Idealized powder diffraction patterns for cellulose polymorphs

USDA-ARS?s Scientific Manuscript database

Cellulose samples are routinely analyzed by X-ray diffraction to determine their crystal type (polymorph) and crystallinity. However, the connection is seldom made between those efforts and the crystal structures of cellulose that have been determined with synchrotron X-radiation and neutron diffrac...

Cation ordering/disordering kinetics in Ba3CoNb2O9: An in situ study using synchrotron x-ray powder diffraction

NASA Astrophysics Data System (ADS)

Mallinson, P. M.; Claridge, J. B.; Rosseinsky, M. J.; Ibberson, R. M.; Wright, J. P.; Fitch, A. N.; Price, T.; Iddles, D. M.

2007-11-01

In situ synchrotron x-ray powder diffraction has been used to study the kinetics of cation ordering and disordering in the microwave dielectric electroceramic Ba3CoNb2O9 with a time resolution of 15s. The method enables the order/disorder temperature (To /d) in this material of 1430°C to be directly observed. The changes in the rate and degree of cation ordering and in the growth of ordered domains between samples ordered from standard precursor material and then subsequently reordered following an annealing period above To /d show that small changes in precursor order state and phase assemblage strongly influence the final domain size.

Mg(1 + x)Ir(1 - x) (x = 0, 0.037 and 0.054), a binary intermetallic compound with a new orthorhombic structure type determined from powder and single-crystal X-ray diffraction.

PubMed

Cerný, Radovan; Renaudin, Guillaume; Favre-Nicolin, Vincent; Hlukhyy, Viktor; Pöttgen, Rainer

2004-06-01

The new binary compound Mg(1 + x)Ir(1 - x) (x = 0-0.054) was prepared by melting the elements in the Mg:Ir ratio 2:3 in a sealed tantalum tube under an argon atmosphere in an induction furnace (single crystals) or by annealing cold-pressed pellets of the starting composition Mg:Ir 1:1 in an autoclave under an argon atmosphere (powder sample). The structure was independently solved from high-resolution synchrotron powder and single-crystal X-ray data: Pearson symbol oC304, space group Cmca, lattice parameters from synchrotron powder data a = 18.46948 (6), b = 16.17450 (5), c = 16.82131 (5) A. Mg(1 + x)Ir(1 - x) is a topologically close-packed phase, containing 13 Ir and 12 Mg atoms in the asymmetric unit, and has a narrow homogeneity range. Nearly all the atoms have Frank-Kasper-related coordination polyhedra, with the exception of two Ir atoms, and this compound contains the shortest Ir-Ir distances ever observed. The solution of a rather complex crystal structure from powder diffraction, which was fully confirmed by the single-crystal method, shows the power of powder diffraction in combination with the high-resolution data and the global optimization method.

Advanced Structural Analyses by Third Generation Synchrotron Radiation Powder Diffraction

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

Sakata, M.; Aoyagi, S.; Ogura, T.

2007-01-19

Since the advent of the 3rd generation Synchrotron Radiation (SR) sources, such as SPring-8, the capabilities of SR powder diffraction increased greatly not only in an accurate structure refinement but also ab initio structure determination. In this study, advanced structural analyses by 3rd generation SR powder diffraction based on the Large Debye-Scherrer camera installed at BL02B2, SPring-8 is described. Because of high angular resolution and high counting statistics powder data collected at BL02B2, SPring-8, ab initio structure determination can cope with a molecular crystals with 65 atoms including H atoms. For the structure refinements, it is found that a kindmore » of Maximum Entropy Method in which several atoms are omitted in phase calculation become very important to refine structural details of fairy large molecule in a crystal. It should be emphasized that until the unknown structure is refined very precisely, the obtained structure by Genetic Algorithm (GA) or some other ab initio structure determination method using real space structural knowledge, it is not possible to tell whether the structure obtained by the method is correct or not. In order to determine and/or refine crystal structure of rather complicated molecules, we cannot overemphasize the importance of the 3rd generation SR sources.« less

Crystal structure of hydrocortisone acetate, C23H32O6

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

Kaduk, James A.; Gindhart, Amy M.; Blanton, Thomas N.

The crystal structure of hydrocortisone acetate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Hydrocortisone acetate crystallizes in space groupP2 1(#4) witha= 8.85173(3) Å,b= 13.53859(3) Å,c= 8.86980(4) Å,β= 101.5438(3)°,V= 1041.455(6) Å 3, andZ= 2. Both hydroxyl groups form hydrogen bonds to the ketone oxygen atom on the steroid ring system, resulting in a three-dimensional hydrogen bond network. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

In search of the elusive IrB{sub 2}: Can mechanochemistry help?

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

Xie, Zhilin; Blair, Richard G.; Department of Physics, University of Central Florida, Orlando, FL 32816

The previously unknown hexagonal ReB{sub 2}-type IrB{sub 2} diboride and orthorhombic IrB monoboride phases were produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. In addition to XRD, scanning electron microscopy and transmission electron microscopy were employed to further characterize the microstructure of the phases produced. - Graphical abstract: ReB{sub 2}-type IrB{submore » 2} and a new IrB have been successfully synthesized for the first time using mechanochemical method. Crystal structures of IrB{sub 2} and IrB were studied by synchrotron X-ray diffraction. Microstructures of the new phases were characterized by SEM and TEM. - Highlights: • ReB{sub 2}-type IrB{sub 2} and a new IrB have been synthesized by mechanochemical method. • Crystal structures of IrB{sub 2} and IrB were studied by synchrotron XRD. • Microstructures of the new phases were characterized by SEM and TEM.« less

Carbonate formation in non-aqueous environments by solid-gas carbonation of silicates

NASA Astrophysics Data System (ADS)

Day, S. J.; Thompson, S. P.; Evans, A.; Parker, J. E.

2012-02-01

We have produced synthetic analogues of cosmic silicates using the Sol Gel method, producing amorphous silicates of composition Mg(x)Ca(1-x)SiO3. Using synchrotron X-ray powder diffraction on Beamline I11 at the Diamond Light Source, together with a newly-commissioned gas cell, real-time powder diffraction scans have been taken of a range of silicates exposed to CO2 under non-ambient conditions. The SXPD is complemented by other techniques including Raman and Infrared Spectroscopy and SEM imaging.

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.

Parts per Million Powder X-ray Diffraction

DOE PAGES

Newman, Justin A.; Schmitt, Paul D.; Toth, Scott J.; ...

2015-10-14

Here in this paper we demonstrate the use of second harmonic generation (SHG) microscopy-guided synchrotron powder X-ray diffraction (PXRD) for the detection of trace crystalline active pharmaceutical ingredients in a common polymer blend. The combined instrument is capable of detecting 100 ppm crystalline ritonavir in an amorphous hydroxypropyl methylcellulose matrix with a high signal-to-noise ratio (>5000). The high spatial resolution afforded by SHG microscopy allows for the use of a minibeam collimator to reduce the total volume of material probed by synchrotron PXRD. The reduction in probed volume results in reduced background from amorphous material. The ability to detect lowmore » crystalline loading has the potential to improve measurements in the formulation pipeline for pharmaceutical solid dispersions, for which even trace quantities of crystalline active ingredients can negatively impact the stability and bioavailability of the final drug product.« less

Crystal structure of methylprednisolone acetate form II, C 24H 32O 6

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

Wheatley, Austin M.; Kaduk, James A.; Gindhart, Amy M.

The crystal structure of methylprednisolone acetate form II, C 24H 32O 6, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Methylprednisolone acetate crystallizes in space groupP2 12 12 1(#19) witha= 8.17608(2),b= 9.67944(3),c= 26.35176(6) Å,V= 2085.474(6) Å 3, andZ= 4. Both hydroxyl groups act as hydrogen bond donors, resulting in a two-dimensional hydrogen bond network in theabplane. C–H…O hydrogen bonds also contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1412.

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.

Synchrotron Powder X-ray Diffraction Study of the Structure and Dehydration Behavior of Sepiolite

NASA Astrophysics Data System (ADS)

Post, J. E.; Bish, D. L.; Heaney, P. J.

2006-05-01

Sepiolite is a hydrous Mg-silicate clay mineral with fibrous morphology that typically occurs as fine-grained, poorly crystalline masses. It occurs in a wide variety of geological environments and has been mined for centuries because of its many uses, e.g. in the pharmaceutical, fertilizer, and pesticide industries. Its versatile functionality derives from the large surface area and microporosity that are characteristic of the material. In recent years, sepiolite has received considerable attention with regard to the adsorption of organics, for use as a support for catalysts, as a molecular sieve, and as an inorganic membrane for ultrafiltration. Because of its fine-grained and poorly crystalline nature, it has not been possible to study sepiolite's crystal structure using single-crystal X-ray diffraction methods, and consequently many details of the structure are still not well known. In this study, Rietveld refinements using synchrotron powder X-ray diffraction data were used to investigate the crystal structure and dehydration behavior of sepiolite from Durango, Mexico. The room- temperature (RT) sepiolite structure in air compares well with previous models but reveals an additional zeolitic water site. The RT structure under vacuum retained only ~1/8 of the zeolitic water and the volume decreased 1.3%. Real-time, temperature-resolved synchrotron powder X-ray diffraction data and Rietveld refinements were used to investigate the behavior of the sepiolite structure from 300 to 925 K. Rietveld refinements revealed that most of the zeolitic water is lost by ~390 K, accompanied by a decrease in the a and c unit-cell parameters. Above ~600 K the sepiolite structure folds as one-half of the crystallographically bound water is lost. Rietveld refinements of the "anhydrous" sepiolite structure reveal that, in general, unit-cell parameters a, b, â and volume steadily decrease with increasing temperature; there is an obvious change in slope at ~820 K suggesting a phase transformation coinciding with the loss of the remaining bound water molecule. These temperature-resolved real-time powder X-ray diffraction studies provide the first comprehensive description of the sepiolite structure and the complex changes it undergoes as it dehydrates. Additional heating and cooling in situ powder X-ray diffraction experiments are underway in order to investigate the relative stabilities and rehydration behaviors of the partially-hydrated sepiolite phases. The results of these studies should provide a more robust model for predicting and modifying the properties and applications of this critical industrial material and environmentally important mineral.

Clay pigment structure characterisation as a guide for provenance determination--a comparison between laboratory powder micro-XRD and synchrotron radiation XRD.

PubMed

Švarcová, Silvie; Bezdička, Petr; Hradil, David; Hradilová, Janka; Žižak, Ivo

2011-01-01

Application of X-ray diffraction (XRD)-based techniques in the analysis of painted artworks is not only beneficial for indisputable identification of crystal constituents in colour layers, but it can also bring insight in material crystal structure, which can be affected by their geological formation, manufacturing procedure or secondary changes. This knowledge might be helpful for art historic evaluation of an artwork as well as for its conservation. By way of example of kaolinite, we show that classification of its crystal structure order based on XRD data is useful for estimation of its provenance. We found kaolinite in the preparation layer of a Gothic wall painting in a Czech church situated near Karlovy Vary, where there are important kaolin deposits. Comparing reference kaolin materials from eight various Czech deposits, we found that these can be differentiated just according to the kaolinite crystallinity. Within this study, we compared laboratory powder X-ray micro-diffraction (micro-XRD) with synchrotron radiation X-ray diffraction analysing the same real sample. We found that both techniques led to the same results.

Structural Mineral Physics at Extreme Conditions

NASA Astrophysics Data System (ADS)

Chariton, S.; Dubrovinsky, L. S.; Dubrovinskaia, N.

2017-12-01

Laser heating techniques in diamond anvil cells (DACs) cover a wide pressure-temperature range - above 300 GPa and up to 5000 K. Recent advantages in on-line laser heating techniques resulted in a significant improvement of reliability of in situ X-ray powder diffraction studies in laser-heated DACs, which have become routine at a number of synchrotron facilities including specialized beam-lines at the 3rd generation synchrotrons. However, until recently, existing DAC laser-heating systems could not be used for structural X-ray diffraction studies aimed at structural refinements, i.e. measuring of the diffraction intensities, and not only at determining of lattice parameters. The reason is that in existing DAC laser-heating facilities the laser beam enters the cell at a fixed angle, and a partial rotation of the DAC, as required in monochromatic structural X-ray diffraction experiments, results in a loss of the target crystal and may be even dangerous if the powerful laser light starts to scatter in arbitrary directions by the diamond anvils. In order to overcome this problem we have develop a portable laser heating system and implement it at different diffraction beam lines. We demonstrate the application of this system for simultaneous high-pressure and high-temperature powder and single crystal diffraction studies using examples of studies of chemical and phase relations in the Fe-O system, transition metals carbonates, and silicate perovskites.

Experimental measurement of lattice strain pole figures using synchrotron x rays

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

Miller, M.P.; Bernier, J.V.; Park, J.-S.

This article describes a system for mechanically loading test specimens in situ for the determination of lattice strain pole figures and their evolution in multiphase alloys via powder diffraction. The data from these experiments provide insight into the three-dimensional mechanical response of a polycrystalline aggregate and represent an extremely powerful material model validation tool. Relatively thin (0.5 mm) iron/copper specimens were axially strained using a mechanical loading frame beyond the macroscopic yield strength of the material. The loading was halted at multiple points during the deformation to conduct a diffraction experiment using a 0.5x0.5 mm{sup 2} monochromatic (50 keV) xmore » ray beam. Entire Debye rings of data were collected for multiple lattice planes ({l_brace}hkl{r_brace}'s) in both copper and iron using an online image plate detector. Strain pole figures were constructed by rotating the loading frame about the specimen transverse direction. Ideal powder patterns were superimposed on each image for the purpose of geometric correction. The chosen reference material was cerium (IV) oxide powder, which was spread in a thin layer on the downstream face of the specimen using petroleum jelly to prevent any mechanical coupling. Implementation of the system at the A2 experimental station at the Cornell High Energy Synchrotron Source (CHESS) is described. The diffraction moduli measured at CHESS were shown to compare favorably to in situ data from neutron-diffraction experiments conducted on the same alloys.« less

Crystal structure of choline fenofibrate (Trilipix®), (C5H14NO) (C17H14ClO4)

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

Kaduk, James A.; Zhong, Kai; Gindhart, Amy M.

2016-04-04

The crystal structure of choline fenofibrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Choline fenofibrate crystallizes in space groupPbca(#61) witha= 12.341 03(2),b= 28.568 70(6),c= 12.025 62(2) Å,V= 4239.84(1) Å 3, andZ= 8. The hydroxyl group of the choline anion makes a strong hydrogen bond to the ionized carboxylate group of the fenofibrate anion. Together with C–H···O hydrogen bonds, these link the cations and anions into layers parallel to theac-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

Synchrotron powder diffraction on Aztec blue pigments

NASA Astrophysics Data System (ADS)

Sánchez Del Río, M.; Gutiérrez-León, A.; Castro, G. R.; Rubio-Zuazo, J.; Solís, C.; Sánchez-Hernández, R.; Robles-Camacho, J.; Rojas-Gaytán, J.

2008-01-01

Some samples of raw blue pigments coming from an archaeological rescue mission in downtown Mexico City have been characterized using different techniques. The samples, some recovered as a part of a ritual offering, could be assigned to the late Aztec period (XVth century). The striking characteristic of these samples is that they seem to be raw pigments prior to any use in artworks, and it was possible to collect a few μg of pigment after manual grain selection under a microscopy monitoring. All pigments are made of indigo, an organic colorant locally known as añil or xiuhquilitl. The colorant is always found in combination with an inorganic matrix, studied by powder diffraction. In one case the mineral base is palygorskite, a rare clay mineral featuring micro-channels in its structure, well known as the main ingredient of the Maya blue pigment. However, other samples present the minerals sepiolite (a clay mineral of the palygorskite family) and calcite. Another sample contains barite, a mineral never reported in prehispanic paints. We present the results of characterization using high resolution powder diffraction recorded at the European Synchrotron Radiation Facility (BM25A, SpLine beamline) complemented with other techniques. All of them gave consistent results on the composition. A chemical test on resistance to acids was done, showing a high resistance for the palygorskite and eventually sepiolite compounds, in good agreement with the excellent resistance of the Maya blue.

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.

Synchrotron X-ray diffraction study of the Ba{sub 1−x}SrSnO{sub 3} solid solution

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

Prodjosantoso, Anti K., E-mail: Prodjosantoso@yahoo.com; Zhou, Qingdi; Kennedy, Brendan J.

At room temperature the sequence of phases with increasing amounts of strontium in the stannate perovskite system Ba{sub 1−x}SrSnO{sub 3} has been established from high resolution synchrotron X-ray powder diffraction. The observed sequence orthorhombic (Pbnm), orthorhombic (Ibmm), tetragonal (I4/mcm), and cubic (Pm3-bar m) is a consequence of the sequential introduction of cooperative tilting of the corner sharing SnO{sub 6} octahedra. The cell volume changes smoothly across the series with no obvious discontinuities associated with the phase transitions. - Graphical abstract: Portions of the synchrotron X-ray diffraction profiles (λ=0.82453 Å) from selected Ba{sub 1−x}Sr{sub x}SnO{sub 3} samples together with the resultsmore » of fitting by the Rietveld method. Highlights: ► Structures of the stannate perovskites Ba{sub 1−x}SrSnO{sub 3} refined from synchrotron XRD. ► The sequence Pm3-bar m→I4/mcm→Ibmm→Pbnm results from tilting of the octahedra. ► The tilting maintains optimal bonding of the cations seen from the BVS analysis.« less

Crystal structure of paliperidone palmitate (INVEGA SUSTENNA®), C39H57FN4O4

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

Kaduk, James A.; Dmitrienko, Artem O.; Gindhart, Amy M.

2017-08-29

The crystal structure of paliperidone palmitate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Paliperidone palmitate crystallizes in space groupP2 1/c(#14) witha= 34.415 40(35),b= 10.093 49(7),c= 10.904 92(9) Å,β= 94.3917(9)°,V= 3776.94(6) Å 3, andZ= 4. The conformation of the paliperidone fragment differs from that of the parent compound. The palmitate chain exhibits a slight twist close to the ester group. Several C–H•••O hydrogen bonds contribute to the crystal packing, which is dominated by van der Waals interactions. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1614.

Neutron powder diffraction and high-pressure synchrotron x-ray diffraction study of tantalum nitrides

NASA Astrophysics Data System (ADS)

Feng, Lei-hao; Hu, Qi-wei; Lei, Li; Fang, Lei-ming; Qi, Lei; Zhang, Lei-lei; Pu, Mei-fang; Kou, Zi-li; Peng, Fang; Chen, Xi-ping; Xia, Yuan-hua; Kojima, Yohei; Ohfuji, Hiroaki; He, Duan-wei; Chen, Bo; Irifune, Tetsuo

2018-02-01

Not Available Project supported by the Research Foundation of Key Laboratory of Neutron Physics (Grant No. 2015BB03), the National Natural Science Foundation of China (Grant Nos. 11774247), the Science Foundation for Excellent Youth Scholars of Sichuan University (Grant No. 2015SCU04A04), and the Joint Usage/Research Center PRIUS (Ehime University, Japan) and Chinese Academy of Sciences (Grant No. 2017-BEPC-PT-000568).

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.

Examination of Short- and Long-Range Atomic Order Nanocrystalline SiC and Diamond by Powder Diffraction Methods

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Gierlotka, S.; Weber, H.-P.; Proffen, T.; Palosz, W.

2002-01-01

The real atomic structure of nanocrystals determines unique, key properties of the materials. Determination of the structure presents a challenge due to inherent limitations of standard powder diffraction techniques when applied to nanocrystals. Alternate methodology of the structural analysis of nanocrystals (several nanometers in size) based on Bragg-like scattering and called the "apparent lattice parameter" (alp) is proposed. Application of the alp methodology to examination of the core-shell model of nanocrystals will be presented. The results of application of the alp method to structural analysis of several nanopowders were complemented by those obtained by determination of the Atomic Pair Distribution Function, PDF. Based on synchrotron and neutron diffraction data measured in a large diffraction vector of up to Q = 25 Angstroms(exp -1), the surface stresses in nanocrystalline diamond and SiC were evaluated.

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 .

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.

SUNY beamline facilities at the National Synchrotron Light Source (Final Report)

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

Coppens, Philip

2003-06-22

The DOE sponsored SUNY synchrotron project has involved close cooperation among faculty at several SUNY campuses. A large number of students and postdoctoral associates have participated in its operation which was centered at the X3 beamline of the National Synchrotron Light Source at Brookhaven National Laboratory. Four stations with capabilities for Small Angle Scattering, Single Crystal and Powder and Surface diffraction and EXAFS were designed and operated with capability to perform experiments at very low as well as elevated temperatures and under high vacuum. A large amount of cutting-edge science was performed at the facility, which in addition provided excellentmore » training for students and postdoctoral scientists in the field.« less

Symmetry and light stuffing of H o 2 T i 2 O 7 ,   E r 2 T i 2 O 7 , and Y b 2 T i 2 O 7 characterized by synchrotron x-ray diffraction

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

Baroudi, Kristen; Gaulin, Bruce D.; Lapidus, Saul H.

2015-07-01

The Ho2Ti2O7, Er2Ti2O7 and Yb2Ti2O7 pyrochlores were studied by synchrotron X-ray diffraction to determine whether the (002) peak, forbidden in the pyrochlore space group Fd-3m but observed in single crystal neutron scattering measurements, is present due to a deviation of their pyrochlore structure from Fd-3m symmetry. Synchrotron diffraction measurements on precisely synthesized stoichiometric and non-stoichiometric powders and a crushed floating zone crystal of Ho2Ti2O7 revealed that the (002) reflection is absent in all cases to a sensitivity of approximately one part in 30,000 of the strongest X-ray diffraction peak. This indicates to high sensitivity that the structural space group ofmore » these rare earth titanate pyrochlores is Fd-3m, and that thus the (002) peak observed in the neutron scattering experiments has a non-structural origin. The cell parameters and internal strain for lightly stuffed Ho2+xTi2-xO7 are also presented.« less

In search of the elusive IrB 2: Can mechanochemistry help?

DOE PAGES

Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; ...

2015-10-20

We produced hexagonal ReB 2-type IrB 2 diboride and orthorhombic IrB monoboride phases, that were previously unknown and saw them produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. Additionally, scanning electron microscopy and transmission electron microscopy were employed, along with XRD, to further characterize the microstructure of the phases produced.

In search of the elusive IrB 2: Can mechanochemistry help?

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

Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina

We produced hexagonal ReB 2-type IrB 2 diboride and orthorhombic IrB monoboride phases, that were previously unknown and saw them produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. Additionally, scanning electron microscopy and transmission electron microscopy were employed, along with XRD, to further characterize the microstructure of the phases produced.

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

Aldridge, James D.; Womick, Jordan M.; Rosmus, Kimberly A.

Novel quaternary lanthanide-substituted oxides of stoichiometry LnxY2-xTi2O7 (where Ln is lanthanum, neodymium, samarium, gadolinium, or ytterbium) were prepared by traditional high-temperature, solid-state techniques and characterized by X-ray powder diffraction. Samples with nominal values of x up to 1.0 were attempted. The well-studied ternary cubic pyrochlore compound yttrium titanium oxide (Y2Ti2O7, space group Fd-3m, Z = 8), served as a parent structural framework in which Ln3+ cations were substituted on the Y3+ site. Laboratory-grade X-ray powder diffraction data revealed pure quaternary pyrochlore phases for LnxY2-xTi2O7 with x ≤ 0.2. Pyrochlore phase purity was verified by Rietveld analysis using high-resolution synchrotron X-raymore » powder diffraction data when x ≤ 0.2, however, for La3+ substitution specifically, pure quaternary pyrochlore formed at x<0.1. Band gap energies on selected samples were determined using optical diffuse reflectance spectroscopy and showed that these materials can be classified as electrical insulators with indirect band gap energies around 3.7 eV.« less

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

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

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction

DOE PAGES

Zhao, Cang; Fezzaa, Kamel; Cunningham, Ross W.; ...

2017-06-15

Here, we employ the high-speed synchrotron hard X-ray imaging and diffraction techniques to monitor the laser powder bed fusion (LPBF) process of Ti-6Al-4V in situ and in real time. We demonstrate that many scientifically and technologically significant phenomena in LPBF, including melt pool dynamics, powder ejection, rapid solidification, and phase transformation, can be probed with unprecedented spatial and temporal resolutions. In particular, the keyhole pore formation is experimentally revealed with high spatial and temporal resolutions. The solidification rate is quantitatively measured, and the slowly decrease in solidification rate during the relatively steady state could be a manifestation of the recalescencemore » phenomenon. The high-speed diffraction enables a reasonable estimation of the cooling rate and phase transformation rate, and the diffusionless transformation from β to α’ phase is evident. The data present here will facilitate the understanding of dynamics and kinetics in metal LPBF process, and the experiment platform established will undoubtedly become a new paradigm for future research and development of metal additive manufacturing.« less

In-situ Diffraction Study of Magnetite at Simultaneous High Pressure and High Temperature Using Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Wang, L.; Zhang, J.; Wang, S.; Chen, H.; Zhao, Y.

2014-12-01

Magnetite intertwined with the evolution of human civilizations, and remains so today. It is technologically and scientifically important by virtue of its unique magnetic and electrical properties. Magnetite is a common mineral found in a variety of geologic environments, and plays an important role in deciphering the oxygen evolution in the Earth's atmosphere and its deep interiors. The latter application asks for the knowledge of the thermal and elastic properties of magnetite at high pressures and temperatures, which is currently not available in literature. We have carried out a few in-situ diffraction experiments on magnetite using white synchrotron radiation at beamline X17B2 of National Synchrotron Light Source (NSLS). A DIA module in an 1100-ton press and WC anvils were employed for compression, and diffraction spectra were collected at simultaneous high pressures (P) and temperatures (T) (up to 9 GPa and 900 oC). Mixture of amorphous boron and epoxy resin was used as pressure medium, and NaCl as pressure marker. Temperature was recorded by W-Re thermocouples. Commercially purchased magnetite powder and a mixture of the said powder and NaCl (1:1) were used as starting material in separate experiments. Preliminary data analyses have yielded following observations: (1) Charge disordering seen at ambient pressure remains active in current experiments, especially at lower pressures (< 6 GPa); (2) Though at each condition potentially complicated by charge disordering process, isothermal compression curves remains simple and reproducible; (3) During cooling, the reversibility and degree of cation disordering depend on the starting material and/or experimental P-T path; and (4) cation disordering notably reduces the apparent bulk moduli of magnetite.

Human insulin polymorphism upon ligand binding and pH variation: the case of 4-ethylresorcinol.

PubMed

Fili, S; Valmas, A; Norrman, M; Schluckebier, G; Beckers, D; Degen, T; Wright, J; Fitch, A; Gozzo, F; Giannopoulou, A E; Karavassili, F; Margiolaki, I

2015-09-01

This study focuses on the effects of the organic ligand 4-ethylresorcinol on the crystal structure of human insulin using powder X-ray crystallography. For this purpose, systematic crystallization experiments have been conducted in the presence of the organic ligand and zinc ions within the pH range 4.50-8.20, while observing crystallization behaviour around the isoelectric point of insulin. High-throughput crystal screening was performed using a laboratory X-ray diffraction system. The most representative samples were selected for synchrotron X-ray diffraction measurements, which took place at the European Synchrotron Radiation Facility (ESRF) and the Swiss Light Source (SLS). Four different crystalline polymorphs have been identified. Among these, two new phases with monoclinic symmetry have been found, which are targets for the future development of microcrystalline insulin drugs.

Human insulin polymorphism upon ligand binding and pH variation: the case of 4-ethylresorcinol

PubMed Central

Fili, S.; Valmas, A.; Norrman, M.; Schluckebier, G.; Beckers, D.; Degen, T.; Wright, J.; Fitch, A.; Gozzo, F.; Giannopoulou, A. E.; Karavassili, F.; Margiolaki, I.

2015-01-01

This study focuses on the effects of the organic ligand 4-ethylresorcinol on the crystal structure of human insulin using powder X-ray crystallography. For this purpose, systematic crystallization experiments have been conducted in the presence of the organic ligand and zinc ions within the pH range 4.50–8.20, while observing crystallization behaviour around the isoelectric point of insulin. High-throughput crystal screening was performed using a laboratory X-ray diffraction system. The most representative samples were selected for synchrotron X-ray diffraction measurements, which took place at the European Synchrotron Radiation Facility (ESRF) and the Swiss Light Source (SLS). Four different crystalline polymorphs have been identified. Among these, two new phases with monoclinic symmetry have been found, which are targets for the future development of microcrystalline insulin drugs. PMID:26306195

Infrastructure development for radioactive materials at the NSLS-II

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

Sprouster, D. J.; Weidner, R.; Ghose, S. K.

2018-02-01

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this article, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. We describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

Infrastructure development for radioactive materials at the NSLS-II

DOE PAGES

Sprouster, David J.; Weidner, R.; Ghose, S. K.; ...

2017-11-04

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this paper, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. Finally, we describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less

Operando Synchrotron X-ray Powder Diffraction and Modulated-Excitation Infrared Spectroscopy Elucidate the CO2 Promotion on a Commercial Methanol Synthesis Catalyst.

PubMed

Martin, Oliver; Mondelli, Cecilia; Cervellino, Antonio; Ferri, Davide; Curulla-Ferré, Daniel; Pérez-Ramírez, Javier

2016-09-05

Optimal amounts of CO2 are added to syngas to boost the methanol synthesis rate on Cu-ZnO-Al2 O3 in the industrial process. The reason for CO2 promotion is not sufficiently understood at the particle level due to the catalyst complexity and the high demands of characterization under true reaction conditions. Herein, we applied operando synchrotron X-ray powder diffraction and modulated-excitation infrared spectroscopy on a commercial catalyst to gain insights into its morphology and surface chemistry. These studies unveiled that Cu and ZnO agglomerate and ZnO particles flatten under CO/H2 and/or CO2 /H2 . Under the optimal CO/CO2 /H2 mixture, sintering is prevented and ZnO crystals adopt an elongated shape due to the minimal presence of the H2 O byproduct, enhancing the water-gas shift activity and thus the methanol production. Our results provide a rationale to the CO2 promotion emphasizing the importance of advanced analytical methods to establish structure-performance relations in heterogeneous catalysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural and microstructural description of the glacial state in triphenyl phosphite from powder synchrotron X-ray diffraction data and Raman scattering investigations

NASA Astrophysics Data System (ADS)

Derollez, P.; Hernandez, O.; Hédoux, A.; Guinet, Y.; Masson, O.; Lefebvre, J.; Descamps, M.

2004-06-01

The structure and microstructure (refinement of the isotropic size and microstrain parameters) of the glacial state in triphenyl phosphite (TPP, P(OC 6H 5) 3) transformed at 222K have been determined from powder synchrotron X-ray diffraction data through a Rietveld and a Le Bail refinement, respectively. It is shown that the glacial state is composed of crystallites of the stable crystal phase coexisting with non-transformed supercooled liquid, the apparent size of the crystallites—depending on the aging temperature at which the glacial state is isothermally formed, [Phys. Rev. B 60 (1999) 9390]—being equal to 329.2(2) Å at 222K. The molecular conformation is slightly less mirror-symmetric than the one in the crystal state, and correlatively only one of the two unusual weak intermolecular C-H⋯O hydrogen bonds already observed in the latter state is encountered in the glacial one. Additional Raman scattering investigations confirm the previous result and reveal in addition that no hydrogen bonding interaction is observed neither in the glass nor in the liquid states.

Nuclear waste viewed in a new light; a synchrotron study of uranium encapsulated in grout.

PubMed

Stitt, C A; Hart, M; Harker, N J; Hallam, K R; MacFarlane, J; Banos, A; Paraskevoulakos, C; Butcher, E; Padovani, C; Scott, T B

2015-03-21

How do you characterise the contents of a sealed nuclear waste package without breaking it open? This question is important when the contained corrosion products are potentially reactive with air and radioactive. Synchrotron X-rays have been used to perform micro-scale in-situ observation and characterisation of uranium encapsulated in grout; a simulation for a typical intermediate level waste storage packet. X-ray tomography and X-ray powder diffraction generated both qualitative and quantitative data from a grout-encapsulated uranium sample before, and after, deliberately constrained H2 corrosion. Tomographic reconstructions provided a means of assessing the extent, rates and character of the corrosion reactions by comparing the relative densities between the materials and the volume of reaction products. The oxidation of uranium in grout was found to follow the anoxic U+H2O oxidation regime, and the pore network within the grout was observed to influence the growth of uranium hydride sites across the metal surface. Powder diffraction analysis identified the corrosion products as UO2 and UH3, and permitted measurement of corrosion-induced strain. Together, X-ray tomography and diffraction provide means of accurately determining the types and extent of uranium corrosion occurring, thereby offering a future tool for isolating and studying the reactions occurring in real full-scale waste package systems. Copyright © 2014 Elsevier B.V. All rights reserved.

In cellulo serial crystallography of alcohol oxidase crystals inside yeast cells

DOE PAGES

Jakobi, Arjen J.; Passon, Daniel M.; Knoops, Kevin; ...

2016-03-01

The possibility of using femtosecond pulses from an X-ray free-electron laser to collect diffraction data from protein crystals formed in their native cellular organelle has been explored. X-ray diffraction of submicrometre-sized alcohol oxidase crystals formed in peroxisomes within cells of genetically modified variants of the methylotrophic yeast Hansenula polymorpha is reported and characterized. Furthermore, the observations are supported by synchrotron radiation-based powder diffraction data and electron microscopy. Based on these findings, the concept of in cellulo serial crystallography on protein targets imported into yeast peroxisomes without the need for protein purification as a requirement for subsequent crystallization is outlined.

In cellulo serial crystallography of alcohol oxidase crystals inside yeast cells

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

Jakobi, Arjen J.; Passon, Daniel M.; Knoops, Kevin

The possibility of using femtosecond pulses from an X-ray free-electron laser to collect diffraction data from protein crystals formed in their native cellular organelle has been explored. X-ray diffraction of submicrometre-sized alcohol oxidase crystals formed in peroxisomes within cells of genetically modified variants of the methylotrophic yeast Hansenula polymorpha is reported and characterized. Furthermore, the observations are supported by synchrotron radiation-based powder diffraction data and electron microscopy. Based on these findings, the concept of in cellulo serial crystallography on protein targets imported into yeast peroxisomes without the need for protein purification as a requirement for subsequent crystallization is outlined.

In cellulo serial crystallography of alcohol oxidase crystals inside yeast cells

PubMed Central

Jakobi, Arjen J.; Passon, Daniel M.; Knoops, Kèvin; Stellato, Francesco; Liang, Mengning; White, Thomas A.; Seine, Thomas; Messerschmidt, Marc; Chapman, Henry N.; Wilmanns, Matthias

2016-01-01

The possibility of using femtosecond pulses from an X-ray free-electron laser to collect diffraction data from protein crystals formed in their native cellular organelle has been explored. X-ray diffraction of submicrometre-sized alcohol oxidase crystals formed in peroxisomes within cells of genetically modified variants of the methylotrophic yeast Hansenula polymorpha is reported and characterized. The observations are supported by synchrotron radiation-based powder diffraction data and electron microscopy. Based on these findings, the concept of in cellulo serial crystallography on protein targets imported into yeast peroxisomes without the need for protein purification as a requirement for subsequent crystallization is outlined. PMID:27006771

Thermal expansion of monogermanides of 3d-metals

NASA Astrophysics Data System (ADS)

Valkovskiy, G. A.; Altynbaev, E. V.; Kuchugura, M. D.; Yashina, E. G.; Sukhanov, A. S.; Dyadkin, V. A.; Tsvyashchenko, A. V.; Sidorov, V. A.; Fomicheva, L. N.; Bykova, E.; Ovsyannikov, S. V.; Chernyshov, D. Yu; Grigoriev, S. V.

2016-09-01

Temperature dependent powder and single-crystal synchrotron diffraction, specific heat, magnetic susceptibility and small-angle neutron scattering experiments have revealed an anomalous response of MnGe. The anomaly becomes smeared out with decreasing Mn content in Mn1-x Co x Ge and Mn1-x Fe x Ge solid solutions. Mn spin state instability is discussed as a possible candidate for the observed effects.

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.

Beamline P02.1 at PETRA III for high-resolution and high-energy powder diffraction

PubMed Central

Dippel, Ann-Christin; Liermann, Hanns-Peter; Delitz, Jan Torben; Walter, Peter; Schulte-Schrepping, Horst; Seeck, Oliver H.; Franz, Hermann

2015-01-01

Powder X-ray diffraction techniques largely benefit from the superior beam quality provided by high-brilliance synchrotron light sources in terms of photon flux and angular resolution. The High Resolution Powder Diffraction Beamline P02.1 at the storage ring PETRA III (DESY, Hamburg, Germany) combines these strengths with the power of high-energy X-rays for materials research. The beamline is operated at a fixed photon energy of 60 keV (0.207 Å wavelength). A high-resolution monochromator generates the highly collimated X-ray beam of narrow energy bandwidth. Classic crystal structure determination in reciprocal space at standard and non-ambient conditions are an essential part of the scientific scope as well as total scattering analysis using the real space information of the pair distribution function. Both methods are complemented by in situ capabilities with time-resolution in the sub-second regime owing to the high beam intensity and the advanced detector technology for high-energy X-rays. P02.1’s efficiency in solving chemical and crystallographic problems is illustrated by presenting key experiments that were carried out within these fields during the early stage of beamline operation. PMID:25931084

Synchrotron WAXS and XANES studies of silica (SiO2) powders synthesized from Indonesian natural sands

NASA Astrophysics Data System (ADS)

Muchlis, Khairanissa; Aini Fauziyah, Nur; Soontaranon, Siriwat; Limpirat, Wanwisa; Pratapa, Suminar

2017-01-01

In this study, we have investigated polymorphic silica (SiO2) powders using, Wide Angle X-ray Scattering (WAXS) and X-Ray Absorption Near Edge Spectroscopy (XANES), laboratory X-Ray Diffraction (XRD) instruments. The WAXS and XANES spectra were collected using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. The silica powders were obtained by processing silica sand from Tanah Laut, South Kalimantan, Indonesia. Purification process of silica sand was done by magnetic separation and immersion with HCl. The purification step was needed to reduce impurity or undesirable non Si elements. Three polymorphs of silica were produced, i.e. amorphous phase (A), quartz (B), and cristobalite (C). WAXS profile for each phase was presented in terms of intensity vs. 2θ prior to analyses. Both XRD (λCuKα=1.54056 Å) and WAXS (λ=1.09 Å) patttern show that (1) A sample contains no crystallites, (2) B sample is monophasic, contains only quartz, and (3) C sample contains cristobalite and trydimite. XRD quantitative analysis using Rietica gave 98,8 wt% cristobalite, while the associated WAXS data provided 98.7 wt% cristobalite. Si K-edge XANES spectra were measured at energy range 1840 to 1920 eV. Qualitatively, the pre-edge and edge features for all phases are similar, but their main peaks in the post-edge region are different.

Exploring Jupiter's icy moons with old techniques and big facilities - new insights on sulfuric acid hydrates

NASA Astrophysics Data System (ADS)

Maynard-Casely, H. E.; Avdeev, M.; Brand, H.; Wallwork, K.

2013-12-01

Sulfuric acid hydrates have been proposed to be abundant on the surface of Europa [1], and hence would be important planetary forming materials for this moon and its companions Ganymede and Callisto. Understanding of the surface features and subsurface of these moons could be advanced by firmer knowledge of the icy materials that comprise them [2], insight into which can be drawn from firmer knowledge of physical properties and phase behaviour of the candidate materials. We wish to present results from a study that started with the question ';What form of sulfuric acid hydrate would form on the surface of Europa'. The intrinsic hydrogen-domination of planetary ices, makes studying these materials with laboratory powder diffraction very challenging. Insights into their crystalline phase behavior and the extraction of a number of thermal and mechanical properties is often only accessible with high-flux synchrotron x-ray diffraction and utilization of the large scattering cross section with neutron diffraction. We have used the Powder Diffraction beamline at Australian synchrotron [4] and the Echidna (High-resolution neutron powder diffraction) instrument of the Australian Nuclear Science and Technology Organization, [5] to obtain an number of new insights into the crystalline phases formed from sulfruic acid and water mixtures. These instruments have enabled the discovery a new water-rich sulfuric acid hydrate form [6], improved structural characterisation of existing forms [7] and a charting the phase diagram of this fundamental binary system [8]. This has revealed exciting potential for understanding more about the surface of Europa from space, perhaps even providing a window into its past. [1] Carlson, R.W., R.E. Johnson, and M.S. Anderson, Science, 1999. 286(5437): p. 97-99. [2] Fortes, A.D. and M. Choukroun. Space Sci Rev, 2010. 153(1-4): p. 185-218. [3] Blake, D., et al., Space Sci Rev,, 2012. 170(1-4): p. 341-399. [4] Wallwork, K.S., Kennedy B. J. and Wang, D., AIP Conf Proc, 2007. 879: p. 879-882. [5] Liss, K.D., et al., Phys B-Cond Mat, 2006. 385-86: p. 1010-1012. [6] Maynard-Casely, H.E., K.S. Wallwork, and M. Avdeev, (In review). [7] Maynard-Casely, H.E., H.E.A. Brand, and K.S. Wallwork, J.of App.Cryst, 2012. 45: p.1198-1207. [8] Maynard-Casely, H.E., K.S. Wallwork, and H.E.A. Brand, (In Preparation). Stages of the crystal structure determination of sulfruic acid octahydrate a) the oxygen and sulfur postions were determined from the synchrotron x-ray data b) Once neutron diffraction data was collected Fourier difference methods were used to locate hydrogen positions to determine c) the full structure of sulfuric acid octahydrate.

Investigation of the Surface Stress in SiC and Diamond Nanocrystals by In-situ High Pressure Powder Diffraction Technique

NASA Technical Reports Server (NTRS)

Palosz, B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Zhao, Y.; Palosz, W.

2003-01-01

The real atomic structure of nanocrystals determines key properties of the materials. For such materials the serious experimental problem lies in obtaining sufficiently accurate measurements of the structural parameters of the crystals, since very small crystals constitute rather a two-phase than a uniform crystallographic phase system. As a result, elastic properties of nanograins may be expected to reflect a dual nature of their structure, with a corresponding set of different elastic property parameters. We studied those properties by in-situ high-pressure powder diffraction technique. For nanocrystalline, even one-phase materials such measurements are particularly difficult to make since determination of the lattice parameters of very small crystals presents a challenge due to inherent limitations of standard elaboration of powder diffractograms. In this investigation we used our methodology of the structural analysis, the 'apparent lattice parameter' (alp) concept. The methodology allowed us to avoid the traps (if applied to nanocrystals) of standard powder diffraction evaluation techniques. The experiments were performed for nanocrystalline Sic and GaN powders using synchrotron sources. We applied both hydrostatic and isostatic pressures in the range of up to 40 GPa. Elastic properties of the samples were examined based on the measurements of a change of the lattice parameters with pressure. The results show a dual nature of the mechanical properties (compressibilities) of the materials, indicating a complex, core-shell structure of the grains.

High-Pressure Polymorph of NaBiO3.

PubMed

Naa, Octavianti; Kumada, Nobuhiro; Miura, Akira; Takei, Takahiro; Azuma, Masaki; Kusano, Yoshihiro; Oka, Kengo

2016-06-20

A new high-pressure polymorph of NaBiO3 (hereafter β-NaBiO3) was synthesized under the conditions of 6 GPa and 600 °C. The powder X-ray diffraction pattern of this new phase was indexed with a hexagonal cell of a = 9.968(1) Å and c = 3.2933(4) Å. Crystal structure refinement using synchrotron powder X-ray diffraction data led to RWP = 8.53% and RP = 5.55%, and the crystal structure was closely related with that of Ba2SrY6O12. No photocatalytic activity for phenol decomposition was observed under visible-light irradiation in spite of a good performance for its mother compound, NaBiO3. The optical band-gap energy of β-NaBiO3 was narrower than that of NaBiO3, which was confirmed with density of states curves simulated by first-principles density functional theory calculation.

Evolution of Microstructure in a Nickel-based Superalloy as a Function of Ageing Time

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

Chen, Wei-Ren; Smith, Gregory Scott; Porcar, L.

2011-01-01

An experimental investigation, combining synchrotron X-ray powder diffraction, small-angle neutron-scattering, and transmission electron microscopy, has been undertaken to study the microstructure of nanoprecipitates in a nickel-based superalloy. Upon increasing the ageing time during a heat-treatment process, the average size of the precipitates first decreases before changing to a monotonical growth stage. Possible reasons for this observed structural evolution, which is predicted thermodynamically, are suggested.

The storage degradation of an 18650 commercial cell studied using neutron powder diffraction

NASA Astrophysics Data System (ADS)

Lee, Po-Han; Wu, She-huang; Pang, Wei Kong; Peterson, Vanessa K.

2018-01-01

Commercial 18650 lithium ion cells containing a blended positive electrode of layered LiNi0.5Mn0.3Co0.2O2 and spinel Li1.1Mn1.9O4 alongside a graphite negative electrode were stored at various depth-of-discharge (DoD) at 60 °C for 1, 2, 4, and 6 months. After storage, the cells were cycled at C/25 at 25 °C between 2.75 and 4.2 V for capacity determination and incremental capacity analysis (ICA). In addition to ICA analysis, the mechanism for capacity fade was investigated by combining the results of neutron powder diffraction under in-situ and operando conditions, in conjunction with post-mortem studies of the electrodes using synchrotron X-ray powder diffraction and inductively-coupled plasma optical emission spectroscopy. Among the cells, those stored at 25% DoD suffered the highest capacity fade due to their higher losses of active Li, NMC, and LMO than cells stored at other DoD. The cells stored at 0% DoD shows second high capacity fade because they exhibit the highest of active LMO and graphite anode among the stored cells and higher losses of active Li and NMC than cells stored at 50% DoD.

Accuracy in Rietveld quantitative phase analysis: a comparative study of strictly monochromatic Mo and Cu radiations.

PubMed

León-Reina, L; García-Maté, M; Álvarez-Pinazo, G; Santacruz, I; Vallcorba, O; De la Torre, A G; Aranda, M A G

2016-06-01

This study reports 78 Rietveld quantitative phase analyses using Cu  K α 1 , Mo  K α 1 and synchrotron radiations. Synchrotron powder diffraction has been used to validate the most challenging analyses. From the results for three series with increasing contents of an analyte (an inorganic crystalline phase, an organic crystalline phase and a glass), it is inferred that Rietveld analyses from high-energy Mo  K α 1 radiation have slightly better accuracies than those obtained from Cu  K α 1 radiation. This behaviour has been established from the results of the calibration graphics obtained through the spiking method and also from Kullback-Leibler distance statistic studies. This outcome is explained, in spite of the lower diffraction power for Mo radiation when compared to Cu radiation, as arising because of the larger volume tested with Mo and also because higher energy allows one to record patterns with fewer systematic errors. The limit of detection (LoD) and limit of quantification (LoQ) have also been established for the studied series. For similar recording times, the LoDs in Cu patterns, ∼0.2 wt%, are slightly lower than those derived from Mo patterns, ∼0.3 wt%. The LoQ for a well crystallized inorganic phase using laboratory powder diffraction was established to be close to 0.10 wt% in stable fits with good precision. However, the accuracy of these analyses was poor with relative errors near to 100%. Only contents higher than 1.0 wt% yielded analyses with relative errors lower than 20%.

An electrochemical cell with sapphire windows for operando synchrotron X-ray powder diffraction and spectroscopy studies of high-power and high-voltage electrodes for metal-ion batteries.

PubMed

Drozhzhin, Oleg A; Tereshchenko, Ivan V; Emerich, Hermann; Antipov, Evgeny V; Abakumov, Artem M; Chernyshov, Dmitry

2018-03-01

A new multi-purpose operando electrochemical cell was designed, constructed and tested on the Swiss-Norwegian Beamlines BM01 and BM31 at the European Synchrotron Radiation Facility. Single-crystal sapphire X-ray windows provide a good signal-to-noise ratio, excellent electrochemical contact because of the constant pressure between the electrodes, and perfect electrochemical stability at high potentials due to the inert and non-conductive nature of sapphire. Examination of the phase transformations in the Li 1-x Fe 0.5 Mn 0.5 PO 4 positive electrode (cathode) material at C/2 and 10C charge and discharge rates, and a study of the valence state of the Ni cations in the Li 1-x Ni 0.5 Mn 1.5 O 4 cathode material for Li-ion batteries, revealed the applicability of this novel cell design to diffraction and spectroscopic investigations of high-power/high-voltage electrodes for metal-ion batteries.

Structure determination of two structural analogs, named 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16F2N4S) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C23H16ClFN4S) by synchrotron X-ray powder diffraction

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

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

Two novel compounds, 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-fluorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16F 2N 4S) (1) and 3-[1-(2-fluoro-4-biphenyl)ethyl]-6-(4-chlorophenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (C 23H 16ClFN 4S) (2), have been designed and synthesized as cytotoxic agents. The compounds were characterized by infrared, proton nuclear magnetic resonance, mass spectral data, elemental analysis and X-ray powder diffraction. The present study comprises spectral data and crystal structures of these novel compounds determined from synchrotron X-ray powder diffraction data. The structure solutions were obtained by simulated annealing. The final structures were achieved by Rietveld refinement using soft restraints for all bond lengths, bond angles, and planar groups. Both compounds crystallize in space groupmore » $$P\\bar 1$$,Z= 2, with the unit-cell parametersa= 6.37433(9),b= 11.3641(2),c= 14.09115(19) Å,α= 80.1740(8)°,β= 85.1164(8)°,γ= 80.9831(10)°,V= 991.55(3) Å 3of compound (1) anda= 6.53736(6),b= 11.55725(15),c= 14.01373(13) Å,α= 80.3323(7)°,β= 84.8939(6)°,γ= 79.3954(8)°,V= 1024.08(2) Å 3of compound (2). Structural analyses reveal that the title compounds are isostructural.« less

X-ray laser–induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene

PubMed Central

Abbey, Brian; Dilanian, Ruben A.; Darmanin, Connie; Ryan, Rebecca A.; Putkunz, Corey T.; Martin, Andrew V.; Wood, David; Streltsov, Victor; Jones, Michael W. M.; Gaffney, Naylyn; Hofmann, Felix; Williams, Garth J.; Boutet, Sébastien; Messerschmidt, Marc; Seibert, M. Marvin; Williams, Sophie; Curwood, Evan; Balaur, Eugeniu; Peele, Andrew G.; Nugent, Keith A.; Quiney, Harry M.

2016-01-01

X-ray free-electron lasers (XFELs) deliver x-ray pulses with a coherent flux that is approximately eight orders of magnitude greater than that available from a modern third-generation synchrotron source. The power density of an XFEL pulse may be so high that it can modify the electronic properties of a sample on a femtosecond time scale. Exploration of the interaction of intense coherent x-ray pulses and matter is both of intrinsic scientific interest and of critical importance to the interpretation of experiments that probe the structures of materials using high-brightness femtosecond XFEL pulses. We report observations of the diffraction of extremely intense 32-fs nanofocused x-ray pulses by a powder sample of crystalline C60. We find that the diffraction pattern at the highest available incident power significantly differs from the one obtained using either third-generation synchrotron sources or XFEL sources operating at low output power and does not correspond to the diffraction pattern expected from any known phase of crystalline C60. We interpret these data as evidence of a long-range, coherent dynamic electronic distortion that is driven by the interaction of the periodic array of C60 molecular targets with intense x-ray pulses of femtosecond duration. PMID:27626076

The structure of graphene oxide membranes in liquid water, ethanol and water-ethanol mixtures

NASA Astrophysics Data System (ADS)

Talyzin, Alexandr V.; Hausmaninger, Tomas; You, Shujie; Szabó, Tamás

2013-12-01

The structure of graphene oxide (GO) membranes was studied in situ in liquid solvents using synchrotron radiation X-ray diffraction in a broad temperature interval. GO membranes are hydrated by water similarly to precursor graphite oxide powders but intercalation of alcohols is strongly hindered, which explains why the GO membranes are permeated by water and not by ethanol. Insertion of ethanol into the membrane structure is limited to only one monolayer in the whole studied temperature range, in contrast to precursor graphite oxide powders, which are intercalated with up to two ethanol monolayers (Brodie) and four ethanol monolayers (Hummers). As a result, GO membranes demonstrate the absence of ``negative thermal expansion'' and phase transitions connected to insertion/de-insertion of alcohols upon temperature variations reported earlier for graphite oxide powders. Therefore, GO membranes are a distinct type of material with unique solvation properties compared to parent graphite oxides even if they are composed of the same graphene oxide flakes.The structure of graphene oxide (GO) membranes was studied in situ in liquid solvents using synchrotron radiation X-ray diffraction in a broad temperature interval. GO membranes are hydrated by water similarly to precursor graphite oxide powders but intercalation of alcohols is strongly hindered, which explains why the GO membranes are permeated by water and not by ethanol. Insertion of ethanol into the membrane structure is limited to only one monolayer in the whole studied temperature range, in contrast to precursor graphite oxide powders, which are intercalated with up to two ethanol monolayers (Brodie) and four ethanol monolayers (Hummers). As a result, GO membranes demonstrate the absence of ``negative thermal expansion'' and phase transitions connected to insertion/de-insertion of alcohols upon temperature variations reported earlier for graphite oxide powders. Therefore, GO membranes are a distinct type of material with unique solvation properties compared to parent graphite oxides even if they are composed of the same graphene oxide flakes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr04631a

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.

Structure elucidation of 3-[1-(6-methoxy-2-naphtyl)ethyl]-6-(2,4-dichlorophenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine, C 23H 18Cl 2N 4OS from synchrotron X-ray powder diffraction

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

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

The 3-[1-(6-methoxy-2-naphtyl)ethyl]-6-(2,4-dichlorophenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine, C 23H 18Cl 2N 4OS compound was synthesized, as a member of the family of novel potential anticancer agents. The structure of the title compound was characterized by IR, 1H-NMR, mass spectroscopy, and elemental analysis, previously. In this study, the crystal structure of this compound has been determined from synchrotron X-ray powder diffraction data. The crystal structure was solved by simulated annealing and the final structure was achieved by Rietveld refinement method using soft restrains on all interatomic bond lengths and angles. This compound crystallizes in space groupP21,Z= 2, with the unit-cell parametersa= 15.55645(11) Å,b= 8.61693(6) Å,c= 8.56702(6)more » Å,β= 104.3270(4)°, andV= 1112.68(1) Å 3. In the crystal structure, strong C-H∙∙∙πand weak intermolecular hydrogen-bonding interactions link the molecules into a three-dimensional network. The molecules are in a head-to-head arrangement in the unit cell.« less

Synthesis and time-resolved structural characterization of framework and mineral sulfides

NASA Astrophysics Data System (ADS)

Cahill, Christopher Langley

A new class of open-framework organic/inorganic hybrid materials based on In-S chemistry has been discovered. The compounds therein exhibit unprecedented structural diversity compared to known porous sulfides, primarily due to variation in framework building units. Further, large increases in pore dimensions (vs. zeolites, for example) are observed as these materials consist of comer and edge linked clusters, e.g. In10S20, In9S17, In4S10 and In6S 15. Choice of organic structure directing agents (templates) and careful control of reaction conditions (temperature, pH) both in the In-S and Ge-S systems is shown not only to dictate which building unit will form, but also to direct the resulting framework topology. Several of the compounds described herein crystallize either as powders, or as crystals too small for standard in-house X-ray structural analysis. Diffraction experiments have thus required synchrotron based single crystal techniques for structure determination. Further, certain reaction mixture compositions result in multi-phase end products, the formation pathways of which have been studied with time resolved, in situ synchrotron powder diffraction. An extension of the applicability of the in situ techniques investigated the role of oxygen in hydrothermal systems. Oxidation state is proposed to dictate speciation in the Ni-Ge-S system and to promote phase transformations in the Fe-S mineral system.

High Pressure X-Ray Diffraction Studies of Nanocrystalline Materials

NASA Technical Reports Server (NTRS)

Palosz, B.; Stel'makh, S.; Grzanka, E.; Gierlotka, S.; Palosz, W.

2004-01-01

Experimental evidence obtained for a variety of nanocrystalline materials suggest that the crystallographic structure of a very small size particle deviates from that in the bulk crystals. In this paper we show the effect of the surface of nanocrystals on their structure by the analysis of generation and distribution of macro- and micro-strains at high pressures and their dependence on the grain size in nanocrystalline powders of Sic. We studied the structure of Sic nanocrystals by in-situ high-pressure powder diffraction technique using synchrotron and neutron sources and hydrostatic or isostatic pressure conditions. The diffraction measurements were done in HASYLAB at DESY using a Diamond Anvil Cell (DAC) in the energy dispersive geometry in the diffraction vector range up to 3.5 - 4/A and under pressures up to 50 GPa at room temperature. In-situ high pressure neutron diffraction measurements were done at LANSCE in Los Alamos National Laboratory using the HIPD and HIPPO diffractometers with the Paris-Edinburgh and TAP-98 cells, respectively, in the diffraction vector range up to 26 Examination of the response of the material to external stresses requires nonstandard methodology of the materials characterization and description. Although every diffraction pattern contains a complete information on macro- and micro-strains, a high pressure experiment can reveal only those factors which contribute to the characteristic diffraction patterns of the crystalline phases present in the sample. The elastic properties of powders with the grain size from several nm to micrometers were examined using three methodologies: (l), the analysis of positions and widths of individual Bragg reflections (used for calculating macro- and micro-strains generated during densification) [I], (2). the analysis of the dependence of the experimental apparent lattice parameter, alp, on the diffraction vector Q [2], and (3), the atomic Pair Distribution Function (PDF) technique [3]. The results of our studies show, that Sic nanocrystals have the features of two phases, each with its distinct elastic properties. and under pressures up to 8 GPa.

Temperature Dependence of the Structural Parameters in the Transformation of Aragonite to Calcite, as Determined from In Situ Synchrotron Powder X-ray-Diffratction Data

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

Antao, Sytle M.; Hassan, Ishmael; West Indies)

The temperature dependency of the crystal structure and the polymorphic transition of CaCO{sub 3} from aragonite to calcite were studied using Rietveld structure refinement and high-temperature in situ synchrotron powder X-ray-diffraction data at ambient pressure, P. The orthorhombic metastable aragonite at room P, space group Pmcn, transforms to trigonal calcite, space group R{bar 3}c, at about T{sub c} = 468 C. This transformation occurs rapidly; it starts at about 420 C and is completed by 500 C, an 80 C interval that took about 10 minutes using a heating rate of 8 C/min. Structurally, from aragonite to calcite, the distributionmore » of the Ca atom changes from approximately hexagonal to cubic close-packing. A 5.76% discontinuous increase in volume accompanies the reconstructive first-order transition. Besides the change in coordination of the Ca atom from nine to six from aragonite to calcite, the CO{sub 3} groups change by a 30{sup o} rotation across the transition.« less

High-resolution synchrotron x-ray powder diffraction study of the incommensurate modulation in the martensite phase of Ni2MnGa: Evidence for nearly 7M modulation and phason broadening

NASA Astrophysics Data System (ADS)

Singh, Sanjay; Petricek, V.; Rajput, Parasmani; Hill, Adrian H.; Suard, E.; Barman, S. R.; Pandey, Dhananjai

2014-07-01

The modulated structure of the martensite phase of Ni2MnGa is revisited using high-resolution synchrotron x-ray powder diffraction measurements, which reveal higher-order satellite reflections up to the third order and phason broadening of the satellite peaks. The structure refinement, using the (3+1) dimensional superspace group approach, shows that the modulated structure of Ni2MnGa can be described by orthorhombic superspace group Immm(00γ)s00 with lattice parameters a=4.218 61(2)Å,b=5.546 96(3)Å, and c=4.187 63(2) Å, and an incommensurate modulation wave vector q =0.43160(3)c*=(3/7+δ)c*, where δ =0.00303(3) is the degree of incommensuration of the modulated structure. Additional satellite peak broadening, which could not be accounted for in terms of the anisotropic strain broadening based on a lattice parameter distribution, has been modeled in terms of phasons using fourth-rank covariant strain-tensor representation for incommensurate structures. The simulation of single-crystal diffraction patterns from the refined structural parameters unambiguously reveals a rational approximant structure with 7M modulation. The inhomogeneous displacement of different atomic sites on account of incommensurate modulation and the presence of phason broadening clearly rule out the adaptive phase model proposed recently by Kaufmann et al. [S. Kaufmann, U. K. Rößler, O. Heczko, M. Wuttig, J. Buschbeck, L. Schultz, and S. Fähler, Phys. Rev. Lett. 104, 145702 (2010), 10.1103/PhysRevLett.104.145702] and suggest that the modulation in Ni2MnGa originates from soft-mode phonons.

Crystal structure of rivastigmine hydrogen tartrate Form I (Exelon®), C 14H 23N 2O 2(C 4H 5O 6)

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

Kaduk, James A.; Zhong, Kai; Gindhart, Amy M.

2016-03-08

The crystal structure of rivastigmine hydrogen tartrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Rivastigmine hydrogen tartrate crystallizes in space groupP2 1(#4) witha= 17.538 34(5),b= 8.326 89(2),c= 7.261 11(2) Å,β= 98.7999(2)°,V= 1047.929(4) Å 3, andZ= 2. The un-ionized end of the hydrogen tartrate anions forms a very strong hydrogen bond with the ionized end of another anion to form a chain. The ammonium group of the rivastigmine cation forms a strong discrete hydrogen bond with the carbonyl oxygen atom of the un-ionized end of the tartrate anion. These hydrogen bondsmore » form a corrugated network in thebc-plane. Both hydroxyl groups of the tartrate anion form intramolecular O–H···O hydrogen bonds. Several C–H···O hydrogen bonds appear to contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File ™as entry 00-064-1501.« less

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages.

PubMed

Stitt, C A; Harker, N J; Hallam, K R; Paraskevoulakos, C; Banos, A; Rennie, S; Jowsey, J; Scott, T B

2015-01-01

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages

PubMed Central

Harker, N. J.; Hallam, K. R.; Paraskevoulakos, C.; Banos, A.; Rennie, S.; Jowsey, J.

2015-01-01

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed. PMID:26176551

In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

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

Álvarez-Pinazo, G.; Cuesta, A.; García-Maté, M.

Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (α). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (α ∼ 70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with β- and α′{sub H}-belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (αmore » ∼ 25% at 1 h) than in the active-BCSA one (α ∼ 10% at 1 h), with differences in the crystallization of ettringite (α ∼ 30% and α ∼ 5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail. -- Highlights: •Belite calcium sulfoaluminate cements early hydration mechanism has been determined. •Belite hydration strongly depends on availability of aluminum hydroxide. •Orthorhombic ye’elimite dissolved at a higher pace than cubic one. •Ye’elimite larger reaction degree yields stratlingite formation by belite reaction. •Rietveld method quantified gypsum, anhydrite and bassanite dissolution rates.« less

Microstructural and micromechanical characterization of IN718 theta shaped specimens built with electron beam melting

DOE PAGES

Cakmak, Ercan; Kirka, Michael M.; Watkins, Thomas R.; ...

2016-02-23

Theta-shaped specimens were additively manufactured out of Inconel 718 powders using an electron beam melting technique, as a model complex load bearing structure. We employed two different build strategies; producing two sets of specimens. Microstructural and micro-mechanical characterizations were performed using electron back-scatter, synchrotron x-ray and in-situ neutron diffraction techniques. In particular, the cross-members of the specimens were the focus of the synchrotron x-ray and in-situ neutron diffraction measurements. The build strategies employed resulted in the formation of distinct microstructures and crystallographic textures, signifying the importance of build-parameter manipulation for microstructural optimization. Large strain anisotropy of the different lattice planesmore » was observed during in-situ loading. Texture was concluded to have a distinct effect upon both the axial and transverse strain responses of the cross-members. In particular, the (200), (220) and (420) transverse lattice strains all showed unexpected overlapping trends in both builds. This was related to the strong {200} textures along the build/loading direction, providing agreement between the experimental and calculated results.« less

Size–strain separation in diffraction line profile analysis

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

Scardi, P.; Ermrich, M.; Fitch, A.

Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size–strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensitymore » values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.« less

Size–strain separation in diffraction line profile analysis

DOE PAGES

Scardi, P.; Ermrich, M.; Fitch, A.; ...

2018-05-29

Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size–strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensitymore » values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.« less

Combining operando synchrotron X-ray tomographic microscopy and scanning X-ray diffraction to study lithium ion batteries

PubMed Central

Pietsch, Patrick; Hess, Michael; Ludwig, Wolfgang; Eller, Jens; Wood, Vanessa

2016-01-01

We present an operando study of a lithium ion battery combining scanning X-ray diffraction (SXRD) and synchrotron radiation X-ray tomographic microscopy (SRXTM) simultaneously for the first time. This combination of techniques facilitates the investigation of dynamic processes in lithium ion batteries containing amorphous and/or weakly attenuating active materials. While amorphous materials pose a challenge for diffraction techniques, weakly attenuating material systems pose a challenge for attenuation-contrast tomography. Furthermore, combining SXRD and SRXTM can be used to correlate processes occurring at the atomic level in the crystal lattices of the active materials with those at the scale of electrode microstructure. To demonstrate the benefits of this approach, we investigate a silicon powder electrode in lithium metal half-cell configuration. Combining SXRD and SRXTM, we are able to (i) quantify the dissolution of the metallic lithium electrode and the expansion of the silicon electrode, (ii) better understand the formation of the Li15Si4 phase, and (iii) non-invasively probe kinetic limitations within the silicon electrode. A simple model based on the 1D diffusion equation allows us to qualitatively understand the observed kinetics and demonstrates why high-capacity electrodes are more prone to inhomogeneous lithiation reactions. PMID:27324109

Combining operando synchrotron X-ray tomographic microscopy and scanning X-ray diffraction to study lithium ion batteries

NASA Astrophysics Data System (ADS)

Pietsch, Patrick; Hess, Michael; Ludwig, Wolfgang; Eller, Jens; Wood, Vanessa

2016-06-01

We present an operando study of a lithium ion battery combining scanning X-ray diffraction (SXRD) and synchrotron radiation X-ray tomographic microscopy (SRXTM) simultaneously for the first time. This combination of techniques facilitates the investigation of dynamic processes in lithium ion batteries containing amorphous and/or weakly attenuating active materials. While amorphous materials pose a challenge for diffraction techniques, weakly attenuating material systems pose a challenge for attenuation-contrast tomography. Furthermore, combining SXRD and SRXTM can be used to correlate processes occurring at the atomic level in the crystal lattices of the active materials with those at the scale of electrode microstructure. To demonstrate the benefits of this approach, we investigate a silicon powder electrode in lithium metal half-cell configuration. Combining SXRD and SRXTM, we are able to (i) quantify the dissolution of the metallic lithium electrode and the expansion of the silicon electrode, (ii) better understand the formation of the Li15Si4 phase, and (iii) non-invasively probe kinetic limitations within the silicon electrode. A simple model based on the 1D diffusion equation allows us to qualitatively understand the observed kinetics and demonstrates why high-capacity electrodes are more prone to inhomogeneous lithiation reactions.

X-ray Diffraction Study of Aluminum Carbide Powder to 50 GPa

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

Ji, C.; Ma, Y; Chyu, M

2009-01-01

The crystal structure and equation of state (EOS) of aluminum carbide (Al{sub 4}C{sub 3}) have been determined directly up to 50.1 GPa at room temperature by the synchrotron x-ray diffraction techniques. The results indicate that Al{sub 4}C{sub 3} remained in rhombohedral structure under all tested pressure-temperature conditions and exhibited anisotropic compressibility, with the c-axis more compressible than the a-axis. Fitting the experimental data to third order Birch-Murnaghan EOS yields a bulk modulus of K{sub OT} = 233 {+-} 6 GPa with its pressure derivative K{sub OT}{prime} = 3.4 {+-} 0.4, while the second-order EOS yields K{sub OT} = 223 {+-}more » 2 GPa.« less

In Situ Investigation of a Self-Accelerated Cocrystal Formation by Grinding Pyrazinamide with Oxalic Acid.

PubMed

Kulla, Hannes; Greiser, Sebastian; Benemann, Sigrid; Rademann, Klaus; Emmerling, Franziska

2016-07-14

A new cocrystal of pyrazinamide with oxalic acid was prepared mechanochemically and characterized by PXRD, Raman spectroscopy, solid-state NMR spectroscopy, DTA-TG, and SEM. Based on powder X-ray diffraction data the structure was solved. The formation pathway of the reaction was studied in situ using combined synchrotron PXRD and Raman spectroscopy. Using oxalic acid dihydrate the initially neat grinding turned into a rapid self-accelerated liquid-assisted grinding process by the release of crystallization water. Under these conditions, the cocrystal was formed directly within two minutes.

In-situ high-pressure powder X-ray diffraction study of α-zirconium phosphate.

PubMed

Readman, Jennifer E; Lennie, Alistair; Hriljac, Joseph A

2014-06-01

The high-pressure structural chemistry of α-zirconium phosphate, α-Zr(HPO4)2·H2O, was studied using in-situ high-pressure diffraction and synchrotron radiation. The layered phosphate was studied under both hydrostatic and non-hydrostatic conditions and Rietveld refinement carried out on the resulting diffraction patterns. It was found that under hydrostatic conditions no uptake of additional water molecules from the pressure-transmitting medium occurred, contrary to what had previously been observed with some zeolite materials and a layered titanium phosphate. Under hydrostatic conditions the sample remained crystalline up to 10 GPa, but under non-hydrostatic conditions the sample amorphized between 7.3 and 9.5 GPa. The calculated bulk modulus, K0 = 15.2 GPa, showed the material to be very compressible with the weak linkages in the structure of the type Zr-O-P.

High-resolution neutron diffraction study of CuNCN: New evidence of structure anomalies at low temperature

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

Jacobs, Philipp; Houben, Andreas; Dronskowski, Richard, E-mail: drons@HAL9000.ac.rwth-aachen.de

Copper carbodiimide (CuNCN) is the nitrogen-containing analogue of cupric oxide. Based on high-resolution neutron-diffraction data, CuNCN's lattice parameters are derived as a function of the temperature. In accordance with a recent synchrotron study, a clear trend in the cell parameter a is observed accompanying the changing magnetic behavior. With decreasing temperature, a slowly decreases to a minimum at ∼100 K after which it rises again. The same trend—albeit more pronounced—is observed for the c lattice parameter at ∼35 K. The herein presented neutron powder-diffraction data also support the conjectured sequence of transitions from the high-temperature one-dimensional resonating valence-bond (RVB) statemore » to a transient two-dimensional RVB state and eventually, at lowest temperatures, into another two-dimensional RVB state, presumably the ground state.« less

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

Newman, Justin A.; Schmitt, Paul D.; Toth, Scott J.

Here in this paper we demonstrate the use of second harmonic generation (SHG) microscopy-guided synchrotron powder X-ray diffraction (PXRD) for the detection of trace crystalline active pharmaceutical ingredients in a common polymer blend. The combined instrument is capable of detecting 100 ppm crystalline ritonavir in an amorphous hydroxypropyl methylcellulose matrix with a high signal-to-noise ratio (>5000). The high spatial resolution afforded by SHG microscopy allows for the use of a minibeam collimator to reduce the total volume of material probed by synchrotron PXRD. The reduction in probed volume results in reduced background from amorphous material. The ability to detect lowmore » crystalline loading has the potential to improve measurements in the formulation pipeline for pharmaceutical solid dispersions, for which even trace quantities of crystalline active ingredients can negatively impact the stability and bioavailability of the final drug product.« less

Insights into the varnishes of historical musical instruments using synchrotron micro-analytical methods

NASA Astrophysics Data System (ADS)

Echard, J.-P.; Cotte, M.; Dooryhee, E.; Bertrand, L.

2008-07-01

Though ancient violins and other stringed instruments are often revered for the beauty of their varnishes, the varnishing techniques are not much known. In particular, very few detailed varnish analyses have been published so far. Since 2002, a research program at the Musée de la musique (Paris) is dedicated to a detailed description of varnishes on famous ancient musical instruments using a series of novel analytical methods. For the first time, results are presented on the study of the varnish from a late 16th century Venetian lute, using synchrotron micro-analytical methods. Identification of both organic and inorganic compounds distributed within the individual layers of a varnish microsample has been performed using spatially resolved synchrotron Fourier transform infrared microscopy. The univocal identification of the mineral phases is obtained through synchrotron powder X-ray diffraction. The materials identified may be of utmost importance to understand the varnishing process and its similarities with some painting techniques. In particular, the proteinaceous binding medium and the calcium sulfate components (bassanite and anhydrite) that have been identified in the lower layers of the varnish microsample could be related, to a certain extent, to the ground materials of earlier Italian paintings.

Copper doped TiO2 nanoparticles characterized by X-ray absorption spectroscopy, total scattering, and powder diffraction--a benchmark structure-property study.

PubMed

Lock, Nina; Jensen, Ellen M L; Mi, Jianli; Mamakhel, Aref; Norén, Katarina; Qingbo, Meng; Iversen, Bo B

2013-07-14

Metal functionalized nanoparticles potentially have improved properties e.g. in catalytic applications, but their precise structures are often very challenging to determine. Here we report a structural benchmark study based on tetragonal anatase TiO2 nanoparticles containing 0-2 wt% copper. The particles were synthesized by continuous flow synthesis under supercritical water-isopropanol conditions. Size determination using synchrotron PXRD, TEM, and X-ray total scattering reveals 5-7 nm monodisperse particles. The precise dopant structure and thermal stability of the highly crystalline powders were characterized by X-ray absorption spectroscopy and multi-temperature synchrotron PXRD (300-1000 K). The combined evidence reveals that copper is present as a dopant on the particle surfaces, most likely in an amorphous oxide or hydroxide shell. UV-VIS spectroscopy shows that copper presence at concentrations higher than 0.3 wt% lowers the band gap energy. The particles are unaffected by heating to 600 K, while growth and partial transformation to rutile TiO2 occur at higher temperatures. Anisotropic unit cell behavior of anatase is observed as a consequence of the particle growth (a decreases and c increases).

Squeezing clathrate cages to host trivalent rare-earth guests

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

Wang, Jian; He, Yuping; Mordvinova, Natalia E.

Strike difference of the trivalent rare-earth cations from their alkali and alkaline-earth peers is in the presence of localized 4f-electrons and strong spin-orbit coupling. Placing trivalent rare-earth cations inside the fullerene molecules or in between the blocks of itinerant magnetic intermetallics gave rise to plethora of fascinating properties and materials. A long-time missing but hardly desired piece is the semiconducting or metallic compound where rare-earth cations are situated inside the oversized polyhedral cages of three-dimensional framework. In this work we present a synthesis of such compounds, rare-earth containing clathrates Ba 8-xR xCu 16P 30. The unambiguous proofs of their compositionmore » and crystal structure were achieved by a combination of synchrotron powder diffraction, time-of-flight neutron powder diffraction, scanning-transmission electron microscopy, and electron energy-loss spectroscopy. Our quantum-mechanical calculations and experimental characterizations show that the incorporation of the rare-earth cations significantly enhances the hole mobility and concentration which results in the drastic increase in the thermoelectric performance.« less

Crystal-structure analysis of four mineral samples of anhydrite, CaSO[subscript 4], using synchrotron high-resolution powder X-ray diffraction data

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

Antao, Sytle M.

2014-05-28

The crystal structures of four samples of anhydrite, CaSO{sub 4}, were obtained by Rietveld refinements using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and space group Amma. As an example, for one sample of anhydrite from Hants County, Nova Scotia, the unit-cell parameters are a = 7.00032(2), b = 6.99234(1), c = 6.24097(1) {angstrom}, and V = 305.487(1) {angstrom}{sup 3} with a > b. The eight-coordinated Ca atom has an average distance of 2.4667(4) {angstrom}. The tetrahedral SO{sub 4} group has two independent S-O distances of 1.484(1) to O1 and 1.478(1) {angstrom} to O2 and an average distancemore » of 1.4810(5) {angstrom}. The three independent O-S-O angles [108.99(8) x 1, 110.38(3) x 4, 106.34(9){sup o} x 1; average [6] = 109.47(2){sup o}] and S-O distances indicate that the geometry of the SO{sub 4} group is quite distorted in anhydrite. The four anhydrite samples have structural trends where the a, b, and c unit-cell parameters increase linearly with increasing unit-cell volume, V, and their average and distances are nearly constant. The grand mean = 2.4660(2) {angstrom}, and grand mean = 1.4848(3) {angstrom}, the latter is longer than 1.480(1) {angstrom} in celestite, SrSO{sub 4}, as expected.« less

Crystal structure of carnidazole form II from synchrotron X-ray powder diffraction: structural comparison with form I, the hydrated form and the low energy conformations in vacuo.

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Blaton, Norbert; Van den Mooter, Guy; De Ridder, Dirk J A; Schenk, Henk

2006-10-01

The crystal structure of carnidazole form II, O-methyl [2-(2-methyl-5-nitro-1H-imidazole-1-yl)ethyl]thiocarbamate, has been determined using synchrotron X-ray powder diffraction in combination with simulated annealing and whole profile pattern matching, and refined by the Rietveld method. For structure solution, 12 degrees of freedom were defined: one motion group and six torsions. Form II crystallizes in space group P2(1)/n, Z=4, with unit cell parameters after Rietveld refinement: a=13.915(4), b=8.095(2), c=10.649(3) A, beta=110.83(1) degrees, and V=1121.1(5) A3. The two polymorphic forms, as well as the hydrate, crystallize in the monoclinic space group P2(1)/n having four molecules in the cell. In form II, the molecules are held together by forming two infinite zig-zag chains via hydrogen bonds of the type N--H...N, the same pattern as in form I. A conformational study of carnidazole, at semiempirical PM3 level, was performed using stochastic approaches based on modification of the flexible torsion angles. The values of the torsion angles for the molecules of the two polymorphic forms and the hydrate of carnidazole are compared to those obtained from the conformational search. Form I and form II are enantiotropic polymorphic pairs this agrees with the fact that the two forms are conformational polymorphs. Copyright (c) 2006 Wiley-Liss, Inc. and the American Pharmacists Association

Structure of Ce2RhIn8: an example of complementary use of high-resolution neutron powder diffraction and reciprocal-space mapping to study complex materials.

PubMed

Moshopoulou, E G; Ibberson, R M; Sarrao, J L; Thompson, J D; Fisk, Z

2006-04-01

The room-temperature crystal structure of the heavy fermion antiferromagnet Ce2RhIn8, dicerium rhodium octaindide, has been studied by a combination of high-resolution synchrotron X-ray reciprocal-space mapping of single crystals and high-resolution time-of-flight neutron powder diffraction. The structure is disordered, exhibiting a complex interplay of non-periodic, partially correlated planar defects, coexistence and segregation of polytypic phases (induced by periodic planar ;defects'), mosaicity (i.e. domain misalignment) and non-uniform strain. These effects evolve as a function of temperature in a complicated way, but they remain down to low temperatures. The room-temperature diffraction data are best represented by a complex mixture of two polytypic phases, which are affected by non-periodic, partially correlated planar defects, differ slightly in their tetragonal structures, and exhibit different mosaicities and strain values. Therefore, Ce2RhIn8 approaches the paracrystalline state, rather than the classic crystalline state and thus several of the concepts of conventional single-crystal crystallography are inapplicable. The structural results are discussed in the context of the role of disorder in the heavy-fermion state and in the interplay between superconductivity and magnetism.

CIT-7, a crystalline, molecular sieve with pores bounded by 8 and 10-membered rings† †Electronic supplementary information (ESI) available: Details of the synthesis and characterization of all materials as well as details on the synchrotron and RED data collection and structure determination, including the cif file. See DOI: 10.1039/c4sc03935a Click here for additional data file.

PubMed Central

Schmidt, Joel E.; Xie, Dan; Rea, Thomas

2015-01-01

A new crystalline molecular sieve, denoted CIT-7, is synthesized using an imidazolium-based diquaternary organic structure directing agent (OSDA). The framework structure is determined from a combination of rotation electron diffraction and synchrotron X-ray powder diffraction data. The structure has 10 crystallographically unique tetrahedral atoms (T-atoms) in the unit cell, and can be described as an ordered arrangement of the [425462] mtw building unit and a previously unreported [4452] building unit. The framework contains a 2-dimensional pore system that is bounded by 10 T-atom rings (10-ring, 5.1 Å × 6.2 Å opening) that are connected with oval 8-rings (2.9 Å × 5.5 Å opening) through medium-sized cavities (∼7.9 Å) at the channel intersections. CIT-7 can be synthesized over a broad range of compositions including pure-silica and heteroatom, e.g., aluminosilicate and titanosilicate, containing variants. PMID:29163872

X-ray metrology of an array of active edge pixel sensors for use at synchrotron light sources

NASA Astrophysics Data System (ADS)

Plackett, R.; Arndt, K.; Bortoletto, D.; Horswell, I.; Lockwood, G.; Shipsey, I.; Tartoni, N.; Williams, S.

2018-01-01

We report on the production and testing of an array of active edge silicon sensors as a prototype of a large array. Four Medipix3RX.1 chips were bump bonded to four single chip sized Advacam active edge n-on-n sensors. These detectors were then mounted into a 2 by 2 array and tested on B16 at Diamond Light Source with an x-ray beam spot of 2um. The results from these tests, compared with optical metrology demonstrate that this type of sensor is sensitive to the physical edge of the silicon, with only a modest loss of efficiency in the final two rows of pixels. We present the efficiency maps recorded with the microfocus beam and a sample powder diffraction measurement. These results give confidence that this sensor technology can be used effectively in larger arrays of detectors at synchrotron light sources.

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.

In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

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

Mesbah, Adel, E-mail: adel.mesbah@cea.fr; Clavier, Nicolas; Elkaim, Erik

The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrousmore » form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.« less

Pressure mapping for sphere and half-sphere enhanced diamond anvil cells using synchrotron x-ray diffraction and fluorescence techniques

NASA Astrophysics Data System (ADS)

Liu, H.; Liu, L. L.; Cai, Z.; Shu, J.

2015-12-01

The measurement for equation of state (EoS) of materials under pressure conditions above 200 GPa is a long-standing challenging subject. Recently, second stage anvil, which was loaded inside the diamond anvil cell (DAC), had been reported by various groups. This method could generate pressure over 300 GPa, or above 600 GPa from the EoS measurement of Re metal between the tiny anvil or 2 half-spheres. Several alternative approaches, using ruby balls, or glassy carbon, or diamond, with single sphere, 2 half-spheres, or multi spheres geometry inside DAC, were tested. The NIST X-ray powder standard, ZnO was selected as pressure marker. Focused ion beam (FIB) was used to cut the half-sphere from diamond anvil top directly to avoid the difficulty of alignment. The synchrotron x-ray diffraction with fine beam size down to 100 nm using zone plate set-up was used to map the pressure gradient at the sphere or half-sphere zone inside DAC. The pressure could be boosted at center of sphere by up to 10 - 70 GPa at about 200 GPa conditions. From broken anvils, trace element analysis using fine focusing synchrotron x-ray fluorescence method revealed the potential anvil damage from FIB cutting the diamond anvil tip, which might decrease the strength of anvils. Fine touch from FIB cutting at final stage using low ion beam current is suggested.

Structure and thermal expansion of Ca9Gd(VO4)7: A combined powder-diffraction and dilatometric study of a Czochralski-grown crystal

NASA Astrophysics Data System (ADS)

Paszkowicz, Wojciech; Shekhovtsov, Alexei; Kosmyna, Miron; Loiko, Pavel; Vilejshikova, Elena; Minikayev, Roman; Romanowski, Przemysław; Wierzchowski, Wojciech; Wieteska, Krzysztof; Paulmann, Carsten; Bryleva, Ekaterina; Belikov, Konstantin; Fitch, Andrew

2017-11-01

Materials of the Ca9RE(VO4)7 (CRVO) formula (RE = rare earth) and whitlockite-related structures are considered for applications in optoelectronics, e.g., in white-light emitting diodes and lasers. In the CRVO structure, the RE atoms are known to share the site occupation with Ca atoms at two or three among four Ca sites, with partial occupancy values depending on the choice of the RE atom. In this work, the structure and quality of a Czochralski-grown crystal of this family, Ca9Gd(VO4)7 (CGVO), are studied using X-ray diffraction methods. The room-temperature structure is refined using the powder diffraction data collected at a high-resolution synchrotron beamline ID22 (ESRF, Grenoble); for comparison purposes, a laboratory diffraction pattern was collected and analyzed, as well. The site occupancies are discussed on the basis of comparison with literature data of isostructural synthetic crystals of the CRVO series. The results confirm the previously reported site-occupation scheme and indicate a tendency of the CGVO compound to adopt a Gd-deficient composition. Moreover, the thermal expansion coefficient is determined for CGVO as a function of temperature in the 302-1023 K range using laboratory diffraction data. Additionally, for CGVO and six other single crystals of the same family, thermal expansion is studied in the 298-473 K range, using the dilatometric data. The magnitude and anisotropy of thermal expansion, being of importance for laser applications, are discussed for these materials.

Acoustic emissions imaging and synchrotron X-ray diffraction analysis of calcite at high pressure and temperature

NASA Astrophysics Data System (ADS)

Gasc, J.; Brantut, N.; Schubnel, A.; Brunet, F.; Mueller, H.

2008-12-01

We have monitored from in-situ X-ray diffraction coupled to Acoustic Emission (AE) imaging, the behavior of a fine grained synthetic calcite aggregate, at 0.66 GPa and for temperatures ranging from ambient to 1200° C. The powder sample was placed in a boron-epoxy assembly with an 8 mm edge-length and loaded in the MAX80 cubic multi-anvil press installed on the German synchrotron (HASYLAB-DESY, Hamburg). AE were recorded using five piezoceramic transducers (5 MHz eigen frequency) glued on each of the five WC anvils (4 side anvils and upper one). Full waveforms were acquired using an eight channel digital oscilloscope and located using the software Insite (ASC Ltd). Beyond 600° C, calcite grains started growing as evidenced by huge changes in the relative intensity of the diffraction lines. This is correlated to a sudden burst of AE which all located within the sample volume. These AE may indicate that stress relaxation, going on as intra-crystalline plasticity mechanisms were activated, released enough acoustic energy to be recorded and located. Although the diffraction data showed that grain growth continued beyond 800° C, the acoustic activity progressively decreased to below the sensitivity of our recording device (i.e. the triggering level). However, at temperature higher than 1000° C, a large number of AE were recorded again ( 2000 events). AE location revealed that the AE front progressed inwards the sample. The complete loss of diffraction signal and the post-mortem recovery of small amounts of CaO suggest that the second AE burst may be related to calcite melting/decarbonation. Perspectives include thorough microstructural analysis of the samples using electron microscopies (SEM and TEM) as well as a statistical and mechanical analysis of the acoustic data.

Kinetic studies of methane-ethane mixed gas hydrates by neutron diffraction and Raman spectroscopy.

PubMed

Murshed, M Mangir; Kuhs, Werner F

2009-04-16

In situ formations of CH(4)-C(2)H(6) mixed gas hydrates were made using high flux neutron diffraction at 270 K and 5 MPa. For this purpose, a feed gas composition of CH(4) and C(2)H(6) (95 mol% CH(4)) was employed. The rates of transformation of spherical grains of deuterated ice Ih into hydrates were measured by time-resolved neutron powder diffraction on D20 at ILL, Grenoble. Phase fractions of the crystalline constituents were obtained from Rietveld refinements. A concomitant formation of structure type I (sI) and structure type II (sII) hydrates were observed soon after the gas pressure was applied. The initial fast formation of sII hydrate reached its maximum volume and started declining very slowly. The formation of sI hydrate followed a sigmoid growth kinetics that slowed down due to diffusion limitation. This observation has been interpreted in terms of a kinetically favored nucleation of the sII hydrate along with a slow transformation into sI. Both powder diffraction and Raman spectroscopic results suggest that a C(2)H(6)-rich sII hydrate was formed at the early part of the clathration, which slowly decreased to approximately 3% after a reaction of 158 days as confirmed by synchrotron XRD. The final persistence of a small portion of sII hydrate points to a miscibility gap between CH(4)-rich sI and C(2)H(6)-rich sII hydrates.

Zigzag spin structure in layered honeycomb L i3N i2Sb O6 : A combined diffraction and antiferromagnetic resonance study

NASA Astrophysics Data System (ADS)

Kurbakov, A. I.; Korshunov, A. N.; Podchezertsev, S. Yu.; Malyshev, A. L.; Evstigneeva, M. A.; Damay, F.; Park, J.; Koo, C.; Klingeler, R.; Zvereva, E. A.; Nalbandyan, V. B.

2017-07-01

The magnetic structure of L i3N i2Sb O6 has been determined by low-temperature neutron diffraction, and the crystal structure has been refined by a combination of synchrotron and neutron powder diffraction. The monoclinic (C 2 /m ) symmetry, assigned previously to this pseudohexagonal layered structure, has been unambiguously proven by peak splitting in the synchrotron diffraction pattern. The structure is based on essentially hexagonal honeycomb-ordered N i2Sb O6 layers alternating with L i3 layers, all cations and anions being in an octahedral environment. The compound orders antiferromagnetically below TN=15 K , with the magnetic supercell being a 2 a ×2 b multiple of the crystal cell. The magnetic structure within the honeycomb layer consists of zigzag ferromagnetic spin chains coupled antiferromagnetically. The ordered magnetic moment amounts to 1.62 (2 ) μB/Ni , which is slightly lower than the full theoretical value. Upon cooling below TN, the spins tilt from the c axis, with a maximum tilting angle of 15 .6∘ at T =1.5 K . Our data imply non-negligible ferromagnetic interactions between the honeycomb layers. The observed antiferromagnetic resonance modes are in agreement with the two-sublattice model derived from the neutron data. Orthorhombic anisotropy shows up in zero-field splitting of Δ =198 ±4 and 218 ±4 GHz . Above TN, the electron spin resonance data imply short-range antiferromagnetic order up to about 80 K.

Absence of pressure-induced amorphization in LiKSO4.

PubMed

Machon, D; Pinheiro, C B; Bouvier, P; Dmitriev, V P; Crichton, W A

2010-08-11

Angle-resolved synchrotron radiation diffraction was used to investigate lithium potassium sulfate (LiKSO(4)) crystals under high pressure. We confirm that the title compound undergoes three phase transitions, α →β, β → γ and γ →δ, observed at around 0.8 GPa, 4.0 GPa and 7.0 GPa, respectively. Two competitive structures are proposed for the β-phase after powder diffraction data Rietveld refinements: an orthorhombic (space group Cmc 2(1)) or a monoclinic (space group Cc) structure. These structures correspond to the models of the low temperature phases. The γ-phase is indexed by a monoclinic structure. Finally, the δ-phase is found to be highly disordered. No evidence of any pressure-induced amorphous phase was observed up to 24 GPa, even under imposed highly non-hydrostatic conditions, contrary to previous propositions.

The single-crystal structure of the organic superconductor betaCO-(BEDT-TTF)2I3 from a powder grain.

PubMed

Madsen; Burghammer; Fiedler; Müller

1999-08-01

Synchrotron radiation diffraction data have been collected at 200 K on a microscopic single crystal (dimensions 12 x 10 x 2 µm) of the title compound, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene, C(10)H(8)S(8). The quality of the diffraction data allowed a full structure refinement and enabled the determination of structural details such as the conformations of the ethylene groups as well as the occupancy of the triiodide sites. The compound was found to be slightly iodine-deficient and better described as beta(CO)-(BEDT-TTF)(2)I(3-x) [x = 0.014 (3)]. One of the ethylene groups of the BEDT-TTF cation is disordered at this temperature and exists in two distinct conformations with occupancies which are identical within the standard uncertainty.

Reaction Heterogeneity in LiNi 0.8 Co 0.15 Al 0.05 O 2 Induced by Surface Layer

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

Grenier, Antonin; Liu, Hao; Wiaderek, Kamila M.

2017-08-15

Through operando synchrotron powder X-ray diffraction (XRD) analysis of layered transition metal oxide electrodes of composition LiNi0.8Co0.15Al0.05O2 (NCA), we decouple the intrinsic bulk reaction mechanism from surface-induced effects. For identically prepared and cycled electrodes stored in different environments, we demonstrate that the intrinsic bulk reaction for pristine NCA follows solid-solution mechanism, not a two-phase as suggested previously. By combining high resolution powder X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and surface sensitive X-ray photoelectron spectroscopy (XPS), we demonstrate that adventitious Li2CO3 forms on the electrode particle surface during exposure to air, through reaction with atmospheric CO2. This surfacemore » impedes ionic and electronic transport to the underlying electrode, with progressive erosion of this layer during cycling giving rise to different reaction states in particles with an intact vs an eroded Li2CO3 surface-coating. This reaction heterogeneity, with a bimodal distribution of reaction states, has previously been interpreted as a “two-phase” reaction mechanism for NCA, as an activation step that only occurs during the first cycle. Similar surface layers may impact the reaction mechanism observed in other electrode materials using bulk probes such as operando powder XRD.« less

Determination of a Two-Phase Structure of Nanocrystals: GaN and SiC

NASA Technical Reports Server (NTRS)

Palosz, W.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Lojkowski, W.; Bismayer, U.; Neuefeind, J.; Weber, H.-P.; Janik, J. F.;

Complete elliptical ring geometry provides energy and instrument calibration for synchrotron-based two-dimensional X-ray diffraction

PubMed Central

Hart, Michael L.; Drakopoulos, Michael; Reinhard, Christina; Connolley, Thomas

2013-01-01

A complete calibration method to characterize a static planar two-dimensional detector for use in X-ray diffraction at an arbitrary wavelength is described. This method is based upon geometry describing the point of intersection between a cone’s axis and its elliptical conic section. This point of intersection is neither the ellipse centre nor one of the ellipse focal points, but some other point which lies in between. The presented solution is closed form, algebraic and non-iterative in its application, and gives values for the X-ray beam energy, the sample-to-detector distance, the location of the beam centre on the detector surface and the detector tilt relative to the incident beam. Previous techniques have tended to require prior knowledge of either the X-ray beam energy or the sample-to-detector distance, whilst other techniques have been iterative. The new calibration procedure is performed by collecting diffraction data, in the form of diffraction rings from a powder standard, at known displacements of the detector along the beam path. PMID:24068840

In situ study of maize starch gelatinization under ultra-high hydrostatic pressure using X-ray diffraction.

PubMed

Yang, Zhi; Gu, Qinfen; Hemar, Yacine

2013-08-14

The gelatinization of waxy (very low amylose) and high-amylose maize starches by ultra-high hydrostatic pressure (up to 6 GPa) was investigated in situ using synchrotron X-ray powder diffraction on samples held in a diamond anvil cell (DAC). The starch pastes, made by mixing starch and water in a 1:1 ratio, were pressurized and measured at room temperature. X-ray diffraction pattern showed that at 2.7 GPa waxy starch, which displayed A-type XRD pattern at atmospheric pressure, exhibited a faint B-type-like pattern. The B-type crystalline structures of high-amylose starch were not affected even when 1.5 GPa pressure was applied. However, both waxy and high-amylose maize starches can be fully gelatinized at 5.9 GPa and 5.1 GPa, respectively. In the case of waxy maize starch, upon release of pressure (to atmospheric pressure) crystalline structure appeared as a result of amylopectin aggregation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Accommodating High Transformation Strains in Battery Electrodes via the Formation of Nanoscale Intermediate Phases: Operando Investigation of Olivine NaFePO 4 [Accommodation of High Transformation Strain in Battery Electrodes via Formation of Nanoscale Intermediate Phases: Operando Structure Investigation of Olivine Sodium Iron Phosphate

DOE PAGES

Xiang, Kai; Xing, Wenting; Ravnsbaek, Dorthe B.; ...

2017-02-21

Virtually all intercalation compounds used as battery electrodes exhibit significant changes in unit cell volume during use. Na xFePO 4 (0 < x < 1, NFP) olivine, of interest as a cathode for sodium-ion batteries, is a model for topotactic, high strain systems as it exhibits one of the largest discontinuous volume changes (~17% by volume) during its first-order transition between two otherwise isostructural phases. Using synchrotron radiation powder X-ray diffraction (PXD) and pair distribution function (PDF) analysis, we discover a new strain-accommodation mechanism wherein a third, <10 nm scale nanocrystalline phase forms to buffer the large lattice mismatch betweenmore » primary phases. The new phase has a and b lattice parameters matching one crystalline endmember phase and c lattice parameter matching the other, and is not detectable by powder diffraction alone. Finally, we suggest that this strain-accommodation mechanism may apply to systems with large transformation strains but in which true “amorphization” does not occur.« less

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

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

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic-inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm -1 for Pb(II) and ca. 1580 cm -1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. Finally, these complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

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

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic–inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm –1 for Pb(II) and ca. 1580 cm –1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. These complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

DOE PAGES

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.; ...

2016-09-07

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K +, Zn 2+, Pb 2+) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic-inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm -1 for Pb(II) and ca. 1580 cm -1 for Zn(II) are consistentmore » with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. Finally, these complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.« less

Accommodating High Transformation Strains in Battery Electrodes via the Formation of Nanoscale Intermediate Phases: Operando Investigation of Olivine NaFePO 4 [Accommodation of High Transformation Strain in Battery Electrodes via Formation of Nanoscale Intermediate Phases: Operando Structure Investigation of Olivine Sodium Iron Phosphate

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

Xiang, Kai; Xing, Wenting; Ravnsbaek, Dorthe B.

Virtually all intercalation compounds used as battery electrodes exhibit significant changes in unit cell volume during use. Na xFePO 4 (0 < x < 1, NFP) olivine, of interest as a cathode for sodium-ion batteries, is a model for topotactic, high strain systems as it exhibits one of the largest discontinuous volume changes (~17% by volume) during its first-order transition between two otherwise isostructural phases. Using synchrotron radiation powder X-ray diffraction (PXD) and pair distribution function (PDF) analysis, we discover a new strain-accommodation mechanism wherein a third, <10 nm scale nanocrystalline phase forms to buffer the large lattice mismatch betweenmore » primary phases. The new phase has a and b lattice parameters matching one crystalline endmember phase and c lattice parameter matching the other, and is not detectable by powder diffraction alone. Finally, we suggest that this strain-accommodation mechanism may apply to systems with large transformation strains but in which true “amorphization” does not occur.« less

Swinging Symmetry, Multiple Structural Phase Transitions, and Versatile Physical Properties in RECuGa3 (RE = La-Nd, Sm-Gd).

PubMed

Subbarao, Udumula; Rayaprol, Sudhindra; Dally, Rebecca; Graf, Michael J; Peter, Sebastian C

2016-01-19

The compounds RECuGa3 (RE = La-Nd, Sm-Gd) were synthesized by various techniques. Preliminary X-ray diffraction (XRD) analyses at room temperature suggested that the compounds crystallize in the tetragonal system with either the centrosymmetric space group I4/mmm (BaAl4 type) or the non-centrosymmetric space group I4mm (BaNiSn3 type). Detailed single-crystal XRD, neutron diffraction, and synchrotron XRD studies of selected compounds confirmed the non-centrosymmetric BaNiSn3 structure type at room temperature with space group I4mm. Temperature-dependent single-crystal XRD, powder XRD, and synchrotron beamline measurements showed a structural transition between centro- and non-centrosymmetry followed by a phase transition to the Rb5Hg19 type (space group I4/m) above 400 K and another transition to the Cu3Au structure type (space group Pm3̅m) above 700 K. Combined single-crystal and synchrotron powder XRD studies of PrCuGa3 at high temperatures revealed structural transitions at higher temperatures, highlighting the closeness of the BaNiSn3 structure to other structure types not known to the RECuGa3 family. The crystal structure of RECuGa3 is composed of eight capped hexagonal prism cages [RE4Cu4Ga12] occupying one rare-earth atom in each ring, which are shared through the edge of Cu and Ga atoms along the ab plane, resulting in a three-dimensional network. Resistivity and magnetization measurements demonstrated that all of these compounds undergo magnetic ordering at temperatures between 1.8 and 80 K, apart from the Pr and La compounds: the former remains paramagnetic down to 0.3 K, while superconductivity was observed in the La compound at T = 1 K. It is not clear whether this is intrinsic or due to filamentary Ga present in the sample. The divalent nature of Eu in EuCuGa3 was confirmed by magnetization measurements and X-ray absorption near edge spectroscopy and is further supported by the crystal structure analysis.

Ball-free mechanochemistry: in situ real-time monitoring of pharmaceutical co-crystal formation by resonant acoustic mixing.

PubMed

Michalchuk, Adam A L; Hope, Karl S; Kennedy, Stuart R; Blanco, Maria V; Boldyreva, Elena V; Pulham, Colin R

2018-04-17

Resonant acoustic mixing (RAM) is a new technology designed for intensive mixing of powders that offers the capability to process powders with minimal damage to particles. This feature is particularly important for mixing impact-sensitive materials such as explosives and propellants. While the RAM technique has been extensively employed for the mixing of powders and viscous polymers, comparatively little is known about its use for mechanosynthesis. We present here the first in situ study of RAM-induced co-crystallisation monitored using synchrotron X-ray powder diffraction. The phase profile of the reaction between nicotinamide and carbamazepine in the presence of a small amount of water was monitored at two different relative accelerations of the mixer. In marked contrast to ball-milling techniques, the lack of milling bodies in the RAM experiment does not hinder co-crystallisation of the two starting materials, which occurred readily and was independent of the frequency of oscillation. The reaction could be optimised by enhancing the number of reactive contacts through mixing and comminution. These observations provide new insight into the role of various experimental parameters in conventional mechanochemistry using liquid-assisted grinding techniques.

Antiferromagnetic interaction between A'-site Mn spins in A-site-ordered perovskite YMn3Al4O12.

PubMed

Tohyama, Takenori; Saito, Takashi; Mizumaki, Masaichiro; Agui, Akane; Shimakawa, Yuichi

2010-03-01

The A-site-ordered perovskite YMn(3)Al(4)O(12) was prepared by high-pressure synthesis. Structural analysis with synchrotron powder X-ray diffraction data and the Mn L-edges X-ray absorption spectrum revealed that the compound has a chemical composition Y(3+)Mn(3+)(3)Al(3+)(4)O(2-)(12) with magnetic Mn(3+) at the A' site and non-magnetic Al(3+) at the B site. An antiferromagnetic interaction between the A'-site Mn(3+) spins is induced by the nearest neighboring Mn-Mn direct exchange interaction and causes an antiferromagnetic transition at 34.3 K.

In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 1: Corrosion in water vapour.

PubMed

Stitt, C A; Paraskevoulakos, C; Banos, A; Harker, N J; Hallam, K R; Davenport, A; Street, S; Scott, T B

2017-08-11

Uranium encapsulated in grout was exposed to water vapour for extended periods of time. Through synchrotron x-ray powder diffraction and tomography measurements, uranium dioxide was determined the dominant corrosion product over a 50-week time period. The oxide growth rate initiated rapidly, with rates comparable to the U + H 2 O reaction. Over time, the reaction rate decreased and eventually plateaued to a rate similar to the U + H 2 O + O 2 reaction. This behaviour was not attributed to oxygen ingress, but instead the decreasing permeability of the grout, limiting oxidising species access to the metal surface.

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.

In situ investigations of phase transformations in Fe-sheathed MgB2 wires

NASA Astrophysics Data System (ADS)

Grivel, J.-C.; Pinholt, R.; Andersen, N. H.; Kovác, P.; Husek, I.; Homeyer, J.

2006-01-01

The phase evolution inside Fe-sheathed wires containing precursor powders consisting of a mixture of Mg and B has been studied in situ by means of x-ray diffraction with hard synchrotron radiation (90 keV). Mg was found to disappear progressively during the heating stage. At 500 °C, the intensity of the Mg diffraction lines is reduced by about 20%. This effect is partly attributable to MgO formation. The MgB2 phase was detected from 575 °C. Fe2B was forming at the interface between the sheath and the ceramic core at sintering temperatures of 780 and 700 °C, but not at 650 °C. The formation rate of this phase is strongly dependent on the heat treatment temperature. Its presence can be readily detected as soon as the average interface reaction thickness exceeds 150-200 nm.

Multiscale understanding of tricalcium silicate hydration reactions.

PubMed

Cuesta, Ana; Zea-Garcia, Jesus D; Londono-Zuluaga, Diana; De la Torre, Angeles G; Santacruz, Isabel; Vallcorba, Oriol; Dapiaggi, Monica; Sanfélix, Susana G; Aranda, Miguel A G

2018-06-04

Tricalcium silicate, the main constituent of Portland cement, hydrates to produce crystalline calcium hydroxide and calcium-silicate-hydrates (C-S-H) nanocrystalline gel. This hydration reaction is poorly understood at the nanoscale. The understanding of atomic arrangement in nanocrystalline phases is intrinsically complicated and this challenge is exacerbated by the presence of additional crystalline phase(s). Here, we use calorimetry and synchrotron X-ray powder diffraction to quantitatively follow tricalcium silicate hydration process: i) its dissolution, ii) portlandite crystallization and iii) C-S-H gel precipitation. Chiefly, synchrotron pair distribution function (PDF) allows to identify a defective clinotobermorite, Ca 11 Si 9 O 28 (OH) 2 . 8.5H 2 O, as the nanocrystalline component of C-S-H. Furthermore, PDF analysis also indicates that C-S-H gel contains monolayer calcium hydroxide which is stretched as recently predicted by first principles calculations. These outcomes, plus additional laboratory characterization, yielded a multiscale picture for C-S-H nanocomposite gel which explains the observed densities and Ca/Si atomic ratios at the nano- and meso- scales.

Time-Resolved Structural Analysis of Cation Exchange Reactions in Birnessite Using Synchrotron XRD

NASA Astrophysics Data System (ADS)

Lopano, C. L.; Heaney, P. J.; Post, J. E.; Hanson, J. C.; Lee, Y.; Komarneni, S.

2002-12-01

Birnessite ((Na,Ca,Mn2+) Mn7O142.8H2O) is a layered Mn-oxide with a 7.2Å spacing between the Mn octahedral sheets. Since birnessite is an abundant phase in soils, desert varnishes, and ocean nodules, it plays a significant role in soil and groundwater chemistry. Experiments by Golden et al. (1986,1987) have demonstrated that Na-buserite (hydrated birnessite) readily exchanges Na+ for a variety of other cations, including K+, Mg2+, Ca2+, Ba2+, Ni2+, and Sr2+. In light of its high cation exchange capacity, birnessite is industrially important for ion and molecular sieves and cathodic materials. In addition, birnessite serves as a precursor in the synthesis of todorokite, which has a 3x3 tunnel structure and is used as an octahedral sieve. We monitored cation-exchange reactions in birnessite by time-resolved X-ray powder diffraction with a simple flow-through cell at the National Synchrotron Light Source. The flow-through cell was developed by Lee and Parise at SUNY-Stony Brook, and this work represents its first application to Mn oxides. A series of synthetic Na-birnessite samples were saturated with chloride solutions containing dissolved K+, Mg2+, and Ba2+, ranging from 0.1M to 0.001M. Powder X-ray diffraction patterns were collected every ~ 3 minutes. The synchrotron experiments revealed that complete cation exchange occurs within three hours, and significant modifications of the arrangements of interlayer cations and water molecules accompany the exchange. Specifically, the replacement of Na by Mg resulted in the continuous growth of a discrete buserite-like phase with a 10Å layer spacing, while replacement of Na by K and Ba retained the 7Å spacing. K replacement of Na resulted in gradually decreasing peak intensity and peak merging. The Ba exchange yielded an abrupt decrease in diffraction intensities followed by a more gradual lattice change over the last 2 hours. Rietveld analysis led to the first determination of the structure of Ba-birnessite in space group C-1. With a final chi-squared parameter of 1.540, the refined lattice parameters were a = 5.178(2)Å, b = 2.850(3)Å, c = 7.320(5)Å, α = 89.512(1)°, β = 102.989(6)°, and γ = 89.893(6)°. However, the lattice parameters of the fully exchanged Ba-birnessite indicate that Ba substitution causes the unit cell to be more monoclinic.

In-situ synchrotron wide-angle X-ray diffraction as a rapid method for cocrystal/salt screening.

PubMed

Dong, Pin; Lin, Ling; Li, Yongcheng; Huang, Zhengwei; Lang, Tianqun; Wu, Chuanbin; Lu, Ming

2015-12-30

The purpose of this work was to explore in-situ synchrotron wide-angle X-ray diffraction (WAXD) as a rapid and accurate tool to screen and monitor the formation of cocrystal/salts during heating. The active pharmaceutical ingredients (caffeine, carbamazepine and lamotrigine) were respectively mixed with the coformer (saccharin), and then heated by the hot stage. Real-time process monitoring was performed using synchrotron WAXD to assess cocrystal formation and subsequently compared to differential scanning calorimetry (DSC) measurements. The effect of heating rates and cocrystal growth behavior were investigated. Synchrotron WAXD was fast and sensitive to detect cocrystal formation with the appearance of characteristic diffraction rings, even at the heating rate of 30°C/min, while DSC curves showed overlapped peaks. Unlike the indirect characterization of DSC on endo/exothermic peaks, synchrotron WAXD can directly and qualitatively determine cocrystal by diffraction peaks. The diffraction intensity-temperature curves and the corresponding first-derivative curves clearly exhibited the growth behavior of cocrystal upon heating, providing useful information to optimize the process temperature of hot melt extrusion to continuously manufacture cocrystal. The study suggests that in-situ synchrotron WAXD could provide a one-step process to screen cocrystal at high efficiency and reveal the details of cocrystal/salts growth behavior. Copyright © 2015 Elsevier B.V. All rights reserved.

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

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

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially-grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high pressure area on the order of a few tens of seconds. This device is then used to scanmore » the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in the experiment the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp→αSm transition proceeds in discontinuous steps at points along the expected phase boundary. Additionally, the unit cell volumes of each phase deviate from the expected thermal expansion behavior just before each transition is observed from the diffraction data. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0 - 10 GPa and 300 - 650 K.« less

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

DOE PAGES

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.; ...

2016-04-07

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially-grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high pressure area on the order of a few tens of seconds. This device is then used to scanmore » the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in the experiment the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp→αSm transition proceeds in discontinuous steps at points along the expected phase boundary. Additionally, the unit cell volumes of each phase deviate from the expected thermal expansion behavior just before each transition is observed from the diffraction data. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0 - 10 GPa and 300 - 650 K.« less

Determination of the solubility of tin indium oxide using in situ and ex x-ray diffraction

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

Gonzalez, G. B.; Mason, T. O.; Okasinski, J. S.

A novel approach to determine the thermodynamic solubility of tin in indium oxide via the exsolution from tin overdoped nano-ITO powders is presented. High-energy, in situ and ex situ synchrotron X-ray diffraction was utilized to study the solubility limit at temperatures ranging from 900 C to 1375 C. The tin exsolution from overdoped nanopowders and the formation of In{sub 4}Sn{sub 3}O{sub 12} were observed in situ during the first 4-48 h of high-temperature treatment. Samples annealed between 900 C and 1175 C were also studied ex situ with heat treatments for up to 2060 h. Structural results obtained from Rietveldmore » analysis include compositional phase analysis, atomic positions, and lattice parameters. The tin solubility in In{sub 2}O{sub 3} was determined using the phase analysis compositions from X-ray diffraction and the elemental compositions obtained from X-ray fluorescence. Experimental complications that can lead to incorrect tin solubility values in the literature are discussed.« less

Periodic order and defects in Ni-based inverse opal-like crystals on the mesoscopic and atomic scale

NASA Astrophysics Data System (ADS)

Chumakova, A. V.; Valkovskiy, G. A.; Mistonov, A. A.; Dyadkin, V. A.; Grigoryeva, N. A.; Sapoletova, N. A.; Napolskii, K. S.; Eliseev, A. A.; Petukhov, A. V.; Grigoriev, S. V.

2014-10-01

The structure of inverse opal crystals based on nickel was probed on the mesoscopic and atomic levels by a set of complementary techniques such as scanning electron microscopy and synchrotron microradian and wide-angle diffraction. The microradian diffraction revealed the mesoscopic-scale face-centered-cubic (fcc) ordering of spherical voids in the inverse opal-like structure with unit cell dimension of 750±10nm. The diffuse scattering data were used to map defects in the fcc structure as a function of the number of layers in the Ni inverse opal-like structure. The average lateral size of mesoscopic domains is found to be independent of the number of layers. 3D reconstruction of the reciprocal space for the inverse opal crystals with different thickness provided an indirect study of original opal templates in a depth-resolved way. The microstructure and thermal response of the framework of the porous inverse opal crystal was examined using wide-angle powder x-ray diffraction. This artificial porous structure is built from nickel crystallites possessing stacking faults and dislocations peculiar for the nickel thin films.

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

NASA Astrophysics Data System (ADS)

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.; Vohra, Y. K.

2016-04-01

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high-pressure area on the order of a few tens of seconds. This device is then used to scan the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in this experiment, the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp → αSm transition proceeds in discontinuous steps at points along the expected phase boundary. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0-10 GPa and 300-650 K.

Unraveling the Hydrogenation of TiO 2 and Graphene Oxide/TiO 2 Composites in Real Time by in Situ Synchrotron X-ray Powder Diffraction and Pair Distribution Function Analysis

DOE PAGES

Nguyen-Phan, Thuy-Duong; Liu, Zongyuan; Luo, Si; ...

2016-02-18

The functionalization of graphene oxide (GO) and graphene by TiO 2 and other metal oxides has attracted considerable attention due to numerous promising applications in catalysis, energy conversion, and storage. We propose hydrogenation of this class of materials as a promising way to tune catalytic properties by altering the structural and chemical transformations that occur upon H incorporation. We also investigate the structural changes that occur during the hydrogenation process using in situ powder X-ray diffraction and pair distribution function analysis of GO–TiO 2 and TiO 2 under H 2 reduction. Sequential Rietveld refinement was employed to gain insight intomore » the evolution of crystal growth of TiO 2 nanoparticles in the presence of two-dimensional (2D) GO nanosheets. GO sheets not only significantly retarded the nucleation and growth of rutile impurities, stabilizing the anatase structure, but was also partially reduced to hydrogenated graphene by the introduction of atomic hydrogen into the honeycomb lattice. We discuss the hydrogenation processes and the resulting composite structure that occurs during the incorporation of atomic H and the dynamic structural transformations that leads to a highly active photocatalyst.« less

Indexing amyloid peptide diffraction from serial femtosecond crystallography: new algorithms for sparse patterns

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

Brewster, Aaron S.; Sawaya, Michael R.; University of California, Los Angeles, CA 90095-1570

2015-02-01

Special methods are required to interpret sparse diffraction patterns collected from peptide crystals at X-ray free-electron lasers. Bragg spots can be indexed from composite-image powder rings, with crystal orientations then deduced from a very limited number of spot positions. Still diffraction patterns from peptide nanocrystals with small unit cells are challenging to index using conventional methods owing to the limited number of spots and the lack of crystal orientation information for individual images. New indexing algorithms have been developed as part of the Computational Crystallography Toolbox (cctbx) to overcome these challenges. Accurate unit-cell information derived from an aggregate data setmore » from thousands of diffraction patterns can be used to determine a crystal orientation matrix for individual images with as few as five reflections. These algorithms are potentially applicable not only to amyloid peptides but also to any set of diffraction patterns with sparse properties, such as low-resolution virus structures or high-throughput screening of still images captured by raster-scanning at synchrotron sources. As a proof of concept for this technique, successful integration of X-ray free-electron laser (XFEL) data to 2.5 Å resolution for the amyloid segment GNNQQNY from the Sup35 yeast prion is presented.« less

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.

Monoclinic deformation of calcite crystals at ambient conditions

NASA Astrophysics Data System (ADS)

Przeniosło, R.; Fabrykiewicz, P.; Sosnowska, I.

2016-09-01

High resolution synchrotron radiation powder diffraction shows that the average crystal structure of calcite at ambient conditions is described with the trigonal space group R 3 bar c but there is a systematic hkl-dependent Bragg peak broadening. A modelling of this anisotropic peak broadening with the microstrain model from Stephens (1999) [15] is presented. The observed lattice parameters' correlations can be described by assuming a monoclinic-type deformation of calcite crystallites. A quantitative model of this monoclinic deformation observed at ambient conditions is described with the space group C 2 / c . The monoclinic unit cell suggested at ambient conditions is related with the monoclinic unit cell reported in calcite at high pressure (Merrill and Bassett (1975) [10]).

Structures of two intermediate phases between the B1 and B2 phases of PbS under high pressure

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

Li, Yanchun, E-mail: liyc@ihep.ac.cn, E-mail: liuj@ihep.ac.cn; Lin, Chuanlong; Li, Xiaodong

2014-12-15

The structural transitions of PbS were investigated at pressures up to 50 GPa using synchrotron powder and single crystal X-ray diffraction (XRD) methods in diamond anvil cells. We found two intermediate phases between the B1 phase under atmospheric pressure and the B2 phase at 21.1 GPa, which is different to previous reports. The structures of these two intermediate phases were indexed as B27 and B33, respectively. Their structural parameters were investigated using density functional theory (DFT) calculations. Our results provide a new insight into understanding the transition pathway between the B1 and B2 phases in PbS.

In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 2: Corrosion in water.

PubMed

Stitt, C A; Paraskevoulakos, C; Banos, A; Harker, N J; Hallam, K R; Pullin, H; Davenport, A; Street, S; Scott, T B

2018-06-18

To reflect potential conditions in a geological disposal facility, uranium was encapsulated in grout and submersed in de-ionised water for time periods between 2-47 weeks. Synchrotron X-ray Powder Diffraction and X-ray Tomography were used to identify the dominant corrosion products and measure their dimensions. Uranium dioxide was observed as the dominant corrosion product and time dependent thickness measurements were used to calculate oxidation rates. The effectiveness of physical and chemical grout properties to uranium corrosion and mobilisation is discussed and Inductively Coupled Plasma Mass Spectrometry was used to measure 238 U (aq) content in the residual water of several samples.

Diffraction and Transmission Synchrotron Imaging at the German Light Source ANKA--Potential Industrial Applications

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

Rack, Alexander; Weitkamp, Timm; European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex

2009-03-10

Diffraction and transmission synchrotron imaging methods have proven to be highly suitable for investigations in materials research and non-destructive evaluation. The high flux and spatial coherence of X-rays from modern synchrotron light sources allows one to work using high resolution and different contrast modalities. This article gives a short overview of different transmission and diffraction imaging methods with high potential for industrial applications, now available for commercial access via the German light source ANKA (Forschungszentrum Karlsruhe) and its new department ANKA Commercial Service (ANKA COS, http://www.anka-cos.de)

Examination of the Atomic Pair Distribution Function (PDF) of SiC Nanocrystals by In-situ High Pressure Diffraction

NASA Technical Reports Server (NTRS)

Grzanka, E.; Stelmakh, S.; Gierlotka, S.; Zhao, Y.; Palosz, B.; Palosz, W.

2003-01-01

Key properties of nanocrystals are determined by their real atomic structure, therefore a reasonable understanding and meaningful interpretation of their properties requires a realistic model of the structure. In this paper we present an evidence of a complex response of the lattice distances to external pressure indicating a presence of a complex structure of Sic nanopowders. The experiments were performed on nanocrystalline Sic subjected to hydrostatic or isostatic pressure using synchrotron and neutron powder diffraction. Elastic properties of the samples were examined based on X-ray diffraction data using a Diamond Anvil Cell (DAC) in HASYLAB at DESY. The dependence'of the lattice parameters and of the Bragg reflections width with pressure exhibits a ha1 nature of the properties (compressibilities) of the powders and indicates a complex structure of the grains. We interpreted tws behaviour as originating from different elastic properties of the grain interior and surface. Analysis of the dependence of individual interatomic distances on pressure was based on in-situ neutron diffraction measurements done with HbD diffractometer at LANSCE in Los Alamos National Laboratory with the Paris-Edinburgh cell under pressures up to 8 GPa (Qmax = 26/A). Interatomic distances were obtained by PDF analysis using the PDFgetN program. We have found that the interatomic distances undergo a complex, non-monotonic changes. Even under substantial pressures a considerable relaxation of the lattice may take place: some interatomic distances increase with an increase in pressure. We relate this phenomenon to: (1), changes of the microstructure of the densified material, in particular breaking of its fractal chain structure and, (2), its complex structure resembling that of a material composed of two phases, each with its distinct elastic properties.

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.

Pressure-Induced Polymerization of LiN(CN) 2

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

Keefer, Derek W.; Gou, Huiyang; Purdy, Andrew P.

The high-pressure behavior of lithium dicyanamide (LiN(CN) 2) was studied with in situ Raman and infrared (IR) spectroscopies, and synchrotron angle-dispersive powder X-ray diffraction (PXRD) in a diamond anvil cell (DAC) to 22 GPa. The fundamental vibrational modes associated with molecular units were assigned using a combination of experimental data and density functional perturbation theory. Some low-frequency modes were observed for the first time. On the basis of spectroscopic and diffraction data, we suggest a polymorphic phase transformation at ~8 GPa, wherein dicyanamide ions remain as discrete molecular species. Above ca. 18 GPa, dicyanamide units polymerize, forming a largely disorderedmore » network, and the extent of polymerization may be increased by annealing at elevated temperature. The polymerized product consists of tricyanomelaminate-like groups containing sp 2-hybidized carbon–nitrogen bonds and exhibits a visible absorption edge near 540 nm. The product is recoverable to ambient conditions but is not stable in air/moisture.« less

A structural diagnostics diagram for metallofullerenes encapsulating metal carbides and nitrides.

PubMed

Maki, Sachiko; Nishibori, Eiji; Terauchi, Ikuya; Ishihara, Masayuki; Aoyagi, Shinobu; Sakata, Makoto; Takata, Masaki; Umemoto, Hisashi; Inoue, Takashi; Shinohara, Hisanori

2013-01-16

Systematic structural studies of 24 different kinds of endohedral metallofullerenes, M(x)C(2n) (M = La, Y, Sc, Lu, Ti, Eu, Er, Hf, Sc(3)N; 34 ≤ n ≤ 43), as 1:1 cocrystals with solvent toluene molecules have been carried out using synchrotron radiation powder diffraction. Thirteen of the 24 molecular structures, including five metal carbides, one metal nitride endohedral fullerene, and one hollow fullerene, have been determined by a combination of the maximum entropy method and Rietveld refinement of the X-ray diffraction data obtained. We have found that the volume for one fullerene and one toluene molecule depends linearly on the number of carbon atoms in the fullerene cage. Fifteen different kinds of metal carbide endohedral fullerenes have been identified, which can be structurally characterized from the obtained lattice constants using only this linear dependence. The linear dependence found in the present study provides a metallofullerene diagnostics diagram that may have universal importance for structural characterization of the so-called cluster endohedral fullerenes.

CIT-7, a crystalline, molecular sieve with pores bounded by 8 and 10-membered rings

DOE PAGES

Schmidt, Joel E.; Xie, Dan; Rea, Thomas; ...

2015-01-23

A new crystalline molecular sieve, denoted CIT-7, is synthesized using an imidazolium-based diquaternary organic structure directing agent (OSDA). The framework structure is determined from a combination of rotation electron diffraction and synchrotron X-ray powder diffraction data. The structure has 10 crystallographically unique tetrahedral atoms (T-atoms) in the unit cell, and can be described as an ordered arrangement of the [4 25 46 2] mtw building unit and a previously unreported [4 45 2] building unit. The framework contains a 2-dimensional pore system that is bounded by 10 T-atom rings (10-ring, 5.1 Å × 6.2 Å opening) that are connected withmore » oval 8-rings (2.9 Å × 5.5 Å opening) through medium-sized cavities (~7.9 Å) at the channel intersections. CIT-7 can be synthesized over a broad range of compositions including pure-silica and heteroatom, e.g., aluminosilicate and titanosilicate, containing variants.« less

Nanophase cobalt, nickel and zinc ferrites: synchrotron XAS study on the crystallite size dependence of metal distribution.

PubMed

Nordhei, Camilla; Ramstad, Astrid Lund; Nicholson, David G

2008-02-21

Nanophase cobalt, nickel and zinc ferrites, in which the crystallites are in the size range 4-25 nm, were synthesised by coprecipitation and subsequent annealing. X-Ray absorption spectroscopy using synchrotron radiation (supported by X-ray powder diffraction) was used to study the effects of particle size on the distributions of the metal atoms over the tetrahedral and octahedral sites of the spinel structure. Deviations from the bulk structure were found which are attributed to the significant influence of the surface on very small particles. Like the bulk material, nickel ferrite is an inverse spinel in the nanoregime, although the population of metals on the octahedral sites increases with decreasing particle size. Cobalt ferrite and zinc ferrite take the inverse and normal forms of the spinel structure respectively, but within the nanoregime both systems show similar trends in being partially inverted. Further, in zinc ferrite, unlike the normal bulk structure, the nanophase system involves mixed coordinations of zinc(ii) and iron(iii) consistent with increasing partial inversion with size.

Mechanisms of lichen resistance to metallic pollution

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

Sarret, C.; Manceau, A.; Eybert-Berard, L.

1998-11-01

Some lichens have a unique ability to grow in heavily contaminated areas due to the development of adaptative mechanisms allowing a high tolerance to metals. Here the authors report on the chemical forms of Pb and Zn in the metal hyperaccumulator Diploschistes muscorum and of Pb in the metal tolerant lichen Xanthoria parietina. The speciation of Zn and Pb has been investigated by powder X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy using the advanced third-generation synchrotron radiation source of the European synchrotron radiation facility (ESRF in Grenoble). This study reveals that in both lichens cells aremore » protected from toxicity by complexation of heavy metals, but the strategies differ: in D. muscorum, Pb and Zn are accumulated through an enhanced synthesis of oxalate, which precipitates toxic elements as insoluble salts, whereas in X. parietina, Pb is complexed to carboxylic groups of the fungal cell walls. The authors conclude that hyperaccumulation of metals results from a reactive mechanism of organic acid production, whereas metallo-tolerance is achieved by a passive complexation to existing functional groups.« less

Denticity and Mobility of the Carbonate Groups in AMCO 3 F Fluorocarbonates: A Study on KMnCO 3 F and High Temperature KCaCO 3 F Polymorph

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

Rousse, Gwenaelle; Ahouari, Hania; Pomjakushin, Vladimir

We report on a thorough structural study on two members of layered fluorocarbonates KMCO3F (M = Ca, Mn). The Ca-based member demonstrates a phase transition at ~320 °C, evidenced for the first time. The crystal structure of the high temperature phase (HT-KCaCO3F) was solved using neutron powder diffraction. A new Mn-based phase KMnCO3F was synthesized, and its crystal structure was solved from electron diffraction tomography data and refined from a combination of X-ray synchrotron and neutron powder diffraction. In contrast to other members of the fluorocarbonate family, the carbonate groups in the KMnCO3F and HT-KCaCO3F structures are not fixed tomore » two distinct orientations corresponding to mono- and bidentate coordinations of the M cation. In KMnCO3F, the carbonate group can be considered as nearly “monodentate”, forming one short (2.14 Å) and one long (3.01 Å) Mn–O contact. This topology provides more flexibility to the MCO3 layer and enables diminishing the mismatch between the MCO3 and KF layers. This conclusion is corroborated by the HT-KCaCO3F structure, in which the carbonate groups can additionally be tilted away from the layer plane thus relieving the strain arising from geometrical mismatch between the layers. The correlation between denticity of the carbonate groups, their mobility, and cation size variance is discussed. KMnCO3 orders antiferromagnetically below TN = 40 K.« less

Complementary use of monochromatic and white-beam X-ray micro-diffraction for the investigation of ancient materials

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

Dejoie, Catherine; Tamura, Nobumichi; Kunz, Martin

Archaeological artefacts are often heterogeneous materials where several phases coexist in a wide grain size distribution. Most of the time, retrieving structure information at the micrometre scale is of great importance for these materials. Particularly, the organization of different phases at the micrometre scale is closely related to optical or mechanical properties, manufacturing processes, functionalities in ancient times and long-term conservation. Between classic X-ray powder diffraction with a millimetre beam and transmission electron microscopy, a gap exists and structure and phase information at the micrometre scale are missing. Using a micrometre-size synchrotron X-ray beam, a hybrid approach combining both monochromaticmore » powder micro-diffraction and Laue single-crystal micro-diffraction was deployed to obtain information from nanometre- and micrometre-size phases, respectively. Therefore providing a way to bridge the aforementioned gap, this unique methodology was applied to three different types of ancient materials that all show a strong heterogeneity. In Roman terra sigillata, the specific distribution of nanocrystalline hematite is mainly responsible for the deep-red tone of the slip, while the distribution of micrometre-size quartz in ceramic bodies reflects the change of manufacturing process between pre-sigillata and high-quality sigillata periods. In the second example, we investigated the modifications occurring in Neolithic and geological flints after a heating process. By separating the diffracted signal coming from the nano- and the micrometre scale, we observed a domain size increase for nanocrystalline quartz in geological flints and a relaxation of the residual strain in larger detritic quartz. In conclusion, through the study of a Roman iron nail, we showed that the carburation process to strengthen the steel was mainly a surface process that formed 10–20 µm size domains of single–crystal ferrite and nanocrystalline cementite.« less

Complementary use of monochromatic and white-beam X-ray micro-diffraction for the investigation of ancient materials

DOE PAGES

Dejoie, Catherine; Tamura, Nobumichi; Kunz, Martin; ...

2015-09-20

Archaeological artefacts are often heterogeneous materials where several phases coexist in a wide grain size distribution. Most of the time, retrieving structure information at the micrometre scale is of great importance for these materials. Particularly, the organization of different phases at the micrometre scale is closely related to optical or mechanical properties, manufacturing processes, functionalities in ancient times and long-term conservation. Between classic X-ray powder diffraction with a millimetre beam and transmission electron microscopy, a gap exists and structure and phase information at the micrometre scale are missing. Using a micrometre-size synchrotron X-ray beam, a hybrid approach combining both monochromaticmore » powder micro-diffraction and Laue single-crystal micro-diffraction was deployed to obtain information from nanometre- and micrometre-size phases, respectively. Therefore providing a way to bridge the aforementioned gap, this unique methodology was applied to three different types of ancient materials that all show a strong heterogeneity. In Roman terra sigillata, the specific distribution of nanocrystalline hematite is mainly responsible for the deep-red tone of the slip, while the distribution of micrometre-size quartz in ceramic bodies reflects the change of manufacturing process between pre-sigillata and high-quality sigillata periods. In the second example, we investigated the modifications occurring in Neolithic and geological flints after a heating process. By separating the diffracted signal coming from the nano- and the micrometre scale, we observed a domain size increase for nanocrystalline quartz in geological flints and a relaxation of the residual strain in larger detritic quartz. In conclusion, through the study of a Roman iron nail, we showed that the carburation process to strengthen the steel was mainly a surface process that formed 10–20 µm size domains of single–crystal ferrite and nanocrystalline cementite.« less

High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

DOEpatents

Von Dreele, Robert B.; D'Amico, Kevin

2006-10-31

A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

Characterization of Oxygen Storage and Structural Properties of Oxygen-Loaded Hexagonal R MnO 3+δ ( R = Ho, Er, and Y)

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

Abughayada, C.; Dabrowski, B.; Kolesnik, S.

2015-09-22

Single-phase polycrystalline samples of stoichiometric RMnO3+delta (R = Er, Y, and Ho) were achieved in the hexagonal P6(3)cm structure through solid state reaction at, similar to 1300 degrees C. Thermogravimetric measurements in oxygen atmospheres demonstrated that samples with the larger Ho and Y show rapid and reversible incorporation of large amounts of excess oxygen (0.3 > delta> 0) at an unusually low temperature range of similar to 190-325 degrees C, indicating the industrial usefulness of RMnO3+delta materials for lower cost thermal swing adsorption processes for oxygen separation from air. Further increase of the excess oxygen intake to delta similar tomore » 0.38 was achieved for all the investigated materials when annealed under high pressures of oxygen. The formation of three oxygen stable phases with 6 = 0, 0.28, and 0.38 was confirmed by thermogravimetric measurements, synchrotron X-rays, and neutron diffraction. In situ synchrotron diffraction proved the thermal stability of these single phases and the regions of their creation and coexistence, and demonstrated that the stability of the delta = 0.28 phase increases with the ionic size of the R ion. Structural modeling using neutron powder diffraction for oxygen excess phases describes the formation and details of a large R3c superstructure observed for HoMnO3.28 by tripling the c-axis of the original parent unit cell. Modeling of the RMnO3.38 (R = Y and Er) oxygen-loaded phase converged on a structural model consistent with the symmetry of Pca2(1).« less

Lattice-Preferred Orientation in Deformed Novaculite - Comparison of in-situ Results Using BEARTEX and Post-Mortem EBSD Analyses

NASA Astrophysics Data System (ADS)

Willenweber, A.; Thomas, S.; Burnley, P. C.

2012-12-01

The Berkeley Texture Package BEARTEX is a Windows-based computer software that combines various algorithms to analyze lattice-preferred orientation in polycrystalline materials. BEARTEX was initially designed to interpret diffraction intensity data from pole figure goniometers. Recently it has been successfully used to process synthetic forsterite powder diffraction data from in-situ synchrotron X-ray diffraction taken during deformation (Bollinger et al. 2012). Our study aims to test the practicability of using BEARTEX to analyze the evolution of lattice-preferred orientation in natural polycrystalline quartz (novaculite) during deformation. In-situ X-ray diffraction data was collected during the deformation of novaculite at 2.5 GPa and up to 1000 °C in a D-DIA apparatus using the ten-element energy-dispersive detector at the NSLS beamline X17B2. Diffraction intensities are a function of crystal orientation, expressed in azimuth angle η and pole distance ψ. The latter is the angle between the normal of a given diffraction plane and the vertical direction of the D-DIA apparatus - our principal stress direction during compression. Orientation-dependent diffraction intensities were corrected for different responses of the single detectors and x-ray absorption effects of the anvils. Orientation distributions (ODs) and inverse pole figures were calculated using BEARTEX. In addition, electron backscatter diffraction (EBSD) analyses were carried out on the deformed novaculite samples. Generated pole figures were compared with those derived from BEARTEX. Textural properties of our novaculite starting material complicated the BEARTEX analyses. The relatively strong variation of grain sizes in our natural specimens caused non-random diffraction intensity distributions. Those lead to non-random distributions of crystal orientations when analyzed with BEARTEX, although pole figures from EBSD data clearly show random crystal orientations. In an attempt to solve this problem, we employed a scanning routine when recording in-situ synchrotron X-ray diffraction and so collected diffraction from multiple sample volumes rather than from one single spot. Here, we will present a comparison of pole figures derived from independent BEARTEX and EBSD analyses for a series of novaculite experiments and discuss the practicability of BEARTEX to analyze the evolution of lattice-preferred orientation in natural polycrystalline quartz. REFERENCES C. BOLLINGER, S. MERKEL AND P. RATERRON (2012): In situ quantitative analysis of stress and texture development in forsterite aggregates deformed at 6 GPa and 1373 K. J. Appl. Cryst., 45, 263-271.

On the reactive occlusion of the (uranium trichloride + lithium chloride + potassium chloride) eutectic salt in zeolite 4A

NASA Astrophysics Data System (ADS)

Lexa, Dusan; Leibowitz, Leonard; Kropf, Jeremy

2000-03-01

The interaction between the (uranium trichloride + lithium chloride + potassium chloride) eutectic salt and zeolite 4A has been studied by temperature-resolved synchrotron powder X-ray diffraction, evolved gas analysis and differential scanning calorimetry, between 300 and 900 K. The onset of salt occlusion by the zeolite has been detected at 450 K. Evidence of a reaction between zeolitic water and uranium trichloride, leading to the formation of uranium dioxide, has appeared at 600 K. The uranium dioxide particle size increases from 2 nm at 600 K to 25 nm at 900 K - an indication of their extra-zeolitic location. No appreciable degradation of the zeolite structure has been observed.

Synthesis and synchrotron characterisation of novel dual-template of hydroxyapatite scaffolds with controlled size porous distribution

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

Lima, Thiago A. R. M.; Ilavsky, Jan; Hammons, Joshua

Hydroxyapatite (HAP) scaffolds with a hierarchical porous architecture were prepared by a new dual-template (corn starch and cetyltrimethylammonium bromide (CTAB) surfactant) used to cast HAP nanoparticles and development scaffolds with size hierarchical porous distribution. The Powder X-Ray diffraction (XRD) results showed that only the HAP crystalline phase is present in the samples after calcination; the Scanning Electron Microscopy (SEM) combined with Small Angle (SAXS) and Ultra-Small Angle X-ray Scattering (USAXS) techniques showed that the porous arrangement is promoted by needle-like HAP nanoparticles, and that the pore size distributions depend on the drip-order of the calcium and the phosphate solutions duringmore » the template preparation stage.« less

Trisodium citrate, Na 3 (C 6 H 5 O 7 )

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

Rammohan, Alagappa; Kaduk, James A.

2016-05-10

The crystal structure of anhydrous trisodium citrate, Na 3(C 6H 5O 7), has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory (DFT). There are two independent five-coordinate Na +and one six-coordinate Na +cations in the asymmetric unit. The [NaO 5] and [NaO 6] polyhedra share edges and corners to form a three-dimensional framework. There are channels parallel to theaandbaxes in which the remainder of the citrate anions reside. The only hydrogen bonds are an intramolecular one between the hydroxy group and one of the terminal carboxylate O atoms and an intermolecular onemore » between a methylene group and the hydroxyl O atom.« less

Charge-density study on layered oxyarsenides (LaO)MAs (M = Mn, Fe, Ni, Zn)

NASA Astrophysics Data System (ADS)

Takase, Kouichi; Hiramoto, Shozo; Fukushima, Tetsuya; Sato, Kazunori; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

2017-12-01

Using synchrotron X-ray powder diffraction, we investigate the charge-density distributions of the layered oxypnictides (LaO)MnAs, (LaO)FeAs, (LaO)NiAs, and (LaO)ZnAs, which are an antiferromagnetic semiconductor, a parent material of an iron-based superconductor, a low-temperature superconductor, and a non-magnetic semiconductor, respectively. For the metallic samples, clear charge densities are observed in both the transition-metal pnictide layers and the rare-earth-oxide layers. However, in the semiconducting samples, there is no finite charge density between the transition-metal element and As. These differences in charge density reflect differences in physical properties. First-principles calculations using density functional theory reproduce the experimental results reasonably well.

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

Pb 2MnTeO 6 Double Perovskite: An Antipolar Anti-ferromagnet

DOE PAGES

Retuerto, Maria; Skiadopoulou, Stella; Li, Man-Rong; ...

2016-04-08

Pb 2MnTeO 6, a new double perovskite, has been synthesized. Its crystal structure was determined by synchrotron X-ray and powder neutron diffraction.Pb 2MnTeO 6 is monoclinic (I2/m) at room temperature with a regular arrangement of all the cations in their polyhedra. However, when the temperature is lowered to ~120 K it undergoes a phase transition from I2/m to C2/c structure. This transition is accompanied by a displacement of the Pb atoms from the center of their polyhedra due to the 6s 2 lone-pair electrons, together with a surprising off-centering of Mn 2+ (d 5) magnetic cations. This strong first-order phasemore » transition is also evidenced by specific heat, dielectric, Raman, and infrared spectroscopy measurements. The magnetic characterizations indicate an anti-ferromagnetic (AFM) order below T N ≈ 20 K; analysis of powder neutron diffraction data confirms the magnetic structure with propagation vector k = (0 1 0) and collinear AFM spins. The observed jump in dielectric permittivity near ~150 K implies possible anti-ferroelectric behavior; however, the absence of switching suggests that Pb 2MnTeO 6 can only be antipolar. First-principle calculations confirmed that the crystal and magnetic structures determined are locally stable and that anti-ferroelectric switching is unlikely to be observed in Pb 2MnTeO 6.« less

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

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

Montgomery, J. M.; Samudrala, G. K.; Vohra, Y. K.

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high-pressure area on the order of a few tens of seconds. This device is then used to scan the phasemore » diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in this experiment, the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp → αSm transition proceeds in discontinuous steps at points along the expected phase boundary. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0–10 GPa and 300–650 K.« less

Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn.

PubMed

Barczak, Sonia A; Buckman, Jim; Smith, Ronald I; Baker, Annabelle R; Don, Eric; Forbes, Ian; Bos, Jan-Willem G

2018-03-30

TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi 1+y Sn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5-3 mW m -1 K -2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m -1 K -1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn.

Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn

PubMed Central

Barczak, Sonia A.; Smith, Ronald I.; Baker, Annabelle R.; Don, Eric; Forbes, Ian

2018-01-01

TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi1+ySn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5–3 mW m−1 K−2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m−1 K−1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn. PMID:29601547

Amorphous and liquid samples structure and density measurements at high pressure - high temperature using diffraction and imaging techniques

NASA Astrophysics Data System (ADS)

Guignot, N.; King, A.; Clark, A. N.; Perrillat, J. P.; Boulard, E.; Morard, G.; Deslandes, J. P.; Itié, J. P.; Ritter, X.; Sanchez-Valle, C.

2016-12-01

Determination of the density and structure of liquids such as iron alloys, silicates and carbonates is a key to understand deep Earth structure and dynamics. X-ray diffraction provided by large synchrotron facilities gives excellent results as long as the signal scattered from the sample can be isolated from its environment. Different techniques already exist; we present here the implementation and the first results given by the combined angle- and energy-dispersive structural analysis and refinement (CAESAR) technique introduced by Wang et al. in 2004, that has never been used in this context. It has several advantages in the study of liquids: 1/ the standard energy-dispersive technique (EDX), fast and compatible with large multi-anvil presses frames, is used for fast analysis free of signal pollution from the sample environment 2/ some limitations of the EDX technique (homogeneity of the sample, low resolution) are irrelevant in the case of liquid signals, others (wrong intensities, escape peaks artifacts, background subtraction) are solved by the CAESAR technique 3/ high Q data (up to 15 A-1 and more) can be obtained in a few hours (usually less than 2). We present here the facilities available on the PSICHE beamline (SOLEIL synchrotron, France) and a few results obtained using a Paris-Edinburgh (PE) press and a 1200 tons load capacity multi-anvil press with a (100) DIA compression module. X-ray microtomography, used in conjunction with a PE press featuring rotating anvils (RotoPEc, Philippe et al., 2013) is also very effective, by simply measuring the 3D volume of glass or liquid spheres at HPHT, thus providing density. This can be done in conjunction with the CAESAR technique and we illustrate this point. Finally, absorption profiles can be obtained via imaging techniques, providing another independent way to measure the density of these materials. References Y. Wang et al., A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation (2004), J. Appl. Cryst. (2004). 37, 947-956 J. Philippe, Y. Le Godec, F. Bergame et M. Morand, Patent INPI 11 62335 (2013)

Analysis of the Photomagnetic Properties of Cyano-Bridged Heterobimetallic Complexes by X-Ray Diffraction

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

Svendsen, Helle; Jørgensen, Mads Ry Vogel; Overgaard, Jacob

2012-10-11

Single crystal synchrotron X-ray diffraction measurements have been carried out on [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O (DMF = dimethyl-formamide), 1; [Y(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 2; [Ce(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 3; [Sm(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 4; [Tb(DMF){sub 4}(H{sub 2}O)3({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 5; [Yb(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 6; and [Nd(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Co(CN){sub 5}] {center_dot} H{sub 2}O, 7, at 15(2) K with and without UV illumination of the crystals. Significant changes in unit cell parameters are observed for all of themore » iron-containing complexes, while compound 7 shows no response to UV illumination. These results are consistent with previous results and are furthermore reproduced by powder synchrotron X-ray diffraction for compounds 1 and 7. Photoexcited crystal structures have been determined for 1-6 from refinements of two-conformer models, and excited state occupancies in the range 80-94% are found. Significant bond length changes are observed for the Fe-ligand bonds (up to 0.06 {angstrom}), the cyano bonds (up to 0.02 {angstrom}), and the lanthanide-ligand bonds (up to 0.1 {angstrom}). On the contrary, powder X-ray diffraction on the simple compound K{sub 3}Fe(CN)6, 8, upon UV illumination does not show any structural changes, suggesting that the photomagnetic effect requires the presence of both the transition metal and the lanthanide ion. Photomagnetic measurements show an increase in magnetization of the excited state of 1 of up to 3%, which is much diminished compared with previously published values of 45%. Furthermore, they show that the isostructural complex [La(DMF){sub 4}(H{sub 2}O){sub 3}({mu}-CN)Fe(CN){sub 5}] {center_dot} H{sub 2}O, 9, exhibits identical magnetic responses in the UV-induced excited crystal structure.« less

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.

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.

Structural anomalies in undoped Gallium Arsenide observed in high resolution diffraction imaging with monochromatic synchrotron radiation

NASA Technical Reports Server (NTRS)

Steiner, B.; Kuriyama, M.; Dobbyn, R. C.; Laor, U.; Larson, D.; Brown, M.

1988-01-01

Novel, streak-like disruption features restricted to the plane of diffraction have recently been observed in images obtained by synchrotron radiation diffraction from undoped, semi-insulating gallium arsenide crystals. These features were identified as ensembles of very thin platelets or interfaces lying in (110) planes, and a structural model consisting of antiphase domain boundaries was proposed. We report here the other principal features observed in high resolution monochromatic synchrotron radiation diffraction images: (quasi) cellular structure; linear, very low-angle subgrain boundaries in (110) directions, and surface stripes in a (110) direction. In addition, we report systematic differences in the acceptance angle for images involving various diffraction vectors. When these observations are considered together, a unifying picture emerges. The presence of ensembles of thin (110) antiphase platelet regions or boundaries is generally consistent not only with the streak-like diffraction features but with the other features reported here as well. For the formation of such regions we propose two mechanisms, operating in parallel, that appear to be consistent with the various defect features observed by a variety of techniques.

Structural anomalies in undoped gallium arsenide observed in high-resolution diffraction imaging with monochromatic synchrotron radiation

NASA Technical Reports Server (NTRS)

Steiner, B.; Kuriyama, M.; Dobbyn, R. C.; Laor, U.; Larson, D.

1989-01-01

Novel, streak-like disruption features restricted to the plane of diffraction have recently been observed in images obtained by synchrotron radiation diffraction from undoped, semi-insulating gallium arsenide crystals. These features were identified as ensembles of very thin platelets or interfaces lying in (110) planes, and a structural model consisting of antiphase domain boundaries was proposed. We report here the other principal features observed in high resolution monochromatic synchrotron radiation diffraction images: (quasi) cellular structure; linear, very low-angle subgrain boundaries in (110) directions, and surface stripes in a (110) direction. In addition, we report systematic differences in the acceptance angle for images involving various diffraction vectors. When these observations are considered together, a unifying picture emerges. The presence of ensembles of thin (110) antiphase platelet regions or boundaries is generally consistent not only with the streak-like diffraction features but with the other features reported here as well. For the formation of such regions we propose two mechanisms, operating in parallel, that appear to be consistent with the various defect features observed by a variety of techniques.

The structure study of thin semiconductor and dielectric films by diffraction of synchrotron radiation

NASA Astrophysics Data System (ADS)

Yurjev, G. S.; Fainer, N. I.; Maximovskiy, E. A.; Kosinova, M. L.; Sheromov, M. A.; Rumyantsev, Yu. M.

1998-02-01

The structure of semiconductor and dielectric thin (100-300 nm) films was studied by diffraction of synchrotron radiation. The diffraction experiments were performed at both the station "Anomalous scattering" of the storage ring synchrotron facility VEPP-3 and DRON-4 diffractometer. The structure of CdS thin films grown on fused silica, single Si(100) and InP(100) substrates was investigated. The structure of Cu 2S thin films grown on fused silica, single Si(100) substrates and CdS/Si(100)-heterostructure was studied. The structure study was performed on Si 3N 4 films grown on GaAs(100) substrates. The structure of thin BN layers grown on single Si(100) substrates was studied. It was established that structural parameters of above-mentioned thin films coincide on the parameters of JCPDS International Centre for Diffraction Data.

Synchrotron X-ray reciprocal-space mapping, topography and diffraction resolution studies of macromolecular crystal quality.

PubMed

Boggon, T J; Helliwell, J R; Judge, R A; Olczak, A; Siddons, D P; Snell, E H; Stojanoff, V

2000-07-01

A comprehensive study of microgravity and ground-grown chicken egg-white lysozyme crystals is presented using synchrotron X-ray reciprocal-space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed reduced intrinsic mosaicities on average, but no differences in terms of strain over their ground-grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the ground-control case only a small volume of the crystal contributed to the intensity at the diffraction peak. The techniques prove to be highly complementary, with the reciprocal-space mapping providing a quantitative measure of the crystal mosaicity and strain (or variation in lattice spacing) and the topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out at the synchrotron.

Observation of divergent-beam X-ray diffraction from a crystal of diamond using synchrotron radiation.

PubMed

Glazer, A M; Collins, S P; Zekria, D; Liu, J; Golshan, M

2004-03-01

In 1947 Kathleen Lonsdale conducted a series of experiments on X-ray diffraction using a divergent beam external to a crystal sample. Unlike the Kossel technique, where divergent X-rays are excited by the presence of fluorescing atoms within the crystal, the use of an external divergent source made it possible to study non-fluorescing crystals. The resulting photographs not only illustrated the complexity of X-ray diffraction from crystals in a truly beautiful way, but also demonstrated unprecedented experimental precision. This long-forgotten work is repeated here using a synchrotron radiation source and, once again, considerable merit is found in Lonsdale's technique. The results of this experiment suggest that, through the use of modern 'third-generation' synchrotron sources, divergent-beam diffraction could soon enjoy a renaissance for high-precision lattice-parameter determination and the study of crystal perfection.

Synchrotron X-Ray Reciprocal Space Mapping, Topography and Diffraction Resolution Studies of Macromolecular Crystal Quality

NASA Technical Reports Server (NTRS)

Boggon, T. J.; Helliwell, J. R.; Judge, Russell A.; Siddons, D. P.; Snell, Edward H.; Stojanoff, V.

2000-01-01

A comprehensive study of microgravity and ground grown chicken egg white lysozyme crystals is presented using synchrotron X-ray reciprocal space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed, on average, reduced intrinsic mosaicities but no differences in terms of stress over their earth grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the earth case at the diffraction peak only a small volume of the crystal contributed to the intensity. The techniques prove to be highly complementary with the reciprocal space mapping providing a quantitative measure of the crystal mosaicity and stress (or variation in lattice spacing) and topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out both at the synchrotron and in the laboratory.

X-ray diffraction imaging (topography) of electroopticcrystals by synchrotron radiation

NASA Technical Reports Server (NTRS)

Steiner, Bruce; Kuriyama, Masao; Dobbyn, Ronald C.; Laor, Uri

1988-01-01

Information of special interest to crystal growers and device physicists now available from monochromatic synchrotron diffraction imaging (topography) is reviewed. Illustrations are taken from a variety of electro-optic crystals. Aspects of the detailed understanding of crystal growth processes obtainable from carefully selected samples are described. Finally, new experimental opportunities now available for exploitation are indicated.

Applications of synchrotron radiation to materials science: Diffraction imaging (topography) and microradiography

NASA Technical Reports Server (NTRS)

Kuriyama, Masao

1988-01-01

Synchrotron radiation sources are now available throughout the world. The use of hard X-ray radiation from these sources for materials science is described with emphasis on diffraction imaging for material characterization. With the availability of synchrotron radiation, real-time in situ measurements of dynamic microstructural phenomena have been started. This is a new area where traditional application of X-rays has been superseded. Examples are chosen from limited areas and are by no means exhaustive. The new emerging information will, no doubt, have great impact on materials science and engineering.

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

Role of initial heat treatment of the ferrite component on magnetic properties in the composite of ferrimagnetic Co1.75Fe1.25O4 ferrite and non-magnetic BaTiO3 oxide

NASA Astrophysics Data System (ADS)

Bhowmik, R. N.; Kazhugasalamoorthy, S.; Sinha, A. K.

2017-12-01

We have prepared a composite of ferrimagnetic ferrite Co1.75Fe1.25O4 and non-magnetic oxide BaTiO3. The ferrite composition Co1.75Fe1.25O4 has been prepared by chemical co-precipitation and subsequently heated at different temperatures. The heat treated ferrite powder has been mixed with BaTiO3 powder with mass ratio 1:1 and the mixed powder has been finally heated at 1000 °C to form composite material. Structural phase of the composite material has been confirmed by high quality Synchrotron X-ray diffraction pattern and Micro-Raman spectra. The grain surface morphology and elemental composition have been studied by Scanning electron microscope and Energy dispersive X-ray analysis. The distribution of magnetic exchange interactions and blocking behavior of the ferrimagnetic grains in composite samples has been understood by analyzing the temperature and magnetic field dependence of dc magnetization. Finally, information on modified micro-structure and ferrimagnetic parameters in composite samples has been obtained as the variation of annealing temperature of the ferrite component before making composite.

Regioselective atomic layer deposition in metal–organic frameworks directed by dispersion interactions

DOE PAGES

Gallington, Leighanne C.; Kim, In Soo; Liu, Wei-Guang; ...

2016-10-03

The application of atomic layer deposition (ALD) to metal–organic frameworks (MOFs) offers a promising new approach to synthesize designer functional materials with atomic precision. While ALD on flat substrates is well established, the complexity of the pore architecture and surface chemistry in MOFs present new challenges. Through in situ synchrotron X-ray powder diffraction, we visualize how the deposited atoms are localized and redistribute within the MOF during ALD. We demonstrate that the ALD is regioselective, with preferential deposition of oxy-Zn(II) species within the small pores of NU-1000. As a result, complementary density functional calculations indicate that this startling regioselectivity ismore » driven by dispersion interactions associated with the preferential adsorption sites for the organometallic precursors prior to reaction.« less

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

Casco, Mirian E.; Silvestre-Albero, Joaquín; Ramírez-Cuesta, Anibal J.

Natural methane hydrates are believed to be the largest source of hydrocarbons on Earth. These structures are formed in specific locations such as deep-sea sediments and the permafrost based on demanding conditions of high pressure and low temperature. We report that, by taking advantage of the confinement effects on nanopore space, synthetic methane hydrates grow under mild conditions (3.5 MPa and 2 degrees C), with faster kinetics (within minutes) than nature, fully reversibly and with a nominal stoichiometry that mimics nature. Furthermore, the formation of the hydrate structures in nanospace and their similarity to natural hydrates is confirmed using inelasticmore » neutron scattering experiments and synchrotron X-ray powder diffraction. Our findings may be a step towards the application of a smart synthesis of methane hydrates in energy-demanding applications (for example, transportation).« less

Regioselective atomic layer deposition in metal–organic frameworks directed by dispersion interactions

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

Gallington, Leighanne C.; Kim, In Soo; Liu, Wei-Guang

The application of atomic layer deposition (ALD) to metal–organic frameworks (MOFs) offers a promising new approach to synthesize designer functional materials with atomic precision. While ALD on flat substrates is well established, the complexity of the pore architecture and surface chemistry in MOFs present new challenges. Through in situ synchrotron X-ray powder diffraction, we visualize how the deposited atoms are localized and redistribute within the MOF during ALD. We demonstrate that the ALD is regioselective, with preferential deposition of oxy-Zn(II) species within the small pores of NU-1000. As a result, complementary density functional calculations indicate that this startling regioselectivity ismore » driven by dispersion interactions associated with the preferential adsorption sites for the organometallic precursors prior to reaction.« less

The Powder Diffraction File: Past, Present, and Future

PubMed Central

Smith, Deane K.; Jenkins, Ron

1996-01-01

The Powder Diffraction file has been the primary reference for Powder Diffraction Data for more than half a century. The file is a collection of about 65 000 reduced powder patterns stored as sets of d/I data along with the appropriate crystallographic, physical and experimental information. This paper reviews the development and growth of the PDF and discusses the role of the ICDD in the maintenance and dissemination of the file. PMID:27805163

Determination of cellulose crystallinity from powder diffraction diagrams: Powder Diffraction Diagrams

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

Lindner, Benjamin; Petridis, Loukas; Langan, Paul

2014-10-01

Commonly one-dimensional (1D) (spherically averaged) powder diffraction diagrams are used to determine the degree of cellulose crystallinity in biomass samples. Here, it is shown using molecular modeling how disorder in cellulose fibrils can lead to considerable uncertainty in conclusions drawn concerning crystallinity based on 1D powder diffraction data alone. For example, cellulose microfibrils that contain both crystalline and noncrystalline segments can lead to powder diffraction diagrams lacking identifiable peaks, while microfibrils without any crystalline segments can lead to such peaks. Moreover, this leads to false positives, that is, assigning disordered cellulose as crystalline, and false negatives, that is, categorizing fibrilsmore » with crystalline segments as amorphous. Finally, the reliable determination of the fraction of crystallinity in any given biomass sample will require a more sophisticated approach combining detailed experiment and simulation.« less

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.

Pressure-induced amorphization of La{sub 1/3}TaO{sub 3}

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

Noked, O., E-mail: noked@bgu.ac.il; Physics Department, Ben-Gurion University, Beer Sheva 84105; Melchior, A.

2013-06-15

La{sub 1/3}TaO{sub 3}, an A-site cation deficient perovskite, has been studied under pressure by synchrotron X-ray powder diffraction and Raman spectroscopy. It undergoes irreversible pressure induced amorphization at P=18.5 GPa. An almost linear unit cell volume decrease vs. pressure is observed from ambient pressure up to the phase transition. The Raman spectroscopy also shows amorphization at the same pressure, with positive shifts of all modes as a function of pressure. The pressure dependence of the E{sub g} and A{sub 1g} Raman modes arising from the octahedral oxygen network is discussed. - Graphical abstract: La{sub 1/3}Tao{sub 3} exhibits linear pressure–volume relationmore » until irreversible pressure induced amorphization at 18.5 Gpa. - Highlights: • La{sub 1/3}TaO{sub 3} has been studied under pressure by synchrotron XRD and Raman spectroscopy. • La{sub 1/3}TaO{sub 3} undergoes irreversible pressure induced amorphization around 18.5 GPa. • The transition is manifested in both XRD and Raman measurements. • A linear P–V relation is observed from ambient pressure up to the phase transition.« less

SESAME, A 3rd Generation Synchrotron Light Source for the Middle East

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

Einfeld, D.; Hasnain, S.S.; Sayers, Z.

2004-05-12

Developed under the auspices of UNESCO, SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) will be a major international research centre in the Middle East and Mediterranean region. On 6th of January 2003, the official foundation of SESAME took place. The facility is located in Allan, Jordan, 30 km North-West of Amman. As of August 2003 the Founding Members are Bahrain, Egypt, Iran, Israel, Jordan, Pakistan, Palestine, Turkey and United Arabic Emirates, representing a population of over 300 million. SESAME will be a 2.5 GeV 3rd Generation light source (emittance 24.6 nm.rad, circumference {approx}125m). About 40% ofmore » the circumference is available for insertion devices (average length 2.75m) in 13 straight sections. Beam lines are up to 36m. The site and a building are provided by Jordan. Construction started in August 2003. The scientific program will start with up to 6 beam lines: MAD Protein Crystallography, SAXS and WAXS for polymers and proteins, Powder Diffraction for material science, UV/VUV/SXR Photoelectron Spectroscopy and Photoabsorption Spectroscopy, IR Spectroscopy, and EXAFS.« less

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

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

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.

Recently, Zr-based metal organic frameworks (MOFs) were shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. Here, we report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. Our experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

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

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.

Zr-based metal organic frameworks (MOFs) have been recently shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. We report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. These experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

DOE PAGES

Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.; ...

2016-12-30

Recently, Zr-based metal organic frameworks (MOFs) were shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. Here, we report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination ofmore » DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. Our experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.« less

Determining the speciation of Zn in soils around the sediment ponds of chemical plants by XRD and XAFS spectroscopy and sequential extraction.

PubMed

Minkina, Tatiana; Nevidomskaya, Dina; Bauer, Tatiana; Shuvaeva, Victoria; Soldatov, Alexander; Mandzhieva, Saglara; Zubavichus, Yan; Trigub, Alexander

2018-09-01

For a correct assessment of risk of polluted soil, it is crucial to establish the speciation and mobility of the contaminants. The aim of this study was to investigate the speciation and transformation of Zn in strongly technogenically transformed contaminated Spolic Technosols for a long time in territory of sludge collectors by combining analytical techniques and synchrotron techniques. Sequential fractionation of Zn compounds in studied soils revealed increasing metal mobility. Phyllosilicates and Fe and Mn hydroxides were the main stabilizers of Zn mobility. A high degree of transformation was identified for the composition of the mineral phase in Spolic Technosols by X-ray powder diffraction. Technogenic phases (Zn-containing authigenic minerals) were revealed in Spolic Technosols samples through the analysis of their Zn K-edge EXAFS and XANES spectra. In one of the samples Zn local environment was formed by predominantly oxygen atoms, and in the other one mixed ZnS and ZnO bonding was found. Zn speciation in the studied technogenically transformed soils was due to the composition of pollutants contaminating the floodplain landscapes for a long time, and, second, this is the combination of physicochemical properties controlling the buffer properties of investigated soils. X-ray spectroscopic and X-ray powder diffraction analyses combined with sequential extraction assays is an effective tool to check the affinity of the soil components for heavy metal cations. Copyright © 2018 Elsevier B.V. All rights reserved.

Investigation of La and Al substitution on the spontaneous polarization and lattice dynamics of the Pb(1-x)LaxTi(1-x)AlxO3 ceramics

NASA Astrophysics Data System (ADS)

Yadav, Arun Kumar; Verma, Anita; Kumar, Sunil; Srihari, Velaga; Sinha, A. K.; Reddy, V. Raghavendra; Liu, Shun Wei; Biring, Sajal; Sen, Somaditya

2018-03-01

The phase purity and crystal structure of Pb(1-x)LaxTi(1-x)AlxO3 (0 ≤ x ≤ 0.25) samples (synthesized via the sol-gel process) were confirmed using synchrotron x-ray powder diffraction (XRD) (wavelength, λ = 0.44573 Å). Rietveld analyses of powder x-ray diffraction data confirmed the tetragonal structure for compositions with x ≤ 0.18 and cubic structure for the sample with x = 0.25. Temperature-dependent XRD was performed to investigate the structural change from tetragonal to cubic structure phase transition. Raman spectroscopy at room temperature also confirmed this phase transition with compositions. Field emission scanning electron microscopy (FESEM) provided information about the surface morphology while an energy dispersive x-ray spectrometer attached with FESEM confirmed the chemical compositions of samples. Temperature and frequency dependent dielectric studies showed that the tetragonal to cubic phase transition decreased from 680 K to 175 K with an increase in the x from 0.03 to 0.25, respectively. This is correlated with the structural studies. Electric field dependent spontaneous polarization showed a proper ferroelectric loop for 0.06 ≤ x ≤ 0.18 belonging to a tetragonal phase, while for x ≥ 0.25, the spontaneous polarization vanishes. Bipolar strain versus electric field revealed a butterfly loop for 0.06 ≤ x ≤ 0.18 compositions. Energy storage efficiency initially increases nominally with substitution but beyond x = 0.18 enhances considerably.

A new soluble and bioactive polymorph of praziquantel.

PubMed

Zanolla, Debora; Perissutti, Beatrice; Passerini, Nadia; Chierotti, Michele R; Hasa, Dritan; Voinovich, Dario; Gigli, Lara; Demitri, Nicola; Geremia, Silvano; Keiser, Jennifer; Cerreia Vioglio, Paolo; Albertini, Beatrice

2018-06-01

Praziquantel is the only available drug to treat Schistosomiasis. However, its utilization is limited by many drawbacks, including the high therapeutic dose needed, resulting in large tablets and capsules difficult to be swallowed, especially from pediatric patients. In this study, an alternative option to overcome these disadvantages is proposed: to switch to a novel crystalline polymorph of racemic compound praziquantel. The preparation of the crystalline polymorph was realized via a neat grinding process in a vibrational mill. The new phase (Form B) was chemically identical to the starting material (as proved by HPLC, 1 H NMR, and polarimetry), but showed different physical properties (as evaluated by SEM, differential scanning calorimetry, thermogravimetry, ATR-FTIR spectroscopy, X-ray powder diffraction, and solid-state NMR). Furthermore, the crystal structure of the new phase was solved from the powder synchrotron X-ray diffraction pattern, resulting in a monoclinic C2/c cell and validated by DFT-D calculation. Moreover the simulated solid-state NMR 13 C chemical shifts were in excellent agreement with the experimental data. The conversion of original praziquantel into Form B showed to affect positively the water solubility and the intrinsic dissolution rate of praziquantel. Both the in vitro and in vivo activity against Schistosoma mansoni were maintained. Our findings suggest that the new phase, that proved to be physically stable for at least one year, is a promising product for designing a new praziquantel formulation. Copyright © 2018 Elsevier B.V. All rights reserved.

Structure and properties of α-NaFeO{sub 2}-type ternary sodium iridates

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

Baroudi, Kristen, E-mail: kbaroudi@princeton.edu; Yim, Cindi; Wu, Hui

2014-02-15

The synthesis, structure, and elementary magnetic and electronic properties are reported for layered compounds of the type Na{sub 3−x}MIr{sub 2}O{sub 6} and Na{sub 3−x}M{sub 2}IrO{sub 6}, where M is a transition metal from the 3d series (M=Zn, Cu, Ni, Co, Fe and Mn). The rhombohedral structures, in space group R−3m, were determined by refinement of neutron and synchrotron powder diffraction data. No clear evidence for long range 2:1 or 1:2 honeycomb-like M/Ir ordering was found in the neutron powder diffraction patterns except in the case of M=Zn, and thus in general the compounds are best designated as sodium deficient α-NaFeO{submore » 2}-type phases with formulas Na{sub 1−x}M{sub 1/3}Ir{sub 2/3}O{sub 2} or Na{sub 1−x}M{sub 2/3}Ir{sub 1/3}O{sub 2}. Synchrotron powder diffraction patterns indicate that several of the compounds likely have honeycomb in-plane metal–iridium ordering with disordered stacking of the layers. All the compounds are sodium deficient under our synthetic conditions and are black and insulating. Weiss constants derived from magnetic susceptibility measurements indicate that Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2}, and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} display dominant antiferromagnetic interactions. For Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2} the dominant magnetic interactions at low temperature are ferromagnetic while at high temperatures they are antiferromagnetic; there is also a change in the effective moment. Low temperature specific heat measurements (to 2 K) on Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2} indicate the presence of a broad magnetic ordering transition. X-ray absorption spectroscopy shows that iridium is at or close to the 4+ oxidation state in all compounds. {sup 23}Na nuclear magnetic resonance measurements comparing Na{sub 2}IrO{sub 3} to Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} provide strong indications that the electron spins are short-range ordered in the latter two materials. Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}, Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} are spin glasses. (CSD-numbers: Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}: 426657, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}: 426659, Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2}: 426658, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}: 426656, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2}: 426655, and Na{sub 2.8}ZnIr{sub 2}O{sub 6}: 426660.) - Graphical abstract: Diffraction patterns of Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2}: neutron diffraction patterns in the main panel and synchrotron diffraction in the insets. The patterns show a small amount of ordering in the transition metal iridium layer. Display Omitted - Highlights: • We report six ternary sodium iridates with the α-NaFeO{sub 2} structure. • Compounds Na{sub 1−x}M{sub 1/3}Ir{sub 2/3}O{sub 2}, M=Co, Ni, Cu, Zn and Na{sub 1−x}M{sub 2/3}Ir{sub 1/3}O{sub 2}, M=Mn, Fe. • Rietveld refinement of powder neutron diffraction data. • All compounds are spin glasses. • NMR comparison to Na{sub 2}IrO{sub 3}.« less

Impact of synchrotron radiation on macromolecular crystallography: a personal view

PubMed Central

Dauter, Zbigniew; Jaskolski, Mariusz; Wlodawer, Alexander

2010-01-01

The introduction of synchrotron radiation sources almost four decades ago has led to a revolutionary change in the way that diffraction data from macromolecular crystals are being collected. Here a brief history of the development of methodologies that took advantage of the availability of synchrotron sources are presented, and some personal experiences with the utilization of synchrotrons in the early days are recalled. PMID:20567074

Insights into the dominant factors of porous gold for CO oxidation

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

Kameoka, Satoshi, E-mail: kameoka@tagen.tohoku.ac.jp; Miyamoto, Kanji; Tanabe, Toyokazu

2016-01-21

Three different porous Au catalysts that exhibit high catalytic activity for CO oxidation were prepared by the leaching of Al from an intermetallic compound, Al{sub 2}Au, with 10 wt. %-NaOH, HNO{sub 3}, or HCl aqueous solutions. The catalysts were investigated using Brunauer-Emmett-Teller measurements, synchrotron X-ray powder diffraction, hard X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy (TEM). Broad diffraction peaks generated during the leaching process correlated with high activity for all the porous Au catalysts. CO oxidation catalyzed by porous Au leached with NaOH and HNO{sub 3} is considered to be dominated by different mechanisms atmore » low (< 320 K) and high (> 370 K) temperatures. Activity in the low-temperature region is mainly attributed to the perimeter interface between residual Al species (AlO{sub x}) and porous Au, whereas activity in the high-temperature region results from a high density of lattice defects such as twins and dislocations, which were evident from diffraction peak broadening and were observed with high-resolution TEM in the porous Au leached with NaOH. It is proposed that atoms located at lattice defects on the surfaces of porous Au are the active sites for catalytic reactions.« less

Spherical quartz crystals investigated with synchrotron radiation

DOE PAGES

Pereira, N. R.; Macrander, A. T.; Hill, K. W.; ...

2015-10-27

The quality of x-ray spectra and images obtained from plasmas with spherically bent crystals depends in part on the crystal's x-ray diffraction across the entire crystal surface. We employ the energy selectivity and high intensity of synchrotron radiation to examine typical spherical crystals from alpha-quartz for their diffraction quality, in a perpendicular geometry that is particularly convenient to examine sagittal focusing. The crystal's local diffraction is not ideal: the most noticeable problems come from isolated regions that so far have failed to correlate with visible imperfections. In conclusion, excluding diffraction from such problem spots has little effect on the focusmore » beyond a decrease in background.« less

Synchrotron FTIR Imaging For The Identification Of Cell Types Within Human Tissues

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

Walsh, Michael J.; Pounder, F. Nell; Nasse, Michael J.

2010-02-03

The use of synchrotron Fourier Transform Infrared spectroscopy (S-FTIR) has been shown to be a very promising tool for biomedical research. S-FTIR spectroscopy allows for the fast acquisition of infrared (IR) spectra at a spatial resolution approaching the IR diffraction limit. The development of the Infrared Environmental Imaging (IRENI) beamline at the Synchrotron Radiation Center (SRC) at the University of Wisconsin-Madison has allowed for diffraction limited imaging measurements of cells in human prostate and breast tissues. This has allowed for the identification of cell types within tissues that would otherwise not have been resolvable using conventional FTIR sources.

JCPDS-ICDD Research Associateship (Cooperative Program with NBS/NIST)

PubMed Central

Wong-Ng, W.; McMurdie, H. F.; Hubbard, C. R.; Mighell, A. D.

2001-01-01

The Research Associateship program of the Joint Committee on Powder Diffraction-International Centre for Diffraction Data (JCPDS-ICDD, now known as the ICDD) at NBS/NIST was a long standing (over 35 years) successful industry-government cooperation. The main mission of the Associateship was to publish high quality x-ray reference patterns to be included in the Powder Diffraction File (PDF). The PDF is a continuing compilation of patterns gathered from many sources, compiled and published by the ICDD. As a result of this collaboration, more than 1500 high quality powder diffraction patterns, which have had a significant impact on the scientific community, were reported. In addition, various research collaborations with NBS/NIST also led to the development of several standard reference materials (SRMs) for instrument calibration and quantitative analyses, and computer software for data collection, calibration, reduction, for the editorial process of powder pattern publication, analysis of powder data, and for quantitative analyses. This article summarizes information concerning the JCPDS-ICDD organization, the Powder Diffraction File (PDF), history and accomplishments of the JCPDS-ICDD Research Associateship. PMID:27500061

Characterization of metal additive manufacturing surfaces using synchrotron X-ray CT and micromechanical modeling

NASA Astrophysics Data System (ADS)

Kantzos, C. A.; Cunningham, R. W.; Tari, V.; Rollett, A. D.

2018-05-01

Characterizing complex surface topologies is necessary to understand stress concentrations created by rough surfaces, particularly those made via laser power-bed additive manufacturing (AM). Synchrotron-based X-ray microtomography (μ XCT) of AM surfaces was shown to provide high resolution detail of surface features and near-surface porosity. Using the CT reconstructions to instantiate a micromechanical model indicated that surface notches and near-surface porosity both act as stress concentrators, while adhered powder carried little to no load. Differences in powder size distribution had no direct effect on the relevant surface features, nor on stress concentrations. Conventional measurements of surface roughness, which are highly influenced by adhered powder, are therefore unlikely to contain the information relevant to damage accumulation and crack initiation.

Characterization of metal additive manufacturing surfaces using synchrotron X-ray CT and micromechanical modeling

NASA Astrophysics Data System (ADS)

Kantzos, C. A.; Cunningham, R. W.; Tari, V.; Rollett, A. D.

2017-12-01

Characterizing complex surface topologies is necessary to understand stress concentrations created by rough surfaces, particularly those made via laser power-bed additive manufacturing (AM). Synchrotron-based X-ray microtomography (μ XCT ) of AM surfaces was shown to provide high resolution detail of surface features and near-surface porosity. Using the CT reconstructions to instantiate a micromechanical model indicated that surface notches and near-surface porosity both act as stress concentrators, while adhered powder carried little to no load. Differences in powder size distribution had no direct effect on the relevant surface features, nor on stress concentrations. Conventional measurements of surface roughness, which are highly influenced by adhered powder, are therefore unlikely to contain the information relevant to damage accumulation and crack initiation.

Synchrotron applications in wood preservation and deterioration

Treesearch

Barbara L. Illman

2003-01-01

Several non-intrusive synchrotron techniques are being used to detect and study wood decay. The techniques use high intensity synchrotron-generated X-rays to determine the atomic structure of materials with imaging, diffraction, and absorption. Some of the techniques are X-ray absorption near edge structure (XANES), X-ray fluorescence spectroscopy (XFS), X-ray...

Total-scattering pair-distribution function of organic material from powder electron diffraction data.

PubMed

Gorelik, Tatiana E; Schmidt, Martin U; Kolb, Ute; Billinge, Simon J L

2015-04-01

This paper shows that pair-distribution function (PDF) analyses can be carried out on organic and organometallic compounds from powder electron diffraction data. Different experimental setups are demonstrated, including selected area electron diffraction and nanodiffraction in transmission electron microscopy or nanodiffraction in scanning transmission electron microscopy modes. The methods were demonstrated on organometallic complexes (chlorinated and unchlorinated copper phthalocyanine) and on purely organic compounds (quinacridone). The PDF curves from powder electron diffraction data, called ePDF, are in good agreement with PDF curves determined from X-ray powder data demonstrating that the problems of obtaining kinematical scattering data and avoiding beam damage of the sample are possible to resolve.

Transformation of hydrazinium azide to molecular N8 at 40 GPa

NASA Astrophysics Data System (ADS)

Duwal, Sakun; Ryu, Young-Jay; Kim, Minseob; Yoo, Choong-Shik; Bang, Sora; Kim, Kyungtae; Hur, Nam Hwi

2018-04-01

Hydrazinium azide (HA) has been investigated at high pressures to 68 GPa using confocal micro-Raman spectroscopy and synchrotron powder x-ray diffraction. The results show that HA undergoes structural phase transitions from solid HA-I to HA-II at 13 GPa, associated with the strengthening of hydrogen bonding, and then to N8 at 40 GPa. The transformation of HA to recently predicted N8 (N≡N+—N-—N=N—-N—+N≡N) is evident by the emergence of new peaks at 2384 cm-1, 1665 cm-1, and 1165 cm-1, arising from the terminal N≡N stretching, the central N=N stretching, and the N—N stretching, respectively. However, upon decompression, N8 decomposes to ɛ-N2 below 25 GPa, but the remnant can be seen as low as 3 GPa.

Pressure-Stabilized Cubic Perovskite Oxyhydride BaScO2H.

PubMed

Goto, Yoshihiro; Tassel, Cédric; Noda, Yasuto; Hernandez, Olivier; Pickard, Chris J; Green, Mark A; Sakaebe, Hikari; Taguchi, Noboru; Uchimoto, Yoshiharu; Kobayashi, Yoji; Kageyama, Hiroshi

2017-05-01

We report a scandium oxyhydride BaScO 2 H prepared by solid state reaction under high pressure. Rietveld refinements against powder synchrotron X-ray and neutron diffraction data revealed that BaScO 2 H adopts the ideal cubic perovskite structure (Pm3̅m), where oxide (O 2- ) and hydride (H - ) anions are disordered. 1 H nuclear magnetic resonance (NMR) spectroscopy provides a positive chemical shift of about +4.4 ppm, which can be understood by the distance to the nearest (and possibly the next nearest) cation from the H nucleus. A further analysis of the NMR data and calculations based on ab initio random structure searches suggest a partial cis preference in ScO 4 H 2 octahedra. The present oxyhydride, if compositionally or structurally tuned, may become a candidate for H - conductors.

A study of tantalum pentoxide Ta 2O 5 structures up to 28 GPa

DOE PAGES

Stavrou, Elissaios; Zaug, Joseph M.; Bastea, Sorin; ...

2017-05-02

In this study, tantalum pentoxide Ta 2O 5 with the orthorhombic L-Ta 2O 5 structure has been experimentally studied up to 28.3 GPa (at ambient temperature) using synchrotron angle-dispersive powder X-ray diffraction (XRD). The ambient pressure phase remains stable up to 25 GPa where with increased pressure a crystalline to amorphous phase transition occurs. A detailed equation of state (EOS), including pressure dependent lattice parameters, is reported. The results of this study were compared with a previous high-pressure XRD study by Li et al. A clear discrepancy between the ambient-pressure crystal structures and, consequently, the reported EOSs between the twomore » studies was revealed. Finally, he origin of this discrepancy is attributed to two different crystal structures used to index the XRD patterns.« less

Methane hydrate formation in confined nanospace can surpass nature

DOE PAGES

Casco, Mirian E.; Silvestre-Albero, Joaquín; Ramírez-Cuesta, Anibal J.; ...

2015-03-02

Natural methane hydrates are believed to be the largest source of hydrocarbons on Earth. These structures are formed in specific locations such as deep-sea sediments and the permafrost based on demanding conditions of high pressure and low temperature. We report that, by taking advantage of the confinement effects on nanopore space, synthetic methane hydrates grow under mild conditions (3.5 MPa and 2 degrees C), with faster kinetics (within minutes) than nature, fully reversibly and with a nominal stoichiometry that mimics nature. Furthermore, the formation of the hydrate structures in nanospace and their similarity to natural hydrates is confirmed using inelasticmore » neutron scattering experiments and synchrotron X-ray powder diffraction. Our findings may be a step towards the application of a smart synthesis of methane hydrates in energy-demanding applications (for example, transportation).« less

Pink-beam serial crystallography

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

Meents, A.; Wiedorn, M. O.; Srajer, V.

Serial X-ray crystallography allows macromolecular structure determination at both X-ray free electron lasers (XFELs) and, more recently, synchrotron sources. The time resolution for serial synchrotron crystallography experiments has been limited to millisecond timescales with monochromatic beams. The polychromatic, “pink”, beam provides a more than two orders of magnitude increased photon flux and hence allows accessing much shorter timescales in diffraction experiments at synchrotron sources. Here we report the structure determination of two different protein samples by merging pink-beam diffraction patterns from many crystals, each collected with a single 100 ps X-ray pulse exposure per crystal using a setup optimized formore » very low scattering background. In contrast to experiments with monochromatic radiation, data from only 50 crystals were required to obtain complete datasets. The high quality of the diffraction data highlights the potential of this method for studying irreversible reactions at sub-microsecond timescales using high-brightness X-ray facilities.« less

Pink-beam serial crystallography

DOE PAGES

Meents, A.; Wiedorn, M. O.; Srajer, V.; ...

2017-11-03

Serial X-ray crystallography allows macromolecular structure determination at both X-ray free electron lasers (XFELs) and, more recently, synchrotron sources. The time resolution for serial synchrotron crystallography experiments has been limited to millisecond timescales with monochromatic beams. The polychromatic, “pink”, beam provides a more than two orders of magnitude increased photon flux and hence allows accessing much shorter timescales in diffraction experiments at synchrotron sources. Here we report the structure determination of two different protein samples by merging pink-beam diffraction patterns from many crystals, each collected with a single 100 ps X-ray pulse exposure per crystal using a setup optimized formore » very low scattering background. In contrast to experiments with monochromatic radiation, data from only 50 crystals were required to obtain complete datasets. The high quality of the diffraction data highlights the potential of this method for studying irreversible reactions at sub-microsecond timescales using high-brightness X-ray facilities.« less

Compression behavior of WC and WC-6%Co up to 50 GPa determined by synchrotron x-ray diffraction and ultrasonic techniques

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

Amulele, George M.; Manghnani, Murli H.; Marriappan, Sekar

2008-07-23

The equations of state (pressure-volume relations) for WC and WC-6%Co have been determined by synchrotron x-ray diffraction measurements on polycrystalline powder samples loaded in a diamond anvil cell as well as by ultrasonic measurements on hot-pressed polycrystalline, cylindrical samples loaded in a multianvil high-pressure apparatus. The third-order Birch-Murnaghan equation of state fitted to the x-ray diffraction pressure-density sets of data, collected up to 50 GPa, yields ambient pressure isothermal bulk moduli of K{sub oT} = 411.8{+-}12.1 GPa and K{sub oT} = 402.4{+-}14.1 GPa, with pressure derivatives of K{sub oT}' = 5.45{+-}0.73 and K{sub oT}' = 7.50{+-}0.86 for WC and WC-6%Co,more » respectively. The ultrasonic measurements, conducted up to 14 GPa, enabled the determination of the pressure dependences of both bulk and shear moduli. Using Eulerian finite strain equations to fit the ultrasonic data, we obtain for WC an ambient pressure adiabatic bulk modulus of K{sub os} = 383.8{+-}0.8 GPa, and K{sub os}' = 2.61{+-}0.07 for its pressure derivative, while values of G{sub os} = 304.0{+-}0.3 GPa and G{sub os}' = 1.50{+-}0.09 were determined for the shear modulus and its pressure derivative, respectively. Meanwhile, for WC-6%Co, we obtain K{sub os} = 357.5{+-}1.0 GPa, K{sub os}' = 5.18{+-}0.14, G{sub os} = 253.5{+-}0.3 GPa, and G{sub os}' = 1.09{+-}0.09. The equations of state derived from the ultrasonic data are in good agreement with extrapolated results reported previously by Day and Ruoff [J. Appl. Phys. 44, 2447 (1973)] and Gerlich and Kennedy [J. Appl. Phys. 50, 3331 (1978)] who carried out measurements up to 0.2 and 1.0 GPa, respectively.« less

(Na,□)5[MnO2]13 nanorods: a new tunnel structure for electrode materials determined ab initio and refined through a combination of electron and synchrotron diffraction data

PubMed Central

Mugnaioli, Enrico; Gemmi, Mauro; Merlini, Marco; Gregorkiewitz, Michele

2016-01-01

(Nax□1 − x)5[MnO2]13 has been synthesized with x = 0.80 (4), corresponding to Na0.31[MnO2]. This well known material is usually cited as Na0.4[MnO2] and is believed to have a romanèchite-like framework. Here, its true structure is determined, ab initio, by single-crystal electron diffraction tomography (EDT) and refined both by EDT data applying dynamical scattering theory and by the Rietveld method based on synchrotron powder diffraction data (χ2 = 0.690, R wp = 0.051, R p = 0.037, R F2 = 0.035). The unit cell is monoclinic C2/m, a = 22.5199 (6), b = 2.83987 (6), c = 14.8815 (4) Å, β = 105.0925 (16)°, V = 918.90 (4) Å3, Z = 2. A hitherto unknown [MnO2] framework is found, which is mainly based on edge- and corner-sharing octahedra and comprises three types of tunnels: per unit cell, two are defined by S-shaped 10-rings, four by egg-shaped 8-rings, and two by slightly oval 6-rings of Mn polyhedra. Na occupies all tunnels. The so-determined structure excellently explains previous reports on the electrochemistry of (Na,□)5[MnO2]13. The trivalent Mn3+ ions concentrate at two of the seven Mn sites where larger Mn—O distances and Jahn–Teller distortion are observed. One of the Mn3+ sites is five-coordinated in a square pyramid which, on oxidation to Mn4+, may easily undergo topotactic transformation to an octahedron suggesting a possible pathway for the transition among different tunnel structures. PMID:27910840

Structure of nanocrystalline calcium silicate hydrates: insights from X-ray diffraction, synchrotron X-ray absorption and nuclear magnetic resonance.

PubMed

Grangeon, Sylvain; Claret, Francis; Roosz, Cédric; Sato, Tsutomu; Gaboreau, Stéphane; Linard, Yannick

2016-06-01

The structure of nanocrystalline calcium silicate hydrates (C-S-H) having Ca/Si ratios ranging between 0.57 ± 0.05 and 1.47 ± 0.04 was studied using an electron probe micro-analyser, powder X-ray diffraction, 29 Si magic angle spinning NMR, and Fourier-transform infrared and synchrotron X-ray absorption spectroscopies. All samples can be described as nanocrystalline and defective tobermorite. At low Ca/Si ratio, the Si chains are defect free and the Si Q 3 and Q 2 environments account, respectively, for up to 40.2 ± 1.5% and 55.6 ± 3.0% of the total Si, with part of the Q 3 Si being attributable to remnants of the synthesis reactant. As the Ca/Si ratio increases up to 0.87 ± 0.02, the Si Q 3 environment decreases down to 0 and is preferentially replaced by the Q 2 environment, which reaches 87.9 ± 2.0%. At higher ratios, Q 2 decreases down to 32.0 ± 7.6% for Ca/Si = 1.38 ± 0.03 and is replaced by the Q 1 environment, which peaks at 68.1 ± 3.8%. The combination of X-ray diffraction and NMR allowed capturing the depolymerization of Si chains as well as a two-step variation in the layer-to-layer distance. This latter first increases from ∼11.3 Å (for samples having a Ca/Si ratio <∼0.6) up to 12.25 Å at Ca/Si = 0.87 ± 0.02, probably as a result of a weaker layer-to-layer connectivity, and then decreases down to 11 Å when the Ca/Si ratio reaches 1.38 ± 0.03. The decrease in layer-to-layer distance results from the incorporation of interlayer Ca that may form a Ca(OH) 2 -like structure, nanocrystalline and intermixed with C-S-H layers, at high Ca/Si ratios.

New Powder Diffraction File (PDF-4) in relational database format: advantages and data-mining capabilities.

PubMed

Kabekkodu, Soorya N; Faber, John; Fawcett, Tim

2002-06-01

The International Centre for Diffraction Data (ICDD) is responding to the changing needs in powder diffraction and materials analysis by developing the Powder Diffraction File (PDF) in a very flexible relational database (RDB) format. The PDF now contains 136,895 powder diffraction patterns. In this paper, an attempt is made to give an overview of the PDF-4, search/match methods and the advantages of having the PDF-4 in RDB format. Some case studies have been carried out to search for crystallization trends, properties, frequencies of space groups and prototype structures. These studies give a good understanding of the basic structural aspects of classes of compounds present in the database. The present paper also reports data-mining techniques and demonstrates the power of a relational database over the traditional (flat-file) database structures.

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.

Local reconstruction in computed tomography of diffraction enhanced imaging

NASA Astrophysics Data System (ADS)

Huang, Zhi-Feng; Zhang, Li; Kang, Ke-Jun; Chen, Zhi-Qiang; Zhu, Pei-Ping; Yuan, Qing-Xi; Huang, Wan-Xia

2007-07-01

Computed tomography of diffraction enhanced imaging (DEI-CT) based on synchrotron radiation source has extremely high sensitivity of weakly absorbing low-Z samples in medical and biological fields. The authors propose a modified backprojection filtration(BPF)-type algorithm based on PI-line segments to reconstruct region of interest from truncated refraction-angle projection data in DEI-CT. The distribution of refractive index decrement in the sample can be directly estimated from its reconstruction images, which has been proved by experiments at the Beijing Synchrotron Radiation Facility. The algorithm paves the way for local reconstruction of large-size samples by the use of DEI-CT with small field of view based on synchrotron radiation source.

Total-scattering pair-distribution function of organic material from powder electron diffraction data

DOE PAGES

Gorelik, Tatiana E.; Billinge, Simon J. L.; Schmidt, Martin U.; ...

2015-04-01

This paper shows for the first time that pair-distribution function analyses can be carried out on organic and organo-metallic compounds from powder electron diffraction data. Different experimental setups are demonstrated, including selected area electron diffraction (SAED) and nanodiffraction in transmission electron microscopy (TEM) or nanodiffraction in scanning transmission electron microscopy (STEM) modes. The methods were demonstrated on organo-metallic complexes (chlorinated and unchlorinated copper-phthalocyanine) and on purely organic compounds (quinacridone). The PDF curves from powder electron diffraction data, called ePDF, are in good agreement with PDF curves determined from X-ray powder data demonstrating that the problems of obtaining kinematical scattering datamore » and avoiding beam-damage of the sample are possible to resolve.« less

Engineering the Transformation Strain in LiMn y Fe 1–y PO 4 Olivines for Ultrahigh Rate Battery Cathodes

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

Ravnsbæk, Dorthe B.; Xiang, Kai; Xing, Wenting

2016-04-13

Alkali ion intercalation compounds used as battery electrodes often exhibit first-order phase transitions during electro-chemical cycling, accompanied by significant transformation strains. Despite 30 years of research into the behavior of such compounds, the relationship between transformation strain and electrode performance, especially the rate at which working ions (e.g., Li) can be intercalated and deintercalated, is still absent. In this work, we use the LiMn yFe 1-yPO 4 system for a systematic study, and measure using operando synchrotron radiation powder X-ray diffraction (SR-PXD) the dynamic strain behavior as a function of the Mn content (y) in powders of similar to 50more » nm average diameter. The dynamically produced strain deviates significantly from what is expected from the equilibrium phase diagrams and demonstrates metastability but nonetheless spans a wide range from 0 to 8 vol % with y. For the first time, we show that the discharge capacity at high C-rates (20-50C rate) varies in inverse proportion to the transformation strain, implying that engineering electrode materials for reduced strain can be used to maximize the power capability of batteries.« less

Time-resolved coherent X-ray diffraction imaging of surface acoustic waves

PubMed Central

Nicolas, Jan-David; Reusch, Tobias; Osterhoff, Markus; Sprung, Michael; Schülein, Florian J. R.; Krenner, Hubert J.; Wixforth, Achim; Salditt, Tim

2014-01-01

Time-resolved coherent X-ray diffraction experiments of standing surface acoustic waves, illuminated under grazing incidence by a nanofocused synchrotron beam, are reported. The data have been recorded in stroboscopic mode at controlled and varied phase between the acoustic frequency generator and the synchrotron bunch train. At each time delay (phase angle), the coherent far-field diffraction pattern in the small-angle regime is inverted by an iterative algorithm to yield the local instantaneous surface height profile along the optical axis. The results show that periodic nanoscale dynamics can be imaged at high temporal resolution in the range of 50 ps (pulse length). PMID:25294979

Time-resolved coherent X-ray diffraction imaging of surface acoustic waves.

PubMed

Nicolas, Jan-David; Reusch, Tobias; Osterhoff, Markus; Sprung, Michael; Schülein, Florian J R; Krenner, Hubert J; Wixforth, Achim; Salditt, Tim

2014-10-01

Time-resolved coherent X-ray diffraction experiments of standing surface acoustic waves, illuminated under grazing incidence by a nanofocused synchrotron beam, are reported. The data have been recorded in stroboscopic mode at controlled and varied phase between the acoustic frequency generator and the synchrotron bunch train. At each time delay (phase angle), the coherent far-field diffraction pattern in the small-angle regime is inverted by an iterative algorithm to yield the local instantaneous surface height profile along the optical axis. The results show that periodic nanoscale dynamics can be imaged at high temporal resolution in the range of 50 ps (pulse length).

Fracture mechanics by three-dimensional crack-tip synchrotron X-ray microscopy

PubMed Central

Withers, P. J.

2015-01-01

To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capable of both imaging and diffraction are beginning to emerge, such as ID15 at the European Synchrotron Radiation Facility and JEEP at the Diamond Light Source. This review explores the concept of three-dimensional crack-tip X-ray microscopy, bringing them together to probe the crack-tip behaviour under realistic environmental and loading conditions and to extract quantitative fracture mechanics information about the local crack-tip environment. X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces. Time-lapse CT, besides providing information about the three-dimensional nature of the crack and its local growth rate, can also provide information as to the activation of extrinsic toughening mechanisms such as crack deflection, crack-tip zone shielding, crack bridging and crack closure. It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement. Finally, further opportunities for synchrotron X-ray microscopy are explored. PMID:25624521

Operation of the Australian Store.Synchrotron for macromolecular crystallography

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

Meyer, Grischa R.; Aragão, David; Mudie, Nathan J.

2014-10-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Severalmore » real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community.« less

Pulsed supercritical synthesis of anatase TiO₂ nanoparticles in a water-isopropanol mixture studied by in situ powder X-ray diffraction.

PubMed

Rostgaard Eltzholtz, Jakob; Tyrsted, Christoffer; Ørnsbjerg Jensen, Kirsten Marie; Bremholm, Martin; Christensen, Mogens; Becker-Christensen, Jacob; Brummerstedt Iversen, Bo

2013-03-21

A new step in supercritical nanoparticle synthesis, the pulsed supercritical synthesis reactor, is investigated in situ using synchrotron powder X-ray diffraction (PXRD) to understand the formation of nanoparticles in real time. This eliminates the common problem of transferring information gained during in situ studies to subsequent laboratory reactor conditions. As a proof of principle, anatase titania nanoparticles were synthesized in a 50/50 mixture of water and isopropanol near and above the critical point of water (P = 250 bar, T = 300, 350, 400, 450, 500 and 550 °C). The evolution of the reaction product was followed by sequentially recording PXRD patterns with a time resolution of less than two seconds. The crystallite size of titania is found to depend on both temperature and residence time, and increasing either parameter leads to larger crystallites. A simple adjustment of either temperature or residence time provides a direct method for gram scale production of anatase nanoparticles of average crystallite sizes between 7 and 35 nm, thus giving the option of synthesizing tailor-made nanoparticles. Modeling of the in situ growth curves using an Avrami growth model gave an activation energy of 66(19) kJ mol(-1) for the initial crystallization. The in situ PXRD data also provide direct information about the size dependent macrostrain in the nanoparticles and with decreasing crystallite size the unit cell contracts, especially along the c-direction. This agrees well with previous ex situ results obtained for hydrothermal synthesis of titania nanoparticles.

X-Ray Crystallographic Studies on Acetylcholinesterase and on Its Interaction with Anticholinesterase Agents.

DTIC Science & Technology

1994-11-24

complexes with reversible ligands, including edrophonium, d-tubocurarine and huperzine A , diffracting to similar resolution. The X26c Laue beam line...The EMBL-DESY synchrotron facility at Hamburg was employed to collect a complete 2.3 A data set for a crystal of native Torpedo AChE, as well as for...at the NSLS synchrotron facility at Brookhaven National Laboratory (BNL) was used to obtain a Laue diffraction pattern for a crystal of native Torpedo

Diffraction imaging (topography) with monochromatic synchrotron radiation

NASA Technical Reports Server (NTRS)

Steiner, Bruce; Kuriyama, Masao; Dobbyn, Ronald C.; Laor, Uri

1988-01-01

Structural information of special interest to crystal growers and device physicists is now available from high resolution monochromatic synchrotron diffraction imaging (topography). In the review, the importance of superior resolution in momentum transfer and in space is described, and illustrations are taken from a variety of crystals: gallium arsenide, cadmium telluride, mercuric iodide, bismuth silicon oxide, and lithium niobate. The identification and understanding of local variations in crystal growth processes are shown. Finally, new experimental opportunities now available for exploitation are indicated.

Synchrotron X-ray diffraction investigations on strains in the oxide layer of an irradiated Zircaloy fuel cladding

NASA Astrophysics Data System (ADS)

Chollet, Mélanie; Valance, Stéphane; Abolhassani, Sousan; Stein, Gene; Grolimund, Daniel; Martin, Matthias; Bertsch, Johannes

2017-05-01

For the first time the microstructure of the oxide layer of a Zircaloy-2 cladding after 9 cycles of irradiation in a boiling water reactor has been analyzed with synchrotron micro-X-ray diffraction. Crystallographic strains of the monoclinic and to some extent of the tetragonal ZrO2 are depicted through the thick oxide layer. Thin layers of sub-oxide at the oxide-metal interface as found for autoclave-tested samples and described in the literature, have not been observed in this material maybe resulting from irradiation damage. Shifts of selected diffraction peaks of the monoclinic oxide show that the uniform strain produced during oxidation is orientated in the lattice and displays variations along the oxide layer. Diffraction peaks and their shifts from families of diffracting planes could be translated into a virtual tensor. This virtual tensor exhibits changes through the oxide layer passing by tensile or compressive components.

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

DOE PAGES

Fan, D.; Huang, J. W.; Zeng, X. L.; ...

2016-05-23

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantifymore » lattice deformation and fracture; diffraction peak broadening is largely caused by fracture-induced strain inhomogeneity. Finally, our results demonstrate the potential of such multiscale measurements for revealing and understanding high strain-rate phenomena at dynamic extremes.« less

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

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

Fan, D.; Huang, J. W.; Zeng, X. L.

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantifymore » lattice deformation and fracture; diffraction peak broadening is largely caused by fracture-induced strain inhomogeneity. Finally, our results demonstrate the potential of such multiscale measurements for revealing and understanding high strain-rate phenomena at dynamic extremes.« less

Operation of the Australian Store.Synchrotron for macromolecular crystallography

PubMed Central

Meyer, Grischa R.; Aragão, David; Mudie, Nathan J.; Caradoc-Davies, Tom T.; McGowan, Sheena; Bertling, Philip J.; Groenewegen, David; Quenette, Stevan M.; Bond, Charles S.; Buckle, Ashley M.; Androulakis, Steve

2014-01-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Several real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community. PMID:25286837

Operation of the Australian Store.Synchrotron for macromolecular crystallography.

PubMed

Meyer, Grischa R; Aragão, David; Mudie, Nathan J; Caradoc-Davies, Tom T; McGowan, Sheena; Bertling, Philip J; Groenewegen, David; Quenette, Stevan M; Bond, Charles S; Buckle, Ashley M; Androulakis, Steve

2014-10-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Several real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community.

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.

An Ultrahigh CO2-Loaded Silicalite-1 Zeolite: Structural Stability and Physical Properties at High Pressures and Temperatures.

PubMed

Marqueño, Tomas; Santamaria-Perez, David; Ruiz-Fuertes, Javier; Chuliá-Jordán, Raquel; Jordá, Jose L; Rey, Fernando; McGuire, Chris; Kavner, Abby; MacLeod, Simon; Daisenberger, Dominik; Popescu, Catalin; Rodriguez-Hernandez, Placida; Muñoz, Alfonso

2018-06-04

We report the formation of an ultrahigh CO 2 -loaded pure-SiO 2 silicalite-1 structure at high pressure (0.7 GPa) from the interaction of empty zeolite and fluid CO 2 medium. The CO 2 -filled structure was characterized in situ by means of synchrotron powder X-ray diffraction. Rietveld refinements and Fourier recycling allowed the location of 16 guest carbon dioxide molecules per unit cell within the straight and sinusoidal channels of the porous framework to be analyzed. The complete filling of pores by CO 2 molecules favors structural stability under compression, avoiding pressure-induced amorphization below 20 GPa, and significantly reduces the compressibility of the system compared to that of the parental empty one. The structure of CO 2 -loaded silicalite-1 was also monitored at high pressures and temperatures, and its thermal expansivity was estimated.

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

DOE PAGES

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

2016-02-24

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

Low-T magnetometry study of S = 1 Q2D [Ni(pyz) 2(H 2O) 2](BF 4) 2 (pyz = pyrazine)

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

Manson, J. L.; Villa, D. Y.; Blackmore, W. J. A.

2017-02-13

[Ni(pyz) 2(H 2O) 2](BF 4) 2 (pyz = N 2C 4H 4) was synthesized by a solvent-free technique and its structure solved by synchrotron X-ray powder diffraction.1 The compound contains S = 1 Ni(II) ions and has tetragonal symmetry. Two-D [Ni(pyz) 2(H 2O) 2] 2+ square lattices propagate in the ab-plane and stack along the c-axis (Fig. 1). Water ligands occupy axial sites and form H-bonds with interlayer BF 4 - ions. SQUID magnetometry shows a possible transition to long-range magnetic order near 3 K. We measured the magnetization of [Ni(pyz) 2(H 2O) 2](BF 4) 2 as a function ofmore » temperature to search for field-induced phase transitions and briefly report those findings here.« less

Reentrant Structural and Optical Properties and Large Positive Thermal Expansion in Perovskite Formamidinium Lead Iodide.

PubMed

Fabini, Douglas H; Stoumpos, Constantinos C; Laurita, Geneva; Kaltzoglou, Andreas; Kontos, Athanassios G; Falaras, Polycarpos; Kanatzidis, Mercouri G; Seshadri, Ram

2016-12-05

The structure of the hybrid perovskite HC(NH 2 ) 2 PbI 3 (formamidinium lead iodide) reflects competing interactions associated with molecular motion, hydrogen bonding tendencies, thermally activated soft octahedral rotations, and the propensity for the Pb 2+ lone pair to express its stereochemistry. High-resolution synchrotron X-ray powder diffraction reveals a continuous transition from the cubic α-phase (Pm3‾ m, #221) to a tetragonal β-phase (P4/mbm, #127) at around 285 K, followed by a first-order transition to a tetragonal γ-phase (retaining P4/mbm, #127) at 140 K. An unusual reentrant pseudosymmetry in the β-to-γ phase transition is seen that is also reflected in the photoluminescence. Around room temperature, the coefficient of volumetric thermal expansion is among the largest for any extended crystalline solid. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synchrotron X-ray micro-beam studies of ancient Egyptian make-up

NASA Astrophysics Data System (ADS)

Martinetto, P.; Anne, M.; Dooryhée, E.; Drakopoulos, M.; Dubus, M.; Salomon, J.; Simionovici, A.; Walter, Ph.

2001-07-01

Vases full of make-up are most often present in the burial furniture of Egyptian tombs dated from the pharaonic period. The powdered cosmetics made of isolated grains are analysed to identify their trace element signature. From this signature we identify the provenance of the mineral ingredients in the make-up and we observe different impurities in products, which have been demonstrated as synthetic substances by previous works. Focused X-ray micro-beam ( 2×5 μm2) is successively tuned at 11 keV, below the L III absorption edge of Pb, and 31.8 keV for global characterisation of the metal impurities. The fluorescence signal integrated over each single grain is detected against the X-ray micro-diffraction pattern collected in transmission with a bi-dimensional detector. Furthermore, for galena grains rich in Zn, the XANES signal at the K-absorption edge of Zn shows its immediate nearest-neighbour environment.

High-pressure structural, elastic, and electronic properties of the scintillator host material KMgF3

NASA Astrophysics Data System (ADS)

Vaitheeswaran, G.; Kanchana, V.; Kumar, Ravhi S.; Cornelius, A. L.; Nicol, M. F.; Svane, A.; Delin, A.; Johansson, B.

2007-07-01

The high-pressure structural behavior of the fluoroperovskite KMgF3 is investigated by theory and experiment. Density functional calculations were performed within the local density approximation and the generalized gradient approximation for exchange and correlation effects, as implemented within the full-potential linear muffin-tin orbital method. In situ high-pressure powder x-ray diffraction experiments were performed up to a maximum pressure of 40GPa using synchrotron radiation. We find that the cubic Pm3¯m crystal symmetry persists throughout the pressure range studied. The calculated ground state properties—the equilibrium lattice constant, bulk modulus, and elastic constants—are in good agreement with experimental results. By analyzing the ratio between the bulk and shear moduli, we conclude that KMgF3 is brittle in nature. Under ambient conditions, KMgF3 is found to be an indirect gap insulator, with the gap increasing under pressure.

The compression behavior of blödite at low and high temperature up to ~10GPa: Implications for the stability of hydrous sulfates on icy planetary bodies

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

Comodi, Paola; Stagno, Vincenzo; Zucchini, Azzurra

Recent satellite inferences of hydrous sulfates as recurrent minerals on the surface of icy planetary bodies link with the potential mineral composition of their interior. Blödite, a mixed Mg-Na sulfate, is here taken as representative mineral of icy satellites surface to investigate its crystal structure and stability at conditions of the interior of icy bodies. To this aim we performed in situ synchrotron angle-dispersive X-ray powder diffraction experiments on natural blödite at pressures up to ~10.4 GPa and temperatures from ~118.8 K to ~490.0 K using diamond anvil cell technique to investigate the compression behavior and establish a low-to-high temperaturemore » equation of state that can be used as reference when modeling the interior of sulfate-rich icy satellites such as Ganymede.« less

Synthesis, Structure, and Rigid Unit Mode-like Anisotropic Thermal Expansion of BaIr 2 In 9

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

Calta, Nicholas P.; Han, Fei; Kanatzidis, Mercouri G.

2015-09-08

This Article reports the synthesis of large single crystals of BaIr 2In 9 using In flux and their characterization by variable-temperature single-crystal and synchrotron powder X-ray diffraction, resistivity, and magnetization measurements. The title compound adopts the BaFe 2Al 9-type structure in the space group P6/mmm with room temperature unit cell parameters a = 8.8548(6) angstrom and c = 4.2696(4) A. BaIr 2In 9 exhibits anisotropic thermal expansion behavior with linear expansion along the c axis more than 3 times larger than expansion in the ab plane between 90 and 400 K. This anisotropic expansion originates from a rigid unit mode-likemore » mechanism similar to the mechanism of zero and negative thermal expansion observed in many anomalous thermal expansion materials such as ZrW 2O 8 and ScF 3.« less

Synthesis, Structure, and Rigid Unit Mode-like Anisotropic Thermal Expansion of BaIr2In9.

PubMed

Calta, Nicholas P; Han, Fei; Kanatzidis, Mercouri G

2015-09-08

This Article reports the synthesis of large single crystals of BaIr2In9 using In flux and their characterization by variable-temperature single-crystal and synchrotron powder X-ray diffraction, resistivity, and magnetization measurements. The title compound adopts the BaFe2Al9-type structure in the space group P6/mmm with room temperature unit cell parameters a = 8.8548(6) Å and c = 4.2696(4) Å. BaIr2In9 exhibits anisotropic thermal expansion behavior with linear expansion along the c axis more than 3 times larger than expansion in the ab plane between 90 and 400 K. This anisotropic expansion originates from a rigid unit mode-like mechanism similar to the mechanism of zero and negative thermal expansion observed in many anomalous thermal expansion materials such as ZrW2O8 and ScF3.

Titan's Lakes in a Beaker

NASA Astrophysics Data System (ADS)

Hodyss, R. P.

2017-12-01

The surface of Titan presents a complex, varied surfaced, with mountains, plains, dunes, rivers, lakes and seas, composed of a layer of organics over a water ice bedrock. Over the past 10 years, our group at JPL has developed a variety of techniques to study the chemistry of Titan's organic surface under relevant temperature and pressure conditions (90-100 K, 1.5 bar). Dissolution, precipitation, and both covalent and non-covalent chemical processes are examined using Raman and infrared spectroscopy, mass spectrometry, optical microscopy, and synchrotron X-ray powder diffraction. Despite the low temperatures, our experiments are revealing that a rich and active organic chemistry is possible on Titan's surface. Laboratory experiments like these can provide crucial insights into the geological processes occurring Titan's surface, and help explain the wealth of observational data returned by the Cassini/Huygens mission. This type of data is also critical for the development of future missions to Titan.

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

Wang, Pei; Wang, Yonggang; Wang, Liping

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

Spontaneous structural distortion of the metallic Shastry-Sutherland system Dy B4 by quadrupole-spin-lattice coupling

NASA Astrophysics Data System (ADS)

Sim, Hasung; Lee, Seongsu; Hong, Kun-Pyo; Jeong, Jaehong; Zhang, J. R.; Kamiyama, T.; Adroja, D. T.; Murray, C. A.; Thompson, S. P.; Iga, F.; Ji, S.; Khomskii, D.; Park, Je-Geun

2016-11-01

Dy B4 has a two-dimensional Shastry-Sutherland (Sh-S) lattice with strong Ising character of the Dy ions. Despite the intrinsic frustrations, it undergoes two successive transitions: a magnetic ordering at TN=20 K and a quadrupole ordering at TQ=12.5 K . From high-resolution neutron and synchrotron x-ray powder diffraction studies, we have obtained full structural information on this material in all phases and demonstrate that structural modifications occurring at quadrupolar transition lead to the lifting of frustrations inherent in the Sh-S model. Our paper thus provides a complete experimental picture of how the intrinsic frustration of the Sh-S lattice can be lifted by the coupling to quadrupole moments. We show that two other factors, i.e., strong spin-orbit coupling and long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in metallic Dy B4 , play an important role in this behavior.

Raman and X-Ray Investigation of High-Temperature Methane in the Diamond Anvil Cell

NASA Astrophysics Data System (ADS)

Spaulding, D.; Weck, G.; Loubeyre, P.; Mezouar, M.

2016-12-01

The chemistry and equations of state of simple molecular systems are of extreme importance to planetary astrophysics and for accurate characterization of reaction products and pathways at high pressures and temperatures. Simple molecules such as H2O, CO2 and CH4 are model systems for understanding the effects of pressure on chemical bonding. Here we present recent work to conduct fine-scale studies of the vibrational, chemical and structural properties of CH4 at pressures and temperatures up to 12 GPa and 1000K, with particular attention to behavior in the vicinity of the melting curve. We present results from resistive and laser-heating experiments, coupled with Raman spectroscopy. In addition, high P/T synchrotron powder x-ray diffraction provides tight constraints on melting and solid structure. Our results favor a somewhat higher melting curve and lower dissociative stability limit for the CH4 molecule than other recent work.

Pressure-induced polymerization of P(CN) 3

DOE PAGES

Gou, Huiyang; Yonke, Brendan L.; Epshteyn, Albert; ...

2015-05-21

Motivated to explore the formation of novel extended carbon-nitrogen solids via well-defined molecular precursor pathways, we studied the chemical reactivity of highly pure phosphorous tricyanide, P(CN) 3, under conditions of high pressure at room temperature. Raman and infrared (IR) spectroscopic measurements reveal a series of phase transformations below 10 GPa, and several low-frequency vibrational modes are reported for the first time. Synchrotron powder Xray diffraction (PXRD) measurements taken during compression show that molecular P(CN) 3 is highly compressible with a bulk modulus of 10.0±0.3 GPa and polymerizes into an amorphous solid above ~10.0 GPa. Raman and infrared (IR) spectra, togethermore » with first-principles molecular-dynamics simulations, show that the amorphization transition is associated with polymerization of the cyanide groups into CN bonds with predominantly sp 2 character, similar to known carbon nitrides, resulting in a novel PCN polymeric phase, which is recoverable to ambient pressure.« less

Li{sub 4}FeH{sub 6}: Iron-containing complex hydride with high gravimetric hydrogen density

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

Saitoh, Hiroyuki, E-mail: cyto@spring8.or.jp; Takagi, Shigeyuki; Matsuo, Motoaki

2014-07-01

Li{sub 4}FeH{sub 6}, which has the highest gravimetric hydrogen density of iron-containing complex hydrides reported so far, is synthesized by hydrogenation of a powder mixture of iron and LiH above 6.1 GPa at 900 °C. In situ synchrotron radiation X-ray diffraction measurements reveal that while kinetics require high temperature and thus high pressure for the synthesis, Li{sub 4}FeH{sub 6} is expected to be thermodynamically stable slightly below room temperature at ambient pressure; further synthetic studies to suppress the kinetic effects may enable us to synthesize Li{sub 4}FeH{sub 6} at moderate pressures. Li{sub 4}FeH{sub 6} can be recovered at ambient conditions wheremore » Li{sub 4}FeH{sub 6} is metastable.« less

Ordered microporous layered lanthanide 1,3,5-benzenetriphosphonates pillared with cationic organic molecules.

PubMed

Araki, Takahiro; Kondo, Atsushi; Maeda, Kazuyuki

2015-04-13

Novel isomorphous pillared-layer-type crystalline lanthanide 1,3,5-benzenetriphosphonates were prepared with bpy and dbo as organic pillars (LnBP-bpy and LnBP-dbo; Ln: Ce, Pr, and Nd). Ab initio crystal structure solution using synchrotron X-ray powder diffraction data revealed that the organic pillars do not exist as neutral coordinating ligands but as cationic molecules. Especially the LnBP-dbo phases have ordered interlayer space filled with water molecules between the dbo pillars, and the interlayer water is successfully removed by heating under vacuum with slightly distorted but basically retained pillared layer structures. Microporosity of the materials is confirmed by adsorption of nitrogen, carbon dioxide, and hydrogen gases. Such microporous layered metal phosphonates pillared with cationic molecules should be unprecedented and should offer new strategies to design ordered microporous materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal structure and phase transition of thermoelectric SnSe.

PubMed

Sist, Mattia; Zhang, Jiawei; Brummerstedt Iversen, Bo

2016-06-01

Tin selenide-based functional materials are extensively studied in the field of optoelectronic, photovoltaic and thermoelectric devices. Specifically, SnSe has been reported to have an ultrahigh thermoelectric figure of merit of 2.6 ± 0.3 in the high-temperature phase. Here we report the evolution of lattice constants, fractional coordinates, site occupancy factors and atomic displacement factors with temperature by means of high-resolution synchrotron powder X-ray diffraction measured from 100 to 855 K. The structure is shown to be cation defective with a Sn content of 0.982 (4). The anisotropy of the thermal parameters of Sn becomes more pronounced approaching the high-temperature phase transition (∼ 810 K). Anharmonic Gram-Charlier parameters have been refined, but data from single-crystal diffraction appear to be needed to firmly quantify anharmonic features. Based on modelling of the atomic displacement parameters the Debye temperature is found to be 175 (4) K. Conflicting reports concerning the different coordinate system settings in the low-temperature and high-temperature phases are discussed. It is also shown that the high-temperature Cmcm phase is not pseudo-tetragonal as commonly assumed.

The hydrothermal decomposition of calcium monosulfoaluminate 14-hydrate to katoite hydrogarnet and β-anhydrite: An in-situ synchrotron X-ray diffraction study

NASA Astrophysics Data System (ADS)

Meller, Nicola; Kyritsis, Konstantinos; Hall, Christopher

2009-10-01

We apply in-situ synchrotron X-ray diffraction to study the transformation of calcium monosulfoaluminate 14-hydrate Ca 4Al 2O 6(SO 4)·14H 2O [monosulfate-14] to hydrogarnet Ca 3Al 2(OH) 12 on the saturated water vapor pressure curve up to 250 °C. We use an aqueous slurry of synthetic ettringite Ca 6Al 2(SO 4) 3(OH) 12·26H 2O as the starting material; on heating, this decomposes at about 115 °C to form monosulfate-14 and bassanite CaSO 4·0.5H 2O. Above 170 °C monosulfate-14 diffraction peaks slowly diminish in intensity, perhaps as a result of loss of crystallinity and the formation of an X-ray amorphous meta-monosulfate. Hydrogarnet nucleates only at temperatures above 210 °C. Bassanite transforms to β-anhydrite (insoluble anhydrite) at about 230 °C and this transformation is accompanied by a second burst of hydrogarnet growth. The transformation pathway is more complex than previously thought. The mapping of the transformation pathway shows the value of rapid in-situ time-resolved synchrotron diffraction.

Synchrotron hard X-ray imaging of shock-compressed metal powders

NASA Astrophysics Data System (ADS)

Rutherford, Michael E.; Chapman, David J.; Collinson, Mark A.; Jones, David R.; Music, Jasmina; Stafford, Samuel J. P.; Tear, Gareth R.; White, Thomas G.; Winters, John B. R.; Drakopoulos, Michael; Eakins, Daniel E.

2015-06-01

This poster will present the application of a new, high-energy (50 to 250 keV) synchrotron X-ray radiography technique to the study of shock-compressed granular materials. Following plate-impact loading, transmission radiography was used to quantitatively observe the compaction and release processes in a range of high-Z metal powders (e.g. Fe, Ni, Cu). By comparing the predictions of 3D numerical models initialized from X-ray tomograms-captured prior to loading-with experimental results, this research represents a new approach to refining mesoscopic compaction models. The authors gratefully acknowledge the ongoing support of Imperial College London, EPSRC, STFC and the Diamond Light Source, and AWE Plc.

Dynamic full-field infrared imaging with multiple synchrotron beams

PubMed Central

Stavitski, Eli; Smith, Randy J.; Bourassa, Megan W.; Acerbo, Alvin S.; Carr, G. L.; Miller, Lisa M.

2013-01-01

Microspectroscopic imaging in the infrared (IR) spectral region allows for the examination of spatially resolved chemical composition on the microscale. More than a decade ago, it was demonstrated that diffraction limited spatial resolution can be achieved when an apertured, single pixel IR microscope is coupled to the high brightness of a synchrotron light source. Nowadays, many IR microscopes are equipped with multi-pixel Focal Plane Array (FPA) detectors, which dramatically improve data acquisition times for imaging large areas. Recently, progress been made toward efficiently coupling synchrotron IR beamlines to multi-pixel detectors, but they utilize expensive and highly customized optical schemes. Here we demonstrate the development and application of a simple optical configuration that can be implemented on most existing synchrotron IR beamlines in order to achieve full-field IR imaging with diffraction-limited spatial resolution. Specifically, the synchrotron radiation fan is extracted from the bending magnet and split into four beams that are combined on the sample, allowing it to fill a large section of the FPA. With this optical configuration, we are able to oversample an image by more than a factor of two, even at the shortest wavelengths, making image restoration through deconvolution algorithms possible. High chemical sensitivity, rapid acquisition times, and superior signal-to-noise characteristics of the instrument are demonstrated. The unique characteristics of this setup enabled the real time study of heterogeneous chemical dynamics with diffraction-limited spatial resolution for the first time. PMID:23458231

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

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

Schmidt, Corinna; Feyand, Mark; Rothkirch, Andre

2012-04-15

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

Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

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

Öztürk, Hande; Noyan, I. Cevdet

A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

DOE PAGES

Öztürk, Hande; Noyan, I. Cevdet

2017-08-24

A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

Thermal analysis, X-ray powder diffraction and electron microscopy data related with the production of 1:1 Caffeine:Glutaric Acid cocrystals.

PubMed

Duarte, Íris; Andrade, Rita; Pinto, João F; Temtem, Márcio

2016-09-01

The data presented in this article are related to the production of 1:1 Caffeine:Glutaric Acid cocrystals as part of the research article entitled "Green production of cocrystals using a new solvent-free approach by spray congealing" (Duarte et al., 2016) [1]. More specifically, here we present the thermal analysis and the X-ray powder diffraction data for pure Glutaric Acid, used as a raw material in [1]. We also include the X-ray powder diffraction and electron microscopy data obtained for the 1:1 Caffeine:Glutaric Acid cocrystal (form II) produced using the cooling crystallization method reported in "Operating Regions in Cooling Cocrystallization of Caffeine and Glutaric Acid in Acetonitrile" (Yu et al., 2010) [2]. Lastly, we show the X-ray powder diffraction data obtained for assessing the purity of the 1:1 Caffeine:Glutaric cocrystals produced in [1].

Synthesis of nanostructured vanadium powder by high-energy ball milling: X-ray diffraction and high-resolution electron microscopy characterization

NASA Astrophysics Data System (ADS)

Krishnan, Vinoadh Kumar; Sinnaeruvadi, Kumaran

2016-10-01

Vanadium metal powders, ball milled with different surfactants viz., stearic acid, KCl and NaCl, have been studied by X-ray diffraction and transmission electron microscopy. The surfactants alter the microstructural and morphological characteristics of the powders. Ball milling with stearic acid results in solid-state amorphization, while powders milled with KCl yield vanadium-tungsten carbide nanocomposite mixtures. NaCl proved to be an excellent surfactant for obtaining nanostructured fusion-grade vanadium powders. In order to understand the reaction mechanism behind any interstitial addition in the ball-milled powders, CHNOS analysis was performed.

High-efficiency thermoelectric Ba8Cu14Ge6P26: bridging the gap between tetrel-based and tetrel-free clathrates† †Electronic supplementary information (ESI) available: Calculated and experimental powder XRD patterns; tables with crystallographic information; SEM and EDS results; additional DSC, thermal conductivities, and ZT figures. CCDC 1568106. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc03482b

PubMed Central

Wang, Jian; Lebedev, Oleg I.; Lee, Kathleen; Dolyniuk, Juli-Anna; Klavins, Peter; Bux, Sabah

2017-01-01

A new type-I clathrate, Ba8Cu14Ge6P26, was synthesized by solid-state methods as a polycrystalline powder and grown as a cm-sized single crystal via the vertical Bridgman method. Single-crystal and powder X-ray diffraction show that Ba8Cu14Ge6P26 crystallizes in the cubic space group Pm3n (no. 223). Ba8Cu14Ge6P26 is the first representative of anionic clathrates whose framework is composed of three atom types of very different chemical natures: a transition metal, tetrel element, and pnicogen. Uniform distribution of the Cu, Ge, and P atoms over the framework sites and the absence of any superstructural or local ordering in Ba8Cu14Ge6P26 were confirmed by synchrotron X-ray diffraction, electron diffraction and high-angle annular dark field scanning transmission electron microscopy, and neutron and X-ray pair distribution function analyses. Characterization of the transport properties demonstrate that Ba8Cu14Ge6P26 is a p-type semiconductor with an intrinsically low thermal conductivity of 0.72 W m–1 K–1 at 812 K. The thermoelectric figure of merit, ZT, for a slice of the Bridgman-grown crystal of Ba8Cu14Ge6P26 approaches 0.63 at 812 K due to a high power factor of 5.62 μW cm–1 K–2. The thermoelectric efficiency of Ba8Cu14Ge6P26 is on par with the best optimized p-type Ge-based clathrates and outperforms the majority of clathrates in the 700–850 K temperature region, including all tetrel-free clathrates. Ba8Cu14Ge6P26 expands clathrate chemistry by bridging conventional tetrel-based and tetrel-free clathrates. Advanced transport properties, in combination with earth-abundant framework elements and congruent melting make Ba8Cu14Ge6P26 a strong candidate as a novel and efficient thermoelectric material. PMID:29568451

The power of in situ pulsed laser deposition synchrotron characterization for the detection of domain formation during growth of Ba0.5Sr0.5TiO3 on MgO.

PubMed

Bauer, Sondes; Lazarev, Sergey; Molinari, Alan; Breitenstein, Andreas; Leufke, Philipp; Kruk, Robert; Hahn, Horst; Baumbach, Tilo

2014-03-01

A highly sophisticated pulsed laser deposition (PLD) chamber has recently been installed at the NANO beamline at the synchrotron facility ANKA (Karlsruhe, Germany), which allows for comprehensive studies on the PLD growth process of dielectric, ferroelectric and ferromagnetic thin films in epitaxial oxide heterostructures or even multilayer systems by combining in situ reflective high-energy diffraction with the in situ synchrotron high-resolution X-ray diffraction and surface diffraction methods. The modularity of the in situ PLD chamber offers the opportunity to explore the microstructure of the grown thin films as a function of the substrate temperature, gas pressure, laser fluence and target-substrate separation distance. Ba0.5Sr0.5TiO3 grown on MgO represents the first system that is grown in this in situ PLD chamber and studied by in situ X-ray reflectivity, in situ two-dimensional reciprocal space mapping of symmetric X-ray diffraction and acquisition of time-resolved diffraction profiles during the ablation process. In situ PLD synchrotron investigation has revealed the occurrence of structural distortion as well as domain formation and misfit dislocation which all depend strongly on the film thickness. The microstructure transformation has been accurately detected with a time resolution of 1 s. The acquisition of two-dimensional reciprocal space maps during the PLD growth has the advantage of simultaneously monitoring the changes of the crystalline structure as well as the formation of defects. The stability of the morphology during the PLD growth is demonstrated to be remarkably affected by the film thickness. A critical thickness for the domain formation in Ba0.5Sr0.5TiO3 grown on MgO could be determined from the acquisition of time-resolved diffraction profiles during the PLD growth. A splitting of the diffraction peak into two distinguishable peaks has revealed a morphology change due to modification of the internal strain during growth.

Sucrose lyophiles: a semi-quantitative study of residual water content by total X-ray diffraction analysis.

PubMed

Bates, S; Jonaitis, D; Nail, S

2013-10-01

Total X-ray Powder Diffraction Analysis (TXRPD) using transmission geometry was able to observe significant variance in measured powder patterns for sucrose lyophilizates with differing residual water contents. Integrated diffraction intensity corresponding to the observed variances was found to be linearly correlated to residual water content as measured by an independent technique. The observed variance was concentrated in two distinct regions of the lyophilizate powder pattern, corresponding to the characteristic sucrose matrix double halo and the high angle diffuse region normally associated with free-water. Full pattern fitting of the lyophilizate powder patterns suggested that the high angle variance was better described by the characteristic diffraction profile of a concentrated sucrose/water system rather than by the free-water diffraction profile. This suggests that the residual water in the sucrose lyophilizates is intimately mixed at the molecular level with sucrose molecules forming a liquid/solid solution. The bound nature of the residual water and its impact on the sucrose matrix gives an enhanced diffraction response between 3.0 and 3.5 beyond that expected for free-water. The enhanced diffraction response allows semi-quantitative analysis of residual water contents within the studied sucrose lyophilizates to levels below 1% by weight. Copyright © 2013 Elsevier B.V. All rights reserved.

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

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

Fan, D.; Luo, S. N., E-mail: sluo@pims.ac.cn; Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantifymore » lattice deformation and fracture; fracture is dominated by splitting cracks followed by wing cracks, and diffraction peaks are broadened likely due to mosaic spread. Our results demonstrate the potential of such multiscale measurements for studying high strain-rate phenomena at dynamic extremes.« less

Anisotropic deformation of extruded magnesium alloy AZ31 under uniaxial compression: A study with simultaneous in situ synchrotron x-ray imaging and diffraction

DOE PAGES

Lu, L.; Huang, J. W.; Fan, D.; ...

2016-08-29

In situ synchrotron x-ray imaging and diffraction are used to investigate anisotropic deformation of an extruded magnesium alloy AZ31 under uniaxial compression along two different directions, with the loading axis (LA) either parallel or perpendicular to the extrusion direction (ED), referred to as LA∥ED and LAED, respectively. Multiscale measurements including stress–strain curves (macroscale), x-ray digital image correlation (mesoscale), and diffraction (microscale) are obtained simultaneously. Electron backscatter diffraction is performed on samples collected at various strains to characterize deformation twins. The rapid increase in strain hardening rate for the LA∥ED loading is attributed to marked {101¯2} extension twinning and subsequent homogenizationmore » of deformation, while dislocation motion leads to inhomogeneous deformation and a decrease in strain hardening rate.« less

Multilayer diffraction at 104 keV

NASA Technical Reports Server (NTRS)

Krieger, Allen S.; Blake, Richard L.; Siddons, D. P.

1993-01-01

We have measured the diffraction peak of a W:Si synthetic multilayer reflector at 104 keV using the High Energy Bonse-Hart Camera at the X-17B hard X-ray wiggler beam line of the National Synchrotron Light Source at Brookhaven National Laboratory. The characteristics of the diffraction peak are described and compared to theory.

Analysis of Short and Long Range Atomic Order in Nanocrystalline Diamonds with Application of Powder Diffractometry

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Neuefiend, J.; Weber, H.-P.; Proffen, T.; VonDreele, R.; Palosz, W.;

A New Camera for Powder Diffraction of Macromolecular Crystallography at SPring-8

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

Miura, Keiko; Inoue, Katsuaki; Goto, Shunji

2004-05-12

A powder diffractometer of Guinier geometry was developed and tested on a beamline, BL40B2, at SPring-8. The long specimen-to-detector distance, 1,000 mm, is advantageous in recording diffraction from Bragg spacing of 20 nm or larger. The angular resolution, 0.012 degrees, was realized together with the focusing optics, the long specimen-to-detector distance and the small pixel size of Blue-type Imaging Plate detector. Such a high resolution makes the peak separation possible in the powder diffraction from microcrystals with large unit cell and low symmetry of biological macromolecules.

Energy research with neutrons (ErwiN) and installation of a fast neutron powder diffraction option at the MLZ, Germany1

PubMed Central

Mühlbauer, Martin J.

2018-01-01

The need for rapid data collection and studies of small sample volumes in the range of cubic millimetres are the main driving forces for the concept of a new high-throughput monochromatic diffraction instrument at the Heinz Maier-Leibnitz Zentrum (MLZ), Germany. A large region of reciprocal space will be accessed by a detector with sufficient dynamic range and microsecond time resolution, while allowing for a variety of complementary sample environments. The medium-resolution neutron powder diffraction option for ‘energy research with neutrons’ (ErwiN) at the high-flux FRM II neutron source at the MLZ is foreseen to meet future demand. ErwiN will address studies of energy-related systems and materials with respect to their structure and uniformity by means of bulk and spatially resolved neutron powder diffraction. A set of experimental options will be implemented, enabling time-resolved studies, rapid parametric measurements as a function of external parameters and studies of small samples using an adapted radial collimator. The proposed powder diffraction option ErwiN will bridge the gap in functionality between the high-resolution powder diffractometer SPODI and the time-of-flight diffractometers POWTEX and SAPHiR at the MLZ. PMID:29896055

Textures of water-rich mud sediments from the continental margin offshore Costa Rica (IODP expeditions 334 and 344)

NASA Astrophysics Data System (ADS)

Kuehn, Rebecca; Stipp, Michael; Leiss, Bernd

2017-04-01

During sedimentation and burial at continental margins, clay-rich sediments develop crystallographic preferred orientations (textures) depending on the ongoing compaction as well as size distribution and shape fabrics of the grains. Such textures can control the deformational properties of these sediments and hence the strain distribution in active continental margins and also the frictional behavior along and around the plate boundary. Strain-hardening and discontinuous deformation may lead to earthquake nucleation at or below the updip limit of the seismogenic zone. We want to investigate the active continental margin offshore Costa Rica where the oceanic Cocos plate is subducted below the Caribbean plate at a rate of approximately 9 cm per year. The Costa Rica trench is well-known for shallow seismogenesis and tsunami generation. As it is an erosive continental margin, both the incoming sediments from the Nazca plate as well as the slope sediments of the continental margin can be important for earthquake nucleation and faulting causing sea-floor breakage. To investigate texture and composition of the sediments and hence their deformational properties we collected samples from varying depth of 7 different drilling locations across the trench retrieved during IODP expeditions 334 and 344 as part of the Costa Rica Seismogenesis Project (CRISP). Texture analysis was carried out by means of synchrotron diffraction, as only this method is suitable for water-bearing samples. As knowledge on the sediment composition is required as input parameter for the texture data analysis, additional X-ray powder diffraction analysis on the sample material has been carried out. Samples for texture measurements were prepared from the original drill cores using an internally developed cutter which allows to produce cylindrical samples with a diameter of about 1.5 cm. The samples are oriented with respect to the drill core axis. Synchrotron texture measurements were conducted at the ESRF (European Synchrotron Radiation Facility) in Grenoble and the DESY (German Electron Synchrotron) in Hamburg. Samples were measured in transmission mode perpendicular to their cylinder axis with a beam diameter of 500 µm. Measurements were taken from 0 to 175° in 5° steps resulting in 36 images from a 2D image plate detector. Measurement time was in a range from 1 to 3 seconds. Due to the different, low symmetric mineral phases a large number of mostly overlapping reflections results. Such data can only be analyzed by the Rietveld method, in our case implemented in the software package MAUD (Materials Analysis Using Diffraction). Preliminary results show distinct textures depending on the composition and the origin of the samples, i.e. on drilling location and depth, which may be critical for strain localization and faulting of these samples. The results are also important for the analysis of experimentally deformed samples from the same drill cores which showed structurally weak and structurally strong deformation behavior during triaxial compression.

Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

NASA Astrophysics Data System (ADS)

Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

2016-03-01

Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization of the resin embedded (originally polycrystalline) silicate sample. We explore the astrophysical implications of this laboratory result as an upper limit to the effect of X-rays on the structure of cosmic silicates.

Structure of nanocrystalline calcium silicate hydrates: insights from X-ray diffraction, synchrotron X-ray absorption and nuclear magnetic resonance

PubMed Central

Grangeon, Sylvain; Claret, Francis; Roosz, Cédric; Sato, Tsutomu; Gaboreau, Stéphane; Linard, Yannick

2016-01-01

The structure of nanocrystalline calcium silicate hydrates (C–S–H) having Ca/Si ratios ranging between 0.57 ± 0.05 and 1.47 ± 0.04 was studied using an electron probe micro-analyser, powder X-ray diffraction, 29Si magic angle spinning NMR, and Fourier-transform infrared and synchrotron X-ray absorption spectroscopies. All samples can be described as nanocrystalline and defective tobermorite. At low Ca/Si ratio, the Si chains are defect free and the Si Q 3 and Q 2 environments account, respectively, for up to 40.2 ± 1.5% and 55.6 ± 3.0% of the total Si, with part of the Q 3 Si being attributable to remnants of the synthesis reactant. As the Ca/Si ratio increases up to 0.87 ± 0.02, the Si Q 3 environment decreases down to 0 and is preferentially replaced by the Q 2 environment, which reaches 87.9 ± 2.0%. At higher ratios, Q 2 decreases down to 32.0 ± 7.6% for Ca/Si = 1.38 ± 0.03 and is replaced by the Q 1 environment, which peaks at 68.1 ± 3.8%. The combination of X-ray diffraction and NMR allowed capturing the depolymerization of Si chains as well as a two-step variation in the layer-to-layer distance. This latter first increases from ∼11.3 Å (for samples having a Ca/Si ratio <∼0.6) up to 12.25 Å at Ca/Si = 0.87 ± 0.02, probably as a result of a weaker layer-to-layer connectivity, and then decreases down to 11 Å when the Ca/Si ratio reaches 1.38 ± 0.03. The decrease in layer-to-layer distance results from the incorporation of interlayer Ca that may form a Ca(OH)2-like structure, nanocrystalline and intermixed with C–S–H layers, at high Ca/Si ratios. PMID:27275135

Aqueous Nucleation and Growth of Titanium Oxides Using Time-Resolved Synchrotron X- ray Diffraction

NASA Astrophysics Data System (ADS)

Hummer, D. R.; Heaney, P. J.; Post, J. E.

2006-05-01

The inorganic precipitation of oxide minerals in soil environments has profound effects on a variety of geochemical processes. These include the removal of metals from the aqueous phase, the production of coatings that reduce the reactive surface area of pre-existing mineral grains, and the generation of feedstocks for microbial metabolic reactions. Recent observations of transient, metastable phases during the growth of oxide crystallites has raised questions about their role in crystallization mechanisms, and created a need for more detailed structural measurements. To better understand the process of nucleation and growth, we investigated the crystallization of Ti oxides from aqueous 0.5 M TiCl4 solutions using synchrotron X-ray diffraction at temperatures of 100 and 150 °C. Solutions were heated in a 1.0 mm internal diameter quartz glass capillary sealed with epoxy. Powder diffraction patterns of the growing crystallites were collected using image plate technology with a time step of ~ 4 minutes, providing high resolution in situ measurements of structural changes during the crystallization process. The data indicate a co-precipitation of the two crystalline phases anatase and rutile within the first 30 minutes of heating, followed by a gradual phase transition from anatase to rutile during particle coarsening throughout the 10 hour duration of an experiment. The co-existence of anatase and rutile at the onset of crystallization lends additional support to the assertion of nearly identical free energies for anatase and rutile at the nanoscale, believed to be due to the prominence of surface energy effects (Ranade et al., 2001). Whole pattern analyses using the Rietveld refinement method also documented previously unobserved changes in lattice parameters of both phases during growth, on the order of 0.2-0.3 % expansion for each axis. The trends in lattice parameters are observed to be temperature dependent, generally having lower values at higher crystallization temperature. In addition to increased surface energy, these small but measurable structural changes may be partially responsible for the observed reversals in thermodynamic stability between crystalline Ti oxide phases at very small particle sizes.

High-resolution neutron diffraction study of microstructural changes in nanocrystalline ball-milled niobium carbide NbC{sub 0.93}

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

Balagurov, Anatoly M.; Bobrikov, Ivan A.; Bokuchava, Gizo D.

2015-11-15

High resolution neutron diffraction was applied for elucidating of the microstructural evolution of nanocrystalline niobium carbide NbC{sub 0.93} powders subjected to high-energy ball milling. The diffraction patterns were collected with the high resolution Fourier diffractometer HRFD by using the reverse time-of-flight (RTOF) mode of data acquisition. The traditional single diffraction line analysis, the Rietveld method and more advanced Whole Powder Pattern Modeling technique were applied for the data analysis. The comparison of these techniques was performed. It is established that short-time milling produces a non-uniform powder, in which two distinct fractions with differing microstructure can be identified. Part of themore » material is in fact milled efficiently, with a reduction in grain size, an increase in the quantity of defects, and a corresponding tendency to decarburize reaching a composition NbC{sub 0.80} after 15 h of milling. The rest of the powder is less efficiently processed and preserves its composition and lower defect content. Larger milling times should have homogenized the system by increasing the efficiently milled fraction, but the material is unable to reach a uniform and homogeneous state. It is definitely shown that RTOF neutron diffraction patterns can provide the very accurate data for microstructure analysis of nanocrystalline powders. - Highlights: • The NbC{sub 0.93} powder was processed by high-energy ball milling. • The microstrain and dislocation density increase with milling time increase. • The corresponding decrease in crystallite size with milling time was observed. • The material exhibits the presence of two fractions after ball milling. • The RTOF neutron diffraction data are suitable for accurate microstructure analysis.« less

Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

PubMed Central

Zhang, Hongjia; Sui, Tan; Daisenberger, Dominik; Fong, Kai Soon

2018-01-01

High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning) or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short). As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation. PMID:29543728

A new theory for X-ray diffraction.

PubMed

Fewster, Paul F

2014-05-01

This article proposes a new theory of X-ray scattering that has particular relevance to powder diffraction. The underlying concept of this theory is that the scattering from a crystal or crystallite is distributed throughout space: this leads to the effect that enhanced scatter can be observed at the `Bragg position' even if the `Bragg condition' is not satisfied. The scatter from a single crystal or crystallite, in any fixed orientation, has the fascinating property of contributing simultaneously to many `Bragg positions'. It also explains why diffraction peaks are obtained from samples with very few crystallites, which cannot be explained with the conventional theory. The intensity ratios for an Si powder sample are predicted with greater accuracy and the temperature factors are more realistic. Another consequence is that this new theory predicts a reliability in the intensity measurements which agrees much more closely with experimental observations compared to conventional theory that is based on `Bragg-type' scatter. The role of dynamical effects (extinction etc.) is discussed and how they are suppressed with diffuse scattering. An alternative explanation for the Lorentz factor is presented that is more general and based on the capture volume in diffraction space. This theory, when applied to the scattering from powders, will evaluate the full scattering profile, including peak widths and the `background'. The theory should provide an increased understanding of the reliability of powder diffraction measurements, and may also have wider implications for the analysis of powder diffraction data, by increasing the accuracy of intensities predicted from structural models.

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

Sun, Pei; Fang, Z. Zak; Koopman, Mark

Hydrogen has been investigated for decades as a temporary alloying element to refine the microstructure of Ti-6Al-4V, and is now being used in a novel powder metallurgy method known as "hydrogen sintering and phase transformation". Pseudo-binary phase diagrams of (Ti-6Al-4V)-xH have been studied and developed, but are not well established due to methodological limitations. In this paper, in situ studies of phase transformations during hydrogenation and dehydrogenation of (Ti-6Al-4V)-xH alloys were conducted using high-energy synchrotron X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The eutectoid phase transformation of β ↔ α + δ was observed in themore » (Ti-6Al-4V)-xH alloy via in situ synchrotron XRD at 211 °C with a hydrogen concentration of 37.5 at.% (measured using TGA-DSC). The relationships of hydrogen composition to partial pressure and temperature were investigated in the temperature range 450-900°C. Based on these results, a partial pseudo-binary phase diagram of (Ti-6Al-4V)-xH is proposed for hydrogen compositions up to 60 at.% in the temperature range 100-900°C. Using the data collected in real time under controlled parameters of temperature, composition and hydrogen partial pressure, this work characterizes relevant phase transformations and microstructural evolution for practical titanium-hydrogen technologies of Ti-6Al-4V.« less

New insights into the toxicity of mineral fibres: A combined in situ synchrotron μ-XRD and HR-TEM study of chrysotile, crocidolite, and erionite fibres found in the tissues of Sprague-Dawley rats.

PubMed

Gualtieri, Alessandro F; Bursi Gandolfi, Nicola; Pollastri, Simone; Burghammer, Manfred; Tibaldi, Eva; Belpoggi, Fiorella; Pollok, Kilian; Langenhorst, Falko; Vigliaturo, Ruggero; Dražić, Goran

2017-05-15

Along the line of the recent research topic aimed at understanding the in vivo activity of mineral fibres and their mechanisms of toxicity, this work describes the morpho-chemical characteristics of the mineral fibres found in the tissues of Sprague-Dawley rats subjected to intraperitoneal/intrapleural injection of UICC chrysotile, UICC crocidolite and erionite-Na from Nevada (USA). The fibres are studied with in situ synchrotron powder diffraction and high resolution transmission electron microscopy to improve our understanding of the mechanisms of toxicity of these mineral fibres. In contact with the tissues of the rats, chrysotile fibres are prone to dissolve, with leaching of Mg and production of a silica rich relict. On the other hand, crocidolite and erionite-Na fibres are stable even for very long contact times within the tissues of the rats, showing just a thin dissolution amorphous halo. These findings support the model of a lower biopersistence of chrysotile with respect to crocidolite and erionite-Na but the formation of a silica-rich fibrous residue after the pseudo-amorphization of chrysotile may justify a higher cytotoxic potential and intense inflammatory activity of chrysotile in the short term in contact with the lung tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

Gas-Phase Synthesis and Characterization of CH4-Loaded Hydroquinone Clathrates

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

Lee, J.; Lee, Y; Takeya, S

2010-01-01

A CH{sub 4}-loaded hydroquinone (HQ) clathrate was synthesized via a gas-phase reaction using the {alpha}-form of crystalline HQ and CH{sub 4} gas at 12 MPa and room temperature. Solid-state {sup 13}C cross-polarization/magic angle spinning (CP/MAS) NMR and Raman spectroscopic measurements confirm the incorporation of CH{sub 4} molecules into the cages of the HQ clathrate framework. The chemical analysis indicates that about 69% of the cages are filled by CH{sub 4} molecules, that is, 0.69 CH{sub 4} per three HQ molecules. Rietveld refinement using synchrotron X-ray powder diffraction (XRD) data shows that the CH{sub 4}-loaded HQ clathrate adopts the {beta}-form ofmore » HQ clathrate in a hexagonal space group R3 with lattice parameters of a = 16.6191 {angstrom} and c = 5.5038 {angstrom}. Time-resolved synchrotron XRD and quadrupole mass spectroscopic measurements show that the CH{sub 4}-loaded HQ clathrate is stable up to 368 K and gradually transforms to the {alpha}-form by releasing the confined CH{sub 4} gases between 368-378 K. Using solid-state {sup 13}C CP/MAS NMR, the reaction kinetics between the {alpha}-form HQ and CH{sub 4} gas is qualitatively described in terms of the particle size of the crystalline HQ.« less

Simultaneous multiscale measurements on dynamic deformation of a magnesium alloy with synchrotron x-ray imaging and diffraction

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

Lu, L.; Sun, T.; Fezzaa, K.

Dynamic split Hopkinson pressure bar experiments with in situ synchrotron x-ray imaging and diffraction are conducted on a rolled magnesium alloy at high strain rates of ~5500 s-1. High speed multiscale measurements including stress–strain curves (macroscale), strain fields (mesoscale), and diffraction patterns (microscale) are obtained simultaneously, revealing strong anisotropy in deformation across different length scales. {1012} extension twinning induces homogenized strain fields and gives rise to rapid increase in strain hardening rate, while dislocation motion leads to inhomogeneous deformation and a decrease in strain hardening rate. During the early stage of plastic deformation, twinning is dominant in dynamic compression, whilemore » dislocation motion prevails in quasi-static loading, manifesting a strain-rate dependence of deformation.« less

Synchrotron radiation microbeam X-ray diffraction for nondestructive assessments of local structural properties of faceted InGaN/GaN quantum wells

NASA Astrophysics Data System (ADS)

Sakaki, Atsushi; Funato, Mitsuru; Kawamura, Tomoaki; Araki, Jun; Kawakami, Yoichi

2018-03-01

Synchrotron radiation (SR) X-ray diffraction with a sub-µm spatial resolution is used to nondestructively evaluate the local thickness and alloy composition of three-dimensionally faceted InGaN/GaN quantum wells (QWs). The (0001) facet QW on a trapezoidal structure composed of (0001), \\{ 11\\bar{2}2\\} , and \\{ 11\\bar{2}0\\} facets is nonuniform, most likely owing to the migration of adatoms between facets. The thickness and composition markedly vary within a short distance for the \\{ 11\\bar{2}2\\} facet QW of another pyramidal structure. The QW parameters acquired by SR microbeam X-ray diffraction reproduce the local emission property assessed by cathodoluminescence, thereby indicating the high reliability of this method.

Synchrotron-Based X-ray Microtomography Characterization of the Effect of Processing Variables on Porosity Formation in Laser Power-Bed Additive Manufacturing of Ti-6Al-4V

NASA Astrophysics Data System (ADS)

Cunningham, Ross; Narra, Sneha P.; Montgomery, Colt; Beuth, Jack; Rollett, A. D.

2017-03-01

The porosity observed in additively manufactured (AM) parts is a potential concern for components intended to undergo high-cycle fatigue without post-processing to remove such defects. The morphology of pores can help identify their cause: irregularly shaped lack of fusion or key-holing pores can usually be linked to incorrect processing parameters, while spherical pores suggest trapped gas. Synchrotron-based x-ray microtomography was performed on laser powder-bed AM Ti-6Al-4V samples over a range of processing conditions to investigate the effects of processing parameters on porosity. The process mapping technique was used to control melt pool size. Tomography was also performed on the powder to measure porosity within the powder that may transfer to the parts. As observed previously in experiments with electron beam powder-bed fabrication, significant variations in porosity were found as a function of the processing parameters. A clear connection between processing parameters and resulting porosity formation mechanism was observed in that inadequate melt pool overlap resulted in lack-of-fusion pores whereas excess power density produced keyhole pores.

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

Improved camera for better X-ray powder photographs

NASA Technical Reports Server (NTRS)

Parrish, W.; Vajda, I. E.

1969-01-01

Camera obtains powder-type photographs of single crystals or polycrystalline powder specimens. X-ray diffraction photographs of a powder specimen are characterized by improved resolution and greater intensity. A reasonably good powder pattern of small samples can be produced for identification purposes.

New frontiers in water purification: highly stable amphopolycarboxyglycinate-stabilized Ag-AgCl nanocomposite and its newly discovered potential

NASA Astrophysics Data System (ADS)

Krutyakov, Yurii A.; Zherebin, Pavel M.; Kudrinskiy, Alexey A.; Zubavichus, Yan V.; Presniakov, Mikhail Yu; Yapryntsev, Alexey D.; Karabtseva, Anastasia V.; Mikhaylov, Dmitry M.; Lisichkin, Georgii V.

2016-09-01

A simple synthetic procedure for high-stable dispersions of porous composite Ag/AgCl nanoparticles stabilized with amphoteric surfactant sodium tallow amphopolycarboxyglycinate has been proposed for the first time. The prepared samples were characterized by UV-vis spectroscopy, x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy, small area electron diffraction (SAED), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and electron probe micro-analysis. In addition, measurements (carried out at the Kurchatov synchrotron radiation source stations) of the Ag K-edge extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge structure (XANES) spectra and XRD of the prepared nanoparticles have been performed. The obtained results suggest that small-sized Ag clusters are homogeneously distributed in the mass of the AgCl nanoparticle (~80 nm) formed during the synthesis. The Ag/AgCl dispersion demonstrates photocatalytic activity (with respect to methyl orange) and high bactericidal activity against E. coli. This activity is superior to the activity of both Ag and AgCl nanoparticles stabilized by the same surfactant. Thus, porous composite Ag/AgCl nanoparticles can be used as a multifunctional agent that is able to remove both pollutants and bacterium from water.

A comprehensive study of magnetic exchanges in the layered oxychalcogenides Sr 3 Fe 2 O 5 Cu 2 Q 2 ( Q = S, Se)

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

Lü, Minfeng; Mentré, Olivier; Gordon, Elijah E.

2017-12-01

The layered oxysulfide Sr3Fe2O5Cu2S2 was prepared, and its crystal structure and magnetic properties were characterized by synchrotron X-ray diffraction (XRD), powder neutron diffraction (PND), Mössbauer spectroscopy measurements and by density functional theory (DFT) calculations. In addition, the spin exchange interactions leading to the ordered magnetic structure of Sr3Fe2O5Cu2S2 were compared with those of its selenium analogue Sr3Fe2O5Cu2Se2. The oxysulfide Sr3Fe2O5Cu2S2 adopts a G-type antiferromagnetic (AFM) structure at a temperature in the range 485–512 K, which is comparable with the three-dimensional (3D) AFM ordering temperature, TN ≈ 490 K, found for Sr3Fe2O5Cu2Se2. Consistent with this observation, the spin exchange interactions ofmore » the magnetic (Sr3Fe2O5)2+ layers are slightly greater (but comparable) for oxysulfide than for the oxyselenide. Attempts to reduce or oxidize Sr3Fe2O5Cu2S2 using topochemical routes yield metallic Fe.« less

Diffraction-Enhanced Computed Tomographic Imaging of Growing Piglet Joints by Using a Synchrotron Light Source

PubMed Central

Rhoades, Glendon W; Belev, George S; Chapman, L Dean; Wiebe, Sheldon P; Cooper, David M; Wong, Adelaine TF; Rosenberg, Alan M

2015-01-01

The objective of this project was to develop and test a new technology for imaging growing joints by means of diffraction-enhanced imaging (DEI) combined with CT and using a synchrotron radiation source. DEI–CT images of an explanted 4-wk-old piglet stifle joint were acquired by using a 40-keV beam. The series of scanned slices was later ‘stitched’ together, forming a 3D dataset. High-resolution DEI-CT images demonstrated fine detail within all joint structures and tissues. Striking detail of vasculature traversing between bone and cartilage, a characteristic of growing but not mature joints, was demonstrated. This report documents for the first time that DEI combined with CT and a synchrotron radiation source can generate more detailed images of intact, growing joints than can currently available conventional imaging modalities. PMID:26310464

Aladdin: Transforming science at SRC

NASA Astrophysics Data System (ADS)

Bisognano, J.; Bissen, M.; Green, M.; Jacobs, K.; Moore, C.; Olson, E.; Severson, M.; Wehlitz, R.

2011-09-01

The Synchrotron Radiation Center (SRC) is dedicated to enabling of innovative research using IR, ultraviolet, and soft X-ray synchrotron radiation. It delivers beam time with high reliability (99%) and continues to improve the Aladdin storage ring complex. A lower emittance tuning has been commissioned to support a microfocus capability. SRC successfully installed an APPLE II undulator providing elliptically polarized light with lattice compensation for flexible scanning. Installation of a new IR beamline at SRC is providing synchrotron chemical imaging with unprecedented structural and chemical information, simultaneously. In addition, SRC has established a strong education and outreach program to bring the knowledge and power of light source science to a wider national community. It is moving forward into the future by developing a new micro focus beamline producing a diffraction-limited focus of about 500 nm at 22 eV, proposing an additional diffraction-limited chemical imaging beamline, and advancing the Wisconsin Free Electron Laser (WiFEL) concept.

Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole

NASA Astrophysics Data System (ADS)

Kürkçüoğlu, Güneş Süheyla; Kiraz, Fulya Çetinkaya; Sayın, Elvan

2015-10-01

The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M = Mn(II), Fe(II) or Co(II); etim = 1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.

CCD sensors in synchrotron X-ray detectors

NASA Astrophysics Data System (ADS)

Strauss, M. G.; Naday, I.; Sherman, I. S.; Kraimer, M. R.; Westbrook, E. M.; Zaluzec, N. J.

1988-04-01

The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron X-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm 2 can be imaged on a 2 cm 2 CCD. With a conversion efficiency of ˜ 1 CCD electron/X-ray photon, a peak saturation capacity of > 10 6 X-rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 × 10 6 pixels/s and the shift rate in the parallel registers is 10 6 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode X-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at a rate of ˜ 1 frame/s or a complete 3-dimensional data set from a single crystal in ˜ 2 min. In electron energy-loss spectroscopy (EELS), the CCD was used in a parallel detection mode which is similar to the mode array detectors are used in dispersive EXAFS. With a beam current corresponding to 3 × 10 9 electron/s on the detector, a series of 64 spectra were recorded on the CCD in a continuous sequence without interruption due to readout. The frame-to-frame pixel signal fluctuations had σ = 0.4% from which DQE = 0.4 was obtained, where the detector conversion efficiency was 2.6 CCD electrons/X-ray photon. These multiple frame series also showed the time-resolved modulation of the electron microscope optics by stray magnetic fields.

A new theory for X-ray diffraction

PubMed Central

Fewster, Paul F.

2014-01-01

This article proposes a new theory of X-ray scattering that has particular relevance to powder diffraction. The underlying concept of this theory is that the scattering from a crystal or crystallite is distributed throughout space: this leads to the effect that enhanced scatter can be observed at the ‘Bragg position’ even if the ‘Bragg condition’ is not satisfied. The scatter from a single crystal or crystallite, in any fixed orientation, has the fascinating property of contributing simultaneously to many ‘Bragg positions’. It also explains why diffraction peaks are obtained from samples with very few crystallites, which cannot be explained with the conventional theory. The intensity ratios for an Si powder sample are predicted with greater accuracy and the temperature factors are more realistic. Another consequence is that this new theory predicts a reliability in the intensity measurements which agrees much more closely with experimental observations compared to conventional theory that is based on ‘Bragg-type’ scatter. The role of dynamical effects (extinction etc.) is discussed and how they are suppressed with diffuse scattering. An alternative explanation for the Lorentz factor is presented that is more general and based on the capture volume in diffraction space. This theory, when applied to the scattering from powders, will evaluate the full scattering profile, including peak widths and the ‘background’. The theory should provide an increased understanding of the reliability of powder diffraction measurements, and may also have wider implications for the analysis of powder diffraction data, by increasing the accuracy of intensities predicted from structural models. PMID:24815975

Ferroelectrics under the Synchrotron Light: A Review.

PubMed

Fuentes-Cobas, Luis E; Montero-Cabrera, María E; Pardo, Lorena; Fuentes-Montero, Luis

2015-12-30

Currently, an intensive search for high-performance lead-free ferroelectric materials is taking place. ABO₃ perovskites (A = Ba, Bi, Ca, K and Na; B = Fe, Nb, Ti, and Zr) appear as promising candidates. Understanding the structure-function relationship is mandatory, and, in this field, the roles of long- and short-range crystal orders and interactions are decisive. In this review, recent advances in the global and local characterization of ferroelectric materials by synchrotron light diffraction, scattering and absorption are analyzed. Single- and poly-crystal synchrotron diffraction studies allow high-resolution investigations regarding the long-range average position of ions and subtle global symmetry break-downs. Ferroelectric materials, under the action of electric fields, undergo crystal symmetry, crystallite/domain orientation distribution and strain condition transformations. Methodological aspects of monitoring these processes are discussed. Two-dimensional diffraction clarify larger scale ordering: polycrystal texture is measured from the intensities distribution along the Debye rings. Local order is investigated by diffuse scattering (DS) and X-ray absorption fine structure (XAFS) experiments. DS provides information about thermal, chemical and displacive low-dimensional disorders. XAFS investigation of ferroelectrics reveals local B-cation off-centering and oxidation state. This technique has the advantage of being element-selective. Representative reports of the mentioned studies are described.

Diffraction-limited storage-ring vacuum technology

PubMed Central

Al-Dmour, Eshraq; Ahlback, Jonny; Einfeld, Dieter; Tavares, Pedro Fernandes; Grabski, Marek

2014-01-01

Some of the characteristics of recent ultralow-emittance storage-ring designs and possibly future diffraction-limited storage rings are a compact lattice combined with small magnet apertures. Such requirements present a challenge for the design and performance of the vacuum system. The vacuum system should provide the required vacuum pressure for machine operation and be able to handle the heat load from synchrotron radiation. Small magnet apertures result in the conductance of the chamber being low, and lumped pumps are ineffective. One way to provide the required vacuum level is by distributed pumping, which can be realised by the use of a non-evaporable getter (NEG) coating of the chamber walls. It may not be possible to use crotch absorbers to absorb the heat from the synchrotron radiation because an antechamber is difficult to realise with such a compact lattice. To solve this, the chamber walls can work as distributed absorbers if they are made of a material with good thermal conductivity, and distributed cooling is used at the location where the synchrotron radiation hits the wall. The vacuum system of the 3 GeV storage ring of MAX IV is used as an example of possible solutions for vacuum technologies for diffraction-limited storage rings. PMID:25177979

Structural studies of the rhombohedral and orthorhombic monouranates: CaUO{sub 4}, α-SrUO{sub 4}, β-SrUO{sub 4} and BaUO{sub 4}

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

Murphy, Gabriel; Kennedy, Brendan J., E-mail: kennedyb@chem.usyd.edu.au; Johannessen, Bernt

The structures of some AUO{sub 4} (A=Ca, Sr, or Ba) oxides have been determined using a combination of neutron and synchrotron X-ray diffraction, supported by X-ray absorption spectroscopic measurements at the U L{sub 3}-edge. The smaller Ca cation favours a rhombohedral AUO{sub 4} structure with 8-coordinate UO{sub 8} moieties whilst an orthorhombic structure based on UO{sub 6} groups is found for BaUO{sub 4}. Both the rhombohedral and orthorhombic structures can be stabilised for SrUO{sub 4}. The structural studies suggest that the bonding requirements of the A site cation play a significant role in determining which structure is favoured. In themore » rhombohedral structure, Bond Valence Sums demonstrate the A site is invariably overbonded, which, in the case of rhombohedral α-SrUO{sub 4}, is compensated for by the formation of vacancies in the oxygen sub-lattice. The uranium cation, with its flexible oxidation state, is able to accommodate this by inducing vacancies along its equatorial coordination site as demonstrated by neutron powder diffraction. - Graphical abstract: Diffraction studies of AUO{sub 4} (A = Ca, Sr, or Ba) oxides reveal the importance of the bonding requirements of the A site cation in determining whether the structure is rhombohedral or orthorhombic. - Highlights: • Structures of AUO{sub 4} ( A = Ca Sr, Ba) refined against X-ray and Neutron diffraction. • The alkali cations size has a dramatic effect on the crystal structure. • Smaller cations favouring a rhombohedral structure. • Oxygen vacancies to stabilise the rhombohedral structure in SrUO{sub 4}.« less

Erratum to: Psammoma bodies in two types of human ovarian tumours: a mineralogical study

NASA Astrophysics Data System (ADS)

Meng, Fanlu; Wang, Changqiu; Li, Yan; Lu, Anhuai; Mei, Fang; Liu, Jianying; Du, Jingyun; Zhang, Yan

2015-06-01

Psammoma body (PB) is a common form of calcification in pathological diagnosis and closely relevant to tumours. This paper focuses on the mineralogical characteristics of PBs in ovarian serous cancer and teratoma by using polarization microscope (POM), environmental scanning electron microscope (ESEM), micro-Fourier transform infrared spectroscopy (micro-FT-IR), transmission electron microscope (TEM), micro-area synchrotron radiation X-ray powder diffraction (μ-SRXRD) and fluorescence (μ-SRXRF). Both the PBs in tissues and separated from eight typical cases were investigated. POM and ESEM observation revealed the inside-out growth pattern of PBs. μ-SRXRD and micro-FT-IR results demonstrated the dominant mineral phase of PBs in ovarian serous cancer and teratoma was AB-type carbonate hydroxyapatite (Ca10[(PO4)6-x-y(CO3)x(HPO4)y][(OH)2-u(CO3)u] with 0 ≤ x,y,u ≤ 2). As observed by ESEM and TEM, the layer-rich PBs in teratoma were up to 70 μm and mainly consisted of 5 nm-wide, 5-12 nm-long columnar crystals; the PBs in ovarian serous cancer with a maximum diameter of 35 μm were composed of slightly longer columnar crystals and granulates with 20-100 nm in diameter. The selected area electron diffraction patterns showed dispersed polycrystalline diffraction rings with arching behavior of (002) diffraction, indicating the aggregated nanocrystals grew in the preferred orientation of (002) face. The EDX and μ-SRXRF results together indicated the existence of Na, Mg, Zn and Sr in PBs. These detailed mineralogical characteristics may help uncover the nature of the pathological PBs in ovary.

Psammoma bodies in two types of human ovarian tumours: a mineralogical study

NASA Astrophysics Data System (ADS)

Fanlu, Meng; Changqiu, Wang; Yan, Li; Anhuai, Lu; Fang, Mei; Jianying, Liu; Jingyun, Du; Yan, Zhang

2015-06-01

Psammoma body (PB) is a common form of calcification in pathological diagnosis and closely relevant to tumours. This paper focuses on the mineralogical characteristics of PBs in ovarian serous cancer and teratoma by using polarization microscope (POM), environmental scanning electron microscope (ESEM), micro-Fourier transform infrared spectroscopy (micro-FT-IR), transmission electron microscope (TEM), micro-area synchrotron radiation X-ray powder diffraction (μ-SRXRD) and fluorescence (μ-SRXRF). Both the PBs in tissues and separated from eight typical cases were investigated. POM and ESEM observation revealed the inside-out growth pattern of PBs. μ-SRXRD and micro-FT-IR results demonstrated the dominant mineral phase of PBs in ovarian serous cancer and teratoma was AB-type carbonate hydroxyapatite (Ca10[(PO4)6-x-y(CO3)x(HPO4 2-)y][(OH)2-u(CO3)u] with 0 ≤ x,y,u ≤ 2). As observed by ESEM and TEM, the layer-rich PBs in teratoma were up to 70 μm and mainly consisted of 5 nm-wide, 5-12 nm-long columnar crystals; the PBs in ovarian serous cancer with a maximum diameter of 35 μm were composed of slightly longer columnar crystals and granulates with 20-100 nm in diameter. The selected area electron diffraction patterns showed dispersed polycrystalline diffraction rings with arching behavior of (002) diffraction, indicating the aggregated nanocrystals grew in the preferred orientation of (002) face. The EDX and μ-SRXRF results together indicated the existence of Na, Mg, Zn and Sr in PBs. These detailed mineralogical characteristics may help uncover the nature of the pathological PBs in ovary.

Crystal-Site-Selective Spectrum of Fe3BO6 by Synchrotron Mössbauer Diffraction with Pure Nuclear Bragg Scattering

NASA Astrophysics Data System (ADS)

Nakamura, Shin; Mitsui, Takaya; Fujiwara, Kosuke; Ikeda, Naoshi; Kurokuzu, Masayuki; Shimomura, Susumu

2017-08-01

We have succeeded in obtaining the crystal-site-selective spectra of the collinear antiferromagnet Fe3BO6 using a synchrotron Mössbauer diffractometer with pure nuclear Bragg scattering at SPring-8 BL11XU. Well-resolved 300, 500, and 700 reflection spectra, having asymmetric line shapes owing to the higher-order interference effect between the nuclear energy levels, were quantitatively analyzed using a formula based on the dynamical theory of diffraction. Reasonable hyperfine parameters were obtained. The intensity ratio of Fe1 to Fe2 subspectra is in accordance with the nuclear structure factor. However, when the spectrum is measured at the peak position of the rocking curve (very near the Bragg position), the value of the center shift deviates from its intrinsic value. This is also due to the dynamical effect of γ-ray diffraction. To avoid this problem, it is necessary to use diffraction angles near the foot of the rocking curve, approximately 0.02° apart from the peak position.

Pressure-induced phase transitions and templating effect in three-dimensional organic-inorganic hybrid perovskites

NASA Astrophysics Data System (ADS)

Lee, Yongjae; Mitzi, David; Barnes, Paris; Vogt, Thomas

2003-07-01

Pressure-induced structural changes of conducting halide perovskites (CH3NH3)SnI3, (CH3NH3)0.5(NH2CH=NH2)0.5SnI3, and (NH2CH=NH2)SnI3, have been investigated using synchrotron x-ray powder diffraction. In contrast to low-temperature structural changes, no evidence of an increased ordering of the organic cations was observed under pressure. Instead, increase in pressure results first in a ReO3-type doubling of the primitive cubic unit cell, followed by a symmetry distortion, and a subsequent amorphization above 4 GPa. This process is reversible and points towards a pressure-induced templating role of the organic cation. Bulk compressions are continuous across the phase boundaries. The compressibilities identify these hybrids as the most compressible perovskite system ever reported. However, the Sn-I bond compressibility in (CH3NH3)SnI3 shows a discontinuity within the supercell phase. This is possibly due to an electronic localization.

Crystal structure of the Chevrel phase Sn Mo6 S8 at high pressure

NASA Astrophysics Data System (ADS)

Ehm, L.; Dera, P.; Knorr, K.; Winkler, B.; Krimmel, A.; Bouvier, P.

2005-07-01

The high-pressure behavior of the Chevrel phase SnMo6S8 was investigated by angular dispersive synchrotron powder diffraction. The experiments were accompanied by first principles calculations at the density functional theory level. The fit of a Birch-Murnaghan equation-of-state gave the volume at zero pressure V0=277(1)Å3 , the bulk modulus at zero pressure B0=84(3)GPa , and the pressure derivative of the bulk modulus B'=3.0(4) for the experimental data and V0=281.6(3)Å3 , B0=76(1)GPa , and B'=4.7(1) for the calculated data. The analysis of the bond distances and the bond population reveals the formation of new bonds and changes of the bond characteristics in the structure under pressure. The compression mechanism is analysed by means of the distortion of the Mo6S8 cluster and the rotation of the cluster with respect to the unit cell edges.

Phase behaviour, thermal expansion and compressibility of SnMo2O8

NASA Astrophysics Data System (ADS)

Araujo, Luiza R.; Gallington, Leighanne C.; Wilkinson, Angus P.; Evans, John S. O.

2018-02-01

The phase behaviour and thermoelastic properties of SnMo2O8, derived from variable temperature and pressure synchrotron powder diffraction data, are reported. SnMo2O8 is a member of the AM2O8 family of negative thermal expansion (NTE) materials, but unexpectedly, has positive thermal expansion. Over the P-T space explored (298-513 K, ambient to 310 MPa) four different forms of SnMo2O8 are observed: α, β, γ and γ‧. The γ to β transition is temperature-, pressure-, and time-dependent. SnMo2O8 is a much softer material (α and γ form have BT = 29 and 26 GPa at 298 K) than other members of the AM2O8 family. Counter-intuitively, its high temperature β phase becomes stiffer with increasing temperature (BT ∼36 GPa at 490 K). The pressure dependence of the thermal expansion for each phase is reported.

Stacking fault density and bond orientational order of fcc ruthenium nanoparticles

NASA Astrophysics Data System (ADS)

Seo, Okkyun; Sakata, Osami; Kim, Jae Myung; Hiroi, Satoshi; Song, Chulho; Kumara, Loku Singgappulige Rosantha; Ohara, Koji; Dekura, Shun; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi

2017-12-01

We investigated crystal structure deviations of catalytic nanoparticles (NPs) using synchrotron powder X-ray diffraction. The samples were fcc ruthenium (Ru) NPs with diameters of 2.4, 3.5, 3.9, and 5.4 nm. We analyzed average crystal structures by applying the line profile method to a stacking fault model and local crystal structures using bond orientational order (BOO) parameters. The reflection peaks shifted depending on rules that apply to each stacking fault. We evaluated the quantitative stacking faults densities for fcc Ru NPs, and the stacking fault per number of layers was 2-4, which is quite large. Our analysis shows that the fcc Ru 2.4 nm-diameter NPs have a considerably high stacking fault density. The B factor tends to increase with the increasing stacking fault density. A structural parameter that we define from the BOO parameters exhibits a significant difference from the ideal value of the fcc structure. This indicates that the fcc Ru NPs are highly disordered.

A co-crystal between benzene and ethane: a potential evaporite material for Saturn’s moon Titan

PubMed Central

Maynard-Casely, Helen E.; Hodyss, Robert; Cable, Morgan L.; Vu, Tuan Hoang; Rahm, Martin

2016-01-01

Using synchrotron X-ray powder diffraction, the structure of a co-crystal between benzene and ethane formed in situ at cryogenic conditions has been determined, and validated using dispersion-corrected density functional theory calculations. The structure comprises a lattice of benzene molecules hosting ethane molecules within channels. Similarity between the intermolecular interactions found in the co-crystal and in pure benzene indicate that the C—H⋯π network of benzene is maintained in the co-crystal, however, this expands to accommodate the guest ethane molecules. The co-crystal has a 3:1 benzene:ethane stoichiometry and is described in the space group with a = 15.977 (1) Å and c = 5.581 (1) Å at 90 K, with a density of 1.067 g cm−3. The conditions under which this co-crystal forms identify it is a potential that forms from evaporation of Saturn’s moon Titan’s lakes, an evaporite material. PMID:27158505

Phase behaviour, thermal expansion and compressibility of SnMo 2 O 8

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

Araujo, Luiza R.; Gallington, Leighanne C.; Wilkinson, Angus P.

The phase behaviour and thermoelastic properties of SnMo2O8, derived from variable temperature and pressure synchrotron powder diffraction data, are reported. SnMo2O8 is a member of the AM2O8 family of negative thermal expansion (NTE) materials, but unexpectedly, has positive thermal expansion. Over the P-T space explored (298–513 K, ambient to 310 MPa) four different forms of SnMo2O8 are observed: α, β, γ and γ'. The γ to β transition is temperature-, pressure-, and time-dependent. SnMo2O8 is a much softer material (α and γ form have BT = 29 and 26 GPa at 298 K) than other members of the AM2O8 family.more » Counter-intuitively, its high temperature β phase becomes stiffer with increasing temperature (BT ~36 GPa at 490 K). The pressure dependence of the thermal expansion for each phase is reported.« less

In-plane chemical pressure essential for superconductivity in BiCh2-based (Ch: S, Se) layered structure

PubMed Central

Mizuguchi, Yoshikazu; Miura, Akira; Kajitani, Joe; Hiroi, Takafumi; Miura, Osuke; Tadanaga, Kiyoharu; Kumada, Nobuhiro; Magome, Eisuke; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

2015-01-01

BiCh2-based compounds (Ch: S, Se) are a new series of layered superconductors, and the mechanisms for the emergence of superconductivity in these materials have not yet been elucidated. In this study, we investigate the relationship between crystal structure and superconducting properties of the BiCh2-based superconductor family, specifically, optimally doped Ce1−xNdxO0.5F0.5BiS2 and LaO0.5F0.5Bi(S1−ySey)2. We use powder synchrotron X-ray diffraction to determine the crystal structures. We show that the structure parameter essential for the emergence of bulk superconductivity in both systems is the in-plane chemical pressure, rather than Bi-Ch bond lengths or in-plane Ch-Bi-Ch bond angle. Furthermore, we show that the superconducting transition temperature for all REO0.5F0.5BiCh2 superconductors can be determined from the in-plane chemical pressure. PMID:26447333

Temperature- and pressure-dependent structural transformation of methane hydrates in salt environments

NASA Astrophysics Data System (ADS)

Shin, Donghoon; Cha, Minjun; Yang, Youjeong; Choi, Seunghyun; Woo, Yesol; Lee, Jong-Won; Ahn, Docheon; Im, Junhyuck; Lee, Yongjae; Han, Oc Hee; Yoon, Ji-Ho

2017-03-01

Understanding the stability of volatile species and their compounds under various surface and subsurface conditions is of great importance in gaining insights into the formation and evolution of planetary and satellite bodies. We report the experimental results of the temperature- and pressure-dependent structural transformation of methane hydrates in salt environments using in situ synchrotron X-ray powder diffraction, solid-state nuclear magnetic resonance, and Raman spectroscopy. We find that under pressurized and concentrated brine solutions methane hydrate forms a mixture of type I clathrate hydrate, ice, and hydrated salts. Under a low-pressure condition, however, the methane hydrates are decomposed through a rapid sublimation of water molecules from the surface of hydrate crystals, while NaCl · 2H2O undergoes a phase transition into a crystal growth of NaCl via the migration of salt ions. In ambient pressure conditions, the methane hydrate is fully decomposed in brine solutions at temperatures above 252 K, the eutectic point of NaCl · 2H2O.

Structural and magnetic phase transitions in EuTi 1-xNb xO 3

DOE PAGES

Li, Ling; Morris, James R.; Koehler, Michael R.; ...

2015-07-30

Here, we investigate the structural and magnetic phase transitions in EuTi 1-xNb xO 3 (0≤x≤0.3) with synchrotron powder x-ray diffraction, resonant ultrasound spectroscopy, and magnetization measurements. Upon Nb doping, the Pmmore » $$\\bar{3}$$m ↔ I4/mcm structural transition shifts to higher temperatures and the room temperature lattice parameter increases while the magnitude of the octahedral tilting decreases. In addition, Nb substitution for Ti destabilizes the antiferromagnetic ground state of the parent compound and long-range ferromagnetic order is observed in the samples with x≥0.1. Moreover, the structural transition in pure and doped compounds is marked by a dramatic step-like softening of the elastic moduli near T S, which resembles that of SrTiO 3 and can be adequately modeled using the Landau free energy model employing the same coupling between strain and octahedral tilting order parameter as previously used to model SrTiO 3.« less

Ammoniated alkali fullerides (ND(3))(x)NaA(2)C(60): ammonia specific effects and superconductivity.

PubMed

Margadonna, Serena; Aslanis, Efstathios; Prassides, Kosmas

2002-08-28

The crystal structure of the superconducting (ND(3))(x)()NaA(2)C(60) (0.7 < or = x < or = 1, A= K, Rb) fullerides (T(c)= 6-15 K) has been studied by synchrotron X-ray and neutron powder diffraction. It is face-centered cubic (fcc) to low temperatures with Na(+)-ND(3) pairs residing in the octahedral interstices. These are disordered over the corners of two "interpenetrating" cubes with the Na(+) ions and the N atoms displaced by approximately 2.0 A and approximately 0.5 A from the center of the site and statically disordered over the corners of the inner and outer cube, respectively. Close contacts between the D atoms of the ND(3) molecules and electron rich 6:6 C-C bonds of neighboring C(60) units provide the signature of weak N-D.pi hydrogen-bonding interactions, which control the intermolecular packing in the crystal and may determine the unusual superconducting properties.

Vacancy-Controlled Na+ Superion Conduction in Na11 Sn2 PS12.

PubMed

Duchardt, Marc; Ruschewitz, Uwe; Adams, Stefan; Dehnen, Stefanie; Roling, Bernhard

2018-01-26

Highly conductive solid electrolytes are crucial to the development of efficient all-solid-state batteries. Meanwhile, the ion conductivities of lithium solid electrolytes match those of liquid electrolytes used in commercial Li + ion batteries. However, concerns about the future availability and the price of lithium made Na + ion conductors come into the spotlight in recent years. Here we present the superionic conductor Na 11 Sn 2 PS 12 , which possesses a room temperature Na + conductivity close to 4 mS cm -1 , thus the highest value known to date for sulfide-based solids. Structure determination based on synchrotron X-ray powder diffraction data proves the existence of Na + vacancies. As confirmed by bond valence site energy calculations, the vacancies interconnect ion migration pathways in a 3D manner, hence enabling high Na + conductivity. The results indicate that sodium electrolytes are about to equal the performance of their lithium counterparts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

DOE PAGES

Dolyniuk, Juli -Anna; Kovnir, Kirill

2016-08-12

Here, the high pressure properties of the novel tetrel-free clathrate, Ba 8Cu 13.1Zn 3.3P 29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the studied pressure range of 0.1–7 GPa. The calculated bulk modulus for Ba 8Cu 13.1Zn 3.3P 29.6 using a third-order Birch-Murnaghan equation of state is 65(6) GPa at 300 K. This bulk modulus is comparable to the bulk moduli of Ge- and Sn-based clathrates, like A 8Ga 16Ge 30 (A = Sr, Ba) and Sn 19.3Cu 4.7P 22I 8, but lowermore » than those for the transition metal-containing silicon-based clathrates, Ba 8 T xSi46–x, T = Ni, Cu; 3 ≤ x ≤ 5.« less

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

PubMed

Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

2016-07-01

Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys

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

Kalay, Yunus Eren

2009-01-01

Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current dissertation involves an extensive set of experimental, analytical, and computational studies designed to increase the overall understanding of morphological selection, phase competition, and structural hierarchy that occursmore » under far-from equilibrium conditions. High pressure gas atomization and Cu-block melt-spinning are the two different rapid solidification techniques applied in this study. The research is mainly focused on Al-Si and Al-Sm alloy systems. Silicon and samarium produce different, yet favorable, systems for exploration when alloyed with aluminum under far-from equilibrium conditions. One of the main differences comes from the positions of their respective T 0 curves, which makes Al-Si a good candidate for solubility extension while the plunging T 0 line in Al-Sm promotes glass formation. The rapidly solidified gas-atomized Al-Si powders within a composition range of 15 to 50 wt% Si are examined using scanning and transmission electron microscopy. The non-equilibrium partitioning and morphological selection observed by examining powders at different size classes are described via a microstructure map. The interface velocities and the amount of undercooling present in the powders are estimated from measured eutectic spacings based on Jackson-Hunt (JH) and Trivedi-Magnin-Kurz (TMK) models, which permit a direct comparison of theoretical predictions. For an average particle size of 10 {micro}m with a Peclet number of ~0.2, JH and TMK deviate from each other. This deviation indicates an adiabatic type solidification path where heat of fusion is reabsorbed. It is interesting that this particle size range is also consistent with the appearance of a microcellular growth. While no glass formation is observed within this system, the smallest size powders appear to consist of a mixture of nanocrystalline Si and Al. Al-Sm alloys have been investigated within a composition range of 34 to 42 wt% Sm. Gas atomized powders of Al-Sm are investigated to explore the morphological and structural hierarchy that correlates with different degrees of departure from full equilibrium conditions. The resultant powders show a variety of structural selection with respect to amount of undercooling, with an amorphous structure appearing at the highest cooling rates. Because of the chaotic nature of gas atomization, Cu-block melt-spinning is used to produce a homogeneous amorphous structure. The as-quenched structure within Al-34 to 42 wt% Sm consists of nanocrystalline fcc-Al (on the order of 5 nm) embedded in an amorphous matrix. The nucleation density of fcc-Al after initial crystallization is on the order of 10 22-10 23m -3, which is 10 5-10 6 orders of magnitude higher than what classical nucleation theory predicts. Detailed analysis of liquid and as-quenched structures using high energy synchrotron X-ray diffraction, high energy transmission electron microscopy, and atom probe tomography techniques revealed an Al-Sm network similar in appearance to a medium range order (MRO) structure. A model whereby these MRO clusters promote the observed high nucleation density of fcc-Al nanocrystals is proposed. The devitrification path was identified using high temperature, in-situ, high energy synchrotron X-ray diffraction techniques and the crystallization kinetics were described using an analytical Johnson-Mehl-Avrami (JMA) approach.« less

Observations on online educational materials for powder diffraction crystallography software.

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

Toby, B. H.

2010-10-01

This article presents a series of approaches used to educate potential users of crystallographic software for powder diffraction. The approach that has been most successful in the author's opinion is the web lecture, where an audio presentation is coupled to a video-like record of the contents of the presenter's computer screen.

Phase relations in KxFe2-ySe2 and the structure of superconducting KxFe2Se2 via high-resolution synchrotron diffraction

NASA Astrophysics Data System (ADS)

Shoemaker, Daniel P.; Chung, Duck Young; Claus, Helmut; Francisco, Melanie C.; Avci, Sevda; Llobet, Anna; Kanatzidis, Mercouri G.

2012-11-01

Superconductivity in iron selenides has experienced a rapid growth, but not without major inconsistencies in the reported properties. For alkali-intercalated iron selenides, even the structure of the superconducting phase is a subject of debate, in part because the onset of superconductivity is affected much more delicately by stoichiometry and preparation than in cuprate or pnictide superconductors. If high-quality, pure, superconducting intercalated iron selenides are ever to be made, the intertwined physics and chemistry must be explained by systematic studies of how these materials form and by and identifying the many coexisting phases. To that end, we prepared pure K2Fe4Se5 powder and superconductors in the KxFe2-ySe2 system, and examined differences in their structures by high-resolution synchrotron and single-crystal x-ray diffraction. We found four distinct phases: semiconducting K2Fe4Se5, a metallic superconducting phase KxFe2Se2 with x ranging from 0.38 to 0.58, the phase KFe1.6Se2 with full K occupancy and no Fe vacancy ordering, and a oxidized phase K0.51(5)Fe0.70(2)Se that forms the PbClF structure upon exposure to moisture. We find that the vacancy-ordered phase K2Fe4Se5 does not become superconducting by doping, but the distinct iron-rich minority phase KxFe2Se2 precipitates from single crystals upon cooling from above the vacancy ordering temperature. This coexistence of separate metallic and semiconducting phases explains a broad maximum in resistivity around 100 K. Further studies to understand the solubility of excess Fe in the KxFe2-ySe2 structure will shed light on the maximum fraction of superconducting KxFe2Se2 that can be obtained by solid state synthesis.

Frequency analysis for modulation-enhanced powder diffraction.

PubMed

Chernyshov, Dmitry; Dyadkin, Vadim; van Beek, Wouter; Urakawa, Atsushi

2016-07-01

Periodic modulation of external conditions on a crystalline sample with a consequent analysis of periodic diffraction response has been recently proposed as a tool to enhance experimental sensitivity for minor structural changes. Here the intensity distributions for both a linear and nonlinear structural response induced by a symmetric and periodic stimulus are analysed. The analysis is further extended for powder diffraction when an external perturbation changes not only the intensity of Bragg lines but also their positions. The derived results should serve as a basis for a quantitative modelling of modulation-enhanced diffraction data measured in real conditions.

In Situ Neutron Diffraction Studies of the Ion Exchange Synthesis Mechanism of Li2Mg2P3O9N: Evidence for a Hidden Phase Transition.

PubMed

Liu, Jue; Whitfield, Pamela S; Saccomanno, Michael R; Bo, Shou-Hang; Hu, Enyuan; Yu, Xiqian; Bai, Jianming; Grey, Clare P; Yang, Xiao-Qing; Khalifah, Peter G

2017-07-12

Motivated by predictions made using a bond valence sum difference map (BVS-DM) analysis, the novel Li-ion conductor Li 2 Mg 2 P 3 O 9 N was synthesized by ion exchange from a Na 2 Mg 2 P 3 O 9 N precursor. Impedance spectroscopy measurements indicate that Li 2 Mg 2 P 3 O 9 N has a room temperature Li-ion conductivity of about 10 -6 S/cm (comparable to LiPON), which is 6 orders of magnitude higher than the extrapolated Na-ion conductivity of Na 2 Mg 2 P 3 O 9 N at this temperature. The structure of Li 2 Mg 2 P 3 O 9 N was determined from ex situ synchrotron and time-of-flight neutron diffraction data to retain the P2 1 3 space group, though with a cubic lattice parameter of a = 9.11176(8) Å that is significantly smaller than the a = 9.2439(1) Å of Na 2 Mg 2 P 3 O 9 N. The two Li-ion sites are found to be very substantially displaced (∼0.5 Å) relative to the analogous Na sites in the precursor phase. The non-molten salt ion exchange method used to prepare Li 2 Mg 2 P 3 O 9 N produces a minimal background in powder diffraction experiments, and was therefore exploited for the first time to follow a Li + /Na + ion exchange reaction using in situ powder neutron diffraction. Lattice parameter changes during ion exchange suggest that the reaction proceeds through a Na 2-x Li x Mg 2 P 3 O 9 N solid solution (stage 1) followed by a two-phase reaction (stage 2) to form Li 2 Mg 2 P 3 O 9 N. However, full Rietveld refinements of the in situ neutron diffraction data indicate that the actual transformation mechanism is more complex and instead involves two thermodynamically distinct solid solutions in which the Li exclusively occupies the Li1 site at low Li contents (stage 1a) and then migrates to the Li3 site at higher Li contents (stage 1b), a crossover driven by the different signs of the local volume change at these sites. In addition to highlighting the importance of obtaining full structural data in situ throughout the ion exchange process, these results provide insights into the general question of what constitutes a thermodynamic phase.

In Situ Neutron Diffraction Studies of the Ion Exchange Synthesis Mechanism of Li 2Mg 2P 3O 9N: Evidence for a Hidden Phase Transition

DOE PAGES

Liu, Jue; Whitfield, Pamela S.; Saccomanno, Michael R.; ...

2017-06-06

Motivated by predictions made using a bond valence sum difference map (BVS-DM) analysis, the novel Li-ion conductor Li 2Mg 2P 3O 9N was synthesized in this paper by ion exchange from a Na 2Mg 2P 3O 9N precursor. Impedance spectroscopy measurements indicate that Li 2Mg 2P 3O 9N has a room temperature Li-ion conductivity of about 10 –6 S/cm (comparable to LiPON), which is 6 orders of magnitude higher than the extrapolated Na-ion conductivity of Na 2Mg 2P 3O 9N at this temperature. The structure of Li 2Mg 2P 3O 9N was determined from ex situ synchrotron and time-of-flight neutronmore » diffraction data to retain the P2 13 space group, though with a cubic lattice parameter of a = 9.11176(8) Å that is significantly smaller than the a = 9.2439(1) Å of Na 2Mg 2P 3O 9N. The two Li-ion sites are found to be very substantially displaced (~0.5 Å) relative to the analogous Na sites in the precursor phase. The non-molten salt ion exchange method used to prepare Li 2Mg 2P 3O 9N produces a minimal background in powder diffraction experiments, and was therefore exploited for the first time to follow a Li +/Na + ion exchange reaction using in situ powder neutron diffraction. Lattice parameter changes during ion exchange suggest that the reaction proceeds through a Na 2–xLi xMg 2P 3O 9N solid solution (stage 1) followed by a two-phase reaction (stage 2) to form Li 2Mg 2P 3O 9N. However, full Rietveld refinements of the in situ neutron diffraction data indicate that the actual transformation mechanism is more complex and instead involves two thermodynamically distinct solid solutions in which the Li exclusively occupies the Li1 site at low Li contents (stage 1a) and then migrates to the Li3 site at higher Li contents (stage 1b), a crossover driven by the different signs of the local volume change at these sites. Finally, in addition to highlighting the importance of obtaining full structural data in situ throughout the ion exchange process, these results provide insights into the general question of what constitutes a thermodynamic phase.« less

In Situ Neutron Diffraction Studies of the Ion Exchange Synthesis Mechanism of Li 2Mg 2P 3O 9N: Evidence for a Hidden Phase Transition

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

Liu, Jue; Whitfield, Pamela S.; Saccomanno, Michael R.

Motivated by predictions made using a bond valence sum difference map (BVS-DM) analysis, the novel Li-ion conductor Li 2Mg 2P 3O 9N was synthesized in this paper by ion exchange from a Na 2Mg 2P 3O 9N precursor. Impedance spectroscopy measurements indicate that Li 2Mg 2P 3O 9N has a room temperature Li-ion conductivity of about 10 –6 S/cm (comparable to LiPON), which is 6 orders of magnitude higher than the extrapolated Na-ion conductivity of Na 2Mg 2P 3O 9N at this temperature. The structure of Li 2Mg 2P 3O 9N was determined from ex situ synchrotron and time-of-flight neutronmore » diffraction data to retain the P2 13 space group, though with a cubic lattice parameter of a = 9.11176(8) Å that is significantly smaller than the a = 9.2439(1) Å of Na 2Mg 2P 3O 9N. The two Li-ion sites are found to be very substantially displaced (~0.5 Å) relative to the analogous Na sites in the precursor phase. The non-molten salt ion exchange method used to prepare Li 2Mg 2P 3O 9N produces a minimal background in powder diffraction experiments, and was therefore exploited for the first time to follow a Li +/Na + ion exchange reaction using in situ powder neutron diffraction. Lattice parameter changes during ion exchange suggest that the reaction proceeds through a Na 2–xLi xMg 2P 3O 9N solid solution (stage 1) followed by a two-phase reaction (stage 2) to form Li 2Mg 2P 3O 9N. However, full Rietveld refinements of the in situ neutron diffraction data indicate that the actual transformation mechanism is more complex and instead involves two thermodynamically distinct solid solutions in which the Li exclusively occupies the Li1 site at low Li contents (stage 1a) and then migrates to the Li3 site at higher Li contents (stage 1b), a crossover driven by the different signs of the local volume change at these sites. Finally, in addition to highlighting the importance of obtaining full structural data in situ throughout the ion exchange process, these results provide insights into the general question of what constitutes a thermodynamic phase.« less

Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery

PubMed Central

Wu, Xiao; Zhang, Weifen; Hayes, Don; Mansour, Heidi M

2013-01-01

In this systematic and comprehensive study, inhalation powders of the polypeptide immunosuppressant drug – cyclosporine A – for lung delivery as dry powder inhalers (DPIs) were successfully designed, developed, and optimized. Several spray drying pump rates were rationally chosen. Comprehensive physicochemical characterization and imaging was carried out using scanning electron microscopy, hot-stage microscopy, differential scanning calorimetry, powder X-ray diffraction, Karl Fischer titration, laser size diffraction, and gravimetric vapor sorption. Aerosol dispersion performance was conducted using a next generation impactor with a Food and Drug Administration-approved DPI device. These DPIs displayed excellent aerosol dispersion performance with high values in emitted dose, respirable fraction, and fine particle fraction. In addition, novel multifunctional inhalation aerosol powder formulations of cyclosporine A with lung surfactant-mimic phospholipids were also successfully designed and developed by advanced organic solution cospray drying in closed mode. The lung surfactantmimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-snglycero- 3-(phosphor-rac-1-glycerol). These cyclosporine A lung surfactant-mimic aerosol powder formulations were comprehensively characterized. Powder X-ray diffraction and differential scanning calorimetry confirmed that the phospholipid bilayer structure in the solid state was preserved following advanced organic solution spray drying in closed mode. These novel multifunctional inhalation powders were optimized for DPI delivery with excellent aerosol dispersion performance and high aerosol performance parameters. PMID:23569375

The High Resolution Powder Diffraction Beam Line at ESRF.

PubMed

Fitch, A N

2004-01-01

The optical design and performance of the high-resolution powder diffraction beam line BM16 at ESRF are discussed and illustrated. Some recent studies carried out on BM16 are described, including crystal structure solution and refinement, anomalous scattering, in situ measurements, residual strain in engineering components, investigation of microstructure, and grazing-incidence diffraction from surface layers. The beam line is built on a bending magnet, and operates in the energy range from 5 keV to 40 keV. After the move to an undulator source in 2002, it will benefit from an extented energy range up to 60 keV and increased flux and resolution. It is anticipated that enhancements to the data quality will be achieved, leading to the solution of larger crystal structures, and improvements in the accuracy of refined structures. The systematic exploitation of anisotropic thermal expansion will help reduce the effects of peak overlap in the analysis of powder diffraction data.

Application of powder X-ray diffraction in studying the compaction behavior of bulk pharmaceutical powders.

PubMed

Bandyopadhyay, Rebanta; Selbo, Jon; Amidon, Gregory E; Hawley, Michael

2005-11-01

This study investigates the effects of crystal lattice deformation on the powder X-ray diffraction (PXRD) patterns of compressed polycrystalline specimen (compacts/tablets) made from molecular, crystalline powders. The displacement of molecules and the corresponding adjustment of interplanar distances (d-spacings) between diffracting planes of PNU-288034 and PNU-177553, which have crystal habits with a high aspect ratio favoring preferred orientation during tableting, are demonstrated by shifts in the diffracted peak positions. The direction of shift in diffracted peak positions suggests a reduction of interplanar d-spacing in the crystals of PNU-288034 and PNU-177553 following compaction. There is also a general reduction of peak intensities following compression at the different compressive loads. The lattice strain representing the reduction in d-spacing is proportional to the original d-spacing of the uncompressed sample suggesting that, as with systems that obey a simple Hooke's law relationship, the further apart the planes of atoms/molecules within the lattice are, the easier it is for them to approach each other under compressive stresses. For a third model compound comprising more equant-shaped crystals of PNU-141659, the shift in diffracted peak positions are consistent with an expansion of lattice spacing after compression. This apparent anomaly is supported by the PXRD studies of the bulk powder consisting of fractured crystals where also, the shift in peak position suggests expansion of the lattice planes. Thus the crystals of PNU-141659 may be fracturing under the compressive loads used to produce the compacts. Additional studies are underway to relate the PXRD observations with the bulk tableting properties of these model compounds.

Pargasite at high pressure and temperature

NASA Astrophysics Data System (ADS)

Comboni, Davide; Lotti, Paolo; Gatta, G. Diego; Merlini, Marco; Liermann, Hanns-Peter; Frost, Daniel J.

2017-08-01

The P-T phase stability field, the thermoelastic behavior and the P-induced deformation mechanisms at the atomic scale of pargasite crystals, from the "phlogopite peridotite unit" of the Finero mafic-ultramafic complex (Ivrea-Verbano Formation, Italy), have been investigated by a series of in situ experiments: (a) at high pressure (up to 20.1 GPa), by single-crystal synchrotron X-ray diffraction with a diamond anvil cell, (b) at high temperature (up to 823 K), by powder synchrotron X-ray diffraction using a hot air blower device, and (c) at simultaneous HP-HT conditions, by single-crystal synchrotron X-ray diffraction with a resistive-heated diamond anvil cell (P max = 16.5 GPa, T max = 1200 K). No phase transition has been observed within the P-T range investigated. At ambient T, the refined compressional parameters, calculated by fitting a second-order Birch-Murnaghan Equation of State (BM-EoS), are: V 0 = 915.2(8) Å3 and K P0,T0 = 95(2) GPa (β P0,T0 = 0.0121(2) GPa-1) for the unit-cell volume; a 0 = 9.909(4) Å and K(a) P0,T0 = 76(2) GPa for the a-axis; b 0 = 18.066(7) Å and K(b) P0,T0 = 111(2) GPa for the b-axis; c 0 = 5.299(5) Å and K(c) P0,T0 = 122(12) GPa for the c-axis [K(c) P0,T0 K(b) P0,T0 > K(a) P0,T0]. The high-pressure structure refinements (at ambient T) show a moderate contraction of the TO4 double chain and a decrease of its bending in response to the hydrostatic compression, along with a pronounced compressibility of the A- and M(4)-polyhedra [K P0, T0(A) = 38(2) GPa, K P0, T0(M4) = 79(5) GPa] if compared to the M(1)-, M(2)-, M(3)-octahedra [K P0, T0(M1,2,3) ≤ 120 GPa] and to the rigid tetrahedra [K P0, T0(T1,T2) 300 GPa]. The thermal behavior, at ambient pressure up to 823 K, was modelled with Berman's formalism, which gives: V 0 = 909.1(2) Å3, α0 = 2.7(2)·10-5 K-1 and α1 = 1.4(6)·10-9 K-2 [with α0(a) = 0.47(6)·10-5 K-1, α0(b) = 1.07(4)·10-5 K-1, and α0(c) = 0.97(7)·10-5 K-1]. The petrological implications for the experimental findings of this study are discussed.

X-ray and synchrotron methods in studies of cultural heritage sites

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

Koval’chuk, M. V.; Yatsishina, E. B.; Blagov, A. E.

2016-09-15

X-ray and synchrotron methods that are most widely used in studies of cultural heritage objects (including archaeological sites)—X-ray diffraction analysis, X-ray spectroscopy, and visualization techniques— have been considered. The reported examples show high efficiency and informativeness of natural science studies when solving most diverse problems of archaeology, history, the study of art, museology, etc.

A comparative structural study of wet and dried ettringite

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

Renaudin, G.; CNRS, UMR 6002, LMI, F-63177 Aubiere; Filinchuk, Y.

2010-03-15

Two different techniques were used to compare structural characteristics of 'wet' ettringite (stored in the synthesis mother liquid) and 'dried' ettringite (dried to 35% relative humidity over saturated CaCl{sub 2} solution). Lattice parameters and the water content in the channel region of the structure (site occupancy factor of the water molecule not bonded to cations) as well as microstructure parameters (size and strain) were determined from a Rietveld refinement on synchrotron powder diffraction data. Local environment of sulphate anions and of the hydrogen bonding network was characterized by Raman spectroscopy. Both techniques led to the same conclusion: the 'wet' ettringitemore » sample immersed in the mother solution from the synthesis presents similar structural features as ettringite dried to 35% relative humidity. An increase of the a lattice parameter combined with a decrease of the c lattice parameter occurs on drying. The amount of structural water, the point symmetry of sulphate and the hydrogen bond network are unchanged when passing from the wet to the dried ettringite powder. Ettringite does not form a high-hydrate polymorph in equilibrium with alkaline solution, in contrast to the AFm phases that lose water molecules on drying. According to these results we conclude that ettringite precipitated in aqueous solution at the early hydration stages is of the same chemical composition as ettringite present in the hardening concrete.« less

Electric field effect on chemical and phase equilibria in nano-TiB 2–TiO 2–TiBO 3 system at <650 °C: an in situ time-resolved energy dispersive x-ray diffraction study with an ultrahigh energy synchrotron probe

DOE PAGES

Özdemir, Tevfik E.; Akdoğan, Enver Koray; Şavklıyıldız, İlyas; ...

2016-12-19

Nano-TiB 2 powder of 58 nm size with TiO 2 and TiBO 3 as secondary phases was heated with 20 °C to <650 °C in argon while applying an electric field. The powder became conductive at 520 and 305 °C (T onset) for 16 and 40 V/cm, respectively, at which point current bursts of 4.5 and 10.0 A (peak value) were observed. Current bursts were accompanied by >1% TiB 2 unit cell expansion, exceeding zero field thermally induced expansion. The current bursts also induced nonisothermal reaction between TiB 2 and TiO 2, yielding TiBO 3 that is absent with nomore » field. Increase from 16 to 40 V/cm shifts the TiB 2 → TiBO 3 reaction forward, decreases T onset but increases reaction rate. Analysis using Van’t Hoff relation, including electrochemical effects, precluded possibility of appreciable Joule heating, which was supported with adiabatic internal temperature calculations. In conclusion, the observed low temperature oxidation of TiB 2 to TiBO 3 that is electrochemically driven and is mediated by the TiO 2 solid electrolyte.« less

In-situ synchrotron micro-diffraction study of surface, interface, grain structure, and strain/stress evolution during Sn whisker/hillock formation

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

Pei, Fei; Jadhav, Nitin; Buchovecky, Eric

2016-03-14

We have performed X-ray synchrotron micro-diffraction measurements to study the processes controlling the formation of hillocks and whiskers in Sn layers on Cu. The studies were done in real-time on Sn layers that were electro-deposited immediately before the X-ray measurements were started. This enabled a region of the sample to be monitored from the as-deposited state until after a hillock feature formed. In addition to measuring the grain orientation and deviatoric strain (via Laue diffraction), the X-ray fluorescence was monitored to quantify the evolution of the Sn surface morphology and the formation of intermetallic compound (IMC) at the Sn-Cu interface.more » The results capture the simultaneous growth of the feature and the corresponding film stress, grain orientation, and IMC formation. The observations are compared with proposed mechanisms for whisker/hillock growth and nucleation.« less

Pressure-induced Lifshitz transition in NbP: Raman, x-ray diffraction, electrical transport, and density functional theory

NASA Astrophysics Data System (ADS)

Gupta, Satyendra Nath; Singh, Anjali; Pal, Koushik; Muthu, D. V. S.; Shekhar, C.; Qi, Yanpeng; Naumov, Pavel G.; Medvedev, Sergey A.; Felser, C.; Waghmare, U. V.; Sood, A. K.

2018-02-01

We report high-pressure Raman, synchrotron x-ray diffraction, and electrical transport studies on Weyl semimetals NbP and TaP along with first-principles density functional theoretical (DFT) analysis. The frequencies of first-order Raman modes of NbP harden with increasing pressure and exhibit a slope change at Pc˜9 GPa. The pressure-dependent resistivity exhibits a minimum at Pc. The temperature coefficient of resistivity below Pc is positive as expected for semimetals but changes significantly in the high-pressure phase. Using DFT calculations, we show that these anomalies are associated with a pressure-induced Lifshitz transition, which involves the appearance of electron and hole pockets in its electronic structure. In contrast, the results of Raman and synchrotron x-ray diffraction experiments on TaP and DFT calculations show that TaP is quite robust under pressure and does not undergo any phase transition.

An Inquiry-Based Project Focused on the X-Ray Powder Diffraction Analysis of Common Household Solids

ERIC Educational Resources Information Center

Hulien, Molly L.; Lekse, Jonathan W.; Rosmus, Kimberly A.; Devlin, Kasey P.; Glenn, Jennifer R.; Wisneski, Stephen D.; Wildfong, Peter; Lake, Charles H.; MacNeil, Joseph H.; Aitken, Jennifer A.

2015-01-01

While X-ray powder diffraction (XRPD) is a fundamental analytical technique used by solid-state laboratories across a breadth of disciplines, it is still underrepresented in most undergraduate curricula. In this work, we incorporate XRPD analysis into an inquiry-based project that requires students to identify the crystalline component(s) of…

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…

Analysis of macromolecules, ligands and macromolecule-ligand complexes

DOEpatents

Von Dreele, Robert B [Los Alamos, NM

2008-12-23

A method for determining atomic level structures of macromolecule-ligand complexes through high-resolution powder diffraction analysis and a method for providing suitable microcrystalline powder for diffraction analysis are provided. In one embodiment, powder diffraction data is collected from samples of polycrystalline macromolecule and macromolecule-ligand complex and the refined structure of the macromolecule is used as an approximate model for a combined Rietveld and stereochemical restraint refinement of the macromolecule-ligand complex. A difference Fourier map is calculated and the ligand position and points of interaction between the atoms of the macromolecule and the atoms of the ligand can be deduced and visualized. A suitable polycrystalline sample of macromolecule-ligand complex can be produced by physically agitating a mixture of lyophilized macromolecule, ligand and a solvent.

Synchrotron-radiation X-ray diffraction evidence of the emergence of ferroelectricity in LiTaO3 by ordering of a disordered Li ion in the polar direction

NASA Astrophysics Data System (ADS)

Zhang, Zhi-Gang; Abe, Tomohiro; Moriyoshi, Chikako; Tanaka, Hiroshi; Kuroiwa, Yoshihiro

2018-07-01

Synchrotron-radiation X-ray diffraction studies as a function of temperature reveal the structural origin of the spontaneous polarization and related lattice strains in stoichiometric LiTaO3. Electron charge density distribution maps visualized by the maximum entropy method clearly demonstrate that ordering of the disordered Li ion in the polar direction accompanied by deformation of the oxygen octahedra lead to the ferroelectric phase transition. The ionic polarization attributed to the ionic displacements is dominant in the polar structure. The structural change occurs continuously at the phase transition temperature, which suggests a second-order phase transition.

A novel high-temperature furnace for combined in situ synchrotron X-ray diffraction and infrared thermal imaging to investigate the effects of thermal gradients upon the structure of ceramic materials

PubMed Central

Robinson, James B.; Brown, Leon D.; Jervis, Rhodri; Taiwo, Oluwadamilola O.; Millichamp, Jason; Mason, Thomas J.; Neville, Tobias P.; Eastwood, David S.; Reinhard, Christina; Lee, Peter D.; Brett, Daniel J. L.; Shearing, Paul R.

2014-01-01

A new technique combining in situ X-ray diffraction using synchrotron radiation and infrared thermal imaging is reported. The technique enables the application, generation and measurement of significant thermal gradients, and furthermore allows the direct spatial correlation of thermal and crystallographic measurements. The design and implementation of a novel furnace enabling the simultaneous thermal and X-ray measurements is described. The technique is expected to have wide applicability in material science and engineering; here it has been applied to the study of solid oxide fuel cells at high temperature. PMID:25178003

Research Associate | Center for Cancer Research

Cancer.gov

PROGRAM DESCRIPTION The Basic Science Program (BSP) pursues independent, multidisciplinary research in basic and applied molecular biology, immunology, retrovirology, cancer biology, and human genetics. Research efforts and support are an integral part of the Center for Cancer Research (CCR) at the Frederick National Laboratory for Cancer Research (FNLCR). KEY ROLES/RESPONSIBILITIES - Research Associate III Dr. Zbigniew Dauter is the head investigator of the Synchrotron Radiation Research Section (SRRS) of CCR’s Macromolecular Crystallography Laboratory. The Synchrotron Radiation Research Section is located at Argonne National Laboratory, Argonne, Illinois; this is the site of the largest U.S. synchrotron facility. The SRRS uses X-ray diffraction technique to solve crystal structures of various proteins and nucleic acids of biological and medical relevance. The section is also specializing in analyzing crystal structures at extremely high resolution and accuracy and in developing methods of effective diffraction data collection and in using weak anomalous dispersion effects to solve structures of macromolecules. The areas of expertise are: Structural and molecular biology Macromolecular crystallography Diffraction data collection Dr. Dauter requires research support in these areas, and the individual will engage in the purification and preparation of samples, crystallize proteins using various techniques, and derivatize them with heavy atoms/anomalous scatterers, and establish conditions for cryogenic freezing. Individual will also participate in diffraction data collection at the Advanced Photon Source. In addition, the candidate will perform spectroscopic and chromatographic analyses of protein and nucleic acid samples in the context of their purity, oligomeric state and photophysical properties.

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.

Step-by-step fabrication of a highly oriented crystalline three-dimensional pillared-layer-type metal-organic framework thin film confirmed by synchrotron X-ray diffraction.

PubMed

Otsubo, Kazuya; Haraguchi, Tomoyuki; Sakata, Osami; Fujiwara, Akihiko; Kitagawa, Hiroshi

2012-06-13

Fabrication of a crystalline ordered thin film based on the porous metal-organic frameworks (MOFs) is one of the practical applications of the future functional nanomaterials. Here, we report the creation of a highly oriented three-dimensional (3-D) porous pillared-layer-type MOF thin film on a metal substrate using a step-by-step approach based on liquid-phase epitaxy. Synchrotron X-ray diffraction (XRD) study clearly indicates that the thin film is crystalline and its orientation is highly controlled in both horizontal and vertical directions relative to the substrate. This report provides the first confirmation of details of not only the crystallinity but also the orientation of 3-D MOF thin film using synchrotron XRD. Moreover, we also demonstrate its guest adsorption/desorption behavior by using in situ XRD measurements. The results presented here would promise useful insights for fabrication of MOF-based nanodevices in the future.

Structure determination of an integral membrane protein at room temperature from crystals in situ

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

Axford, Danny; Foadi, James; Imperial College London, London SW7 2AZ

2015-05-14

The X-ray structure determination of an integral membrane protein using synchrotron diffraction data measured in situ at room temperature is demonstrated. The structure determination of an integral membrane protein using synchrotron X-ray diffraction data collected at room temperature directly in vapour-diffusion crystallization plates (in situ) is demonstrated. Exposing the crystals in situ eliminates manual sample handling and, since it is performed at room temperature, removes the complication of cryoprotection and potential structural anomalies induced by sample cryocooling. Essential to the method is the ability to limit radiation damage by recording a small amount of data per sample from many samplesmore » and subsequently assembling the resulting data sets using specialized software. The validity of this procedure is established by the structure determination of Haemophilus influenza TehA at 2.3 Å resolution. The method presented offers an effective protocol for the fast and efficient determination of membrane-protein structures at room temperature using third-generation synchrotron beamlines.« less

Polaron hopping in olivine phosphates studied by nuclear resonant scattering

NASA Astrophysics Data System (ADS)

Tracy, Sally June

Valence fluctuations of Fe2+ and Fe3+ were studied in a solid solution of LixFePO4 by nuclear resonant forward scattering of synchrotron x rays while the sample was heated in a diamond-anvil pressure cell. The spectra acquired at different temperatures and pressures were analyzed for the frequencies of valence changes using the Blume-Tjon model of a system with a fluctuating Hamiltonian. These frequencies were analyzed to obtain activation energies and an activation volume for polaron hopping. There was a large suppression of hopping frequency with pressure, giving an anomalously large activation volume. This large, positive value is typical of ion diffusion, which indicates correlated motions of polarons, and Li+ ions that alter the dynamics of both. In a parallel study of NaxFePO4, the interplay between sodium ordering and electron mobility was investigated using a combination of synchrotron x-ray diffraction and nuclear resonant scattering. Conventional Mossbauer spectra were collected while the sample was heated in a resistive furnace. An analysis of the temperature evolution of the spectral shapes was used to identify the onset of fast electron hopping and determine the polaron hopping rate. Synchrotron x-ray diffraction measurements were carried out in the same temperature range. Reitveld analysis of the diffraction patterns was used to determine the temperature of sodium redistribution on the lattice. The diffraction analysis also provides new information about the phase stability of the system. The temperature evolution of the iron site occupancies from the Mossbauer measurements, combined with the synchrotron diffraction results give strong evidence for a relationship between the onset of fast electron dynamics and the redistribution of sodium in the lattice. Measurements of activation barriers for polaron hopping gave fundamental insights about the correlation between electronic carriers and mobile ions. This work established that polaron-ion interactions can alter the local dynamics of electron and ion transport. These types of coupled processes may be common in many materials used for battery electrodes, and new details concerning the influence of polaron-ion interactions on the charge dynamics are relevant to optimizing their electrochemical performance.

Dislocation density evolution of AA 7020-T6 investigated by in-situ synchrotron diffraction under tensile load

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

Zhong, Z.Y., E-mail: zhengye.zhong@hzg.de; Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht; Brokmeier, H.-G.

2015-10-15

The dislocation density evolution along the loading axis of a textured AA 7020-T6 aluminum alloy during uniaxial tension was investigated by in-situ synchrotron diffraction. The highly parallel synchrotron beam at the High Energy Materials Science beamline P07 in PETRA III, DESY, offers excellent conditions to separate different influences for line broadening from which micro-strains are obtained using the modified Williamson–Hall method which is also for defect density investigations. During tensile loading the dislocation density evolution was documented from the as-received material (initial micro-strain state) to the relaxation of the strains during elastic deformation. After yield, the increasing rate of dislocationmore » density growth was relatively fast till half-way between yield and UTS. After that, the rate started to decrease and the dislocation density fluctuated as the elongation increased due to the generation and annihilation of dislocations. When dislocation generation is dominant, the correlation between the flow stress and dislocation density satisfies the Taylor equation. Besides, a method to correct the thickness effect on peak broadening is developed in the present study. - Highlights: • In-situ synchrotron diffraction was applied to characterize peak broadening. • Dislocation evolution along the loading axis during uniaxial tension was investigated. • A method to correct the sample thickness effect on peak broadening was developed. • Dislocation density and flow stress satisfy the Taylor equation at a certain range. • The texture before load and after sample fracture was analyzed.« less

Application of Powder Diffraction Methods to the Analysis of the Atomic Structure of Nanocrystals: The Concept of the Apparent Lattice Parameter (ALP)

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The applicability of standard methods of elaboration of powder diffraction data for determination of the structure of nano-size crystallites is analysed. Based on our theoretical calculations of powder diffraction data we show, that the assumption of the infinite crystal lattice for nanocrystals smaller than 20 nm in size is not justified. Application of conventional tools developed for elaboration of powder diffraction data, like the Rietveld method, may lead to erroneous interpretation of the experimental results. An alternate evaluation of diffraction data of nanoparticles, based on the so-called 'apparent lattice parameter' (alp) is introduced. We assume a model of nanocrystal having a grain core with well-defined crystal structure, surrounded by a surface shell with the atomic structure similar to that of the core but being under a strain (compressive or tensile). The two structural components, the core and the shell, form essentially a composite crystal with interfering, inseparable diffraction properties. Because the structure of such a nanocrystal is not uniform, it defies the basic definitions of an unambiguous crystallographic phase. Consequently, a set of lattice parameters used for characterization of simple crystal phases is insufficient for a proper description of the complex structure of nanocrystals. We developed a method of evaluation of powder diffraction data of nanocrystals, which refers to a core-shell model and is based on the 'apparent lattice parameter' methodology. For a given diffraction pattem, the alp values are calculated for every individual Bragg reflection. For nanocrystals the alp values depend on the diffraction vector Q. By modeling different a0tomic structures of nanocrystals and calculating theoretically corresponding diffraction patterns using the Debye functions we showed, that alp-Q plots show characteristic shapes which can be used for evaluation of the atomic structure of the core-shell system. We show, that using a simple model of a nanocrystal with spherical shape and centro-symmetric strain at the surface shell we obtain theoretical alp-Q values which match very well the alp-Q plots determined experimentally for Sic, GaN, and diamond nanopowders. The theoretical models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the surface shell. According to our calculations, the part of the diffraction pattern measured at relatively low diffraction vectors Q (below 10/angstrom) provides information on the surface strain, whle determination of the lattice parameters in the grain core requires measurements at large Q-values (above 15 - 20/angstrom).

In- Situ Synchrotron Diffraction Studies on Transformation Strain Development in a High-Strength Quenched and Tempered Structural Steel—Part II. Martensitic Transformation

NASA Astrophysics Data System (ADS)

Dutta, R. K.; Huizenga, R. M.; Petrov, R. H.; Amirthalingam, M.; King, A.; Gao, H.; Hermans, M. J. M.; Richardson, I. M.

2014-01-01

In-situ synchrotron diffraction studies on the kinetics of phase transformation and transformation strain development during bainitic transformation were presented in part I of the current article. In the current article, in-situ phase transformation behavior of a high-strength (830 MPa yield stress) quenched and tempered S690QL1 [Fe-0.16C-0.2Si-0.87Mn-0.33Cr-0.21Mo (wt. pct)] structural steel, during continuous cooling and under different mechanical loading conditions to promote martensitic transformation, has been studied. Time-temperature-load resolved 2D synchrotron diffraction patterns were recorded and used to calculate the phase fractions and lattice parameters of the phases during heating and cooling cycles under different loading conditions. In addition to the thermal expansion behavior, the effects of the applied stress on the elastic strains during the martensitic transformation were calculated. The results show that small tensile stresses applied at the transformation temperature do not change the kinetics of the phase transformation. The start temperature for the martensitic transformation increases with the increasing applied tensile stress. The elastic strains are not affected significantly with the increasing tensile stress. The variant selection during martensitic transformation under small applied loads (in the elastic region) is weak.

Ferroelectrics under the Synchrotron Light: A Review

PubMed Central

Fuentes-Cobas, Luis E.; Montero-Cabrera, María E.; Pardo, Lorena; Fuentes-Montero, Luis

2015-01-01

Currently, an intensive search for high-performance lead-free ferroelectric materials is taking place. ABO3 perovskites (A = Ba, Bi, Ca, K and Na; B = Fe, Nb, Ti, and Zr) appear as promising candidates. Understanding the structure–function relationship is mandatory, and, in this field, the roles of long- and short-range crystal orders and interactions are decisive. In this review, recent advances in the global and local characterization of ferroelectric materials by synchrotron light diffraction, scattering and absorption are analyzed. Single- and poly-crystal synchrotron diffraction studies allow high-resolution investigations regarding the long-range average position of ions and subtle global symmetry break-downs. Ferroelectric materials, under the action of electric fields, undergo crystal symmetry, crystallite/domain orientation distribution and strain condition transformations. Methodological aspects of monitoring these processes are discussed. Two-dimensional diffraction clarify larger scale ordering: polycrystal texture is measured from the intensities distribution along the Debye rings. Local order is investigated by diffuse scattering (DS) and X-ray absorption fine structure (XAFS) experiments. DS provides information about thermal, chemical and displacive low-dimensional disorders. XAFS investigation of ferroelectrics reveals local B-cation off-centering and oxidation state. This technique has the advantage of being element-selective. Representative reports of the mentioned studies are described. PMID:28787814

High-energy-resolution monochromator for nuclear resonant scattering of synchrotron radiation by Te-125 at 35.49 keV

NASA Astrophysics Data System (ADS)

Imai, Yasuhiko; Yoda, Yoshitaka; Kitao, Shinji; Masuda, Ryo; Higashitaniguchi, Satoshi; Inaba, Chika; Seto, Makoto

2007-09-01

We have developed a high-resolution monochromator (HRM) for the measurement of nuclear resonant scattering (NRS) of synchrotron radiation by Te-125 at 35.49 keV using the backscattering of sapphire (9 1 -10 68). HRMs for nuclei with excitation energies less than 30 keV have been successfully developed using high angle diffractions by silicon crystals. Nearly perfect silicon crystal, however, is not suitable for high efficient HRMs at higher energy regions because the symmetry of the crystal structure is high and the Debye-temperature is low. Therefore, we used high quality synthetic sapphire crystal, which has low symmetry of crystal structure and high Debye-temperature. The temperature of the crystal was precisely controlled around 218 K to diffract synchrotron radiation with a Bragg angle of π/2 - 0.52 mrad. Energy was tuned by changing the crystal temperature under the condition of constant diffraction angle. Energy resolution was measured by detecting nuclear forward scattering by Te-125 in enriched TeO II. The relative energy resolution of 2.1×10 -7 is achieved, that is 7.5 meV in energy bandwidth. This HRM opens studies on element-specific dynamics and electronic state of substances containing Te-125.

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

Frølich, S.; Leemreize, H.; Jakus, A.

A model sample consisting of two different hydroxyapatite (hAp) powders was used as a bone phantom to investigate the extent to which X-ray diffraction tomography could map differences in hAp lattice constants and crystallite size. The diffraction data were collected at beamline 1-ID, the Advanced Photon Source, using monochromatic 65 keV X-radiation, a 25 × 25 µm pinhole beam and translation/rotation data collection. The diffraction pattern was reconstructed for each volume element (voxel) in the sample, and Rietveld refinement was used to determine the hAp lattice constants. The crystallite size for each voxel was also determined from the 00.2 hApmore » diffraction peak width. The results clearly show that differences between hAp powders could be measured with diffraction tomography.« less

PSICHE: a new beamline dedicated to X-ray diffraction and tomography at high pressure at synchrotron SOLEIL

NASA Astrophysics Data System (ADS)

Guignot, N.; Itié, J.; Zerbino, P.; Delmotte, A.; Moreno, T.

2013-12-01

The PSICHE beamline (for 'Pressure, Structure and Imaging by Contrast at High Energy') is a new facility opened for high pressure experiments at synchrotron SOLEIL (St-Aubin, France). With its source, optics, detectors and 3 experimental stations, it can handle a large variety of experimental setups. High energy photons are produced with an in-vacuum wiggler. The white beam obtained, with photons energy ranging continuously from 15 to 80 keV (from a 2.75 GeV machine), is used on the first experimental station for energy dispersive X-ray diffraction (EDX) measurements using different pressure cells. The main setup is a 1200 tons load capacity multi-anvil press featuring a (100) DIA compression module with a 15° horizontal aperture, allowing measurements up to 30° in 2theta by rotating the press. Other setups are a Paris-Edinburgh (PE) large volume press and diamond anvil cells (DACs). On the detection side we have a rotating Ge detector, based on the CAESAR design described by Wang et al. (2004) (combination of EDX and angular dispersive X-ray diffraction, ADX). One of the difficulties when building such setups is the rotation mechanism which cannot be physically attached to the rotation axis, potentially leading to large circle of confusions on the horizontal position of this axis. Thanks to translation corrections done at each angle step, the circle of confusion is minimized to 3x6 μm2 along the 35° travel, making possible measurements on very small objects. Combining EDX and ADX has a lot of advantages and we will present our first results obtained using this setup. The PSICHE focusing optics and monochromator are also used to focus monochromatic beams (up to 52 keV) on 2 different experimental stations. The first focal point at 31 m gives a beam size of 100x50 μm2 (HxV) and is useful for low pressure experiments and experiments done with the PE press associated with Soller slits. A PerkinElmer flatpanel detector can be precisely scanned in 3 directions, making ADX measurements at the highest possible resolution on this beamline. This station will also be used for diffraction tomography experiments. The second focal point at 37.6 m is located behind KB mirrors on the third experimental station. 10x10 μm2 beam sizes (full width) are expected. This station will be used for DAC experiments, with or without our future laser heating setup. Finally, parallel beams can be produced with sizes up to 15x5 mm2 (HxV) for tomography experiments, in pink (filtered white) beam or monochromatic beam. We plan to use rotating anvils presses such as the rotoPEc (J. Philippe et al., 2013) to take full advantage of this beam mode, but it can be opened to other techniques. The PSICHE beamline is opened for users since July 2013. Some stations are not available yet, and will be opened through 2014 and 2015. References X. Dong et al., Ray tracing application in hard x-ray optical development: Soleil first wiggler beamline (PSICHÉ) case" (2011), Proc. SPIE 8141, 814113 Y. Wang et al., A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation (2004), J. Appl. Cryst. 37, 947-956 J. Philippe, Y. Le Godec, F. Bergame et M. Morand, Patent INPI 11 62335 (2013)

Crystallographic Study of Itokawa Particle, RA-QD02-0127 by Using Energy-Scanning X-Ray Diffraction Method with Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Hagiya, K.; Ohsumi, K.; Komatsu, M.; Mikouchi, T.; Zolensky, M. E.; Hirata, A.; Yamaguchi, S.; Kurokawa, A.

2016-08-01

Crystallographic study of Itokawa particle, RA-QD02-0127 by using new X-ray diffraction method was performed. The purpose of this study is to understand better the metamorphic and impact shock history of asteroid Itokawa, and other S-class asteroids.

Bragg coherent diffraction imaging and metrics for radiation damage in protein micro-crystallography.

PubMed

Coughlan, H D; Darmanin, C; Kirkwood, H J; Phillips, N W; Hoxley, D; Clark, J N; Vine, D J; Hofmann, F; Harder, R J; Maxey, E; Abbey, B

2017-01-01

The proliferation of extremely intense synchrotron sources has enabled ever higher-resolution structures to be obtained using data collected from smaller and often more imperfect biological crystals (Helliwell, 1984). Synchrotron beamlines now exist that are capable of measuring data from single crystals that are just a few micrometres in size. This provides renewed motivation to study and understand the radiation damage behaviour of small protein crystals. Reciprocal-space mapping and Bragg coherent diffractive imaging experiments have been performed on cryo-cooled microcrystals of hen egg-white lysozyme as they undergo radiation damage. Several well established metrics, such as intensity-loss and lattice expansion, are applied to the diffraction data and the results are compared with several new metrics that can be extracted from the coherent imaging experiments. Individually some of these metrics are inconclusive. However, combining metrics, the results suggest that radiation damage behaviour in protein micro-crystals differs from that of larger protein crystals and may allow them to continue to diffract for longer. A possible mechanism to account for these observations is proposed.

Bragg coherent diffraction imaging and metrics for radiation damage in protein micro-crystallography

DOE PAGES

Coughlan, H. D.; Darmanin, C.; Kirkwood, H. J.; ...

2017-01-01

The proliferation of extremely intense synchrotron sources has enabled ever higher-resolution structures to be obtained using data collected from smaller and often more imperfect biological crystals. Synchrotron beamlines now exist that are capable of measuring data from single crystals that are just a few micrometres in size. This provides renewed motivation to study and understand the radiation damage behaviour of small protein crystals. Reciprocal-space mapping and Bragg coherent diffractive imaging experiments have been performed on cryo-cooled microcrystals of hen egg-white lysozyme as they undergo radiation damage. Several well established metrics, such as intensity-loss and lattice expansion, are applied to themore » diffraction data and the results are compared with several new metrics that can be extracted from the coherent imaging experiments. Individually some of these metrics are inconclusive. However, combining metrics, the results suggest that radiation damage behaviour in protein micro-crystals differs from that of larger protein crystals and may allow them to continue to diffract for longer. As a result, a possible mechanism to account for these observations is proposed.« less

Bragg coherent diffraction imaging and metrics for radiation damage in protein micro-crystallography

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

Coughlan, H. D.; Darmanin, C.; Kirkwood, H. J.

The proliferation of extremely intense synchrotron sources has enabled ever higher-resolution structures to be obtained using data collected from smaller and often more imperfect biological crystals. Synchrotron beamlines now exist that are capable of measuring data from single crystals that are just a few micrometres in size. This provides renewed motivation to study and understand the radiation damage behaviour of small protein crystals. Reciprocal-space mapping and Bragg coherent diffractive imaging experiments have been performed on cryo-cooled microcrystals of hen egg-white lysozyme as they undergo radiation damage. Several well established metrics, such as intensity-loss and lattice expansion, are applied to themore » diffraction data and the results are compared with several new metrics that can be extracted from the coherent imaging experiments. Individually some of these metrics are inconclusive. However, combining metrics, the results suggest that radiation damage behaviour in protein micro-crystals differs from that of larger protein crystals and may allow them to continue to diffract for longer. As a result, a possible mechanism to account for these observations is proposed.« less

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 multi-dataset data-collection strategy produces better diffraction data

PubMed Central

Liu, Zhi-Jie; Chen, Lirong; Wu, Dong; Ding, Wei; Zhang, Hua; Zhou, Weihong; Fu, Zheng-Qing; Wang, Bi-Cheng

2011-01-01

A multi-dataset (MDS) data-collection strategy is proposed and analyzed for macromolecular crystal diffraction data acquisition. The theoretical analysis indicated that the MDS strategy can reduce the standard deviation (background noise) of diffraction data compared with the commonly used single-dataset strategy for a fixed X-ray dose. In order to validate the hypothesis experimentally, a data-quality evaluation process, termed a readiness test of the X-ray data-collection system, was developed. The anomalous signals of sulfur atoms in zinc-free insulin crystals were used as the probe to differentiate the quality of data collected using different data-collection strategies. The data-collection results using home-laboratory-based rotating-anode X-ray and synchrotron X-ray systems indicate that the diffraction data collected with the MDS strategy contain more accurate anomalous signals from sulfur atoms than the data collected with a regular data-collection strategy. In addition, the MDS strategy offered more advantages with respect to radiation-damage-sensitive crystals and better usage of rotating-anode as well as synchrotron X-rays. PMID:22011470

Entrainment of lactose inhalation powders: a study using laser diffraction.

PubMed

Watling, C P; Elliott, J A; Cameron, R E

2010-07-11

We have investigated the mechanism of entrainment of lactose inhalation blends released from a dry powder inhaler using a diffraction particle size analyser (Malvern Spraytec). Whether a powder blend entrains as a constant stream of powder (the "erosion" mechanism) or as a few coarse plugs (the "fracture" mechanism) was found by comparing transmission data with particle size information. This technique was then applied to a lactose grade with 0, 5 and 10wt% added fine particles. As the wt% fines increased, the entrainment mechanism was found to change from a mild fracture, consisting of multiple small plugs, to more severe fracture with fewer plugs. The most severe fracture mechanism consisted of either the powder reservoir emptying as a single plug, or of the reservoir emptying after a delay of the order of 0.1s due to the powder sticking to its surroundings. Further to this, three different inhalation grades were compared, and the severity of the fracture was found to be inversely proportional to the flowability of the powder (measured using an annular ring shear tester). By considering the volume of aerosolised fine particles in different blends it was determined that the greater the volume of fines added to a powder, the smaller the fraction of fines that were aerosolised. This was attributed to different behaviour when fines disperse from carrier particles compared with when they disperse from agglomerates of fines. In summary, this paper demonstrates how laser diffraction can provide a more detailed analysis of an inhalation powder than just its size distribution. 2010. Published by Elsevier B.V. All rights reserved.

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

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

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage ofmore » energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.« less

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

PubMed Central

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

2017-01-01

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function. PMID:28989711

Structural phase transition in d-benzil characterised by capacitance measurements and neutron powder diffraction

NASA Astrophysics Data System (ADS)

Goossens, D. J.; Wu, Xiaodong; Prior, M.

2005-12-01

The ferroelectric phase transition in deuterated benzil, C 14H 10O 2, has been studied using capacitance measurements and neutron powder diffraction. Hydrogenous benzil shows a phase transition at 83.5 K from a high temperature P3 121 phase to a cell-doubled P2 1 phase. The phase transition in d-benzil occurs at 88.1 K, a small isotope effect. Neutron powder diffraction was consistent with a low temperature phase of space group P2 1. Upon deuteration the transition remained first-order and the dynamics of the phenyl ring dominated the behaviour. The isotope effect can be attributed to the difference in mass and moment of inertia between C 6H 5 and C 6D 5.

Synthesis and characterization of Mn-Bi alloy

NASA Astrophysics Data System (ADS)

Mishra, Ashutosh; Patil, Harsha; Jain, G.; Mishra, N.

2012-06-01

High purity MnBi low temperature phase has been prepared and analyzed using X-ray diffraction, Lorentz-Polarization Factor and Fourier transforms infrared measurement. After synthesis of samples structural characterization has done on samples by X-ray diffraction, which shows that after making the bulk sample is in no single phase MnBi has been prepared by sintering Mn and Bi powders. By Lorentz-Polarization Factor is affecting the relative intensity of diffraction lines on a powder form. And by FTIR which shows absorption peaks of MnBi alloys.

Charge ordering transition in GdBaCo2O5: Evidence of reentrant behavior

NASA Astrophysics Data System (ADS)

Allieta, M.; Scavini, M.; Lo Presti, L.; Coduri, M.; Loconte, L.; Cappelli, S.; Oliva, C.; Ghigna, P.; Pattison, P.; Scagnoli, V.

2013-12-01

We present a detailed study on the charge ordering transition in a GdBaCo2O5.0 system by combining high-resolution synchrotron powder/single-crystal diffraction with electron paramagnetic resonance experiments as a function of temperature. We found a second-order structural phase transition at TCO = 247 K (Pmmm to Pmma) associated with the onset of long-range charge ordering. At Tmin ≈ 1.2TCO, the electron paramagnetic resonance linewidth rapidly broadens, providing evidence of antiferromagnetic spin fluctuations. This likely indicates that, analogously to manganites, the long-range antiferromagnetic order in GdBaCo2O5.0 sets in at ≈TCO. Pair distribution function analysis of diffraction data revealed signatures of structural inhomogeneities at low temperature. By comparing the average and local bond valences, we found that above TCO the local structure is consistent with a fully random occupation of Co2+ and Co3+ in a 1:1 ratio and with a complete charge ordering below TCO. Below T ≈ 100 K the charge localization is partially melted at the local scale, suggesting a reentrant behavior of charge ordering. This result is supported by the weakening of superstructure reflections and the temperature evolution of electron paramagnetic resonance linewidth that is consistent with paramagnetic reentrant behavior reported in the GdBaCo2O5.5 parent compound.

High-pressure X-ray diffraction, Raman, and computational studies of MgCl2 up to 1 Mbar: Extensive pressure stability of the β-MgCl2 layered structure.

PubMed

Stavrou, Elissaios; Yao, Yansun; Zaug, Joseph M; Bastea, Sorin; Kalkan, Bora; Konôpková, Zuzana; Kunz, Martin

2016-08-12

Magnesium chloride (MgCl2) with the rhombohedral layered CdCl2-type structure (α-MgCl2) has been studied experimentally using synchrotron angle-dispersive powder x-ray diffraction and Raman spectroscopy using a diamond-anvil cell up to 100 GPa at room temperature and theoretically using first-principles density functional calculations. The results reveal a pressure-induced second-order structural phase transition to a hexagonal layered CdI2-type structure (β-MgCl2) at 0.7 GPa: the stacking sequence of the Cl anions are altered resulting in a reduction of the c-axis length. Theoretical calculations confirm this phase transition sequence and the calculated transition pressure is in excellent agreement with the experiment. Lattice dynamics calculations also reproduce the experimental Raman spectra measured for the ambient and high-pressure phase. According to our experimental results MgCl2 remains in a 2D layered phase up to 100 GPa and further, the 6-fold coordination of Mg cations is retained. Theoretical calculations of relative enthalpy suggest that this extensive pressure stability is due to a low enthalpy of the layered structure ruling out kinetic barrier effects. This observation is unusual, as it contradicts with the general structural behavior of highly compressed AB2 compounds.

High-pressure X-ray diffraction, Raman, and computational studies of MgCl 2 up to 1 Mbar: Extensive pressure stability of the β-MgCl 2 layered structure

DOE PAGES

Stavrou, Elissaios; Yao, Yansun; Zaug, Joseph M.; ...

2016-08-12

We studied magnesium chloride (MgCl 2) with the rhombohedral layered CdCl 2-type structure (α-MgCl 2), experimentally, using synchrotron angle-dispersive powder x-ray diffraction and Raman spectroscopy using a diamond-anvil cell up to 100 GPa at room temperature and theoretically using first-principles density functional calculations. Our results reveal a pressure-induced second-order structural phase transition to a hexagonal layered CdI 2-type structure (β-MgCl 2) at 0.7 GPa: the stacking sequence of the Cl anions are altered resulting in a reduction of the c-axis length. Theoretical calculations confirm this phase transition sequence and the calculated transition pressure is in excellent agreement with the experiment.more » Lattice dynamics calculations also reproduce the experimental Raman spectra measured for the ambient and high-pressure phase. According to our experimental results MgCl 2 remains in a 2D layered phase up to 100 GPa and further, the 6-fold coordination of Mg cations is retained. Theoretical calculations of relative enthalpy suggest that this extensive pressure stability is due to a low enthalpy of the layered structure ruling out kinetic barrier effects. Our observation is unusual, as it contradicts with the general structural behavior of highly compressed AB 2 compounds.« less

Room Temperature Ferromagnetism of Fe Doped Indium Tin Oxide Based on Dispersed Fe3O4 Nanoparticles

NASA Astrophysics Data System (ADS)

Okada, Koichi; Kohiki, Shigemi; Nishi, Sachio; Shimooka, Hirokazu; Deguchi, Hiroyuki; Mitome, Masanori; Bando, Yoshio; Shishido, Toetsu

2007-09-01

Transmission electron microscopy revealed that Fe3O4 nanoparticles with diameter of ≈200 nm dispersed in Fe doped indium tin oxide (Fe@ITO) powders exhibiting co-occurrence of room temperature ferromagnetism and superparamagnetism. Although we observed no X-ray diffraction peak from Fe related compounds for Fe0.19@ITO (ITO: In1.9Sn0.1O3) powders, the powders showed both hysteresis loop in field dependent magnetization at 300 K and divergence of zero-field-cooled magnetization from field-cooled magnetization. Scanning transmission electron microscopy with energy dispersive X-ray spectroscopy demonstrated that the nanoparticle with diameter of ≈200 nm consists of Fe and oxygen. Transmission electron diffraction revealed that crystal structure of the nanoparticle is inverse spinel type Fe3O4. The Fe3O4 crystalline phase by electron diffraction is consistent with the saturation magnetization of 1.3 μB/Fe and magnetic anomaly at ≈110 K observed for the powders.

Structural and Spectral Characterization of Co2+- and Ni2+-DOPED CdO Powder Prepared From Solution at Room Temperature

NASA Astrophysics Data System (ADS)

Reddy, C. V.; Rao, L. V. Krishna; Satish, D. V.; Shim, J.; Ravikumar, R. V. S. S. N.

2015-11-01

The mild and simple solution method was used for the synthesis of Co2+- and Ni2+-doped CdO powders at room temperature. The prepared powders were characterized using powder X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), optical absorption, and Fourier transform infrared spectroscopy (FTIR). From the powder X-ray diffraction patterns, it has been observed that the prepared Co2+ and Ni2+ ion-doped CdO powders belong to the cubic phase, and the evaluated average crystalline sizes of the powders are 20 and 14 nm, respectively. The SEM images and the EDS spectra show that the prepared powders are distributed over different sizes in the grain boundaries. Optical absorption studies allow determination of site symmetry of the metal ion with its ligands. The crystal field (Dq) and inter-electronic repulsion (B and C) parameters have been evaluated from the optical absorption spectra. The FTIR spectra show the characteristic fundamental vibrations of the metal oxide and CdO.

In situ Raman and synchrotron X-ray diffraction study on crystallization of Choline chloride/Urea deep eutectic solvent under high pressure

NASA Astrophysics Data System (ADS)

Yuan, Chaosheng; Chu, Kunkun; Li, Haining; Su, Lei; Yang, Kun; Wang, Yongqiang; Li, Xiaodong

2016-09-01

Pressure-induced crystallization of Choline chloride/Urea (ChCl/Urea) deep eutectic solvent (DES) has been investigated by in-situ Raman spectroscopy and synchrotron X-ray diffraction. The results indicated that high pressure crystals appeared at around 2.6 GPa, and the crystalline structure was different from that formed at ambient pressure. Upon increasing the pressure, the Nsbnd H stretching modes of Urea underwent dramatic change after liquid-solid transition. It appears that high pressures may enhance the hydrogen bonds formed between ChCl and Urea. P versus T phase diagram of ChCl/Urea DES was constructed, and the crystallization mechanism of ChCl/Urea DES was discussed in view of hydrogen bonds.

Observation of Threading Dislocations in Ammonothermal Gallium Nitride Single Crystal Using Synchrotron X-ray Topography

NASA Astrophysics Data System (ADS)

Yao, Y.; Ishikawa, Y.; Sugawara, Y.; Takahashi, Y.; Hirano, K.

2018-04-01

Synchrotron monochromatic-beam x-ray topography observation has been performed on high-quality ammonothermal gallium nitride single crystal to evaluate threading dislocations (TD) in a nondestructive manner. Asymmetric diffractions with six equivalent g-vectors of 11-26, in addition to a symmetric diffraction with g = 0008, were applied to determine the Burgers vectors (b) of dislocations. It was found that pure edge-type TDs with \\varvec b = < {11 - 20} > /3 did not exist in the sample. A dominant proportion of TDs were of mixed type with \\varvec b = < {11 - 20} > /3 + < {0001} > , i.e., so-called c + a dislocations. Pure 1c screw dislocations with \\varvec b = < {0001} > and TDs with c-component larger than 1c were also observed.

Development of a synchrotron biaxial tensile device for in situ characterization of thin films mechanical response.

PubMed

Geandier, G; Thiaudière, D; Randriamazaoro, R N; Chiron, R; Djaziri, S; Lamongie, B; Diot, Y; Le Bourhis, E; Renault, P O; Goudeau, P; Bouaffad, A; Castelnau, O; Faurie, D; Hild, F

2010-10-01

We have developed on the DIFFABS-SOLEIL beamline a biaxial tensile machine working in the synchrotron environment for in situ diffraction characterization of thin polycrystalline films mechanical response. The machine has been designed to test compliant substrates coated by the studied films under controlled, applied strain field. Technological challenges comprise the sample design including fixation of the substrate ends, the related generation of a uniform strain field in the studied (central) volume, and the operations from the beamline pilot. Preliminary tests on 150 nm thick W films deposited onto polyimide cruciform substrates are presented. The obtained results for applied strains using x-ray diffraction and digital image correlation methods clearly show the full potentialities of this new setup.

Multifit / Polydefix : a framework for the analysis of polycrystal deformation using X-rays

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

Merkel, Sébastien; Hilairet, Nadège

2015-06-27

Multifit/Polydefixis an open source IDL software package for the efficient processing of diffraction data obtained in deformation apparatuses at synchrotron beamlines.Multifitallows users to decompose two-dimensional diffraction images into azimuthal slices, fit peak positions, shapes and intensities, and propagate the results to other azimuths and images.Polydefixis for analysis of deformation experiments. Starting from output files created inMultifitor other packages, it will extract elastic lattice strains, evaluate sample pressure and differential stress, and prepare input files for further texture analysis. TheMultifit/Polydefixpackage is designed to make the tedious data analysis of synchrotron-based plasticity, rheology or other time-dependent experiments very straightforward and accessible tomore » a wider community.« less

Ecological and agricultural applications of synchrotron IR microscopy

NASA Astrophysics Data System (ADS)

Raab, T. K.; Vogel, J. P.

2004-10-01

The diffraction-limited spot size of synchrotron-based IR microscopes provides cell-specific, spectrochemical imaging of cleared leaf, stem and root tissues of the model genetic organism Arabidopsis thaliana, and mutant plants created either by T-DNA insertional inactivation or chemical mutagenesis. Spectra in the wavelength region from 6 to 12 μm provide chemical and physical information on the cell wall polysaccharides of mutants lacking particular biosynthetic enzymes ("Cellulose synthase-like" genes). In parallel experiments, synchrotron IR microscopy delineates the role of Arabidopsis cell wall enzymes as susceptibility factors to the fungus Erysiphe cichoracearum, a causative agent of powdery mildew disease. Three genes, pmr4, pmr5, and pmr6 have been characterized by these methods, and biochemical relations between two of the genes suggested by IR spectroscopy and multivariate statistical techniques could not have been inferred through classical molecular biology. In ecological experiments, live plants can also be imaged in small microcosms with mid-IR transmitting ZnSe windows. Small exudate molecules may be spatially mapped in relation to root architecture at diffraction-limited resolution, and the effect of microbial symbioses on the quantity and quality of exudates inferred. Synchrotron IR microscopy provides a useful adjunct to molecular biological methods and underground observatories in the ongoing assessment of the role of root-soil-microbe communication.

X-ray diffraction studies of shocked lunar analogs

NASA Technical Reports Server (NTRS)

Hanss, R. E.

1979-01-01

The X-ray diffraction experiments on shocked rock and mineral analogs of particular significance to lunar geology are described. Materials naturally shocked by meteorite impact, nuclear-shocked, or artificially shocked in a flat plate accelerator were utilized. Four areas were outlined for investigation: powder diffractometer studies of shocked single crystal silicate minerals (quartz, orthoclase, oligoclase, pyroxene), powder diffractometer studies of shocked polycrystalline monomineralic samples (dunite), Debye-Scherrer studies of single grains of shocked granodiorite, and powder diffractometer studies of shocked whole rock samples. Quantitative interpretation of peak shock pressures experienced by materials found in lunar or terrestrial impact structures is presented.

Real-time phase evolution of Selective Laser Melted (SLM) Inconel 718 with temperature through synchrotron X-rays

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

Sarley, Brooke A.; Manero, Albert; Cotelo, Jose

2017-01-01

Selective laser melting (SLM) is an additive manufacturing process that uses laser scanning to achieve melting and solidification of a metal powder bed. This process, when applied to develop high temperature material systems, holds great promise for more efficient manufacturing of turbine components that withstand extreme temperatures, heat fluxes, and high mechanical stresses associated with engine environments. These extreme operational conditions demand stringent tolerances and an understanding of the material evolution under thermal loading. This work presents a real-time approach to elucidating the evolution of precipitate phases in SLM Inconel 718 (IN718) under high temperatures using high-energy synchrotron x-ray diffraction.more » Four representative samples (taken along variable build height) were studied in room temperature conditions. Two samples were studied as-processed (samples 1 and 4) and two samples after different thermal treatments (samples 2 and 3). The as-processed samples were found to contain greater amounts of weakening phase, δ. Precipitation hardening of Sample 2 reduced the detectable volume of δ, while also promoting growth of γ00 in the γ matrix. Inversely, solution treatment of Sample 3 produced an overall decrease in precipitate phases. High-temperature, in-situ synchrotron scans during ramp-up, hold, and cool down of two different thermal cycles show the development of precipitate phases. Sample 1 was held at 870°C and subsequently ramped up to 1100°C, during which the high temperature instability of strengthening precipitate, γ00, was seen. γ00 dissolution occurred after 15 minutes at 870°C and was followed by an increase of δ-phase. Sample 4 was held at 800°C and exhibited growth of γ00 after 20 minutes at this temperature. These experiments use in-situ observations to understand the intrinsic thermal effect of the SLM process and the use of heat treatment to manipulate the phase composition of SLM IN718.« less

On the possibility of using polycrystalline material in the development of structure-based generic assays

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

Allaire, Marc, E-mail: allaire@bnl.gov; Moiseeva, Natalia; Botez, Cristian E.

The correlation coefficients calculated between raw powder diffraction profiles can be used to identify ligand-bound/unbound states of lysozyme. The discovery of ligands that bind specifically to a targeted protein benefits from the development of generic assays for high-throughput screening of a library of chemicals. Protein powder diffraction (PPD) has been proposed as a potential method for use as a structure-based assay for high-throughput screening applications. Building on this effort, powder samples of bound/unbound states of soluble hen-egg white lysozyme precipitated with sodium chloride were compared. The correlation coefficients calculated between the raw diffraction profiles were consistent with the known bindingmore » properties of the ligands and suggested that the PPD approach can be used even prior to a full description using stereochemically restrained Rietveld refinement.« less

Addressing the amorphous content issue in quantitative phase analysis: the certification of NIST standard reference material 676a.

PubMed

Cline, James P; Von Dreele, Robert B; Winburn, Ryan; Stephens, Peter W; Filliben, James J

2011-07-01

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum (α-Al(2)O(3)) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Under the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% ± 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.

Combined Diffraction and Density Functional Theory Calculations of Halogen-Bonded Cocrystal Monolayers

PubMed Central

2013-01-01

This work describes the combined use of synchrotron X-ray diffraction and density functional theory (DFT) calculations to understand the cocrystal formation or phase separation in 2D monolayers capable of halogen bonding. The solid monolayer structure of 1,4-diiodobenzene (DIB) has been determined by X-ray synchrotron diffraction. The mixing behavior of DIB with 4,4′-bipyridyl (BPY) has also been studied and interestingly is found to phase-separate rather than form a cocrystal, as observed in the bulk. DFT calculations are used to establish the underlying origin of this interesting behavior. The DFT calculations are demonstrated to agree well with the recently proposed monolayer structure for the cocrystal of BPY and 1,4-diiodotetrafluorobenzene (DITFB) (the perfluorinated analogue of DIB), where halogen bonding has also been identified by diffraction. Here we have calculated an estimate of the halogen bond strength by DFT calculations for the DITFB/BPY cocrystal monolayer, which is found to be ∼20 kJ/mol. Computationally, we find that the nonfluorinated DIB and BPY are not expected to form a halogen-bonded cocrystal in a 2D layer; for this pair of species, phase separation of the components is calculated to be lower energy, in good agreement with the diffraction results. PMID:24215390

Combined diffraction and density functional theory calculations of halogen-bonded cocrystal monolayers.

PubMed

Sacchi, Marco; Brewer, Adam Y; Jenkins, Stephen J; Parker, Julia E; Friščić, Tomislav; Clarke, Stuart M

2013-12-03

This work describes the combined use of synchrotron X-ray diffraction and density functional theory (DFT) calculations to understand the cocrystal formation or phase separation in 2D monolayers capable of halogen bonding. The solid monolayer structure of 1,4-diiodobenzene (DIB) has been determined by X-ray synchrotron diffraction. The mixing behavior of DIB with 4,4'-bipyridyl (BPY) has also been studied and interestingly is found to phase-separate rather than form a cocrystal, as observed in the bulk. DFT calculations are used to establish the underlying origin of this interesting behavior. The DFT calculations are demonstrated to agree well with the recently proposed monolayer structure for the cocrystal of BPY and 1,4-diiodotetrafluorobenzene (DITFB) (the perfluorinated analogue of DIB), where halogen bonding has also been identified by diffraction. Here we have calculated an estimate of the halogen bond strength by DFT calculations for the DITFB/BPY cocrystal monolayer, which is found to be ∼20 kJ/mol. Computationally, we find that the nonfluorinated DIB and BPY are not expected to form a halogen-bonded cocrystal in a 2D layer; for this pair of species, phase separation of the components is calculated to be lower energy, in good agreement with the diffraction results.

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).

Crystallization and preliminary X-ray diffraction analysis of a novel Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis venom

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

Murakami, Mário T.; Center for Applied Toxinology, CAT-CEPID, São Paulo, SP; Advanced Center for Genomics and Proteomics, UNESP-State University of São Paulo, São José do Rio Preto 15054-000

2007-07-01

A single crystal of zhaoermiatoxin with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å. Zhaoermiatoxin, an Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis (formerly Trimeresurus mangshanensis, Ermia mangshanensis) venom is a novel member of the PLA{sub 2}-homologue family that possesses an arginine residue at position 49, probably arising from a secondary Lys49→Arg substitution that does notmore » alter the catalytic inactivity towards phospholipids. Like other Lys49 PLA{sub 2} homologues, zhaoermiatoxin induces oedema and strong myonecrosis without detectable PLA{sub 2} catalytic activity. A single crystal with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å.« less

Multiscale measurements on temperature-dependent deformation of a textured magnesium alloy with synchrotron x-ray imaging and diffraction

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

Lu, L.; Bie, B. X.; Li, Q. H.

2017-06-01

In situ synchrotron x-ray imaging and diffraction are used to investigate deformation of a rolled magnesium alloy under uniaxial compression at room and elevated temperatures along two different directions. The loading axis (LA) is either perpendicular or parallel to the normal direction, and these two cases are referred to as LA⊥ and LAk loading, respectively. Multiscale measurements including stressestrain curves (macroscale), strain fields (mesoscale), and diffraction patterns (microscale) are obtained simultaneously. Due to initial texture, f1012g extension twinning is predominant in the LA⊥ loading, while dislocation motion prevails in the LAk loading. With increasing temperature, fewer f1012g extension twins aremore » activated in the LA⊥ samples, giving rise to reduced strain homogenization, while pyramidal slip becomes readily activated, leading to more homogeneous deformation for the LAk loading. The difference in the strain hardening rates is attributed to that in strain field homogenization for these two loading directions« less

Observation of Structure of Surfaces and Interfaces by Synchrotron X-ray Diffraction: Atomic-Scale Imaging and Time-Resolved Measurements

NASA Astrophysics Data System (ADS)

Wakabayashi, Yusuke; Shirasawa, Tetsuroh; Voegeli, Wolfgang; Takahashi, Toshio

2018-06-01

The recent developments in synchrotron optics, X-ray detectors, and data analysis algorithms have enhanced the capability of the surface X-ray diffraction technique. This technique has been used to clarify the atomic arrangement around surfaces in a non-contact and nondestructive manner. An overview of surface X-ray diffraction, from the historical development to recent topics, is presented. In the early stage of this technique, surface reconstructions of simple semiconductors or metals were studied. Currently, the surface or interface structures of complicated functional materials are examined with sub-Å resolution. As examples, the surface structure determination of organic semiconductors and of a one-dimensional structure on silicon are presented. A new frontier is time-resolved interfacial structure analysis. A recent observation of the structure and dynamics of the electric double layer of ionic liquids, and an investigation of the structural evolution in the wettability transition on a TiO2 surface that utilizes a newly designed time-resolved surface diffractometer, are presented.

Effect of the Chemical State of the Surface on the Relaxation of the Surface Shell Atoms in SiC and GaN Nanocrystals

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H. P.; Janik, J. F.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The effect of the chemical state of the surface of nanoparticles on the relaxation in the near-surface layer was examined using the concept of the apparent lattice parameter (alp) determined for different diffraction vectors Q. The apparent lattice parameter is a lattice parameter determined either from an individual Bragg reflection, or from a selected region of the diffraction pattern. At low diffraction vectors the Bragg peak positions are affected mainly by the structure of the near-surface layer, while at high Q-values only the interior of the nano-grain contributes to the diffraction pattern. Following the measurements on raw (as prepared) powders we investigated powders cleaned by annealing at 400C under vacuum, and the same powders wetted with water. Theoretical alp-Q plots showed that the structure of the surface layer depends on the sample treatment. Semi-quantitative analysis based on the comparison of the experimental and theoretical alp-Q plots was performed. Theoretical alp-Q relations were obtained from the diffraction patterns calculated for models of nanocrystals with a strained surface layer using the Debye functions.

Characterization of composite materials based on cement-ceramic powder blended binder

NASA Astrophysics Data System (ADS)

Kulovaná, Tereza; Pavlík, Zbyšek

2016-06-01

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.

Phase analysis of ZrO2-SiO2 systems synthesized through Ball milling mechanical activations

NASA Astrophysics Data System (ADS)

Nurlaila, Rizka; Musyarofah, Muwwaqor, Nibras Fuadi; Triwikantoro, Kuswoyo, Anton; Pratapa, Suminar

2017-01-01

Zircon powders have been produced from raw materials of amorphous zirconia and amorphous silica powders obtained from natural zircon sand of Kalimantan Tengah, Indonesia. Synthesis process was started with the extraction of zircon powder to produce sodium silicate solution and pure zircon powder. The amorphous zirconia and silica powders were prepared by alkali fusion and co-precipitation techniques. The powders were mixed using a planetary ball mill, followed by a calcination of various holding time of 3, 10, and 15 h. Phase characterization was done using X-Ray Diffraction (XRD) technique and analysis of the diffraction data was carried out using Rietica and MAUD software. The identified phases after the calcination were zircon, tetragonal zirconia, and cristobalite. The highest zircon content was obtained in the sample calcinated for15 hours - reaching 99.66 %wt. Crystallite size analysis revealed that the samples calcinated for 3, 10, and 15 h exhibited zircon crystal size of 176 (1) nm, 191 (1) nm and 233 (1) nm respectively.

Characterization of composite materials based on cement-ceramic powder blended binder

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

Kulovaná, Tereza; Pavlík, Zbyšek

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO{sub 2} emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzedmore » by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.« less

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

NASA Astrophysics Data System (ADS)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

Fabrication, characterization and fracture study of a machinable hydroxyapatite ceramic.

PubMed

Shareef, M Y; Messer, P F; van Noort, R

1993-01-01

In this study the preparation of a machinable hydroxyapatite from mixtures of a fine, submicrometer powder and either a coarse powder composed of porous aggregates up to 50 microns or a medium powder composed of dense particles of 3 microns median size is described. These were characterized using X-ray diffraction, transmission and scanning electron microscopy and infra-red spectroscopy. Test-pieces were formed by powder pressing and slip casting mixtures of various combinations of the fine, medium and coarse powders. The fired test-pieces were subjected to measurements of firing shrinkage, porosity, bulk density, tensile strength and fracture toughness. The microstructure and composition were examined using scanning electron microscopy and X-ray diffraction. For both processing methods, a uniform interconnected microporous structure was produced of a high-purity hydroxyapatite. The maximum tensile strength and fracture toughness that could be attained while retaining machinability were 37 MPa and 0.8 MPa m1/2 respectively.

Polymorphism of Alprazolam (Xanax): a review of its crystalline phases and identification, crystallographic characterization, and crystal structure of a new polymorph (form III).

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Van den Mooter, Guy; Blaton, Norbert

2007-05-01

A new polymorphic form of Alprazolam (Xanax), 8-chloro-1-methyl-6-phenyl-4H-[1,2,4]triazolo-[4,3-alpha][1,4]benzodiazepine, C(17)H(13)ClN(4), has been investigated by means of X-ray powder diffraction (XRPD), single crystal X-ray diffraction, and differential scanning calorimetry (DSC). This polymorphic form (form III) was obtained during DSC experiments after the exothermic recrystallization of the melt of form I. The crystal unit cell dimensions for form III were determined from diffractometer methods. The monoclinic unit cell found for this polymorph using XRPD after indexing the powder diffractogram was confirmed by the cell parameters obtained from single crystal X-ray diffractometry on a crystal isolated from the DSC pans. The single crystal unit cell parameters are: a = 28.929(9), b = 13.844(8), c = 7.361(3) angstroms, beta = 92.82(3) degrees , V = 2944(2) angstroms(3), Z = 8, space group P2(1) (No.4), Dx = 1.393 Mg/m(3). The structure obtained from single crystal X-ray diffraction was used as initial model for Rietveld refinement on the powder diffraction data of form III. The temperature phase transformations of alprazolam were also studied using high temperature XRPD. A review of the different phases available in the Powder Diffraction File (PDF) database for this drug is described bringing some clarification and corrections. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

Beam-smiling in bent-Laue monochromators

NASA Astrophysics Data System (ADS)

Ren, B.; Dilmanian, F. A.; Chapman, L. D.; Wu, X. Y.; Zhong, Z.; Ivanov, I.; Thomlinson, W. C.; Huang, X.

1997-07-01

When a wide fan-shaped x-ray beam is diffracted by a bent crystal in the Laue geometry, the profile of the diffracted beam generally does not appear as a straight line, but as a line with its ends curved up or curved down. This effect, referred to as "beam-smiling", has been a major obstacle in developing bent-Laue crystal monochromators for medical applications of synchrotron x-ray. We modeled a cylindrically bent crystal using the Finite Element Analysis (FEA) method, and we carried out experiments at the National Synchrotron Light Source and Cornell High Energy Synchrotron Source. Our studies show that, while beam-smiling exists in most of the crystal's area because of anticlastic bending effects, there is a region parallel to the bending axis of the crystal where the diffracted beam is "smile-free". By applying asymmetrical bending, this smile-free region can be shifted vertically away from the geometric center of the crystal, as desired. This leads to a novel method of compensating for beam-smiling. We will discuss the method of "differential bending" for smile removal, beam-smiling in the Cauchios and the polychromatic geometry, and the implications of the method on developing single- and double-bent Laue monochromators. The experimental results will be discussed, concentrating on specific beam-smiling observation and removal as applied to the new monochromator of the Multiple Energy Computed Tomography [MECT] project of the Medical Department, Brookhaven National Laboratory.

Ice Recrystallization in a Solution of a Cryoprotector and Its Inhibition by a Protein: Synchrotron X-Ray Diffraction Study.

PubMed

Zakharov, Boris; Fisyuk, Alexander; Fitch, Andy; Watier, Yves; Kostyuchenko, Anastasia; Varshney, Dushyant; Sztucki, Michael; Boldyreva, Elena; Shalaev, Evgenyi

2016-07-01

Ice formation and recrystallization is a key phenomenon in freezing and freeze-drying of pharmaceuticals and biopharmaceuticals. In this investigation, high-resolution synchrotron X-ray diffraction is used to quantify the extent of disorder of ice crystals in binary aqueous solutions of a cryoprotectant (sorbitol) and a protein, bovine serum albumin. Ice crystals in more dilute (10 wt%) solutions have lower level of microstrain and larger crystal domain size than these in more concentrated (40 wt%) solutions. Warming the sorbitol-water mixtures from 100 to 228 K resulted in partial ice melting, with simultaneous reduction in the microstrain and increase in crystallite size, that is, recrystallization. In contrast to sorbitol solutions, ice crystals in the BSA solutions preserved both the microstrain and smaller crystallite size on partial melting, demonstrating that BSA inhibits ice recrystallization. The results are consistent with BSA partitioning into quasi-liquid layer on ice crystals but not with a direct protein-ice interaction and protein sorption on ice surface. The study shows for the first time that a common (i.e., not-antifreeze) protein can have a major impact on ice recrystallization and also presents synchrotron X-ray diffraction as a unique tool for quantification of crystallinity and disorder in frozen aqueous systems. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

A novel synthesis of polymeric CO via useful hard X-ray photochemistry

NASA Astrophysics Data System (ADS)

Pravica, Michael; Sneed, Daniel; Smith, Quinlan; Billinghurst, Brant; May, Tim; White, Melanie; Dziubek, Kamil

2016-12-01

We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC2O4) pressurized to 7 GPa inside a diamond anvil cell (DAC). After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO2 even under ambient conditions with the sample exposed to air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part) with dispersed CO2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press) without the need for the dangerous and complex loading of toxic CO. A novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.

High-pressure structural study of MnF 2

DOE PAGES

Stavrou, Elissaios; Yao, Yansun; Goncharov, Alexander F.; ...

2015-02-01

In this study, manganese fluoride (MnF 2) with the tetragonal rutile-type structure has been studied using a synchrotron angle-dispersive powder x-ray diffraction and Raman spectroscopy in a diamond anvil cell up to 60 GPa at room temperature combined with first-principles density functional calculations. The experimental data reveal two pressure-induced structural phase transitions with the following sequence: rutile → SrI 2 type (3 GPa)→ α–PbCl 2 type (13 GPa). Complete structural information, including interatomic distances, has been determined in the case of MnF 2 including the exact structure of the debated first high-pressure phase. First-principles density functional calculations confirm this phasemore » transition sequence, and the two calculated transition pressures are in excellent agreement with the experiment. Lattice dynamics calculations also reproduce the experimental Raman spectra measured for the ambient and high-pressure phases. The results are discussed in line with the possible practical use of rutile-type fluorides in general and specifically MnF 2 as a model compound to reveal the HP structural behavior of rutile-type SiO 2 (Stishovite).« less

Hydration mechanisms of two polymorphs of synthetic ye'elimite

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

Cuesta, A.; Álvarez-Pinazo, G.; Sanfélix, S.G.

2014-09-15

Ye'elimite is the main phase in calcium sulfoaluminate cements and also a key phase in sulfobelite cements. However, its hydration mechanism is not well understood. Here we reported new data on the hydration behavior of ye'elimite using synchrotron and laboratory powder diffraction coupled to the Rietveld methodology. Both internal and external standard methodologies have been used to determine the overall amorphous contents. We have addressed the standard variables: water-to-ye'elimite ratio and additional sulfate sources of different solubilities. Moreover, we report a deep study of the role of the polymorphism of pure ye'elimites. The hydration behavior of orthorhombic stoichiometric and pseudo-cubicmore » solid-solution ye'elimites is discussed. In the absence of additional sulfate sources, stoichiometric-ye'elimite reacts slower than solid-solution-ye'elimite, and AFm-type phases are the main hydrated crystalline phases, as expected. Moreover, solid-solution-ye'elimite produces higher amounts of ettringite than stoichiometric-ye'elimite. However, in the presence of additional sulfates, stoichiometric-ye'elimite reacts faster than solid-solution-ye'elimite.« less

Structures, Phase Transitions and Tricritical Behavior of the Hybrid Perovskite Methyl Ammonium Lead Iodide

DOE PAGES

Whitfield, P. S.; Herron, N.; Guise, W. E.; ...

2016-10-21

Here, we examine the crystal structures and structural phase transitions of the deuterated, partially deuterated and hydrogenous organic-inorganic hybrid perovskite methyl ammonium lead iodide (MAPbI 3) using time-of-flight neutron and synchrotron X-ray powder diffraction. Near 330 K the high temperature cubic phases transformed to a body-centered tetragonal phase. The variation of the order parameter Q for this transition scaled with temperature T as Q (T c-T) , where T c is the critical temperature and the exponent was close to , as predicted for a tricritical phase transition. We also observed coexistence of the cubic and tetragonal phases over amore » range of temperature in all cases, demonstrating that the phase transition was in fact first-order, although still very close to tricritical. Upon cooling further, all the tetragonal phases transformed into a low temperature orthorhombic phase around 160 K, again via a first-order phase transition. Finally, based upon these results, we discuss the impact of the structural phase transitions upon photovoltaic performance of MAPbI 3 based solar cells.« less

U(v) in metal uranates: A combined experimental and theoretical study of MgUO 4, CrUO 4, and FeUO 4

DOE PAGES

Guo, Xiaofeng; Tiferet, Eitan; Qi, Liang; ...

2016-01-01

Although pentavalent uranium can exist in aqueous solution, its presence in the solid state is uncommon. Metal monouranates, MgUO 4, CrUO 4 and FeUO 4 were synthesized for detailed structural and energetic investigations. Structural characteristics of these uranates used powder X-ray diffraction, synchrotron X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and 57Fe-Mossbauer spectroscopy. Enthalpies of formation were measured by high temperature oxide melt solution calorimetry. Density functional theory (DFT) calculations provided both structural and energetic information. The measured structural and thermodynamic properties show good consistency with those predicted from DFT. The presence of U 5+ has been solidly confirmed in CrUOmore » 4 and FeUO 4, which are thermodynamically stable compounds, and the origin and stability of U 5+ in the system was elaborated by DFT. Lastly, the structural and thermodynamic behaviour of U 5+ elucidated in this work is relevant to fundamental actinide redox chemistry and to applications in the nuclear industry and radioactive waste disposal.« less

Debye–Waller coefficient of heavily deformed nanocrystalline iron1

PubMed Central

Abdellatief, M.

2017-01-01

Synchrotron radiation X-ray diffraction (XRD) patterns from an extensively ball-milled iron alloy powder were collected at 100, 200 and 300 K. The results were analysed together with those using extended X-ray absorption fine structure, measured on the same sample at liquid nitrogen temperature (77 K) and at room temperature (300 K), to assess the contribution of static disorder to the Debye–Waller coefficient (B iso). Both techniques give an increase of ∼20% with respect to bulk reference iron, a noticeably smaller difference than reported by most of the literature for similar systems. Besides good quality XRD patterns, proper consideration of the temperature diffuse scattering seems to be the key to accurate values of the Debye–Waller coefficient. Molecular dynamics simulations of nanocrystalline iron aggregates, mapped on the evidence provided by XRD in terms of domain size distribution, shed light on the origin of the observed B iso increase. The main contribution to the static disorder is given by the grain boundary, while line and point defects have a much smaller effect. PMID:28381974

Lattice parameters and structural phase transition of lanthanum titanate perovskite, La0.68(Ti0.95,Al0.05)O3.

PubMed

Ali, Roushown; Yashima, Masatomo

2003-05-01

Lattice parameters and the structural phase transition of La(0.68)(Ti(0.95),Al(0.05))O(3) have been investigated in situ in the temperature range 301-689 K by the synchrotron radiation powder diffraction (SR-PD) technique. High-angular-resolution SR-PD is confirmed to be a powerful technique for determining precise lattice parameters around a phase-transition temperature. The title compound exhibits a reversible phase transition between orthorhombic and tetragonal phases at 622.3 +/- 0.6 K. The following results were obtained: (i) the lattice parameters increased continuously with temperature, while the b/a ratio decreased continuously with temperature and became unity at the orthorhombic-tetragonal transition point; (ii) no hysteresis was observed between the lattice-parameter values measured on heating and on cooling. Results (i) and (ii) indicate that the orthorhombic-tetragonal phase transition is continuous and reversible. The b/a ratio is found to exhibit a more continuous temperature evolution than does the order parameter for a typical second-order phase transition based on Landau theory.

A radially accessible tubular in situ X-ray cell for spatially resolved operando scattering and spectroscopic studies of electrochemical energy storage devices

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

Liu, Hao; Allan, Phoebe K.; Borkiewicz, Olaf J.

2016-09-16

A tubularoperandoelectrochemical cell has been developed to allow spatially resolved X-ray scattering and spectroscopic measurements of individual cell components, or regions thereof, during device operation. These measurements are enabled by the tubular cell geometry, wherein the X-ray-transparent tube walls allow radial access for the incident and scattered/transmitted X-ray beam; by probing different depths within the electrode stack, the transformation of different components or regions can be resolved. The cell is compatible with a variety of synchrotron-based scattering, absorption and imaging methodologies. The reliability of the electrochemical cell and the quality of the resulting X-ray scattering and spectroscopic data are demonstratedmore » for two types of energy storage: the evolution of the distribution of the state of charge of an Li-ion battery electrode during cycling is documented using X-ray powder diffraction, and the redistribution of ions between two porous carbon electrodes in an electrochemical double-layer capacitor is documented using X-ray absorption near-edge spectroscopy.« less

Zirconium-Based Metal–Organic Framework for Removal of Perrhenate from Water

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

Banerjee, Debasis; Xu, Wenqian; Nie, Zimin

2016-09-06

Efficient removal of pertechnetate (TcO4-) anions from liquid waste or melter off-gas solution for alternative treatment is one of the promising options to manage 99Tc in legacy nuclear waste. Safe immobilization of 99Tc is of major importance due to its long half-life (t1/2= 2.13 × 105 yrs) and environmental mobility. Different types of inorganic and solid state ion-exchange materials such as layered double hydroxides have been shown to absorb TcO4- anions from water. However, both high capacity and selectivity have yet to be achieved in a single material. Herein, we show that a protonated version of an ultra-stable zirconium basedmore » metal-organic framework can adsorb perrhenate (ReO4-) anions, a non-radioactive sur-rogate for TcO4-, from water even in the presence of other common anions. Synchrotron based powder X-ray diffraction and molecular simulations were used to identify the position of the adsorbed ReO4- (surrogate for TcO4-) molecule within the framework.« less

Experimental and theoretical charge density studies at subatomic resolution.

PubMed

Fischer, A; Tiana, D; Scherer, W; Batke, K; Eickerling, G; Svendsen, H; Bindzus, N; Iversen, B B

2011-11-17

Analysis of accurate experimental and theoretical structure factors of diamond and silicon reveals that the contraction of the core shell due to covalent bond formation causes significant perturbations of the total charge density that cannot be ignored in precise charge density studies. We outline that the nature and origin of core contraction/expansion and core polarization phenomena can be analyzed by experimental studies employing an extended Hansen-Coppens multipolar model. Omission or insufficient treatment of these subatomic charge density phenomena might yield erroneous thermal displacement parameters and high residual densities in multipolar refinements. Our detailed studies therefore suggest that the refinement of contraction/expansion and population parameters of all atomic shells is essential to the precise reconstruction of electron density distributions by a multipolar model. Furthermore, our results imply that also the polarization of the inner shells needs to be adopted, especially in cases where second row or even heavier elements are involved in covalent bonding. These theoretical studies are supported by direct multipolar refinements of X-ray powder diffraction data of diamond obtained from a third-generation synchrotron-radiation source (SPring-8, BL02B2).

Unusual transformation from strong negative to positive thermal expansion in PbTiO3-BiFeO3 perovskite.

PubMed

Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

2013-03-15

Tetragonal PbTiO(3)-BiFeO(3) exhibits a strong negative thermal expansion in the PbTiO(3)-based ferroelectrics that consist of one branch in the family of negative thermal expansion materials. Its strong negative thermal expansion is much weakened, and then unusually transforms into positive thermal expansion as the particle size is slightly reduced. This transformation is a new phenomenon in the negative termal expansion materials. The detailed structure, temperature dependence of unit cell volume, and lattice dynamics of PbTiO(3)-BiFeO(3) samples were studied by means of high-energy synchrotron powder diffraction and Raman spectroscopy. Such unusual transformation from strong negative to positive thermal expansion is highly associated with ferroelectricity weakening. An interesting zero thermal expansion is achieved in a wide temperature range (30-500 °C) by adjusting particle size due to the negative-to-positive transformation character. The present study provides a useful method to control the negative thermal expansion not only for ferroelectrics but also for those functional materials such as magnetics and superconductors.

Debye–Waller coefficient of heavily deformed nanocrystalline iron

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

Scardi, P.; Rebuffi, L.; Abdellatief, M.

2017-02-17

Synchrotron radiation X-ray diffraction (XRD) patterns from an extensively ball-milled iron alloy powder were collected at 100, 200 and 300 K. The results were analysed together with those using extended X-ray absorption fine structure, measured on the same sample at liquid nitrogen temperature (77 K) and at room temperature (300 K), to assess the contribution of static disorder to the Debye–Waller coefficient (B iso). Both techniques give an increase of ~20% with respect to bulk reference iron, a noticeably smaller difference than reported by most of the literature for similar systems. Besides good quality XRD patterns, proper consideration of themore » temperature diffuse scattering seems to be the key to accurate values of the Debye–Waller coefficient. Molecular dynamics simulations of nanocrystalline iron aggregates, mapped on the evidence provided by XRD in terms of domain size distribution, shed light on the origin of the observedB isoincrease. The main contribution to the static disorder is given by the grain boundary, while line and point defects have a much smaller effect.« less

Probing the evolution of palladium species in Pd@MOF catalysts during the Heck coupling reaction: An operando X-ray absorption spectroscopy study.

PubMed

Yuan, Ning; Pascanu, Vlad; Huang, Zhehao; Valiente, Alejandro; Heidenreich, Niclas; Leubner, Sebastian; Inge, A Ken; Gaar, Jakob; Stock, Norbert; Persson, Ingmar; Martin-Matute, Belen; Zou, Xiaodong

2018-06-11

The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance ( 1 H NMR) kinetic studies. A custom-made reaction cell was used allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is pro-posed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl - ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.

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

Asthalter,T.; Sergueev, I.; Van Burck, U.

The low- and high-temperature phases of octamethyl ferrocene were studied in detail, using high-resolution X-ray powder diffraction, differential scanning calorimetry and nuclear resonant scattering, in particular the novel technique of synchrotron radiation perturbed angular correlations (SRPAC). Much as in the case of an analogous but more unsymmetrical molecule, octamethyl ethinyl ferrocene, the high-temperature phase possesses the space group R{bar 3}m source with lattice parameters a = b = 12.5568(1) Angstroms, c = 9.6045(1) Angstroms, which in the rhombohedral setting correspond to a = 7.9251(1) Angstroms, {alpha}=104.79 degrees. An increase of the volume per formula unit of about 12% across themore » phase transition is observed. The rotation of the electric field gradient, which can be identified with the rotation of the entire molecule within the lattice, follows Arrhenius behavior with a high activation energy of (40.3 {+-} 3.3)kJ mol{sup -1}. Whereas precursor effects and a change in activation energy were observed for octamethyl ethinyl ferrocene, no such effects are observed for octamethyl ferrocene. We relate this difference to the absence of the ethinyl substituent in octamethyl ferrocene.« less

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

Antao, S.M.

The crystal structure of a biogenic aragonite from the nacre of an ammonite shell was obtained using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and Rietveld structure refinement. The well-preserved ammonite sample is from Alberta, Canada, and is from the Cretaceous period. The aragonite structure was refined in space group Pmcn, Z = 4, and the cell parameters obtained are a = 4.96265(2), b = 7.97016(4), c = 5.74474(3) {angstrom}, and V = 227.222(2) {angstrom}{sup 3}. The chemical analyses indicate a formula of [Ca{sub 0.995}Sr{sub 0.004}Ba{sub 0.001}]{Sigma} = 1.0(CO{sub 3}). The average and distances are 2.5281(3) and 1.2871(6)more » {angstrom}, respectively, and the average angle is 119.94(8){sup o}. The CO{sub 3} groups are non-planar. Based on crystal-structure data for biogenic and non-biogenic aragonite samples, aragonite from ammonite nacre has minimal structural distortions and is very similar to non-biogenic aragonite, in particular, a sample from Spain.« less

High pressure structure studies of 6H-SrIrO{sub 3} and the octahedral tilting in 3C-SrIrO{sub 3} towards a post-perovskite

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

Kronbo, Camilla H.; Nielsen, Morten B.; Kevy, Simone M.

The high pressure behaviors of the two perovskite structures (hexagonal 6H-SrIrO{sub 3} and orthorhombic 3C-SrIrO{sub 3}) have been studied in diamond anvil cells to 43 and 60 GPa, respectively, using synchrotron powder X-ray diffraction. 6H-SrIrO{sub 3} was first synthesized at ambient pressure and subsequently transformed into 3C-SrIrO{sub 3} in a large volume press at 8.8 GPa and 1000 °C. Both polymorphs were found to retain the initial symmetry up to the highest pressures measured, but in the case of 6H-SrIrO{sub 3}, two anomalies were identified: a change in the axial compressibilities at 24 GPa and a change in both themore » axial and volume compressibilities at 32 GPa. Fitting a 3rd order Birch-Murnaghan equation of state to the obtained P-V data yielded bulk moduli of K{sub 0}=151.5(12) GPa (fitted range 0« less

Roller compaction of different pseudopolymorphic forms of theophylline: Effect on compressibility and tablet properties.

PubMed

Hadzović, Ervina; Betz, Gabriele; Hadzidedić, Seherzada; El-Arini, Silvia Kocova; Leuenberger, Hans

2010-08-30

The effect of roller compaction on disintegration time, dissolution rate and compressibility of tablets prepared from theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate was studied. In addition, the influence of adding microcrystalline cellulose, a commonly used excipient, in mixtures with these materials was investigated. Theophylline anhydrate powder was used as a model drug to investigate the influence of different compaction pressures on the tablet properties. Tablets with same porosity were prepared by direct compaction and by roller compaction/re-compaction. Compressibility was characterized by Heckel and modified Heckel equations. Due to the property of polymorphic materials to change their form during milling and compression, X-ray diffraction analysis of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate powders and granules was carried out. After roller compaction the disintegration time and the dissolution rate of the tablets were significantly improved. Compressibility of theophylline anhydrate powder and theophylline anhydrate fine powder was decreased, while theophylline monohydrate showed higher compressibility after roller compaction. Microcrystalline cellulose affected compressibility of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate whereby the binary mixtures showed higher compressibility than the individual materials. X-ray diffraction analyses confirmed that there were no polymorphic/pseudopolymorphic changes after roller compaction. Copyright 2010 Elsevier B.V. All rights reserved.

Variable Magnification With Kirkpatrick-Baez Optics for Synchrotron X-Ray Microscopy

PubMed Central

Jach, Terrence; Bakulin, Alex S.; Durbin, Stephen M.; Pedulla, Joseph; Macrander, Albert

2006-01-01

We describe the distinction between the operation of a short focal length x-ray microscope forming a real image with a laboratory source (convergent illumination) and with a highly collimated intense beam from a synchrotron light source (Köhler illumination). We demonstrate the distinction with a Kirkpatrick-Baez microscope consisting of short focal length multilayer mirrors operating at an energy of 8 keV. In addition to realizing improvements in the resolution of the optics, the synchrotron radiation microscope is not limited to the usual single magnification at a fixed image plane. Higher magnification images are produced by projection in the limit of geometrical optics with a collimated beam. However, in distinction to the common method of placing the sample behind the optical source of a diverging beam, we describe the situation in which the sample is located in the collimated beam before the optical element. The ultimate limits of this magnification result from diffraction by the specimen and are determined by the sample position relative to the focal point of the optic. We present criteria by which the diffraction is minimized. PMID:27274930

Interpretation of small-angle diffraction experiments on opal-like photonic crystals

NASA Astrophysics Data System (ADS)

Marlow, F.; Muldarisnur, M.; Sharifi, P.; Zabel, H.

2011-08-01

Comprehensive structural information on artificial opals involving the deviations from the strongly dominating face-centered cubic structure is still missing. Recent structure investigations with neutrons and synchrotron sources have shown a high degree of order but also a number of unexpected scattering features. Here, we point out that the exclusion of the allowed 002-type diffraction peaks by a small atomic form factor is not obvious and that surface scattering has to be included as a possible source for the diffraction peaks. Our neutron diffraction data indicate that surface scattering is the main reason for the smallest-angle peaks in the diffraction patterns.

High-energy X-ray powder diffraction and atomic-pair distribution-function studies of charged/discharged structures in carbon-hybridized Li2MnSiO4 nanoparticles as a cathode material for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Moriya, Maki; Miyahara, Masahiko; Hokazono, Mana; Sasaki, Hirokazu; Nemoto, Atsushi; Katayama, Shingo; Akimoto, Yuji; Hirano, Shin-ichi; Ren, Yang

2014-10-01

The stable cycling performance with a high discharge capacity of ∼190 mAh g-1 in a carbon-hybridized Li2MnSiO4 nanostructured powder has prompted an experimental investigation of the charged/discharged structures using synchrotron-based and laboratory-based X-rays and atomic-pair distribution-function (PDF) analyses. A novel method of in-situ spray pyrolysis of a precursor solution with glucose as a carbon source enabled the successful synthesis of the carbon-hybridized Li2MnSiO4 nanoparticles. The XRD patters of the discharged (lithiated) samples exhibit a long-range ordered structure characteristic of the (β) Li2MnSiO4 crystalline phase (space group Pmn21) which dissipates in the charged (delithiated) samples. However, upon discharging the long-range ordered structure recovers in each cycle. The disordered structure, according to the PDF analysis, is mainly due to local distortions of the MnO4 tetrahedra which show a mean Mn-O nearest neighbor distance shorter than that of the long-range ordered phase. These results corroborate the notion of the smaller Mn3+/Mn4+ ionic radii in the Li extracted phase versus the larger Mn2+ ionic radius in Li inserted phase. Thus Li extraction/insertion drives the fluctuation between the disordered and the long-range ordered structures.

In situ TEM and synchrotron characterization of U–10Mo thin specimen annealed at the fast reactor temperature regime

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

Yun, Di, E-mail: diyun1979@xjtu.edu.cn; Xi'an Jiao Tong University, 28 Xian Ning West Road, Xi'an 710049; Mo, Kun

2015-12-15

U–Mo metallic alloys have been extensively used for the Reduced Enrichment for Research and Test Reactors (RERTR) program, which is now known as the Office of Material Management and Minimization under the Conversion Program. This fuel form has also recently been proposed as fast reactor metallic fuels in the recent DOE Ultra-high Burnup Fast Reactor project. In order to better understand the behavior of U–10Mo fuels within the fast reactor temperature regime, a series of annealing and characterization experiments have been performed. Annealing experiments were performed in situ at the Intermediate Voltage Electron Microscope (IVEM-Tandem) facility at Argonne National Laboratorymore » (ANL). An electro-polished U–10Mo alloy fuel specimen was annealed in situ up to 700 °C. At an elevated temperature of about 540 °C, the U–10Mo specimen underwent a relatively slow microstructure transition. Nano-sized grains were observed to emerge near the surface. At the end temperature of 700 °C, the near-surface microstructure had evolved to a nano-crystalline state. In order to clarify the nature of the observed microstructure, Laue diffraction and powder diffraction experiments were carried out at beam line 34-ID of the Advanced Photon Source (APS) at ANL. Phases present in the as-annealed specimen were identified with both Laue diffraction and powder diffraction techniques. The U–10Mo was found to recrystallize due to thermally-induced recrystallization driven by a high density of pre-existing dislocations. A separate in situ annealing experiment was carried out with a Focused Ion Beam processed (FIB) specimen. A similar microstructure transition occurred at a lower temperature of about 460 °C with a much faster transition rate compared to the electro-polished specimen. - Highlights: • TEM annealing experiments were performed in situ at the IVEM facility up to fast reactor temperature. • At 540 °C, the U-10Mo specimen underwent a slow microstructure transition where nano-sized grains were observed to emerge. • UO{sub 2} phase exists at the thin area of the as-annealed specimen whereas U-10Mo γ phase dominated at the thicker part. • Bcc γ U-10Mo recrystallized to become nano-meter sized crystallites near the specimen surface. • A separateannealing experiment was conducted with a FIB processed specimen where similar transition occurred at a lower temperature of 460 °C with a faster rate.« less

Identification of ancient textile fibres from Khirbet Qumran caves using synchrotron radiation microbeam diffraction

NASA Astrophysics Data System (ADS)

Müller, Martin; Murphy, Bridget; Burghammer, Manfred; Riekel, Christian; Roberts, Mark; Papiz, Miroslav; Clarke, David; Gunneweg, Jan; Pantos, Emmanuel

2004-10-01

Archaeological textiles fragments from the caves of Qumran in the Dead Sea region were investigated by means of X-ray microbeam diffraction on single fibres. This non-destructive technique made the identification of the used plant textile fibres possible. Apart from bast fibres (mainly flax), cotton was identified which was most unexpected in the archaeological context.

Development of a synchrotron biaxial tensile device for in situ characterization of thin films mechanical response

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

Geandier, G.; Synchrotron SOLEIL, L'Orme des Merisiers, BP 48, 91192 Gif sur Yvette; LPMTM, UPR 9001 CNRS, Universite Paris-Nord, 93430 Villetaneuse

2010-10-15

We have developed on the DIFFABS-SOLEIL beamline a biaxial tensile machine working in the synchrotron environment for in situ diffraction characterization of thin polycrystalline films mechanical response. The machine has been designed to test compliant substrates coated by the studied films under controlled, applied strain field. Technological challenges comprise the sample design including fixation of the substrate ends, the related generation of a uniform strain field in the studied (central) volume, and the operations from the beamline pilot. Preliminary tests on 150 nm thick W films deposited onto polyimide cruciform substrates are presented. The obtained results for applied strains usingmore » x-ray diffraction and digital image correlation methods clearly show the full potentialities of this new setup.« less

Probing the Li Insertion Mechanism of ZnFe 2O 4 in Li-Ion Batteries: A Combined X-Ray Diffraction, Extended X-Ray Absorption Fine Structure, and Density Functional Theory Study [Probing the Li insertion mechanism of ZnFe 2O 4 in Li ion batteries: A combined XRD, EXAFS, and DFT study

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

Zhang, Yiman; Pelliccione, Christopher J.; Brady, Alexander B.

Here, we report an extensive study on fundamental properties that determine the functional electrochemistry of ZnFe 2O 4 spinel (theoretical capacity of 1000 mAh/g). For the first time, the reduction mechanism is followed through a combination of in situ X-ray diffraction data, synchrotron based powder diffraction, and ex-situ extended X-ray absorption fine structure allowing complete visualization of reduction products irrespective of their crystallinity. The first 0.5 electron equivalents (ee) do not significantly change the starting crystal structure. Subsequent lithiation results in migration of Zn 2+ ions from 8a tetrahedral sites into vacant 16c sites. Density functional theory shows that Limore » + ions insert into 16c site initially and then 8a site with further lithiation. Fe metal is formed over the next eight ee of reduction with no evidence of concurrent Zn 2+ reduction to Zn metal. Despite the expected formation of LiZn alloy from the electron count, we find no evidence for this phase under the tested conditions. Additionally, upon oxidation to 3 V, we observe an FeO phase with no evidence of Fe 2O 3. Electrochemistry data show higher electron equivalent transfer than can be accounted for solely based on ZnFe 2O 4 reduction indicating excess capacity ascribed to carbon reduction or surface electrolyte interphase formation.« less

Probing the Li Insertion Mechanism of ZnFe 2O 4 in Li-Ion Batteries: A Combined X-Ray Diffraction, Extended X-Ray Absorption Fine Structure, and Density Functional Theory Study [Probing the Li insertion mechanism of ZnFe 2O 4 in Li ion batteries: A combined XRD, EXAFS, and DFT study

DOE PAGES

Zhang, Yiman; Pelliccione, Christopher J.; Brady, Alexander B.; ...

2017-04-24

Here, we report an extensive study on fundamental properties that determine the functional electrochemistry of ZnFe 2O 4 spinel (theoretical capacity of 1000 mAh/g). For the first time, the reduction mechanism is followed through a combination of in situ X-ray diffraction data, synchrotron based powder diffraction, and ex-situ extended X-ray absorption fine structure allowing complete visualization of reduction products irrespective of their crystallinity. The first 0.5 electron equivalents (ee) do not significantly change the starting crystal structure. Subsequent lithiation results in migration of Zn 2+ ions from 8a tetrahedral sites into vacant 16c sites. Density functional theory shows that Limore » + ions insert into 16c site initially and then 8a site with further lithiation. Fe metal is formed over the next eight ee of reduction with no evidence of concurrent Zn 2+ reduction to Zn metal. Despite the expected formation of LiZn alloy from the electron count, we find no evidence for this phase under the tested conditions. Additionally, upon oxidation to 3 V, we observe an FeO phase with no evidence of Fe 2O 3. Electrochemistry data show higher electron equivalent transfer than can be accounted for solely based on ZnFe 2O 4 reduction indicating excess capacity ascribed to carbon reduction or surface electrolyte interphase formation.« less

Improvement of the piezoelectric properties in (K,Na)NbO3-based lead-free piezoelectric ceramic with two-phase co-existing state

NASA Astrophysics Data System (ADS)

Yamada, H.; Matsuoka, T.; Kozuka, H.; Yamazaki, M.; Ohbayashi, K.; Ida, T.

2015-06-01

Two phases of (K,Na)NbO3 (KNN) co-exist in a KNN-based composite lead-free piezoelectric ceramic 0.910(K1-xNax)0.86Ca0.04Li0.02Nb0.85O3-δ-0.042K0.85Ti0.85Nb1.15O5-0.036BaZrO3-0.0016Co3O4- 0.0025Fe2O3-0.0069ZnO system, over a wide range of Na fractions, where 0.56 ≤ x ≤ 0.75. The crystal systems of the two KNN phases are identified to tetragonal and orthorhombic by analyzing the synchrotron powder X-ray diffraction (XRD) data, high-resolution transmission electron microscopy (HR-TEM), and selected-area electron diffraction (SAD). In the range 0.33 ≤ x ≤ 0.50, the main component of the composite system is found to be single-phase KNN with a tetragonal structure. Granular nanodomains of the orthorhombic phase dispersed in the tetragonal matrix have been identified by HR-TEM and SAD for 0.56 ≤ x ≤ 0.75. Only a trace amount of the orthorhombic phase has been found in the SAD patterns at the composition x = 0.56. However, the number of orthorhombic nanodomains gradually increases with increasing Na content up to x < 0.75, as observed from the HR-TEM images. An abrupt increase and agglomeration of the nanodomains are observed at x = 0.75, where weak diffraction peaks of the orthorhombic phase have also become detectable from the XRD data. The maximum value of the electromechanical coupling coefficient, kp = 0.56, has been observed at the composition x = 0.56.

Structures of Astromaterials Revealed by EBSD

NASA Technical Reports Server (NTRS)

Zolensky, M.

2018-01-01

Groups at the Johnson Space Center and the University of Tokyo have been using electron back-scattered diffraction (EBSD) to reveal the crystal structures of extraterrestrial minerals for many years. Even though we also routinely use transmission electron microscopy, synchrotron X-ray diffraction (SXRD), and conventional electron diffraction, we find that EBSD is the most powerful technique for crystal structure elucidation in many instances. In this talk I describe a few of the cases where we have found EBSD to provide crucial, unique information. See attachment.

Synthesis and Structural Characterization of the Aluminosilicate LZ-135, a Zeolite Related to ZSM-10

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

McCusker, Lynne B.; Baerlocher, Christian; Wilson, Stephen T.

2009-09-02

The aluminosilicate LZ-135 was one of the first zeolites to be prepared in the presence of two or more organic structure-directing agents (in this case, Me{sub 4}N{sup +} (TMA) and Et{sub 4}N{sup +} (TEA)) and was patented 20 years ago. However, the material was polycrystalline, and at the time, its aluminosilicate framework structure could not be determined. In view of the fact that methods of structure determination from powder diffraction data have developed considerably in the meantime, a fresh analysis of the problem was undertaken. High-resolution synchrotron powder diffraction data were collected on a calcined sample of LZ-135 (as synthesizedmore » composition ca. |Na{sub 26}TMA{sub 6}|[Si{sub 76}Al{sub 32}O{sub 216}]), and the new powder charge-flipping structure-solution algorithm was applied. The framework structure (P6{sub 3}/mmc; a = 31.3830(2) {angstrom}, c = 7.6513(1) {angstrom}) was revealed immediately, and then the positions of the Na{sup +} ions and a few water molecules were located in a series of difference electron density maps. The [001] projection of the framework structure is identical to that of ZSM-10 (P6{sub 3}/mmm), but the (up-down) orientations of the (Si,Al) tetrahedra, and therefore their connectivities, are different, and this leads to a distinctly different topology with two 1-dimensional, 12-ring channel systems with effective pore widths of 7.2 and 6.5 {angstrom}. The new framework has been assigned the framework type code LTF by the International Zeolite Association. The framework structures of LZ-135 and ZSM-10 are related to one another in the same way as are those of mazzite and zeolite L. Approximately 27.5 Na{sup +} ions were located in six different sites, and all are coordinated to oxygen atoms of the framework. Twelve H{sub 2}O molecules per unit cell are associated with one of the Na{sup +} ion positions, where they serve to complete an octahedral coordination geometry around the ion, and 5.2 are located in the larger of the two 12-ring channels, where they make hydrogen-bonding contacts to framework oxygen atoms and are probably associated with protons.« less

A comparative study of the use of powder X-ray diffraction, Raman and near infrared spectroscopy for quantification of binary polymorphic mixtures of piracetam.

PubMed

Croker, Denise M; Hennigan, Michelle C; Maher, Anthony; Hu, Yun; Ryder, Alan G; Hodnett, Benjamin K

2012-04-07

Diffraction and spectroscopic methods were evaluated for quantitative analysis of binary powder mixtures of FII(6.403) and FIII(6.525) piracetam. The two polymorphs of piracetam could be distinguished using powder X-ray diffraction (PXRD), Raman and near-infrared (NIR) spectroscopy. The results demonstrated that Raman and NIR spectroscopy are most suitable for quantitative analysis of this polymorphic mixture. When the spectra are treated with the combination of multiplicative scatter correction (MSC) and second derivative data pretreatments, the partial least squared (PLS) regression model gave a root mean square error of calibration (RMSEC) of 0.94 and 0.99%, respectively. FIII(6.525) demonstrated some preferred orientation in PXRD analysis, making PXRD the least preferred method of quantification. Copyright © 2012 Elsevier B.V. All rights reserved.

Neutron and X-ray powder diffraction study of skutterudite thermoelectrics

DOE PAGES

Wang, H.; Kirkham, M. J.; Watkins, T. R.; ...

2016-02-17

N- and p-type filled-skutterudite materials prepared for thermoelectric power generation modules were analyzed by neutron diffraction at the POWGEN beam line of the Spallation Neutron Source (SNS) and X-ray diffraction (XRD). The skutterudite powders were processed by melt spinning, followed by ball milling and annealing. The n-type material consists of Ba–Yb–Co–Sb and the p-type material consists of Di–Fe–Ni–Sb or Di–Fe–Co–Sb (Di = didymium, an alloy of Pr and Nd). Powders for prototype module fabrication from General Motors and Marlow Industries were analyzed in this study. XRD and neutron diffraction studies confirm that both the n- and p-type materials have cubicmore » symmetry. Structural Rietveld refinements determined the lattice parameters and atomic parameters of the framework and filler atoms. The cage filling fraction was found to depend linearly on the lattice parameter, which in turn depends on the average framework atom size. Ultimately, this knowledge may allow the filling fraction of these skutterudite materials to be purposefully adjusted, thereby tuning the thermoelectric properties.« less

Synthesis of cerium oxide (CeO 2) by co-precipitation for application as a reference material for X-ray powder diffraction peak widths

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

de Lima Batista, Anderson Márcio; Miranda, Marcus Aurélio Ribeiro; Martins, Fátima Itana Chaves Custódio

Several methods can be used to obtain, from powder diffraction patterns, crystallite size and lattice strain of polycrystalline samples. Some examples are the Scherrer equation, Williamson–Hall plots, Warren/Averbach Fourier decomposition, Whole Powder Pattern Modeling, and Debye function analysis. To apply some of these methods, it is necessary to remove the contribution of the instrument to the widths of the diffraction peaks. Nowadays, one of the main samples used for this purpose is the LaB6 SRM660b commercialized by the National Institute of Standard Technology; the width of the diffraction peak of this sample is caused only by the instrumental apparatus. However,more » this sample can be expensive for researchers in developing countries. In this work, the authors present a simple route to obtain micron-sized polycrystalline CeO 2that have a full width at half maximum comparable with the SRM660b and therefore it can be used to remove instrumental broadening.« less

GAPD: a GPU-accelerated atom-based polychromatic diffraction simulation code.

PubMed

E, J C; Wang, L; Chen, S; Zhang, Y Y; Luo, S N

2018-03-01

GAPD, a graphics-processing-unit (GPU)-accelerated atom-based polychromatic diffraction simulation code for direct, kinematics-based, simulations of X-ray/electron diffraction of large-scale atomic systems with mono-/polychromatic beams and arbitrary plane detector geometries, is presented. This code implements GPU parallel computation via both real- and reciprocal-space decompositions. With GAPD, direct simulations are performed of the reciprocal lattice node of ultralarge systems (∼5 billion atoms) and diffraction patterns of single-crystal and polycrystalline configurations with mono- and polychromatic X-ray beams (including synchrotron undulator sources), and validation, benchmark and application cases are presented.

Structure and stability of hydrous minerals at high pressure

NASA Technical Reports Server (NTRS)

Duffy, T. S.; Fei, Y.; Meade, C.; Hemley, R. J.; Mao, H. K.

1994-01-01

The presence of even small amounts of hydrogen in the Earth's deep interior may have profound effects on mantle melting, rheology, and electrical conductivity. The recent discovery of a large class of high-pressure H-bearing silicates further underscores the potentially important role for hydrous minerals in the Earth's mantle. Hydrogen may also be a significant component of the Earth's core, as has been recently documented by studies of iron hydride at high pressure. In this study, we explore the role of H in crystal structures at high pressure through detailed Raman spectroscopic and x ray diffraction studies of hydrous minerals compressed in diamond anvil cells. Brucite, Mg(OH)2, has a simple structure and serves as an analogue for the more complex hydrous silicates. Over the past five years, this material has been studied at high pressure using shock-compression, powder x ray diffraction, infrared spectroscopy, Raman spectroscopy, and neutron diffraction. In addition, we have recently carried out single-crystal synchrotron x-ray diffraction on Mg(OH)2 and Raman spectroscopy on Mg(OD)2 at elevated pressure. From all these studies, an interesting picture of the crystal chemical behavior of this material at high pressure is beginning to emerge. Some of the primary conclusions are as follows: First, hydrogen bonding is enhanced by the application of pressure. Second, layered minerals which are elastically anisotropic at low pressure may not be so at high pressure. Furthermore, the brucite data place constraints on the effect of hydrogen on seismic velocities and density at very high pressure. Third, the stability of hydrous minerals may be enhanced at high P by subtle structural rearrangements that are difficult to detect using traditional probes and require detailed spectroscopic analyses. Finally, brucite appears to be unique in that it undergoes pressure-induced disordering that is confined solely to the H-containing layers of the structure.

Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics.

PubMed

Canestrari, Niccolo; Chubar, Oleg; Reininger, Ruben

2014-09-01

X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick-Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in the Synchrotron Radiation Workshop (SRW) computer code and extensively tested against the geometrical ray-tracing code SHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between the SRW and SHADOW simulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

Addressing the amorphous content issue in quantitative phase analysis : the certification of NIST SRM 676a.

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

Cline, J. P.; Von Dreele, R. B.; Winburn, R.

2011-07-01

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum ({alpha}-Al{sub 2}O{sub 3}) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Undermore » the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% {+-} 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.« less

Addressing the Amorphous Content Issue in Quantitative Phase Analysis: The Certification of NIST Standard Reference Material 676a

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

J Cline; R Von Dreele; R Winburn

2011-12-31

A non-diffracting surface layer exists at any boundary of a crystal and can comprise a mass fraction of several percent in a finely divided solid. This has led to the long-standing issue of amorphous content in standards for quantitative phase analysis (QPA). NIST standard reference material (SRM) 676a is a corundum ({alpha}-Al{sub 2}O{sub 3}) powder, certified with respect to phase purity for use as an internal standard in powder diffraction QPA. The amorphous content of SRM 676a is determined by comparing diffraction data from mixtures with samples of silicon powders that were engineered to vary their specific surface area. Undermore » the (supported) assumption that the thickness of an amorphous surface layer on Si was invariant, this provided a method to control the crystalline/amorphous ratio of the silicon components of 50/50 weight mixtures of SRM 676a with silicon. Powder diffraction experiments utilizing neutron time-of-flight and 25 keV and 67 keV X-ray energies quantified the crystalline phase fractions from a series of specimens. Results from Rietveld analyses, which included a model for extinction effects in the silicon, of these data were extrapolated to the limit of zero amorphous content of the Si powder. The certified phase purity of SRM 676a is 99.02% {+-} 1.11% (95% confidence interval). This novel certification method permits quantification of amorphous content for any sample of interest, by spiking with SRM 676a.« less

Synchrotron X-ray studies of model SOFC cathodes, part II: Porous powder cathodes

DOE PAGES

Chang, Kee-Chul; Ingram, Brian; Ilavsky, Jan; ...

2017-10-28

Infiltrated La 0.6Sr 0.4Co 0.2Fe 0.8O 3-δ (LSCF) sintered porous powder cathodes for solid oxide fuel cells have been investigated by synchrotron ultra-small angle x-ray scattering (USAXS). Here, we demonstrated that atomic layer deposition (ALD) is the method for a uniform coating and liquid-phase infiltration for growing nanoscale particles on the porous LSCF surfaces. The MnO infiltrate, grown by ALD, forms a conformal layer with a uniform thickness throughout the pores evidenced by USAXS thickness fringes. The La 0.6Sr 0.4CoO 3 (LSC) and La 2Zr 2O 7 (LZO) infiltrates, grown by liquid-phase infiltration, were found to form nanoscale particles onmore » the surfaces of LSCF particles resulting in increased surface areas. In conclusion, impedance measurements suggest that the catalytic property of LSC infiltrate, not the increased surface area of LZO, is important for increasing oxygen reduction activities.« less

Synchrotron X-ray studies of model SOFC cathodes, part II: Porous powder cathodes

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

Chang, Kee-Chul; Ingram, Brian; Ilavsky, Jan

Infiltrated La 0.6Sr 0.4Co 0.2Fe 0.8O 3-δ (LSCF) sintered porous powder cathodes for solid oxide fuel cells have been investigated by synchrotron ultra-small angle x-ray scattering (USAXS). Here, we demonstrated that atomic layer deposition (ALD) is the method for a uniform coating and liquid-phase infiltration for growing nanoscale particles on the porous LSCF surfaces. The MnO infiltrate, grown by ALD, forms a conformal layer with a uniform thickness throughout the pores evidenced by USAXS thickness fringes. The La 0.6Sr 0.4CoO 3 (LSC) and La 2Zr 2O 7 (LZO) infiltrates, grown by liquid-phase infiltration, were found to form nanoscale particles onmore » the surfaces of LSCF particles resulting in increased surface areas. In conclusion, impedance measurements suggest that the catalytic property of LSC infiltrate, not the increased surface area of LZO, is important for increasing oxygen reduction activities.« less

Effects of water on P-V-T equation of state of pyrope

NASA Astrophysics Data System (ADS)

Fan, Dawei; Lu, Chang; Xu, Jingui; Yan, Bingmin; Yang, Bin; Chen, Jiuhua

2017-06-01

High-pressure single-crystal/powder synchrotron X-ray diffraction was carried out on a hydrous pure magnesium pyrope (Mg3Al2Si3O12) containing 900 ppmw H2O, synthesized at 4.0 GPa and 1300 K. The pressure-volume (P-V) single-crystal data from room pressure to 9.81 GPa at ambient temperature were fitted by a third-order Birch-Murnaghan equation of state (BM-EoS) yielding a unit-cell volume of V0 = 1505.14 ± 0.38 Å3, an isothermal bulk modulus of K0 = 160 ± 3 GPa and its pressure derivative K‧0 = 5.2 ± 0.4. When fixing K'0 = 4.0, the data yielded V0 = 1504.58 ± 0.32 Å3 and K0 = 166 ± 2 GPa. The pressure-volume-temperature (P-V-T) EoS of the synthetic hydrous pyrope was also measured at temperatures up to 900 K and pressures up to 16.75 GPa, using a diamond anvil cell in conjunction with in situ synchrotron angle-dispersive powder X-ray diffraction. The P-V data at room temperature and in a pressure range of 0.0001-14.81 GPa were then analyzed by a third-order BM-EoS and yielded V0 = 1505.35 ± 0.25 Å3, K0 = 161 ± 2 GPa, K‧0 = 5.0 ± 0.3. With K'0 fixed to 4.0, we also obtained V0 = 1505.04 ± 0.29 Å3 and K0 = 167 ± 1 GPa. Consequently, we fitted the P-V-T data with the high-temperature third-order BM-EoS approach and obtained the thermoelastic parameters of V0 = 1505.4 ± 0.3 Å3, K0 = 162 ± 1 GPa, K‧0 = 4.9 ± 0.2, the temperature derivative of the bulk modulus (∂K0/∂T)P = -0.018 ± 0.004 GPa K-1, and the thermal expansion coefficient at ambient conditions α0 = (3.2 ± 0.1) × 10-5 K-1. These properties were consistent with the thermal pressure EoS analysis. These new results on hydrous pyrope were also compared with previous studies of anhydrous pyrope. The main effect of hydration on pyrope is to decrease K0 and increase K'0 by increasing the vacancies or unoccupied volume in the structure. The entire dataset enabled us to examine the thermoelastic properties of important mantle garnets and this data has further applications for modeling the P-T conditions in the upper mantle of the Earth's interior using deep mineral assemblages.

Structural Chemistry of Functional Nano-Materials for Environmental Remediation

NASA Astrophysics Data System (ADS)

John, Jesse

Nano minerals and materials have become a focal point of Geoscience research due to the unique physical, chemical, optical, magnetic, electronic, and reactive properties. Many of these desired properties in Nano technology have the potential to impact society by improving remediation, photovoltaics, medicine and the sustainability limits on Earth for an expanding population. Despite the progress made on the discovery, synthesis, and manufacturing of numerous nano-materials, the atomistic cause of their desired properties is poorly understood. To gain a better understanding of the atomic structure of nano materials and their bulk counterparts we combined several crystallographic techniques to solve the crystal structure and performed formative characterization to ascertain the atomistic source of the desired application. These strategies and tools can be used to expedite discovery, development and the goals of the National Nanotechnology Initiative (NNI). This thesis will cover the optimization of the reaction conditions and resolve the atomic structure to produce pure synthetic nano nolanite (SNN) Fe2V3O7OH. The complete structural model of nolanite was described from a bulk mineral to the nano-regime using a combination of single crystal X-ray diffraction (SC-XRD), pair distribution function analysis (PDF) and neutron powder diffraction from synthetic material. Nolanite is isostructural to ferrihydrite, a ubiquitous nano-mineral, both of these mineral structures have been the subject for debate for the last half of century. A comparative study of the isostructural minerals nolanite, akdalaite and ferrihydrite was utilized to address the discrepancies and consolidate the structural models. Lastly, we developed a structural model for nano-crystalline titanium-based material; mono sodium titanate (MST) using high energy total X-ray scattering and PDF coupled with scanning transmission electron microscope (STEM). In the USA we have accumulated over 76000 metric tons of nuclear waste and the nuclear industry continues to generate an additional 2000 tons every year. MST is the baseline material used for to effectively remove 90Sr and alpha-emitting actinides from strongly alkaline, high-level nuclear waste solutions at the Savannah River site. Despite the success of MST in the remediation of high-level radioactive waste (HLW) the process by which the metals are structurally incorporated is still poorly understood, and there is still no structural model. This study aims to better understand the ion exchange mechanism of MST by generating a structural model derived from synchrotron X-ray powder diffraction data.

Chemical applications of synchrotron radiation: Workshop report

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

Not Available

1989-04-01

The most recent in a series of topical meetings for Advanced Photon Source user subgroups, the Workshop on Chemical Applications of Synchrotron Radiation (held at Argonne National Laboratory, October 3-4, 1988) dealt with surfaces and kinetics, spectroscopy, small-angle scattering, diffraction, and topography and imaging. The primary objectives were to provide an educational resource for the chemistry community on the scientific research being conducted at existing synchrotron sources and to indicate some of the unique opportunities that will be made available with the Advanced Photon Source. The workshop organizers were also interested in gauging the interest of chemists in the fieldmore » of synchrotron radiation. Interest expressed at the meeting has led to initial steps toward formation of a Chemistry Users Group at the APS. Individual projects are processed separately for the data bases.« less

Additional evidence from x-ray powder diffraction patterns that icosahedral quasi-crystals of intermetallic compounds are twinned cubic crystals

PubMed Central

Pauling, Linus

1988-01-01

Analysis of the measured values of Q for the weak peaks (small maxima, usually considered to be background fluctuations, “noise”) on the x-ray powder diffraction curves for 17 rapidly quenched alloys leads directly to the conclusion that they are formed by an 820-atom or 1012-atom primitive cubic structure that by icosahedral twinning produces the so-called icosahedral quasi-crystals. PMID:16593948

Test and Delivery of the Chemin Mineralogical Instrument for Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Blake, D. F.; Vaniman, D.; Anderson, R.; Bish, D.; Chipera, S.; Chemtob, S.; Crisp, J.; DesMarais, D. J.; Downs, R.; Feldman, S.;

X-ray tomography of powder injection moulded micro parts using synchrotron radiation

NASA Astrophysics Data System (ADS)

Heldele, R.; Rath, S.; Merz, L.; Butzbach, R.; Hagelstein, M.; Haußelt, J.

2006-05-01

Powder injection moulding is one of the most promising replication methods for the mass production of metal and ceramic micro parts. The material for injection moulding, a so-called feedstock, consists of thermoplastic binder components and inorganic filler with approximately equal volume fractions. Injection moulding of the feedstock leads to a green part that can be processed to a dense metal or ceramic micro part by debinding and sintering. During the injection moulding process extremely high shear rates are applied. This promotes the separation of powder and binder leading to a particle density variation in the green part causing anisotropic shrinkage during post-processing. The knowledge of introducing density gradients and defects would consequently allow the optimization of the feedstock, the moulding parameters and the validation of a simulation tool based on the Dissipative Particle Dynamics which is currently under development, as well. To determine the particle density and defect distribution in micro parts synchrotron radiation tomography in absorption mode was used. Due to its parallel and monochromatic character a quantitative reconstruction, free of beam hardening artifacts, is possible. For the measurement, bending bars consisting of dispersed fused silica particles in a polymeric matrix were used. The presented results using this set-up show that crucial defects and density variations can be detected.

Streaking images that appear only in the plane of diffraction in undoped GaAs single crystals: Diffraction imaging (topography) by monochromatic synchrotron radiation

NASA Technical Reports Server (NTRS)

Kuriyama, Masao; Steiner, Bruce; Dobbyn, Ronald C.; Laor, Uri; Larson, David; Brown, Margaret

1988-01-01

Streaking images restricted to the direction of the diffraction (scattering) vector have been observed on transmission through undoped GaAs. These disruption images (caused by the reduction of diffraction in the direction of observation) appear both in the forward and in Bragg diffracted directions in monochromatic synchrontron radiation diffraction imaging. This previously unobserved phenomenon can be explained in terms of planar defects (interfaces) or platelets which affects the absorption coefficient in anomalous transmission. Such regions of the crystal look perfect despite the presence of imperfections when the scattering vector is not perpendicular to the normal of the platelets. The observed crystallographic orientation of these interfaces strongly indicates that they are antiphase boundaries.

High-pressure Irreversible Amorphization of La1/3NbO3

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

I Halevy; A Hen; A Broide

2011-12-31

The crystallographic structure of La{sub 1/3}NbO{sub 3} perovskite was studied at high pressures using a diamond-anvil cell and synchrotron radiation. High-pressure energy dispersive (EDS) x-ray diffraction and high-pressure angle dispersive (ADS) x-ray diffraction revealed an irreversible amorphization at {approx}10 GPa. A large change in the bulk modulus accompanied the high-pressure amorphization.

Symposium LL: Nanowires--Synthesis Properties Assembly and Application

DTIC Science & Technology

2010-09-10

dedicated hard x - ray microscopy beamline is operated in partnership with the Advanced Photon Source to provide fluorescence, diffraction, and...characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X - ray diffraction (XRD) measurements, proving it to be...Investigation of Preferred Growth Direction of GaN Nanorods by Synchrotron X - ray Reciprocal Space Mapping. Yuri Sohn1, Sanghwa Lee1, Chinkyo Kim1 and Dong

In Situ Assessment of Lattice in an Al-Li Alloy

NASA Technical Reports Server (NTRS)

Beaudoin, A. J.; Obstalecki, M.; Tayon, W.; Hernquist, M.; Mudrock, R.; Kenesei, P.; Lienert, U.

2013-01-01

The lattice strains of individual grains are measured in an Al-Li alloy, AA 2195, using high-energy X-ray diffraction at a synchrotron source. The diffraction of individual grains in this highly textured production alloy was isolated through use of a depth-defining aperture. It is shown that hydrostatic stress, and in turn the stress triaxiality, can vary significantly from grain to grain.

Clifford G. Shull, Neutron Diffraction, Hydrogen Atoms, and Neutron

Science.gov Websites

Analysis of NaH and NaD, DOE Technical Report, April 1947 The Diffraction of Neutrons by Crystalline Powders; DOE Technical Report; 1948 Neutron Diffraction Studies, DOE Technical Report, 1948 Laue Structure of Thorium and Zirconium Dihydrides by X-ray and Neutron Diffraction, DOE Technical Report, April

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.

Synthesis of nano-forsterite powder by making use of natural silica sand

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

Nurbaiti, Upik, E-mail: upik-nurbaiti@mail.unnes.ac.id; Department of Physics, Faculty of Mathematics and Natural Sciences Semarang State University Jl. Raya Sekaran GunungPati, Semarang 50221; Suud, Fikriyatul Azizah

2016-02-08

Nano-forsterite powder with natural silica sand and magnesium powder as the raw materials have been succesfully synthesized. The silica sand was purified followed by a coprecipitation process to obtain colloidal silica. The magnesium powder was dissolved in a chloric acid solution to obtain MgCl{sub 2} solution. The nanoforsterite powder was synthesised using a sol-gel method which included the mixing the colloidal silica and the MgCl{sub 2} solution with various aging and filtering processes. The samples were dried at 100 °C using a hot plate and then the dried powders were calcinated at 900 °C for 2 hours. The samples weremore » characetised for their elements and phase compositions using X-ray Flourescence (XRF) and X-ray Diffraction (XRD) methods, respectively. The diffraction data were qualitatively analyzed using Match!2 software and quantitatively using Rietica software. The crystallite size was verified using Transmission Electron Microscopy (TEM). Results of XRD data analysis showed that the forsterite content reached up to 90.5% wt. The TEM average crystallite size was approximately 53(6) nm.« less

Electrochemical reactions in fluoride-ion batteries: mechanistic insights from pair distribution function analysis

DOE PAGES

Grenier, Antonin; Porras-Gutierrez, Ana-Gabriela; Groult, Henri; ...

2017-07-05

Detailed analysis of electrochemical reactions occurring in rechargeable Fluoride-Ion Batteries (FIBs) is provided by means of synchrotron X-ray diffraction (XRD) and Pair Distribution Function (PDF) analysis.

Local lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys investigated by synchrotron X-ray diffraction

DOE PAGES

Tong, Yang; Jin, Ke; Bei, Hongbin; ...

2018-05-26

Severe lattice distortion is presumptively considered as a core effect of high-entropy alloys, but quantitative measurements are still missing. Here, we demonstrate that the lattice distortion in high-entropy alloys can be quantitatively analyzed based on pair distribution function obtained from synchrotron X-ray diffraction. By applying this method to equiatomic NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys, we found that the local lattice distortion in the NiCoCr (0.23%) and FeCoNiCrMn (0.24%) alloys are comparable while negligible in the FeCoNiCr alloy (0.04%). Furthermore, the origin of local lattice distortion in the NiCoCr and FeCoNiCrMn concentrated alloys was discussed.

Local lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys investigated by synchrotron X-ray diffraction

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

Tong, Yang; Jin, Ke; Bei, Hongbin

Severe lattice distortion is presumptively considered as a core effect of high-entropy alloys, but quantitative measurements are still missing. Here, we demonstrate that the lattice distortion in high-entropy alloys can be quantitatively analyzed based on pair distribution function obtained from synchrotron X-ray diffraction. By applying this method to equiatomic NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys, we found that the local lattice distortion in the NiCoCr (0.23%) and FeCoNiCrMn (0.24%) alloys are comparable while negligible in the FeCoNiCr alloy (0.04%). Furthermore, the origin of local lattice distortion in the NiCoCr and FeCoNiCrMn concentrated alloys was discussed.

Phase formation and strain relaxation of Ga2O3 on c-plane and a-plane sapphire substrates as studied by synchrotron-based x-ray diffraction

NASA Astrophysics Data System (ADS)

Cheng, Zongzhe; Hanke, Michael; Vogt, Patrick; Bierwagen, Oliver; Trampert, Achim

2017-10-01

Heteroepitaxial Ga2O3 was deposited on c-plane and a-plane oriented sapphire by plasma-assisted molecular beam epitaxy and probed by ex-situ and in-situ synchrotron-based x-ray diffraction. The investigation on c-plane sapphire determined a critical thickness of around 33 Å, at which the monoclinic β-phase forms on top of the hexagonal α-phase. A 143 Å thick single phase α-Ga2O3 was observed on a-plane sapphire, much thicker than the α-Ga2O3 on c-plane sapphire. The α-Ga2O3 relaxed very fast in the first 30 Å in both out-of-plane and in-plane directions as measured by the in-situ study.

Structural and conformational properties of 1-decyl-3-methylimidazolium tetrafluoroborate under high pressure

NASA Astrophysics Data System (ADS)

Chen, Liucheng; Li, Haining; Zhu, Xiang; Su, Lei; Yang, Kun; Yuan, Chaosheng; Yang, Guoqiang; Li, Xiaodong

2017-06-01

In situ crystalization of 1-decyl-3-methylimidazolium tetrafluoroborate ([C10MIM][BF4]) from melt has been investigated under high pressure up to 3.4 GPa at room temperature by using Raman spectroscopy and synchrotron X-ray diffraction measurement. Raman spectral analysis indicated that [C10MIM][BF4] experienced two successive phase transitions at about 0.3 GPa and 1.6 GPa. And the polymorphism was also discussed in view of the conformational isomerism of [C10MIM]+ cation between gauche and trans conformers. Notably, liquid-crystal and crystal-crystal phase transitions were further confirmed by synchrotron X-ray diffraction measurement. Moreover, it also indicated that high structural flexibility of the cations with long alkyl chain might have effect on the degree of disorder of pressure-induced crystallization for ionic liquids.

New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team

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

Meng, Yue; Hrubiak, Rostislav; Rod, Eric

An overview of the in situ laser heating system at the High Pressure Collaborative Access Team, with emphasis on newly developed capabilities, is presented. Since its establishment at the beamline 16-ID-B a decade ago, laser-heated diamond anvil cell coupled with in situ synchrotron x-ray diffraction has been widely used for studying the structural properties of materials under simultaneous high pressure and high temperature conditions. Recent developments in both continuous-wave and modulated heating techniques have been focusing on resolving technical issues of the most challenging research areas. Furthermore, the new capabilities have demonstrated clear benefits and provide new opportunities in researchmore » areas including high-pressure melting, pressure-temperature-volume equations of state, chemical reaction, and time resolved studies.« less

New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team

DOE PAGES

Meng, Yue; Hrubiak, Rostislav; Rod, Eric; ...

2015-07-17

An overview of the in situ laser heating system at the High Pressure Collaborative Access Team, with emphasis on newly developed capabilities, is presented. Since its establishment at the beamline 16-ID-B a decade ago, laser-heated diamond anvil cell coupled with in situ synchrotron x-ray diffraction has been widely used for studying the structural properties of materials under simultaneous high pressure and high temperature conditions. Recent developments in both continuous-wave and modulated heating techniques have been focusing on resolving technical issues of the most challenging research areas. Furthermore, the new capabilities have demonstrated clear benefits and provide new opportunities in researchmore » areas including high-pressure melting, pressure-temperature-volume equations of state, chemical reaction, and time resolved studies.« less

New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team

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

Meng, Yue; Hrubiak, Rostislav; Rod, Eric

An overview of the in situ laser heating system at the High Pressure Collaborative Access Team, with emphasis on newly developed capabilities, is presented. Since its establishment at the beamline 16-ID-B a decade ago, laser-heated diamond anvil cell coupled with in situ synchrotron x-ray diffraction has been widely used for studying the structural properties of materials under simultaneous high pressure and high temperature conditions. Recent developments in both continuous-wave and modulated heating techniques have been focusing on resolving technical issues of the most challenging research areas. The new capabilities have demonstrated clear benefits and provide new opportunities in research areasmore » including high-pressure melting, pressure-temperature-volume equations of state, chemical reaction, and time resolved studies.« less

3D Experimental Measurement of Lattice Strain and Fracture Behavior of Sand Particles Using Synchrotron X-Ray Diffraction and Tomography

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

Cil, Mehmet B.; Alshibli, Khalid A.; Kenesei, Peter

3D synchrotron X-ray diffraction (3DXRD) and synchrotron micro-computed tomography (SMT) techniques were used to measure and monitor the lattice strain evolution and fracture behavior of natural Ottawa sand particles subjected to 1D compression loading. The particle-averaged lattice strain within sand particles was measured using 3DXRD and then was used to calculate the corresponding lattice stress tensor. In addition, the evolution and mode of fracture of sand particles was investigated using high-resolution 3D SMT images. The results of diffraction data analyses revealed that the major principal component of the lattice strain or stress tensor increased in most of the particles asmore » the global applied compressive load increased until the onset of fracture. Particle fracture and subsequent rearrangements caused significant variation and fluctuations in measured lattice strain/stress values from one particle to another and from one load step to the next one. SMT image analysis at the particle-scale showed that cracks in fractured sand particles generally initiate and propagate along the plane that connects the two contact points. Fractured particles initially split into two or three major fragments followed by disintegration into multiple smaller fragments in some cases. In conclusion, microscale analysis of fractured particles showed that particle position, morphology, the number and location of contact points play a major role in the occurrence of particle fracture in confined comminution of the sand assembly.« less

3D Experimental Measurement of Lattice Strain and Fracture Behavior of Sand Particles Using Synchrotron X-Ray Diffraction and Tomography

DOE PAGES

Cil, Mehmet B.; Alshibli, Khalid A.; Kenesei, Peter

2017-05-27

3D synchrotron X-ray diffraction (3DXRD) and synchrotron micro-computed tomography (SMT) techniques were used to measure and monitor the lattice strain evolution and fracture behavior of natural Ottawa sand particles subjected to 1D compression loading. The particle-averaged lattice strain within sand particles was measured using 3DXRD and then was used to calculate the corresponding lattice stress tensor. In addition, the evolution and mode of fracture of sand particles was investigated using high-resolution 3D SMT images. The results of diffraction data analyses revealed that the major principal component of the lattice strain or stress tensor increased in most of the particles asmore » the global applied compressive load increased until the onset of fracture. Particle fracture and subsequent rearrangements caused significant variation and fluctuations in measured lattice strain/stress values from one particle to another and from one load step to the next one. SMT image analysis at the particle-scale showed that cracks in fractured sand particles generally initiate and propagate along the plane that connects the two contact points. Fractured particles initially split into two or three major fragments followed by disintegration into multiple smaller fragments in some cases. In conclusion, microscale analysis of fractured particles showed that particle position, morphology, the number and location of contact points play a major role in the occurrence of particle fracture in confined comminution of the sand assembly.« less

Capture and X-ray diffraction studies of protein microcrystals in a microfluidic trap array

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

Lyubimov, Artem Y.; Stanford University, Stanford, CA 94305; Stanford University, Stanford, CA 94305

A microfluidic platform has been developed for the capture and X-ray analysis of protein microcrystals, affording a means to improve the efficiency of XFEL and synchrotron experiments. X-ray free-electron lasers (XFELs) promise to enable the collection of interpretable diffraction data from samples that are refractory to data collection at synchrotron sources. At present, however, more efficient sample-delivery methods that minimize the consumption of microcrystalline material are needed to allow the application of XFEL sources to a wide range of challenging structural targets of biological importance. Here, a microfluidic chip is presented in which microcrystals can be captured at fixed, addressablemore » points in a trap array from a small volume (<10 µl) of a pre-existing slurry grown off-chip. The device can be mounted on a standard goniostat for conducting diffraction experiments at room temperature without the need for flash-cooling. Proof-of-principle tests with a model system (hen egg-white lysozyme) demonstrated the high efficiency of the microfluidic approach for crystal harvesting, permitting the collection of sufficient data from only 265 single-crystal still images to permit determination and refinement of the structure of the protein. This work shows that microfluidic capture devices can be readily used to facilitate data collection from protein microcrystals grown in traditional laboratory formats, enabling analysis when cryopreservation is problematic or when only small numbers of crystals are available. Such microfluidic capture devices may also be useful for data collection at synchrotron sources.« less

GeoSoilEnviroCARS: A National User Facility for Synchrotron Radiation Research

NASA Astrophysics Data System (ADS)

Rivers, M. L.; Sutton, S. R.

2002-12-01

GeoSoilEnviroCARS (GSECARS) is a national user facility for frontier research in the earth sciences using synchrotron radiation at the Advanced Photon Source, Argonne National Laboratory. GSECARS provides earth scientists with access to the high-brilliance hard x-rays from this third-generation synchrotron light source. Both an undulator and a bending magnet beamline are available. All principal synchrotron-based analytical techniques in demand by earth scientists are being brought to bear on earth science problems: (1) high-pressure/high-temperature crystallography and spectroscopy using the diamond anvil cell; (2) high-pressure/high-temperature crystallography using the large-volume press; (3) powder, single crystal and interface diffraction; (4) inelastic x-ray scattering; (5) x-ray absorption fine structure (XAFS) spectroscopy; (6) x-ray fluorescence microprobe analysis; and (7) microtomography. The major instrumentation includes 250 and 1000 MN multianvil presses, a double-sided laser heating system, a large general-purpose 5-circle diffractometer, a focused microprobe, and a Raman laboratory. A proposal-based system for beamtime allocation, open to all earth scientists, has been in place since Fall, 1998. Since then, over 450 beamtime proposals have been received and more than 320 outside users have conducted experiments at GSECARS. The research conducted by these investigators has resulted in more than 170 publications. The unique capabilities of the APS and GSECARS have allowed groundbreaking experiments to be conducted. These include: (1) phase transformations in the Mg-Si-O system at mantle conditions; (2) structure of hydrated a-Al2O3 surfaces; (3) alloying properties of silicon in the Earth's core; (4) dynamics of iron-rich melt segregation from silicates during core formation; (5) electronic spin state of FeO at high pressure and temperature; (6) elastic wave velocities of mantle minerals at lower mantle conditions; (7) copper partitioning and speciation in natural hydrothermal fluids; and (8) mechanisms of arsenic sequestration at a Superfund site. The GSECARS mission is to provide a research environment where users receive expert assistance in planning and conducting experiments, and in analyzing data. The facility operation is funded by the NSF EAR Instrumentation and Facilities program and the DOE Geosciences program. Major instrumentation was also provided by the W.M. Keck Foundation. Information and applications for beam time can be found at http://gsecars.org.

Magnetic x-ray scattering studies of holmium using synchro- tron radiation

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

Gibbs, D.; Moncton, D.E.; D'Amico, K.L.

1985-07-08

We present the results of magnetic x-ray scattering experiments on the rare-earth metal holmium using synchrotron radiation. Direct high-resolution measurements of the nominally incommensurate magnetic satellite reflections reveal new lock-in behavior which we explain within a simple spin-discommensuration model. As a result of magnetoelastic coupling, the spin-discommensuration array produces additional x-ray diffraction satellites. Their observation further substantiates the model and demonstrates additional advantages of synchrotron radiation for magnetic-structure studies.

rac-6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxamide from synchrotron data

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

Brzezinski, Krzysztof; Dauter, Zbigniew; Baj, Aneta

2012-05-29

The crystal structure of the title water-soluble analogue of vitamin E, trolox amide, C{sub 14}H{sub 19}NO{sub 3}, solved and refined against synchrotron diffraction data, contains two molecules in the asymmetric unit. In both molecules, the heterocyclic ring is in a half-chair conformation. The crystal packing features a herring-bone pattern generated by N-H...O hydrogen bonds between the hydroxy and amide groups. O-H...O hydrogen bonds also occur.

Effects of Peripheral Architecture on the Properties of Aryl Polyhedral Oligomeric Silsesquioxanes

DTIC Science & Technology

2012-07-26

POSS) molecules are described. These POSS materials were synthesized in our laboratory and characterized by single-crystal and powder X - ray diffraction ...powder X - ray diffraction (XRD), where applicable. 1H, 13C, and 29Si NMR spectra were obtained on Bruker 300 and 400 MHz spectrometers using 5 mm o.d...degree of cage ordering during precipitation. Referring back to Figure 14, strong X - ray scattering peaks in the spectra for 1 in the d- spacing range

Insertion of Guest Molecules into a Mixed Ligand Metal-Organic Framework via Single-Crystal-to-Single Crystal Guest Exchange

DTIC Science & Technology

2014-07-01

powder x-ray diffraction (PXRD), thermogravimentric analysis (TGA), and Fourier transform infrared (FTIR). 15. SUBJECT TERMS Metal organic frame work...the inclusion by using a variety of analytical techniques, such as powder x-ray diffraction (PXRD), thermo-gravimetric analysis (TGA), Fourier...Characterizations Analysis of the MOF and the complexes with the MOF and the guest molecules was performed using an Agilent GC-MS (Model 6890N GC and Model 5973N

Understanding Inhomogeneous Reactions in Li‐Ion Batteries: Operando Synchrotron X‐Ray Diffraction on Two‐Layer Electrodes

PubMed Central

Villevieille, Claire; Takeuchi, Yoji

2015-01-01

To understand inhomogeneous reactions perpendicular to the current collector in an electrode for batteries, a method combining operando synchrotron X‐ray diffraction and two‐layer electrodes with different porosities is developed. The two layers are built using two different active materials (LiNi0.80Co0.15Al0.05O2 and LiMn2O4), therefore, tracing each diffraction pattern reveals which active material is reacting during the electrochemical measurement in transmission mode. The results demonstrate that the active material close to the separator is obviously more active than that one close to the current collector in the case of low porosity electrodes. This inhomogeneity should be due to the rate‐limitation and especially to low average ionic conductivity of the electrolyte in the porous electrode because the current flows first mainly into the electrode regions close to the separator. The inhomogeneity is found to be mitigated by the adjustment of the electrode density and thus porosity. Hence, the novel operando method reveals a clear inhomogeneous reaction perpendicular to the current collector. PMID:27708998

Structural changes induced by lattice-electron interactions: SiO2 stishovite and FeTiO3 ilmenite.

PubMed

Yamanaka, Takamitsu

2005-09-01

The bright source and highly collimated beam of synchrotron radiation offers many advantages for single-crystal structure analysis under non-ambient conditions. The structure changes induced by the lattice-electron interaction under high pressure have been investigated using a diamond anvil pressure cell. The pressure dependence of electron density distributions around atoms is elucidated by a single-crystal diffraction study using deformation electron density analysis and the maximum entropy method. In order to understand the bonding electrons under pressure, diffraction intensity measurements of FeTiO3 ilmenite and gamma-SiO2 stishovite single crystals at high pressures were made using synchrotron radiation. Both diffraction studies describe the electron density distribution including bonding electrons and provide the effective charge of the cations. In both cases the valence electrons are more localized around the cations with increasing pressure. This is consistent with molecular orbital calculations, proving that the bonding electron density becomes smaller with pressure. The thermal displacement parameters of both samples are reduced with increasing pressure.

Rastering strategy for screening and centring of microcrystal samples of human membrane proteins with a sub-10 µm size X-ray synchrotron beam

PubMed Central

Cherezov, Vadim; Hanson, Michael A.; Griffith, Mark T.; Hilgart, Mark C.; Sanishvili, Ruslan; Nagarajan, Venugopalan; Stepanov, Sergey; Fischetti, Robert F.; Kuhn, Peter; Stevens, Raymond C.

2009-01-01

Crystallization of human membrane proteins in lipidic cubic phase often results in very small but highly ordered crystals. Advent of the sub-10 µm minibeam at the APS GM/CA CAT has enabled the collection of high quality diffraction data from such microcrystals. Herein we describe the challenges and solutions related to growing, manipulating and collecting data from optically invisible microcrystals embedded in an opaque frozen in meso material. Of critical importance is the use of the intense and small synchrotron beam to raster through and locate the crystal sample in an efficient and reliable manner. The resulting diffraction patterns have a significant reduction in background, with strong intensity and improvement in diffraction resolution compared with larger beam sizes. Three high-resolution structures of human G protein-coupled receptors serve as evidence of the utility of these techniques that will likely be useful for future structural determination efforts. We anticipate that further innovations of the technologies applied to microcrystallography will enable the solving of structures of ever more challenging targets. PMID:19535414

Rapid time-resolved diffraction studies of protein structures using synchrotron radiation

NASA Astrophysics Data System (ADS)

Bartunik, Hans D.; Bartunik, Lesley J.

1992-07-01

The crystal structure of intermediate states in biological reactions of proteins of multi-protein complexes may be studied by time-resolved X-ray diffraction techniques which make use of the high spectral brilliance, continuous wavelength distribution and pulsed time structure of synchrotron radiation. Laue diffraction methods provide a means of investigating intermediate structures with lifetimes in the millisecond time range at presently operational facilities. Third-generation storage rings which are under construction may permit one to reach a time resolution of one microsecond for non-cyclic and one nanosecond for cyclic reactions. The number of individual exposures required for exploring reciprocal space and hence the total time scale strongly depend on the lattice order that may be affected, e.g., by conformational changes. Time-resolved experiments require high population of a specific intermediate which has to be homogeneous over the crystal volume. A number of external excitation techniques have been developed including in situ liberation of active metabolites by laser pulse photolysis of photolabile inactive precursors. First applications to crystal structure analysis of catalytic intermediates of enzymes demonstrate the potential of time-resolved protein crystallography.

Micron Scale Mineralogy

NASA Astrophysics Data System (ADS)

Caldwell, W. A.; Tamura, N.; Celestre, R. S.; Padmore, H. A.; Patel, J. R.

2002-12-01

Although x-ray diffraction has been used for nearly a century as the mineralogist's definitive tool in determining crystalline structures, it has proved impossible to use this technique to spatially resolve the highly heterogeneous nature of many minerals at the mesoscopic level. Due to recent revolutions in the brightness of x-ray sources and in our ability to focus x-rays, we can now carry out conventional monochromatic rotation crystallography as well as Laue diffraction with sub-micron spatial resolution and produce maps of orientation, strain, mineral type, and even chemical speciation over tens of microns in a short amount of time. We have pioneered the development of these techniques at the 3rd generation synchrotron radiation source (Advanced Light Source) in Berkeley, and will describe their application to understanding the structure of a quartz-geode. Our results show the manner in which grain structure and texture change as a function of distance from the cavity wall and are compared with models of crystal growth in such systems. This example highlights the great utility of a synchrotron based x-ray micro-diffraction beamline and the possibilities it opens to the mineralogist.

Testing the limits of sensitivity in a solid-state structural investigation by combined X-ray powder diffraction, solid-state NMR, and molecular modelling.

PubMed

Filip, Xenia; Borodi, Gheorghe; Filip, Claudiu

2011-10-28

A solid state structural investigation of ethoxzolamide is performed on microcrystalline powder by using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct space methods with information from (13)C((15)N) solid-state Nuclear Magnetic Resonance (SS-NMR) and molecular modeling. Quantum chemical computations of the crystal were employed for geometry optimization and chemical shift calculations based on the Gauge Including Projector Augmented-Wave (GIPAW) method, whereas a systematic search in the conformational space was performed on the isolated molecule using a molecular mechanics (MM) approach. The applied methodology proved useful for: (i) removing ambiguities in the XRPD crystal structure determination process and further refining the derived structure solutions, and (ii) getting important insights into the relationship between the complex network of non-covalent interactions and the induced supra-molecular architectures/crystal packing patterns. It was found that ethoxzolamide provides an ideal case study for testing the accuracy with which this methodology allows to distinguish between various structural features emerging from the analysis of the powder diffraction data. This journal is © the Owner Societies 2011

Monochromator for continuous spectrum x-ray radiation

DOEpatents

Staudenmann, J.L.; Liedl, G.L.

1983-12-02

A monochromator for use with synchrotron x-ray radiation comprises two diffraction means which can be rotated independently and independent means for translationally moving one diffraction means with respect to the other. The independence of the rotational and translational motions allows Bragg angles from 3.5/sup 0/ to 86.5/sup 0/, and facilitates precise and high-resolution monochromatization over a wide energy range. The diffraction means are removably mounted so as to be readily interchangeable, which allows the monochromator to be used for both non-dispersive and low dispersive.

Monochromator for continuous spectrum x-ray radiation

DOEpatents

Staudenmann, Jean-Louis; Liedl, Gerald L.

1987-07-07

A monochromator for use with synchrotron x-ray radiation comprises two diffraction means which can be rotated independently and independent means for translationally moving one diffraction means with respect to the other. The independence of the rotational and translational motions allows Bragg angles from 3.5.degree. to 86.5.degree., and facilitates precise and high-resolution monochromatization over a wide energy range. The diffraction means are removably mounted so as to be readily interchangeable, which allows the monochromator to be used for both non-dispersive and low dispersive work.

Composition and particle size of electrolytic copper powders prepared in water-containing dimethyl sulfoxide electrolytes

NASA Astrophysics Data System (ADS)

Mamyrbekova, Aigul'; Abzhalov, B. S.; Mamyrbekova, Aizhan

2017-07-01

The possibility of the electroprecipitation of copper powder via the cathodic reduction of an electrolyte solution containing copper(II) nitrate trihydrate and dimethyl sulfoxide (DMSO) is shown. The effect electrolysis conditions (current density, concentration and temperature of electrolyte) have on the dimensional characteristics of copper powder is studied. The size and shape of the particles of the powders were determined by means of electron microscopy; the qualitative composition of the powders, with X-ray diffraction.

A novel synthesis of polymeric CO via useful hard X-ray photochemistry

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

Pravica, Michael; Sneed, Daniel; Smith, Quinlan

We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC 2O 4) pressurized to 7 GPa inside a diamond anvil cell (DAC). After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO 2 even under ambient conditions with the sample exposed tomore » air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part) with dispersed CO 2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO 2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press) without the need for the dangerous and complex loading of toxic CO. As a result, a novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.« less

A novel synthesis of polymeric CO via useful hard X-ray photochemistry

DOE PAGES

Pravica, Michael; Sneed, Daniel; Smith, Quinlan; ...

2016-03-30

We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC 2O 4) pressurized to 7 GPa inside a diamond anvil cell (DAC). After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO 2 even under ambient conditions with the sample exposed tomore » air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part) with dispersed CO 2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO 2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press) without the need for the dangerous and complex loading of toxic CO. As a result, a novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.« less

Crystallographic Determination of Molecular Parameters for K2SiF6: A Physical Chemistry Laboratory Experiment.

ERIC Educational Resources Information Center

Loehlin, James H.; Norton, Alexandra P.

1988-01-01

Describes a crystallography experiment using both diffraction-angle and diffraction-intensity information to determine the lattice constant and a lattice independent molecular parameter, while still employing standard X-ray powder diffraction techniques. Details the method, experimental details, and analysis for this activity. (CW)

Structural, microstructural and magnetic evolution in cryo milled carbon doped MnAl.

PubMed

Fang, Hailiang; Cedervall, Johan; Hedlund, Daniel; Shafeie, Samrand; Deledda, Stefano; Olsson, Fredrik; von Fieandt, Linus; Bednarcik, Jozef; Svedlindh, Peter; Gunnarsson, Klas; Sahlberg, Martin

2018-02-06

The low cost, rare earth free τ-phase of MnAl has high potential to partially replace bonded Nd 2 Fe 14 B rare earth permanent magnets. However, the τ-phase is metastable and it is experimentally difficult to obtain powders suitable for the permanent magnet alignment process, which requires the fine powders to have an appropriate microstructure and high τ-phase purity. In this work, a new method to make high purity τ-phase fine powders is presented. A high purity τ-phase Mn 0.55 Al 0.45 C 0.02 alloy was synthesized by the drop synthesis method. The drop synthesized material was subjected to cryo milling and  followed by a flash heating process. The crystal structure and microstructure of the drop synthesized, cryo milled and flash heated samples were studied by X-ray in situ powder diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy and electron backscatter diffraction. Magnetic properties and magnetic structure of the drop synthesized, cryo milled, flash heated  samples were characterized by magnetometry and neutron powder diffraction, respectively. The results reveal that the 2 and 4 hours cryo milled and flash heated samples both exhibit high τ-phase purity and micron-sized round particle shapes. Moreover, the flash heated samples display high saturation magnetization as well as increased coercivity.

In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

DOE PAGES

Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; ...

2015-04-16

Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronalmore » annealing between 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO 2 and ThO 2, respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO 2 and ThO 2.« less

Comparison of diffraction-enhanced computed tomography and monochromatic synchrotron radiation computed tomography of human trabecular bone.

PubMed

Connor, D M; Hallen, H D; Lalush, D S; Sumner, D R; Zhong, Z

2009-10-21

Diffraction-enhanced imaging (DEI) is an x-ray-based medical imaging modality that, when used in tomography mode (DECT), can generate a three-dimensional map of both the apparent absorption coefficient and the out-of-plane gradient of the index of refraction of the sample. DECT is known to have contrast gains over monochromatic synchrotron radiation CT (SRCT) for soft tissue structures. The goal of this experiment was to compare contrast-to-noise ratio (CNR) and resolution in images of human trabecular bone acquired using SRCT with images acquired using DECT. All images were acquired at the National Synchrotron Light Source (Upton, NY, USA) at beamline X15 A at an x-ray energy of 40 keV and the silicon [3 3 3] reflection. SRCT, apparent absorption DECT and refraction DECT slice images of the trabecular bone were created. The apparent absorption DECT images have significantly higher spatial resolution and CNR than the corresponding SRCT images. Thus, DECT will prove to be a useful tool for imaging applications in which high contrast and high spatial resolution are required for both soft tissue features and bone.

Ultrapressure materials science

NASA Technical Reports Server (NTRS)

Ruoff, A. L.

1984-01-01

Three active areas of research at ultra pressure are pursued, i.e., diffraction studies with the Cornell High Energy Synchrotron Source (CHESS), band gap and absorption edge effects, indentor-anvil experiments and theory and research to attain higher pressures. The range over which X-ray diffraction data and absorption edge data are obtained is extended to 700 kbars. Using the indentor technique pressures of 2.1 Mbars are obtained. Research results and methods are discussed.

The Molecular Architecture for the Intermediate Filaments of Hard α -Keratin Based on the Superlattice Data Obtained from a Study of Mammals Using Synchrotron Fibre Diffraction

DOE PAGES

James, Veronica

2011-01-01

High- and low-angle X-ray diffraction studies of hard α -keratin have been studied, and various models have been proposed over the last 70 years. Most of these studies have been confined to one or two forms of alpha keratin. This high- and low-angle synchrotron fibre diffraction study extends the study to cover all available data for all known forms of hard α -keratin including hairs, fingernails, hooves, horn, and quills from mammals, marsupials, and a monotreme, and it confirms that the model proposed is universally acceptable for all mammals. A complete Bragg analysis of the meridional diffraction patterns, including multiple-timemore » exposures to verify any weak reflections, verified the existence of a superlattice consisting of two infinite lattices and three finite lattices. An analysis of the equatorial patterns establishes the radii of the oligomeric levels of dimers, tetramers, and intermediate filaments (IFs) together with the centre to centre distance for the IFs, thus confirming the proposed helices within helices molecular architecture for hard α -keratin. The results verify that the structure proposed by Feughelman and James meets the criteria for a valid α -keratin structure.« less

The Molecular Architecture for the Intermediate Filaments of Hard [alpha]-Keratin Based on the Superlattice Data Obtained from a Study ofMammals Using Synchrotron Fibre Diffraction

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

James, Veronica

2014-09-24

High- and low-angle X-ray diffraction studies of hard {alpha}-keratin have been studied, and various models have been proposed over the last 70 years. Most of these studies have been confined to one or two forms of alpha keratin. This high- and low-angle synchrotron fibre diffraction study extends the study to cover all available data for all known forms of hard {alpha}-keratin including hairs, fingernails, hooves, horn, and quills from mammals, marsupials, and a monotreme, and it confirms that the model proposed is universally acceptable for all mammals. A complete Bragg analysis of the meridional diffraction patterns, including multiple-time exposures tomore » verify any weak reflections, verified the existence of a superlattice consisting of two infinite lattices and three finite lattices. An analysis of the equatorial patterns establishes the radii of the oligomeric levels of dimers, tetramers, and intermediate filaments (IFs) together with the centre to centre distance for the IFs, thus confirming the proposed helices within helices molecular architecture for hard {alpha}-keratin. The results verify that the structure proposed by Feughelman and James meets the criteria for a valid {alpha}-keratin structure.« less

The Molecular Architecture for the Intermediate Filaments of Hard α -Keratin Based on the Superlattice Data Obtained from a Study of Mammals Using Synchrotron Fibre Diffraction

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

James, Veronica

High- and low-angle X-ray diffraction studies of hard α -keratin have been studied, and various models have been proposed over the last 70 years. Most of these studies have been confined to one or two forms of alpha keratin. This high- and low-angle synchrotron fibre diffraction study extends the study to cover all available data for all known forms of hard α -keratin including hairs, fingernails, hooves, horn, and quills from mammals, marsupials, and a monotreme, and it confirms that the model proposed is universally acceptable for all mammals. A complete Bragg analysis of the meridional diffraction patterns, including multiple-timemore » exposures to verify any weak reflections, verified the existence of a superlattice consisting of two infinite lattices and three finite lattices. An analysis of the equatorial patterns establishes the radii of the oligomeric levels of dimers, tetramers, and intermediate filaments (IFs) together with the centre to centre distance for the IFs, thus confirming the proposed helices within helices molecular architecture for hard α -keratin. The results verify that the structure proposed by Feughelman and James meets the criteria for a valid α -keratin structure.« less

Invited Article: Refined analysis of synchrotron radiation for NIST's SURF III facility

NASA Astrophysics Data System (ADS)

Shirley, Eric L.; Furst, Mitchell; Arp, Uwe

2018-04-01

We have developed a new method for the exact calculation of synchrotron radiation for the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility, SURF III. Instead of using the Schwinger formula, which is only an approximation, we develop formulae based on Graf's addition theorem for Bessel functions and accurate asymptotic expansions for Hankel functions and Bessel functions. By measuring the radiation intensity profile at two distances from the storage ring, we also confirm an apparent vertical emittance that is consistent with the vertical betatron oscillations that are intentionally introduced to extend beam lifetime by spreading the electron beam spatially. Finally, we determine how much diffraction by beamline apertures enhances the spectral irradiance at an integrating sphere entrance port at the end station. This should eliminate small but treatable components of the uncertainty budget that one should consider when using SURF III or similar synchrotrons as standard, calculable sources of ultraviolet and other radiation.

Phase diagram of the relaxor ferroelectric (1- x )Pb(Mg 1/3Nb 2/3)O 3+ x PbTiO 3 revisited: a neutron powder diffraction study of the relaxor skin effect

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

Phelan, D.; Rodriguez, E. E.; Gao, J.

2014-11-17

We revisit the phase diagram of the relaxor ferroelectric PMN- xPT using neutron powder diffraction to test suggestions that residual oxygen vacancies and/or strain affect the ground state crystal structure. Powdered samples of PMN- xPT were prepared with nominal compositions of x = 0:10, 0.20, 0.30, and 0.40 and divided into two identical sets, one of which was annealed in air to relieve grinding-induced strain and to promote an ideal oxygen stoichiometry. For a given composition and temperature the same structural phase is observed for each specimen. However, the distortions in all of the annealed samples are smaller than thosemore » in the as-grown samples. Further, the diffraction patterns for x = 0:10, 0.20, and 0.30 are best refined using the monoclinic Cm space group. By comparing our neutron diffraction results to those obtained on single crystals having similar compositions, we conclude that the relaxor skin effect in PMN- xPT vanishes on the Ti-rich side of the morphotropic phase boundary.« less

Hydrogenation properties of Li{sub x}Sr{sub 1−x}AlSi studied by quantum-chemical methods (0≤x≤1) and in-situ neutron powder diffraction (x=1)

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

Kunkel, Nathalie, E-mail: nathalie.kunkel@chimie-paristech.fr; FR 8.1 Universität des Saarlandes, Postach 151150, 66041 Saarbrücken; Reichert, Christian

2015-01-15

In-situ neutron powder diffraction studies of the Half-Heusler phase LiAlSi under high deuterium pressures and first principle calculations of solid solutions of Li{sub x}Sr{sub 1−x}AlSi and their hydrides Li{sub x}Sr{sub 1−x}AlSiH were carried out. In contrast to an earlier study, there is no experimental evidence for hydrogen (deuterium) uptake up to gas pressures of 15 MPa and temperatures of 550 °C. Instead a slow decomposition reaction according to LiAlSi+1/2H{sub 2}=LiH+Al+Si was found by in-situ neutron powder diffraction. Theoretical calculations by DFT methods on hypothetical solid solutions of Li{sub x}Sr{sub 1−x}AlSi show the LiAlSi type to be the energetically most stablemore » structure for 0.7« less

Single-crystal diffraction at megabar conditions by synchrotron radiation

NASA Astrophysics Data System (ADS)

Merlini, Marco; Hanfland, Michael

2013-08-01

Crystal structure determination at extreme pressures is currently possible at synchrotron beamlines optimized for such a purpose. We report the description of the experimental setup available at European Synchrotron Radiation Facility ID09 beamline (Grenoble, France) and, with two examples, we illustrate the state-of-the-art experiments currently performed at third-generation synchrotrons. The first example concerns the determination of the equation of state and the structural behavior of low-spin Fe-bearing siderite in the megabar pressure range. Siderite, in fact, undergoes a first-order isosymmetric transition at 45 GPa, and, above this pressure, it features Fe2+ in electronic low-spin configuration. The local configuration of Fe coordination polyhedra, determined by structural refinements, significantly deviates from a regular octahedron. Nevertheless, no further structural transition is detected up to the maximum pressure reached in our experiments, 135 GPa. The analysis of the Fe-O bond length extrapolated to ambient pressure, which indicates that the difference in ionic radii between the high- and the low-spin state of Fe2+ is 0.172 Å, in excellent agreement with the tabulated data by Shannon and Prewitt [Effective ionic radii in oxides and fluorides. Acta Crystallogr. 1969;B25:925-946]. The second example concerns the determination and refinement of the oP8 structure adopted by sodium in the pressure interval 118-125 GPa, using an experimental dataset collected at 118 GPa. The orthorhombic [a=4.7687(15) Å, b=3.0150(6) Å, c=5.2423(7) Å, V=75.4(3) Å3] oP8 structure is topologically related to the MnP structure, with two non-equivalent atoms in the unit cell. Despite the weak scattering factor of Na atoms, the quality of the data also allows meaningful displacement parameters refinements (R1=4.6%, 14 parameters, 190 diffractions, and 105 unique) demonstrating that the current accuracy of diffraction data at extreme pressures can be comparable with ambient condition measurements.

Characterization of Metal Powders Used for Additive Manufacturing.

PubMed

Slotwinski, J A; Garboczi, E J; Stutzman, P E; Ferraris, C F; Watson, S S; Peltz, M A

2014-01-01

Additive manufacturing (AM) techniques can produce complex, high-value metal parts, with potential applications as critical parts, such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials (e.g., metal powders) with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to structure and chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process.

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

Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.

PubMed

Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Evgenii, Emelin; Petsiuk, Andrei; Leitenberger, Wolfram; Erko, Alexei

2017-04-01

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La 3 Ga 5 SiO 14 ) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space-time modulation of an X-ray beam.

Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry1

PubMed Central

Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Evgenii, Emelin; Petsiuk, Andrei; Leitenberger, Wolfram; Erko, Alexei

2017-01-01

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space–time modulation of an X-ray beam. PMID:28381976

Time-resolved structural studies at synchrotrons and X-ray free electron lasers: opportunities and challenges

PubMed Central

Neutze, Richard; Moffat, Keith

2012-01-01

X-ray free electron lasers (XFELs) are potentially revolutionary X-ray sources because of their very short pulse duration, extreme peak brilliance and high spatial coherence, features that distinguish them from today’s synchrotron sources. We review recent time-resolved Laue diffraction and time-resolved wide angle X-ray scattering (WAXS) studies at synchrotron sources, and initial static studies at XFELs. XFELs have the potential to transform the field of time-resolved structural biology, yet many challenges arise in devising and adapting hardware, experimental design and data analysis strategies to exploit their unusual properties. Despite these challenges, we are confident that XFEL sources are poised to shed new light on ultrafast protein reaction dynamics. PMID:23021004

Synchrotron Study on Crystallization Kinetics of Milk Fat under Shear Flow

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

Mazzanti, G.; Marangoni, A; Idziak, S

A detailed synchrotron X-ray diffraction study on the kinetics of crystallization of anhydrous milk fat (AMF) and milk fat triacylglycerols (MFT) was done in a Couette cell at 17 C, 17.5 C and 20 C under shear rates between 0 and 2880 s-1. We observed shear-induced acceleration of the transition from phase ? to ?? and the presence of crystalline orientation, but no effect of shear on the onset time of phase ? was observed. A two stage regime was observed for the growth of phase ??. The first stage follows a series-parallel system of differential equations describing the conversionmore » between liquid and crystalline phases. The second stage follows a diffusion-controlled regime. These mechanisms are consistent with the crystalline orientation, the growth of the crystalline domains and the observed displacement of the diffraction peak positions. The absence of the polar lipids explains the faster kinetics of MFT.« less

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

Polarized vacuum ultraviolet and X-radiation

NASA Technical Reports Server (NTRS)

Samson, J. A. R.

1978-01-01

The most intense source of polarized vacuum UV and X radiation is synchrotron radiation, which exhibits a degree of partially polarized light between about 80-100%. However, the radiation transmitted by vacuum UV monochromators can also be highly polarized. The Seya-Namioka type of monochromator can produce partially polarized radiation between 50-80%. For certain experiments it is necessary to know the degree of polarization of the radiation being used. Also, when synchrotron radiation and a monochromator are combined the polarization characteristic of both should be known in order to make full use of these polarization properties. The polarizing effect of monochromators (i.e., diffraction gratings) have been measured at the Seya angle and at grazing angles for various spectral orders. Experimental evidence is presented which shows that the reciprocity law holds for polarization by reflection where the angle of incidence and diffraction are unequal. These results are reviewed along with the techniques for measuring the degree of polarization.

Insights on the origin of the Tb5Ge4 magnetocaloric effect

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

Belo, J. H.; Barbosa, M. B.; Pires, A. L.

2017-05-01

In this report the magnetic, atomic structures and spin-lattice coupling have been thoroughly studied through high magnetic field magnetometry, Synchrotron X-ray diffraction under applied magnetic field and magnetostriction measurements in the Tb5Ge4 compounds. A field induced phase transition from an antiferromagnetic towards a ferromagnetic ordering was confirmed but with absence of structural transformation. This absence has been confirmed experimentally through synchrotron x-ray diffraction under applied field (up to 30 T). Moreover, this absence was explained via a thermodynamic free energy model: first principles calculations determined a large energy gap (ΔE=0.65 eV) between the two possible structures, O(I) and O(II). Frommore » magnetic and structural properties, a H-T phase diagram has been proposed for Tb5Ge4. Finally it was observed a large magnetostriction (up to 600 ppm) induced by ΔH=7 T.« less

Intergranular stress study of TC11 titanium alloy after laser shock peening by synchrotron-based high-energy X-ray diffraction

NASA Astrophysics Data System (ADS)

Su, R.; Li, L.; Wang, Y. D.; Nie, Z. H.; Ren, Y.; Zhou, X.; Wang, J.

2018-05-01

The distribution of residual lattice strain as a function of depth were carefully investigated by synchrotron-based high energy X-ray diffraction (HEXRD) in TC11 titanium alloy after laser shock peening (LSP). The results presented big compressive residual lattice strains at surface and subsurface, then tensile residual lattice strains in deeper region, and finally close to zero lattice strains in further deep interior with no plastic deformation thereafter. These evolutions in residual lattice strains were attributed to the balance of direct load effect from laser shock wave and the derivative restriction force effect from surrounding material. Significant intergranular stress was evidenced in the processed sample. The intergranular stress exhibited the largest value at surface, and rapidly decreased with depth increase. The magnitude of intergranular stress was proportional to the severity of the plastic deformation caused by LSP. Two shocks generated larger intergranular stress than one shock.

Shining a light on planetary processes using synchrotron techniques

NASA Astrophysics Data System (ADS)

Brand, H. E. A.; Kimpton, J. A.

2017-12-01

The Australian Synchrotron is a world-class national research facility that uses accelerator technology to produce X-rays and infrared for research. It is available for researchers from all institutions and disciplines. This contribution is intended to inform the community of the current capabilities at the facility using examples drawn from planetary research across the beamlines. Examples will include: formation of jarosite minerals with a view to Mars; studies of Micrometeorites; and large volume CT imaging of geological samples. A suite of new beamlines has been proposed for the growth of the facility and one of these, ADS, the Advanced Diffraction and Scattering beamline, is intended to be a high energy X-ray diffraction beamline capable of reaching extreme conditions and carrying out challenging in situ experiments. There is an opportunity to develop complex new sample environments which could be of relevance to shock metamorphic processes and this will form part of the discussion.

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

Synchrotron x-ray diffraction studies of the structural properties of electrode materials in operating battery cells

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

Thurston, T.R.; Jisrawi, N.M.; Mukerjee, S.

Hard x rays from a synchrotron source were utilized in diffraction experiments which probed the bulk of electrode materials while they were operating {ital in} {ital situ} in battery cells. Two technologically relevant electrode materials were examined; an {ital AB}{sub 2}-type anode in a nickel{endash}metal{endash}hydride cell and a LiMn{sub 2}O{sub 4} cathode in a Li-ion {open_quote}{open_quote}rocking chair{close_quote}{close_quote} cell. Structural features such as lattice expansions and contractions, phase transitions, and the formation of multiple phases were easily observed as either hydrogen or lithium was electrochemically intercalated in and out of the electrode materials. The relevance of this technique for future studiesmore » of battery electrode materials is discussed. {copyright} {ital 1996 American Institute of Physics.}« less

Polarization-resolved second-harmonic generation microscopy as a method to visualize protein-crystal domains

PubMed Central

DeWalt, Emma L.; Begue, Victoria J.; Ronau, Judith A.; Sullivan, Shane Z.; Das, Chittaranjan; Simpson, Garth J.

2013-01-01

Polarization-resolved second-harmonic generation (PR-SHG) microscopy is described and applied to identify the presence of multiple crystallographic domains within protein-crystal conglomerates, which was confirmed by synchrotron X-ray diffraction. Principal component analysis (PCA) of PR-SHG images resulted in principal component 2 (PC2) images with areas of contrasting negative and positive values for conglomerated crystals and PC2 images exhibiting uniformly positive or uniformly negative values for single crystals. Qualitative assessment of PC2 images allowed the identification of domains of different internal ordering within protein-crystal samples as well as differentiation between multi-domain conglomerated crystals and single crystals. PR-SHG assessments of crystalline domains were in good agreement with spatially resolved synchrotron X-ray diffraction measurements. These results have implications for improving the productive throughput of protein structure determination through early identification of multi-domain crystals. PMID:23275165

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

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

Fixed target matrix for femtosecond time-resolved and in situ serial micro-crystallography

PubMed Central

Mueller, C.; Marx, A.; Epp, S. W.; Zhong, Y.; Kuo, A.; Balo, A. R.; Soman, J.; Schotte, F.; Lemke, H. T.; Owen, R. L.; Pai, E. F.; Pearson, A. R.; Olson, J. S.; Anfinrud, P. A.; Ernst, O. P.; Dwayne Miller, R. J.

2015-01-01

We present a crystallography chip enabling in situ room temperature crystallography at microfocus synchrotron beamlines and X-ray free-electron laser (X-FEL) sources. Compared to other in situ approaches, we observe extremely low background and high diffraction data quality. The chip design is robust and allows fast and efficient loading of thousands of small crystals. The ability to load a large number of protein crystals, at room temperature and with high efficiency, into prescribed positions enables high throughput automated serial crystallography with microfocus synchrotron beamlines. In addition, we demonstrate the application of this chip for femtosecond time-resolved serial crystallography at the Linac Coherent Light Source (LCLS, Menlo Park, California, USA). The chip concept enables multiple images to be acquired from each crystal, allowing differential detection of changes in diffraction intensities in order to obtain high signal-to-noise and fully exploit the time resolution capabilities of XFELs. PMID:26798825

Study of the mechanical behavior of the hydride blister/rim structure in Zircaloy-4 using in-situ synchrotron X-ray diffraction

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

Lin, Jun-li; Han, Xiaochun; Heuser, Brent J.

2016-04-01

High-energy synchrotron X-ray diffraction was utilized to study the mechanical response of the f.c.c delta hydride phase, the intermetallic precipitation with hexagonal C14 lave phase and the alpha-Zr phase in the Zircaloy-4 materials with a hydride rim/blister structure near one surface of the material during in-situ uniaxial tension experiment at 200 degrees C. The f.c.c delta was the only hydride phase observed in the rim/blister structure. The conventional Rietveld refinement was applied to measure the macro-strain equivalent response of the three phases. Two regions were delineated in the applied load versus lattice strain measurement: a linear elastic strain region andmore » region that exhibited load partitioning. Load partitioning was quantified by von Mises analysis. The three phases were observed to have similar elastic modulus at 200 degrees C.« less

Validating a Model for Welding Induced Residual Stress Using High-Energy X-ray Diffraction

NASA Astrophysics Data System (ADS)

Mach, J. C.; Budrow, C. J.; Pagan, D. C.; Ruff, J. P. C.; Park, J.-S.; Okasinski, J.; Beaudoin, A. J.; Miller, M. P.

2017-05-01

Integrated computational materials engineering (ICME) provides a pathway to advance performance in structures through the use of physically-based models to better understand how manufacturing processes influence product performance. As one particular challenge, consider that residual stresses induced in fabrication are pervasive and directly impact the life of structures. For ICME to be an effective strategy, it is essential that predictive capability be developed in conjunction with critical experiments. In the present work, simulation results from a multi-physics model for gas metal arc welding are evaluated through x-ray diffraction using synchrotron radiation. A test component was designed with intent to develop significant gradients in residual stress, be representative of real-world engineering application, yet remain tractable for finely spaced strain measurements with positioning equipment available at synchrotron facilities. The experimental validation lends confidence to model predictions, facilitating the explicit consideration of residual stress distribution in prediction of fatigue life.

Fixed target matrix for femtosecond time-resolved and in situ serial micro-crystallography.

PubMed

Mueller, C; Marx, A; Epp, S W; Zhong, Y; Kuo, A; Balo, A R; Soman, J; Schotte, F; Lemke, H T; Owen, R L; Pai, E F; Pearson, A R; Olson, J S; Anfinrud, P A; Ernst, O P; Dwayne Miller, R J

2015-09-01

We present a crystallography chip enabling in situ room temperature crystallography at microfocus synchrotron beamlines and X-ray free-electron laser (X-FEL) sources. Compared to other in situ approaches, we observe extremely low background and high diffraction data quality. The chip design is robust and allows fast and efficient loading of thousands of small crystals. The ability to load a large number of protein crystals, at room temperature and with high efficiency, into prescribed positions enables high throughput automated serial crystallography with microfocus synchrotron beamlines. In addition, we demonstrate the application of this chip for femtosecond time-resolved serial crystallography at the Linac Coherent Light Source (LCLS, Menlo Park, California, USA). The chip concept enables multiple images to be acquired from each crystal, allowing differential detection of changes in diffraction intensities in order to obtain high signal-to-noise and fully exploit the time resolution capabilities of XFELs.

Mechanical behaviour of pressed and sintered CP Ti and Ti-6Al-7Nb alloy obtained from master alloy addition powder.

PubMed

Bolzoni, L; Weissgaerber, T; Kieback, B; Ruiz-Navas, E M; Gordo, E

2013-04-01

The Ti-6Al-7Nb alloy was obtained using the blending elemental approach with a master alloy and elemental titanium powders. Both the elemental titanium and the Ti-6Al-7Nb powders were characterised using X-ray diffraction, differential thermal analysis and dilatometry. The powders were processed using the conventional powder metallurgy route that includes uniaxial pressing and sintering. The trend of the relative density with the sintering temperature and the microstructural evolution of the materials sintered at different temperatures were analysed using scanning electron microscopy and X-ray diffraction. A minimum sintering temperature of 1200°C has to be used to ensure the homogenisation of the alloying elements and to obtain a pore structure composed of spherical pores. The sintered samples achieve relative density values that are typical for powder metallurgy titanium and no intermetallic phases were detected. Mechanical properties comparable to those specified for wrought Ti-6Al-7Nb medical devices are normally obtained. Therefore, the produced materials are promising candidates for load bearing applications as implant materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metrology of variable-line-spacing x-ray gratings using the APS Long Trace Profiler

NASA Astrophysics Data System (ADS)

Sheung, Janet; Qian, Jun; Sullivan, Joseph; Thomasset, Muriel; Manton, Jonathan; Bean, Sunil; Takacs, Peter; Dvorak, Joseph; Assoufid, Lahsen

2017-09-01

As resolving power targets have increased with each generation of beamlines commissioned in synchrotron radiation facilities worldwide, diffraction gratings are quickly becoming crucial optical components for meeting performance targets. However, the metrology of variable-line-spacing (VLS) gratings for high resolution beamlines is not widespread; in particular, no metrology facility at any US DOE facility is currently equipped to fully characterize such gratings. To begin to address this issue, the Optics Group at the Advanced Photon Source at Argonne, in collaboration with SOLEIL and with support from Brookhaven National Laboratory (BNL), has developed an alternative beam path addition to the Long Trace Profiler (LTP) at Argonne's Advanced Photon Source. This significantly expands the functionality of the LTP not only to measure mirrors surface slope profile at normal incidence, but also to characterize the groove density of VLS diffraction gratings in the Littrow incidence up to 79°, which covers virtually all diffraction gratings used at synchrotrons in the first order. The LTP light source is a 20mW HeNe laser, which yields enough signal for diffraction measurements to be performed on low angle blazed gratings optimized for soft X-ray wavelengths. We will present the design of the beam path, technical requirements for the optomechanics, and our data analysis procedure. Finally, we discuss challenges still to be overcome and potential limitations with use of the LTP to perform metrology on diffraction gratings.

Thermal behavior of polyhalite: a high-temperature synchrotron XRD study

DOE PAGES

Xu, Hongwu; Guo, Xiaofeng; Bai, Jianming

2016-09-17

As an accessory mineral in marine evaporites, polyhalite, K 2MgCa 2(SO 4) 4·2H 2O, coexists with halite (NaCl) in salt formations, which have been considered as potential repositories for permanent storage of high-level nuclear wastes. However, because of the heat generated by radioactive decays in the wastes, polyhalite may dehydrate, and the released water will dissolve its neighboring salt, potentially affecting the repository integrity. Thus, studying the thermal behavior of polyhalite is important. In this paper, a polyhalite sample containing a small amount of halite was collected from the Salado formation at the WIPP site in Carlsbad, New Mexico. Tomore » determine its thermal behavior, in situ high-temperature synchrotron X-ray diffraction was conducted from room temperature to 1066 K with the sample powders sealed in a silica-glass capillary. At about 506 K, polyhalite started to decompose into water vapor, anhydrite (CaSO 4) and two langbeinite-type phases, K 2Ca x Mg 2-x (SO 4) 3, with different Ca/Mg ratios. XRD peaks of the minor halite disappeared, presumably due to its dissolution by water vapor. With further increasing temperature, the two langbeinite solid solution phases displayed complex variations in crystallinity, composition and their molar ratio and then were combined into the single-phase triple salt, K 2CaMg(SO 4) 3, at ~919 K. Rietveld analyses of the XRD data allowed determination of structural parameters of polyhalite and its decomposed anhydrite and langbeinite phases as a function of temperature. Finally, from the results, the thermal expansion coefficients of these phases have been derived, and the structural mechanisms of their thermal behavior been discussed.« less

Single-drop optimization of protein crystallization.

PubMed

Meyer, Arne; Dierks, Karsten; Hilterhaus, Dierk; Klupsch, Thomas; Mühlig, Peter; Kleesiek, Jens; Schöpflin, Robert; Einspahr, Howard; Hilgenfeld, Rolf; Betzel, Christian

2012-08-01

A completely new crystal-growth device has been developed that permits charting a course across the phase diagram to produce crystalline samples optimized for diffraction experiments. The utility of the device is demonstrated for the production of crystals for the traditional X-ray diffraction data-collection experiment, of microcrystals optimal for data-collection experiments at a modern microbeam insertion-device synchrotron beamline and of nanocrystals required for data collection on an X-ray laser beamline.

The structural and magnetic phase transitions in a ``parent'' Fe pnictide compound

NASA Astrophysics Data System (ADS)

Ni, Ni; Allred, Jared; Cao, Huibo; Tian, Wei; Liu, Lian; Cho, Kyuil; Krogstad, Matthew; Ma, Jie; Taddei, Keith; Tanatar, Makariy; Prozorov, Ruslan; Matsuda, Masaaki; Rosenkranz, Stephan; Uemura, Yasutomo; Jiang, Shan

2015-03-01

We will present transport, thermodynamic, synchrotron X-ray, neutron diffraction, μSR, ARPES and polarized optical image measurements on the ``parent'' compound of the 112 high Tc superconducting Fe pnictide family. Structural and magnetic phase transitions are revealed. Detailed magnetic structure was solved by single crystal neutron diffraction. We will discuss the similarity and difference of these transitions comparing to the parent compounds of other Fe pnictide superconductors.