN) at UNL for help on X - Ray diffraction (XRD) measurements, and Professor Steve W. Martin and Dr. Young Sik Kim from the Department of Material...spectroscopy and X - ray diffraction ................... 62 4.4 Conclusions

Effects of interfaces on the thermal conductivity in Si/Si0.75Ge0.25 multilayer with varying Au layers

NASA Astrophysics Data System (ADS)

Hu, Yangsen; Wu, Zhenghua; Ye, Fengjie; Hu, Zhiyu

2018-02-01

The manoeuvre of thermal transport property across multilayer films with inserted metal layers through controlling the metal-nonmetal interfaces is of fundamental interest. In this work, amorphous Si/Si0.75Ge0.25 multilayer films inserted with varying Au layers were fabricated by magnetron sputtering. The structure and sharp interface of multilayers films were characterized by low angle x-ray diffraction (LAXRD), grazing incidence small angle x-ray scattering (GISAXS) and scanning electron microscopy (SEM). A differential 3ω method was applied to measure the effective thermal conductivity. The measurements show that thermal conductivity has changed as varying Au layers. Thermal conductivity increased from 0.94 to 1.31 Wm-1K-1 while Si0.75Ge0.25 layer was replaced by different Au layers, which was attributed to the strong electron-phonon coupling and interface thermal resistance in a metal-nonmetal multilayered system. Theoretical calculation combined with experimental results indicate that the thermal conductivity of the multilayer film could be facilely controlled by introducing different number of nanoconstructed metal-nonmetal interfaces, which provide a more insightful understanding of the thermal transport manipulation mechanism of the thin film system with inserting metal layers.

A novel cetyltrimethyl ammonium silver bromide complex and silver bromide nanoparticles obtained by the surfactant counterion.

PubMed

Liu, Xian-Hao; Luo, Xiao-Hong; Lu, Shu-Xia; Zhang, Jing-Chang; Cao, Wei-Liang

2007-03-01

A novel cetyltrimethyl ammonium silver bromide (CTASB) complex has been prepared simply through the reaction of silver nitrate with cetyltrimethyl ammonium bromide (CTAB) in aqueous solution at room temperature by controlling the concentration of CTAB and the molar ratio of CTAB to silver nitrate in the reaction solution, in which halogen in CTAB is used as surfactant counterion. The structure and thermal behavior of cetyltrimethyl ammonium silver bromide have been investigated by using X-ray diffraction (XRD), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), UV/vis spectroscopy, thermal analysis (TG-DTA), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that the complex possesses a metastable layered structure. Upon heating the CTASB aqueous dispersion to above 80 degrees C, the structure change of the complex took place and CTAB-capped nanosized silver bromide particles further formed.

Synthesis and characterization of nanocrystalline Co-Fe-Nb-Ta-B alloy

NASA Astrophysics Data System (ADS)

Raanaei, Hossein; Fakhraee, Morteza

2017-09-01

In this research work, structural and magnetic evolution of Co57Fe13Nb8Ta4B18 alloy, during mechanical alloying process, have been investigated by using, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electron dispersive X-ray spectroscopy, differential thermal analysis and also vibrating sample magnetometer. It is observed that at 120 milling time, the crystallite size reaches to about 7.8 nm. Structural analyses show that, the solid solution of the initial powder mixture occurs at160 h milling time. The coercivity behavior demonstrates a rise, up to 70 h followed by decreasing tendency up to final stage of milling process. Thermal analysis of 160 h milling time sample reveals two endothermic peaks. The characterization of annealed milled sample for 160 h milling time at 427 °C shows crystallite size growth accompanied by increasing in saturation magnetization.

Development of improved amorphous materials for laser systems

NASA Technical Reports Server (NTRS)

Neilson, G. F.; Weinberg, M. C.

1974-01-01

Crystallization calculations were performed in order to determine the possibility of forming a particular type of laser glass with the avoidance of devitrification in an outer space laboratory. It was demonstrated that under the homogenuous nucleating conditions obtainable in a zero gravity laboratory this laser glass may be easily quenched to a virtually crystal-free product. Experimental evidence is provided that use of this material as a host in a neodymium glass laser would result in more than a 10 percent increase in efficiency when compared to laser glass rods of a similar composition currently commercially available. Differential thermal analysis, thermal gradient oven, X-ray diffraction, and liquidus determination experiments were carried out to determine the basics of the crystallization behavior of the glass, and small-angle X-ray scattering and splat-cooling experiments were performed in order to provide additional evidence for the feasibility of producing this laser glass material, crystal free, in an outer space environment.

Influence of reaction time and synthesis temperature on the physical properties of ZnO nanoparticles synthesized by the hydrothermal method

NASA Astrophysics Data System (ADS)

Wasly, H. S.; El-Sadek, M. S. Abd; Henini, Mohamed

2018-01-01

Influence of synthesis temperature and reaction time on the structural and optical properties of ZnO nanoparticles synthesized by the hydrothermal method was investigated using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray, Fourier transform infra-red spectroscopy, and UV-visible and fluorescence spectroscopy. The XRD pattern and HR-TEM images confirmed the presence of crystalline hexagonal wurtzite ZnO nanoparticles with average crystallite size in the range 30-40 nm. Their energy gap determined by fluorescence was found to depend on the synthesis temperature and reaction time with values in the range 2.90-3.78 eV. Thermal analysis, thermogravimetric and the differential scanning calorimetry were used to study the thermal reactions and weight loss with heat of the prepared ZnO nanoparticles.

Phytosynthesis and applications of bioactive SnO{sub 2} nanoparticles

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

Vidhu, V.K.; Philip, Daizy, E-mail: philipdaizy@yahoo.co.in

2015-03-15

A facile, eco-friendly, cost effective and versatile synthesis of SnO{sub 2} nanoparticles of size in the range 2.2–3.2 nm using fenugreek seeds is reported. The structural and morphological properties of SnO{sub 2} nanoparticles have been studied using X-ray diffraction, Transmission Electron Microscopy and Energy Dispersive X-ray spectroscopy. UV–visible spectra show a blue shift of the absorption band arising from quantum size effect. Studies on thermal conductivity, viscosity, antibacterial and antioxidant properties of the synthesized SnO{sub 2} nanoparticles highlight the possible applications in nanofluids and biomedical field. - Graphical abstract: Display Omitted - Highlights: • Bioactive SnO{sub 2} nanoparticles are synthesizedmore » using Fenugreek seeds. • Structural, morphological and optical characterizations have been done. • Thermal conductivity and rheological properties are reported. • Antioxidant and antibacterial activities are highlighted.« less

Study of the normal emissivity of molybdenum during thermal oxidation process

NASA Astrophysics Data System (ADS)

Xu, Yihan; Li, Longfei; Yu, Kun; Liu, Yufang

2018-04-01

The infrared normal spectral emissivity of the oxidized molybdenum was measured during thermal oxidation process, and the integral emissivity was calculated from the data of spectral emissivity. It is found that the surface oxidation has a remarkable effect on the spectral emissivity of molybdenum, and the spectral emissivity curves become more fluctuant with the increase in oxidation time. The integral emissivity grows exponentially with the oxidation time at 773 K, remains almost constant at 823 K, and fluctuates at 873 and 923 K. The X-ray fluorescence spectrometer, the X-ray diffraction, and the scanning electron microscopy were employed to analyze the changes in surface composition and surface morphology. The results show that the most probable reason for the variation of integral emissivity is the change in surface roughness caused by the variation in the size and shape of oxide particle on specimen surface.

Pt deposited TiO2 catalyst fabricated by thermal decomposition of titanium complex for solar hydrogen production

NASA Astrophysics Data System (ADS)

Truong, Quang Duc; Le, Thanh Son; Ling, Yong-Chien

2014-12-01

C, N codoped TiO2 catalyst has been synthesized by thermal decomposition of a novel water-soluble titanium complex. The structure, morphology, and optical properties of the synthesized TiO2 catalyst were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of the Pt deposited TiO2 catalysts synthesized at different temperatures was evaluated by means of hydrogen evolution reaction under both UV-vis and visible light irradiation. The investigation results reveal that the photocatalytic H2 evolution rate strongly depended on the crystalline grain size as well as specific surface area of the synthesized catalyst. Our studies successfully demonstrate a simple method for the synthesis of visible-light responsive Pt deposited TiO2 catalyst for solar hydrogen production.

Two-dimensional time-resolved X-ray diffraction study of liquid/solid fraction and solid particle size in Fe-C binary system with an electrostatic levitator furnace

NASA Astrophysics Data System (ADS)

Yonemura, M.; Okada, J.; Watanabe, Y.; Ishikawa, T.; Nanao, S.; Shobu, T.; Toyokawa, H.

2013-03-01

Liquid state provides functions such as matter transport or a reaction field and plays an important role in manufacturing processes such as refining, forging or welding. However, experimental procedures are significantly difficult for an observation of solidification process of iron and iron-based alloys in order to identify rapid transformations subjected to fast temperature evolution. Therefore, in order to study the solidification in iron and iron-based alloys, we considered a combination of high energy X-ray diffraction measurements and an electrostatic levitation method (ESL). In order to analyze the liquid/solid fraction, the solidification of melted spherical specimens was measured at a time resolution of 0.1 seconds during rapid cooling using the two-dimensional time-resolved X-ray diffraction. Furthermore, the observation of particle sizes and phase identification was performed on a trial basis using X-ray small angle scattering with X-ray diffraction.

Imaging single cells in a beam of live cyanobacteria with an X-ray laser.

PubMed

van der Schot, Gijs; Svenda, Martin; Maia, Filipe R N C; Hantke, Max; DePonte, Daniel P; Seibert, M Marvin; Aquila, Andrew; Schulz, Joachim; Kirian, Richard; Liang, Mengning; Stellato, Francesco; Iwan, Bianca; Andreasson, Jakob; Timneanu, Nicusor; Westphal, Daniel; Almeida, F Nunes; Odic, Dusko; Hasse, Dirk; Carlsson, Gunilla H; Larsson, Daniel S D; Barty, Anton; Martin, Andrew V; Schorb, Sebastian; Bostedt, Christoph; Bozek, John D; Rolles, Daniel; Rudenko, Artem; Epp, Sascha; Foucar, Lutz; Rudek, Benedikt; Hartmann, Robert; Kimmel, Nils; Holl, Peter; Englert, Lars; Duane Loh, Ne-Te; Chapman, Henry N; Andersson, Inger; Hajdu, Janos; Ekeberg, Tomas

2015-02-11

There exists a conspicuous gap of knowledge about the organization of life at mesoscopic levels. Ultra-fast coherent diffractive imaging with X-ray free-electron lasers can probe structures at the relevant length scales and may reach sub-nanometer resolution on micron-sized living cells. Here we show that we can introduce a beam of aerosolised cyanobacteria into the focus of the Linac Coherent Light Source and record diffraction patterns from individual living cells at very low noise levels and at high hit ratios. We obtain two-dimensional projection images directly from the diffraction patterns, and present the results as synthetic X-ray Nomarski images calculated from the complex-valued reconstructions. We further demonstrate that it is possible to record diffraction data to nanometer resolution on live cells with X-ray lasers. Extension to sub-nanometer resolution is within reach, although improvements in pulse parameters and X-ray area detectors will be necessary to unlock this potential.

Morphological, structural and thermal studies of gallium nitride ferrite

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

Indrakanti, Rajani; Rao, V. Brahmaji; Kiran, C. Udaya

2016-05-06

We report the synthesis and Characterization of III-V doped Nano ferrite Ga{sub (2x+2)}N Fe{sub 2(49-x)}O{sub 3} for x=1 and x=5 by Sol-Gel method. The Morphological, structural and Thermal characterisation studies are done by using Transmission Electron Microscopy, Energy Dispersive X-ray Analysis, Selected Area Electron Diffraction, Thermo-Gravimetric Analysis and Differential Thermal Analysis. Using the Sci-Finder software we could not trace any reports related to GaNFe{sub 2}O{sub 3} in the literature. It has been observed from our studies that the particles are in the Cylindrical and the Globular structure. The particle diameter values from the Histograms are in good agreement with themore » XRD values that were communicated by us earlier. The SAED and the EDAX studies reveal the confirmation of the composition and also that the synthesized Ferrite exhibits crystalline nature. The TG-DTA results show that the compound indicates constant sample weight.« less

Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

NASA Astrophysics Data System (ADS)

Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to present which type of physical information can be obtained from the positions of the Bragg peaks, their intensity and their shape, as well as from the diffuse scattering beyond Bragg peaks. An important physical feature is to take into consideration the difference in nature between a photoinduced phase transition and conventional homogeneous photoinduced chemical or biochemical processes where molecules transform in an independent way each other. Actually the photoinduced phase transition with the establishment of the new electronic and structural oscopic order is preceded by precursor co-operative phenomena due to the formation of nano-scale correlated objects. These are the counterpart of pre-transitional fluctuations at thermal equilibrium which take place above the transition temperature (short range order preceding long range one). Moreover ultra-fast X-ray scattering will play a central role within the fascinating field of manipulating coherence, for instance to directly observe coherent atomic motions induced by a light pulse, such as optical phonons. In the first part of this contribution we present what experimental features are accessible by X-ray scattering to describe the physical picture for a photoinduced structural phase transition. The second part shows how a time-resolved X-ray scattering experiment can be performed with regards to the different pulsed X-ray sources. The first time-resolved X-ray diffraction experiments on photoinduced phase transitions are described and discussed in the third part. Finally some challenges for future are briefly indicated in the conclusion.

Amorphous Phase Characterization Through X-Ray Diffraction Profile Modeling: Implications for Amorphous Phases in Gale Crater Rocks and Soils

NASA Technical Reports Server (NTRS)

Achilles, C. N.; Downs, G. W.; Downs, R. T.; Morris, R. V.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.;

AEGIS: An Astrophysics Experiment for Grating and Imaging Spectroscopy---a Soft X-ray, High-resolution Spectrometer

NASA Astrophysics Data System (ADS)

Huenemoerder, David; Bautz, M. W.; Davis, J. E.; Heilmann, R. K.; Houck, J. C.; Marshall, H. L.; Neilsen, J.; Nicastro, F.; Nowak, M. A.; Schattenburg, M. L.; Schulz, N. S.; Smith, R. K.; Wolk, S.; AEGIS Team

2012-01-01

AEGIS is a concept for a high-resolution soft X-ray spectroscopic observatory developed in response to NASA's request for definitions of the next X-ray astronomy mission. At a small fraction of the cost of the once-planned International X-ray Observatory (IXO), AEGIS has capabilities that surpass IXO grating spectrometer requirements, and which are far superior to those of existing soft X-ray spectrometers. AEGIS incorporates innovative technology in X-ray optics, diffraction gratings and detectors. The mirror uses high area-to-mass ratio segmented glass architecture developed for IXO, but with smaller aperture and larger graze angles optimized for high-throughput grating spectroscopy with low mass and cost. The unique Critical Angle Transmission gratings combine low mass and relaxed figure and alignment tolerances of Chandra transmission gratings but with high diffraction efficiency and resolving power of blazed reflection gratings. With more than an order of magnitude better performance over Chandra and XMM grating spectrometers, AEGIS can obtain high quality spectra of bright AGN in a few hours rather than 10 days. Such high resolving power allows detailed kinematic studies of galactic outflows, hot gas in galactic haloes, and stellar accretion flows. Absorption line spectroscopy will be used to study large scale structure, cosmic feedback, and growth of black holes in thousands of sources to great distances. AEGIS will enable powerful multi-wavelength investigations, for example with Hubble/COS in the UV to characterize the intergalactic medium. AEGIS will be the first observatory with sufficient resolution below 1 keV to resolve thermally-broadened lines in hot ( 10 MK) plasmas. Here we describe key science investigations enable by Aegis, its scientific payload and mission plan. Acknowledgements: Support was provided in part by: NASA SAO contract SV3-73016 to MIT for the Chandra X-ray Center and Science Instruments; NASA grant NNX08AI62G; and the MKI Instrumentation Development Fund.

Preparation and structure of BiCrTeO{sub 6}: A new compound in Bi–Cr–Te–O system. Thermal expansion studies of Cr{sub 2}TeO{sub 6}, Bi{sub 2}TeO{sub 6} and BiCrTeO{sub 6}

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

Vats, Bal Govind; Phatak, Rohan; Krishnan, K.

Graphical abstract: A new compound BiCrTeO{sub 6} in the Bi–Cr–Te–O system was prepared by solid state route and characterized by X-ray diffraction method. The crystal structure of BiCrTeO{sub 6} shows that there is one distinct site for bismuth (Bi) atom (pink color), one chromium rich (Cr/Te = 68/32) (blue/green color), one tellurium rich (Te/Cr = 68/32) sites (green/blue color), and one distinct site for oxygen (O) atom (red color) in the unit cell. All cations in this structure show an octahedral coordination with oxygen atoms at the corners. The thermogram (TG) of the compound in air shows that it ismore » stable up to 1103 K and decomposes thereafter. The thermal expansion behaviour of BiCrTeO{sub 6} was studied using high temperature X-ray diffraction method from room temperature to 923 K under vacuum of 10{sup −8} atmosphere and showed positive thermal expansion with the average volume thermal expansion coefficients of 16.0 × 10{sup −6}/K. - Highlights: • A new compound BiCrTeO{sub 6} in Bi–Cr–Te–O system was prepared and characterized. • The crystal structure of BiCrTeO{sub 6} was determined by Rietveld refinement method. • The structure of BiCrTeO{sub 6} shows an octahedral coordination for all the metal ions. • The thermal expansion behavior of BiCrTeO{sub 6} from room temperature to 923 K showed a positive thermal expansion. • The average volume thermal expansion coefficient for BiCrTeO{sub 6} is 16.0 × 10{sup −6}/K. - Abstract: A new compound BiCrTeO{sub 6} in Bi–Cr–Te–O system was prepared by solid state reaction of Bi{sub 2}O{sub 3}, Cr{sub 2}O{sub 3} and H{sub 6}TeO{sub 6} in oxygen and characterized by X-ray diffraction (XRD) method. It could be indexed on a trigonal lattice, with the space group P-31c, unit cell parameters a = 5.16268(7) Å and c = 9.91861(17) Å. The crystal structure of BiCrTeO{sub 6} was determined by Rietveld refinement method using the powder XRD data. Structure shows that there is one distinct site for bismuth (Bi) atom, one chromium rich (Cr/Te = 68/32), and one tellurium rich (Te/Cr = 68/32) sites, and one distinct site for oxygen (O) atom in the unit cell. All cations in this structure show an octahedral coordination with oxygen atoms at the corners. The thermogravimetric analysis (TGA) of the compound in air shows that it is stable up to 1103 K and decomposes thereafter. The thermal expansion behavior of Cr{sub 2}TeO{sub 6}, Bi{sub 2}TeO{sub 6} and BiCrTeO{sub 6} was studied using High Temperature X-ray diffraction (HTXRD) method from room temperature to 973, 873 and 923 K respectively under vacuum of 10{sup −8} atmospheres. All the compounds showed positive thermal expansion with the average volume thermal expansion coefficients of 14.38 × 10{sup −6}/K, 22.0 × 10{sup −6}/K and 16.0 × 10{sup −6}/K respectively.« less

Phase development in the Bi 2Sr 2CaCu 2O y system . Effects of oxygen pressure

NASA Astrophysics Data System (ADS)

List, F. A.; Hsu, H.; Cavin, O. B.; Porter, W. D.; Hubbard, C. R.; Kroeger, D. M.

1992-11-01

Studies have been undertaken using thermal analysis, in conjunction with high-temperature and room temperature X-ray diffraction, fraction, to elucidate phase relationships during thermal processing of thick films of initially phase pure Bi 2Sr 2CaCu 2O y (2212) on silver substrates in various oxygen-containing atmospheres (0.001 to 100% O 2). Exothermic events on cooling at 10°C/min from a partially liquid state vary with oxygen partial pressure and can be grouped into three sets (I-III). Set I is prominent for 0.001% and 0.1% O 2 in the range of 740-775°C and is believed to be associated with the crystallization of a Cu-free ∼ Bi 5Sr 3Ca 1 oxide phase. Set II results from the crystallization of 2212; it is observed for p(O 2)≥1.0% in the temperature range 800-870°C. Set III appears for 21% and 100% O 2 in the temperature range 880-910°C, and its origin is not clear from the results of this study. Subsequent room temperature X-ray diffraction from these samples suggests that in general high oxygen partial pressures (100% O 2) tend to favor the formation of Bi 2Sr 2CuO 6 (2201), whereas low oxygen partial pressures (0.001-0.1% O 2) lead to the formation of a Cu-free, Bi-Sr-Ca oxide phase. The 2212 phase forms at this cooling rate predominantly for intermediate oxygen partial pressures (7.6-21% O 2). High-temperature X-ray diffraction during cooling (2°C/h) from the partially liquid state shows a pronounced dependence of the order of evolution of crystalline 2212 and 2201 phases on p(O 2). For an oxygen partial pressure of 1.0% the formation of 2212 precedes that of 2201, whereas for 0.01% O 2 2201 crystallizes at a higher temperature than 2212. The implications of these results pertaining to thermal processing of thick 2212 films are discussed.

X-ray Diffraction, Big and Small

NASA Image and Video Library

2012-10-30

A conventional X-ray diffraction instrument left is the size of a large refrigerator, in contrast to the compact size of the Chemistry and Mineralogy CheMin instrument on NASA Curiosity rover top right.

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

PubMed Central

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J.; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N.; Daurer, Benedikt J.; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F.; Higashiura, Akifumi; Hogue, Brenda G.; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A.; Reddy, Hemanth K.N.; Lan, Ti-Yen; Larsson, Daniel S.D.; Liu, Haiguang; Loh, N. Duane; Maia, Filipe R.N.C.; Mancuso, Adrian P.; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M. Marvin; Sellberg, Jonas A.; Sierra, Raymond G.; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A.; Westphal, Daniel; Wiedorn, Max O.; Williams, Garth J.; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-01-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here. PMID:27478984

Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

DOE PAGES

Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; ...

2009-01-01

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution imagesmore » using fewer photons. As a result, this can be an important advantage for studying radiation-sensitive biological and soft matter specimens.« less

Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment

DOE PAGES

Cha, Wonsuk; Liu, Wenjun; Harder, Ross; ...

2016-07-26

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible with in situ sample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifyingin situchamber design. This approach was demonstrated with Au nanoparticles and will enable,more » for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.« less

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

DOE PAGES

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; ...

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. Here, the diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB)more » as a resource for algorithm development, the contents of which are described here.« less

Influence of neutron irradiation on the microstructure of nuclear graphite: An X-ray diffraction study

NASA Astrophysics Data System (ADS)

Zhou, Z.; Bouwman, W. G.; Schut, H.; van Staveren, T. O.; Heijna, M. C. R.; Pappas, C.

2017-04-01

Neutron irradiation effects on the microstructure of nuclear graphite have been investigated by X-ray diffraction on virgin and low doses (∼ 1.3 and ∼ 2.2 dpa), high temperature (750° C) irradiated samples. The diffraction patterns were interpreted using a model, which takes into account the turbostratic disorder. Besides the lattice constants, the model introduces two distinct coherent lengths in the c-axis and the basal plane, that characterise the volumes from which X-rays are scattered coherently. The methodology used in this work allows to quantify the effect of irradiation damage on the microstructure of nuclear graphite seen by X-ray diffraction. The results show that the changes of the deduced structural parameters are in agreement with previous observations from electron microscopy, but not directly related to macroscopic changes.

Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment.

PubMed

Cha, Wonsuk; Liu, Wenjun; Harder, Ross; Xu, Ruqing; Fuoss, Paul H; Hruszkewycz, Stephan O

2016-09-01

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible with in situ sample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifying in situ chamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.

Time-spliced X-ray diffraction imaging of magnetism dynamics in a NdNiO3 thin film

NASA Astrophysics Data System (ADS)

Beyerlein, Kenneth R.

2018-03-01

Diffraction imaging of nonequilibrium dynamics at atomic resolution is becoming possible with X-ray free-electron lasers. However, there are unresolved problems with applying this method to objects that are confined in only one dimension. Here I show that reliable one-dimensional coherent diffraction imaging is possible by splicing together images recovered from different time delays in an optical pump X-ray probe experiment. The time and space evolution of antiferromagnetic order in a vibrationally excited complex oxide heterostructure is recovered from time-resolved measurements of a resonant soft X-ray diffraction peak. Midinfrared excitation of the substrate is shown to lead to a demagnetization front that propagates at a velocity exceeding the speed of sound, a critical observation for the understanding of driven phase transitions in complex condensed matter.

Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source.

PubMed

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N; Daurer, Benedikt J; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F; Higashiura, Akifumi; Hogue, Brenda G; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A; Reddy, Hemanth K N; Lan, Ti-Yen; Larsson, Daniel S D; Liu, Haiguang; Loh, N Duane; Maia, Filipe R N C; Mancuso, Adrian P; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M Marvin; Sellberg, Jonas A; Sierra, Raymond G; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A; Westphal, Daniel; Wiedorn, Max O; Williams, Garth J; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.

Time-spliced X-ray diffraction imaging of magnetism dynamics in a NdNiO3 thin film.

PubMed

Beyerlein, Kenneth R

2018-02-27

Diffraction imaging of nonequilibrium dynamics at atomic resolution is becoming possible with X-ray free-electron lasers. However, there are unresolved problems with applying this method to objects that are confined in only one dimension. Here I show that reliable one-dimensional coherent diffraction imaging is possible by splicing together images recovered from different time delays in an optical pump X-ray probe experiment. The time and space evolution of antiferromagnetic order in a vibrationally excited complex oxide heterostructure is recovered from time-resolved measurements of a resonant soft X-ray diffraction peak. Midinfrared excitation of the substrate is shown to lead to a demagnetization front that propagates at a velocity exceeding the speed of sound, a critical observation for the understanding of driven phase transitions in complex condensed matter.

Preliminary small-angle X-ray scattering and X-ray diffraction studies of the BTB domain of lola protein from Drosophila melanogaster

NASA Astrophysics Data System (ADS)

Boyko, K. M.; Nikolaeva, A. Yu.; Kachalova, G. S.; Bonchuk, A. N.; Dorovatovskii, P. V.; Popov, V. O.

2017-11-01

The Drosophila genome has several dozens of transcription factors (TTK group) containing BTB domains assembled into octamers. The LOLA protein belongs to this family. The purification, crystallization, and preliminary X-ray diffraction and small-angle X-ray scattering (SAXS) studies of the BTB domain of this protein are reported. The crystallization conditions were found by the vapor-diffusion technique. A very low diffraction resolution (8.7 Å resolution) of the crystals was insufficient for the determination of the threedimensional structure of the BTB domain. The SAXS study demonstrated that the BTB domain of the LOLA protein exists as an octamer in solution.

Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation

NASA Astrophysics Data System (ADS)

Lima, Enju; Chushkin, Yuriy; van der Linden, Peter; Kim, Chae Un; Zontone, Federico; Carpentier, Philippe; Gruner, Sol M.; Pernot, Petra

2014-10-01

We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into ˜10-μm-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.

Synchrotron X-ray powder diffraction data of LASSBio-1515: A new N-acylhydrazone derivative compound

NASA Astrophysics Data System (ADS)

Costa, F. N.; Braz, D.; Ferreira, F. F.; da Silva, T. F.; Barreiro, E. J.; Lima, L. M.; Colaço, M. V.; Kuplich, L.; Barroso, R. C.

2014-02-01

In this work, synchrotron X-ray powder diffraction data allowed for a successful indexing of LASSBio-1515 compound, candidate to analgesic and anti-inflammatory activity. X-ray powder diffraction data collected in transmission and high-throughput geometries were used to analyze this compound. The X-ray wavelength of the synchrotron radiation used in this study was determined to be λ=1.55054 Å. LASSBio-1515 was found to be monoclinic with space group P21/c and unit cell parameters a=11.26255(16) Å, b=12.59785(16) Å, c=8.8540(1) Å, β=90.5972(7)° and V=1256.17(3) Å3.

Thermal effects of laser marking on microstructure and corrosion properties of stainless steel.

PubMed

Švantner, M; Kučera, M; Smazalová, E; Houdková, Š; Čerstvý, R

2016-12-01

Laser marking is an advanced technique used for modification of surface optical properties. This paper presents research on the influence of laser marking on the corrosion properties of stainless steel. Processes during the laser beam-surface interaction cause structure and color changes and can also be responsible for reduction of corrosion resistance of the surface. Corrosion tests, roughness, microscopic, energy dispersive x-ray, grazing incidence x-ray diffraction, and ferrite content analyses were carried out. It was found that increasing heat input is the most crucial parameter regarding the degradation of corrosion resistance of stainless steel. Other relevant parameters include the pulse length and pulse frequency. The authors found a correlation between laser processing parameters, grazing incidence x-ray measurement, ferrite content, and corrosion resistance of the affected surface. Possibilities and limitations of laser marking of stainless steel in the context of the reduction of its corrosion resistance are discussed.

Influence of gamma irradiation on structural, thermal and antibacterial properties of HPMC/ZnO nanocomposites

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

Rao, B. Lakshmeesha; Madhukumar, R.; Latha, S.

This work was carried out to evaluate the effect of gamma irradiation on the structural, thermal and antibacterial properties of HPMC/ZnO nanocomposite films exposed to Cobalt-60 (Average energy: 1.25 MeV). The X-ray diffraction study revealed that the crystallite size (L in Å) decreased as irradiation dose increased. The crystallinity (X{sub c}) of the nanocomposites initially increased and at higher doses it was decreased. The thermal stability of the nanocomposites increased up to 50 kGy and after that decreased as the irradiation dose increased. But, HPMC/ZnO nanocomposite films, showed a promising range of antimicrobial activity against tested micro-organisms making nanocomposites suitablemore » for food packing and other biomedical applications.« less

Sonochemical syntheses of a new nano-sized porous lead(II) coordination polymer as precursor for preparation of lead(II) oxide nanoparticles

NASA Astrophysics Data System (ADS)

Ranjbar, Zohreh Rashidi; Morsali, Ali

2009-11-01

Nano-scale of a new Pb(II) coordination polymer, {[Pb(bpacb)(OAc)]·DMF} n ( 1); bpacbH = 3,5-bis[(4-pyridylamino)carbonyl]benzoic acid], were synthesized by a sonochemical method. The nano-material was characterized by scanning electron microscopy, X-ray powder diffraction (XRD), 1H, 13C NMR, IR spectroscopy and elemental analyses. Crystal structure of compound 1 was determined by X-ray crystallography. Calcination of the nano-sized compound 1 at 700 °C under air atmospheres yields PbO nanoparticles. Thermal stability of nano-sized and single crystalline samples of compound 1 were studied and compared with each other.

Picosecond x-ray strain rosette reveals direct laser excitation of coherent transverse acoustic phonons

PubMed Central

Lee, Sooheyong; Williams, G. Jackson; Campana, Maria I.; Walko, Donald A.; Landahl, Eric C.

2016-01-01

Using a strain-rosette, we demonstrate the existence of transverse strain using time-resolved x-ray diffraction from multiple Bragg reflections in laser-excited bulk gallium arsenide. We find that anisotropic strain is responsible for a considerable fraction of the total lattice motion at early times before thermal equilibrium is achieved. Our measurements are described by a new model where the Poisson ratio drives transverse motion, resulting in the creation of shear waves without the need for an indirect process such as mode conversion at an interface. Using the same excitation geometry with the narrow-gap semiconductor indium antimonide, we detected coherent transverse acoustic oscillations at frequencies of several GHz. PMID:26751616

High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging.

PubMed

Tokuhisa, Atsushi; Arai, Junya; Joti, Yasumasa; Ohno, Yoshiyuki; Kameyama, Toyohisa; Yamamoto, Keiji; Hatanaka, Masayuki; Gerofi, Balazs; Shimada, Akio; Kurokawa, Motoyoshi; Shoji, Fumiyoshi; Okada, Kensuke; Sugimoto, Takashi; Yamaga, Mitsuhiro; Tanaka, Ryotaro; Yokokawa, Mitsuo; Hori, Atsushi; Ishikawa, Yutaka; Hatsui, Takaki; Go, Nobuhiro

2013-11-01

Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 10(6) noisy X-ray diffraction patterns, each for an unknown random target orientation. To cope with the severe quantum noise, patterns need to be classified according to their similarities and average similar patterns to improve the signal-to-noise ratio. A high-speed scalable scheme has been developed to carry out classification on the K computer, a 10PFLOPS supercomputer at RIKEN Advanced Institute for Computational Science. It is designed to work on the real-time basis with the experimental diffraction pattern collection at the X-ray free-electron laser facility SACLA so that the result of classification can be feedback for optimizing experimental parameters during the experiment. The present status of our effort developing the system and also a result of application to a set of simulated diffraction patterns is reported. About 1 × 10(6) diffraction patterns were successfully classificatied by running 255 separate 1 h jobs in 385-node mode.

High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging

PubMed Central

Tokuhisa, Atsushi; Arai, Junya; Joti, Yasumasa; Ohno, Yoshiyuki; Kameyama, Toyohisa; Yamamoto, Keiji; Hatanaka, Masayuki; Gerofi, Balazs; Shimada, Akio; Kurokawa, Motoyoshi; Shoji, Fumiyoshi; Okada, Kensuke; Sugimoto, Takashi; Yamaga, Mitsuhiro; Tanaka, Ryotaro; Yokokawa, Mitsuo; Hori, Atsushi; Ishikawa, Yutaka; Hatsui, Takaki; Go, Nobuhiro

2013-01-01

Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 106 noisy X-ray diffraction patterns, each for an unknown random target orientation. To cope with the severe quantum noise, patterns need to be classified according to their similarities and average similar patterns to improve the signal-to-noise ratio. A high-speed scalable scheme has been developed to carry out classification on the K computer, a 10PFLOPS supercomputer at RIKEN Advanced Institute for Computational Science. It is designed to work on the real-time basis with the experimental diffraction pattern collection at the X-ray free-electron laser facility SACLA so that the result of classification can be feedback for optimizing experimental parameters during the experiment. The present status of our effort developing the system and also a result of application to a set of simulated diffraction patterns is reported. About 1 × 106 diffraction patterns were successfully classificatied by running 255 separate 1 h jobs in 385-node mode. PMID:24121336

Elucidating the Wavelength Dependence of Phonon Scattering in Nanoparticle-Matrix Composites using Phonon Spectroscopy

DTIC Science & Technology

2016-07-11

composites with x - ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Rutherford backscattering spectroscopy...RBS), particle-induced x - ray emission (PIXE), and energy dispersive x - ray spectroscopy (EDX). This work complements earlier works on CdSe...sample shows only In2Se3 and CdIn2Se4 XRD peaks (Figure 1.4e), it is stoichiometrically   Figure 1.4. X - ray diffraction patterns of (a) γ-In2Se3