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1

EFFECT OF SATELLITE LINES FROM X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS  

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. PA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predict...

2

Spatial super-resolution for line parallel imaging in energy dispersive X-ray diffraction  

E-print Network

Spatial super-resolution for line parallel imaging in energy dispersive X-ray diffraction Ferr茅ol V茅lizy cedex Abstract We present a proof of concept for a new approach for Energy Dispersive X Ray of a collimated poly-chromatic X-ray source and a collimated spectroscopic detector D placed at angle from

Boyer, Edmond

3

X-Ray Diffraction.  

ERIC Educational Resources Information Center

Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

Smith, D. K.; Smith, K. L.

1980-01-01

4

X-Ray Diffraction  

NSDL National Science Digital Library

This site from the University of London presents a tutorial on several methods of X-ray diffraction, including the powder, rotating crystal, and Laue methods Each section includes interactive Java applets, exercises, and links to a glossary of terms.

Matter.org

5

X-ray Diffraction  

NSDL National Science Digital Library

A series of laboratory activities on x-ray diffraction physics using the Teltron Tel-X-Ometer System. Detailed explanations on the production and delivery of the beam is included, as well as a very complete safety protocol for conducting the experiments.

Langan, Shawn

2012-03-08

6

Ultrafast X-ray diffraction  

Microsoft Academic Search

This study presents recent developments and applications of ultrafast X-ray diffraction. These include optical pump\\/X-ray probe experiments for performing ultrafast X-ray spectroscopy, time-resolved X-ray diffraction for the investigation of electronically induced solid-liquid phase transformations in semiconductors, and time-resolved X-ray diffraction for monitoring the rapid changes of the atomic configuration associated with the lattice waves.

D. von der Linde; K. Sokolowski-Tinten

2003-01-01

7

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

NASA Astrophysics Data System (ADS)

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, tungsten and rhodium targets were investigated with different window materials for -30kV to -100kV applied potential. Heat loading and thermal management of the target has been investigated computationally using COMSOL code package, and experimental measurements of target temperature rise was taken via thermocouples attached to the target. Temperature measurements for low voltage, low current regime without active cooling were compared to computational results for code-experiment benchmarking. Two different phantoms were used in the simulation of DEI images, which showed that the designed x-ray source with DEI setup could produce images with significant improved contrast. The computational results, along with experimental measurements on the prototype setup, indicate the possibility of scale up to larger area x-ray source adequate for DEI applications.

Wang, Xiaoqin

8

THE EFFECT OF SATELLITE LINES FROM THE X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS  

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...

9

In-line holography and coherent diffractive imaging with x-ray waveguides  

SciTech Connect

A Fresnel coherent diffraction imaging experiment with hard x rays is here presented, using two planar crossed waveguides as optical elements, leading to a virtual pointlike source. The coherent wave field obtained with this setup is used to illuminate a micrometric single object having the shape of a butterfly. A digital two-dimensional in-line holographic reconstruction of the unknown object at low resolution (200 nm) has been obtained directly via fast Fourier transform (FFT) of the raw data. The object and its twin image are well separated because suitable geometrical conditions are satisfied. A good estimate of the incident wave field phase has been extracted directly from the FFT of the raw data. A partial object reconstruction with 50 nm spatial resolution was achieved by fast iterative phase retrieval, the major limitation for a full reconstruction being the nonideal structure of the guided beam. The method offers a route for fast and reliable phase retrieval in x-ray coherent diffraction.

De Caro, L.; Giannini, C.; Guagliardi, A. [Istituto di Cristallografia, Consiglio Nazionale delle Ricerche (IC-CNR), via Amendola 122/O, I-70126 Bari (Italy); Pelliccia, D. [Dipartimento di Fisica, Universita di Roma 'La Sapienza' and INFN Sezione Roma 1, Roma (Italy); Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche (IFN-CNR), via Cineto Romano 42, I-00156 Roma (Italy); Mocuta, C.; Metzger, T. H. [ESRF, Boite Postale 220, F-38043 Grenoble Cedex (France); Cedola, A.; Burkeeva, I.; Lagomarsino, S. [Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche (IFN-CNR), via Cineto Romano 42, I-00156 Roma (Italy)

2008-02-15

10

X-Ray Diffraction Apparatus  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

11

THE CHARACTERIZATION OF A SOLID SORBENT WITH CRYSTALLITE SIZE AND STRAIN DATA FROM X-RAY DIFFRACTION LINE BROADENING  

EPA Science Inventory

The paper gives results of the characterization of a solid sorbent with crystallite size and strain data from x-ray diffraction line broadening, as part of an EPA investigation of the injection of dry Ca(OH)2 into coal-fired electric power plant burners for the control of SO2 emi...

12

In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite-cementite microstructure in steel  

E-print Network

In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite-dependent electrical properties of ferroelectric BaTi2O5 single crystal J. Appl. Phys. 109, 024107 (2011) Improved;In-line X-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite

van Vliet, Lucas J.

13

Structural Transitions of NiMn Precipitation Nanostructures as Determined by X-ray Diffraction Line Broadening and M鰏sbauer Spectroscopy  

NASA Astrophysics Data System (ADS)

Structural transitions of nanometer-sized NiMn preprecipitates during isothermal aging of Fe-Ni-Mn alloys have been faintly indicated by the measurement of hardness and electrical resistivity changes. It is shown that a precise measurement of X-ray diffraction (XRD) line breadths in association with M鰏sbauer spectroscopy aims a better understanding of the structural transition of the precipitation nanostructures. Changes in the XRD line breadths clearly identified three stages corresponding to the stimulated clustering of solute elements, the formation of Guinier-Preston (GP) zones and subsequent transformation to the second-phase precipitates. Effective hardening takes place when preliminary solute clusters evolve to paramagnetic GP zones.

Movaghar Garabagh, Mohamad Reza; Hossein Nedjad, Syamak

2015-01-01

14

Diffraction line-profile shape by synchrotron and laboratory x-ray sources* Davor Balzar `Jo,Peter W. Stephens 2,and Hassel Ledbetter 1  

E-print Network

Diffraction line-profile shape by synchrotron and laboratory x-ray sources* Davor Balzar `Jo Department, Ruder Bo&ovic Institute, P.O. Box 1016, 10001 Zagreb, Croatia ABSTRACT We compared diffraction-line profiles obtained at the X3Bl NSLS powder-diffraction beamline and with a standard CuKa,,, sealed source

Balzar, Davor

15

X-ray diffraction line profile analysis of deformation microstructure in boron modified Ti-6Al-4V alloy  

SciTech Connect

X-ray diffraction line profile analysis (XRDLPA) techniques have been applied to investigate the deformed microstructure of a recently developed boron modified two-phase titanium alloy Ti-6Al-4V. The alloy was hot compressed at 750 deg. C up to 50% height reduction at two different strain rates (10{sup -3} S{sup -1} and 1 S{sup -1}). Microstructural parameters like average domain size, average microstrain within the domain and dislocation density of the two phases were determined using X-ray diffraction line profile analysis. The results indicate an increase in the microstrain and dislocation density for the {alpha}-phase and decrease for the {beta}-phase in the case of boron modified alloys as compared to the normal material. Microstructural modifications viz. the grain refinement and the presence of hard, brittle TiB particles in the case of boron modified alloy are held responsible for the observed difference in the dislocation density. - Research Highlights: {yields} Microstructural examination of hot compressed Ti64 with and without boron addition by XRDLPA. {yields} Smaller average domain size in alpha-phase compared to the corresponding alpha-phase in all cases. {yields} Higher microstrain and dislocation density for {alpha} phase and lower for {beta} phase in case of Ti64+B. {yields} Decrease in domain size while increase in micro-strain and dislocation density with strain rate. {yields} Strain accumulation around TiB particles responsible for high dislocation density in {alpha} phase.

Sarkar, Apu; Roy, Shibayan; Suwas, Satyam, E-mail: satyamsuwas@materials.iisc.ernet.in

2011-01-15

16

In-Line Monitoring of Fab Processing Using X-Ray Diffraction  

NASA Astrophysics Data System (ADS)

As the materials shift that started with Cu continues to advance in the semiconductor industry, new issues related to materials microstructure have arisen. While x-ray diffraction (XRD) has long been used in development applications, in this paper we show that results generated in real time by a unique, high throughput, fully automated XRD metrology tool can be used to develop metrics for qualification and monitoring of critical processes in current and future manufacturing. It will be shown that these metrics provide a unique set of data that correlate to manufacturing issues. For example, ionized-sputtering is the current deposition method of choice for both the Cu seed and TaNx/Ta barrier layers. The alpha phase of Ta is widely used in production for the upper layer of the barrier stack, but complete elimination of the beta phase requires a TaNx layer with sufficient N content, but not so much as to start poisoning the target and generating particle issues. This is a well documented issue, but traditional monitoring by sheet resistance methods cannot guarantee the absence of the beta phase, whereas XRD can determine the presence of even small amounts of beta. Nickel silicide for gate metallization is another example where monitoring of phase is critical. As well being able to qualify an anneal process that gives only the desired NiSi phase everywhere across the wafer, XRD can be used to determine if full silicidation of the Ni has occurred and characterize the crystallographic microstructure of the Ni to determine any effect of that microstructure on the anneal process. The post-anneal nickel silicide phase and uniformity of the silicide microstructure can all be monitored in production. Other examples of the application of XRD to process qualification and production monitoring are derived from the dependence of certain processes, some types of defect generation, and device performance on crystallographic texture. The data presented will show that CMP dishing problems could be traced to texture of the barrier layer and mitigated by adjusting the barrier process. The density of pits developed during CMP of electrochemically deposited (ECD) Cu depends on the fraction of (111) oriented grains. It must be emphasized that the crystallographic texture is not only a key parameter for qualification of high yielding and reliable processes, but also serves as a critical parameter for monitoring tool health. The texture of Cu and W are sensitive not only to deviations in performance of the tool depositing or annealing a particular film, but also highly sensitive to the texture of the barrier underlayers and thus any performance deviations in those tools. The XRD metrology tool has been designed with production monitoring in mind and has been fully integrated into both 200 mm and 300 mm fabs. Rapid analysis is achieved by using a high intensity fixed x-ray source, coupled with a large area 2D detector. The output metrics from one point are generated while the tool is measuring a subsequent point, giving true on-the-fly analysis; no post-processing of data is necessary. Spatial resolution on the wafer surface ranging from 35 ?m to 1 mm is available, making the tool suitable for monitoring of product wafers. Typical analysis times range from 10 seconds to 2 minutes per point, depending on the film thickness and spot size. Current metrics used for process qualification and production monitoring are phase, FWHM of the primary phase peaks (for mean grain size tracking), and crystallographic texture.

Gittleman, Bruce; Kozaczek, Kris

2005-09-01

17

Time-resolved x-ray diffraction with subpicosecond x-ray pulses  

Microsoft Academic Search

The emission from plasmas created with fs-lasers provides sub-picosecond x-ray pulses in the keV-range. Intense emission of K(alpha) lines as well as quasi continuum x-rays can be used for time-resolved diffraction and spectroscopy, i.e. to study lattice or atomic dynamics with sub-picosecond resolution by using a laser pump x-ray probe technique. The x-ray yield and x-ray pulse duration of the

Ingo Uschmann; Eckhart Foerster; Paul Gibbon; Christian Reich; Thomas Feurer; Andreas Morak; Roland A. Sauerbrey; Antoine Rousse; Patrick Audebert; Jean-Paul Geindre; Jean-Claude J. Gauthier

2001-01-01

18

X-ray Diffraction (XRD) 1.0 What is X-ray Diffraction  

E-print Network

X-ray Diffraction (XRD) 路 1.0 What is X-ray Diffraction 路 2.0 Basics of Crystallography 路 3.0 Production of X-rays 路 4.0 Applications of XRD 路 5.0 Instrumental Sources of Error 路 6.0 Conclusions #12 why the cleavage faces of crystals appear to reflect X-ray beams at certain angles of incidence (theta

Moeck, Peter

19

Polymorphic transformation of L-glutamic acid monitored using combined on-line video microscopy and X-ray diffraction  

NASA Astrophysics Data System (ADS)

Enhancement of process monitoring for detecting transformations of the organic solid state is an important, strategic area currently of substantial interest particularly to the pharmaceutical sector and, more generally, manufacturers of speciality chemical products. A feasibility study is reported in which a solution-mediated polymorphic transformation of L-glutamic acid (LGA) was monitored using, concurrently, both video microscopy accompanied by advanced image processing and, on-line X-ray diffraction. The applicability of these monitoring approaches, applied individually, has been demonstrated previously; however, it was useful to assess the relative sensitivity of the two techniques by their direct comparison, via simultaneous use, during application on-line to monitor a polymorphic transformation process. It was found that the onset of the polymorphic transformation, manifested as the point in time when crystals of the ? phase of LGA were first detected, was elucidated as being significantly sooner via video microscopy. This reflects the fact that the concentration regimes of maximum sensitivity for the individual approaches are complementary, hence video microscopy provides considerable added-value allowing detection of the early stages of the transformation process. Currently, the upper bound on solids concentration that is compatible with extracting useful information about the phase composition using video microscopy, based on particle shape, is restricted. However, it is anticipated that improvements to both the experimental design and the image processing algorithms applied will substantially increase this upper bound allowing practical application under realistic processing conditions.

Dharmayat, Spoorthi; Calderon De Anda, Jorge; Hammond, Robert B.; Lai, Xaiojun; Roberts, Kevin J.; Wang, Xue Z.

2006-08-01

20

Beyond hard x-ray photoelectron spectroscopy: Simultaneous combination with x-ray diffraction  

SciTech Connect

Hard x-ray photoelectron spectroscopy (HAXPES) is a powerful and novel emerging technique for the nondestructive determination of electronic properties and chemical composition of bulk, buried interfaces and surfaces. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons, increasing the information depth up to several tens of nanometers. Complementing HAXPES with an atomic structure sensitive technique (such as x-ray diffraction) opens a new research field with major applications for materials science. At SpLine, the Spanish CRG beamline at the European Synchrotron Radiation Facility, we have developed a novel experimental set-up that combines HAXPES and x-ray diffraction (x-ray reflectivity, surface x-ray diffraction, grazing incidence x-ray diffraction, and reciprocal space maps). Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a robust 2S + 3D diffractometer hosting a ultrahigh vacuum chamber equipped with a unique photoelectron spectrometer (few eV < electron kinetic energy < 15 keV), x-ray tube (Mg/Ti), 15 keV electron gun, and auxiliary standard surface facilities (molecular beam epitaxy evaporator, ion gun, low energy electron diffraction, sample heating/cooling system, leak valves, load-lock sample transfer, etc.). This end-station offers the unique possibility of performing simultaneous HAXPES + x-ray diffraction studies. In the present work, we describe the experimental set-up together with two experimental examples that emphasize its outstanding capabilities: (i) nondestructive characterization of the Si/Ge and HfO{sub 2}/SiO{sub 2} interfaces on Ge-based CMOS devices, and (ii) strain study on La{sub 0.7}Ca{sub 0.3}MnO{sub 3} ultrathin films grown on SrTiO{sub 3}(001) substrate.

Rubio-Zuazo, Juan; Castro, German R. [SpLine, Spanish CRG beamline at the European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France) and ICMM-CSIC Cantoblanco, E-28049 Madrid (Spain)

2013-05-15

21

Single Particle X-ray Diffractive Imaging  

SciTech Connect

In nanotechnology, strategies for the creation and manipulation of nanoparticles in the gas phase are critically important for surface modification and substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified the capability of single-shot imaging of nanoscale objects at sub-optical resolutions beyond the radiation-induced damage threshold. By intercepting electrospray-generated particles with a single 15 femtosecond soft-X-ray pulse, we demonstrate diffractive imaging of a nanoscale specimen in free flight for the first time, an important step toward imaging uncrystallized biomolecules.

Bogan, M J; Benner, W H; Boutet, S; Rohner, U; Frank, M; Seibert, M; Maia, F; Barty, A; Bajt, S; Riot, V; Woods, B; Marchesini, S; Hau-Riege, S P; Svenda, M; Marklund, E; Spiller, E; Hajdu, J; Chapman, H N

2007-10-01

22

Polychromatic x-ray source for diffraction apparatus using polychromatic x-rays  

Microsoft Academic Search

A polychromatic x-ray source used in a polychromatic x-ray diffraction apparatus is described. The polychromatic x-rays are cast upon a sample to be analyzed, the energies of the x-rays diffracted from the crystallographic planes of the sample are measured and the physical properties of the sample are detected on the basis of the measured energies. The polychromatic x-ray source has

Y. Fukuda; S. Kusumoto; S. Nemoto; N. Sakurama

1981-01-01

23

X-ray Diffraction Practicals 1 Graphics Programs  

E-print Network

X-ray Diffraction Practicals 1 Graphics Programs that will read SHELX or CIF files J. Reibenspies, N. Bhuvanesh ver 1.0.0 #12;X-ray Diffraction Practicals 2 Free software. Gretep : Reads SHELX files-ray Diffraction Practicals 3 Examples Gretep #12;X-ray Diffraction Practicals 4 Balls and Sticks example #12;X

Meagher, Mary

24

Tomographic Femtosecond X-Ray Diffractive Imaging  

NASA Astrophysics Data System (ADS)

A method is proposed for obtaining three simultaneous projections of a target from a single radiation pulse, which also allows the relative orientation of successive targets to be determined. The method has application to femtosecond x-ray diffraction, and does not require solution of the phase problem. We show that the principal axes of a compact charge-density distribution can be obtained from projections of its autocorrelation function, which is directly accessible in diffraction experiments. The results may have more general application to time resolved tomographic pump-probe experiments and time-series imaging.

Schmidt, K. E.; Spence, J. C. H.; Weierstall, U.; Kirian, R.; Wang, X.; Starodub, D.; Chapman, H. N.; Howells, M. R.; Doak, R. B.

2008-09-01

25

X-ray diffraction without sample preparation  

NASA Astrophysics Data System (ADS)

The author has recently invented a novel X-ray diffraction (XRD) technique which exhibits almost complete insensitivity to the sample morphology. This unique property allows XRD analysis of rocks and regolith while avoiding the need for resourceintensive and technically-challenging lander/rover sample preparation and distribution systems. The technique implements energy-dispersive XRD (EDXRD) in a back-reflection geometry. The intrinsic geometry of the method and the simplicity inherent to EDXRD enables a compact lightweight instrument design with no moving parts, suitable for deployment on a robotic arm. Details of the concept are presented here, along with a method to uncover diffraction peaks which are otherwise obscured by fluorescence peaks.

Hansford, G. M.

2012-09-01

26

X-ray FE line studies  

NASA Technical Reports Server (NTRS)

We present the first broadband, moderate-resolution X-ray spectral observations of the Seyfert galaxies NGC 4151 and NGC 1068. The Seyfert 1 galaxy NGC 4151 is shown to have a complex X-ray spectrum with multiple components and a strong, intrinsically narrow Fe K emission line. The characteristics of the scattering medium of the Seyfert 2 galaxy NGC 1068 are determined using the very strong Fe line emission and the lack of features due to oxygen in the X-ray spectrum. The soft X-ray flux from Mrk 3 and Mrk 348 are consistent with that expected from electron scattered X-rays from an obscured Seyfert 1 nucleus. A survey of the X-ray properties of Seyfert 2 galaxies indicates that a substantial fraction may have column densities of about 10 exp 23, suggesting that NGC 1068 has an unusually thick obscuring torus.

Marshall, F. E.; Arnaud, K.; Boldt, E. A.; Holt, S. S.; Jahoda, K. M.; Kelley, R.; Mushotzky, R. F.; Netzer, H.; Petre, R.; Serlemitsos, P. J.

1992-01-01

27

Transient x-ray diffraction and its application to materials science and x-ray optics  

SciTech Connect

Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

1997-12-01

28

X-ray Diffraction Laboratory Department of Chemistry  

E-print Network

X-ray Diffraction Laboratory Department of Chemistry Texas A & M University College Station, Texas Phone : 979-845-9125 www.chem.tamu.edu/xray xray@tamu.edu X-rayDiffractionLaboratory Departmentof-ray diffraction analysis to the Texas A & M University system and to educate our students in the science

Meagher, Mary

29

Combined x-ray absorption spectroscopy and x-ray powder diffraction  

Microsoft Academic Search

The complementary nature of x-ray absorption fine structure (XAFS) spectroscopy and x-ray diffraction (XRD) is described. In particular XAFS records the local structure while XRD detects the long-range crystallinity enabling the heterogeneity of materials like single-phase catalysts to be explored. Both measurements can be combined to facilitate novel in situ experiments. We have used a horizontal energy dispersed x-ray beam

Andrew J. Dent; Gareth E. Derbyshire; G. N. Greaves; Christine A. Ramsdale; J. W. Couves; Richard Jones; C. R. Catlow; John M. Thomas

1991-01-01

30

Modeling of Transient X-ray Diffraction from X-ray and Laser Shocked Crystals  

Microsoft Academic Search

The diagnosis of shocked crystals by transient x-ray diffraction is of interest as it allows observation of material response on the lattice level. Recent experiments at LLNL utilising the Nova laser have generated shock waves of approximately 300-kbar in single crystal silicon by using x-rays from a hohlraum target as the drive. X-rays from a separate Ti target were used

J. S. Wark; N. C. Woolsey; B. A. Remington; D. H. Kalantar; J. Colvin; D. Griswold; R. Cauble; R. Lee; A. Hauer; G. A. Kyrala; T. Boehley; A. Rubenchik

1996-01-01

31

X-Ray Diffraction and Scattering Equipment and General Area Detector Diffraction System (GADDS)  

E-print Network

X-Ray Diffraction and Scattering Equipment and General Area Detector Diffraction System (GADDS) The materials characterization laboratory is equipped with state-of-the-art analytical x-ray diffraction, and structure refinement by the Rietveld method. Figure 1: State-of-the-art analytical x-ray diffraction

Gelfond, Michael

32

1. Diffraction and the X-Ray Powder Diffractometer  

E-print Network

1. Diffraction and the X-Ray Powder Diffractometer 1.1 Diffraction 1.1.1 Introduction to Diffraction Materials are made of atoms. Knowledge of how atoms are arranged into crystal structures experimental techniques, but most of them involve diffraction. To date, most of our knowledge about the spatial

33

X-ray powder diffraction study of polytetrafluoroethylene  

SciTech Connect

Samples of polytetrafluoroethylene were studied by X-ray diffraction. A quantitative X-ray powder diffraction analysis of three components of the polymer was performed for the first time. All samples of polytetrafluoroethylene were found to be three-phase and consist of one crystalline and two amorphous phases. One of the amorphous phases is composed of low-molecular-weight products. The structure of the latter phase was established for the first time by X-ray diffraction methods and computer simulation.

Lebedev, Yu. A., E-mail: y_levedev@mail.ru; Korolev, Yu. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation); Polikarpov, V. M. [Tambov State Technical University (Russian Federation); Ignat'eva, L. N. [Russian Academy of Sciences, Institute of Chemistry, Far East Division (Russian Federation); Antipov, E. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

2010-07-15

34

Multiwavelength Anomalous Diffraction at High X-Ray Intensity  

NASA Astrophysics Data System (ADS)

The multiwavelength anomalous diffraction (MAD) method is used to determine phase information in x-ray crystallography by employing anomalous scattering from heavy atoms. X-ray free-electron lasers (FELs) show promise for revealing the structure of single molecules or nanocrystals, but the phase problem remains largely unsolved. Because of the ultrabrightness of x-ray FEL, samples experience severe electronic radiation damage, especially to heavy atoms, which hinders direct implementation of MAD with x-ray FELs. Here, we propose a generalized version of MAD phasing at high x-ray intensity. We demonstrate the existence of a Karle-Hendrickson-type equation in the high-intensity regime and calculate relevant coefficients with detailed electronic damage dynamics of heavy atoms. The present method offers a potential for ab initio structural determination in femtosecond x-ray nanocrystallography.

Son, Sang-Kil; Chapman, Henry N.; Santra, Robin

2011-11-01

35

Diffraction enhanced X-ray imaging of mammals crystalline lens  

E-print Network

Diffraction enhanced X-ray imaging of mammals crystalline lens A. Antunes a,*, M.G. Ho篓nnicke b , A of the lens. In this work, internal structure of mammal lenses regarding the long-range ordering of the fibers: 07.85.Q; 87.59.Bh; 87.59.?e; 42.66.Ct Keywords: Diffraction enhanced X-ray imaging; Mammals

Morelh茫o, S茅rgio Luiz

36

X-ray diffraction assisted spectroscopy of Rydberg states  

SciTech Connect

X-ray diffraction combined with conventional spectroscopy could provide a powerful means to characterize electronically excited atoms and molecules. We demonstrate theoretically how x-ray diffraction from laser excited atoms can be used to determine electronic structure, including angular momentum composition, principal quantum numbers, and channel populations. A theoretical formalism appropriate for highly excited atoms, and easily extended to molecules, is presented together with numerical results for Xe and H atoms.

Kirrander, Adam [ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

2012-10-21

37

Residual stress measurement using X-ray diffraction  

E-print Network

-zero for the unit cell. By using a monochromatic x-ray beam of known wavelength and measuring the diffraction angle 2? , it is possible to determine interplanar spacing dhkl. This technique is the basis of structure analysis and of residual stress measurement... RESIDUAL STRESS MEASUREMENT USING X-RAY DIFFRACTION A Thesis by OSMAN ANDEROGLU Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

Anderoglu, Osman

2005-02-17

38

In-situ mechanical testing during X-ray diffraction  

SciTech Connect

Deforming metals during recording X-ray diffraction patterns is a useful tool to get a deeper understanding of the coupling between microstructure and mechanical behaviour. With the advances in flux, detector speed and focussing techniques at synchrotron facilities, in-situ mechanical testing is now possible during powder diffraction and Laue diffraction. The basic principle is explained together with illustrative examples.

Van Swygenhoven, Helena, E-mail: helena.vanswygenhoven@psi.ch; Van Petegem, Steven

2013-04-15

39

Transient x-ray diffraction to measure the dynamic response of shocked lithium fluoride single crystal  

NASA Astrophysics Data System (ADS)

Transient x-ray diffraction, also called time-resolved x-ray diffraction and dynamic x-ray diffraction, is one novel diagnostic technique for probing shocked solids. It can provide direct information about microscopic mechanisms governing shock-induced deformation and structural changes at atomistic scales with nanosecond and picoseconds resolution, and lately, it has become possible to measure the structure of transients with sub-picoseconds and sub-Angstrom resolution with the development of ultrafast lasers which can produce femtosecond electron and x-ray pulses in the form of characteristics emission lines as well as x-ray continua in the keV range. In this paper, we detect and measure directly the dynamic response of lithium fluoride single crystal shocked compressed by laser irradiation in SHENGUANG II. In our experiments, high-intensity lasers irradiated a thin Cu foil to generate helium-like rays as x-ray source. Film (IP--image plate) recorded x rays diffracted from multiple lattice planes both perpendicular and oblique angles to the shock loading direction [100]. We gained the diffraction signals of the lattice planes (200) shocked and unshocked, what's more, other lattices (113), (1-13). The positions of the diffraction lines associated with the (200) lattice plane indicated compression of the lattice along [100] direction by 13%. In the experiment, a large-angle detector consists of two films-one rectangular in shape,one triangular in shape that are positioned to record x rays diffracted from a shocked single crystal nearly within a full ? steradian. The experiment shows that transient x-ray diffraction can diagnose the dynamical response of solid with higher resolution.

Wang, Hai-rong; Ye, Yan; Yang, Qing-guo; Li, Mu; Xiao, Sha-li; Li, Ze-ren

2013-08-01

40

1. Diffraction and the X-Ray Powder Diffractometer . . . . . . . . 1 1.1 Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1  

E-print Network

Contents 1. Diffraction and the X-Ray Powder Diffractometer . . . . . . . . 1 1.1 Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1.1 Introduction to Diffraction . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1.2 Bragg Diffraction . . . . . . . . . . . . . . . . . 25 1.3.3 Monochromators, Filters, Mirrors

41

X-Ray Diffraction Microscopy of Magnetic Structures  

SciTech Connect

We report the first proof-of-principle experiment of iterative phase retrieval from magnetic x-ray diffraction. By using the resonant x-ray excitation process and coherent x-ray scattering, we show that linearly polarized soft x rays can be used to image both the amplitude and the phase of magnetic domain structures. We recovered the magnetic structure of an amorphous terbium-cobalt thin film with a spatial resolution of about 75 nm at the Co L{sub 3} edge at 778 eV. In comparison with soft x-ray microscopy images recorded with Fresnel zone plate optics at better than 25 nm spatial resolution, we find qualitative agreement in the observed magnetic structure.

Turner, J.; Lima, E.; Huang, X.; Krupin, O.; Seu, K.; Parks, D.; Kevan, S.; Kisslinger, K.; McNulty, I.; Gambino, R.; Mangin, S.; Roy, S. and Fischer, P.

2011-07-14

42

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

SciTech Connect

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.

Not Available

1992-02-01

43

Cryogenic X-ray diffraction microscopy for biological samples.  

PubMed

X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast. PMID:20365956

Lima, Enju; Wiegart, Lutz; Pernot, Petra; Howells, Malcolm; Timmins, Joanna; Zontone, Federico; Madsen, Anders

2009-11-01

44

Cryogenic X-Ray Diffraction Microscopy for Biological Samples  

NASA Astrophysics Data System (ADS)

X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.

Lima, Enju; Wiegart, Lutz; Pernot, Petra; Howells, Malcolm; Timmins, Joanna; Zontone, Federico; Madsen, Anders

2009-11-01

45

X-ray diffraction of lipid model membranes.  

PubMed

In this chapter the use of X-ray diffraction to study the structure of lyotropic phases and lipid model membranes is described. Determination of the phase symmetry and lattice parameters from small-angle X-ray scattering (SAXS), and of the nature of the hydrocarbon chain packing from wide-angle X-ray scattering (WAXS), are discussed. Methods by which the sign of the interfacial curvature of non-lamellar phases may be determined are then presented. Finally, the calculation of electron density profiles from the intensities of the observed Bragg peaks is described, for the lamellar phase and for the inverse hexagonal phase. PMID:25331138

Tyler, Arwen I I; Law, Robert V; Seddon, John M

2015-01-01

46

Fabrication of diffraction grating for X-ray Talbot interferometer  

Microsoft Academic Search

Imaging technology using the phase data attracts attention from many researchers as the observation technique of a biomechanical\\u000a material. We produced a diffraction grating for obtaining high-resolution phase data. We designed the new process flow and\\u000a developed the fabrication technique composed of MEMS technology, X-ray lithography, and micro electroplating. The X-ray lithography\\u000a process was performed using the NewSUBARU synchrotron radiation

Masatake Matsumoto; Kinji Takiguchi; Makoto Tanaka; Yoichi Hunabiki; Hiroaki Takeda; Atsushi Momose; Yuichi Utsumi; Tadashi Hattori

2007-01-01

47

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

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

48

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPUSERFD form that can be accessed by the X-ray diffraction webpage. RESPONSIBILITY: The X-ray Diffraction and suggestions in a timely manner. MATERIALS: 路 Computer Database 路 Web interface #12;X-ray Diffraction

Meagher, Mary

49

X-ray server : an outline resource for simulations of x-ray diffraction and scattering.  

SciTech Connect

X-ray Server is a public project operational at the APS since 1997 with the goals to explore novel network technologies for providing wide scientific community with access to personal research results, establishing scientific collaborations, and refining scientific software. The Server provides Web-based access to a number of programs developed by the author in the field of X-ray diffraction and scattering. The software code operates directly on the Server available for use without downloading. Currently seven programs are accessible that have been used more than 85,000 times. This report discusses the Server philosophy, provides an overview of the physical models and algorithms beneath the codes and demonstrates some applications of the programs. It is shown with examples and statistics how the Server goals are achieved. The plans for further X-ray Server development are outlined.

Stepanov, S.; Biosciences Division

2004-01-01

50

Ultrafast x-ray diffraction of laser-irradiated crystals  

SciTech Connect

An apparatus has been developed for measuring time-dependent x-ray diffraction. X-ray pulses from an Advanced Light Source bend magnet are diffracted by a sagittally-focusing Si(111) crystal and then by a sample crystal, presently InSb(111). Laser pulses with 100 fs duration and a repetition rate of 1 KHz irradiate the sample inducing a phase transition. Two types of detectors are being employed: an x-ray streak camera and an avalanche photodiode. The streak camera is driven by a photoconductive switch and has a 2 ps temporal resolution determined by trigger jitter. The avalanche photodiode has high quantum efficiency and sufficient time resolution to detect single x-ray pulses in ALS two bunch or camshaft operation. A beamline is under construction dedicated for time resolved and micro-diffraction experiments. In the new beamline a toroidal mirror collects 3 mrad horizontally and makes a 1:1 image of the bend magnet source in the x-ray hutch. A laser induced phase transition has been observed in InSb occurring within 70 ps.

Heimann, P.A. [Lawrence Berkeley National Lab., CA (US). Advanced Light Source; Larsson, J. [Univ. of California, Berkeley, CA (US). Physics Dept.; Chang, Z. [Univ. of Michigan, Ann Arbor, MI (US). Center for Ultrafast Optical Science

1997-09-01

51

Remote X-Ray Diffraction and X-Ray Fluorescence Analysis on Planetary Surfaces  

NASA Technical Reports Server (NTRS)

The legacy of planetary X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) began in 1960 when W. Parish proposed an XRD instrument for deployment on the moon. The instrument was built and flight qualified, but the Lunar XRD program was cancelled shortly before the first human landing in 1969. XRF chemical data have been collected in situ by surface landers on Mars (Viking 1 & 2, Pathfinder) and Venus (Venera 13 & 14). These highly successful experiments provide critical constraints on our current understanding of surface processes and planetary evolution. However, the mineralogy, which is more critical to planetary surface science than simple chemical analysis, will remain unknown or will at best be imprecisely constrained until X-ray diffraction (XRD) data are collected. Recent progress in X-ray detector technology allows the consideration of simultaneous XRD (mineralogic analysis) and high-precision XRF (elemental analysis) in systems miniaturized to the point where they can be mounted on fixed landers or small robotic rovers. There is a variety of potential targets for XRD/XRF equipped landers within the solar system, the most compelling of which are the poles of the moon, the southern highlands of Mars and Europa.

Blake, David F.; DeVincenzi, D. (Technical Monitor)

1999-01-01

52

Diffraction and Imaging Study of Imperfections of Protein Crystals with Coherent X-rays  

NASA Technical Reports Server (NTRS)

High angular-resolution x-ray diffraction and phase contrast x-ray imaging were combined to study defects and perfection of protein crystals. Imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of a uniformly grown lysozyme crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in diffraction images. X-ray imaging and diffraction characterization of the quality of apoferritin crystals will also be discussed in the presentation.

Hu, Z. W.; Thomas, B. R.; Chernov, A. A.; Chu, Y. S.; Lai, B.

2004-01-01

53

X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications  

Microsoft Academic Search

This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely

Dip Narayan Mahato

2009-01-01

54

X-Ray Diffraction Project Final Report, Fiscal Year 2006  

SciTech Connect

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.

Dane V. Morgan

2006-10-01

55

Laboratory Manual 1.0.6 What is X-ray Diffraction?  

E-print Network

Laboratory Manual 1.0.6 Background What is X-ray Diffraction? X-rays scatter off of electrons, in a process of absorption and re-admission. Diffraction is the accumulative result of the x-ray scattering-rays in 1895 enabled scientists to probe crystalline structure at the atomic level. X-ray diffraction has been

Meagher, Mary

56

Laboratory Manual 1.0.7 What is X-ray Diffraction?  

E-print Network

Laboratory Manual 1.0.7 Background What is X-ray Diffraction? X-rays scatter off of electrons, in a process of absorption and re-admission. Diffraction is the accumulative result of the x-ray scattering-rays in 1895 enabled scientists to probe crystalline structure at the atomic level. X-ray diffraction has been

Meagher, Mary

57

Brown pelican eggshells: X-Ray diffraction studies  

Microsoft Academic Search

Summary X-ray diffraction studies of Brown Pelican eggshells from various localities in North America have shown that the crystalline shell material consists of three calcium carbonate polymorphs, calcite, aragonite and vaterite. The data suggest that thin eggshells show a high calcite to vaterite ratio compared with thicker Florida shells.

Robert W. Gould

1972-01-01

58

X-Ray Diffraction Simulation Using Laser Pointers and Printers.  

ERIC Educational Resources Information Center

Uses a laser pointer to demonstrate the analogy between optical and X-ray diffraction and a laser printer with 600 or 1200 dot resolution to create and modify arrays, print them on transparencies, and illuminate them with laser pointers. Includes 14 references. (Author/YDS)

Johnson, Neil E.

2001-01-01

59

Single photon energy dispersive x-ray diffraction  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

60

Single photon energy dispersive x-ray diffraction  

SciTech Connect

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.

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)] [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)] [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)] [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, California 94720 (United States)

2014-03-15

61

Single photon energy dispersive x-ray diffraction.  

PubMed

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. PMID:24689599

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

2014-03-01

62

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

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

63

X-ray diffraction from intact tau aggregates in human brain tissue  

SciTech Connect

We describe an instrument to record X-ray diffraction patterns from diseased regions of human brain tissue by combining an in-line visible light fluorescence microscope with an X-ray diffraction microprobe. We use thiazine red fluorescence to specifically label and detect the filamentous tau protein pathology associated with Pick's disease, as several laboratories have done previously. We demonstrate that thiazine red-enhanced regions within the tissue show periodic structure in X-ray diffraction, which is not observed in healthy tissue. One observed periodicity (4.2 {angstrom}) is characteristic of cross-beta sheet structure, consistent with previous results from powder diffraction studies performed on purified, dried tau protein.

Landahl, Eric C.; Antipova, Olga; Bongaarts, Angela; Barrea, Raul; Berry, Robert; Binder, Lester I.; Irving, Thomas; Orgel, Joseph; Vana, Laurel; Rice, Sarah E. (DePaul); (IIT); (NWU)

2011-09-15

64

Wavefront aberrations of x-ray dynamical diffraction beams.  

PubMed

The effects of dynamical diffraction in x-ray diffractive optics with large numerical aperture render the wavefront aberrations difficult to describe using the aberration polynomials, yet knowledge of them plays an important role in a vast variety of scientific problems ranging from optical testing to adaptive optics. Although the diffraction theory of optical aberrations was established decades ago, its application in the area of x-ray dynamical diffraction theory (DDT) is still lacking. Here, we conduct a theoretical study on the aberration properties of x-ray dynamical diffraction beams. By treating the modulus of the complex envelope as the amplitude weight function in the orthogonalization procedure, we generalize the nonrecursive matrix method for the determination of orthonormal aberration polynomials, wherein Zernike DDT and Legendre DDT polynomials are proposed. As an example, we investigate the aberration evolution inside a tilted multilayer Laue lens. The corresponding Legendre DDT polynomials are obtained numerically, which represent balanced aberrations yielding minimum variance of the classical aberrations of an anamorphic optical system. The balancing of classical aberrations and their standard deviations are discussed. We also present the Strehl ratio of the primary and secondary balanced aberrations. PMID:25322219

Liao, Keliang; Hong, Youli; Sheng, Weifan

2014-10-01

65

Fabrication of Diffraction Grating with High Aspect Ratio Using X-ray Lithography Technique for X-ray Phase Imaging  

NASA Astrophysics Data System (ADS)

The use of conventional X-ray radiography is limited due to weak absorption. This problem is resolved by using phase-sensitive imaging methods to improve the contrast, such as X-ray Talbot interferometry. With a spatially coherent light source and two diffraction gratings for Talbot interferometry, we measured the phase change differential. Using this technique, diffraction gratings were designed to have a fine high-accuracy high-aspect-ratio structure. Then, we fabricated a high-aspect-ratio diffraction grating using a deep X-ray lithography technique. A diffraction grating with a period of 8 ?m and a height of about 30 ?m was fabricated. This diffraction grating can be used for X-ray phase imaging for X-ray Talbot interferometry.

Noda, Daiji; Tanaka, Makoto; Shimada, Kazuma; Hattori, Tadashi

2007-02-01

66

Discovery and development of x-ray diffraction  

NASA Astrophysics Data System (ADS)

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.

Jeong, Yeuncheol; Yin, Ming; Datta, Timir

2013-03-01

67

X-ray Diffraction from Membrane Protein Nanocrystals  

PubMed Central

Membrane proteins constitute >30% of the proteins in an average cell, and yet the number of currently known structures of unique membrane proteins is <300. To develop new concepts for membrane protein structure determination, we have explored the serial nanocrystallography method, in which fully hydrated protein nanocrystals are delivered to an x-ray beam within a liquid jet at room temperature. As a model system, we have collected x-ray powder diffraction data from the integral membrane protein Photosystem I, which consists of 36 subunits and 381 cofactors. Data were collected from crystals ranging in size from 100爊m to 2 ?m. The results demonstrate that there are membrane protein crystals that contain <100 unit cells (200 total molecules) and that 3D crystals of membrane proteins, which contain <200 molecules, may be suitable for structural investigation. Serial nanocrystallography overcomes the problem of x-ray damage, which is currently one of the major limitations for x-ray structure determination of small crystals. By combining serial nanocrystallography with x-ray free-electron laser sources in the future, it may be possible to produce molecular-resolution electron-density maps using membrane protein crystals that contain only a few hundred or thousand unit cells. PMID:21190672

Hunter, M.S.; DePonte, D.P.; Shapiro, D.A.; Kirian, R.A.; Wang, X.; Starodub, D.; Marchesini, S.; Weierstall, U.; Doak, R.B.; Spence, J.C.H.; Fromme, P.

2011-01-01

68

Exploration of crystal strains using coherent x-ray diffraction  

NASA Astrophysics Data System (ADS)

We measured coherent x-ray diffraction (CXD) on zeolite microcrystals in order to gain information on internal density distribution and to learn more about the strain developed during the synthesis and attachment process on the substrate. From the distortion and asymmetry of the diffraction pattern on the (020) Bragg peak, the strain field distribution is estimated. We inverted the diffraction patterns from a less strained crystal to obtain the three-dimensional image of the shape and internal strain fields using the error reduction and hybrid input-output phase retrieval algorithms. We also show a few examples of characteristic distortion modes relevant to CXD of zeolites.

Cha, Wonsuk; Song, Sanghoon; Jeong, Nak Cheon; Harder, Ross; Yoon, Kyung Byung; Robinson, Ian K.; Kim, Hyunjung

2010-03-01

69

X-ray line widths and coronal heating  

NASA Technical Reports Server (NTRS)

Preliminary results of spectroscopy and imaging of a solar active region and flare plasma in soft X-ray emission lines are presented. Observed X-ray line widths in a nonflaring active region are broader than the Doppler width corresponding to the local electron temperature. An analysis of 41 soft X-ray flares within a single active region reveals a preference for flares to occur at locations that already show enhanced X-ray emission and to favor magnetic complexity over high gradient. However, flares do not appear to be directly responsible for the heating and X-ray production of the active regions.

Acton, L. W.; Wolfson, C. J.; Joki, E. G.; Culhane, J. L.; Rapley, C. G.; Bentley, R. D.; Gabriel, A. H.; Phillips, K. J. H.; Hayes, R. W.; Antonucci, E.

1981-01-01

70

Pressure Dependence of Crystal Structure of AG2O by X-Ray Diffraction Measurement  

NASA Astrophysics Data System (ADS)

X-ray diffraction measurements have been performed on powder Ag2O prepared with different pressing pressure at 295 K. Integral breadth of Bragg lines increases with the increase of pressing pressure in the region of 0 to 30 MPa. Rietveld refinement analysis on the X-ray diffraction pattern of Ag2O was performed by assuming cubic cuprite type structure with the space group Pnbar{3}m. Integral breadth was analyzed by a theory which includes particle size and the strain effect. The increase of strain in Ag2O was found with the increase of pressure in the region of 0 to 30 MPa.

Wada, T.; Sakai, R.; Itakura, M.; Hayashi, Y.; Watanabe, M.; Makhsun; Sakuma, T.; Takahashi, H.; Danilkin, S. A.

2013-07-01

71

Coherent X-ray Diffraction Imaging of Zeolite Microcrystals  

SciTech Connect

We measured coherent x-ray diffraction (CXD), an emerging technique to obtain three-dimensional internal and external images of crystals, on ZSM-5 zeolite microcrystals to get internal density distribution and to map deformation field of strain. The experiments were performed at the beamline 34-ID-C in Advanced Photon Source at Argonne National Laboratory in the US. The CXD patterns of ZSM-5 zeolite microcrystals with sizes of 2 {mu}m by monochromatic coherent x-rays with energy of 9 keV were obtained under continuously surrounding and Bragg conditions as a function of temperature. The oversampled diffraction patterns are inverted to obtain three-dimensional images of the shapes and internal strain fields of zeolite microcrystals using phase retrieval algorithms of error reduction and a hybrid input-output method. The internal density and strain distribution as a function of temperature are discussed.

Cha, Wonsuk; Song, Sanghoon; Kim, Hyunjung [Department of Physics and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul (Korea, Republic of); Jeong, Nak Cheon; Yoon, Kyung Byung [Department of Chemistry, Sogang University, Seoul (Korea, Republic of); Harder, Ross; Robinson, Ian K. [Department of Physics and Astronomy, University College London, London (United Kingdom)

2009-04-19

72

Coherent X-ray Diffraction Imaging of Zeolite Microcrystals (abstract)  

NASA Astrophysics Data System (ADS)

We measured coherent x-ray diffraction (CXD), an emerging technique to obtain three-dimensional internal and external images of crystals, on ZSM-5 zeolite microcrystals to get internal density distribution and to map deformation field of strain. The experiments were performed at the beamline 34-ID-C in Advanced Photon Source at Argonne National Laboratory in the US. The CXD patterns of ZSM-5 zeolite microcrystals with sizes of 2 ?m by monochromatic coherent x-rays with energy of 9 keV were obtained under continuously surrounding and Bragg conditions as a function of temperature. The oversampled diffraction patterns are inverted to obtain three-dimensional images of the shapes and internal strain fields of zeolite microcrystals using phase retrieval algorithms of error reduction and a hybrid input-output method. The internal density and strain distribution as a function of temperature are discussed.

Cha, Wonsuk; Song, Sanghoon; Jeong, Nak Cheon; Yoon, Kyung Byung; Harder, Ross; Robinson, Ian K.; Kim, Hyunjung

2009-04-01

73

Devices for low frequency stroboscopic x-ray diffraction imaging  

NASA Astrophysics Data System (ADS)

Two stroboscopic shutters, adapted for the study of periodic phenomena in the 1-400 Hz range, were developed and tested. The principle, advantages and drawbacks of these devices are pointed out. Results obtained by x-ray diffraction imaging (topography) on a vibrating silicon crystal, and on the investigation of defects produced in KTiOPO4 by the application of an electric field, illustrate the possibilities of this stroboscopic imaging technique at low frequencies.

Lorut, F.; Pernot, E.; Pernot-Rejm醤kov, P.; Baruchel, J.

2003-05-01

74

Coherent x-ray diffraction from quantum dots  

SciTech Connect

Coherent x-ray diffraction is a new experimental method for studying perfect and imperfect crystals. Instead of incoherent averaging, a coherent sum of amplitudes produces a coherent diffraction pattern originating from the real space arrangement of the sample. We applied this method for studying quantum dot samples that were specially fabricated GeSi islands of nanometer size and in a regular array embedded into a Si substrate. A coherent beam was focused by special Kirkpatric-Baez optics to a micrometer size. In the experiment it was observed that such a microfocused coherent beam produced coherent diffraction pattern with Bragg spots and broad diffuse maxima. The diffuse peak breaks up into a fine speckle pattern. The grazing incidence diffraction pattern has a typical shape resulting from the periodic array of identical islands. We used this diffraction pattern to reconstruct the average shape of the islands using a model independent approach.

Vartanyants, I.A. [HASYLAB, DESY, Notkestr. 85, Hamburg D-22607 (Germany); Department of Physics, University of Illinois, 1110 W. Green St., Urbana, Illinois 61801 (United States); Robinson, I. K.; Onken, J.D.; Pfeifer, M.A.; Williams, G.J. [Department of Physics, University of Illinois, 1110 W. Green St., Urbana, Illinois 61801 (United States); Pfeiffer, F. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Metzger, H. [ESRF, BP 220, 38043 Grenoble (France); Zhong, Z. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Insitut fuer Hableiter-und Festkoeperphysik, Johannes Kepler Universitaet Linz, A-4040 Linz (Austria); Bauer, G. [Insitut fuer Hableiter-und Festkoeperphysik, Johannes Kepler Universitaet Linz, A-4040 Linz (Austria)

2005-06-15

75

Fabricating Blazed Diffraction Gratings by X-Ray Lithography  

NASA Technical Reports Server (NTRS)

Gray-scale x-ray lithography is undergoing development as a technique for fabricating blazed diffraction gratings. As such, gray-scale x-ray lithography now complements such other grating-fabrication techniques as mechanical ruling, holography, ion etching, laser ablation, laser writing, and electron-beam lithography. Each of these techniques offers advantages and disadvantages for implementing specific grating designs; no single one of these techniques can satisfy the design requirements for all applications. Gray-scale x-ray lithography is expected to be advantageous for making gratings on steeper substrates than those that can be made by electron-beam lithography. This technique is not limited to sawtooth groove profiles and flat substrates: various groove profiles can be generated on arbitrarily shaped (including highly curved) substrates with the same ease as sawtooth profiles can be generated on flat substrates. Moreover, the gratings fabricated by this technique can be made free of ghosts (spurious diffraction components attributable to small spurious periodicities in the locations of grooves). The first step in gray-scale x-ray lithography is to conformally coat a substrate with a suitable photoresist. An x-ray mask (see Figure 1) is generated, placed between the substrate and a source of collimated x-rays, and scanned over the substrate so as to create a spatial modulation in the exposure of the photoresist. Development of the exposed photoresist results in a surface corrugation that corresponds to the spatial modulation and that defines the grating surface. The grating pattern is generated by scanning an appropriately shaped x-ray area mask along the substrate. The mask example of Figure 1 would generate a blazed grating profile when scanned in the perpendicular direction at constant speed, assuming the photoresist responds linearly to incident radiation. If the resist response is nonlinear, then the mask shape can be modified to account for the nonlinearity and produce a desired groove profile. An example of grating grooves generated by this technique is shown in Figure 2. A maximum relative efficiency of 88 percent has been demonstrated.

Mouroulis, Pantazis; Hartley, Frank; Wilson, Daniel

2004-01-01

76

Borman effect in resonant diffraction of X-rays  

SciTech Connect

A dynamic theory of resonant diffraction (occurring when the energy of incident radiation is close to the energy of the absorption edge of an element in the composition of a given substance) of synchronous X-rays is developed in the two-wave approximation in the coplanar Laue geometry for large grazing angles in perfect crystals. A sharp decrease in the absorption coefficient in the substance with simultaneously satisfied diffraction conditions (Borman effect) is demonstrated, and the theoretical and first experimental results are compared. The calculations reveal the possibility of applying this approach in analyzing the quadrupole-quadrupole contribution to the absorption coefficient.

Oreshko, A. P., E-mail: ap.oreshko@physics.msu.ru [Moscow State University (Russian Federation)

2013-08-15

77

X-ray crystal spectroscopy with stationary-state single-crystal utilizing Laue diffraction  

Microsoft Academic Search

A new type of x-ray crystal spectrometry has been designed to characterize a hard x-ray spectrum of each pulse emission from a laser-induced plasma x-ray source. Utilizing the Laue diffraction and a two-dimensional detector, it makes possible the measurement of diffracted monochromatic x rays without any time difference using a single crystal in a stationary state. Thus, a hard x-ray

Kazumasa Honda; Tadayuki Ohchi; Isao Kojima; Shigeki Hayashi

2001-01-01

78

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPDATAP2. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

79

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPALIGNA data possible. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

80

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPABSSTR. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

81

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPDATAP1. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

82

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPDATGAD. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

83

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPDATSM1. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

84

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPLABSEC that will prevent unwanted access to X-ray diffraction laboratory by unauthorized users. POLICY: All entrance to the X-ray Diffraction Laboratory is controlled by magnetic ID cards issued by Texas A & M University

Meagher, Mary

85

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPPOWGAD AND PRECAUTIONS 1. Powder X-ray diffraction is a method by which investigators can identify the materials) guidelines pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor

Meagher, Mary

86

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPSAXSLA Rev;Operation of Siemens D-500 X-ray Diffractometers Approved :JHR 1/8/2009 路 The X-ray Diffraction Laboratory applicable training assignments in accordance the EHSO guidelines. #12;Xray Diffraction Laboratory: Texas

Meagher, Mary

87

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPALIGNS data possible. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

88

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPDATSMA. BACKGROUND AND PRECAUTIONS 1. Single-Crystal X-ray diffraction is a method by which investigators can pertaining to radiation producing devices. 路 The X-ray Diffraction Laboratory manager will monitor the proper

Meagher, Mary

89

Lattice Misfit Measurement in Inconel 625 BY X-Ray Diffraction Technique  

Microsoft Academic Search

Determination of lattice misfit and microstructural parameters of the coherent precipitates in Ni based alloy Inconel-625 is a challenging problem as the diffraction peaks of the precipitate and the matrix are completely overlapping. X-ray Diffraction Line Profile Analysis (XRDLPA) has been used to characterize the bulk samples of Inconel 625 at different heat-treated conditions to determine the lattice parameters of

A. Sarkar; P. Mukherjee; P. Barat; T. Jayakumar; S. Mahadevan; Sanjay K. Rai

2008-01-01

90

Low temperature x-ray diffraction study on phase transitions  

NASA Astrophysics Data System (ADS)

By using the low temperature x-ray diffraction (LTXD) we investigated several phase transitions which accompany with the crystal distortion. In our present report we will mainly discuss the integrated intensity (I.I.) of the x-ray spectrum. The temperature dependence of I.I can be expressed by the Debye-Waller factor. As a precursor effect of the crystal phase transition, the softening of the lattice occurs. Due to the softening of the lattice, the I.I drastically decreases down to the crystal phase transition temperature. We observed this effect in many materials. Here we will show some of them, iron pnictide superconductor SmFe0.925Co0.075AsO, and magnetic ordering compounds PrCu4Ag and Nd2Ti2O7.

Suzuki, H.; Kaneko, H.; Xue, Y.; Shumsun, N.; Savinkov, A.; Xing, H.; Xu, Z. A.; Zhang, S.; Isikawa, Y.

2012-12-01

91

Identifications studies of Lauha Bhasma by X-ray diffraction and X-ray fluorescence  

PubMed Central

Procedures for preparation of Lauha Bhasma are described in ancient texts of Ayurveda. These procedures also begin with different source material for iron such as Teekshna Lauha and Kanta Lauha etc. In the present study, we have selected different source materials viz. magnetite iron ore for Kanta Lauha and pure (Armco grade) iron turnings for Teekshna Lauha. The standard procedures of preparation of Lauha Bhasma are carried out in identical conditions for these two raw materials. The final product from the Puta are characterized by using X-ray diffraction and X-ray fluorescence spectroscopy to understanding the crystallographic form or forms of iron oxides and their composition at the end of each Puta. The iron content at the end of repeated Putas (18 for Kanta Lauha and 20 for Teekshna Lauha) have shown a decrease in case of Teekshna Lauha since the starting material is pure iron while it showed only marginal decreases in the case of Kanta Lauha because the Fe3O4 of magnetite is undergoing oxidation to Fe2O3. The trace elements remain within the Bhasma in the form of various oxides of Si, Al, Ca, etc. PMID:23049200

Bhargava, S. C.; Reddy, K. R. C; Sastry, G. V. S

2012-01-01

92

Identifications studies of Lauha Bhasma by X-ray diffraction and X-ray fluorescence.  

PubMed

Procedures for preparation of Lauha Bhasma are described in ancient texts of Ayurveda. These procedures also begin with different source material for iron such as Teekshna Lauha and Kanta Lauha etc. In the present study, we have selected different source materials viz. magnetite iron ore for Kanta Lauha and pure (Armco grade) iron turnings for Teekshna Lauha. The standard procedures of preparation of Lauha Bhasma are carried out in identical conditions for these two raw materials. The final product from the Puta are characterized by using X-ray diffraction and X-ray fluorescence spectroscopy to understanding the crystallographic form or forms of iron oxides and their composition at the end of each Puta. The iron content at the end of repeated Putas (18 for Kanta Lauha and 20 for Teekshna Lauha) have shown a decrease in case of Teekshna Lauha since the starting material is pure iron while it showed only marginal decreases in the case of Kanta Lauha because the Fe(3)O(4) of magnetite is undergoing oxidation to Fe(2)O(3). The trace elements remain within the Bhasma in the form of various oxides of Si, Al, Ca, etc. PMID:23049200

Bhargava, S C; Reddy, K R C; Sastry, G V S

2012-01-01

93

Scandium(III) hydration in aqueous solution from X-ray diffraction and X-ray absorption fine structure measurements  

NASA Astrophysics Data System (ADS)

Measurements of X-ray diffraction (XD) on 1 and 3 M Sc(CIO 4) 3 aqueous solutions and of X-ray absorption fine structure (XAFS) on a 4.6 M Sc(CF 3SO 3) 3 aqueous solution have been made at room temperature. Both the XD and XAFS data have revealed that about seven water molecules are bound to a Sc 3+ ion with a Sc 3+-H 2O distance of 2.18 . The results are discussed with those obtained by Raman spectroscopy and single crystal X-ray diffraction.

Yamaguchi, Toshio; Niihara, Mami; Takamuku, Toshiyuki; Wakita, Hisanobu; Kanno, Hitoshi

1997-08-01

94

DiffractX: A Simulation Toolbox for Diffractive X-ray Optics  

NASA Astrophysics Data System (ADS)

X-ray wavefront propagation is a powerful technique when simulating the performance of x-ray optical components. Using various numerical methods, interesting parameters such as focusing capability and efficiency can be investigated. Here we present the toolbox DiffractX, implemented in MATLAB. It contains many different wave propagation methods for the simulation of diffractive x-ray optics, including Fresnel propagation, the finite difference method (FDM), the thin object approximation, the rigorous coupled wave theory (RCWT), and the finite element method (FEM). All tools are accessed through a graphical interface, making the design of simulations fast and intuitive, even for users with little or no programming experience. The tools have been utilized to characterize realistic as well as idealized optical components. This will aid further developments of diffractive x-ray optics.

Selin, M.; Bertilson, M.; Nilsson, D.; von Hofsten, O.; Hertz, H. M.; Vogt, U.

2011-09-01

95

X-ray diffraction studies of shocked lunar analogs  

NASA Technical Reports Server (NTRS)

The X-ray diffraction experiments on shocked rock and mineral analogs of particular significance to lunar geology are described. Materials naturally shocked by meteorite impact, nuclear-shocked, or artificially shocked in a flat plate accelerator were utilized. Four areas were outlined for investigation: powder diffractometer studies of shocked single crystal silicate minerals (quartz, orthoclase, oligoclase, pyroxene), powder diffractometer studies of shocked polycrystalline monomineralic samples (dunite), Debye-Scherrer studies of single grains of shocked granodiorite, and powder diffractometer studies of shocked whole rock samples. Quantitative interpretation of peak shock pressures experienced by materials found in lunar or terrestrial impact structures is presented.

Hanss, R. E.

1979-01-01

96

Lanthanum indium oxide from X-ray powder diffraction.  

PubMed

LaInO(3), a promising ion conductor for a holistic solid oxide fuel cell, was synthesized by a solid-state reaction method. The structure was refined by the Rietveld method using X-ray powder diffraction data. The structure of LaInO(3) is distorted by the in-phase and antiphase tilting of oxygen octahedra in the a(+)b(-)b(-) system of the InO(6) polyhedra. In the Pmna space group, the In atom lies on an inversion centre and the La atom and one of the O atoms lie on a mirror plane. PMID:14671337

Park, Hyun Min; Lee, Hwack Joo; Park, Sang Hyun; Yoo, Han Ill

2003-12-01

97

X-ray diffraction of the calcified tissues in Polypterus  

Microsoft Academic Search

Summary牋Pyrolyzed scales, fin spines, and bone from the ray-finned bony fishPolypterus (Actinopterygii) showed two mineral phases on X-ray diffraction: hydroxyapatite (HA), Ca5(PO4)3OH, and whitlockite, Ca3(PO4)2. The ratio of HA\\/whitlockite varied with the structure (scale, spine, bone) within each individual fish. The relative proportions\\u000a of HA to whitlockite in pyrolyzed samples reflected the Ca\\/P ratio of the sample. Whitlockite appears after

D. K. Meinke; H. C. W. Skinner; K. S. Thomson

1979-01-01

98

The three dimensional X-ray diffraction technique  

SciTech Connect

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 are sketched. Examples of the use of the technique are given and future trends and developments are suggested. The primary aim of the paper is to give 3DXRD novices an easy introduction to the technique and to describe a way from a dream to reality and new results.

Jensen, D. Juul, E-mail: doje@dtu.dk [Danish Chinese Center for Nanometals, Materials Science and Advanced Characterization Section, Department of Wind Energy, Technical University of Denmark, Riso Campus (Denmark); Poulsen, H.F. [Department of Physics, Technical University of Denmark, Lyngby Campus (Denmark)] [Department of Physics, Technical University of Denmark, Lyngby Campus (Denmark)

2012-10-15

99

X -Ray Diffraction and Microhardness Studies of Tin Monoselenide  

NASA Astrophysics Data System (ADS)

Tin Monoselenide (SnSe) crystals have been grown by the Physical Vapour Deposition (PVD) method. X-ray diffraction studies were carried out on the as grown crystals and the lattice parameters were found to be a = 11.506 , b = 4.149 and c = 4.447 . The values were found to be comparable with that reported in the PDF card for SnSe. The microhardness of the crystals has been determined by using Vickers microhardness indenter.

Sreedevi, K. R.; Chandrasekharan, K. A.; Kunjomana, A. G.

2011-07-01

100

Anomalous X-ray Diffraction Studies for Photovoltaic Applications  

SciTech Connect

Anomalous X-ray Diffraction (AXRD) has become a useful technique in characterizing bulk and nanomaterials as it provides specific information about the crystal structure of materials. In this project we present the results of AXRD applied to materials for photovoltaic applications: ZnO loaded with Ga and ZnCo{sub 2}O{sub 4} spinel. The X-ray diffraction data collected for various energies were plotted in Origin software. The peaks were fitted using different functions including Pseudo Voigt, Gaussian, and Lorentzian. This fitting provided the integrated intensity data (peaks area values), which when plotted as a function of X-ray energies determined the material structure. For the first analyzed sample, Ga was not incorporated into the ZnO crystal structure. For the ZnCo{sub 2}O{sub 4} spinel Co was found in one or both tetrahedral and octahedral sites. The use of anomalous X-ray diffraction (AXRD) provides element and site specific information for the crystal structure of a material. This technique lets us correlate the structure to the electronic properties of the materials as it allows us to probe precise locations of cations in the spinel structure. What makes it possible is that in AXRD the diffraction pattern is measured at a number of energies near an X-ray absorption edge of an element of interest. The atomic scattering strength of an element varies near its absorption edge and hence the total intensity of the diffraction peak changes by changing the X-ray energy. Thus AXRD provides element specific structural information. This method can be applied to both crystalline and liquid materials. One of the advantages of AXRD in crystallography experiments is its sensitivity to neighboring elements in the periodic tables. This method is also sensitive to specific crystallographic phases and to a specific site in a phase. The main use of AXRD in this study is for transparent conductors (TCs) analysis. TCs are considered to be important materials because of their efficiency and low risk of environmental pollution. These materials are important to solar cells as a result of their remarkable combination of optical and electrical properties, including high electrical conductivity and high optical transparency in the spectrum of visible light. TCs provide a transparent window, which allows sunlight to pass through while also allowing electricity to conduct out of the cell. Spinel materials have the chemical form AB{sub 2}O{sub 4}, and are made of a face-centered cubic (FCC) lattice of oxygen anions and cations in specific interstitial sites. A normal spinel has all A cations on tetrahedral sites and B cations on octahedral sites. In contrast; an inverse spinel has the A and half of the B cations on octahedral sites and the other half of the B cations on tetrahedral sites; a mixed spinel lies between. In the spinel structure, 8 of 64 possible tetrahedral sites and 16 of 32 possible octahedral sites are filled. Normal spinels have particularly high conduction as the linear octahedral chains of B cations likely serve as conduction paths. In this paper we present how the data obtained with AXRD is used to analyze TCs properties as they apply to photovoltaic applications. One of the materials used for this analysis is zinc oxide. It has been loaded with 5% and 10% of Ga, which has an absorption edge of 10367 eV. The peak (100) was measured for the zinc oxide loaded with 10% Ga. In the case of 5% Ga, we measured peaks (100) and (101). With the information provided by the AXRD we can identify if Ga is being incorporated in the ZnO crystal structure. The analysis of 311 plane in the ZnCo{sub 2}O{sub 4} spinel shows if Co is in tetrahedral or octahedral site.

Not Available

2011-06-22

101

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

DOEpatents

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

Sommargren, Gary E. (Santa Cruz, CA); Weaver, H. Joseph (Livermore, CA)

1991-01-01

102

Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction Ferrol Souleza,b,1,  

E-print Network

Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction Ferr茅ol Souleza to restore energy dispersive X-ray diffraction (EDXRD) spectra and to extract diffraction peaks. It follows. It separates peaks due to the diffraction by crystalline material from a countinuous background. Tested on real

Paris-Sud XI, Universit茅 de

103

X-ray Diffraction Studies of Striated Muscles  

SciTech Connect

In this short review a number of recent X-ray diffraction results on the highly ordered striated muscles in insects and in bony fish have been briefly described. What is clear is that this technique applied to muscles which are amenable to rigorous analysis, taken together with related data from other sources (e.g. protein crystallography, biochemistry, mechanics, computer modelling) can provide not only the best descriptions yet available on the myosin head organisations on different myosin filaments in the relaxed state, but can also show the sequence of molecular events that occurs in the contractile cycle, and may also help to explain such phenomena as stretch-activation. X-ray diffraction is clearly an enormously powerful tool in studies of muscle. It has already provided a wealth of detail on muscle ultrastructure; it is providing ever more fascinating insights into molecular events in the 50-year old sliding filament mechanism, and there remains a great deal more potential that is as yet untapped.

Squire, J.M.; Knupp, C.; Roessle, M.; Al-Khayat, H.A.; Irving, T.C.; Eakins, F.; Mok, N.-S.; Harford, J.J.; Reedy, M.K. (IIT); (Duke); (ESRF); (ICL)

2006-04-24

104

CCMR: X-Ray Diffraction Studies of Pulsed Laser Deposition  

NSDL National Science Digital Library

Pulsed laser deposition is an extremely effective method of growing thin films of materials on substrates. In this particular experiment the deposition of various pervoskite molecules onto different substrates were monitored via x-ray diffraction from a synchrotron source. Molecular compounds that were chosen were CaTiO3, SrTiO3, and BaTiO3 due to there structural similarities and correspondingly different lattice constants. The lattice constants for CaTiO3, SrTiO3, and BaTiO3 are 3.80, 3.90, and 4.06 respectively. These materials all have the same valence structure. Based upon the intensities of the diffracted x-rays at the anti-Bragg peak position, the growth of the film was monitored on a monolayer by monolayer scale at 750癈. The film quality of CaTiO3 on SrTiO3 and BaTiO3 on SrTiO3 were compared to a homoepitaxial film of SrTiO3 to determine how the strain at the interface affected growth. It was determined that the tensilely strain film, CaTiO3, grew more smoothly than the ompressively strained material BaTiO3.

Ferguson, John

2004-08-17

105

Thermal X-Ray Line Emission from Accreting Black Holes  

E-print Network

We present model X-ray spectra of accreting black holes with advection-dominated accretion flows, paying attention to thermal emission lines from the hot plasma. We show that the Advanced X-ray Astrophysical Facility (AXAF) might be able to observe lines from X-ray binaries such as V404 Cyg in quiescence, the Galactic Center black hole Sagittarius A*, and the nuclei of nearby galaxies such as M87. Line intensities can provide new diagnostics to study the accreting plasma in these and related systems.

Ramesh Narayan; John Raymond

1998-11-25

106

A furnace to 1200 K for in situ heating x-ray diffraction, small angle x-ray scattering, and x-ray absorption fine structure experiments  

NASA Astrophysics Data System (ADS)

A furnace with a water-cooled outside shell has been assembled to do in situ x-ray diffraction (XRD), small angle x-ray scattering (SAXS), and x-ray absorption fine structure (XAFS) experiments. The details of the furnace are described in this paper. The in situ XRD, SAXS, and XAFS experiments during the heating process demonstrate that the available temperature range of this furnace is from room temperature to 1200 K with a temperature accuracy of 0.1 K. By using this furnace, in situ XRD, SAXS, and XAFS experimental techniques with temperature change can be easily combined together.

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

2008-12-01

107

Fabrication of X-ray Mask using Poly-Si Microstructure for Diffraction Grating  

Microsoft Academic Search

There is an X-ray Talbot interferometer in one of the imaging technology by X-ray phase information. A diffraction grating is necessary for a Talbot interferometer, but the manufacture is difficult. In this study, we decided to make a diffraction grating to use it for a Talbot interferometer in X-ray lithography. For the development of a fine and high-precision X-ray mask,

K. Shimada; H. Tsujii; D. Noda; T. Hattori

2007-01-01

108

Characterization of X-Ray Diffraction System with a Microfocus X-Ray Source and a Polycapillary Optic  

NASA Technical Reports Server (NTRS)

We present here an optimized microfocus x-ray source and polycapillary optic system designed for diffraction of small protein crystals. The x-ray beam is formed by a 5.5mm focal length capillary collimator coupled with a 40 micron x-ray source operating at 46Watts. Measurements of the x-ray flux, the divergence and the spectral characteristics of the beam are presented, This optimized system provides a seven fold greater flux than our recently reported configuration [M. Gubarev, et al., J. of Applied Crystallography (2000) 33, in press]. We now make a comparison with a 5kWatts rotating anode generator (Rigaku) coupled with confocal multilayer focusing mirrors (Osmic, CMF12- 38Cu6). The microfocus x-ray source and polycapillary collimator system delivers 60% of the x-ray flux from the rotating anode system. Additional ways to improve our microfocus x-ray system, and thus increase the x-ray flux will be discussed.

Gubarev, Mikhail; Marshall, Joy K.; Ciszak, Ewa; Ponomarev, Igor

2000-01-01

109

X-ray diffraction diagnostic design for the National Ignition Facility  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

110

Development of Coherent X-ray Diffraction Apparatus with Kirkpatrick-Baez Mirror Optics  

SciTech Connect

To realize coherent x-ray diffraction microscopy with higher spatial resolution, it is necessary to increase the density of x-ray photons illuminated onto the sample. In this study, we developed a coherent x-ray diffraction apparatus with Kirkpatrick-Baez mirror optics. By using mirrors fabricated by elastic emission machining, a high-density coherent x-ray beam was produced. In a demonstration experiment using a silver nanocube as a sample, a high-contrast coherent x-ray diffraction pattern was observed over a wide-q range. This proves that both the density and the degree of coherence of the focused beam were high.

Takahashi, Y. [Frontier Research Base for Global Young Researchers, Frontier Research Center, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Tsutsumi, R.; Mimura, H.; Matsuyama, S. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishino, Y. [Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021 (Japan); Ishikawa, T. [RIKEN SPring-8 Center, Kouto, Sayo, Sayo, Hyogo 679-5148 (Japan); Yamauchi, K. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Research Center for Ultra-precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2011-09-09

111

X-Ray Diffraction and Imaging Study of Imperfections of Crystallized Lysozyme with Coherent X-Rays  

NASA Technical Reports Server (NTRS)

Phase-sensitive x-ray diffraction imaging and high angular-resolution diffraction combined with phase contrast radiographic imaging are employed to characterize defects and perfection of a uniformly grown tetragonal lysozyme crystal in symmetric Laue case. The fill width at half-maximum (FWHM) of a 4 4 0 rocking curve measured from the original crystal is approximately 16.7 arcseconds, and defects, which include point defects, line defects, and microscopic domains, have been clearly observed in the diffraction images of the crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front, and they have been found to originate mostly at a central growth area and occasionally at outer growth regions. Individual point defects trapped at a crystal nucleus are resolved in the images of high sensitivity to defects. Slow dehydration has led to the broadening of the 4 4 0 rocking curve by a factor of approximately 2.4. A significant change of the defect structure and configuration with drying has been revealed, which suggests the dehydration induced migration and evolution of dislocations and lattice rearrangements to reduce overall strain energy. The sufficient details of the observed defects shed light upon perfection, nucleation and growth, and properties of protein crystals.

Hu, Zheng-Wei; Chu, Y. S.; Lai, B.; Cai, Z.; Thomas, B. R.; Chernov, A. A.

2003-01-01

112

Hard X-ray nanoimaging method using local diffraction from metal wire  

SciTech Connect

A simple hard X-ray imaging method achieving a high spatial resolution is proposed. Images are obtained by scanning a metal wire through the wave field to be measured and rotating the sample to collect data for back projection calculations; the local diffraction occurring at the edges of the metal wire operates as a narrow line probe. In-line holograms of a test sample were obtained with a spatial resolution of better than 100?nm. The potential high spatial resolution of this method is shown by calculations using diffraction theory.

Takano, Hidekazu, E-mail: htakano@sci.u-hyogo.ac.jp; Konishi, Shigeki; Shimomura, Sho; Azuma, Hiroaki; Tsusaka, Yoshiyuki; Kagoshima, Yasushi [Center for Novel Material Science under Multi-Extreme Conditions, Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan)

2014-01-13

113

Biological imaging by soft X-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

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-hydrated yeast indicate that the frozen specimens do not exhibit these changes even with doses as high as 5 x 109 Gray.

Shapiro, David

114

X-ray diffraction characterization of thin superconductive films  

SciTech Connect

The physical and mechanical properties of thin films are often different from the properties of bulk material and are dictated by the film/substrate orientation relationship, crystal anisotropy and crystalgraphic texture of the film. X-ray diffraction texture analysis provides information about preferential film growth and can be used for optimization of deposition parameters and prediction of properties of thin films. An x-ray back reflection technique using the Braga-Brentano geometry with experimental corrections for absorption and defocusing was used to study thin ceramic films deposited by combustion chemical vapor deposition (CCVD). The film/substrate orientation relationships of YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) superconducting thin films deposited via CCVD on single crystal MgO and polycrystalline silver substrates were studied. The as-deposited films on single crystal (100) MgO substrates showed strong preferential growth with the basal plane parallel to the substrate surface (c-axis up growth). Texture analysis showed two in-plane alignment orientations of the film with respect to the substrate, with YBCO [100] and [110] aligned with the [100] MgO substrate. YBCO films deposited on cold-rolled polycrystalline silver displayed c-axis up growth indicating that the orientation of the polycrystalline substrate (brass type texture) did not induce detectable in-plane preferential growth of the YBCO.

Kozaczek, K.J.; Watkins, T.R. [Oak Ridge National Lab., TN (United States); Book, G.W.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

1995-12-31

115

The first X-ray diffraction measurements on Mars.  

PubMed

The Mars Science Laboratory landed in Gale crater on Mars in August 2012, and the Curiosity rover then began field studies on its drive toward Mount Sharp, a central peak made of ancient sediments. CheMin is one of ten instruments on or inside the rover, all designed to provide detailed information on the rocks, soils and atmosphere in this region. CheMin is a miniaturized X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument that uses transmission geometry with an energy-discriminating CCD detector. CheMin uses onboard standards for XRD and XRF calibration, and beryl:quartz mixtures constitute the primary XRD standards. Four samples have been analysed by CheMin, namely a soil sample, two samples drilled from mudstones and a sample drilled from a sandstone. Rietveld and full-pattern analysis of the XRD data reveal a complex mineralogy, with contributions from parent igneous rocks, amorphous components and several minerals relating to aqueous alteration. In particular, the mudstone samples all contain one or more phyllosilicates consistent with alteration in liquid water. In addition to quantitative mineralogy, Rietveld refinements also provide unit-cell parameters for the major phases, which can be used to infer the chemical compositions of individual minerals and, by difference, the composition of the amorphous component. PMID:25485131

Bish, David; Blake, David; Vaniman, David; Sarrazin, Philippe; Bristow, Thomas; Achilles, Cherie; Dera, Przemyslaw; Chipera, Steve; Crisp, Joy; Downs, R T; Farmer, Jack; Gailhanou, Marc; Ming, Doug; Morookian, John Michael; Morris, Richard; Morrison, Shaunna; Rampe, Elizabeth; Treiman, Allan; Yen, Albert

2014-11-01

116

The first X-ray diffraction measurements on Mars  

PubMed Central

The Mars Science Laboratory landed in Gale crater on Mars in August 2012, and the Curiosity rover then began field studies on its drive toward Mount Sharp, a central peak made of ancient sediments. CheMin is one of ten instruments on or inside the rover, all designed to provide detailed information on the rocks, soils and atmosphere in this region. CheMin is a miniaturized X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument that uses transmission geometry with an energy-discriminating CCD detector. CheMin uses onboard standards for XRD and XRF calibration, and beryl:quartz mixtures constitute the primary XRD standards. Four samples have been analysed by CheMin, namely a soil sample, two samples drilled from mudstones and a sample drilled from a sandstone. Rietveld and full-pattern analysis of the XRD data reveal a complex mineralogy, with contributions from parent igneous rocks, amorphous components and several minerals relating to aqueous alteration. In particular, the mudstone samples all contain one or more phyllosilicates consistent with alteration in liquid water. In addition to quantitative mineralogy, Rietveld refinements also provide unit-cell parameters for the major phases, which can be used to infer the chemical compositions of individual minerals and, by difference, the composition of the amorphous component. PMID:25485131

Bish, David; Blake, David; Vaniman, David; Sarrazin, Philippe; Bristow, Thomas; Achilles, Cherie; Dera, Przemyslaw; Chipera, Steve; Crisp, Joy; Downs, R. T.; Farmer, Jack; Gailhanou, Marc; Ming, Doug; Morookian, John Michael; Morris, Richard; Morrison, Shaunna; Rampe, Elizabeth; Treiman, Allan; Yen, Albert

2014-01-01

117

Special properties of X-ray diffraction on carbon onions  

SciTech Connect

The kinematic theory of X-ray diffraction was applied to the study of the most intense Bragg's reflection observed for carbon onions. It was shown that the agreement with experimental data was attained using a convolution of a Lorentzian contour with regard to the distribution of onion sizes and of an asymmetric contour taking into account the fluctuations of intershell distances inside the particle. It can be assumed that the observed scatter in intershell distances indicates a nonequilibrium state of the internal configuration of onion shells. It appeared to be possible to estimate not only the average onion size, which exceeds the average size of pristine nanodiamonds that are used for onion preparation by annealing, but their size distribution function as well.

Yastrebov, S. G., E-mail: yastrebov@mail.ioffe.ru; Ivanov-Omskii, V. I. [Russian Academy of Sciences, Ioffe Physicotechnical Instutute (Russian Federation)

2007-12-15

118

CCMR: X-Ray Diffraction of Magnetic Tunnel Junctions  

NSDL National Science Digital Library

We examined CoFeB/MgO/CoFeB magnetic tunnel junctions with X-ray diffraction in order to determine the effects of anneal temperature, MgO growth type, and seed layer structure on electrode and tunnelbarrier crystallinity. For various sample structures and growth methods, we show electrode crystallinity and texturing improving with increasing anneal temperature, while MgO texturing peaks between 350 C and 400 C. We find the amount and texturing of electrode and barrier crystallinity varies widely with the MgO growth method, with electrode crystallization greatest in samples with MgO grown using ebeam evaporation. Finally, we report that for our sample structures, Ta/CuN seed layers promote the highest level of CoFeB electrode texturing.

Huang, Pinshane Y.

2007-08-29

119

High pressure X-ray diffraction study of tungsten disulfide  

NASA Astrophysics Data System (ADS)

Synchrotron X-ray diffraction was used in conjunction with a diamond anvil cell to investigate the properties of tungsten disulfide (WS2) to 25.5 GPa at room temperature. No pressure medium was used to generate hydrostatic pressure. No phase transformation was observed in the pressure range studied. By fitting the pressure-volume data to the third-order Birch-Murnaghan equation of state, the bulk modulus was determined to be K0T=611 GPa with its pressure derivative K?0T=9.00.3. It is also found that the c-direction of the hexagonal structure is much more compressible than the a-direction.

Selvi, Emre; Ma, Yanzhang; Aksoy, Resul; Ertas, Atila; White, Allen

2006-09-01

120

High pressure x-ray diffraction study of tungsten disulfide  

SciTech Connect

Synchrotron X-ray diffraction was used in conjunction with a diamond anvil cell to investigate the properties of tungsten disulfide (WS{sub 2}) to 25.5 GPa at room temperature. No pressure medium was used to generate hydrostatic pressure. No phase transformation was observed in the pressure range studied. By fitting the pressure-volume data to the third-order Birch-Murnaghan equation of state, the bulk modulus was determined to be K{sub 0T}=61{+-}1 GPa with its pressure derivative K{prime}{sub 0T}=9.0{+-}0.3. It is also found that the c-direction of the hexagonal structure is much more compressible than the a-direction.

Selvi,E.; Ma, Y.; Aksoy, R.; Ertas, A.; White, A.; Sandhu, J.

2006-01-01

121

Powder X-ray diffraction laboratory, Reston, Virginia  

USGS Publications Warehouse

The powder x-ray diffraction (XRD) laboratory is managed jointly by the Eastern Mineral and Environmental Resources and Eastern Energy Resources Science Centers. Laboratory scientists collaborate on a wide variety of research problems involving other U.S. Geological Survey (USGS) science centers and government agencies, universities, and industry. Capabilities include identification and quantification of crystalline and amorphous phases, and crystallographic and atomic structure analysis for a wide variety of sample media. Customized laboratory procedures and analyses commonly are used to characterize non-routine samples including, but not limited to, organic and inorganic components in petroleum source rocks, ore and mine waste, clay minerals, and glassy phases. Procedures can be adapted to meet a variety of research objectives.

Piatak, Nadine M.; Dulong, Frank T.; Jackson, John C.; Folger, Helen W.

2014-01-01

122

MULTI-PSF MODELLING FOR X-RAY DIFFRACTION PATTERN RECONSTRUCTION  

Microsoft Academic Search

In this paper, we present a point spread function (PSF) mod- elling technique to improve restoration of x-ray diffraction pattern (XRD). Different diffraction areas have different dis- tortion orientations due to diffuse light distortion (DLD). A new multiple PSF model is introduced and used to restore XRD data. Raw PSFs are collected from isolated spots from x-ray diffraction pattern in

Daan Zhu; Moe Razaz; Andrew Hemmnings; Binhai Wang

123

Spatially resolved soft X-ray spectrometry from single-image diffraction  

E-print Network

LETTERS Spatially resolved soft X-ray spectrometry from single-image diffraction M. PRAEGER1 *, A information spatially across an X-ray beam. As only a single diffraction image is required per measurement-spatial information was obtained through analysis of the diffraction pattern created by a nickel wire mesh inserted

Loss, Daniel

124

X-ray Diffraction / MSE 603 Spring 2002 Qun Shen / CHESS qs11@cornell.edu  

E-print Network

X-ray Diffraction / MSE 603 Spring 2002 Qun Shen / CHESS qs11@cornell.edu 1. X-ray production & basic properties 颅 common sources for diffraction experiments 颅 synchrotron radiation 颅 response to x. Diffraction from surface structures 颅 specular reflectivity 颅 crystal truncation rod (CTR) 颅 grazing incidence

Shen, Qun

125

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPPOWD8 Standard Operating Procedure Title: X-ray Powder Diffraction: D8 Advanced Rev No: Issue date: 1.001 12-ray Powder Diffraction: D8 Advanced PURPOSE: This Standard Operating Procedure (SOP) states

Meagher, Mary

126

Lattice Misfit Measurement in Inconel 625 BY X-Ray Diffraction Technique  

NASA Astrophysics Data System (ADS)

Determination of lattice misfit and microstructural parameters of the coherent precipitates in Ni based alloy Inconel-625 is a challenging problem as the diffraction peaks of the precipitate and the matrix are completely overlapping. X-ray Diffraction Line Profile Analysis (XRDLPA) has been used to characterize the bulk samples of Inconel 625 at different heat-treated conditions to determine the lattice parameters of the parent phase and also the coherent precipitates by the separation of the overlapping peaks. The lattice misfits of the coherent precipitates with the matrix and their microstructural parameters like size and strain have also been determined.

Sarkar, A.; Mukherjee, P.; Barat, P.; Jayakumar, T.; Mahadevan, S.; Rai, Sanjay K.

127

X-Ray Absorbed, Broad-Lined, Red AGN and the Cosmic X-Ray Background  

NASA Technical Reports Server (NTRS)

We have obtained XMM spectra for five red, 2MASS AGN, selected from a sample observed by Chandra to be X-ray bright and to cover a range of hardness ratios. Our results confirm the presence of substantial absorbing material in three sources which have optical classifications ranging from Type 1 to Type 2, with an intrinsically flat (hard) power law continuum indicated in the other two. The presence of both X-ray absorption and broad optical emission lines with the usual strength suggests either a small (nuclear) absorber or a favored viewing angle so as to cover the X-ray source but not the broad emission line region (BELR). A soft excess is detected in all three Type 1 sources. We speculate that this soft X-ray emission may arise in an extended region of ionized gas, perhaps linked with the polarized (scattered) light which is a feature of these sources. The spectral complexity revealed by XMM emphasizes the limitations of the low S/N Chandra data. Overall, the new XMM results strengthen our conclusions (Wilkes et al. 2002) that the observed X-ray continua of red AGN are unusually hard at energies greater than 2 keV. Whether due to substantial line-of-sight absorption or to an intrinsically hard or reflection-dominated spectrum, these 'red' AGN have an observed spectral form consistent with contributing significantly to the missing had absorbed population of the Cosmic X-ray Background (CXRB). When absorption and or reflection is taken into account, all these AGN have power law slopes typical of broad-line (Type 1) AGN (Gamma approximately 1.9). This appears to resolve the spectral paradox which for so long has existed between the CXRB and the AGN thought to be the dominant contributors. It also suggests two scenarios whereby Type 1 AGN/QSOs may be responsible for a significant fraction of the CXRB at energies above 2 keV: 1) X-ray absorbed AGN/QSOs with visible broad emission lines; 2) AGN/QSOs with complex spectra whose hardness greater than 2 keV is not detectable in the typically low S/N data of X-ray surveys. Even if absorption is present in only half of the population, the large number of 'red' AGN suggests a development of unification models, where the continuum source is surrounded, over a substantial solid angle, by the wind or atmosphere of an accretion disk/torus. X-ray observations of such AGN not only provide a check on the presence of absorption, but also a unique probe of the absorbing material. Improved information on their space density, in particular as a function of redshift, will soon be provided by Spitzer-Chandra wide area surveys, allowing better estimates of both the importance of red AGN to the full AGN population and their contribution to the CXRB.

Mushotzky, Richard (Technical Monitor); Wilkes, Belinda

2005-01-01

128

X-ray Diffraction Study of Molybdenum to 900 GPa  

NASA Astrophysics Data System (ADS)

Molybdenum (Mo) is a transition metal that is important as a high-pressure standard. Its equation of state, structure, and melting behavior have been explored extensively in both experimental and theoretical studies. Melting data up to the Mbar pressure region from static compression experiments in the diamond anvil cell [Errandonea et al. 2004] are inconsistent with shock wave sound velocity measurements [Hixson et al., 1989]. There are also conflicting reports as to whether body-centered cubic (BCC) Mo transforms to a face-centered cubic (FCC), hexagonal close packed (HCP) or double hexagonal close packed (DHCP) structure at either high pressure or high pressure and temperature conditions [Belonoshko et al. 2008, Mikhaylushkin et al., 2008 and Cazorla et al., 2008]. Recently, a phase transition from BCC to the DHCP phase at 660 GPa and 0 K was predicted using the particle swam optimization (PSO) method (Wang et al, 2013). Here we report an x-ray diffraction study of dynamically compressed molybdenum. Experiments were conducted using the Omega laser at the Laboratory for Laser Energetics at the University of Rochester. Mo targets were either ramp or shock compressed using a laser drive. In ramp loading, the sample is compressed sufficiently slowly that a shock wave does not form. This results in lower temperatures, keeping the sample in the solid state to higher pressures. X-ray diffraction measurements were performed using quasi-monochromatic x-rays from a highly ionized He-? Cu source and image plate detectors. Upon ramp compression, we found no evidence of phase transition in solid Mo up to 900 GPa. The observed peaks can be assigned to the (110) and (200) or (220) reflections of BCC Mo up to the highest pressure, indicating that Mo does not melt under ramp loading to maximum pressure reached. Under shock loading, we did not observe any evidence for the solid-solid phase transformation around 210 GPa as reported in previous work (Hixson et al, 1989). The BCC phase of Mo remained stable along the Hugoniot up to at least 350 GPa. Our observation of diffraction peaks from shocked Mo shows that Hugoniot does not cross the melting curve until at least this pressure. This indicates that previous diamond cell experiments (Errandonea et al., 2004) have underestimated the Mo melting curve. We acknowledge the Omega staff at LLE for their assistance, and the Target Engineering Team at LLNL for fabrication of the targets used in these experiments. The research was supported by NNSA/DOE through the National Laser Users' Facility Program under contracts DE-NA0000856 and DE-FG52-09NA29037. References: [1] R.S. Hixson, D.A. Boness, and J.W. Shaner, Phys. Rev. Lett., 62, 637 (1989). [2] D. Errandonea, B. Schwager, R. Ditz, C. Gessmann, R. Boehler, and M. Ross, Phys. Rev. B, 63, 132104 (2004). [3] A.B. Belonoshko, L. Burakovsky, S.P. Chen, B. Johansson, A.S. Mikhaylushkin, D.L. Preston, S.I. Simak, and D.C. Swift, Phys. Rev. Lett., 100, 135701 (2008). [4] C. Cazorla, D. Alf, and M.J. Gillan, Phys. Rev. Lett. 101, 049601 (2008). [5] A.S. Mikhaylushkin, S.I. Simak ,L. Burakovsky, S.P. Chen, B. Johansson, D.L. Preston, D.C. Swift, and A.B. Belonoshko Phys. Rev. Lett., 101, 049602 (2008). [6] B. Wang, G. Zhang, and Y. Wang, J. Alloys Compd., 556, 116-120, (2013).

Wang, J.; Coppari, F.; Smith, R.; Eggert, J.; Boehly, T.; Collins, G. W.; Duffy, T. S.

2013-12-01

129

Soft X-ray diffraction microscopy of a frozen hydrated yeast cell.  

PubMed

We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 degrees C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics. PMID:20365955

Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; Lima, Enju; Marchesini, Stefano; Miao, Huijie; Neiman, Aaron M; Shapiro, David; Steinbrener, Jan; Stewart, Andrew; Turner, Joshua J; Jacobsen, Chris

2009-11-01

130

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

SciTech Connect

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.

Schimpf, C., E-mail: schimpf@iww.tu-freiberg.de; Motylenko, M.; Rafaja, D.

2013-12-15

131

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

ERIC Educational Resources Information Center

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

Crouse, David T.

2007-01-01

132

IDENTIFICATION OF COMPOUNDS IN PARTICULATE POLLUTION BY X-RAY DIFFRACTION  

EPA Science Inventory

X-ray diffraction is a valuable tool for the identification of crystalline compounds in a multicomponent sample. Two x-ray diffraction techniques (Seeman-Bohlin and Bragg-Brentano) were examined for the identification of small amounts of material deposited on low-mass substrates....

133

X-ray diffraction study of crystalline barium titanate ceramics  

SciTech Connect

In this study, BaTiO{sub 3} ceramics have been prepared via solid-state reaction method. The powders were calcined for 2 hours at different temperatures ranging from 600癈 to 1200癈. Using X-ray diffraction with a Rietveld analysis, the phase formation and crystal structure of the BaTiO{sub 3} powders were studied. Change in crystallite size and tetragonality as a function of calcination temperature were also discussed. It has been found that the formation of pure perovskite phase of BaTiO{sub 3} began at calcination condition of 1000 癈 for 2 hours. The crystal structure of BaTiO{sub 3} formed is in the tetragonal structure. The second phases of BaCO{sub 3} and TiO{sub 2} existed with calcination temperature below 1000 癈. Purity, crystallite size and tetragonality of BaTiO{sub 3} powders were found to increase with increasing calcination temperature.

Zali, Nurazila Mat; Mahmood, Che Seman; Mohamad, Siti Mariam; Foo, Choo Thye; Murshidi, Julie Adrianny [Malaysian Nuclear Agency, Bangi, 43000 Kajang Selangor (Malaysia)

2014-02-12

134

Direct modeling of x-ray diffraction pattern from skeletal muscle in rigor.  

PubMed Central

Available high-resolution structures of F-actin, myosin subfragment 1 (S1), and their complex, actin-S1, were used to calculate a 2D x-ray diffraction pattern from skeletal muscle in rigor. Actin sites occupied by myosin heads were chosen using a "principle of minimal elastic distortion energy" so that the 3D actin labeling pattern in the A-band of a sarcomere was determined by a single parameter. Computer calculations demonstrate that the total off-meridional intensity of a layer line does not depend on disorder of the filament lattice. The intensity of the first actin layer A1 line is independent of tilting of the "lever arm" region of the myosin heads. Myosin-based modulation of actin labeling pattern leads not only to the appearance of the myosin and "beating" actin-myosin layer lines in rigor diffraction patterns, but also to changes in the intensities of some actin layer lines compared to random labeling. Results of the modeling were compared to experimental data obtained from small bundles of rabbit muscle fibers. A good fit of the data was obtained without recourse to global parameter search. The approach developed here provides a background for quantitative interpretation of the x-ray diffraction data from contracting muscle and understanding structural changes underlying muscle contraction. PMID:12124288

Koubassova, Natalia A; Tsaturyan, A K

2002-01-01

135

X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications  

NASA Astrophysics Data System (ADS)

This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely used in microbeam x-ray fluorescence analysis. In this thesis, their potential application to powder diffraction and focused beam orthovoltage cancer therapy has been investigated. In conventional x-ray therapy, very high energy ( MeV) beams are used, partly to reduce the skin dose. For any divergent beam, the dose is necessarily highest at the entry point, and decays exponentially into the tissue. To reduce the skin dose, high energy beams, which have long absorption lengths, are employed, and rotated about the patient to enter from different angles. This necessitates large expensive specialized equipment. A focused beam could concentrate the dose within the patient. Since this is inherently skin dose sparing, lower energy photons could be employed. A primary concern in applying focused beams to therapy is whether the focus would be maintained despite Compton scattering within the tissue. To investigate this, transmission and focal spot sizes as a function of photon energy of two polycapillary focusing lenses were measured. The effects of tissue-equivalent phantoms of different thicknesses on the focal spot size were studied. Scatter fraction and depth dose were calculated. For powder diffraction, the polycapillary optics provide clean Gaussian peaks, which result in angular resolution that is much smaller than the peak width due to the beam convergence. Powder diffraction (also called coherent scatter) without optics can also be used to distinguish between tissue types that, because they have different nanoscale structures, scatter at different angles. Measurements were performed on the development of coherent scatter imaging to provide tissue type information in mammography. Atomic coordinates from x-ray diffraction data were used to study the nuclear quadrupole interactions and nature of molecular binding in DNA/RNA nucleobases and molecular solid BF3 systems.

Mahato, Dip Narayan

136

High intensity line source for x-ray spectrometer calibration  

SciTech Connect

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

Thoe, R.S.

1986-06-01

137

Diffraction and imaging study of imperfections of crystallized lysozyme with coherent X-rays  

NASA Technical Reports Server (NTRS)

Phase-contrast X-ray diffraction imaging and high-angular-resolution diffraction combined with phase-contrast radiographic imaging were employed to characterize defects and perfection of a uniformly grown tetragonal lysozyme crystal in the symmetric Laue case. The full-width at half-maximum (FWHM) of a 4 4 0 rocking curve measured from the original crystal was approximately 16.7 arcsec and imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of the crystal. The observed line defects carry distinct dislocation features running approximately along the <1 1 0> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Inclusions of impurities or formations of foreign particles in the central growth region are resolved in the images with high sensitivity to defects. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in X-ray diffraction images. The details of the observed defects and the significant change in the revealed microstructures with drying provide insight into the nature of imperfections, nucleation and growth, and the properties of protein crystals.

Hu, Z. W.; Chu, Y. S.; Lai, B.; Thomas, B. R.; Chernov, A. A.

2004-01-01

138

In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries  

E-print Network

Information ABSTRACT: Rechargeable lithium-sulfur (Li-S) batteries hold great potential for high not well understood. In this Article, these changes in Li-S batteries are studied in operando by X understanding of the reaction mechanism is needed. However, previous X-ray studies of Li-S batteries have been

Cui, Yi

139

X-rayEmissionfromMassiveStars: UsingEmissionLineProfilestoConstrainWind  

E-print Network

X-rayEmissionfromMassiveStars: UsingEmissionLineProfilestoConstrainWind Kinematics Introduction:thecontextofhotstarX-rays Lineprofilediagnostics Whatdotheobservationslooklike? Whattrendsemerge? Pup:windX-rays,butlessabsorptionthanexpected OriandOri:similarsituation,verylittlewind absorption

Cohen, David

140

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

141

Lensless Diffractive Imaging Using Tabletop Coherent High-Harmonic Soft-X-Ray Beams  

SciTech Connect

We present the first experimental demonstration of lensless diffractive imaging using coherent soft x rays generated by a tabletop soft-x-ray source. A 29 nm high harmonic beam illuminates an object, and the subsequent diffraction is collected on an x-ray CCD camera. High dynamic range diffraction patterns are obtained by taking multiple exposures while blocking small-angle diffraction using beam blocks of varying size. These patterns reconstruct to images with 214 nm resolution. This work demonstrates a practical tabletop lensless microscope that promises to find applications in materials science, nanoscience, and biology.

Sandberg, Richard L.; Paul, Ariel; Raymondson, Daisy A.; Haedrich, Steffen; Gaudiosi, David M.; Holtsnider, Jim; Tobey, Ra'anan I.; Cohen, Oren; Murnane, Margaret M.; Kapteyn, Henry C.; Song, Changyong; Miao Jianwei; Liu Yanwei; Salmassi, Farhad [JILA and Department of Physics, University of Colorado and NSF Engineering Research Center in Extreme Ultraviolet Science and Technology, Boulder, Colorado 80309 (United States); Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2007-08-31

142

Analysis of diatomite sediments from a paleolake in central Mexico using PIXE, X-ray tomography and X-ray diffraction  

Microsoft Academic Search

Diatomite samples from paleolake Tlaxcala, in Central Mexico, have been analyzed using proton induced X-ray emission (PIXE), X-ray tomography and X-ray diffraction. Chiseled blocks were scanned with a 0.7 MeV proton beam, 0.1 mm in diameter, in 0.25 mm steps across the sediments. X-ray tomography with the same step sizes was then applied, in order to compare the concentrations obtained

J. Miranda; A. Oliver; G. Vilaclara; R. Rico-Montiel; V. M. Mac韆s; J. L. Ruvalcaba; M. A. Zenteno

1994-01-01

143

Combined measurement of X-ray photon correlation spectroscopy and diffracted X-ray tracking using pink beam X-rays.  

PubMed

Combined X-ray photon correlation spectroscopy (XPCS) and diffracted X-ray tracking (DXT) measurements of carbon-black nanocrystals embedded in styrene-butadiene rubber were performed. From the intensity fluctuation of speckle patterns in a small-angle scattering region (XPCS), dynamical information relating to the translational motion can be obtained, and the rotational motion is observed through the changes in the positions of DXT diffraction spots. Graphitized carbon-black nanocrystals in unvulcanized styrene-butadiene rubber showed an apparent discrepancy between their translational and rotational motions; this result seems to support a stress-relaxation model for the origin of super-diffusive particle motion that is widely observed in nanocolloidal systems. Combined measurements using these two techniques will give new insights into nanoscopic dynamics, and will be useful as a microrheology technique. PMID:23955045

Shinohara, Yuya; Watanabe, Akira; Kishimoto, Hiroyuki; Amemiya, Yoshiyuki

2013-09-01

144

Real-time X-ray Diffraction Measurements of Shocked Polycrystalline Tin and Aluminum  

SciTech Connect

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35-ns pulse. The characteristic K? lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K? line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3-mm by 6-mm spot and 1 full-width-half-maximum (FWHM) angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device (CCD) camera through a coherent fiberoptic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1-mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic (fcc) aluminum lattice with no phase transformation.

Dane V. Morgan, Don Macy, Gerald Stevens

2008-11-22

145

An X-ray diffraction study of defect parameters in a Ti-base alloy  

Microsoft Academic Search

Detailed studies based on the well established method of Fourier line shape analysis have been made on the X-ray diffraction\\u000a profile of hexagonal titanium alloy of nominal composition Ti-6.58% Al-3.16% Mo-1.81% Zr-008% Fe-0.012% N-0.0078% C. While\\u000a deformation fault probability, ?, has been found to be quite high compared to that of pure titanium, the deformation growth\\u000a fault parameter, ?, shows

G. Karmaker; P. Mukherjee; A. K. Meikap; S. K. Chattopadhyay; S. K. Chatterjee

2001-01-01

146

MLEM deconvolution of protein X-ray diffraction images based on a multiple-PSF model  

Microsoft Academic Search

In this paper we analyze the degradation of protein X-ray diffraction images by diffuse light distortion (DLD). In order to correct the degradation, a new multiple point spread function (PSF) model is introduced and used to restore X-ray diffraction image data (XRD). Raw PSFs are collected from isolated spots in high-resolution areas on the diffraction patterns which represent the orientation

Daan Zhu; Moe Razaz; Andrew Hemmings

2006-01-01

147

X-ray diffraction study of surface acoustic wave device under acoustic excitation  

Microsoft Academic Search

The acoustic field inside a surface acoustic wave device was studied by means of double-crystal x-ray diffraction. Angular satellites in the diffraction pattern were observed due to the coherent scattering on the acoustic superlattice. Satellite dynamics allows determination of the acoustic wave amplitude. Due to the sensitivity of x-ray diffraction to the direction of atomic displacements, the amplitude of different

E. Zolotoyabko; E. Jacobsohn; D. Shechtman; B. Kantor; J. Salzman

1993-01-01

148

Characterization of microstructures in Inconel 625 using X-ray diffraction peak broadening and lattice parameter measurements  

Microsoft Academic Search

This study demonstrates that, three parameters which are microstrain, lattice parameter and crystallite size, obtained from X-ray diffraction line profile analysis, can be used in a complementary way to study the precipitation\\/dissolution of various intermetallics and carbides in nickel base superalloy Inconel 625, without extracting the precipitates from the matrix.

Sanjay K. Rai; Anish Kumar; Vani Shankar; T. Jayakumar; K. Bhanu Sankara Rao; Baldev Raj

2004-01-01

149

X-Ray Diffraction Studies on Material Corrosions in Renewable Energy Storage Electrolyzers  

NASA Astrophysics Data System (ADS)

As a core component of the proton exchange water electrolyzer system, membrane electrode assemblies degrade due to the corrosion of the material. This creates a loss of interfacial contact necessary for the electron transports and electrochemical reactions, thus decreasing the performance. X-ray diffraction has been demonstrated to be an effective method that readily provides quantitative information about the phase-composition of solid materials. In this study, a group of materials have been selected and tested in the standard conditions for investigating the corrosion mechanisms with X-ray diffraction. The material lattice parameter and the crystal size were examined by X-ray diffraction spectrum.

Mo, J.; Steen, S. M., Iii; Zhang, F.-Y.

2014-11-01

150

High Resolution X-Ray Diffraction of Macromolecules with Synchrotron Radiation  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

151

X-RAY DIFFRACTION PHASE ANALYSIS OF PROCESS AND POLLUTION CONTROL DEVICE SAMPLES  

EPA Science Inventory

The paper describes the application of x-ray diffraction (XRD) analysis to several samples which show the information available from the technique. X-ray fluorescence (XRF) spectrometry was used for the elemental analysis because it provides very complete information with minimal...

152

Diffractive optical elements for differential interference contrast x-ray microscopy  

Microsoft Academic Search

In this paper we introduce phase diffractive optical elements (DOEs) that beside simple focusing, can perform new optical functions in the range of x-rays. In particular, the intensity of the wavefront can be distributed with almost complete freedom. We calculated and fabricated high resolution DOEs that can focus a monochromatic x-ray beam into multiple spots displaced in a single or

Enzo Mario di Fabrizio; Dan Cojoc; Stefano Cabrini; Burkhard Kaulich; Jean Susini; Paolo Facci; Thomas Wilhein

2003-01-01

153

Fitting dynamical x-ray diffraction data over the World Wide Web.  

SciTech Connect

The first implementation of fitting X-ray Bragg diffraction profiles from strained multilayer crystals at a remote web-based X-ray software server is presented. The algorithms and the software solutions involved in the process are described. The suggested technology can be applied to a wide range of scientific research and has the potential to promote remote collaborations across scientific communities.

Stepanov, S.; Forrest, R.; Biosciences Division; Univ. of Houston

2008-01-01

154

X-Ray Spectrum of a Narrow-Line QSO  

NASA Technical Reports Server (NTRS)

During the reporting period, seven papers using ASCA data, supported in whole or in part by this grant, were published or submitted to refereed journals. Their abstracts are given in this report, and the complete bibliographic references are listed in the Appendix. Titles include (1) A Broad-Band X-ray Study of the Geminga Pulsar; (2) ASCA Observations of PSR 1920+10 and PSR 0950+08; (3) X-ray and Optical Spectroscopy of IRAS 20181-2244: Not a Type 2 QSO, but a I Zw I Object; (4) Models for X-ray Emission from Isolated Pulsars; (5) Optical and X-ray Spectroscopy of 1E 0449.4-1823: Demise of the Original Type 2 QSO; (6) The ASCA Spectrum of the Broad-Line Radio Galaxy Pictor A: A Simple Power Law with No Fe Ka Line; and (7) ASCA Spectra of NGC 4388 and ESO 103-G35: Absorption, Reflection, and Variability in Intermediate Type Seyfert Galaxies.

Halpern, Jules P.

1998-01-01

155

X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S. Duffy  

E-print Network

X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S of tungsten was determined under static high pressures to 69 GPa using x-ray diffraction techniques in a diamond anvil cell. Analysis of x-ray diffraction peak broadening and measurement of peak shifts

Duffy, Thomas S.

156

A Bayesian Approach to Surface X-ray Diffraction  

SciTech Connect

We report on the development of an iterative method to directly invert surface x-ray diffraction (SXRD) data and thereby provide a map of electron density in the near-surface region of a solid. We have termed this method PARADIGM, which stands for Phase and Amplitude Recovery And Diffraction Image Generation Method. Significant advances in the PARADIGM theory were made during the grant period, and experimental milestones have also been achieved. The two components of the research program worked in concert, each spurring progress in the other. The method works by iteratively recovering the phases of surface scattering factors. Initially, random phases are assigned to the structure factors. After subtracting off the known bulk component, a Fourier transform converts these factors into an estimate of the real-space electron density map. This map is subjected to a support constraint, which holds that the electron density may only be non-zero near the solid surface. The modified electron density is then subjected to an inverse Fourier transform, and the bulk contributions are added back in. This renders an improved estimate of the phases of the surface structure factors. A constraint in reciprocal space is then applied, namely, the amplitudes of the scattering factors are set equal to the experimentally observed ones. This cycle is repeated, transforming between real and reciprocal space and applying constraints in each, until convergence is reached. The result renders a good initial model of the unknown surface structure. Such a direct method is important because conventional structural refinement methods rely on having a guess of the starting structure that sufficiently good that it may be refined into a model with the correct atomic positions. If the starting model has, for example, the wrong number or identity of atoms in the surface unit cell, it can never refine to the correct model. Even in cases where the starting model contains the correct number and identity of atoms, it is relatively easy for refinement routines to get trapped in false minima; finding a global minimum of a multi-parameter phase space is a notoriously difficult problem. The utility of the present method, then, stems from its ability to, independently of preconceived notions, identify robust starting models for testing by conventional refinement techniques. The method has been shown to work well on three independent experimental data sets. First, the efficacy of the method was demonstrated on a known reconstruction, the well-known missing-row Au(110)-(2x1) surface. The method recovered all known structural features of this reconstruction. Next, the method was applied to two heretofore unknown reconstructions of the Au(110) surface that are induced by Sb adsorption, the c(2x2) and the (rt(3)xrt(3))R54.7 reconstructions. In each case, the direct method provided an excellent starting model for later refinement by conventional means.

Lyman, Paul F.; Saldin, Dilano K.

2006-11-17

157

Bragg diffraction using a 100ps 17.5 keV x-ray backlighter and the Bragg Diffraction Imager  

SciTech Connect

A new diagnostic for measuring Bragg diffraction from a laser-driven crystal using a 100ps 17.5 kV x-ray backlighter source is designed and tested successfully at the Omega EP laser facility on static Mo and Ta single crystal samples using a Mo Ka backlighter. The Bragg Diffraction Imager (BDI) consists of a heavily shielded enclosure and a precisely positioned beam block, attached to the main enclosure by an Aluminum arm. Image plate is used as the x-ray detector. The diffraction lines from Mo and Ta <222> planes are clearly detected with a high signal-to-noise using the 17.5 keV and 19.6 keV characteristic lines generated by a petawatt-driven Mo foil. This technique will be applied to shock and ramp-loaded single crystals on the Omega EP laser. Pulsed x-ray diffraction of shock- and ramp-compressed materials is an exciting new technique that can give insight into the dynamic behavior of materials at ultra-high pressure not achievable by any other means to date. X-ray diffraction can be used to determine not only the phase and compression of the lattice at high pressure, but by probing the lattice compression on a timescale equal to the 3D relaxation time of the material, information about dislocation mechanics, including dislocation multiplication rate and velocity, can also be derived. Both Bragg, or reflection, and Laue, or transmission, diffraction have been developed for shock-loaded low-Z crystalline structures such as Cu, Fe, and Si using nano-second scale low-energy implosion and He-{alpha} x-ray backlighters. However, higher-Z materials require higher x-ray probe energies to penetrate the samples, such as in Laue, or probe deep enough into the target, as in the case of Bragg diffraction. Petawatt laser-generated K{alpha} x-ray backlighters have been developed for use in high-energy radiography of dense targets and other HED applications requiring picosecond-scale burst of hard x-rays. While short pulse lasers are very efficient at producing high-energy x-rays, the characteristic x-rays produced in these thin foil targets are superimposed on a broad bremsstrahlung background and can easily saturate a detector if careful diagnostic shielding and experimental geometry are not implemented. A new diagnostic has been designed to measure Bragg diffraction from laser-driven crystal targets using characteristic x-rays from a short-pulse laser backlighter on the Omega EP laser. The Bragg Diffraction Imager, or BDI, is a TIM-mounted instrument consisting of a heavily shielded enclosure made from 3/8-inch thick Heavymet (W-Fe-Ni alloy) and a precisely positioned beam bock, attached to the main enclosure by an Aluminum arm. The beam block is made of 1-inch thick, Al-coated Heavymet and serves to block the x-rays directly from the petawatt backlight, while allowing the diffraction x-rays from the crystal to pass to the enclosure. A schematic of the BDI is shown in Fig. 1a. Image plates are used as the x-ray detector and are loaded through the top of the diagnostic in an Aluminum, light-tight cartridge. The front of the enclosure can be fitted with various filters to maximize the diffraction signal-to-noise.

Maddox, B R; Park, H; Hawreliak, J; Comley, A; Elsholz, A; Van Maren, R; Remington, B A; Wark, J

2010-05-13

158

Electrochemical discharge of nanocrystalline magnetite: structure analysis using X-ray diffraction and X-ray absorption spectroscopy.  

PubMed

Magnetite (Fe3O4) is an abundant, low cost, environmentally benign material with potential application in batteries. Recently, low temperature coprecipitation methods have enabled preparation of a series of nanocrystalline magnetite samples with a range of crystallite sizes. Electrochemical cells based on Li/Fe3O4 show a linear increase in capacity with decreasing crystallite size at voltages ?1.2 V where a 2 capacity improvement relative to commercial (26.2 nm) magnetite is observed. In this report, a combination of X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) is used to measure magnetite structural changes occurring upon electrochemical reduction, with parent Fe3O4 crystallite size as a variable. Notably, XAS provides evidence of metallic iron formation at high levels of electrochemical reduction. PMID:24077019

Menard, Melissa C; Takeuchi, Kenneth J; Marschilok, Amy C; Takeuchi, Esther S

2013-11-14

159

(X-ray diffraction experiments with condenser matter)  

SciTech Connect

This report discusses research on the following topics: high-{Tc} superconductors; The response of crystal to an applied electric field; quasicrystals; surface structure and kinetics of surface layer formation; EXAFS studies of superconductors and heterostructures; effect of iron on the crystal structure of perovskite; x-ray detector development; and SAXS experiments. (LSP)

Coppens, P.

1990-01-01

160

Electrochemical in situ reaction cell for X-ray scattering, diffraction and spectroscopy.  

PubMed

A versatile electrochemical in situ reaction cell for long-term hard X-ray experiments on battery electrodes is described. Applications include the small-angle scattering, diffraction and absorption spectroscopy of lithium manganese oxide electrodes. PMID:12824932

Braun, A; Shrout, S; Fowlks, A C; Osaisai, B A; Seifert, S; Granlund, E; Cairns, E J

2003-07-01

161

Designing and optimizing gratings for soft X-ray diffraction efficiency.  

E-print Network

??The diffraction efficiency is critical to the speed and sensitivity of grating-based spectroscopy instruments. This becomes particularly important for soft x-ray instruments, used on material (more)

Boots, Mark

2013-01-01

162

X-Ray Diffraction Powder Patterns and Thin Section Observations from the Sierra Madera Impact Structure  

NASA Astrophysics Data System (ADS)

X-Ray powder diffraction analysis and thin section observations of carbonate and siliciclastic samples from the Sierra Madera impact structure indicate moderate shock pressures (8 to 30 GPa) were generated during the formation of this crater.

Huson, S. A.; Foit, F. F.; Watkinson, A. J.; Pope, M. C.

2006-03-01

163

Bulk metallic glass gasket for high pressure, in situ x-ray diffraction  

NASA Astrophysics Data System (ADS)

Amorphous metallic alloys lack long-range atomic order and consequently exhibit excellent homogeneity, no microstructure discontinuities, and no sharp x-ray diffraction peaks. Moreover they have higher tensile fracture strength and hardness than those of traditional crystalline metals. These excellent physical properties make bulk metallic glasses good candidates for high pressure gaskets for in situ x-ray/neutron diffraction experiments. We tested the Pd40Ni40P20 amorphous alloy as a gasket material in three experiments. The behavior of the Pd40Ni40P20 amorphous alloy under a hydrostatic/nonhydrostatic pressure of over 100 GPa was investigated by in situ synchrotron x-ray diffraction. The pressure gradient of the amorphous metallic gasket in the diamond anvil cell was measured on the ruby fluorescence scale during compression and decompression. The results show that bulk metallic glasses are good high-pressure gasket materials for in situ x-ray diffraction experiments.

He, Duanwei; Zhao, Yusheng; Sheng, T. D.; Schwarz, R. B.; Qian, J.; Lokshin, K. A.; Bobev, S.; Daemen, L. L.; Mao, H. K.; Hu, J. Z.; Shu, J.; Xu, J.

2003-06-01

164

X-ray diffraction from thin film structures : characterization and modeling.  

E-print Network

??InAs/GaSb superlattices grown via molecular beam epitaxy, and containing InSb-like interfacial layers, were analyzed with a combination of x-ray diffraction (XRD) and structural refinement techniques. (more)

Liu, Ge

2007-01-01

165

Reactive sputter magnetron reactor for preparation of thin films and simultaneous in situ structural study by X-ray diffraction  

SciTech Connect

The purpose of the designed reactor is (i) to obtain polycrystalline and/or amorphous thin films by controlled deposition induced by a reactive sputtering magnetron and (ii) to perform a parallel in situ structural study of the deposited thin films by X-ray diffraction, in real time, during the whole growth process. The designed reactor allows for the control and precise variation of the relevant processing parameters, namely, magnetron target-to-sample distance, dc magnetron voltage, and nature of the gas mixture, gas pressure and temperature of the substrate. On the other hand, the chamber can be used in different X-ray diffraction scanning modes, namely, {theta}-2{theta} scanning, fixed {alpha}-2{theta} scanning, and also low angle techniques such as grazing incidence small angle X-ray scattering and X-ray reflectivity. The chamber was mounted on a standard four-circle diffractometer located in a synchrotron beam line and first used for a preliminary X-ray diffraction analysis of AlN thin films during their growth on the surface of a (100) silicon wafer.

Buergi, J.; Molleja, J. Garcia; Feugeas, J. [Instituto de Fisica Rosario (CONICET-UNR), Bv. 27 de Febrero 210 bis, S2000EZP Rosario (Argentina); Neuenschwander, R. [Laboratorio Nacional Luz Sincrotron (LNLS), Caixa Postal 6192, CEP13083-970 Campinas (Brazil); Kellermann, G. [Departamento de Fisica (Universidade Federal do Parana), Caixa Postal 19044, CEP81531-990 Curitiba (Brazil); Craievich, A. F. [Instituto de Fisica (Universidade de Sao Paulo), Rua do Matao Travessa R 187, CEP05508-090 Sao Paulo (Brazil)

2013-01-15

166

Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys  

DOEpatents

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

Berman, R.M.; Cohen, I.

1988-04-26

167

ELECTRON MICROSCOPE AND LOW-ANGLE X-RAY DIFFRACTION STUDIES OF THE NERVE MYELIN SHEATH  

PubMed Central

1. A close correlation has been obtained between high resolution electron microscopy and low-angle x-ray diffraction studies of the myelin sheath of frog and rat peripheral and central nerves. Extensive studies were performed by application of both techniques to the same specimens, prepared for examination by OsO4 or KMnO4 fixation, and embedding either in methacrylate or in gelatin employing a new procedure. Controlled physical and chemical modifications of the myelin sheath prior to fixation were also investigated. 2. A correspondence was established between the layer spacings observed in electron micrographs and the fundamental radial repeating unit indicated by the low-angle x-ray diffraction patterns. The variations in relative intensities of the low-angle x-ray reflections could be related to the radial density distributions seen in the electron micrographs. 3. An analysis of the preparation procedures revealed that OsO4 fixation introduces a greater shrinkage of the layer spacings and more pronounced changes in the density distribution within the layers than KMnO4 fixation. The effects of methacrylate and gelatin embedding are described, and their relative merits considered in relation to the preservation of myelin structure by OsO4 fixation. 4. The experimental modifications introduced by freezing and thawing of fresh whole nerve are described, particularly the enhancement of the intermediate lines and the dissociation of the layer components in the myelin sheath. A characteristic collapsing of the radial period of the sheath is observed after subjecting fresh nerve trunks to prolonged and intense ultracentrifugation. 5. Controlled extraction of fresh nerve with acetone at 0癈., which preferentially removes cholesterol, produces characteristic, differentiated modifications of the myelin sheath structure. Electron microscopy reveals several types of modifications within a single preparation, including both expanded and collapsed layer systems, and internal rearrangements of the layer components. Alcohol extraction leads to a more extensive structural breakdown, but in certain areas collapsed layer systems can still be observed. The components of the lipide extracts could be identified by means of x-ray diffraction. These modifications emphasize the importance of cholesterol in the myelin structure, and disclose a resistance of the dense osmiophilic lines to lipide solvents. 6. The significance of these structures is discussed in relation to present concepts of the molecular organization of myelin. The available evidence is consistent with the suggestion that the primary site of osmium deposition is at the lipoprotein interfaces and that the light bands probably represent regions occupied by lipide chains. The electron microscope and x-ray diffraction data also indicate the possibility of a regular organization within the plane of the layers, probably involving units of 60 to 80 A. The myelin sheath is regarded as a favourable cell membrane model for detailed analysis by combined application of x-ray diffraction and electron microscopy. PMID:13475388

Fern醤dez-mor醤, H.; Finean, J. B.

1957-01-01

168

Particle size distribution function of supported metal catalysts by x-ray diffraction  

Microsoft Academic Search

An X-ray diffraction method which is capable of determining average particle size, microstrain, and the particle distribution function existing in crystalline materials is presented. The method is based on the analysis of a single X-ray diffraction profile. Results obtained on coprecipitated nickel oxide on alumina- and silica-supported catalytic materials indicate that appreciable strains exist. It is suggested that the strains

P. Ganesan; H. K. Kuo; A. Saavedra; R. J. De Angelis

1978-01-01

169

Measurement of piezoelectric constants of lanthanum-gallium tantalate crystal by X-ray diffraction methods  

SciTech Connect

A method for measuring piezoelectric constants of crystals of intermediate systems by X-ray quasi-multiple-wave diffraction is proposed and implemented. This technique makes it possible to determine the piezoelectric coefficient by measuring variations in the lattice parameter under an external electric field. This method has been approved, its potential is evaluated, and a comparison with high-resolution X-ray diffraction data is performed.

Blagov, A. E.; Marchenkov, N. V., E-mail: marchenkov@ns.crys.ras.ru; Pisarevsky, Yu. V.; Prosekov, P. A.; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2013-01-15

170

X-ray diffraction characterization of suspended structures forMEMS applications  

SciTech Connect

Mechanical stress control is becoming one of the major challenges for the future of micro and nanotechnologies. Micro scanning X-ray diffraction is one of the promising techniques that allows stress characterization in such complex structures at sub micron scales. Two types of MEMS structure have been studied: a bilayer cantilever composed of a gold film deposited on poly-silicon and a boron doped silicon bridge. X-ray diffraction results are discussed in view of numerical simulation experiments.

Goudeau, P.; Tamura, N.; Lavelle, B.; Rigo, S.; Masri, T.; Bosseboeuf, A.; Sarnet, T.; Petit, J.-A.; Desmarres, J.-M.

2005-09-15

171

Better Living Through Minerals: X-Ray Diffraction of Household Products  

NSDL National Science Digital Library

X-ray diffraction is a quick and valuable tool for identifying minerals. Minerals are an integral portion of our everyday life, in addition to composing our planet! They help bring electricity into our homes and remove our bathtub rings. In this lab, students analyze the X-ray diffraction patterns of three household cleansers, Ajax, White Magic, and Soft Scrub, in order to identify the abrasive minerals in each.

Barb Dutrow

172

Ris-R-1266(EN) The 3D X-Ray Diffraction Microscope  

E-print Network

Ris酶-R-1266(EN) The 3D X-Ray Diffraction Microscope and its Application to the Study Preface 3 1 Introduction 5 2 The 3D X-Ray Diffraction Microscope 7 2.1 Experimental set-up 8 2.1.1 The x.3 Discussion and outlook 27 3 Recrystallization Kinetics and the 3DXRD Microscope 29 3.1 Experimental 30 3

173

Temperature-dependent X-ray diffraction as a probe of protein structural dynamics  

Microsoft Academic Search

X-ray diffraction at four temperatures from 220 to 300 K coupled with crystallographic refinement yields the mean-square displacements and conformational potentials of all 1,261 non-hydrogen atoms of metmyoglobin. The results are interpreted to indicate a condensed core around the haem, semi-liquid regions towards the outside and a possible pathway for ligands. It is concluded that X-ray diffraction can provide the

Hans Frauenfelder; Gregory A. Petsko; Demetrius Tsernoglou

1979-01-01

174

X-ray powder diffraction study of the high pressure behaviour of uranium dioxide  

E-print Network

L-171 X-ray powder diffraction study of the high pressure behaviour of uranium dioxide U. Benedict du bioxyde d'uranium sous des pressions jusqu'脿 40 GPa a 茅t茅 茅tudi茅 par diffraction X sur poudre dans 脿 une d茅localisation d'茅lectrons 5f. Abstract. 2014 Uranium dioxide was studied by X-ray powder

Paris-Sud XI, Universit茅 de

175

Structure-induced negatively skewed X-ray diffraction pattern of carbon onions  

NASA Astrophysics Data System (ADS)

The idea is discussed that a gradual change of intershell separation in carbon onions may introduce a negative skewness into the most intense X-ray diffraction band. As an example, the experimental X-ray diffraction pattern of carbon onions is analysed using a weighted Lorentzian X-ray profile broadening model for each intershell separation contributing to the profile. The dependence of the mean radius for carbon onion shells on the intershell spacing between the adjacent shells is derived from the model analysis. Comparison with the internal distribution of atomic density in carbon onions measured with high resolution transmission electron microscopy is discussed.

Siklitskaya, Alexandra; Yastrebov, Sergey; Smith, Roger

2013-10-01

176

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

NASA Astrophysics Data System (ADS)

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.

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-09-01

177

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPPOWCAP Standard Operating Procedure Title: Mounting Samples for Micro Powder Diffraction Rev No: Issue date: 1: 1/1/2009 Mounting Samples for Micro- Powder Diffraction PURPOSE: This Standard Operating Procedure

Meagher, Mary

178

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University  

E-print Network

X-ray Diffraction Laboratory: Department of Chemistry Texas A & M University Doc. No: SOPSAMPOW Standard Operating Procedure Title: Mounting Samples for Powder Diffraction Rev No: Issue date: 1.001 12/1/2009 Mounting Samples for Powder Diffraction PURPOSE: This Standard Operating Procedure (SOP) states

Meagher, Mary

179

Compressive single-pixel snapshot x-ray diffraction imaging.  

PubMed

We present a method for realizing snapshot, depth-resolved material identification using only a single, energy-sensitive pixel. To achieve this result, we employ a coded aperture with subpixel features to modulate the energy spectrum of coherently scattered photons and recover the object properties using an iterative inversion algorithm based on compressed sensing theory. We demonstrate high-fidelity object estimation at x-ray wavelengths for a variety of compression ratios exceeding unity. PMID:24365835

Greenberg, Joel; Krishnamurthy, Kalyani; Brady, David

2014-01-01

180

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

DOEpatents

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.

Gibson, David M. (Voorheesville, NY); Gibson, Walter M. (Voorheesville, NY); Huang, Huapeng (Latham, NY)

2007-06-26

181

Phase Sensitive X-Ray Diffraction Imaging Study of Protein Crystals  

NASA Technical Reports Server (NTRS)

The study of defects and growth of protein crystals is of importance in providing a fundamental understanding of this important category of systems and the rationale for crystallization of better ordered crystals for structural determination and drug design. Yet, as a result of the extremely weak scattering power of x-rays in protein and other biological macromolecular crystals, the extinction lengths for those crystals are extremely large and, roughly speaking, of the order of millimeters on average compared to the scale of micrometers for most small molecular crystals. This has significant implication for x-ray diffraction and imaging study of protein crystals, and presents an interesting challenge to currently available x-ray analytical techniques. We proposed that coherence-based phase sensitive x-ray diffraction imaging could provide a way to augment defect contrast in x-ray diffraction images of weakly diffracting biological macromolecular crystals. I shall examine the principles and ideas behind this approach and compare it to other available x-ray topography and diffraction methods. I shall then present some recent experimental results in two model protein systems-cubic apofemtin and tetragonal lysozyme crystals to demonstrate the capability of the coherence-based imaging method in mapping point defects, dislocations, and the degree of perfection of biological macromolecular crystals with extreme sensitivity. While further work is under way, it is intended to show that the observed new features have yielded important information on protein crystal perfection and nucleation and growth mechanism otherwise unobtainable.

Hu, Z. W.

2003-01-01

182

Femtosecond X-ray Diffraction From Two-Dimensional Protein Crystals  

SciTech Connect

Here we present femtosecond x-ray diffraction patterns from two-dimensional (2-D) protein crystals using an x-ray free electron laser (XFEL). To date it has not been possible to acquire x-ray diffraction from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permits a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy methodology at the Linac Coherent Light Source, we observed Bragg diffraction to better than 8.5 resolution for two different 2-D protein crystal samples that were 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.

Frank, Matthias; Carlson, David B.; Hunter, Mark; Williams, Garth J.; Messerschmidt, Marc; Zatsepin, Nadia A.; Barty, Anton; Benner, Henry; Chu, Kaiqin; Graf, Alexander; Hau-Riege, Stefan; Kirian, Rick; Padeste, Celestino; Pardini, Tommaso; Pedrini, Bill; Segelke, Brent; Seibert, M. M.; Spence , John C.; Tsai, Ching-Ju; Lane, Steve M.; Li, Xiao-Dan; Schertler, Gebhard; Boutet, Sebastien; Coleman, Matthew A.; Evans, James E.

2014-02-28

183

Generating x-ray lines from annihilating dark matter  

NASA Astrophysics Data System (ADS)

We propose different scenarios where a keV dark matter annihilates to produce a monochromatic signal. The process is generated through the exchange of a light scalar of mass of order 300 keV-50 MeV coupling to photon through loops or higher-dimensional operators. For natural values of the couplings and scales, the model can generate a gamma-ray line which can fit with the recently identified 3.5 keV x-ray line.

Dudas, Emilian; Heurtier, Lucien; Mambrini, Yann

2014-08-01

184

RIS-M-2268 SYNCHROTRON X-RAY DIFFRACTION DSING TRIPLE-AXIS SPECTROMETRY  

E-print Network

The bread wavelength band of intense electromagnetic radiation associated with the centripetal acceleration width of the CuK . line from a conventional X-ray tube, but for identical monochromators at a storage ring (E = 4.3 GeV, I s 50 mA) and at an X-ray tube, the monochromatic beam from the former is more than

185

Measurement of grain size of polycrystalline materials with confocal energy dispersive micro-X-ray diffraction technology based on polycapillary X-ray optics  

NASA Astrophysics Data System (ADS)

The confocal energy dispersive micro-X-ray diffraction (EDMXRD) based on polycapillary X-ray optics was used to determine the grain size of polycrystalline materials. The grain size of a metallographic specimen of nickel base alloy was measured by using the confocal EDMXRD. The experimental results demonstrated that the confocal EDMXRD had potential applications in measuring large grain size.

Sun, Weiyuan; Liu, Zhiguo; Sun, Tianxi; Peng, Song; Ma, Yongzhong; Li, Fangzuo; Sun, Xuepeng; Ding, Xunliang

2014-11-01

186

Synchrotron-based ultrafast x-ray diffraction at high repetition rates  

NASA Astrophysics Data System (ADS)

We present a setup for ultrafast x-ray diffraction (UXRD) based at the storage ring BESSY II, in particular, a pump laser that excites the sample using 250 fs laser-pulses at repetition rates ranging from 208 kHz to 1.25 MHz. We discuss issues connected to the high heat-load and spatio-temporal alignment strategies in the context of a UXRD experiment at high repetition rates. The spatial overlap between laser pump and x-ray probe pulse is obtained with 10 ?m precision and transient lattice changes can be recorded with an accuracy of ?a/a0 = 10-6. We also compare time-resolved x-ray diffraction signals from a laser excited LSMO/STO superlattice with phonon dynamics simulations. From the analysis we determine the x-ray pulse duration to 120 ps in standard operation mode and below 10 ps in low-? mode.

Navirian, H.; Shayduk, R.; Leitenberger, W.; Goldshteyn, J.; Gaal, P.; Bargheer, M.

2012-06-01

187

Study on quasiperiodic Ta/Al multilayer films by x-ray diffraction  

SciTech Connect

Quasiperiodic (Fibonacci) Ta/Al multilayer films with Ta(110) and Al(111) textures were fabricated by magnetron sputtering. The structure of the multilayers was characterized in detail by x-ray diffraction. The diffraction peaks at low and high angles can be indexed by the projection method from the high-dimension periodic structure. The experimental results were in good agreement with the numerical calculation using the model for the compositionally modulated multilayers. The diffraction spectrum of the quasiperiodic Ta/Al multilayers is totally different from that of periodic structure, and the possible application of Fibonacci films as optical elements in a soft x-ray region is discussed.

Peng, R.W.; Hu, A.; Jiang, S.S. (Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210008 (People's Republic of China))

1991-11-11

188

Nanosecond x-ray Laue diffraction apparatus suitable for laser shock compression experiments.  

PubMed

We have used nanosecond bursts of x-rays emitted from a laser-produced plasma, comprised of a mixture of mid-Z elements, to produce a quasiwhite-light spectrum suitable for performing Laue diffraction from single crystals. The laser-produced plasma emits x-rays ranging in energy from 3 to in excess of 10 keV, and is sufficiently bright for single shot nanosecond diffraction patterns to be recorded. The geometry is suitable for the study of laser-shocked crystals, and single-shot diffraction patterns from both unshocked and shocked silicon crystals are presented. PMID:20815613

Suggit, Matthew; Kimminau, Giles; Hawreliak, James; Remington, Bruce; Park, Nigel; Wark, Justin

2010-08-01

189

Nanosecond x-ray Laue diffraction apparatus suitable for laser shock compression experiments  

NASA Astrophysics Data System (ADS)

We have used nanosecond bursts of x-rays emitted from a laser-produced plasma, comprised of a mixture of mid-Z elements, to produce a quasiwhite-light spectrum suitable for performing Laue diffraction from single crystals. The laser-produced plasma emits x-rays ranging in energy from 3 to in excess of 10 keV, and is sufficiently bright for single shot nanosecond diffraction patterns to be recorded. The geometry is suitable for the study of laser-shocked crystals, and single-shot diffraction patterns from both unshocked and shocked silicon crystals are presented.

Suggit, Matthew; Kimminau, Giles; Hawreliak, James; Remington, Bruce; Park, Nigel; Wark, Justin

2010-08-01

190

Phase sensitive x-ray diffraction imaging of defects in biological macromolecular crystals  

NASA Technical Reports Server (NTRS)

Conventional x-ray diffraction topography is currently used to map defects in the bulk of protein crystals, but the lack of sufficient contrast is frequently a limiting factor. We experimentally demonstrate that this barrier can be circumvented using a method that combines phase sensitive and diffraction imaging principles. Details of defects revealed in tetragonal lysozyme and cubic ferritin crystals are presented and discussed. The approach enabling the detection of the phase changes of diffracted x rays should prove to be useful in the study of defect structures in a broad range of biological macromolecular crystals.

Hu, Z. W.; Lai, B.; Chu, Y. S.; Cai, Z.; Mancini, D. C.; Thomas, B. R.; Chernov, A. A.

2001-01-01

191

Weak Hard X-Ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-Ray Weakness  

NASA Astrophysics Data System (ADS)

We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z < 1.3. However, their rest-frame ?2 keV luminosities are 14 to >330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with <~ 45 counts in the 3-24 keV band, and the other three are not detected. The hard X-ray (8-24 keV) weakness observed by NuSTAR requires Compton-thick absorption if these objects have nominal underlying X-ray emission. However, a soft stacked effective photon index (?eff ? 1.8) for this sample disfavors Compton-thick absorption in general. The uniform hard X-ray weakness observed by NuSTAR for this and the pilot samples selected with <10 keV weakness also suggests that the X-ray weakness is intrinsic in at least some of the targets. We conclude that the NuSTAR observations have likely discovered a significant population (gsim 33%) of intrinsically X-ray weak objects among the BAL quasars with significantly weak <10 keV emission. We suggest that intrinsically X-ray weak quasars might be preferentially observed as BAL quasars.

Luo, B.; Brandt, W. N.; Alexander, D. M.; Stern, D.; Teng, S. H.; Ar関alo, P.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Farrah, D.; Gandhi, P.; Hailey, C. J.; Harrison, F. A.; Koss, M.; Ogle, P.; Puccetti, S.; Saez, C.; Scott, A. E.; Walton, D. J.; Zhang, W. W.

2014-10-01

192

Computed tomography of x-ray index of refraction using the diffraction enhanced imaging method  

Microsoft Academic Search

Diffraction enhanced imaging (DEI) is a new, synchrotron-based, x-ray radiography method that uses monochromatic, fan-shaped beams, with an analyser crystal positioned between the subject and the detector. The analyser allows the detection of only those x-rays transmitted by the subject that fall into the acceptance angle (central part of the rocking curve) of the monochromator\\/analyser system. As shown by Chapman

F. A. Dilmanian; Z. Zhong; B. Ren; X. Y. Wu; L. D. Chapman; I. Orion; W. C. Thomlinson

2000-01-01

193

Analysis of Amorphous and Nanocrystalline Solids from Their X-Ray Diffraction Patterns  

Microsoft Academic Search

Purpose牋The purpose of this paper is to provide a physical description of the amorphous state for pharmaceutical materials and to investigate the pharmaceutical implications. Techniques to elucidate structural differences in pharmaceutical solids exhibiting characteristic X-ray amorphous powder patterns are also presented.Materials and Methods牋The X-ray amorphous powder diffraction patterns of microcrystalline cellulose, indomethacin, and piroxicam were measured with laboratory XRPD instrumentation.

Simon Bates; George Zografi; David Engers; Kenneth Morris; Kieran Crowley; Ann Newman

2006-01-01

194

Ultrafast Structural Dynamics in InSb Probed by Time-Resolved X-Ray Diffraction  

SciTech Connect

Ultrafast structural dynamics in laser-perturbed InSb are studied using time-resolved x-ray diffraction with a novel femtosecond x-ray source. We report the first observation of a delay in the onset of lattice expansion, which we attribute to energy relaxation processes and lattice strain propagation. In addition, we observe direct indications of ultrafast disordering on a subpicosecond time scale. {copyright} {ital 1999} {ital The American Physical Society }

Chin, A.H.; Shank, C.V. [Department of Physics, University of California, Berkeley, California 94720 (United States)] [Department of Physics, University of California, Berkeley, California 94720 (United States); Chin, A.H.; Schoenlein, R.W.; Shank, C.V. [Material Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Material Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Glover, T.E. [Advanced Light Source, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Advanced Light Source, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leemans, W.P. [Center for Beam Physics, Accelerator and Fusion Research Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Center for Beam Physics, Accelerator and Fusion Research Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Balling, P. [Institute of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000, Aarhus C (Denmark)] [Institute of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000, Aarhus C (Denmark)

1999-07-01

195

Ultrafast Structural Dynamics in InSb Probed by Time-Resolved X-Ray Diffraction  

Microsoft Academic Search

Ultrafast structural dynamics in laser-perturbed InSb are studied using time-resolved x-ray diffraction with a novel femtosecond x-ray source. We report the first observation of a delay in the onset of lattice expansion, which we attribute to energy relaxation processes and lattice strain propagation. In addition, we observe direct indications of ultrafast disordering on a subpicosecond time scale. {copyright} {ital 1999}

A. H. Chin; C. V. Shank; R. W. Schoenlein; T. E. Glover; W. P. Leemans; P. Balling

1999-01-01

196

Transient x-ray diffraction of shock compressed crystals using the Nova laser  

Microsoft Academic Search

We are conducting experiments on the Nova laser to investigate the Rayleigh-Taylor instability in metal foils maintained in the solid state. In support of this effort, we are developing dynamic diffraction as a diagnostic of material state for shock compressed samples. We use a hohlraum x-ray drive to shock compress the crystal samples, and x-rays from a point backlighter to

D. H. Kalantar; E. A. Chandler; J. D. Colvin; R. Lee; B. A. Remington; S. V. Weber; L. G. Wiley; B. H. Failor; A. Hauer; J. S. Wark; M. Meyers; G. Ravichandran

1998-01-01

197

Transient x-ray diffraction used to diagnose shock compressed solids on the Nova laser  

Microsoft Academic Search

We are conducting experiments on the Nova laser to investigate the Rayleigh-Taylor instability in metal foils maintained in the solid state. In support of this effort, we are developing dynamic diffraction as a diagnostic of material state for shock compressed samples. We use a hohlraum x-ray drive to shock compress the samples, and x-rays from a point backlighter to measure

D. H. Kalantar; E. A. Chandler; J. D. Colvin; R. Lee; B. A. Remington; S. V. Weber; L. G. Wiley; B. H. Failor; A. Hauer; J. S. Wark; M. Meyers; G. Ravichandran

1997-01-01

198

Bond-orientational anisotropy in metallic glasses observed by x-ray diffraction  

Microsoft Academic Search

The structural anisotropy in metallic glasses induced by mechanical creep was observed by x-ray diffraction, using energy-dispersive x-ray diffractometry. The creep-induced anisotropy is the origin of the anelasticity in metallic glasses. The structural anisotropy was analyzed in terms of the anisotropic structure factor and anisotropic pair distribution function. The results show that the observed anisotropy is due to the atomic-bond-orientational

Y. Suzuki; J. Haimovich; T. Egami

1987-01-01

199

Titration of a Solid Acid Monitored by X-Ray Diffraction  

ERIC Educational Resources Information Center

An experiment is described to introduce students to an important class of solid-state reactions while reinforcing concepts of titration by using a pH meter and a powder X-ray diffractometer. The experiment was successful in teaching students the abstract concepts of solid-state structure and diffraction by applying the diffraction concepts learned

Dungey, Keenan E.; Epstein, Paul

2007-01-01

200

Study of titanate nanotubes by X-ray and electron diffraction and electron microscopy  

SciTech Connect

The structure of titanate nanotubes (Ti-NTs) was studied by a combination of powder X-ray diffraction (PXRD), electron diffraction and high resolution transmission electron microscopy (HRTEM). Ti-NTs are prepared by hydrothermal treatment of TiO{sub 2} powder. The structure is identified by powder X-ray diffraction as the one based on the structure of H{sub 2}Ti{sub 2}O{sub 5}稨{sub 2}O phase. The same structure is obtained by projected potential from HRTEM through-focus image series. The structure is verified by simulated PXRD pattern with the aid of the Debye formula. The validity of the model is tested by computing Fourier transformation of a single nanotube which is proportional to measured electron diffraction intensities. A good agreement of this calculation with measured precession electron diffraction data is achieved. - Highlights: Titanate nanotubes were prepared by hydrothermal method. X-ray powder diffraction indicated their structure based on that of H{sub 2}Ti{sub 2}O{sub 5}稨{sub 2}O. Structural model was created with the aid of high-resolution electron microscopy. The model was verified with electron diffraction data. X-ray powder diffraction pattern was calculated with the aid of the Debye formula.

Brunatova, Tereza [Charles University, Faculty of Mathematics and Physics, Dept. of Condensed Matter Physics, Prague (Czech Republic); Popelkova, Daniela [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Wan, Wei [Berzelii Center EXSELENT on Porous Materials, Stockholm University, SE-106 91 Stockholm (Sweden); Dept. of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Oleynikov, Peter [Dept. of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Danis, Stanislav [Charles University, Faculty of Mathematics and Physics, Dept. of Condensed Matter Physics, Prague (Czech Republic); Zou, Xiaodong [Berzelii Center EXSELENT on Porous Materials, Stockholm University, SE-106 91 Stockholm (Sweden); Dept. of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Kuzel, Radomir, E-mail: kuzel@karlov.mff.cuni.cz [Charles University, Faculty of Mathematics and Physics, Dept. of Condensed Matter Physics, Prague (Czech Republic)

2014-01-15

201

Synchrotron X-Ray Diffraction Studies of Olivine from Comet Wild 2  

NASA Technical Reports Server (NTRS)

We have analyzed a collection of the Comet Wild 2 coma grains returned by the NASA Stardust Mission, using micro-area Laue diffraction equipment. The purpose of the diffraction experiment is to permit the structure refinement of olivine including site occupancies. In addition to the intrinsic importance of the olivine structures for revealing the thermal history of Wild 2 materials, we wish to test reports that olivine recovered after hypervelocity capture in silica aerogel has undergone a basic structural change due to capture heating [1]. The diffraction equipment placed at beam line BL- 4B1 of PF, KEK was developed with a micropinhole and an imaging plate (Fuji Co. Ltd.) using the Laue method combined with polychromatic X-ray of synchrotron radiation operated at energy of 2.5 GeV. The incident beam is limited to 1.6 m in diameter by a micropinhole set just upstream of the sample [2, 3]. It is essential to apply a microbeam to obtain diffracted intensities with high signal to noise ratios. This equipment has been successfully applied to various extraterrestrial materials, including meteorites and interplanetary dust particles [4]. The Laue pattern of the sample C2067,1,111,4 (Fig. 1) was successfully taken on an imaging plate after a 120 minute exposure (Fig. 2).

2008-01-01

202

Exploring X-Ray Lines as Scotogenic Signals  

E-print Network

We consider some implications of X-ray lines from certain astronomical objects as potential effects of dark matter decay in the context of the scotogenic model, where neutrinos acquire mass radiatively via one-loop interactions with dark matter. As an example, we focus on the 3.5 keV line recently detected in the X-ray spectra of galaxy clusters, assuming that it stands future scrutiny. We explore the scenario in which the line originates from the slow decay of fermionic dark matter in the model. After obtaining a number of benchmark points representing the parameter space consistent with the new data and various other constraints, we make predictions on several observables in leptonic processes. They include the effective Majorana mass in neutrinoless double-beta decay, the sum of neutrino masses, and the rate of flavor-changing decay mu -> e gamma, as well as the cross sections of e+e- collisions into final states containing nonstandard particles in the model. These are testable in ongoing or future experiments and thus offer means to probe the scotogenic scenario studied.

Gaber Faisel; Shu-Yu Ho; Jusak Tandean

2014-10-10

203

Intermediate phase formation during Hg-2212 synthesis by in-situ X-ray synchrotron diffraction  

NASA Astrophysics Data System (ADS)

The synthesis of Hg 2Ba 2YCu 2O 8-? (Hg-2212) requires a high pressure - high temperature process. The determination of the reaction path is an important piece of information for its optimization. In-situ X-ray diffraction at high pressure - high temperature has been performed to monitor this process by using the synchrotron source of ESRF (Grenoble-France, ID30 beam line). The synthesis was followed at 4 GPa from room temperature to 850癈. When the starting powder is a mixture of oxides (BaO 2, Y 2O 3, CuO) and Cu, a transient oxide phase composed at least of Ba and Hg is formed that is then converted into the final Hg-2212 product. Conversely no intermediate phase can be detected when a pre-reacted precursor 揃a 2YCu 2Oy mixed with HgO is used.

Toulemonde, P.; Le Floch, S.; Bordet, P.; Capponi, J. J.; Mezouar, M.; Odier, P.

204

X-Ray Diffraction Study on the Strain Anisotropy and Dislocation Structure of Deformed Lath Martensite  

NASA Astrophysics Data System (ADS)

18Ni (300) maraging steel possessing lath martensite structure was deformed by four passes of equal-channel angular pressing (ECAP) at ambient temperature. Line profile analysis (LPA) of X-ray diffraction (XRD) patterns identified strong strain anisotropy and remarkable increases in the relative fraction of screw dislocations after ECAP. The strain anisotropy was reasonably accounted for by the anisotropy of elastic constants. Domination of screw dislocations in the deformed structure was attributed to the preferred annihilation of edge dislocations in the early stages of deformation along with the difficulties for annihilation of screw dislocations by cross slipping. Cobalt addition was mainly assumed to make cross slipping difficult by reducing stacking-fault energy and favoring short-range ordering.

Hossein Nedjad, S.; Hosseini Nasab, F.; Movaghar Garabagh, M. R.; Damadi, S. R.; Nili Ahmadabadi, M.

2011-08-01

205

Quality experimental and calculated powder x-ray diffraction  

SciTech Connect

For several years, we have submitted quality powder XRD patterns to the International Centre for Diffraction Data for inclusion as reference standards in their Powder Diffraction File. The procedure followed is described; examples used are {beta}-UH{sub 3}, {alpha}- BaT{sub 2}, alpha-lithium disilicate ({alpha}-Li{sub 2}Si{sub 2}O{sub 5}), and 2,2`,4,4`,6,6`hexanitroazobenzene-III (HNAB-III).

Sullenger, D.B.; Cantrell, J.S.; Beiter, T.A.; Tomlin, D.W.

1996-08-01

206

Ultrafast X-ray Diffraction of Photodissociation of Iodoform in Solution  

SciTech Connect

We studied structural dynamics in the photodissociation of iodoform (CHI3) dissolved in methanol by time-resolved x-ray diffraction. A femtosecond laser pulse induces the bond-breaking of an iodine atom from iodoform and an x-ray pulse generated from a synchrotron gives time-dependent diffraction signal which contains the structural information of photoproducts with 100 ps time-resolution and 0.001 Aa spatial resolution. CHI2 radical and I atom are formed by the results of the ultrafast photodissociation of iodoform and these intermediates recombine to form iodoform again via geminate recombination. The iodine atoms which escape from the cages nongeminately recombine to form I2. Solvent dynamics, heating and solvent expansion, caused by photodissociation, are also explained from time-resolved x-ray diffraction data.

Lee, Jae Hyuk; Kim, Tae Kyu; Kim, Joonghan; Ihee, Hyotcherl [Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701 (Korea, Republic of); Lorenc, Maciej; Kong, Qingyu; Wulff, Michael [European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220 (France)

2007-01-19

207

Submicron X-ray diffraction and its applications to problems in materials and environmental science  

SciTech Connect

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.

Tamura, N.; Celestre, R.S.; MacDowell, A.A.; Padmore, H.A.; Spolenak, R.; Valek, B.C.; Meier Chang, N.; Manceau, A.; Patel, J.R.

2002-03-26

208

Submicron X-Ray Diffraction and its Applications to Problems in Materials and Environmental Science  

SciTech Connect

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.

Patel, J. R.

2002-08-16

209

Computed tomography of x-ray index of refraction using the diffraction enhanced imaging method.  

PubMed

Diffraction enhanced imaging (DEI) is a new, synchrotron-based, x-ray radiography method that uses monochromatic, fan-shaped beams, with an analyser crystal positioned between the subject and the detector. The analyser allows the detection of only those x-rays transmitted by the subject that fall into the acceptance angle (central part of the rocking curve) of the monochromator/analyser system. As shown by Chapman et al, in addition to the x-ray attenuation, the method provides information on the out-of-plane angular deviation of x-rays. New images result in which the image contrast depends on the x-ray index of refraction and on the yield of small-angle scattering, respectively. We implemented DEI in the tomography mode at the National Synchrotron Light Source using 22 keV x-rays, and imaged a cylindrical acrylic phantom that included oil-filled, slanted channels. The resulting 'refraction CT image' shows the pure image of the out-of-plane gradient of the x-ray index of refraction. No image artefacts were present, indicating that the CT projection data were a consistent set. The 'refraction CT image' signal is linear with the gradient of the refractive index, and its value is equal to that expected. The method, at the energy used or higher, has the potential for use in clinical radiography and in industry. PMID:10795982

Dilmanian, F A; Zhong, Z; Ren, B; Wu, X Y; Chapman, L D; Orion, I; Thomlinson, W C

2000-04-01

210

Femtosecond free-electron laser x-ray diffraction data sets for algorithm development.  

PubMed

We describe femtosecond X-ray diffraction data sets of viruses and nanoparticles collected at the Linac Coherent Light Source. The data establish the first large benchmark data sets for coherent diffraction methods freely available to the public, to bolster the development of algorithms that are essential for developing this novel approach as a useful imaging technique. Applications are 2D reconstructions, orientation classification and finally 3D imaging by assembling 2D patterns into a 3D diffraction volume. PMID:22418172

Kassemeyer, Stephan; Steinbrener, Jan; Lomb, Lukas; Hartmann, Elisabeth; Aquila, Andrew; Barty, Anton; Martin, Andrew V; Hampton, Christina Y; Bajt, Sa歛; Barthelmess, Miriam; Barends, Thomas R M; Bostedt, Christoph; Bott, Mario; Bozek, John D; Coppola, Nicola; Cryle, Max; DePonte, Daniel P; Doak, R Bruce; Epp, Sascha W; Erk, Benjamin; Fleckenstein, Holger; Foucar, Lutz; Graafsma, Heinz; Gumprecht, Lars; Hartmann, Andreas; Hartmann, Robert; Hauser, G黱ter; Hirsemann, Helmut; H鰉ke, Andr; Holl, Peter; J鰊sson, Olof; Kimmel, Nils; Krasniqi, Faton; Liang, Mengning; Maia, Filipe R N C; Marchesini, Stefano; Nass, Karol; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Schmidt, Carlo; Schulz, Joachim; Shoeman, Robert L; Sierra, Raymond G; Soltau, Heike; Spence, John C H; Starodub, Dmitri; Stellato, Francesco; Stern, Stephan; Stier, Gunter; Svenda, Martin; Weidenspointner, Georg; Weierstall, Uwe; White, Thomas A; Wunderer, Cornelia; Frank, Matthias; Chapman, Henry N; Ullrich, Joachim; Str黡er, Lothar; Bogan, Michael J; Schlichting, Ilme

2012-02-13

211

High Pressure X-Ray Diffraction Studies of Nanocrystalline Materials  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

212

X-Ray Diffraction Techniques for a Field Instrument: Patterns of Lithologic Provences  

NASA Technical Reports Server (NTRS)

Future exploration of Mars will attempt to shed light on the mineralogy of surface materials. Instruments deployed from remote platforms should have the capability to conduct both intensive analyses as well as rapid, reconnaissance surveys while they function in the martian environment as surrogate geologists. In order to accommodate the reconnaissance mode of analysis and to compensate for analytical limitations imposed by the space-flight conditions, data analysis methods are being developed that will permit interpretation of data by recognition of signatures or "fingerprints". Specifically, we are developing a technique which will allow interpretation of diffraction patterns by recognition of characteristic signatures of different lithologic provences. This technique allows a remote vehicle to function in a rapid-scan mode using the lithologic signature to determine where a more thorough analysis is needed. An x-ray diffraction pattern is characterized by the angular positions of diffracted x-rays, x-ray intensity levels and background radiation levels. These elements may be used to identify a generalized x-ray signature. Lithologic signatures are being developed in two ways. A signature is composed using the ideal powder diffraction indices from the mineral assembledge common to a specific lithologic provence. This is then confirmed using a laboratory diffraction pattern of a whole rock powder. Preliminary results comparing the diffraction signatures of the major mineral assembledges common to basalt, carbonate, and evaporite basin deposits indicate that lithologies are differentiable as a "fingerprint". Statistical analyses are being performed to establish the confidence levels of this technique.

Marshall, J.; Keaten, R.

1999-01-01

213

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

SciTech Connect

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{sub 0.67}Sr{sub 0.33}MnO{sub 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.

Sun, Cheng-Jun, E-mail: cjsun@aps.anl.gov; Brewe, Dale L.; Heald, Steve M. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Zhang, Bangmin [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore); NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore); Chen, Jing-Sheng; Chow, G. M. [Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore)] [Department of Materials Science and Engineering, National University of Singapore, 117575 Singapore (Singapore); Venkatesan, T. [NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore) [NUSNNI-Nanocore, National University of Singapore, 117411 Singapore (Singapore); Department of Physics, National University of Singapore, 117542 Singapore (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 117575 Singapore (Singapore)

2014-04-15

214

X-ray Diffraction and Absorption Spectroscopy in Pulsed High Magnetic Fields  

NASA Astrophysics Data System (ADS)

Recent results of high-magnetic-field X-ray diffraction and absorption spectroscopy experiments using pulsed magnets are reviewed. Pulsed magnetic fields of up to 30--40 T are utilized. Structural changes induced by magnetic fields in rare-earth intermetallic compounds, transition-metal oxides and low-dimensional quantum spin compounds are presented as results of X-ray diffraction experiments. The structural changes are interpreted by several mechanisms such as the interspin distance dependence of exchange interactions, the symmetry change owing to the geometrical frustration effect, and the Jahn--Teller effect. In addition to the Thomson scattering experiment, a magnetic X-ray scattering experiment on TbB4 has been conducted at 30 T. Regarding X-ray absorption spectroscopy, the valence state transition in magnetic fields is observed in Yb-, Ce-, and Eu-based intermetallic compounds. Magnetic-field-induced changes in the structural and electronic states in transition-metal and rare-earth compounds were investigated using X-ray absorption spectra. The microscopic magnetic properties were examined by X-ray magnetic circular dichroism.

Matsuda, Yasuhiro H.; Inami, Toshiya

2013-02-01

215

Pump-probe X-ray Diffraction Technique for Irreversible Phase Change Materials  

NASA Astrophysics Data System (ADS)

We have developed a pump-probe X-ray diffraction measurement system for a sample with irreversible reaction at BL40XU in the SPring-8. The system mainly consists of a time-resolved measurement system, a sample disk rotation system, and an X-ray microbeam system. The time-resolved measurement system gives time resolution of 50 ps in laser-pump and X-ray probe method. A sample disk rotation system for repetitive measurements was made to give a virgin sample for every measurement. The number of repetitions for one sample disk was increased by using the X-ray microbeam technique. To keep the overlap of the X-ray microbeam and the laser beam on the sample surface during the disk rotation, the sample disk rotation system was constructed by a low-eccentric spindle motor. By using this system, the pump-probe X-ray diffraction measurement was demonstrated for a crystallization process of a DVD material.

Fukuyama, Yoshimitsu; Yasuda, Nobuhiro; Kimura, Shigeru; Tanaka, Yoshihito; Osawa, Hitoshi; Kim, Jungeun; Murayama, Haruno; Moritomo, Yutaka; Toriumi, Koshiro; Tanaka, Hitoshi; Takata, Masaki

2010-06-01

216

Pump-probe X-ray Diffraction Technique for Irreversible Phase Change Materials  

SciTech Connect

We have developed a pump-probe X-ray diffraction measurement system for a sample with irreversible reaction at BL40XU in the SPring-8. The system mainly consists of a time-resolved measurement system, a sample disk rotation system, and an X-ray microbeam system. The time-resolved measurement system gives time resolution of 50 ps in laser-pump and X-ray probe method. A sample disk rotation system for repetitive measurements was made to give a virgin sample for every measurement. The number of repetitions for one sample disk was increased by using the X-ray microbeam technique. To keep the overlap of the X-ray microbeam and the laser beam on the sample surface during the disk rotation, the sample disk rotation system was constructed by a low-eccentric spindle motor. By using this system, the pump-probe X-ray diffraction measurement was demonstrated for a crystallization process of a DVD material.

Fukuyama, Yoshimitsu; Yasuda, Nobuhiro; Kimura, Shigeru; Osawa, Hitoshi; Kim, Jungeun [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Tanaka, Yoshihito; Takata, Masaki [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Murayama, Haruno [Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan); Moritomo, Yutaka [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8571 (Japan); Toriumi, Koshiro [Japan Science and Technology Agency, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Tanaka, Hitoshi [RIKEN XFEL Joint Project/SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2010-06-23

217

Studies of Materials at the Nanometer Scale Using Coherent X-Ray Diffraction Imaging  

NASA Astrophysics Data System (ADS)

For many years, x-ray microscopy has been attractive for materials studies with its ability to image thick samples and provide nanometer-scale resolution. However, the ability to manufacture high-resolution x-ray optics has been a hurdle to achieving the full potential of diffraction limited x-ray imaging. Recently, the advent of bright and coherent x-ray sources at synchrotrons and x-ray free electron lasers has enabled a lensless imaging technique called coherent diffractive imaging (CDI). Since it was first demonstrated in 1999, CDI has been rapidly developing into a materials imaging technique with resolutions approaching a few nanometers. This review provides an overview of the development of CDI and several applications to nanometer-scale imaging in two and three dimensions of biological and condensed mater materials. Also, we review the development of tabletop, coherent, soft x-ray sources that provide a complimentary and potentially more accessible source for nanometer-scale coherent imaging of materials.

Sandberg, Richard L.; Huang, Zhifeng; Xu, Rui; Rodriguez, Jose A.; Miao, Jianwei

2013-09-01

218

Coherent x-ray diffraction imaging of paint pigmentparticles by scanning a phase plate modulator  

SciTech Connect

We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

Chu Y. S.; Chen B.; Zhang F.; Berenguer F.; Bean R.; Kewish C.; Vila-Comamala J.; Rodenburg J.; Robinson I.

2011-10-19

219

Diffraction-Enhanced Imaging of Musculoskeletal Tissues Using a Conventional X-Ray Tube  

SciTech Connect

DEI based on a conventional x-ray tube allows the visualization of skeletal and soft tissues simultaneously. Although more in-depth testing and optimization of the DEI setup must be carried out, these data demonstrate a proof of principle for further development of the technology for future clinical imaging. In conventional projection radiography, cartilage and other soft tissues do not produce enough radiographic contrast to be distinguishable from each other. Diffraction-enhanced imaging (DEI) uses a monochromatic x-ray beam and a silicon crystal analyzer to produce images in which attenuation contrast is greatly enhanced and x-ray refraction at tissue boundaries can be detected. The aim of this study was to test the efficacy of conventional x-ray tube-based DEI for the detection of soft tissues in experimental samples.

Muehleman, C.; Li, J; Connor, D; Parham, C; Pisano, E; Zhong, Z

2009-01-01

220

A framework for 3-D coherent diffraction imaging by focused beam x-ray Bragg ptychography.  

SciTech Connect

We present the framework for convergent beam Bragg ptychography, and, using simulations, we demonstrate that nanocrystals can be ptychographically reconstructed from highly convergent x-ray Bragg diffraction. The ptychographic iterative engine is extended to three dimensions and shown to successfully reconstruct a simulated nanocrystal using overlapping raster scans with a defocused curved beam, the diameter of which matches the crystal size. This object reconstruction strategy can serve as the basis for coherent diffraction imaging experiments at coherent scanning nanoprobe x-ray sources.

Hruszkewycz, S. O.; Holt, M. V.; Tripathi, A.; Maser, J.; Fuoss, P. H. (Center for Nanoscale Materials); ( MSD); (Univ. of California at San Diego)

2011-06-15

221

Antibiotic amphotericin B-DPPC lipid complex: X-ray diffraction and FTIR studies  

NASA Astrophysics Data System (ADS)

In this work, we studied the formation of a complex between the polyene antibiotic amphotericin B (AmB) and dipalmitoylphosphatidylcholine (DPPC) lipid multibilayers by means of X-ray diffraction and FTIR spectroscopy. The complex formation can be detected in multibilayers by characteristic reflection around 2.2 -1. The FTIR spectra indicate that in this case AmB lowers the main phase transition of DPPC. Additionally, with an increase in temperature, a shift of AmB towards the hydrophilic part of the DPPC bilayer is observed. For the first time, such complex formation has been observed by X-ray diffraction and discussed.

Kami?ski, Daniel M.; Arczewska, Marta; Pociecha, Damian; G髍ecka, Ewa; St?pniewski, Andrzej; Gago?, Mariusz

2015-01-01

222

Phase Sensitive X-Ray Diffraction Imaging of Defects in Biological Macromolecular Crystals  

NASA Technical Reports Server (NTRS)

Characterization of defects and/or disorder in biological macromolecular crystals presents much greater challenges than in conventional small-molecule crystals. The lack of sufficient contrast of defects is often a limiting factor in x-ray diffraction topography of protein crystals. This has seriously hampered efforts to understand mechanisms and origins of formation of imperfections, and the role of defects as essential entities in the bulk of macromolecular crystals. In this report, we employ a phase sensitive x-ray diffraction imaging approach for augmenting the contrast of defects in protein crystals.

Hu, Z. W.; Lai, B.; Chu, Y. S.; Cai, Z.; Mancini, D. C.; Thomas, B. R.; Chernov, A. A.; Curreri, Peter A. (Technical Monitor)

2002-01-01

223

X-ray diffraction of krypton and xenon mixtures adsorbed on graphite T. Ceva, M. Goldmann (*) and C. Marti  

E-print Network

1527 X- ray diffraction of krypton and xenon mixtures adsorbed on graphite T. Ceva, M. Goldmann 1986) R茅sum茅. 2014 En 茅tudiant, par diffraction des rayons X, les m茅langes xenon-krypton absorb茅s sur. Abstract 2014 Mixtures of xenon and krypton adsorbed on graphite at 45 K are studied by X ray diffraction

Boyer, Edmond

224

Normalization schemes for ultrafast x-ray diffraction using a table-top laser-driven plasma source  

SciTech Connect

We present an experimental setup of a laser-driven x-ray plasma source for femtosecond x-ray diffraction. Different normalization schemes accounting for x-ray source intensity fluctuations are discussed in detail. We apply these schemes to measure the temporal evolution of Bragg peak intensities of perovskite superlattices after ultrafast laser excitation.

Schick, D.; Bojahr, A.; Herzog, M. [Institut fuer Physik and Astronomie, Universitaet Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam (Germany); Korff Schmising, C. von [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Strasse des 17. Juni 135, 10623 Berlin (Germany); Shayduk, R.; Leitenberger, W.; Gaal, P.; Bargheer, M. [Helmholtz Zentrum Berlin, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

2012-02-15

225

Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging  

SciTech Connect

X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 12 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.

Evans, P. G., E-mail: evans@engr.wisc.edu; Spalenka, J. W. [Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Chahine, G.; Grifone, R.; Jacques, V. L. R.; Sch黮li, T. U. [European Synchrotron Radiation Facility, Grenoble 38043 (France)] [European Synchrotron Radiation Facility, Grenoble 38043 (France)

2013-11-15

226

High Resolution Triple Axis X-Ray Diffraction Analysis of II-VI Semiconductor Crystals  

NASA Technical Reports Server (NTRS)

The objective of this research program is to develop methods of structural analysis based on high resolution triple axis X-ray diffractometry (HRTXD) and to carry out detailed studies of defect distributions in crystals grown in both microgravity and ground-based environments. HRTXD represents a modification of the widely used double axis X-ray rocking curve method for the characterization of grown-in defects in nearly perfect crystals. In a double axis rocking curve experiment, the sample is illuminated by a monochromatic X-ray beam and the diffracted intensity is recorded by a fixed, wide-open detector. The intensity diffracted by the sample is then monitored as the sample is rotated through the Bragg reflection condition. The breadth of the peak, which is often reported as the full angular width at half the maximum intensity (FWHM), is used as an indicator of the amount of defects in the sample. This work has shown that high resolution triple axis X-ray diffraction is an effective tool for characterizing the defect structure in semiconductor crystals, particularly at high defect densities. Additionally, the technique is complimentary to X-ray topography for defect characterization in crystals.

Volz, H. M.; Matyi, R. J.

1999-01-01

227

High Pressure X-Ray Diffraction Studies on Nanocrystalline Materials  

NASA Technical Reports Server (NTRS)

Application of in situ high pressure powder diffraction technique for examination of specific structural properties of nanocrystals based on the experimental data of SiC nanocrystalline powders of 2 to 30 nrn diameter in diameter is presented. Limitations and capabilities of the experimental techniques themselves and methods of diffraction data elaboration applied to nanocrystals with very small dimensions (< 30 nm) are discussed. It is shown that due to the complex structure, constituting a two-phase, core/surface shell system, no unique lattice parameter value and, consequently, no unique compressibility coefficient can satisfactorily describe the behavior of nanocrystalline powders under pressure. We offer a tentative interpretation of the distribution of macro- and micro-strains in nanoparticles of different grain size.

Palosz, B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Pielaszek, R.; Bismayer, U.; Werner, S.; Palosz, W.

2003-01-01

228

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

NASA Astrophysics Data System (ADS)

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.

Ghammraoui, B.; Tabary, J.; Pouget, S.; Paulus, C.; Moulin, V.; Verger, L.; Duvauchelle, Ph.

2012-02-01

229

Method of X-Ray Anomalous Diffraction for Lipid Structures  

PubMed Central

The structures of the unit cells of lipid phases that exhibit long-range crystalline order but short-range liquid-like disorder are of biological interests. In particular, the recently discovered rhombohedral phase has a unit cell containing either the structure of a membrane fusion intermediate state or that of a peptide-induced transmembrane pore, depending on the lipid composition and participating peptides. Diffraction from such systems generally presents a difficult phase problem. The existing methods of phase determination all have their limitations. Therefore it is of general interest to develop a new phasing method. The method of multi-wavelength anomalous dispersion is routinely used in protein crystallography, but the same method is difficult for lipid systems for the practical reason that the commonly used lipid samples for diffraction do not have a well-defined thickness. Here we describe a practical approach to use the multi-wavelength anomalous dispersion method for lipid structures. The procedure is demonstrated with the lamellar phase of a brominated lipid. The method is general to all phases as long as anomalous diffraction is applicable. PMID:16632507

Wang, Wangchen; Pan, Deng; Song, Yang; Liu, Wenhan; Yang, Lin; Huang, Huey W.

2006-01-01

230

Natural Language Processing for Lines and Devices in Portable Chest X-Rays  

E-print Network

Natural Language Processing for Lines and Devices in Portable Chest X-Rays Journal: AMIA 2010 in Portable Chest X-Rays Daniel Rubin, MD, MS,1,2 Dan Wang, PhD,1 Dallas A. Chambers,1 Justin G. Chambers,1 exploration based on mining radiology reports. Introduction Portable chest X-ray (CXR) imaging is a prevalent

Rubin, Daniel L.

231

X-Ray Weak Broad-Line Quasars: Absorption or Intrinsic X-Ray Weakness  

NASA Technical Reports Server (NTRS)

XMM observations of X-ray weak quasars have been performed during 2003. The data for all but the last observation are now available (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed these data, and obtained interesting preliminary scientific results. Out of the eight sources, 4 are confirmed to be extrimely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confirmed to be highly variable both in flux (by factors 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects, an article is in preparation. Preliminary results have been presented at an international workshop on AGN surveys in December 2003, in Cozumel (Mexico). In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations, and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations will be performed in early 2004, and will complement the XMM data, in order to understand whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circumnuclear material.

Risaliti, Guido; Mushotzky, Richard F. (Technical Monitor)

2004-01-01

232

Hydrothermal formation of tobermorite studied by in situ X-ray diffraction under autoclave condition.  

PubMed

Hydrothermal formation of tobermorite from a pre-cured cake has been investigated by transmission X-ray diffraction (XRD) using high-energy X-rays from a synchrotron radiation source in combination with a newly designed autoclave cell. The autoclave cell has a large and thin beryllium window for wide-angle X-ray diffraction; nevertheless, it withstands a steam pressure of more than 1.2 MPa, which enables in situ XRD measurements in a temperature range of 373 to 463 K under a saturated steam pressure. Formation and/or decomposition of several components has been successfully observed during 7.5 h of reaction time. From the intensity changes of the intermediate materials, namely non-crystalline C-S-H and hydroxylellestadite, two pathways for tobermorite formation have been confirmed. Thus, the newly developed autoclave cell can be used for the analyses of reaction mechanisms under specific atmospheres and temperatures. PMID:19713643

Kikuma, Jun; Tsunashima, Masamichi; Ishikawa, Tetsuji; Matsuno, Shin-ya; Ogawa, Akihiro; Matsui, Kunio; Sato, Masugu

2009-09-01

233

X-ray diffraction of indirect flight muscle from Drosohila in vivo  

SciTech Connect

The indirect flight muscle (IFM) of the fruit fly, Drosophila, represents a powerful model system for integrated structure and function studies because of the ease of genetically manipulating this organism. Recent advances in synchrotron technology have allowed collection of high quality two dimensional x-ray fiber diffraction patterns from the IFM of living fruit flies both at rest and during tethered flight. Based on many decades of x-ray and electron microscopic studies of vertebrate muscle and IFM from the waterbug, Lethocerus, there now exists a framework for interpreting changes in the x-ray diffraction patterns in terms of structural changes at the myofilament level. These developments allow testing of hypotheses concerning muscle function in a truly in vivo system.

Irving, T. (IIT)

2007-02-09

234

Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation  

NASA Astrophysics Data System (ADS)

We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into 10-?m-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.

Lima, Enju; Chushkin, Yuriy; van der Linden, Peter; Kim, Chae Un; Zontone, Federico; Carpentier, Philippe; Gruner, Sol M.; Pernot, Petra

2014-10-01

235

Hydrogen atoms in protein structures: high-resolution X-ray diffraction structure of the DFPase  

PubMed Central

Background Hydrogen atoms represent about half of the total number of atoms in proteins and are often involved in substrate recognition and catalysis. Unfortunately, X-ray protein crystallography at usual resolution fails to access directly their positioning, mainly because light atoms display weak contributions to diffraction. However, sub-舗gstrom diffraction data, careful modeling and a proper refinement strategy can allow the positioning of a significant part of hydrogen atoms. Results A comprehensive study on the X-ray structure of the diisopropyl-fluorophosphatase (DFPase) was performed, and the hydrogen atoms were modeled, including those of solvent molecules. This model was compared to the available neutron structure of DFPase, and differences in the protein and the active site solvation were noticed. Conclusions A further examination of the DFPase X-ray structure provides substantial evidence about the presence of an activated water molecule that may constitute an interesting piece of information as regard to the enzymatic hydrolysis mechanism. PMID:23915572

2013-01-01

236

Perspective: Structural dynamics in condensed matter mapped by femtosecond x-ray diffraction  

SciTech Connect

Ultrashort soft and hard x-ray pulses are sensitive probes of structural dynamics on the picometer length and femtosecond time scales of electronic and atomic motions. Recent progress in generating such pulses has initiated new directions of condensed matter research, exploiting a variety of x-ray absorption, scattering, and diffraction methods to probe photoinduced structural dynamics. Atomic motion, changes of local structure and long-range order, as well as correlated electron motion and charge transfer have been resolved in space and time, providing a most direct access to the physical mechanisms and interactions driving reversible and irreversible changes of structure. This perspective combines an overview of recent advances in femtosecond x-ray diffraction with a discussion on ongoing and future developments.

Elsaesser, T.; Woerner, M. [Max-Born-Institut f黵 Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin (Germany)] [Max-Born-Institut f黵 Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin (Germany)

2014-01-14

237

An X-ray diffractometer using mirage diffraction  

PubMed Central

Some characteristics are reported of a triple-crystal diffractometer with a (+,??,?+) setting of Si(220) using mirage diffraction. The first crystal is flat, while the second and third crystals are bent. Basically, the first crystal is used as a collimator, the second as a monochromator and the third as the sample. The third crystal also works as an analyzer. The advantages of this diffractometer are that its setup is easy, its structure is simple, the divergence angle from the second crystal is small and the energy resolution of the third crystal is high, of the order of sub-meV. PMID:25242911

Fukamachi, Tomoe; Jongsukswat, Sukswat; Ju, Dongying; Negishi, Riichirou; Hirano, Keiichi; Kawamura, Takaaki

2014-01-01

238

An X-ray diffractometer using mirage diffraction.  

PubMed

Some characteristics are reported of a triple-crystal diffractometer with a (+,?-,?+) setting of Si(220) using mirage diffraction. The first crystal is flat, while the second and third crystals are bent. Basically, the first crystal is used as a collimator, the second as a monochromator and the third as the sample. The third crystal also works as an analyzer. The advantages of this diffractometer are that its setup is easy, its structure is simple, the divergence angle from the second crystal is small and the energy resolution of the third crystal is high, of the order of sub-meV. PMID:25242911

Fukamachi, Tomoe; Jongsukswat, Sukswat; Ju, Dongying; Negishi, Riichirou; Hirano, Keiichi; Kawamura, Takaaki

2014-08-01

239

Diffraction crystals for sagittally focusing x-rays  

DOEpatents

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, G.E.; Sparks, C.J. Jr.

1982-06-07

240

Mapping Strain in Nanocrystalline Nitinol: an X-ray Diffraction Method (SULI paper)  

SciTech Connect

Understanding the mechanical properties of biomedical devices is critical in predicting and preventing their failure in the body. Such knowledge is essential, for example, in the design of biomedical stents, which must undergo repeated strain over their ten year lifetimes without breaking. Computational models are used to predict mechanical response of a device, but these models are not complete; there are significant deviations from the predictions, especially when devices are subjected to repeated multi-axial loads. Improving these models requires comparisons with actual measurements of strained nitinol. Local measurements of the full strain tensor can be made using X-ray diffraction techniques, but they are currently limited to materials whose grain size is larger than the X-ray beam size or require several diffraction patterns produced by rotation of the sample. Nitinol stents are nanocrystalline, with grains smaller than any available X-ray beam. We present a method for measuring the local strain in a nanocrystalline material from a single X-ray diffraction pattern by extending current powder diffraction techniques. The components of the strain tensor are mapped onto a displacement ellipsoid, which is then reconstructed from diffraction data through Bragg's law and least-squares fitting. Using simulated diffraction data, we performed sensitivity tests to examine how the accuracy of the method depends on how much of the diffraction pattern is measured. We found that strain can be accurately calculated from measurements of at least three diffraction arcs of at least 20{sup o} in length. Thus we believe that our method is a viable approach to calculating strain provided a sufficient amount of diffraction pattern is recorded.

Bibee, Mathew; /SLAC, SSRL

2006-01-04

241

Magnetic symmetries in neutron and resonant x-ray Bragg diffraction patterns of four iridium oxides  

NASA Astrophysics Data System (ADS)

The magnetic properties of Sr2IrO4, Na2IrO3, Sr3Ir2O7 and CaIrO3 are discussed, principally in the light of experimental data in recent literature for Bragg intensities measured in x-ray diffraction with enhancement at iridium L-absorption edges. The electronic structure factors we report, which incorporate parity-even and acentric entities, serve the immediate purpose of making full use of crystal and magnetic symmetry to refine our knowledge of the magnetic properties of the four iridates from resonant x-ray diffraction data. They also offer a platform on which to interpret future investigations, using dichroic signals, resonant x-ray diffraction and neutron diffraction, for example, as well as ab initio calculations of electronic structure. Unit-cell structure factors, suitable for x-ray Bragg diffraction enhanced by an electric dipole-electric dipole (E1-E1) event, reveal exactly which iridium multipoles are visible, e.g., a magnetic dipole parallel to the crystal c-axis (z-axis) and an electric quadrupole with yz-like symmetry in the specific case of CaIrO3. Magnetic space-groups are assigned to Sr2IrO4, Sr3Ir2O7 and CaIrO3, namely, PIcca, PAban and Cm?cm?, respectively, in the Belov-Neronova-Smirnova notation. The assignment for Sr2IrO4 is possible because of our new high-resolution neutron diffraction data, gathered on a powder sample. In addition, the new data are used to show that the ordered magnetic moment of an Ir4+ ion in Sr2IrO4 does not exceed 0.29(4) ?B. Na2IrO3 has two candidate magnetic space-groups that are not resolved with currently available resonant x-ray data.

Lovesey, S. W.; Khalyavin, D. D.; Manuel, P.; Chapon, L. C.; Cao, G.; Qi, T. F.

2012-12-01

242

X-ray diffraction phase analysis of the crystalline phase of polytetrafluoroethylene  

SciTech Connect

Samples of ultradispersed polytetrafluoroethylene, which were prepared with the use of different technological approaches, were studied by X-ray diffraction. The samples were found to belong to the monoclinic system. For some samples, basal reflections, which can be related to paraffins, were found for the first time. This indicates that polymer chains can form yet another type of monoclinic structure.

Lebedev, Yu. A., E-mail: y_lebedev@mail.ru; Korolev, Yu. M.; Rebrov, A. V. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation); Ignat'eva, L. N. [Russian Academy of Sciences, Institute of Chemistry, Far East Division (Russian Federation); Antipov, E. M. [Russian Academy of Sciences, Topchiev Institute of Petrochemical Synthesis (Russian Federation)

2010-07-15

243

Femtosecond time-resolved powder diffraction experiments using hard X-ray free-electron lasers.  

PubMed

In the next decade the scientific community expects a strong impact in physics, chemistry, biology, material research and life sciences by the availability of high-brilliance X-ray radiation from free-electron laser (FEL) sources. In particular, in the field of ultrafast science these new sources will allow new types of experiments, enabling new phenomena to be discovered. Whereas today ultrafast X-ray diffraction experiments are strongly restricted by the limited X-ray flux of current sources of sub-picosecond X-ray pulses, FELs will provide short pulses of typically 10(12) photons with a duration of the order of 100 fs and monochromaticity of 10(-3). Here, the feasibility of time-resolved single-shot powder diffraction experiments using these intense pulses, and the requirements of these experiments, are discussed. The detector count rates are estimated for diffraction from a model compound in a wide q-regime under the special consideration of high resolving power. In the case of LCLS radiation parameters, single-shot experiments will be feasible although high-resolution powder diffraction will require a reduction of the intrinsic FEL radiation bandwidth. PMID:16239753

Blome, C; Tschentscher, Th; Davaasambuu, J; Durand, P; Techert, S

2005-11-01

244

Structural Order-Disorder Transformations Monitored by X-Ray Diffraction and Photoluminescence  

ERIC Educational Resources Information Center

A study was conducted to examine the structural order-disorder transformation promoted by controlled heat treatment using X-ray diffraction technique (XRD) and photoluminescence (PL) techniques as tools to monitor the degree of structural order. The experiment was observed to be versatile and easily achieved with low cost which allowed producing

Lima, R. C.; Paris, E. C.; Leite, E. R.; Espinosa, J. W. M.; Souza, A. G.; Longo, E.

2007-01-01

245

Energy Dispersive X Ray Diffraction to identify Explosive Substances : spectra analysis procedure optimization  

E-print Network

Energy Dispersive X Ray Diffraction to identify Explosive Substances : spectra analysis procedure, France tel: 0033472437084 Abstract: To detect the presence of explosives in packages, automated systems for explosive detection and identification. To this end, a database has been constructed, containing measured X

Paris-Sud XI, Universit茅 de

246

Synchrotron X-ray diffraction characterization of healthy and fluorotic human dental enamel  

NASA Astrophysics Data System (ADS)

With the introduction of fluoride as the main anticaries agent used in preventive dentistry, and perhaps an increase in fluoride in our food chain, dental fluorosis has become an increasing world-wide problem. Visible signs of fluorosis begin to become obvious on the enamel surface as opacities, implying some porosity in the tissue. The mechanisms that conduct the formation of fluorotic enamel are unknown, but should involve modifications in the basic physical-chemistry reactions of demineralization and remineralisation of the enamel of the teeth, which is the same reaction of formation of the enamel's hydroxyapatite (HAp) in the maturation phase. The increase of the amount of fluoride inside of the apatite will result in gradual increase of the lattice parameters. The aim of this work is to characterize the healthy and fluorotic enamel in human tooth using Synchrotron X-ray diffraction. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the Brazilian Synchrotron Light Laboratory桳NLS, Campinas, Brazil. X-ray diffraction experiments were performed both in powder samples and polished surfaces. The powder samples were analyzed to obtain the characterization of a typical healthy enamel pattern. The polished surfaces were analyzed in specific areas that have been identified as fluorotic ones. X-ray diffraction data were obtained for all samples and these data were compared with the control samples and also with the literature data.

Cola鏾, M. V.; Barroso, R. C.; Porto, I. M.; Gerlach, R. F.; Costa, F. N.; Braz, D.; Droppa, R.; de Sousa, F. B.

2012-10-01

247

A-DNA and B-DNA: Comparing Their Historical X-Ray Fiber Diffraction Images  

ERIC Educational Resources Information Center

A-DNA and B-DNA are two secondary molecular conformations (among other allomorphs) that double-stranded DNA drawn into a fiber can assume, depending on the relative water content and other chemical parameters of the fiber. They were the first two forms to be observed by X-ray fiber diffraction in the early 1950s, respectively by Wilkins and

Lucas, Amand A.

2008-01-01

248

Scanning AC nanocalorimetry combined with in-situ X-ray Diffraction  

E-print Network

,c , Kechao Xiao2,c , Patrick J. McCluskey3,b , Darren Dale4 , Joost J. Vlassak2,a 1 Joint Center1 Scanning AC nanocalorimetry combined with in-situ X- ray Diffraction John M. Gregoire1,b of solid-state reactions and phase transformations. a) e-mail address: vlassak@esag.harvard.edu b

249

Systematic corrections in Bragg x-ray diffraction of flat and curved crystals  

Microsoft Academic Search

Measurements of spectral wavelengths in Bragg diffraction from crystals often require refractive index corrections to allow a detailed comparison of experiment with theory. These corrections are typically 100--300 ppm in the x-ray regime, and simple estimates may sometimes be accurate to 5% or better. The inadequacies of these estimates are discussed. Even with a improved index of refraction estimate, this

C. T. Chantler; R. D. Deslattes

1995-01-01

250

Synchrotron X-ray diffraction study of the room temperature incommensurate phase in graphite-bromine  

E-print Network

L-761 Synchrotron X-ray diffraction study of the room temperature incommensurate phase in graphite-bromine- bromine en second stade 脿 temp茅rature ambiante. Le compos茅 graphite-brome a 茅t茅 pr茅par茅 脿 partir d- perature incommensurate phase in stage-2 graphite-bromine prepared with single crystal graphite in bromine

Paris-Sud XI, Universit茅 de

251

Silicon carbide surface structure investigated by synchrotron radiation-based x-ray diffraction  

E-print Network

Silicon carbide surface structure investigated by synchrotron radiation-based x-ray diffraction H silicon or germanium surfaces. 漏 2003 American Vacuum Society. DOI: 10.1116/1.1588650 Silicon carbide Si, with alternating silicon and carbon atomic planes in the 100 direction, so that one can expect some similarity

Chiang, Shirley

252

X-ray diffraction by a crystal in a permanent external electric field: general considerations.  

PubMed

The variations of X-ray diffraction intensities from a crystal in the presence of a permanent external electric field is modeled analytically using a first-order stationary perturbation theory. The change in a crystal, induced by an external electric field, is separated into two contributions. The first one is related to a pure polarization of an electron subsystem, while the second contribution can be reduced to the displacements of the rigid pseudoatoms from their equilibrium positions. It is shown that a change of the X-ray diffraction intensities mainly originates from the second contribution, while the influence of the pure polarization of a crystal electron subsystem is negligibly small. The quantities restored from an X-ray diffraction experiment in the presence of an external electric field were analyzed in detail in terms of a rigid pseudoatomic model of electron density and harmonic approximation for the atomic thermal motion. Explicit relationships are derived that link the properties of phonon spectra with E-field-induced variations of a structure factor, pseudoatomic displacements and piezoelectric strains. The displacements can be numerically estimated using a model of independent atomic motion if the Debye-Waller factors and pseudoatomic charges are known either from a previous single-crystal X-ray diffraction study or from density functional theory calculations. The above estimations can be used to develop an optimum strategy for a data collection that avoids the measurements of reflections insensitive to the electric-field-induced variations. PMID:15972991

Gorfman, Semen V; Tsirelson, Vladimir G; Pietsch, Ullrich

2005-07-01

253

Structural investigation of porcine stomach mucin by X-ray fiber diffraction and homology modeling  

SciTech Connect

Research highlights: {yields} Techniques to get oriented mucin fibre. {yields} X-ray fibre diffraction pattern for mucin. {yields} Molecular modeling of mucin based on X-ray fibre diffraction pattern. -- Abstract: The basic understanding of the three dimensional structure of mucin is essential to understand its physiological function. Technology has been developed to achieve orientated porcine stomach mucin molecules. X-ray fiber diffraction of partially orientated porcine stomach mucin molecules show d-spacing signals at 2.99, 4.06, 4.22, 4.7, 5.37 and 6.5 A. The high intense d-spacing signal at 4.22 A is attributed to the antiparallel {beta}-sheet structure identified in the fraction of the homology modeled mucin molecule (amino acid residues 800-980) using Nidogen-Laminin complex structure as a template. The X-ray fiber diffraction signal at 6.5 A reveals partial organization of oligosaccharides in porcine stomach mucin. This partial structure of mucin will be helpful in establishing a three dimensional structure for the whole mucin molecule.

Veluraja, K., E-mail: veluraja@msuniv.ac.in [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu 627012 (India); Vennila, K.N. [CAS in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, Tamilnadu 600025 (India)] [CAS in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, Tamilnadu 600025 (India); Umamakeshvari, K.; Jasmine, A. [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu 627012 (India)] [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu 627012 (India); Velmurugan, D. [CAS in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, Tamilnadu 600025 (India)] [CAS in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, Tamilnadu 600025 (India)

2011-03-25

254

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

NASA Astrophysics Data System (ADS)

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. 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 and the full width at half maximum intensity (FWHM) 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 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 relationship, it was suggested that direct expectation of the life consumption rate was feasible.

Yoo, Keun Bong; Hwang, Kwon Tae; Chang, Jung Chel; Kim, Jae Hoon

2009-07-01

255

X-Ray Diffraction Study of L2005 AG17 (IDPs) by Using SR  

NASA Technical Reports Server (NTRS)

X-ray diffraction study revealed the existence of magnetite and new type of pyrrhotite with the chemical formula of Fe0.56S in L2005 AG17. Considering the total chemical formula of Fe0.83S, residual iron in amorphous state might exist in this sample. Additional information is contained in the original extended abstract.

Ohsumi, K. O.; Hagiya, K. H.; Zolensky, M. E.

2002-01-01

256

Molecular packing in new Langmuir-Blodgett systems investigated by X-ray specular reflectivity and grazing incidence X-ray diffraction  

Microsoft Academic Search

In this work we investigate the periodic arrangementand crystalline order of Langmuir-Blodgett multilayers of a perylene-3,4,9,10-tetracarboxyldimide derivative (PTCDI-Opent) and of a long chain ammonium salt of 12-phosphomolybdate (PMo12O403?) deposited on (111)-oriented Si substrates by X-ray specular reflectivity (XSR) and grazing incidence X-ray diffraction measurements (GIXD). This is the first experimental study of the structural order performed on these complex compounds.

C. Giannini; L. Tapfer; M. Sauvagesimkin; Y. Garreau; N. Jedrecy; M. B. V閞on; R. Pinchaux; M. Burghard; S. Roth

1996-01-01

257

Characterization of phases formed in the iron carbide process by X-ray diffraction, mossbauer, X-ray photoelectron spectroscopy, and raman spectroscopy analyses  

Microsoft Academic Search

Iron carbide was prepared by iron ore reduction and iron cementation using Ar-H2-CH4 gas mixture with and without sulfur. Phases formed in the reduction\\/cementation process were examined by X-ray diffraction\\u000a (XRD), Mossbauer, and Raman spectroscopy. The sample surface was also analyzed by X-ray photoelectron spectroscopy (XPS).\\u000a XRD and Mossbauer analyses showed that iron oxide was first reduced to metallic iron,

Oleg Ostrovski; Jianqiang Zhang; Stuart Thomson; Russell Howe

2001-01-01

258

Development of an x-ray diffraction camera used in magnetic fields up to 10 T  

SciTech Connect

A high-field x-ray diffraction (HF-XRD) camera was developed to observe structural changes of magnetic materials in magnetic fields up to 10 T. The instrument mainly consists of a Debye-Scherrer-type camera with a diameter of 80.1 mm, a 10-T cryocooled superconducting magnet with a 100-mm room-temperature bore, an x-ray source, a power supply, and a chiller for the x-ray source. An x-ray detector (image plate) in the HF-XRD camera can be taken out and inserted into the magnet without changing the sample position. The performance of the instrument was tested by measuring the HF-XRD for silicon and ferromagnetic MnBi powders. A change of x-ray diffraction pattern was observed due to the magnetic orientation of MnBi, showing that the instrument is useful for studying field-induced orientation processes and structural properties of field-controlled materials.

Mitsui, Yoshifuru; Takahashi, Kohki; Watanabe, Kazuo [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Koyama, Keiichi [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Graduate School for Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan)

2011-12-15

259

X-Ray Powder Diffraction from SubMicron Crystals of Photosystem1 Membrane Protein  

Microsoft Academic Search

We demonstrate that powder diffraction data can be collected from sub-micron crystals of a mbrane protein with nearly two orders of magnitude more atoms than the molecules commonly used for powder diffraction. The crystals of photosystem-1 protein were size-selected using a 500 nm pore- size filter and delivered to a soft x-ray beam with a photon energy of 1.5 keV

D. A. Shapiro; D. DePonte; R. B. Doak; P. Fromme; G. Hembree; M. Hunter; S. Marchesini; K. Schmidt; D. Starodub; U. Weierstall; H. Chapman; J. Spence

2008-01-01

260

Broadened X-ray-diffraction profile analysis of cold-rolled aluminium-magnesium alloys  

Microsoft Academic Search

A cold-rolled, commercial pure aluminium and three aluminium-magnesium alloys (containing, respectively, 1 wt%, 3 wt% and 5 wt% magnesium) were studied by X-ray-diffraction (XRD) profile analysis. The investigated equivalent plastic deformations of the materials were ranged between 0.1 and 5.0. With increases in the amounts of magnesium, the diffraction peaks widened. For each alloy, the peak width (which gives first

N. Ji; J. L. Lebrun; P. Sainfort

1994-01-01

261

Improved system for energy-dispersive X-ray diffraction with synchrotron radiation  

NASA Astrophysics Data System (ADS)

Recent improvements made in an energy-dispersive X-ray diffraction facility at the Stanford Synchrotron Radiation Laboratory are discussed. These include better collimation of the incident beam to eliminate unwanted scatter from the gasket and to reduce background noise, a procedure for relatively rapid adjustment of the receiving beam collimator window for optimum resolution, a device for pneumatically controlling the cell pressure, and a custom-designed microcomputer system and support hardware for both experiment control and on-line data analysis. It is estimated that with the improved system, a well defined diffraction peak can be identified with a precision of better than 0.04 percent and in a net area with a precision of better than 3 percent for scans of 10s or longer. The facility has been used to study the kinetics of the pressure induced B1-to-B2 structural phase transition in KBr. The volume discontinuity measured for this transition is 10.41 + or - 0.10 percent, in excellent agreement with most previous instruments.

Skelton, E. F.; Webb, A. W.; Qadri, S. B.; Lee, C. W.; Kirkland, J. P.

1983-04-01

262

X-ray diffraction pattern of a Gulyaev-Bleustein surface acoustic wave in grazing geometry  

SciTech Connect

The X ray diffraction pattern of a Gulyaev-Bleustein surface acoustic wave (SAW) under grazing angles of incidence in noncoplanar symmetric Laue geometry has been considered. It is supposed that the propagation direction of an SAW makes a small angle with the diffraction vector. It is shown that small deviations from the Bragg angle ({approx}0.01'' induced by the SAW and do not affect the reflection coefficient lead to the formation of diffraction satellites both in the cases of standing and traveling SAWs. It has been established that the recorded diffraction pattern, which is a time-averaged intensity distribution, has characteristic profiles for odd and even satellites.

Levonyan, L. V., E-mail: gurgen@iapp.sci.am; Khachaturyan, G. K. [Academy of Sciences of Armenia, Institute of Applied Physics Problems (Armenia)

2006-12-15

263

MBE apparatus for in situ grazing incidence x-ray diffraction  

NASA Astrophysics Data System (ADS)

A molecular beam epitaxy (MBE) apparatus furnished with two E-gun evaporators, two Knudsen cells and RHEED, was built for in situ grazing incidence x-ray diffraction studies. By adopting horizontal sample setting geometry, the entire ultrahigh vacuum chamber was rotated simply with the aid of a spring, and a large sample area was irradiated by the x-rays. Using this apparatus, we observed the 77 superstructure on a Si(111) surface and at a SiO2/Si(111) interface.

Akimoto, K.; Mizuki, J.; Hirosawa, I.; Matsui, J.

1989-07-01

264

Synchrotron X-ray diffraction measurements of single-crystal hydrogen to 26.5 gigapascals  

NASA Technical Reports Server (NTRS)

The crystal structure and equation of state of solid hydrogen have been determined directly to 26.5 gigapascals at room temperature by new synchrotron X-ray diffraction techniques. Solid hydrogen remains in the hexagonal close packed structure under these pressure-temperature conditions and exhibits increasing structural anisotropy with pressure. The pressure-volume curve determined from the X-ray data represents the most accurate experimental measurement of the equation of state to date in this pressure range. The results remove the discrepancy between earlier indirect determinations and provide a new experimental constraint on the molecular-to-atomic transition predicted at higher pressures.

Mao, H. K.; Jephcoat, A. P.; Hemley, R. J.; Finger, L. W.; Zha, C. S.

1988-01-01

265

Interaction between Lipid Monolayers and Poloxamer 188: An X-Ray Reflectivity and Diffraction Study  

PubMed Central

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 separating from the lipids, forces the lipid molecules to pack tightly and restore the barrier function of the membrane. Upon compression to bilayer equivalent pressure, P188 is squeezed out from the lipid monolayer, allowing a graceful exit of P188 when the membrane integrity is restored. PMID:16100276

Wu, Guohui; Majewski, Jaroslaw; Ege, Canay; Kjaer, Kristian; Weygand, Markus Jan; Lee, Ka Yee C.

2005-01-01

266

High-pressure structural studies of dysprosium using angle-dispersive x-ray diffraction  

SciTech Connect

We present structural results under pressure for elemental dysprosium (Dy) up to 87 GPa using in situ angle-dispersive x-ray diffraction measurements with synchrotron x rays and a diamond-anvil cell. Dy exhibits the structural transition sequence, hP2{yields}hR9{yields}hP4{yields}distorted cF4, from Rietveld full-profile refinements. Clear evidence is documented for the high-pressure distorted cF4 phase observed above 45 GPa to be an orthorhombic oS8 (Cmmm) structure for Dy in the lanthanide phase diagram.

Shen Yongrong; Kumar, Ravhi S.; Cornelius, Andrew L.; Nicol, Malcolm F. [Department of Physics and High Pressure Science and Engineering Center, University of Nevada Las Vegas, Las Vegas, Nevada 89154-4002 (United States)

2007-02-01

267

Characterization of SiGe Layer during Ge Condensation Process by X-ray Diffraction Methods  

NASA Astrophysics Data System (ADS)

We fabricated a Ge-on-insulator (GOI) structure by the Ge condensation method and characterized the SiGe layer during the condensation process by X-ray reciprocal space mapping and synchrotron microbeam X-ray diffraction. The crystalline quality of the SiGe layer degraded during the initial 1 h of oxidation at 1050 癈 and it also rapidly degraded during 1 h of oxidation at 900 癈 immediately before the formation of GOI structures. The slight degradation was caused by annealing in Ar, indicating that the degradation during the initial 1-h condensation is accelerated by Ge atoms being ejected from the oxidized interface.

Shimura, Takayoshi; Inoue, Tomoyuki; Shimokawa, Daisuke; Hosoi, Takuji; Imai, Yasuhiko; Sakata, Osami; Kimura, Shigeru; Watanabe, Heiji

2011-01-01

268

Study of X-ray diffraction from a surface acoustic wave in the grazing geometry with allowance for the curvature of the unperturbed crystal surface  

SciTech Connect

Fresnel X-ray diffraction from a concave crystal surface in the presence of a surface acoustic wave (SAW) has been considered for grazing angles of incidence in noncoplanar symmetric Laue geometry. It is shown that the main peak and diffraction satellites are focused at different distances from a crystal. The effect of deviation from the Bragg angle, the spectral line width, and the SAW amplitude on the X-ray diffraction pattern has been analyzed. It is established that the contrast of an X-ray diffraction pattern of an SAW in Bragg-Laue grazing geometry is related to the character of irregularities of the crystal surface, and the pattern details depend on the measurement mode. The sensitivity of the method is about a nanometer. The focal image of the SAW serves as a scale landmark for determining the crystal surface characteristics.

Mkrtchyan, A. R., E-mail: gurgen@iapp.sci.am; Kocharyan, V. R.; Levonyan, L. V.; Khachaturyan, G. K. [Academy of Sciences of Armenia, Institute of Applied Physics Problems (Armenia)

2006-12-15

269

X-ray diffraction study of thermal stress relaxation in ZnO films deposited by magnetron sputtering  

E-print Network

are in a high compressive stress state. In situ X-ray diffraction measurements inside a furnace revealed inducing high compressive intrinsic stresses in ZnO thin films around 1 GPa [6,20], which causes film degraX-ray diffraction study of thermal stress relaxation in ZnO films deposited by magnetron sputtering

270

A laboratory based system for Laue micro x-ray diffraction  

SciTech Connect

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 {mu}m beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the ''knife edge'' approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt % Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 deg. with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis.

Lynch, P. A.; Stevenson, A. W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N. [Commonwealth Scientific and Industrial Research Organization, Manufacturing and Infrastructure Technology, Private Bag 33, Clayton South MDC, 3169 (Australia); Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

2007-02-15

271

A laboratory based system for Laue micro x-ray diffraction  

SciTech Connect

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References).

Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N.

2007-02-28

272

Ultra-high aspect ratio high-resolution nanofabrication for hard X-ray diffractive optics.  

PubMed

Although diffractive optics have played a major role in nanoscale soft X-ray imaging, high-resolution and high-efficiency diffractive optics have largely been unavailable for hard X-rays where many scientific, technological and biomedical applications exist. This is owing to the long-standing challenge of fabricating ultra-high aspect ratio high-resolution dense nanostructures. Here we report significant progress in ultra-high aspect ratio nanofabrication of high-resolution, dense silicon nanostructures using vertical directionality controlled metal-assisted chemical etching. The resulting structures have very smooth sidewalls and can be used to pattern arbitrary features, not limited to linear or circular. We focus on the application of X-ray zone plate fabrication for high-efficiency, high-resolution diffractive optics, and demonstrate the process with linear, circular, and spiral zone plates. X-ray measurements demonstrate high efficiency in the critical outer layers. This method has broad applications including patterning for thermoelectric materials, battery anodes and sensors among others. PMID:24970569

Chang, Chieh; Sakdinawat, Anne

2014-01-01

273

Serial femtosecond X-ray diffraction of 30S ribosomal subunit microcrystals in liquid suspension at ambient temperature using an X-ray free-electron laser.  

PubMed

High-resolution ribosome structures determined by X-ray crystallography have provided important insights into the mechanism of translation. Such studies have thus far relied on large ribosome crystals kept at cryogenic temperatures to reduce radiation damage. Here, the application of serial femtosecond X-ray crystallography (SFX) using an X-ray free-electron laser (XFEL) to obtain diffraction data from ribosome microcrystals in liquid suspension at ambient temperature is described. 30S ribosomal subunit microcrystals diffracted to beyond 6? resolution, demonstrating the feasibility of using SFX for ribosome structural studies. The ability to collect diffraction data at near-physiological temperatures promises to provide fundamental insights into the structural dynamics of the ribosome and its functional complexes. PMID:23989164

Demirci, Hasan; Sierra, Raymond G; Laksmono, Hartawan; Shoeman, Robert L; Botha, Sabine; Barends, Thomas R M; Nass, Karol; Schlichting, Ilme; Doak, R Bruce; Gati, Cornelius; Williams, Garth J; Boutet, S閎astien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E; Gregory, Steven T; Bogan, Michael J

2013-09-01

274

Transient x-ray diffraction with simultaneous imaging under high strain-rate loading.  

PubMed

Real time, in situ, multiframe, diffraction, and imaging measurements on bulk samples under high and ultrahigh strain-rate loading are highly desirable for micro- and mesoscale sciences. We present an experimental demonstration of multiframe transient x-ray diffraction (TXD) along with simultaneous imaging under high strain-rate loading at the Advanced Photon Source beamline 32ID. The feasibility study utilizes high strain-rate Hopkinson bar loading on a Mg alloy. The exposure time in TXD is 2-3 ?s, and the frame interval is 26.7-62.5 ?s. Various dynamic deformation mechanisms are revealed by TXD, including lattice expansion or compression, crystal plasticity, grain or lattice rotation, and likely grain refinement, as well as considerable anisotropy in deformation. Dynamic strain fields are mapped via x-ray digital image correlation, and are consistent with the diffraction measurements and loading histories. PMID:25430119

Fan, D; Lu, L; Li, B; Qi, M L; E, J C; Zhao, F; Sun, T; Fezzaa, K; Chen, W; Luo, S N

2014-11-01

275

HRTEM and X-ray diffraction analysis of Au wire bonding interface in microelectronics packaging  

NASA Astrophysics Data System (ADS)

Interfacial microstructures of thermosonic Au wire bonding to an Al pad of die were investigated firstly by high-resolution transmission electron microscopy (HRTEM) and X-ray micro-diffractometer. The equal-thickness interference structures were observed by HRTEM due to diffusion and reaction activated by ultrasonic and thermal at the Au/Al bond interface. And X-ray diffraction results showed that three different interplanar crystal spacings ('d' value) of the interfacial microstructures were 2.2257 , 2.2645 , and 2.1806 respectively from the high intensity of diffraction to the low intensity of diffraction. These indicated that the intermetallic phase AlAu 2 formed within a very short time. It would be helpful to further research wire bonding technology.

Junhui, Li; Ruishan, Wang; Lei, Han; Fuliang, Wang; Zhili, Long

2011-01-01

276

Strain Fields in Zeolite Microcrystals by Coherent X-ray Diffraction  

NASA Astrophysics Data System (ADS)

We measured coherent X-ray diffraction (CXD) on zeolite microcrystals in order to get information on internal density distribution and to map deformation field of stress or strain during the fabrication process. The experiments were performed at the beamline 34-ID-C in Advanced Photon Source and employed monochromatic radiation with x-ray energy of 9 keV. The sample size was about 2?m. The diffraction patterns were obtained at (200) Bragg condition with unfocused beam. We inverted the diffraction patterns to obtain three dimensional images of the shapes and internal strain fields of zeolite microcrystals using phase retrieval algorithms of error reduction and hybrid input-output method. The internal density and strain distribution as a function of temperature will be discussed.

Kim, Hyunjung; Cha, Wonsuk; Song, Sanghoon; Jeong, Nak Cheon; Yoon, Kyung Byung; Harder, Ross; Robinson, Ian K.

2009-03-01

277

Investigation of a semiconductor superlattice by use of grazing incidence X-ray diffraction  

NASA Astrophysics Data System (ADS)

A GaInAs/InP superlattice with 10 periods grown by a MOCVD technique on [001] InP was measured by X-ray diffraction under grazing incidence. The details of the GID technique are explained and the results on the superlattice real structure are interpreted in terms of a kinematical scattering approach. Because the depth probed by the X-rays is extremely reduced to a near-surface region both the thickness of the supercell (44 1 monolayers) and of the (GaIn)As quantum wells (2 1 monolayers) can be determined with monolayer accuracy. By successively increasing the penetration depth of the X-rays, the vertical density profile is probed in different regions below the sample surface. The measurements indicate that the thickness of the solid solution layer varies by about 1-2 monolayers laterally and in depth. The composition of the layers is different from that expected from the growth conditions.

Pietsch, U.; Seifert, W.; Fornell, J.-O.; Rhan, H.; Metzger, H.; Rugel, S.; Peisl, J.

1992-01-01

278

Spatially resolved soft X-ray spectrometry from single-image diffraction  

NASA Astrophysics Data System (ADS)

High-harmonic generation (HHG) offers better coherence, shorter pulse durations and far greater accessibility than synchrotron sources. These factors make HHG an increasingly important source of soft X-rays and an excellent resource in many emerging areas, for example, the time-resolved study of conformational changes in single biological molecules. Here, we demonstrate a novel technique that enables us to reconstruct spectral information spatially across an X-ray beam. As only a single diffraction image is required per measurement, this technique is well suited to time-resolved studies. This technique is applicable to many types of X-ray source and can be adapted for different spectral regions. Here, results are obtained using a capillary high-harmonic source, revealing detailed information that brings new insight into the physical processes occurring inside the source and enabling us to show the first measurement of radial variation of harmonic order in the emission from an HHG capillary.

Praeger, M.; de Paula, A. M.; Froud, C. A.; Rogers, E. T. F.; Stebbings, S. L.; Brocklesby, W. S.; Baumberg, J. J.; Hanna, D. C.; Frey, J. G.

2007-03-01

279

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

PubMed Central

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

Kern, Jan; Alonso-Mori, Roberto; Tran, Rosalie; Hattne, Johan; Gildea, Richard J.; Echols, Nathaniel; Gl鯿kner, Carina; Hellmich, Julia; Laksmono, Hartawan; Sierra, Raymond G.; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Lampe, Alyssa; Han, Guangye; Gul, Sheraz; DiFiore, D鰎te; 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, S閎astien; Messinger, Johannes; Zouni, Athina; Sauter, Nicholas K.; Yachandra, Vittal K.; Bergmann, Uwe; Yano, Junko

2013-01-01

280

SEARCHING FOR NARROW EMISSION LINES IN X-RAY SPECTRA: COMPUTATION AND METHODS Taeyoung Park,1  

E-print Network

The detection and quantification of narrow emission lines in X-ray spectra is a challenging statistical task quasar emission. The detection of weak lines in noisy spectra is the main statistical problem- portant X-ray emission feature identified in AGN and quasar spectra is the iron K emission line (see

van Dyk, David

281

Study of properties of chemically modified samples of halloysite mineral with X-ray fluorescence and X-ray powder diffraction methods  

NASA Astrophysics Data System (ADS)

Elemental and chemical composition of raw and activated samples of halloysite mineral using wavelength dispersive X-ray fluorescence (WDXRF), total reflection X-ray fluorescence (TXRF) and X-ray powder diffraction (XRPD) methods were determined. As the result, it has been shown that application of the complementary X-ray spectrometry techniques allows very precise observation of changes in composition of halloysite mineral samples caused by its chemical modifications. Sample preparation procedure and usability of the research methods applied are described in details. Procedure of activation of raw halloysite mineral samples by etching them in sulfuric acid of various concentrations has been described and discussed. The ability of the samples to adsorb lead from intentionally contaminated water was tested and confirmed.

Bana?, D.; Kubala-Kuku?, A.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Mo?ko, J.; Czech, K.; Garnuszek, M.; S?omkiewicz, P.; Szczepanik, B.

2013-12-01

282

Determination of line profiles on nano-structured surfaces using EUV and x-ray scattering  

NASA Astrophysics Data System (ADS)

Non-imaging techniques like X-ray scattering are supposed to play an important role in the further development of CD metrology for the semiconductor industry. Grazing Incidence Small Angle X-ray Scattering (GISAXS) provides directly assessable information on structure roughness and long-range periodic perturbations. The disadvantage of the method is the large footprint of the X-ray beam on the sample due to the extremely shallow angle of incidence. This can be overcome by using wavelengths in the extreme ultraviolet (EUV) spectral range, EUV small angle scattering (EUVSAS), which allows for much steeper angles of incidence but preserves the range of momentum transfer that can be observed. Generally, the potentially higher momentum transfer at shorter wavelengths is counterbalanced by decreasing diffraction efficiency. This results in a practical limit of about 10 nm pitch for which it is possible to observe at least the +/- 1st diffraction orders with reasonable efficiency. At the Physikalisch-Technische Bundesanstalt (PTB), the available photon energy range extends from 50 eV up to 10 keV at two adjacent beamlines. PTB commissioned a new versatile Ellipso-Scatterometer which is capable of measuring 6" square substrates in a clean, hydrocarbon-free environment with full flexibility regarding the direction of the incident light polarization. The reconstruction of line profiles using a geometrical model with six free parameters, based on a finite element method (FEM) Maxwell solver and a particle swarm based least-squares optimization yielded consistent results for EUV-SAS and GISAXS. In this contribution we present scatterometry data for line gratings and consistent reconstruction results of the line geometry for EUV-SAS and GISAXS.

Soltwisch, Victor; Wernecke, Jan; Haase, Anton; Probst, J黵gen; Schoengen, Max; Krumrey, Michael; Scholze, Frank; Pomplun, Jan; Burger, Sven

2014-09-01

283

Optimal mapping of x-ray laser diffraction patterns into three dimensions using routing algorithms  

NASA Astrophysics Data System (ADS)

Coherent diffractive imaging with x-ray free-electron lasers (XFEL) promises high-resolution structure determination of noncrystalline objects. Randomly oriented particles are exposed to XFEL pulses for acquisition of two-dimensional (2D) diffraction snapshots. The knowledge of their orientations enables 3D imaging by multiview reconstruction, combining 2D diffraction snapshots in different orientations. Here we introduce a globally optimal algorithm that can infer these orientations. We apply it to experimental XFEL data of nanoparticles and so determine their 3D electron density.

Kassemeyer, Stephan; Jafarpour, Aliakbar; Lomb, Lukas; Steinbrener, Jan; Martin, Andrew V.; Schlichting, Ilme

2013-10-01

284

X-Ray Diffraction Study of the Internal Structure of Supercooled Water  

NASA Technical Reports Server (NTRS)

A Bragg X-ray spectrometer equipped with a volume-sensitive Geiger counter and Soller slits and employing filtered molybdenum Ka radiation was used to obtain a set of diffracted intensity curves as a Punction of angle for supercooled water. Diffracted intensity curves in the temperature region of 21 to -16 C were obtained. The minimum between the two main diffraction peaks deepened continuously with lowering temperature, indicating a gradual change in the internal structure of the water. No discontinuity in this trend was noted at the melting point. The internal structure of supercooled water was concluded to become progressively more ice-like as the temperature is lowered.

Dorsch, Robert G.; Boyd, Bemrose

1951-01-01

285

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements  

PubMed Central

X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis1. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information14. Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage. Instead, the diffracted X-rays are gated by a rapid loss of crystalline periodicity, producing apparent pulse lengths significantly shorter than the duration of the incident pulse. The shortest apparent pulse lengths occur at the highest resolution, and our measurements indicate that current X-ray free-electron laser technology5 should enable structural determination from submicrometre protein crystals with atomic resolution. PMID:24078834

Barty, Anton; Caleman, Carl; Aquila, Andrew; Timneanu, Nicusor; Lomb, Lukas; White, Thomas A.; Andreasson, Jakob; Arnlund, David; Bajt, Sa歛; Barends, Thomas R. M.; Barthelmess, Miriam; Bogan, Michael J.; Bostedt, Christoph; Bozek, John D.; Coffee, Ryan; Coppola, Nicola; Davidsson, Jan; DePonte, Daniel P.; Doak, R. Bruce; Ekeberg, Tomas; Elser, Veit; Epp, Sascha W.; Erk, Benjamin; Fleckenstein, Holger; Foucar, Lutz; Fromme, Petra; Graafsma, Heinz; Gumprecht, Lars; Hajdu, Janos; Hampton, Christina Y.; Hartmann, Robert; Hartmann, Andreas; Hauser, G黱ter; Hirsemann, Helmut; Holl, Peter; Hunter, Mark S.; Johansson, Linda; Kassemeyer, Stephan; Kimmel, Nils; Kirian, Richard A.; Liang, Mengning; Maia, Filipe R. N. C.; Malmerberg, Erik; Marchesini, Stefano; Martin, Andrew V.; Nass, Karol; Neutze, Richard; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Scott, Howard; Schlichting, Ilme; Schulz, Joachim; Seibert, M. Marvin; Shoeman, Robert L.; Sierra, Raymond G.; Soltau, Heike; Spence, John C. H.; Stellato, Francesco; Stern, Stephan; Str黡er, Lothar; Ullrich, Joachim; Wang, X.; Weidenspointner, Georg; Weierstall, Uwe; Wunderer, Cornelia B.; Chapman, Henry N.

2013-01-01

286

Study on the structure of aqueous potassium chloride solutions using the X-ray diffraction and Raman spectroscopy methods  

NASA Astrophysics Data System (ADS)

Many researchers have studied potassium chloride aqueous solutions, whereas, for the tests were carried out at different conditions, the results with diverse concentrations were not comparable. In this study, the structure of aqueous potassium chloride solutions were determined by X-ray diffraction (both using the synchrotron beam line and laboratory X-ray source) and Raman spectroscopy. Potassium chloride solutions at the concentrations ranging from 0.07% to 26.00% were systematically tested through these methods. For the solutions studied, a semi quantitative structural analysis was performed at the level of the reduced pair distribution functions (RPDFs) deduced from X-ray diffraction diagrams. The structure features can be seen directly from the RPDFs, which show systematic variations with the increase of the solutions. According to the results, when the concentration was above 15.00%, characteristic peak of K+-Cl- contact ion pairs was observed in the RPDFs at 3.15 , and their contributions became more and more significant with the increase of the concentrations. Furthermore, O-H bond lengths in water molecules are stretched with the increase of the concentration. Raman spectroscopy was carried out to support the conclusion that the hydrogen bonds in the aqueous solutions were disrupted with the increase of the potassium chloride concentration.

Li, Fei; Yuan, Junsheng; Li, Dongchan; Li, Shenyu; Han, Zhen

2015-02-01

287

Water-DNA interactions as studied by X-ray and neutron fibre diffraction.  

PubMed Central

X-ray fibre-diffraction studies indicate a high degree of stereochemical specificity in interactions between water and the DNA double helix. Evidence for this comes from data that show that the molecular conformations assumed by DNA in fibres are highly reproducible and that the hydration-driven transitions between these conformations are fully reversible. These conformational transitions are induced by varying the relative humidity of the fibre environment and hence its water content. Further evidence for stereochemical specificity comes from the observed dependence of the conformation assumed on the ionic content of the fibre and the nucleotide sequence of the DNA. For some transitions, information on stereochemical pathways has come from real-time X-ray fibre diffraction using synchrotron radiation; information on the location of water with respect to the double helix for a number of DNA conformations has come from neutron fibre diffraction. This structural information from fibre-diffraction studies of DNA is complemented by information from X-ray single-crystal studies of oligonucleotides. If the biochemical processes involving DNA have evolved to exploit the structural features observed in DNA fibres and oligonucleotide single crystals, the challenges in developing alternatives to a water environment can be expected to be very severe. PMID:15306379

Fuller, Watson; Forsyth, Trevor; Mahendrasingam, Arumugam

2004-01-01

288

Bayesian orientation estimate and structure information from sparse single-molecule x-ray diffraction images  

NASA Astrophysics Data System (ADS)

We developed a Bayesian method to extract macromolecular structure information from sparse single-molecule x-ray free-electron laser diffraction images. The method addresses two possible scenarios. First, using a "seed" structural model, the molecular orientation is determined for each of the provided diffraction images, which are then averaged in three-dimensional reciprocal space. Subsequently, the real space electron density is determined using a relaxed averaged alternating reflections algorithm. In the second approach, the probability that the "seed" model fits to the given set of diffraction images as a whole is determined and used to distinguish between proposed structures. We show that for a given x-ray intensity, unexpectedly, the achievable resolution increases with molecular mass such that structure determination should be more challenging for small molecules than for larger ones. For a sufficiently large number of recorded photons (>200) per diffraction image an M1/6 scaling is seen. Using synthetic diffraction data for a small glutathione molecule as a challenging test case, successful determination of electron density was demonstrated for 20000 diffraction patterns with random orientations and an average of 82 elastically scattered and recorded photons per image, also in the presence of up to 50% background noise. The second scenario is exemplified and assessed for three biomolecules of different sizes. In all cases, determining the probability of a structure given set of diffraction patterns allowed successful discrimination between different conformations of the test molecules. A structure model of the glutathione tripeptide was refined in a Monte Carlo simulation from a random starting conformation. Further, effective distinguishing between three differently arranged immunoglobulin domains of a titin molecule and also different states of a ribosome in a tRNA translocation process was demonstrated. These results show that the proposed method is robust and enables structure determination from sparse and noisy x-ray diffraction images of single molecules spanning a wide range of molecular masses.

Walczak, Micha?; Grubm黮ler, Helmut

2014-08-01

289

X-Ray Continua of Broad Absorption Line Quasars  

NASA Technical Reports Server (NTRS)

The targets for this program, PG1416-129 and LBQS 2212-1759 were known to be Broad Absorption Line Quasars (BALQSOs). BALQSOs are highly absorbed in soft X-rays. Good high energy response of Rossi-XTE made them ideal targets for observation. We observed LBQS 2212-1759 with PCA. We have now analyzed the data and found that the source was not detected. Since our target was expected to be faint, reliable estimate of background was very important. With the release of new FTOOLS (version 4.1) we were able to do so. We also analyzed a well known bright object and verified our results with the published data. This gave us confidence in the non-detection of our target LBQS 2212-1759. We are currently investigating the implications of this non-detection. Due to some scheduling problems, our second target PG1416-129 was not observed in A01. It was observed on 06/26/98. This target was detected with RXTE. We are now working on the spectral analysis with XSPEC.

Mathur, S.

1999-01-01

290

Diagnostics of plasma based on K, L and M x-ray line positions  

NASA Astrophysics Data System (ADS)

Ionization can affect the energy of characteristic x-ray lines sufficiently for a single line to be of value in plasma diagnostics. Recently, the ionization of a hot, dense tungsten plasma was determined from a detailed analysis of a single, highly resolved L x-ray line, and in an iridium plasma the change in energy of a single K x-ray line confirmed the theoretical estimate of the ionization. Diagnosing plasmas by these ionization energy shifts depends essentially on computations that can now be performed with sufficient accuracy, e.g. with the multi-configuration Dirac-Fock method. Besides extending earlier computations on the influence of outer-shell ionization on the energy of tungsten's K and L x-ray lines, this paper also presents the effect of ionization on the lower-energy M x-ray lines and a discussion of their relative merits for plasma diagnostics.

S?abkowska, Katarzyna; Szyma?ska, Ewa; Starosta, Joanna; Polasik, Marek; Pereira, Nino R.; Rzadkiewicz, Jacek; Kubkowska, Monika; Czarnecka, Agata

2014-05-01

291

Realizing in-plane surface diffraction by x-ray multiple-beam diffraction with large incidence angle  

NASA Astrophysics Data System (ADS)

Based on rigorous dynamical-theory calculations, we demonstrate the principle of an x-ray multiple-beam diffraction (MBD) scheme that overcomes the long-lasting difficulties of high-resolution in-plane diffraction from crystal surfaces. This scheme only utilizes symmetric reflection geometry with large incident angles but activates the out-of-plane and in-plane diffraction processes simultaneously and separately in the continuous MBD planes. The in-plane diffraction is realized by detoured MBD, where the intermediate diffracted waves propagate parallel to the surface, which corresponds to an absolute Bragg surface diffraction configuration that is extremely sensitive to surface structures. A series of MBD diffraction and imaging techniques may be developed from this principle to study surface/interface (misfit) strains, lateral nanostructures, and phase transitions of a wide range of (pseudo)cubic crystal structures, including ultrathin epitaxial films and multilayers, quantum dots, strain-engineered semiconductor or (multi)ferroic materials, etc.

Huang, Xian-Rong; Peng, Ru-Wen; Gog, Thomas; Siddons, D. P.; Assoufid, Lahsen

2014-11-01

292

X-ray diffraction imaging of metal-oxide epitaxial tunnel junctions made by optical lithography: use of focused and unfocused X-ray beams.  

PubMed

X-ray diffraction techniques are used in imaging mode in order to characterize micrometre-sized objects. The samples used as models are metal-oxide tunnel junctions made by optical lithography, with lateral sizes ranging from 150 祄 down to 10 祄 and various shapes: discs, squares and rectangles. Two approaches are described and compared, both using diffraction contrast: full-field imaging (topography) and raster imaging (scanning probe) using a micrometre-sized focused X-ray beam. It is shown that the full-field image gives access to macroscopic distortions (e.g. sample bending), while the local distortions, at the micrometre scale (e.g. tilts of the crystalline planes in the vicinity of the junction edges), can be accurately characterized only using focused X-ray beams. These local defects are dependent on the junction shape and larger by one order of magnitude than the macroscopic curvature of the sample. PMID:23412494

Mocuta, Cristian; Barbier, Antoine; Stanescu, Stefan; Matzen, Sylvia; Moussy, Jean Baptiste; Ziegler, Eric

2013-03-01

293

X-ray diffraction imaging of metal杘xide epitaxial tunnel junctions made by optical lithography: use of focused and unfocused X-ray beams  

PubMed Central

X-ray diffraction techniques are used in imaging mode in order to characterize micrometre-sized objects. The samples used as models are metal杘xide tunnel junctions made by optical lithography, with lateral sizes ranging from 150?祄 down to 10?祄 and various shapes: discs, squares and rectangles. Two approaches are described and compared, both using diffraction contrast: full-field imaging (topography) and raster imaging (scanning probe) using a micrometre-sized focused X-ray beam. It is shown that the full-field image gives access to macroscopic distortions (e.g. sample bending), while the local distortions, at the micrometre scale (e.g. tilts of the crystalline planes in the vicinity of the junction edges), can be accurately characterized only using focused X-ray beams. These local defects are dependent on the junction shape and larger by one order of magnitude than the macroscopic curvature of the sample. PMID:23412494

Mocuta, Cristian; Barbier, Antoine; Stanescu, Stefan; Matzen, Sylvia; Moussy, Jean-Baptiste; Ziegler, Eric

2013-01-01

294

Dimorphism in methylammonium aluminum alum studied by X-ray diffraction and electron paramagnetic resonance  

NASA Astrophysics Data System (ADS)

We have found a reliable method of growing single-phase methyl-ammonium alum (MASD) crystallising in the infrequently-occurring ? alum structure; the presence of the perchlorate ion, ClO 4-, in growth solutions induces the crystallisation of ? MASD crystals. Seeding the growth solution with ? MASD crystals also induces crystallisation of new ? MASD crystals. The X-ray powder diffraction pattern and the EPR spectrum of the Cr 3+ ions doped into ? MASD are drastically different from those for the more frequently occuring ? MASD. The linewidths of Cr 3+ in ? and ? MASD show anomalous angular dependence. The inhomogeneous line broadening observed for ? MASD could be explained by a random distribution in the orientation of the symmetry axis of the trigonal [ Cr( H2O) 6] 3+ complex. The linewidth anomaly shows a more complicated angular dependence for ? MASD; it could be that not only the orientation of the symmetry axis but also the magnitude of the axial crystal field of [ Cr( H2O) 6] 3+ suffer random distributions.

Lou, Ssu-Hao; Yu, Jiang-Tsu

1992-11-01

295

Edge diffraction effect at the refraction of X rays in a diamond prism  

NASA Astrophysics Data System (ADS)

The refraction of monochromatic X-ray radiation in an optically polished diamond prism has been studied. Measurements have been performed on the ID10 channel of the ESRF synchrotron (Grenoble). It has been found that parabolic geometric deviations of the profile of the refractive face of the prism from a plane are responsible for the interference pattern that is similar in the structure of oscillations to an edge diffraction effect. As a result, a diffraction pattern characteristic of the near-field Fresnel zone can be observed in the farfield zone. A high sensitivity to phase perturbations ensures the possibility of using this effect to analyze the parameters of an X-ray wavefront with a dimension of about 1 ?m.

Tur'yanskii, A. G.; Konovalov, O. V.; Gizha, S. S.; Beilin, N. D.

2014-12-01

296

Structural investigation of GaInP nanowires using X-ray diffraction  

PubMed Central

In this work the structure of ternary GaxIn1?爔P nanowires is investigated with respect to the chemical composition and homogeneity. The nanowires were grown by metal杘rganic vapor-phase epitaxy. For the investigation of ensemble fluctuations on several lateral length scales, X-ray diffraction reciprocal space maps have been analyzed. The data reveal a complicated varying materials composition across the sample and in the nanowires on the order of 20%. The use of modern synchrotron sources, where beam-sizes in the order of several 10?m are available, enables us to investigate compositional 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. PMID:24089580

Kriegner, D.; Persson, J.M.; Etzelstorfer, T.; Jacobsson, D.; Wallentin, J.; Wagner, J.B.; Deppert, K.; Borgstr鰉, M.T.; Stangl, J.

2013-01-01

297

Determination of volume fraction in multiphase systems using incomplete pole figures. [X ray diffraction metallography  

NASA Technical Reports Server (NTRS)

The determination of the volume fraction of a second phase in a multiphase sample by X-ray diffraction becomes more difficult if the diffracting planes have a preferred orientation. Lopata and Kula have described a method of treating this problem using complete pole figures for each of the phases. With some samples, it is not always possible or convenient to obtain data over the full hemisphere. Equations and an example are given which require X-ray data over a limited range of approximately 0 to 75 deg. This can be obtained by reflection without a specially cut sample or transmission data. A series of Legendre polynomials are fitted to data collected while spinning the sample about its normal. An extrapolation is made possible by introducing two conditions on the end points which must be satisfied if the extrapolation functions are to be valid.

Houska, C. R.; Rao, V.

1978-01-01

298

X-ray and neutron diffraction study of nanocrystalline Ti-Ru-Fe-O compounds  

SciTech Connect

The effect of adding oxygen on the structure of nanocrystalline Ti-Ru-Fe compounds obtained by high-energy ball-milling has been studied by X-ray and neutron diffraction using a Rietveld refinement analysis. It is shown that oxygen atoms readily oxidize Ti to form various types of titanium oxides depending on the oxygen content. In each case, a simple cubic structure (cP2-CsCl) is also formed during milling but with a concentration higher than expected on the basis of various reaction schemes. Through a detailed analysis of the neutron and X-ray diffraction peaks, it is shown that the 1a site of the CsCl-type unit cell is depleted from Ti atoms by preferential substitution with Fe. At high oxygen concentration, the alloy is a multiphase material containing Ti{sub 2{minus}x}Ru{sub 1+y}Fe{sub 1+z}, Ti oxides, Ru, and Fe.

Blouin, M.; Guay, D. [INRS-Energie et Materiaux, Varennes, Quebec (Canada)] [INRS-Energie et Materiaux, Varennes, Quebec (Canada); Huot, J.; Schulz, R. [Inst. de recherche d`Hydro-Quebec, Varennes, Quebec (Canada). Technologies Emergentes de Production et de Stockage] [Inst. de recherche d`Hydro-Quebec, Varennes, Quebec (Canada). Technologies Emergentes de Production et de Stockage; Swainson, I.P. [National Research Council, Chalk River, Ontario (Canada). Chalk River Labs.] [National Research Council, Chalk River, Ontario (Canada). Chalk River Labs.

1998-11-01

299

Method for characterizing mask defects using image reconstruction from X-ray diffraction patterns  

DOEpatents

The invention applies techniques for image reconstruction from X-ray diffraction patterns on the three-dimensional imaging of defects in EUVL multilayer films. The reconstructed image gives information about the out-of-plane position and the diffraction strength of the defect. The positional information can be used to select the correct defect repair technique. This invention enables the fabrication of defect-free (since repaired) X-ray Mo--Si multilayer mirrors. Repairing Mo--Si multilayer-film defects on mask blanks is a key for the commercial success of EUVL. It is known that particles are added to the Mo--Si multilayer film during the fabrication process. There is a large effort to reduce this contamination, but results are not sufficient, and defects continue to be a major mask yield limiter. All suggested repair strategies need to know the out-of-plane position of the defects in the multilayer.

Hau-Riege, Stefan Peter (Fremont, CA)

2007-05-01

300

SrTiO{sub 3} Displacive Transition Revisited via Coherent X-Ray Diffraction  

SciTech Connect

We present a coherent x-ray diffraction study of the antiferrodistortive displacive transition of SrTiO{sub 3}, a prototypical example of a phase transition for which the critical fluctuations exhibit two length scales and two time scales. From the microbeam x-ray coherent diffraction patterns, we show that the broad (short-length scale) and the narrow (long-length scale) components can be spatially disentangled, due to 100-{mu}m-scale spatial variations of the latter. Moreover, both components exhibit a speckle pattern, which is static on a {approx}10 mn time scale. This gives evidence that the narrow component corresponds to static ordered domains. We interpret the speckles in the broad component as due to a very slow dynamical process, corresponding to the well-known central peak seen in inelastic neutron scattering.

Ravy, S. [Synchrotron SOLEIL, L'Orme des merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette cedex (France); Bolloc'h, D. Le [Laboratoire de physique des solides, Universite Paris-sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Currat, R. [Institut Laue-Langevin, 6, rue Jules Horowitz, Boite postale 156, 38042 Grenoble Cedex 9 (France); Fluerasu, A.; Mocuta, C. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, Boite postale 220, 38043 Grenoble Cedex (France); Dkhil, B. [Laboratoire Structures, Proprietes et Modelisation des Solides, Ecole Centrale Paris, CNRS, UMR 8580, Grande Voie des Vignes, F-92295 Chatenay-Malabry Cedex (France)

2007-03-09

301

Small-Angle X-ray Diffraction of Muscle Using Undulator Radiation from the Tristan Main Ring at KEK.  

PubMed

Time-resolved X-ray diffraction of muscle has demanded ever-increasing flux into small sample volumes with low beam divergence. Results are reported of static and time-resolved small-angle X-ray diffraction studies on muscle fibers using a hard X-ray undulator installed in the Tristan main ring at KEK, Tsukuba, Japan, as an innovative source of synchrotron radiation more intense and better collimated than that available with the Photon Factory bending-magnet beamline. Static studies used the low divergence of the source to obtain detailed high-quality diffraction patterns of stable muscle states. The diffraction patterns from live skeletal muscles showed the numerous (over 100) meridional reflections. The well collimated beam from the undulator made it possible to clearly resolve, with an angular resolution of ca 700 nm, the closely spaced diffraction peaks arising from the two halves of the thick filaments centred on the M lines in a sarcomere, in addition, the diffraction peaks from the thin filaments on opposite sides of the Z bands could be resolved with an angular resolution of ca 1000 nm. The detailed structure of the meridional pattern defines the nature of the molecular packing in the thick and thin filaments. Time-resolved experiments using a focusing mirror aimed to prove cross-bridge states in striated muscle fibers by collecting X-ray diffraction data at a 0.185 ms time resolution from sinusoidally oscillating chemically skinned rabbit muscle fibers during active contraction and in rigor. When sinusoidal length changes at 500 Hz with a peak-to-peak amplitude of 0.6% of the muscle length were applied to a small fiber bundle, the tension showed a simple elastic response during the length oscillation. In the active muscle the intensity of the 14.5 nm myosin-based meridional reflection changed out of phase with the tension change during the oscillating length change. In contrast, in the rigor muscle it occurred in phase with the tension change. The high time-resolved experiments provide an insight into the coupling between conformational changes and force generation of the actomyosin cross-bridges. These studies provide a preview of the expected gains for muscle studies from the more widespread use of undulator radiation at third-generation synchrotron sources. PMID:16702697

Yagi, N; Wakabayashi, K; Iwamoto, H; Horiuti, K; Kojima, I; Irving, T C; Takezawa, Y; Sugimoto, Y; Iwamoto, S; Majima, T; Amemiya, Y; Ando, M

1996-11-01

302

Grain orientation measurement of passivated aluminum interconnectsby x-ray micro diffraction  

SciTech Connect

The crystallographic orientations of individual grains in apassivated aluminum interconnect line of 0.7-mu m width were investigatedby using an incidentwhite x-ray microbeam at the Advanced Light Source,Berkeley National Laboratory. Intergrain orientation mapping was obtainedwith about 0.05o sensitivity by the micro Laue diffractiontechnique.

Chang, Chang-Hwan; Valek, B.C.; Padmore,H.A.; MacDowell, A.A.; Celestre, R.; Marieb, T.; Bravman, J.C.; Koo, Y.M.; Patel, J.R.

1999-07-01

303

X-ray and neutron diffraction measurements of dislocation density and subgrain size in a friction stir welded aluminum alloy  

SciTech Connect

The dislocation density and subgrain size were determined in the base material and friction-stir welds of 6061-T6 aluminum alloy. High-resolution X-ray diffraction measurement was performed in the base material. The result of the line profile analysis of the X-ray diffraction peak shows that the dislocation density is about 4.5 x 10{sup 14} m{sup 02} and the subgrain size is about 200 nm. Meanwhile, neutron diffraction measurements have been performed to observe the diffraction peaks during friction-stir welding (FSW). The deep penetration capability of the neutron enables us to measure the peaks from the midplane of the Al plate underneath the tool shoulder of the friction-stir welds. The peak broadening analysis result using the Williamson-Hall method shows the dislocation density of about 3.2 x 10{sup 15} m{sup -2} and subgrain size of about 160 nm. The significant increase of the dislocation density is likely due to the severe plastic deformation during FSW. This study provides an insight into understanding the transient behavior of the microstructure under severe thermomechanical deformation.

Claussen, Bjorn [Los Alamos National Laboratory; Woo, Wanchuck [ORNL; Zhili, Feng [ORNL; Edward, Kenik [ORNL; Ungar, Tamas [EOTVOS UNIV.

2009-01-01

304

Surface x-ray speckles : coherent surface diffraction from Au(0 01).  

SciTech Connect

We present coherent speckled x-ray diffraction patterns obtained from a monolayer of surface atoms. We measured both the specular anti-Bragg reflection and the off-specular hexagonal reconstruction peak for the Au(001) surface reconstruction. We observed fluctuations of the speckle patterns even when the integrated intensity appears static. By autocorrelating the speckle patterns, we were able to identify two qualitatively different surface dynamic behaviors of the hex reconstruction depending on the sample temperature.

Pierce, M. S.; Chang, K. C.; Hennessy, D.; Komanicky, V.; Sprung, M.; Sandy, A.; You, H.; Safarik Univ.; HASYLAB

2009-10-16

305

Precise orientation of single crystals by a simple x-ray diffraction rocking curve method  

SciTech Connect

A simple method has been developed for accurately measuring the crystallographic orientation of a single crystal boule, employing a conventional four-circle x-ray diffraction arrangement in the rocking curve mode which relaxes the need for precise instrument and/or reference alignment. By acquiring a total of eight rocking curve measurements at specific orientations about the specimen azimuth, the absolute miscut angle between a crystal surface and the desired crystallographic plane can be resolved to within {+-}0.01 deg.

Doucette, L.D.; Pereira da Cunha, M.; Lad, R.J. [Laboratory for Surface Science and Technology, University of Maine, Orono, Maine 04469 (United States); Department of Physics and Astronomy, University of Maine, Orono, Maine 04469 (United States); Department of Electrical and Computer Engineering, University of Maine, Orono, Maine 04469 (United States); Laboratory for Surface Science and Technology, University of Maine, Orono, Maine 04469 (United States); Laboratory for Surface Science and Technology, University of Maine, Orono, Maine 04469 (United States); Department of Physics and Astronomy, University of Maine, Orono, Maine 04469 (United States)

2005-03-01

306

Static High Pressure X-Ray Diffraction of TI-6AL-4V  

NASA Astrophysics Data System (ADS)

Ti-6Al-4V was examined under static-high pressure conditions using a diamond anvil cell. The angle-dispersive x-ray diffraction experiments were performed at the Advanced Photon Source, Argonne National Laboratory. Radial and axial geometry were used to examine multiple samples. The purpose of the experiment was to generate pressure-volume data at room temperature (which is non-existent in literature) and to examine deviatoric stress effects on such a hard alloy.

Chesnut, Gary N.; Velisavljevic, Nenad; Sanchez, Lilliana

2007-12-01

307

X-Ray Diffraction Study of Elemental Erbium to 65 GPa  

SciTech Connect

We have investigated phase transitions in elemental erbium in a diamond anvil cell up to 65 GPa using x-ray powder diffraction methods. We present preliminary evidence of a series of phase transitions that appear to follow the expected hcp {yields} Sm-type {yields} dhcp {yields} distorted fcc sequence. In particular, we believe that we have evidence for the predicted dhcp {yields} distorted fcc transition between 43 GPa and 65 GPa.

Pravica, M.G.; Lipinska-Kalita, K.; Quine, Z.; Romano, E.; Nicol, M.F. (UNLV)

2006-02-02

308

X-ray Diffraction Studies of Crystal-Vapor and Crystal-Solution Interfaces  

Microsoft Academic Search

X-ray diffraction allows the determination of the structure and morphology of crystals growing in a wide range of environments. After an introduction of the technique, recent results are shown on the structure at solid-liquid interfaces. It is found that both sides of the interface differ from their bulk structure: at the crystalline part relaxation and\\/or chemisorption may occur, while the

Elias Vlieg; Elias

2007-01-01

309

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

Microsoft Academic Search

L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3燝Pa. The material is found to transform to a tetragonal structure between 2 and 3燝Pa and to a monoclinic structure between 8 and 10燝Pa. The experimental bulk modulus is 25(5)燝Pa for the orthorhombic phase. The results are compared with previous measurements of L-ALANINE.

J. Staun Olsen; L. Gerward; A. G. Souza Filho; P. T. C. Freire; J. Mendes Filho; F. E. A. Melo

2006-01-01

310

Spectral and x-ray diffraction analyses of lanthanide oxide sulfides  

SciTech Connect

Results of investigations are presented of the homogeneity as well as the crystallochemical and optical properties of lanthanide oxide sulfides used as luminophors. The investigations carried out have made it possible to ascertain the unit-cell parameters of the REE oxide sulfides, to obtain for the first time the diffusion reflection spectra, and to show the scope for monitoring the phase composition during the synthesis of REE oxide sulfides by x-ray diffraction analysis.

Laptev, V.I.; Suponitskii, Y.L.; Vorob'ev, A.F.

1985-06-01

311

High pressure X-ray diffraction study of ?-Si 3N 4  

NASA Astrophysics Data System (ADS)

X-ray diffraction data collected at quasi-hydrostatic pressures of 5-34 GPa yield an average zero-pressure bulk modulus and pressure derivative of K0 = 270(5) GPa and K0' = 4.0(1.8) for ?-Si 3N 4 at room temperature. Similar linear incompressibilities along the a and c crystallographic directions document that compression is nearly isotropic.

Li, Y. M.; Kruger, M. B.; Nguyen, J. H.; Caldwell, W. A.; Jeanloz, Raymond

1997-07-01

312

A surface X-ray diffraction study of Ni(1 1 0) c(2 2)-CN  

NASA Astrophysics Data System (ADS)

Surface X-ray diffraction (SXRD) has been employed to elucidate the geometry of Ni(1 1 0) c(2 2)-CN. It is concluded that the CN overlayer induces an expansion of the outermost Ni layer spacing of 11 2%, relative to bulk-termination. In contrast to an earlier hypothesis, however, no substantive evidence for a significant substrate reconstruction is found. These results are in accord with previously published quantitative structure determinations of this system.

Daniels, B. G.; Schedin, F.; Bikondoa, O.; Thornton, G.; Lindsay, R.

2004-11-01

313

Structure of metal nanowires in nanoporous alumina membranes studied by EXAFS and X-ray diffraction  

Microsoft Academic Search

: 牋The structure of nanowires of different metals grown within nanoporous alumina membranes has been studied by EXAFS, WAXS and\\u000a high energy X-ray diffraction. Nanowires of gold, silver, copper and iron adopt the lattice structure and bond distances of\\u000a the bulk metals. Cobalt nanowires on the other hand were composed of a mixture of hcp phase, stable at room temperature,

R. E. Benfield; D. Grandjean; J. C. Dore; Z. Wu; M. Kr鰈l; T. Sawitowski; G. Schmid

2001-01-01

314

Parametric X-ray emission under conditions of extremely asymmetric diffraction  

NASA Astrophysics Data System (ADS)

The spectral and angular distributions of parametric X-ray emission (PXE) are found under conditions of extremely asymmetric diffraction. An expression is derived for the total number of photons recorded by a detector with a given angular resolution. The influence that multiple electron scattering and the mosaic structure of real crystals has on the nature of PXE is discussed. It was found that the theory explaining PXE in the case of extreme asymmetry agrees well with experimental measurements.

Baryshevskii, V. G.; Grubich, A. O.; Feranchuk, I. D.

1986-05-01

315

Systematic corrections in Bragg x-ray diffraction of flat and curved crystals  

Microsoft Academic Search

Measurements of spectral wavelengths in Bragg diffraction from crystals often require refractive index corrections to allow a detailed comparison of experiment with theory. These corrections are typically 100300 ppm in the x-ray regime, and simple estimates may sometimes be accurate to 5% or better. The inadequacies of these estimates are discussed. Even with a possibly improved index of refraction estimate,

C. T. Chantler; R. D. Deslattes

1995-01-01

316

Electrochemistry and in-situ X-ray diffraction of InSb in lithium batteries  

Microsoft Academic Search

The electrochemical reactions of lithium with the intermetallic compound, InSb, were studied in lithium coin cells using laminate electrodes fabricated from either single-crystal InSb wafers or ball-milled samples. In-situ X-ray diffraction data show that the InSb zinc-blende framework is unstable to extensive reaction with lithium; In is extruded from a fixed Sb lattice during `discharge' and is partially incorporated back

C. S. Johnson; J. T. Vaughey; M. M. Thackeray; T. Sarakonsri; S. A. Hackney; L. Fransson; K. Edstr鰉; J. O. Thomas

2000-01-01

317

Lattice Misfit Measurement in Inconel 625 by X-Ray Diffraction Technique  

Microsoft Academic Search

Determination of lattice misfit and microstructural parameters of the coherent precipitates in Ni based alloy Inconel-625 is a challenging problem as their peaks are completely overlapping among themselves and also with the matrix. We have used a novel X-ray diffraction technique on the bulk samples of Inconel 625 at different heat-treated conditions to determine the lattice parameters, the lattice misfit

P. Mukherjee; A. Sarkar; P. Barat; T. Jayakumar; S. Mahadevan; Sanjay K. Rai

2006-01-01

318

Residual stress analysis in aged graphite\\/PMR15 composites using X-ray diffraction  

Microsoft Academic Search

In this paper, we present and discuss the methodology to monitor average residual stresses in aged high temperature unidirectional and woven graphite fiber\\/PMR-15 composites. The aging experiments were performed at 315癈 for 1170h in nitrogen and 1064h in air, respectively. The proposed methodology was based on X-ray diffraction (XRD) strain measurements in embedded crystalline metallic inclusions. The aging experiments performed

B. Benedikt; M. Lewis; P. Rangaswamy; M. Kumosa; P. Predecki; L. Kumosa; M. Gentz

2006-01-01

319

Spin Density Wave Dislocation in Chromium Probed by Coherent X-ray Diffraction  

SciTech Connect

We report on the study of a magnetic dislocation in pure chromium. Coherent X-ray diffraction profiles obtained on the incommensurate Spin Density Wave (SDW) reflection are consistent with the presence of a dislocation of the magnetic order, embedded at a few micrometers from the surface of the sample. Beyond the specific case of magnetic dislocations in chromium, this work may open up a new method for the study of magnetic defects embedded in the bulk.

Wilkins, S.B.; Jacques, V.L.R.; Le Bolloc抙, D.; Ravy, S.; Giles, C.; Livet, F.

2009-08-19

320

Lamellar twisting in ? isotactic polypropylene transcrystallinity investigated by synchrotron microbeam X-ray diffraction  

Microsoft Academic Search

We report for the first time details of the morphology of ? isotactic polypropylene transcrystallinity induced by aramid fibers as determined by high spatial resolution X-ray diffraction. We suggest that the parent lamellae nucleate at the fiber surface with the crystallite c-axes parallel to the fiber axis, twist one quarter turn about the parent a?-axis within an approximate distance of

E. Assouline; E. Wachtel; S. Grigull; A. Lustiger; H. D. Wagner; G. Marom

2001-01-01

321

X-ray diffraction studies of phase transformations in heavy-metal fluoride glasses  

NASA Technical Reports Server (NTRS)

Powder X-ray diffraction and differential scanning calorimetry studies of the crystallization properties of five ZrF4-based glass compositions have indicated that the crystalline phase in Zr-Ba-La-Pb fluoride glass is beta-BaZrF6; no such identification of crystal phases was obtainable, however, for the other glasses. Reversible polymorphic phase transformations occur in Zr-Ba-La-Li and Zr-Ba-La-Na fluoride glasses, upon heating to higher temperatures.

Bansal, N. P.; Doremus, R. H.

1985-01-01

322

Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction  

SciTech Connect

Characteristic K-? x-rays used for single-pulse XRD are conventionally produced by a 37-stage high-voltage Marx pulse generator coupled to a vacuum needle-and-washer x-ray diode via coaxial transmission line. A large field-of-view x-ray image plate detection system typically enables observation of several Debye-Scherrer rings. Recently, we have developed a fiber-optic reducer, coupled to a CCD camera, to obtain low-noise, large field-of-view images. The direct beam spot is produced by bremsstrahlung radiation attenuated by a twomillimeter tungsten beam stop. Determination of the direct beam position is necessary to perform the ring integration.

Dane V. Morgan

2011-05-25

323

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

Microsoft Academic Search

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抯 stone part and along the carinar process梒entral prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase

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

2002-01-01

324

Carrier-driven disordering in semiconductors: Time-resolved x-ray diffraction and density functional perturbation theory investigations  

Microsoft Academic Search

Time-resolved x-ray science has opened the door to a previously inaccessible experimental world. Now the possibility of imaging ultrafast events with atomic spatial resolution is a reality. This dissertation highlights these new experimental techniques and uses them to study the effects of carrier photo-excitation in semiconductors using both time-resolved x-ray diffraction and time-resolved x-ray absorption spectroscopy. I have probed the

Patrick Brian Hillyard

2009-01-01

325

X-Ray Diffraction Analysis of NLO Crystals: Traditional Applications and More New Opportunities  

NASA Technical Reports Server (NTRS)

Single crystal X-ray diffraction analysis is one of the more important methods for the molecular and crystal structure determination of matter and therefore it has a great importance in material science including design and engineering of different compounds with non-linear optical (NLO) properties. It was shown in our previous publications that this method provides unique information about molecular structure of NLO compounds, their crystal symmetry and crystal packing arrays, molecular conformation and geometries and many other structural and electronic characteristics that are important for understanding the nature of NLO properties of solids. A very new application of the X-ray diffraction method is related to analysis of the electron density distribution p(r) in crystals and some of its characteristics (atomic and group charges, dipole and higher multipole moments, etc.), that may be obtained directly form the diffraction measurements. In the present work, we will discuss our preliminary low temperature high-resolution X-ray data for the m-nitroaniline (mNA) single crystal (VI). This is one of the "classical" organic NLO materials and electron density distribution analysis in this simple compound has a great scientific interest.

Antipin, Mikhail Yu.; Clark, Ronald D.; Nesterov, Vladimir N.

1998-01-01

326

A Deep ROSAT Survey - X. X-ray-luminous narrow-emission-line galaxies  

Microsoft Academic Search

X-ray luminous narrow-emission-line galaxies (NELGs) have been previously identified and proposed as an important class of extragalactic X-ray source, with a potentially significant contribution to the total extragalactic X-ray flux at energies below ~10 keV. In order to investigate and clarify this possibility, we have used a sample of NELGs found in five deep ROSAT fields, and similar samples belonging

R. E. Griffiths; R. della Ceca; Ioannis Georgantopoulos; B. J. Boyle; G. C. Stewart; Tom Shanks; Antonella Fruscione

1996-01-01

327

Real-time, high-resolution x-ray diffraction measurements on shocked crystals at a synchrotron facility  

SciTech Connect

The Advanced Photon Source (APS) at Argonne National Laboratory was used to obtain real-time, high-resolution x-ray diffraction measurements to determine the microscopic response of shock-compressed single crystals. Disk shaped samples were subjected to plane shock wave compression by impacting them with half-inch diameter, flat-faced projectiles. The projectiles were accelerated to velocities ranging between 300 and 1200 m/s using a compact powder gun designed specifically for use at a synchrotron facility. The experiments were designed to keep the sample probed volume under uniaxial strain and constant stress for a duration longer than the 153.4 ns spacing between x-ray bunches. X-rays from a single pulse (<100 ps duration) out of the periodic x-ray pulses emitted by the synchrotron were used for the diffraction measurements. A synchronization and x-ray detection technique was developed to ensure that the measured signal was obtained unambiguously from the desired x-ray pulse incident on the sample while the sample was in a constant uniaxial strain state. The synchronization and x-ray detection techniques described can be used for a variety of x-ray measurements on shock compressed solids and liquids at the APS. Detailed procedures for applying the Bragg-Brentano parafocusing approach to single crystals at the APS are presented. Analytic developments to determine the effects of crystal substructure and non-ideal geometry on the diffraction pattern position and shape are presented. Representative real-time x-ray diffraction data, indicating shock-induced microstructural changes, are presented for a shock-compressed Al(111) sample. The experimental developments presented here provided, in part, the impetus for the Dynamic Compression Sector (DCS) currently under development at the APS. Both the synchronization/x-ray detection methods and the analysis equations for high-resolution single crystal x-ray diffraction can be used at the DCS.

Gupta, Y. M.; Turneaure, Stefan J.; Perkins, K.; Zimmerman, K.; Arganbright, N. [Institute for Shock Physics and the Department of Physics, Washington State University, Pullman, Washington 99164-2816 (United States); Shen, G.; Chow, P. [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60437 (United States)

2012-12-15

328

Real-time, high-resolution x-ray diffraction measurements on shocked crystals at a synchrotron facility.  

PubMed

The Advanced Photon Source (APS) at Argonne National Laboratory was used to obtain real-time, high-resolution x-ray diffraction measurements to determine the microscopic response of shock-compressed single crystals. Disk shaped samples were subjected to plane shock wave compression by impacting them with half-inch diameter, flat-faced projectiles. The projectiles were accelerated to velocities ranging between 300 and 1200 m/s using a compact powder gun designed specifically for use at a synchrotron facility. The experiments were designed to keep the sample probed volume under uniaxial strain and constant stress for a duration longer than the 153.4 ns spacing between x-ray bunches. X-rays from a single pulse (<100 ps duration) out of the periodic x-ray pulses emitted by the synchrotron were used for the diffraction measurements. A synchronization and x-ray detection technique was developed to ensure that the measured signal was obtained unambiguously from the desired x-ray pulse incident on the sample while the sample was in a constant uniaxial strain state. The synchronization and x-ray detection techniques described can be used for a variety of x-ray measurements on shock compressed solids and liquids at the APS. Detailed procedures for applying the Bragg-Brentano parafocusing approach to single crystals at the APS are presented. Analytic developments to determine the effects of crystal substructure and non-ideal geometry on the diffraction pattern position and shape are presented. Representative real-time x-ray diffraction data, indicating shock-induced microstructural changes, are presented for a shock-compressed Al(111) sample. The experimental developments presented here provided, in part, the impetus for the Dynamic Compression Sector (DCS) currently under development at the APS. Both the synchronization?x-ray detection methods and the analysis equations for high-resolution single crystal x-ray diffraction can be used at the DCS. PMID:23278003

Gupta, Y M; Turneaure, Stefan J; Perkins, K; Zimmerman, K; Arganbright, N; Shen, G; Chow, P

2012-12-01

329

High Pressure X-Ray Diffraction Study of URu2Si2  

NASA Astrophysics Data System (ADS)

We have performed high pressure X-ray diffraction measurements on a powder sample of the tetragonal heavy-electron compound URu2Si2 at low temperatures and pressure up to 3 GPa, in order to investigate a pressure-induced phase transition at Pc= 1.5 GPa, which was indicated in the neutron diffraction experiment under pressure. The pressure variations of the lattice parameters a and c at 15 K decrease monotonously with increasing pressure. No discontinuity of the lattice parameters of URu2Si2 around Pc is observed within experimental error.

Kuwahara, K.; Sagayama, H.; Iwasa, K.; Kohgi, M.; Miyazaki, S.; Nozaki, J.; Nogami, J.; Yokoyama, M.; Amitsuka, H.; Nakao, H.; Murakami, Y.

2003-08-01

330

Commissioning of Angle Dispersive X-ray Diffraction Beamline on Indus-2  

SciTech Connect

An Angle dispersive x-ray diffraction (ADXRD) beamline on bending magnet source of Indus-2 synchrotron (2.5 GeV, 300 mA) has been commissioned, for the study of single and polycrystalline samples. The beamline optics is based on vertically focusing Pt-coated pre and post mirrors and sagittal focusing Si (311) based double crystal monochromator. Experimental station consists of a six circle diffractometer equipped with scintillation detector and an image plate area detector for powder diffraction. XRD experiments have been performed to study single crystal and polycrystalline samples.

Sinha, A. K.; Sagdeo, Archna; Gupta, Pooja; Kumar, Ashok; Singh, M. N.; Gupta, R. K.; Kane, S. R.; Deb, S. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Center for Advanced Technology, Indore 452013 (India)

2011-07-15

331

High resolution X-ray diffraction imaging of lead tin telluride  

NASA Technical Reports Server (NTRS)

High resolution X-ray diffraction images of two directly comparable crystals of lead tin telluride, one Bridgman-grown on Space Shuttle STS 61A and the other terrestrially Bridgman-grown under similar conditions from identical material, present different subgrain structure. In the terrestrial, sample 1 the appearance of an elaborate array of subgrains is closely associated with the intrusion of regions that are out of diffraction in all of the various images. The formation of this elaborate subgrain structure is inhibited by growth in microgravity.

Steiner, Bruce; Dobbyn, Ronald C.; Black, David; Burdette, Harold; Kuriyama, Masao; Spal, Richard; Simchick, Richard; Fripp, Archibald

1991-01-01

332

On the microstructure of nanoporous gold: an x-ray diffraction study  

SciTech Connect

The evolution of the grain structure, internal stresses, and the lattice misorientations of nanoporous gold (npAu) during dealloying of bulk (3D) Ag-Au alloy samples was studied by various in-situ and ex-situ X-ray diffraction techniques including powder and Laue diffraction. The experiments reveal that the dealloying process preserves the original crystallographic structure, but leads to a small spread in orientations within individual grains. Furthermore, most grains develop in-plane tensile stress. The feature size of the developing nanoporous structure increases with increasing dealloying time.

Van Petegem, S; Brandstetter, S; Maa?, R; Schmitt, B; Borca, C; Van Swygenhoven, H; Hodge, A M; El-Dasher, B S; Biener, J

2008-08-26

333

Tensile behavior of bulk metallic glasses by in situ x-ray diffraction  

NASA Astrophysics Data System (ADS)

The authors report the use of in situ high-energy x-ray diffraction to detect the tensile behavior of two Zr- and La-based bulk metallic glasses (BMGs). Based on the diffraction data, the tensile elastic modulus and Poisson's ratio can be accurately evaluated. No excess free volume appears in the fractured region. However, a drastic change in atomic-level strains is found in the La-based BMG along the tensile direction, while a tiny crystalline component is detected in the fracture region of Zr-based BMG, which may be the different factors leading to the catastrophic failure of them, respectively.

Wang, X. D.; Bednarcik, J.; Saksl, K.; Franz, H.; Cao, Q. P.; Jiang, J. Z.

2007-08-01

334

NEUTRON AND SYNCHROTRON X-RAY FIBER DIFFRACTION STUDIES OF CELLULOSE POLYMORPHS.  

SciTech Connect

Although the crystalline nature of cellulose has been one of most studied structural problems in polymer science there remain many open questions. Cellulose is a polymer formed by (1-4)-linked {beta}-D-glucosyl residues that are alternately rotated by 180o along the polymer axis to form flat ribbon-like chains. Each glucosyl unit bears three hydroxyl groups, one an hydroxymethyl group. It has been long recognized that these hydroxyl groups and their ability to bond via hydrogen bonding not only play a major role in directing how the crystal structure of cellulose forms but also in governing important physical properties of cellulose materials. Through the development of new techniques we have been able to prepare fiber samples of cellulose with exceptionally high order. The quality of these samples is allowing us to exploit the unique properties of synchrotron X-ray and neutron sources in order to collect diffraction data to near atomic resolution. Synchrotron X-rays are used to provide accurate crystallographic parameters for C and O atoms. However, because of the relatively weak scattering power of H atoms for X-rays, neutrons are used to determine H atom parameters. We have developed methods for replacing labile H atoms with D, without any loss in crystalline perfection. Deuterated fibers can diffract neutrons with intensities that are substantially different from the intensities diffracted from hydrogenated fibers. These differences, along with the phases calculated from the C and O positions determined in our X-ray studies, are used to calculate Fourier difference syntheses in which density associated with labile hydrogen atoms is imaged. The unprecedented high resolution of these data is revealing new information on cellulose structure and hydrogen bonding.

Los Alamos National Laboratory

2001-01-01

335

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

NASA Astrophysics Data System (ADS)

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

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

2006-05-01

336

The use of X-ray diffraction for analyzing biomodification of crystalline cellulose by wood decay fungi  

Microsoft Academic Search

X-ray diffraction (XRD) is based on the creation of an interference pattern by x- rays when they encounter a regularly spaced matrix. In wood, this process has been used to determine among other things the average width of the cellulose microcrystals, the percent of crystalline cellulose within the wood, and can be used to examine the changes in these parameters

Caitlin Howell; Anne Christine; Steenkj鎟 Hastrup; Jody Jellison

337

Novel Cell Design for Combined In Situ Acoustic Emission and X-ray Diffraction of Cycling Lithium Ion Batteries  

Microsoft Academic Search

An in situ acoustic emission (AE) and X-ray diffraction (XRD) cell for use in the study of battery electrode materials has been devised and tested. This cell uses commercially available coin cell hardware retrofitted with a metalized polyethylene terephthalate (PET) disk which acts as both an X-ray window and a current collector. In this manner the use of beryllium and

Kevin J Rhodes; Melanie J Kirkham; Roberta Ann Meisner; Chad M Parish; Nancy J Dudney; Claus Daniel

2011-01-01

338

Strength and structural phase transitions of gadolinium at high pressure from radial X-ray diffraction  

NASA Astrophysics Data System (ADS)

Lattice strength and structural phase transitions of gadolinium (Gd) were determined under nonhydrostatic compression up to 55 GPa using an angle-dispersive radial x-ray diffraction technique in a diamond-anvil cell at room temperature. Three new phases of fcc structure, dfcc structure, and new monoclinic structure were observed at 25 GPa, 34 GPa, and 53 GPa, respectively. The radial x-ray diffraction data yield a bulk modulus K0 = 36(1) GPa with its pressure derivate K0' = 3.8(1) at the azimuthal angle between the diamond cell loading axis and the diffraction plane normal and diffraction plane ? = 54.7. With K0' fixed at 4, the derived K0 is 34(1) GPa. In addition, analysis of diffraction data with lattice strain theory indicates that the ratio of differential stress to shear modulus (t/G) ranges from 0.011 to 0.014 at pressures of 12-55 GPa. Together with estimated high-pressure shear moduli, our results show that Gd can support a maximum differential stress of 0.41 GPa, while it starts to yield to plastic deformation at 16 GPa under uniaxial compression. The yield strength of Gd remains approximately a constant with increasing pressure, and reaches 0.46 GPa at 55 GPa.

Xiong, Lun; Liu, Jing; Bai, Ligang; Li, Xiaodong; Lin, Chuanlong; Lin, Jung-Fu

2014-12-01

339

Static and Dynamic X-Ray Diffraction Recordings from Living Mammalian and Amphibian Skeletal Muscles  

PubMed Central

Static and time-resolved two-dimensional x-ray diffraction patterns, recorded from the living mouse diaphragm muscle, were compared with those from living frog sartorius muscle. The resting pattern of mouse muscle was similar to that of frog muscle, and consisted of actin- and myosin-based reflections with spacings basically identical to those of frog. As a notable exception, the sampling pattern of the myosin layer lines (MLL's) indicated that the mouse myofilaments were not organized into a superlattice as in frog. The intensity changes of reflections upon activation were also similar. The MLL's of both muscles were markedly weakened. Stereospecific (rigorlike) actomyosin species were not significantly populated in either muscle, as was evidenced by the 6th actin layer line (ALL), which was substantially enhanced but without a shift in its peak position or a concomitant rise of lower order ALL's. On close examination of the mouse pattern, however, a few lower order ALL's were found to rise, slightly but definitely, at the position expected for stereospecific binding. Their quick rise after the onset of stimulation indicates that this stereospecific complex is generated in the process of normal contraction. However, their rise is still too small to account for the marked enhancement of the 6th ALL, which is better explained by a myosin-induced structural change of actin. Since the forces of the two muscles are comparable regardless of the amount of stereospecific complex, it would be natural to consider that most of the force of skeletal muscle is supported by nonstereospecific actomyosin species. PMID:14507712

Iwamoto, Hiroyuki; Wakayama, Jun'ichi; Fujisawa, Tetsuro; Yagi, Naoto

2003-01-01

340

X-ray diffraction study of crystallite size-distribution and strain in carbon blacks T. Ungr, J. Gubicza, G. Ribrik and T. W. Zerda1  

E-print Network

X-ray diffraction study of crystallite size-distribution and strain in carbon blacks T. Ung谩r, J blacks by a recently developed procedure of X-ray diffraction peak profile analysis. The Fourier. INTRODUCION X-ray diffraction peak profile analysis is a widely used method for the determination

Gubicza, Jen玫

341

Thirty-Meter X-Ray Pencil Beam Line at the Institute of Space and Astronautical Science  

Microsoft Academic Search

A 30-m-long X-ray beam line has been built at the Institute of Space and Astronautical Science (ISAS) to evaluate the performance of X-ray optical instruments for space programs, in particular for the X-ray telescope onboard the Astro-D (Asca) satellite. This beam line consists of an X-ray generator, a 30-m-long vacuum duct, and measuring chambers. Strong and stable X-ray pencil beams

Hideyo Kunieda; Yoshiyuki Tsusaka; Hisanori Suzuki; Yasushi Ogasaka; Hisamitsu Awaki; Yuzuru Tawara; Koujun Yamashita; Takashi Yamazaki; Masayuki Itoh; Tsuneo Kii; Fumiyoshi Makino; Yoshiaki Ogawara; Hiroshi Tsunemi; Kiyoshi Hayashida; Susumu Nomoto; Mikio Wada; Emi Miyata; Isamu Hatsukade

1993-01-01

342

X-ray line profile analysis of equal channel angular pressing processed Cu  

NASA Astrophysics Data System (ADS)

The effect of equal channel angular pressing on the microstructure of copper samples was studied by X-ray line profile analysis. Pure Cu samples were processed by equal channel angular pressing with 3 passes in route A. Samples were taken from the vicinity of the channel intersection, and along a profile across the deformation zone, microhardness and XRD measurements were performed. For the high resolution line profile analysis of the diffraction spectra, convolutional-multiple-whole-profile CMWP method was applied, dislocation density and grain size were calculated, furthermore the density of twin boundaries were determined. Results show a rearrangement in the dislocations in the third pass leading to a rise in the density of twin boundaries.

J髇i, B.; Gonda, V.; Ver, B.; Ung醨, T.

2014-08-01

343

Ultrafast structural dynamics with table top femtosecond hard X-ray and electron diffraction setups  

NASA Astrophysics Data System (ADS)

The following tutorial review is directed to graduate students willing to be part of the emerging field of ultrafast structural dynamics. It provides them with an introduction to the field and all the very basic assumptions and experimental tricks involved in femtosecond (fs) diffraction techniques. The concept of stroboscopic photography and its implication in ultrafast science are introduced. Special attention is paid to the generation of ultrashort electron and hard X-ray pulses in table top setups, and a direct comparison in terms of brightness and temporal resolution between current table top and facility-based methodologies is given for proper calibration. This review is focused on ultrafast X-ray and electron diffraction techniques. The progress in the development of fs-structural probes during the last twenty years has been tremendous. Current ultrafast structural probes provide us with the temporal and spatial resolutions required to observe atoms in motion. Different compression approaches have made it possible the generation of ultrashort and ultrabright electron pulses with an effective brightness close to that of fs-hard X-ray pulses produced by free electron lasers. We now have in hand a variety of ultrafast structural cameras ready to be applied for the study of an endless list of dynamical phenomena at the atomic level of inspection.

Hada, M.; Pichugin, K.; Sciaini, G.

2013-07-01

344

Flux monitoring by x-ray diffracting crystals under ambient air conditions  

NASA Astrophysics Data System (ADS)

An electrical response of a diffracting diamond (111) crystal was studied in a single electrode configuration where the electrode was deposited on a small portion of the crystal entrance surface. The experiment was performed in ambient air using an x-ray beam after a Si (111) double-crystal monochromator with the diamond crystal set in the Bragg diffraction condition. It was found that the electric current as a function of the Bragg angle exhibits behavior characteristic of secondary yield curves (e.g.,1). It is proposed to utilize this effect to monitor the intensity of the Bragg reflected x-ray beam. Such non-invasive monitoring does not rely on the use of stand-alone radiation monitors (e.g., ionization chambers) and is expected to facilitate x-ray optics alignment procedures. As an attempt to improve signal-to-noise ratio by containing the electric field in the optical element an electric response of a high-resistivity silicon crystal was studied in a two-electrode configuration. Preliminary results are reported.

Stoupin, Stanislav; Baryshev, Sergey V.; Antipov, Sergey P.

2014-09-01

345

Mineral identification in Colombian coals using M鰏sbauer spectroscopy and X-ray diffraction  

NASA Astrophysics Data System (ADS)

Minerals were identified in three Colombian coal samples from the Southwest of the country using M鰏sbauer 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 祄 were used in the study. Using M鰏sbauer 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. M鰏sbauer 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.

Fajardo, M.; Mojica, J.; Barraza, J.; P閞ez Alc醶ar, G. A.; Tabares, J. A.

1999-11-01

346

Imaging live cell in micro-liquid enclosure by X-ray laser diffraction  

NASA Astrophysics Data System (ADS)

Emerging X-ray free-electron lasers with femtosecond pulse duration enable single-shot snapshot imaging almost free from sample damage by outrunning major radiation damage processes. In bioimaging, it is essential to keep the sample close to its natural state. Conventional high-resolution imaging, however, suffers from severe radiation damage that hinders live cell imaging. Here we present a method for capturing snapshots of live cells kept in a micro-liquid enclosure array by X-ray laser diffraction. We place living Microbacterium lacticum cells in an enclosure array and successively expose each enclosure to a single X-ray laser pulse from the SPring-8 Angstrom Compact Free-Electron Laser. The enclosure itself works as a guard slit and allows us to record a coherent diffraction pattern from a weakly-scattering submicrometre-sized cell with a clear fringe extending up to a 28-nm full-period resolution. The reconstructed image reveals living whole-cell structures without any staining, which helps advance understanding of intracellular phenomena.

Kimura, Takashi; Joti, Yasumasa; Shibuya, Akemi; Song, Changyong; Kim, Sangsoo; Tono, Kensuke; Yabashi, Makina; Tamakoshi, Masatada; Moriya, Toshiyuki; Oshima, Tairo; Ishikawa, Tetsuya; Bessho, Yoshitaka; Nishino, Yoshinori

2014-01-01

347

Room temperature femtosecond X-ray diffraction of photosystem II microcrystals  

PubMed Central

Most of the dioxygen on earth is generated by the oxidation of water by photosystem II (PS營I) using light from the sun. This light-driven, four-photon reaction is catalyzed by the Mn4CaO5 cluster located at the lumenal side of PS營I. Various X-ray studies have been carried out at cryogenic temperatures to understand the intermediate steps involved in the water oxidation mechanism. However, the necessity for collecting data at room temperature, especially for studying the transient steps during the O朞 bond formation, requires the development of new methodologies. In this paper we report room temperature X-ray diffraction data of PS營I microcrystals obtained using ultrashort (<50爁s) 9爇eV X-ray pulses from a hard X-ray free electron laser, namely the Linac Coherent Light Source. The results presented here demonstrate that the 攑robe before destroy approach using an X-ray free electron laser works even for the highly-sensitive Mn4CaO5 cluster in PS營I at room temperature. We show that these data are comparable to those obtained in synchrotron radiation studies as seen by the similarities in the overall structure of the helices, the protein subunits and the location of the various cofactors. This work is, therefore, an important step toward future studies for resolving the structure of the Mn4CaO5 cluster without any damage at room temperature, and of the reaction intermediates of PS營I during O朞 bond formation. PMID:22665786

Kern, Jan; Alonso-Mori, Roberto; Hellmich, Julia; Tran, Rosalie; Hattne, Johan; Laksmono, Hartawan; Gl鯿kner, Carina; Echols, Nathaniel; Sierra, Raymond G.; Sellberg, Jonas; Lassalle-Kaiser, Benedikt; Gildea, Richard J.; Glatzel, Pieter; Grosse-Kunstleve, Ralf W.; Latimer, Matthew J.; McQueen, Trevor A.; DiFiore, D鰎te; Fry, Alan R.; Messerschmidt, Marc; Miahnahri, Alan; Schafer, Donald W.; Seibert, M. Marvin; Sokaras, Dimosthenis; Weng, Tsu-Chien; Zwart, Petrus H.; White, William E.; Adams, Paul D.; Bogan, Michael J.; Boutet, S閎astien; Williams, Garth J.; Messinger, Johannes; Sauter, Nicholas K.; Zouni, Athina; Bergmann, Uwe; Yano, Junko; Yachandra, Vittal K.

2012-01-01

348

X-ray Diffraction Results from Mars Science Laboratory: Mineralogy of Rocknest at Gale Crater  

NASA Astrophysics Data System (ADS)

The Mars Science Laboratory rover Curiosity scooped samples of soil from the Rocknest aeolian bedform in Gale crater. Analysis of the soil with the Chemistry and Mineralogy (CheMin) x-ray diffraction (XRD) instrument revealed plagioclase (~An57), forsteritic olivine (~Fo62), augite, and pigeonite, with minor K-feldspar, magnetite, quartz, anhydrite, hematite, and ilmenite. The minor phases are present at, or near, detection limits. The soil also contains 27 14 weight percent x-ray amorphous material, likely containing multiple Fe3+- and volatile-bearing phases, including possibly a substance resembling hisingerite. The crystalline component is similar to the normative mineralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites. The amorphous component is similar to that found on Earth in places such as soils on the Mauna Kea volcano, Hawaii.

Bish, D. L.; Blake, D. F.; Vaniman, D. T.; Chipera, S. J.; Morris, R. V.; Ming, D. W.; Treiman, A. H.; Sarrazin, P.; Morrison, S. M.; Downs, R. T.; Achilles, C. N.; Yen, A. S.; Bristow, T. F.; Crisp, J. A.; Morookian, J. M.; Farmer, J. D.; Rampe, E. B.; Stolper, E. M.; Spanovich, N.; Achilles, Cherie; Agard, Christophe; Verdasca, Jos Alexandre Alves; Anderson, Robert; Anderson, Ryan; Archer, Doug; Armiens-Aparicio, Carlos; Arvidson, Ray; Atlaskin, Evgeny; Atreya, Sushil; Aubrey, Andrew; Baker, Burt; Baker, Michael; Balic-Zunic, Tonci; Baratoux, David; Baroukh, Julien; Barraclough, Bruce; Bean, Keri; Beegle, Luther; Behar, Alberto; Bell, James; Bender, Steve; Benna, Mehdi; Bentz, Jennifer; Berger, Gilles; Berger, Jeff; Berman, Daniel; Bish, David; Blake, David F.; Avalos, Juan J. Blanco; Blaney, Diana; Blank, Jen; Blau, Hannah; Bleacher, Lora; Boehm, Eckart; Botta, Oliver; B鰐tcher, Stephan; Boucher, Thomas; Bower, Hannah; Boyd, Nick; Boynton, Bill; Breves, Elly; Bridges, John; Bridges, Nathan; Brinckerhoff, William; Brinza, David; Bristow, Thomas; Brunet, Claude; Brunner, Anna; Brunner, Will; Buch, Arnaud; Bullock, Mark; Burmeister, S鰊ke; Cabane, Michel; Calef, Fred; Cameron, James; Campbell, John "Iain"; Cantor, Bruce; Caplinger, Michael; Rodr韌uez, Javier Caride; Carmosino, Marco; Bl醶quez, Isa韆s Carrasco; Charpentier, Antoine; Chipera, Steve; Choi, David; Clark, Benton; Clegg, Sam; Cleghorn, Timothy; Cloutis, Ed; Cody, George; Coll, Patrice; Conrad, Pamela; Coscia, David; Cousin, Agn鑣; Cremers, David; Crisp, Joy; Cros, Alain; Cucinotta, Frank; d'Uston, Claude; Davis, Scott; Day, Mackenzie "Kenzie"; Juarez, Manuel de la Torre; DeFlores, Lauren; DeLapp, Dorothea; DeMarines, Julia; DesMarais, David; Dietrich, William; Dingler, Robert; Donny, Christophe; Downs, Bob; Drake, Darrell; Dromart, Gilles; Dupont, Audrey; Duston, Brian; Dworkin, Jason; Dyar, M. Darby; Edgar, Lauren; Edgett, Kenneth; Edwards, Christopher; Edwards, Laurence; Ehlmann, Bethany; Ehresmann, Bent; Eigenbrode, Jen; Elliott, Beverley; Elliott, Harvey; Ewing, Ryan; Fabre, C閏ile; Fair閚, Alberto; Farley, Ken; Farmer, Jack; Fassett, Caleb; Favot, Laurent; Fay, Donald; Fedosov, Fedor; Feldman, Jason; Feldman, Sabrina; Fisk, Marty; Fitzgibbon, Mike; Flesch, Greg; Floyd, Melissa; Fl點kiger, Lorenzo; Forni, Olivier; Fraeman, Abby; Francis, Raymond; Fran鏾is, Pascaline; Franz, Heather; Freissinet, Caroline; French, Katherine Louise; Frydenvang, Jens; Gaboriaud, Alain; Gailhanou, Marc; Garvin, James; Gasnault, Olivier; Geffroy, Claude; Gellert, Ralf; Genzer, Maria; Glavin, Daniel; Godber, Austin; Goesmann, Fred; Goetz, Walter; Golovin, Dmitry; G髆ez, Felipe G髆ez; G髆ez-Elvira, Javier; Gondet, Brigitte; Gordon, Suzanne; Gorevan, Stephen; Grant, John; Griffes, Jennifer; Grinspoon, David; Grotzinger, John; Guillemot, Philippe; Guo, Jingnan; Gupta, Sanjeev; Guzewich, Scott; Haberle, Robert; Halleaux, Douglas; Hallet, Bernard; Hamilton, Vicky; Hardgrove, Craig; Harker, David; Harpold, Daniel; Harri, Ari-Matti; Harshman, Karl; Hassler, Donald; Haukka, Harri; Hayes, Alex; Herkenhoff, Ken; Herrera, Paul; Hettrich, Sebastian; Heydari, Ezat; Hipkin, Victoria; Hoehler, Tori; Hollingsworth, Jeff; Hudgins, Judy; Huntress, Wesley; Hurowitz, Joel; Hviid, Stubbe; Iagnemma, Karl; Indyk, Steve; Isra雔, Guy; Jackson, Ryan; Jacob, Samantha; Jakosky, Bruce; Jensen, Elsa; Jensen, Jaqueline Kl鴙gaard; Johnson, Jeffrey; Johnson, Micah; Johnstone, Steve; Jones, Andrea; Jones, John; Joseph, Jonathan; Jun, Insoo; Kah, Linda; Kahanp滗, Henrik; Kahre, Melinda; Karpushkina, Natalya; Kasprzak, Wayne; Kauhanen, Janne; Keely, Leslie; Kemppinen, Osku; Keymeulen, Didier; Kim, Myung-Hee; Kinch, Kjartan; King, Penny; Kirkland, Laurel; Kocurek, Gary; Koefoed, Asmus; K鰄ler, Jan; Kortmann, Onno; Kozyrev, Alexander; Krezoski, Jill; Krysak, Daniel; Kuzmin, Ruslan; Lacour, Jean Luc; Lafaille, Vivian; Langevin, Yves; Lanza, Nina; Lasue, Jeremie; Le Mou閘ic, St閜hane; Lee, Ella Mae; Lee, Qiu-Mei; Lees, David; Lefavor, Matthew; Lemmon, Mark; Malvitte, Alain Lepinette; Leshin, Laurie; L関eill, Richard; Lewin-Carpintier, 蓃ic; Lewis, Kevin; Li, Shuai; Lipkaman, Leslie; Little, Cynthia; Litvak, Maxim; Lorigny, Eric; Lugmair, Guenter; Lundberg, Angela; Lyness, Eric; Madsen, Morten; Mahaffy, Paul; Maki, Justin; Malakhov, Alexey; Malespin, Charles; Malin, Michael; Mangold, Nicolas; Manhes, G閞ard; Manning, Heidi; Marchand, Genevi鑦e; Jim閚ez, Mercedes Mar韓; Garc韆, C閟ar Mart韓; Martin, Dave; Martin, Mildred; Mart韓ez-Fr韆s, Jes鷖; Mart韓-Soler, Javier; Mart韓-Torres, F. Javier; Mauchien, Patrick

2013-09-01

349

Time-, frequency-, and wavevector-resolved x-ray diffraction from single molecules  

NASA Astrophysics Data System (ADS)

Using a quantum electrodynamic framework, we calculate the off-resonant scattering of a broadband X-ray pulse from a sample initially prepared in an arbitrary superposition of electronic states. The signal consists of single-particle (incoherent) and two-particle (coherent) contributions that carry different particle form factors that involve different material transitions. Single-molecule experiments involving incoherent scattering are more influenced by inelastic processes compared to bulk measurements. The conditions under which the technique directly measures charge densities (and can be considered as diffraction) as opposed to correlation functions of the charge-density are specified. The results are illustrated with time- and wavevector-resolved signals from a single amino acid molecule (cysteine) following an impulsive excitation by a stimulated X-ray Raman process resonant with the sulfur K-edge. Our theory and simulations can guide future experimental studies on the structures of nano-particles and proteins.

Bennett, Kochise; Biggs, Jason D.; Zhang, Yu; Dorfman, Konstantin E.; Mukamel, Shaul

2014-05-01

350

RASOR: an advanced instrument for soft x-ray reflectivity and diffraction.  

PubMed

We report the design and construction of a novel soft x-ray diffractometer installed at Diamond Light Source. The beamline endstation RASOR is constructed for general users and designed primarily for the study of single crystal diffraction and thin film reflectivity. The instrument is comprised of a limited three circle (theta, 2theta, and chi) diffractometer with an additional removable rotation (phi) stage. It is equipped with a liquid helium cryostat, and post-scatter polarization analysis. Motorized motions are provided for the precise positioning of the sample onto the diffractometer center of rotation, and for positioning the center of rotation onto the x-ray beam. The functions of the instrument have been tested at Diamond Light Source, and initial test measurements are provided, demonstrating the potential of the instrument. PMID:20687739

Beale, T A W; Hase, T P A; Iida, T; Endo, K; Steadman, P; Marshall, A R; Dhesi, S S; van der Laan, G; Hatton, P D

2010-07-01

351

Automated high pressure cell for pressure jump x-ray diffraction  

SciTech Connect

A high pressure cell for small and wide-angle x-ray diffraction measurements of soft condensed matter samples has been developed, incorporating a fully automated pressure generating network. The system allows both static and pressure jump measurements in the range of 0.1-500 MPa. Pressure jumps can be performed as quickly as 5 ms, both with increasing and decreasing pressures. Pressure is generated by a motorized high pressure pump, and the system is controlled remotely via a graphical user interface to allow operation by a broad user base, many of whom may have little previous experience of high pressure technology. Samples are loaded through a dedicated port allowing the x-ray windows to remain in place throughout an experiment; this facilitates accurate subtraction of background scattering. The system has been designed specifically for use at beamline I22 at the Diamond Light Source, United Kingdom, and has been fully integrated with the I22 beamline control systems.

Brooks, Nicholas J.; Gauthe, Beatrice L. L. E.; Templer, Richard H.; Ces, Oscar; Seddon, John M. [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Terrill, Nick J. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Rogers, Sarah E. [ISIS, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)

2010-06-15

352

Time-, frequency-, and wavevector-resolved x-ray diffraction from single molecules  

SciTech Connect

Using a quantum electrodynamic framework, we calculate the off-resonant scattering of a broadband X-ray pulse from a sample initially prepared in an arbitrary superposition of electronic states. The signal consists of single-particle (incoherent) and two-particle (coherent) contributions that carry different particle form factors that involve different material transitions. Single-molecule experiments involving incoherent scattering are more influenced by inelastic processes compared to bulk measurements. The conditions under which the technique directly measures charge densities (and can be considered as diffraction) as opposed to correlation functions of the charge-density are specified. The results are illustrated with time- and wavevector-resolved signals from a single amino acid molecule (cysteine) following an impulsive excitation by a stimulated X-ray Raman process resonant with the sulfur K-edge. Our theory and simulations can guide future experimental studies on the structures of nano-particles and proteins.

Bennett, Kochise, E-mail: kcbennet@uci.edu; Biggs, Jason D.; Zhang, Yu; Dorfman, Konstantin E.; Mukamel, Shaul, E-mail: smukamel@uci.edu [University of California, Irvine, California 92697-2025 (United States)

2014-05-28

353

Time-, Frequency-, and Wavevector-Resolved X-Ray Diffraction from Single Molecules  

E-print Network

Using a quantum electrodynamic framework, we calculate the off-resonant scattering of a broad-band X-ray pulse from a sample initially prepared in an arbitrary superposition of electronic states. The signal consists of single-particle (incoherent) and two-particle (coherent) contributions that carry different particle form factors that involve different material transitions. Single-molecule experiments involving incoherent scattering are more influenced by inelastic processes compared to bulk measurements. The conditions under which the technique directly measures charge densities (and can be considered as diffraction) as opposed to correlation functions of the charge-density are specified. The results are illustrated with time- and wavevector-resolved signals from a single amino acid molecule (cysteine) following an impulsive excitation by a stimulated X-ray Raman process resonant with the sulfur K-edge. Our theory and simulations can guide future experimental studies on the structures of nano-particles and ...

Bennett, Kochise; Zhang, Yu; Dorfman, Konstantin E; Mukamel, Shaul

2014-01-01

354

High-Angular-Resolution Microbeam X-Ray Diffraction with CCD Detector  

SciTech Connect

We have introduced a CCD-type two-dimensional X-ray detector for a microbeam X-ray diffraction system using synchrotron radiation, so that we can measure local reciprocal space maps (RSM) of samples rapidly. A local RSM of a strain-relaxed SiGe 004 grown on a Si (001) substrate was measured in higher-angular-resolution and faster than a conventional way. The measurement was achieved in 1 h 40 min. with the 2theta resolution of 80 murad and the spatial resolution of 1.4(h)x0.5(v) {mu}m{sup 2}. The introduction of the CCD enabled us to measure RSMs at many points in a sample, that is, the distribution of strain fields and lattice tilts can be revealed in high-angular- and high-spatial-resolution.

Imai, Yasuhiko; Kimura, Shigeru; Sakaia, Akira [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Sakata, Osami [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 670-8531 (Japan)

2010-04-06

355

High-Angular-Resolution Microbeam X-Ray Diffraction with CCD Detector  

NASA Astrophysics Data System (ADS)

We have introduced a CCD-type two-dimensional X-ray detector for a microbeam X-ray diffraction system using synchrotron radiation, so that we can measure local reciprocal space maps (RSM) of samples rapidly. A local RSM of a strain-relaxed SiGe 004 grown on a Si (001) substrate was measured in higher-angular-resolution and faster than a conventional way. The measurement was achieved in 1 h 40 min. with the 2? resolution of 80 ?rad and the spatial resolution of 1.4(h)0.5(v) ?m2. The introduction of the CCD enabled us to measure RSMs at many points in a sample, that is, the distribution of strain fields and lattice tilts can be revealed in high-angular- and high-spatial-resolution.

Imai, Yasuhiko; Kimura, Shigeru; Sakata, Osami; Sakaia, Akira

2010-04-01

356

A novel wafer-scale CMOS APS X-ray detector for breast cancer diagnosis using X-ray diffraction studies  

NASA Astrophysics Data System (ADS)

The current study uses a novel large area (12.8 cm 13.1 cm) complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) X-ray detector, named Dynamic range Adjustable for Medical Imaging Technology (DynAMITe), for breast cancer diagnosis. The detector consists of two geometrically superimposed grids: a) 2560 2624 fine-pitch grid of pixels (50 ?m pitch), named Sub-Pixels (SP camera), for low intrinsic noise and high spatial resolution and b) 1280 1312 large-pitch grid of pixels (100 ?m pitch), named Pixels (P camera), for high dynamic range. X-ray performance characterization measurements show that the detective quantum efficiency (DQE) of the SP camera is in the range 0.7-0.75 at low spatial frequencies using a tungsten (W) anode X-ray source at 28 kV. Hence, the detector is suitable for mammography. Furthermore, we used the SP camera to combine mammograms with angle dispersive X-ray diffraction (ADXRD) measurements in order to apply the X-ray biopsy concept in one examination. The results show that ADXRD technique indicates the presence of cancer in suspicious areas on the mammogram. Hence, it could be used to determine the region affected by cancer and assist in planning surgery. This study is the proof of concept that mammography and ADXRD can be combined in one examination.

Konstantinidis, A.; Zheng, Y.; Philip, D.; Vinnicombe, S.; Speller, R.

2012-12-01

357

X-ray diffraction effect from surface acoustic waves traveling on a deposited multilayer  

SciTech Connect

We investigate the x-ray diffraction effects from surface acoustic waves (SAW) traveling along a multilayer. The diffraction intensity distribution depends on the incidence angle and the multilayer SAW (MLSAW) amplitude. Particularly, a small departure deviating from the Bragg incidence angle at a certain amplitude will produce a larger variation of the intensity distribution. This shows that the diffraction intensity from MLSAW has an extremely high sensitivity to the Bragg incidence angle, which is different from a SAW traveling along a solid surface without deposited layers. By carefully analyzing the relationship between the intensity distribution I and the incidence angle {theta}, the corresponding analytic expression of the intensity distribution is theoretically derived. Our theoretical prediction is in great agreement with the experimental results previously obtained. A theoretical model that can be applied to study the x-ray diffraction effect from MLSAW is developed. The extremely high sensitivity to the Bragg angle will help us in acousto-optic instrument research with MLSAW.

Dong Jun; Qi Jianxia; Miao Runcai

2010-04-10

358

X-ray diffraction study of short-period AlN/GaN superlattices  

NASA Astrophysics Data System (ADS)

The structure of short-period hexagonal GaN/AlN superlattices (SLs) has been investigated by X-ray diffraction. The samples have been grown by metalorganic vapor-phase epitaxy (MOVPE) in a horizontal reactor at a temperature of 1050癈 on (0001)Al2O3 substrates using GaN and AlN buffer layers. The SL period changes from 2 to 6 nm, and the thickness of the structure varies in a range from 0.3 to 1 ?m. The complex of X-ray diffraction techniques includes a measurement of ?-2? rocking curves of symmetric Bragg reflection, the construction of intensity maps for asymmetric reflections, a measurement and analysis of peak broadenings in different diffraction geometries, a precise measurement of lattice parameters, and the determination of radii of curvature. The thickness and strain of separate SL layers are determined by measuring the ?-2? rocking curves subsequent simulation. It is shown that most SL samples are completely relaxed as a whole. At the same time, relaxation is absent between sublayers, which is why strains in the AlN and GaN sublayers (on the order of 1.2 10-2) have different signs. An analysis of diffraction peak half-widths allows us to determine the densities of individual sets of dislocations and observe their change from buffer layers to SLs.

Kyutt, R. N.; Shcheglov, M. P.; Ratnikov, V. V.; Yagovkina, M. A.; Davydov, V. Yu.; Smirnov, A. N.; Rozhavskaya, M. M.; Zavarin, E. E.; Lundin, V. V.

2013-12-01

359

Tracing the conversion of aurichalcite to a copper catalyst by combined X-ray absorption and diffraction  

Microsoft Academic Search

EVER since X-ray sources first became available, the merit of deploying diffraction and absorption spectroscopic studies simultaneously has been acknowledged1. Information on oxidation states and local (~6- radius) atomic environments is now obtained routinely from X-ray absorption measurements using synchrotron sources2-4. Synchrotron radiation is also used commonly for high-resolution powder diffraction crystallography. We report here an instrumental arrangement that has

John W. Couves; John Meurig Thomas; David Waller; Richard H. Jones; Andrew J. Dent; Gareth E. Derbyshire; G. Neville Greaves

1991-01-01

360

Structure investigation of narrow banded spherulites in polyhydroxyalkanoates by microbeam X-ray diffraction with synchrotron radiation  

Microsoft Academic Search

Narrow banded structures of spherulites of poly[(R)-3-hydroxybutyrate] (P(3HB)) and its copolymers, with different second monomer unit of 4-hydroxybutyrate, 3-hydroxyhexanoate or 6-hydroxyhexanoate, were investigated by microbeam X-ray diffraction with Fresnel Zone Plate technique in synchrotron radiation (SPring-8). Radial scanning of spherulites were performed in 2 or 4?m steps with 0.5?m beam diameter of fine microfocus beam. The X-ray diffraction patterns for

Toshihisa Tanaka; Masahiro Fujita; Akihisa Takeuchi; Yoshio Suzuki; Kentaro Uesugi; Yoshiharu Doi; Tadahisa Iwata

2005-01-01

361

Analysis of energy dispersive x-ray diffraction profiles for material identification, imaging and system control  

NASA Astrophysics Data System (ADS)

This thesis presents the analysis of low angle X-ray scatter measurements taken with an energy dispersive system for substance identification, imaging and system control. Diffraction measurements were made on illicit drugs, which have pseudo- crystalline structures and thus produce diffraction patterns comprising a se ries of sharp peaks. Though the diffraction profiles of each drug are visually characteristic, automated detection systems require a substance identification algorithm, and multivariate analysis was selected as suitable. The software was trained with measured diffraction data from 60 samples covering 7 illicit drugs and 5 common cutting agents, collected with a range of statistical qual ities and used to predict the content of 7 unknown samples. In all cases the constituents were identified correctly and the contents predicted to within 15%. Soft tissues exhibit broad peaks in their diffraction patterns. Diffraction data were collected from formalin fixed breast tissue samples and used to gen erate images. Maximum contrast between healthy and suspicious regions was achieved using momentum transfer windows 1.04-1.10 and 1.84-1.90 nm_1. The resulting images had an average contrast of 24.6% and 38.9% compared to the corresponding transmission X-ray images (18.3%). The data was used to simulate the feedback for an adaptive imaging system and the ratio of the aforementioned momentum transfer regions found to be an excellent pa rameter. Investigation into the effects of formalin fixation on human breast tissue and animal tissue equivalents indicated that fixation in standard 10% buffered formalin does not alter the diffraction profiles of tissue in the mo mentum transfer regions examined, though 100% unbuffered formalin affects the profile of porcine muscle tissue (a substitute for glandular and tumourous tissue), though fat is unaffected.

Cook, Emily Jane

2008-12-01

362

Advanced combined application of micro-X-ray diffraction/micro-X-ray fluorescence with conventional techniques for the identification of pictorial materials from Baroque Andalusia paintings.  

PubMed

The process of investigating paintings includes the identification of materials to solve technical and historical art questions, to aid in the deduction of the original appearance, and in the establishment of the chemical and physical conditions for adequate restoration and conservation. In particular, we have focused on the identification of several samples taken from six famous canvases painted by Pedro Atanasio Bocanegra, who created a very special collection depicting the life of San Ignacio, which is located in the church of San Justo y Pastor of Granada, Spain. The characterization of the inorganic and organic compounds of the textiles, preparation layers, and pictorial layers have been carried out using an XRD diffractometer, SEM observations, EDX spectrometry, FT-IR spectrometry (both in reflection and transmission mode), pyrolysis/gas chromatography/mass spectrometry and synchrotron-based micro-X-ray techniques. In this work, the advantages over conventional X-ray diffraction of using combined synchrotron-based micro-X-ray diffraction and micro-X-ray fluorescence in the identification of multi-layer paintings is demonstrated. PMID:19782194

Herrera, L K; Montalbani, S; Chiavari, G; Cotte, M; Sol, V A; Bueno, J; Duran, A; Justo, A; Perez-Rodriguez, J L

2009-11-15

363

Discovery of an X-ray Violently Variable Broad Absorption Line Quasar  

NASA Technical Reports Server (NTRS)

In this letter, we report on a quasar that is violently variable in the X-rays, XVV. It is also a broad absorption line quasar (BALQSO) that exhibits both high ionization and low ionization UV absorption lines (LoBALQSO). It is very luminous in the X-rays (approximately 10(exp 46) ergs s(sup -l) over the entire X-ray band). Surprisingly, this does not over ionize the LoBAL outflow. The X-rays vary by a factor of two within minutes in the quasar rest frame, which is shorter than 1/30 of the light travel time across a scale length equal to the black hole radius. We concluded that the X-rays are produced in a relativistic jet beamed toward earth in which variations in the Doppler enhancement produce the XVV behavior.

Ghosh, Kajal K.; Gutierrez, Carlos M.; Punsly, Brian; Chevallier, Loic; Goncalves, Anabela C.

2006-01-01

364

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

DOEpatents

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

Green, Lanny A. (Knoxville, TN); Heck, Jr., Joaquim L. (Knoxville, TN)

1987-01-01

365

Furthering the understanding of silicate-substitution in ?-tricalcium phosphate: an X-ray diffraction, X-ray fluorescence and solid-state nuclear magnetic resonance study.  

PubMed

High-purity (SupT) and reagent-grade (ST), stoichiometric and silicate-containing ?-tricalcium phosphate (?-TCP: ST0/SupT0 and Si-TCP x=0.10: ST10/SupT10) were prepared by solid-state reaction based on the substitution mechanism Ca3(PO4)(2-x)(SiO4)x. Samples were determined to be phase pure by X-ray diffraction (XRD), and Rietveld analysis performed on the XRD data confirmed inclusion of Si in the ?-TCP structure as determined by increases in unit cell parameters; particularly marked increases in the b-axis and ?-angle were observed. X-ray fluorescence (XRF) confirmed the presence of expected levels of Si in Si-TCP compositions as well as significant levels of impurities (Mg, Al and Fe) present in all ST samples; SupT samples showed both expected levels of Si and a high degree of purity. Phosphorus ((31)P) magic-angle-spinning solid-state nuclear magnetic resonance (MAS NMR) measurements revealed that the high-purity reagents used in the synthesis of SupT0 can resolve the 12 expected peaks in the (31)P spectrum of ?-TCP compared to the low-purity ST0 that showed significant spectral line broadening; line broadening was also observed with the inclusion of Si which is indicative of induced structural disorder. Silicon ((29)Si) MAS NMR was also performed on both Si-TCP samples which revealed Q(0) species of Si with additional Si Q(1)/Q(2) species that may indicate a potential charge-balancing mechanism involving the inclusion of disilicate groups; additional Q(4) Si species were also observed, but only for ST10. Heating and cooling rates were briefly investigated by (31)P MAS NMR which showed no significant line broadening other than that associated with the emergence of ?-TCP which was only realised with the reagent-grade sample ST0. This study provides an insight into the structural effects of Si-substitution in ?-TCP and could provide a basis for understanding how substitution affects the physicochemical properties of the material. PMID:24287162

Duncan, J; Hayakawa, S; Osaka, A; MacDonald, J F; Hanna, J V; Skakle, J M S; Gibson, I R

2014-03-01

366

In situ energy-dispersive x-ray diffraction system for time-resolved thin-film growth studies  

NASA Astrophysics Data System (ADS)

Energy-dispersive x-ray diffraction (EDXRD) with synchrotron light can be used for in situ-structural analysis during polycrystalline thin-film growth, due to its fast data collection and the fixed diffraction angle. An in situ deposition and analysis set-up for the investigation of nucleation and growth of thin films during magnetron sputtering was constructed and installed at the synchrotron radiation source Hamburger Synchrotronstrahlungs Labor (Hamburg). The polychromatic synchrotron beam passes the sputtering chamber through Kapton windows and hits the substrate with the growing film. The diffracted beam, observed under a fixed diffraction angle of between 1 and 10 was energy-analysed by a high-purity germanium detector. The measurement time for a single XRD spectrum can be as short as 10 s for a beam line at a bending magnet, which allows a time-resolved monitoring of film growth. The performance of the in situ EDXRD set-up is demonstrated for the growth of zinc oxide and tin-doped indium oxide films prepared by reactive magnetron sputtering from ceramic and metallic targets. From the position and the width of the diffraction lines the internal mechanical strain and the grain size of the growing films can be derived. The prospects for thin-film growth investigations using such an instrument are assessed.

Ellmer, K.; Mientus, R.; Wei, V.; Rossner, H.

2003-03-01

367

Characterization of an Yb:LuVO 4 single crystal using X-ray topography, high-resolution X-ray diffraction, and X-ray photoelectron spectroscopy  

Microsoft Academic Search

Knowledge on the defect and electronic structure allows for improved modeling of material properties. A short literature review has shown that the information on defect structure of rare earth orthovanadate single crystals is limited. In this paper, defect and electronic structure of a needle-shaped Yb:LuVO4 single crystal grown by the slow cooling method have been studied by means of X-ray

W. Paszkowicz; P. Romanowski; J. Bak-Misiuk; W. Wierzchowski; K. Wieteska; W. Graeff; R. J. Iwanowski; M. H. Heinonen; O. Ermakova; H. Dabkowska

2011-01-01

368

X-Ray Diffraction and Fluorescence Measurements for In Situ Planetary Instruments  

NASA Astrophysics Data System (ADS)

The ESA/NASA ExoMars mission, due for launch in 2018, has a combined X-ray fluorescence/diffraction instrument, Mars-XRD, as part of the onboard analytical laboratory. The results of some XRF (X-ray fluorescence) and XRD (X-ray diffraction) tests using a laboratory chamber with representative performance are reported. A range of standard geological reference materials and analogues were used in these tests. The XRD instruments are core components of the forthcoming NASA Mars Science Laboratory (MSL) and ESA/NASA ExoMars missions and will provide the first demonstrations of the capabilities of combined XRD/XRF instrumentation in situ on an extraterrestrial planetary surface. The University of Leicester team is part of the Italy-UK collaboration that is responsible for building the ExoMars X-ray diffraction instrument, Mars-XRD [1,2]. Mars-XRD incorporates an Fe-55 radioisotope source and three fixed-position charge-coupled devices (CCDs) to simultaneously acquire an X-ray fluorescence spectrum and a diffraction pattern providing a measurement of both elemental and mineralogical composition. The CCDs cover an angular range of 2? = 6 to 73 enabling the analysis of a wide range of geologically important minerals including phyllosilicates, feldspars, oxides, carbonates and evaporites. The identification of hydrous minerals may help identify past Martian hydrothermal systems capable of preserving traces of life. Here we present some initial findings from XRF and XRD tests carried out at the University of Leicester using an Fe-55 source and X-ray sensitive CCD. The XRF/XRD test system consists of a single CCD on a motorised arm, an Fe-55 X-ray source, a collimator and a sample table which approximately replicate the reflection geometry of the Mars-XRD instrument. It was used to test geological reference standard materials and Martian analogues. This work was funded by the Science and Technology Facilities Council, UK. References [1] Marinangeli, L., Hutchinson, I., Baliva, A., Stevoli, A., Ambrosi, R., Critani, F., Delhez, R., Scandelli, L., Holland, A., Nelms, N. & the Mars-XRD Team, Proceedings of the 38th Lunar and Planetary Science Conference, 12 - 16 March 2007, League City, Texas, USA. [2] L. Marinangeli, I. B. Hutchinson, A. Stevoli, G. Adami, R. Ambrosi, R. Amils, V. Assis Fernandes, A. Baliva, A. T. Basilevsky, G. Benedix, P. Bland, A. J. B鰐tger, J. Bridges, G. Caprarelli, G. Cressey, F. Critani, N. d'Alessandro, R. Delhez, C. Domeneghetti, D. Fernandez-Remolar, R. Filippone, A. M. Fioretti, J. M. Garcia Ruiz, M. Gilmore, G. M. Hansford, G. Iezzi, R. Ingley, M. Ivanov, G. Marseguerra, L. Moroz, C. Pelliciari, P. Petrinca, E. Piluso, L. Pompilio, J. Sykes, F. Westall and the MARS-XRD Team, EPSC-DPS Joint Meeting 2011, 3 - 7 October 2011, La Cit Internationale des Congr鑣 Nantes M閠ropole, Nantes, France.

Hansford, G.; Hill, K. S.; Talboys, D.; Vernon, D.; Ambrosi, R.; Bridges, J.; Hutchinson, I.; Marinangeli, L.

2011-12-01

369

Modeling kinematical x-ray diffraction excited by a coherent nanobeam.  

SciTech Connect

A rigorous model of a diffraction experiment utilizing a coherent, monochromatic, X-ray beam, focused by a Fresnel zone plate onto a thin, perfect, single-crystal layer is presented. In this model, first the coherent wave emanating from an ideal zone plate equipped with a direct-beam stop and order-sorting aperture is computed. Then, diffraction of the focused wavefront by a thin silicon film positioned at the primary focal spot is calculated. This diffracted wavefront is propagated to the detector position, and the intensity distribution at the detector plane is extracted. The predictions of this model agree quite well with experimental data measured at the Center for Nanoscale Materials nanoprobe instrument at Sector 26 of the Advanced Photon Source.

Ying, A.; Osting, B.; Noyan, I. C.; Murray, C. E.; Holt, H. V.; Maser, J. (Center for Nanoscale Materials); ( PSC-USR); (Columbia Univ.); (IBM)

2010-01-01

370

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

NASA Astrophysics Data System (ADS)

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

Allahkarami, Masoud

371

Laboratory manual: mineral X-ray diffraction data retrieval/plot computer program  

USGS Publications Warehouse

The Mineral X-Ray Diffraction Data Retrieval/Plot Computer Program--XRDPLT (VanTrump and Hauff, 1976a) is used to retrieve and plot mineral X-ray diffraction data. The program operates on a file of mineral powder diffraction data (VanTrump and Hauff, 1976b) which contains two-theta or 'd' values, and intensities, chemical formula, mineral name, identification number, and mineral group code. XRDPLT is a machine-independent Fortran program which operates in time-sharing mode on a DEC System i0 computer and the Gerber plotter (Evenden, 1974). The program prompts the user to respond from a time-sharing terminal in a conversational format with the required input information. The program offers two major options: retrieval only; retrieval and plot. The first option retrieves mineral names, formulas, and groups from the file by identification number, by the mineral group code (a classification by chemistry or structure), or by searches based on the formula components. For example, it enables the user to search for minerals by major groups (i.e., feldspars, micas, amphiboles, oxides, phosphates, carbonates) by elemental composition (i.e., Fe, Cu, AI, Zn), or by a combination of these (i.e., all copper-bearing arsenates). The second option retrieves as the first, but also plots the retrieved 2-theta and intensity values as diagrammatic X-ray powder patterns on mylar sheets or overlays. These plots can be made using scale combinations compatible with chart recorder diffractograms and 114.59 mm powder camera films. The overlays are then used to separate or sieve out unrelated minerals until unknowns are matched and identified.

Hauff, Phoebe L.; VanTrump, George

1976-01-01

372

Effect of grain size on stability of X-ray diffraction patterns used for threat detection  

NASA Astrophysics Data System (ADS)

Energy Dispersive X-ray Diffraction (EDXRD) is well-suited to detecting narcotics and a wide range of explosives. The integrated intensity of an X-ray diffraction peak is proportional to the number of grains in the inspected object which are oriented such that they satisfy Bragg's condition. Several parameters have a significant influence on this number. Among them, we can list grain size and the fill rate for polycrystalline materials that both may significantly vary for a same material according to its way of production. Consequently, peak intensity may change significantly from one measurement to another one, thus increasing the risk of losing peaks. This instability is one of the many causes of false alarms. To help avoid these, we have developed a model to quantify the stability of the diffraction patterns measured. Two methods (extension of the detector in a direction perpendicular to the diffractometer plane and slow rotation of both source and detector) can be used to decrease the coefficient of variation, leading to a more stable spectral measurement.

Ghammraoui, B.; Rebuffel, V.; Tabary, J.; Paulus, C.; Verger, L.; Duvauchelle, Ph.

2012-08-01

373

Spontaneous soft x-ray fluorescence from a superlattice under Kossel diffraction conditions  

NASA Astrophysics Data System (ADS)

The present study gives the proof of principle of a technique that is an extension of Kossel diffraction both from crystals to superlattices and toward the soft x-ray region, allowing the characterization of the interfaces within a periodic structure. We measure the intensity of the Co L? and Mg K? characteristic fluorescence emissions from a Mg/Co superlattice upon soft x-ray excitation. The observation is made so that the angle between the sample surface and the detection direction is scanned around the first and second Bragg peaks of the fluorescence emissions. Clear modulations of the emitted intensities are observed and well reproduced by simulations based on the reciprocity theorem and assuming a perfect stack. The present work gives evidence that such a superlattice plays the role of an optical cavity for the spontaneous emission generated within the stack. This should also be the case for stimulated emission, which when combined with pumping free electron laser, will open the road to innovative x-ray distributed feedback lasers.

Jonnard, P.; Yuan, Y.-Y.; Le Guen, K.; Andr, J.-M.; Zhu, J.-T.; Wang, Z.-S.; Bridou, F.

2014-08-01

374

X-ray diffraction studies and equation of state of methane at 200 GPa  

SciTech Connect

Solid methane (CH{sub 4}) was compressed up to 202 GPa at 300 K in a diamond-anvil cell. The crystal structure and equation of state over this entire range were determined from angle dispersive X-ray diffraction results. CH{sub 4} undergoes phase transitions from rhombohedral to a simple cubic phase at 19 GPa and from simple cubic to a higher pressure cubic phase at approximately 94 GPa. This higher pressure cubic phase was stable to the maximum pressure investigated. Combined with previous optical measurements, it was found that at room temperature compressed CH{sub 4} remains an insulator with cubic structure to 202 GPa. X-ray images of the solid CH{sub 4} at three pressures, showing the high pressure phase with cubic structure persisting up to 202 GPa. At high pressure the XRD from the sample became increasingly weaker. To improve the quality of XRD pattern, we reduced the X-ray focus spot size and clean-up slits at 171 GPa, and increased the exposure time for each measurement.

Sun, L.

2010-02-24

375

Determination of line profiles on photomasks using DUV, EUV, and x-ray scattering  

NASA Astrophysics Data System (ADS)

Non-imaging techniques like X-ray scattering are supposed to play an important role in the further development of CD metrology for the semiconductor industry. GISAXS provides directly assessable information on structure roughness and long-range periodic perturbations. The disadvantage of the method is the large footprint of the X-ray beam on the sample due to the extremely shallow angle of incidence. This can be overcome by using wavelengths in the extreme ultraviolet (EUV) spectral range which allow for much steeper angles of incidence but preserve the large range of momentum transfer that can be observed. At the Physikalisch-Technische Bundesanstalt (PTB), the available photon energy range extends from 50 eV up to 10 keV at two adjacent beamlines. PTB commissioned a new versatile Ellipso-Scatterometer which is capable of measuring 6" square substrates in a clean, hydrocarbon-free environment with full flexibility regarding the direction of the incident light polarization. The reconstruction of line profiles using a geometrical model with six free parameters, a finite element method (FEM) Maxwell solver and least-squares optimization yielded consistent results for EUV and deep ultraviolet (DUV) scatterometry. For EUV photomasks, the actinic wavelength EUV scatterometry yields particular advantages. A significant polarization dependence of the diffraction intensities for 0th and +1st orders in the geometry with the grating lines perpendicular to the plane of reflection is observed and the 0th order intensity shows sufficient sensitivity to the line width such that a CD-resolution below 0.1 nm is within reach. In this contribution we present scatterometry data for line gratings using GISAXS, and EUV and DUV scatterometry and consistent reconstruction results of the line geometry for EUV and DUV scatterometry.

Scholze, F.; Bodermann, B.; Burger, S.; Endres, J.; Haase, A.; Krumrey, M.; Laubis, C.; Soltwisch, V.; Ullrich, A.; Wernecke, J.

2014-10-01

376

Massive Submandibular Sialolith: Complete Radiographic Registration and Biochemical Analysis through X-Ray Diffraction  

PubMed Central

Sialolithiasis is a pathologic condition that affects 60 million people per year, which is caused by the presence of calcified structures, named sialoliths, inside the salivary glands and their salivary ducts. Despite the large incidence of sialolithiasis, its etiology is still unknown. In the present case report, a 47-year-old female patient, presenting with local pain and hampered mouth opening, underwent a surgical approach for the removal of a 20?mm sialolith, which was further analyzed through X-ray diffraction. In parallel, a radiographic registration of 8 years, covering all the period for sialolith formation, is presented along the case report. PMID:25258693

de Carvalho Mattos, Mayara Jessica; Ferrari, Francine; dos Reis Neto, Jos Manoel; Carta Gambus, Luiz Carlos; Couto Souza, Paulo Henrique; Berti-Couto, Soraya de Azambuja

2014-01-01

377

X-ray diffraction identification of minerals in lunar regolith returned by Luna 16 automatic station  

NASA Technical Reports Server (NTRS)

The methods of powder and monocrystal X-ray diffraction served in identifying the mineral composition of gross samples of regolith from different levels of the drill core and about 80 individual regolith particles returned by the Luna 16 station. It was established that the Sea of Fertility regolith includes pyroxenes of the augite-pigeonite series, anorthites, ilmenite, olivines, spinels, alpha cristobalite, iron particles, glass, and several as yet unidentified particles. Crystallographic and roentgenometric data are given for all the lunar minerals found.

Makarov, Y. S.; Ivanov, V. I.; Mokeyeva, V. I.; Tobelko, K. I.; Bukin, V. I.; Volkova, A. Y.; Kuznetsova, G. A.; Kuznetsov, L. M.

1974-01-01

378

Crystallization and preliminary X-ray diffraction analysis of red clover necrotic mosaic virus  

SciTech Connect

Red clover necrotic mosaic virus (RCNMV) is a species that belongs to the Tombusviridae family of plant viruses with a T = 3 icosahedral capsid. RCNMV virions were purified and were crystallized for X-ray analysis using the hanging-drop vapor-diffusion method. Self-rotation functions and systematic absences identified the space group as I23, with two virions in the unit cell. The crystals diffracted to better than 4 {angstrom} resolution but were very radiation-sensitive, causing rapid decay of the high-resolution reflections. The data were processed to 6 {angstrom} in the analysis presented here.

Martin, Stanton L.; Guenther, Richard H.; Sit, Tim L.; Swartz, Paul D.; Meilleur, Flora; Lommel, Steven A.; Rose, Robert B. (NCSU)

2010-11-12

379

Crystallization and preliminary X-ray diffraction analysis of alanine racemase from Pseudomonas putida YZ-26.  

PubMed

A recombinant form of alanine racemase (Alr) from Pseudomonas putida YZ-26 has been crystallized by the sitting-drop vapour diffusion method. X-ray diffraction data were collected to 2.4? resolution. The crystals belong to the space group C222(1), with unit-cell parameters a = 118.08, b = 141.86, c = 113.83?, and contain an Alr dimer in the asymmetric unit. The Matthews coefficient and the solvent content were calculated to be 2.8?(3)?Da(-1) and approximately 50%, respectively. PMID:23027757

Liu, Junlin; Feng, Lei; Shi, Yawei; Feng, Wei

2012-10-01

380

MEASURING THE PLASTIC RESPONSE IN POLYCRSYTALLINE MATERIALS USING IN-SITU X-RAY DIFFRACTION  

SciTech Connect

The insight provided by ultra-fast lattice level measurements during high strain rate high pressure experiments is key to understanding kinetic material properties like plasticity. In-situ x-ray diffraction provides a diagnostic technique which can be used to study the governing physical phenomena of plasticity at the relevant time and spatial scale. Here we discuss the recent development of a geometry capable of investigating plasticity in polycrystalline foils. We also present some preliminary data of investigations into shock compressed rolled copper foils.

Hawreliak, J; Butterfield, M; El-Dasher, B; McNaney, J; Lorenzana, H

2008-10-01

381

Quantitative X-ray diffraction analysis of oxides formed on superalloys  

NASA Technical Reports Server (NTRS)

Methods were developed for quantitative analysis by X-ray diffraction of the oxides Al2O3, NiO, Cr2O3, CoO, and CoCr2O4 within a standard deviation of about 10 percent of the weight fraction reported or within 1 percent absolute. These error limits assume that the sample oxides are well characterized and that the physiochemical structure of the oxides in the samples are identical with those in the synthesized standards. Results are given for the use of one of the techniques in the analysis of spalls from a series of oxidation tests of the cobalt base alloy WI-52.

Garlick, R. G.

1972-01-01

382

A novel X-ray diffraction technique with almost complete insensitivity to sample morphology  

NASA Astrophysics Data System (ADS)

The author has recently invented a novel X-ray diffraction (XRD) technique which exhibits almost complete insensitivity to the sample morphology, and also to the sample distance other than an intensity factor. The method is suitable for planetary applications, requiring no or very minimal sample preparation. The technique implements energydispersive XRD (EDXRD) in a back-reflection geometry. The intrinsic geometry of the method and the simplicity inherent to EDXRD enables a compact lightweight instrument design with no moving parts. Details of the basic concept and of proof-of-principle experiments are presented here.

Hansford, G. M.

2011-10-01

383

Residual Stress Analysis of Overspeeded Disk with Central Hole by X-ray Diffraction  

NASA Technical Reports Server (NTRS)

An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.

Good, James N

1948-01-01

384

Atomic disorder in Heusler Co2MnGe measured by anomalous x-ray diffraction  

NASA Astrophysics Data System (ADS)

Heusler alloys Co2MnX, where X is Ge or Si, are predicted by the band theory to be a half-metallic ferromagnets, i.e., metals with all conduction electrons of the same spin state. To date, Heusler alloys have been measured with spin polarizations of 50%-60%, higher than Fe (40%), but not a true half metal. Structural defects involving site swapping between the Co and Mn sublattices have been proposed as a mechanism to diminish spin polarization. In this work, we present an anomalous x-ray diffraction measurement on Co2MnGe to determine antisite disorder in thin films with a high precision.

Ravel, B.; Cross, J. O.; Raphael, M. P.; Harris, V. G.; Ramesh, R.; Saraf, L. V.

2002-10-01

385

[X-ray diffraction study of high hydrostatic pressure on crystalline structure of different type starches].  

PubMed

Crystalline changes of different type starches after high hydrostatic pressure treated under 300, 450, 600 MPa were studied by X-ray diffraction. Waxy maize (A type, 100% amylopectin), hylon VII (B type, 30% amylopectin) and tapioca starch (C type, 83% amylopectin) were chosen. The results indicated that for waxy maize starch, annealing effect was observed at 300 MPa, disappearance of crystalline structure happened at 450 MPa and retrogradation at 600 MPa. The results proved that the granule under high hydrostatic pressure processing experiences "three development stages" including annealling effect, disappearance of crystalline structure and recrystalline after granule disintegration. PMID:23240443

Liu, Pei-Ling; Shen, Qun; Hu, Xiao-Song; Wu, Ji-Hong

2012-09-01

386

Directly Observing Squeezed Phonon States with Femtosecond X-Ray Diffraction  

SciTech Connect

Squeezed states are quantum states of a harmonic oscillator in which the variance of two conjugate variables each oscillate out of phase. Ultrafast optical excitation of crystals can create squeezed phonon states, where the variance of the atomic displacements oscillates due to a sudden change in the interatomic bonding strength. With femtosecond x-ray diffraction we measure squeezing oscillations in bismuth and conclude that they are consistent with a model in which electronic excitation softens all phonon modes by a constant scaling factor.

Johnson, S. L.; Beaud, P.; Vorobeva, E.; Ingold, G. [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Milne, C. J. [Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland); Murray, E. D. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States); Fahy, S. [Tyndall National Institute and Department of Physics, University College, Cork (Ireland)

2009-05-01

387

Aortic valvular tophus: identification by X-ray diffraction of urate and calcium phosphates.  

PubMed Central

A typical gouty tophus with birefringent, dichroic, needle shaped crystals was found in a resected calcified aortic valve on routine histological examination. The patient, an elderly man, had a long history of gout. X-ray diffraction confirmed the presence of sodium acid urate monohydrate and identified hydroxyapatite and whitlockite in the accompanying dystrophic calcification of the aortic valves. Previous reports indicate that gouty tophi of the cardiac valves are rare: of the nine cases reported, eight occurred in the mitral valve. Images PMID:4031099

Gawoski, J M; Balogh, K; Landis, W J

1985-01-01

388

X-ray diffraction investigation of 1-phenyl-3-isopropyl-5-(benzothiazol-2-yl)formazan  

SciTech Connect

The crystal structure of 1-phenyl-3-isopropyl-5-(benzothiazol-2-yl)formazan is investigated using X-ray diffraction. The compound crystallizes in the form of two crystallographically independent molecules (A and B) in identical conformations that are stabilized by intermolecular hydrogen bonds. The intermolecular hydrogen bonds N-H-N (N-N, 2.892 and 2.939 A) link molecules into AB dimers. Both molecules have a flattened structure, except for the isopropyl fragment. The bonds in the formazan chains are delocalized. Molecules A and B have close geometric characteristics.

Slepukhin, P. A. [Russian Academy of Sciences, Postovskii Institute of Organic Synthesis, Ural Division (Russian Federation)], E-mail: slepukhin@ios.uran.ru; Pervova, I. G.; Rezinskikh, Z. G. [Ural State Forestry Engineering University (Russian Federation); Lipunova, G. N. [Ural State Technical University (UPI) (Russian Federation); Gorbatenko, Yu. A.; Lipunov, I. N. [Ural State Forestry Engineering University (Russian Federation)

2008-01-15

389

X-ray diffraction from flight muscle with a headless myosin mutation: implications for interpreting reflection patterns.  

PubMed

Fruit fly (Drosophila melanogaster) is one of the most useful animal models to study the causes and effects of hereditary diseases because of its rich genetic resources. It is especially suitable for studying myopathies caused by myosin mutations, because specific mutations can be induced to the flight muscle-specific myosin isoform, while leaving other isoforms intact. Here we describe an X-ray-diffraction-based method to evaluate the structural effects of mutations in contractile proteins in Drosophila indirect flight muscle. Specifically, we describe the effect of the headless myosin mutation, Mhc (10) -Y97, in which the motor domain of the myosin head is deleted, on the X-ray diffraction pattern. The loss of general integrity of the filament lattice is evident from the pattern. A striking observation, however, is the prominent meridional reflection at d = 14.5 nm, a hallmark for the regularity of the myosin-containing thick filament. This reflection has long been considered to arise mainly from the myosin head, but taking the 6th actin layer line reflection as an internal control, the 14.5-nm reflection is even stronger than that of wild-type muscle. We confirmed these results via electron microscopy, wherein image analysis revealed structures with a similar periodicity. These observations have major implications on the interpretation of myosin-based reflections. PMID:25400584

Iwamoto, Hiroyuki; Trombit醩, K醨oly; Yagi, Naoto; Suggs, Jennifer A; Bernstein, Sanford I

2014-01-01

390

X-ray diffraction from flight muscle with a headless myosin mutation: implications for interpreting reflection patterns  

PubMed Central

Fruit fly (Drosophila melanogaster) is one of the most useful animal models to study the causes and effects of hereditary diseases because of its rich genetic resources. It is especially suitable for studying myopathies caused by myosin mutations, because specific mutations can be induced to the flight muscle-specific myosin isoform, while leaving other isoforms intact. Here we describe an X-ray-diffraction-based method to evaluate the structural effects of mutations in contractile proteins in Drosophila indirect flight muscle. Specifically, we describe the effect of the headless myosin mutation, Mhc10-Y97, in which the motor domain of the myosin head is deleted, on the X-ray diffraction pattern. The loss of general integrity of the filament lattice is evident from the pattern. A striking observation, however, is the prominent meridional reflection at d = 14.5 nm, a hallmark for the regularity of the myosin-containing thick filament. This reflection has long been considered to arise mainly from the myosin head, but taking the 6th actin layer line reflection as an internal control, the 14.5-nm reflection is even stronger than that of wild-type muscle. We confirmed these results via electron microscopy, wherein image analysis revealed structures with a similar periodicity. These observations have major implications on the interpretation of myosin-based reflections. PMID:25400584

Iwamoto, Hiroyuki; Trombit醩, K醨oly; Yagi, Naoto; Suggs, Jennifer A.; Bernstein, Sanford I.

2014-01-01

391

Stability of dislocation structures in copper towards stress relaxation investigated by high angular resolution 3D x-ray diffraction.  

SciTech Connect

300 {micro}m thick tensile specimen of OFHC copper is subjected to a tensile loading sequence and deformed to a maximal strain of 3.11%. Using the novel three-dimensional X-ray diffraction method High angular resolution 3DXRD', the evolution of the microstructure within a deeply embedded grain is characterized in-situ by the behavior of individual subgrains. The loading sequence consists of three continuous deformation stages with strain rates of 1.1 x 10{sup -6} s{sup -1} and 3 x 10{sup -2} s{sup -1}, in each case followed by a period of extended stress relaxation at fixed motor positions, as well as an unloading step. In contrast to the deformation stages, during each stress relaxation stage, number, size and orientation of subgrains are found to be constant, while a minor amount of clean-up of the microstructure is observed as narrowing of the radial X-ray diffraction line profile. The associated decrease in the width of the strain distribution indicates homogenization of the elastic strains present in the deformation structure. During reloading, the subgrain structure seemingly starts to develop further when the entire dislocation structure is deforming plastically. Upon unloading of the sample, the average backward strain of the subgrains increases.

Jakobsen, B.; Poulsen, H. F.; Lienert, U.; Bernier, J.; Gundlach, C.; Pantleon, W.; Riso National Lab.; Roskilde Univ.; LLNL; European Synchrotron Research Facility

2008-01-01

392

Ray-tracing simulations of spherical Johann diffraction spectrometer for in-beam X-ray experiments  

NASA Astrophysics Data System (ADS)

The results of the Monte-Carlo ray-tracing simulations for a Johann-type Bragg spectrometer with spherically curved-crystal designed to detect the X-rays from a fast-moving source are reported. These calculations were performed to optimize the X-ray spectrometer to be used at the gas-target installed at ion storage ring for high-resolution X-ray experiments. In particular, the two-dimensional distributions of detected photons were studied using the Monte-Carlo method both for the stationary and moving X-ray sources, taking into account a detailed description of X-ray source and X-ray diffraction on the crystal as well as a role of the Doppler effect for in-beam experiments. The origin of the asymmetry of observed X-ray profiles was discussed in detail and the procedure to derive a precise (sub-eV) X-ray transition energy for such asymmetric profiles was proposed. The results are important for the investigations of 1s2pP23?1s2sS13 intrashell transition in excited He-like uranium ions in in-beam X-ray experiments.

Jagodzi?ski, P.; Pajek, M.; Bana?, D.; Beyer, H. F.; Trassinelli, M.; Sto╤lker, Th.

2014-07-01

393

Selective imaging of nano-particle contrast agents by a single-shot x-ray diffraction technique  

PubMed Central

Iron oxide nano-particles have very different x-ray diffraction properties from tissue. They can be clearly visualized against suppressed tissue background in a single-shot x-ray diffraction imaging technique. This technique is able to acquire both diffraction and absorption images from a single grating-modulated projection image through analysis in the spatial frequency domain. We describe the use of two orthogonal transmission gratings to selectively retain diffraction signal from iron oxide particles that are larger than a threshold size, while eliminating the background signal from soft tissue and bone. This approach should help the tracking of functionalized particles in cell labeling and targeted therapy. PMID:20588456

Stein, Ashley F.; Ilavsky, Jan; Kopace, Rael; Bennett, Eric E.; Wen, Han

2011-01-01

394

Microbeam high-resolution x-ray diffraction in strained InGaAlAs-based multiple quantum well laser structures grown selectively on masked  

E-print Network

Microbeam high-resolution x-ray diffraction in strained InGaAlAs-based multiple quantum well laser Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 S. O'Malley Department studied. An x-ray beam of 10 m diameter generated by a microbeam high-resolution x-ray diffraction -HRXRD

Sirenko, Andrei

395

Commissioning of a Soft X-ray Beamline PF-BL-16A with a Variable-Included-Angle Varied-Line-Spacing Grating Monochromator  

NASA Astrophysics Data System (ADS)

The design and commissioning of a new soft X-ray beamline, BL-16A, at the Photon Factory is presented. The beamline consists of a pre-focusing mirror, an entrance slit, a variable-included-angle varied-line-spacing plane grating monochromator, and a post-focusing system as usual, and provides circularly and linearly polarized soft X rays in the energy range 200-1500 eV with an APPLE-II type undulator. The commissioning procedure for the beamline optics is described in detail, especially the check of the focal position for the zero-th order and diffracted X rays.

Amemiya, Kenta; Toyoshima, Akio; Kikuchi, Takashi; Kosuge, Takashi; Nigorikawa, Kazuyuki; Sumii, Ryohei; Ito, Kenji

2010-06-01

396

Absolute x-ray energy calibration over a wide energy range using a diffraction-based iterative method.  

PubMed

In this paper, we report a method of precise and fast absolute x-ray energy calibration over a wide energy range using an iterative x-ray diffraction based method. Although accurate x-ray energy calibration is indispensable for x-ray energy-sensitive scattering and diffraction experiments, there is still a lack of effective methods to precisely calibrate energy over a wide range, especially when normal transmission monitoring is not an option and complicated micro-focusing optics are fixed in place. It is found that by using an iterative algorithm the x-ray energy is only tied to the relative offset of sample-to-detector distance, which can be readily varied with high precision of the order of 10(-5) -10(-6) spatial resolution using gauge blocks. Even starting with arbitrary initial values of 0.1 A?, 0.3 A?, and 0.4 A?, the iteration process converges to a value within 3.5 eV for 31.122 keV x-rays after three iterations. Different common diffraction standards CeO(2), Au, and Si show an energy deviation of 14 eV. As an application, the proposed method has been applied to determine the energy-sensitive first sharp diffraction peak of network forming GeO(2) glass at high pressure, exhibiting a distinct behavior in the pressure range of 2-4 GPa. Another application presented is pair distribution function measurement using calibrated high-energy x-rays at 82.273 keV. Unlike the traditional x-ray absorption-based calibration method, the proposed approach does not rely on any edges of specific elements, and is applicable to the hard x-ray region where no appropriate absorption edge is available. PMID:22755637

Hong, Xinguo; Chen, Zhiqiang; Duffy, Thomas S

2012-06-01

397

Application of the X-ray fluorescence analysis and X-ray diffraction in geochemical studies of the Pleistocene tills from Holy Cross Mountains  

NASA Astrophysics Data System (ADS)

X-ray fluorescence analysis methods (wavelength dispersive X-ray fluorescence analysis (WDXRF) and total reflection X-ray fluorescence (TXRF)) and X-ray powder diffraction (XRPD) have been applied in complementary geochemical studies of the Pleistocene till samples. The XRPD technique gave information about the mineral composition of the analyzed samples while the WDXRF and TXRF studies allowed the fast elemental analysis. The till samples were collected from different regions of Holy Cross Mountains (located in central Poland) which are still not unambiguously described in the context of the geochemical studies of the Quaternary sediments. The analysis was concentrated on the geochemical composition of the till samples both for materials occurring on the surface (characterized by continuous weathering processes) and for samples taken from core borehole. The overriding purpose of these studies is determination of the local lithotype of the tills and its lithologic and petrographic diagnostic properties, including the chemical composition of clay and minerals found in the clay. In the presented work the experimental sets up, sample preparation procedure and measurements programme will be discussed in details. Finally, the elemental and mineral compositions will be presented for studied different groups of the samples.

Kubala-Kuku?, A.; Ludwikowska-K?dzia, M.; Bana?, D.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Mo?ko, J.

2013-12-01

398

Taking Snapshots of Photosynthetic Water Oxidation Using Femtosecond X-ray Diffraction and Spectroscopy  

PubMed Central

The dioxygen we breathe is formed from water by its light-induced oxidation in photosystem II. O2 formation takes place at a catalytic manganese cluster within milliseconds after the photosystem II reaction center is excited by three single-turnover flashes. Here we present combined X-ray emission spectra and diffraction data of 2 flash (2F) and 3 flash (3F) photosystem II samples, and of a transient 3F? state (250 ?s after the third flash), collected under functional conditions using an X-ray free electron laser. The spectra show that the initial O-O bond formation, coupled to Mn-reduction, does not yet occur within 250 ?s after the third flash. Diffraction data of all states studied exhibit an anomalous scattering signal from Mn but show no significant structural changes at the present resolution of 4.5 . This study represents the initial frames in a molecular movie of the structural changes during the catalytic reaction in photosystem II. PMID:25006873

Kern, Jan; Tran, Rosalie; Alonso-Mori, Roberto; Koroidov, Sergey; Echols, Nathaniel; Hattne, Johan; Ibrahim, Mohamed; Gul, Sheraz; Laksmono, Hartawan; Sierra, Raymond G.; Gildea, Richard J.; Han, Guangye; Hellmich, Julia; Lassalle-Kaiser, Benedikt; Chatterjee, Ruchira; Brewster, Aaron S.; Stan, Claudiu A.; Gl鯿kner, Carina; Lampe, Alyssa; DiFiore, D鰎te; Milathianaki, Despina; Fry, Alan R.; Seibert, M. Marvin; Koglin, Jason E.; Gallo, Erik; Uhlig, Jens; Sokaras, Dimosthenis; Weng, Tsu-Chien; Zwart, Petrus H.; Skinner, David E.; Bogan, Michael J.; Messerschmidt, Marc; Glatzel, Pieter; Williams, Garth J.; Boutet, S閎astien; Adams, Paul D.; Zouni, Athina; Messinger, Johannes; Sauter, Nicholas K.; Bergmann, Uwe; Yano, Junko; Yachandra, Vittal K.

2014-01-01

399

Radiation-induced melting in coherent X-ray diffractive imaging at the nanoscale  

PubMed Central

Coherent X-ray diffraction techniques play an increasingly significant role in the imaging of nanoscale structures, ranging from metallic and semiconductor to biological objects. In material science, X-rays are usually considered to be of a low-destructive nature, but under certain conditions they can cause significant radiation damage and heat loading on the samples. The qualitative literature data concerning the tolerance of nanostructured samples to synchrotron radiation in coherent diffraction imaging experiments are scarce. In this work the experimental evidence of a complete destruction of polymer and gold nanosamples by the synchrotron beam is reported in the case of imaging at 110?nm spatial resolution. Numerical simulations based on a heat-transfer model demonstrate the high sensitivity of temperature distribution in samples to macroscopic experimental parameters such as the conduction properties of materials, radiation heat transfer and convection. However, for realistic experimental conditions the calculated rates of temperature rise alone cannot explain the melting transitions observed in the nanosamples. Comparison of these results with the literature data allows a specific scenario of the sample destruction in each particular case to be presented, and a strategy for damage reduction to be proposed. PMID:21685675

Ponomarenko, O.; Nikulin, A. Y.; Moser, H. O.; Yang, P.; Sakata, O.

2011-01-01

400

Taking snapshots of photosynthetic water oxidation using femtosecond X-ray diffraction and spectroscopy  

NASA Astrophysics Data System (ADS)

The dioxygen we breathe is formed by light-induced oxidation of water in photosystem II. O2 formation takes place at a catalytic manganese cluster within milliseconds after the photosystem II reaction centre is excited by three single-turnover flashes. Here we present combined X-ray emission spectra and diffraction data of 2-flash (2F) and 3-flash (3F) photosystem II samples, and of a transient 3F state (250??s after the third flash), collected under functional conditions using an X-ray free electron laser. The spectra show that the initial O-O bond formation, coupled to Mn reduction, does not yet occur within 250??s after the third flash. Diffraction data of all states studied exhibit an anomalous scattering signal from Mn but show no significant structural changes at the present resolution of 4.5?. This study represents the initial frames in a molecular movie of the structural changes during the catalytic reaction in photosystem II.

Kern, Jan; Tran, Rosalie; Alonso-Mori, Roberto; Koroidov, Sergey; Echols, Nathaniel; Hattne, Johan; Ibrahim, Mohamed; Gul, Sheraz; Laksmono, Hartawan; Sierra, Raymond G.; Gildea, Richard J.; Han, Guangye; Hellmich, Julia; Lassalle-Kaiser, Benedikt; Chatterjee, Ruchira; Brewster, Aaron S.; Stan, Claudiu A.; Gl鯿kner, Carina; Lampe, Alyssa; Difiore, D鰎te; Milathianaki, Despina; Fry, Alan R.; Seibert, M. Marvin; Koglin, Jason E.; Gallo, Erik; Uhlig, Jens; Sokaras, Dimosthenis; Weng, Tsu-Chien; Zwart, Petrus H.; Skinner, David E.; Bogan, Michael J.; Messerschmidt, Marc; Glatzel, Pieter; Williams, Garth J.; Boutet, S閎astien; Adams, Paul D.; Zouni, Athina; Messinger, Johannes; Sauter, Nicholas K.; Bergmann, Uwe; Yano, Junko; Yachandra, Vittal K.

2014-07-01

401

Mossbauer spectroscopy and X-ray diffraction of samples from the Santa Catharina iron meteorite  

NASA Technical Reports Server (NTRS)

Conversion electron Mossbauer spectroscopy (CEMS) of samples from the Santa Catharina iron meteorite shows the presence of the ordered iron-nickel phase with 50% Ni, tetrataenite, and of the paramagnetic iron-nickel phase with 25% Ni. The FeNi phase with 50% Ni amounts to 70% of the iron-nickel alloys. Futhermore, the CEM spectra show the presence of small peaks from one or more spinel compounds. These small peaks are more pronounced when regions near the rim of the samples are analyzed. The X-ray diffraction of different areas of the samples, both optically dark and optically light areas, shows the presence of a diffraction pattern from a single f.c.c. lattice with a lattice parameter of a=3.58A This means that the two different Fe-Ni phases seen in the CEMS analysis occupy the same lattice. The X-ray photographs also show the presence of super-structure reflections from the ordered FeNi phase, and that the orientation of the f.c.c. lattice is the same within the whole sample.

Roy-Poulsen, H.; Clarke, R. S., Jr.; Jensen, G. B.; Knudsen, J. M.; Larsen, L.; Roy-Poulsen, N. O.; Vistisen, L.

1984-01-01

402

Optical and X-ray diffraction study of AgI clusters incorporated into zeolite LTA  

NASA Astrophysics Data System (ADS)

AgI clusters are incorporated into cages of zeolite LTA. The loading density of AgI is systematically changed from 0.2 to 4.0 molecules per ?-cage. The electronic states and structures of the AgI clusters, with regard to their optical absorption spectra and X-ray powder diffraction patterns, are discussed. At a dilute loading, a notable absorption band, assigned to the AgI molecule, appears at 5.6 eV. With increasing loading densities, new absorption bands appear at 4.7, 4.2, 4.1, and 3.6 eV. These bands show that (AgI)n (n=2-4) clusters with larger sizes are formed with increasing loading density. These clusters seem to exist in ?-cages. The X-ray diffraction (XRD) patterns exhibit superlattice reflections at high loading densities. The appearance of the extra reflections has a correlation with the formation of (AgI)3 and (AgI)4 clusters. The Ag and I atoms of the cluster seem to be situated at the position of tetrahedral-based symmetry in the ?-cage.

Kodaira, T.; Ikeda, T.; Takeo, H.

403

High-pressure powder x-ray diffraction study of EuVO4  

E-print Network

The high-pressure structural behavior of europium orthovanadate has been studied using in-situ, synchrotron based, high-pressure x-ray powder diffraction technique. Angle-dispersive x-ray diffraction measurements were carried out at room temperature up to 34.7 GPa using a diamond-anvil cell, extending the pressure range reported in previous experiments. We confirmed the occurrence of zircon-scheelite phase transition at 6.8 GPa and the coexistence of low- and high-pressure phases up to 10.1 GPa. In addition, clear evidence of a scheelite-fregusonite transition is found at 23.4 GPa. The fergusonite structure remains stable up to 34.7 GPa, the highest pressure reached in the present measurements. A partial decomposition of EuVO4 was also observed from 8.1 to 12.8 GPa, however, this fact did not preclude the identification of the different crystal structures of EuVO4. The crystal structures of the different phases have been Rietveld refined and their equations of state (EOS) have been determined. The results are...

Garg, Alka B

2015-01-01

404

Analysis of urinary stone composition in Eastern India by X-ray diffraction crystallography  

PubMed Central

Background: Stones in the urinary system are common in our country. This study was done to assess the composition of the urinary stones in eastern part of India. Materials and Methods: A prospective study was done over a period of thirty months. A total of 90 stones were analyzed in this time period by using X-ray diffraction crystallography. Results: Of the 90 stones analyzed, 77 were renal stones, 12 were ureteric stones and one was a bladder stone. Six stones (all renal) did not have properties to be represented by X-ray diffraction crystallography. The overall prevalence of the oxalate containing stones was 85.7% with calcium oxalate monohydrate (COM) being the major constituent. Calcium oxalate dihydrate (COD) was the next most common constituent. Struvite stones constituted 9.5% of the stones analyzed. Pure calcium phosphate stones were found in 4.7% of the cases. Conclusion: Our study reveals that the stone composition in the eastern part of India is different from that in other parts of the country. We have a comparatively lower prevalence of oxalate stones while a higher prevalence of phosphate and struvite stones. PMID:25337533

Jindal, Tarun; Mandal, Soumendra Nath; Sonar, Pankaj; Kamal, Mir Reza; Ghosh, Nabankur; Karmakar, Dilip

2014-01-01

405

An X-ray diffraction study on a single rod outer segment from frog retina  

PubMed Central

X-ray diffraction patterns were recorded from isolated single rod outer segments of frog. The outer segments in Ringer抯 solution were exposed to a 6?祄 microbeam (15?keV) at the BL40XU beamline, SPring-8. The diffraction pattern demonstrated a remarkable regularity in the stacking and flatness of the disk membranes. The electron density profile calculated from the intensity of up to tenth-order reflections showed a pair of bilayers that comprise a disk membrane. The structure of the disk membrane and the changes in the profile on swelling generally agreed with previous reports. Radiation damage was significant with an irradiation of 5 105?Gy which is much lower than the known damaging dose on proteins at the liquid-nitrogen temperature. PMID:22713892

Yagi, Naoto; Matsuo, Tatsuhito; Ohta, Noboru

2012-01-01

406

Single-crystal X-ray diffraction at megabar pressures and temperatures of thousands of degrees  

SciTech Connect

The most reliable information about crystal structures and their response to changes in pressure and temperature is obtained from single-crystal diffraction experiments. We have developed a methodology to perform single-crystal X-ray diffraction experiments in laser-heated diamond anvil cells and demonstrate that structural refinements and accurate measurements of the thermal equation of state of metals, oxides and silicates from single-crystal intensity data are possible in pressures ranging up to megabars and temperatures of thousands of degrees. A new methodology was applied to solve the in situ high pressure, high temperature structure of iron oxide and study structural variations of iron and aluminum bearing silicate perovskite at conditions of the Earth's lower mantle.

Dubrovinsky, L.; Boffa-Ballaran, T.; Glazyrin, K.; Kurnosov, A.; Frost, D.; Merlini, M.; Hanfland, M.; Prakapenka, V.B.; Schouwink, P.; Pippinger, T.; Dubrovinskaia, N. (Heidelberg); (Bayreuth); (UDSDF); (ESRF); (UC)

2011-08-09

407

An X-ray diffraction method for semiquantitative mineralogical analysis of Chilean nitrate ore  

USGS Publications Warehouse

Computer analysis of X-ray diffraction (XRD) data provides a simple method for determining the semiquantitative mineralogical composition of naturally occurring mixtures of saline minerals. The method herein described was adapted from a computer program for the study of mixtures of naturally occurring clay minerals. The program evaluates the relative intensities of selected diagnostic peaks for the minerals in a given mixture, and then calculates the relative concentrations of these minerals. The method requires precise calibration of XRD data for the minerals to be studied and selection of diffraction peaks that minimize inter-compound interferences. The calculated relative abundances are sufficiently accurate for direct comparison with bulk chemical analyses of naturally occurring saline mineral assemblages.

Jackson, J.C.; Ericksent, G.E.

1997-01-01

408

An x-ray diffraction method for semiquantitative mineralogical analysis of chilean nitrate ore  

USGS Publications Warehouse

Computer analysis of X-ray diffraction (XRD) data provides a simple method for determining the semiquantitative mineralogical composition of naturally occurring mixtures of saline minerals. The method herein described was adapted from a computer program for the study of mixtures of naturally occurring clay minerals. The program evaluates the relative intensities of selected diagnostic peaks for the minerals in a given mixture, and then calculates the relative concentrations of these minerals. The method requires precise calibration of XRD data for the minerals to be studied and selection of diffraction peaks that minimize inter-compound interferences. The calculated relative abundances are sufficiently accurate for direct comparison with bulk chemical analyses of naturally occurring saline mineral assemblages.

John, C.; George, J.; Ericksen, E.

1997-01-01

409

Coherent X-Ray Diffraction Imaging and Characterization of Strain in Silicon-on-Insulator Nanostructures.  

PubMed

Coherent X-ray diffraction imaging (CDI) has emerged in the last decade as a promising high resolution lens-less imaging approach for the characterization of various samples. It has made significant technical progress through developments in source, algorithm and imaging methodologies thus enabling important scientific breakthroughs in a broad range of disciplines. In this report, we will introduce the principles of forward scattering CDI and Bragg geometry CDI (BCDI), with an emphasis on the latter. BCDI exploits the ultra-high sensitivity of the diffraction pattern to the distortions of crystalline lattice. Its ability of imaging strain on the nanometer scale in three dimensions is highly novel. We will present the latest progress on the application of BCDI in investigating the strain relaxation behavior in nanoscale patterned strained silicon-on-insulator (sSOI) materials, aiming to understand and engineer strain for the design and implementation of new generation semiconductor devices. PMID:24955950

Xiong, Gang; Moutanabbir, Oussama; Reiche, Manfred; Harder, Ross; Robinson, Ian

2014-12-01

410

Coherent X-Ray Diffraction Imaging and Characterization of Strain in Silicon-on-Insulator Nanostructures  

PubMed Central

Coherent X-ray diffraction imaging (CDI) has emerged in the last decade as a promising high resolution lens-less imaging approach for the characterization of various samples. It has made significant technical progress through developments in source, algorithm and imaging methodologies thus enabling important scientific breakthroughs in a broad range of disciplines. In this report, we will introduce the principles of forward scattering CDI and Bragg geometry CDI (BCDI), with an emphasis on the latter. BCDI exploits the ultra-high sensitivity of the diffraction pattern to the distortions of crystalline lattice. Its ability of imaging strain on the nanometer scale in three dimensions is highly novel. We will present the latest progress on the application of BCDI in investigating the strain relaxation behavior in nanoscale patterned strained silicon-on-insulator (sSOI) materials, aiming to understand and engineer strain for the design and implementation of new generation semiconductor devices. PMID:24955950

Xiong, Gang; Moutanabbir, Oussama; Reiche, Manfred; Harder, Ross; Robinson, Ian

2014-01-01

411

Shape and Size of Microfine Aggregates: X-ray Microcomputed Tomgraphy vs. Laser Diffraction  

SciTech Connect

Microfine rock aggregates, formed naturally or in a crushing process, pass a No. 200 ASTM sieve, so have at least two orthogonal principal dimensions less than 75 {mu}m, the sieve opening size. In this paper, for the first time, we capture true 3-D shape and size data of several different types of microfine aggregates, using X-ray microcomputed tomography ({mu}CT) with a voxel size of 2 {mu}m. This information is used to generate shape analyses of various kinds. Particle size distributions are also generated from the {mu}CT data and quantitatively compared to the results of laser diffraction, which is the leading method for measuring particle size distributions of sub-millimeter size particles. By taking into account the actual particle shape, the differences between {mu}CT and laser diffraction can be qualitatively explained.

Erdogan,S.; Garboczi, E.; Fowler, D.

2007-01-01

412

Crystallization and preliminary X-ray diffraction analysis of the human XRCC4朮LF complex  

PubMed Central

XRCC4 and XLF are key proteins in the repair of DNA double-strand breaks through nonhomologous end-joining. Together, they form a complex that stimulates the ligation of double-strand breaks. Owing to the suggested filamentous nature of this complex, structural studies via X-ray crystallography have proven difficult. Multiple truncations of the XLF and XRCC4 proteins were cocrystallized, but yielded low-resolution diffraction (?20?). However, a燾ombination of microseeding, dehydration and heavy metals improved the diffraction of XRCC4?157朮LF?224 crystals to 3.9? resolution. Although molecular replacement alone was unable to produce a solution, when combined with the anomalous signal from tantalum bromide clusters initial phasing was successfully obtained. PMID:22102241

Andres, Sara N.; Junop, Murray S.

2011-01-01

413

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

NASA Astrophysics Data System (ADS)

The lattice thermal expansion characteristics of Inconel-600 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 ?m thickness. The diffraction profiles have been accurately calibrated to offset the shift in 2 ? 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 10 -6 K -1.

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

2004-02-01

414

An X-ray diffraction study on a single rod outer segment from frog retina.  

PubMed

X-ray diffraction patterns were recorded from isolated single rod outer segments of frog. The outer segments in Ringer's solution were exposed to a 6?祄 microbeam (15?keV) at the BL40XU beamline, SPring-8. The diffraction pattern demonstrated a remarkable regularity in the stacking and flatness of the disk membranes. The electron density profile calculated from the intensity of up to tenth-order reflections showed a pair of bilayers that comprise a disk membrane. The structure of the disk membrane and the changes in the profile on swelling generally agreed with previous reports. Radiation damage was significant with an irradiation of 5 10(5)?Gy which is much lower than the known damaging dose on proteins at the liquid-nitrogen temperature. PMID:22713892

Yagi, Naoto; Matsuo, Tatsuhito; Ohta, Noboru

2012-07-01

415

Development of a hard X-ray delay line for X-ray photon correlation spectroscopy and jitter-free pump杙robe experiments at X-ray free-electron laser sources  

PubMed Central

A hard X-ray delay line capable of splitting and delaying single X-ray pulses has been developed with the aim of performing X-ray photon correlation spectroscopy (XPCS) and X-ray pump杙robe experiments at hard X-ray free-electron laser sources. The performance of the device was tested with 8.39?keV synchrotron radiation. Time delays up to 2.95?ns have been demonstrated. The feasibility of the device for performing XPCS studies was tested by recording static speckle patterns. The achieved speckle contrast of 56% indicates the possibility of performing ultra-fast XPCS studies with the delay line. PMID:21525658

Roseker, Wojciech; Franz, Hermann; Schulte-Schrepping, Horst; Ehnes, Anita; Leupold, Olaf; Zontone, Federico; Lee, Sooheyong; Robert, Aymeric; Gr黚el, Gerhard

2011-01-01

416

Texture analysis in cubic phase polycrystals by single exposure synchrotron X-ray diffraction  

NASA Astrophysics Data System (ADS)

We discuss the possibility of determining orientation distribution function (ODF) of cubic phase polycrystals from single exposure Debye-Scherrer diffraction data by a systematic numerical simulation. The fundamental zone of cubic phase crystals is discretised as 5白 5 5 cubic cells, and the aim is to find out those preferred orientations represented by the cells centres which cannot be determined by single exposure Debye-Scherrer diffraction data. Two simulated ODFs corresponding to two different types of linear combination of single preferred orientations are used to validate if the method is suitable for more complicated textures. A data processing routine as well as experimental procedure that enable texture evaluation in metallic cubic phase polycrystals by single exposure high energy monochromatic synchrotron X-ray diffraction with area detector is presented. MTEX is used to estimate ODFs from both single exposure and multi-exposure 2D diffraction patterns. An extruded tungsten wire and a copper cylinder machined from a rolled plate are used to illustrate the whole method. Careful error comparison is made between the ODFs obtained from single exposure and multi-exposure data. Besides, all the diffraction patterns are processed by MAUD to provide a comparison to the MTEX approach, and good agreement is seen between ODFs produced by MAUD and MTEX.

Xie, M. Y.; Baimpas, N.; Reinhard, C.; Korsunsky, A. M.

2013-10-01

417

Using electron microscopy to complement X-ray powder diffraction data to solve complex crystal structures.  

PubMed

High-resolution X-ray powder diffraction and electron microscopy techniques yield remarkably complementary information for crystal structure determination. By combining the two types of data, structures of polycrystalline materials that resist solution by more conventional methods can be tackled. In particular, crystallographic phase information extracted either from high-resolution transmission electron microscopy (HRTEM) images or from precession electron diffraction (PED) data has proven to be extremely useful in such cases. PED data can also be used to identify weak reflections in the diffraction pattern, and this information, in turn, can be exploited to improve the partitioning of the intensities of reflections that overlap in the powder diffraction pattern. The dual-space (diffraction and real space) structure determination programs Focus and pCF have been shown to be especially well-suited for combining the two different types of data. The power of this approach is illustrated with the details of the solutions of the structures of TNU-9, IM-5 and SSZ-74, the three most complex zeolite framework structures known. PMID:19277355

McCusker, Lynne B; Baerlocher, Christian

2009-03-28

418

High-pressure X-ray diffraction and X-ray emission studies on iron-bearing silicate perovskite under high pressures  

SciTech Connect

Iron-bearing silicate perovskite is believed to be the most abundant mineral of the Earth's lower mantle. Recent studies have shown that Fe{sup 2+} exists predominantly in the intermediate-spin state with a total spin number of 1 in silicate perovskite in the lower part of the lower mantle. Here we have measured the spin states of iron and the pressure-volume relation in silicate perovskite [(Mg{sub 0.6},Fe{sub 0.4})SiO{sub 3}] at pressure conditions relevant to the lowermost mantle using in situ X-ray emission and X-ray diffraction in a diamond cell. Our results showed that the intermediate-spin Fe{sup 2+} is stable in the silicate perovskite up to {approx} 125 GPa but starts to transition to the low-spin state at approximately 135 GPa. Concurrent X-ray diffraction measurements showed a decrease of approximately 1% in the unit cell volume in the silicate perovskite [(Mg{sub 0.6},Fe{sub 0.4})SiO{sub 3}], which is attributed to the intermediate-spin to the low-spin transition. The transition pressure coincides with the pressure conditions of the lowermost mantle, raising the possibility of the existence of the silicate perovskite phase with the low-spin Fe{sup 2+} across the transition from the post-perovskite to the perovskite phases in the bottom of the D{double_prime} layer.

Lin, Jung-Fu; Speciale, Sergio; Prakapenka, Vitali B.; Dera, Przemek; Lavina, Babara; Watson, Heather C. (NIU); (UC); (Texas); (GFZ)

2010-06-22

419

Defining X-Ray Diffraction Parameters for the Design and Operation of a Planetary-Surface Rock Analyzer  

NASA Technical Reports Server (NTRS)

Our joint research effort was aimed at developing techniques for X-ray diffractometry that was being investigated by NASA as possible flight instrumentation for the exploration of Mars. SJSU would provide the use of in-house X-ray facilities for calibration of the instrumentation , and would provide technical expertise regarding interpretation of data acquired during both laboratory testing, and during field testing of instruments on the Marsokhod rover at Ames. Accomplishments are: (1) quantification of X-ray signals from rock surfaces using San Jose State University (SJSU) diffractometer; (2) development of criteria for fingerprinting rock samples using pattern recognition of diffraction spectra, and augmentation of diffraction data with X-ray fluorescence information; (3) calibration of NASA instrumentation using SJSU-generator data; and (4) assistance in the development, lab testing, and field deployment of the NASA instrument on the Russian Marsokhod roving vehicle designed for martian exploration.

Metzger, Ellen P.; Keaten, Rendy; Marshall, John R.; Kojiro, Dan

1996-01-01

420

X-ray diffraction and absorption spectroscopic studies of copper mixed ligand complexes with aminophenol as one of the ligands  

NASA Astrophysics Data System (ADS)

X-ray diffraction (XRD) and X-ray absorption spectroscopic (XAS) studies have been conducted on two copper complexes, i.e., copper macrocyclic complex of succinic acid and ortho aminophenol (complex-1) and copper macrocyclic complex of pthalic acid and ortho aminophenol (complex-2). The diffraction pattern of the complexes have been recorded using Rigaku RINT-2000 X-ray diffractometer equipped with rotating anode X-ray tube operated at 40 kV and 100 mA. The X-ray absorption spectra of the complexes have been recorded at the K-edge of copper on Cauchois type bent crystal spectrograph having radius 0.4 m employing a mica crystal, oriented to reflect from (100) planes, for dispersion. The X-ray absorption near edge structure (XANES) parameters, viz., chemical shift, energy position of the principal absorption maximum and edge-width have been determined and discussed. From the extended X-ray absorption fine structure (EXAFS) data, the bond lengths have been calculated using three methods, namely, Levy's method, Lytle, Sayers and Stern's (LSS) method and Fourier transformation method. The results obtained have been compared with each other and discussed.

Mishra, A.; Jain, Garima; Patil, H.

2012-05-01

421

Study of the defect structure of paratellurite crystal using multiwave diffraction and normal X-ray diffractometry methods  

SciTech Connect

Multiwave X-ray diffraction has been used to study the structure of crystalline samples. A cycle of local measurements of rocking curves (RCs) of the (220) and (371) reflections under conditions of multiwave diffraction (MD) has been carried out in a paratellurite crystal. The data obtained are used to compare the sensitivity to structure defects of two-beam diffraction with that of MD, which makes it possible to study the X-ray wave phase. The comparison has revealed a higher ability of the phase-sensitive method to detect defects.

Marchenkov, N. V., E-mail: marchenkov@ns.crys.ras.ru; Blagov, A. E.; Lomonov, B. A.; Pisarevsky, Yu. V.; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2013-03-15

422

[A quantitation method for andrographolide and dehydroandrographolide by X-ray powder diffraction Fourier fingerprint pattern technique].  

PubMed

The powder X-ray diffraction Fourier fingerprint pattern technique was used to develop a new quantitation method for the analysis of andrographolide and dehydroandrographolide. And the high performance liquid chromatography method was used to evaluate the quantity of andrographolide and dehydroandrographolide. The relationship of diffraction peak intensity and content of andrographolide and dehydroandrographolide was investigated. The powder X-ray diffraction Fourier fingerprint pattern analysis technique can be used to evaluate the quantity of andrographolide and dehydroandrographolide in the herb simultaneously. PMID:20931774

Gong, Ning-Bo; L, Li-Juan; Liu, Chao; Ma, Lin; Chen, Ruo-Yun; L, Yang

2010-05-01

423

Delayed crystallization of ultrathin Gd2O3 layers on Si(111) observed by in situ X-ray diffraction  

PubMed Central

We studied the early stages of Gd2O3 epitaxy on Si(111) in real time by synchrotron-based, high-resolution X-ray diffraction and by reflection high-energy electron diffraction. A comparison between model calculations and the measured X-ray scattering, and the change of reflection high-energy electron diffraction patterns both indicate that the growth begins without forming a three-dimensional crystalline film. The cubic bixbyite structure of Gd2O3 appears only after a few monolayers of deposition. PMID:22458962

2012-01-01

424

Single-shot x-ray differential phase contrast and diffraction imaging using two-dimensional transmission gratings  

PubMed Central

We describe an x-ray differential phase contrast imaging method based on two-dimensional transmission gratings that are directly resolved by an x-ray camera. X-ray refraction and diffraction in the sample lead to variations of the positions and amplitudes of the grating fringes on the camera. These effects can be quantified through spatial harmonic analysis. The use of 2D gratings allows differential phase contrast in several directions to be obtained from a single image. When compared to previous grating-based interferometry methods, this approach obviates the need for multiple exposures and separate measurements for different directions, and thereby accelerates imaging speed. PMID:20548343

Wen, Harold H.; Bennett, Eric E.; Kopace, Rael; Stein, Ashley F.; Pai, Vinay

2011-01-01

425

High pressure studies on non-crystalline samples using synchrotron x-ray tomographic and diffraction techniques  

NASA Astrophysics Data System (ADS)

Taking advantage of synchrotron x-ray tomographic techniques, the compressibility of non-crystalline samples could be obtained under high-pressure conditions. Several model cases will be presented: The procedure of crystallization of amorphous Se upon compression at room temperture, which was studied in diamond anvil cell combined synchrotron x-ray scattering, diffraction and 3D imaging techniques; As well as the melting and solidification procedure of Ga in large volume press at room and high temperature.

Liu, L. L.; Liu, H.; Li, R.; Li, L.; Xiao, X.; De Carlo, F.; Yu, T.

2013-12-01

426

In situ characterisation by anomalous X-ray diffraction of the cationic distribution of dehydrated SrRbX zeolite  

Microsoft Academic Search

An in situ X-ray diffraction cell (consisting in a motorised sample holder and a small tubular furnace) and a methodology implying X-ray anomalous diffusion (method of contrast) were developed to study structural modifications induced by the dehydration of SrRbX zeolite.The experiments realised on beamline D2AM, near and far from both Sr and Rb K-absorption edges, have shown the validity of

C. Pichon; H. Palancher; B. Rebours; J. Lynch; J. F. B閞ar; J. L. Hodeau

2004-01-01

427

Gold model anodes for Li-ion batteries: Single crystalline systems studied by in situ X-ray diffraction  

Microsoft Academic Search

We present the first results of experiments on the electrochemically driven alloying and de-alloying of Au substrates with Li-ions from organic electrolytes studied by in situ X-ray diffraction employing synchrotron radiation. Au(111) single crystals, 111-textured thin Au films and nanometer-sized Au particles on highly oriented pyrolytic graphite (HOPG) have been examined using a specially designed in situ X-ray cell. Starting

F. U. Renner; H. Kageyama; Z. Siroma; M. Shikano; S. Sch鰀er; Y. Gr黱der; O. Sakata

2008-01-01

428

Effect of high pressure-temperature on silicon layered structures as determined by X-ray diffraction and electron microscopy  

Microsoft Academic Search

Defects in the Si layered structures, Si:H(D), prepared by implantation with H2^+\\/D^+, and their changes resulting from the treatment under enhanced pressure (HP), were investigated by X-ray diffraction and transmission electron microscopy (XTEM). Such treatment affects out-diffusion of hydrogen (deuterium) as well as the shape and concentration of the H(D)-filled cavities. The relation between X-ray and XTEM results is discussed.

J. Bak-Misiuk; A. Misiuk; J. Ratajczak; A. Shalimov; I. Antonova; J. Trela

2004-01-01

429

Determination of local strains in a monocrystalline turbine blade by microbeam X-ray diffraction with synchrotron radiation  

Microsoft Academic Search

X-ray peak profiles of the types {400} and {300} of monocrystalline nickel-based superalloy turbine blades were measured with a new microbeam synchrotron radiation X-ray diffraction technique. Under the coating of a turbine blade in the virgin state, a plastically deformed layer was found which is responsible for anomalous rafting. In a turbine blade subjected to an 揳ccelerated mission test, the

H. Biermann; B. von Grossmann; T. Ung醨; S. Mechsner; A. Souvorov; M. Drakopoulos; A. Snigirev; H. Mughrabi

2000-01-01

430

CHARACTERIZATION OF THE EVOLUTIONARY ASPECTS OF GREAT WHITE SHARK TEETH BY X-RAY DIFFRACTION METHODS AND OTHER SUPPORTING TECHNIQUES  

Microsoft Academic Search

In a research program to explore evolutionary aspects of structural changes in elasmobranch teeth, a natural composite material, dentine and enamel sections of fossilized Great White shark teeth (ranging in age from 4, 12 and 40 million years old) have been examined by X-ray Diffraction Methods (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FT-IR) Spectroscopy, and Differential Scanning Calorimetry

Mehmet Kesmez; Jessica Lyon; James Westgate; Hylton McWhinney; Tony L. Grady

431

Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav  

NASA Astrophysics Data System (ADS)

The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893-972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts.

Blagoev, K.; Grozeva, M.; Malcheva, G.; Neykova, S.

2013-01-01

432

Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium stabilised amorphous calcium  

E-print Network

stabilised amorphous calcium carbonate G. Cobourne a , G. Mountjoy a, , J.D. Rodriguez-Blanco b,c , L online xxxx Keywords: Amorphous calcium carbonate; EPSR modelling; Neutron diffraction; X-ray diffraction Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron

Benning, Liane G.

433

Studies of Dynamic Properties of Shock Compressed Solids by In-Situ Transient X-Ray Diffraction  

Microsoft Academic Search

In the transient diffraction NLYF proposal we set forward a program of work to investigate the response of crystals to shock compression in regions of strain rates previously unexplored, in a coordinated experimental, computational, and analytical program. Time resolved x-ray diffraction was used to directly determine the lattice parameters of crystals during shock loading previously on the Nova and Trident

H Baldis; D H Kalantar; B A Remington; S V Weber; M A Meyers; J S Wark; G Ravichandran; A A Hauer

2000-01-01

434

X-Ray Emission from Seyfert 2 Galaxies with Optical Polarized Broad Lines  

Microsoft Academic Search

We analyze the 0.5-10 keV spectra of six Seyfert 2 galaxies observed with the X-ray satellite ASCA: Mrk 3, Mrk 348, Mrk 1210, Mrk 477, NGC 7212, and Was 49b. These galaxies were selected based on their possession of optical polarized broad lines. In the 2-10 keV band, their spectra are heavily absorbed, with 2-10 keV absorption-corrected X-ray luminosities ranging

Hisamitsu Awaki; Shiro Ueno; Yoshiaki Taniguchi; Kimberly A. Weaver

2000-01-01

435

X-ray Spectroscopy of Hot Dense Plasmas: Experimental Limits, Line Shifts and Field Effects  

SciTech Connect

High-resolution x-ray spectroscopy is capable of providing complex information on environmental conditions in hot dense plasmas. Benefiting from application of modern spectroscopic methods, we report experiments aiming at identification of different phenomena occurring in laser-produced plasma. Fine features observed in broadened profiles of the emitted x-ray lines and their satellites are interpreted using theoretical models predicting spectra modification under diverse experimental situations.

Renner, Oldrich [Institute of Physics, Academy of Sciences CR, Na Slovance 2, 18221 Prague (Czech Republic); Sauvan, Patrick [Dept. de Ingenieria Energetica-UNED, 28040 Madrid (Spain); Dalimier, Elisabeth; Riconda, Caterina; Rosmej, Frank B. [Physique Atomique dans les Plasmas Denses, LULI, UMR 7605, CNRS-CEA-Ecole Polytechnique- Universite Paris 6, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Weber, Stefan [Physique Atomique dans les Plasmas Denses, LULI, UMR 7605, CNRS-CEA-Ecole Polytechnique- Universite Paris 6, 4 Place Jussieu, 75252 Paris Cedex 05 (France); CELIA Universite Bordeaux-CEA, 33405 Talence (France); Nicolai, Philippe; Peyrusse, Olivier [CELIA Universite Bordeaux-CEA, 33405 Talence (France); Uschmann, Ingo; Hoefer, Sebastian; Kaempfer, Tino; Loetzsch, Robert; Zastrau, Ulf; Foerster, Eckhart [Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, 07743 Jena (Germany); Oks, Eugene [Physics Department, 206 Allison Laboratory, Auburn University, Auburn, AL 36849 (United States)

2008-10-22

436

DETAILED X-RAY LINE PROPERTIES OF {theta}{sup 2} Ori A IN QUIESCENCE  

SciTech Connect

We investigate X-ray emission properties of the peculiar X-ray source {theta}{sup 2} Ori A in the Orion Trapezium region using more than 500 ks of HETGS spectral data in the quiescent state. The amount of exposure provides tight constraints on several important diagnostics involving O, Ne, Mg, and Si line flux ratios from He-like ion triplets, resonance line ratios of the H- and He-like lines, and line widths. Accounting for the influence of the strong UV radiation field of the O9.5V star, we can now place the He-like line origin well within two stellar radii of the O-star's surface. The lines are resolved with average line widths of 341 {+-} 38 km s{sup -1}. In the framework of standard wind models, this likely implies a rather weak wind with moderate post-shock velocities. The emission measure distribution of the X-ray spectrum, as reported previously, includes very high temperature components which are not easily explained in this framework. The X-ray properties are also not consistent with coronal emissions from an unseen low-mass companion nor with typical signatures from colliding wind interactions. The properties are more consistent with X-ray signatures observed in the massive Trapezium star {theta}{sup 1} Ori C which has recently been successfully modeled with a magnetically confined wind model.

Mitschang, Arik W.; Nichols, Joy S.; Testa, Paola [Smithsonian Astrophysical Observatory (SAO), Cambridge, MA (United States); Schulz, Norbert S.; Huenemoerder, David P., E-mail: arik.mitschang@mq.edu.au [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States)

2011-06-10

437

Emphysema early diagnosis using X-ray diffraction enhanced imaging at synchrotron light source  

PubMed Central

Background Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide, and emphysema is a common component of COPD. Currently, it is very difficult to detect early stage emphysema using conventional radiographic imaging without contrast agents, because the change in X-ray attenuation is not detectable with absorption-based radiography. Compared with the absorption-based CT, phase contrast imaging has more advantages in soft tissue imaging, because of its high spatial resolution and contrast. Methods In this article, we used diffraction enhanced imaging (DEI) method to get the images of early stage emphysematous and healthy samples, then extract X-ray absorption, refraction, and ultra-small-angle X-ray scattering (USAXS) information from DEI images using multiple image radiography (MIR). We combined the absorption image with the USAXS image by a scatter plot. The critical threshold in the scatter plot was calibrated using the linear discriminant function in the pattern recognition. Results USAXS image was sensitive to the change of tissue micro-structure, it could show the lesions which were invisible in the absorption image. Combined with the absorption-based image, the USAXS information enabled better discrimination between healthy and emphysematous lung tissue in a mouse model. The false-color images demonstrated that our method was capable of classifying healthy and emphysematous tissues. Conclusion Here we present USAXS images of early stage emphysematous and healthy samples, where the dependence of the USAXS signal on micro-structures of biomedical samples leads to improved diagnosis of emphysema in lung radiographs. PMID:24952622

2014-01-01

438

X-ray Diffraction Studies of Forward and Reverse Plastic Flow in Nanoscale Layers during Thermal Cycling  

SciTech Connect

The biaxial stress-strain response of layers within Cu/Ni nanolaminates is determined from in-plane x-ray diffraction spectra during heating/cooling. Thinner (11 nm) Cu and Ni layers with coherent, cube-on-cube interfaces reach ~1.8 GPa (Cu) and ~2.9 GPa (Ni) without yielding. Thicker (21 nm) layers with semi-coherent interfaces exhibit unusual plastic phenomena, including extraordinary plastic work hardening rates, and forward vs. reverse plastic flow with small (~10%) changes in stress, and evidence that threshold plastic stress in Ni layers is altered by preceding plastic flow in Cu layers. Line energy, pinning strength, net interfacial dislocation density and hardness are provided.

Gram, Michael D [Ohio State University, Columbus; Carpenter, John S [Los Alamos National Laboratory (LANL); Payzant, E Andrew [ORNL; Misra, Amit [Los Alamos National Laboratory (LANL); Anderson, Peter M [Ohio State University, Columbus

2013-01-01

439

In situ time-resolved X-ray diffraction of tobermorite synthesis process under hydrothermal condition  

NASA Astrophysics Data System (ADS)

Hydrothermal synthesis process of tobermorite (5CaO.6SiO2.5H2O) has been investigated by in situ X-ray diffraction (XRD) using high-energy X-rays from a synchrotron radiation source in combination with a laboratory-made autoclave cell and a photon-counting pixel array detector. Three types of quartz sand having different particle size distributions were used. Not only the dissolution rate of quartz but also that of portlandite (Ca(OH)2) were largely affected by particle size distribution of quartz in starting mixtures. The effect of ?-Al2O3 on quartz dissolution and tobermorite formation was also investigated. In all cases, portlandite dissolved completely before the tobermorite formation, while a certain amount of quartz remained undissolved at the timing for tobermorite to start to be detected (denoted as T0). However, the composition (Ca/Si) of non-crystalline C-S-H at T0 was identical regardless of the quartz dissolution rate. Possible reaction mechanism for tobermorite formation has been discussed in terms of distribution of Ca/Si in non-crystalline C-S-H.

Kikuma, J.; Tsunashima, M.; Ishikawa, T.; Matsuno, S.; Ogawa, A.; Matsui, K.; Sato, M.

2011-03-01

440

X-ray diffraction analysis and source apportionment of Denver aerosol  

NASA Astrophysics Data System (ADS)

Continuous sampling of airborne particulate matter at Commerce City in northeast metropolitan Denver was carried out for 3-1/2 days in late January 1982.The resulting low-volume and dichotomous filter samples were analyzed by X-ray powder diffraction, X-ray transmission and optical polarizing microscopy. Major species identified in the coarse fraction include quartz, clays, two varieties of feldspar (one, potassiumrich) and muscovite. Carbonaceous matter occurs primarily in the fine fraction where 52.9 % was observed in the dichotomous sample. Artifact sodium nitrate was observed deep within the fine fraction filter substrate of the dichotomous sample. A least squares effective variance source apportionment was applied to both sample sets yielding the following mass-weighted average source contributions: soil material, 47 %; salt aerosol from street standing, 5 %; normal vehicular combustion, 4 %; and local diesel emissions, 20.5 %. Also observed was 2.6 % nitrate of undefined source and approximately 1 % receptor mass, each from adjacent flour mill activities and a nearby coal-fired power plant.

Davis, Briant L.

441

Redetermination of LaZn5 based on single crystal X-ray diffraction data  

PubMed Central

The crystal structure of the already known binary title compound LaZn5 (lanthanum penta瓃inc) (space group P6/mmm, Pearson symbol hP6, CaCu5 structure type) has been redetermined from single-crystal X-ray diffraction data. In contrast to previous determinations based on X-ray powder data [Nowotny (1942). Z. Metallkd. 34, 247253; de Negri et al. (2008). Inter璵etallics, 16, 168178], where unit-cell parameters and assignment of the structure type were reported, the present study reveals anisotropic displacement parameters for all atoms. The crystal structure consists of three crytallographically distinct atoms. The La atom (Wyckoff site 1a, site symmetry 6/mmm) is surrounded by 18 Zn atoms and two La atoms. The coordination polyhedron around one of the Zn atoms (Wyckoff site 2c, site symmetry -6m2) is an icosa環edron made up from three La and nine Zn atoms. The other Zn atom (Wyckoff site 3g, site symmetry mmm) is surrounded by four La and eight Zn atoms. Bonding between atoms is explored by means of the TB朙MTO朅SA (tight-binding linear muffin-tin orbital atomic spheres approximation) program package. The positive charge density is localized around La atoms, and the negative charge density is around Zn atoms, with weak covalent bonding between the latter. PMID:22259311

Oshchapovsky, Igor; Zelinska, Oksana; Rozdzynska-Kielbik, Beata; Pavlyuk, Volodymyr

2012-01-01

442

Impurity precipitation in atomized particles evidenced by nano x-ray diffraction computed tomography  

NASA Astrophysics Data System (ADS)

Performances and physical properties of high technology materials are influenced or even determined by their initial microstructure and by the behavior of impurity phases. Characterizing these impurities and their relations with the surrounding matrix is therefore of primary importance but it unfortunately often requires a destructive approach, with the risk of misinterpreting the observations. The improvement we have done in high resolution X-ray diffraction computed tomography combined with the use of an X-ray nanoprobe allows non-destructive crystallographic description of materials with microscopic heterogeneous microstructure (with a grain size between 10 nm and 10 ?m). In this study, the grain localization in a 2D slice of a 20 ?m solidified atomized ?U-Mo particle is shown and a minority U(C,O) phase (1 wt. %) with sub-micrometer sized grains was characterized inside. Evidence is presented showing that the onset of U(C,O) grain crystallization can be described by a precipitation mechanism since one single U-Mo grain has direct orientation relationship with more than one surrounding U(C,O) grains.

Bonnin, Anne; Wright, Jonathan P.; Tucoulou, R閙i; Palancher, Herv

2014-08-01

443

Solution Synchrotron X-ray Diffraction Reveals Structural Details of Lipid Domains in Ternary Mixtures  

SciTech Connect

The influence of cholesterol on lipid bilayer structure is significant and the effect of cholesterol on lipid sorting and phase separation in lipid-raft-forming model membrane systems has been well investigated by microscopy methods on giant vesicles. An important consideration however is the influence of fluorescence illumination on the phase state of these lipids and this effect must be carefully minimized. In this paper, we show that synchrotron x-ray scattering on solution lipid mixtures is an effective alternative technique for the identification and characterization of the l o (liquid ordered) and l d (liquid disordered) phases. The high intensity of synchrotron x rays allows the observation of up to 5 orders of diffraction from the l o phase, whereas only two are clearly visible when the l d phase alone is present. This data can be collected in approximately 1 min/sample, allowing rapid generation of phase data. In this paper, we measure the lamellar spacing in both the liquid-ordered and liquid-disordered phases simultaneously, as a function of cholesterol concentration in two different ternary mixtures. We also observe evidence of a third gel-phaselike population at 10-12 mol % cholesterol and determine the thickness of the bilayer for this phase. Importantly we are able to look at phase coexistence in the membrane independent of photoeffects.

Yuan, J.; Kiss, A; Pramudya, Y; Nguyen, L; Hirst, L

2009-01-01

444

Upgrade of X-ray Magnetic Diffraction Experimental System and Its Application to Ferromagnetic Material  

SciTech Connect

We have performed X-ray magnetic diffraction (XMD) experiment of ferromagnets at the Photon Factory (PF) of the High Energy Accelerator Research Organization (KEK) in Tsukuba. In this study, we have upgraded the XMD experimental system in order to apply this method to as many samples as possible. Upgrade was made for (1) the X-ray counting system and related measurement program, (2) the electromagnet, and (3) the refrigerator. The performance of the system was enhanced so that (1) the counting rate capability was improved from 104cps to 105cps, (2) the maximum magnetic field was increased from 0.85T to 2.15T, and (3) the lowest sample temperature was reduced from 15K to 5K. The new system was applied to an orbital ordering compound of YTiO3, and we obtained spin magnetic form factor for the reflection plane (010) perpendicular to the b axis. The magnetic field of 2T was needed to saturate the magnetization of YTiO3 along the b axis. These are the first data with the magnetization of YTiO3 saturated along the b axis by the XMD.

Suzuki, Kosuke; Tsuji, Naruki; Akiyama, Hiromitu [Graduate School of Engineering, Gunma University, Tenjin-cho 1-5-1, Kiryu, Gunma 376-8515 (Japan); Ito, Masahisa; Kitani, Kensuke [Faculty of Engineering, Gunma University, Tenjin-cho 1-5-1, Kiryu, Gunma 376-8515 (Japan); Adachi, Hiromichi; Kawata, Hiroshi [Institute of Materials Structure Science, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan)

2007-01-19

445

Metrology of Epitaxial Thin Films and Periodic Nanostructures using High Resolution X-Ray Diffraction Techniques  

NASA Astrophysics Data System (ADS)

The continued scaling of device size to achieve higher performance and/or lower power operation at lower cost is driving research and development into new, 3D transistor structures such as the FinFET. This research and development effort is highlighting the need for new, advanced measurement capability that is highly accurate, reliable, rapid, and nondestructive. Periodic arrays of fin structures enable process monitoring at each level of fabrication and the maintenance of overall device yield. High resolution x-ray diffraction (HR XRD) has been shown to provide unique capability of characterizing blanket thin films and structural parameters of periodic arrays of fins fabricated in single crystal materials. Application of HR XRD techniques to characterize fin structures with critical dimensions of 1x-2x nm has been very limited. The main objective of my research is to develop and apply HR XRD techniques that analyze critical parameters such as the lithographic pitch, pitch walking, sidewall slope, and fin top width in arrays of advanced fin structures. This research also investigates the stress state of initially pseudomorphic epilayers at the top of the fin, and identification of defects. The results for non-patterned epitaxial fully strained SiGe and GeSn alloys are presented and the methods of detecting periodicity, strain state and shape of arrays of lithographically patterned silicon and silicon-germanium fins are demonstrated using synchrotron source and laboratory x-ray diffractometers.

Medikonda, Manasa

446