Two-dimensional x-ray diffraction

CERN Document Server

He, Bob B

2009-01-01

Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

X-ray diffraction imaging of material microstructures

KAUST Repository

Varga, Laszlo

2016-10-20

Various examples are provided for x-ray imaging of the microstructure of materials. In one example, a system for non-destructive material testing includes an x-ray source configured to generate a beam spot on a test item; a grid detector configured to receive x- rays diffracted from the test object; and a computing device configured to determine a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the test object. In another example, a method for determining a microstructure of a material includes illuminating a beam spot on the material with a beam of incident x-rays; detecting, with a grid detector, x-rays diffracted from the material; and determining, by a computing device, a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the material.

Femtosecond X-ray diffraction from two-dimensional protein crystals

Directory of Open Access Journals (Sweden)

Matthias Frank

2014-03-01

Full Text Available X-ray diffraction patterns from two-dimensional (2-D protein crystals obtained using femtosecond X-ray pulses from an X-ray free-electron laser (XFEL are presented. To date, it has not been possible to acquire transmission X-ray diffraction patterns from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permit a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy approach at the Linac Coherent Light Source, Bragg diffraction was acquired to better than 8.5 Å resolution for two different 2-D protein crystal samples each less than 10 nm thick and maintained at room temperature. These proof-of-principle results show promise for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.

Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

Directory of Open Access Journals (Sweden)

M. S. Conconi

2014-12-01

Full Text Available The firing transformations of traditional (clay based ceramics are of technological and archeological interest, and are usually reported qualitatively or semiquantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite, the low crystalline (metakaolinite and/or spinel type pre-mullite and glassy phases evolution of a triaxial (clay-quartz-feldspar ceramic fired in a wide temperature range between 900 and 1300 ºC. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 ºC spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and

Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

International Nuclear Information System (INIS)

Conconi, M.S.; Gauna, M.R.; Serra, M.F.; Suarez, G.; Aglietti, E.F.; Rendtorff, N.M.

2014-01-01

The firing transformations of traditional (clay based) ceramics are of technological and archaeological interest, and are usually reported qualitatively or semi quantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite), the low crystalline (metakaolinite and/or spinel type pre-mullite) and glassy phases evolution of a triaxial (clay-quartz-feldspar) ceramic fired in a wide temperature range between 900 and 1300 deg C. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 deg C) spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy) phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and materials

Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

Energy Technology Data Exchange (ETDEWEB)

Conconi, M.S.; Gauna, M.R.; Serra, M.F. [Centro de Tecnologia de Recursos Minerales y Ceramica (CETMIC), Buenos Aires (Argentina); Suarez, G.; Aglietti, E.F.; Rendtorff, N.M., E-mail: rendtorff@cetmic.unlp.edu.ar [Universidad Nacional de La Plata (UNLP), Buenos Aires (Argentina). Fac. de Ciencias Exactas. Dept. de Quimica

2014-10-15

The firing transformations of traditional (clay based) ceramics are of technological and archaeological interest, and are usually reported qualitatively or semi quantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite), the low crystalline (metakaolinite and/or spinel type pre-mullite) and glassy phases evolution of a triaxial (clay-quartz-feldspar) ceramic fired in a wide temperature range between 900 and 1300 deg C. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 deg C) spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy) phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and materials

X-ray diffraction microtomography using synchrotron radiation

CERN Document Server

Barroso, R C; Jesus, E F O; Oliveira, L F

2001-01-01

The X-ray diffraction computed tomography technique is based on the interference phenomena of the coherent scatter. For low-momentum transfer, it is most probable that the scattering interaction will be coherent. A selective discrimination of a given element in a scanned specimen can be realized by fixing the Bragg angle which produces an interference peak and then, to carry out the computed tomography in the standard mode. The image reconstructed exalts the presence of this element with respect to other ones in a sample. This work reports the feasibility of a non-destructive synchrotron radiation X-ray diffraction imaging technique. This research was performed at the X-ray Diffraction beam line of the National Synchrotron Light Laboratory (LNLS) in Brazil. The coherent scattering properties of different tissue and bone substitute materials were evaluated. Furthermore, diffraction patterns of some polycrystalline solids were studied due to industrial and environmental human exposure to these metals. The obtai...

Phase transformation in δ-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

International Nuclear Information System (INIS)

Ravat, B.; Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F.

2009-01-01

In order to investigate the martensitic transformation, an isothermal hold at -130 deg. C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct δ → α' + δ phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the δ-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the δ and α' phases. The amount of α'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the δ-grain edges and the α'-phase had a plate-like morphology.

Phase transformation in δ-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

Science.gov (United States)

Ravat, B.; Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F.

2009-09-01

In order to investigate the martensitic transformation, an isothermal hold at -130 °C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct δ → α' + δ phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the δ-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the δ and α' phases. The amount of α'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the δ-grain edges and the α'-phase had a plate-like morphology.

Phase transformation in delta-Pu alloys at low temperature: An in situ microstructural characterization using X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Ravat, B., E-mail: brice.ravat@cea.f [CEA, Valduc, F-21120 Is-sur-Tille (France); Platteau, C.; Texier, G.; Oudot, B.; Delaunay, F. [CEA, Valduc, F-21120 Is-sur-Tille (France)

2009-09-15

In order to investigate the martensitic transformation, an isothermal hold at -130 deg. C for 48 h was performed on a highly homogenized PuGa alloy. The modifications of the microstructure were characterized in situ thanks to a specific tool. This device was developed at the CEA-Valduc to analyze the crystalline structure of plutonium alloys as a function of temperature and more especially at low temperature using X-ray diffraction. The analysis of the recorded diffraction patterns highlighted that the martensitic transformation for this alloy is the result of a direct delta -> alpha' + delta phase transformation. Moreover, a significant Bragg's peaks broadening corresponding to the delta-phase was observed. A microstructural analysis was made to characterize anisotropic microstrain resulting from the stress induced by the unit cell volume difference between the delta and alpha' phases. The amount of alpha'-phase evolved was analyzed within the framework of the Avrami theory in order to characterize the nucleation process. The results suggested that the growth mechanism corresponded to a general mechanism where the nucleation sites were in the delta-grain edges and the alpha'-phase had a plate-like morphology.

Thermal expansion studies on Inconel-600[reg] by high temperature X-ray diffraction

International Nuclear Information System (INIS)

Raju, S.; Sivasubramanian, K.; Divakar, R.; Panneerselvam, G.; Banerjee, A.; Mohandas, E.; Antony, M.P.

2004-01-01

The lattice thermal expansion characteristics of Inconel-600[reg] have been studied by high temperature X-ray diffraction (HT-XRD) technique in the temperature range 298-1200 K. Altogether four experimental runs were conducted on thin foils of about 75-100 μm thickness. The diffraction profiles have been accurately calibrated to offset the shift in 2θ values introduced by sample buckling at elevated temperatures. The corrected lattice parameter data have been used to estimate the instantaneous and mean linear thermal expansion coefficients as a function of temperature. The thermal expansion values estimated in the present study show a fair degree of agreement with other existing dilatometer based bulk thermal expansion estimates. The lattice parameter for this alloy at 300 K is found to be 0.3549(1) nm. The mean linear thermal expansivity is found to be 11.4 x 10 -6 K -1

High temperature X-ray diffraction studies on HfO2-Gd2O3 system

International Nuclear Information System (INIS)

Panneerselvam, G.; Antony, M.P.; Ananthasivan, K.; Joseph, M.

2016-01-01

High temperature X-ray diffraction (HTXRD) technique is an important experimental tool for measuring thermal expansion of materials of interest. A series of solid solutions containing GdO 1.5 in HfO 2 ,Hf 1-y Gd y )O 2 (y = 0.15, 0.2, 0.3, 0.41 and 0.505) were prepared by solid state method. Structural characterization and computation of lattice parameter was carried out by using room temperature X-ray diffraction measurements. The room temperature lattice parameter estimated for (Hf 1-y Gd y )O 2 (y=0.15, 0.2, 0.3, 0.41 and 0.505) are 0.51714 nm, 0.51929 nm, 0.52359nm, 0.52789nm and 0.53241 nm, respectively. Thermal expansion coefficients and percentage linear thermal expansion of the HfO 2 -Gd 2 O 3 solid solutions containing 20 and 41 mol% GdO 1.5 were determined using HTXRD in the temperature range 298 to 1673K. The mean linear thermal expansion coefficients of the solid solutions containing 20 and 41 mol. %Gd are 11.65 x 10 -6 K -1 and 12.07 x 10 -6 K -1 , respectively. (author)

Surface structure of Bi₂Se₃(111) determined by low-energy electron diffraction and surface x-ray diffraction

DEFF Research Database (Denmark)

dos Reis, Diogo Duarte; Barreto, Lucas; Bianchi, Marco

2013-01-01

The surface structure of the prototypical topological insulator Bi2Se3 is determined by low-energy electron diffraction and surface x-ray diffraction at room temperature. Both approaches show that the crystal is terminated by an intact quintuple layer. Specifically, an alternative termination by ...... by a bismuth bilayer is ruled out. Surface relaxations obtained by both techniques are in good agreement with each other and found to be small. This includes the relaxation of the van der Waals gap between the first two quintuple layers....

X-ray topography and multiple diffraction

International Nuclear Information System (INIS)

Chang, S.-L.

1983-01-01

A short summary on X-ray topography, which is based on the dynamical theory of X-ray diffraction, is made. The applications and properties related to the use of the multiple diffraction technique are analized and discussed. (L.C.) [pt

Study about uranium oxides at high temperature by X-ray diffraction

International Nuclear Information System (INIS)

Costa, M.I.

1978-01-01

In this work a technique to study the lattice parameters in the crystalline substances at hight temperature by X-rays diffraction is developed. The results obtained agree very well with the experimental data found in the literature. The crystalline structure of uranium oxide at different temperature is studied in detail by this technique. At the range of the temperature investigated, i.e., 20 0 C to 640 0 C, the following forms for uranium oxide: U 3 O 8 in its hexagonal modification, cubic UO 2 , cubic U 4 O 9 and tetragonal U 3 O 7 is observed. The appearance of two hexagonal units observed in this work is identified by Milne. A good reproducibillity is observed for measurements at the same temperature [pt

A study of the reactivity of elemental Cr/Se/Te thin multilayers using X-ray reflectometry, in situ X-ray diffraction and X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Behrens, Malte; Tomforde, Jan; May, Enno; Kiebach, Ragnar; Bensch, Wolfgang; Haeussler, Dietrich; Jaeger, Wolfgang

2006-01-01

The reactivity of [Cr/Se/Te] multilayers under annealing was investigated using X-ray reflectometry, in situ X-ray diffraction, X-ray absorption fine structure (XAFS) measurements and transmission electron microscopy. For all samples, interdiffusion was complete at temperatures between 100 and 300 deg. C, depending on the repeating tri-layer thickness. A crystalline phase nucleated approximately 20 deg. C above the temperature where interdiffusion was finished. The first crystalline phase in a binary Cr/Te sample was layered CrTe 3 nucleating at 230 deg. C. In ternary samples (Se:Te=0.6-1.2), the low-temperature nucleation of such a layered CrQ 3 (Q=Se, Te) phase is suppressed and instead the phase Cr 2 Q 3 nucleates first. Interestingly, this phase decomposes around 500 deg. C into layered CrQ 3 . In contrast, binary Cr/Se samples form stable amorphous alloys after interdiffusion and Cr 3 Se 4 nucleates around 500 deg. C as the only crystalline phase. Evaluation of the XAFS data of annealed samples yield Se-Cr distances of 2.568(1) and 2.552(1) A for Cr 2 Q 3 and CrQ 3 , respectively. In the latter sample, higher coordination shells around Se are seen accounting for the Se-Te contacts in the structure. - Graphical abstract: The first step of the reaction of elemental Cr/Te/Se-multilayers is the interdiffusion of the elements as evidenced by the decay of the modulation peaks in the low-angle region of the X-ray diffraction patterns. The subsequent growth of Bragg peaks at higher scattering angles indicates crystallization of chromium chalcogenide Cr 2 Te 3- x Se x

Nanocalorimeter platform for in situ specific heat measurements and x-ray diffraction at low temperature

Energy Technology Data Exchange (ETDEWEB)

Willa, K. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Diao, Z. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Laboratory of Mathematics, Physics and Electrical Engineering, Halmstad University, P.O. Box 823, SE-301 18 Halmstad, Sweden; Campanini, D. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Welp, U. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Divan, R. [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Hudl, M. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden; Islam, Z. [X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Kwok, W. -K. [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Rydh, A. [Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden

2017-12-01

Recent advances in electronics and nanofabrication have enabled membrane-based nanocalorimetry for measurements of the specific heat of microgram-sized samples. We have integrated a nanocalorimeter platform into a 4.5 T split-pair vertical-field magnet to allow for the simultaneous measurement of the specific heat and x-ray scattering in magnetic fields and at temperatures as low as 4 K. This multi-modal approach empowers researchers to directly correlate scattering experiments with insights from thermodynamic properties including structural, electronic, orbital, and magnetic phase transitions. The use of a nanocalorimeter sample platform enables numerous technical advantages: precise measurement and control of the sample temperature, quantification of beam heating effects, fast and precise positioning of the sample in the x-ray beam, and fast acquisition of x-ray scans over a wide temperature range without the need for time-consuming re-centering and re-alignment. Furthermore, on an YBa2Cu3O7-delta crystal and a copper foil, we demonstrate a novel approach to x-ray absorption spectroscopy by monitoring the change in sample temperature as a function of incident photon energy. Finally, we illustrate the new insights that can be gained from in situ structural and thermodynamic measurements by investigating the superheated state occurring at the first-order magneto-elastic phase transition of Fe2P, a material that is of interest for magnetocaloric applications.

Fatigue life assessment for pipeline welds by x-ray diffraction technique

International Nuclear Information System (INIS)

Lee, Sang Guk; Yoo, Keun Bong

2006-01-01

The objective of this study is to estimate the feasibility of X-ray diffraction method application for fatigue life assessment of the high-temperature pipeline steel such as main steam pipe, re-heater pipe and header etc. in power plant. In this study, X-ray diffraction tests using various types of specimen simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages such as 1/4, l/2 and 3/4 of fatigue life, respectively. As a result off-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio. And also, He ratio of the full width at half maximum intensity due to fatigue damage has linear relationship with fatigue life ratio algebraically. From this relationship, it was suggested that direct expectation of the life consumption rate was feasible.

Diffraction enhanced x-ray imaging

International Nuclear Information System (INIS)

Thomlinson, W.; Zhong, Z.; Johnston, R.E.; Sayers, D.

1997-09-01

Diffraction enhanced imaging (DEI) is a new x-ray radiographic imaging modality using synchrotron x-rays which produces images of thick absorbing objects that are almost completely free of scatter. They show dramatically improved contrast over standard imaging applied to the same phantoms. The contrast is based not only on attenuation but also the refraction and diffraction properties of the sample. The diffraction component and the apparent absorption component (absorption plus extinction contrast) can each be determined independently. This imaging method may improve the image quality for medical applications such as mammography

Simultaneous Femtosecond X-ray Spectroscopy and Diffraction of Photosystem II at Room Temperature

Science.gov (United States)

Kern, Jan; Alonso-Mori, Roberto; Tran, Rosalie; Hattne, Johan; Gildea, Richard J.; Echols, Nathaniel; Glöckner, Carina; Hellmich, Julia; Laksmono, Hartawan; Sierra, Raymond G.; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Lampe, Alyssa; Han, Guangye; Gul, Sheraz; DiFiore, Dörte; Milathianaki, Despina; Fry, Alan R.; Miahnahri, Alan; Schafer, Donald W.; Messerschmidt, Marc; Seibert, M. Marvin; Koglin, Jason E.; Sokaras, Dimosthenis; Weng, Tsu-Chien; Sellberg, Jonas; Latimer, Matthew J.; Grosse-Kunstleve, Ralf W.; Zwart, Petrus H.; White, William E.; Glatzel, Pieter; Adams, Paul D.; Bogan, Michael J.; Williams, Garth J.; Boutet, Sébastien; Messinger, Johannes; Zouni, Athina; Sauter, Nicholas K.; Yachandra, Vittal K.; Bergmann, Uwe; Yano, Junko

2013-01-01

Intense femtosecond X-ray pulses produced at the Linac Coherent Light Source (LCLS) were used for simultaneous X-ray diffraction (XRD) and X-ray emission spectroscopy (XES) of microcrystals of Photosystem II (PS II) at room temperature. This method probes the overall protein structure and the electronic structure of the Mn4CaO5 cluster in the oxygen-evolving complex of PS II. XRD data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. Our simultaneous XRD/XES study shows that the PS II crystals are intact during our measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies. PMID:23413188

A diamond-anvil high-pressure cell for X-ray diffraction on a single crystal

International Nuclear Information System (INIS)

Malinowski, M.

1987-01-01

A new diamond-anvil high-pressure cell is described which can be used in single-crystal X-ray diffraction instruments to collect X-ray intensity data from single-crystal samples up to hydrostatic pressures of about 10 GPa. A unique design allows two types of diffraction geometry to be applied in single-crystal high-pressure diffraction experiments. More than 85% of the Ewald sphere is accessible, and a continuous range of 2θ values is available from 0 up to about 160 0 . Pressure may be calibrated by the ruby fluorescence technique or by the use of an internal X-ray-standard single crystal. The design of our diamond-anvil cell would allow, with little or no modification, operation at high and low temperatures, optical studies and powder diffractometer work. (orig.)

Low energy x-ray spectrometer

International Nuclear Information System (INIS)

Woodruff, W.R.

1981-01-01

A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

High resolution X-ray diffraction studies on unirradiated

Indian Academy of Sciences (India)

High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li3+ ion beams at room temperature with a fluence value of 1 × 1014 ions/cm2. The diffraction curves of the ...

Single photon energy dispersive x-ray diffraction

International Nuclear Information System (INIS)

Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando; Suggit, Matthew J.; Wark, Justin S.; Hawreliak, James A.; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H.; Tang, Henry

2014-01-01

With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored

Single photon energy dispersive x-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando; Suggit, Matthew J.; Wark, Justin S. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Hawreliak, James A.; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Tang, Henry [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, California 94720 (United States)

2014-03-15

With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.

Apparatus development for high-pressure X-ray diffraction using synchrotron radiation

International Nuclear Information System (INIS)

Martinez, L.G.; Orlando, M.T.D.; Rossi, J.L.; Passamai Junior, J.L.; Melo, F.C.L.; Ferreira, F.F.

2006-01-01

Some phenomena in the field of condensed matter physics can be studied when the matter is submitted to extreme conditions of pressure, magnetic fields or temperatures. Once submitted to these conditions it is generally necessary to measure the properties of the matter in situ. The existence of a synchrotron light laboratory in Brazil opens up the chance of studying materials in extreme conditions by techniques like X-ray diffraction and absorption. However, when compared to high-energy synchrotrons accelerators, the Brazilian source offers a narrower energy range and lower flux. These facts impose limitation to perform diffraction experiments by energy dispersion and, consequently, the use of pressure cells with denser anvils like diamond. However, for a lower-pressure range, preliminary studies showed the viability of measurements in an angular dispersion configuration. This allows the use of silicon carbide anvils B 4C . In this work it is described the development of a hydrostatic pressure cell suitable for X-rays diffraction measurements in the Brazilian Synchrotron Light Laboratory using materials and technologies developed by the institutions and researchers involved in this project (IPEN, UFES, CTA and LNLS). This development can provide the scientific community with the possibility of performing X-ray diffraction measurements under hydrostatic pressure, initially up to 2 GPa, with possibilities of increasing the maximum pressure to higher values, with or without application of magnetic fields and high or low temperatures. (author)

Observation of parametric X-ray radiation in an anomalous diffraction region

Energy Technology Data Exchange (ETDEWEB)

Alexeyev, V.I., E-mail: vial@x4u.lebedev.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Eliseyev, A.N., E-mail: elisseev@pluton.lpi.troitsk.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Irribarra, E., E-mail: esteban.irribarra@epn.edu.ec [Escuela Politécnica Nacional, Ladrón de Guevara E11-253, Quito (Ecuador); Kishin, I.A., E-mail: ivan.kishin@mail.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Kubankin, A.S., E-mail: kubankin@bsu.edu.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation); Nazhmudinov, R.M., E-mail: fizeg@bk.ru [P.N. Lebedev Physical Institute RAS, 53 Leninskiy prospect, Moscow (Russian Federation); Belgorod National Research University, 85 Pobedy st., Belgorod (Russian Federation)

2016-08-19

A new possibility to expand the energy region of diffraction processes based on the interaction of relativistic charged particles with crystalline structures is presented. Diffracted photons related to parametric X-ray radiation produced by relativistic electrons are detected below the low energy threshold for the X-ray diffraction mechanism in crystalline structures for the first time. The measurements were performed during the interaction of 7 MeV electrons with a textured polycrystalline tungsten foil and a highly oriented pyrolytic graphite crystal. The experiment results are in good agreement with a developed model based on the PXR kinematical theory. The developed experimental approach can be applied to separate the contributions of real and virtual photons to the total diffracted radiation generated during the interaction of relativistic charged particles with crystalline targets. - Highlights: • Parametric X-ray radiation below the low energy threshold for diffraction of free X-rays. • Experimental separation of the contributions from different radiation mechanisms. • PXR from relativistic electrons in mosaic crystals and textured polycrystlas.

Diffraction peaks in x-ray spectroscopy: Friend or foe?

International Nuclear Information System (INIS)

Tissot, R.G.; Goehner, R.P.

1992-01-01

Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra. In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample

Characterization of calcium crystals in Abelia using x-ray diffraction and electron microscopes

Science.gov (United States)

Localization, chemical composition, and morphology of calcium crystals in leaves and stems of Abelia mosanensis and A. ×grandiflora were analyzed with a variable pressure scanning electron microscope (VP-SEM) equipped with an X-ray diffraction system, low temperature SEM (LT-SEM) and a transmission ...

Crystallized solids characterization by X-ray diffraction

International Nuclear Information System (INIS)

Broll, N.

1996-01-01

This work deals with the crystallized solids characterization by X-ray diffraction. The powders diffraction principle is described. Then are given the different powders diffraction experimental methods. An X-ray diffraction device is essentially constituted of three parts: the X-rays source, the sample and the detector. The source is usually constituted by an X-rays tube whereas the sample can be fixed on a photographic chamber or put on a goniometer. The different photographic chambers which can be used (Debye-Scherrer, Seeman-Bohlin and Guinier) are described. The powders diffractometer the most used is a Bragg-Brentano focusing diffractometer because it allows to obtain very sharp spectral lines and an important diffracted intensity. The detectors which are the mainly used are the scintillation counters. The most important use in powders diffractometry is the identification of the different phases of a sample. The phases identification consists to compare the unknown sample spectrum at those of standard materials indexed until now. Two methods exist at present. They are explained and their limits in the phases search are given. Another use of the X-ray diffraction is the quantitative analysis. It consists to determine the concentrations of each crystal phases of a sample. The principles of these quantitative methods are given. The lattice parameters of a polycrystal material can be determined from its X-ray pattern too with a very high precision. The way to index powders patterns is given. The residual stresses of materials can also be estimated. The principle of this measured method is explained. It is at last possible to study from an X-ray pattern, the material grain orientations during the different steps of preparation and working. (O.M.). 13 refs., 19 figs., 1 tab

Time-resolved x-ray diffraction measurement of C60 under high pressure and temperature using synchrotron radiation

International Nuclear Information System (INIS)

Horikawa, T; Suito, K; Kobayashi, M; Onodera, A

2002-01-01

C 60 has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C 60 structure are presented and the relevance to the hardness of materials derived from C 60 is discussed

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

Science.gov (United States)

Girardin, E; Millet, P; Lodini, A

2000-02-01

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

Residual stress evaluation and fatigue life prediction in the welded joint by X-ray diffraction

International Nuclear Information System (INIS)

Yoo, Keun Bong; Kim, Jae Hoon

2009-01-01

In the fossil power plant, the reliability of the components which consist of the many welded parts depends on the quality of welding. The residual stress is occurred by the heat flux of high temperature during weld process. This decreases the mechanical properties as the strength of fatigue and fracture or occurs the stress corrosion cracking and fatigue fracture. The residual stress of the welded part in the recently constructed power plants has been the cause of a variety of accidents. The objective of this study is measurement of the residual stress by X-ray diffraction method and to estimate the feasibility of this application for fatigue life assessment of the high-temperature pipeline. The materials used for the study is P92 steel for the use of high temperature pipe on super critical condition. The test results were analyzed by the distributed characteristics of residual stresses and the Full Width at Half Maximum intensity (FWHM) in x-ray diffraction intensity curve. Also, X-ray diffraction tests using specimens simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages. As a result of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the ratio of the FWHM due to fatigue damage has linear relationship with fatigue life ratio algebraically. From this relationships, it was suggested that direct expectation of the life consumption rate was feasible.

100 years of discovery of X-ray diffraction

International Nuclear Information System (INIS)

Zhang Tao

2012-01-01

X-ray diffraction was discovered by Max von Laue a hundred years ago. Later, through the work of William H. Bragg and William L. Bragg, an experimental analysis method was developed to solve the structure of molecules at the atomic level. Over the past hundred years, science and technology has been dramatically changed by X-ray diffraction analysis, which has also undergone considerable development. The recent emergence of hard X-ray free electron lasers has provided a new dimension for X-ray diffraction analysis, promising even greater progress in the fields of physics, chemistry and biology. (author)

Scattering of x rays from low-Z materials

International Nuclear Information System (INIS)

Gaines, J.L.; Kissel, L.D.; Catron, H.C.; Hansen, R.A.

1980-01-01

X rays incident on thin beryllium, boron, carbon, and other low-Z materials undergo both elastic and inelastic scattering as well as diffraction from the crystalline or crystalline-like structure of the material. Unpolarized monoenergetic x rays in the 1.5 to 8.0-keV energy range were used to determine the absolute scattering efficiency of thin beryllium, carbon, and boron foils. These measurements are compared to calculated scattering efficiencies predicted by single-atom theories. In addition, the relative scattering efficiency versus x-ray energy was measured for other low-Z foils using unpolarized bremsstrahlung x rays. In all the low-Z foils examined, we observed Bragg-like x-ray diffraction due to the ordered structure of the materials

In situ X-ray powder diffraction, synthesis, and magnetic properties of InVO 3

Science.gov (United States)

Lundgren, Rylan J.; Cranswick, Lachlan M. D.; Bieringer, Mario

2006-12-01

We report the first synthesis and high-temperature in situ X-ray diffraction study of InVO 3. Polycrystalline InVO 3 has been prepared via reduction of InVO 4 using a carbon monoxide/carbon dioxide buffer gas. InVO 3 crystallizes in the bixbyite structure in space group Ia-3 (206) with a=9.80636(31) Å with In 3+/V 3+ disorder on the (8 b) and (24 d) cation sites. In situ powder X-ray diffraction experiments and thermal gravimetric analysis in a CO/CO 2 buffer gas revealed the existence of the metastable phase InVO 3. Bulk samples with 98.5(2)% purity were prepared using low-temperature reduction methods. The preparative methods limited the crystallinity of this new phase to approximately 225(50) Å. Magnetic susceptibility and neutron diffraction experiments suggest a spin-glass ground state for InVO 3.

Diffracted X-ray tracking: new system for single molecular detection with X-rays

CERN Document Server

Sasaki, Y C; Adachi, S; Suzuki, Y; Yagi, N

2001-01-01

We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements.

Diffracted X-ray tracking: new system for single molecular detection with X-rays

International Nuclear Information System (INIS)

Sasaki, Y.C.; Okumura, Y.; Adachi, S.; Suzuki, Y.; Yagi, N.

2001-01-01

We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements

Introducing the ARL X'Tra x-ray diffraction system

International Nuclear Information System (INIS)

Harris, L.

2002-01-01

Full text: The ARL X'Tra is a state-of-the-art solution for powder X-ray diffraction in a large range of applications such as pharmaceuticals and biosciences, chemicals, earth sciences, semi-conductors, metallurgy and ceramics. The X'Tra offers the latest technology in key diffraction components to produce a high performance instrument at an affordable price. This presentation examines some of the hardware and performance features of this instrument. Copyright (2002) Australian X-ray Analytical Association Inc

Application of in-situ nano-scanning calorimetry and X-ray diffraction to characterize Ni–Ti–Hf high-temperature shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

McCluskey, Patrick J., E-mail: mccluske@ge.com [GE Global Research, One Research Circle, Niskayuna, NY 12309 (United States); Xiao, Kechao [School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 (United States); Gregoire, John M. [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Dale, Darren [Cornell High Energy Synchrotron Source, Ithaca, NY 14853 (United States); Vlassak, Joost J. [School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 (United States)

2015-03-10

Combinatorial nanocalorimetry and synchrotron X-ray diffraction were combined to study the martensite–austenite (M–A) phase transformation behavior of Ni–Ti–Hf shape memory alloys. A thin-film library of Ni–Ti–Hf samples with a range of compositions was deposited on a parallel nano-scanning calorimeter device using sputter deposition. Crystallization of each amorphous as-deposited sample by local heating at approximately 10{sup 4} K/s produced a nanoscale grain structure of austenite and martensite. Individual samples were then cycled through the M–A transformation, while the transformation enthalpy was measured by nanocalorimetry and the low- and high-temperature phase compositions were determined by X-ray diffraction. The techniques enable correlation of the observed behavior during thermal cycling with the thermodynamic and structural properties of the samples.

Evaluation of In-Vacuum Imaging Plate Detector for X-Ray Diffraction Microscopy

International Nuclear Information System (INIS)

Nishino, Yoshinori; Takahashi, Yukio; Yamamoto, Masaki; Ishikawa, Tetsuya

2007-01-01

We performed evaluation tests of a newly developed in-vacuum imaging plate (IP) detector for x-ray diffraction microscopy. IP detectors have advantages over direct x-ray detection charge-coupled device (CCD) detectors, which have been commonly used in x-ray diffraction microscopy experiments, in the capabilities for a high photon count and for a wide area. The detector system contains two IPs to make measurement efficient by recording data with the one while reading or erasing the other. We compared speckled diffraction patterns of single particles taken with the IP and a direct x-ray detection CCD. The IP was inferior to the CCD in spatial resolution and in signal-to-noise ratio at a low photon count

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

International Nuclear Information System (INIS)

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

2016-01-01

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

X-ray diffraction investigation of spin reorientation in SmFe2

International Nuclear Information System (INIS)

Gaviko, V.S.; Korolyov, A.V.; Mushnikov, N.V.

1996-01-01

Spontaneous magnetoelastic crystal lattice distortions in the spin reorientation region of high magnetostrictive SmFe 2 have been investigated by X-ray diffraction in the temperature range 80-300 K. Comparison of experimental shapes of X-ray diffraction lines with calculated shapes shows that, in the region of the spin reorientation transition, a mixture of left angle 110 right angle and left angle 111 right angle phases rather than the angular left angle uuw right angle -type phase is realized. The temperature dependence of the relative volume content of left angle 110 right angle and left angle 111 right angle phases is determined using least-squares fitting. (orig.)

Submicron X-ray diffraction

International Nuclear Information System (INIS)

MacDowell, Alastair; Celestre, Richard; Tamura, Nobumichi; Spolenak, Ralph; Valek, Bryan; Brown, Walter; Bravman, John; Padmore, Howard; Batterman, Boris; Patel, Jamshed

2000-01-01

At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The instrument is for instance, capable of probing a sub-micron size volume inside micron sized aluminum metal grains buried under a silicon dioxide insulating layer. The resulting Laue pattern is collected on a large area CCD detector and automatically indexed to yield the grain orientation and deviatoric (distortional) strain tensor of this sub-micron volume. A four-crystal monochromator is then inserted into the beam, which allows monochromatic light to illuminate the same part of the sample. Measurement of diffracted photon energy allows for the determination of d spacings. The combination of white and monochromatic beam measurements allow for the determination of the total strain/stress tensor (6 components) inside each sub-micron sized illuminated volume of the sample

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

Energy Technology Data Exchange (ETDEWEB)

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.; Hunt, D.; Hahn, D.; Cradick, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Morgan, D. V. [National Security Technologies LLC, Los Alamos, New Mexico 87544 (United States)

2016-08-15

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

Determination of equilibrium humidities using temperature and humidity controlled X-ray diffraction (RH-XRD)

International Nuclear Information System (INIS)

Linnow, Kirsten; Steiger, Michael

2007-01-01

Confined growth of crystals in porous building materials is generally considered to be a major cause of damage. We report on the use of X-ray diffraction under controlled conditions of temperature and relative humidity (RH-XRD) for the investigation of potentially deleterious phase transition reactions. An improved procedure based on rate measurements is used for the accurate and reproducible determination of equilibrium humidities of deliquescence and hydration reactions. The deliquescence humidities of NaCl (75.4 ± 0.5% RH) and Ca(NO 3 ) 2 .4H 2 O (50.8 ± 0.7% RH) at 25 deg. C determined with this improved RH-XRD technique are in excellent agreement with available literature data. Measurement of the hydration of anhydrous Ca(NO 3 ) 2 to form Ca(NO 3 ) 2 .2H 2 O revealed an equilibrium humidity of 10.2 ± 0.3%, which is also in reasonable agreement with available data. In conclusion, dynamic X-ray diffraction measurements are an appropriate method for the accurate and precise determination of equilibrium humidities with a number of interesting future applications

Temperature gradient method for lipid phase diagram construction using time-resolved x-ray diffraction

International Nuclear Information System (INIS)

Caffrey, M.; Hing, F.S.

1987-01-01

A method that enables temperature-composition phase diagram construction at unprecedented rates is described and evaluated. The method involves establishing a known temperature gradient along the length of a metal rod. Samples of different compositions contained in long, thin-walled capillaries are positioned lengthwise on the rod and equilibrated such that the temperature gradient is communicated into the sample. The sample is then moved through a focused, monochromatic synchrotron-derived x-ray beam and the image-intensified diffraction pattern from the sample is recorded on videotape continuously in live-time as a function of position and, thus, temperature. The temperature at which the diffraction pattern changes corresponds to a phase boundary, and the phase(s) existing (coexisting) on either side of the boundary can be identified on the basis of the diffraction pattern. Repeating the measurement on samples covering the entire composition range completes the phase diagram. These additional samples can be conveniently placed at different locations around the perimeter of the cylindrical rod and rotated into position for diffraction measurement. Temperature-composition phase diagrams for the fully hydrated binary mixtures, dimyristoylphosphatidylcholine (DMPC)/dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE)/DPPC, have been constructed using the new temperature gradient method. They agree well with and extend the results obtained by other techniques. In the DPPE/DPPC system structural parameters as a function of temperature in the various phases including the subgel phase are reported. The potential limitations of this steady-state method are discussed

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

Energy Technology Data Exchange (ETDEWEB)

Murray, Thomas D. [University of California, Berkeley, CA 94720 (United States); Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Lyubimov, Artem Y. [Stanford University, Stanford, CA 94305 (United States); Ogata, Craig M. [Argonne National Laboratory, Argonne, IL 60439 (United States); Vo, Huy [Johns Hopkins University, Baltimore, MD 21205 (United States); Uervirojnangkoorn, Monarin; Brunger, Axel T., E-mail: brunger@stanford.edu [Stanford University, Stanford, CA 94305 (United States); Berger, James M., E-mail: brunger@stanford.edu [Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); University of California, Berkeley, CA 94720 (United States)

2015-09-26

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs. Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming 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.

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

International Nuclear Information System (INIS)

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.; Vo, Huy; Uervirojnangkoorn, Monarin; Brunger, Axel T.; Berger, James M.

2015-01-01

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs. Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming 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

Three-dimensional x-ray diffraction detection and visualization

International Nuclear Information System (INIS)

Allahkarami, Masoud; Hanan, Jay C

2014-01-01

A new method of sensing and analyzing three-dimensional (3D) x-ray diffraction (XRD) cones was introduced. Using a two-dimensional area detector, a sequence of frames was collected while moving the detector away from the sample with small equally spaced steps and keeping all other parameters constant. A 3D dataset was created from the subsequent frames. The 3D x-ray diffraction (XRD 3 ) pattern contains far more information than a one-dimensional profile collected with the conventional diffractometer and 2D x-ray diffraction (XRD 2 ). The present work discusses some fundamentals about XRD 3 , such as the data collection method, 3D visualization, diffraction data interpretation and potential applications of XRD 3 . (paper)

Time-resolved x-ray diffraction measurement of C{sub 60} under high pressure and temperature using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Horikawa, T [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Suito, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Kobayashi, M [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Onodera, A [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

2002-11-11

C{sub 60} has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C{sub 60} structure are presented and the relevance to the hardness of materials derived from C{sub 60} is discussed.

Performances for confocal X-ray diffraction technology based on polycapillary slightly focusing X-ray optics

Energy Technology Data Exchange (ETDEWEB)

Liu, Hehe; Liu, Zhiguo [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi, E-mail: stxbeijing@163.com [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Peng, Song [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Ma, Yongzhong [Center for Disease Control and Prevention of Beijing, Beijing 100013 (China); Sun, Weiyuan; Li, Yude; Lin, Xiaoyan; Zhao, Weigang; Zhao, Guangcui; Luo, Ping; Pan, Qiuli; Ding, Xunliang [The Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

2013-09-21

The confocal X-ray diffraction (XRD) technology based on a polycapillary slightly focusing X-ray lens (PSFXRL) in excitation channel and a polycapillary parallel X-ray lens (PPXRL) with a long input focal distance in detection channel was developed. The output focal spot of the PSFXRL and the input focal spot of the PPXRL were adjusted in confocal configuration, and only the X-rays from the volume overlapped by these foci could be accordingly detected. This confocal configuration was helpful in decreasing background. The convergence of the beam focused by the PSFXRL and divergence of the beam which could be collected by the PPXRL with a long input focal distance were both about 9 mrad at 8 keV. This was helpful in improving the resolution of lattice spacing of this confocal XRD technology. The gain in power density of such PSFXRL and PPXRL was about 120 and 7 at 11 keV, respectively, which was helpful in using the low power source to perform XRD analysis efficiently. The performances of this confocal XRD technology were provided, and some common plastics were analyzed. The experimental results demonstrated that the confocal diffraction technology base on polycapillary slightly focusing X-ray optics had wide potential applications.

Rapid, low dose X-ray diffractive imaging of the malaria parasite Plasmodium falciparum

International Nuclear Information System (INIS)

Jones, Michael W.M.; Dearnley, Megan K.; Riessen, Grant A. van; Abbey, Brian; Putkunz, Corey T.; Junker, Mark D.; Vine, David J.; McNulty, Ian; Nugent, Keith A.; Peele, Andrew G.; Tilley, Leann

2014-01-01

Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. - Highlights: • Phase-diverse coherent X-ray diffraction microscopy provides high-resolution and high-contrast images of intact biological samples. • Rapid nanoscale resolution imaging is demonstrated at orders of magnitude lower dose than previously possible. • Phase-diverse coherent X-ray diffraction microscopy is a robust technique for rapid, quantitative, and correlative X-ray phase imaging

Rapid, low dose X-ray diffractive imaging of the malaria parasite Plasmodium falciparum

Energy Technology Data Exchange (ETDEWEB)

Jones, Michael W.M., E-mail: michael.jones@latrobe.edu.au [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Dearnley, Megan K. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia); Riessen, Grant A. van [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Abbey, Brian [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Melbourne Centre for Nanofabrication, Victoria 3168 (Australia); Putkunz, Corey T. [ARC Centre of Excellence for Coherent X-Ray Science, School of Physics, The University of Melbourne, Victoria 3010 (Australia); Junker, Mark D. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Vine, David J. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); McNulty, Ian [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Centre for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Nugent, Keith A. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Peele, Andrew G. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Australian Synchrotron, 800 Blackburn Road, Clayton 3168 (Australia); Tilley, Leann [ARC Centre of Excellence for Coherent X-Ray Science, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia)

2014-08-01

Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. - Highlights: • Phase-diverse coherent X-ray diffraction microscopy provides high-resolution and high-contrast images of intact biological samples. • Rapid nanoscale resolution imaging is demonstrated at orders of magnitude lower dose than previously possible. • Phase-diverse coherent X-ray diffraction microscopy is a robust technique for rapid, quantitative, and correlative X-ray phase imaging.

Thin film characterisation by advanced X-ray diffraction techniques

International Nuclear Information System (INIS)

Cappuccio, G.; Terranova, M.L.

1996-09-01

The Fifth School on X-ray diffraction from polycrystalline materials was devoted to thin film characterization by advanced X-ray diffraction techniques. Twenty contributions are contained in this volume; all twenty are recorded in the INIS Database. X-ray diffraction is known to be a powerful analytical tool for characterizing materials and understanding their structural features. The aim of these articles is to illustrate the fundamental contribution of modern diffraction techniques (grazing incidence, surface analysis, standing waves, etc.) to the characterization of thin and ultra-thin films, which have become important in many advanced technologies

Multiple x-ray diffraction simulation and applications

International Nuclear Information System (INIS)

Costa, C.A.B.S. da.

1989-09-01

A computer program (MULTX) was implemented for simulation X-ray multiple diffraction diagrams in Renninger geometries. The program uses the X-ray multiple diffraction theory for imperfect crystals. The iterative calculation of the intensities is based on the Taylor series general term, and the primary beam power expansion is given as function of the beam x penetration in the crystal surface. This development allows to consider the simultaneous interaction of the beams involved in the multiple diffraction phenomenon. The simulated diagrams are calculated point-to-point and the tests for the Si and GaAs presented good reproduction of the experimental diagrams for different primary reflections. (L.C.J.A.)

CCD-based X-ray detectors for X-ray diffraction studies

International Nuclear Information System (INIS)

Ito, K.; Amemiya, Y.

1999-01-01

CCD-based X-ray detectors are getting to be used for X-ray diffraction studies especially in the studies where real time (automated) measurements and time-resolved measurements are required. Principles and designs of two typical types of CCD-based detectors are described; one is ths system in which x-ray image intensifiers are coupled to maximize the detective quantum efficiency for time-resolved measurements, and the other is the system in which tapered optical fibers are coupled for the reduction of the image into the CCD, which is optimized for automated measurements for protein crystallography. These CCD-based X-ray detectors have an image distortion and non-uniformity of response to be corrected by software. Correction schemes which we have developed are also described. (author)

EPR and X-ray diffraction investigation of some Greek marbles and limestones

International Nuclear Information System (INIS)

Duliu, Octavian; Grecu, Maria Nicoleta; Cristea, Corina

2009-01-01

Twelve different marble and limestone samples collected from well-known Greek quarries have been investigated by X-ray diffraction and electron paramagnetic resonance (EPR). X-ray diffraction spectra permitted to determine both major (calcite and dolomite) and minor (quartz or magnesite) mineralogical components. EPR has been used to investigate the same samples unirradiated and after 10 kGy gamma-ray irradiation. The unirradiated samples display typical EPR spectra of Mn 2+ in calcite and dolomite as well as a superposition of these while some samples displayed EPR free radicals signals of centers (low field signal) and centers (high field signal). From X-ray diffraction and EPR spectra it was possible to extract numerical values of several numerical parameters such as dolomite to calcite ratio, EPR intensity parameter, and low field to high field EPR signals intensity ratio. These values as well as the correlation coefficients between the digital functions that described the low field Mn 2+ ions EPR line have been used as entry data for cluster analysis to quantify the resemblance and differences between analyzed samples. (authors)

In-situ oxidation study of Pd(100) by surface x-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Kilic, Volkan; Franz, Dirk; Stierle, Andreas [AG Grenzflaechen, Universitaet Siegen (Germany); Martin, Natalia; Lundgren, Edvin [Department of Synchrotron Radiation Research, Lund University (Sweden); Mantilla, Miguel [MPI fuer Metallforschung, Stuttgart (Germany)

2011-07-01

The oxidation of the Pd(100) surface at oxygen pressures in the 10{sup -6} mbar to 10{sup 3} mbar range and temperatures up to 1000 K has been studied in-situ by surface x-ray diffraction (SXRD). The SXRD experiments were performed at the MPI beamline at the Angstrom Quelle Karlsruhe (ANKA). We present the surface and crystal truncation rod (CTR) data from the ({radical}(5) x {radical}(5)) surface layer. We show that the transformation from the surface oxide to PdO bulk oxide can be observed in-situ under specific pressure and temperature conditions. We compare our results with previously proposed structure models based on low energy electron diffraction (LEED) I(V) curves and density functional theory calculations. Finally, we elucidate the question of commensurability of the surface oxide layer with respect to the Pd(100) substrate.

X-ray diffraction

International Nuclear Information System (INIS)

Einstein, J.R.; Wei, C.H.

1982-01-01

We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

X-ray diffraction device comprising cooling medium connections provided on the x-ray tube

NARCIS (Netherlands)

1996-01-01

An X-ray diffraction device comprises a water-cooled X-ray tube which exhibits a line focus as well as, after rotation through 90 DEG , a point focus. Contrary to customary X-ray tubes, the cooling water is not supplied via the housing (12) in which the X-ray tube is mounted, but the cooling water

Characterization of Metalloproteins and Biomaterials by X-ray Absorption Spectroscopy and X-ray Diffraction

DEFF Research Database (Denmark)

Frankær, Christian Grundahl

This thesis presents thework on combining complementary X-rays techniques for studying the structures of proteins and other biomaterials, and consists of three different projects: (i) Characterization of protein powders with X-ray powder diffraction (XRPD). (ii) The combination of X-ray...... crystallography and X-ray absorption spectroscopy (XAS) applied to studying different hexameric insulin conformations. (iii) The structures of polymorphs of strontium ranelate and the distribution of strontium in bone tissue. A procedure for fast identification and verification of protein powders using XRPD...... was correction for disordered bulk-solvent, but also correction for background and optimization of unit cell parameters have to be taken into account. A sample holder was designed for collecting powder diffraction data on a standard laboratory X-ray powder diffractometer. The background was reduced by use...

Space resolved x-ray diffraction measurements of the supercooled state of polymers

International Nuclear Information System (INIS)

Asano, Tsutomu; Yoshida, Shinya; Nishida, Akira; Mina, M.F.

2002-01-01

In order to measure an ordering process of polymers, the supercooled state near the crystallizing surface was observed by a space resolved X-ray diffraction method at Photon Factory (PF). Using temperature slope crystallization, low density polyethylene and even-number paraffins were examined during crystallization from the melt state. The results indicate that polyethylene shows a sharp b-axis orientation where the lamellar normal and crystalline c-axis are perpendicular to the temperature slope. The crystalline lamellae are well-developed with lamellar thickness of 180 A. The supercooled melt state just above the crystallizing plane shows some diffraction in the small angle region without any crystalline reflection in the wide angle. This fact suggests that a long-range ordering (lamellar structure) appears prior to the short-range one (crystalline structure). The in-situ crystallizing surface was observed by an optical microscope connected to a TV system. The crystallizing surface of even-number paraffins moves to upwards in the temperature slope. In-situ X-ray measurements at PF revealed that the crystalline c-axis and lamellar normal of the even number paraffins are parallel to the temperature slope. From these results, the crystalline ordering and the surface movement of even number paraffins are explained using special nucleation mechanism including a screw dislocation. (author)

Serial femtosecond X-ray diffraction of enveloped virus microcrystals

Directory of Open Access Journals (Sweden)

Robert M. Lawrence

2015-07-01

Full Text Available Serial femtosecond crystallography (SFX using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ∼700 Å diameter. Microcrystals delivered in viscous agarose medium diffracted to ∼40 Å resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is an important step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

X-ray photoelectron spectroscopy, high-resolution X-ray diffraction ...

Indian Academy of Sciences (India)

the crystalline quality through full-width at half-maximum values. .... angular divergence of ∆α = 12 arc sec. X-rays generated from the monochromator were diffracted from (0 0 6) LiNbO3 atomic planes with the (+, −, −, +, +) geometry. [8].

High-pressure X-ray diffraction studies of potassium chlorate

Energy Technology Data Exchange (ETDEWEB)

Pravica, Michael; Bai, Ligang; Bhattacharya, Neelanjan (UNLV)

2012-03-15

Two static high-pressure X-ray diffraction (XRD) studies of potassium chlorate have been performed at pressures of up to {approx}14.3 GPa in a diamond anvil cell at ambient temperature using the 16 ID-B undulator beamline at the Advanced Photon Source for the X-ray source. The first experiment was conducted to ascertain decomposition rates of potassium chlorate as a function of pressure. Below 2 GPa, the sample was observed to decompose rapidly in the presence of the X-ray beam and release oxygen. Above 2 GPa (near the phase I phase II transition), the decomposition rate dramatically slowed so that good quality XRD patterns could be acquired. This suggests a phase-dependent decomposition rate. In the second study, X-ray diffraction spectra were collected at pressures from 2 to 14.3 GPa by aligning virgin portions of the sample into the focused X-ray beam at each pressure. The results suggest the co-existence of mixed monoclinic (I) and rhombohedral (II) phases of potassium chlorate near 2 GPa. At pressures beyond 4 GPa, the XRD patterns show a very good fit to KClO{sub 3} in the rhombohedral phase with space group R3m, in agreement with earlier studies. No further phase transitions were observed with pressure. Decompression of the sample to ambient pressure indicated mixed phases I and II coupled with a small amount of synchrotron X-ray-induced decomposition product. The equation of state within this pressure regime has been determined.

Polarisation resonance in X-ray diffraction

International Nuclear Information System (INIS)

Goodman, P.; Paterson, D.; Matheson, S.

1994-01-01

The study of crystal structures by means of dynamic X-ray diffraction has placed a challenge to theoreticians to revise the X-ray diffraction theory based on Maxwell's equation. In this paper the feasibility of using 'polarisation resonance' as a tool in the determination of absolute configuration for asymmetric structures is investigated. Two (left- and right-handed), σ + and σ- , circular polarization states for 3-beam conditions are considered. Moreover, extending interaction into the 3 rd. dimension (normal to the beam) opens the possibility of absolute configuration determination of asymmetric structures in 3 dimensions. The computational scheme used is shown in terms of scattering diagrams. 7 refs., 1 tab., 6 figs

On the theory of time-resolved x-ray diffraction

DEFF Research Database (Denmark)

Henriksen, Niels Engholm; Møller, Klaus Braagaard

2008-01-01

We derive the basic theoretical formulation for X-ray diffraction with pulsed fields, using a fully quantized description of light and matter. Relevant time scales are discussed for coherent as well as incoherent X-ray pulses, and we provide expressions to be used for calculation...... of the experimental diffraction signal for both types of X-ray sources. We present a simple analysis of time-resolved X-ray scattering for direct bond breaking in diatomic molecules. This essentially analytical approach highlights the relation between the signal and the time-dependent quantum distribution...

Soft x-ray resonant magnetic powder diffraction on PrNiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Staub, U [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); GarcIa-Fernandez, M [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Mulders, A M [Department of Applied Physics, Curtin University of Technology, GPO Box U1987, Perth WA 6845 (Australia); Bodenthin, Y [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); MartInez-Lope, M J [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain); Alonso, J A [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain)

2007-03-07

We report on the first soft x-ray resonant powder diffraction experiments performed at the Ni L{sub 2,3} edges of PrNiO{sub 3}. The temperature, polarization and energy dependence of the (1/2 0 1/2) reflection indicates a magnetic origin for the signal. This experiment demonstrates that x-ray resonant magnetic powder diffraction can be relatively easily performed in the soft x-ray regime due to the very large enhancement factors at the absorption edges. Such experiments allow us to extract important information on the electronic states of the d shell. Similar results can be anticipated from orbital reflections measured in a powder. (fast track communication)

High-pressure X-ray diffraction of L-ALANINE crystal

DEFF Research Database (Denmark)

Olsen, J.S.; Gerward, Leif; Souza, A.G.

2006-01-01

L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3 GPa. The material is found to transform to a tetragonal structure between 2 and 3 GPa. and to a monoclinic structure between 8 and 10 GPa. The experimental bulk modulus is 25(5) GPa for the orthorhombic...

X-ray diffraction and imaging with a coherent beam: application to X-ray optical elements and to crystals exhibiting phase inhomogeneities

International Nuclear Information System (INIS)

Masiello, F.

2011-05-01

The exceptional properties of synchrotron light sources have been exploited in very different disciplines, from archaeology to chemistry, from material science to biology, from medicine to physics. Among these properties it is important to mention the high brilliance, continuum spectrum, high degree of polarization, time structure, small source size and divergence of the beam, the last resulting in a high transversal coherence of the produced radiation. This high transversal coherence of the synchrotron sources has permitted the development of new techniques, e.g. phase contrast imaging, X-ray photon correlation spectroscopy and coherent X-ray diffraction imaging (CXDI). This thesis work will consist essentially of three parts. In the first part it will be presented the work done as a member of the X-ray Optics Group of ESRF in the characterization of high quality diamond crystals foreseen as X-ray optical elements. The characterization has been done using different complementary X-ray techniques, such as high resolution diffraction, topography, grazing incidence diffraction, reflectivity and measurements of the coherence preservation using the Talbot effect. In the second part, I will show the result obtained in the study of the temperature behaviours of the domain in periodically poled ferroelectrics crystals. This type of measurements, based on Bragg-Fresnel diffraction, are possible only thanks to the high degree of coherence of the beam. In the third part, I will present the results obtained in the characterization of diamonds foreseen for applications other than X-ray optical elements. (author)

Controlled molecules for X-ray diffraction experiments at free-electron lasers

International Nuclear Information System (INIS)

Stern, Stephan

2013-12-01

performed on a gas-phase ensemble of the prototypical molecule 2,5-diiodobenzonitrile (C 7 H 3 I 2 N, DIBN) at the X-ray free-electron laser LCLS. The target molecules were laser-aligned along a common axis in the laboratory frame by a Nd:YAG laser. Reaching a strong degree of molecular alignment, was an important step in this experiment. Therefore, a significant part of the work was dedicated to gaining control of the molecular degrees of freedom. In order to reach a high degree of alignment, the target molecules were prepared in low rotational quantum states by means of efficient cooling in a supersonic expansion from a pulsed valve followed by spatial quantum-state selection in an electrostatic deflector. Utilization of the deflector significantly improved alignment of the DIBN molecules. Further applications of the deection technique such as, e.g., the spatial separation of several species of molecular complexes/clusters are presented in this thesis as well. The quantum-state selected and strongly laser-aligned samples were probed by the X-ray pulses of LCLS and the obtained diffraction patterns show a significant difference when comparing diffraction from aligned and isotropically-distributed DIBN which agrees well with theory. The results represent an important step in the effort of pushing diffractive imaging of non-crystalline samples at XFELs towards the single-molecule limit. Concepts and experimental requirements for future experiments of this kind are discussed, involving, e.g., the step towards imaging of laser-aligned large (bio)macromolecules or imaging of ultrafast fragmentation dynamics in femtosecond pump-probe experiments at XFELs.

Controlled molecules for X-ray diffraction experiments at free-electron lasers

Energy Technology Data Exchange (ETDEWEB)

Stern, Stephan

2013-12-15

performed on a gas-phase ensemble of the prototypical molecule 2,5-diiodobenzonitrile (C{sub 7}H{sub 3}I{sub 2}N, DIBN) at the X-ray free-electron laser LCLS. The target molecules were laser-aligned along a common axis in the laboratory frame by a Nd:YAG laser. Reaching a strong degree of molecular alignment, was an important step in this experiment. Therefore, a significant part of the work was dedicated to gaining control of the molecular degrees of freedom. In order to reach a high degree of alignment, the target molecules were prepared in low rotational quantum states by means of efficient cooling in a supersonic expansion from a pulsed valve followed by spatial quantum-state selection in an electrostatic deflector. Utilization of the deflector significantly improved alignment of the DIBN molecules. Further applications of the deection technique such as, e.g., the spatial separation of several species of molecular complexes/clusters are presented in this thesis as well. The quantum-state selected and strongly laser-aligned samples were probed by the X-ray pulses of LCLS and the obtained diffraction patterns show a significant difference when comparing diffraction from aligned and isotropically-distributed DIBN which agrees well with theory. The results represent an important step in the effort of pushing diffractive imaging of non-crystalline samples at XFELs towards the single-molecule limit. Concepts and experimental requirements for future experiments of this kind are discussed, involving, e.g., the step towards imaging of laser-aligned large (bio)macromolecules or imaging of ultrafast fragmentation dynamics in femtosecond pump-probe experiments at XFELs.

X-ray topography under conditions of monochromatic spherical wave diffraction

International Nuclear Information System (INIS)

Aristov, V.V.; Polovinkina, V.I.; Ibhikawa, Tetsuya; Kiduta, Seishi.

1981-01-01

An X-ray topographic scheme was developed in which there is a large distance between the X-ray source and the specimen. A monochromatic X-ray beam with an angular divergence 6 x 10 - 5 rad obtained by double successive diffraction in the (n 1 , +n 2 ) setting was used. This scheme enables diffraction focusing of a weakly absorbed wave field onto the exit surface of the crystal to be performed. Topographs of a wedge-shaped silicon crystal were obtained. Interference effects such as focusing, anomalous and ordinary Pendelloesung effects peculiar to X-ray spherical wave diffraction were observed in the topographs with high resolution. (author)

The phase problem and perspectives of surface X-ray diffraction

International Nuclear Information System (INIS)

Tajiri, Hiroo; Takahashi, Toshio

2009-01-01

The emergence of synchrotron radiation sources has accelerated the application of diffraction techniques to surface sciences. Surface X-ray diffraction has become the state-of-the-art technique for determining ordered structures of atoms on crystal surfaces. We introduce surface X-ray diffraction briefly from the historical point of view and describe the concept that not only determine constellation of surface atoms but also view surface atoms as image. The progress in experimental and theoretical studies of surface X-ray diffraction including crystallographic direct methods is reviewed. (author)

Au/iron oxide catalysts: temperature programmed reduction and X-ray diffraction characterization

International Nuclear Information System (INIS)

Neri, G.; Visco, A.M.; Galvagno, S.; Donato, A.; Panzalorto, M.

1999-01-01

Gold on iron oxides catalysts have been characterized by temperature programmed reduction (TPR) and X-ray diffraction spectroscopy (XRD). The influence of preparation method, gold loading and pretreatment conditions on the reducibility of iron oxides have been investigated. On the impregnated Au/iron oxide catalysts as well as on the support alone the partial reduction of Fe(III) oxy(hydroxides) to Fe 3 O 4 starts in the 550 and 700 K temperature range. On the coprecipitated samples, the temperature of formation of Fe 3 O 4 is strongly dependent on the presence of gold. The reduction temperature is lowered as the gold loading is increased. The reduction of Fe 3 O 4 to FeO occurs at about 900 K and is not dependent on the presence of gold and the preparation method. It is suggested that the effect of gold on the reducibility of the iron oxides is related to an increase of the structural defects and/or of the surface hydroxyl groups. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Line x-ray source for diffraction enhanced imaging in clinical and industrial applications

Science.gov (United States)

Wang, Xiaoqin

Mammography is one type of imaging modalities that uses a low-dose x-ray or other radiation sources for examination of breasts. It plays a central role in early detection of breast cancers. The material similarity of tumor-cell and health cell, breast implants surgery and other factors, make the breast cancers hard to visualize and detect. Diffraction enhanced imaging (DEI), first proposed and investigated by D. Chapman is a new x-ray radiographic imaging modality using monochromatic x-rays from a synchrotron source, which produced images of thick absorbing objects that are almost completely free of scatter. It shows dramatically improved contrast over standard imaging when applied to the same phantom. The contrast is based not only on attenuation but also on the refraction and diffraction properties of the sample. This imaging method may improve image quality of mammography, other medical applications, industrial radiography for non-destructive testing and x-ray computed tomography. However, the size, and cost, of a synchrotron source limits the application of the new modality to be applicable at clinical levels. This research investigates the feasibility of a designed line x-ray source to produce intensity compatible to synchrotron sources. It is composed of a 2-cm in length tungsten filament, installed on a carbon steel filament cup (backing plate), as the cathode and a stationary oxygen-free copper anode with molybdenum coating on the front surface serves as the target. Characteristic properties of the line x-ray source were computationally studied and the prototype was experimentally investigated. SIMIION code was used to computationally study the electron trajectories emanating from the filament towards the molybdenum target. A Faraday cup on the prototype device, proof-of-principle, was used to measure the distribution of electrons on the target, which compares favorably to computational results. The intensities of characteristic x-ray for molybdenum

An X-ray diffraction study of corrosion products from low carbon steel

International Nuclear Information System (INIS)

Morales, A. L.

2003-01-01

It was found in earlier work a decrease in the corrosion rate from low carbon steel when it was subjected to the action of a combined pollutant concentration (SO 4 ''2-=10''-4 M+Cl=1.5x 10''-3 M). It was also found that large magnetic content of the rust was related to higher corrosion rates. In the present study corrosion products are further analyzed by means of X-ray diffraction to account for composition changes during the corrosion process. it is found that lepidocrocite and goethite are the dominant components for the short-term corrosion in all batches considered while for log-term corrosion lepidocrite and goethite dominates if the corrosion rates is low and magnetite dominates if the corrosion rate is high. The mechanism for decreasing the corrosion rate is related to the inhibition of magnetite production at this particular concentration. (Author) 15 refs

Synchrotron x-ray diffraction study of liquid surfaces

DEFF Research Database (Denmark)

Als-Nielsen, Jens Aage; Pershan, P.S.

1983-01-01

A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented.......A spectrometer for X-ray diffraction and refraction studies of horizontal, free surfaces of liquids is described. As an illustration smetic-A layering at the surface of a liquid crystal is presented....

Fusion bonding of Si wafers investigated by x ray diffraction

DEFF Research Database (Denmark)

Weichel, Steen; Grey, Francois; Rasmussen, Kurt

2000-01-01

The interface structure of bonded Si(001) wafers with twist angle 6.5 degrees is studied as a function of annealing temperature. An ordered structure is observed in x-ray diffraction by monitoring a satellite reflection due to the periodic modulation near the interface, which results from...

Small angles X-ray diffraction and Mössbauer characterization of ...

Indian Academy of Sciences (India)

The effect of thermal annealing on the structure and magnetic properties of crystalline Tb/Fe multilayers has been studied using conversion electron Mössbauer spectrometry and small-angle X-ray diffraction. The growth of Tb–Fe amorphous alloy from the interface is observed with increasing annealing temperature.

Diffractive sub-picosecond manipulation of x-rays

International Nuclear Information System (INIS)

Adams, B.

2004-01-01

A class of X-ray optical elements for the sub-picosecond manipulation of X-rays is proposed. The design of these elements is based upon a time-dependent dynamical diffraction theory that synthesizes the eikonal theory with the Takagi-Taupin theory. A brief outline of the theory is given

X-CHIP: an integrated platform for high-throughput protein crystallization and on-the-chip X-ray diffraction data collection

International Nuclear Information System (INIS)

Kisselman, Gera; Qiu, Wei; Romanov, Vladimir; Thompson, Christine M.; Lam, Robert; Battaile, Kevin P.; Pai, Emil F.; Chirgadze, Nickolay Y.

2011-01-01

The X-CHIP (X-ray Crystallography High-throughput Integrated Platform) is a novel microchip that has been developed to combine multiple steps of the crystallographic pipeline from crystallization to diffraction data collection on a single device to streamline the entire process. The X-CHIP (X-ray Crystallization High-throughput Integrated Platform) is a novel microchip that has been developed to combine multiple steps of the crystallographic pipeline from crystallization to diffraction data collection on a single device to streamline the entire process. The system has been designed for crystallization condition screening, visual crystal inspection, initial X-ray screening and data collection in a high-throughput fashion. X-ray diffraction data acquisition can be performed directly on-the-chip at room temperature using an in situ approach. The capabilities of the chip eliminate the necessity for manual crystal handling and cryoprotection of crystal samples, while allowing data collection from multiple crystals in the same drop. This technology would be especially beneficial for projects with large volumes of data, such as protein-complex studies and fragment-based screening. The platform employs hydrophilic and hydrophobic concentric ring surfaces on a miniature plate transparent to visible light and X-rays to create a well defined and stable microbatch crystallization environment. The results of crystallization and data-collection experiments demonstrate that high-quality well diffracting crystals can be grown and high-resolution diffraction data sets can be collected using this technology. Furthermore, the quality of a single-wavelength anomalous dispersion data set collected with the X-CHIP at room temperature was sufficient to generate interpretable electron-density maps. This technology is highly resource-efficient owing to the use of nanolitre-scale drop volumes. It does not require any modification for most in-house and synchrotron beamline systems and offers

X-CHIP: an integrated platform for high-throughput protein crystallization and on-the-chip X-ray diffraction data collection

Energy Technology Data Exchange (ETDEWEB)

Kisselman, Gera; Qiu, Wei; Romanov, Vladimir; Thompson, Christine M.; Lam, Robert [Ontario Cancer Institute, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2C4 (Canada); Battaile, Kevin P. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Pai, Emil F.; Chirgadze, Nickolay Y., E-mail: nchirgad@uhnresearch.ca [Ontario Cancer Institute, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2C4 (Canada); University of Toronto, Toronto, Ontario M5S 1A8 (Canada)

2011-06-01

The X-CHIP (X-ray Crystallography High-throughput Integrated Platform) is a novel microchip that has been developed to combine multiple steps of the crystallographic pipeline from crystallization to diffraction data collection on a single device to streamline the entire process. The X-CHIP (X-ray Crystallization High-throughput Integrated Platform) is a novel microchip that has been developed to combine multiple steps of the crystallographic pipeline from crystallization to diffraction data collection on a single device to streamline the entire process. The system has been designed for crystallization condition screening, visual crystal inspection, initial X-ray screening and data collection in a high-throughput fashion. X-ray diffraction data acquisition can be performed directly on-the-chip at room temperature using an in situ approach. The capabilities of the chip eliminate the necessity for manual crystal handling and cryoprotection of crystal samples, while allowing data collection from multiple crystals in the same drop. This technology would be especially beneficial for projects with large volumes of data, such as protein-complex studies and fragment-based screening. The platform employs hydrophilic and hydrophobic concentric ring surfaces on a miniature plate transparent to visible light and X-rays to create a well defined and stable microbatch crystallization environment. The results of crystallization and data-collection experiments demonstrate that high-quality well diffracting crystals can be grown and high-resolution diffraction data sets can be collected using this technology. Furthermore, the quality of a single-wavelength anomalous dispersion data set collected with the X-CHIP at room temperature was sufficient to generate interpretable electron-density maps. This technology is highly resource-efficient owing to the use of nanolitre-scale drop volumes. It does not require any modification for most in-house and synchrotron beamline systems and offers

Characterization of polymorphic solid-state changes using variable temperature X-ray powder diffraction

DEFF Research Database (Denmark)

Karjalainen, Milja; Airaksinen, Sari; Rantanen, Jukka

2005-01-01

The aim of this study was to use variable temperature X-ray powder diffraction (VT-XRPD) to understand the solid-state changes in the pharmaceutical materials during heating. The model compounds studied were sulfathiazole, theophylline and nitrofurantoin. This study showed that the polymorph form...... of sulfathiazole SUTHAZ01 was very stable and SUTHAZ02 changed as a function of temperature to SUTHAZ01. Theophylline monohydrate changed via its metastable form to its anhydrous form during heating and nitrofurantoin monohydrate changed via amorphous form to its anhydrous form during heating. The crystallinity...... to the anhydrous form. The average crystallite size of sulfathiazole samples varied only a little during heating. The average crystallite size of both theophylline and nitrofurantoin monohydrate decreased during heating. However, the average crystallite size of nitrofurantoin monohydrate returned back to starting...

New tubes and techniques for flash X-ray diffraction and high contrast radiography

International Nuclear Information System (INIS)

Charbonnier, F.M.; Barbour, J.P.; Brewster, J.L.

High energy electrons are particularly efficient in producing characteristic X-rays and soft polychromatic. A line of wide spectrum beryllium window flash X-ray tubes, ranging from 150 to 600kV, has been developed to exploit this property. Laue and Debye Scherrer flash X-ray diffraction patterns have been obtained using a single 30 ns pulse exposure. X-ray diffraction tests obtained are shown. Extremely high contrast flash radiography of small, low density objects has been obtained using industrial film without screen. Alternatively, particularly at high voltages and for subjects which include a broad range of materials and thicknesses, special film techniques can be used to produce extremely wide latitudes. Equipment, techniques and results are discussed

Diffraction enhanced kinetic depth X-ray imaging

Science.gov (United States)

Dicken, A.

An increasing number of fields would benefit from a single analytical probe that can characterise bulk objects that vary in morphology and/or material composition. These fields include security screening, medicine and material science. In this study the X-ray region is shown to be an effective probe for the characterisation of materials. The most prominent analytical techniques that utilise X-radiation are reviewed. The study then focuses on methods of amalgamating the three dimensional power of kinetic depth X-ray (KDFX) imaging with the materials discrimination of angular dispersive X-ray diffraction (ADXRD), thus providing KDEX with a much needed material specific counterpart. A knowledge of the sample position is essential for the correct interpretation of diffraction signatures. Two different sensor geometries (i.e. circumferential and linear) that are able to collect end interpret multiple unknown material diffraction patterns and attribute them to their respective loci within an inspection volume are investigated. The circumferential and linear detector geometries are hypothesised, simulated and then tested in an experimental setting with the later demonstrating a greater ability at discerning between mixed diffraction patterns produced by differing materials. Factors known to confound the linear diffraction method such as sample thickness and radiation energy have been explored and quantified with a possible means of mitigation being identified (i.e. via increasing the sample to detector distance). A series of diffraction patterns (following the linear diffraction approach) were obtained from a single phantom object that was simultaneously interrogated via KDEX imaging. Areas containing diffraction signatures matched from a threat library have been highlighted in the KDEX imagery via colour encoding and match index is inferred by intensity. This union is the first example of its kind and is called diffraction enhanced KDEX imagery. Finally an additional

X-ray powder diffraction camera for high-field experiments

International Nuclear Information System (INIS)

Koyama, K; Mitsui, Y; Takahashi, K; Watanabe, K

2009-01-01

We have designed a high-field X-ray diffraction (HF-XRD) camera which will be inserted into an experimental room temperature bore (100 mm) of a conventional solenoid-type cryocooled superconducting magnet (10T-CSM). Using the prototype camera that is same size of the HF-XRD camera, a XRD pattern of Si is taken at room temperature in a zero magnetic field. From the obtained results, the expected ability of the designed HF-XRD camera is presented.

High-resolution X-ray spectra from low-temperature, highly charged ions

International Nuclear Information System (INIS)

Beiersdorfer, P.

1996-09-01

The electron beam ion traps (EBIT) at Livermore were designed for studying the x-ray emission of highly charged ions produced and excited by a monoenergetic electron beam. The precision with which the x-ray emission can be analyzed has recently been increased markedly when it became possible to decouple the temperature of the ions from the energy of the electron beam by several orders of magnitude. By adjusting the trap parameters, ion temperatures as low as 15.8±4.4 eV for Ti 20+ and 59.4±9.9 eV for Cs 45+ were achieved. These temperatures were more than two orders of magnitude lower than the energy of the multi-keV electron beam used for the production and excitation of the ions. A discussion of the techniques used to produce and study low-temperature highly charged ions is presented in this progress report. The low ion temperatures enabled measurements heretofore impossible. As an example, a direct observation of the natural line width of fast electric dipole allowed x-ray transitions is described. From the observed natural line width and b making use of the time-energy relations of the uncertainty principle we were able to determine a radiative transition rate of 1.65 fs for the 2p-3d resonance transition in neonlike Cs 45+ . A brief discussion of other high-precision measurements enabled by our new technique is also given

Coherent X-ray diffraction studies of mesoscopic materials

International Nuclear Information System (INIS)

Shabalin, Anatoly

2015-12-01

This thesis is devoted to three separate projects, which can be considered as independent. First, the dynamical scattering effects in the Coherent X-ray Diffractive Imaging (CXDI) method are discussed. Based on the simulation results, a straightforward method for correction for the refraction and absorption artifacts in the Bragg CXDI reconstruction is suggested. The second part summarizes the results of an Coherent X-ray Diffractive Imaging experiment with a single colloidal crystal grain. A remarkable result is that positions of individual particles in the crystal lattice have been resolved in three dimensions. The third project is devoted to X-ray diffraction experimental studies of structural evolution of colloidal crystalline films upon incremental heating. Based on the results of the analysis a model of structural evolution of a colloidal crystal upon heating on nanoscopic and mesoscopic length scales is suggested.

Raman spectroscopy and X-ray diffraction studies on celestite

International Nuclear Information System (INIS)

Chen Yenhua; Yu Shucheng; Huang, Eugene; Lee, P.-L.

2010-01-01

High-pressure Raman spectroscopy and X-ray diffraction studies of celestite (SrSO 4 ) were carried out in a diamond anvil cell at room temperature. Variation in the Raman vibrational frequency and change of lattice parameters with pressure indicate that a transformation occurs in celestite. This transformation caused an adjustment in the Sr-O polyhedra that affected the stretching-force constant of SO 4 . Moreover, compressibilities along the crystallographic axes decreased in the order a to c to b. From the compression data, the bulk modulus of the celestite was 87 GPa. Both X-ray and Raman data show that the transition in celestite is reversible.

X-ray diffraction characteristics of curved monochromators for sychrotron radiation

International Nuclear Information System (INIS)

Boeuf, A.; Rustichelli, F.; Mazkedian, S.; Puliti, P.; Melone, S.

1978-01-01

A theoretical study is presented concerning the diffraction characteristics of curved monochromators for X-ray synchrotron radiation used at the laboratories of Hamburg, Orsay and Stanford. The investigation was performed by extending to the X-ray case a simple model recently developed and fruitfully employed to describe the neutron diffraction properties of curved monochromators. Several diffraction patterns were obtained corresponding to different monochromator materials (Ge, Si) used by the different laboratories, for different reflecting planes (111), (220), asymmetry angles, X-ray wave-lengths (Mo Kα, Cu Kα, Cr Kα) and curvature radii. The results are discussed in physical terms and their implications on the design of curved monochromators for synchrotron radiation are presented. In particular, the study shows that all the monochromators used in the different laboratories should behave practically as perfect crystals and therefore should have a very low integrated reflectivity corresponding to an optimized wavelength passband Δlambda/lambda approximately 10 -4 . The gain that can be obtained by increasing the curvature, by introducing a gradient in the lattice spacing or by any other kind of imperfection is quite limited and much lower than the desirable value. The adopted model can help in obtaining a possible moderate gain in intensity by also taking into consideration other parameters, such as crystal material, reflecting plane, asymmetry of the reflection and X-ray wavelength. (Auth.)

X-ray diffraction and X-ray standing-wave study of the lead stearate film structure

Energy Technology Data Exchange (ETDEWEB)

Blagov, A. E.; Dyakova, Yu. A.; Kovalchuk, M. V.; Kohn, V. G.; Marchenkova, M. A.; Pisarevskiy, Yu. V.; Prosekov, P. A., E-mail: prosekov@crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2016-05-15

A new approach to the study of the structural quality of crystals is proposed. It is based on the use of X-ray standing-wave method without measuring secondary processes and considers the multiwave interaction of diffraction reflections corresponding to different harmonics of the same crystallographic reflection. A theory of multiwave X-ray diffraction is developed to calculate the rocking curves in the X-ray diffraction scheme under consideration for a long-period quasi-one-dimensional crystal. This phase-sensitive method is used to study the structure of a multilayer lead stearate film on a silicon substrate. Some specific structural features are revealed for the surface layer of the thin film, which are most likely due to the tilt of the upper layer molecules with respect to the external normal to the film surface.

Preparation of specimens for analysis by: X-ray diffraction and X-ray fluorescence analysis

International Nuclear Information System (INIS)

Banos L, L.

2004-01-01

Specimen preparation is one of the most important requirements in the analysis of samples by X-ray Diffraction and X-ray Fluorescence. This statement is especially true for samples containing different types of materials. There are many forms of specimen suitable for X-ray analysis and the type of the sample as received will generally determine the method of pretreatment. It is convenient to refer to the material received for analysis as the sample, and that, which is actually analyzed as the specimen. The powder Diffraction method assumes that the particles in the specimen are ideally random orientation and that there are enough crystallites in the specimen to achieve a representative intensity distribution for these crystallites. X ray Fluorescence is essentially a comparative method of analysis, it is vital that all standards and unknowns be presented to the spectrometer in a reproducible and identical manner. (Author) 3 refs., 6 figs

Femtosecond x-ray photoelectron diffraction on gas-phase dibromobenzene molecules

International Nuclear Information System (INIS)

Rolles, D; Boll, R; Epp, S W; Erk, B; Foucar, L; Hömke, A; Adolph, M; Gorkhover, T; Aquila, A; Chapman, H N; Coppola, N; Delmas, T; Gumprecht, L; Holmegaard, L; Bostedt, C; Bozek, J D; Coffee, R; Decleva, P; Filsinger, F; Johnsson, P

2014-01-01

We present time-resolved femtosecond photoelectron momentum images and angular distributions of dissociating, laser-aligned 1,4-dibromobenzene (C 6 H 4 Br 2 ) molecules measured in a near-infrared pump, soft-x-ray probe experiment performed at an x-ray free-electron laser. The observed alignment dependence of the bromine 2p photoelectron angular distributions is compared to density functional theory calculations and interpreted in terms of photoelectron diffraction. While no clear time-dependent effects are observed in the angular distribution of the Br(2p) photoelectrons, other, low-energy electrons show a pronounced dependence on the time delay between the near-infrared laser and the x-ray pulse. (paper)

Room-temperature serial crystallography using a kinetically optimized microfluidic device for protein crystallization and on-chip X-ray diffraction

Directory of Open Access Journals (Sweden)

Michael Heymann

2014-09-01

Full Text Available An emulsion-based serial crystallographic technology has been developed, in which nanolitre-sized droplets of protein solution are encapsulated in oil and stabilized by surfactant. Once the first crystal in a drop is nucleated, the small volume generates a negative feedback mechanism that lowers the supersaturation. This mechanism is exploited to produce one crystal per drop. Diffraction data are measured, one crystal at a time, from a series of room-temperature crystals stored on an X-ray semi-transparent microfluidic chip, and a 93% complete data set is obtained by merging single diffraction frames taken from different unoriented crystals. As proof of concept, the structure of glucose isomerase was solved to 2.1 Å, demonstrating the feasibility of high-throughput serial X-ray crystallography using synchrotron radiation.

X-ray diffraction study of the polymorphism of hydrated diacyl- and dialkylphosphatidylethanolamines.

Science.gov (United States)

Seddon, J M; Cevc, G; Kaye, R D; Marsh, D

1984-06-05

The structure and polymorphism of a homologous series of diacyl- and of dialkylphosphatidylethanolamines have been investigated by X-ray diffraction, calorimetry, and density measurement. The compositional dependence of the repeat spacings of the gel (L beta or L beta'), fluid bilayer (L alpha), and inverted hexagonal (HII) phases has been determined both for the short chain length (di-C12) dialkyl didodecylphosphatidylethanolamine (DDPE) and for the long chain length (di-C20) diacyl diarachinoylphosphatidylethanolamine (DAPE). These data, in conjunction with the measured phase transition temperatures obtained both by X-ray diffraction and by differential scanning calorimetry, have been used to construct phase diagrams for the two lipids. DDPE exhibits metastable behavior in the L beta and L alpha phases below 44 degrees C at all water contents and forms cubic and other nonlamellar phases between the L alpha and HII phases. At low water contents, crystalline and fluid phases coexist at temperatures up to 83 degrees C. For DAPE, the behavior is simpler. In the gel phase, the hydrocarbon chains are tilted at 29 degrees to the bilayer normal, and metastability is only observed at water contents below 3 wt %. The L alpha phase is adopted within a narrow temperature range and then transforms directly to the HII phase. The structural parameters of the L beta (L beta'), L alpha, and HII phases of DDPE and DAPE have been calculated from the X-ray data, in conjunction with the measured values of lipid partial specific volume. In addition, the chain-length dependence of the repeat spacings of the phases has been measured for the homologous series of diacyl and dialkyl lipids. Taken together, the results allow a detailed description of the effects of temperature, hydration, and chain length on the polymorphism of the saturated phosphatidylethanolamines.

Determination of the strain hardening rate of metals and alloys by X ray diffraction

International Nuclear Information System (INIS)

Cadalbert, Robert

1977-01-01

This report for engineering graduation is based on the study of X ray diffraction line profile which varies with the plastic strain rate of the metal. After some generalities of strain hardening (consequence of a plastic deformation on the structure of a polycrystalline metal, means to study a strain hardened structure, use of X ray diffraction to analyse the strain hardened crystalline structure), the author reports the strain hardening rate measurement by using X ray diffraction. Several aspects are addressed: principles, experimental technique, apparatus, automation and programming of the measurement cycle, method sensitivity and precision. In the next part, the author reports applications: measurement of the strain hardening rate in different materials (tubes with hexagonal profile, cylindrical tubes in austenitic steel), and study of the evolution of strain hardening with temperature [fr

X-ray diffraction 2 - diffraction principles

International Nuclear Information System (INIS)

O'Connor, B.

1999-01-01

Full text: The computation of powder diffraction intensities is based on the principle that the powder pattern comprises the summation of the intensity contributions from each of the crystallites (or single crystals) in the material. Therefore, it is of value for powder diffractionists to appreciate the form of the expression for calculating single crystal diffraction pattern intensities. This knowledge is especially important for Rietveld analysis practitioners in terms of the (i) mathematics of the method and (ii) retrieving single crystal structure data from the literature. We consider the integrated intensity from a small single crystal being rotated at velocity ω through the Bragg angle θ for reflection (hkl).... I(hkl) = [l o /ω]. [e 4 /m 2 c 4 ]. [λ 3 δV F(hkl) 2 /υ 2 ].[(1+cos 2 2θ)/2sin2θ] where e, m and c are the usual fundamental constants; λ is the x-ray wavelength, δV is the crystallite volume; F(hkl) is the structure factor; υ is the unit cell volume; and (1+cos 2 θ)/2sin2θ] is the Lorentz-polarisation factor for an unpolarised incident beam. The expression does not include a contribution for extinction. The influence of factors λ, δV, F(hkl) and υ on the intensities should be appreciated by powder diffractionists, especially the structure factor, F(hkl), which is responsible for the fingerprint nature of diffraction patterns, such as the rise and fall of intensity from peak to peak. The structure factor expression represents the summation of the scattered waves from each of the j scattering centres (i e atoms) in the unit cell: F(hkl) Σ f j exp[2πi (h.x j +k.y i +l. z i )] T j . Symbol f is the scattering factor (representing the atom-type scattering efficiency); (x, y, z) are the fractional position coordinates of atom j within the unit cell; and T is the thermal vibration factor for the atom given by: T j = 8π 2 2 > sin 2 θ/λ 2 with 2 > being the mean-square vibration amplitude of the atom (assumed to be isotropic). The

Three-dimensional visualization of a human chromosome using coherent x-ray diffraction

International Nuclear Information System (INIS)

Nishino, Yoshinori; Ishikawa, Tetsuya; Takahashi, Yukio; Imamoto, Naoko; Maeshima, Kazuhiro

2010-01-01

We succeeded in observing a human chromosome in two- and three-dimensions using x-ray diffraction microscopy. X-ray diffraction microscopy is a lens-less imaging technique utilizing coherent x-ray diffraction, and can overcome various limitations in conventional lens-based x-ray microscopy. Biological applications of the method have been limited to 2D observation, and 3D observation has been long waited. We found that the reconstructed chromosome images contain high-density axial structure, which has not been observed under unstained or unlabeled conditions. The result experimentally demonstrates the effectiveness of x-ray diffraction microscopy in observing internal structures of unstained biological samples with high image contrast. (author)

X-ray diffraction without sample preparation: Proof-of-principle experiments

International Nuclear Information System (INIS)

Hansford, Graeme M.

2013-01-01

The properties of a novel X-ray diffraction (XRD) technique having very low sensitivity to the sample morphology were previously elucidated through theoretical considerations and model simulations (Hansford, 2011). This technique opens up the possibility of mineralogical analysis by XRD without sample preparation. Here, the results of proof-of-principle experimental tests are presented. Two sets of experiments were performed using a vacuum chamber equipped with an X-ray tube source, sample holder and charge-coupled detector. Firstly, a pressed-powder pellet of α-quartz was placed in three different positions relative to the X-ray source and detector. The changes in position represent gross sample movements which would be inconceivable in conventional XRD analysis. The resulting back-reflection energy-dispersive spectra show a very high degree of correspondence other than an overall intensity factor dependent on the distance between the sample and detector. Secondly, the back-reflection spectrum of an unprepared limestone hand specimen, having mm-scale surface morphology, was compared to the spectrum of a calcite pressed-powder pellet. The correspondence of the diffraction peaks in the spectra demonstrate that the limestone is comprised dominantly of calcite. In both cases, the claims of the earlier paper are fully supported by the results of these experimental tests. -- Highlights: • Proof-of-principle tests of a novel X-ray diffraction (XRD) method were conducted. • Very low sensitivity to sample position and orientation was demonstrated. • Insensitivity to sample morphology is inferred. • A simple analysis of an unprepared limestone hand specimen was performed. • This technique enables mineralogical analysis by XRD without sample preparation

Intensity of diffracted X-rays from biomolecules with radiation damage caused by strong X-ray pulses

International Nuclear Information System (INIS)

Kai, Takeshi; Tokuhisa, Atsushi; Moribayashi, Kengo; Fukuda, Yuji; Kono, Hidetoshi; Go, Nobuhiro

2014-01-01

In order to realize the coherent X-ray diffractive imaging of single biomolecules, the diffraction intensities, per effective pixel of a single biomolecule with radiation damage, caused by irradiation using a strong coherent X-ray pulse, were examined. A parameter survey was carried out for various experimental conditions, using a developed simulation program that considers the effect of electric field ionization, which was slightly reported on in previous studies. The two simple relationships among the parameters were identified as follows: (1) the diffraction intensity of a biomolecule slightly increases with the incident X-ray energy; and that (2) the diffraction intensity is approximately proportional to the target radius, when the radius is longer than 400 Å, since the upper limit of the incident intensity for damage to the biomolecules marginally changes with respect to the target radius. (author)

Extended X-ray absorption fine structure and X-ray diffraction studies on supported Ni catalysts

International Nuclear Information System (INIS)

Aldea, N.; Marginean, P.; Yaning, Xie; Tiandou, Hu; Tao, Liu; Wu, Zhongua; ZhenYa, Dai

1999-01-01

In the first part of this paper, we present a study based on EXAFS spectroscopy. This method can yield structural information about the local environment around a specific atomic constituent in the amorphous materials, the location and chemical state of any catalytic atom on any support or point defect structures, in alloys and composites. EXAFS is a specific technique of the scattering of X-ray on materials. The present study is aimed toward elucidation of the local structure of Ni atoms and their interaction with oxide support. The second goal of the paper consists in X-ray diffraction on the same samples. X-ray diffraction method that is capable to determine average particle size, microstrains, probability of faults as well as particle size distribution function of supported Ni catalysts is presented. The method is based on the Fourier analysis of a single X-Ray diffraction profile. The results obtained on supported nickel catalysts, which are used in H/D isotopic exchange reactions are reported. The global structure is obtained with a new fitting method based on the Generalised Fermi Function facilities for approximation and Fourier transform of the experimental X-Ray line profiles. Both types of measurements were performed on Beijing Synchrotron Radiation Facilities (BSRF). (authors)

Single shot diffraction of picosecond 8.7-keV x-ray pulses

Directory of Open Access Journals (Sweden)

F. H. O’Shea

2012-02-01

Full Text Available We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111 crystal. 10^{2} diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 10^{2} x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 10^{4}; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

A high resolution position sensitive X-ray MWPC for small angle X-ray diffraction

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Tappern, G.J.

1981-02-01

A small sealed-off delay line readout MWPC X-ray detector has been designed and built for small angle X-ray diffraction applications. Featuring a sensitive area of 100 mm x 25 mm it yields a spatial resolution of 0.13 mm (standard deviation) with a high rate capability and good quantum efficiency for copper K radiation. (author)

Characteristics of a molybdenum X-pinch X-ray source as a probe source for X-ray diffraction studies

International Nuclear Information System (INIS)

Zucchini, F.; Chauvin, C.; Combes, P.; Sol, D.; Loyen, A.; Roques, B.; Grunenwald, J.; Bland, S. N.

2015-01-01

X-ray emission from a molybdenum X-pinch has been investigated as a potential probe for the high pressure states made in dynamic compression experiments. Studies were performed on a novel 300 kA, 400 ns generator which coupled the load directly to a low inductance capacitor and switch combination. The X-pinch load consisted of 4 crossed molybdenum wires of 13 μm diameter, crossed at an angle of 62°. The load height was 10 mm. An initial x-ray burst generated at the wire crossing point, radiated in the soft x-ray range (hυ < 10 keV). This was followed, 2–5 ns later, by at least one harder x-ray burst (hυ > 10 keV) whose power ranged from 1 to 7 MW. Time integrated spectral measurements showed that the harder bursts were dominated by K-alpha emission; though, a lower level, wide band continuum up to at least 30 keV was also present. Initial tests demonstrated that the source was capable of driving Laue diffraction experiments, probing uncompressed samples of LiF and aluminium

X-Ray diffraction on rare earth-3d Laves phase compound ErCo2 in magnetic field

International Nuclear Information System (INIS)

Yagasaki, Katsuma; Notsu, Shiko; Takaesu, Yoshinao; Nakama, Takao; Sakai, Eijiro; Koyama, Keiichi; Watanabe, Kazuo; Burkov, Alexander T.

2006-01-01

X-Ray powder diffraction method is used to investigate the effect of magnetic ordering and external magnetic field on crystal structure of Laves phase intermetallic compound ErCo 2 . The diffraction patterns were recorded at temperatures from 300K down to 8.5K in magnetic field up to 5T. Distortion of the room-temperature cubic structure was found in magnetically ordered state below 32K. The symmetry at low temperature is rhombohedral in agreement with literature results, or lower symmetry than it. However the symmetry of the unit cell increases to cubic in external magnetic field of 5T

Theory of time-resolved inelastic x-ray diffraction

DEFF Research Database (Denmark)

Lorenz, Ulf; Møller, Klaus Braagaard; Henriksen, Niels Engholm

2010-01-01

Starting from a general theory of time-resolved x-ray scattering, we derive a convenient expression for the diffraction signal based on a careful analysis of the relevant inelastic scattering processes. We demonstrate that the resulting inelastic limit applies to a wider variety of experimental...... conditions than similar, previously derived formulas, and it directly allows the application of selection rules when interpreting diffraction signals. Furthermore, we present a simple extension to systems simultaneously illuminated by x rays and a laser beam....

Oxygen partial pressure control during in-situ high temperature X-ray diffraction on cerium dioxide

International Nuclear Information System (INIS)

Strach, M.; Belin, R.C.; Richaud, J-C.; Rogez, J.

2014-01-01

Cerium dioxide is widely used as a surrogate for plutonium dioxide in the studies of MOX type nuclear fuel. Thus, obtaining an accurate description of the structures present in this system in a range of temperatures is of importance to the development of fuel for the IV. generation of nuclear reactors. However, such a study requires appropriate scientific tools, in particular regarding the control and monitoring of the oxygen partial pressure (pO 2 ). Here we discuss several in-situ X-ray diffraction experiments performed to determine the phases present in the hypo-stoichiometric CeO 2-x region of the phase diagram and clearly demonstrate the need for controlling the pO 2 . (authors)

In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

Energy Technology Data Exchange (ETDEWEB)

Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

2007-06-29

We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

Surface and interface strains studied by x-ray diffraction

International Nuclear Information System (INIS)

Akimoto, Koichi; Emoto, Takashi; Ichimiya, Ayahiko

1998-01-01

The authors have developed a technique of X-ray diffraction in order to measure strain fields near semiconductor surface and interface. The diffraction geometry is using the extremely asymmetric Bragg-case bulk reflection of a small incident angle to the surface and a large angle exiting from the surface. The incident angle of the X-rays is set near critical angle of total reflection by tuning X-ray energy of synchrotron radiation at the Photon Factory, Japan. For thermally grown-silicon oxide/Si(100) interface, the X-ray intensity of the silicon substrate 311 reflection has been measured. From comparison of the full width at half maxima (FWHM) of X-ray rocking curves of various thickness of silicon oxides, it has been revealed that silicon substrate lattice is highly strained in the thin (less than about 5 nm) silicon oxide/silicon system. In order to know the original silicon surface strain, the authors have also performed the same kind of measurements in the ultra-high vacuum chamber. A clean Si(111) 7x7 surface gives sharper X-ray diffraction peak than that of the native oxide/Si(111) system. From these measurements, it is concluded that the thin silicon oxide film itself gives strong strain fields to the silicon substrates, which may be the reason of the existence of the structural transition layer at the silicon oxide/Si interface

X-ray diffraction imaging of biological cells

CERN Document Server

Nakasako, Masayoshi

2018-01-01

In this book, the author describes the development of the experimental diffraction setup and structural analysis of non-crystalline particles from material science and biology. Recent advances in X-ray free electron laser (XFEL)-coherent X-ray diffraction imaging (CXDI) experiments allow for the structural analysis of non-crystalline particles to a resolution of 7 nm, and to a resolution of 20 nm for biological materials. Now XFEL-CXDI marks the dawn of a new era in structural analys of non-crystalline particles with dimensions larger than 100 nm, which was quite impossible in the 20th century. To conduct CXDI experiments in both synchrotron and XFEL facilities, the author has developed apparatuses, named KOTOBUKI-1 and TAKASAGO-6 for cryogenic diffraction experiments on frozen-hydrated non-crystalline particles at around 66 K. At the synchrotron facility, cryogenic diffraction experiments dramatically reduce radiation damage of specimen particles and allow tomography CXDI experiments. In addition, in XFEL ex...

A more general expression for the average X-ray diffraction intensity of crystals with an incommensurate one-dimensional modulation

International Nuclear Information System (INIS)

Lam, E.J.W.; Beurskens, P.T.; Smaalen, S. van

1994-01-01

Statistical methods are used to derive an expression for the average X-ray diffraction intensity, as a function of (sinθ)/λ, of crystals with an incommensurate one-dimensional modulation. Displacive and density modulations are considered, as well as a combination of these two. The atomic modulation functions are given by truncated Fourier series that may contain higher-order harmonics. The resulting expression for the average X-ray diffraction intensity is valid for main reflections and low-order satellite reflections. The modulation of individual atoms is taken into account by the introduction of overall modulation amplitudes. The accuracy of this expression for the average X-ray diffraction intensity is illustrated by comparison with model structures. A definition is presented for normalized structure factors of crystals with an incommensurate one-dimensional modulation that can be used in direct-methods procedures for solving the phase problem in X-ray crystallography. A numerical fitting procedure is described that can extract a scale factor, an overall temperature parameter and overall modulation amplitudes from experimental reflection intensities. (orig.)

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

Energy Technology Data Exchange (ETDEWEB)

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

International Nuclear Information System (INIS)

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons

X-ray diffraction study of surface-layer structure in parallel grazing rays

International Nuclear Information System (INIS)

Shtypulyak, N.I.; Yakimov, I.I.; Litvintsev, V.V.

1989-01-01

An x-ray diffraction method is described for study of thin polycrystalline and amorphous films and surface layers in an extremely asymmetrical diffraction system in parallel grazing rays using a DRON-3.0 diffractometer. The minimum grazing angles correspond to diffraction under conditions of total external reflection and a layer depth of ∼ 2.5-8 nm

High-resolution X-ray diffraction studies of multilayers

DEFF Research Database (Denmark)

Christensen, Finn Erland; Hornstrup, Allan; Schnopper, H. W.

1988-01-01

High-resolution X-ray diffraction studies of the perfection of state-of-the-art multilayers are presented. Data were obtained using a triple-axis perfect-crystal X-ray diffractometer. Measurements reveal large-scale figure errors in the substrate. A high-resolution triple-axis set up is required...

Measurements of transient electron density distributions by femtosecond X-ray diffraction

International Nuclear Information System (INIS)

Freyer, Benjamin

2013-01-01

This thesis concerns measurements of transient charge density maps by femtosecond X-ray diffraction. Different X-ray diffraction methods will be considered, particularly with regard to their application in femtosecond X-ray diffraction. The rotation method is commonly used in stationary X-ray diffraction. In the work in hand an X-ray diffraction experiment is demonstrated, which combines the method with ultrafast X-ray pulses. This experiment is the first implementation which makes use of the rotation method to map transient intensities of a multitude of Bragg reflections. As a prototype material Bismuth is used, which previously was studied frequently by femtosecond X-ray diffraction by measuring Bragg reflections successively. The experimental results of the present work are compared with the literature data. In the second part a powder-diffraction experiment will be presented, which is used to study the dynamics of the electron-density distribution on ultrafast time scales. The experiment investigates a transition metal complex after photoexcitation of the metal to ligand charge transfer state. Besides expected results, i. e. the change of the bond length between the metal and the ligand and the transfer of electronic charge from the metal to the ligand, a strong contribution of the anion to the charge transfer was found. Furthermore, the charge transfer has predominantly a cooperative character. That is, the excitation of a single complex causes an alteration of the charge density of several neighboring units. The results show that more than 30 transition-metal complexes and 60 anions contribute to the charge transfer. This collective response is a consequence of the strong coulomb interactions of the densely packed ions.

Low-temperature crystallization of amorphous silicon and amorphous germanium by soft X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Heya, Akira, E-mail: heya@eng.u-hyogo.ac.jp [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Kanda, Kazuhiro [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Toko, Kaoru; Sadoh, Taizoh [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Amano, Sho [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Matsuo, Naoto [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Miyamoto, Shuji [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Miyao, Masanobu [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Mochizuki, Takayasu [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan)

2013-05-01

The low-temperature-crystallization effects of soft X-ray irradiation on the structural properties of amorphous Si and amorphous Ge films were investigated. From the differences in crystallization between Si and Ge, it was found that the effects of soft X-ray irradiation on the crystallization strongly depended on the energy band gap and energy level. The crystallization temperatures of the amorphous Si and amorphous Ge films decreased from 953 K to 853 K and 773 K to 663 K, respectively. The decrease in crystallization temperature was also related to atoms transitioning into a quasi-nucleic phase in the films. The ratio of electron excitation and migration effects to thermal effects was controlled using the storage-ring current (photon flux density). Therefore, we believe that low-temperature crystallization can be realized by controlling atomic migration through electron excitation. - Highlights: • This work investigates the crystallization mechanism for soft X-ray irradiation. • The soft X-ray crystallization depended on the energy band gap and energy level. • The decrease in the crystallization temperature for Si and Ge films was 100 K. • This decrement was related to atoms transitioning into a quasi-nucleic phase.

Historical development of synchrotron x-ray diffraction topography

International Nuclear Information System (INIS)

Kawado, Seiji

2011-01-01

After a short history of X-ray diffraction topography, from the early stage of laboratory X-ray topography to recent synchrotron-radiation applications, is described, the development of science and technology for the synchrotron X-ray topography and its industrial applications are reviewed in more detail. In addition, the recent trend to synchrotron topography research is clarified on the basis of several data obtained from 256 papers which have been published since 2000. (author)

X-ray Microprobe for Fluorescence and Diffraction Analysis

International Nuclear Information System (INIS)

Ice, G.E.

2005-01-01

X-ray diffraction (see unit 1.1) and x-ray excited fluorescence analysis are powerful techniques for the nondestructive measurement of crystal structure and chemical composition. X-ray fluorescence analysis is inherently nondestructive with orders of magnitude lower power deposited for the same detectable limit as with fluorescence excited by charged particle probes (Sparks, 1980). X-ray diffraction analysis is sensitive to crystal structure with orders-of-magnitude greater sensitivity to crystallographic strain than electron probes (Rebonato, et al. 1989). When a small-area x-ray microbeam is used as the probe, chemical composition (Z>14), crystal structure, crystalline texture, and crystalline strain distributions can be determined. These distributions can be studied both at the surface of the sample and deep within the sample (Fig. 1). Current state-of-the-art can achieve an ∼1 mm-D x-ray microprobe and an ∼0.1 mm-D x-ray microprobe has been demonstrated (Bilderback, et al., 1994). Despite their great chemical and crystallographic sensitivities, x-ray microprobe techniques have until recently been restricted by inefficient x-ray focusing optics and weak x-ray sources; x-ray microbeam analysis was largely superseded by electron techniques in the 50's. However, interest in x-ray microprobe techniques has now been revived (Howells, et al., 1983; Ice and Sparks, 1984; Chevallier, et al., 1997; Riekel 1992; Thompson, el al., 1992; and Making and Using... 1997) by the development of efficient x-ray focusing optics and ultra-high intensity synchrotron x-ray sources (Buras and Tazzari, 1984; Shenoy, et al., 1988). These advances have increased the achievable microbeam flux by more than 11 orders of magnitude (Fig. 2) (Ice, 1997); the flux in a tunable 1 mm-D beam on a 'so called' 3rd-generation synchrotron source such as the APS can exceed the flux in a fixed-energy mm2 beam on a conventional source. These advances make x-ray microfluorescence and x-ray

Neutron und X-ray diffraction study on the superstructure of a sodium-rich low plagioclase An sub(16.5)

International Nuclear Information System (INIS)

Joswig, W.; Korekawa, M.

1977-01-01

Neutron and X-ray diffraction experiments had been carried out on a sodium-rich low plagioclase Ansub(16.5) from Sultan Hamud, Kenya. In constrast to previous work very weak (g) reflections (satellites) for all reflections Okl, except reflections 001, could be observed. It is shown that the neutron diffraction method is advantageous to study on submicroscopic periodic domain structure as reported here. (orig.) [de

X-ray diffraction studies of NiTi shape memory alloys

OpenAIRE

E. Łągiewka; Z. Lekston

2007-01-01

Purpose: The purpose of this paper is to present the results of the investigations of phase transitions of TiNiCo and Ni-rich NiTi shape memory alloys designed for medical applications.Design/methodology/approach: Temperature X-ray diffraction (TXRD), differential scanning calorimetry (DSC), electrical resistivity (ER) and the temperature shape recovery measurements in three-point bending ASTM 2082-01 tests were used.Findings: It has been found in this work that ageing after solution treatme...

High-temperature x-ray diffraction study of HfTiO4-HfO2 solid solutions

International Nuclear Information System (INIS)

Carpenter, D.A.

1975-01-01

High-temperature x-ray diffraction techniques were used to determine the axial thermal expansion curves of HfTiO 4 -HfO 2 solid solutions as a function of composition. Data show increasing anisotropy with increasing HfO 2 content. An orthorhombic-to-monoclinic phase transformation was detected near room temperature for compositions near the high HfO 2 end of the orthorhombic phase field and for compositions within the two-phase region (HfTiO 4 solid solution plus HfO 2 solid solution). An orthorhombic-to-cubic phase transformation is indicated by data from oxygen-deficient materials at greater than 1873 0 K. (U.S.)

X-ray diffraction using the time structure of the SRS

International Nuclear Information System (INIS)

Tanner, B.K.

1983-01-01

The subject is discussed under the headings: introduction (advances in the techniques of X-ray topography; comparison with transmission electron microscopy); stroboscopic X-ray topography; stroboscopic X-ray topography of travelling surface acoustic waves; possible general diffraction experiments. (U.K.)

Preliminary small-angle X-ray scattering and X-ray diffraction studies of the BTB domain of lola protein from Drosophila melanogaster

Science.gov (United States)

Boyko, K. M.; Nikolaeva, A. Yu.; Kachalova, G. S.; Bonchuk, A. N.; Dorovatovskii, P. V.; Popov, V. O.

2017-11-01

The Drosophila genome has several dozens of transcription factors (TTK group) containing BTB domains assembled into octamers. The LOLA protein belongs to this family. The purification, crystallization, and preliminary X-ray diffraction and small-angle X-ray scattering (SAXS) studies of the BTB domain of this protein are reported. The crystallization conditions were found by the vapor-diffusion technique. A very low diffraction resolution (8.7 Å resolution) of the crystals was insufficient for the determination of the threedimensional structure of the BTB domain. The SAXS study demonstrated that the BTB domain of the LOLA protein exists as an octamer in solution.

Characterization of Polycrystalline Materials Using Synchrotron X-ray Imaging and Diffraction Techniques

DEFF Research Database (Denmark)

Ludwig, Wolfgang; King, A.; Herbig, M.

2010-01-01

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...

Two-dimensional time-resolved X-ray diffraction study of directional solidification in steels

International Nuclear Information System (INIS)

Yonemura, Mitsuharu

2009-01-01

Full text: The high intensity heat source used for fusion welding creates steep thermal gradients of 100 degree C/s from 1800 degree Celsius. Further, the influence of a preferred orientation is serious for observation of a directional solidification that follows the dendrite growth along the direction toward the moving heat source. Therefore, we observed the rapid solidification of weld metal at a time resolution of 0.01∼0.1seconds by the Two-Dimensional Time-Resolved X-ray Diffraction (2DTRXRD) system for real welding. The diffraction ring was dynamically observed by 2DTRXRD during arc-passing over the irradiation area of X-ray with synchrotron energy of 18 KeV. The arc power output was 10 V - 150 A, and a scan speed of the arc was 1.0 mm/s. The temperature rise of instruments was suppressed by the water-cooled copper plate under the sample. Further, the temperature distribution of the weld metal was measured by the thermocouple and related to the diffraction patterns. Consequently, solidification and solid phase transformation of low carbon steels and stainless steels were observed during rapid cooling by 2DTRXRD. In the low-carbon steel, the microstructure is formed in the 2 step process; (i) formation of crystallites and (ii) increase of crystallinity. In the stainless steel, the irregular interface layer of σ/y in the quenched metal after solidification is expected that it is easy for dendrites to move at the lower temperature. In the carbide precipitation stainless steel, it is easy for NbC to grow on σ phase with a little under cooling. Further, a mist-like pattern, which differs from the halo-pattern, in the fusion zone gave some indication of the possibilities to observe the nucleation and the early solidification by 2DTRXRD. (author)

Measurement of thickness of thin films by the X-ray diffraction method

International Nuclear Information System (INIS)

Srinivasan, C.; Balasingh, C.; Singh, A.K.

1979-07-01

X-ray diffraction method can be used to measure the thickness of thin films (coatings). The principle and the experimental details of the x-ray diffraction methods are described. The intensities of the diffracted beams are derived assuming a random orientation of the crystallites in the diffracting medium. Consequently, the expressions are not valid when the sample has preferred orientation. To check the performance of the method, thicknesses of nickel deposits on mild steel plates were determined by the x-ray diffraction method and the results compared with those obtained by the weighing method and metallographic examination. The weighing method which gives an accuracy of +- 0.1 micron is taken as the standard. The x-ray diffraction methods and the metallographic examinations give values within +- 1 micron of the value obtained by the weighing method. (author)

Three-Dimensional X-Ray Diffraction Technique for Metals Science

DEFF Research Database (Denmark)

Zhang, Yubin; Fan, Guohua

2017-01-01

The three-dimensional X-ray diffraction (3DXRD) is a new, advanced technique for materials characterization. This technique utilizes high-energy synchrotron X-rays to characterize the 3D crystallographic structure and strain/stress state of bulk materials. As the measurement is non......-destructive, the microstructural evolution as a function of time can be followed, i.e. it allows 4D (x, y, z characterizations, t). The high brilliance of synchrotron X-rays ensures that diffraction signals from volumes of micrometer scale can be quickly detected and distinguished from the background noise, i.e. its spatial...... implemented in several large synchrotron facilities, e.g. the Advanced Photon Source (APS) in USA and the Spring-8 in Japan. Another family of 3DXRD technique that utilizes white beam synchrotron X-rays has also been developed in parallel in cooperation between Oak Ridge National Laboratory and APS...

Synchrotron X-ray diffraction analysis for quantitative defect evaluation in GaP/Si nanolayers

Energy Technology Data Exchange (ETDEWEB)

Nguyen Thanh, T.; Robert, C. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); Létoublon, A., E-mail: Antoine.letoublon@insa-rennes.fr [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); Cornet, C. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); Quinci, T. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); CEA LCP, INES, 50 av. du Lac Léman, Savoie Technolac, 73375 Le Bourget du Lac (France); Giudicelli, E.; Almosni, S. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); Boudet, N. [CRG-D2AM, ESRF and Inst. Néel, CNRS-UJF, 25 Av des Martyrs, 38042 Grenoble (France); Ponchet, A. [CEMES, CNRS, Université de Toulouse, 29 rue J. Marvig BP 94347, 31055 Toulouse Cedex 4 (France); Kuyyalil, J. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France); Danila, M. [National Institute for Research and Development in Microtechnologies (IMT), 126A Erou Iancu Nicolae Street, 077190, Bucharest (Romania); Durand, O.; Bertru, N.; Le Corre, A. [Université Européenne de Bretagne, INSA, FOTON, UMR 6082, F-35708 RENNES (France)

2013-08-31

In the context of III–V monolithic integration on silicon, synchrotron X-ray diffraction has been employed in this study using a bi-dimensional large area hybrid pixel detector (XPAD third generation) to characterize defects in the GaP layers. Despite a very coherent interface (low plastic relaxation) of GaP/Si, 2 types of defect are detected. Micro-twins contributions are evidenced and quantitatively evaluated from additional reflections analysis. Antiphase domains are evidenced using the Williamson-Hall-like plot method applied to transverse scans extracted directly from single XPAD images taken on specular GaP reflections. - Highlights: ► Antiphase domain evidence and characterization in GaP/Si using X-ray diffraction ► Microtwin evidence and characterization ► Synchrotron diffraction ► Large area X-ray hybrid pixel detector.

Takagi-Taupin description of x-ray dynamical diffraction from diffractive optics with large numerical aperture

International Nuclear Information System (INIS)

Yan Hanfei; Maser, Joerg; Macrander, Albert; Shen Qun; Vogt, Stefan; Stephenson, G. Brian; Kang, Hyon Chol

2007-01-01

We present a formalism of x-ray dynamical diffraction from volume diffractive optics with large numerical aperture and high aspect ratio, in an analogy to the Takagi-Taupin equations [Acta Crystallogr. 15, 1311 (1962); Bull. Soc. Fr. Mineral. Crystallogr. 87, 469 (1964)] for strained single crystals. We derive a set of basic equations for dynamical diffraction from volume diffractive optics, which enable us to study the focusing property of these optics with various grating profiles. We study volume diffractive optics that satisfy the Bragg condition to various degrees, namely, flat, tilted, and wedged geometries, and derive the curved geometries required for ultimate focusing. We show that the curved geometries satisfy both the Bragg condition everywhere and phase requirement for point focusing and effectively focus hard x rays to a scale close to the wavelength. Our calculations were made for an x-ray wavelength of 0.064 nm (19.5 keV)

The determination of the crystal structures of some uranium compounds by means of x-ray and neutron diffraction

International Nuclear Information System (INIS)

Adrian, H.W.W.

1977-10-01

In industrial uranium processing or reprocessing procedures, aqueous uranyl nitrate solutions are an intermediate product. The compounds, whose structures are reported, might prove valuable as alternative crystallization products to existing methods of extracting the uranium from solution. The compounds are obtained by the addition of hydroxylammonium to the uranyl nitrate solution and are of the general formula UO 2 (NH 2 0) 2 .xH 2 0, where x can take the values zero, two, three and four. In addition a compound of the formula UO 2 (NH 2 0) 2 .2(NH 2 CH).2H 2 0 was obtained. The UO 2 (NH 2 0) compound crystallized in a monoclinic crystal form. Crystals large enough for neutron diffraction were not obtained. The structure of the UO 2 (NH 2 0) 2 .2H 2 0 could not be solved because only disordered crystalline material was available. The structure of UO 2 (NH 2 0) 2 .3H 2 0 was solved by means of room- and low-temperature neutron diffraction. The unit cell is orthorhombic. The structure of α-UO 2 (NH 2 0) 2 .4H 2 0 was investigated by means of room-temperature x-ray and room- and low-temperature neutron diffraction. The unit cell is triclinic. This compound strongly resembles the trihydrate. The UO 2 (NH 2 0) 2 .2(NH 2 0H).2H 2 0 compound gave crystals large enough for single crystal x-ray but not neutron diffraction. The unit cell is orthorhombic. The characteristic powder patterns (indexed except for the dihydrate compound) of the above compounds are reported [af

Illicit drug detection using energy dispersive x-ray diffraction

Science.gov (United States)

Cook, E. J.; Griffiths, J. A.; Koutalonis, M.; Gent, C.; Pani, S.; Horrocks, J. A.; George, L.; Hardwick, S.; Speller, R.

2009-05-01

Illicit drugs are imported into countries in myriad ways, including via the postal system and courier services. An automated system is required to detect drugs in parcels for which X-ray diffraction is a suitable technique as it is non-destructive, material specific and uses X-rays of sufficiently high energy to penetrate parcels containing a range of attenuating materials. A database has been constructed containing the measured powder diffraction profiles of several thousand materials likely to be found in parcels. These include drugs, cutting agents, packaging and other innocuous materials. A software model has been developed using these data to predict the diffraction profiles which would be obtained by X-ray diffraction systems with a range of suggested detector (high purity germanium, CZT and scintillation), source and collimation options. The aim of the model was to identify the most promising system geometries, which was done with the aid of multivariate analysis (MVA). The most promising systems were constructed and tested. The diffraction profiles of a range of materials have been measured and used to both validate the model and to identify the presence of drugs in sample packages.

X-ray diffraction identification of clay minerals by microcomputer

International Nuclear Information System (INIS)

Rodrigues, S.; Imasava, F.J.

1988-01-01

The identification of clay minerals by X-ray powder diffraction are done by searching an unknown pattern with a file of standard X-ray diffraction patterns. For this searching done by hand is necessary a long time. This paper shows a program in ''Basic'' language to be utilized in microcomputers for the math of the unknown pattern, using the high velocity of comparison of the microcomputer. A few minutes are used for the match. (author) [pt

Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA

International Nuclear Information System (INIS)

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-01-01

The software suite SITENNO is developed for processing diffraction data collected in coherent X-ray diffraction imaging experiments of non-crystalline particles using an X-ray free-electron laser. Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the ‘diffraction before destruction’ scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles

Performance of room temperature mercuric iodide (HgI2) detectors in the ultra low energy x-ray region

International Nuclear Information System (INIS)

Dabrowski, A.J.; Iwanczyk, J.S.; Barton, J.B.; Huth, G.C.; Whited, R.; Ortale, C.; Economou, T.E.; Turkevich, A.L.

1980-01-01

Performance of room temperature mercuric iodide x-ray spectrometers has been recently improved through new fabrication techniques and further development of low noise associated electronic systems. This progress has extended the range of measurements to the ultra low energy x-ray region at room temperature. This paper reports the study of the effect of contact material on the performance of HgI 2 detectors in the low energy x-ray region

Modern trends in x-ray powder diffraction

International Nuclear Information System (INIS)

Goebel, H.E.; Snyder, R.L.

1985-01-01

The revival of interest in X-ray powder diffraction, being quoted as a metamorphosis from the 'ugly duckling' to a 'beautiful swan', can be attributed to a number of modern developments in instrumentation and evaluation software. They result in faster data collection, improved accuracy and resolution, and better detectability of minor phases. The ease of data evaluation on small computers coupled direct to the instrument allows convenient execution of previously tedious and time-consuming off-line tasks like qualitative and quantitative analysis, characterization of microcrystalline properties, indexing, and lattice-constant refinements, as well as structure refinements or even exploration of new crystal structures. Powder diffraction has also progressed from an isolated analytical laboratory method to an in situ technique for analysing solid-state reactions or for the on-stream control of industrial processes. The paper surveys these developments and their real and potential applications, and tries to emphasize new trends that are regarded as important steps for the further progress of X-ray powder diffraction

Phase transitions of Cu.sub.3+x./sub.Si observed by temperature-dependent x-ray powder diffraction

Czech Academy of Sciences Publication Activity Database

Correa, Cinthia Antunes; Poupon, Morgane; Kopeček, Jaromír; Král, Robert; Zemenová, Petra; Lecourt, J.; Barrier, N.; Brázda, Petr; Klementová, Mariana; Palatinus, Lukáš

2017-01-01

Roč. 91, Dec (2017), s. 129-139 ISSN 0966-9795 R&D Projects: GA ČR GC15-08842J Institutional support: RVO:68378271 Keywords : X-ray powder diffraction * differential scanning calorimetry * phase transitions * Cu3+xSi Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.140, year: 2016

Development of a new micro-furnace for "in situ" high-temperature single crystal X-ray diffraction measurements

Science.gov (United States)

Alvaro, Matteo; Angel, Ross J.; Marciano, Claudio; Zaffiro, Gabriele; Scandolo, Lorenzo; Mazzucchelli, Mattia L.; Milani, Sula; Rustioni, Greta; Domeneghetti, Chiara M.; Nestola, Fabrizio

2015-04-01

Several experimental methods to reliably determine elastic properties of minerals at non-ambient conditions have been developed. In particular, different techniques for generating high-pressure and high-temperature have been successfully adopted for single-crystal and powder X-ray diffraction measurements. High temperature devices for "in-situ" measurements should provide the most controlled isothermal environment as possible across the entire sample. It is intuitive that in general, thermal gradients across the sample increase as the temperature increases. Even if the small isothermal volume required for single-crystal X-ray diffraction experiments makes such phenomena almost negligible, the design of a furnace should also aim to reduce thermal gradients by including a large thermal mass that encloses the sample. However this solution often leads to complex design that results in a restricted access to reciprocal space or attenuation of the incident or diffracted intensity (with consequent reduction of the accuracy and/or precision in lattice parameter determination). Here we present a newly-developed H-shaped Pt-Pt/Rh resistance microfurnace for in-situ high-temperature single-crystal X-ray diffraction measurements. The compact design of the furnace together with the long collimator-sample-detector distance allows us to perform measurements up to 2θ = 70° with no further restrictions on any other angular movement. The microfurnace is equipped with a water cooling system that allows a constant thermal gradient to be maintained that in turn guarantees thermal stability with oscillations smaller than 5°C in the whole range of operating T of room-T to 1200°C. The furnace has been built for use with a conventional 4-circle Eulerian geometry equipped with point detector and automated with the SINGLE software (Angel and Finger 2011) that allows the effects of crystal offsets and diffractometer aberrations to be eliminated from the refined peak positions by the 8

Interaction between lipid monolayers and poloxamer 188: An X-ray reflectivity and diffraction study

DEFF Research Database (Denmark)

Wu, G.H.; Majewski, J.; Ege, C.

2005-01-01

The mechanism by which poloxamer 188 (P188) seals a damaged cell membrane is examined using the lipid monolayer as a model system. X-ray reflectivity and grazing-incidence x-ray diffraction results show that at low nominal lipid density, P188, by physically occupying the available area and phase ...

Modern X-ray diffraction. X-ray diffractometry for materials scientists, physicists, and chemicists. 2. rev. and enl. ed.

International Nuclear Information System (INIS)

Spiess, Lothar; Teichert, Gerd; Schwarzer, Robert; Behnken, Herfried; Genzel, Christoph

2009-01-01

This book offers a comprehensive survey over the applications of X-ray diffractions in fields like materials technique, metallurgy, electrotechniques, mechanical engineering, as well as micro- and nanotechniques. The necessary baic knowledges of X-ray diffraction are mediated foundedly and illustratively. Thereby new techniques and evaluation procedures are presented as well as well known methods

Calculated efficiencies of three-material low stress coatings for diffractive x-ray transmission optics

International Nuclear Information System (INIS)

Kubec, Adam; Braun, Stefan; Gawlitza, Peter; Menzel, Maik; Leson, Andreas

2016-01-01

Diffractive X-ray optical elements made by thin film coating techniques such as multilayer Laue lenses (MLL) and multilayer zone plates (MZP) are promising approaches to achieve resolutions in hard X-ray microscopy applications of less than 10 nm. The challenge is to make a lens with a large numerical aperture on the one hand and a decent working distance on the other hand. One of the limiting factors with the coated structures is the internal stress in the films, which can lead to significant bending of the substrate and various types of unwanted diffraction effects. Several approaches have been discussed to overcome this challenge. One of these is a three-material combination such as Mo/MoSi_2/Si, where four single layers per period are deposited. Mo and Si represent the absorber and spacer in this case while MoSi_2 forms a diffusion barrier; in addition the thicknesses of absorber and spacer are chosen to minimize residual stress of the overall coating. Here the diffraction efficiency as well as the profile of the beam in the focal plane are discussed in order to find a tradeoff between lowest residual stress and best diffraction properties.

Interdiffusion in nanometer-scale multilayers investigated by in situ low-angle x-ray diffraction

Science.gov (United States)

Wang, Wei-Hua; Bai, Hai Yang; Zhang, Ming; Zhao, J. H.; Zhang, X. Y.; Wang, W. K.

1999-04-01

An in situ low-angle x-ray diffraction technique is used to investigate interdiffusion phenomena in various metal-metal and metal-amorphous Si nanometer-scale compositionally modulated multilayers (ML's). The temperature-dependent interdiffusivities are obtained by accurately monitoring the decay of the first-order modulation peak as a function of annealing time. Activation enthalpies and preexponential factors for the interdiffusion in the Fe-Ti, Ag-Bi, Fe-Mo, Mo-Si, Ni-Si, Nb-Si, and Ag-Si ML's are determined. Activation enthalpies and preexponential factors for the interdiffusion in the ML's are very small compared with that in amorphous alloys and crystalline solids. The relation between the atomic-size difference and interdiffusion in the ML's are investigated. The observed interdiffusion characteristics are compared with that in amorphous alloys and crystalline α-Zr, α-Ti, and Si. The experimental results suggest that a collective atomic-jumping mechanism govern the interdiffusion in the ML's, the collective proposal involving 8-15 atoms moving between extended nonequilibrium defects by thermal activation. The role of the interdiffusion in the solid-state reaction in the ML's is also discussed.

X-ray diffraction from single GaAs nanowires

Energy Technology Data Exchange (ETDEWEB)

Biermanns, Andreas

2012-11-12

In recent years, developments in X-ray focussing optics have allowed to produce highly intense, coherent X-ray beams with spot sizes in the range of 100 nm and below. Together with the development of new experimental stations, X-ray diffraction techniques can now be applied to study single nanometer-sized objects. In the present work, X-ray diffraction is applied to study different aspects of the epitaxial growth of GaAs nanowires. Besides conventional diffraction methods, which employ X-ray beams with dimensions of several tens of {mu}m, special emphasis lies on the use of nanodiffraction methods which allow to study single nanowires in their as-grown state without further preparation. In particular, coherent X-ray diffraction is applied to measure simultaneously the 3-dimensional shape and lattice parameters of GaAs nanowires grown by metal-organic vapor phase epitaxy. It is observed that due to a high density of zinc-blende rotational twins within the nanowires, their lattice parameter deviates systematically from the bulk zinc-blende phase. In a second step, the initial stage in the growth of GaAs nanowires on Si (1 1 1) surfaces is studied. This nanowires, obtained by Ga-assisted growth in molecular beam epitaxy, grow predominantly in the cubic zinc-blende structure, but contain inclusions of the hexagonal wurtzite phase close to their bottom interface. Using nanodiffraction methods, the position of the different structural units along the growth axis is determined. Because the GaAs lattice is 4% larger than silicon, these nanowires release their lattice mismatch by the inclusion of dislocations at the interface. Whereas NWs with diameters below 50 nm are free of strain, a rough interface structure in nanowires with diameters above 100 nm prevents a complete plastic relaxation, leading to a residual strain at the interface that decays elastically along the growth direction. Finally, measurements on GaAs-core/InAs-shell nanowire heterostructures are presented

X-ray diffraction studies of NbTe 2 single crystal

Indian Academy of Sciences (India)

The composition of the grown crystals was confirmed on the basis of energy dispersive analysis by X-ray (EDAX) and remaining structural characterization was also accomplished by X-ray diffraction (XRD) studies. Lattice parameters, volume and X-ray density have been carried out for the grown crystals. The particle size ...

Diamond Thermal Expansion Measurement Using Transmitted X-ray Back-diffraction.

OpenAIRE

Giles, Carlos; Adriano, Cris; Lubambo, Adriana Freire; Cusatis, Cesar; Mazzaro, Irineu; Hönnicke, Marcelo Goncalves

2015-01-01

The linear thermal expansion coefficient of diamond has been measured using forward-diffracted profiles in X-ray backscattering. This experimental technique is presented as an alternative way of measuring thermal expansion coefficients of solids in the high-resolution Bragg backscattering geometry without the intrinsic difficulty of detecting the reflected beam. The temperature dependence of the lattice parameter is obtained from the high sensitivity of the transmitted profiles to the Bragg a...

An introduction to three-dimensional X-ray diffraction microscopy

DEFF Research Database (Denmark)

Poulsen, Henning Friis

2012-01-01

Three-dimensional X-ray diffraction microscopy is a fast and nondestructive structural characterization technique aimed at studies of the individual crystalline elements (grains or subgrains) within millimetre-sized polycrystalline specimens. It is based on two principles: the use of highly...... penetrating hard X-rays from a synchrotron source and the application of tomographic reconstruction algorithms for the analysis of the diffraction data. In favourable cases, the position, morphology, phase and crystallographic orientation can be derived for up to 1000 elements simultaneously. For each grain...

Preliminary study of determination of UO2 grain size using X-ray diffraction method

International Nuclear Information System (INIS)

Mulyana, T.; Sambodo, G. D.; Juanda, D.; Fatchatul, B.

1998-01-01

The determination of UO 2 grain size has accomplished using x-ray diffraction method. The UO 2 powder is obtained from sol-gel process. A copper target as radiation source in the x-ray diffractometer was used in this experiment with CμKα characteristic wavelength 1.54433 Angstrom. The result indicate that the UO 2 mean grain size on presintered (temperature 800 o C) has the value 456.8500 Angstrom and the UO 2 mean grain size on sintered (temperature 1700 o C) has value 651.4934 Angstrom

Highly sensitive x-ray detectors in the low-energy range on n-type 4H-SiC epitaxial layers

Energy Technology Data Exchange (ETDEWEB)

Mandal, Krishna C.; Muzykov, Peter G. [Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States); Russell Terry, J. [Space Science and Applications Group (ISR-1), Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-07-30

Schottky diodes on n-type 4H-SiC epitaxial layers have been fabricated for low-energy x-ray detection. The detectors were highly sensitive to soft x-rays and showed improved response compared to the commercial SiC UV photodiodes. Current-voltage characteristics at 475 K showed low leakage current revealing the possibility of high temperature operation. The high quality of the epi-layer was confirmed by x-ray diffraction and chemical etching. Thermally stimulated current measurements performed at 94-550 K revealed low density of deep levels which may cause charge trapping. No charge trapping on detectors' responsivity in the low x-ray energy was found.

Diffraction anomalous fine structure using X-ray anomalous dispersion

International Nuclear Information System (INIS)

Soejima, Yuji; Kuwajima, Shuichiro

1998-01-01

A use of X-ray anomalous dispersion effects for structure investigation has recently been developed by using synchrotron radiation. One of the interesting method is the observation of anomalous fine structure which arise on diffraction intensity in energy region of incident X-ray at and higher than absorption edge. The phenomenon is so called Diffraction Anomalous Fine Structure (DAFS). DAFS originates in the same physical process an that of EXAFS: namely photoelectric effect at the corresponding atom and the interaction of photoelectron waves between the atom and neighboring atoms. In contrast with EXAFS, the method is available for only the crystalline materials, but shows effective advantages of the structure investigations by a use of diffraction: one is the site selectivity and the other is space selectivity. In the present study, demonstrations of a use of X-ray anomalous dispersion effect for the superstructure determination will be given for the case of PbZrO 3 , then recent trial investigations of DAFS in particular on the superlattice reflections will be introduced. In addition, we discuss about Forbidden Reflection near Edge Diffraction (FRED) which is more recently investigated as a new method of the structure analysis. (author)

Residual stress measurements by X-ray and neutron diffractions in heat-treated SiCw/A2014 composites

International Nuclear Information System (INIS)

Ohnuki, Takahisa; Fujita, Motoo; Tomota, Yo; Ono, Masayoshi

1998-01-01

Residual stresses due to various heat treatments in a 22 volume percent SiC whisker/A2014 metal matrix composite (MMC) were measured by using X-ray and neutron diffractions. Micro residual stresses generated from the differences in thermal expansion coefficients of the constituents and macro residual stresses associated with different cooling rates in the outer and inner regions of an MMC specimen must be distinguished in X-ray stress measurements. The conventional sin 2 ψ method under an assumption of plane stress condition has been found not to be applicable to the present MMC, because interactions among whiskers in the X-ray penetrating area yields σ 33 where the x 3 -axis is normal with respect to specimen's surface. An average value of σ 33 can be measured by X-ray diffraction technique, but does not seem enough to evaluate micro residual stresses. It is found that neutron diffraction is the most powerful method to measure micro residual stresses in the constituents. Elastic residual strains obtained by neutron diffraction in solution treated or T6 heat treated samples show good agreements with predictions calculated by using Eshelby inclusion theory coupled with the Mori-Tanaka mean field concept, indicating that the influence of stress relaxation is negligible. In addition, internal stresses relaxations during holding at room temperature, slow cooling from solution treatment temperature, or subzero cooling are discussed. (author)

X-ray powder diffraction data on miscellaneous lanthanide compounds

International Nuclear Information System (INIS)

Ferguson, I.F.; Hughes, T.E.

1978-08-01

Recent work on neutron absorbing materials has produced various new X-ray diffraction powder patterns of compounds of the lanthanides. Various inconsistencies in previously published data have been noted, and accurate measurements have been made of the lattice parameters of the rare earth oxides Sm 2 0 3 , Eu 2 0 3 , Gd 2 0 3 which have the monoclinic rare earth type B- structure, as well as Eu0. These data are recorded for reference. The optimum conditions for obtaining X-ray powder diffraction data from europium compounds are also noted. (author)

X-ray diffraction of multilayers and superlattices

International Nuclear Information System (INIS)

Bartels, W.J.; Hornstra, J.; Lobeek, D.J.W.

1986-01-01

Recursion formulae for calculating the reflected amplitude ratio of multilayers and superlattices have been derived from the Takagi-Taupin differential equations, which describe the dynamical diffraction of X-rays in deformed crystals. Calculated rocking curves of complicated layered structures, such as non-ideal superlattices on perfect crystals, are shown to be in good agreement with observed diffraction profiles. The kinematical theory can save computing time only in the case of an ideal superlattice, for which a geometric series can be used, but the reflections must be below 10% so that multiple reflections can be neglected. For a perfect crystal of arbitrary thickness the absorption at the center of the dynamical reflection is found to be proportional to the square root of the reflectivity. Sputter-deposited periodic multilayers of tungsten and carbon can be considered as an artificial crystal, for which dynamical X-ray diffraction calculations give results very similar to those of a macroscopic optical description in terms of the complex index of refraction and Fresnel reflection coefficients. (orig.)

X-ray and Neutron Diffraction in the Study of Organic Crystalline Hydrates

Directory of Open Access Journals (Sweden)

Katharina Fucke

2010-07-01

Full Text Available A review. Diffraction methods are a powerful tool to investigate the crystal structure of organic compounds in general and their hydrates in particular. The laboratory standard technique of single crystal X-ray diffraction gives information about the molecular conformation, packing and hydrogen bonding in the crystal structure, while powder X-ray diffraction on bulk material can trace hydration/dehydration processes and phase transitions under non-ambient conditions. Neutron diffraction is a valuable complementary technique to X-ray diffraction and gives highly accurate hydrogen atom positions due to the interaction of the radiation with the atomic nuclei. Although not yet often applied to organic hydrates, neutron single crystal and neutron powder diffraction give precise structural data on hydrogen bonding networks which will help explain why hydrates form in the first place.

Coded diffraction system in X-ray crystallography using a boolean phase coded aperture approximation

Science.gov (United States)

Pinilla, Samuel; Poveda, Juan; Arguello, Henry

2018-03-01

Phase retrieval is a problem present in many applications such as optics, astronomical imaging, computational biology and X-ray crystallography. Recent work has shown that the phase can be better recovered when the acquisition architecture includes a coded aperture, which modulates the signal before diffraction, such that the underlying signal is recovered from coded diffraction patterns. Moreover, this type of modulation effect, before the diffraction operation, can be obtained using a phase coded aperture, just after the sample under study. However, a practical implementation of a phase coded aperture in an X-ray application is not feasible, because it is computationally modeled as a matrix with complex entries which requires changing the phase of the diffracted beams. In fact, changing the phase implies finding a material that allows to deviate the direction of an X-ray beam, which can considerably increase the implementation costs. Hence, this paper describes a low cost coded X-ray diffraction system based on block-unblock coded apertures that enables phase reconstruction. The proposed system approximates the phase coded aperture with a block-unblock coded aperture by using the detour-phase method. Moreover, the SAXS/WAXS X-ray crystallography software was used to simulate the diffraction patterns of a real crystal structure called Rhombic Dodecahedron. Additionally, several simulations were carried out to analyze the performance of block-unblock approximations in recovering the phase, using the simulated diffraction patterns. Furthermore, the quality of the reconstructions was measured in terms of the Peak Signal to Noise Ratio (PSNR). Results show that the performance of the block-unblock phase coded apertures approximation decreases at most 12.5% compared with the phase coded apertures. Moreover, the quality of the reconstructions using the boolean approximations is up to 2.5 dB of PSNR less with respect to the phase coded aperture reconstructions.

Measuring the x-ray resolving power of bent potassium acid phthalate diffraction crystals

International Nuclear Information System (INIS)

Haugh, M. J.; Jacoby, K. D.; Wu, M.; Loisel, G. P.

2014-01-01

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals that we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories in Albuquerque, New Mexico. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a double crystal diffractometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed

Measuring the x-ray resolving power of bent potassium acid phthalate diffraction crystals

Energy Technology Data Exchange (ETDEWEB)

Haugh, M. J., E-mail: haughmj@nv.doe.gov; Jacoby, K. D. [National Security Technologies, LLC, Livermore, California 94550 (United States); Wu, M.; Loisel, G. P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)

2014-11-15

This report presents the results from measuring the X-ray resolving power of a curved potassium acid phthalate (KAP(001)) spectrometer crystal using two independent methods. It is part of a continuing effort to measure the fundamental diffraction properties of bent crystals that are used to study various characteristics of high temperature plasmas. Bent crystals like KAP(001) do not usually have the same diffraction properties as corresponding flat crystals. Models that do exist to calculate the effect of bending the crystal on the diffraction properties have simplifying assumptions and their accuracy limits have not been adequately determined. The type of crystals that we measured is being used in a spectrometer on the Z machine at Sandia National Laboratories in Albuquerque, New Mexico. The first technique for measuring the crystal resolving power measures the X-ray spectral line width of the characteristic lines from several metal anodes. The second method uses a diode X-ray source and a double crystal diffractometer arrangement to measure the reflectivity curve of the KAP(001) crystal. The width of that curve is inversely proportional to the crystal resolving power. The measurement results are analyzed and discussed.

X-ray diffraction and chemical bonding

International Nuclear Information System (INIS)

Bats, J.W.

1976-01-01

Chemical bonds are investigated in sulfamic acid (H 3 N-SO 3 ), sodium sulfonlate dihydrate (H 2 NC 6 H 4 SO 3 Na.2H 2 O), 2,5-dimercaptothiadiazole (HS-C 2 N 2 S-SH), sodium cyanide dihydrate (NaCN.2H 2 O), sodium thiocyanate (NaSCN) and ammonium thiocyanate (NH 4 SCN) by X-ray diffraction, and if necessary completed with neutron diffraction. Crystal structures and electron densities are determined together with bond length and angles. Also the effects of thermal motion are discussed

Mineralogical analysis of clays in hardsetting soil horizons, by X-ray fluorescence and X-ray diffraction using Rietveld method

International Nuclear Information System (INIS)

Prandel, L.V.; Saab, S.C.; Brinatti, A.M.; Giarola, N.F.B.; Leite, W.C.; Cassaro, F.A.M.

2014-01-01

Diffraction and spectroscopic techniques have been shown to be suitable for obtaining physical and mineralogical properties in polycrystalline soil samples, and also in their precursor compounds. For instance, the X-ray fluorescence (XRF) spectroscopy allows obtaining the elemental composition of an investigated sample, while the X-ray diffraction (XRD) technique permits obtaining qualitative and quantitative composition of the soil minerals through the Rietveld method (RM). In this study Yellow Latosol (Oxisol), Yellow Argisol (Ultisol) and Gray Argisol (Ultisol) soil samples, classified as “hardsetting soils”, extracted from areas located at Northeast and Southeast of Brazilian coast were investigated. The soils and their fractions were analyzed in an EDX-700 and an XRD-6000 (Cu K α radiation). XRF results indicate high percentages of Si and Al, and small percentage of Fe and Ti in the investigated samples. The DRX data and RM indicate that there was a predominance of kaolinite and halloysite minerals (kaolin group minerals) in the clay fractions, which are presumably responsible for the formation of kaolinitic plasma in these soils. Also, the obtained results showed that the XRF, XRD techniques and RM were very helpful for investigating the mineralogical composition of a hardsetting soil. - Highlights: ► Elemental composition of soil samples through X-Ray fluorescence. ► Mineralogical quantification through X-ray diffraction and Rietveld method. ► Oxisol and Ultisol, Brazil ‘Barreiras’ formation. ► High amounts of Si and Al oxides and low amounts of Fe and Ti oxides. ► Predominance of kaolinite in the clay fraction

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

Science.gov (United States)

Crouse, David T.

2007-01-01

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

The three dimensional X-ray diffraction technique

DEFF Research Database (Denmark)

Juul Jensen, Dorte; Poulsen, Henning Friis

2012-01-01

This introductory tutorial describes the so called 3 dimensional X-ray diffraction (3DXRD) technique, which allows bulk non-destructive structural characterizations of crystalline materials. The motivations and history behind the development of this technique are described and its potentials...

Effect of Pressure on Valence and Structural Properties of YbFe₂Ge₂ Heavy Fermion Compound A Combined Inelastic X-ray Spectroscopy, X-ray Diffraction, and Theoretical Investigation

Energy Technology Data Exchange (ETDEWEB)

Kumar, Ravhi S.; Svane, Axel; Vaitheeswaran; #8741; , Ganapathy; Kanchana, Venkatakrishnan; Antonio, Daniel; Cornelius, Andrew L.; Bauer, Eric D.; Xiao, Yuming; Chow, Paul (Aarhus); (CIW); (Hyderabad - India); (IIT-India); (LANL); (UNLV)

2016-06-03

The crystal structure and the Yb valence of the YbFe₂Ge₂ heavy fermion compound was measured at room temperature and under high pressures using high-pressure powder X-ray diffraction and X-ray absorption spectroscopy via both partial fluorescence yield and resonant inelastic X-ray emission techniques. Furthermore, the measurements are complemented by first-principles density functional theoretical calculations using the self-interaction corrected local spin density approximation investigating in particular the magnetic structure and the Yb valence. While the ThCr₂Si₂-type tetragonal (I4/mmm) structure is stable up to 53 GPa, the X-ray emission results show an increase of the Yb valence from v = 2.72(2) at ambient pressure to v = 2.93(3) at ~9 GPa, where at low temperature a pressure-induced quantum critical state was reported.

Bone mineral change during experimental calcination: an X-ray diffraction study.

Science.gov (United States)

Galeano, Sergio; García-Lorenzo, Mari Luz

2014-11-01

The effects of calcination (400-1200°C) on pig bones have been studied using powder X-ray diffraction (XRD) and secondary modifications, such as color change and weight loss. The characterisation by powder XRD confirmed the presence of the crystalline phase of hydroxyapatite, and comparison of the results obtained at different temperatures suggested that at 650°C, all the organic components and carbonate substitutions were completely removed. Accordingly, these samples were white. In addition, the crystallinity degree and the crystallite size progressively increased with the calcination temperature until 650°C, remaining stable until 1200°C. Below 650°C, bone samples presented organic compounds, resulting in background noise in the diffractogram and gray or black color. In addition, impurities in the lattice correspond to low crystallite sizes. © 2014 American Academy of Forensic Sciences.

Phase transformation in sol-gel prepared zirconia using in-situ high temperature X-ray diffraction

International Nuclear Information System (INIS)

Srinivasan, R.; Davis, B.H.; Hubbard, C.R.; Cavin, O.B.; Porter, W.D.

1991-01-01

Zirconia was precipitated at a pH of 10.5 by admixing a solution of ZrCl 4 and NH 4 OH both rapidly (∼ 1 min) and slowly (∼ 8 hr). The precipitate was calcined at 500C for 5 hours and then furnace cooled. The former exhibited monoclinic phase while the latter yielded tetragonal phase. The pathway from amorphous to crystalline form was followed by in-situ high temperature X-ray diffraction in flowing air and in He. The data showed the evolution of the tetragonal crystalline phase on heating. On rapid cooling the tetragonal phase is retained at R.T., and on slow cooling the transformation to monoclinic phase occurs in air

Experimental issues in in-situ synchrotron x-ray diffraction at high pressure and temperature by using a laser-heated diamond-anvil cell

International Nuclear Information System (INIS)

Yoo, C.S.

1997-01-01

An integrated technique of diamond-anvil cell, laser-heating and synchrotron x-ray diffraction technologies is capable of structural investigation of condensed matter in an extended region of high pressures and temperatures above 100 GPa and 3000 K. The feasibility of this technique to obtain reliable data, however, strongly depends on several experimental issues, including optical and x-ray setups, thermal gradients, pressure homogeneity, preferred orientation, and chemical reaction. In this paper, we discuss about these experimental issues together with future perspectives of this technique for obtaining accurate data

Quantitative determination of mineral composition by powder X-ray diffraction

International Nuclear Information System (INIS)

Pawloski, G.A.

1986-01-01

A method is described of quantitatively determining the mineral composition in a test sample containing a number (m) of minerals from a group (n) of known minerals, wherein n=13, where mless than or equal ton, by x-ray diffraction, comprising: determining from standard samples of the known minerals a set of (n) standard coefficients K/sub j/=(X/sub j//X/sub l/)(I/sub l//I/sub j/) for each mineral (j=2...n) in the group of known minerals (j=2...n) relative to one mineral (l) in the group selected as a reference mineral, where X is the weight fraction of the mineral in a standard sample, and I is the x-ray integrated intensity peak of each mineral obtained from the standard sample; obtaining an x-ray diffraction pattern of the test sample; identifying each of the (m) minerals in the test sample for the x-ray diffraction pattern; calculating the relative weight fractions X/sub j//X/sub l/ for each mineral (j=2...m) compared to the reference mineral (l) from the ratio of the measured highest integrated intensity peak I/sub j/ of each mineral in the test sample to the measured highest integrated intensity peak I/sub l/ of the reference mineral in the test sample, and from the previously determined standard coefficients, X/sub j//X/sub l/=K/sub j/(I/sub j//I/sub l/

Individual GaAs nanorods imaged by coherent X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Pietsch, Ullrich; Biermanns, Andreas; Davydok, Anton [Universitaet Siegen (Germany); Paetzelt, Hendrik [Universitaet Leipzig (Germany); IOM Leipzig (Germany); Diaz, Ana; Metzger, Hartmut [ID01 Beamline, ESRF (France); Gottschalch, Volker [Universitaet Leipzig (Germany)

2010-07-01

Semiconductor nanorods are of particular interest for new semiconductor devices because the nanorod approach can be used to form heterostructures of materials with a large lattice mismatch and to define nanorod arrays with tailored inter-rod distance. However, all applications require objects with uniform physical properties based on uniform morphology. Complementary to electron microscopy techniques, destruction free X-ray diffraction techniques can be used to determine structural and morphological details. Using scanning X-ray diffraction microscopy with a spot size of 220 x 600 nm{sup 2} we were able to inspect individual GaAs nanorods grown by seed-free MOVPE through circular openings in a SiN{sub x} mask in a periodic array with 3 {mu}m spacing on GaAs[111]B. The focussed X-ray beam allows the determination of the strain state of individual rods and in combination with coherent diffraction imaging, we were able to characterize also morphological details. Rods grown at different positions in the array show significant differences in shape, size and strain state.

Elasticity of Tantalum to 105 Gpa using a stress and angle-resolved x-ray diffraction

International Nuclear Information System (INIS)

Cynn, H; Yoo, C S

1999-01-01

Determining the mechanical properties such as elastic constants of metals at Mbar pressures has been a difficult task in experiment. Following the development of anisotropic elastic theory by Singh et al.[l], Mao et a1.[2] have recently developed a novel experimental technique to determine the elastic constants of Fe by using the stress and energy-dispersive x-ray diffraction (SEX). In this paper, we present an improved complementary technique, stress and angle-resolved x-ray diffraction (SAX), which we have applied to determine the elastic constants of tantalum to 105 GPa. The extrapolation of the tantalum elastic data shows an excellent agreement with the low-pressure ultrasonic data[3]. We also discuss the improvement of this SAX method over the previous SEX.[elastic constant, anisotropic elastic theory, angle-dispersive synchrotron x-ray diffraction, mechanical properties

X-Ray Diffraction Project Final Report, Fiscal Year 2006

International Nuclear Information System (INIS)

Dane V. Morgan

2006-01-01

An x-ray diffraction diagnostic system was developed for determining real-time shock-driven lattice parameter shifts in single crystals at the gas gun at TA-IV at Sandia National Laboratories (SNL). The signal-to-noise ratio and resolution of the system were measured using imaging plates as the detector and by varying the slit width. This report includes tests of the x-ray diffraction system using a phosphor coupled to a charge-coupled device (CCD) camera by a coherent fiber-optic bundle. The system timing delay was measured with a newly installed transistor-transistor logic (TTL) bypass designed to reduce the x-ray delay time. The axial misalignment of the Bragg planes was determined with respect to the optical axis for a set of eight LiF [lithium fluoride] crystals provided by SNL to determine their suitability for gas gun experiments

Dehydration reactions of gypsum: A neutron and X-ray diffraction study

Science.gov (United States)

Abriel, W.; Reisdorf, K.; Pannetier, J.

1990-03-01

The kinetics of the dehydration of gypsum was investigated by powder diffraction methods. Using the incoherent scattering effect of H with the neutron beam, the background intensity as a measure of the water content was checked in the temperature range 295-623 K. The superposed Bragg peaks yielded four major phases: Gypsum, subhydratesCaSO 4(H 2O) x (1 > x > 0),AIII-CaSO 4, AII-CaSO 4. For the subhydrates a maximum water content of x > = 0.74was determined. A different kinetic was found using Guinier X-ray technique with the heated sample prepared on a thin foil. Only with high local H 2O steam pressure, produced in the comparable larger sample container of the neutron diffraction experiment, could this high H 2O occupation of the subhydrate tunnel structure be found. A topotactic mechanism can describe the phase transitions for this reaction.

Diffractive-refractive optics: (+,-,-,+) X-ray crystal monochromator with harmonics separation.

Science.gov (United States)

Hrdý, Jaromír; Mikulík, Petr; Oberta, Peter

2011-03-01

A new kind of two channel-cut crystals X-ray monochromator in dispersive (+,-,-,+) position which spatially separates harmonics is proposed. The diffracting surfaces are oriented so that the diffraction is inclined. Owing to refraction the diffracted beam is sagittally deviated. The deviation depends on wavelength and is much higher for the first harmonics than for higher harmonics. This leads to spatial harmonics separation. The idea is supported by ray-tracing simulation.

Disorder and transport properties of In3SbTe2 - an X-ray, neutron and electron diffraction study

International Nuclear Information System (INIS)

Schroeder, Thorsten; Rosenthal, Tobias; Grott, Sebastian; Stiewe, Christian; Boor, Johannes de; Oeckler, Oliver

2013-01-01

Quenched metastable In 3 SbTe 2 was investigated by X-ray and neutron powder diffraction as well as by single-crystal X-ray diffraction. The average structure corresponds to the rocksalt type, the anion position being occupied by antimony and tellurium. Neutron data indicate no antisite disorder of indium and antimony. The compound is a high-temperature phase that can be quenched to yield a metastable compound at ambient temperature which, upon heating, decomposes at ca. 320 C into InSb and InTe. Diffuse scattering in reconstructed X-ray and selected area electron diffraction patterns indicates local distortions of the crystal structure due to static atom displacement along <100> from the average positions, caused by the different size of the anions, but no superstructure. The electrical conductivity of In 3 SbTe 2 is 3.2 x 10 4 S.cm -1 at 25 C, the temperature characteristics correspond to metallic behavior. Consequently, the thermal conductivity is also rather high. The decomposition into InSb and InTe reduces the electrical conductivity by a factor of 3 in heterogeneous microstructures. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

X-ray diffraction analysis of InAs nanowires

International Nuclear Information System (INIS)

Davydok, Anton

2013-01-01

Semiconductor nanowires have attracted great interest as building blocks for future electronic and optoelectronic devices. The variability of the growth process opens the opportunity to control and combine the various properties tailoring for specific application. It was shown that the electrical and optical characteristics of the nanowires are strongly connected with their structure. Despite intensive research in this field, the growth process is still not fully understood. In particular, extensive real structure investigations are required. Most of the reports dedicated on the structural researches are based on the results of scanning electron microscopy (SEM) or transmission electron microscopy (TEM). SEM provides an image of the surface with nanostructures and is mainly used to describe the morphology of the sample, but it does not bring information about the internal structure, phase composition and defect structure. At the same time, the internal structure can be examined by TEM down to atomic scale. TEM image of good quality are very expensive due to the efforts in sample preparation and in localisation of a single object. All these aspects make the statistical structural analysis difficult. In the present work, X-ray diffraction analysis has been applied for structural investigation of InAs nanowires grown by different techniques. Using various X-ray diffraction geometries, the nanowire systems were investigated in terms of the lattice parameters, phase composition, strains and displacement fields and stacking defects. In particular, realizing grazing incidence diffraction and controlling the penetration depth of X-ray beam, we characterized sample series grown by Au-assisted metal organic phase epitaxy on GaAs [111]B substrate with different growth time. According to the results of SEM and X-ray investigations, a model of the growth process has been proposed. A more detailed analysis was performed on InAs nanowires grown by molecular beam epitaxy (MBE) on

New opportunities for 3D materials science of polycrystalline materials at the micrometre lengthscale by combined use of X-ray diffraction and X-ray imaging

DEFF Research Database (Denmark)

Ludwig, W.; King, A.; Reischig, P.

2009-01-01

Non-destructive, three-dimensional (3D) characterization of the grain structure in mono-phase polycrystalline materials is an open challenge in material science. Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting possibilities for mapping 3D grain shapes....... A recent extension of this methodology, termed X-ray diffraction contrast tomography (DCT), combines the principles of X-ray diffraction imaging, three-dimensional X-ray diffraction microscopy (3DXRD) and image reconstruction from projections. DCT provides simultaneous access to 3D grain shape...

X-ray diffraction studies on single and mixed confectionery fats using synchrotron radiation

International Nuclear Information System (INIS)

MacMillan, S.C.; Roberts, K.J.; Wells, M.; Polgreen, M.; Smith, I.

1999-01-01

Full text: Understanding and refining the molecular-scale processes involved in the manufacture of structured materials such as long-chain hydrocarbon compounds is important in many commercial areas such as the petrochemical, biochemical, food, pharmaceutical and soap industries. In such processes crystallisation is an important separation, purification and preparation technique. Despite this our knowledge of the crystallisation process itself is surprisingly limited. In order to improve the crystallisation of confectionery fats, the crystallisation of it's main component, cocoa butter fat, must be properly understood. Cocoa butter fat can exhibit up to 6 polymorphic forms of different crystallographic structures with melting points varying from 17.3 deg C to 36.3 deg C. During the production of chocolate it is essential to control the polymorphic form of fats present, in order to produce a final product with the correct physical and rheological properties. Both shear rate and temperature are thought to play a crucial role in this process. The most widely used method for studying polymorphism is X-ray diffraction. Typical X-ray diffraction patterns of fats exhibit two groups of diffraction lines corresponding to the long and short spacings. The long spacings correspond to the planes formed by the methyl end groups and are dependent on the chain length and the angle of tilt of the component fatty acids of the glyceride molecules. The short spacings refer to the cross sectional packing of the hydrocarbon chain and are independent of the chain length. The relationship between crystallisation rate, polymorphic form, shear and the fat composition has for the first time been quantified, which will enable more accurate control of the polymorhic form in chocolate production. This has been achieved by developing an improved in-situ cell for X-ray studies. The X-ray studies are necessary for the examination of on-line studies under well controlled conditions of temperature

X-ray diffraction studies on single and mixed confectionery fats using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

MacMillan, S.C.; Roberts, K.J.; Wells, M.; Polgreen, M.; Smith, I. [Heriot-Watt University, Edinburgh, (United Kingdom). Department of Mechanical and Chemical Engineering, Centre for Molecular and Interface Engineering

1999-12-01

Full text: Understanding and refining the molecular-scale processes involved in the manufacture of structured materials such as long-chain hydrocarbon compounds is important in many commercial areas such as the petrochemical, biochemical, food, pharmaceutical and soap industries. In such processes crystallisation is an important separation, purification and preparation technique. Despite this our knowledge of the crystallisation process itself is surprisingly limited. In order to improve the crystallisation of confectionery fats, the crystallisation of it`s main component, cocoa butter fat, must be properly understood. Cocoa butter fat can exhibit up to 6 polymorphic forms of different crystallographic structures with melting points varying from 17.3 deg C to 36.3 deg C. During the production of chocolate it is essential to control the polymorphic form of fats present, in order to produce a final product with the correct physical and rheological properties. Both shear rate and temperature are thought to play a crucial role in this process. The most widely used method for studying polymorphism is X-ray diffraction. Typical X-ray diffraction patterns of fats exhibit two groups of diffraction lines corresponding to the long and short spacings. The long spacings correspond to the planes formed by the methyl end groups and are dependent on the chain length and the angle of tilt of the component fatty acids of the glyceride molecules. The short spacings refer to the cross sectional packing of the hydrocarbon chain and are independent of the chain length. The relationship between crystallisation rate, polymorphic form, shear and the fat composition has for the first time been quantified, which will enable more accurate control of the polymorhic form in chocolate production. This has been achieved by developing an improved in-situ cell for X-ray studies. The X-ray studies are necessary for the examination of on-line studies under well controlled conditions of temperature

Structural investigation of GaInP nanowires using X-ray diffraction

DEFF Research Database (Denmark)

Kriegner, D.; Persson, Johan Mikael; Etzelstorfer, T.

2013-01-01

In this work the structure of ternary GaxIn1−xP nanowires is investigated with respect to the chemical composition and homogeneity. The nanowires were grown by metal–organic vapor-phase epitaxy. For the investigation of ensemble fluctuations on several lateral length scales, X-ray diffraction...... gradients along the sample by recording diffraction patterns at different positions. In addition, compositional variations were found also within single nanowires in X-ray energy dispersive spectroscopy measurements....

Two-dimensional time-resolved x-ray diffraction study of dual phase rapid solidification in steels

Science.gov (United States)

Yonemura, Mitsuharu; Osuki, Takahiro; Terasaki, Hidenori; Komizo, Yuichi; Sato, Masugu; Toyokawa, Hidenori; Nozaki, Akiko

2010-01-01

The high intensity heat source used for fusion welding creates steep thermal gradients of 100 °C/s from 1800 °C. Further, the influence of preferred orientation is important for the observation of a directional solidification that follows the dendrite growth along the ⟨100⟩ direction toward the moving heat source. In the present study, we observed the rapid solidification of weld metal at a time resolution of 0.01-0.1 s by a two-dimensional time-resolved x-ray diffraction (2DTRXRD) system for real welding. The diffraction rings were dynamically observed by 2DTRXRD with synchrotron energy of 18 keV while the arc passes over the irradiation area of the x-rays. The arc power output was 10 V-150 A, and the scan speed of the arc was 1.0 mm/s. The temperature rise in instruments was suppressed by a water-cooled copper plate under the specimen. Further, the temperature distribution of the weld metal was measured by a thermocouple and correlated with the diffraction patterns. Consequently, solidification and solid phase transformation of low carbon steels and stainless steels were observed during rapid cooling by 2DTRXRD. In the low carbon steel, the microstructure is formed in a two step process, (i) formation of crystallites and (ii) increase of crystallinity. In stainless steel, the irregular interface layer of δ/γ in the quenched metal after solidification is expected to show the easy movement of dendrites at a lower temperature. In carbide precipitation stainless steel, it is easy for NbC to grow on δ phase with a little undercooling. Further, a mistlike pattern, which differs from the halo pattern, in the fusion zone gave some indication of the possibilities to observe the nucleation and the early solidification by 2DTRXRD.

A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

International Nuclear Information System (INIS)

Bohndiek, Sarah E; Cook, Emily J; Arvanitis, Costas D; Olivo, Alessandro; Royle, Gary J; Clark, Andy T; Prydderch, Mark L; Turchetta, Renato; Speller, Robert D

2008-01-01

X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable

Neutron and X-ray diffraction from modulated structures

International Nuclear Information System (INIS)

Harris, P.

1994-07-01

This thesis describes X-ray and neutron scattering experiments performed on two examples of modulated structures. After an introduction to the subject of modulated structures, the thesis is divided in three parts. A single crystal elastic neutron scattering experiment between 4.2 and 115 Κ has been performed and four-circle X-ray data have been collected at 8 Κ for the monoclinic low-temperature phase of the layered perovskite PAMC. The results from the neutron scattering experiment indicate that magnetoelastic effects influence the ordering of the crystal. The X-ray experiments have made it possible to determine the crystal structure in the low-temperature phase. The superspace group is P2 1 /b(β-30)Os, with β = 1/3. A small-angle neutron scattering experiment has been performed on the magnetic structure of manganese silicide. When a magnetic field is applied, the modulation vectors turn towards the field direction, showing domain growth and diverging peak widths as they approach the field direction. Phase 'A' is established to have the modulation vectors directed perpendicular to the field direction. Cooling in zero field shows increasing peak widths at low temperatures, indicating a lock-in transition below the lowest reached temperature. To be able to analyse the data of the magnetic order in MnSi, and analytical calculation of the three dimensional resolution function for a small-angle neutron scattering spectrometer has been performed. The calculation is done by application of a combination of phase space analysis and Gaussian approximations for the neutron distribution as well as for the transmission functions of the different apertures. A finite mosaic spread of the crystal and finite correlation widths of the Bragg reflections have been included in the cross section. (au) (3 tabs., 48 ills., 100 refs.)

Basic of X-ray diffraction

International Nuclear Information System (INIS)

Giacovazzo, C.

1996-01-01

The basic concepts of X-ray diffraction may be more easily understood if it is made preliminary use of a mathematical background. In these pages the authors will first define the delta function and its use for the representation of a lattice. Then the concepts of Fourier transform and convolution are given. At the end of this talk one should realize that a crystal is the convolution of the lattice with a function representing the content of the unit cell

Basic of X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Giacovazzo, C [Bari Univ. (Italy). Dip. Geomineralogico

1996-09-01

The basic concepts of X-ray diffraction may be more easily understood if it is made preliminary use of a mathematical background. In these pages the authors will first define the delta function and its use for the representation of a lattice. Then the concepts of Fourier transform and convolution are given. At the end of this talk one should realize that a crystal is the convolution of the lattice with a function representing the content of the unit cell.

Residual stress characterization of welds using x-ray diffraction techniques

International Nuclear Information System (INIS)

Pineault, J.A.; Brauss, M.E.

1996-01-01

Neglect of residual stresses created during processes lead to stress corrosion cracking, distortion, fatigue cracking, premature failures in components, and instances of over design. Automated residual stress mapping and truly portable equipment have now made the characterization of residual stresses using x-ray diffraction (XRI) practical. The nondestructive nature of the x-ray diffraction technique has made the tile residual stress characterization of welds a useful tool for process optimization and failure analysis, particularly since components can be measured before and after welding and post welding processes. This paper illustrates the importance of residual stress characterization in welds and presents examples where x-ray diffraction techniques were applied in the characterization of various kinds of welds. arc welds, TIG welds, resistance welds, laser welds and electron beam welds. Numerous techniques are available to help manage potentially harmfull residual stresses created during the welding process thus, the effects of a few example post weld processes such as grinding, heat treating and shot peening are also addressed

AUSPEX: a graphical tool for X-ray diffraction data analysis.

Science.gov (United States)

Thorn, Andrea; Parkhurst, James; Emsley, Paul; Nicholls, Robert A; Vollmar, Melanie; Evans, Gwyndaf; Murshudov, Garib N

2017-09-01

In this paper, AUSPEX, a new software tool for experimental X-ray data analysis, is presented. Exploring the behaviour of diffraction intensities and the associated estimated uncertainties facilitates the discovery of underlying problems and can help users to improve their data acquisition and processing in order to obtain better structural models. The program enables users to inspect the distribution of observed intensities (or amplitudes) against resolution as well as the associated estimated uncertainties (sigmas). It is demonstrated how AUSPEX can be used to visually and automatically detect ice-ring artefacts in integrated X-ray diffraction data. Such artefacts can hamper structure determination, but may be difficult to identify from the raw diffraction images produced by modern pixel detectors. The analysis suggests that a significant portion of the data sets deposited in the PDB contain ice-ring artefacts. Furthermore, it is demonstrated how other problems in experimental X-ray data caused, for example, by scaling and data-conversion procedures can be detected by AUSPEX.

High-temperature dehydration of talc: a kinetics study using in situ X-ray powder diffraction

Science.gov (United States)

Wang, Duojun; Yi, Li; Huang, Bojin; Liu, Chuanjiang

2015-06-01

High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10-15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processes ? where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc is ? The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials

Science.gov (United States)

Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K.

2007-11-01

An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T =255K.

Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials.

Science.gov (United States)

Kulriya, P K; Singh, F; Tripathi, A; Ahuja, R; Kothari, A; Dutt, R N; Mishra, Y K; Kumar, Amit; Avasthi, D K

2007-11-01

An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

X-ray detectors for diffraction studies and their use with synchrotron radiation

International Nuclear Information System (INIS)

Milch, J.

1976-02-01

All techniques for X-ray diffraction studies on biological materials exhibit certain limitations. The characteristics of several X-ray detection systems, namely film, multiwire proportional counter and image intensified TV, are discussed and compared for application to specific biological studies. For the high count-rate situation existing at a synchrotron, it is shown that film is a good choice, but that the image intensified TV exhibits significant advantages. The details of such a system now being used at Princeton with a low intensity source are given and current results presented

Mineral identification in Colombian coals using Moessbauer spectroscopy and X-ray diffraction

International Nuclear Information System (INIS)

Fajardo, M.; Mojica, J.; Barraza, J.; Perez Alcazar, G.A.; Tabares, J.A.

1999-01-01

Minerals were identified in three Colombian coal samples from the Southwest of the country using Moessbauer spectroscopy and X-ray diffraction. Original and sink separated coal fractions of specific gravity 1.40 and 1.60 with particle size less than 600 μm were used in the study. Using Moessbauer spectroscopy, the minerals identified in the original coal samples were pyrite jarosite, ankerite, illite and ferrous sulfate, whereas by means of X-ray diffraction, minerals identified were kaolinite, quartz, pyrite, and jarosite. Differences in mineral composition were found in the original and sink separated fractions using both techniques. Moessbauer spectra show that the mineral phases in low concentrations such as illite, ankerite and ferrous sulfate do not always appear in the spectra of sink coals, despite of those minerals occurring in the original coal, due to the fact that they are associated with the organic matter and not liberated in the grinding process. X-ray results show that the peak intensity grows as the specific gravity is increased indicating that the density separation method could be an effective process to clean coal

Note: Application of a pixel-array area detector to simultaneous single crystal x-ray diffraction and x-ray absorption spectroscopy measurements

International Nuclear Information System (INIS)

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

2014-01-01

X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr 0.67 Sr 0.33 MnO 3 film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam

X-ray diffraction studies of chitosan acetate-based polymer electrolytes

International Nuclear Information System (INIS)

Osman, Z.; Ibrahim, Z.A.; Abdul Kariem Arof

2002-01-01

Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. This paper presents the x-ray diffraction patterns of chitosan acetate, plasticised chitosan acetate and plasticised-salted chitosan acetate films. The results show that the chitosan acetate based polymer electrolyte films are not completely amorphous but it is partially crystalline. X-ray diffraction study also confirms the occurrence of the complexation between chitosan and the salt and the interaction between salt and plasticizer. The salt-chitosan interaction is clearly justified by infrared spectroscopy. (Author)

Contained x-ray diffraction goniometer for examination of radioactive materials

International Nuclear Information System (INIS)

Smith, P.K.; Osgood, B.C.; Blaser, D.E.; Howell, R.E.; Stuhler, H.; Stauver, J.

1987-11-01

Radioactive materials are being characterized for chemical form and certain physical properties with an x-ray diffraction goniometer customized for containment in a shielded alpha glovebox. A Siemens D500 goniometer was customized by Siemens to locate the associated electronics and x-ray generator outside the glovebox to minimize corrosion and facilitate maintenance. A graphite monochromator is used with a shielded scintillation detector to separate diffracted x-radiation from nuclear radiation. The diffraction system is computer automated for data acquisition and reduction. The facility is designed to handle primarily alpha- and beta-emitting samples with moderate neutron and gamma radiation. Samples containing plutonium, enriched uranium, and other transuranic elements are analyzed in support of site nuclear operations and development programs on nuclear waste, chemical separations, reactor fuels, and product forms

Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

OpenAIRE

Soichiro Tsujino; Takashi Tomizaki

2016-01-01

Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinn...

Moessbauer spectroscopy and X-ray diffraction study of 304 L stainless steel thin films

International Nuclear Information System (INIS)

Boubeker, B.; Eymery, J.P.; Goudeau, P.; Sayouty, E.H.

1994-01-01

304 L stainless steel films (SS) were elaborated using an ion-beam sputtering technique. The target material was a sheet of commercial grade 304 L SS. The starting material was first analysed by both conversion electron Moessbauer spectroscopy (CEMS) and X-ray diffraction. The nonmagnetic state and f.c.c. structure of this material were confirmed. The films were deposited on various substrates with thicknesses in the 175-800 nm range. The films are found to have both b.c.c. structure and ferromagnetic character. X-ray diffraction technique was also used in order to determine the residual stresses developed during the deposition process. The second stage of the work is devoted to the evolution of the film structure as a function of annealing treatments. So isochronal and isothermal kinetics at temperatures higher than 913 K have allowed to follow the alpha --> gamma phase transformation using X-ray diffraction and CEMS technique.The X-ray diffractograms reveal the existence of both b.c.c. and f.c.c. phases. Similar results can be deduced from Moessbauer spectra due to the single line coming from the non-magnetic phase and the sextet coming from the ferromagnetic phase. In addition the CEMS spectra reveal that the ferromagnetic component is split into two parts which indicates the existence of two iron sites. 1 fig., 4 refs.(author)

Instrumentation of x-ray diffraction and materials research on the National Synchrotron Light Source. Progress report, October 30, 1981-November 30, 1982

International Nuclear Information System (INIS)

Liedl, G.L.

1982-07-01

MATRIX was organized in 1980 to formulate a research team to design, construct and utilize a beam line at NSLS for x-ray diffraction studies. Membership includes twenty-one scientists from nine institutions and an Executive Committee with a Director administers the organization. The basic design of the system has been completed with initial installation and testing to be started in the fall of 1982 and completed in the spring of 1983. The system is designed to span 0.02 to 0.6 nm wavelength range with a unique and flexible monochromator employing silicon, germanium or graphite in a fixed exit system. A Huber 4-circle diffractometer with low temperature (10-300 0 K), high temperature (300-1600 0 K) and surface studies chambers provides the basic diffraction system. A time resolving counting system augments the conventional detection systems. The research program of MATRIX will concentrate on two primary areas: Phase Transformation Studies and X-Ray Surface Diffraction Studies

A differential scanning calorimetric and X-ray diffraction

Indian Academy of Sciences (India)

X-ray diffraction analysis of the two groups demonstrated predominance of austenitic ... Discrete crystallographic structure and absence of multiple phases showed ... Division of Orthodontics, Indian Army, 10 Corps Dental Unit, C/O 56 APO, ...

Detectors for X-ray diffraction and scattering: a user's overview

International Nuclear Information System (INIS)

Bruegemann, Lutz; Gerndt, E.K.E.

2004-01-01

An overview of the applications of X-ray detectors to material research is given. Four experimental techniques and their specific detector requirements are described. Detector types are classified and critical parameters described in the framework of X-ray diffraction and X-ray scattering experiments. The article aims at building a bridge between detector end-users and detector developers. It gives limits of critical detector parameters, like angular resolution, energy resolution, dynamic range, and active area

Discovery and development of x-ray diffraction

Science.gov (United States)

Jeong, Yeuncheol; Yin, Ming; Datta, Timir

2013-03-01

In 1912 Max Laue at University of Munich reasoned x-rays to be short wavelength electromagnetic waves and figured interference would occur when scattered off crystals. Arnold Sommerfeld, W. Wien, Ewald and others, raised objections to Laue's idea, but soon Walter Friedrich succeeded in recording x-ray interference patterns off copper sulfate crystals. But the Laue-Ewald's 3-dimensional formula predicted excess spots. Fewer spots were observed. William Lawrence Bragg then 22 year old studying at Cambridge University heard the Munich results from father William Henry Brag, physics professor at Univ of Leeds. Lawrence figured the spots are 2-d interference of x-ray wavelets reflecting off successive atomic planes and derived a simple eponymous equation, the Bragg equation d*sin(theta) = n*lamda. 1913 onward the Braggs dominated the crystallography. Max Laue was awarded the physics Nobel in 1914 and the Braggs shared the same in 1915. Starting with Rontgen's first ever prize in 1901, the importance of x-ray techniques is evident from the four out of a total 16 physics Nobels between 1901-1917. We will outline the historical back ground and importance of x-ray diffraction giving rise to techniques that even in 2013, remain work horses in laboratories all over the globe.

Thermal expansion and phase transformations of nitrogen-expanded austenite studied with in situ synchrotron X-ray diffraction

DEFF Research Database (Denmark)

Brink, Bastian; Ståhl, Kenny; Christiansen, Thomas Lundin

2014-01-01

Nitrogen-expanded austenite, _N, with high and low nitrogen contents was produced from AISI 316 grade stainless steel powder by gaseous nitriding in ammonia/hydrogen gas mixtures. In situ synchrotron X-ray diffraction was applied to investigate the thermal expansion and thermal stability...... as a fitting parameter. The stacking fault density is constant for temperatures up to 680 K, whereafter it decreases to nil. Surprisingly, a transition phase with composition M4N (M = Fe, Cr, Ni, Mo) appears for temperatures above 770 K. The linear coefficient of thermal expansion depends on the nitrogen...

Glancing angle synchrotron X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Cernik, R J [Daresbury Lab., Warrington, WA (United States)

1996-09-01

This paper describes in basic detail some of the techniques that can be used to study thin films and surfaces. These are all in the X-ray region and cover reflectivity, diffraction form polycrystalline films, textured films and single crystal films. Other effects such as fluorescence and diffuse scattering are mentioned but not discussed in detail. Two examples of the reflectivity from multilayers and the diffraction from iron oxide films are discussed. The advantages of the synchrotron for these studies is stressed and the experimental geometries that can be employed are described i detail. A brief bibliography is provided at the end to accompany this part of the 1996 Frascati school.

Glancing angle synchrotron X-ray diffraction

International Nuclear Information System (INIS)

Cernik, R.J.

1996-01-01

This paper describes in basic detail some of the techniques that can be used to study thin films and surfaces. These are all in the X-ray region and cover reflectivity, diffraction form polycrystalline films, textured films and single crystal films. Other effects such as fluorescence and diffuse scattering are mentioned but not discussed in detail. Two examples of the reflectivity from multilayers and the diffraction from iron oxide films are discussed. The advantages of the synchrotron for these studies is stressed and the experimental geometries that can be employed are described i detail. A brief bibliography is provided at the end to accompany this part of the 1996 Frascati school

Design and fabrication of micro X-ray diffraction system

International Nuclear Information System (INIS)

Park, Yang Soon; Han, Sun Ho; Kim, Jong Goo; Jee, Kwang Yong

2006-10-01

It has been observed that microstructure changes occur at the pellet periphery(rim) of the fuel at very high burn-up. Despite its narrow range (below some hundreds microns in depth), this peripheral region(rim) determines the behaviour of nuclear fuel. To determine lattice parameter with XRD at intervals as small as 30-50 μ m in radial direction of irradiated fuel samples, a micro X-ray diffraction system was designed and fabricated. This report describes the micro X-ray diffraction system consisted of an X-ray microbeam alignment system and a sample micro translation system, its characterization, and its performance test through the analysis for the micro region of some specimens. This system will be set in a radiation shielded glove box, and then used for analysis of lattice parameter change and the phase change at intervals as small as 30-50 μ m in radial direction of the rim of an irradiated fuel sample and a fuel cladding

Design and fabrication of micro X-ray diffraction system

Energy Technology Data Exchange (ETDEWEB)

Park, Yang Soon; Han, Sun Ho; Kim, Jong Goo; Jee, Kwang Yong

2006-10-15

It has been observed that microstructure changes occur at the pellet periphery(rim) of the fuel at very high burn-up. Despite its narrow range (below some hundreds microns in depth), this peripheral region(rim) determines the behaviour of nuclear fuel. To determine lattice parameter with XRD at intervals as small as 30-50 {mu} m in radial direction of irradiated fuel samples, a micro X-ray diffraction system was designed and fabricated. This report describes the micro X-ray diffraction system consisted of an X-ray microbeam alignment system and a sample micro translation system, its characterization, and its performance test through the analysis for the micro region of some specimens. This system will be set in a radiation shielded glove box, and then used for analysis of lattice parameter change and the phase change at intervals as small as 30-50 {mu} m in radial direction of the rim of an irradiated fuel sample and a fuel cladding.

Determination of densities from chemical composition and X-Ray diffraction

International Nuclear Information System (INIS)

Azevedo, A.L.T. de

1980-01-01

X-ray diffraction method applied to retained austenite measurements gives volume per cent results, whereas the same kind of measurement made by Moessbauer Effect gives iron percentages. To compare both results one needs to convert the volume % to weight % or vice-versa. This necessitates, among other things, in determining the densities of the α and #betta# phases in the steel being studied. A method for calculating the densities, based on the application of the definition of density to just one unit cell, using X-ray diffraction and chemical results, are described. (Author) [pt

Magnetic x-ray circular dichroism in spin-polarized photoelectron diffraction

International Nuclear Information System (INIS)

Waddill, G.D.; Tobin, J.G.

1994-01-01

The first structural determination with spin-polarized, energy-dependent photoelectron diffraction using circularly-polarized x-rays is reported for Fe films on Cu(001). Circularly-polarized x-rays produced spin-polarized photoelectrons from the Fe 2p doublet, and intensity asymmetries in the 2p 3/2 level are observed. Fully spin-specific multiple scattering calculations reproduced the experimentally-determined energy and angular dependences. A new analytical procedure which focuses upon intensity variations due to spin-dependent diffraction is introduced. A sensitivity to local geometric and magnetic structure is demonstrated

Sample cell for powder x-ray diffraction at up to 500 bars and 200 deg. C

International Nuclear Information System (INIS)

Jupe, Andrew C.; Wilkinson, Angus P.

2006-01-01

A low cost sample cell for powder diffraction at high pressure and temperature that employs either sapphire or steel pressure tubes is described. The cell can be assembled rapidly, facilitating the study of chemically reacting systems, and it provides good control of both pressure and temperature in a regimen where diamond anvil cells and multianvil apparatus cannot be used. The design provides a relatively large sample volume making it suitable for the study of quite large grain size materials, such as hydrating cement slurries. However, relatively high energy x rays are needed to penetrate the pressure tube

High-energy X-ray diffraction studies of short- and intermediate-range structure in oxide glasses

International Nuclear Information System (INIS)

Suzuya, Kentaro

2002-01-01

The feature of high-energy X-ray diffraction method is explained. The oxide glasses studies by using BL04B2, high-energy X-ray diffraction beam line of SPring-8, and the random system materials by high-energy monochromatic X-ray diffraction are introduced. An advantage of third generation synchrotron radiation is summarized. On SPring-8, the high-energy X-ray diffraction experiments of random system are carried out by BL04B2 and BL14B1 beam line. BL04B2 can select Si (111)(E=37.8 keV, λ=0.033 nm) and Si(220)(E=61.7 keV, λ=0.020 nm) as Si monochromator. The intermediate-range structure of (MgO) x (P 2 O 5 ) 1-x glass ,MgP 2 O 6 glass, B 2 O 3 glass, SiO 2 and GeO 2 are explained in detail. The future and application of high-energy X-ray diffraction are stated. (S.Y.)

Hut clusters on Ge(001) surfaces studied by STM and synchrotron X-ray diffraction

DEFF Research Database (Denmark)

Nielsen, M.; Smilgies, D.-M.; Feidenhans'l, R.

1996-01-01

Nanoscale hut clusters formed on Ge(001) surfaces by depositing one monolayer of indium and annealing at temperatures between 350 and 500 degrees C were studied by scanning tunnelling microscopy and synchrotron X-ray diffraction. It was found that the hut clusters form regular arrays over...

X-ray diffraction studies of NbTe2 single crystal

Indian Academy of Sciences (India)

Unknown

X-ray (EDAX) and remaining structural characterization was also accomplished by X-ray diffraction (XRD) studies. Lattice parameters, volume and ... The layered structure compound, NbTe2, is one of the typical materials which lead to charge .... financial assistance to carry out this work. References. Brown B E 1966 Acta ...

Thermal expansion behavior study of Co nanowire array with in situ x-ray diffraction and x-ray absorption fine structure techniques

Science.gov (United States)

Mo, Guang; Cai, Quan; Jiang, Longsheng; Wang, Wei; Zhang, Kunhao; Cheng, Weidong; Xing, Xueqing; Chen, Zhongjun; Wu, Zhonghua

2008-10-01

In situ x-ray diffraction and x-ray absorption fine structure techniques were used to study the structural change of ordered Co nanowire array with temperature. The results show that the Co nanowires are polycrystalline with hexagonal close packed structure without phase change up until 700 °C. A nonlinear thermal expansion behavior has been found and can be well described by a quadratic equation with the first-order thermal expansion coefficient of 4.3×10-6/°C and the second-order thermal expansion coefficient of 5.9×10-9/°C. The mechanism of this nonlinear thermal expansion behavior is discussed.

Characterization of room temperature recrystallization kinetics in electroplated copper thin films with concurrent x-ray diffraction and electrical resistivity measurements

Energy Technology Data Exchange (ETDEWEB)

Treger, Mikhail; Noyan, I. C. [Department of Applied Physics and Applied Mathematics, Columbia University, New York 10027 (United States); Witt, Christian [GlobalFoundries, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Cabral, Cyril; Murray, Conal; Jordan-Sweet, Jean [IBM, T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Rosenberg, Robert [State University of New York, the University at Albany, Albany, NY 12203 (United States); Eisenbraun, Eric [College of Nanoscale Science and Engineering, University at Albany, Albany, NY 12203 (United States)

2013-06-07

Concurrent in-situ four-point probe resistivity and high resolution synchrotron x-ray diffraction measurements were used to characterize room temperature recrystallization in electroplated Cu thin films. The x-ray data were used to obtain the variation with time of the integrated intensities and the peak-breadth from the Cu 111 and 200 reflections of the transforming grains. The variation of the integrated intensity and resistivity data with time was analyzed using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model. For both 111-textured and non-textured electroplated Cu films, four-point probe resistivity measurements yielded shorter transformation times than the values obtained from the integrated intensities of the corresponding Cu 111 reflections. In addition, the JMAK exponents fitted to the resistivity data were significantly smaller. These discrepancies could be explained by considering the different material volumes from which resistivity and diffraction signals originated, and the physical processes which linked these signals to the changes in the evolving microstructure. Based on these issues, calibration of the resistivity analysis with direct structural characterization techniques is recommended.

X-ray Diffraction Study of Arsenopyrite at High Pressure

Energy Technology Data Exchange (ETDEWEB)

D Fan; M Ma; W Zhou; S Wei; Z Chen; H Xie

2011-12-31

The high-pressure X-ray diffraction study of a natural arsenopyrite was investigated up to 28.2 GPa using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at National Synchrotron Light Source, Brookhaven National Laboratory. The 16:3:1 methanol-ethanol-water mixture was used as a pressure-transmitting medium. Pressures were measured using the ruby-fluorescence method. No phase change has been observed up to 28.2 GPa. The isothermal equation of state (EOS) was determined. The values of K{sub 0}, and K'{sub 0} refined with a third-order Birch-Murnaghan EOS are K{sub 0} = 123(9) GPa, and K'{sub 0} = 5.2(8). Furthermore, we confirm that the linear compressibilities ({beta}) along a, b and c directions of arsenopyrite is elastically isotropic ({beta}{sub a} = 6.82 x 10{sup -4}, {beta}{sub b} = 6.17 x 10{sup -4} and {beta}{sub c} = 6.57 x 10{sup -4} GPa{sup -1}).

A new theory for X-ray diffraction.

Science.gov (United States)

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.

Thermal expansion behavior of empressite, AgTe: A structural study by means of in situ high-temperature single-crystal X-ray diffraction

International Nuclear Information System (INIS)

Bindi, Luca

2009-01-01

The crystal structure of empressite, AgTe, a rare silver telluride, has been investigated by in situ X-ray single-crystal diffraction methods within the temperature range 298-463 K. AgTe remains orthorhombic, space group Pmnb (Pnma as standard), and shows only normal thermal expansion over the entire temperature range. The unit-cell parameters show a gradual increase with the increase of temperature. Slight adjustments in the geometry of Ag-tetrahedra and in the crystal-chemical environment of tellurium atoms occur in a continuous way without abrupt structural changes. The coefficients of thermal expansion along various axes are: α a = 1.5 x 10 -5 K -1 , α b = 3.0 x 10 -5 K -1 , α c = 2.2 x 10 -5 K -1 , and the bulk thermal expansion coefficient α V is 5.4 x 10 -5 K -1 for the temperature range 298-463 K

Characterization of diffraction gratings by use of a tabletop soft-x-ray laser

International Nuclear Information System (INIS)

Seminario, Max; Rocca, Jorge J.; Depine, Ricardo A.; Bach, Benny; Bach, Bernie

2001-01-01

We have demonstrated the use of a high-repetition-rate 46.9-mm tabletop laser to characterize diffraction gratings designed for grazing-incidence operation in the soft-x-ray spectral region. The efficiencies for various diffraction orders were measured as a function of angle of incidence and compared with the results of model simulations. This measurement technique provides benchmarks with which to improve electromagnetic codes used in the design of soft-x-ray diffraction gratings. The results illustrate the potential of compact tabletop soft-x-ray lasers for use as a new tool for characterization of short-wavelength optics at the manufacturer's site

Variable-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type barium titanate phases.

Science.gov (United States)

Nakatani, Tomotaka; Yoshiasa, Akira; Nakatsuka, Akihiko; Hiratoko, Tatsuya; Mashimo, Tsutomu; Okube, Maki; Sasaki, Satoshi

2016-02-01

A variable-temperature single-crystal X-ray diffraction study of a synthetic BaTiO3 perovskite has been performed over the temperature range 298-778 K. A transition from a tetragonal (P4mm) to a cubic (Pm3m) phase has been revealed near 413 K. In the non-centrosymmetric P4mm symmetry group, both Ti and O atoms are displaced along the c-axis in opposite directions with regard to the Ba position fixed at the origin, so that Ti(4+) and Ba(2+) cations occupy off-center positions in the TiO6 and BaO12 polyhedra, respectively. Smooth temperature-dependent changes of the atomic coordinates become discontinuous with the phase transition. Our observations imply that the cations remain off-center even in the high-temperature cubic phase. The temperature dependence of the mean-square displacements of Ti in the cubic phase includes a significant static component which means that Ti atoms are statistically distributed in the off-center positions.

X-ray diffraction study of delta-stabilized plutonium alloys under pressure

Energy Technology Data Exchange (ETDEWEB)

Faure, Ph, E-mail: philippe.faure@cea.f [CEA, Valduc, F-21120 Is-sur-Tille (France); Genestier, C. [CEA, Valduc, F-21120 Is-sur-Tille (France)

2010-02-15

Previous extensive studies of the delta -> alpha'-phase transformation induced by temperature and/or by pressure in delta-stabilized plutonium alloys indicate strong dependence on parameters such as solute type, solute distribution, chemical impurities, kinetics, thermodynamic path.... The present paper reports results obtained on two Pu-2.3at.%Ga binary alloys differing by solute homogenization treatment and studied under pressure by in situ by X-ray diffraction in diamond anvil cells. The gamma'-phase appears as an intermediate phase during the delta -> alpha'-phase transformation. In cored samples, unexpanded alpha'-phase is formed at the beginning of the transformation, from domains with low solute content, and expanded alpha'-phase subsequently forms (from domains with higher solute content) as the transformation progresses with the pressure increase.

Temperature-Dependent Change of Packing Structure of Condensed-Phase in a Micro-Phase Separated Langmuir Monolayer Studied by Grazing-Incidence X-ray Diffraction

Energy Technology Data Exchange (ETDEWEB)

Iimura, Ken-ichi [Department of Applied Chemisty, Faculty of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Utsunomiya (Japan); Kato, Teiji [Department of Applied Chemisty, Faculty of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Utsunomiya (Japan); Brezesinski, Gerald [Max-Planck Instutite of Colloids and Interfaces, Research Campus Golm, D-14476 Potsdam (Germany)

2007-10-15

Packing structure of condensed-phase in a binary mixed Langmuir monolayer of behenic acid (C22) and perfluoro-2,5,8-trimethyl-3,6,9-trioxadodecanoic acid (PFPE) on a cadmium acetate aqueous solution was studied by grazing incidence X-ray diffraction (GIXD) as a function of the subphase temperature. The measurements were made during temperature scan at a fixed molecular area to explain the morphological change of the condensed-phase domains due to a thermal treatment reported previously. Analysis of GIXD data implies that the condensed-phase domains are composed of only the C22 molecules perpendicularly oriented and very closely packed in a centered rectangular unit cell with orthorhombic distortion at low temperatures. As the temperature increases the area occupied by molecule increases, and above 25 deg. C the lattice becomes disordered, which would allow morphological transformation of the condensed-phase domains. The process of packing structure change is almost reversible except for non-equilibrium phases observed for the monolayer spread at a low temperature, 5.5 deg. C.

Temperature-Dependent Change of Packing Structure of Condensed-Phase in a Micro-Phase Separated Langmuir Monolayer Studied by Grazing-Incidence X-ray Diffraction

International Nuclear Information System (INIS)

Iimura, Ken-ichi; Kato, Teiji; Brezesinski, Gerald

2007-01-01

Packing structure of condensed-phase in a binary mixed Langmuir monolayer of behenic acid (C22) and perfluoro-2,5,8-trimethyl-3,6,9-trioxadodecanoic acid (PFPE) on a cadmium acetate aqueous solution was studied by grazing incidence X-ray diffraction (GIXD) as a function of the subphase temperature. The measurements were made during temperature scan at a fixed molecular area to explain the morphological change of the condensed-phase domains due to a thermal treatment reported previously. Analysis of GIXD data implies that the condensed-phase domains are composed of only the C22 molecules perpendicularly oriented and very closely packed in a centered rectangular unit cell with orthorhombic distortion at low temperatures. As the temperature increases the area occupied by molecule increases, and above 25 deg. C the lattice becomes disordered, which would allow morphological transformation of the condensed-phase domains. The process of packing structure change is almost reversible except for non-equilibrium phases observed for the monolayer spread at a low temperature, 5.5 deg. C

X-ray filter for x-ray powder diffraction

Science.gov (United States)

Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.; Dooryhee, Eric; Ghose, Sanjit

2018-01-23

Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and walls defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.

A combined temperature-dependent electron and single-crystal X-ray diffraction study of the fresnoite compound Rb2V4+V25+O8

International Nuclear Information System (INIS)

Withers, R.L.; Hoeche, Thomas; Liu Yun; Esmaeilzadeh, Saeid; Keding, Ralf; Sales, Brian

2004-01-01

High-purity Rb 2 V 3 O 8 has been grown and temperature-dependent electron and single-crystal X-ray diffraction used to carefully investigate its fresnoite-type reciprocal lattice. In contrast to other recently investigated representatives of the fresnoite family of compounds, Rb 2 V 3 O 8 is not incommensurately modulated with an incommensurate basal plane primary modulation wave vector given by q∼0.3 *. A careful low-temperature electron diffraction study has, however, revealed the existence of weak incommensurate satellite reflections characterized by the primitive primary modulation wave vector q 1 ∼0.16c*. The reciprocal space positioning of these incommensurate satellite reflections, the overall (3+1)-d superspace group symmetry, as well as the shapes of the refined displacement ellipsoids determined from single-crystal XRD refinement, are all consistent with their arising from a distinct type of condensed rigid unit modes (RUMs) of distortion of the Rb 2 V 3 O 8 parent structure

Thermal expansion and phase transformation studies on some materials by high temperature x-ray powder diffractometry

International Nuclear Information System (INIS)

Rajagopalan, S.; Kutty, K.V.G.; Jajoo, H.K.; Ananthakrishnan, S.K.; Asurvatharaman, R.

1988-01-01

A high temperature chamber based on electrical resistance heating has been integrated to an existing x-ray powder diffractometer. The system is capable of going upto 2500degC at programmed rates of heating. Temperature measurement is carried out by means by Pt/Rh or W/Re thermocouples or by optical pyrometry depending upon the temperature range. Provision exists for performing high temperature x-ray diffractometry in vacuum or in a gaseous atmosphere of low x-ray absorption. The x-ray optical alignment has been ensured by accurately measuring the unit cell lengths of x-ray diffraction standards like silicon and tungsten. The thermocouples have been calibrated within the system by monitoring the melting points of gold and silver. The well characterized transformation of zirconia from the monoclinic to tetragonal structure occuring around 1100degC has been satisfactorily reproduced . The high temperature phase transitions in some rare earth oxides have been studi ed. lattice parameter measurements on a variety of materials as a function of temperature upto 1500degC have been carried out and the data found to be in agreement with the literature values. From the measured lattice parameter values, percentage thermal expansion and coefficients of thermal expansion have been calculated for many substances from room temperature to 15000degC. (author). 20 refs., 9 figs

Mechanical characterisation of surface layers by x-ray diffraction -application to tribology

International Nuclear Information System (INIS)

Farrahi, G.H.

1996-01-01

The results presented in this paper show that X-ray diffraction can be employed for the characterisation of surface layer damage through residual stresses and work hardening by some tribological actions such as fretting and dry sliding. X-ray diffraction technique can also be employed for a rapid and non-destructive measurement of hardness of hardened steel. The diffraction profile analysis can offer a good indication about the materials characteristics and the microstructural evolution caused by heat treatment or by mechanical loading

State-of-the-art and problems of X-ray diffraction analysis of biomacromolecules

International Nuclear Information System (INIS)

Andreeva, N. S.

2006-01-01

The state-of-the-art of X-ray diffraction studies of biomacromolecules is briefly characterized, and the challenge imposed by science is discussed. These studies are characterized by a wide scope and extensive use. This field of science is of great interest and is developed in many countries. The main purpose is to solve practical problems in medicine consisting in the design of drugs against various diseases. X-ray diffraction analysis of enzymes brought the pharmaceutical industry to a new level, thus allowing the rational design of drugs against formerly untreatable diseases. Modern X-ray diffraction studies of biomacromolecules laid the basis for a new science called structural biology. This method allows one to solve fundamental problems of physical chemistry for a new state of matter existing in living systems. Here, science poses numerous problems in analysis of X-ray diffraction data on biological macromolecules. Many of theses problems are in their infancy

Quantitative determination of phases by X-ray diffraction

International Nuclear Information System (INIS)

Azevedo, A.L.T.

1979-01-01

The internal standard method for the quantitative determination of phases by X-ray diffraction is presented. The method is applicable to multi-phase materials which may be treated as powder. A discussion on sample preparation and some examples follow. (Author) [pt

Direct methods for surface X-ray diffraction

International Nuclear Information System (INIS)

Saldin, D. K.; Harder, R.; Shneerson, V. L.; Vogler, H.; Moritz, W.

2000-01-01

We develop of a direct method for surface X-ray diffraction that exploits the holographic feature of a known reference wave from the substrate. A Bayesian analysis of the optimal inference to be made from an incomplete data set suggests a maximum entropy algorithm that balances agreement with the data and other statistical considerations

X-ray topography using the forward transmitted beam under multiple-beam diffraction conditions

Energy Technology Data Exchange (ETDEWEB)

Tsusaka, Y., E-mail: tsusaka@sci.u-hyogo.ac.jp; Takano, H. [Graduate School of Material Science, University of Hyogo, 3-2-1, Kouto, Kamigori, Hyogo 678-1297 (Japan); Takeda, S. [SPring-8 Service Co., Ltd., 1-20-5, Kouto, Shingu, Tatsuno, Hyogo 679-5165 (Japan); Yokoyama, K.; Matsui, J. [Synchrotron Radiation Nanotechnology Center, University of Hyogo, 1-490-2, Kouto, Shingu, Tatsuno, Hyogo 679-5165 (Japan); Kagoshima, Y. [Graduate School of Material Science, University of Hyogo, 3-2-1, Kouto, Kamigori, Hyogo 678-1297 (Japan); Synchrotron Radiation Nanotechnology Center, University of Hyogo, 1-490-2, Kouto, Shingu, Tatsuno, Hyogo 679-5165 (Japan)

2016-02-15

X-ray topographs are taken for a sapphire wafer with the [0001] surface normal, as an example, by forward transmitted synchrotron x-ray beams combined with two-dimensional electronic arrays in the x-ray detector having a spatial resolution of 1 μm. They exhibit no shape deformation and no position shift of the dislocation lines on the topographs. Since the topography is performed under multiple-beam diffraction conditions, the topographic images of a single diffraction (two-wave approximation condition) or plural diffractions (six-wave approximation condition) can be recorded without large specimen position changes. As usual Lang topographs, it is possible to determine the Burgers vector of each dislocation line. Because of high parallelism of the incoming x-rays and linear sensitivity of the electronic arrays to the incident x-rays, the present technique can be used to visualize individual dislocations in single crystals of the dislocation density as high as 1 × 10{sup 5} cm{sup −2}.

Low Energy X-Ray and γ-Ray Detectors Fabricated on n-Type 4H-SiC Epitaxial Layer

Science.gov (United States)

Mandal, Krishna C.; Muzykov, Peter G.; Chaudhuri, Sandeep K.; Terry, J. Russell

2013-08-01

Schottky barrier diode (SBD) radiation detectors have been fabricated on n-type 4H-SiC epitaxial layers and evaluated for low energy x- and γ-rays detection. The detectors were found to be highly sensitive to soft x-rays in the 50 eV to few keV range and showed 2.1 % energy resolution for 59.6 keV gamma rays. The response to soft x-rays for these detectors was significantly higher than that of commercial off-the-shelf (COTS) SiC UV photodiodes. The devices have been characterized by current-voltage (I-V) measurements in the 94-700 K range, thermally stimulated current (TSC) spectroscopy, x-ray diffraction (XRD) rocking curve measurements, and defect delineating chemical etching. I-V characteristics of the detectors at 500 K showed low leakage current ( nA at 200 V) revealing a possibility of high temperature operation. The XRD rocking curve measurements revealed high quality of the epitaxial layer exhibiting a full width at half maximum (FWHM) of the rocking curve 3.6 arc sec. TSC studies in a wide range of temperature (94-550 K) revealed presence of relatively shallow levels ( 0.25 eV) in the epi bulk with a density 7×1013 cm-3 related to Al and B impurities and deeper levels located near the metal-semiconductor interface.

Diffracted X-ray tracking for monitoring intramolecular motion in individual protein molecules using broad band X-ray

Energy Technology Data Exchange (ETDEWEB)

Ichiyanagi, Kouhei; Sasaki, Yuji C. [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Sekiguchi, Hiroshi; Hoshino, Masato; Kajiwara, Kentaro; Senba, Yasunori; Ohashi, Haruhiko; Ohta, Noboru [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Hoshisashi, Kentaro; Jae-won, Chang; Tokue, Maki; Matsushita, Yufuku [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Nishijima, Masaki; Inoue, Yoshihisa [Department of Applied Chemistry and Office for University-Industry Collaboration, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yagi, Naoto [Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2013-10-15

Diffracted X-ray tracking (DXT) enables the tilting and twisting motions of single protein molecules to be monitored with micro- to milliradian resolution using a highly brilliant X-ray source with a wide energy bandwidth. We have developed a technique to monitor single molecules using gold nanocrystals attached to individual protein molecules using the BL28B2 beamline at SPring-8. In this paper we present the installation of a single toroidal X-ray mirror at BL28B2 to focus X-rays in an energy range of 10–20 keV (△E/E = 82% for an X-ray with a wide energy bandwidth). With this beamline we tracked diffraction spots from gold nanocrystals over a wide angle range than that using quasi-monochromatic X-rays. Application of the wide angle DXT technique to biological systems enabled us to observe the on-site motions of single protein molecules that have been functionalized in vivo. We further extend the capability of DXT by observing the fractional tilting and twisting motions of inner proteins under various conditions. As a proof of this methodology and to determine instrumental performance the intramolecular motions of a human serum albumin complex with 2-anthracenecarboxylic acid was investigated using the BL28B2 beamline. The random tilting and twisting intramolecular motions are shown to be directly linked to the movement of individual protein molecules in the buffer solution.

Diffractive-refractive optics: (+,-,-,+) X-ray crystal monochromator with harmonics separation

Czech Academy of Sciences Publication Activity Database

Hrdý, Jaromír; Mikulík, P.; Oberta, Peter

2011-01-01

Roč. 18, č. 2 (2011), s. 299-301 ISSN 0909-0495 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : diffractive-refractive optics * x-ray synchrotron radiation monochromator * x-ray crystal monochromator * harmonics separation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.726, year: 2011

X-ray diffraction topography. Stages and tendencies of development

International Nuclear Information System (INIS)

Shul'pina, I.L.

2000-01-01

The physical foundation of X-ray diffraction topography, its methods, the achievements in image theory, the stages of evolution were described in this review. It was found that modern topography is well along in development associated with the use of third-generation synchrotron radiation and with its adaptation to advance materials and problems of materials science. Some proposals about prospects for X-ray topography progress in the future have been made [ru

Advances in thin film diffraction instrumentation by X-ray optics

International Nuclear Information System (INIS)

Haase, A.

1996-01-01

The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves

Advances in thin film diffraction instrumentation by X-ray optics

Energy Technology Data Exchange (ETDEWEB)

Haase, A [Rich. Seifert and Co., Analytical X-ray Systems, Ahrensburg (Germany)

1996-09-01

The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves.

X-ray diffraction on nanoparticles chromium and nickel oxides obtained by gelatin using synchrotron radiation

International Nuclear Information System (INIS)

Menezes, Alan Silva de; Medeiros, Angela Maria de Lemos; Miranda, Marcus Aurelio Ribeiro; Almeida, Juliana Marcela Abraao; Remedios, Claudio Marcio Rocha; Silva, Lindomar R.D. da; Gouveia, S.T.; Sasaki, Jose Marcos; Jardim, P.M.

2003-01-01

Full text: Cr 2 O 3 nanoparticles has many applications like green pigments, wear resistance, and coating materials for thermal protection. Several methods to produce chromium oxide nanoparticles have already been studied, gas condensation, laser induced pyrolysis, microwave plasma, sol-gel and gamma radiation methods. Many applications for this kind of material can be provide concerning the particle size. For instance, particle size approximately of 200 nm are preferable as pigment due to its opacity and below 50 nm can be used as transparent pigment. In this work we have demonstrated that chromium and nickel oxide nanoparticles can be prepared by gelatin method. X-Ray diffraction (XRD) show that mean particle size for chromium oxide of 15-150 nm and nickel oxide of 90 nm were obtained for several temperature of sintering. The X-Ray powder diffraction pattern were performed using Synchrotron Radiation X-Ray source at XRD1 beamline in National Laboratory of Light Synchrotron (LNLS). (author)

Extinction correction in white X-ray and neutron diffraction

International Nuclear Information System (INIS)

Tomiyoshi, S.; Yamada, M.; Watanabe, H.

1980-01-01

Extinction effects in white-beam X-ray and neutron diffraction are considered. In white-beam diffraction, a small deviation of the wavelength from the Bragg condition Δlambda is a variable which represents the line profile of the diffraction peaks, so that by using the new parameter Δlambda the theory is converted to one in white-beam diffraction. It is shown that for a convex crystal, primary extinction agrees with the results calculated already for monochromatic diffraction. The same relation is shown to hold in secondary extinction. It is concluded that extinction theory derived for monochromatic diffraction is applicable without any modification in white-beam diffraction. (Auth.)

Femtosecond X-ray diffraction from an aerosolized beam of protein nanocrystals.

Science.gov (United States)

Awel, Salah; Kirian, Richard A; Wiedorn, Max O; Beyerlein, Kenneth R; Roth, Nils; Horke, Daniel A; Oberthür, Dominik; Knoska, Juraj; Mariani, Valerio; Morgan, Andrew; Adriano, Luigi; Tolstikova, Alexandra; Xavier, P Lourdu; Yefanov, Oleksandr; Aquila, Andrew; Barty, Anton; Roy-Chowdhury, Shatabdi; Hunter, Mark S; James, Daniel; Robinson, Joseph S; Weierstall, Uwe; Rode, Andrei V; Bajt, Saša; Küpper, Jochen; Chapman, Henry N

2018-02-01

High-resolution Bragg diffraction from aerosolized single granulovirus nanocrystals using an X-ray free-electron laser is demonstrated. The outer dimensions of the in-vacuum aerosol injector components are identical to conventional liquid-microjet nozzles used in serial diffraction experiments, which allows the injector to be utilized with standard mountings. As compared with liquid-jet injection, the X-ray scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. Such reduction is required for diffraction measurements of small macromolecular nanocrystals and single particles. High particle speeds are achieved, making the approach suitable for use at upcoming high-repetition-rate facilities.

X-ray diffraction investigation of the sulphur induced 4x1 reconstruction of Ni(110)

DEFF Research Database (Denmark)

Foss, M.; Feidenhans'l, R.; Nielsen, M.

1993-01-01

The atomic structure of the Ni(110)4 x 1-S reconstruction has been determined on the basis of surface X-ray diffraction measurements. An analysis of the in-plane diffraction data shows that the model consists of Ni rows along the [001] direction, two for every 4 x 1 unit cell, corresponding to 0....

Facile Low Temperature Hydrothermal Synthesis of BaTiO3 Nanoparticles Studied by In Situ X-ray Diffraction

Directory of Open Access Journals (Sweden)

Ola G. Grendal

2018-06-01

Full Text Available Ferroelectric materials are crucial for today’s technological society and nanostructured ferroelectric materials are important for the downscaling of devices. Controlled and reproducible synthesis of these materials are, therefore, of immense importance. Hydrothermal synthesis is a well-established synthesis route, with a large parameter space for optimization, but a better understanding of nucleation and growth mechanisms is needed for full utilization and control. Here we use in situ X-ray diffraction to follow the nucleation and growth of BaTiO3 formed by hydrothermal synthesis using two different titanium precursors, an amorphous titania precipitate slurry and a Ti-citric acid complex solution. Sequential Rietveld refinement was used to extract the time dependency of lattice parameters, crystallite size, strain, and atomic displacement parameters. Phase pure BaTiO3 nanoparticles, 10–15 nm in size, were successfully synthesized at different temperatures (100, 125, and 150 °C from both precursors after reaction times, ranging from a few seconds to several hours. The two precursors resulted in phase pure BaTiO3 with similar final crystallite size. Finally, two different growth mechanisms were revealed, where the effect of surfactants present during hydrothermal synthesis is discussed as one of the key parameters.

Thermal expansion behavior of empressite, AgTe: A structural study by means of in situ high-temperature single-crystal X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Bindi, Luca [Museo di Storia Naturale, sez. di Mineralogia, Universita di Firenze, Via La Pira 4, I-50121 Firenze (Italy)], E-mail: luca.bindi@unifi.it

2009-04-03

The crystal structure of empressite, AgTe, a rare silver telluride, has been investigated by in situ X-ray single-crystal diffraction methods within the temperature range 298-463 K. AgTe remains orthorhombic, space group Pmnb (Pnma as standard), and shows only normal thermal expansion over the entire temperature range. The unit-cell parameters show a gradual increase with the increase of temperature. Slight adjustments in the geometry of Ag-tetrahedra and in the crystal-chemical environment of tellurium atoms occur in a continuous way without abrupt structural changes. The coefficients of thermal expansion along various axes are: {alpha}{sub a} = 1.5 x 10{sup -5} K{sup -1}, {alpha}{sub b} = 3.0 x 10{sup -5} K{sup -1}, {alpha}{sub c} = 2.2 x 10{sup -5} K{sup -1}, and the bulk thermal expansion coefficient {alpha}{sub V} is 5.4 x 10{sup -5} K{sup -1} for the temperature range 298-463 K.

Ultrafast coherent diffractive imaging of nanoparticles using X-ray free-electron laser radiation

International Nuclear Information System (INIS)

Kassemeyer, Stephan

2014-01-01

Coherent diffractive imaging with X-ray free-electron lasers (X-FEL) promises high-resolution structure determination of single microscopic particles without the need for crystallization. The diffraction signal of small samples can be very weak, a difficulty that can not be countered by merely increasing the number of photons because the sample would be damaged by a high absorbed radiation dose. Traditional X-ray crystallography avoids this problem by bringing many sample particles into a periodic arrangement, which amplifies the individual signals while distributing the absorbed dose. Depending on the sample, however, crystallization can be very difficult or even impossible. This thesis presents algorithms for a new imaging approach using X-FEL radiation that works with single, non-crystalline sample particles. X-FELs can deliver X-rays with a peak brilliance many orders of magnitude higher than conventional X-ray sources, compensating for their weak interaction cross sections. At the same time, FELs can produce ultra-short pulses down to a few femtoseconds. In this way it is possible to perform ultra-fast imaging, essentially ''freezing'' the atomic positions in time and terminating the imaging process before the sample is destroyed by the absorbed radiation. This thesis primarily focuses on the three-dimensional reconstruction of single (and not necessarily crystalline) particles using coherent diffractive imaging at X-FELs: in order to extract three-dimensional information from scattering data, two-dimensional diffraction patterns from many different viewing angles must be combined. Therefore, the diffraction signal of many identical sample copies in random orientations is measured. The main result of this work is a globally optimal algorithm that can recover the sample orientations solely based on the diffraction signal, enabling three-dimensional imaging for arbitrary samples. The problem of finding three-dimensional orientations is

Control of synchrotron x-ray diffraction by means of standing acoustic waves

International Nuclear Information System (INIS)

Zolotoyabko, E.; Quintana, J.P.

2004-01-01

Synchrotron x-ray diffraction measurements in quartz crystals of different thickness excited by standing acoustic waves were carried out at the Advanced Photon Source of Argonne National Laboratory. We demonstrated the ability to significantly modify the quartz rocking curves for 20-25 keV x rays by changing the shear wave parameters in the frequency range between 15 and 105 MHz. Dynamic deformation introduced into the crystal lattice by acoustic waves resulted in a remarkable broadening of the rocking curves. The broadening effect strongly depends on the strength of the ultrasound, which can be easily regulated by changing the acoustic amplitude or frequency near the resonance. The maximum rocking curve broadening reached 17 times, which corresponds to the wavelength band, Δλ/λ=4x10 -3 , when used as a monochromator or analyzer for 20-25 keV x rays. The initial rocking curve shape is restored by sweeping the acoustic frequency within a 50-100 kHz range near the resonance. The tunable broadening effect allows effective manipulation of x-ray intensities in time domain. Time-resolved x-ray diffraction measurements under a 19.6 MHz acoustic wave excitation were performed by synchronizing the acoustic wave and x-ray burst periodicity. We used the fact that twice per period the standing wave produces a zero net deformation across the crystal thickness. By introducing an oscillating delay to the acoustic excitation, we were able to effectively change the phase of the acoustic wave relative to the x-ray burst periodicity. The x-ray diffraction intensity was strongly affected by tuning the timing of the x-ray arrivals to the minimum or maximum acoustic deformation. A deep modulation of x rays was observed in a wide frequency range between 0.1 Hz and 1 MHz, which certifies that acoustically excited quartz crystals can potentially be used as slow and fast x-ray modulators with high duty cycle

In situ electrochemical high-energy X-ray diffraction using a capillary working electrode cell geometry

Energy Technology Data Exchange (ETDEWEB)

Young, Matthias J.; Bedford, Nicholas M.; Jiang, Naisheng; Lin, Deqing; Dai, Liming

2017-05-26

The ability to generate new electrochemically active materials for energy generation and storage with improved properties will likely be derived from an understanding of atomic-scale structure/function relationships during electrochemical events. Here, the design and implementation of a new capillary electrochemical cell designed specifically forin situhigh-energy X-ray diffraction measurements is described. By increasing the amount of electrochemically active material in the X-ray path while implementing low-Zcell materials with anisotropic scattering profiles, an order of magnitude enhancement in diffracted X-ray signal over traditional cell geometries for multiple electrochemically active materials is demonstrated. This signal improvement is crucial for high-energy X-ray diffraction measurements and subsequent Fourier transformation into atomic pair distribution functions for atomic-scale structural analysis. As an example, clear structural changes in LiCoO₂under reductive and oxidative conditions using the capillary cell are demonstrated, which agree with prior studies. Accurate modeling of the LiCoO₂diffraction data using reverse Monte Carlo simulations further verifies accurate background subtraction and strong signal from the electrochemically active material, enabled by the capillary working electrode geometry.

X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth.

Science.gov (United States)

Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D

2002-07-01

Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.

Correct interpretation of diffraction properties of quartz crystals for X-ray optics applications

Energy Technology Data Exchange (ETDEWEB)

Huang, Xian-Rong; Gog, Thomas; Kim, Jungho; Kasman, Elina; Said, Ayman H.; Casa, Diego M.; Wieczorek, Michael; Hönnicke, Marcelo G.; Assoufid, Lahsen

2018-02-01

Quartz has hundreds of strong Bragg reflections that may offer a great number of choices for making fixed-angle X-ray analyzers and polarizers at virtually any hard X-ray energies with selectable resolution. However, quartz crystals, unlike silicon and germanium, are chiral and may thus appear in two different forms of handedness that are mirror images. Furthermore, because of the threefold rotational symmetry along thecaxis, the {h₁h₂h₃L} and {h₂h₁h₃L} Bragg reflections may have quite different Darwin bandwidth, reflectivity and angular acceptance, although they have the same Bragg angle. The design of X-ray optics from quartz crystals therefore requires unambiguous determination of the orientation, handedness and polarity of the crystals. The Laue method and single-axis diffraction technique can provide such information, but the variety of conventions used in the literature to describe quartz structures has caused widespread confusion. The current studies give detailed guidelines for design and fabrication of quartz X-ray optics, with special emphasis on the correct interpretation of Laue patterns in terms of the crystallography and diffraction properties of quartz. Meanwhile, the quartz crystals examined were confirmed by X-ray topography to have acceptably low densities of dislocations and other defects, which is the foundation for developing high-resolution quartz-based X-ray optics.

High-Pressure X-ray Diffraction Study of Tungsten Diselenide

International Nuclear Information System (INIS)

Selvi, E.; Aksoy, R.; Knudson, R.; Ma, Y.

2008-01-01

Synchrotron X-ray diffraction was used in conjunction with a diamond anvil cell to investigate the properties of a tungsten diselenide (WSe2) sample to 35.8 GPa at room temperature. By fitting the pressure-volume data to the third-order Birch-Murnaghan equation of state, the bulk modulus, K0T, of WSe2 was determined to be 72±1 GPa with its pressure derivative, K(prime) 0T , being 4.1±0.1. It was also found that the c-direction of the hexagonal structure is significantly more compressible than the a-direction. No phase transformation was clearly observed in the pressure range of our measurements.

X-Ray diffraction Investigation of Electrochemically Deposited Copper

DEFF Research Database (Denmark)

Pantleon, Karen; Jensen, Jens Dahl; Somers, Marcel A.J.

2004-01-01

by the determination of X-ray diffraction (XRD) pole figures and the calculation of the orientation distribution functions. XRD results are discussed in relation to the morphologies of the electrodeposits as investigated with light optical microscopy and correlated with the process parameters during electrodeposition....

Size effect in X-ray and electron diffraction patterns from hydroxyapatite particles

International Nuclear Information System (INIS)

Suvorova, E.I.; Buffat, P.-A.

2001-01-01

High-resolution transmission electron microscopy (HRTEM), electron microdiffraction, and X-ray diffraction were used to study hydroxyapatite specimens with particle sizes from a few nanometers to several hundreds of nanometers. Diffuse scattering (without clear reflections in transmission diffraction patterns) or strongly broadened peaks in X-ray diffraction patterns are characteristic for agglomerated hydroxyapatite nanocrystals. However, HRTEM and microdiffraction showed that this cannot be considered as an indication of the amorphous state of the matter but rather as the demonstration of size effect and the morphological and structural features of hydroxyapatite nanocrystals

X-ray diffraction patterns of thermally-reduced graphenes

International Nuclear Information System (INIS)

Ju, Hae-Mi; Choi, Sung-Ho; Huh, Seung-Hun

2010-01-01

Thermally-reduced graphenes (GPs) from graphene oxides (GOs) in the range of 200 - 800 .deg. C have been investigated by using X-ray diffraction (XRD). The temperature-dependent evolutions of the (002) peaks show that exfoliation of GO sheets occurs, along with wrinkling, at ∼200 .deg. C and that high-quality GPs are produced at ∼ 600 .deg. C (GP 600 ). These phenomena are explained by the vaporization of intercalated water molecules and the effective removal of the oxide groups of GO by thermal annealing, respectively. GP 600 exhibited a clean and sharp (002) peak corresponding to an interlayer distance of 3.392 A, which is close to that of conventional graphene (∼3.4 A). The structure of GP 600 is further discussed.

Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

Energy Technology Data Exchange (ETDEWEB)

Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Shvyd’ko, Yuri; Trakhtenberg, Emil; Liu, Zunping; Lang, Keenan; Huang, Xianrong; Wieczorek, Michael; Kasman, Elina; Hammonds, John; Macrander, Albert; Assoufid, Lahsen [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2016-07-27

We report progress on implementation and commissioning of sequential X-ray diffraction topography at 1-BM Optics Testing Beamline of the Advanced Photon Source to accommodate growing needs of strain characterization in diffractive crystal optics and other semiconductor single crystals. The setup enables evaluation of strain in single crystals in the nearly-nondispersive double-crystal geometry. Si asymmetric collimator crystals of different crystallographic orientations were designed, fabricated and characterized using in-house capabilities. Imaging the exit beam using digital area detectors permits rapid sequential acquisition of X-ray topographs at different angular positions on the rocking curve of a crystal under investigation. Results on sensitivity and spatial resolution are reported based on experiments with high-quality Si and diamond crystals. The new setup complements laboratory-based X-ray topography capabilities of the Optics group at the Advanced Photon Source.

X-ray diffraction study on the evaluation of the damage of steel structures subjected to earthquake

International Nuclear Information System (INIS)

Kaneta, Kiyoshi; Nishizawa, Hidekazu; Koshika, Norihide.

1985-01-01

The purpose of this study is to investigate the behavior of steel structures subjected to a strong earthquake and to evaluate the damage from a microscopic point of view. For this purpose, the authors have adopted two kinds of research techniques. The first is the ''ON-LINE EARTHQUAKE RESPONSE SIMULATION SYSTEM (ON-LINE SIMULATION SYSTEM)'', which is composed of an electro-hydrauric testing machine controled by a computer and a full scale specimen. Since a term of restoring force in the equation of motion is to be substituted by the actual reaction of a specimen under test, we can obtain the non-linear response of structure without any assumption about the hysteretic characteristics. Based on this method, the dynamic behavior of simple steel structures subjected to an intense earthquakes were simulated. The second technique is the ''X-RAY DIFFRACTION METHOD''. Although this method is usually regarded an experimental technique particular to the material science, we have realized the good applicability for the study of structural engineering. Because X-ray diffraction method is advantageous in investigating the microscopic behavior of steel member such as the plastic deformation and the low cycle fatigue. From the view point stated above, we have adopted this method for the evaluation of low cycle fatigue damage of steel member subjected to an earthquake. The experiment has been performed by radiating the X-ray at several stages of the ON-LINE SIMULATION. As has been expected, the X-ray diffraction patterns have changed in a regular manner depending on the degree of fatigue damage, and the results have shown a good possibility that the X-ray diffraction approach can offer a powerful tool for the detection of the earthquake damage of steel members. (author)

Microprocessor-based system for automatic X-ray diffraction and fluorescence

International Nuclear Information System (INIS)

Souza, A.M. de; Carmo, L.C.S. do; Pereira, V.J.E.; Soares, E.A.

1984-01-01

A data acquisition and processing device appropriate for X-ray analysis and goniometer control was built. The Z-80 based system as well as the whole architeture is described. The advantages and new possibilities of the automated instrument as compared to the traditional ones are listed. The X-ray diffraction and fluorescence techniques can take advantage of the automation. (Author) [pt

Origin of nondetectable x-ray diffraction peaks in nanocomposite CuTiZr alloys

DEFF Research Database (Denmark)

Jiang, Jianzhong; Kato, H.; Ohsuna, T.

2003-01-01

Microscopic structures of Cu60Ti10+xZr30-x (x=0 and 10) alloys have been investigated by transmission electron microscopy, x-ray diffraction (XRD) and differential scanning calorimeter (DSC). In the Cu60Ti10Zr30 samples annealed at 708 K for times ranging from 0 to 130 min, where the enthalpy...... of the first exothermic peak decreases by 80%, the corresponding XRD patterns still look similar to that for the as-prepared sample. However, the simulated XRD patterns for the pure Cu51Zr14 phase, which is the crystalline phase formed during the first exothermic reaction, with small grain sizes and defects...... clearly show a broadened amorphous-like feature. This might be the reason that no diffraction peaks from the nanocrystalline component were detected in the XRD patterns recorded for the as-cast or as-spun Cu60Ti10+xZr30-x (x=0 and 10) alloys and for the alloys annealed at lower temperatures, in which...

On the evaluation of X-ray diffraction experiments by the regularization method

Energy Technology Data Exchange (ETDEWEB)

Trubin, V.A.; Szasz, A. (Lab. of Surface and Interface Physics, Eoetvoes Univ., Budapest (Hungary))

1991-05-16

The characteristic property of diffractometers as the presence of occasional and systematic errors in measured patterns requires such an evaluation which is as informative as possible. This circumstance gives rise to the problem of optimal planning of the experiment. The X-ray diffraction optimization problem with application of the regularization method is studied. The proposal permits to determine more accurately the unknown true characteristics of the X-ray diffraction experiment. (orig.).

On the evaluation of X-ray diffraction experiments by the regularization method

International Nuclear Information System (INIS)

Trubin, V.A.; Szasz, A.

1991-01-01

The characteristic property of diffractometers as the presence of occasional and systematic errors in measured patterns requires such an evaluation which is as informative as possible. This circumstance gives rise to the problem of optimal planning of the experiment. The X-ray diffraction optimization problem with application of the regularization method is studied. The proposal permits to determine more accurately the unknown true characteristics of the X-ray diffraction experiment. (orig.)

Direct observation of ultrafast atomic motion using time-resolved X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Shymanovich, U.

2007-11-13

This thesis is dedicated to the study of the atomic motion in laser irradiated solids on a picosecond to subpicosecond time-scale using the time-resolved X-ray diffraction technique. In the second chapter, the laser system, the laser-plasma based X-ray source and the experimental setup for optical pump / X-ray probe measurements were presented. Chapter 3 is devoted to the characterization and comparison of different types of X-ray optics. Chapter 4 presented the time-resolved X-ray diffraction experiments performed for this thesis. The first two sections of this chapter discuss the measurements of initially unexpected strain-induced transient changes of the integrated reflectivity of the X-ray probe beam. The elimination of the strain-induced transient changes of the integrated reflectivity represented an important prerequisite to perform the study of lattice heating in Germanium after femtosecond optical excitation by measuring the transient Debye-Waller effect. The third section describes the investigations of acoustic waves upon ultrafast optical excitation and discusses the two different pressure contributions driving them: the thermal and the electronic ones. (orig.)

Direct observation of ultrafast atomic motion using time-resolved X-ray diffraction

International Nuclear Information System (INIS)

Shymanovich, U.

2007-01-01

This thesis is dedicated to the study of the atomic motion in laser irradiated solids on a picosecond to subpicosecond time-scale using the time-resolved X-ray diffraction technique. In the second chapter, the laser system, the laser-plasma based X-ray source and the experimental setup for optical pump / X-ray probe measurements were presented. Chapter 3 is devoted to the characterization and comparison of different types of X-ray optics. Chapter 4 presented the time-resolved X-ray diffraction experiments performed for this thesis. The first two sections of this chapter discuss the measurements of initially unexpected strain-induced transient changes of the integrated reflectivity of the X-ray probe beam. The elimination of the strain-induced transient changes of the integrated reflectivity represented an important prerequisite to perform the study of lattice heating in Germanium after femtosecond optical excitation by measuring the transient Debye-Waller effect. The third section describes the investigations of acoustic waves upon ultrafast optical excitation and discusses the two different pressure contributions driving them: the thermal and the electronic ones. (orig.)

Energy-dispersive X-ray diffraction beamline at Indus-2 synchrotron ...

Indian Academy of Sciences (India)

An energy-dispersive X-ray diffraction beamline has been designed, developed and commissioned at BL-11 bending magnet port of the Indian synchrotron source, Indus-2. The performance of this beamline has been benchmarked by measuring diffraction patterns from various elemental metals and standard inorganic ...

Plasticity-induced martensitic transformation in austenitic stainless steels SUS 304 and SUS 316 L at room and liquid nitrogen temperatures. Quantitative measurement using X-ray diffraction method

International Nuclear Information System (INIS)

Iwasaki, Yoshifumi; Nakasone, Yuji; Shimizu, Tetsu; Kobayashi, Noboru

2006-01-01

The present study investigates plasticity-induced martensitic transformation in two types of austenitic stainless steels SUS 304 and 316 L subjected to uniform tensile stresses at room and liquid nitrogen temperatures. The X-ray diffraction method was used in order to measure volume fractions of transformed α' and ε' martensitic phases and to obtain the dependence of the volume fractions of these phases on the applied strain level ε. The difficulty in the measurement of the martensitic phases by the X-ray diffraction method caused by the preferred orientation which had been introduced during the rolling process and during the tensile tests was overcome by the help of Arnell's Method. Two types of target materials, i.e. Cu and Mo for the X-ray source were used to verify the accuracy and reproducibility of the present X-ray diffraction analyses. The results were also compared with those obtained by the saturation magnetization method using VSM, or vibrating-sample magnetometer reported elsewhere. It was revealed that α' was transformed in SUS 304 both at 297 and 77 K whereas in SUS 316L only at 77 K. Another type of martensitic phase, i.e., ε was transformed in the both steels only at 77 K. Almost the same values of the volume fractions of α' and ε' phases were obtained by the two types of target materials. The plots of α' volume fraction obtained by the X-ray diffraction methods vs. that by VSM showed a good linear correlation. (author)

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

International Nuclear Information System (INIS)

Parrot, I.M.; Urban, V.; Gardner, K.H.; Forsyth, V.T.

2005-01-01

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar[reg] or Twaron[reg

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers.

Energy Technology Data Exchange (ETDEWEB)

Parrot, I. M. [Institut Laue-Langevin (ILL); Urban, Volker S [ORNL; Gardner, K. H. [DuPont Experimental Station; Forsyth, V. T. [Institut Laue Langevin and Keele University

2005-04-01

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar{reg_sign} or Twaron{reg_sign}.

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

Science.gov (United States)

Parrot, I. M.; Urban, V.; Gardner, K. H.; Forsyth, V. T.

2005-08-01

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar® or Twaron®.

Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

Energy Technology Data Exchange (ETDEWEB)

Parrot, I.M. [Institut Laue Langevin, 6 Rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Institute of Science and Technology in Medicine, Keele University Medical School, Staffordshire ST4 7QB (United Kingdom); Urban, V. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6100 (United States); Gardner, K.H. [Department of Materials Science and Engineering University of Delaware, Newark, DE 19719 (United States); Forsyth, V.T. [Institut Laue Langevin, 6 Rue Jules Horowitz, 38042 Grenoble Cedex 9 (France) and Institute of Science and Technology in Medicine, Keele University Medical School, Staffordshire ST4 7QB (United Kingdom)]. E-mail: tforsyth@ill.fr

2005-08-15

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar[reg] or Twaron[reg].

Non-destructive analysis of micro texture and grain boundary character from X-ray diffraction contrast tomography

DEFF Research Database (Denmark)

King, A.; Herbig, M.; Ludwig, W.

2010-01-01

Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting new possibilities for mapping 3D grain shapes and crystallographic orientations in different classes of polycrystalline materials. X-ray diffraction contrast tomography (DCT) is a monochromatic beam...... imaging technique combining the principles of X-ray micro-tomography and three-dimensional X-ray diffraction microscopy (3DXRD). DCT provides simultaneous access to 3D grain shape, crystallographic orientation and attenuation coefficient distribution at the micrometer length scale. The microtexture...

X-ray diffraction diagnostic design for the National Ignition Facility

Science.gov (United States)

Ahmed, Maryum F.; House, Allen; Smith, R. F.; Ayers, Jay; Lamb, Zachary S.; Swift, David W.

2013-09-01

This paper describes the design considerations for Target Diffraction In-Situ (TARDIS), an x-ray diffraction diagnostic at the National Ignition Facility. A crystal sample is ramp-compressed to peak pressures between 10 and 30 Mbar and, during a pressure hold period, is probed with quasi-monochromatic x-rays emanating from a backlighter source foil. The crystal spectrography diffraction lines are recorded onto image plates. The crystal sample, filter, and image plates are packaged into one assembly, allowing for accurate and repeatable target to image plate registration. Unconverted laser light impinges upon the device, generating debris, the effects of which have been mitigated. Dimpled blast shields, high strength steel alloy, and high-z tungsten are used to shield and protect the image plates. A tapered opening was designed to provide adequate thickness of shielding materials without blocking the drive beams or x-ray source from reaching the crystal target. The high strength steel unit serves as a mount for the crystal target and x-ray source foil. A tungsten body contains the imaging components. Inside this sub-assembly, there are three image plates: a 160 degree field of view curved plate directly opposite the target opening and two flat plates for the top and bottom. A polycarbonate frame, coated with the appropriate filter material and embedded with registration features for image plate location, is inserted into the diagnostic body. The target assembly is metrologized and then the diagnostic assembly is attached.

Quantitative analysis of minerals by X-ray diffraction

International Nuclear Information System (INIS)

Pietroluongo, L.R.V.; Veiga, M.M. da

1982-01-01

Considerations about the X-ray diffraction technique for quantitative analyses are made; some experiments carried out at CETEM - Centro de Tecnologia Mineral (Rio de Janeiro, Brazil) with synthetic samples and real samples of diatomites (from northeastern region of Brazil) are described. Quartz quantification has been a problem for analytical chemists and is of great importance to the industries which use this raw material. Comments are made about the main factors influencing the intensity of diffracted X-rays, such as: the crystallinity of the mineral phase; the granulometry, the preferential orientation; sample preparation and pressing, the chemical composition of standards and experimental analytical conditions. Several analytical methods used are described: direct measurement of the height or area of a peak resulting from a particular reflection and comparison with a pre-calibrated curve; method of sequential addition of the mineral of interest in the sample and extrapolation of results for ZERO addition; methods of external and internal standards. (C.L.B.) [pt

Reflectivity and diffraction of X rays applied to organic thin films

International Nuclear Information System (INIS)

Rieutord, Francois

1987-01-01

This research thesis reports the study of organic thin films by using X-ray-based technologies, and more particularly X-ray reflectivity. After some recalls on X ray diffraction, and on the fabrication of Langmuir-Blodgett films, the author shows how, by combining three X-ray-based techniques, it is possible to study a volume structure of a thin film. He describes the technique of measurement by X- ray reflexivity, its experimental implementation, and methods for result interpretation. In the next part, the author reports the study of peculiar interference effects which are noticed in reflexivity on Langmuir-Blodgett films, and then describes the nature of these films by correlating results of X ray reflexivity with direct observations performed by electronic microscopy on replica [fr

High-Pressure and High-Temperature in situ X-Ray Diffraction Study of FeP2 up to 70 GPa

International Nuclear Information System (INIS)

Gu Ting-Ting; Wu Xiang; Qin Shan; Liu Jing; Li Yan-Chun; Zhang Yu-Feng

2012-01-01

The high-pressure and high-temperature structural behavior of FeP 2 is investigated by means of synchrotron x-ray powder diffraction combined with a laser heating technique up to 70 GPa and at least 1800 K. No phase transition of FeP 2 occurs up to 68 GPa at room temperature. While a new phase of FeP 2 assigned to the CuAl 2 -type structure (I4/mcm, Z = 4) is observed at 70 GPa after laser-heating. This new phase presents a quenchable property on decompression to ambient conditions. Our results update previous experimental data and are consistent with theoretical studies. (condensed matter: structure, mechanical and thermal properties)

New structural studies of liquid crystal by reflectivity and resonant X-ray diffraction

International Nuclear Information System (INIS)

Fernandes, P.

2007-04-01

This memory presents three structural studies of smectic Liquid Crystals by reflectivity and resonant diffraction of X-rays. It is divided in five chapters. In the first a short introduction to Liquid Crystals is given. In particular, the smectic phases that are the object of this study are presented. The second chapter is consecrated to the X-ray experimental techniques that were used in this work. The three last chapters present the works on which this thesis can be divided. Chapter three demonstrates on free-standing films of MHPOBC (historic liquid crystal that possesses the antiferroelectric sub-phases) the possibility to extend the technique of resonant X-ray diffraction to liquid crystals without resonant element. In the fourth chapter the structure of the B 2 liquid crystal phase of bent-core molecules (or banana molecules) is elucidated by using resonant X-ray diffraction combined with polarization analysis of the diffracted beam. A model of the polarization of the resonant beam diffracted by four different structures proposed for the B 2 phase is developed in this chapter. In the fifth chapter a smectic binary mixture presenting a very original critical point of phase separation is studied by X-ray reflectivity and optical microscopy. A concentration gradient in the direction perpendicular to the plane of the film seems to be induced by the free-standing film geometry. The results of a simplified model of the system are compatible with this interpretation

A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

Science.gov (United States)

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-09-01

It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.

A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

International Nuclear Information System (INIS)

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-01-01

It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude. (orig.)

X-Ray diffraction analysis of thermally evaporated copper tin selenide thin films at different annealing temperature

International Nuclear Information System (INIS)

Mohd Amirul Syafiq Mohd Yunos; Zainal Abidin Talib; Wan Mahmood Mat Yunus; Josephine Liew Ying Chyi; Wilfred Sylvester Paulus

2010-01-01

Semiconductor thin films Copper Tin Selenide, Cu 2 SnSe 3 , a potential compound for semiconductor radiation detector or solar cell applications were prepared by thermal evaporation method onto well-cleaned glass substrates. The as-deposited films were annealed in flowing purified nitrogen, N 2 , for 2 hours in the temperature range from 100 to 500 degree Celsius. The structure of as-deposited and annealed films has been studied by X-ray diffraction technique. The semi-quantitative analysis indicated from the Reitveld refinement show that the samples composed of Cu 2 SnSe 3 and SnSe. These studies revealed that the films were structured in mixed phase between cubic space group F-43 m (no. 216) and orthorhombic space group P n m a (no. 62). The crystallite size and lattice strain were determined from Scherrer calculation method. The results show that increasing in annealing temperature resulted in direct increase in crystallite size and decrease in lattice strain. (author)

Diffractive X-Ray Telescopes

International Nuclear Information System (INIS)

Skinner, G.K.; Skinner, G.K

2010-01-01

Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro arc seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed atmospheric absorption

Thin film characterisation by advanced X-ray diffraction techniques

Energy Technology Data Exchange (ETDEWEB)

Cappuccio, G; Terranova, M L [eds.; INFN, Laboratori Nazionali di Frascati, Rome (Italy)

1996-09-01

This report described the papers presented at the 5. School on X-ray diffraction from polycrystalline materials held at Frascati (Rome) in 2-5 October 1996. A separate abstract was prepared for each of the papers.

Study of caprine bones after moist and dry heat processes by X-ray diffraction

International Nuclear Information System (INIS)

Barbosa, Caroline M.; Azeredo, Soraia R.; Lopes, Ricardo T.; Souza, Sheila M.F.M de

2013-01-01

Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I rel ). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)

Study of caprine bones after moist and dry heat processes by X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Caroline M., E-mail: carolmattosb@yahoo.com.br [Instituto de Arqueologia Brasileira (IAB), Belford Roxo, RJ (Brazil); Azeredo, Soraia R.; Lopes, Ricardo T., E-mail: soraia@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/LIN/UFRJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Instrumentacao Nuclear; Souza, Sheila M.F.M de, E-mail: sferraz@ensp.fiocruz.br [Fundacao Oswaldo Cruz (ENSP/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Escola Nacional de Saude Publica Sergio Arouca

2013-07-01

Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I{sub rel}). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)

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

Science.gov (United States)

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

2007-06-26

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

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

2018-04-24

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.

The discovery of X-ray diffraction by crystals and its great impact on science

International Nuclear Information System (INIS)

Mai Zhenhong

2012-01-01

In April 1912, Friedrich, Knipping and Laue discovered X-ray diffraction in a CuSO 4 crystal. Later, Laue derived the famous Laue equations which explain the diffraction phenomenon. For this, Laue was awarded a Nobel Prize for Physics in 1914. In 1912 W. H. Bragg and W. L. Bragg received news of Laue 's discovery, and from X-ray diffraction experiments in a ZnS crystal they derived the famous Bragg equation. For this work, father and son were together awarded the Nobel Prize for Physics in 1915, To commemorate the 100th anniversary of the discovery of X-ray diffraction, this article reviews the important contributions of the early pioneers and their historic impact on science and technology worldwide. (author)

Growth of ω inclusions in Ti alloys: An X-ray diffraction study

International Nuclear Information System (INIS)

Šmilauerová, J.; Harcuba, P.; Pospíšil, J.; Matěj, Z.; Holý, V.

2013-01-01

We investigated the size and crystal structure of nanometer-sized ω inclusions in single crystals of β-Ti alloys by X-ray diffraction pole-figure measurements and reciprocal space mapping. We studied the topotactical relation of the β and ω crystal lattices, and from the positions and shapes of the diffraction maxima of the ω lattice determined the mean size of the ω inclusions and the misfit of the inclusion lattice with respect to the host lattice, as well as their changes during ageing. The lattice of the ω inclusions exhibits a large positive misfit already before ageing and the misfit is subsequently reduced during the ageing process. Using the theories of elasticity and X-ray scattering we simulated diffuse X-ray scattering around the β diffraction maxima and demonstrated that the diffuse scattering is caused mainly by local elastic strains in the β host phase around the ω inclusions

Biological imaging by soft X-ray diffraction microscopy

Science.gov (United States)

Shapiro, David

We have developed a microscope for soft x-ray diffraction imaging of dry or frozen hydrated biological specimens. This lensless imaging system does not suffer from the resolution or specimen thickness limitations that other short wavelength microscopes experience. The microscope, currently situated at beamline 9.0.1 of the Advanced Light Source, can collect diffraction data to 12 nm resolution with 750 eV photons and 17 nm resolution with 520 eV photons. The specimen can be rotated with a precision goniometer through an angle of 160 degrees allowing for the collection of nearly complete three-dimensional diffraction data. The microscope is fully computer controlled through a graphical user interface and a scripting language automates the collection of both two-dimensional and three-dimensional data. Diffraction data from a freeze-dried dwarf yeast cell, Saccharomyces cerevisiae carrying the CLN3-1 mutation, was collected to 12 run resolution from 8 specimen orientations spanning a total rotation of 8 degrees. The diffraction data was phased using the difference map algorithm and the reconstructions provide real space images of the cell to 30 nm resolution from each of the orientations. The agreement of the different reconstructions provides confidence in the recovered, and previously unknown, structure and indicates the three dimensionality of the cell. This work represents the first imaging of the natural complex refractive contrast from a whole unstained cell by the diffraction microscopy method and has achieved a resolution superior to lens based x-ray tomographic reconstructions of similar specimens. Studies of the effects of exposure to large radiation doses were also carried out. It was determined that the freeze-dried cell suffers from an initial collapse, which is followed by a uniform, but slow, shrinkage. This structural damage to the cell is not accompanied by a diminished ability to see small features in the specimen. Preliminary measurements on frozen

X-ray diffraction analysis and in vitro characterization of the UAM2 protein from Oryza sativa

DEFF Research Database (Denmark)

Welner, Ditte Hededam; Tsai, Alex Yi-Lin; DeGiovanni, Andy M.

2017-01-01

protein from Oryza sativa (OsUAM2) were undertaken. Here, X-ray diffraction data are reported, as well as analysis of the oligomeric state in the crystal and in solution. OsUAM2 crystallizes readily but forms highly radiation-sensitive crystals with limited diffraction power, requiring careful low......, a requirement for a structural metal ion....

The application of X-ray, γ-ray and neutron diffraction to the characterization of single crystal perfection

International Nuclear Information System (INIS)

Freund, A.; Schneider, J.R.

1976-01-01

The work is divided into the following three chapters: 1) diffraction by perfect and imperfect crystals, 2) experimental apparatus (describing gamma ray, X-ray and neutron diffractometers), 3) application of diffraction methods to the development of neutron monochromators. (WBU) [de

Classification of glutinous rice (Oryza sativa L.) starches based on X-ray diffraction pattern

Energy Technology Data Exchange (ETDEWEB)

Zhang, Q.; Abe, T.; Ando, H.; Sasahara, T.

1993-07-01

This study was carried out to analyse the cultivar variability of the X-ray diffraction pattern of glutinous rice starches. Four peaks in the X-ray diffractograms were identified, i.e. 3b, 4a, 4b and 6a. The four peaks were measured from the base line for 71 cultivars and three M{sub 3} lines which were irradiated by γ-rays at the rates of 10, 20 and 30 kr, respectively. Glutinous rice starches were classified into two types by discriminant analysis based on the values of 3b/4b, 4a/4b and 6a/4b. The X-ray diffraction type of the three cultivars did not change with the cultivation areas of different latitude, while that of eleven cultivars varied. Degree of crystallinity was estimated using the formula, (I{sub max} — I{sub i})/I{sub max} where I{sub max} is the maximum height from background intensity line among cultivars, and I{sub i} represents the four peaks. These ratios indicated that the changes in the order of crystallinity were similar to those with the water content and/or hydration and temperature for gelatinization among and/or within cultivars. (author)

IL 12: Femtosecond x-ray powder diffraction

International Nuclear Information System (INIS)

Woerner, M.; Zamponi, F.; Rothhardt, P.; Ansari, Z.; Dreyer, J.; Freyer, B.; Premont-Schwarz, M.; Elsaesser, T.

2010-01-01

A chemical reaction generates new compounds out of one or more initial species. On a molecular level, the spatial arrangement of electrons and nuclei changes. While the structure of the initial and the product molecules can be measured routinely, the transient structures and molecular motions during a reaction have remained unknown in most cases. This knowledge, however, is a key element for the exact understanding of the reaction. The ultimate dream is a 'reaction microscope' which allows for an in situ imaging of the molecules during a reaction. We report on the first femtosecond x-ray powder diffraction experiment in which we directly map the transient electronic charge density in the unit cell of a crystalline solid with 30 pico-meter spatial and 100 femtosecond temporal resolution. X-ray diffraction from polycrystalline powder samples, the Debye Scherrer diffraction technique, is a standard method for determining equilibrium structures. The intensity of the Debye Scherrer rings is determined by the respective x-ray structure factor which represents the Fourier transform of the spatial electron density. In our experiments, the transient intensity and angular positions of up to 20 Debye Scherrer reactions from a polycrystalline powder are measured and unravel for the first time a concerted electron and proton transfer in hydrogen-bonded ionic (NH 4 ) 2 SO 4 crystals. Photoexcitation of ammonium sulfate induces a sub-100 fs electron transfer from the sulfate groups into a highly conned electron channel along the z-axis of the unit cell. The latter geometry is stabilized by transferring protons from the adjacent ammonium groups into the channel. Time-dependent charge density maps derived from the diffraction data display a periodic modulation of the channels charge density by low-frequency lattice motions with a concerted electron and proton motion between the channel and the initial proton binding site. A deeper insight into the underlying microscopic

X-ray Diffraction from Isolated and Strongly Aligned Gas-Phase Molecules with a Free-Electron Laser

DEFF Research Database (Denmark)

Küpper, Jochen; Stern, Stephan; Holmegaard, Lotte

2014-01-01

We report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles of the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using the Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive...... imaging of distinct structures of individual, isolated gas-phase molecules. We confirm several key ingredients of single molecule diffraction experiments: the abilities to detect and count individual scattered x-ray photons in single shot diffraction data, to deliver state-selected, e. g., structural......-isomer-selected, ensembles of molecules to the x-ray interaction volume, and to strongly align the scattering molecules. Our approach, using ultrashort x-ray pulses, is suitable to study ultrafast dynamics of isolated molecules....

X-ray Absorption and Diffraction Studies of the Mixed-phase State of (CrxV1-x)2O3

Energy Technology Data Exchange (ETDEWEB)

D Pease; A Frenkel; V Krayzman; T Huang; P Shanthakumar; J Budnick; P Metcalf; F Chudnovsky; E Stern

2011-12-31

X-ray diffraction and vanadium x-ray absorption near-edge structure (XANES) data have been obtained for (V{sub 1-x}Cr{sub x}){sub 2}O{sub 3} samples containing several concentrations of Cr, crossing the metal-insulator transition boundary. For single-phase single-crystal samples our theoretical results are generally in good qualitative agreement with our experimental single-crystal XANES, for both crystal orientations relative to the incident-beam electric vector. However, an anomalous peak occurs for both orientations in the K pre-edge of the single-crystal sample containing 1.2% Cr, a paramagnetic insulator sample that is in the concentration regime corresponding to the room-temperature two-phase (coexistence) region of the phase diagram. Upon increasing the temperature of the 0.4% Cr powdered material to 400 K so that one enters the two-phase region of the phase diagram, a similar peak appears and then diminishes at 600 K. These results, as well as experiments done by others involving room-temperature and low-temperature XANES of a 1.1% Cr sample, suggest that this feature in the V pre-edge structure is associated with the appearance under some circumstances of a small amount of highly distorted VO{sub 6} octahedra in the interface region between coexisting metal and insulating phases. Finally, we find that, for the two-phase regime, the concentration ratio of the metal-to-insulating phase varies between different regions from a sample batch of uniform composition made by the skull melting method.

Characterization of titanium silicide thin films by X-ray diffraction techniques

International Nuclear Information System (INIS)

Morimoto, N.J.

1987-01-01

This thesis deals with characterization techniques of thin films by means of X-ray diffraction. This includes phase identification and residual stress, microstress and crystallite size calculations. The techniques developed were applied on the study of the titanium silicide formation obtained by means of Rapidy Thermal Processing (RTP) pf Ti films deposited on silicon substratum. The different phases were studied in relation with processing temperature and time in one and two anneling steps. The low resistivity TiSi 2 phase was observed for temperature of 700 0 C and higher. The experimental results indicate that the residual stress of TiSi 2 films doesn't vary significantly with the annealing conditions. On the other hand, the microstress is reduced with annealing time at 800 0 C, while the crystallite size is almost not affected. For the microstress and the crystallite size determination technique, two methods were implemented and compared. The Riella's method appeared to be very efficient, while the Gangulle's method seemed to be inadequate, because the results oscillate too much [pt

Measurement of Mechanical Coherency Temperature and Solid Volume Fraction in Al-Zn Alloys Using In Situ X-ray Diffraction During Casting

Science.gov (United States)

Drezet, Jean-Marie; Mireux, Bastien; Kurtuldu, Güven; Magdysyuk, Oxana; Drakopoulos, Michael

2015-09-01

During solidification of metallic alloys, coalescence leads to the formation of solid bridges between grains or grain clusters when both solid and liquid phases are percolated. As such, it represents a key transition with respect to the mechanical behavior of solidifying alloys and to the prediction of solidification cracking. Coalescence starts at the coherency point when the grains begin to touch each other, but are unable to sustain any tensile loads. It ends up at mechanical coherency when the solid phase is sufficiently coalesced to transmit macroscopic tensile strains and stresses. Temperature at mechanical coherency is a major input parameter in numerical modeling of solidification processes as it defines the point at which thermally induced deformations start to generate internal stresses in a casting. This temperature has been determined for Al-Zn alloys using in situ X-ray diffraction during casting in a dog-bone-shaped mold. This setup allows the sample to build up internal stress naturally as its contraction is prevented. The cooling on both extremities of the mold induces a hot spot at the middle of the sample which is irradiated by X-ray. Diffraction patterns were recorded every 0.5 seconds using a detector covering a 426 × 426 mm2 area. The change of diffraction angles allowed measuring the general decrease of the lattice parameter of the fcc aluminum phase. At high solid volume fraction, a succession of strain/stress build up and release is explained by the formation of hot tears. Mechanical coherency temperatures, 829 K to 866 K (556 °C to 593 °C), and solid volume fractions, ca. 98 pct, are shown to depend on solidification time for grain refined Al-6.2 wt pct Zn alloys.

Non-destructive assessment of the polarity of GaN nanowire ensembles using low-energy electron diffraction and x-ray photoelectron diffraction

Czech Academy of Sciences Publication Activity Database

Romanyuk, Olexandr; Fernández-Garrido, S.; Jiříček, Petr; Bartoš, Igor; Geelhaar, L.; Brandt, O.; Paskova, T.

2015-01-01

Roč. 106, č. 2 (2015), "021602-1"-"021602-4" ISSN 0003-6951 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : GaN nanowires * X-ray photoelectron diffraction * LEED I-V * GaN polarity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.142, year: 2015

Complete k-space visualization of x-ray photoelectron diffraction

International Nuclear Information System (INIS)

Denlinger, J.D.; Lawrence Berkeley Lab., CA; Rotenberg, E.; Lawrence Berkeley Lab., CA; Kevan, S.D.; Tonner, B.P.

1996-01-01

A highly detailed x-ray photoelectron diffraction data set has been acquired for crystalline Cu(001). The data set for bulk Cu 3p emission encompasses a large k-space volume (k = 3--10 angstrom -1 ) with sufficient energy and angular sampling to monitor the continuous variation of diffraction intensities. The evolution of back-scattered intensity oscillations is visualized by energy and angular slices of this volume data set. Large diffraction data sets such as this will provide rigorous experimental tests of real-space reconstruction algorithms and multiple-scattering simulations

Diffraction enhanced X-ray imaging of mammals crystalline lens

International Nuclear Information System (INIS)

Antunes, A.; Hoennicke, M.G.; Safatle, A.M.V.; Cusatis, C.; Moraes Barros, P.S.; Morelhao, S.L.

2005-01-01

Crystalline lenses are transparent biological materials where the organization of the lens fibers can also be affected by changes at molecular level, and therefore the structure and morphology of the tissue can be correlated to the loss of transparency of the lens. In this work, internal structure of mammal lenses regarding the long-range ordering of the fibers are investigated by diffraction enhanced X-ray imaging (DEI) radiography. Moreover, DEI and absorption X-ray synchrotron radiographs for healthy and cataractous crystalline lenses are compared. Significant differences in healthy and cataractous crystalline lenses are observed

Temperature- and density-dependent x-ray scattering in a low-Z plasma

International Nuclear Information System (INIS)

Brown, R.T.

1976-06-01

A computer program is described which calculates temperature- and density-dependent differential and total coherent and incoherent x-ray scattering cross sections for a low-Z scattering medium. Temperature and density are arbitrary within the limitations of the validity of local thermodynamic equilbrium, since ionic populations are calculated under this assumption. Scattering cross sections are calculated in the form factor approximation. The scattering medium may consist of any mixure of elements with Z less than or equal to 8, with this limitation imposed by the availability of atomic data

X-ray diffraction patterns and diffracted intensity of Kα spectral lines of He-like ions

Science.gov (United States)

Goyal, Arun; Khatri, Indu; Singh, A. K.; Sharma, Rinku; Mohan, Man

2017-09-01

In the present paper, we have calculated fine-structure energy levels related to the configurations 1s2s, 1s2p, 1s3s and 1s3p by employing GRASP2K code. We have also computed radiative data for transitions from 1s2p 1 P1o, 1s2p 3 P2o, 1s2p 3 P1o and 1s2s 3S1 to the ground state 1s2. We have made comparisons of our presented energy levels and transition wavelengths with available results compiled by NIST and good agreement is achieved. We have also provided X-ray diffraction (XRD) patterns of Kα spectral lines, namely w, x, y and z of Cu XXVIII, Kr XXXV and Mo with diffraction angle and maximum diffracted intensity which is not published elsewhere in the literature. We believe that our presented results may be beneficial in determination of the order parameter, X-ray crystallography, solid-state drug analysis, forensic science, geological and medical applications.

Quantitative description of microstructure defects in hexagonal boron nitrides using X-ray diffraction analysis

International Nuclear Information System (INIS)

Schimpf, C.; Motylenko, M.; Rafaja, D.

2013-01-01

A routine for simultaneous quantification of turbostratic disorder, amount of puckering and the dislocation and stacking fault density in hexagonal materials was proposed and tested on boron nitride powder samples that were synthesised using different methods. The routine allows the individual microstructure defects to be recognised according to their effect on the anisotropy of the X-ray diffraction line broadening. For quantification of the microstructure defects, the total line broadening is regarded as a linear combination of the contributions from the particular defects. The total line broadening is obtained from the line profile fitting. As testing material, graphitic boron nitride (h-BN) was employed in the form of hot-isostatically pressed h-BN, pyrolytic h-BN or a h-BN, which was chemically vapour deposited at a low temperature. The kind of the dominant microstructure defects determined from the broadening of the X-ray diffraction lines was verified by high resolution transmission electron microscopy. Their amount was attempted to be verified by alternative methods. - Highlights: • Reliable method for quantification of microstructure defects in BN was suggested. • The method is based on the analysis of anisotropic XRD line broadening. • This XRD line broadening is unique and characteristic of the respective defect. • Thus, the quantification of coexistent microstructure defects is possible. • The method was tested on hexagonal BN, which was produced by different techniques

Physical methods for studying minerals and solid materials: X-ray, electron and neutron diffraction; scanning and transmission electron microscopy; X-ray, electron and ion spectrometry

International Nuclear Information System (INIS)

Eberhart, J.-P.

1976-01-01

The following topics are discussed: theoretical aspects of radiation-matter interactions; production and measurement of radiations (X rays, electrons, neutrons); applications of radiation interactions to the study of crystalline materials. The following techniques are presented: X-ray and neutron diffraction, electron microscopy, electron diffraction, X-ray fluorescence analysis, electron probe microanalysis, surface analysis by electron emission spectrometry (ESCA and Auger electrons), scanning electron microscopy, secondary ion emission analysis [fr

Characterization of Brazilian asphalt using X-ray diffraction

International Nuclear Information System (INIS)

Cardoso, Edson R.; Pinto, Nivia G.V.; Almeida, Ana P.G.; Braz, Delson; Lopes, Ricardo T.; Barroso, Regina C.; Motta, Laura M.G.

2007-01-01

Asphalt is a sticky, black and highly viscous liquid or semi-solid that is presented in most crude petroleum and in some natural deposits. The X ray diffraction can give valuable information over the characteristics of a material. Thus, the X-ray diffraction (XRD) method was employed to investigate parameters that characterize and differentiate asphalt groups (Boscan, CAP20, CAP40, CAP50/60, CAP50/70 and CAP85/100). The scattering measurements were carried out in θ-2θ reflection geometry using a powder diffractometer Shimadzu XRD-6000 at the Nuclear Instrumentation Laboratory, Brazil. Scans were typically done from 8 deg to 28 deg every 0.05. The parameters analyzed were: FWHM, peak area, peak center, peak height, left half width and right half width. Thus, in this study, scattering profiles from different asphalt groups were carefully measured in order to establish characteristic signatures of these materials. The results indicate that by using three parameters (peak centroid, peak area and peak intensity) it is possible to characterize and differentiate the asphalt. (author)

Capillary based Li-air batteries for in situ synchrotron X-ray powder diffraction studies

DEFF Research Database (Denmark)

Storm, Mie Møller; Johnsen, Rune E.; Younesi, Reza

2015-01-01

For Li-air batteries to reach their full potential as energy storage system, a complete understanding of the conditions and reactions in the battery during operation is needed. To follow the reactions in situ a capillary-based Li-O2 battery has been developed for synchrotron-based in situ X......-ray powder diffraction (XRPD). In this article, we present the results for the analysis of 1st and 2nd deep discharge and charge for a cathode being cycled between 2 and 4.6 V. The crystalline precipitation of Li2O2 only is observed in the capillary battery. However, there are indications of side reactions...... of constant exposure of X-ray radiation to the electrolyte and cathode during charge of the battery was also investigated. X-ray exposure during charge leads to changes in the development of the intensity and the FWHM of the Li2O2 diffraction peaks. The X-ray diffraction results are supported by ex situ X...

Modelling the X-ray powder diffraction of nitrogen-expanded austenite using the Debye formula

DEFF Research Database (Denmark)

Oddershede, Jette; Christiansen, Thomas; Ståhl, Kenny

2008-01-01

Stress-free and homogeneous samples of nitrogen-expanded austenite, a defect-rich f.c.c. structure with a high interstitial nitrogen occupancy (between 0.36 and 0.61), have been studied using X-ray powder diffraction and Debye simulations. The simulations confirm the presence of deformation...... to be indistinguishable to X-ray powder diffraction....

X-ray diffraction microstructural analysis of bimodal size distribution MgO nano powder

International Nuclear Information System (INIS)

Suminar Pratapa; Budi Hartono

2009-01-01

Investigation on the characteristics of x-ray diffraction data for MgO powdered mixture of nano and sub-nano particles has been carried out to reveal the crystallite-size-related microstructural information. The MgO powders were prepared by co-precipitation method followed by heat treatment at 500 degree Celsius and 1200 degree Celsius for 1 hour, being the difference in the temperature was to obtain two powders with distinct crystallite size and size-distribution. The powders were then blended in air to give the presumably bimodal-size- distribution MgO nano powder. High-quality laboratory X-ray diffraction data for the powders were collected and then analysed using Rietveld-based MAUD software using the lognormal size distribution. Results show that the single-mode powders exhibit spherical crystallite size (R) of 20(1) nm and 160(1) nm for the 500 degree Celsius and 1200 degree Celsius data respectively with the nano metric powder displays narrower crystallite size distribution character, indicated by lognormal dispersion parameter of 0.21 as compared to 0.01 for the sub-nano metric powder. The mixture exhibits relatively more asymmetric peak broadening. Analysing the x-ray diffraction data for the latter specimen using single phase approach give unrealistic results. Introducing two phase models for the double-phase mixture to accommodate the bimodal-size-distribution characteristics give R = 100(6) and σ = 0.62 for the nano metric phase and R = 170(5) and σ= 0.12 for the σ sub-nano metric phase. (author)

The phases of Pb/Ge(111): A surface X-ray diffraction study

International Nuclear Information System (INIS)

Grey, F.

1988-03-01

This report describes the results of several surface X-ray diffraction measurements of a chemisorbed overlayer of Pb on the Ge(111) surface. Three phases of Pb/Ge(111) exist in the monolayer regime: the α- and β-phases with a √3x√3R30 0 unit cell, and a high-temperature 1x1 phase. In the 1x1 phase of Pb/Ge(111), isotropic X-ray scattering is observed consistent with a two-dimensional liquid phase. Measurements of the integer-order Bragg reflections through the √3x√3R30 0 →1x1 transition confirm the liquid-like nature of the 1x1 phase, and show that the liquid layer is modulated by the periodic potential of the substrate. By measuring variations of the (2/3,2/3) surface Bragg reflection from the √3x√3R30 0 phase as a function of temperature and coverage, a simple phase diagram for Pb/Ge(111) is deduced. Below 1/3ML (where 1 ML is one Pb atom per Ge surface atom) the α-phase coexists with the 1x1 phase. Between 1/3ML and 4/3ML, α- and β-phases form a two-phase system displaying phase separation. Analogies with simple theoretical phase diagrams are emphasized. (orig.) With 11 tabs., 40 figs., 67 refs

Study of the solid solution formation in mixed oxides by X-ray diffraction

International Nuclear Information System (INIS)

Riella, H.G.

1984-01-01

A method to determine the plutonium distribution in mixed oxides - UO 2 /PuO 2 is described. The distribution function and the medium size of crystallite are obtained from the X-ray diffraction profile. Through the deconvolution by Fourier analysis, the X-ray diffraction profile is obtained without the influence of the difractrometer. Some experimental results for different samples of UO 2 -PuO 2 discussed. (Author) [pt

Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

Science.gov (United States)

Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to present which type of physical information can be obtained from the positions of the Bragg peaks, their intensity and their shape, as well as from the diffuse scattering beyond Bragg peaks. An important physical feature is to take into consideration the difference in nature between a photoinduced phase transition and conventional homogeneous photoinduced chemical or biochemical processes where

Quadrupole lamp furnace for high temperature (up to 2050 K) synchrotron powder x-ray diffraction studies in air in reflection geometry

International Nuclear Information System (INIS)

Sarin, P.; Yoon, W.; Jurkschat, K.; Zschack, P.; Kriven, W. M.

2006-01-01

A four-lamp thermal image furnace has been developed to conduct high temperature x-ray diffraction in reflection geometry on oxide ceramic powder samples in air at temperatures ≤2050 K using synchrotron radiation. A refractory crucible made of Pt20%Rh alloy was used as a specimen holder. A material with well characterized lattice expansion properties was used as an internal crystallographic thermometer to determine the specimen temperature and displacement. The performance of the apparatus was verified by measurement of the thermal expansion properties of CeO 2 , MgO, and Pt which were found to be within ±3% of the acceptable values. The advantages, limitations, and important considerations of the instrument developed are discussed

Residual cold-work determination by X-ray diffraction

International Nuclear Information System (INIS)

Pireau, A.; Vanderborck, Y.

1990-01-01

The determination of the cold-work level of materials for fast breeder reactors can be made by different techniques. The report compares different methods for an application on austenitic stainless steels and demonstrates that the X-ray diffraction procedure is a reliable technique. A round robin test has been performed between three laboratories; the results are presented and discussed

New imaging technique based on diffraction of a focused x-ray beam

Energy Technology Data Exchange (ETDEWEB)

Kazimirov, A [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Kohn, V G [Russian Research Center ' Kurchatov Institute, 123182 Moscow (Russian Federation); Cai, Z-H [Advanced Photon Source, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)], E-mail: ayk7@cornell.edu

2009-01-07

We present first experimental results from a new diffraction depth-sensitive imaging technique. It is based on the diffraction of a focused x-ray beam from a crystalline sample and recording the intensity pattern on a high-resolution CCD detector positioned at a focal plane. Structural non-uniformity inside the sample results in a region of enhanced intensity in the diffraction pattern. The technique was applied to study silicon-on-insulator thin layers of various thicknesses which revealed a complex strain profile within the layers. A circular Fresnel zone plate was used as a focusing optic. Incoherent diffuse scattering spreads out of the diffraction plane and results in intensity recorded outside of the focal spot providing a new approach to separately register x-rays scattered coherently and incoherently from the sample. (fast track communication)

Small angle X ray diffraction investigation of twinned opal_like structures

NARCIS (Netherlands)

Samusev, A.K.; Sinev, I.S.; Samusev, K.B.; Rybin, M.V.; Mistonov, A.A.; Grigoryeva, N.A.; Grigoriev, S.V.; Petukhov, A.V.; Byelov, D.; Trofimova, E.Y.; Kurdyukov, D.A.; Golubev, V.G.; Limonov, M.F.

2012-01-01

Small angle X ray diffraction from synthetic opal films has been investigated as a function of the orientation of the sample. All the observed (hkl) diffraction reflections have been interpreted. The reconstruct tion of the reciprocal lattice of the studied opal films has been carried out. The

Peculiarities of section topograms for the multiple diffraction of X rays

Energy Technology Data Exchange (ETDEWEB)

Kohn, V. G., E-mail: kohnvict@yandex.ru [National Research Centre “Kurchatov Institute” (Russian Federation); Smirnova, I. A. [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)

2016-07-15

The distortion of interference fringes on the section topograms of single crystal due to the multiple diffraction of X rays has been investigated. The cases of the 220 and 400 reflections in a silicon crystal in the form of a plate with a surface oriented normally to the [001] direction are considered both theoretically and experimentally. The same section topogram exhibits five cases of multiple diffraction at small azimuthal angles for the 400 reflection and MoK{sub α} radiation, while the topogram for the 220 reflection demonstrates two cases of multiple diffraction. All these cases correspond to different combinations of reciprocal lattice vectors. Exact theoretical calculations of section topograms for the aforementioned cases of multiple diffraction have been performed for the first time. The section topograms exhibit two different distortion regions. The distortions in the central region of the structure are fairly complex and depend strongly on the azimuthal angle. In the tails of the multiple diffraction region, there is a shift of two-beam interference fringes, which can be observed even with a laboratory X-ray source.

Characterization of x-ray diffraction and electron spin resonance: Effects of sintering time and temperature on bovine hydroxyapatite

International Nuclear Information System (INIS)

Kusrini, Eny; Sontang, Muhammad

2012-01-01

The physical and chemical properties of a hydroxyapatite produced by the sintering of bovine bone were investigated by powder x-ray diffraction (PXRD), electron spin resonance (ESR), energy dispersive x-ray spectroscopy (EDX), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and differential thermal analysis (DTA). A bovine bone powder was sintered at different temperatures ranging from 500 to 1400 °C. The influences of post-irradiation storage on the radiation ESR response of the bovine bone powder before and after sintering were also studied. The results indicate that the sintered bovine bone powder contained hydroxyapatite. Diffraction patterns were sharp and clear based on the (211), (300), and (202) reflections corresponding to bovine hydroxyapatite (BHA), which confirmed the phase purity and high crystalline grade of the BHA produced. The PXRD profile of BHA was dependent on sintering temperatures and times. The molecular formula of BHA was determined by Rietveld analysis showed a similar structure and composition to calcium hydroxyapatite in hexagonal P6 3 /m space group a=b=9.435 Å and c=6.895 Å. ESR data showed that the sintering process can decrease the number of free radicals in BHA; it also revealed that the number of free radicals is constant during long storage periods (75 days). The sintering technique described in this study may be used to extract hydroxyapatite from biowaste bovine bone, leading to its application as a bone filler. - Highlights: ► Natural hydroxyapatite was produced from the bio-wasting bovine bones by sintering method. ► PXRD profile of BHA is dependent on the different temperatures and times in sintering process. ► ESR data is useful to study the typical of free radicals formed in the samples after irradiation. ► Stability and physicochemical properties of BHA is dependent on the different storage times. ► Technique is able to be used to find the natural hydroxyapatite applicable for bone filler.

The Scherrer equation and the dynamical theory of X-ray diffraction.

Science.gov (United States)

Muniz, Francisco Tiago Leitão; Miranda, Marcus Aurélio Ribeiro; Morilla Dos Santos, Cássio; Sasaki, José Marcos

2016-05-01

The Scherrer equation is a widely used tool to determine the crystallite size of polycrystalline samples. However, it is not clear if one can apply it to large crystallite sizes because its derivation is based on the kinematical theory of X-ray diffraction. For large and perfect crystals, it is more appropriate to use the dynamical theory of X-ray diffraction. Because of the appearance of polycrystalline materials with a high degree of crystalline perfection and large sizes, it is the authors' belief that it is important to establish the crystallite size limit for which the Scherrer equation can be applied. In this work, the diffraction peak profiles are calculated using the dynamical theory of X-ray diffraction for several Bragg reflections and crystallite sizes for Si, LaB6 and CeO2. The full width at half-maximum is then extracted and the crystallite size is computed using the Scherrer equation. It is shown that for crystals with linear absorption coefficients below 2117.3 cm(-1) the Scherrer equation is valid for crystallites with sizes up to 600 nm. It is also shown that as the size increases only the peaks at higher 2θ angles give good results, and if one uses peaks with 2θ > 60° the limit for use of the Scherrer equation would go up to 1 µm.

S tudies on the phase transitions and properties of tungsten (VI oxide nanoparticles by X - Ray diffraction (XRD and thermal analysis

Directory of Open Access Journals (Sweden)

S.F. Abdullah

2017-11-01

Full Text Available Tungsten (VI oxide, WO3nanoparticles were synthesized by colloidal gas aphrons(CGAs technique.The resultant WO3nanoparticleswere characterized by thermogravimetric-differential thermal analysis (TG-DTA and X-Ray diffraction (XRD measurements in order to determine the phase transitions, the crystallinity and the size of theWO3nanoparticles. As a comparison, transmission electron microscope (TEM was used to investigate the size of the WO3nanoparticles. The result from XRD and DTA show that the formation of polymorphsWO3nanoparticles have the following sequence: orthorhombic (b-WO3®monoclinic (g-WO3 ®triclinic (d-WO3 ®monoclinic (e-WO3 with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared, suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of theWO3nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ±5, (50 ±5, (150 ±10 and (200 ±10 nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 –1.4 % from 30 until 600°C for the WO3nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3nanoparticleshave been examined by X-Ray photoelectron spectroscopy (XPS. Theresults indicate no significant changes to the composition and the purity of the WO3nanoparticle produced due to the temperature variations

Long wave-length x-ray diffraction crystal and method of manufacturing same

International Nuclear Information System (INIS)

Zingaro, W.P.; Sicignano, A.

1980-01-01

An x-ray diffraction crystal of the Langemuir-Blodgett type capable of detecting radiation having a wavelength greater than 50 Arystroms and a method of making such a crystal are described. The crystal consists of a pair of alternate monolayers, one a heavy metal soap, and one a light metal soap. Selecting cation pairs with a significant difference in atomic number and dispersing power, such as Pb and Be, Mg, or Ca, increases the effective interplanar distance since the Pb planes cause the predominant x-ray diffraction. (LL)

A temperature-controlled cell for X-ray study of liquid systems using a commercial DRON-UM1 diffractometer

International Nuclear Information System (INIS)

Petrun'kin, S.P.; Garavina, E.V.; Trostin, V.N.

1995-01-01

A container (cell) and a temperature-control system have been designed enabling one to carry out x-ray diffraction study of liquid samples both at a fixed temperature and within a certain temperature range using a commercial DRON-UMl x-ray diffractometer. Special features of the cell and the materials used for it allow one to study both chemically inert and corrosive liquids

X-ray and neutron single-crystal diffraction on [Rbx(NH4)1-x]3H(SO4)2. I. Refinement of crystal structure of phase II with x=0.11 at 300 K

International Nuclear Information System (INIS)

Loose, A.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Natkaniec, I.; Frontas'eva, M.V.; Pomyakushina, E.V.; Baranov, A.I.; Dolbinina, V.V

2006-01-01

The study of [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals by X-ray single-crystal diffraction is known up to now only for x=0.57 at the temperatures 293 and 180 K. The crystal structures at these temperatures as was determined [1] belong to monoclinic phase II (C2/c sp. gr., Z=4). In accordance with this work, ammonium ions should be considered as deformed tetrahedra. Monoclinic phase II on the x-T phase diagram of [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals, which has earlier been determined by the dielectric spectroscopy, is stabilized below room temperature if Rb concentration exceeds 9%. The presented results of X-ray and neutron single-crystal diffraction of the [Rb 0.11 (NH 4 ) 0.89 ] 3 H(SO 4 ) 2 mixed crystal at T= 300 K show that ammonium ions could be considered as regular tetrahedra

Exploring the behavior of molybdenum diboride (MoB2): A high pressure x-ray diffraction study

International Nuclear Information System (INIS)

Liu, Pingping; Peng, Fang; Yin, Shuai; Liu, Fangming; Wang, Qiming; Zhu, Xuhui; Wang, Pei; He, Duanwei; Liu, Jing

2014-01-01

Investigation of the equation of state of molybdenum diboride (MoB 2 ) has been performed to 24.1 GPa using synchrotron radiation angle-dispersive x-ray diffraction techniques (ADXRD) in a diamond anvil cell (DAC) at room temperature. Rietveld refinement of the X-ray powder diffraction data reveals that the rhombohedral structure MoB 2 is stable up to 24.1 GPa. The ADXRD data yield a bulk modulus K 0  = 314(11) GPa with a pressure derivative K 0 ′  = 6.4(1.5). The experimental data are discussed and compared to the results of first-principles calculations. In addition, the compressibility of the unit cell axes (a and c axes) of MoB 2 demonstrates an anisotropic property with pressure increasing

Pressure-induced crystallization and phase transformation of amorphous selenium: Raman spectroscopy and x-ray diffraction studies

International Nuclear Information System (INIS)

Yang Kaifeng; Cui Qiliang; Hou Yuanyuan; Liu Bingbing; Zhou Qiang; Hu Jingzhu; Mao, H-K; Zou Guangtian

2007-01-01

High-pressure Raman spectroscopy studies have been carried out on amorphous Se (a-Se) at room temperature in a diamond anvil cell with an 830 nm exciting line. Raman evidence for the pressure-induced crystallization of a-Se and the coexistence of the unknown high-pressure phase with the hexagonal phase is presented for the first time. Further experimental proof of high-pressure angle-dispersive x-ray diffraction studies for a-Se indicates that the unknown high-pressure phase is also a mixture phase of the tetragonal I4 1 /acd and Se IV structure. Our Raman and x-ray diffraction results suggest that hexagonal Se I undergoes a direct transition to triclinic Se III at about 19 GPa, which is in good agreement with the theoretical prediction

Refraction angle and edge visibility in X-ray diffraction enhanced imaging

International Nuclear Information System (INIS)

Chen Yu; Jia Quanjie; Li Gang; Wang Yuzhu; Xue Xianying; Jiang Xiaoming

2007-01-01

Diffraction-enhanced X-ray imaging could extract accurately the refraction angles of the sample, which is very important to increase the image contrast of low Z samples. In this paper, the DEI experiments with X-rays of different energies were performed both on wedge-shaped and rounded model samples. Refraction angles of the two samples were all obtained accurately, and the results agreed well with the calculations. Quantitative analyses based on Edge Visibility were performed for the wedge-shaped model sample. The results revealed that the calculated positions for the Best Edge Visibility of the slope with fixed refraction angle were calculable in good agreement with the experimental results. A quantitative research on the Edge Visibility of real tissues sample was carried out and the optimal condition for best contrast of DEI images were discussed. (authors)

Analytic theory of soft x-ray diffraction by lamellar multilayer gratings

NARCIS (Netherlands)

Kozhevnikov, I.V.; van der Meer, R.; Bastiaens, Hubertus M.J.; Boller, Klaus J.; Bijkerk, Frederik

2011-01-01

An analytic theory describing soft x-ray diffraction by Lamellar Multilayer Gratings (LMG) has been developed. The theory is derived from a coupled waves approach for LMGs operating in the single-order regime, where an incident plane wave can only excite a single diffraction order. The results from

Structural refinement and extraction of hydrogen atomic positions in polyoxymethylene crystal based on the first successful measurements of 2-dimensional high-energy synchrotron X-ray diffraction and wide-angle neutron diffraction patterns of hydrogenated and deuterated species

International Nuclear Information System (INIS)

Tashiro, Kohji; Hanesaka, Makoto; Ohhara, Takashi; Kurihara, Kazuo; Tamada, Taro; Kuroki, Ryota; Fujiwara, Satoru; Ozeki, Tomoji; Kitano, Toshiaki; Nishu, Takashi; Tanaka, Ichiro; Niimura, Nobuo

2007-01-01

2-Dimensional X-ray and neutron diffraction patterns have been successfully measured for deuterated and hydrogenated polyoxymethylene (POM) samples obtained by γ-ray induced solid-state polymerization reaction. More than 700 reflections were collected from the X-ray diffraction data at -150degC by utilizing a high-energy synchrotron X-ray beam at SPring-8, Japan, from which the crystal structure of POM has been refined thoroughly including the extraction of hydrogen atomic positions at clearly seen in the difference Fourier synthesis map. As the first trial the nonuniform (9/5) helical model was analyzed with the reliability factor (R factor) 6.9%. The structural analysis was made also using the X-ray reflections of about 400 observed at room temperature (R 8.8%), and the thermal parameters of constituent atoms were compared between the low and high temperatures to discuss the librational thermal motion of the chains. The 2-dimensional neutron diffraction data, collected for the deuterated and hydrogenated POM samples using an imaging plate system specifically built-up for neutron scattering experiment, have allowed us to pick up the D and H atomic positions clearly in the Fourier synthesis maps. Another possible model, (29/16) helix, which was proposed by several researches, has been also investigated on the basis of the X-ray diffraction data at -150degC. The direct method succeeded in extracting this (29/16) model straightforwardly. The R factor was 8.6%, essentially the same as that of (9/5) helical model. This means that the comparison of the diffraction intensity between the data collected from the full-rotation X-ray diffraction pattern and the intensity calculated for both the (9/5) and (29/16) models cannot be used for the unique determination of the superiority of the model, (9/5) or (29/16) helix. However, we have found the existence of 001 and 002 reflections which give the longer repeating period 55.7 A. Besides there observed a series of meridional

Nano structured materials studied by coherent X-ray diffraction

International Nuclear Information System (INIS)

Gulden, Johannes

2013-03-01

Structure determination with X-rays in crystallography is a rapidly evolving field. Crystallographic methods for structure determination are based on the assumptions about the crystallinity of the sample. It is vital to understand the structure of possible defects in the crystal, because they can influence the structure determination. All conventional methods to characterize defects require a modelling through simulated data. No direct methods exist to image the core of defects in crystals. Here a new method is proposed, which will enable to visualize the individual scatterers around and at defects in crystals. The method is based on coherent X-ray scattering. X-rays are perfectly suited since they can penetrate thick samples and buried structures can be investigated Recent developments increased the coherent flux of X-Ray sources such as synchrotrons by orders of magnitude. As a result, the use of the coherent properties of X-rays is emerging as a new aspect of X-ray science. New upcoming and operating X-ray laser sources will accelerate this trend. One new method which has the capacity to recover structural information from the coherently scattered photons is Coherent X-ray Diffraction Imaging (CXDI). The main focus of this thesis is the investigation of the structure and the dynamics of colloidal crystals. Colloidal crystals can be used as a model for atomic crystals in order to understand the growth and defect structure. Despite the large interest in these structures, many details are still unknown.Therefore, it is vital to develop new approaches to measure the core of defects in colloidal crystals. After an introduction into the basics of the field of coherent X-ray scattering, this thesis introduces a novel method, Small Angle Bragg Coherent Diffractive Imaging, (SAB-CDI). This new measurement technique which besides the relevance to colloidal crystals can be applied to a large variety of nano structured materials. To verify the experimental possibilities the

Nano structured materials studied by coherent X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Gulden, Johannes

2013-03-15

Structure determination with X-rays in crystallography is a rapidly evolving field. Crystallographic methods for structure determination are based on the assumptions about the crystallinity of the sample. It is vital to understand the structure of possible defects in the crystal, because they can influence the structure determination. All conventional methods to characterize defects require a modelling through simulated data. No direct methods exist to image the core of defects in crystals. Here a new method is proposed, which will enable to visualize the individual scatterers around and at defects in crystals. The method is based on coherent X-ray scattering. X-rays are perfectly suited since they can penetrate thick samples and buried structures can be investigated Recent developments increased the coherent flux of X-Ray sources such as synchrotrons by orders of magnitude. As a result, the use of the coherent properties of X-rays is emerging as a new aspect of X-ray science. New upcoming and operating X-ray laser sources will accelerate this trend. One new method which has the capacity to recover structural information from the coherently scattered photons is Coherent X-ray Diffraction Imaging (CXDI). The main focus of this thesis is the investigation of the structure and the dynamics of colloidal crystals. Colloidal crystals can be used as a model for atomic crystals in order to understand the growth and defect structure. Despite the large interest in these structures, many details are still unknown.Therefore, it is vital to develop new approaches to measure the core of defects in colloidal crystals. After an introduction into the basics of the field of coherent X-ray scattering, this thesis introduces a novel method, Small Angle Bragg Coherent Diffractive Imaging, (SAB-CDI). This new measurement technique which besides the relevance to colloidal crystals can be applied to a large variety of nano structured materials. To verify the experimental possibilities the

X-ray diffraction and Moessbauer studies of structural changes and L10 ordering kinetics during annealing of polycrystalline Fe51Pt49 thin films

International Nuclear Information System (INIS)

Spada, F.E.; Parker, F.T.; Platt, C.L.; Howard, J.K.

2003-01-01

Room-temperature x-ray diffraction and Moessbauer effect techniques have been used to characterize the structural features and local atomic environments of sputtered Fe 51 Pt 49 thin films following various isothermal treatments. Both techniques show that no significant changes occur in the chemically ordered L1 0 tetragonal phase after it has formed. In contrast, changes in the disordered face-centered-cubic (fcc) phase are observed prior to the transformation into the ordered tetragonal phase. Moessbauer measurements indicate the development of increasing short-range order in the disordered fcc phase with increasing annealing temperature. Asymmetries in the fcc x-ray diffraction profiles also suggest the presence of lattice distortions caused by atomic size differences commonly found in the quenched disordered fcc phase of materials that form ordered structures. Quasi-real-time kinetic measurements of the disorder→order transformation in sputtered Fe 51 Pt 49 thin films within the temperature range 300 deg. C≤T≤400 deg. C have also been conducted using high-temperature x-ray diffraction techniques. Significant differences are observed between the kinetic parameters determined in this study and those of previous reports. It is proposed that these differences arise from the lower temperature range investigated in the present work, where the gradual changes occurring in the fcc phase can influence the rate of the ordering transformation. Furthermore, because the initial state of disorder in Fe ∼50 Pt ∼50 films can be influenced by the deposition conditions, variability in the low-temperature ordering kinetics should be expected among Fe ∼50 Pt ∼50 films prepared under different conditions

Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.

Science.gov (United States)

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.

Modern X-ray difraction. X-ray diffractometry for material scientists, physicists, and chemicists

International Nuclear Information System (INIS)

Spiess, L.; Schwarzer, R.; Behnken, H.; Teichert, G.

2005-01-01

The book yields a comprehensive survey over the applications of X-ray diffraction in fields like material techniques, metallurgy, electrotechniques, machine engineering, as well as micro- and nanotechniques. The necessary fundamental knowledge on X-ray diffraction are mediated foundedly and illustratively. Thereby new techniques and evaluation procedures are presented as well as well known methods. The content: Production and properties of X radiation, diffraction of X radiation, hardware for X-ray diffraction, methods of X-ray diffraction, lattice-constant determination, phase analysis, X-ray profile analysis, crystal structure analysis, X-ray radiographic stress analysis, X-ray radiographic texture analysis, crystal orientation determination, pecularities at thin films, small angle scattering

X-ray diffraction imaging with the Multiple Inverse Fan Beam topology: Principles, performance and potential for security screening

Energy Technology Data Exchange (ETDEWEB)

Harding, G., E-mail: Geoffrey.Harding@Morphodetection.com [Morpho Detection Germany GmbH, Heselstuecken 3, 22453 Hamburg (Germany); Fleckenstein, H.; Kosciesza, D.; Olesinski, S.; Strecker, H.; Theedt, T.; Zienert, G. [Morpho Detection Germany GmbH, Heselstuecken 3, 22453 Hamburg (Germany)

2012-07-15

The steadily increasing number of explosive threat classes, including home-made explosives (HMEs), liquids, amorphous and gels (LAGs), is forcing up the false-alarm rates of security screening equipment. This development can best be countered by increasing the number of features available for classification. X-ray diffraction intrinsically offers multiple features for both solid and LAGs explosive detection, and is thus becoming increasingly important for false-alarm and cost reduction in both carry-on and checked baggage security screening. Following a brief introduction to X-ray diffraction imaging (XDI), which synthesizes in a single modality the image-forming and material-analysis capabilities of X-rays, the Multiple Inverse Fan Beam (MIFB) XDI topology is described. Physical relationships obtaining in such MIFB XDI components as the radiation source, collimators and room-temperature detectors are presented with experimental performances that have been achieved. Representative X-ray diffraction profiles of threat substances measured with a laboratory MIFB XDI system are displayed. The performance of Next-Generation (MIFB) XDI relative to that of the 2nd Generation XRD 3500{sup TM} screener (Morpho Detection Germany GmbH) is assessed. The potential of MIFB XDI, both for reducing the exorbitant cost of false alarms in hold baggage screening (HBS), as well as for combining 'in situ' liquid and solid explosive detection in carry-on luggage screening is outlined. - Highlights: Black-Right-Pointing-Pointer X-ray diffraction imaging (XDI) synthesizes analysis and imaging in one x-ray modality. Black-Right-Pointing-Pointer A novel XDI beam topology comprising multiple inverse fan-beams (MIFB) is described. Black-Right-Pointing-Pointer The MIFB topology is technically easy to realize and has high photon collection efficiency. Black-Right-Pointing-Pointer Applications are envisaged in checkpoint, hold baggage and cargo screening.

X-ray diffraction study of directionally grown perylene crystallites

DEFF Research Database (Denmark)

Breiby, Dag W.; Lemke, H. T.; Hammershøj, P.

2008-01-01

Using grazing incidence X-ray diffraction, perylene crystallites grown on thin highly oriented poly(tetrafluoroethylene) (PTFE) films on silicon substrates have been investigated. All the perylene crystallites are found to orient with the ab plane of the monoclinic unit cell parallel to the subst......Using grazing incidence X-ray diffraction, perylene crystallites grown on thin highly oriented poly(tetrafluoroethylene) (PTFE) films on silicon substrates have been investigated. All the perylene crystallites are found to orient with the ab plane of the monoclinic unit cell parallel...... to the substrate. The scattering data is interpreted as a trimodal texture of oriented perylene crystallites, induced by interactions between the perylene molecules and the oriented PTFE substrate. Three families of biaxial orientations are seen, with the axes (h = 1, 2, or 3) parallel to the PTFE alignment......, all having the ab-plane parallel to the substrate. About 92% of the scattered intensity corresponds to a population with highly parallel to (PTFE)....

Characterization of sintered samples of La/Sr/Cu/O by X-ray diffraction, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS)

International Nuclear Information System (INIS)

Gonzalez, C.O. de; Polla, Griselda; Manghi, Estela

1987-01-01

Samples of La/Sr/Cu/O were sinterized by solid state reaction starting from a nominal composition of La 1 .8, Sr 0 .2, CuO 4 . They presented superconductive properties with T c = 40.9 K (onset) and δ T c = 17 K. Two phases were observed by X-ray diffraction and the more abundant was the tetragonal phase. The mean grain size was 1-5 μm. The X-ray photoelectron spectroscopy measurements were carried out using Mg kα (1486.6 eV) as incident radiation. Sample temperature was varied between -180 deg C and 420 deg C, approximately. The temperature variation produces a change in the atomic concentration of the surface components. Deconvolutions of the O 1s peaks show three components with binding energies (B.E.). The decomposition of Cu 2p 3 /2 peaks presents two components corresponding to Cu + and Cu 2+ . (Author) [es

Diamond-anvil cell for radial x-ray diffraction

International Nuclear Information System (INIS)

Chesnut, G N; Schiferl, D; Streetman, B D; Anderson, W W

2006-01-01

We have designed a new diamond-anvil cell capable of radial x-ray diffraction to pressures of a few hundred GPa. The diffraction geometry allows access to multiple angles of Ψ, which is the angle between each reciprocal lattice vector g(hkl) and the compression axis of the cell. At the 'magic angle', Ψ∼54.7 0 , the effects of deviatoric stresses on the interplanar spacings, d(hkl), are significantly reduced. Because the systematic errors, which are different for each d(hkl), are significantly reduced, the crystal structures and the derived equations of state can be determined reliably. At other values of Ψ, the effects of deviatoric stresses on the diffraction pattern could eventually be used to determine elastic constants

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

International Nuclear Information System (INIS)

Tanaka, M; Katsuya, Y; Matsushita, Y

2013-01-01

The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe 2 O 4 and Fe 3 O 4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe 2+ /Fe 3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.

An ultrahigh-vacuum apparatus for resonant diffraction experiments using soft x rays (hν=300-2000 eV)

International Nuclear Information System (INIS)

Takeuchi, T.; Chainani, A.; Takata, Y.; Tanaka, Y.; Oura, M.; Tsubota, M.; Senba, Y.; Ohashi, H.; Mochiku, T.; Hirata, K.; Shin, S.

2009-01-01

We have developed an ultrahigh-vacuum instrument for resonant diffraction experiments using polarized soft x rays in the energy range of hν=300-2000 eV at beamline BL17SU of SPring-8. The diffractometer consists of modified differentially pumped rotary feedthroughs for θ-2θ stages, a sample manipulator with motor-controlled x-y-z-, tilt (χ)-, and azimuth (φ)-axes, and a liquid helium flow-type cryostat for temperature dependent measurements between 30 and 300 K. Test results indicate that the diffractometer exhibits high reproducibility (better than 0.001 deg.) for a Bragg reflection of α-quartz 100 at a photon energy of hν=1950 eV. Typical off- and on-resonance Bragg reflections in the energy range of 530-1950 eV could be measured using the apparatus. The results show that x-ray diffraction experiments with energy-, azimuth-, and incident photon polarization-dependence can be reliably measured using soft x rays in the energy range of ∼300-2000 eV. The facility can be used for resonant diffraction experiments across the L-edge of transition metals, M-edge of lanthanides, and up to the Si K-edge of materials.

Neutron and X-ray diffraction analysis of the effect of irradiation dose and temperature on microstructure of irradiated HT-9 steel

International Nuclear Information System (INIS)

Mosbrucker, P.L.; Brown, D.W.; Anderoglu, O.; Balogh, L.; Maloy, S.A.; Sisneros, T.A.; Almer, J.; Tulk, E.F.; Morgenroth, W.; Dippel, A.C.

2013-01-01

Material harvested from several positions within a nuclear fuel duct (the ACO-3 duct) used in a 6-year irradiation of a fuel assembly in the Fast Flux Test Reactor Facility (FFTF) was examined using neutron and high-energy X-ray diffraction. Samples with a wide range of irradiation dose and irradiation temperature history, reaching doses of up to 147 dpa and temperatures of up to 777 K, were examined. The response of various microstructural characteristics such as the weight fraction of M 23 C 6 carbides, the dislocation density and character, and the crystallographic texture were determined using whole profile analysis of the diffraction data and related to the macroscopic mechanical behavior. For instance, the dislocation density was observed to be intimately linked with observed flow strength of the irradiated materials, following the Taylor law. In general, at the high doses studied in this work, the irradiation temperature is the predominant controlling factor of the dislocation density and, thus, the flow strength of the irradiated material. The results, representing some of the first diffraction work done on samples exposed to such a high received dose, demonstrate how non-destructive and stand-off diffraction techniques can be used to characterize irradiation induced microstructure and at least estimate mechanical properties in irradiated materials without exposing workers to radiation hazards

A study of the thermal behavior of terrestrial tridymite by continuous X-ray diffraction

Science.gov (United States)

Smelik, Eugene A.; Reeber, Robert R.

1990-06-01

Phase transition behavior of two types of terrestrial tridymite; crystals from Topaz Mountain in the Thomas Range of northwestern Utah and Smith Peak in Plumas County, California; were investigated. The Topaz Mtn. samples were characterized at room temperature using optical, X-ray diffraction (Debye-Scherrer, rotation, and Laue), and transmission electron microscopy (TEM) methods. Least-squares refinement of the powder data yielded an orthorhombic cell with a = 17.072 Å, b = 9.923 Å, and c = 16.291 Å. The tridymite is designated PO-2 (nomenclature of Nukui and Nakazawa 1980). This material is complexly twinned and has severe stacking disorder parallel to [001]. Additional X-ray experiments were performed on one Plumas County crystal and four Topaz Mtn. crystals during heating from room temperature to a minimum of 320° C with one run attaining a maximum temperature of 532° C. Crystal to crystal behavior was somewhat variable suggesting kinetic barriers to transition controlled by the detailed structural state of each crystal. The Laue results indicated that the transition behavior of these multiple twinned tridymites could be conveniently divided into two classes: discontinuous and continuous. The discontinuous diffraction effects were generally associated with major structural transitions. Continuous diffraction effects involved gradual structural distortions of the tridymite framework that occurred over discrete ranges of temperature. Upon cooling, many of the minor effects were not reversible while the major transitions were reversible with some temperature hysteresis. Comparison of initial and final diffraction patterns indicated that the starting and ending structures were very similar but not identical. From the five experiments, three distinct patterns emerged based on the major transitions observed: Type I behavior (Topaz Mtn.) characterized by three major changes at 175 187° C, 283 302° C, and 348 352° C, Type II behavior (Plumas Co.) characterized

Investigations of the phase transition in V3O5 using energy dispersive X-ray diffraction and synchrotron radiation white beam X-ray topography

International Nuclear Information System (INIS)

Asbrink, S.; Gerward, L.; Staun Olsen, J.

1985-01-01

The reversible first order phase transition in V 3 O 5 at T t =155 0 C has been studied using a specially constructed oven, where the temperature can be kept constant within a few hundredths of a degree for several hours. Energy dispersive diffraction measurements have beem made in a temperature region around the phase transition with the fixed crystal method and the θ/2θ scanning method. White beam X-ray topographs have been obtained from the same crystal in the same temperature region using synchrotron radiation. The integrated intensities of the strong h 0 0 reflections show anomalies that are correlated with the corresponding X-ray topographs. Thus, an unexpected increase of crystal perfection is observed a few hundredths of a degree below T t . The energy dependence of the intensity maximum at T t for strong reflections has been determined and semi-quantitatively explained on the basis of extinction theory. (orig.)

Structural studies of disordered materials using high-energy x-ray diffraction from ambient to extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Kohara, Shinji [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Itou, Masayoshi [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Suzuya, Kentaro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Inamura, Yasuhiro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Sakurai, Yoshiharu [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Ohishi, Yasuo [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Takata, Masaki [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2007-12-19

High-energy x-rays from a synchrotron radiation source allow us to obtain high-quality diffraction data for disordered materials from ambient to extreme conditions, which is necessary for revealing the detailed structures of glass, liquid and amorphous materials. We introduced high-energy x-ray diffraction beamlines and a dedicated diffractometer for glass, liquid and amorphous materials at SPring-8 and report the recent developments of ancillary equipment. Furthermore, the structures of liquid and amorphous materials determined from the high-energy x-ray diffraction data obtained at SPring-8 are discussed.

In situ synchrotron X-ray diffraction study on epitaxial-growth dynamics of III–V semiconductors

Science.gov (United States)

Takahasi, Masamitu

2018-05-01

The application of in situ synchrotron X-ray diffraction (XRD) to the molecular-beam epitaxial (MBE) growth of III–V semiconductors is overviewed along with backgrounds of the diffraction theory and instrumentation. X-rays are sensitive not only to the surface of growing films but also to buried interfacial structures because of their large penetration depth. Moreover, a spatial coherence length up to µm order makes X-rays widely applicable to the characterization of low-dimensional structures, such as quantum dots and wires. In situ XRD studies during growth were performed using an X-ray diffractometer, which was combined with an MBE chamber. X-ray reciprocal space mapping at a speed matching a typical growth rate was achieved using intense X-rays available from a synchrotron light source and an area detector. The importance of measuring the three-dimensional distribution of XRD intensity in a reciprocal space map is demonstrated for the MBE growth of two-, one-, and zero-dimensional structures. A large amount of information about the growth process of two-dimensional InGaAs/GaAs(001) epitaxial films has been provided by three-dimensional X-ray reciprocal mappings, including the anisotropic strain relaxation, the compositional inhomogeneity, and the evolution of surface and interfacial roughness. For one-dimensional GaAs nanowires grown in a Au-catalyzed vapor-liquid–solid mode, the relationship between the diameter of the nanowires and the formation of polytypes has been suggested on the basis of in situ XRD measurements. In situ three-dimensional X-ray reciprocal space mapping is also shown to be useful for determining the lateral and vertical sizes of self-assembled InAs/GaAs(001) quantum dots as well as their internal strain distributions during growth.

Quantitative X-ray diffraction analysis of alumina, silicon carbide and zirconium carbide in ceramic composites

International Nuclear Information System (INIS)

Veiga, Sonia M.B.; Bressiani, Jose Carlos; Veiga, Marcello M.; Chaklader, Asoke C.D.

1995-01-01

The x-ray diffraction technique has been successfully applied to determine the phases formed in a carbo thermal synthesis of ceramic composites (Al 2 O 3 -Si C and Al 2 O 3 -Si C-Zr C) using kaolinite, cyanite and zircon as precursors. The powder method using fluorite as internal standard has shown reliable results to estimate accurately phases in composites (relative error as low as 5%). In addition, quantitative X-ray analysis allows an indirect evaluation of Si O (gas) losses from the system during the carbo thermal reaction. (author)

New software to model energy dispersive X-ray diffraction in polycrystalline materials

Energy Technology Data Exchange (ETDEWEB)

Ghammraoui, B., E-mail: bahaa.ghammraoui@cea.fr [CEA-Leti, MINATEC Campus, 17 rue des Martyrs, F 38054 Grenoble, Cedex 9 (France); Tabary, J. [CEA-Leti, MINATEC Campus, 17 rue des Martyrs, F 38054 Grenoble, Cedex 9 (France); Pouget, S. [CEA-INAC Sciences de la matieres, 17 rue des Martyrs, F 38054 Grenoble, Cedex 9 (France); Paulus, C.; Moulin, V.; Verger, L. [CEA-Leti, MINATEC Campus, 17 rue des Martyrs, F 38054 Grenoble, Cedex 9 (France); Duvauchelle, Ph. [CNDRI-Insa Lyon, Universite de Lyon, F-69621, Villeurbanne Cedex (France)

2012-02-01

Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including amorphous background, into account. Many system parameters can be tuned: geometry, collimators (slit and cylindrical), sample properties, X-ray source and detector energy resolution. Good agreement between simulations and experimental data was obtained. Simulations using explosive materials indicated that parameters such as the diffraction angle or the energy resolution of the detector have a significant impact on the diffraction signature of the material inspected. This software will be a convenient tool to test many diffractometer configurations, providing information on the one that best restores the spectral diffraction signature of the materials of interest.

Molecular beam epitaxial growth mechanism of ZnSe epilayers on (100) GaAs as determined by reflection high-energy electron diffraction, transmission electron microscopy and X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Ruppert, P.; Hommel, D.; Behr, T.; Heinke, H.; Waag, A.; Landwehr, G. (Physikalisches Inst., Univ. Wuerzburg (Germany))

1994-04-14

The properties of molecular beam epitaxial growth of ZnSe epilayers deposited directly on a GaAs substrate are compared to those grown on a GaAs buffer layer. The superior quality of the latter is confirmed by RHEED, TEM and X-ray diffraction. Based on RHEED oscillation studies, a model explaining the dependence of the ZnSe growth rate on Zn and Se fluxes and the substrate temperature is developed taking into account physisorbed and chemisorbed states. For partially relaxed epilayers, the correlation between the relaxation state and the crystalline mosaicity, as found by high resolution X-ray diffraction, is discussed

High-pressure powder X-ray diffraction at the turn of the century

International Nuclear Information System (INIS)

Paszkowicz, W.

2002-01-01

Studies at extreme pressures and temperatures are helpful for understanding the physical properties of the solid state, including such classes of materials as semiconductors, superconductors or minerals. This is connected with the opportunity of tuning the pressure by many orders of magnitude. Diamond-anvil and large-anvil pressure cells installed at dedicated synchrotron beamlines are efficient tools for examination of crystal structure, equation of state, compressibility and phase transitions. One of basic methods in such studies is powder diffraction. This review is devoted to methods of powder X-ray diffraction at high-pressures generated by devices installed at synchrotron radiation sources, in particular to the principles of operation of high-pressure-high-temperature cells. General information on high-pressure diffraction facilities installed at 11 synchrotron storage rings in the world is provided. Measurement aspects are considered, including (i) pressure generation and calibration, (ii) strain in the sample, the pressure marker and the pressure-transmitting medium and (iii) pressure and temperature distributions within the cells. Sources of interest in high-pressure diffraction studies (design of new materials, observation of new phenomena, confrontation of theory with experiment) are briefly discussed. Recent developments of high-pressure methods make that pressure becomes a variable playing a key role in investigation of condensed matter. The paper ends with some remarks on the possible future developments of the technique

Thermogravimetric and x-ray diffraction analyses of Luna-24 regolith samples

International Nuclear Information System (INIS)

Deshpande, V.V.; Dharwadkar, S.R.; Jakkal, V.S.

1979-01-01

Two samples of Luna-24 were analysed by X-ray diffraction and thermogravimetric (TG) techniques. The sample 24123.12 shows a weight loss of nearly 0.85 percent between 23O-440deg C and followed by 1.16 percent weight gain from 500 to 800deg C. The sample 23190.13 showed only a weight gain of about 1.5 percent from 5O0deg C to 900deg C. X-ray diffraction analyses show the presence of olivine, plagioclase, pigeonite, enstatite, and native iron in both the virgin samples. The heated samples, however, show that only the native iron got oxidized to iron oxide. The other constituents remain unaltered. (auth.)

X-ray diffraction and dielectric studies across morphotropic phase boundary in (1 - x) [Pb(Mg0.5W0.5)O3]-xPbTiO3 ceramics

International Nuclear Information System (INIS)

Singh, A.K.; Singh, Akhilesh Kumar

2011-01-01

Research highlights: → Structural studies reveal pseudocubic structure of PMW-xPT for the x ≤ 0.42, tetragonal for the x ≥ 0.72 and the coexistences of the two phases for intermediate compositions (0.46 ≤ x 0.68). → Temperature dependent dielectric constant for compositions in the two phase region shows two dielectric anomalies above room temperature and not just one as reported by earlier workers. → Rietveld structural analysis of PMW-xPT ceramics is presented for the first time to determine the fraction of the coexisting phases in MPB region. - Abstract: We present here the results of comprehensive X-ray diffraction and dielectric studies on several compositions of (1 - x)[Pb(Mg 0.5 W 0.5 )O 3 ]-xPbTiO 3 (PMW-xPT) solid solution across the morphotropic phase boundary. Rietveld analysis of the powder X-ray diffraction data reveals cubic (space group Fm3m) structure of PMW-xPT ceramics for the compositions with x ≤ 0.42, tetragonal (space group P4mm) structure for the compositions with x ≥ 0.72 and coexistence of the tetragonal and cubic phases for the intermediate compositions (0.46 ≤ x ≤ 0.68). Temperature dependence of the dielectric permittivity above room temperature exhibits diffuse nature of phase transitions for the compositions in the cubic and two phase region while the compositions with tetragonal structure at room temperature exhibit sharp ferroelectric to paraelectric phase transition. The PMW-xPT compositions with coexistence of tetragonal and cubic phases at room temperature exhibit two anomalies in the temperature dependence of the dielectric permittivity above room temperature. Using results of structural and dielectric studies a partial phase diagram of PMW-xPT ceramics is also presented.

Investigation of electronic order using resonant soft X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Schlappa, J.

2006-12-01

The aim of this PhD work was the application of resonant soft X-ray diffraction technique for the investigation of electronic order in transition metal oxides at the TM L{sub 2,3}-edge, trying to obtain a quantitative understanding of the data. The method was first systematically explored through application to a model system in order to test the feasibility of the technique and to understand of how X-ray optical effects have to be taken into account. Two more complex systems were investigated; stripe order in La{sub 1.8}Sr{sub 0.2}NiO{sub 4} and charge and orbital order in Fe{sub 3}O{sub 4}. The main focus of the work was on the spectroscopic potential of the technique, trying to obtain a level of quantitative description of the data. For X-ray absorption spectroscopy (XAS) from transition metal oxides, cluster configuration interaction calculation provides a powerful and realistic microscopic theory. In the frame work of this thesis cluster theory, considering explicit hybridization effects between the TM-ion and the surrounding oxygen ligands, has been applied for the first time to describe resonant diffraction data. (orig.)

Investigation of electronic order using resonant soft X-ray diffraction

International Nuclear Information System (INIS)

Schlappa, J.

2006-01-01

The aim of this PhD work was the application of resonant soft X-ray diffraction technique for the investigation of electronic order in transition metal oxides at the TM L 2,3 -edge, trying to obtain a quantitative understanding of the data. The method was first systematically explored through application to a model system in order to test the feasibility of the technique and to understand of how X-ray optical effects have to be taken into account. Two more complex systems were investigated; stripe order in La 1.8 Sr 0.2 NiO 4 and charge and orbital order in Fe 3 O 4 . The main focus of the work was on the spectroscopic potential of the technique, trying to obtain a level of quantitative description of the data. For X-ray absorption spectroscopy (XAS) from transition metal oxides, cluster configuration interaction calculation provides a powerful and realistic microscopic theory. In the frame work of this thesis cluster theory, considering explicit hybridization effects between the TM-ion and the surrounding oxygen ligands, has been applied for the first time to describe resonant diffraction data. (orig.)

Quantitative mineralogical analysis of sandstones using x-ray diffraction techniques

International Nuclear Information System (INIS)

Ward, C.R.; Taylor, J.C.

1999-01-01

Full text: X-ray diffraction has long been used as a definitive technique for mineral identification based on the measuring the internal atomic or crystal structures present in powdered rocks; soils and other mineral mixtures. Recent developments in data gathering and processing, however, have provided an improved basis for its use as a quantitative tool, determining not only the nature of the minerals but also the relative proportions of the different minerals present. The mineralogy of a series of sandstone samples from the Sydney and Bowen Basins of eastern Australia has been evaluated by X-ray diffraction (XRD) on a quantitative basis using the Australian-developed SIROQUANT data processing technique. Based on Rietveld principles, this technique generates a synthetic X-ray diffractogram by adjusting and combining full-profile patterns of minerals nominated as being present in the sample and interactively matches the synthetic diffractogram under operator instructions to the observed diffractogram of the sample being analysed. The individual mineral patterns may be refined in the process, to allow for variations in crystal structure of individual components or for factors such as preferred orientation in the sample mount. The resulting output provides mass percentages of the different minerals in the mixture, and an estimate of the error associated with each individual percentage determination. The chemical composition of the mineral mixtures indicated by SIROQUANT for each individual sandstone studied was estimated using a spreadsheet routine, and the indicated proportion of each oxide in each sample compared to the actual chemical analysis of the same sandstone as determined independently by X-ray fluorescence spectrometry. The results show a high level of agreement for all major chemical constituents, indicating consistency between the SIROQUANT XRD data and the whole-rock chemical composition. Supplementary testing with a synthetic corundum spike further

Non-Destructive Quantification of Plastic Deformation in Steel: Employing X-Ray Diffraction Peak Broadening Analysis

Science.gov (United States)

2013-09-01

justifier l’élaboration d’une nouvelle analyse des pics de DRX dans les installations de RDDC Atlantique. Résultats : Plusieurs auteurs se sont penchés...2 3 X-Ray Diffraction Theory ...3 X-Ray Diffraction Theory The manifestation of desirable physical and chemical material properties may be readily discerned through investigation

X-ray absorption spectroscopy and neutron diffraction study of the perovskite-type rare-earth cobaltites

Science.gov (United States)

Sikolenko, V.; Efimova, E.; Franz, A.; Ritter, C.; Troyanchuk, I. O.; Karpinsky, D.; Zubavichus, Y.; Veligzhanin, A.; Tiutiunnikov, S. I.; Sazonov, A.; Efimov, V.

2018-05-01

Correlations between local and long-range structure distortions in the perovskite-type RE1-xSrxCoO3-δ (RE = La, Pr, Nd; x = 0.0 and 0.5) compounds have been studied at room temperature by extended X-ray absorption fine structure (EXAFS) at the Co K-edge and high-resolution neutron powder diffraction (NPD). The use of two complementary experimental techniques allowed us to explore the influence of the type of rare-earth element and strontium substitution on unusual behavior of static and dynamic features of both the Co-O bond lengths.

X-ray optics and X-ray microscopes: new challenges

International Nuclear Information System (INIS)

Susini, J.

2004-01-01

main fields of applications are driven by the unique attributes of X-ray microscopy in the multi-keV energy range: i) access to K-absorption edges and fluorescence emission lines of medium-light elements and L,M - edges of heavy materials for micro-spectroscopy (e.g. XANES), chemical or trace element mapping ii) higher penetration depths compared to soft X-rays allowing imaging of thicker samples, iii) favorable wavelengths for diffraction studies and iv) generally large focal lengths and depths of focus which are advantageous for the use of specific sample environments (high pressure, controlled temperatures....). Typical experiments can be broadly divided into two categories: i) morphological studies which require high spatial resolution and are therefore well adapted to 2D or 3D transmission full-field microscopy. ii) studies dealing with co-localization and/or speciation of trace elements in heterogeneous matrices at the micron scale. Following a brief account on the basic principles and methods, strengths and weaknesses of X-ray microscopy and spectro-microscopy techniques in the 1 - 30 keV range will be discussed and illustrated by examples of applications. The main technical developments, involving new focusing lenses or novel phase contrast geometry, will be presented. (author)

Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

Science.gov (United States)

Tsujino, Soichiro; Tomizaki, Takashi

2016-05-01

Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinning of the crystal within a levitating droplet ensured an efficient sampling of the reciprocal space. The datasets were processed with a program suite developed for serial femtosecond crystallography (SFX). The structure, which was solved by molecular replacement, was found to be identical to the structure obtained by the conventional oscillation method for up to a 1.8-Å resolution limit. In particular, the absence of protein crystal damage resulting from the acoustic levitation was carefully established. These results represent a key step towards a fully automated sample handling and measurement pipeline, which has promising prospects for a high acquisition rate and high sample efficiency for room temperature X-ray crystallography.

Characterization of nanophase materials by x-ray diffraction and computer simulation

International Nuclear Information System (INIS)

Eastman, J.A.; Thompson, L.J.

1989-06-01

X-ray diffraction experiments on nanophase Pd have been performed with the primary goal of determining the nature of grain boundary structures in nanophase materials. A kinematical diffraction analysis has been developed to interpret x-ray θ--2θ data by comparing actual scans with scans produced by computer simulation. This simulation program has been used to explore the effects on diffracted intensity of a variety of microstructural and grain boundary structural parameters such as void concentration, grain size, grain boundary width, and changes in interplanar spacing and density in grain boundary regions. It has been found that a reasonable match to experimental data is produced by at least two model structures; in one, the material contains randomly positioned voids or vacancies, while in the other, the interplanar spacings in grain boundary regions are varied with respect to the spacings found in the grain interiors. 7 refs., 4 figs

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

Science.gov (United States)

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

2010-01-01

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

New structural studies of liquid crystal by reflectivity and resonant X-ray diffraction; Nouvelles etudes structurales de cristaux liquides par reflectivite et diffraction resonante des rayons X

Energy Technology Data Exchange (ETDEWEB)

Fernandes, P

2007-04-15

This memory presents three structural studies of smectic Liquid Crystals by reflectivity and resonant diffraction of X-rays. It is divided in five chapters. In the first a short introduction to Liquid Crystals is given. In particular, the smectic phases that are the object of this study are presented. The second chapter is consecrated to the X-ray experimental techniques that were used in this work. The three last chapters present the works on which this thesis can be divided. Chapter three demonstrates on free-standing films of MHPOBC (historic liquid crystal that possesses the antiferroelectric sub-phases) the possibility to extend the technique of resonant X-ray diffraction to liquid crystals without resonant element. In the fourth chapter the structure of the B{sub 2} liquid crystal phase of bent-core molecules (or banana molecules) is elucidated by using resonant X-ray diffraction combined with polarization analysis of the diffracted beam. A model of the polarization of the resonant beam diffracted by four different structures proposed for the B{sub 2} phase is developed in this chapter. In the fifth chapter a smectic binary mixture presenting a very original critical point of phase separation is studied by X-ray reflectivity and optical microscopy. A concentration gradient in the direction perpendicular to the plane of the film seems to be induced by the free-standing film geometry. The results of a simplified model of the system are compatible with this interpretation.

X-ray diffraction study of thermal stress relaxation in ZnO films deposited by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Conchon, F. [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Renault, P.O., E-mail: pierre.olivier.renault@univ-poitiers.f [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Le Bourhis, E.; Krauss, C.; Goudeau, P. [Institut P' , Universite de Poitiers-Ensma-UPR CNRS 3346, 86962 Futuroscope (France); Barthel, E.; Grachev, S. Yu.; Sondergard, E. [Lab. Surface du Verre et Interfaces (SVI), UMR 125, 93303 Aubervilliers (France); Rondeau, V.; Gy, R. [Lab. Recherche de Saint-Gobain (SGR), 93303 Aubervilliers (France); Lazzari, R.; Jupille, J. [Institut des Nanosciences de Paris (INSP), UMR 7588, 75015 Paris (France); Brun, N. [Lab. Physique des Solides (LPS), UMR 8502, 91405 Orsay (France)

2010-12-30

X-ray diffraction stress analyses have been performed on two different thin films deposited onto silicon substrate: ZnO and ZnO encapsulated into Si{sub 3}N{sub 4} layers. We showed that both as-deposited ZnO films are in a high compressive stress state. In situ X-ray diffraction measurements inside a furnace revealed a relaxation of the as-grown stresses at temperatures which vary with the atmosphere in the furnace and change with Si{sub 3}N{sub 4} encapsulation. The observations show that Si{sub 3}N{sub 4} films lying on both sides of the ZnO film play an important role in the mechanisms responsible for the stress relaxation during heat treatment. The different temperatures observed for relaxation in ambient and argon atmospheres suggest that the thermally activated stress relaxation may be attributed to a variation of the stoichiometry of the ZnO films. The present observations pave the way to fine tuning of the residual stresses through thermal treatment parameters.

The comparative study of contents of zinc and lead in ore samples of Namtu-Bawdwin Mine by wet analysis, X-ray fluorescence and X-ray diffraction methods

Energy Technology Data Exchange (ETDEWEB)

Kyaw-Soe,

1990-05-01

Lead-zinc ores taken from Namtu-Bawdwin area had been analyzed by wet processes in the Department of Chemistry, 1984. These ore samples have been analyzed by energy dispersive X-ray fluorescence method in the Department of Physics and X-ray diffraction method is also used to determine elements of lead and zinc compounds in these ore samples in the University`s Research Centre. In brief, we study comparatively the contents of lead and zinc and their compounds using the methods of wet processes, X-ray fluorescence and X-ray diffraction. (author).

Measurements of transient electron density distributions by femtosecond X-ray diffraction; Messungen transienter Elektronendichteverteilungen durch Femtosekunden-Roentgenbeugung

Energy Technology Data Exchange (ETDEWEB)

Freyer, Benjamin

2013-05-02

This thesis concerns measurements of transient charge density maps by femtosecond X-ray diffraction. Different X-ray diffraction methods will be considered, particularly with regard to their application in femtosecond X-ray diffraction. The rotation method is commonly used in stationary X-ray diffraction. In the work in hand an X-ray diffraction experiment is demonstrated, which combines the method with ultrafast X-ray pulses. This experiment is the first implementation which makes use of the rotation method to map transient intensities of a multitude of Bragg reflections. As a prototype material Bismuth is used, which previously was studied frequently by femtosecond X-ray diffraction by measuring Bragg reflections successively. The experimental results of the present work are compared with the literature data. In the second part a powder-diffraction experiment will be presented, which is used to study the dynamics of the electron-density distribution on ultrafast time scales. The experiment investigates a transition metal complex after photoexcitation of the metal to ligand charge transfer state. Besides expected results, i. e. the change of the bond length between the metal and the ligand and the transfer of electronic charge from the metal to the ligand, a strong contribution of the anion to the charge transfer was found. Furthermore, the charge transfer has predominantly a cooperative character. That is, the excitation of a single complex causes an alteration of the charge density of several neighboring units. The results show that more than 30 transition-metal complexes and 60 anions contribute to the charge transfer. This collective response is a consequence of the strong coulomb interactions of the densely packed ions.

Photoemission measurements for low energy x-ray detector applications

International Nuclear Information System (INIS)

Day, R.H.

1981-01-01

Photoemission has been studied for nearly 100 years as both a means of investigating quantum physics, and as a practical technique for transducing optical/x-ray photons into electrical currents. Numerous x-ray detection schemes, such as streak cameras and x-ray sensitive diodes, exploit this process because of its simplicity, adaptability, and speed. Recent emphasis on diagnostics for low temperature, high density, and short-lived, plasmas for inertial confinement fusion has stimulated interest in x-ray photoemission in the sub-kilovolt regime. In this paper, a review of x-ray photoemission measurements in the 50 eV to 10 keV x-ray region is given and the experimental techniques are reviewed. A semiempirical model of x-ray photoemission is discussed and compared to experimental measurements. Finally, examples of absolutely calibrated instruments are shown

Advanced x-ray stress analysis method for a single crystal using different diffraction plane families

International Nuclear Information System (INIS)

Imafuku, Muneyuki; Suzuki, Hiroshi; Sueyoshi, Kazuyuki; Akita, Koichi; Ohya, Shin-ichi

2008-01-01

Generalized formula of the x-ray stress analysis for a single crystal with unknown stress-free lattice parameter was proposed. This method enables us to evaluate the plane stress states with any combination of diffraction planes. We can choose and combine the appropriate x-ray sources and diffraction plane families, depending on the sample orientation and the apparatus, whenever diffraction condition is satisfied. The analysis of plane stress distributions in an iron single crystal was demonstrated combining with the diffraction data for Fe{211} and Fe{310} plane families

Nondestructive strain depth profiling with high energy X-ray diffraction: System capabilities and limitations

Science.gov (United States)

Zhang, Zhan; Wendt, Scott; Cosentino, Nicholas; Bond, Leonard J.

2018-04-01

Limited by photon energy, and penetration capability, traditional X-ray diffraction (XRD) strain measurements are only capable of achieving a few microns depth due to the use of copper (Cu Kα1) or molybdenum (Mo Kα1) characteristic radiation. For deeper strain depth profiling, destructive methods are commonly necessary to access layers of interest by removing material. To investigate deeper depth profiles nondestructively, a laboratory bench-top high-energy X-ray diffraction (HEXRD) system was previously developed. This HEXRD method uses an industrial 320 kVp X-Ray tube and the Kα1 characteristic peak of tungsten, to produces a higher intensity X-ray beam which enables depth profiling measurement of lattice strain. An aluminum sample was investigated with deformation/load provided using a bending rig. It was shown that the HEXRD method is capable of strain depth profiling to 2.5 mm. The method was validated using an aluminum sample where both the HEXRD method and the traditional X-ray diffraction method gave data compared with that obtained using destructive etching layer removal, performed by a commercial provider. The results demonstrate comparable accuracy up to 0.8 mm depth. Nevertheless, higher attenuation capabilities in heavier metals limit the applications in other materials. Simulations predict that HEXRD works for steel and nickel in material up to 200 µm, but experiment results indicate that the HEXRD strain profile is not practical for steel and nickel material, and the measured diffraction signals are undetectable when compared to the noise.

Slow scan sit detector for x-ray diffraction studies using synchrotron radiation

International Nuclear Information System (INIS)

Milch, J.R.

1978-01-01

A TV-type x-ray detector using a SIT vidicon has been used for biological diffraction studies at the EMBL outstation at DESY, Hamburg, Germany. The detector converts the two-dimensional diffraction pattern to a charge pattern on the vidicon target, which is read out in the slow-scan mode. This detector has high DOE, no count-rate limit, and is simple and inexpensive to construct. Radiation from the storage ring DORIS was used to study the structure of live muscle at various phases of contraction. Typically the count-rate on the detector was 10 6 x-rays/sec and a total exposure of a few seconds was needed to record the weak diffraction from muscle. This compares with usual exposure times of several hours using a rotating anode generator and film

High temperature behavior of eucryptite by means of in situ X ray diffraction studies; Comportamiento de la eucriptita a alta temperatura mediante estudio in situ por difraccion de Rayos X

Energy Technology Data Exchange (ETDEWEB)

Garcia-Moreno, O.; Khainakov, S.; Torrecillas, R.

2012-11-01

Eucryptite is a lithium aluminosilicate with striking thermal expansion properties: it has negative expansion, i. e. it contracts upon heating in one of its crystallographic dimensions. Due to this characteristic, eucryptite is used in the fabrication of very low coefficient of thermal expansion materials. Two different eucryptite solid solution compositions were synthesized in this study with Li{sub 2}O:Al{sub 2}O{sub 3}:SiO{sub 2} contents of 1:1:3 and 1:1:2. The synthesis was prepared using kaolinite, lithium carbonate and TEOS and o {gamma} Al{sub 2}O{sub 3}, respectively. High resolution X Ray diffraction characterization was performed at high temperature for both compositions between 25 and 1200 degree centigrade. The temperature effect on structure and composition was studied by determining cell parameters and crystal structures. The relation between the observed changes and the CTE variations with the sintering temperature of materials based in these compositions was finally determined. (Author) 19 refs.

MSL Chemistry and Mineralogy X-Ray Diffraction X-Ray Fluorescence (CheMin) Instrument

Science.gov (United States)

Zimmerman, Wayne; Blake, Dave; Harris, William; Morookian, John Michael; Randall, Dave; Reder, Leonard J.; Sarrazin, Phillipe

2013-01-01

This paper provides an overview of the Mars Science Laboratory (MSL) Chemistry and Mineralogy Xray Diffraction (XRD), X-ray Fluorescence (XRF) (CheMin) Instrument, an element of the landed Curiosity rover payload, which landed on Mars in August of 2012. The scientific goal of the MSL mission is to explore and quantitatively assess regions in Gale Crater as a potential habitat for life - past or present. The CheMin instrument will receive Martian rock and soil samples from the MSL Sample Acquisition/Sample Processing and Handling (SA/SPaH) system, and process it utilizing X-Ray spectroscopy methods to determine mineral composition. The Chemin instrument will analyze Martian soil and rocks to enable scientists to investigate geophysical processes occurring on Mars. The CheMin science objectives and proposed surface operations are described along with the CheMin hardware with an emphasis on the system engineering challenges associated with developing such a complex instrument.

X-ray diffraction investigation of self-annealing in nanocrystalline copper electrodeposits

DEFF Research Database (Denmark)

Pantleon, Karen; Somers, Marcel A. J.

2006-01-01

X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multip...... twinning during self-annealing. The kinetics of self-annealing depends on the layer thickness as well as on the orientation and/or the size of the as-deposited crystallites. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.......X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multiple...

High pressure in-situ X-ray diffraction study on Zn-doped magnetite nanoparticles

Science.gov (United States)

Ferrari, S.; Bilovol, V.; Pampillo, L. G.; Grinblat, F.; Errandonea, D.

2018-03-01

We have performed high pressure synchrotron X-ray powder diffraction experiments on two different samples of Zn-doped magnetite nanoparticles (formula Fe(3-x)ZnxO4; x = 0.2, 0.5). The structural behavior of then a noparticles was studied up to 13.5 GPa for x = 0.2, and up to 17.4 GPa for x = 0.5. We have found that both systems remain in the cubic spinel structure as expected for this range of applied pressures. The analysis of the unit cell volume vs. pressure results in bulk modulus values lower than in both end-members, magnetite (Fe3O4) and zinc ferrite (ZnFe2O4), suggesting that chemical disorder may favor compressibility, which is expected to improve the increase of the Neel temperature under compression.

X-ray fluorescence holography.

Science.gov (United States)

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

2012-03-07

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

X-ray fluorescence holography

International Nuclear Information System (INIS)

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu Wen; Matsushita, Tomohiro

2012-01-01

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy. (topical review)

Submicron x-ray diffraction and its applications to problems in materials and environmental science

Science.gov (United States)

Tamura, N.; Celestre, R. S.; MacDowell, A. A.; Padmore, H. A.; Spolenak, R.; Valek, B. C.; Meier Chang, N.; Manceau, A.; Patel, J. R.

2002-03-01

The availability of high brilliance third generation synchrotron sources together with progress in achromatic focusing optics allows us to add submicron spatial resolution to the conventional century-old x-ray diffraction technique. The new capabilities include the possibility to map in situ, grain orientations, crystalline phase distribution, and full strain/stress tensors at a very local level, by combining white and monochromatic x-ray microbeam diffraction. This is particularly relevant for high technology industry where the understanding of material properties at a microstructural level becomes increasingly important. After describing the latest advances in the submicron x-ray diffraction techniques at the Advanced Light Source, we will give some examples of its application in material science for the measurement of strain/stress in metallic thin films and interconnects. Its use in the field of environmental science will also be discussed.

Submicron X-Ray Diffraction and its Applications to Problems in Materials and Environmental Science

Energy Technology Data Exchange (ETDEWEB)

Patel, J. R.

2002-08-16

The availability of high brilliance 3rd generation synchrotron sources together with progress in achromatic focusing optics allow to add submicron spatial resolution to the conventional century-old X-ray diffraction technique. The new capabilities include the possibility to map in-situ, grain orientations, crystalline phase distribution and full strain/stress tensors at a very local level, by combining white and monochromatic X-ray microbeam diffraction. This is particularly relevant for high technology industry where the understanding of material properties at a microstructural level becomes increasingly important. After describing the latest advances in the submicron X-ray diffraction techniques at the ALS, we will give some examples of its application in material science for the measurement of strain/stress in metallic thin films and interconnects. Its use in the field of environmental science will also be discussed.

Submicron X-ray diffraction and its applications to problems in materials and environmental science