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1

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

2

Submicron X-ray diffraction  

Microsoft Academic Search

At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The beam line has a unity magnification toroidal mirror that produces a 50 by

A. A. MacDowell; R. S. Celestre; N. Tamura; R. Spolenak; B. Valek; W. L. Brown; J. C. Bravman; H. A. Padmore; B. W. Batterman; J. R. Patel

2000-01-01

3

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

4

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

5

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

6

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...

7

Observation of semiconductor device channel strain using in-line high resolution X-ray diffraction  

NASA Astrophysics Data System (ADS)

In-line high resolution X-ray diffraction has been used to analyze embedded silicon-germanium (eSiGe) epitaxially grown in the source/drain regions of complementary metal-oxide-semiconductor devices. Compared to blanket films, the diffraction from patterned devices exhibited distinct features corresponding to the eSiGe in the source/drain regions and Si under the gate and SiGe. The diffraction features modulated with structural changes, alloy composition, and subsequent thermal processing. Reciprocal space measurements taken around the (224) diffraction peak revealed both in-plane (h) and out-of-plane (l) lattice deformation, along with features corresponding to the regular spacing between the gates.

Holt, Judson R.; Madan, Anita; Harley, Eric C. T.; Stoker, Matt W.; Pinto, Teresa; Schepis, Dominic J.; Adam, Thomas N.; Murray, Conal E.; Bedell, Stephen W.; Holt, Martin

2013-10-01

8

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

9

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

10

Interdiffusion of CdS/CdTe thin films: Modeling x-ray diffraction line profiles  

NASA Astrophysics Data System (ADS)

A method for analyzing the diffusion process for CdS into CdTe thin films using x-ray diffraction is presented, allowing both bulk and grain boundary diffusion coefficients to be estimated. The equilibrium phase diagram for the CdTe1-xSx and CdS1-yTey alloy system was determined for temperatures from 625 °C to 415 °C. Measured diffraction line profiles for time-progressive diffusion of CdS into CdTe films resulting from thermal treatment at 440° were modeled using bulk and grain boundary diffusion coefficients of 1.25×10-13 cm2/s and 1.5×10-8 cm2/s, respectively. Modeling diffraction line profiles of samples treated at temperatures from 380 °C to 480 °C yielded Arrhenius activation energies for bulk and grain boundary diffusion processes of 2.8 eV and 2.0 eV, respectively. The bulk diffusion coefficients obtained from thin film structures were comparable to those obtained by Auger depth profiles for CdS/CdTe couples using CdTe single crystals.

McCandless, Brian E.; Engelmann, Michael G.; Birkmire, Robert W.

2001-01-01

11

Interdiffusion of CdS/CdTe thin films: Modeling x-ray diffraction line profiles  

SciTech Connect

A method for analyzing the diffusion process for CdS into CdTe thin films using x-ray diffraction is presented, allowing both bulk and grain boundary diffusion coefficients to be estimated. The equilibrium phase diagram for the CdTe{sub 1-x}S{sub x} and CdS{sub 1-y}Te{sub y} alloy system was determined for temperatures from 625{sup o}C to 415{sup o}C. Measured diffraction line profiles for time-progressive diffusion of CdS into CdTe films resulting from thermal treatment at 440{sup o} were modeled using bulk and grain boundary diffusion coefficients of 1.25x10{sup -13}cm{sup 2}/s and 1.5x10{sup -8}cm{sup 2}/s, respectively. Modeling diffraction line profiles of samples treated at temperatures from 380{sup o}C to 480{sup o}C yielded Arrhenius activation energies for bulk and grain boundary diffusion processes of 2.8 eV and 2.0 eV, respectively. The bulk diffusion coefficients obtained from thin film structures were comparable to those obtained by Auger depth profiles for CdS/CdTe couples using CdTe single crystals.

McCandless, Brian E.; Engelmann, Michael G.; Birkmire, Robert W.

2001-01-15

12

Stacking Fault Energies of fcc Fe-Ni Alloys by X-Ray Diffraction Line Profile Analysis.  

National Technical Information Service (NTIS)

The stacking fault energies of the fcc alloy series Fe-28 Ni to pure Ni were investigated using x-ray diffraction line profile analysis. A minimum stacking fault energy of about 70 mJ/sq m occurs at the approximate composition of Fe 40Ni. From this point,...

R. E. Schramm R. P. Reed

1975-01-01

13

A variance analysis of broadened X-ray diffraction lines from evaporated thin films of aluminium  

Microsoft Academic Search

Thin films of aluminium evaporated onto glass substrates under ultra-high vacuum conditions (? 10 torr) have been examined by x-ray diffraction and found to consist of randomly arranged polycrystals with moderate to strong [111] fibre texture.Two films evaporated simultaneously onto substrates at 25°c and –196°c have been examined in detail using copper K? radiation and variance as a measure of

N. W. Grimes; J. M. Pearson; R. W. Fane; W. E. J. Neal

1970-01-01

14

Submicron X-ray diffraction  

SciTech Connect

At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The beam line has a unity magnification toroidal mirror that produces a 50 by 200 micron focus just inside an x-ray hutch at the position of an x-y slit. The beam path in the hutch consists of source defining slits, a four bounce Ge or Si monochromator, followed by elliptically bent Kirkpatrick-Baez mirror pair which focuses the beam from the slits to sub micron dimensions (0.8 x 0.8 microns). An important2048ture of this arrangement is the ability to switch between white and monochromatic beams that are essential for characterizing crystals or crystal grains in the sub-micron range. Since sample rotation is fixed they have facilities for precision translation of the specimen to allow them to scan different crystal regions or grains. The sample stage rests on a state of the art six-circle diffractometer equipped with encoders in the main rotation stages calibrated to a second of arc. The detector is a 4K x 4K CCD (Bruker) with a 9 x 9 cm view area mounted on a detector arm that can be positioned around the sample. The detector itself can also be positioned to better than 1 micron along the detector arm. Using this facility they have been able to measure the orientation structure of single grains of passivated or buried Al interconnect test structures. Such structures or their equivalents are important in connecting individual components on integrated circuits. Their sub-micron dimensions result in very high current densities that can result in interconnect failures. The variation in sub-grain structure in a single grain is rich in detail. They have obtained detailed maps of misorientations in single grains using white beam Laue diffraction patterns From these they have been able to determine the deviatoric part of the strain tensor. Switching to a monochromatic beam they can measure the strain in a single grain. They find that there are large variations in the strain and orientation from grain to grain and even within an individual grain, reflecting the highly strained and confined geometry of passivated metal lines deposited at high temperature. They can also follow quite easily the energy shift of a single reflection as they heat or cool the sample. With the facility to switch between white or monochromatic x-rays combined with sub-micron focusing it is evident that this technique can be applied to a host of problems in Materials Science Technology and the Physics of sub micron crystallites.

MacDowell, A.A.; Celestre, R.S.; Tamura, N.; Spolenak, R.; Valek, B.; Brown, W.L.; Bravman, J.C.; Padmore, H.A.; Batterman, B.W.; Patel, J.R.

2000-02-26

15

An energy dispersive X-ray diffraction station at a VEPP-4 synchrotron beam line for structural studies at high pressure  

NASA Astrophysics Data System (ADS)

The energy dispersive X-ray diffraction (EDXRD) station at a VEPP-4 synchrotron beam line is presented. The first results obtained with a high pressure chamber at the VEPP-3 synchrotron beam line are shown.

Ancharov, A. I.; Tolochko, B. P.; Chidambaram, R.; Sikka, S. K.; Momin, S. N.; Vijayakumar, V.; Kulipanov, G. N.

1995-02-01

16

The features of identifying lines in a diffraction image formed by a widely divergent X-ray beam  

SciTech Connect

A method for identifying lines in a diffraction image formed by a widely divergent X-ray beam and a technique for measuring the crystal structure parameters in the case of asymmetric crystal position have been developed. It is established that, once the distances between a crystal and a photographic plate and between the points of intersection of the hyperbola branches in a diffraction image are known, one can determine the angle between the crystal's zone axis and the wave vector, which leads to multiwave diffraction. Relations linking this angle with the parameters of two atomic planes are obtained. It is found that, to measure the parameters of atomic planes belonging to a given zone, one can use different sets of crossed hyperbolas formed by radiations K{sub {alpha}} and K{sub {beta}}. The measurements and calculations performed for the same sample (Si crystal), mounted symmetrically and asymmetrically, confirm the reliability of the proposed method.

Avetyan, K. T., E-mail: nazaryan.ernest@netsys.am; Levonyan, L. V.; Arakelyan, M. M., E-mail: marakelyan@ysu.am; Semerjian, H. S.; Grigoryan, P. A.; Hovhannisyan, G. M. [Yerevan State University (Armenia)

2009-05-15

17

Diffractive X-Ray Telescopes  

NASA Technical Reports Server (NTRS)

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

Skinner, Gerald K.

2010-01-01

18

X-Ray Diffractive Optics  

NASA Technical Reports Server (NTRS)

X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

Dennis, Brian; Li, Mary; Skinner, Gerald

2013-01-01

19

Strain Fields in Crystalline Solids: Prediction and Measurement of X-Ray Diffraction Patterns and Electron Diffraction Contrast Images.  

National Technical Information Service (NTIS)

Contents: General Introduction; X-Ray Diffraction Line Shift and Broadening of Precipitating Alloys; Part I: Model Description and Study of 'Size' Broadening Effects; X-Ray Diffraction Line Shift and Broadening of Precipitating Alloys; Part II Study of 'S...

E. J. Mittemeijer E. van der Giessen

2000-01-01

20

Emission lines from X ray binaries  

NASA Technical Reports Server (NTRS)

Emission lines are probes of the conditions in the accretion flows associated with binary X-ray sources. The hard X-ray iron K line, soft X-ray lines, and UV lines, and what they indicate about the conditions in binary X-ray sources are discussed. These lines are interpreted using an X-ray illuminated accretion disk model. The structure and dynamics of the heated disk, its spectral signatures, and the major unsolved theoretical issues surrounding them are investigated.

Kallman, T. R.

1989-01-01

21

Diffraction enhanced x-ray imaging  

SciTech Connect

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

Thomlinson, W.; Zhong, Z. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source; Chapman, D. [Illinois Inst. of Tech., Chicago, IL (United States); Johnston, R.E. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Radiology; Sayers, D. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics

1997-09-01

22

X-Ray Diffraction Analysis Program  

NASA Technical Reports Server (NTRS)

SOPAD separates overlapping peaks and analyzes derivatives of X-ray diffraction data. SOPAD helps analyst get most information out of available diffraction data. SOPAD uses Marquardt-type nonlinear regression routine to refine initial estimates of individual peak positions, intensities, shapes, and half-widths.

Wiedemann, K. E.; Unnam, J.; Naidu, S. V. N.; Houska, C. R.

1986-01-01

23

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

24

The Dynamical Theory of X Ray Diffraction  

ERIC Educational Resources Information Center

Summarizes the Darwin theory of x-ray diffraction in thin crystals or crystals with a mosaic texture and its modified application to crystals with three-dimensional electrostatic dipoles. Indicates that the dynamical theory is brought into its present relevance by the improvement of single crystal growth techniques. (CC)

Balchin, A. A.; Whitehouse, C. R.

1974-01-01

25

Standard X-Ray Diffraction Powder Patterns.  

National Technical Information Service (NTIS)

Standard x-ray diffraction powder patterns are presented for the following fifty-one substances: 3A12O3.2SiO2, (mullite); (NH4)2BeF4; NH4BF4; Sb2Se3*; Sb2Te3*; As2O3*, claudetite; BaBr2.H2O*; BaSnO3; BiPO4 (monoclinic); Bi2Te3, (tellurobismuthite); Bi2O3,...

H. E. Swanson M. C. Morris E. H. Evans L. Ulmer

1964-01-01

26

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

NASA Astrophysics Data System (ADS)

This work presents the development of a non-destructive imaging technique for the investigation of the microstructure of cementite grains embedded in a ferrite matrix of medium-carbon steel. The measurements were carried out at the material science beamline of the European Synchrotron Radiation Facility (ESRF) ID11. It was shown that in-line X-ray phase-contrast tomography (PCT) can be used for the detection of cementite grains of several microns in size. X-ray PCT of the cementite structure can be achieved by either a `single distance' or a `multiple distance' acquisition protocol. The latter permits quantitative phase retrieval. A second imaging technique, X-ray diffraction-contrast tomography (DCT), was employed to obtain information about the shapes and crystallographic orientations of the distinct ferrite grains surrounding the cementite structures. The initial results demonstrate the feasibility of determining the geometry of the cementite grains after the austenite-ferrite phase-transformation in a non-destructive manner. The results obtained with PCT and DCT are verified with ex-situ optical microscopy studies of the same specimen.

Kostenko, Alexander; Sharma, Hemant; Dere, E. Gözde; King, Andrew; Ludwig, Wolfgang; Oel, Wim Van; Offerman, S. Erik; Stallinga, Sjoerd; Vliet, Lucas J. van

2012-05-01

27

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

28

Ultrafast X-ray diffraction and X-ray absorption spectroscopy  

Microsoft Academic Search

Summary form only given. Recently developed ultrafast laser-driven X-ray sources enable the observation of atomic motions in crystals and in solutions on the timescale of chemical bond formation and breakage. Using such a laboratory-based X-ray source the propagation of coherent phonon wave packets through GaAs(111) crystals after photo excitation has been imaged by ultrafast X-ray difraction. While ultrafast x-ray diffraction

C. Rose-Petruck

2000-01-01

29

X-ray line emission from Capella  

NASA Technical Reports Server (NTRS)

X-ray emission-line components from Mg, Si, S, and Fe are unambiguously detected from Capella with the solid-state spectrometer onboard the Einstein Observatory. The X-ray spectrum is inconsistent with an isothermal corona, and requires components between 6-million K and at least 24-million K for an adequate fit. An inhomogeneous corona in which the X-ray emitting plasma is confined to magnetically contained loops appears to be reconcilable with all of the experimental evidence.

Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J.; White, N. E.; Becker, R. H.; Mushotzky, R. F.; Smith, B. W.

1979-01-01

30

Synchrotron Radiation X-ray Diffraction and X-ray Photoelectron Spectroscopy Investigation on Si-based Structures for SubMicron Si-IC Applications  

Microsoft Academic Search

Synchrotron radiation X-ray diffraction and X-ray photoelectron spectroscopy techniques have been employed for the investigation on Si-based layer structures for sub-micron Si-IC Applications. The high energy synchrotron radiation light sources have produced plenty of X-ray lines with high index diffraction and strong X-ray photoelectron emissions. The useful information will increase our understanding of these materials which are applied extensively to

Zhe Chuan Feng; Li-Chi Cheng; Chu-Wan Huang; Ying-Lang Wang; T. R. Yang

2006-01-01

31

Studies on X-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

This dissertation includes three main parts: studies on coherence requirements for the diffraction microscopy experiments, ice formation on frozen-hydrated sample during data collection, and centering of the diffraction data sets. These three subjects are all in support of our groups overall goal of high resolution 3D imaging of frozen hydrated eukaryotic cells via x-ray diffraction microscopy. X-ray diffraction microscopy requires coherent illumination. However, the actual degree of coherence at some beamlines has never been tested. In research on coherence, our first aim is to determine the transverse coherence width at the sample plane at BL 9.0.1 at the Advanced Light Source in Lawrence Berkeley National Laboratory. An analytical calculation of the coherence at the sample plane is presented. Experimental diffraction patterns of pinhole-pair samples were also taken at the beamline to determine the coherence. Due to the irregular shape of the pinholes and other optics complexity, it was very difficult to fit the data with known theoretical equations as it was traditionally done with 1D data. However, we found out that the auto-correlation function shows clearly three spots. Theoretical calculation have been carried out to show that the degree of coherence can be obtained from the intensities of the three spots. These results are compared with the results from the analytical calculation. We then perform a simulation, showing the required transverse coherence width for reconstructing samples with a given size. Ice accumulation has been a major problem in X-ray diffraction microscopy with frozen hydrated samples. Since the ice structure is different from point to point, we cannot subtract the scattering from ice, nor assume a completely "empty" region outside the finite support constraint area as required for reconstruction. Ice forms during the sample preparation and transfer. However, from the tests we did in September 2007, we found that the ice layer thickens significantly during the data collecting process. One of the tests we did was putting a dry room-temperature grid into the beam, cooling it down to liquid nitrogen temperature, and then collecting the diffraction pattern of it over time. This test showed that, after the cold grid remained in the chamber for a while, a ring could be observed in the diffraction pattern. The time necessary for this ring to be visible is highly dependent on the pressure and vacuum history of the chamber. We will discuss how the chamber pressure influences the ice accumulation rate, how an anti-contamination device can help to reduce the rate, and how this ring forms. The last part of the research is based on simulations and a real data set collected on beamline 9.0.1 at the ALS in Berkeley. In X-ray diffraction microscopy, one of the major challenges when processing the data is to accurately determine the true center of the recorded data; that is, the zero spatial frequency position. Simulations of reconstructing shifted data show that if the center of a 2D diffraction pattern is shifted by more than 3 pixels from its true center, the positivity constraint to the phase, which otherwise might be applied to improve the convergence of the reconstruction algorithm, cannot be imposed. Moreover, the phase unwrapping problem may appear during the reconstruction. These issues undermine the quality of the reconstruction of 2D data. Furthermore, the individual shift in each 2D pattern will lead to errors when assembling a 3D diffraction data cube, making the 3D reconstruction very difficult. We developed a method which uses power spectra of the partial diffraction pattern to pre-align the data. A reconstruction without severe phase unwrapping can then be obtained from the pre-aligned data. Next, the precise zero spatial frequency position can be found by examining the linear ramp present in the reconstructed phase. This method was applied to a freeze-dried yeast data set to show that this approach is effective with experimental data.

Miao, Huijie

32

First X-ray fluorescence excited Kossel diffraction in SEM  

Microsoft Academic Search

.  We present, for the first time, X-ray fluorescence excited Kossel patterns in the scanning electron microscope by way of a\\u000a compact X-ray tube and a focusing polycapillary lens. Both the diffraction geometry in transmission and in back reflection\\u000a can be carried out. The way is paved for the advantageous combination of micro-X-ray fluorescence analysis, the Laue method,\\u000a and the X-ray

Enrico Langer; Michael Haschke; Siegfried Däbritz

2008-01-01

33

Nanostructure Analysis using Coherent X-ray Diffraction  

NASA Astrophysics Data System (ADS)

X-ray crystallography can routinely determine the atomic structure of crystalline materials. The method can be extended to non-crystalline materials by using coherent X-ray diffraction. In X-ray diffraction microscopy, coherent X-ray diffraction patterns are sampled finely enough to satisfy the oversampling condition for solving the phase problem, and the iterative phase retrieval method is used for the sample image reconstruction. Recently, we succeeded in three-dimensional visualization of an unstained human chromosome by X-ray diffraction microscopy. It is the first hard X-ray tomography for cellular organelles. The reconstructed images revealed the internal axial structure, demonstrating an excellent image-contrast of the method.

Nishino, Yoshinori

34

Phase retrieval in x-ray coherent Fresnel projection-geometry diffraction  

NASA Astrophysics Data System (ADS)

Coherent x-ray diffraction experiments were performed in Fresnel regime, within a line-projection geometry. A planar x-ray waveguide was used to focus coherent cylindrical waves onto a 7.2 ?m Kevlar fiber, which acts as a phase object for hard x rays. The phase was retrieved, by using a Fourier-based iterative phasing algorithm, consistent with measured diffraction data and known constraints in real space, with a submicrometer spatial resolution.

de Caro, Liberato; Giannini, Cinzia; Cedola, Alessia; Pelliccia, Daniele; Lagomarsino, Stefano; Jark, Werner

2007-01-01

35

Dynamical x-ray diffraction from an icosahedral quasicrystal  

SciTech Connect

We present direct evidence of dynamical diffraction of x rays from a quasicrystal. High-resolution x-ray-diffraction measurements of the Al-Pd-Mn face-centered icosahedral quasicrystal were performed, revealing a mosaic full width at half maximum of less than 0.001[degree]. In a second experiment, the anomalous transmission of x rays (the Borrmann effect) was observed. These measurements show that nearly perfect quasicrystals may be grown to centimeter-size dimensions allowing x-ray techniques based upon dynamical diffraction to be brought to bear on the analysis of icosahedral structures.

Kycia, S.W.; Goldman, A.I. (Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)); Lograsso, T.A.; Delaney, D.W. (Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)); Black, D. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)); Sutton, M.; Dufresne, E.; Bruening, R. (Department of Physics, Centre for the Physics of Materials, McGill University, Montreal, Quebec, H3A 2T8 (Canada)); Rodricks, B. (Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States))

1993-08-01

36

Investigation of the Phase Shift in X-Ray Forward Diffraction Using an X-Ray Interferometer  

Microsoft Academic Search

The phase shift of forward-diffracted x rays by a perfect crystal is discussed on the basis of the dynamical theory of x-ray diffraction. By means of a triple Laue-case x-ray interferometer, the phase shift of forward-diffracted x rays by a diamond crystal slab was investigated. It was verified that the phase shift in x-ray forward diffraction actually follows the dynamical

K. Hirano; A. Momose

1996-01-01

37

Neutron and X-Ray Diffraction Studies of Advanced Materials  

SciTech Connect

The selection of articles in the special topic 'Neutron and X-Ray Studies of Advanced Materials' is based on the materials presented during the TMS 2009 annual meeting in San Francisco, CA, February 15-19, 2009. The development of ultrabrilliant third-generation synchrotron X-ray sources, together with advances in X-ray optics, has created intense X-ray microbeams, which provide the best opportunities for in-depth understanding of mechanical behavior in a broad spectrum of materials. Important applications include ultrasensitive elemental detection by X-ray fluorescence/absorption and microdiffraction to identify phase and strain with submicrometer spatial resolution. X-ray microdiffraction is a particularly exciting application compared with alternative probes of crystalline structure, orientation, and strain. X-ray microdiffraction is nondestructive with good strain resolution, competitive or superior spatial resolution in thick samples, and with the ability to probe below the sample surface. Moreover, the high-energy X-ray diffraction technique provides an effective tool for characterizing the mechanical and functional behavior in various environments (temperature, stress, and magnetic field). At the same time, some neutron diffraction instruments constructed mainly for the purpose of engineering applications can be found at nearly all neutron facilities. The first generation-dedicated instruments designed for studying in-situ mechanical behavior have been commissioned and used, and industrial standards for reliable and repeatable measurements have been developed. Furthermore, higher penetration of neutron beams into most engineering materials provides direct measurements on the distribution of various stresses (i.e., types I, II, and III) beneath the surface up to several millimeters, even tens of millimeters for important industrial components. With X-ray and neutron measurements, it is possible to characterize material behavior at different length scales. It is predicted that the application of these techniques, in combination with theoretical simulations and numerical modeling, will lead to major breakthroughs in materials science in the foreseeable future, which will contribute to the development of materials technology and industrial innovation. Specifically, the use of these techniques provides bulk material properties that further augment new characterization tools including the increased use of atom probe tomography and high-resolution transmission electron microscopy systems. The combination of these techniques greatly assists the material property models that address multi-length-scale mechanisms. Different applications of diffuse scattering for understanding the fundamental materials properties are illustrated in the articles of Welberry et al., Goossens and Welberry, Campbell, Abe et al., Gilles et al., and Zhang et al. Analysis of thin films and two-dimensional structures is described in the articles of Gramlich et al., Brock et al., Vigliante et al., Kuzel et al., and Davydok et al. Recent advances in the line profile analysis are represented by the the articles of Scardi et al., Ungar et al., and Woo et al. Characterization of modern alloys is presented by the articles of Wollmershauser et al., Eidenberger et al., Garlea et al., Jia et al., Soulami et al., Wilson et al., and Wang et al. The collected articles are written by different scientific X-ray and neutron research groups. They represent a general trend in the development and application of diffraction techniques all over the world.

Barabash, Rozaliya [ORNL; Tiley, Jaimie [Air Force Research Laboratory, Wright-Patterson AFB, OH; Wang, Yandong [Northeast University China; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2010-01-01

38

Ultrahigh-Resolution Soft-X-Ray Microscopy with Zone Plates in High Orders of Diffraction  

SciTech Connect

We present an x-ray optical approach to overcome the current limitations in spatial resolution of x-ray microscopes. Our new BESSY full-field x-ray microscope operates with an energy resolution up to E/DELTAE=10{sup 4}. We demonstrate that under these conditions it is possible to employ high orders of diffraction for imaging. Using the third order of diffraction of a zone plate objective with 25 nm outermost zone width, 14 nm lines and spaces of a multilayer test structure were clearly resolved. We believe that high-order imaging paves the way towards sub-10-nm real space x-ray imaging.

Rehbein, S.; Heim, S.; Guttmann, P.; Werner, S.; Schneider, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

2009-09-11

39

X-ray diffraction studies of tungsten substituted molybdenum disulphide  

Microsoft Academic Search

Transition metal dichalcogenide single crystals of tungsten substituted molybdenum disulphide have been grown by chemical vapour transport technique using iodine as transporting agent and direct vapour transport technique. The composition of grown crystals was confirmed on the basis of energy dispersive analysis of X-ray (EDAX) and remaining structural characterization was determined by X-ray diffraction (XRD). The growth condition, growth mechanism

Atul K Shah; P N Gajjar

40

X-ray phase-contrast imaging with submicron resolution by using extremely asymmetric Bragg diffractions  

Microsoft Academic Search

We have obtained x-ray phase-contrast images with high spatial resolution by using extremely asymmetric Si 111 Bragg diffractions near the critical angle of the total reflection. The x-ray image could be magnified to 294 times in both vertical and horizontal directions. By using this x-ray microscopy system, we have observed clear phase-contrast images of a 0.7-mum-wide gold-line pattern.

Kenji Kobayashi; Koichi Izumi; Hidekazu Kimura; Shigeru Kimura; Takashi Ibuki; Yoshiyuki Yokoyama; Yoshiyuki Tsusaka; Yasushi Kagoshima; Junji Matsui

2001-01-01

41

In situ high-pressure x-ray diffraction study of H2O ice VII  

Microsoft Academic Search

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser

Maddury Somayazulu; Jinfu Shu; Chang-Sheng Zha; Alexander F. Goncharov; Oliver Tschauner; Ho-Kwang Mao; Russell J. Hemley

2008-01-01

42

X-Ray Diffraction Studies of Shocked Lunar Analogs.  

National Technical Information Service (NTIS)

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 uti...

R. E. Hanss

1979-01-01

43

An X-ray diffraction study of titanium oxidation  

NASA Technical Reports Server (NTRS)

Titanium specimens of commercial purity were exposed at 1100 to 1400 F to laboratory air for times up to 100 hours. The extent of substrate contamination by interstitial oxygen was was determined by a new X-ray diffraction analysis involving transformation of X-ray diffraction intensity bands. The oxygen solid-solubility at the oxide-metal interfaces and its variation with time at temperature were also determined. Diffusion coefficients are deduced from the oxygen depth profiles.

Wiedemann, K. E.; Unnam, J.

1984-01-01

44

Microbeam X-Ray Standing Wave and High Resolution Diffraction  

SciTech Connect

Post-focusing collimating optics are introduced as a tool to condition X-ray microbeams for the use in high-resolution X-ray diffraction and scattering techniques. As an example, a one-bounce imaging capillary and miniature Si(004) channel-cut crystal were used to produce a microbeam with 10 {mu}m size and an ultimate angular resolution of 2.5 arc sec. This beam was used to measure the strain in semiconductor microstructures by using X-ray high resolution diffraction and standing wave techniques to {delta}d/d < 5x10-4.

Kazimirov, A.; Bilderback, D.H.; Huang, R. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Sirenko, A. [New Jersey Institute of Technology, Department of Physics, Newark, NJ 07102 (United States)

2004-05-12

45

White lines in L-edge x-ray absorption spectra and their implications for anomalous diffraction studies of biological materials.  

PubMed Central

We have measured high-resolution x-ray absorption spectra of lanthanide (Ln) and heavy transition metal complexes that display prominent narrow absorption peaks near the L2 and L3 absorption edges. The anomalous scattering factors (f' and f"), which are mathematically related to the absorption cross section, have correspondingly sharp changes in their magnitude within 5-10 eV of the absorption edge. Calculations of the magnitude of the change in f' and f" demonstrate that significant changes (on the order of 20 electrons in f') can be expected for these materials. These substantial changes in the anomalous scattering factors have applications to deriving structural information for macromolecules from x-ray diffraction studies. The magnitude of the changes indicate that the anomalous scattering technique is a powerful means of obtaining structural characteristics for macromolecules in single crystals, in solution, and in biological membranes.

Lye, R C; Phillips, J C; Kaplan, D; Doniach, S; Hodgson, K O

1980-01-01

46

Precise rotational alignment of x-ray transmission diffraction gratings  

SciTech Connect

Gold transmission diffraction gratings used for x-ray spectroscopy must sometimes be rotationally aligned to the axis of a diagnostic instrument to within sub-milliradian accuracy. We have fabricated transmission diffraction gratings with high line-densities (grating period of 200 and 300 nm) using uv holographic and x-ray lithography. Since the submicron features of the gratings are not optically visible, precision alignment is time consuming and difficult to verify in situ. We have developed a technique to write an optically visible alignment pattern onto these gratings using a scanning electron microscope (SEM). At high magnification (15000 X) several submicron lines of the grating are observable in the SEM, making it possible to write an alignment pattern parallel to the grating lines in an electron-beam-sensitive coating that overlays the grating. We create an alignment pattern by following a 1-cm-long grating line using the SEM's joystick-controlled translation stage. By following the same grating line we are assured the traveled direction of the SEM electron beam is parallel to the grating to better than 10 ..mu..radian. The electron-beam-exposed line-width can be large (5 to 15 ..mu..m wide) depending on the SEM magnification, and is therefore optically visible. The exposed pattern is eventually made a permanent feature of the grating by ion beam etching or gold electroplating. The pattern can be used to accurately align the grating to the axis of a diagnostic instrument. More importantly, the alignment of the grating can be quickly verified in situ.

Hill, S.L.

1988-03-28

47

X-ray diffraction as a local probe tool.  

PubMed

For the structural characterization of nanoscale objects, X-ray diffraction is widely used as a technique complementing local probe analysis methods such as scanning electron microscopy and transmission electron microscopy. Details on strain distributions, chemical composition, or size and shape of nanostructures are addressed. X-ray diffraction traditionally obtains very good statistically averaged properties over large ensembles-provided this averaging is meaningful for ensembles with sufficiently small dispersion of properties. In many cases, however, it is desirable to combine different analysis techniques on exactly the same nano-object, for example, to gain a more detailed insight into the interdependence of properties. X-ray beams focused to diameters in the sub-micron range, which are available at third-generation synchrotron sources, allow for such X-ray diffraction studies of individual nano-objects. PMID:19856372

Stangl, J; Mocuta, C; Diaz, A; Metzger, T H; Bauer, G

2009-12-01

48

Use of Computers for X-Ray Absorption Edge, X-Ray Fluorescence, Electron Probe, and X-Ray Diffraction Analyses at Oak Ridge National Laboratory  

Microsoft Academic Search

Computers have been used by the X-Ray Analysis Section at Oak Ridge National Laboratory (ORNL) for several years. Codes are used for processing x-ray absorption edge, x-ray fluorescence, and electron probe data. A subroutine is available for plotting the x-ray fluorescence and electron probe data. The computer is also used to calculate lattice parameters from powder x-ray diffraction data.

H. W. Dunn

1972-01-01

49

Crystal diffraction systems for X-ray spectroscopy, imaging, and interferometry of laser fusion targets  

SciTech Connect

Recent developments in X-ray diagnosis of laser produced plasmas, involving X-ray diffraction systems, are reviewed. Three methods currently under development are described: Von Hamos focusing crystal X-ray spectrograph, Laue crystal spectrograph and imaging devices, and X-ray interferometry crystal devices. Some of the results shown are a method of using mosaic crystals in a geometry which yields both high sensitivity and resolution; ionic spectral lines of higher energy (12-14 keV) than has been previously observed; and two-dimensional achromatic Laue imaging of about 10 ..mu..m resolution.

Yaakobi, B.; Burek, A.J.

1983-12-01

50

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

51

X-ray diffraction microscopy of magnetic structures.  

PubMed

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 L3 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. PMID:21838360

Turner, Joshua J; Huang, Xiaojing; Krupin, Oleg; Seu, Keoki A; Parks, Daniel; Kevan, Stephen; Lima, Enju; Kisslinger, Kim; McNulty, Ian; Gambino, Richard; Mangin, Stephane; Roy, Sujoy; Fischer, Peter

2011-07-15

52

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

53

Cryogenic X-Ray Diffraction Microscopy for Biological Samples  

SciTech Connect

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 [European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France)

2009-11-06

54

Three-dimensional x-ray diffraction detection and visualization  

NASA Astrophysics Data System (ADS)

A new method of sensing and analyzing three-dimensional (3D) x-ray diffraction (XRD) cones was introduced. Using a two-dimensional area detector, a sequence of frames was collected while moving the detector away from the sample with small equally spaced steps and keeping all other parameters constant. A 3D dataset was created from the subsequent frames. The 3D x-ray diffraction (XRD3) pattern contains far more information than a one-dimensional profile collected with the conventional diffractometer and 2D x-ray diffraction (XRD2). The present work discusses some fundamentals about XRD3, such as the data collection method, 3D visualization, diffraction data interpretation and potential applications of XRD3.

Allahkarami, Masoud; Hanan, Jay C.

2014-05-01

55

Coherent grating x-ray diffraction (CGXD) and its applications  

SciTech Connect

We show that an x-ray interference phenomenon, coherent grating x-ray diffraction (CGXD), can be used to study lateral nanostructure arrays on crystal surfaces and interfaces. Compared to Fraunhofer grating diffraction of visible light, x-ray grating diffraction contains information not only about geometric profiles of the surface but also about the internal crystalline structures and lattice strain distributions in the grating features. The grating diffraction pattern can also be measured in a white-beam Laue method using highly collimated polychromatic synchrotron radiation, which provides a parallel data collection scheme and may be useful in {ital in} {ital situ} studies on evolution of nanostructure arrays. {copyright} {ital 1996 American Institute of Physics.}

Shen, Q. [Cornell High Energy Synchrotron Source (CHESS) and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)] [Cornell High Energy Synchrotron Source (CHESS) and School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)

1996-09-01

56

Recent progress in ultrafast X-ray diffraction.  

PubMed

X-ray diffraction with femtosecond time-resolution represents a direct probe of ultrafast structural changes in condensed matter. The generation of ultrashort X-ray pulses in laser-driven plasma and/or accelerator-based sources has made substantial progress, and has allowed for studies of transient structures with an unprecedented accuracy. Herein, recent work on transient crystalline structures is reviewed, with the focus on laser-based experiments. PMID:16596604

Bargheer, M; Zhavoronkov, N; Woerner, M; Elsaesser, T

2006-04-10

57

X-Ray Diffraction Analysis of Lipstick and Gunpowder Samples  

Microsoft Academic Search

Using polycrystalline x-ray diffraction (XRD), we analyzed the chemical components of lipstick and gunpowder. Our three lipstick samples, although from the same manufacturer, were processed slightly differently. After obtaining an experimental pattern from the lipstick sample using a rotating Philips Expo diffractometer, we used the Philips HighScore computer program to compare our diffraction pattern with those from the International Center

Raheem Balogun; Samantha Berstler; Brian Kutsop

58

Ferroelectric Perovskite X-Ray and Neutron Diffraction Study.  

National Technical Information Service (NTIS)

The atomic positions have been determined for ferroelectric BiFeO3 employing both X-ray single crystal and neutron powder diffraction. The oxygen atomic positions could be determined only by neutron diffraction and are interpreted as a rotation of rigid o...

C. Michel J. M. Moreau R. Gerson W. J. James

1970-01-01

59

X-Ray Diffraction of Myelin Membrane  

PubMed Central

The phase signs of the five main X-ray reflections from normal frog sciatic nerve have been determined as all positive using a technique of labeling with very small amounts of heavy metal. The changes in intensity of the individual reflections were studied as a function of uptake of metal label by the membrane. The possible localization of the metal label was decided from computer-analogue studies and from Patterson calculations. These phases are different from those determined by previous workers using techniques of trial of the best set of phases, or a step model, to give the best fit of the combined intensity data of normal and swollen myelin membranes. The electron density map has been calculated using eight reflections and their experimentally determined phases. The map shows an inner low electron density region which is different from that shown by earlier calculations. The center of the low electron density region shows a small region of increased electron density. However, without fixing absolute electron density levels in the map, it is not yet possible to allocate regions of low electron density to pure lipid or lipoprotein. The map shows the two sides of the membranes to be different in molecular structure without significant water spaces between the membranes.

Akers, C. K.; Parsons, D. F.

1970-01-01

60

Coherent Diffraction Imaging with Hard X-Ray Waveguides  

NASA Astrophysics Data System (ADS)

Coherent X-ray diffraction imaging (CXDI) has been widely applied in the nanoscopic world, offering nanometric-scale imaging of noncrystallographic samples, and permitting the next-generation structural studies on living cells, single virus particles and biomolecules. The use of curved wavefronts in CXDI has caused a tidal wave in the already promising application of this emergent technique. The non-planarity of the wavefront allows to accelerate any iterative phase-retrieval process and to guarantee a reliable and unique solution. Nowadays, successful experiments have been performed with Fresnel zone plates and planar waveguides as optical elements. Here we describe the use of a single planar waveguide as well as two crossed waveguides in the experiments which first showed this optical element a promising tool for producing a line- or point-like coherent source, respectively.

Caro, Liberato De; Giannini, Cinzia; Pelliccia, Daniele; Cedola, Alessia; Lagomarsino, Stefano

2013-01-01

61

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

62

High-throughput baggage scanning employing x-ray diffraction for accurate explosives detection  

NASA Astrophysics Data System (ADS)

X-ray systems dominate the installed base of airport baggage scanning systems for explosives detection. The majority are conveyer systems with projection line scanners. These systems can achieve a high throughput but exhibit a high false positive rate and require significant operator involvement. Systems employing computed tomography (CT) are currently being installed at a rapid rate. These can provide good discrimination of levels of xray absorption coefficient and can largely circumvent superimposition effects. Nonetheless CT measures only x-ray absorption coefficient per voxel which does not provide a means of specific material identification resulting in many false positives, and it is relatively straightforward to configure explosive materials so that they are undetectable by CT systems. Diffraction-based x-ray systems present a solution to this problem. They detect and measure atomic layer spacings in crystalline and microcrystalline materials with high sensitivity. This provides a means of specific material identification. The majority of explosive compounds are well crystallized solids at room temperature. X-ray diffraction systems using both conventional wavelength-dispersive diffraction and fixed-angle, multi-wavelength diffraction for improved throughput are described. Large-area, flat-panel x-ray detector technology coupled with an extended x-ray source will permit a full 3D volumetric x-ray diffraction scan of a bag in a single pass, (patent pending).

Green, Michael C.; Partain, Larry D.

2003-07-01

63

Flash X-Ray Diffraction System for Ultrafast Temperature and Phase Transition Measurements  

SciTech Connect

A novel ultrafast diagnostic for determining bulk temperature and phase transitions for polycrystalline metal objects has been developed. The diagnostic consists of a 38-stage Marx bank with a cable-coupled X-ray diode that produces a 35-ns pulse of mostly 0.71 Å monochromatic X rays, and a P-43 fluor coupled to a cooled charge-coupled device camera by a coherent fiber-optic bundle for detection of scattered X rays. The X-ray beam is collimated to a 1° divergence in the scattering plane with the combination of a 1.5-mm tungsten pinhole and a 1.5-mm diameter molybdenum anode. The X-ray diode, in a needle-and-washer configuration, is heavily shielded in all directions other than the collimated beam. The X-ray diode has a sealed reentrant system, which allows the X rays to be produced inside a vacuum containment vessel, close to the sample under study. The direct correlation between the solid-state structure and the coherent X-ray diffraction pattern from a metal surface allows an unequivocal determination of a phase transition. This correlation has been tested in the laboratory with samples of indium and tin. For both metals, diffraction lines were observed at temperatures just below the melt temperature, along with background consisting of Compton scattering and sample fluorescence. Upon melt, the diffraction lines were observed to disappear; however, the background from Compton scattering and sample fluorescence remained. Flash X-ray diffraction also enables direct ultrafast measurements of the bulk temperature of the sample under study. According to the Debye-Waller theory, the diffracted line intensity reduces as the temperature of the sample increases. The amplitude of the reduced diffracted signal also depends on the Debye temperature of the sample, the scattering angle of the diffracted X rays, and the X-ray wavelength. The feasibility of using the Debye-Waller theory for flash X-ray diffraction measurements of the bulk temperature is currently being studied.

Dane Morgan, Don Macy, Michael Madlener, Jaiming Morgan

2007-06-01

64

Towards high-resolution ptychographic x-ray diffraction microscopy  

SciTech Connect

Ptychographic x-ray diffraction microscopy is a lensless imaging technique with a large field of view and high spatial resolution, which is also useful for characterizing the wavefront of an x-ray probe. The performance of this technique is degraded by positioning errors due to the drift between the sample and illumination optics. We propose an experimental approach for correcting the positioning errors and demonstrate success by two-dimensionally reconstructing both the wavefront of the focused x-ray beam and the complex transmissivity of the weakly scattering objects at the pixel resolution of better than 10 nm in the field of view larger than 5 {mu}m. This method is applicable to not only the observation of organelles inside cells or nano-mesoscale structures buried within bulk materials but also the characterization of probe for single-shot imaging with x-ray free electron lasers.

Takahashi, Yukio; Suzuki, Akihiro; Yamauchi, Kazuto [Graduate School of Engineering, Osaka University, 2-1 Yamada oka, Suita, Osaka 565-0871 (Japan); Zettsu, Nobuyuki [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furocho, Chikusa-ku, Nagoya 4648603 (Japan); Kohmura, Yoshiki; Ishikawa, Tetsuya [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Senba, Yasunori; Ohashi, Haruhiko [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo 679-5198 (Japan)

2011-06-01

65

Hard x-ray nanobeam characterization by coherent diffraction microscopy  

SciTech Connect

We have carried out a ptychographic scanning coherent diffraction imaging experiment on a test object in order to characterize the hard x-ray nanobeam in a scanning x-ray microscope. In addition to a high resolution image of the test object, a detailed quantitative picture of the complex wave field in the nanofocus is obtained with high spatial resolution and dynamic range. Both are the result of high statistics due to the large number of diffraction patterns. The method yields a complete description of the focus, is robust against inaccuracies in sample positioning, and requires no particular shape or prior knowledge of the test object.

Schropp, A.; Boye, P.; Feldkamp, J. M.; Hoppe, R.; Patommel, J.; Samberg, D.; Stephan, S.; Schroer, C. G. [Institute of Structural Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany); Giewekemeyer, K.; Wilke, R. N.; Salditt, T. [Institute of X-Ray Physics, Universitaet Goettingen, D-37077 Goettingen (Germany); Gulden, J.; Mancuso, A. P.; Vartanyants, I. A.; Weckert, E. [Deutsches Elektronen Synchrotron DESY, D-22607 Hamburg (Germany); Schoeder, S.; Burghammer, M. [European Synchrotron Radiation Facility (ESRF), BP 220, F-38043 Grenoble Cedex (France)

2010-03-01

66

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

67

High-resolution Hard-x-ray Microscopy using Second-order Zone-plate Diffraction  

SciTech Connect

Odd-order diffraction of zone plates (ZPs) is already used for x-ray microscopy but the potential offered by even-order diffraction must still be fully exploited. Width differences between lines and interline spaces transfer intensity from odd-order to even-order diffractions. Here we show that the resulting intense second-order diffraction provides a reasonable tradeoff between spatial resolution and intensity - and constitutes a viable strategy for x-ray microscopy to reach sub-20 nm resolution, in spite of the imperfections of high-aspect-ratio ZPs and of other difficulties.

J Yi; Y Chu; Y Chen; T Chen; Y Hwu; G Margaritondo

2011-12-31

68

Ultrafast x-ray diffraction of laser-irradiated crystals  

NASA Astrophysics Data System (ADS)

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.; Larsson, J.; Chang, Z.; Lindenberg, A.; Schuck, P. J.; Judd, E.; Padmore, H. A.; Bucksbaum, P. H.; Lee, R. W.; Murnane, M.; Kapteyn, H.; Wark, J. S.; Falcone, R. W.

1997-07-01

69

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

70

Portable energy dispersive X-ray fluorescence and X-ray diffraction and radiography system for archaeometry  

Microsoft Academic Search

Starting on a laboratory developed portable X-ray fluorescence (PXRF) spectrometer; three different analytical results can be performed: analysis of chemical elements, analysis of major chemical crystalline phase and structural analysis, which represents a contribution to a new, low cost development of portable X-ray analyzer; since these results are respectively obtained with independent equipments for X-ray fluorescence, X-ray diffraction and radiography.

Ariadna Mendoza Cuevas; Homero Perez Gravie

2011-01-01

71

Phase retrieval for in-line hard x-ray phase-contrast imaging with the Yang-Gu algorithm  

Microsoft Academic Search

X-ray phase-contrast imaging is an important diagnostic tool in medicine, biology and materials science. In-line hard x-ray phase-contrast imaging is based on Fresnel diffraction of x-ray, therefore we propose to make phase retrieval calculations between arbitrary planes interrelated through the Fresnel domain. A new approach to the numerical reconstruction of object phase by the diffraction intensity for in-line x-ray phase-contrast

Bin Yu; Xiang Peng; Jindong Tian; Hanben Niu

2006-01-01

72

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

73

Fractal analysis of powder X-ray diffraction patterns  

Microsoft Academic Search

X-ray diffraction (XRD) patterns with broad background are commonly found in the characterization of materials with a certain degree of amorphicity, so the sharp intensity peaks associated with material phases are not well defined. This work used rescaled range (denoted by R\\/S) analysis, a method intended for fractal analysis of noisy signals, to characterize XRD patterns with broad background. It

A. Ortiz-Cruz; C. Santolalla; E. Moreno; J. A. de los Reyes-Heredia; J. Alvarez-Ramirez

74

INFL Guideline on X-Ray Diffraction (XRD).  

National Technical Information Service (NTIS)

X-Ray Diffraction (XRD) is an analytical technique used to identify crystalline compounds. It is a bulk technique, though the volume of material sampled is relatively small (approximately 0.01 cm3 ). Specimens are typically examined in the form of powders...

D. S. Schwartz

2013-01-01

75

Quantitative Mineralogical Analysis by X-ray diffraction.  

National Technical Information Service (NTIS)

Work was done in two phases on different combinations of soil-like crystalline materials that were mixed in the laboratory to develop a simple, rapid, and inexpensive method of doing quantitative mineralogical analyses, largely by X-ray diffraction (XRD)....

A. D. Buck

1972-01-01

76

A Practical Method of Simulating X-Ray Diffraction  

ERIC Educational Resources Information Center

Describes an experiment in which the beam of X-rays is simulated through the use of a laser as a monochromatic light source and the crystal is replaced by photographically prepared masks. A strong diffraction pattern as large as 20 cm. can be obtained. (GS)

Brisse, F.; Sundararajan, P. R.

1975-01-01

77

Coherent X-ray diffraction from collagenous soft tissues  

PubMed Central

Coherent X-ray diffraction has been applied in the imaging of inorganic materials with great success. However, its application to biological specimens has been limited to some notable exceptions, due to the induced radiation damage and the extended nature of biological samples, the last limiting the application of most part of the phasing algorithms. X-ray ptychography, still under development, is a good candidate to overcome such difficulties and become a powerful imaging method for biology. We describe herein the feasibility of applying ptychography to the imaging of biological specimens, in particular collagen rich samples. We report here speckles in diffraction patterns from soft animal tissue, obtained with an optimized small angle X-ray setup that exploits the natural coherence of the beam. By phasing these patterns, dark field images of collagen within tendon, skin, bone, or cornea will eventually be obtained with a resolution of 60–70 nm. We present simulations of the contrast mechanism in collagen based on atomic force microscope images of the samples. Simulations confirmed the ‘speckled’ nature of the obtained diffraction patterns. Once inverted, the patterns will show the disposition and orientation of the fibers within the tissue, by enhancing the phase contrast between protein and no protein regions of the sample. Our work affords the application of the most innovative coherent X-ray diffraction tools to the study of biological specimens, and this approach will have a significant impact in biology and medicine because it overcomes many of the limits of current microscopy techniques.

Berenguer de la Cuesta, Felisa; Wenger, Marco P. E.; Bean, Richard J.; Bozec, Laurent; Horton, Michael A.; Robinson, Ian K.

2009-01-01

78

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

79

Crystal cavity resonance for hard x rays: A diffraction experiment  

SciTech Connect

We report the details of the recent x-ray back diffraction experiments, in which interference fringes due to x-ray cavity resonance are unambiguously observed. The Fabry-Perot type cavities, the tested crystal devices of reflectivity R{approx_equal}0.5 and finesse F{approx_equal}2.3, consist of monolithic two-plate and eight-plate silicon crystals. They were prepared by using x-ray lithographic techniques. The thicknesses of the crystal plates and the gaps between the two adjacent plates are a few tens to hundreds {mu}m. The (12 4 0) back reflection and synchrotron x-radiation of energy resolution {delta}E=0.36 meV at 14.4388 keV are employed. Interference fringes in angle- and photon-energy scans for two-plate and eight-plate cavities are shown. Considerations on the temporal and spatial coherence for observable resonance interference fringes using synchrotron x-rays are presented. The details about the accompanied simultaneous 24-beam diffraction in relation to x-ray photon energy are also described.

Chang, S.-L. [Department of Physics, National Tsing Hua University (NTHU), Hsinchu, Taiwan, 300 (China); National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan, 300 (China); Stetsko, Yu. P.; Tang, M.-T.; Shew, B.-Y. [National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan, 300 (China); Lee, Y.-R.; Sun, W.-H.; Wu, H.-H.; Kuo, T.-T.; Chen, S.-Y.; Chang, Y.-Y.; Shy, J.-T. [Department of Physics, National Tsing Hua University (NTHU), Hsinchu, Taiwan, 300 (China); Yabashi, M. [Spring-8/JASRI, Mikazuki, Hyogo 679-5198 (Japan); Ishikawa, T. [Spring-8/JASRI, Mikazuki, Hyogo 679-5198 (Japan); Spring-8/RIKEN, Mikazuki, Hyogo 679-5148 (Japan); Lin, Y.-H. [Scientific Instrumentation Research and Development Center, Hsinchu, Taiwan, 300 (China); Tamasaku, K.; Miwa, D. [Spring-8/RIKEN, Mikazuki, Hyogo 679-5148 (Japan)

2006-10-01

80

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

81

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

82

Diamond-anvil cell for radial x-ray diffraction  

Microsoft Academic Search

We have designed a new diamond-anvil cell capable of radial x-ray diffraction to pressures of a few hundred GPa. The diffraction geometry allows access to multiple angles of Psi, which is the angle between each reciprocal lattice vector g(hkl) and the compression axis of the cell. At the 'magic angle', Psiap54.7°, the effects of deviatoric stresses on the interplanar spacings,

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

2006-01-01

83

X-Ray Diffraction from Live Muscle Fibres  

NASA Astrophysics Data System (ADS)

The previous chapter shows how small-angle X-ray Diffraction can be used to study the organization of collagen fibres in tissue, proposing this technique as a diagnosis tool. In this chapter, synchrotron small-angle X-ray diffraction (SAXD) by using high-angle and temporal resolution is presented as an essential tool in structural functional studies of skeletal muscle tissues. SAXD studies of muscle fibres involve the combination of mechanical and diffraction methods and provide insights into the molecular mechanisms responsible for the generation of force and motion in active muscle. These studies are made possible because of the highly ordered arrangement of the contractile proteins, myosin and actin, in the sarcomere, the smallest functional repeating unit of the muscle cell. The possibility to collect diffraction diagrams with high angular and temporal resolutions at modern third-generation synchrotron radiation sources together with new data processing algorithms together and two-dimensional photon counting detectors allow structural and functional studies of live muscle tissues. The review covers the basics of X-ray small-angle diffraction, instrumentation and mathematical methods used in data analysis. A general description of each of these points has been presented in Chap.1 and 2. It provides new results on the axial disposition of the myosin heads and their interpretation from analysing the interference fringes that carve the diffraction orders into clusters of peaks.

Svensson, A.; Bordas, J.; de La Cuesta, F. B.

84

X-ray diffraction line profile analysis for defect study in Cu-1 wt.% Cr-0.1 wt.% Zr alloy  

SciTech Connect

X-ray line profile analysis (LPA) has been used for microstructural analysis of a Cu-1 wt.% Cr-0.1 wt.% Zr alloy. Using this technique, the stacking fault probability (SFP) and stacking fault energy (SFE) has been determined for the pure Cu and the Cu-1 wt.% Cr-0.1 wt.% Zr alloy. It is observed that there is an increase in the stacking fault probability (and corresponding decrease in stacking fault energy) in case of the alloy. The increased formation of faulted regions in the Cu-1 wt.% Cr-0.1 wt.% Zr alloy is supported by the observation of extended dislocation nodes and fringe contrast due to staking faults under TEM, and higher work hardening rate in the tension test. The high thermal fatigue resistance of this alloy is attributed to decrease in the stacking fault energy by addition of Cr and Zr to Cu.

Kapoor, K. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India)]. E-mail: kapoork@nfc.ernet.in; Lahiri, D. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India); Batra, I.S. [Materials Science Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 094 (India); Rao, S.V.R. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India); Sanyal, T. [Advanced Materials Characterisation Laboratory, Nuclear Fuel Complex, Hyderabad 500 062 (India)

2005-02-15

85

A double crystal X-ray monochromator for the SpLine diffraction and absorption synchrotron bending magnet beamline at the ESRF  

NASA Astrophysics Data System (ADS)

The CRG BM25-SpLine Beamline is located at bending magnet 25 of the ESRF. The beamline, which is split in two branches, is devoted to XAS, XRD and HAXPES. The photon energy covered by both branches range between 5 and 45 keV. The beamline double crystal monochromator (DCM) uses two parallel Si(111) crystals in (+, -) configuration to produce a monochromatic exit beam parallel to the incident white X-ray beam. It accepts 2mrad of radiation from the bending magnet. The DCM has been recently upgraded. Several special features concerning the cooling of the first crystal, second crystal positioning and sagittal focusing mechanism has been improved. In this work a detailed description of the performed modifications is presented.

Rubio-Zuazo, J.; Collado-Negro, Victor; Heyman, C.; Ferrer, Pilar; da Silva, Iván; Gallastegui, J. A.; Gutiérrez-León, A.; Castro, G. R.

2013-03-01

86

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

87

In Operando X-ray diffraction and transmission X-ray microscopy of lithium sulfur batteries.  

PubMed

Rechargeable lithium-sulfur (Li-S) batteries hold great potential for high-performance energy storage systems because they have a high theoretical specific energy, low cost, and are eco-friendly. However, the structural and morphological changes during electrochemical reactions are still not well understood. In this Article, these changes in Li-S batteries are studied in operando by X-ray diffraction and transmission X-ray microscopy. We show recrystallization of sulfur by the end of the charge cycle is dependent on the preparation technique of the sulfur cathode. On the other hand, it was found that crystalline Li(2)S does not form at the end of discharge for all sulfur cathodes studied. Furthermore, during cycling the bulk of soluble polysulfides remains trapped within the cathode matrix. Our results differ from previous ex situ results. This highlights the importance of in operando studies and suggests possible strategies to improve cycle life. PMID:22432568

Nelson, Johanna; Misra, Sumohan; Yang, Yuan; Jackson, Ariel; Liu, Yijin; Wang, Hailiang; Dai, Hongjie; Andrews, Joy C; Cui, Yi; Toney, Michael F

2012-04-11

88

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

89

Characterization of (111) Gaas and (111) InP substrates and homoepitaxial layers by divergent x-ray beam diffraction  

Microsoft Academic Search

The back-reflection diffraction of a divergent x-ray beam has been studied for the characterization of (111) GaAs and (111) InP substrates and homoepitaxial layers with different states of surface perfection. Diffraction conditions for generating back-reflection pseudo-Kossel patterns from (111) GaAs and (111) InP are presented. Mechanical polishing was observed to produce x-ray diffraction line broadening. Uneven line broadening was found

Alice L. Lin; Lee F. Donaghey

1977-01-01

90

X-ray diffraction data for plutonium compounds  

SciTech Connect

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Centre for Diffraction Data. The Los Alamos National Laboratory has been very much involved in the study of the properties of plutonium and its compounds. During the past 45 years the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structure of a number of plutonium intermetallic compounds have been determined at Los Alamos. Due to the importance of plutonium as a representative of the actinide series of elements, it is deemed advisable to have available information on the x-ray diffraction of plutonium and its compounds for the purpose of identification of these materials. It is hoped that the information presented here will be of value in this regard.

Roof, R.B.

1989-10-01

91

Ultrafast time resolved x-ray diffraction, extended x-ray absorption fine structure and x-ray absorption near edge structure  

NASA Astrophysics Data System (ADS)

Ultrafast time resolved x-ray absorption and x-ray diffraction have made it possible to measure, in real time, transient phenomena structures and processes induced by optical femtosecond pulses. To illustrate the power of these experimental methods, we present several representative examples from the literature. (I) Time resolved measurements of photon/electron coupling, electron/phonon interaction, pressure wave formation, melting and recrystallization by means of time resolved x-ray diffraction. (II) Ultrafast x-ray absorption, EXAFS, for the direct measurement of the structures and their kinetics, evolved during electron transfer within molecules in liquid phase. (III) XANES experiments that measure directly pathway for the population of high spin states and the study of the operating mechanism of dye activated TiO2 solar cell devices. The construction and use of novel polycapillary x-ray lenses that focus and collimate hard x-rays efficiently are described.

Oguz Er, Ali; Chen, Jie; Rentzepis, Peter M.

2012-08-01

92

Coherent X-ray Diffraction with Focused Radiation  

NASA Astrophysics Data System (ADS)

Hard x-ray beams that possess a high degree of spatial (i.e. phase) coherence are becoming available from ultra high brilliance synchrotron radiation sources. As discussed at a recent workshop, coherent x-ray are likely to afford new insight on the structure and dynamics of materials at atomic length scales. When focusing is used to increase the intensity of illumination on a specimen, how is information in the diffraction pattern affected? We have written a MATLAB computer program to explore the influence of focusing on diffraction patterns from very simple systems. Our results offer guidance about when concentrating optics may be useful, and on how sensitive these patterns are to phase variation in the incident beam. http://staff.chess.cornell.edu/ shen/workshop2003/proceedings.html This work is based on research conducted at CHESS which is supported by the NSF and NIH/NIGMS under award DMR 0225180.

Finkelstein, K. D.; McGaugh, S.

2004-03-01

93

Liquid detection trial with x-ray diffraction  

NASA Astrophysics Data System (ADS)

SALOME (an acronym for Small Angle Lab Operation Measuring Equipment) is a versatile, energy-dispersive x-ray diffraction imaging (XDi) test-bed facility commissioned and supported by the Transportation Security Laboratory, Atlantic City, USA. In work presented here, the Inverse Fan-beam (IFB) topology has been realized on SALOME and used to investigate the liquids identification capability of x-ray diffraction (XRD). Liquids were investigated from four classes of materials of relevance to security screening of aircraft passenger luggage; namely: dilute aqueous liquids; concentrated aqueous liquids; hydrocarbon fuels; and oxidizers. A set of features associated with the Molecular Interference Function (MIF) were used to classify the liquids. Within the limited scope of this investigation, XRD proved to have excellent capability for discriminating liquids from one another; in particular, for isolating the threat materials without raising false alarms from either household or innocuous substances. Consequences for XRD-based screening of air passenger luggage are summarized.

Harding, G.; Fleckenstein, H.; Olesinski, S.; Zienert, G.

2010-08-01

94

Structured illumination for tomographic X-ray diffraction imaging.  

PubMed

Tomographic imaging of the molecular structure of an object is important for a variety of applications, ranging from medical and industrial radiography to security screening. X-ray diffraction imaging is the preeminent technique for performing molecular analysis of large volumes. Here we propose and demonstrate a new measurement architecture to improve the source and detector efficiency for diffraction imaging. In comparison with previous techniques, our approach reduces the required overall scan time by 1-2 orders of magnitude, which makes possible real-time scanning of a broad range of materials over a large volume using a table-top setup. This method, which relies on structuring spatially the illumination incident on an object moving relative to the X-ray source, is compatible with existing systems and has the potential to significantly enhance performance in an array of areas, such as medical diagnostic imaging and explosives detection. PMID:24340351

Greenberg, Joel A; Hassan, Mehadi; Krishnamurthy, Kalyani; Brady, David

2014-02-21

95

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

96

Out of Plane Detector for Surface X-ray Diffraction.  

National Technical Information Service (NTIS)

An out of plane detector movement has been built for the detector arm of the surface X-ray diffractometer on the wiggler beam line 9.4 on the synchrotron radiation source at Daresbury Lab. For a relative small cost, significantly increases the volume of r...

J. S. G. Taylor C. Norris E. Vlieg M. Lohmeier T. S. Turner

1995-01-01

97

Advanced Method for Fourier Analysis of X Ray Diffraction Profiles.  

National Technical Information Service (NTIS)

The use of two arcs of Pearson type VII distribution makes possible an accurate fitting of X-rays experimental line profile even in the asymmetrical case. This representation can be used, for the Fourier analysis of Bragg reflections, after having done, w...

S. Zirilli

1983-01-01

98

X-Ray Diffraction Studies of Chrome-Steel Slags  

Microsoft Academic Search

X-ray diffraction studies of the crystalline constituents in the acid open hearth chrome-steel samples showed that chromium exists in these samples as a chrome-iron spinel of the form, FeO·Cr2O3. Its density was 5.109 g?cc and its melting 2160°C. It crystallized in the face-centered cubic structure with a0=8.348A and Z=8.

G. P. Chatterjee; S. S. Sidhu

1947-01-01

99

Image reconstruction algorithm to X-ray diffraction tomography  

Microsoft Academic Search

The X-ray diffraction computed tomography technique is based on the interference phenomena. For low-momentum transfer, the scattering cannot be explained as being due to free atoms being necessary to consider solid-state scattering process. A selective discrimination of a given element in a scanned specimen can be realized by fixing the Bragg angle which produces an interference peak and then, to

R. C Barroso; R. T Lopes; O. D Gonçalves; J. T. de Assis

1999-01-01

100

Starch Gelatinization: An X-ray Diffraction Study  

Microsoft Academic Search

Cereal Chem. 65(6):443-446 Starch gelatinization was defined as the melting of starch crystallites, as granule fatty acids. Formation of these complexes partly explains determined by X-ray diffraction, in which the complete destruction of differences reported for heat of gelatinization values of amylose\\/lipid- crystallite integrity was observed as a function of moisture content and bearing starches because of competing melting and

H. F. ZOBEL; S. N. YOUNG; L. A. ROCCA

101

Coherent X-ray diffraction from collagenous soft tissues.  

PubMed

Coherent X-ray diffraction has been applied in the imaging of inorganic materials with great success. However, its application to biological specimens has been limited to some notable exceptions, due to the induced radiation damage and the extended nature of biological samples, the last limiting the application of most part of the phasing algorithms. X-ray ptychography, still under development, is a good candidate to overcome such difficulties and become a powerful imaging method for biology. We describe herein the feasibility of applying ptychography to the imaging of biological specimens, in particular collagen rich samples. We report here speckles in diffraction patterns from soft animal tissue, obtained with an optimized small angle X-ray setup that exploits the natural coherence of the beam. By phasing these patterns, dark field images of collagen within tendon, skin, bone, or cornea will eventually be obtained with a resolution of 60-70 nm. We present simulations of the contrast mechanism in collagen based on atomic force microscope images of the samples. Simulations confirmed the 'speckled' nature of the obtained diffraction patterns. Once inverted, the patterns will show the disposition and orientation of the fibers within the tissue, by enhancing the phase contrast between protein and no protein regions of the sample. Our work affords the application of the most innovative coherent X-ray diffraction tools to the study of biological specimens, and this approach will have a significant impact in biology and medicine because it overcomes many of the limits of current microscopy techniques. PMID:19706395

Berenguer de la Cuesta, Felisa; Wenger, Marco P E; Bean, Richard J; Bozec, Laurent; Horton, Michael A; Robinson, Ian K

2009-09-01

102

X-ray diffraction analysis of Si0 2 structure  

Microsoft Academic Search

The structural differences between vitreous silica and porous Si02 glass prepared by chemical extraction of Na20 · B203 · Si02 glasses were analysed by the method of X-ray diffraction. These investigations have given evidence for regularities of continuous silica networks beyond the well known short-range order which are discussed with respect to network topology. This network topology will be considered

B. Himmel; Th. Gerber; W. Heyer; W. Blau

1987-01-01

103

X-ray diffraction microscopy on frozen hydrated specimens  

NASA Astrophysics Data System (ADS)

X-rays are excellent for imaging thick samples at high resolution because of their large penetration depth compared to electrons and their short wavelength relative to visible light. To image biological material, the absorption contrast of soft X-rays, especially between the carbon and oxygen K-shell absorption edges, can be utilized to give high contrast, high resolution images without the need for stains or labels. Because of radiation damage and the desire for high resolution tomography, live cell imaging is not feasible. However, cells can be frozen in vitrified ice, which reduces the effect of radiation damage while maintaining their natural hydrated state. X-ray diffraction microscopy (XDM) is an imaging technique which eliminates the limitations imposed by current focusing optics simply by removing them entirely. Far-field coherent diffraction intensity patterns are collected on a pixelated detector allowing every scattered photon to be collected within the limits of the detector's efficiency and physical size. An iterative computer algorithm is then used to invert the diffraction intensity into a real space image with both absorption and phase information. This technique transfers the emphasis away from fabrication and alignment of optics, and towards data processing. We have used this method to image a pair of freeze-dried, immuno-labeled yeast cells to the highest resolution (13 nm) yet obtained for a whole eukaryotic cell. We discuss successes and challenges in working with frozen hydrated specimens and efforts aimed at high resolution imaging of vitrified eukaryotic cells in 3D.

Nelson, Johanna

104

The effect of silica on polymorphic precipitation of calcium carbonate: an on-line energy-dispersive X-ray diffraction (EDXRD) study  

NASA Astrophysics Data System (ADS)

Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2 sequestration technologies.Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2 sequestration technologies. Electronic supplementary information (ESI) available: Additiona

Kellermeier, Matthias; Glaab, Fabian; Klein, Regina; Melero-García, Emilio; Kunz, Werner; García-Ruiz, Juan Manuel

2013-07-01

105

The effect of silica on polymorphic precipitation of calcium carbonate: an on-line energy-dispersive X-ray diffraction (EDXRD) study.  

PubMed

Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2 sequestration technologies. PMID:23807473

Kellermeier, Matthias; Glaab, Fabian; Klein, Regina; Melero-García, Emilio; Kunz, Werner; García-Ruiz, Juan Manuel

2013-08-01

106

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

107

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

108

Synchrotron x-ray powder diffraction studies in pulsed magnetic fields  

SciTech Connect

X-ray powder diffraction experiments under pulsed magnetic fields were carried out at the DUBBLE beamline (BM26B) at the ESRF. A mobile generator delivered 110 kJ to the magnet coil, which was sufficient to generate peak fields of 30 T. A liquid He flow cryostat allowed us to vary the sample temperature accurately between 8 and 300 K. Powder diffraction patterns of several samples were recorded using 21 keV monochromatic x-rays and an on-line image plate detector. Here we present the first results on the suppression of the Jahn-Teller structural distortion in TbVO{sub 4} by magnetic field. These data clearly demonstrate the feasibility of x-ray powder diffraction experiments under pulsed magnetic fields with relatively inexpensive instrumentation.

Frings, P.; Vanacken, J.; Detlefs, C.; Duc, F.; Lorenzo, J. E.; Nardone, M.; Billette, J.; Zitouni, A.; Bras, W.; Rikken, G. L. J. A. [Laboratoire National des Champs Magnetiques Pulses, 143, Avenue de Rangueil, F-31400 Toulouse (France); Laboratoire National des Champs Magnetiques Pulses, 143, Avenue de Rangueil, F-31400 Toulouse, France and Pulsveldengroep, Institute for Nanoscale Physics and Chemistry, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Laboratoire National des Champs Magnetiques Pulses, 143, Avenue de Rangueil, F-31400 Toulouse, France and European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France); Centre d'Elaboration de Materiaux et d'Etudes Structurales, CNRS, B.P. 94347, F-31055 Toulouse (France); Laboratoire de Cristallographie, CNRS, B.P. 166X, F-38043 Grenoble (France); Laboratoire National des Champs Magnetiques Pulses, 143, Avenue de Rangueil, F-31400 Toulouse (France); Netherlands Organisation for Scientific Research (NWO), DUBBLE CRG-ESRF, B.P. 220, F-38043 Grenoble (France); Laboratoire National des Champs Magnetiques Pulses, 143, Avenue de Rangueil, F-31400 Toulouse (France)

2006-06-15

109

X-ray diffraction measurement at 0.20 K  

NASA Astrophysics Data System (ADS)

We have developed an X-ray diffraction measurement system for powder samples below 1 K. We use a dilution refrigerator (D.R.) of Oxford Instr. Kelvinox VT, which was modified for the X-ray measurement (J. Low Temp. Phys. 128 (2002) to be published). After our previous publication, we improved our measuring system. The X-ray beam was reduced approximately {1}/{12}, after passing through the windows of the dilution refrigerator. The windows are consist of four walls of Be 2 mm thick, two Al film 10 ?m thick and two aluminized mylar walls. The lowest temperature of the X-ray measurement was about 0.20 K. We have studied the temperature gradient between the specimen and the thermometer (RuO 2) which was attached to the mixing chamber. The results of our measurement suggest that there is no temperature difference between the RuO 2 on the mixing chamber of D.R. and the specimen down to 0.5 K. Below this temperature the gradient was observed to some extent.

Naher, S.; Suzuki, H.; Mizuno, M.; Xue, Y.; Fujishita, H.

2003-05-01

110

Portable energy dispersive X-ray fluorescence and X-ray diffraction and radiography system for archaeometry  

NASA Astrophysics Data System (ADS)

Starting on a laboratory developed portable X-ray fluorescence (PXRF) spectrometer; three different analytical results can be performed: analysis of chemical elements, analysis of major chemical crystalline phase and structural analysis, which represents a contribution to a new, low cost development of portable X-ray analyzer; since these results are respectively obtained with independent equipments for X-ray fluorescence, X-ray diffraction and radiography. Detection limits of PXRF were characterized using standard reference materials for ceramics, glass, bronze and bones, which are the main materials requiring quantitative analysis in art and archeological objects. A setup for simultaneous energy dispersive X-ray fluorescence and diffraction (ED (XRF-XRD)) in the reflection mode has been tested for in situ and non-destructive analysis according to the requirements of art objects inspection. The system uses a single low power X-ray tube and an X-ray energy dispersive detector to measure X-ray diffraction spectrum at a fixed angle. Application to the identification of jadeite-jade mineral in archeological objects by XRD is presented. A local high resolution radiography image obtained with the same low power X-ray tube allows for studies in painting and archeological bones.

Mendoza Cuevas, Ariadna; Perez Gravie, Homero

2011-03-01

111

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

112

X-ray diffraction studies of amorphous materials  

NASA Astrophysics Data System (ADS)

This thesis presents a study on two types of X-ray diffraction methodologies applied to the characterization of amorphous materials. The purpose of this study was to assess the feasibility of measuring the diffractive spectrum of amorphous materials by Energy-Dispersive X-ray Diffraction (EDXRD) utilizing Cadmium Zinc Telluride detectors. The total scattering intensity (coherent plus incoherent scatter) spectra precisely measured by high-energy Wide-Angle X-ray Scattering (WAXS) were compared to the EDXRD spectra to determine the level of agreement between the two techniques. The EDXRD spectra were constructed by applying a spectra fusing technique which combined the EDXRD spectra collected at different scattering angles rendering a continuous total scattering spectrum. The spectra fusing technique extended the momentum transfer range of the observed scattered spectrum beyond the limitations of the X-ray source and CZT detection efficiencies. Agreement between the WAXS and fused EDXRD spectra was achieved. In addition, this thesis presents the atomic pair correlation functions and coordination numbers of the first coordination shell for four hydrogen peroxide solutions of varying mass concentrations using Empirical Potential Structural Refinement (EPSR). The results are compared to the state-of-the art ad initio quantum mechanical charge field molecular dynamics (QMCF MD) model of the hydrogen peroxide in solution to support the model's predictions on why hydrogen peroxide is stable in water. The EPSR results using the coherent scattering intensity calculated from the WAXS data set predicts a hydration shell of 6.4 molecules of water surrounding hydrogen peroxide. The results also indicate that hydrogen peroxide is more likely to behave as a proton donor than acceptor. These findings are in agreement with QMCF MD model of aqueous hydrogen peroxide.

Palma, Joseph J., Jr.

113

Quantum-dot-array diffraction grating with single order diffraction property for soft x-ray region  

SciTech Connect

A gold transmission grating is used routinely to disperse the x-ray spectrum at the Z soft x-ray facility to measure the spectrum and temporal history of the absolute soft x-ray power emitted from z-pinch and hohlraum radiation sources. A quantum-dot-array diffraction grating (QDADG) of 250 lines/mm for soft x-ray is designed and fabricated for the first time according to the principle of binary sinusoidal transmission grating. The diffraction efficiencies of the grating are measured in the 150-300 eV photon energy range on the Beamline 3W1B of Beijing Synchrotron Radiation Facility. This article describes the basic concept and calibration techniques and presents calibration results. It is shown that the 250 lines/mm QDADG can be used to disperse light without higher-order diffractions in soft x-ray range, and the diffraction efficiencies of this grating are nearly constant (about 25%), which is beneficial in the spectrum analysis.

Kuang Longyu [Key Laboratory of Plasma Science and Technology, Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang, Sichuan 621900 (China); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Wang Chuanke; Wang Zhebin; Cao Leifeng; Liu Shenye; Ding Yongkun [Key Laboratory of Plasma Science and Technology, Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang, Sichuan 621900 (China); Zhu Xiaoli; Xie Changqing [Key Laboratory of Nano-fabrication and Novel Devices Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

2010-07-15

114

In situ high-pressure x-ray diffraction study of H[subscript 2]O ice VII  

Microsoft Academic Search

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser

M. Somayazulu; J. Shu; C.-S. Zha; A. F. Goncharov

2008-01-01

115

X-ray Laue diffraction from crystals of xylose isomerase.  

PubMed Central

The Laue method (stationary crystal, polychromatic x-rays) was used to collect native and heavy-atom-derivative data on crystals of xylose isomerase (EC 5.3.1.5). These data were used to find the heavy-atom positions. The positions found by use of Laue data are the same as those found by use of monochromatic data collected on a diffractometer. These results confirm that Laue diffraction data sets, which can be obtained on a millisecond time scale, can be used to locate small molecules bound to protein active sites. The successful determination of heavy-atom positions also indicates that x-ray crystallographic data collected by the Laue method can be used to solve protein structures. Images

Farber, G K; Machin, P; Almo, S C; Petsko, G A; Hajdu, J

1988-01-01

116

A system for x-ray diffraction and fluorescence imaging of nanoparticle biomarkers  

Microsoft Academic Search

Both x-ray diffraction and x-ray fluorescence techniques have proven beneficial for identifying and characterizing biological tissues. X-ray diffraction analysis uses the elemental composition of the sample to discriminate between tissue types, and can provide a considerable enhancement in contrast over conventional x-ray imaging. X-ray fluorescence, in this case, is being used to locate the presence of nanoparticles, such as gold,

Kate Pepper; Christiana Christodoulou; Chiara Guazzoni; Andrea Castoldi; Cigdem Ozkan; Nicola Sodini; Diego Dreossi; Jennifer A. Griffiths; Adam P. Gibson; Gary J. Royle

2010-01-01

117

Diffraction imaging of crystals with focused x-ray beams  

SciTech Connect

We describe an imaging technique based on diffraction of a focused x-ray beam in crystals. A focused beam is formed by a zone plate and Bragg diffracted from a crystalline sample positioned between the zone plate and the focus. The intensity pattern is recorded by a high-resolution charge-coupled-device detector placed in the focus. Diffraction images recorded from perfect Si and GaAs crystals for various reflections demonstrate the broadening of the focused beam due to a finite scattering length. The images from semiconductor epitaxial films and heterostructures show additional peaks originating from the interfaces with their spatial position corresponding to the depth from the surface. Diffraction images from isolated defects in Si crystal demonstrate capabilities to study bulk defects. Theoretical simulations for perfect crystals show excellent agreement with experiments. We demonstrate that the new imaging technique is depth sensitive and combines structural sensitivity of traditional x-ray topography methods with spatial in-plane resolution provided by focusing.

Kazimirov, A. [CHESS, Cornell University, Ithaca, New York 14853 (United States); Kohn, V. G. [Russian Research Center 'Kurchatov Institute', 123182 Moscow (Russian Federation); Cai, Z.-H. [Advanced Photon Source, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

2010-06-01

118

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

Microsoft Academic Search

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

Daiji Noda; Makoto Tanaka; Kazuma Shimada; Tadashi Hattori

2007-01-01

119

X-ray diffraction patterns from samples in the laser-heated diamond anvil cell  

Microsoft Academic Search

Thermal pressure and thermal expansion have competing effects on x-ray diffraction patterns obtained from polycrystalline samples at high pressures (10-100 GPa) and temperatures (300-4000 K) within the laser-heated diamond cell. Modeling shows that realistic temperature and pressure variations within the sample cause systematic shifts in diffraction-line positions and shapes, predicting that inferred values of pressure and thermal expansion coefficient can

Wendy R. Panero; Raymond Jeanloz

2002-01-01

120

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

121

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 Å. 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

122

X-ray diffraction data for plutonium compounds  

SciTech Connect

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Center for Diffraction Data. Los Alamos National Laboratory has been involved in the study of the properties of plutonium and its compounds. During the past 45 years, the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. These phase diagrams have been published in a special report of the Laboratory, LA-3870, Constitution of Plutonium Alloys,'' authored by F.H. Ellinger, W.N. Miner, D.R. O'Boyle, and F.W. Schonfeld. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structures of a number of plutonium intermetallic compounds have been determined at Los Alamos and published in the general literature by D.T. Cromer, A.C. Larson, and R.B. Roof over the last 35 years.

Roof, R.B.

1991-06-01

123

X-ray diffraction imaging using perfect crystals.  

PubMed

The imaging properties of perfect crystals, used for controlling and directing x-ray beams in imaging systems, are analyzed using optical transfer functions. The optical transfer functions are related to the point-spread functions for the crystal imaging system and are derived from a one-dimensional Fourier transform of the Takagi-Taupin equations. Images obtained using diffracting crystals as optical elements are simulated for the Laue and Bragg geometries using a Fourier transform method and the imaging characteristics of each of these crystal configurations are analyzed. It is demonstrated that the perfect crystals act as spatial filters of the object wave. PMID:21307532

Davis, T J

1996-01-01

124

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

125

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

126

High Pressure X-ray Diffraction Study of Potassium Azide  

SciTech Connect

Crystal structure and compressibility of potassium azide was investigated by in-situ synchrotron powder X-ray diffraction in a diamond anvil cell at room temperature up to 37.7 GPa. In the body-centered tetragonal (bct) phase, an anisotropic compressibility was observed with greater compressibility in the direction perpendicular to the plane containing N{sub 3}{sup -} ions than directions within that plane. The bulk modulus of the bct phase was determined to be 18.6(7) GPa. A pressure-induced phase transition may occur at 15.5 GPa.

C Ji; F Zhang; D Hong; H Zhu; J Wu; M Chyu; V Levitas; Y Ma

2011-12-31

127

X-ray Diffraction by Magnetic Charges (Monopoles)  

NASA Astrophysics Data System (ADS)

Magnetic charges, or magnetic monopoles, may form in the electronic structure of magnetic materials where ions are deprived of symmetry with respect to spatial inversion. Predicted in 2009, the strange magnetic, pseudo-scalars have recently been found different from zero in simulations of electronic structures of some magnetically ordered, orthorhombic, lithium orthophosphates (LiMPO4). We prove that magnetic charges in lithium orthophosphates diffract x-rays tuned in energy to an atomic resonance, by calculating exact unit-cell structure factors for monoclinic LiCoPO4 and orthorhombic LiNiPO4.

Lovesey, Stephen William; Khalyavin, Dmitry Dmitrievich

2013-10-01

128

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

129

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

130

Diffraction peaks restoration and extraction in energy dispersive X-ray diffraction  

NASA Astrophysics Data System (ADS)

This paper proposes a method to restore energy dispersive X-ray diffraction (EDXRD) spectra and to extract diffraction peaks. It follows a maximum a posteriori approach using a physical model of the formation of the EDXRD data to remove blur caused by both the detector and the coarse angular resolution of X-ray tube based EDXRD setup. It separates peaks due to the diffraction by crystalline material from a continuous background. Tested on real data (graphite and NaCl), our algorithm achieved to detect diffraction peaks with a good precision (about 1 keV depending on the peak position) even at high energy where very few photons were measured.

Soulez, Ferréol; Crespy, Charles; Kaftandjian, Valérie; Duvauchelle, Philippe

2011-10-01

131

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

132

Accurate determination of X-ray energies using powder diffraction  

NASA Astrophysics Data System (ADS)

We report synchrotron energy determinations using the powder diffraction patterns of Si (640b) and LaB6 (660) standard reference powders at a number of energies between 5 and 20 keV. The fitted peak positions of all peaks recorded on image plates were used in each energy determination. Several sources of systematic error were investigated and their connection led to physically reasonable and consistent fitting parameters. The energies were determined to better than 0.025% at all energies. Our procedure shows that the use of the accurately known lattice parameters of standard materials makes it possible to determine X-ray energies without involving the full panoply of the Rietveld technique (which involves the crystal structure, crystal perfection, particle size, preferred orientation and other parameters affecting the full powder diffraction pattern).

Rae, N. A.; Chantler, C. T.; Tran, C. Q.; Barnea, Z.

2006-11-01

133

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) [Santa Cruz, CA; Weaver, H. Joseph (Livermore, CA) [Livermore, CA

1991-01-01

134

X-ray fluorescence\\/diffraction analyzer for the SELENE-B lander\\/rover mission  

Microsoft Academic Search

A miniaturized X-ray fluorescence and diffraction analyzer is being developed for the SELENE-B, a future Japanese lunar lander and rover mission, to analyze major elemental composition and mineralogy. An onboard micro X-ray tube with a fine focus collimator is used to generate primary X-rays that excite fluorescence X-rays characteristic of major elements in collected samples; the primary X-rays are also

K. Shirai; M. Aoki; T. Okada; Y. Yamamoto; T. Arai; K. Akagawa; M. Kato

2003-01-01

135

A new theory for X-ray diffraction  

PubMed Central

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

Fewster, Paul F.

2014-01-01

136

Quantitative Analysis of Airborne Asbestos by X-Ray Diffraction: Feasibility Study.  

National Technical Information Service (NTIS)

Special x-ray diffraction geometry has been developed to distinguish chrysotile asbestos from serpentine and other clay minerals. The x-ray method requires alignment of the chrysotile fibers, and the technique for accomplishing this alignment has been dev...

E. T. Johnson J. V. Gilfrich L. S. Birks M. Fatemi

1975-01-01

137

X-Ray Detectors for Diffraction Studies and Their Use with Synchrotron Radiation.  

National Technical Information Service (NTIS)

All techniques for X-ray diffraction studies on biological materials exhibit certain limitations. The characteristics of several X-ray detection systems, namely film, multiwire proportional counter and image intensified TV, are discussed and compared for ...

J. Milch

1976-01-01

138

Fabrication of large area X-ray diffraction grating for X-ray phase imaging  

NASA Astrophysics Data System (ADS)

X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi

2012-07-01

139

Fabrication of large area X-ray diffraction grating for X-ray phase imaging  

SciTech Connect

X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori, Ako, Hyogo 678-1205 (Japan); Nanocreate Co., Ltd, 9-8-6 Tsujii, Himeji, Hyogo 670-0083 (Japan)

2012-07-31

140

Quantitative Analysis of Mt. St. Helens Ash by X-Ray Diffraction and X-Ray Fluorescence Spectrometry  

Microsoft Academic Search

A quantitative study by x-ray diffraction, optical polarizing microscopy, and x-ray fluorescence spectrometry of fallout and ambient ash from three Mt. St. Helens eruptions has revealed a consistent picture of the mineralogical and elemental composition. The major components observed are amorphous glass, plagioclase of about An50 composition, minor amounts of quartz and other SiO2 polymorphs, as well as ferromagnesian constituents

Briant L. Davis; L. Ronald Johnson; Dana T. Griffen; William Revell Phillips; Robert K. Stevens; David Maughan

1981-01-01

141

High-pressure behaviour of germanate olivines studied by X-ray diffraction and X-ray absorption spectroscopy  

Microsoft Academic Search

Germanate olivines Mg2GeO4, Ca2GeO4 and CaMgGeO4 have been studied by high-pressure X-ray Diffraction and high-pressure X-ray Absorption Spectroscopy. The three compounds were compressed, in the 0 30 GPa pressure range, at room temperature in a diamond-anvil cell, silicon oil being used as the pressure transmitting medium. Values of K0 are 166 ± 15, 117 ± 15 and 152 ± 14

P. E. Petit; F. Guyot; G. Fiquet; J. P. Itié

1996-01-01

142

Myelin membrane structure as revealed by x-ray diffraction.  

PubMed

The present work consists of a new interpretation of the data presented in the article entitled "X-Ray Diffraction of Myelin Membrane. II" by C. K. Akers and D. F. Parsons (1970, Biophys. J.10:116). It will be shown that the projection of the electron density onto the normal to the myelin multilayer derived by these authors is no more consistent with their data than another electron density function, or, perhaps, its negative. (A density function and its negative are related as follows: one of them is a certain density distribution, the other is the same function subtracted from a constant uniform density. Two density functions so related produce identical diffracted intensities.) The Fourier series for the projection of the electron density onto the normal to the myelin multilayer has coefficients +/-[hI(h)](1/2) where I(h) are the intensities of the five orders of reflection; data from which these can be estimated are presented by Akers and Parsons. The sequence of signs found here is + - - + + for the positive density (or - + + - - for the negative one). Quantitative agreement exists between the five X-ray diffraction data of Akers and Parsons and the same intensities calculated from the new model of the myelin structure described here. In this model the myelin double layer, 171 A thick, consists of a central lipid layer 72.4 A thick covered on both surfaces by protein layers 6.9 A thick; these protein layers are covered, in turn, by other lipid layers 42.4 A thick. Minor modifications of this model will no doubt be required to produce agreement between the observed and calculated intensities of the higher order reflections. PMID:4673584

Harker, D

1972-10-01

143

Experimental Qualification of a Novel X-Ray Diffraction Imaging Setup Based on Polycapillary X-Ray Optics  

Microsoft Academic Search

X-ray Diffraction Imaging is a technique able to highlight the differences in the molecular composition of the sample under analysis owing to the difference in their scattering properties. A laboratory based imaging system that will allow well-resolved diffraction images in space and energy was designed, setup and experimentally qualified. The key features of the proposed system are the following: (i)

A. Castoldi; C. Ozkan; C. Guazzoni; A. Bjeoumikhov; R. Hartmann

2010-01-01

144

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

145

(Diffraction gratings used in x-ray spectroscopy): Final report  

SciTech Connect

This subcontract was initiated in order to facilitate the development at MIT of technologies for fabricating the very fine diffraction grating required in x-ray spectroscopy at Lawrence Livermore Laboratory (LLL). These gratings are generally gold transmission gratings with spatial periods of 200 nm or less. The major focus of our efforts was to develop a means of fabricating gratings of 100 nm period. We explored two approaches: e-beam fabrication of x-ray lithography masks, and achromatic holographic lithography. This work was pursued by Erik Anderson as a major component of his Ph.D. thesis. Erik was successful in both the e-beam and holographic approaches. However, the e-beam method proved to be highly impractical: exposure times of about 115 days would be required to cover an area of 1 cm/sup 2/. The achromatic holography, on the other hand, should be capable of exposing areas well in excess of 1 cm/sup 2/ in times under 1 hour. Moreover, 100 nm-period gratings produced by achromatic holography are coherent over their entire area whereas gratings produced by e-beam lithography are coherent only over areas /approximately/100 ..mu..m. The remainder of this report consists of portions excerpted from Erik Anderson's thesis. These contain all the details of our work on 100 nm period gratings. 26 refs., 17 figs.

Smith, H.I.

1988-11-01

146

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

147

Relativistic component of chemical shift of Uranium X-ray emission lines  

Microsoft Academic Search

Twelve most intensive hard X-ray emission lines belonging to two multiplets (2p-3d and 2p-4d) and three doublets (2s-3p, 2s-4p, and 2p-3s) of the uranium L-series were studied by using a precise crystal-diffraction X-ray spectrometer. Chemical shift (CS) values were obtained for the first time for uranium (VI) oxide and uranium fluoride with respect to uranium (IV) oxide. The first attempt

Yuri F Batrakov; Andrey G Krivitsky; Elena V Puchkova

2004-01-01

148

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

149

Point diffraction interferometry at soft x-ray wavelengths  

SciTech Connect

To achieve the image performance necessary for soft x-ray projection lithography, interferometric testing at the design wavelength is required to accurately characterize the wavefront of the imaging system. The wavefront depends not only on the surface figure of the individual optics and on their relative alignment, but also on aperture dependent phase shifts induced by the resonant multilayer coatings on the optical surfaces. This paper describes the design and lithographic fabrication of an array of point diffraction interferometers on a silicon nitride membrane that has been over-coated with a spatially graded partially transmitting film to provide fringe contrast control. Experimental results using a visible light analogue (larger pinholes and different transmission gradient) will be shown.

Sommargren, G.E. [Lawrence Livermore National Lab., CA (United States); Hostetler, R. [AlliedSignal Technical Services, Livermore, CA (United States)

1993-07-01

150

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

151

Transmission geometry X-ray diffraction for materials research  

NASA Astrophysics Data System (ADS)

A study of both Energy Dispersive X-ray diffraction (EDXRD) and Angular Dispersive XRD (ADXRD) in a transmission geometry, for materials research purposes has been carried out. Both techniques are sufficiently sensitive to observe structural changes that occur in steel, whether through heating of a sample to induce a phase transformation, or through plastic deformation. EDXRD using HPGe detectors provides the 'gold standard' for measurements under laboratory conditions. The information retrievable with the relaxed resolution of a Cadmium-Zinc-Telluride (CZT) detector compares favourably to that of the HPGe. An ADXRD measurement using a more robust apparatus, suitable for more challenging environmental conditions, is sufficiently sensitive to observe the ferrite to austenite phase transformation.

Garrity, D. J.; Jenneson, P. M.; Vincent, S. M.

2007-09-01

152

Characterization of fiber texture by ?-scan x-ray diffraction  

NASA Astrophysics Data System (ADS)

On the basis of ?-scan x-ray diffraction (XRD), quantitative and qualitative characterization methods for fiber texture are proposed. The physical meaning of ?-scan curve is discussed in detail, and it is shown that the relative intensity curve of ?-scan XRD for a certain crystal plane is proportional to the pole density of the plane. Then qualitative and quantitative characterization methods for fiber texture are proposed from the concept of pole density. The proposed methods can be used in any crystal system. As an example for experimental verification, an orientation distribution function (ODF) experiment and a series of ?-scan XRD experiments are performed on a sputtered platinum film. From the comparison between the result of the ODF experiment and that of the analyses on the ?-scan XRD experiments, it is proved that the proposed qualitative and quantitative methods are effective and simple.

Fei, W. D.; Liu, C. Q.; Ding, M. H.; Li, W. L.; Wang, L. D.

2009-09-01

153

Observations of Shocked Metallic Surfaces with Single-Pulse X-Ray Diffraction  

SciTech Connect

A single-pulse x-ray diffraction (XRD) diagnostic has been developed for the investigation of shocked material properties on a very short time scale. The diagnostic, which consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, produces line and bremsstrahlung x-ray emission in a 40-ns pulse. A selected anode of either silver or molybdenum produces characteristic K? lines used for diffraction. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 2-mm by 5-mm spot and 1° full-width-half-maximum angular divergence. Coherent scattering from the sample produces a Debye-Scherrer diffraction pattern on an image plate 75 mm from the polycrystalline sample surface. An experimental study of the polycrystalline structures of zirconium and tin under high-pressure shock loading has been conducted with single-pulse XRD. The experimental targets were 0.1-mm-thick foils of zirconium and tin using 0.4-mm-thick vitreous carbon back windows for shock-loading, and the shocks were produced by either Detasheet or PBX-9501 high explosives buffered by 1-mm-thick 6061-T6 aluminum. The diffraction patterns from both shocked zirconium and tin indicated a phase transition into a polymorphic mix of amorphous and new solid phases.

Dane V. Morgan, Mike Grover, Don Macy, Mike Madlener, Gerald Stevens, William D. Turley

2009-07-31

154

Elimination of higher-order diffraction using zigzag transmission grating in soft x-ray region  

SciTech Connect

We present a realization of the sinusoidal transmission function using a series of zigzag-profiled strips where the transmission takes on the binary values 0 and 1 in a two-dimensional distribution. A zigzag transmission grating of 1000 line/mm has been fabricated and demonstrated on the soft x-ray beam of synchrotron radiation. The axial single-order diffraction indicates that the zigzag transmission grating is adequate for spectroscopic application.

Zang, H. P.; Wang, C. K. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Gao, Y. L.; Zhou, W. M.; Kuang, L. Y.; Wei, L.; Fan, W.; Zhang, W. H.; Zhao, Z. Q.; Cao, L. F.; Gu, Y. Q.; Zhang, B. H. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Jiang, G. [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Zhu, X. L.; Xie, C. Q. [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Zhao, Y. D.; Cui, M. Q. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2012-03-12

155

Synthesis and X-ray diffraction pattern for MgCu 2  

Microsoft Academic Search

To clarify the inconsistency between calculated and existing experimental X-ray diffraction (XRD) pattern for dicopper magnesium (MgCu2) and to identify the impurity phase in Cu-sheathed MgB2 superconductors, polycrystalline MgCu2 samples were synthesized and studied by XRD measurement. The XRD result shows that the (220), (422), (620), and (642) reflection lines, which are missing from the standard pattern of MgCu2 in

G. Liang; Z. Tang; H. Fang; D. Katz; K. Salama

2006-01-01

156

Coherent X-ray diffraction investigation of twinned microcrystals.  

PubMed

Coherent X-ray diffraction has been used to study pseudo-merohedrally twinned manganite microcrystals. The analyzed compositions were Pr(5/8)Ca(3/8)MnO(3) and La(0.275)Pr(0.35)Ca(3/8)MnO(3). The prepared loose powder was thermally attached to glass (and quartz) capillary walls by gentle heating to ensure positional stability during data collection. Many diffraction data sets were recorded and some of them were split as expected from the main observed twin law: 180° rotation around [101]. The peak splitting was measured with very high precision owing to the high-resolution nature of the diffraction data, with a resolution (?d/d) better than 2.0 × 10(-4). Furthermore, when these microcrystals are illuminated coherently, the different crystallographic phases of the structure factors induce interference in the form of a speckle pattern. The three-dimensional speckled Bragg peak intensity distribution has been measured providing information about the twin domains within the microcrystals. Research is ongoing to invert the measured patterns. Successful phase retrieval will allow mapping out the twin domains and twin boundaries which play a key role in the physical properties. PMID:20975220

Aranda, Miguel A G; Berenguer, Felisa; Bean, Richard J; Shi, Xiaowen; Xiong, Gang; Collins, Stephen P; Nave, Colin; Robinson, Ian K

2010-11-01

157

Phosphor Scanner For Imaging X-Ray Diffraction  

NASA Technical Reports Server (NTRS)

Improved optoelectronic scanning apparatus generates digitized image of x-ray image recorded in phosphor. Scanning fiber-optic probe supplies laser light stimulating luminescence in areas of phosphor exposed to x rays. Luminescence passes through probe and fiber to integrating sphere and photomultiplier. Sensitivity and resolution exceed previously available scanners. Intended for use in x-ray crystallography, medical radiography, and molecular biology.

Carter, Daniel C.; Hecht, Diana L.; Witherow, William K.

1992-01-01

158

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

SciTech Connect

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

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

2013-10-15

159

X-ray Weak Broad-line Qquasars: Absorption or Intrinsic X-ray Weakness  

NASA Technical Reports Server (NTRS)

XMM observations of X-ray weak quasars have been performed during 2003 and 2004. The data for all the observations have become available in 2004 (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 all the data, and obtained interesting scientific results. Out of the eight sources, 4 are confirmed to be extremely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confined to be highly variable both in flux (by factor 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects we are completing a publication: 1) For the X-ray weak sources, a paper is submitted with a complete analysis of the X-ray spectra both from Chandra and XMM-Newton, and a comparison with optical and near-IR photometry obtained from all-sky surveys. Possible models for the unusual spectral energy distribution of these sources are also presented. 2) For the variable sources, a paper is being finalized where the X-ray spectra obtained with XMM-Newton are compared with previous X-ray observations and with observations at other wavelengths. It is shown that these sources are high luminosity and extreme cases of the highly variable class of narrow-line Seyfert Is. 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 have been performed in early 2004. They will complement the XMM data and will lead to understanding of whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circum-nuclear material. The infrared spectra of the variable sources have been already analyzed and are discussed in the paper by Memola et al. which will be soon submitted.

Mushotzky, Richard (Technical Monitor); Risaliti, Guida

2005-01-01

160

Eta Carinae: X-ray Line Variations during the 2003 X-ray Minimum, and the Orbit Orientation  

NASA Technical Reports Server (NTRS)

The future evolution of Eta Carinae will be as a supernova (or hypernova) and black hole. The evolution is highly contingent on mass and angular momentum changes and instabilities. The presence of a companion can serve to trigger instabilities and provide pathways for mass and angular momentum exchange loss. X-rays can be used a a key diagnostic tool: x-ray temperatures trace pre-shock wind velocities, periodic x-ray variability traces the orbit, and x-ray line variations traces the flow and orientation of shocked gas. This brief presentation highlights x-ray line variations from the HETG and presents a model of the colliding wind flow.

Corcoran, M. F.; Henley, D.; Hamaguchi, K.; Khibashi, K.; Pittard, J. M.; Stevens, I. R.; Gull, T. R.

2007-01-01

161

A study of the Si(111) 3× 3-Ag surface by transmission X-ray diffraction and X-ray diffraction topography  

NASA Astrophysics Data System (ADS)

The adsorption site of Ag atoms with respect to the unreconstructed Si crystal was uniquely determined using transmission X-ray diffraction. The result is consistent with one of the two honeycomb-chained triangle models previously proposed by the authors using reflection X-ray diffraction. Next, the reconstruction of Si was analyzed; an Si trimer layer is about 0.8 Å below the Ag layer, and at least two double layers of Si are reconstructed, having the component of the honeycomb arrangement. Finally, the capability of surface X-ray diffraction topography was shown by observing the integral-order spot near the Bragg point.

Toshio Takahashi; Shinichiro Nakatani; Naoko Okamoto; Tetsuya Ishikawa; Seishi Kikuta

1991-02-01

162

Quantitative Determination of Chrysotile, Amosite and Crocidolite by X-ray Diffraction  

Microsoft Academic Search

The determination of asbestos by x-ray diffraction in environmental samples is described. Evenly distributed mats of asbestos samples on molecular membrane filters are prepared for x-ray diffraction examination. Each asbestos mineral has its characteristic x-ray diffraction pattern. A qualitative scan of a mounted filtered sample identifies the crystalline substances present including the asbestos minerals. A quantitative determination of a given

John V. Crable

1966-01-01

163

Characterization of (111) Gaas and (111) InP substrates and homoepitaxial layers by divergent x-ray beam diffraction  

Microsoft Academic Search

The back-reflection diffraction of a divergent x-ray beam has been studied for the characterization of (111) GaAs and (111)\\u000a InP substrates and homoepitaxial layers with different states of surface perfection. Diffraction conditions for generating\\u000a back-reflection pseudo-Kossel patterns from (111) GaAs and (111) InP are presented. Mechanical polishing was observed to produce\\u000a x-ray diffraction line broadening. Uneven line broadening was found

Alice L. Lin; Lee F. Donaghey

1977-01-01

164

Study of the diffraction contrast of dislocations in X-ray topo-tomography: A computer simulation and image analysis  

NASA Astrophysics Data System (ADS)

Oblique X-ray diffraction images of individual dislocations in the symmetric Laue geometry from a plane-parallel silicon plate have been calculated based on the Takagi-Taupin equations and analyzed. Computer simulation is used to develop a general mathematical model of the formation of oblique images which correspond to sample rotation around the diffraction vector h in X-ray topo-tomography. The results of numerical calculations and analysis of different oblique images of straight-line dislocations, where the dislocation line vector ? lies in a plane parallel to input surface of {111}Si plate with a diffraction vector h <220>, are presented.

Besedin, I. S.; Chukhovskii, F. N.; Asadchikov, V. E.

2014-05-01

165

In-Situ X-Ray Diffraction System Using Sources and Detectors at Fixed Angular Positions.  

National Technical Information Service (NTIS)

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 res...

D. M. Gibson H. Huang W. M. Gibson

2006-01-01

166

X-ray emission lines from cooling flows  

NASA Technical Reports Server (NTRS)

Techniques employing individual X-ray line strengths to estimate the rate at which gas cools in the intracluster medium are discussed. It is demonstrated that departures from ionization equilibrium in the cooling plasma are not important at X-ray temperatures. Nonrestrictive upper limits are obtained for four cooling flow clusters. The results favor the existence of substantial cooling flows and argue against the dominance of conduction or other heat sources.

Canizares, Claude R.; Markert, Thomas H.; Donahue, Megan E.

1988-01-01

167

Quantitative biological imaging by ptychographic x-ray diffraction microscopy  

PubMed Central

Recent advances in coherent x-ray diffractive imaging have paved the way to reliable and quantitative imaging of noncompact specimens at the nanometer scale. Introduced a year ago, an advanced implementation of ptychographic coherent diffractive imaging has removed much of the previous limitations regarding sample preparation and illumination conditions. Here, we apply this recent approach toward structure determination at the nanoscale to biological microscopy. We show that the projected electron density of unstained and unsliced freeze-dried cells of the bacterium Deinococcus radiodurans can be derived from the reconstructed phase in a straightforward and reproducible way, with quantified and small errors. Thus, the approach may contribute in the future to the understanding of the highly disputed nucleoid structure of bacterial cells. In the present study, the estimated resolution for the cells was 85 nm (half-period length), whereas 50-nm resolution was demonstrated for lithographic test structures. With respect to the diameter of the pinhole used to illuminate the samples, a superresolution of about 15 was achieved for the cells and 30 for the test structures, respectively. These values should be assessed in view of the low dose applied on the order of ?1.3·105 Gy, and were shown to scale with photon fluence.

Giewekemeyer, Klaus; Thibault, Pierre; Kalbfleisch, Sebastian; Beerlink, Andre; Kewish, Cameron M.; Dierolf, Martin; Pfeiffer, Franz; Salditt, Tim

2010-01-01

168

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

PubMed

An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K. PMID:18052482

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

2007-11-01

169

Very High Resolution Solar X-ray Imaging Using Diffractive Optics  

NASA Technical Reports Server (NTRS)

This paper describes the development of X-ray diffractive optics for imaging solar flares with better than 0.1 arcsec angular resolution. X-ray images with this resolution of the greater than or equal to 10 MK plasma in solar active regions and solar flares would allow the cross-sectional area of magnetic loops to be resolved and the coronal flare energy release region itself to be probed. The objective of this work is to obtain X-ray images in the iron-line complex at 6.7 keV observed during solar flares with an angular resolution as fine as 0.1 arcsec - over an order of magnitude finer than is now possible. This line emission is from highly ionized iron atoms, primarily Fe xxv, in the hottest flare plasma at temperatures in excess of approximately equal to 10 MK. It provides information on the flare morphology, the iron abundance, and the distribution of the hot plasma. Studying how this plasma is heated to such high temperatures in such short times during solar flares is of critical importance in understanding these powerful transient events, one of the major objectives of solar physics.We describe the design, fabrication, and testing of phase zone plate X-ray lenses with focal lengths of approximately equal to 100 m at these energies that would be capable of achieving these objectives. We show how such lenses could be included on a two-spacecraft formation-flying mission with the lenses on the spacecraft closest to the Sun and an X-ray imaging array on the second spacecraft in the focal plane approximately equal to 100 m away. High resolution X-ray images could be obtained when the two spacecraft are aligned with the region of interest on the Sun. Requirements and constraints for the control of the two spacecraft are discussed together with the overall feasibility of such a formation-flying mission.

Dennis, B. R.; Skinner, G. K.; Li, M. J.; Shih, A. Y.

2012-01-01

170

Very High-Resolution Solar X-Ray Imaging Using Diffractive Optics  

NASA Astrophysics Data System (ADS)

This paper describes the development of X-ray diffractive optics for imaging solar flares with better than 0.1 arcsec angular resolution. X-ray images with this resolution of the ? 10 MK plasma in solar active regions and solar flares would allow the cross-sectional area of magnetic loops to be resolved and the coronal flare energy release region itself to be probed. The objective of this work is to obtain X-ray images in the iron-line complex at 6.7 keV observed during solar flares with an angular resolution as fine as 0.1 arcsec - over an order of magnitude finer than is now possible. This line emission is from highly ionized iron atoms, primarily Fe xxv, in the hottest flare plasma at temperatures in excess of ? 10 MK. It provides information on the flare morphology, the iron abundance, and the distribution of the hot plasma. Studying how this plasma is heated to such high temperatures in such short times during solar flares is of critical importance in understanding these powerful transient events, one of the major objectives of solar physics. We describe the design, fabrication, and testing of phase zone plate X-ray lenses with focal lengths of ? 100 m at these energies that would be capable of achieving these objectives. We show how such lenses could be included on a two-spacecraft formation-flying mission with the lenses on the spacecraft closest to the Sun and an X-ray imaging array on the second spacecraft in the focal plane ? 100 m away. High-resolution X-ray images could be obtained when the two spacecraft are aligned with the region of interest on the Sun. Requirements and constraints for the control of the two spacecraft are discussed together with the overall feasibility of such a formation-flying mission.

Dennis, B. R.; Skinner, G. K.; Li, M. J.; Shih, A. Y.

2012-08-01

171

The new diffractometer for surface X-ray diffraction at beamline BL9 of DELTA.  

PubMed

The experimental endstation of the hard X-ray beamline BL9 of the Dortmund Electron Accelerator is equipped with a Huber six-circle diffractometer. It is dedicated to grazing-incidence X-ray diffraction and X-ray reflectivity experiments on solid surfaces and thin films as well as to powder diffraction measurements. A new set-up for grazing-incidence X-ray scattering of liquids has been built up using a silicon mirror to reflect the incident X-ray to the liquid surface at angles of incidence around the critical angle of total reflection of the sample. X-ray reflectivity measurements of a polymer film and grazing-incidence X-ray diffraction measurements of an epitaxically grown Gd40Y60 film, an oxidized surface of Fe-15at.%Al alloy and aqueous salt solutions are presented and discussed. PMID:16371703

Krywka, Christof; Paulus, Michael; Sternemann, Christian; Volmer, Martin; Remhof, Arndt; Nowak, Gregor; Nefedov, Alexei; Pöter, Birgit; Spiegel, Michael; Tolan, Metin

2006-01-01

172

A comparison of different methods for x-ray diffraction line broadening analysis of Ti and Ag UHV deposited thin films: nanostructural dependence on substrate temperature and film thickness  

NASA Astrophysics Data System (ADS)

The influence of substrate temperature and film thickness on the nanostructure of titanium (HCP) and silver (FCC) thin films deposited on glass substrates under UHV conditions by electron beam evaporation is investigated. The preferred orientation, nanostrain and stacking and twin fault probabilities in Ag and Ti films are determined as a function of film thickness and substrate temperature. A (111) preferred orientation is observed for silver films, which is dependent on both the film thickness and substrate temperature, with the highest value at a substrate temperature of 500 K. Ti/glass films showed a (002) preferred orientation. Nanostructural parameters such as the crystallite size (size of coherently diffracting domains) and nanostrain are evaluated using the Scherrer and Stocks-Wilson relations, the Williamson-Hall plot, and the single-Voigt (SV), double-Voigt (DV) and Warren-Averbach (WA) methods. Analysis of the results obtained using these methods showed that the most suitable approaches to x-ray diffraction line broadening analysis, applicable to both FCC and HCP polycrystalline thin film structures, are SV, DV and WA. The results show that the crystallite sizes increase with substrate temperature and film thickness, while the nanostrain and lattice constants decrease with thickness. The crystallite size distribution function was obtained from the size broadened part of the DV function, and the results show a shift in the maximum to larger sizes with increasing temperature and thickness.

Savaloni, H.; Gholipour-Shahraki, M.; Player, M. A.

2006-05-01

173

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

NASA Astrophysics Data System (ADS)

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

Liu, Hehe; Liu, Zhiguo; Sun, Tianxi; Peng, Song; Ma, Yongzhong; Sun, Weiyuan; Li, Yude; Lin, Xiaoyan; Zhao, Weigang; Zhao, Guangcui; Luo, Ping; Pan, Qiuli; Ding, Xunliang

2013-09-01

174

Flash X-Ray Diffraction System for Fast, Single-PulseTemperature and Phase Transition Measurements (Pre-print)  

SciTech Connect

A new, fast, single-pulse diagnostic for determining phase transitions and measuring the bulk temperature of polycrystalline metal objects has been developed. The diagnostic consists of a 37-stage Marx bank with a cable-coupled X-ray diode that produces a 35-ns pulse of mostly 0.71-{angstrom} monochromatic X rays and a P-43 fluor coupled to a cooled, charge-coupled device camera by a coherent fiber-optic bundle for detection of scattered X rays. The X-ray beam is collimated to a 1{sup o} divergence in the scattering plane with the combination of a 1.5-mm tungsten pinhole and a 1.5-mm-diameter molybdenum anode. X rays are produced by a high-energy electron beam transiting inward from the cathode to the anode in a needle-and-washer configuration. The anode's characteristic K-{alpha} X-ray emission lines are utilized for this diffraction system. The X-ray anode is heavily shielded in all directions other than the collimated beam. The X-ray diode has a sealed reentrant system, allowing X rays to be produced inside a vacuum containment vessel, close to the sample under study.

Michael J. Madlener; Dane V. Morgan

2007-06-12

175

Atomic calculations for the Fe XX X-ray lines  

NASA Technical Reports Server (NTRS)

The atomic data presented here and in Bhatia and Mason (1980) allow the calculation of theoretical intensity ratios for all the EUV, UV, and X-ray lines from Fe XX. Tabulations are presently given for the transitions between levels in the 2s2 2p3, 2s2 2p2 3s, and 2s2 2p2 3d configurations of Fe(19+), and electron collision strengths are calculated by means of the 'distorted wave' approximation. In addition to the theoretical X-ray line intensity ratios, new spectral line identifications from a solar flare are presented.

Mason, H. E.; Bhatia, A. K.

1983-01-01

176

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.

177

In Situ High Pressure Angle Dispersive X-ray Diffraction Experiments:With Sagittally-Bent Double Laue Monochomator  

Microsoft Academic Search

A Sagittally-bent double Laue monochomator is used at the wiggler beam line X17C of NSLS, BNL. It can provide high-energy X-ray tunable from 20 keV to 40 keV. The monochomator consists of two Si crystals of 0.76 mm thick, with surface corresponding to the (001) planes. The 111 reflections of both crystals are used to diffract the x-ray. The two

J. Hu; Z. Zhong; H. Liu; Q. Guo; H. Mao; R. J. Hemley

2003-01-01

178

DEVELOPMENT OF MgO CERAMIC STANDARDS FOR X-RAY AND NEUTRON LINE BROADENING ASSESSMENTS  

Microsoft Academic Search

An MgO ceramic line profile standard has been developed for strain-size evaluations with x-ray diffraction (XRD) and neutron diffraction (ND) data. The production of these is of interest to the authors for general-purpose XRD and ND line profile work as the popular LaB6 NIST SRM 660 standard cannot be used in neutron investigations due the severity of neutron attenuation. The

Suminar Pratapa; Brian O'Connor

179

Federated repositories of X-ray diffraction images.  

PubMed

There is a pressing need for the archiving and curation of raw X-ray diffraction data. This information is critical for validation, methods development and improvement of archived structures. However, the relatively large size of these data sets has presented challenges for storage in a single worldwide repository such as the Protein Data Bank archive. This problem can be avoided by using a federated approach, where each institution utilizes its institutional repository for storage, with a discovery service overlaid. Institutional repositories are relatively stable and adequately funded, ensuring persistence. Here, a simple repository solution is described, utilizing Fedora open-source database software and data-annotation and deposition tools that can be deployed at any site cheaply and easily. Data sets and associated metadata from federated repositories are given a unique and persistent handle, providing a simple mechanism for search and retrieval via web interfaces. In addition to ensuring that valuable data is not lost, the provision of raw data has several uses for the crystallographic community. Most importantly, structure determination can only be truly repeated or verified when the raw data are available. Moreover, the availability of raw data is extremely useful for the development of improved methods of image analysis and data processing. PMID:18566516

Androulakis, Steve; Schmidberger, Jason; Bate, Mark A; DeGori, Ross; Beitz, Anthony; Keong, Cyrus; Cameron, Bob; McGowan, Sheena; Porter, Corrine J; Harrison, Andrew; Hunter, Jane; Martin, Jennifer L; Kobe, Bostjan; Dobson, Renwick C J; Parker, Michael W; Whisstock, James C; Gray, Joan; Treloar, Andrew; Groenewegen, David; Dickson, Neil; Buckle, Ashley M

2008-07-01

180

Characterization of high-resolution diffractive X-ray optics by ptychographic coherent diffractive imaging.  

PubMed

We have employed ptychographic coherent diffractive imaging to completely characterize the focal spot wavefield and wavefront aberrations of a high-resolution diffractive X-ray lens. The ptychographic data from a strongly scattering object was acquired using the radiation cone emanating from a coherently illuminated Fresnel zone plate at a photon energy of 6.2 keV. Reconstructed images of the object were retrieved with a spatial resolution of 8 nm by combining the difference-map phase retrieval algorithm with a non-linear optimization refinement. By numerically propagating the reconstructed illumination function, we have obtained the X-ray wavefield profile of the 23 nm round focus of the Fresnel zone plate (outermost zone width, ?r = 20 nm) as well as the X-ray wavefront at the exit pupil of the lens. The measurements of the wavefront aberrations were repeatable to within a root mean square error of 0.006 waves, and we demonstrate that they can be related to manufacturing aspects of the diffractive optical element and to errors on the incident X-ray wavefront introduced by the upstream beamline optics. PMID:22108984

Vila-Comamala, Joan; Diaz, Ana; Guizar-Sicairos, Manuel; Mantion, Alexandre; Kewish, Cameron M; Menzel, Andreas; Bunk, Oliver; David, Christian

2011-10-24

181

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

182

Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil  

SciTech Connect

This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography/diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).

Kappen, P. [Department of Physics, La Trobe University, Victoria 3086 (Australia); Arhatari, B. D.; Luu, M. B.; Balaur, E. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Caradoc-Davies, T. [Australian Synchrotron, 800 Blackburn Road, Victoria 3168 (Australia)

2013-06-15

183

Soft X-ray Excesses and X-ray Line Variability in Cygnus X-3  

NASA Astrophysics Data System (ADS)

Cygnus X-3 is an X-ray binary (XRB) system containing a stellar-mass compact object, most likely a black hole, and a Wolf-Rayet companion star, which produces collimated, relativistic jets, placing it in the sub-class of XRBs known as microquasars. During a Swift/XRT monitoring program of Cygnus X-3, a soft X-ray excess (below 1 keV) was observed at certain states and phases of activity. This soft excess appears to be similar to the variable soft emission observed in Seyfert galaxies. The presence of these features in Cygnus X-3 would argue for a greater support of the black-hole nature of the compact object and serve to better highlight the similarities of microquasars and AGN. We present the results of our investigations of these soft excesses, as well as the variations of the X-ray Fe line region (6.4-7.0 keV) as a function of the state activity and orbital phase.

Varlotta, Angelo; McCollough, Michael L

2014-06-01

184

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

185

A Computer Program for Calculation of Calibration Curves for Quantitative X-Ray Diffraction Analysis.  

ERIC Educational Resources Information Center

Describes a FORTRAN IV program written to supplement a laboratory exercise dealing with quantitative x-ray diffraction analysis of mixtures of polycrystalline phases in an introductory course in x-ray diffraction. Gives an example of the use of the program and compares calculated and observed calibration data. (Author/GS)

Blanchard, Frank N.

1980-01-01

186

Measurement of strain in Al{endash}Cu interconnect lines with x-ray microdiffraction  

SciTech Connect

We report measurement of strain in patterned Al{endash}Cu interconnect lines with x-ray microdiffraction technique with a {approximately}1 {mu}m spatial resolution. Monochromatized x rays from an undulator were focused on the sample using a phase fresnel zone plate and diffracted light was collected by an area detector in a symmetric, angle dispersive x-ray diffraction geometry. Measurements were made before and after the line sample was stressed for electromigration. Results show an increase in inter- and intra-grain strain variation after the testing. Differences in strain behavior of grains with (111) and (200) crystallographic planes parallel to the substrate surface were observed. A position dependent variation of strain after the testing was measured whereas no such dependence was found before the testing. {copyright} {ital 1999 American Institute of Physics.}

Solak, H.H.; Vladimirsky, Y.; Cerrina, F. [Department of Electrical and Computer Engineering, University of Wisconsin--Madison, Madison, Wisconsin 53706 (United States)] [Department of Electrical and Computer Engineering, University of Wisconsin--Madison, Madison, Wisconsin 53706 (United States); Lai, B.; Yun, W.; Cai, Z.; Ilinski, P.; Legnini, D.; Rodrigues, W. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

1999-07-01

187

Instrumentation of x-ray diffraction and materials research on the National Synchrotron Light Source. Final report  

SciTech Connect

MATRIX was organized in 1980 to formulate a research team to design and construct a beam line at NSLS for x-ray diffraction studies of materials. A versatile system was designed to allow a full range of experimental capabilities for wide angle x-ray scattering experiments including surface diffraction studies. The design and construction of the system has been completed. Testing of parts of the system was completed at CHESS and with x-ray sources or other equipment at member institutions. Installation of the beam line at NSLS is in progress and will proceed in parallel with the commissioning of the x-ray ring at NSLS. Full operation of the beam line is expected to be ready by December 1, 1984 being limited only by the source power of NSLS at that time. Useful experiments could be started if the power is at least 2 GeV and 100ma. The MATRIX beam line was one of the first x-ray beam lines to see light in the beam line in early spring of 1984. In July of 1984, the MATRIX beam line as the first port at NSLS to have a monochromatic beam and to scan part of the spectrum from the source. As part of this contract, six publications have resulted from the various projects. Three publications are concerned directly with the beam line and/or its operation while the other three publications are the result of research associated with the project.

Liedl, G.L.

1984-11-01

188

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

189

Quantitative x-ray powder-diffraction analysis of air particulate samples  

SciTech Connect

The design, operation, and calibration of an x-ray powder diffraction system for the analysis of air particulate samples are described. The instrument analyzes a sample nondestructively for its major crystalline components. The system was optimized for the nondestructive analysis of major crystalline species deposited on samples collected with dichotomous air samplers. It includes a position-sensitive detector for increased sensitivity and a small computer for rapid on-line data analysis. A calibration procedure was developed to give direct quantitative measurements of the primary chemical compounds on the sample. This system was used to analyze 18 pairs of samples of the Houston aerosol. The results of this analysis when combined with the measurement of the elemental concentrations by x-ray fluorescence analysis give additional discrimination in source receptor models.

Thompson, A.C.; Johnson, L.R.; Jaklevic, J.M.

1982-10-01

190

In Situ High-Pressure X-ray Diffraction Study of H2O Ice VII  

SciTech Connect

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu,M.; Shu, J.; Zha, C.; Goncharov, A.; Tschauner, O.; Mao, H.; Hemley, R.

2008-01-01

191

perovskite: a single-crystal X-ray diffraction study  

NASA Astrophysics Data System (ADS)

Magnesium silicate perovskite is the predominant phase in the Earth's lower mantle, and it is well known that incorporation of iron has a strong effect on its crystal structure and physical properties. To constrain the crystal chemistry of (Mg, Fe)SiO3 perovskite more accurately, we synthesized single crystals of Mg0.946(17)Fe0.056(12)Si0.997(16)O3 perovskite at 26 GPa and 2,073 K using a multianvil press and investigated its crystal structure, oxidation state and iron-site occupancy using single-crystal X-ray diffraction and energy-domain Synchrotron Mössbauer Source spectroscopy. Single-crystal refinements indicate that all iron (Fe2+ and Fe3+) substitutes on the A-site only, where based on Mössbauer spectroscopy. Charge balance likely occurs through a small number of cation vacancies on either the A- or the B-site. The octahedral tilt angle ( ?) calculated for our sample from the refined atomic coordinates is 20.3°, which is 2° higher than the value calculated from the unit-cell parameters ( a = 4.7877 Å, b = 4.9480 Å, c = 6.915 Å) which assumes undistorted octahedra. A compilation of all available single-crystal data (atomic coordinates) for (Mg, Fe)(Si, Al)O3 perovskite from the literature shows a smooth increase of ? with composition that is independent of the nature of cation substitution (e.g., or substitution mechanism), contrary to previous observations based on unit-cell parameter calculations.

Sinmyo, Ryosuke; Bykova, Elena; McCammon, Catherine; Kupenko, Ilya; Potapkin, Vasily; Dubrovinsky, Leonid

2014-06-01

192

Low-Aberration Diffraction Mirror to Focus X-Rays  

Microsoft Academic Search

Radiography of laser-driven implosions is important for the development of inertial confinement fusion, and it is challenging to obtain adequate diagnostic radiographs of the compression of the fuel capsule. X-ray imaging, through the use of x-ray mirrors, can potentially increase the resolution and accuracy of radiographs, for instance by allowing radiography at locally normal incidence through an imploding spherical capsule.

Achim Seifter; Damian Swift; James Hawreliak

2007-01-01

193

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. Macías; J. L. Ruvalcaba; M. A. Zenteno

1994-01-01

194

A method for implementing the diffraction of a widely divergent X-ray beam  

SciTech Connect

A method for implementing the diffraction of a widely divergent characteristic X-ray beam from a standard X-ray tube with a linear focal spot was improved. X rays, passing through a diaphragm 30 {mu}m in diameter, diffract from a crystal adjacent to the diaphragm. The crystal, together with a photographic plate, rotates around the axis perpendicular to the plate. It is shown that the diffraction image is a set of hyperbolas in this case. The equations of the hyperbolas are obtained and investigated. A method for interpreting the diffraction images in the case of small crystal asymmetry is proposed.

Avetyan, K. T.; Arakelyan, M. M., E-mail: marakelyan@ysu.am [Yerevan State University (Armenia)

2008-11-15

195

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

NASA Astrophysics Data System (ADS)

We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO2 laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO2 laser yielded 6×107 x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111) crystal. 102 diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 102 x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 104; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

O'Shea, F. H.; Williams, O.; Andonian, G.; Barber, S.; Sakai, Y.; Rosenzweig, J. B.; Pogorelsky, I.; Fedurin, M.; Kusche, K.; Yakimenko, V.

2012-02-01

196

Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum.  

PubMed

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(alpha) 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(beta) line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3 x 6 mm(2) spot and 1 degrees full width half maximum 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 degrees . 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 camera through a coherent fiber-optic 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 aluminum lattice with no phase transformation. PMID:19045900

Morgan, Dane V; Macy, Don; Stevens, Gerald

2008-11-01

197

Real-time x-ray diffraction measurements of shocked polycrystalline tin and aluminum  

NASA Astrophysics Data System (ADS)

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 3×6 mm2 spot and 1° full width half maximum 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 camera through a coherent fiber-optic 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 aluminum lattice with no phase transformation.

Morgan, Dane V.; Macy, Don; Stevens, Gerald

2008-11-01

198

Retrieval of the atomic displacements in the crystal from the coherent X-ray diffraction pattern.  

PubMed

The retrieval of spatially resolved atomic displacements is investigated via the phases of the direct(real)-space image reconstructed from the strained crystal's coherent X-ray diffraction pattern. It is demonstrated that limiting the spatial variation of the first- and second-order spatial displacement derivatives improves convergence of the iterative phase-retrieval algorithm for displacements reconstructions to the true solution. This approach is exploited to retrieve the displacement in a periodic array of silicon lines isolated by silicon dioxide filled trenches. PMID:24971974

Minkevich, A A; Köhl, M; Escoubas, S; Thomas, O; Baumbach, T

2014-07-01

199

X-ray diffraction and Raman scattering studies of proton-induced, modified polyethylene terephthalate microfiber  

NASA Astrophysics Data System (ADS)

Polyethylene terephthalate (PET) microfiber of 1.5 denier per filament (dpf) has been irradiated with 3-MeV proton at two different fluences: 1 × 1013 and 1 × 1015p/cm2. Molecular deformation because of in-air proton irradiation straining of PET filaments has been investigated. Study of the effects of irradiation by using X-ray diffraction (XRD), Raman spectroscopy and Instron technique shows microstress and crosslinks on the surface of fiber (as revealed from XRD line shift and Raman shift). However, the Young's modulus is found to be larger at an irradiation dose of 1 × 1013p/cm2.

Mallick, B.; Behera, R. C.; Tiwari, T. N.; Panigrahi, S.; Samal, S. K.

200

X-ray diffraction study of phason strain field in oriented icosahedral Al-Mn  

SciTech Connect

We have produced large area (some square centimeters), crystallographically oriented icosahedral-phase material by implanting Mn ions directly into single-crystal Al substrates. High-resolution x-ray measurements of the positions and line shapes of the quasicrystal diffraction peaks reveal systematic deviations from perfect icosahedral symmetry. A quantitative analysis of the data shows that the samples contain a simple form of phason strain field which depends on the kinetics of grain formation. The results rule out the icosatwin model proposed by Pauling.

Budai, J.D.; Tischler, J.Z.; Habenschuss, A.; Ice, G.E.; Elser, V.

1987-06-01

201

Highly intense monochromatic X-ray diffraction facility for high-pressure research at SPring8  

Microsoft Academic Search

Beamline BL10XU at SPring-8, designed for X-ray diffraction experiments using diamond anvil cells at high pressure and low\\/high temperature, is continuously upgraded. The X-ray source, optics, and attractive experimental equipment such as simultaneous measurement systems have been optimized over the past years. The high energy and high intensity monochromatic X-ray beams emitted by an undulator source, focused using a characteristic

Yasuo Ohishi; Naohisa Hirao; Nagayoshi Sata; Kei Hirose; Masaki Takata

2008-01-01

202

Coherent x-ray transition and diffraction radiation of microbunched beams  

NASA Astrophysics Data System (ADS)

Theoretical and numerical results on angular and spectral distributions and total number of photons of several types of coherent radiation produced by microbunched beams passing through radiators are presented: coherent x-ray bremsstrahlung, x-ray transition, resonance transition, and diffraction radiations. The possibility of observation and application of these new types of radiation for the study of parameters of electron beam microbunching, which is important for the effectiveness of x-ray free electron lasers, is discussed.

Ispirian, K. A.; Ispiryan, M.

2013-02-01

203

An x-ray diffraction study of microstructural deformation induced by cyclic loading of selected steel  

Microsoft Academic Search

X-ray double crystal diffractometry (XRDCD) and X-ray scanning diffractometry (XRSD) were used to assess cyclic microstructural deformation in a face centered cubic (fcc) steel (AISI304) and a body centered cubic (bcc) steel (SA508 class 2). The objectives of the investigation were to determine if X-ray diffraction could be used effectively to monitor cyclic microstructural deformation in polycrystalline Fe alloys and

Patrick Michael Fourspring

1997-01-01

204

Raster polycapillary collimating system for position-sensitive detector of diffracted x-rays  

Microsoft Academic Search

To improve the resolving capacity of position-sensitive detector, a polycapillary raster system permitting filtration of diffracted x-rays is suggested. Glass polycapillary collimating system has a spherical shape, while tubular channels are oriented along the radii of this spherical surface. This allows maximum utilization of diffracted x-rays. Spatial collimation enables minimization of the instrumental width of diffraction maximum and FWHH values

N. S. Ibraimov; A. V. Lyuttsau; E. V. Likhoushina; S. V. Zarembo; M. V. Yudina; A. E. Bulkin

2005-01-01

205

Coding and sampling for compressive x-ray diffraction tomography  

NASA Astrophysics Data System (ADS)

Coded apertures and energy resolving detectors may be used to improve the sampling efficiency of x-ray tomography and increase the physical diversity of x-ray phenomena measured. Coding and decompressive inference enable increased molecular specificity, reduced exposure and scan times. We outline a specific coded aperture x-ray coherent scatter imaging architecture that demonstrates the potential of such schemes. Based on this geometry, we develop a physical model using both a semi-analytic and Monte Carlo-based framework, devise an experimental realization of the system, describe a reconstruction algorithm for estimating the object from raw data, and propose a classification scheme for identifying the material composition of the object at each location

Greenberg, Joel A.; Krishnamurthy, Kalyani; Lakshmanan, Manu; MacCabe, Kenneth; Wolter, Scott; Kapadia, Anuj; Brady, David

2013-09-01

206

Setup for in situ X-ray diffraction studies of thin film growth by magnetron sputtering  

NASA Astrophysics Data System (ADS)

A novel method is described for the in situ-investigation of nucleation and growth of thin films during magnetron sputtering. Energy dispersive X-ray diffraction with synchrotron light is used for the structural analysis during film growth. An in situ-magnetron sputtering chamber was constructed and installed at a synchrotron radiation beam line with a bending magnet. The white synchrotron light (1-70 keV) passes the sputtering chamber through Kapton windows and hits one of the substrates on a four-fold sample holder. The diffracted beam, observed under a fixed diffraction angle between 3° and 10°, is energy analyzed by a high purity Ge-detector. The in situ-EDXRD setup is demonstrated for the growth of tin-doped indium oxide (ITO) films prepared by reactive magnetron sputtering from a metallic target.

Ellmer, K.; Mientus, R.; Weiß, V.; Rossner, H.

2001-07-01

207

Hard X-ray imaging of bacterial cells: nano-diffraction and ptychographic reconstruction.  

PubMed

Ptychographic coherent X-ray diffractive imaging (PCDI) has been combined with nano-focus X-ray diffraction to study the structure and density distribution of unstained and unsliced bacterial cells, using a hard X-ray beam of 6.2keV photon energy, focused to about 90nm by a Fresnel zone plate lens. While PCDI provides images of the bacteria with quantitative contrast in real space with a resolution well below the beam size at the sample, spatially resolved small angle X-ray scattering using the same Fresnel zone plate (cellular nano-diffraction) provides structural information at highest resolution in reciprocal space up to 2nm(-1). We show how the real and reciprocal space approach can be used synergistically on the same sample and with the same setup. In addition, we present 3D hard X-ray imaging of unstained bacterial cells by a combination of ptychography and tomography. PMID:23038565

Wilke, R N; Priebe, M; Bartels, M; Giewekemeyer, K; Diaz, A; Karvinen, P; Salditt, T

2012-08-13

208

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

209

Reconstructing longitudinal strain pulses using time-resolved x-ray diffraction  

NASA Astrophysics Data System (ADS)

Time-resolved x-ray diffraction is a very powerful tool for visualizing transient one-dimensional crystalline strains, ranging from crystal growth to shockwave production. In this work, we use picosecond x-ray diffraction to visualize transient strain formation from nanometer-scaled laser-excited gold films into crystalline substrates. We show that there is a direct correspondence between the measured time-resolved x-ray diffraction pattern and the transient acoustic wave, providing a straightforward method to make a reconstruction of the transient strain. In addition, we discuss real-world experimental constraints that place limits on the validity of the reconstructed transient acoustic wave.

Gao, Y.; Chen, Z.; Bond, Z.; Loether, A.; Howard, L. E.; LeMar, S.; White, S.; Watts, A.; Walker, B. C.; DeCamp, M. F.

2013-07-01

210

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

211

Beam-induced damage on diffractive hard X-ray optics  

PubMed Central

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both ambient and inert atmospheres. Diffraction gratings fabricated by three different techniques are considered: electroplated Au gratings both with and without the polymer mold, and Ir-coated Si gratings. The beam-induced damage is monitored by X-ray diffraction and evaluated using scanning electron microscopy.

Nygard, K.; Gorelick, S.; Vila-Comamala, J.; Farm, E.; Bergamaschi, A.; Cervellino, A.; Gozzo, F.; Patterson, B. D.; Ritala, M.; David, C.

2010-01-01

212

Femtosecond X-ray diffraction from two-dimensional protein crystals  

PubMed Central

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

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

2014-01-01

213

X-ray photoelectron spectroscopy and diffraction in the hard X-ray regime: Fundamental considerations and future possibilities  

NASA Astrophysics Data System (ADS)

The prospects for extending X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) measurements into the hard X-ray regime of 5-15 keV excitation energies are discussed from a fundamental point of view, in some cases using prior results obtained in the 1-2 keV range as starting points of discussion, together with theoretical estimates of behavior at higher energies. Subjects treated are: the instrumentation improvements needed to optimize peak intensities; the tuning of experimental conditions to achieve bulk or surface sensitivity; the use of grazing incidence to suppress spectral backgrounds; the use of standing waves created by Bragg reflection from crystal planes or synthetic multilayers to achieve position-sensitive densities of states, compositions, and magnetizations; photoelectron diffraction and Kikuchi-band effects as element-specific local structure probes; and valence-level measurements, including the role of non-dipole effects and mechanisms leading to complete Brillouin zone averaging and density-of-states like spectra. Several distinct advantages are found for such high-energy extensions of the XPS and XPD techniques.

Fadley, Charles S.

2005-07-01

214

Miniature diamond anvil pressure cell for single crystal x-ray diffraction studies  

Microsoft Academic Search

A new miniature gasketed diamond anvil high pressure cell has been constructed to perform optical and x-ray diffraction studies on single crystals under hydrostatic pressure. For x-ray studies the cell is mounted on a standard goniometer head which may be attached to either a standard precession camera or single crystal orienter taking advantage of counting methods. The pressure cell has

Leo Merrill; William A. Bassett

1974-01-01

215

Study of carbon steel corrosion layer by X-ray diffraction and absorption methods  

Microsoft Academic Search

To predict the behavior of structural metallic materials into the CANDU nuclear reactor, the oxide films on the surface were growth in a controlled manner using an autoclave simulating the environment specific to the nuclear reactor. In order to establish the structural changes of the oxide films, the X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX)

V. Malinovschi; C. Ducu; N. Aldea; M. Fulger

2006-01-01

216

Structural determination using magnetic x-ray circular dichroism in spin-polarized photoelectron diffraction.  

National Technical Information Service (NTIS)

The first structural determination with spin-polarized, energy-dependent photoelectron diffraction using circularly-polarized x-rays is reported for Fe films on Cu(001). Circularly-polarized x-rays produce spin-polarized photoelectrons from the Fe 2p doub...

G. D. Waddill J. G. Tobin X. Guo S. Y. Tong

1994-01-01

217

Nano-Cylinder Structure Studied by X-ray Diffraction.  

National Technical Information Service (NTIS)

The study of nano-cylinder structure has attracted much attention due to the application of multi-wall carbon nanotubes (MWCNTs). while some TEM observations indicate that they are formed by seamless concentric cylinders, other TEM and high pressure X-ray...

G. Xu J. Lin J. J. Vittal Z. Feng Z. Popovic

2001-01-01

218

(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

219

X-ray Diffraction Crystal Calibration and Characterization  

SciTech Connect

National Security Technologies’ X-ray Laboratory is comprised of a multi-anode Manson type source and a Henke type source that incorporates a dual goniometer and XYZ translation stage. The first goniometer is used to isolate a particular spectral band. The Manson operates up to 10 kV and the Henke up to 20 kV. The Henke rotation stages and translation stages are automated. Procedures have been developed to characterize and calibrate various NIF diagnostics and their components. The diagnostics include X-ray cameras, gated imagers, streak cameras, and other X-ray imaging systems. Components that have been analyzed include filters, filter arrays, grazing incidence mirrors, and various crystals, both flat and curved. Recent efforts on the Henke system are aimed at characterizing and calibrating imaging crystals and curved crystals used as the major component of an X-ray spectrometer. The presentation will concentrate on these results. The work has been done at energies ranging from 3 keV to 16 keV. The major goal was to evaluate the performance quality of the crystal for its intended application. For the imaging crystals we measured the laser beam reflection offset from the X-ray beam and the reflectivity curves. For the curved spectrometer crystal, which was a natural crystal, resolving power was critical. It was first necessary to find sources of crystals that had sufficiently narrow reflectivity curves. It was then necessary to determine which crystals retained their resolving power after being thinned and glued to a curved substrate.

Michael J. Haugh; Richard Stewart; Nathan Kugland

2009-06-05

220

Characterization of the Work Hardening Structure of Austenitic Steels by X-Ray Diffraction. Application to the Determination of Work Hardening Gradients and the Study of Recovery.  

National Technical Information Service (NTIS)

A method has been developed to determine quantitatively the work hardening of austenitic steels by measurement of the broadening of X-ray diffraction lines. This simple, rapid, accurate and sensible method enables to determine work hardening variations in...

R. Cadalbert J. L. Baron

1977-01-01

221

Early stages of formation of the Ag-Ni(111) interface studied by grazing incidence x-ray diffraction and x-ray photoelectron diffraction  

NASA Astrophysics Data System (ADS)

Ultra-thin Ag/Ni(111) reconstructed interfaces have been revisited by a combination of in-situ grazing incidence x-ray diffraction (GIXD) and x-ray photoelectron diffraction (XPD) in order to determine the growth mode and to evaluate the interface spacing. Evidence for predominance of single-layer growth in the early stages was obtained through the analysis of the x-ray diffraction rods from the Ag/Ni(111) (52×52)R13.9? reconstructed interface, whereas photoelectron diffraction patterns could reveal traces of second-layer Ag scatterers before full wetting of the substrate. Refinement of the atomic coordinates provided by quenched molecular dynamics simulation on the basis of the new x-ray data set enabled us to assess the Ag/Ni average interplanar distance, which was found unexpanded at 2.44 ± 0.07 Å, in contrast with recent determination by low-energy electron diffraction and microscopy. For increasing deposited amounts, both GIXD and XPD showed the expected features of two- and three-layer silver epitaxial overgrowths.

Chambon, C.; Coati, A.; Sauvage-Simkin, M.; Garreau, Y.; Creuze, J.; Verdini, A.; Cossaro, A.; Floreano, L.; Morgante, A.

2011-10-01

222

Layer-Thickness Variations and X ray Diffraction Patterns, a General Treatment.  

National Technical Information Service (NTIS)

The effects of random thickness variations in a compositionally modulated material on the X-ray diffraction pattern is expressed in terms of the distribution function. This distribution is incorporated via its Fourier transform in a function describing th...

M. A. Hollanders B. J. Thijsse

1990-01-01

223

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

SciTech Connect

An electrochemical in-situ reaction cell for hard X-ray experiments with battery electrodes is described. Applications include the small angle scattering, diffraction, and near-edge spectroscopy of lithium manganese oxide electrodes.

Braun, Artur; Granlund, Eric; Cairns, Elton J.

2003-01-27

224

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

SciTech Connect

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

Andreeva, N. S. [Russian Academy of Sciences, Engelhardt Institute of Molecular Biology (Russian Federation)], E-mail: andreeva@eimb.ru

2006-12-15

225

Curved anode wire chambers for x-ray diffraction applications  

SciTech Connect

Curved position sensitive proportional detectors are described. The first has a radius of curvature of 135 mm and a 60/sup 0/ angular range. The second has a radius of curvature of 360 mm and a 45/sup 0/ angular range. For high quantum efficiency for x-ray energies up to 60 keV, a relatively large x-ray path and high gas pressure are required. The anode wires are suspended in circular arcs by the interaction of a current flowing through them and a magnetic field provided by two permanent magnets placed above and below the wire running parallel to it over the full length of the curved chambers. Anode wire stability under the combined action of the magnetic and electrostatic forces is discussed. (LEW)

Perez-Mendez, V.; Wiedenbeck, P.; Wagner, C.N.J.; Woelfel, E.

1983-01-01

226

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

Berman, Robert M. (Pittsburgh, PA) [Pittsburgh, PA; Cohen, Isadore (Pittsburgh, PA) [Pittsburgh, PA

1990-01-01

227

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°C., 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.

Fernandez-moran, H.; Finean, J. B.

1957-01-01

228

Study of partial melting at high-pressure using in situ X-ray diffraction  

Microsoft Academic Search

The high-pressure melting behavior of different iron alloys was investigated using the classical synchrotron-based in situ X-ray diffraction techniques. As they offer specific advantages and disadvantages, both energy-dispersive (EDX) and angle-dispersive (ADX) X-ray diffraction methods were performed at the BL04B1 beamline of SPring8 (Japan) and at the ID27-30 beamline of the ESRF (France), respectively. High-pressure vessels and pressure ranges investigated

D. Andrault; G. Morard; N. Bolfan-Casanova; O. Ohtaka; H. Fukui; H. Arima; N. Guignot; K. Funakoshi; P. Lazor; M. Mezouar

2006-01-01

229

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

Microsoft Academic Search

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

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

2003-01-01

230

X-ray diffraction and equation of state of solid neon to 110 GPa  

Microsoft Academic Search

Solid neon was compressed under static conditions at 300 K to pressures in the 100 GPa (megabar) range using diamond-anvil cell techniques. The crystal structure and P-V equation of state were determined by energy-dispersive x-ray diffraction with microcollimated synchrotron radiation. Pressures were determined from ruby fluorescence spectra and from x-ray diffraction of tungsten powder contained within the sample. Solid neon

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

1989-01-01

231

X-ray diffraction and equation of state of solid neon to 110 GPa  

Microsoft Academic Search

Solid neon was compressed under static conditions at 300 K to pressures in the 100 GPa (megabar) range using diamond-anvil cell techniques. The crystal structure and \\/ital P\\/-\\/ital V\\/ equation of state were determined by energy-dispersive x-ray diffraction with microcollimated synchrotron radiation. Pressures were determined from ruby fluorescence spectra and from x-ray diffraction of tungsten powder contained within the sample.

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

1989-01-01

232

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

Microsoft Academic Search

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.

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

2002-01-01

233

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

234

Morphological determination of face-centered-cubic metallic nanoparticles by X-ray diffraction.  

PubMed

X-ray diffraction studies of face-centered-cubic metallic nanoparticles with different morphologies are discussed based on the experimental data and the calculation of the Debye equation with the truncated and perfect strain models. At least four basic morphologies frequently observed in face-centered-cubic metallic nanoparticles, namely sphere, cube, decahedron, and icosahedron, can be clearly distinguished from their characteristic integrated intensity ratios of the first two X-ray diffraction peaks, that is, (200) to (111). PMID:22239984

Lee, Chi-Feng; Chang, Chia-Lun; Yang, Jing-Cyuan; Lai, Hsiang-Yu; Chen, Chun-Hua

2012-03-01

235

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

236

On the characteristics of line emissions from binary X-ray sources and supernova remnants  

Microsoft Academic Search

The paper considers the characteristics of line emissions from binary X-ray sources and supernova remnants. X-ray spectroscopy of celestial X-ray sources can yield useful data on physical conditions and processes responsible for emission from binary X-ray sources; iron line emission at about 6.8 keV from many supernova remnants and X-ray binaries has been observed and the available data on iron

T. M. K. Marar; V. S. Iyengar; K. Kasturirangan; U. R. Rao

1979-01-01

237

An atomic layer deposition chamber for in situ x-ray diffraction and scattering analysis.  

PubMed

The crystal structure of thin films grown by atomic layer deposition (ALD) will determine important performance properties such as conductivity, breakdown voltage, and catalytic activity. We report the design of an atomic layer deposition chamber for in situ x-ray analysis that can be used to monitor changes to the crystal structural during ALD. The application of the chamber is demonstrated for Pt ALD on amorphous SiO2 and SrTiO3 (001) using synchrotron-based high resolution x-ray diffraction, grazing incidence x-ray diffraction, and grazing incidence small angle scattering. PMID:24880424

Geyer, Scott M; Methaapanon, Rungthiwa; Johnson, Richard W; Kim, Woo-Hee; Van Campen, Douglas G; Metha, Apurva; Bent, Stacey F

2014-05-01

238

Three-Dimensional Visualization of a Human Chromosome Using Coherent X-Ray Diffraction  

NASA Astrophysics Data System (ADS)

Coherent x-ray diffraction microscopy is a lensless phase-contrast imaging technique with high image contrast. Although electron tomography allows intensive study of the three-dimensional structure of cellular organelles, it has inherent difficulty with thick objects. X rays have the unique benefit of allowing noninvasive analysis of thicker objects and high spatial resolution. We observed an unstained human chromosome using coherent x-ray diffraction. The reconstructed images in two or three dimensions show an axial structure, which has not been observed under unstained conditions.

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

2009-01-01

239

Three-Dimensional Visualization of a Human Chromosome Using Coherent X-Ray Diffraction  

SciTech Connect

Coherent x-ray diffraction microscopy is a lensless phase-contrast imaging technique with high image contrast. Although electron tomography allows intensive study of the three-dimensional structure of cellular organelles, it has inherent difficulty with thick objects. X rays have the unique benefit of allowing noninvasive analysis of thicker objects and high spatial resolution. We observed an unstained human chromosome using coherent x-ray diffraction. The reconstructed images in two or three dimensions show an axial structure, which has not been observed under unstained conditions.

Nishino, Yoshinori; Ishikawa, Tetsuya [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Takahashi, Yukio [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Imamoto, Naoko; Maeshima, Kazuhiro [Cellular Dynamics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2009-01-09

240

An atomic layer deposition chamber for in situ x-ray diffraction and scattering analysis  

NASA Astrophysics Data System (ADS)

The crystal structure of thin films grown by atomic layer deposition (ALD) will determine important performance properties such as conductivity, breakdown voltage, and catalytic activity. We report the design of an atomic layer deposition chamber for in situ x-ray analysis that can be used to monitor changes to the crystal structural during ALD. The application of the chamber is demonstrated for Pt ALD on amorphous SiO2 and SrTiO3 (001) using synchrotron-based high resolution x-ray diffraction, grazing incidence x-ray diffraction, and grazing incidence small angle scattering.

Geyer, Scott M.; Methaapanon, Rungthiwa; Johnson, Richard W.; Kim, Woo-Hee; Van Campen, Douglas G.; Metha, Apurva; Bent, Stacey F.

2014-05-01

241

Plasticity and X-ray Line Profile Analysis of the semicrystalline polymer poly(3-hydroxybutyrate)  

NASA Astrophysics Data System (ADS)

The evolution of the microstructure during compressive deformation of the biodegradable polymer poly(3-hydroxybutyrate) (P3HB) was investigated in-situ via X-ray diffraction using synchrotron radiation. Flow curves were measured in-situ together with X-ray profiles for several degrees of deformation. The profiles were analysed using Multi-Reflection X-ray Line Profile Analysis (MXPA) adapted by the authors for semicrystalline polymers providing lamella thickness, crystallinity, and the presence and density of dislocations as a function of the deformation. In contrast to previous investigations in ? crystallised isotactic polypropylene (?-iPP), P3HB does not exhibit a deformation induced increase of the dislocation density which suggests mechanisms other than dislocations to be involved in plastic deformation of P3HB.

Spieckermann, F.; Wilhelm, H.; Schafler, E.; Kerber, M.; Bernstorff, S.; Zehetbauer, M. J.

2010-07-01

242

Quantitative mineral phase analysis of dry powders using energy-dispersive X-ray diffraction.  

PubMed

Energy-dispersive X-ray diffraction (EDXRD) spectrometry is being investigated as a means to perform direct on-line quantitative mineral phase analysis on industrial mineral process streams. A laboratory prototype EDXRD analyser has been developed and a preliminary study has been made to determine its suitability for measuring mineral samples. This was carried out by collecting the diffraction spectra of 20 samples each containing six powdered minerals in dry form and using a linear regression analysis model to determine the mass of each mineral component contained in the samples. Using this method it was found that mineral components could be determined to an accuracy of better than 1 wt%. PMID:18502649

O'Dwyer, J N; Tickner, J R

2008-10-01

243

Analysis of carbon fibers and carbon composites by asymmetric X-ray diffraction technique  

Microsoft Academic Search

The effect of annealing on the microstructure of three sets of carbon fibers and their composites with a phenol-formaldehyde matrix was investigated by X-ray diffraction. An asymmetric diffraction geometry with parallel beam optics was used to get more information in comparison with conventional diffraction experiments. It was found that the microstructure of the samples is improved after annealing up to

L. Dobiášová; V. Starý; P. Glogar; V. Valvoda

1999-01-01

244

Multi-Fiber Polycapillary-Based X-Ray Collimating Lens for X-Ray Diffraction  

Microsoft Academic Search

A prototype multi fiber polycapillary-based collimating lens has been characterized and indirectly compared to a collimating slit system used in diffraction experiments. Performance of the prototype lens expressed in term of intensity gain ranged from 2 up to 7.5 compared to that of the collimating slit of width ranging from 2^circ down to 0.5^circ. The collimating slit was installed in

Kardiawarman

1995-01-01

245

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

NASA Astrophysics Data System (ADS)

We propose to observe a sample of 23 soft X-ray weak, optically red quasars, discovered by the Hamburg Quasar Survey. The lack of detection in the ROSAT PSPC, despite their relatively bright optical emission make them a peculiar class of quasars, classified as type 1 in the optical but type 2 in the X-rays. Establishing the X-ray properties of these objects is important for (1) the X-ray background synthesis models (they could be the missing "QSO2s"), (2) the unified models (they challenge the traditional torus model) and (3) the long debated problem on the discrepancy between optical and X-ray luminosity functions. With 180 ks with ACIS-S we can observe a well defined sample of sources and measure their absorption column density in many cases.

Risaliti, Guido

2001-09-01

246

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

247

Quality experimental and calculated powder x-ray diffraction.  

National Technical Information Service (NTIS)

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...

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

1996-01-01

248

Application of Laser Plasma X-rays to Time-resolved Debye-Sherrer Diffraction  

SciTech Connect

We have studied Laser Plasma X-ray(LPX) in order to apply to time-resolved protein crystallography. We consider that our works will contribute for application of X-ray pulse and breed short pulse handling techniques. LPX pulse duration is femto{approx}pico-second. So, we expect that the laser plasma X-ray system has the potential to satisfy the requirement of time-scale to resolve the early period of protein's structural change. We need about more than 1012photns/shot X-ray to get a diffraction image of organics. We have reinforced our LPX system to get a diffraction image. Now, we try laser pre-pulse effect by experiments and calculations. As the first step of our aim, we will obtain the Debey-Sherrer diffraction image of a biological sample.

Kanegae, Y.; Kinoshita, K.; Hosokai, T.; Ohkubo, T.; Yoshii, K.; Ueda, T.; Watanabe, T.; Zhidkov, A.; Uesaka, M. [Nuclear Engineering Research Laboratory, University of Tokyo, 2-22 Shirakata-Sirane, Toukai-mura, Naka-gun, Ibaraki-ken, 319-1188 (Japan)

2003-08-26

249

Stoichiometry optimization of homoepitaxial oxide thin films using x-ray diffraction.  

SciTech Connect

Homoepitaxial SrTiO{sub 3} thin films grown by molecular beam epitaxy are analyzed using high-resolution x-ray diffraction and transmission electron microscopy. Measured 00L x-ray scans from stoichiometric and nonstoichiometric films are compared with calculations that account for the effects of film thickness, lattice parameter, fractional site occupancy, and an offset between film and substrate at the interface. It is found that thickness fringes, commonly observed around Bragg reflections even in stoichiometric homoepitaxial SrTiO{sub 3} films, arise from a film/substrate interface offset. Transmission electron microscopy studies confirm the presence of strain at those homoepitaxial interfaces that show an offset in x-ray diffraction. The consequences for stoichiometry optimization of homoepitaxial films using high-resolution x-ray diffraction and the quality of regrown oxide interfaces are discussed.

LeBeau, J. M.; Engel-Herbert, R.; Jalan, B.; Cagnon, J.; Moetakef, P.; Stemmer, S.; Stephenson, G. B.; Materials Science Division; Univ. of California at Santa Barbara

2009-10-05

250

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

SciTech Connect

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

Nishino, Yoshinori; Takahashi, Yukio; Yamamoto, Masaki; Ishikawa, Tetsuya [SPring-8 / RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2007-01-19

251

Industrial aspects of synchrotron X-ray powder diffraction  

Microsoft Academic Search

This paper describes some of the applications of powder diffraction using synchrotron radiation with possible applications to industry. The advantages of differing synchrotron diffraction geometries, Debye-Scherrer, Analyser crystal, Hart Parrish, and Energy Dispersive, are discussed. The paper is not a comprehensive review but nevertheless considers the wider role of these powder diffraction geometries in elucidating crystal structures, highlighted examples being

R. J. Cernik; P. Barnes

1995-01-01

252

First results from a next-generation off-plane X-ray diffraction grating  

NASA Astrophysics Data System (ADS)

Future NASA X-ray spectroscopy missions will require high throughput, high resolving power grating spectrometers. Off-plane reflection gratings are capable of meeting the performance requirements needed to realize the scientific goals of these missions. We have identified a novel grating fabrication method that utilizes common lithographic and microfabrication techniques to produce the high fidelity groove profile necessary to achieve this performance. Application of this process has produced an initial pre-master that exhibits a radial (variable line spacing along the groove dimension), high density (> 6000 grooves/mm), laminar profile. This pre-master has been tested for diffraction efficiency at the BESSY II synchrotron light facility and diffracts up to 55 % of incident light into usable spectral orders. Furthermore, tests of spectral resolving power show that these gratings are capable of obtaining resolving powers well above 1300 ( ?/? ?) with limitations due to the test apparatus, not the gratings. Obtaining these results has provided confidence that this fabrication process is capable of producing off-plane reflection gratings for the next generation of X-ray observatories.

McEntaffer, Randall; DeRoo, Casey; Schultz, Ted; Gantner, Brennan; Tutt, James; Holland, Andrew; O'Dell, Stephen; Gaskin, Jessica; Kolodziejczak, Jeffrey; Zhang, William W.; Chan, Kai-Wing; Biskach, Michael; McClelland, Ryan; Iazikov, Dmitri; Wang, Xinpeng; Koecher, Larry

2013-08-01

253

Human Interleukin4 and Variant R88Q: Phasing X-ray Diffraction Data by Molecular Replacement Using X-ray and Nuclear Magnetic Resonance Models  

Microsoft Academic Search

The structure of recombinant human interleukin-4 (hIL-4) as been determined by both NMR and X-ray diffraction methods in several laboratories, including ours. The X-ray and NMR structures were successfully applied for solving the X-ray crystal structure by molecular replacement. Due to the small size of the hIL-4 molecule (129 residues) and its lack of structural diversity (4-helix bundle), this task

Thomas Müller; Frank Oehlenschläger; Manfred Buehner

1995-01-01

254

Dynamical x-ray diffraction from an icosahedral Al-Pd-Mn quasicrystal  

SciTech Connect

Primary extinction effects in diffraction from single grains of Al-Pd- Mn, and presumably many other FCI alloys, may be significant and should be corrected for prior to use of diffraction data in structural determinations. Probes based on dynamical diffraction effects, such as x-ray standing wave fluorescence, multiple beam interference, and x-ray transmission topographs, may now be used to study the bulk and surface structure of some quasicrystals. The observation of dynamical diffraction from icosahedral Al-Pd-Mn is a striking confirmation of the fact that quasicrystals can present a degree of structural perfection comparable to that found in the best periodic intermetallic crystals.

Kycia, S.

1996-04-23

255

The rotating-crystal method in femtosecond X-ray diffraction.  

PubMed

We report the first implementation of the rotating-crystal method in femtosecond X-ray diffraction. Applying a pump-probe scheme with 100 fs hard X-ray probe pulses from a laser-driven plasma source, the novel technique is demonstrated by mapping structural dynamics of a photoexcited bismuth crystal via changes of the diffracted intensity on a multitude of Bragg reflections. The method is compared to femtosecond powder diffraction and to Bragg diffraction from a crystal with stationary orientation. PMID:21934913

Freyer, B; Stingl, J; Zamponi, F; Woerner, M; Elsaesser, T

2011-08-01

256

Defect studies by X-ray diffraction, electrical and optical properties of layer type tungsten mixed molybdenum sulphoselenide  

Microsoft Academic Search

Layer type tungsten mixed molybdenum sulphoselenide, Mo0.5W0.5SxSe2?x (0?x?2) starting from ternary Mo0.5W0.5Se2 compound and by substituting selenium with sulphur ended with Mo0.5W0.5S2 which is also a ternary compound, have been prepared and characterized. X-ray diffraction studies showed that all the compounds possess 2H–MoS2 structure with a small change in a- and c-parameters. X-ray line profile analysis has been used to

S. K. Srivastava; D. Palit

2005-01-01

257

Mössbauer and X-Ray Diffraction Investigations of a Series of B-Doped Ferrihydrites  

NASA Astrophysics Data System (ADS)

X-ray diffraction and 57Fe Mössbauer spectroscopy are used to characterize the influence of borate on two-line ferrihydrite's structure and develop likely models for its attachment. Particle sizes were in the 2 4 nm range, and as borate sorption increased, the ferrihydrite particle size decreased. The d-spacings of two-line ferrihydrite increased with increased borate adsorption. Isomer shift and quadrupole splitting exhibit slight increasing trends as well. Also, the phase transformation temperature of ferrihydrite to hematite is significantly raised due to borate coating of the surface. We suggest borate is sorbed onto the surface by attachment to the oxygen corners of the iron octahedra that are on the surface of the nanoparticles, placing boron in a tetrahedral molecular geometry.

Stevens, John G.; Khasanov, Airat M.; Mabe, David R.

2005-02-01

258

In Situ Mineralogical Analysis of Planetary Materials Using X-Ray Diffraction and X-Ray Fluorescence  

NASA Technical Reports Server (NTRS)

Remote observations of Mars have led scientists to believe that its early climate was similar to that of the early Earth, having had abundant liquid water and a dense atmosphere. One of the most fascinating questions of recent times is whether simple bacterial life developed on Mars (as it did on the Earth) during this early element period. Analyses of SNC meteorites have broadened considerably our knowledge of the chemistry of certain types of Martian rocks, underscoring the tantalizing possibility of early hydrothermal systems and even of ancient bacterial life. Detailed analyses of SNC meteorites in Terrestrial laboratories utilize the most sophisticated organic, isotopic and microscopic techniques in existence. Indeed; it is unlikely that the key biogenic indicators used in McKay et al (ibid) could be identified by a remote instrument on the surface of Mars. As a result, it is probable that any robotic search for evidence of an ancient Martian biosphere will have as its focus the identification of key minerals in likely host rocks rather than the direct detection of organic or isotopic biomarkers. Even on a sample return mission, mineralogical screening will be utilized to choose the most likely candidate rocks. X-ray diffraction (XRD) is the only technique that can provide a direct determination of the crystal structures of the phases present within a sample. When many different crystalline phases are present, quantitative analysis is better constrained if used in conjunction with a determination of elemental composition, obtainable by X-ray fluorescence (XRF) using the same X-ray source as for XRD. For planetary surface analysis, a remote instrument combining XRD and XRF could be used for mineralogical characterization of both soils and rocks. We are designing a remote XRD/XRF instrument with this objective in mind. The instrument concept pays specific attention to constraints in sample preparation, weight, volume, power, etc. Based on the geometry of a pinhole camera (transmission geometry, flat two-dimensional detector perpendicular to the direct beam), the instrument (which we call CHEMIN, for Chemistry and Mineralogy) uses an X-ray sensitive CCD detector which will allow concurrent positional and energy-dispersive analysis of collected photons. Thus XRF (energy) and XRD (geometry) analysis of transmitted X-rays will be performed at the same time. Tests performed with single minerals and simple mixtures give promising results. Refinements of the prototype promise interpretable results on complex samples.

Sarrazin, P.; Blake, D.; Vaniman, D.; Chang, Sherwood (Technical Monitor)

1996-01-01

259

Closing the gap to the diffraction limit: Near wavelength limited tabletop soft x-ray coherent diffractive imaging  

NASA Astrophysics Data System (ADS)

Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to around 200 nm. Using novel imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens using techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy and structured illumination microscopy [1--3]. This dissertation presents a versatile soft x-ray diffraction microscope with 50 nm resolution using tabletop coherent soft x-ray sources. This work represents the first high resolution demonstrations of coherent diffractive or lensless imaging using tabletop extreme ultraviolet and soft x-ray sources [4, 5]. This dissertation also presents the first use of field curvature correction in x-ray coherent imaging which allows high numerical aperture imaging and near-diffraction-limited resolution of 1.5lambda. The relevant theory behind high harmonic generation, the primary tabletop source used in this work, will be discussed as well as the theory behind coherent diffractive imaging. Additionally, the first demonstration of tabletop soft x-ray Fourier Transform holography is shown with important applications to shorter wavelength imaging with high harmonic generation with limited flux. A tabletop soft x-ray diffraction microscope should find broad applications in biology, nanoscience, and materials science due to its simple optical design, high resolution, large depth of field, 3D imaging capability, scalability to shorter wavelengths, and ultrafast temporal resolution.

Sandberg, Richard Lunt

260

Using X-Ray Diffraction Microscopy for Imaging Magnetic Domain Structures of Magnetic Thin Films  

NASA Astrophysics Data System (ADS)

We report the application of iterative phase retrieval from magnetic x-ray diffraction for imaging magnetic domain structures of magnetic thin films. Using coherent x-ray scattering at the x-ray photon energy corresponding to the L3,2 absorption edges of the 3d material Co, we demonstrate that linearly polarized soft x rays can be used to obtain the element specific information about both the amplitude and the phase of magnetic domain structures existing in thin films. We successfully recovered an image of the magnetic structure of an amorphous terbium-cobalt thin film with a spatial resolution of about 75 nm and could differentiate between the magnetization directions, finding qualitative agreement with soft x-ray microscopy images recorded with Fresnel zone plate optics having better than 25 nm spatial resolution.

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

2012-02-01

261

Measurement of coronal X-ray emission lines from Capella  

NASA Technical Reports Server (NTRS)

The Einstein Observatory's Focal Plane Crystal Spectrometer has detected X-ray emission lines due to O VIII, Fe XVII, and Fe XX, from the binary star system Capella. Line luminosities are well fitted by an emitting plasma at a single temperature of 6.29 + or - 0.01 - 0.03 million K, and a volume emission measure of about 8.6 x 10 to the 52nd/cu cm, corresponding to the low temperature component previously observed. A high temperature component is undetectable, since the observed lines are not produced in plasma at temperatures above about 20 million K. Nearly isothermal plasma would be expected if many of the magnetically confined coronal loops have similar sizes and pressures, and a second population of longer loops would be required to account for the hotter component. An alternative interpretation of the observed X-ray line emission and upper limit is that the plasma contains a continuous distribution of emission measure versus temperature that rises sharply to 3 million K and then falls by nearly a decade to 16 million. An extrapolation of the loop sizes suggested by this alternative to hotter, longer loops may also account for the higher temperature emission.

Vedder, P. W.; Canizares, C. R.

1983-01-01

262

Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis  

Microsoft Academic Search

This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant

M. Manso; S. Valadas; S. Pessanha; A. Guilherme; I. Queralt; A. E. Candeias; M. L. Carvalho

2010-01-01

263

Comparison of a CCD and an APS for soft X-ray diffraction  

NASA Astrophysics Data System (ADS)

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 ?m on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

2011-12-01

264

X-ray diffraction microscopy of lithiated silicon microstructures  

NASA Astrophysics Data System (ADS)

Optically patterned silicon microstructures show great promise as lithium ion battery electrodes as they can balance the high intrinsic charge capacity of silicon with its large volume changes during repeated cycling. Previous scanning electron microscopy showed that lithiation initially occurs at (110)-oriented facets, but was not directly sensitive to the amount of crystalline silicon within the core of each microstructure. Here, we image the extent of the lithiation and the degree of residual crystallinity in individual silicon micro-posts directly using full-field x-ray reflection interfacial microscopy (XRIM). Images of the silicon posts are interpreted using a straightforward model relevant for XRIM images obtained from large scale topological features. This approach should be widely applicable to a broad range of battery materials and for probing the liquid/solid interfaces of complex heterostructures during lithiation reactions.

Fister, Tim T.; Goldman, Jason L.; Long, Brandon R.; Nuzzo, Ralph G.; Gewirth, Andrew A.; Fenter, Paul A.

2013-04-01

265

X-ray resistant packaging for X-ray line detectors  

Microsoft Academic Search

The challenges of electronics packaging and system integration require new non-destructive evaluation (NDE) techniques during production processes for fast and reliable detecting of small defects like shorts, missing parts or contacts and voids. X-ray techniques like radiography, limited angle tomography and computed tomography are very important methods. Today the common detector principle for X-rays is the so called scintillation detector

Martin Oppermann; T. Lohse; R. Metasch; T. Zerna; K.-J. Wolter

2010-01-01

266

X-ray Obscured Broad-Line AGN  

NASA Astrophysics Data System (ADS)

While the vast majority of Type I AGN show little or no X-ray obscuration, approximately 10% are heavily obscured with X-ray column densities of N_H > 10^22 cm^-2. In addition to providing a unique and necessary test of the unified model, the study of these AGN has significant consequences for our understanding of the cosmic X-ray and infrared backgrounds, and therefore for the cosmic accretion and star-formation histories of the universe. A number of explanations have been proposed to explain the seemingly contradictory behavior of these X-ray obscured, broad-line AGN, including (1) dust sublimation near the central engine, (2) dust coagulation, (3) obscuration by clouds in the broad-line region, (4) column density variability, and (5) scattering of the broad emission lines off a reflecting medium. We therefore propose for MIPS and IRAC observations of the 11 sources in our sample of 13 for which this data is not yet available. In addition, we propose low-resolution IRS spectroscopy for the brightest 5 sources as well as 1 faint source with an exceptionally high column density, and IRS Peak-Up imaging at 16 microns for the remaining 7 sources. The MIPS, IRAC, and IRS Peak-Up photometry will allow us to test for the presence of hot dust, which may be in the process of being destroyed through dust sublimation. IRS spectroscopy will allow us to test for the presence of the 9.7 micron silicate feature, which should not be present if the dust distribution is dominated by large grains as predicted in some models, or which may be seen in emission if the broad-line region clouds are themselves responsible for the odd behavior of these AGN. In combination with polarimetric data and high-quality optical spectra from the Bok 90' telescope, these observations will provide us with the ideal dataset to test concretely for the first time the many potential explanations for the strange behavior of these unexpected AGN.

Rieke, George; Donley, Jennifer; Shi, Yong; Smith, Paul

2008-03-01

267

Development of a calibration method for quantitative x-ray powder diffraction of size-segregated aerosols.  

National Technical Information Service (NTIS)

X-ray power diffraction (XPD) is an important tool for the chemical characterization of atmospheric aerosol samples particularly when combined with elemental analysis obtained from x-ray fluorescence (XRF) measurements of the same specimen. The present st...

R. D. Giauque J. M. Jaklevic L. E. Sindelar

1990-01-01

268

Theory of x-ray diffraction from laser-aligned molecules.  

SciTech Connect

We present the theory of x-ray diffraction from an ensemble of symmetric-top molecules aligned by an intense optical laser pulse at finite rotational temperature. Using QED, the x-ray/molecule interaction is treated as an electronically elastic one-photon scattering process. In the practically important case that the x-ray pulse is quasi-monochromatic and its coherence time is much shorter than the time scale of molecular rotational dynamics in the laser field, there is a simple connection between the rotational wave-packet dynamics and the diffraction pattern obtained. Our theory thus opens up a new perspective for quantum molecular imaging using x-ray radiation.

Ho, P. J.; Santra, R. (Chemical Sciences and Engineering Division)

2010-06-01

269

Stress Determination in Nickel Monosilicide Films Using X-ray Diffraction  

SciTech Connect

Lattice spacing measurements of the (211)/(202), (020)/(013), and (111)/(102) reflections were used to calculate the residual stresses in a Ni monosilicide film after cooling from its formation temperature. The ability to measure stresses in crystalline materials using x-ray diffraction requires the use of appropriate x-ray elastic constants, which link the measured strain to the stress tensor of the grains that satisfy the diffraction condition. X-ray elastic constants were calculated in the Neerfeld-Hill (NH) limit for a polycrystalline aggregate composed of orthorhombic crystals. The anisotropy in grains that possess orthorhombic elasticity introduces significant variation in the stresses determined among the three sets of reflections. However, the in-plane stress calculated due to thermal expansion mismatch between NiSi and the underlying Si substrate shows a close correspondence to the average of x-ray measurements.

Murray, C.; Zhang, Z; Lavoie, C

2009-01-01

270

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

PubMed

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/a(0) = 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. PMID:22755618

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

2012-06-01

271

Spin-specific photoelectron diffraction using magnetic x ray circular dichroism  

NASA Astrophysics Data System (ADS)

The first observation of spin-dependent photoelectron diffraction using circularly-polarized x-rays is reported for monolayer ferromagnetic fcc Fe films on Cu(001). Circularly polarized x-rays are used to produce spin polarized photoelectrons from the Fe 2p spin-orbit split doublet, and intensity asymmetries in the 2p3/2 level of approximately 3% are observed. The asymmetry is dependent on the relative orientation of the x-ray polarization vector and the Fe magnetic moment. This spin-dependent technique promises the direct, element-specific determination not only of local atomic structure, but magnetic structure as well.

Tobin, J. G.; Waddill, G. D.; Guo, X.; Tong, S. Y.

1994-04-01

272

Apparatus for use in examining the lattice of a semiconductor wafer by X-ray diffraction  

NASA Technical Reports Server (NTRS)

An improved apparatus for examining the crystal lattice of a semiconductor wafer utilizing X-ray diffraction techniques was presented. The apparatus is employed in a method which includes the step of recording the image of a wafer supported in a bent configuration conforming to a compound curve, produced through the use of a vacuum chuck provided for an X-ray camera. The entire surface thereof is illuminated simultaneously by a beam of incident X-rays which are projected from a distant point-source and satisfy conditions of the Bragg Law for all points on the surface of the water.

Parker, D. L.; Porter, W. A. (inventor)

1978-01-01

273

Two-dimensional energy dispersive x-ray diffraction at high pressures and temperatures  

Microsoft Academic Search

Diffraction studies at extreme pressure-temperature conditions encounter intrinsic difficulties due to the small access angle of the diamond anvil cell and the high background of the diffraction peaks. Energy-dispersive x-ray diffraction is ideal for overcoming these difficulties and allows the collection and display of diffracted signals on the order of seconds, but is limited to one-dimensional information. Materials at high

Yanzhang Ma; Ho-Kwang Mao; Russell J. Hemley; Stephen A. Gramsch; Guoyin Shen; Maddury Somayazulu

2001-01-01

274

High-energy X-ray diffraction beamline: BL04B2 at SPring-8  

NASA Astrophysics Data System (ADS)

High-energy X-ray diffraction beamline, one of the bending-magnet beamline at SPring-8, was constructed, for the diffraction and scattering experiments at high energy ( E>37.8 keV). A single-bounce, bent-crystal monochromator that deflects the beam horizontally is adopted for the use of high-energy, modest-resolution, and focused X-rays. Four kinds of experimental device were equipped in tandem in the experimental hutch. This beamline has the advantage for structural studies in amorphous and liquid, and high-pressure diffraction experiments which need high penetration ability.

Isshiki, M.; Ohishi, Y.; Goto, S.; Takeshita, K.; Ishikawa, T.

2001-07-01

275

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

Microsoft Academic Search

Purpose  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  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

276

X-ray diffraction in the pulsed laser heated diamond anvil cell  

Microsoft Academic Search

We have developed in situ x-ray synchrotron diffraction measurements of samples heated by a pulsed laser in the diamond anvil cell at pressure up to 60 GPa. We used an electronically modulated 2–10 kHz repetition rate, 1064–1075 nm fiber laser with 1–100 ?s pulse width synchronized with a gated x-ray detector (Pilatus) and time-resolved radiometric temperature measurements. This enables the

Alexander F. Goncharov; Vitali B. Prakapenka; Viktor V. Struzhkin; Innokenty Kantor; Mark L. Rivers; D. Allen Dalton

2010-01-01

277

X-ray diffraction in the pulsed laser heated diamond anvil cell  

Microsoft Academic Search

We have developed in situ x-ray synchrotron diffraction measurements of samples heated by a pulsed laser in the diamond anvil cell at pressure up to 60 GPa. We used an electronically modulated 2-10 kHz repetition rate, 1064-1075 nm fiber laser with 1-100 mus pulse width synchronized with a gated x-ray detector (Pilatus) and time-resolved radiometric temperature measurements. This enables the

Alexander F. Goncharov; Vitali B. Prakapenka; Viktor V. Struzhkin; Innokenty Kantor; Mark L. Rivers; D. Allen Dalton

2010-01-01

278

In situ time-resolved X-ray diffraction of iron sulfides during hydrothermal pyrite growth  

Microsoft Academic Search

Pyrite formation under hydrothermal conditions has been studied using in situ time-resolved X-ray diffraction (XRD). This study employed two different synchrotron X-ray sources (National Synchrotron Light Source (NSLS), Advanced Photon Source (APS); Brookhaven and Argonne National Laboratories, USA, respectively) and two types of reaction cells (capillary and hydrothermal autoclave type) to examine reactions in the Fe–S system under both anoxic

C. L. Cahill; L. G. Benning; H. L. Barnes; J. B. Parise

2000-01-01

279

Photoelectron dynamics in x-ray free-electron-laser diffractive imaging of biological samples.  

PubMed

X-ray free electron lasers hold the promise of enabling atomic-resolution diffractive imaging of single biological molecules. We develop a hybrid continuum-particle model to describe the x-ray induced damage and find that the photoelectron dynamics and electrostatic confinement strongly affect the time scale of the damage processes. These phenomena are not fully captured in hydrodynamic modeling approaches. PMID:23003992

Hau-Riege, Stefan P

2012-06-01

280

Continuous Time-Resolved X-ray Diffraction of the Biocatalyzed Reduction of Mn Oxide  

Microsoft Academic Search

Here we report the first continuous time-resolved X-ray diffraction analysis of a biologically mediated mineral reaction. We incubated total membrane (TM) fractions of the facultative anaerobe Shewanella oneidensis in an anoxic environmental reaction cell with formate (as electron donor via formate dehydrogenase) and powdered birnessite, a layered Mn{sup 3+,4+} oxide common to many soils. Using both synchrotron and conventional X-ray

T. B. Fischer; P. J. Heaney; J.-H. Jang; D. E. Ross; S. L. Brantley; J. E. Post; M. Tien

2008-01-01

281

Fast neutron irradiation induced clusters in silicon-single-crystals, using X-ray diffraction  

Microsoft Academic Search

Clusters induced as effects of exposing silicon single-crystals in fast neutron reactor ambiant are studied as a damage phenomenon used in inducing well controlled and reproducible effects to be used in semiconductor materials and device technology. Single-silicon-crystal X-ray diffraction has become a well-established branch of X-ray crystallography. Widely used as a method of investigation of bulk structural properties, it can

E. Halmagean; O. Birau; A. Ciuhandu; M. Udrea-Spenea

1995-01-01

282

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

283

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

284

Proposal of a novel Diffraction Enhanced Imaging setup based on polycapillary X-ray optics  

Microsoft Academic Search

Diffraction Enhanced Imaging (DEI) is a recent technique developed to improve the diagnostic capabilities of radiography by exploiting coherently scattered X-rays to generate images that provide higher contrast than conventional transmission imaging. Earlier experiments, carried out in the synchrotron environment using a mechanical parallel-hole collimator coupled to a 2D X-ray imager, confirmed the potential of this technique in mammography. The

Andrea Castoldi; C. Ozkan; C. Guazzoni; A. Bjeoumikhov; J. Griffiths; G. Royle; R. Hartmann

2008-01-01

285

Femtosecond diffractive imaging with a soft-X-ray free-electron laser  

Microsoft Academic Search

Theory predicts that, with an ultrashort and extremely bright coherent X-ray pulse, a single diffraction pattern may be recorded from a large macromolecule, a virus or a cell before the sample explodes and turns into a plasma. Here we report the first experimental demonstration of this principle using the FLASH soft-X-ray free-electron laser. An intense 25fs, 4×1013Wcm-2 pulse, containing 1012

Henry N. Chapman; Anton Barty; Michael J. Bogan; Sébastien Boutet; Matthias Frank; Stefan P. Hau-Riege; Stefano Marchesini; Bruce W. Woods; Sasa Bajt; W. Henry Benner; Richard A. London; Elke Plönjes; Marion Kuhlmann; Rolf Treusch; Stefan Düsterer; Thomas Tschentscher; Jochen R. Schneider; Eberhard Spiller; Thomas Möller; Christoph Bostedt; Matthias Hoener; David A. Shapiro; Keith O. Hodgson; David van der Spoel; Florian Burmeister; Magnus Bergh; Carl Caleman; Gösta Huldt; M. Marvin Seibert; Filipe R. N. C. Maia; Richard W. Lee; Abraham Szöke; Nicusor Timneanu; Janos Hajdu

2006-01-01

286

Femtosecond Diffractive Imaging with a Soft-X-Ray Free-Electron Laser  

Microsoft Academic Search

Theory predicts that with an ultrashort and extremely bright coherent X-ray pulse, a single diffraction pattern may be recorded from a large macromolecule, a virus, or a cell before the sample explodes and turns into a plasma. Here we report the first experimental demonstration of this principle using the FLASH soft X-ray free-electron laser. An intense 25 fs, 4 x

Bogan; Michael James

2010-01-01

287

Quantitative determination of mineral composition by powder X-ray diffraction  

DOEpatents

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, Gayle A. (Livermore, CA)

1986-01-01

288

Development of a Novel Instrument for X-Ray Photoelectron Diffraction and Holography  

Microsoft Academic Search

For X-ray photoelectron diffraction (XPED) and holography measurements we developed a novel laboratory instrument with the multienergy high power X-ray source and the high energy and high angular resolution photoelectron spectrometer system. The photon intensities of Al Kalpha, Cr Lalpha and Cu Kalpha were estimated at 4.6 × 1011 cps, 7.5 × 1010 cps and 7.2 × 1010 cps, respectively.

Hideshi Ishii; Susumu Shiraki; Keiji Tamura; Wei-Guo Chu; Masanori Owari; Ryuichi Shimizu; Yoshimasa Nihei

2003-01-01

289

Industrial aspects of synchrotron X-ray powder diffraction  

NASA Astrophysics Data System (ADS)

This paper describes some of the applications of powder diffraction using synchrotron radiation with possible applications to industry. The advantages of differing synchrotron diffraction geometries, Debye-Scherrer, Analyser crystal, Hart Parrish, and Energy Dispersive, are discussed. The paper is not a comprehensive review but nevertheless considers the wider role of these powder diffraction geometries in elucidating crystal structures, highlighted examples being taken from polymers, catalyst and new drug materials, in addition to specific studies on polymer electrolyte complexes, textured materials (e.g. asbestos), pyrochlores, zeolites and cements. In the latter two cases rapid time-resolved powder diffraction is seen to be emerging as an important development in synchrotron-based techniques.

Cernik, R. J.; Barnes, P.

1995-03-01

290

Quantitative Analysis of Asbestos Minerals by the Reference Intensity X-Ray Diffraction Procedure  

Microsoft Academic Search

X-ray diffraction analysis of asbestos-bearing materials has been completed using reference intensity ratios. The procedure includes a sample preparation method for suspension of a finely pulverized material and for deorienting the particles on a glass fiber filter. Diffraction intensifies are corrected for matrix and transparency. Reference intensity ratios have been determined in this study for chrysotile, amosite, anthophyllite, crocidolite, and

BRIANT L. DAVIS

1990-01-01

291

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

292

Dynamical theory for diffractive x-ray imaging of one-dimensional periodic objects  

SciTech Connect

A dynamical theory for diffractive x-ray imaging of one-dimensional periodic objects is derived by solving the Helmholtz equation in the parabolic approximation using the coupled-wave theory. A method to account for volume-diffraction effects, based on propagating backwards the eigenmodes of the microfluidic array, is demonstrated for a colloidal suspension in confinement.

Nygaard, K.; Satapathy, D. K.; Bunk, O.; David, C. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Pfeiffer, F. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Veen, J. F. van der [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); ETH Zuerich, CH-8093 Zuerich (Switzerland)

2008-05-26

293

An X-Ray Phase Plate Using Bragg-Case Diffraction  

Microsoft Academic Search

An X-ray phase plate using two-beam Bragg case diffraction is proposed. The variation of the polarization state of the transmitted (forward-diffracted) beam through the incident angle was observed. Left-handed and right-handed circular polarizations whose degree of circular polarizations were ± 0.90 were experimentally produced.

Keiichi Hirano; Koichi Izumi; Tetsuya Ishikawa; Shoichi Annaka; Seishi Kikuta

1991-01-01

294

X-ray diffraction study of aluminum oxide. II. full-profile x-ray analysis of low-temperature forms  

SciTech Connect

A full-profile analysis has been made of the x-ray diffraction patterns of lowtemperature forms of aluminum oxide. Structural models are proposed for these forms, describing the experimental data with a high confidence factor.

Ushakov, V.A.; Moroz, E.M.

1986-02-01

295

Optomechanical design of a high-precision detector robot arm system for x-ray nano-diffraction with x-ray nanoprobe  

NASA Astrophysics Data System (ADS)

Collaboration between Argonne National Laboratory and Brookhaven National Laboratory has created a design for the high-precision detector robot arm system that will be used in the x-ray nano-diffraction experimental station at the Hard X-ray Nanoprobe (HXN) beamline for the NSLS-II project. The robot arm system is designed for positioning and manipulating an x-ray detector in three-dimensional space for nano-diffraction data acquisition with the HXN x-ray microscope. It consists of the following major component groups: a granite base with air-bearing support, a 2-D horizontal base stage, a vertical axis goniometer, a 2-D vertical plane robot arm, a 3-D fast scanning stages group, and a 2-D x-ray pixel detector. The design specifications and unique optomechanical structure of this novel high-precision detector robot arm system will be presented in this paper.

Shu, D.; Kalbfleisch, S.; Kearney, S.; Anton, J.; Chu, Y. S.

2014-03-01

296

In situ X-ray diffraction investigation of nanocrystallization of amorphous Co-Fe-Zr-B alloys  

NASA Astrophysics Data System (ADS)

Cobalt-rich soft-magnetic alloys were recently developed as amorphous materials with promising engineering properties, e.g. high mechanical strength, excellent magnetic properties and high corrosion resistance. The crystallization of the as-prepared amorphous alloys plays a crucial role in most technological applications of these advanced soft-magnetic nanomaterials. Amorphous ribbons with nominal composition Co 56Fe 16Zr 8B 20 (at%) were here obtained by single-roller melt spinning. The nucleation and growth of nanoscale phases during constant-rate heating of as-quenched and of high-energy ball-milled Co-rich amorphous soft-magnetic alloys were investigated by differential scanning calorimetry and by in situ high-temperature powder X-ray diffraction using synchrotron radiation. The temperature/time evolution of the crystallite size and of average microstrain was obtained from the X-ray diffraction line-profile analysis (LPA) of the powder diffraction patterns.

Bednar?ík, J.; Nicula, R.; Stir, M.; Burkel, E.

2007-09-01

297

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

Microsoft Academic Search

The reactivity of [Cr\\/Se\\/Te] multilayers under annealing was investigated using X-ray reflectometry, in situ X-ray diffraction, X-ray absorption fine structure (XAFS) measurements and transmission electron microscopy. For all samples, interdiffusion was complete at temperatures between 100 and 300°C, depending on the repeating tri-layer thickness. A crystalline phase nucleated approximately 20°C above the temperature where interdiffusion was finished. The first crystalline

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

2006-01-01

298

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

299

X-ray powder diffraction patterns for certain beta-lactam, tetracycline and macrolide antibiotic drugs.  

PubMed

X-ray powder diffraction (XRD) data for eight beta-lactam viz., ampicillin sodium, ampicillin trihydrate, penicillin G procaine, benzathine penicillin, benzyl penicillin sodium, cefalexin, cefotaxime sodium and ceftriaxone sodium; three tetracyclines viz., doxycycline hydrochloride, oxytetracycline dihydrate and tetracycline hydrochloride; and two macrolide viz., azithromycin and erythromycin estolate antibiotic drugs were obtained using a powder diffractometer. The drugs were scanned from Bragg angles (2theta) of 10 degrees to 70 degrees. The obtained data were tabulated in terms of the lattice spacing (A) and relative line intensities (I/I(I)). This new information may be useful for identifying these drugs from confiscated materials, which has been frequently encountered in forensic laboratories. PMID:16038505

Thangadurai, S; Abraham, J T; Srivastava, A K; Moorthy, M Nataraja; Shukla, S K; Anjaneyulu, Y

2005-07-01

300

Structural characterization of SrLaMnRuO 6 by synchrotron X-ray powder diffraction and X-ray absorption spectroscopy  

Microsoft Academic Search

Single-phase polycrystalline powder samples of SrLaMnRuO6 were prepared by solid-state synthesis method and its crystal structure was studied using synchrotron X-ray diffraction and X-ray absorption spectroscopies. The Rietveld analysis of the room temperature synchrotron X-ray diffraction data shows that it has a double perovskite structure with disordered arrangements of Sr\\/La and Mn\\/Ru and adopts orthorhombic space group Pbnm [a=5.5004(3)Å, b=5.5445(3)Å,

Javaid Bashir; Rubina Shaheen; Muhammad Nasir Khan

2008-01-01

301

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

302

X-Ray Diffraction Patterns from Plant Fibres  

Microsoft Academic Search

DIFFRACTION patterns obtained from plant fibres, ramie, hemp, etc., by using a method similar to that of Hull for crystal powders (Phys. Review, 10, 2, 661, 1917), do not agree in certain particulars with the data reported by Herzog and Jancke in Zeits. für Physik, 3-3, 196 to 198, 1920. They give a list of eight sets of planes, based

O. L. Sponsler

1925-01-01

303

Quantification of minor phases in growth kinetics experiments with powder x-ray diffraction.  

SciTech Connect

Minor amounts of clay minerals precipitated from aqueous solution can be rapidly identified and quantified in a mineral mixture with powder X-ray diffraction using a rotating-anode source and a position-sensitive detector. For the case of gibbsite precipitated on a kaolinite powder substrate we demonstrate a simple method having a minimum detection limit of 0.1 wt%, using pure gibbsite as the intensity reference in mechanical mixtures of gibbsite and kaolinite. The amount of gibbsite precipitated onto kaolinite at 80 C, pH 3 is higher when determined from solution chemistry than from the X-ray method, and the difference in amounts increases with increasing Al concentration in solution. This discrepancy can be explained by assuming that a fraction of the precipitated material is effectively invisible to the X-ray diffraction technique, either due to a small diffracting domain size along the gibbsite [001] direction or formation of an Al-phase that is amorphous to X-rays. This method should be generally useful for a range of mineral mixtures where at least one intense reflection for the phase of interest is not obscured. The ability to identify, characterize, and quantify trace phases by X-ray diffraction, especially when combined with surface analysis by electron or atomic force imaging, is an important complement to the conventional approach of monitoring solution composition in growth kinetics experiments.

Hanchar, J. M.; Nagy, K. L.; Fenter, P.; Finch, R. J.; Beno, D. J.; Sturchio, N. C.; Environmental Research; Sandia National Lab.

2000-01-01

304

Coherent x-ray zoom condenser lens for diffractive and scanning microscopy.  

PubMed

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers. PMID:23609637

Kimura, Takashi; Matsuyama, Satoshi; Yamauchi, Kazuto; Nishino, Yoshinori

2013-04-22

305

Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy  

PubMed Central

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution images using fewer photons. This can be an important advantage for studying radiation-sensitive biological and soft matter specimens.

Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

2010-01-01

306

On the origin of sharp peaks in the X-ray diffraction patterns of xanthan powders.  

PubMed

A series of xanthans containing different levels of the charged group pyruvate has been examined. The X-ray diffraction patterns of the powders of these materials had different levels of a sharp pattern superimposed on an amorphous background. As the moisture content increased so the intensity of the sharp pattern increased up to a level between 20% and 40% moisture content where the sharp pattern disappeared. X-ray diffraction pattern identification software and an inorganic X-ray diffraction database showed the origin of the sharp peaks to be due to sodium sulphate polymorphs. The behaviour of the xanthans was thought to be due to the differences in charge on the molecule; however, the increase in the crystalline component observed with increased amounts of water was unexpected. The possibility of the drying of samples was considered but the interplay between ions, the charged polymer and the water present was considered necessary to more closely describe the results. PMID:23561220

Lad, M; Todd, T; Morris, G A; MacNaughtan, W; Sworn, G; Foster, T J

2013-08-15

307

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

308

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

309

Accurate determination of X-ray energies using powder diffraction  

Microsoft Academic Search

We report synchrotron energy determinations using the powder diffraction patterns of Si (640b) and LaB6 (660) standard reference powders at a number of energies between 5 and 20keV. The fitted peak positions of all peaks recorded on image plates were used in each energy determination. Several sources of systematic error were investigated and their connection led to physically reasonable and

N. A. Rae; C. T. Chantler; C. Q. Tran; Z. Barnea

2006-01-01

310

Accurate determination of X-ray energies using powder diffraction  

Microsoft Academic Search

We report synchrotron energy determinations using the powder diffraction patterns of Si (640b) and LaB6 (660) standard reference powders at a number of energies between 5 and 20 keV. The fitted peak positions of all peaks recorded on image plates were used in each energy determination. Several sources of systematic error were investigated and their connection led to physically reasonable

N. A. Rae; C. T. Chantler; C. Q. Tran; Z. Barnea

2006-01-01

311

X-ray diffraction study of detonation nanodiamonds  

Microsoft Academic Search

The paper addresses a structural analysis of detonation nanodiamonds. An analysis procedure is described which has been elaborated\\u000a on the basis of a comparison between experimental and theoretical diffraction patterns calculated using computer models of\\u000a nanodiamonds. Detonation nanodiamonds are characterized in terms of their shape, size, crystal lattice parameters, and distribution\\u000a of atoms in them. The lattice parameters have been

G. S. Yur’ev; V. Yu. Dolmatov

2010-01-01

312

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

313

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.

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

2006-01-01

314

Method of X-ray anomalous diffraction for lipid structures  

SciTech Connect

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 new phasing method. The method of multi-wavelength anomalous dispersion (MAD) 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 MAD 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.

Wang,W.; Pan, D.; Song, Y.; Liu, W.; Yang, L.; Huang, H.

2006-01-01

315

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

NASA Astrophysics Data System (ADS)

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.

Chen, Bo; Zhang, Fucai; Berenguer, Felisa; Bean, Richard J.; Kewish, Cameron M.; Vila-Comamala, Joan; Chu, Yong S.; Rodenburg, John M.; Robinson, Ian K.

2011-10-01

316

X-ray spectral power measurements utilizing the diffraction pattern of a slit  

NASA Astrophysics Data System (ADS)

An instrument is described which can obtain x-ray spectral power measurements utilizing the diffraction pattern produced when x rays pass through a slit. Traditionally, these types of measurements yielding low to moderate spectral resolution have been made with filtered x-ray diodes or with a transmission grating. The instrument described below has several advantages over filtered x-ray diodes in determining the spectral power profile such as an insensitivity to surface contamination. In addition, this instrument does not require the use of filters which can be destroyed during a shot making absolute measurements difficult and very time consuming. The advantages over a transmission grating system include cost, mechanical robustness, and fewer components which require spectral calibration.

Baker, K. L.; Porter, J. L.; Ruggles, L. E.; Chrien, R. E.; Idzorek, G. C.

1999-03-01

317

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

318

Bone structure studies with HNDT and x-ray diffraction methods  

NASA Astrophysics Data System (ADS)

Changes in molecular texture and structure of isolated radioulnar bones of subadult European moose collected in various environmental pollution areas of Finland were investigated by using HNDT and x-ray diffraction methods. By using small caudo-cranial bending forces, the bones were tested by using HNDT. For bone molecular texture and structure studies by using x-ray diffraction methods, samples were taken from the ulnar metaphyse (Olecranon). Results show that the bones obtained from the Harjavalta area and one from North Karelia showed changes in molecular texture and structure compared with samples from apparently normal animals.

Silvennoinen, Raimo V. J.; Nygren, Kaarlo; Rouvinen, Juha; Petrova, Valentina V.

1993-09-01

319

Amorphous X-Ray Diffraction at High Pressure: Polyamorphic Silicon and Amyloid Fibrils  

NASA Astrophysics Data System (ADS)

Amorphous x-ray diffraction is used to obtain structural information on amorphous solids and liquids at high pressure as well as other materials without long range crystalline order including biologically important macromolecules and nanomaterials. The intense x-ray beams provided by synchrotron sources are ideal for diffraction studies of noncrystalline materials. We illustrate this with studies of the transition between low- and high-density forms of amorphous Si in the diamond anvil cell at high pressure, and the compressibility of amyloid fibrils.

Mcmillan, Paul F.; Daisenberger, Dominik; Cabrera, Raul Quesada; Meersman, Filip

320

X-ray diffraction study of fluorene, 9-fluorenone, and 9-dicyanomethylenefluorene derivatives  

SciTech Connect

The results of a single-crystal X-ray diffraction analysis of fluorene, 9-fluorenone, and 9-dicyanomethylenefluorene derivatives as individual compounds, as well as their crystal solvates, molecular complexes, and charge-transfer complexes, are generalized. The most interesting features of the molecular geometry and conformation and the molecular packing in the crystals are discussed. The structural formula of 95 compounds and the R factors for X-ray diffraction analysis, which characterize the reliability of determining the structure, are summarized in three tables.

Chetkina, L. A.; Belsky, V. K., E-mail: vkb@rfbr.ru [Karpov Institute of Physical Chemistry (Russian Federation)

2013-01-15

321

Transmission diffraction-tomography system using a high-energy X-ray tube.  

PubMed

A high-energy bench-top energy dispersive X-ray diffraction (EDXRD) system for 3-dimensional mapping of the crystalline structure and phase transformations in steel is described, for which preliminary data and system development are presented here. The use of precision tungsten slit screens with up to 225 keV X-rays allows for diffraction through samples of 304 L austenitic stainless steel of thickness 3-10 mm, while sample positioning is carried out with a precision goniometer and translation stage system. PMID:19962905

Garrity, D J; Jenneson, P M; Crook, R; Vincent, S M

2010-01-01

322

X-Ray Powder Diffraction as a Tool to Investigate the Ultrastructure of Nanoparticles  

NASA Astrophysics Data System (ADS)

The potential of x-ray powder diffraction to analyze the size and ultrastructure of metallic nanoparticles (silver, gold, silver-gold alloy, and calcium phosphate) is demonstrated. By the Rietveld analysis, it is possible to estimate the crystallite size for such nanoparticles, even if they are very small (4 nm), using the effect of peak broadening in small crystallites. The results correspond well to crystallite size as determined by transmission electron microscopy (TEM), also confirming the twinned nature of the metallic nanoparticles. For calcium phosphate nanorods which are not twinned, the results by x-ray powder diffraction and TEM are in good agreement.

Prymak, O.; Ristig, S.; Meyer-Zaika, V.; Rostek, A.; Ruiz, L.; González-Calbet, J. M.; Vallet-Regi, M.; Epple, M.

2014-02-01

323

Toward the diffraction limit with transmissive x-ray lenses in astronomy.  

PubMed

We develop an analytical approach to refractive, blazed diffractive, and achromatic x-ray lenses of scalable dimensions for energies from 1 to 20 keV. Based on the parabolic wave equation, their wideband imaging properties are compared and optimized for a given spectral range. Low-Z lens materials for massive cores and rugged alternatives, such as polycarbonate or Si for flat Fresnel components, are investigated with respect to their suitability for diffraction-limited high-energy astronomy. Properly designed "hybrid" combinations can serve as an approach to x-ray telescopes with an enhanced efficiency throughout the whole considered band, nearly regardless of their inherent absorption. PMID:22781239

Braig, Christoph; Predehl, Peter

2012-07-10

324

Nanoscale Imaging of Mineral Crystals inside Biological Composite Materials Using X-Ray Diffraction Microscopy  

NASA Astrophysics Data System (ADS)

We for the first time applied x-ray diffraction microscopy to the imaging of mineral crystals inside biological composite materials—intramuscular fish bone—at the nanometer scale resolution. We identified mineral crystals in collagen fibrils at different stages of mineralization. Based on the experimental results and biomineralization analyses, we suggested a dynamic model to account for the nucleation and growth of mineral crystals in the collagen matrix. The results obtained from this study not only further our understanding of the complex structure of bone, but also demonstrate that x-ray diffraction microscopy will become an important tool to study biological materials.

Jiang, Huaidong; Ramunno-Johnson, Damien; Song, Changyong; Amirbekian, Bagrat; Kohmura, Yoshiki; Nishino, Yoshinori; Takahashi, Yukio; Ishikawa, Tetsuya; Miao, Jianwei

2008-01-01

325

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

326

Elastic properties of supported polycrystalline thin films and multilayers: An X-ray diffraction study  

SciTech Connect

Numerous experimental and theoretical studies have shown that thin film elastic behavior may be different from the bulk one due to size effects related to grain boundaries, free surfaces and interfaces. In addition, thin films often present high compressive residual stresses which may be responsible of thin film buckling. These two features will be discussed in this communication through recent x-ray diffraction experiments: in situ tensile testing for elastic constant analysis and scanning x-ray micro diffraction for stress relaxation measurements associated with film buckling.

Goudeau, P.; Villain, P.; Tamura, N.; Renault, P.-O.; Badawi, K.F.; Padmore, H.A.

2003-08-13

327

Charge Density Wave Dislocation as Revealed by Coherent X-Ray Diffraction  

SciTech Connect

Coherent x-ray diffraction experiments have been performed on high quality crystals of the charge density wave (CDW) system K{sub 0.3}MoO{sub 3}. The satellite reflections associated with the CDW have been measured as a function of the 20-{mu}m-diameter beam position. For some positions, regular fringes have been observed. We show that this observation is consistent with the presence of a single CDW dislocation. Beyond charge density wave systems, this experiment shows that coherent x-ray diffraction is a suitable tool to probe topological defects embedded in the bulk.

Le Bolloc'h, D. [Laboratoire de Physique des Solides (CNRS-UMR 8502), Batiment 510, Universite Paris-sud, 91405 Orsay cedex (France); Ravy, S. [Synchrotron SOLEIL, L'Orme des merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette cedex (France); Dumas, J.; Marcus, J. [Laboratoire d'Etude des Proprietes Electroniques des Solides-CNRS, BP 166, 38042 Grenoble cedex (France); Livet, F. [LTPCM (CNRS-UMR 5614), ENSEEG-Domaine Universitaire, BP 75, 38402 Saint Martin d'Heres cedex (France); Detlefs, C.; Yakhou, F.; Paolasini, L. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble cedex (France)

2005-09-09

328

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

SciTech Connect

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

Waddill, G.D.; Tobin, J.G. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.; Guo, X.; Tong, S.Y. [Univ. of Wisconsin, Milwaukee, WI (United States)

1994-07-12

329

Soft X-Ray Microscopy at HZB: Zone Plate Development and Imaging Using the Third Order of Diffraction  

NASA Astrophysics Data System (ADS)

The Helmholtz-Zentrum Berlin (HZB) operates a transmission x-ray microscope (TXM) in the soft x-ray photon energy range with an energy resolution up to E/?E = 104 [1]. An approach to achieve ultrahigh spatial resolution with conventional, standard zone plate optics is to employ higher orders of diffraction of the zone plate objective [2]. In this paper, we demonstrate that 11-nm lines and spaces of a multilayer test structure are clearly resolved by the x-ray microscope using the third order of diffraction of a zone plate objective with 20-nm outermost zone width. The disadvantage of high-order imaging is an about one order of magnitude lower diffraction efficiency of the used zone plates employed in the third order compared to the first order of diffraction. In addition, the measured background signal in the TXM images is no longer negligible. Therefore, we worked on the fabrication of zone plates with sub-20-nm outermost zone width to increase the spatial resolution in the first order of diffraction. A new high-resolution 100-keV e-beam lithography system from VISTEC, which was recently installed at the Helmholtz-Zentrum Berlin, makes these developments possible. Initial results on zone plates with an outermost zone width down to 15 nm exposed with the new e-beam system are presented. Furthermore, the contrast transfer function of the transmission x-ray microscope operating in partial coherence mode is measured by using the first and third diffraction order of the zone plate objective.

Rehbein, S.; Guttmann, P.; Werner, S.; Schneider, G.

2011-09-01

330

Soft X-Ray Microscopy at HZB: Zone Plate Development and Imaging Using the Third Order of Diffraction  

SciTech Connect

The Helmholtz-Zentrum Berlin (HZB) operates a transmission x-ray microscope (TXM) in the soft x-ray photon energy range with an energy resolution up to E/{Delta}E = 10{sup 4}. An approach to achieve ultrahigh spatial resolution with conventional, standard zone plate optics is to employ higher orders of diffraction of the zone plate objective. In this paper, we demonstrate that 11-nm lines and spaces of a multilayer test structure are clearly resolved by the x-ray microscope using the third order of diffraction of a zone plate objective with 20-nm outermost zone width. The disadvantage of high-order imaging is an about one order of magnitude lower diffraction efficiency of the used zone plates employed in the third order compared to the first order of diffraction. In addition, the measured background signal in the TXM images is no longer negligible. Therefore, we worked on the fabrication of zone plates with sub-20-nm outermost zone width to increase the spatial resolution in the first order of diffraction. A new high-resolution 100-keV e-beam lithography system from VISTEC, which was recently installed at the Helmholtz-Zentrum Berlin, makes these developments possible. Initial results on zone plates with an outermost zone width down to 15 nm exposed with the new e-beam system are presented. Furthermore, the contrast transfer function of the transmission x-ray microscope operating in partial coherence mode is measured by using the first and third diffraction order of the zone plate objective.

Rehbein, S.; Guttmann, P.; Werner, S.; Schneider, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen-Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2011-09-09

331

Comparison of polycapillary and curved crystal optics for convergent beam powder x-ray diffraction  

NASA Astrophysics Data System (ADS)

Comparisons were made of diffracted ring width, ring uniformity, system resolution and diffracted beam intensity for convergent beam powder diffraction using two different types of x-rays optics, doubly curved crystal optics^2 and polycapillary x-ray optics.^3,4 Measurements were made using very low power microfocus sources for small inorganic and organic standard samples. Detailed source and optics characterizations were performed to develop comparisons with theoretical calculations. Resolution and intensity were in good agreement with those obtained from simple geometrical calculations. ^2Z. W. Chen, N. Mail, F.Z. Wei, C. A. MacDonald, W. M. Gibson ``Total reflection x-ray fluorescence with low power sources coupled to doubly curved crystal optics,'' Spectrochimica. Acta. B, 60 (4), pp.471-8, 2005. ^3C.A. MacDonald and W.M. Gibson, ``Applications and Advances In Polycapillary Optics'', X-ray Spectrometry, 32 (3), 2003, pp 258-268. ^4C.A. MacDonald, S.M. Owens, and W.M. Gibson, ``Polycapillary X-Ray Optics for Microdiffraction,'' Journal of Applied Crystallography, 32, pp160-7, 1999.

Bingobali, Ayhan; Zhou, Wei; MacDonald, Carolyn

2006-03-01

332

X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue.  

PubMed

This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol. 47 2327-39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation of standard aqueous solutions were used for the quantification of the elements. The present developments concentrate on increasing the convergence between the tissue samples and the calibration models, therefore improving accuracy. For this purpose the composition of the samples in terms of adipose and fibrous tissue was evaluated, using an energy dispersive x-ray diffraction (EDXRD) system. The relationships between the attenuation and scatter properties of the two tissue components and water were determined through Monte Carlo simulations. The results from the simulations and the EDXRD measurements allowed the XRF data from each specimen to be corrected according to its composition. The statistical analysis of the elemental concentrations of the different groups of specimens reveals that all four elements are found in elevated levels in the tumour specimens. The increase is less pronounced for iron and copper and most for potassium and zinc. Other observed features include the substantial degree of inhomogeneity of elemental distributions within the volume of the specimens, varying between 4% and 36% of the mean, depending on the element and the type of the sample. The accuracy of the technique, based on the measurement of a standard reference material, proved to be between 3% and 22% depending on the element, which presents only a marginal improvement (1%-3%) compared to the accuracy of the previously reported results. The measurement precision was between 1% and 9% while the calculated uncertainties on the final elemental concentrations ranged between 10% and 16%. PMID:14971775

Geraki, K; Farquharson, M J; Bradley, D A

2004-01-01

333

X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue  

NASA Astrophysics Data System (ADS)

This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol. 47 2327-39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation of standard aqueous solutions were used for the quantification of the elements. The present developments concentrate on increasing the convergence between the tissue samples and the calibration models, therefore improving accuracy. For this purpose the composition of the samples in terms of adipose and fibrous tissue was evaluated, using an energy dispersive x-ray diffraction (EDXRD) system. The relationships between the attenuation and scatter properties of the two tissue components and water were determined through Monte Carlo simulations. The results from the simulations and the EDXRD measurements allowed the XRF data from each specimen to be corrected according to its composition. The statistical analysis of the elemental concentrations of the different groups of specimens reveals that all four elements are found in elevated levels in the tumour specimens. The increase is less pronounced for iron and copper and most for potassium and zinc. Other observed features include the substantial degree of inhomogeneity of elemental distributions within the volume of the specimens, varying between 4% and 36% of the mean, depending on the element and the type of the sample. The accuracy of the technique, based on the measurement of a standard reference material, proved to be between 3% and 22% depending on the element, which presents only a marginal improvement (1%-3%) compared to the accuracy of the previously reported results. The measurement precision was between 1% and 9% while the calculated uncertainties on the final elemental concentrations ranged between 10% and 16%.

Geraki, K.; Farquharson, M. J.; Bradley, D. A.

2004-01-01

334

Single-shot femtosecond x-ray diffraction from randomly oriented ellipsoidal nanoparticles  

NASA Astrophysics Data System (ADS)

Coherent diffractive imaging of single particles using the single-shot “diffract and destroy” approach with an x-ray free electron laser (FEL) was recently demonstrated. A high-resolution low-noise coherent diffraction pattern, representative of the object before it turns into a plasma and explodes, results from the interaction of the FEL with the particle. Iterative phase retrieval algorithms are used to reconstruct two-dimensional projection images of the object from the recorded intensities alone. Here we describe the first single-shot diffraction data set that mimics the data proposed for obtaining 3D structure from identical particles. Ellipsoidal iron oxide nanoparticles (250nm×50nm) were aerosolized and injected through an aerodynamic lens stack into a soft x-ray FEL. Particle orientation was not controlled with this injection method. We observed that, at the instant the x-ray pulse interacts with the particle, a snapshot of the particle’s orientation is encoded in the diffraction pattern. The results give credence to one of the technical concepts of imaging individual nanometer and subnanometer-sized objects such as single molecules or larger clusters of molecules using hard x-ray FELs and will be used to help develop robust algorithms for determining particle orientations and 3D structure.

Bogan, M. J.; Boutet, S.; Barty, A.; Benner, W. H.; Frank, M.; Lomb, L.; Shoeman, R.; Starodub, D.; Seibert, M. M.; Hau-Riege, S. P.; Woods, B.; Decorwin-Martin, P.; Bajt, S.; Schulz, J.; Rohner, U.; Iwan, B.; Timneanu, N.; Marchesini, S.; Schlichting, I.; Hajdu, J.; Chapman, H. N.

2010-09-01

335

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

336

Spectrometer for hard X-ray free-electron laser based on diffraction focusing.  

PubMed

X-ray free-electron lasers (XFELs) generate sequences of ultra-short spatially coherent pulses of X-ray radiation. A diffraction focusing spectrometer (DFS), which is able to measure the whole energy spectrum of the radiation of a single XFEL pulse with an energy resolution of ?E/E 2 × 10(-6), is proposed. This is much better than for most modern X-ray spectrometers. Such resolution allows one to resolve the fine spectral structure of the XFEL pulse. The effect of diffraction focusing occurs in a single-crystal plate due to dynamical scattering, and is similar to focusing in a Pendry lens made from a metamaterial with a negative refraction index. Such a spectrometer is easier to operate than those based on bent crystals. It is shown that the DFS can be used in a wide energy range from 5 keV to 20 keV. PMID:23412482

Kohn, V G; Gorobtsov, O Y; Vartanyants, I A

2013-03-01

337

Synchrotron x-ray diffraction measurements of strain in metallic nanoparticles with oxide shells.  

SciTech Connect

We describe synchrotron x-ray diffraction measurements of strain in Cu and Pd metal nanoparticles (1.7-40 nm diameter) both with an air-formed oxide shell and after reduction of the oxide by treatment in a hydrogen-containing atmosphere. Oxide removal is evident from x-ray diffraction (for Cu) and x-ray absorption spectroscopy (for Pd). A simple model that uses bulk elastic properties is applied to each system. In the Pd case the model predictions agree well with the experiment. For Cu the observed strains are much smaller than predicted. This discrepancy is attributed to (a) the presence of multiple grains within the Cu particles and (b) the incoherency of the oxide with the metal core.

Ingham, B.; Hendy, S. C.; Fong, D. D.; Fuoss, P. H.; Eastman, J. A.; Lassesson, A.; Tee, K .C.; Convers, P. Y.; Brown, S. A.; Ryan, M. P.; Toney, M. F.; Materials Science Division; Industrial Research Ltd.; The MacDiarmid Inst. for Advanced Materials and Nanotechnology; Univ. of Canterbury; Imperial Coll. London; Stanford Synchrotron Radiation Lightsource

2010-02-04

338

Data management and visualization of x-ray diffraction spectra from thin film ternary composition spreads  

SciTech Connect

We discuss techniques for managing and visualizing x-ray diffraction spectrum data for thin film composition spreads which map large fractions of ternary compositional phase diagrams. An in-house x-ray microdiffractometer is used to obtain spectra from over 500 different compositions on an individual spread. The MATLAB software is used to quickly organize the data and create various plots from which one can quickly grasp different information regarding structural and phase changes across the composition spreads. Such exercises are valuable in rapidly assessing the 'overall' picture of the structural evolution across phase diagrams before focusing in on specific composition regions for detailed structural analysis. We have also shown that simple linear correlation analysis of the x-ray diffraction peak information (position, intensity and full width at half maximum) and physical properties such as magnetization can be used to obtain insight about the physical properties.

Takeuchi, I.; Long, C.J.; Famodu, O.O.; Murakami, M.; Hattrick-Simpers, J.; Rubloff, G.W.; Stukowski, M.; Rajan, K. [Department of Materials Science and Engineering and Center for Superconducting Research, University of Maryland, College Park, Maryland 20742 (United States); Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2005-06-15

339

Optimized performance of graded multilayer optics for x-ray single-crystal diffraction  

NASA Astrophysics Data System (ADS)

We present recent developments in the production of X-ray multilayer optics for Cu K? laboratory single crystal diffraction equipment for protein crystallography and structural proteomics. The paper shows design, simulations and properties of Montel optics comprised of two elliptically bent focusing multilayers, optimized for the use with modern rotating anode X-ray generators. The multilayers are sputter deposited with a graded d-spacing along the length of the substrate. The various beam properties such as flux density and divergence are investigated in detail. After optimization of the optic for a state-of-the-art rotating anode x-ray generator, we obtain a flux density of 1 x 1010 photons/s/mm2. Results for a typical protein structure will be shown, illustrating the advantage of Montel optics in the field of single-crystal diffraction and protein crystallography for life sciences.

Michaelsen, Carsten; Wiesmann, Joerg; Hoffmann, Christian; Oehr, A.; Storm, A. B.; Seijbel, L. J.

2004-01-01

340

Coherent X-Ray Diffraction Imaging of Morphology and Strain in Nanomaterials  

NASA Astrophysics Data System (ADS)

The last decade has seen a remarkable surge in x-ray characterization methods (Willmott, An Introduction to Synchrotron Radiation, John Wiley & Sons, Inc., New York, 2011). Imaging with x-rays has evolved from simple radiography, to image internal structure and diagnose injury, to a full-fledged tool for nanoscale characterization (Holt et al., Annu Rev Mater Res 43:1, 2013). Central to this development has been the advent of high-brilliance synchrotron and free electron laser sources of x-rays. The high degree of spacial coherence of the resulting beams has enabled novel imaging methods. Of these, coherent diffraction imaging has proven highly successful at imaging the structure in nano materials (Miao et al., Nature 400:342, 1999). In addition, this imaging method can be combined with Bragg diffraction to image strain with high sensitivity (Pfeifer et al., Nature 442:63, 2006; Robinson and Harder, Nat Mater 8:291, 2009).

Harder, Ross; Robinson, Ian K.

2013-09-01

341

STRUCTURE AND CATION ORDER IN MANGANILVAITE: A COMBINED X-RAY-DIFFRACTION, NEUTRON-DIFFRACTION AND MOSSBAUER STUDY  

Microsoft Academic Search

The crystal structure of manganilvaite, CaFe2+Fe3+(Mn2+,Fe2+)(Si2O7)O(OH), from the Ossikovo Pb-Zn skarn deposit, Rhodope Mountains, Bulgaria, was refi ned in space group P21\\/a, with a 13.0250(7), b 8.8514(5), c 5.8486(3) Å, ? 90.167(1)°, V 674.28(7) Å3, Z = 4, using combined neutron and X-ray powder diffraction as well as single-crystal X-ray-diffraction data. The empirical chemical formula proposed on the basis of

NIKOLAY ZOTOV; WINFRIED KOCKELMANN; STEVEN D. JACOBSEN; IVAN MITOV; DANIELA PANEVA; ROSSITSA D. VASSILEVA; IVAN K. BONEV

2005-01-01

342

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

343

Quantitative X-Ray Diffraction Analysis of Crocidolite and Amosite in Bulk or Settled Dust Samples  

Microsoft Academic Search

A quantitative procedure for determining crocidolite and amosite in bulk or settled dust samples is described. Crocidolite and amosite are two of the three major types of asbestos fibers used in the United States asbestos industry. Each has a crystalline structure which provides a distinct x-ray diffraction pattern of sufficient intensity to be used in quantitative analysis. Quartz is used

John V. Crable; Marta J. Knott

1966-01-01

344

Stereochemistry Determination by Powder X-ray Diffraction Analysis and NMR Spectroscopy Residual Dipolar Couplings  

SciTech Connect

A matter of technique: For a new steroidal lactol, jaborosalactol 24 (1), isolated from Jaborosa parviflora, NMR spectroscopy residual dipolar couplings and powder X-ray diffraction analysis independently gave the same stereochemistry at C23-C26. Conventional NMR spectroscopic techniques, such as NOE and {sup 3}J coupling-constant analysis failed to unambiguously determine this stereochemistry.

Garcia, M.; Pagola, S; Navarro-Vasquez, A; Phillips, D; Gayathri, C; Krakauer, H; Stephens, P; Nicotra, V; Gil, R

2009-01-01

345

APPLICATION OF SYNCHROTRON RADIATION TO HIGH PRESSURE X~RAY DIFFRACTION  

Microsoft Academic Search

The availability of dedicated, high brightness synchrotron radia­ tion sources is leading to many improvements in x-ray diffraction techniques. In addition to the widely discussed polychromatic energy dispersive tech­ niques, significant advances can be made by the use of monochromatic radiation in either angle- or wavelength-scanning. The application of these techniques, being developed at Daresbury, for high pressure investigations is

F. D. Hatton

346

New diamond anvil cells for gigahertz ultrasonic interferometry and X-ray diffraction  

Microsoft Academic Search

Two new diamond anvil cells have been designed for ultrasonic and X-ray diffraction measurements on a single crystal sample up to 6 GPa and 250 ºC. Advances in the generation and transmission of coherent GHz ultrasonic signals with wavelengths of the order of micrometers now make it practical to measure elastic properties of samples small enough to be subjected to

W. A. BASSETT; H.-J. REICHMANN; R. J. ANGEL; H. SPETZLER; J. R. SMYTH

347

CRYSTALLINITY AND AVERAGE CARBON NUMBER OF PETROLEUM WAXES BY X-RAY DIFFRACTION  

Microsoft Academic Search

Crystallinity and average carbon number of different petroleum waxes have been determined by means of X-ray diffraction. The effect of oil and polymers, viz, polyethylene (PE) and ethylene vinyl acetate (EVA) co-polymer on the crystallinity and average carbon number of petroleum waxes have also been studied. Crystallinity data has been correlated with composition and properties of the waxes.

A. K. Gupta; K. M. Agrawal

2000-01-01

348

DAFS: A new x-ray structural technique. [DAFS (diffraction anomalous fine structure)  

Microsoft Academic Search

The simple theory and potential applications of a new x-ray structural technique, Diffraction Anomalous Fine Structure (DAFS), are described. DAFS measurements determine the fine structure versus photon energy in the elastic, fixed momentum transfer, Bragg reflection intensities as the energy is tuned to an absorption edge of an atom in a crystal. DAFS provides all of the conventional short-range order

Stragier

1993-01-01

349

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

350

Determining the Structure of Biomaterials Interfaces using Synchrotron-based X-ray Diffraction.  

National Technical Information Service (NTIS)

The purpose of this project is to explore the feasibility of using surface X-ray diffraction (SXRD) to determine the structure of biomineral surfaces in electrolyte solutions and of the adsorbed layer of acidic amino acids that are believed to play a cent...

M. McBride

2002-01-01

351

X-RAY POWDER DIFFRACTION SYSTEM FOR CHEMICAL SPECIATION OF PARTICULATE AEROSOL SAMPLES  

EPA Science Inventory

An x-ray powder diffraction system has been developed for the automated measurement and analysis of particulate aerosol samples. The system is optimized to process samples with particle loadings of about 100 micrograms/sq cm which are acquired with dichotomous air samplers. A pos...

352

X-ray diffraction studies of polyaniline doped with Zn(NO3)2  

NASA Astrophysics Data System (ADS)

Polyaniline (PANI) and PANI/zinc nitrate composites were synthesized by in situ chemical oxidative polymerization of aniline with Zn(NO3)2 using ammonium peroxidisulphate (APS) as an oxidant. These composites were characterized by X-ray diffraction (XRD) and the results were compared with pure Polyaniline and zinc nitrate.

Goyal, Sneh Lata; Sharma, Smriti; Kumar, Devinder; Kishore, Nawal

2013-06-01

353

X-Ray Diffraction Studies of Homologous Series of 4-Alkyl-4' Cyanostilbene.  

National Technical Information Service (NTIS)

Various members of the series 4-alkyl-4'-cyanostilbene (n=4,...11) have been examined by x ray diffraction using monodomain samples aligned in .2 T magnetic field. A moving film technique has been employed with Fe K radiation (=1.937 A) to record the zero...

L. V. Azaroff S. Bhattacharjee

1988-01-01

354

Synchrotron X-ray Powder Diffraction Studies in Pulsed Magnetic Fields  

SciTech Connect

X-ray powder diffraction experiments under pulsed magnetic fields were carried out at the DUBBLE beamline (BM26B) at the ESRF. A mobile generator delivered 110kJ to the magnet coil, which was sufficient to generate peak fields of 30T. A liquid He flow cryostat allowed us to vary the sample temperature accurately between 8K and 300K.

Detlefs, C. [European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France); Frings, P.; Duc, F.; Nardone, M.; Billette, J.; Zitouni, A.; Rikken, G. L. J. A. [Laboratoire National des Champs Magnetiques Pulses, 143, avenue de Rangueil, F-31400 Toulouse (France); Vanacken, J. [Laboratoire National des Champs Magnetiques Pulses, 143, avenue de Rangueil, F-31400 Toulouse (France); Pulsveldengroep, Institute for Nanoscale Physics and Chemistry, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Lorenzo, J. E. [Laboratoire de Cristallographie, CNRS, B.P. 166X, F-38043 Grenoble (France); Bras, W. [Netherlands Organisation for Scientific Research (NWO), DUBBLE CRG at ESRF, BP 220, F-38043 Grenoble (France)

2007-01-19

355

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

356

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—LNLS, 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.

Colaço, 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

357

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

358

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

359

Quantitative X-Ray Diffraction Analysis of Oxides Formed on Superalloys.  

National Technical Information Service (NTIS)

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...

R. G. Garlick

1972-01-01

360

Texture of poled tetragonal PZT detected by synchrotron X-ray diffraction and micromechanics analysis  

Microsoft Academic Search

The texture and lattice elastic strain due to electrical poling of tetragonal PZT (lead zirconate titanate) ceramics have been measured using high energy synchrotron X-ray diffraction. It is shown that XRD peak intensity ratios associated with crystal planes of the form {002}, {112} and {202} exhibit a linear dependence on cos?2?, where ? represents the orientation angle between the plane

D. A. Hall; A. Steuwer; B. Cherdhirunkorn; P. J. Withers; T. Mori

2005-01-01

361

High Pressure Studies Using Energy Dispersive Diffraction of High Energy X-Rays.  

National Technical Information Service (NTIS)

The smooth continuum of white radiation produced by a 160 kV generator has been combined with Energy Dispersive X Ray Diffraction (EDXRD) and a Drickamer type cell for high pressure studies. The theory of EDXRD is briefly reviewed and the advantages of th...

W. F. Sherman D. Haeusermann

1987-01-01

362

X-ray diffraction study of mineral components in calcareous algae (Corallinaceae, Rhodophyta)  

Microsoft Academic Search

The mineral composition of nine species of red calcareous algae (Corallinaceae, Rhodophyta) collected in the Adriatic Sea in 1987 and 1988 was examined by X-ray powder diffraction (counter diffractometer, monochromatized CuKa radiation). In addition, a comparison between the calcareous algae from the north Adriatic (Rovinj area) and the central Adriatic (Kornati Islands) with regard to genus, species and environmental factors

D. Medakovi?; S. Popovi?; N. Zavodnik; B. Gržeta; M. Plazonic

1995-01-01

363

Columnar Phases in Liquid Crystal Dendrimers: Variable Pressure X-Ray Diffraction  

Microsoft Academic Search

The structures of the third and fifth generation of a liquid crystal dendrimer have been studied as a function of temperature and pressure using X-ray diffraction. The third generation LC dendrimer showed a crystal to smectic transition and increasing pressure simply increased the transition temperature. The fifth generation showed two different rectangular columnar phases and one hexagonal columnar phase. The

R. M. Richardson; S. Hanna; N. J. Brooks; B. L. L. E. Gauthe; C. Pizzey; E. Agina; N. Boiko; V. P. Shibaev

2011-01-01

364

Short Range Order in some Polymer Melts from x ray Diffraction  

Microsoft Academic Search

Wide angle x ray diffraction measurements were performed on a series of polymer melts, to study the dependence of the short range structure of polymer liquids on chain architecture. These results are useful in testing single chain models of vinyl polymers, which in turn are needed to validate integral equation theories of polymer melts and blends. The polymers studied were

A. Habenschuss; J. D. Londono; J. J. Rajasekaran; J. G. Curro; J. D. Honeycutt

1996-01-01

365

Interdiffusion Reactions in Ni/Ta Multilayers Studied by X ray Diffraction.  

National Technical Information Service (NTIS)

The results of an analogous interdiffusion study on Ni/Ta multilayers are reported. Diffusion induced phase transformations were studied in Ni/beta-Ta multilayers between 523 and 823 K, using X-ray diffraction. The multilayers had a modulation length, of ...

M. A. Hollanders C. G. Duterloo B. J. Thijsse E. J. Mittemeijer

1990-01-01

366

High spatial resolution X-ray and gamma ray imaging system using diffraction crystals  

DOEpatents

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

Smither, Robert K. (Hinsdale, IL) [Hinsdale, IL

2011-05-17

367

X-Ray Powder Diffraction as a Tool for the Identification of Impact Deformed Rocks  

Microsoft Academic Search

Previous X-ray powder diffraction (XRD) studies indicated shock deformed minerals have broader XRD peaks when compared to those of unshocked samples. Entire XRD patterns, single peak profiles and Rietveld refined parameters of carbonate samples from the Sierra Madera impact crater, west Texas and the Mission Canyon Formation of southwest Montana and western Wyoming were used to evaluate the use of

S. Huson; M. Pope; F. Foit; A. Watkinson

2007-01-01

368

X-ray diffraction study of 1,5-bis(2-Formylphenoxy)pentane  

SciTech Connect

1,5-Bis(2-Formylphenoxy)pentane was studied by X-ray diffraction. There are two crystallographically independent molecules with similar geometric parameters in the asymmetric unit of the crystal structure. The molecules occupy special positions on a rotation axis.

Pervova, I. G., E-mail: biosphera@usfeu.ru; Zaidman, A. V. [Ural State Forest Engineering University (Russian Federation); Lipunov, I. N.; Slepukhin, P. A., E-mail: slepukhin@ios.uran.ru [Russian Academy of Sciences, Postovsky Institute of Organic Synthesis, Ural Division (Russian Federation)

2010-03-15

369

Small-Angle X-Ray Powder Diffraction, Morphology, and Structure of Allophane and Imogolite  

Microsoft Academic Search

Small-angle X-ray powder diffraction analyses and high-resolution electron microscopy of allophane samples (SiOJAlzO3 ratio, 1.12 to 1.68) showed that allophanes consist of nearly identical spherical particles with diameters of about 40 A and retain their characteristic \\

S. J. van der Gaast; K. WADA; S.-I. WADA; Y. KAKUTO

1985-01-01

370

X-Ray Diffraction and Other Studies of the Calcareous Deposits in Human Pineal Glands.  

National Technical Information Service (NTIS)

The calcareous deposits in human pineal glands, when examined after NaOH extraction or by drying the whole gland in air, reveal the x-ray diffraction powder pattern of a poorly resolved apatite. After wet or dry ashing of the gland a much better resolved ...

K. M. Earle

1964-01-01

371

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

372

Optimization of Paris-Edinburgh press cell assemblies for in situ monochromatic X-ray diffraction and X-ray absorption  

Microsoft Academic Search

We describe some important improvements allowed by the development of new cell assemblies coupled to opposed conical sintered diamond anvils in the Paris–Edinburgh press. We provide X-ray absorption and diffraction experiments carried out at pressures up to 16.5 GPa. The maximum temperature reached was 1800 K for P<10 GPa and 1300 K for higher pressures. The sintered diamond anvils are X-ray transparent and give

G. Morard; M. Mezouar; N. Rey; R. Poloni; A. Merlen; S. Le Floch; P. Toulemonde; S. Pascarelli; A. San-Miguel; C. Sanloup; G. Fiquet

2007-01-01

373

Energy dispersive x-ray diffraction in the diamond anvil, high-pressure apparatus: Comparison of synchrotron and conventional x-ray sources  

Microsoft Academic Search

The use of both conventional fixed-anode X-ray sources and synchrotron radiation to carry out energy-dispersive X-ray diffraction experiments at high pressure in a diamond anvil cell, is discussed. The photon flux at the sample and at the detector for the two cases are compared and the results are presented in graphs. It is shown that synchrotron radiation experiments can be

Ian L. Spain; David R. Black

1985-01-01

374

Amorphisation mechanism of a flint aggregate during the alkali–silica reaction: X-ray diffraction and X-ray absorption XANES contributions  

Microsoft Academic Search

Flint samples at different stages of the Alkali–Silica Reaction were prepared and analyzed by X-ray diffraction (XRD) and silicon K-edge X-ray absorption near edge structure techniques (XANES). The results are compared to those of measurements performed on alpha quartz c-SiO2 and rough flint aggregate. The molar fraction of Q3 sites is determined as a function of the time of reaction.

J. Verstraete; L. Khouchaf; D. Bulteel; E. Garcia-Diaz; A. M Flank; M. H. Tuilier

2004-01-01

375

An X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) investigation in human and animal fossil bones from Holocene to Middle Triassic  

Microsoft Academic Search

We examined by Rietveld refinement of X-ray Diffraction patterns a series of 61 human and animal fossil bones in an age range from present time to Middle Triassic (around 245Ma). This approach, supplemented by elemental analysis according to X-ray Fluorescence, has permitted to obtain a quantitative evaluation of the mineralogical phases in the specimens, thus allowing to reconstruct the mineralization

Giampaolo Piga; Andrés Santos-Cubedo; Salvador Moya Solà; Antonio Brunetti; Assumpciò Malgosa; Stefano Enzo

2009-01-01

376

Applications of Synchrotron-Based X-Ray Diffraction and X-Ray Absorption Spectroscopy to the Understanding of Poorly Crystalline and Metal-Substituted Iron Oxides  

Microsoft Academic Search

The octahedral site in iron oxides has been shown to undergo changes in its occupation when iron oxides form in the presence of single and multiple foreign metals in controlled laboratory settings as well as the natural environment. X-ray absorption spectroscopy coupled with the increased precision of synchrotron-based X-ray diffraction (SXRD) have shed new light on important basic mechanisms controlling

Balwant Singh; Markus Gräfe; Navdeep Kaur; Andrea Liese

2010-01-01

377

Characterization of Pumice-Supported Ag–Pd and Cu–Pd Bimetallic Catalysts by X-Ray Photoelectron Spectroscopy and X-Ray Diffraction  

Microsoft Academic Search

Bimetallic Ag–Pd and Cu–Pd catalysts supported on pumice have been prepared in order to be used in the selective hydrogenation of dienes. The catalysts were obtained by the classical impregnation method and in the case of the Cu–Pd system also by organometallic precursors. They were analysed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). XPS allowed us to determine

A. M. Venezia; L. F. Liotta; G. Deganello; Z. Schay; L. Guczi

1999-01-01

378

A wide-beam X-ray source suitable for diffraction enhanced imaging applications  

NASA Astrophysics Data System (ADS)

Research in diffraction-enhanced imaging (DEI), using a synchrotron source with an X-ray flux of 1.4×10 12 ph/mm 2/s, has shown strong potential in obtaining high-resolution images as compared to conventional radiographs. This research investigates the feasibility of developing a large area circular X-ray source with fluxes comparable to a synchrotron source. The source should be capable of integration into a compact system with peak powers not to exceed 200 kW to be feasible for use in a major medical facility, industrial complex or screening facility (such as cargo or airport). A computational study of a circular concentric filament wide-beam area X-ray source has been investigated in this research. The design features are based on generating electrons from three concentric circular filaments to provide an area electron flux, with a 60 kV accelerating potential and a beam current of up to 3 A. The X-ray target is a grounded stationary oxygen-free copper target with a layer of molybdenum. This target feature differs from standard rotating X-ray targets in conventional X-ray systems. Studies of electron trajectories and their distribution on the target were conducted using the SIMION 3D code. Heat loading and thermal management were studied using heat transfer modules from the coupled FEMLAB multi-physics and MATLAB codes. The Monte Carlo code MCNP 5 was used to obtain the X-ray flux and energy distribution for aluminum and beryllium windows. This computational study shows that this target configuration generates X-rays with photon flux comparable to synchrotron source and sufficient for DEI applications. The maximum target temperature rise is 1357 K after 70 s when cooling the back of the target to liquid nitrogen temperature using cold finger contact, and 325 K for an invaded target, in which liquid nitrogen circulates inside the target.

Kim, Chang H.; Bourham, Mohamed A.; Michael Doster, J.

2006-10-01

379

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

380

Design and performance of an imaging plate system for X-ray diffraction study  

NASA Astrophysics Data System (ADS)

A new readout system for a BaFBr: Eu 2+ photostimulable phosphor screen (imaging plate) was constructed by modifying a drum scanner, with a design optimized for X-ray diffraction and scattering applications. An effort was made to achieve a high detective quantum efficiency below 20 keV, a small pixel size (25 ?m × 25 ?m), a low quantization noise (0.22%) using 12-bit A/D converters, and the capability to cover an inherent dynamic range (1:10 5) of the photostimulated luminescence by using two photomultiplier tubes. This system is being used in several synchrotron radiation experiments: Laue diffraction of protein crystals, small angle diffraction from a single muscle fiber, powder diffraction from crystals in a diamond anvil cell, and time-resolved small-angle X-ray scattering from a synthetic polymer during stretching.

Amemiya, Yoshiyuki; Matsushita, Tadashi; Nakagawa, Atsushi; Satow, Yoshinori; Miyahara, Junji; Chikawa, Jun-ichi

1988-04-01

381

Photoinduced structural dynamics of polar solids studied by femtosecond X-ray diffraction.  

PubMed

Femtosecond X-ray diffraction allows for real-time mapping of structural changes in condensed matter on atomic length and timescales. Sequences of diffraction patterns provide both transient geometries and charge-density maps of crystalline materials. This article reviews recent progress in this field, the main emphasis being on experimental work done with laser-driven hard X-ray sources. Both Bragg diffraction techniques for bulk and nanostructured single crystals as well as the recently implemented powder diffraction from polycrystalline samples are discussed. In ferroelectric superlattice structures, coherent phonon motions and the driving stress mechanisms are observed in real time. In molecular crystals charge-transfer processes and the concomitant changes of the lattice geometry are analyzed. PMID:20164640

Elsaesser, Thomas; Woerner, Michael

2010-03-01

382

Femtosecond powder diffraction with a laser-driven hard X-ray source.  

PubMed

X-ray powder diffraction with a femtosecond time resolution is introduced to map ultrafast structural dynamics of polycrystalline condensed matter. Our pump-probe approach is based on photoexcitation of a powder sample with a femtosecond optical pulse and probing changes of its structure by diffracting a hard X-ray pulse generated in a laser-driven plasma source. We discuss the key aspects of this scheme including an analysis of detection sensitivity and angular resolution. Applying this technique to the prototype molecular material ammonium sulfate, up to 20 powder diffraction rings are recorded simultaneously with a time resolution of 100 fs. We describe how to derive transient charge density maps of the material from the extensive set of diffraction data in a quantitative way. PMID:20173917

Zamponi, F; Ansari, Z; Woerner, M; Elsaesser, T

2010-01-18

383

Single-crystal X-ray diffraction at high pressures with diamond-anvil cells  

Microsoft Academic Search

The past twenty years have seen the widespread development of diamond-anvil pressure cells (DAC's) suitable for carrying out single-crystal X-ray diffraction experiments to pressures in excess of 10 GPa. The relative advantages and disadvantages of the various types of DAC are discussed and the basic techniques for their operation, including pressure measurement and the collection of diffraction data, are described.

R. J. Angel; N. L. Ross; I. G. Wood; P. A. Woods

1992-01-01

384

High-pressure radial X-ray diffraction study of osmium to 58 GPa  

Microsoft Academic Search

Nonhydrostatic compression behavior of osmium (Os) was investigated up to\\u000a 58.2 GPa using radial X-ray diffraction (RXRD) together with lattice strain\\u000a theory in a diamond-anvil cell. The apparent bulk modulus of Os derived from\\u000a RXRD data varies from 262 GPa to 413 GPa, depending on ?, the orientation of\\u000a the diffraction planes with respect to the loading axis. Fitting to

H. Chen; D. He; J. Liu; Y. Li; F. Peng; Z. Li; J. Wang; L. Bai

2010-01-01

385

Synthesis and X-ray diffraction study of polyaniline doped with chromium oxide  

NASA Astrophysics Data System (ADS)

Polyaniline (PANI) and PANI / chromium oxide composites were synthesized by in situ chemical oxidative polymerization of aniline with CrO3 using ammonium peroxidisulphate as an oxidant. These composites were characterized by X-ray diffraction (XRD) and the results were compared with XRD of pure PANI and chromium oxide. The intensity of diffraction peaks of composites was lower than that for CrO3 and increases with increasing concentration of CrO3.

Asha; Goyal, Sneh Lata; Kishore, Nawal

2013-06-01

386

Investigation of Renal Stones by X-ray and Neutron Diffraction  

NASA Astrophysics Data System (ADS)

Renal stones were investigated by X-ray diffraction. The obtained results showed only one crystal phase in every sample. With the aim to verify eventual availability of second phase (under 3 volume %) the same renal stones were investigated by neutron diffraction. The neutron spectra proved that additional crystal phase was absent in the renal stones. The obtained results are scientific-practical, in aid of the medicine, especially in the case of renal stone disease.

Baeva, M.; Beskrovnyi, A. I.; Boianova, A.; Shelkova, I.

2007-04-01

387

Synchrotron X-ray diffraction and imaging of ancient Chinese bronzes  

Microsoft Academic Search

High-energy synchrotron X-ray diffraction and imaging experiments were performed at the Advanced Photon Source on two ancient\\u000a Chinese bronzes from the Art Institute of Chicago with the goal to nondestructively study their microstructure. The first\\u000a object, a bronze fragment from an early Western Zhou dynasty vessel (Hu, 11th\\/10th century B.C.), was investigated with spatially-resolved\\u000a diffraction to reveal the depth and

M. L. Young; F. Casadio; S. Schinepp; J. Almer; D. R. Haeffner; D. C. Dunand

2006-01-01

388

Powder x-ray diffraction procedures for the Mound aging\\/surveillance program. [Lead styphnate; hexanitroazobenzene  

Microsoft Academic Search

Power x-ray diffraction procedures were developed and utilized for routine analysis of samples containing lead styphnate, hexanitroazobenzene and mixtures of titanium hydride and potassium perchlorate, in support of the aging\\/surveillance program at Mound. Diffraction data were collected with an automated Rigaku wide-angle powder diffractometer under remote control of a DEC PDP-11\\/44 computer that was connected to it with optical wave

D. B. Sullenger; E. F. Jendrek; B. L. Sorrell

1985-01-01

389

X-ray photoelectron diffraction investigation of the cleavage plane in 1 T -transition metal dichalcogenides  

Microsoft Academic Search

We present a detailed study of the three members of the 1T-transition metal dichalcogenides: TiSe2, TaSe2 and TaS2 by means of the X-ray photoelectron diffraction combined with single-scattering simulations. Our simulations of different surface terminations and their comparison with the measured diffraction patterns allow to determine that the cleavage occurs within the van der Waals gap. Single-scattering calculations are shown

D. Stoltz; S. E. Stoltz

2007-01-01

390

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

391

Evaluation of the dehydration performance of zeolite NaA membrane on porous alumina tube by the alumina X-ray diffraction intensity.  

PubMed

A zeolite NaA (A-type zeolite of ca. 0.4 nm pore size; Linde Type A, LTA) membrane for the dehydration of alcohol was characterized by X-ray diffraction analysis (XRD). Also, the relationship between the X-ray absorption and the EtOH/H2O pervaporation (PV) dehydration performance (water selectivity and permeation flux) of the LTA membrane was first investigated. The LTA membranes used here were gel-synthesized hydrothermally on an alumina porous support tube. Since diffraction lines from the alumina generate from a deeper layer than those of the LTA crystal, and are absorbed by both the surface LTA crystal and materials embedded in the alumina porous support, the alumina (113) diffraction line was intensively monitored to estimate the overall X-ray absorption by the LTA membrane. The intensity of the alumina (113) diffraction line showed a good correlation with the PV dehydration performance of the LTA membrane, that is, lower values with the water selectivity and higher values with the permeation flux. The lower diffraction intensity means stronger X-ray absorption by the LTA membrane. The major factor causing the difference in the X-ray absorption is the thickness or quantity of materials embedded in an alumina porous support, rather than those of the surface LTA crystal. These phenomena can be used conveniently (without real PV experiments) to determine the EtOH/H2O PV dehydration performance of the LTA membrane. PMID:16512430

Kyotani, Tomohiro; Inoue, Soushi; Kakui, Sonoko; Saito, Junji

2006-02-01

392

Polarity determination of wurtzite-type crystals using hard x-ray photoelectron diffraction  

NASA Astrophysics Data System (ADS)

The surface structure of a single-crystal ZnO wafer was studied by angle-resolved x-ray photoelectron spectroscopy (ARXPS) using synchrotron radiation. As a result, well-defined x-ray photoelectron diffraction (XPD) patterns were obtained for the (0001) and (000 1¯) polar surfaces using the photoemission from the Zn 2p 3/2 and O 1s core levels. The XPD patterns were indexed assuming forward scattering of photoelectrons by neighboring ions. Further, the XPD patterns for the (0001) and (000 1¯) surfaces were different from each other, indicating the possibility for using the XPD technique for polarity determination.

Williams, Jesse R.; Kobata, Masaaki; Pis, Igor; Ikenaga, Eiji; Sugiyama, Takeharu; Kobayashi, Keisuke; Ohashi, Naoki

2011-07-01

393

X-ray powder diffraction study of poly/carbon monofluoride/, CF/1.12/  

NASA Technical Reports Server (NTRS)

Data from X-ray diffraction studies of the poly(carbon monofluoride) with empirical formula CF(1.09-1.15) are reported, and possible intercalation arrangements for the substance are discussed. The data do not conform to true hexagonal symmetry, indicating that the carbon atoms are not coplanar. Each bond angle of carbon is 118.8 deg, and the carbon-carbon distance is 1.47 A. The interlayer distance is 5.76 A. A total absence of (hkl) reflections in the X-ray pattern shows that the separate CF layers are not regularly arranged with respect to one another.

Mahajan, V. K.; Badachhape, R. B.; Margrave, J. L.

1974-01-01

394

In Situ High Pressure Angle Dispersive X-ray Diffraction Experiments:With Sagittally-Bent Double Laue Monochomator  

NASA Astrophysics Data System (ADS)

A Sagittally-bent double Laue monochomator is used at the wiggler beam line X17C of NSLS, BNL. It can provide high-energy X-ray tunable from 20 keV to 40 keV. The monochomator consists of two Si crystals of 0.76 mm thick, with surface corresponding to the (001) planes. The 111 reflections of both crystals are used to diffract the x-ray. The two crystals are bent Sagittelly to 1 m radius and used in the Laue mode [1, 2]. The bent Laue crystals provide high energy-resolution beam with a flux one order of magnitude greater than that of a flat-crystal monochromator. For high-pressure diamond-anvil cell experiments using angular dispersive x-ray diffraction, K-B mirrors are used to focus the incident beam from 0.180mm x 0.180mm to 0.025mm x 0.025mm. Two samples were studied with different x-ray energies. The Ag2O2 sample was studied at pressures up to 20 GPa using energy of 38.9246 keV (0.031851 nm) x-ray. The problem of strong Ag fluorescence causing Ge-detector to saturate in energy dispersive x-ray diffraction was not an issue in the present angular dispersive experiments. With energy of 30.4912keV (0.040663 nm) x-ray, NaMgF3 was studied to 30 GPa. Exposure time was 1 to 6 minutes for different pressures. No phase transition was found in the pressure range. The P-V data fitting to a third order Birch- Murnahgan equation yields a bulk modulus Ko=68.9 1.7 GPa and Ko­_=6.3. [1] Z. Zhong, et. al., Acta. Cryst. A 59 (2003) 1-6 [2] Z. Zhong, et. al. J. Appl. Cryst., 34 (2001) 646-653

Hu, J.; Zhong, Z.; Liu, H.; Guo, Q.; Mao, H.; Hemley, R. J.

2003-12-01

395

Fabrication of the 3 Dimension Resist Microstructure Using X-Ray Diffraction and Applying to LIGA Process  

NASA Astrophysics Data System (ADS)

The LIGA process consists of lithography, electroforming and molding has attracted attention in microstructure fabrication techniques. At the molding process of LIGA process, it is difficult to pull out from the mold that is assumed especially in the case of high aspect ratio structures. However, release from mold is improved by tapered structure. In this research, we have proposed a method for achieving tapered structure using the diffraction exposure technique which makes use of diffraction phenomenon. Diffraction is caused by providing a clearance between a resist structure and an X-ray mask. The fabricated structure was the lines and intermediate space whose processed depth was 200 µm and designated the taper angle of 5 degrees as set point. The variable parameters were the slit width, the X-ray dose and the gap between the X-ray mask and the resist structure. It is controlled that discovering the conditions for taper angle 5 degrees and inspecting the relationship between a taper angle and a mold releasability by electroforming and the molding of the LIGA process. We have fabricated the mold with taper angle of 2.5 degrees by electroforming. The Ni mold could partially copy the master pattern well.

Sawa, Yoshitaka; Tanabiki, Kyo; Noda, Daiji; Hattori, Tadashi

396

High-Pressure Raman and X-ray Diffraction Study of [beta]- and [gamma]-Polymorphs of Aluminum Hydride  

Microsoft Academic Search

Three polymorphs of alane, AlH, (, , and ) were synthesized and studied at high-pressure in diamond anvil cell by Raman spectroscopy and synchrotron X-ray diffraction. According to synchrotron X-ray diffraction study, -AlH is stable up to 6 GPa, followed by transformation into phase at higher pressures. X-ray-induced decomposition -AlH into constituent elements was found at 15 GPa. Raman scattering

Vadym Drozd; Subrahmanyam Garimella; Surendra Saxena; Jiuhua Chen; Taras Palasyuk

2012-01-01

397

Time-Resolved Synchrotron X-ray Diffraction on Pulse Laser Heated Iron in Diamond Anvil Cell  

Microsoft Academic Search

The authors present time-resolved synchrotron x-ray diffraction to probe the {var_epsilon}- phase transition of iron during pulse-laser heating in a diamond anvil cell. The system utilizes a monochromatic synchrotron x-ray beam, a two-dimensional pixel array x-ray detector and a dual beam, double side laser-heating system. Multiple frames of the diffraction images are obtained in real-time every 22 ms over 500

C S Yoo; H Wei; R Dias; G Shen; J Smith; J Y Chen; W Evans

2011-01-01

398

Time-Resolved Synchrotron X-ray Diffraction on Pulse Laser Heated Iron in Diamond Anvil Cell  

Microsoft Academic Search

We present time-resolved synchrotron x-ray diffraction to probe the ?-? phase transition of iron during pulse-laser heating in a diamond anvil cell. The system utilizes a monochromatic synchrotron x-ray beam, a two-dimensional pixel array x-ray detector and a dual beam, double side laser-heating system. Multiple frames of the diffraction images are obtained in real-time every 22 ms over 500 ms

Choong-Shik Yoo; Haoyan Wei; Ranga Dias; Guoyin Shen; Jesse Smith; Jing-Yin Chen; William Evans

2012-01-01

399

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

400

Thermal transport in thin films measured by time-resolved, grazing incidence x-ray diffraction.  

SciTech Connect

We use depth- and time-resolved x-ray diffraction to study thermal transport across single crystal Bi films grown on sapphire in order to determine the thermal conductivity of the film and the Kapitza conductance of the interface. Ultrafast Ti:sapphire laser pulses were used to heat the films; x-ray diffraction then measured the film's lattice expansion. Use of grazing incidence diffraction geometry provided depth sensitivity, as the x-ray angle of incidence was varied near the critical angle. The shift of the film's Bragg peak position with time was used to determine the film temperature averaged over an x-ray penetration depth that could be selected by choice of the angle of incidence. For films that were thick compared to the laser penetration depth, we observed a large temperature gradient at early times. In this case, measurements with the incident angle near or well above the critical angle were more sensitive to the film conductivity or Kapitza conductance, respectively. For thinner films, however, cooling was dominated by the Kapitza conductance at all accessible time scales.

Walko, D. A.; Sheu, Y.-M.; Trigo, M.; Reis, D. A. (X-Ray Science Division); (Univ. of Michigan,); (SLAC National Accelerator Lab.); (Stanford Univ.)

2011-01-01

401

Thermal transport in thin films measured by time-resolved, grazing incidence x-ray diffraction  

NASA Astrophysics Data System (ADS)

We use depth- and time-resolved x-ray diffraction to study thermal transport across single crystal Bi films grown on sapphire in order to determine the thermal conductivity of the film and the Kapitza conductance of the interface. Ultrafast Ti:sapphire laser pulses were used to heat the films; x-ray diffraction then measured the film's lattice expansion. Use of grazing incidence diffraction geometry provided depth sensitivity, as the x-ray angle of incidence was varied near the critical angle. The shift of the film's Bragg peak position with time was used to determine the film temperature averaged over an x-ray penetration depth that could be selected by choice of the angle of incidence. For films that were thick compared to the laser penetration depth, we observed a large temperature gradient at early times. In this case, measurements with the incident angle near or well above the critical angle were more sensitive to the film conductivity or Kapitza conductance, respectively. For thinner films, however, cooling was dominated by the Kapitza conductance at all accessible time scales.

Walko, D. A.; Sheu, Y.-M.; Trigo, M.; Reis, D. A.

2011-11-01

402

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

403

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

PubMed Central

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?Å 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.

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, Sebastien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E.; Gregory, Steven T.; Bogan, Michael J.

2013-01-01

404

Optimizing Monocapillary Optics for Synchrotron X-ray Diffraction, Fluorescence Imaging, and Spectroscopy Applications  

SciTech Connect

A number of synchrotron x-ray applications such as powder diffraction in diamond anvil cells, microbeam protein crystallography, x-ray fluorescence imaging, etc. can benefit from using hollow glass monocapillary optics to improve the flux per square micron on a sample. We currently draw glass tubing into the desired elliptical shape so that only one-bounce under total reflection conditions is needed to bring the x-ray beam to a focus at a 25 to 50 mm distance beyond the capillary tip. For modest focal spot sizes of 10 to 20 microns, we can increase the intensity per square micron by factors of 10 to 1000. We show some of the results obtained at CHESS and Hasylab with capillaries focusing 5 to 40 keV radiation, their properties, and how even better the experimental results could be if more ideal capillaries were fabricated in the future.

Bilderback, Donald H.; Kazimirov, Alexander; Gillilan, Richard; Cornaby, Sterling; Woll, Arthur; Zha, Chang-Sheng [CHESS, Wilson Laboratory, Cornell University, Ithaca, New York, 14853 (United States); Huang Rong [Center for Advanced Radiation Sources, U. of Chicago, Chicago, Illinois, 60637 (United States)

2007-01-19

405

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

NASA Astrophysics Data System (ADS)

We present time-resolved femtosecond photoelectron momentum images and angular distributions of dissociating, laser-aligned 1,4-dibromobenzene (C6H4Br2) molecules measured in a near-infrared pump, soft-x-ray probe experiment performed at an x-ray free-electron laser. The observed alignment dependence of the bromine 2p photoelectron angular distributions is compared to density functional theory calculations and interpreted in terms of photoelectron diffraction. While no clear time-dependent effects are observed in the angular distribution of the Br(2p) photoelectrons, other, low-energy electrons show a pronounced dependence on the time delay between the near-infrared laser and the x-ray pulse.

Rolles, D.; Boll, R.; Adolph, M.; Aquila, A.; Bostedt, C.; Bozek, J. D.; Chapman, H. N.; Coffee, R.; Coppola, N.; Decleva, P.; Delmas, T.; Epp, S. W.; Erk, B.; Filsinger, F.; Foucar, L.; Gumprecht, L.; Hömke, A.; Gorkhover, T.; Holmegaard, L.; Johnsson, P.; Kaiser, Ch; Krasniqi, F.; Kühnel, K.-U.; Maurer, J.; Messerschmidt, M.; Moshammer, R.; Quevedo, W.; Rajkovic, I.; Rouzée, A.; Rudek, B.; Schlichting, I.; Schmidt, C.; Schorb, S.; Schröter, C. D.; Schulz, J.; Stapelfeldt, H.; Stener, M.; Stern, S.; Techert, S.; Thøgersen, J.; Vrakking, M. J. J.; Rudenko, A.; Küpper, J.; Ullrich, J.

2014-06-01

406

Application of X-ray Diffraction to the Determination of Chrysotile in Bulk or Settled Dust Samples  

Microsoft Academic Search

A quantitative procedure has been developed for analyzing bulk or settled dust samples for chrysotile, the asbestos fiber most widely used in the United States asbestos industry. This asbestos mineral is a hydrated magnesium silicate with a crystalline structure which provides a distinct x-ray diffraction pattern of sufficient intensity to be used in quantitative analyses. X-ray diffraction is utilized for

John V. Crable; Marta J. Knott

1966-01-01

407

Image observation of diffraction spots using FZP and coherent X-ray beam  

SciTech Connect

New small angle X-ray dispersion speckle method by the condensing optical system using FZP (Fresnel zone plate) was performed. And single crystal diffraction spot image was observed using this optical system. High photon flux with the FZP of 100-micron-diameter is obtained than that with a 5-micron-diameter pinhole. S/N ratio of data improved and measurement time also became short. The minimum beam size focused with the FZP was 0.25 {mu}m. The speckle image resulting from the non-ordering structure and periodic structure of 10nm order is successfully observed. This optical system was applicable also to diffraction spot image observation. We show a possibility that the information of the periodic and/or random structural analysis with sub-{mu}m order which were unsuitable with the conventional single crystal x-ray diffraction analysis.

Suzuki, Takuya; Yoshizuka, Kazuharu [Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, 808-0135 (Japan); Takano, Hidekazu [College of Humanities and Sciences, Nippon University, 3-25-40 sakurazyousui, Setagaya-ku, Tokyo, 156-8550 (Japan); Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio [JASRI/SPring-8, 1-1-1 Kouto Mikazuki-cho Sayo-gun Hyogo 679-5198 (Japan); Kohmura, Yoshiki [RIKEN/SPring-8, 1-1-1 Kouto Mikazuki-cho Sayo-gun Hyogo 679-5148 (Japan); Hasegawa, Masashi [Institute for Materials Research, Tohoku University, 2-1-1 Aobaku Katahira, Sendai, 980-8577 (Japan)

2004-05-12

408

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

409

Single-particle structure determination by correlations of snapshot X-ray diffraction patterns  

NASA Astrophysics Data System (ADS)

Diffractive imaging with free-electron lasers allows structure determination from ensembles of weakly scattering identical nanoparticles. The ultra-short, ultra-bright X-ray pulses provide snapshots of the randomly oriented particles frozen in time, and terminate before the onset of structural damage. As signal strength diminishes for small particles, the synthesis of a three-dimensional diffraction volume requires simultaneous involvement of all data. Here we report the first application of a three-dimensional spatial frequency correlation analysis to carry out this synthesis from noisy single-particle femtosecond X-ray diffraction patterns of nearly identical samples in random and unknown orientations, collected at the Linac Coherent Light Source. Our demonstration uses unsupported test particles created via aerosol self-assembly, and composed of two polystyrene spheres of equal diameter. The correlation analysis avoids the need for orientation determination entirely. This method may be applied to the structural determination of biological macromolecules in solution.

Starodub, D.; Aquila, A.; Bajt, S.; Barthelmess, M.; Barty, A.; Bostedt, C.; Bozek, J. D.; Coppola, N.; Doak, R. B.; Epp, S. W.; Erk, B.; Foucar, L.; Gumprecht, L.; Hampton, C. Y.; Hartmann, A.; Hartmann, R.; Holl, P.; Kassemeyer, S.; Kimmel, N.; Laksmono, H.; Liang, M.; Loh, N. D.; Lomb, L.; Martin, A. V.; Nass, K.; Reich, C.; Rolles, D.; Rudek, B.; Rudenko, A.; Schulz, J.; Shoeman, R. L.; Sierra, R. G.; Soltau, H.; Steinbrener, J.; Stellato, F.; Stern, S.; Weidenspointner, G.; Frank, M.; Ullrich, J.; Strüder, L.; Schlichting, I.; Chapman, H. N.; Spence, J. C. H.; Bogan, M. J.

2012-12-01

410

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 Å, 2.2645 Å, and 2.1806 Å 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

411

High-pressure X-ray diffraction studies of potassium chlorate  

SciTech Connect

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

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

2012-03-15

412

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

413

Assessment of a MEDIPIX2 Detector for Coherent X-ray Diffractive Imaging  

NASA Astrophysics Data System (ADS)

Our group is concerned with addressing the limitations of current x-ray imaging devices for Coherent X-ray Diffractive Imaging (CXDI). CCDs are well established in this area of research. However the signal to noise ratio and dynamic range of integrating devices are sub-optimal for CXDI. For successful CXDI image reconstruction the recorded signal should be accurately measured over a wide dynamic range. This is best achieved by measuring precisely the number of photons registered by a pixel. Accurate data sets allow reconstruction algorithms to converge in a shorter time than if noisy estimates of the intensities are used. Using modern very large scale integrated circuit (VLSI) technology complex pixel readout circuitry can be fabricated with a footprint of less than 100 microns square. Placing an x-ray sensitive material above such a circuit matrix and electrically or optically connecting to it, produces a versatile and accurate x-ray detector. The name given to such a device is a hybrid pixel detector (HPD). We have chosen the MEDIPIX2 HPD to assess against the demands of CXDI. This paper reports on laboratory tests of a device with a 300 micron thick silicon as the x-ray converter, and an array of 256×256 pixels each of 55 microns square.

Hall, Chris; Spiers, Kathryn; Fullagar, Wilfred; Lewis, Rob

2010-06-01

414

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

415

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

416

I-line, DUV, VUV, or x ray?  

NASA Astrophysics Data System (ADS)

It is no longer possible to have just the best technology in the semiconductor equipment and materials market and remain successful. Each product tends to last for only one generation of IC devices. This high rate of imaging technology change means that the material or equipment manufacturer must have a large base of expertise to keep up with the rapidly changing needs and requirements of the technology. Also necessary is a large source of capital to finance development, manufacturing, and testing equipment. Unfortunately, the sequence of short business cycles, with limited lifetimes for each lithographic technology, is expected to continue for at least another ten years, until some technology or technologies, with long lifetimes through a large number of device generations, is firmly in place. The intent of this paper is to compare the potential IC manufacturing requirements, product timing, and the technological capabilities of i-line, DUV (248 nm), VUV (193 nm), and x ray. From this we intend to project the technological potential of each. To do this we intend to determine the limiting resolution and DOF of each technology, evaluate the resist and processing capabilities, examine the engineering requirements. We evaluate the impact of phase shift mask technology, surface imaging, and planarization and their impact on lithographic potential. From this information we provide a comparison of these four technologies. This data is then compared to IC device requirements and timetables from which a lithographic product need and lifetime relationship can be determined for each technology.

Johnson, Donald W.; Mack, Chris A.

1992-06-01

417

Structure of confined fluids by x-ray interferometry using diffraction gratings.  

PubMed

We develop a novel method for structure determination of confined fluids using diffraction-grating-based x-ray interferometry.Within this approach, diffraction from a microfluidic array, which acts both as confinement and transmission diffraction grating, provides the reference wave, whereas the density modulations of the confined fluid, acting as a weak phase object, generate the object wave. The ensemble-averaged density profile of the fluid perpendicular to the confining channel is then unambiguously obtained from the interference between the reference and object waves by direct Fourier inversion. PMID:19065191

Nygård, K; Satapathy, D K; Bunk, O; Diaz, A; Perret, E; Buitenhuis, J; Pfeiffer, F; David, C; van der Veen, F

2008-12-01

418

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

PubMed

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. PMID:24229216

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

2013-10-01

419

Coherent convergent-beam time-resolved X-ray diffraction.  

PubMed

The use of coherent X-ray lasers for structural biology allows the use of nanometre diameter X-ray beams with large beam divergence. Their application to the structure analysis of protein nanocrystals and single particles raises new challenges and opportunities. We discuss the form of these coherent convergent-beam (CCB) hard X-ray diffraction patterns and their potential use for time-resolved crystallography, normally achieved by Laue (polychromatic) diffraction, for which the monochromatic laser radiation of a free-electron X-ray laser is unsuitable. We discuss the possibility of obtaining single-shot, angle-integrated rocking curves from CCB patterns, and the dependence of the resulting patterns on the focused beam coordinate when the beam diameter is larger or smaller than a nanocrystal, or smaller than one unit cell. We show how structure factor phase information is provided at overlapping interfering orders and how a common phase origin between different shots may be obtained. Their use in refinement of the phase-sensitive intensity between overlapping orders is suggested. PMID:24914153

Spence, John C H; Zatsepin, Nadia A; Li, Chufeng

2014-07-17

420

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 information1–4. 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.

Barty, Anton; Caleman, Carl; Aquila, Andrew; Timneanu, Nicusor; Lomb, Lukas; White, Thomas A.; Andreasson, Jakob; Arnlund, David; Bajt, Sasa; 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, Gunter; 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; Struder, Lothar; Ullrich, Joachim; Wang, X.; Weidenspointner, Georg; Weierstall, Uwe; Wunderer, Cornelia B.; Chapman, Henry N.

2013-01-01

421

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements  

NASA Astrophysics Data System (ADS)

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 analysis. 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 information. 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 technology should enable structural determination from submicrometre protein crystals with atomic resolution.

Barty, Anton; Caleman, Carl; Aquila, Andrew; Timneanu, Nicusor; Lomb, Lukas; White, Thomas A.; Andreasson, Jakob; Arnlund, David; Bajt, Saša; 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, Günter; 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; Strüder, Lothar; Ullrich, Joachim; Wang, X.; Weidenspointner, Georg; Weierstall, Uwe; Wunderer, Cornelia B.; Chapman, Henry N.

2012-01-01

422

In situ high-pressure x-ray diffraction study of H[subscript 2]O ice VII  

SciTech Connect

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu, M.; Shu, J.; Zha, C.-S.; Goncharov, A.F. (CIW)

2008-06-30

423

X-ray Diffraction from a Left Ventricular Wall of Rat Heart  

PubMed Central

We studied x-ray diffraction from the left ventricular wall of an excised, perfused whole heart of a rat using x rays from the third-generation synchrotron radiation facility, SPring-8. With the beam at right angles to the long axis of the left ventricle, well-oriented, strong equatorial reflections were observed from the epicardium surface. The reflections became vertically split arcs when the beam passed through myocardium deeper in the wall, and rings were observed when the beam passed into the inner myocardium of the wall. These diffraction patterns were explained by employing a layered-spiral model of the arrangement of muscle fibers in the heart. In a quiescent heart with an expanded left ventricle, the muscle fibers at the epicardium surface were found to have a (1,0) lattice spacing smaller than in the rest of the wall. The intensity ratio of the (1,0) and (1,1) equatorial reflections decreased on contraction with a similar time course in all parts of the wall. The results show that it is possible to assign the origin of reflections in a diffraction diagram from a whole heart. This study offers a basis for interpretation of x-ray diffraction from a beating heart under physiologically and pathologically different conditions.

Yagi, Naoto; Shimizu, Juichiro; Mohri, Satoshi; Araki, Jun'ichi; Nakamura, Kazufumi; Okuyama, Hiroshi; Toyota, Hiroko; Morimoto, Taro; Morizane, Yuki; Kurusu, Mie; Miura, Tatsushi; Hashimoto, Katsushi; Tsujioka, Katsuhiko; Suga, Hiroyuki; Kajiya, Fumihiko

2004-01-01

424

X-ray Diffraction Studies of the Thick Filament in Permeabilized Myocardium from Rabbit  

SciTech Connect

Low angle x-ray diffraction patterns from relaxed permeabilized rabbit cardiac trabeculae and psoas muscle fibers were compared. Temperature was varied from 25{sup o}C to 5{sup o}C at 200 mM and 50 mM ionic strengths ({mu}), respectively. Effects of temperature and {mu} on the intensities of the myosin layer lines (MLL), the equatorial intensity ratio I{sub 1,1}/I{sub 1,0}, and the spacing of the filament lattice are similar in both muscles. At 25{sup o}C, particularly at {mu} = 50 mM, the x-ray patterns exhibited up to six orders of MLL and sharp meridional reflections, signifying that myosin heads (cross-bridges) are distributed in a well-ordered helical array. Decreasing temperature reduced MLL intensities but increased I{sub 1,1}/I{sub 1,0}. Decreases in the MLL intensities indicate increasing disorder in the distribution of cross-bridges on the thick filaments surface. In the skeletal muscle, order/disorder is directly correlated with the hydrolysis equilibrium of ATP by myosin, [M.ADP.P{sub i}]/[M.ATP]. Similar effects of temperature on MLL and similar biochemical ATP hydrolysis pathway found in both types of muscles suggest that the order/disorder states of cardiac cross-bridges may well be correlated with the same biochemical and structural states. This implies that in relaxed cardiac muscle under physiological conditions, the unattached cross-bridges are largely in the M.ADP.P{sub i} state and with the lowering of the temperature, the equilibrium is increasingly in favor of [M.ATP] and [A.M.ATP]. There appear to be some differences in the diffraction patterns from the two muscles, however. Mainly, in the cardiac muscle, the MLL are weaker, the I{sub 1,1}/I{sub 1,0} ratio tends to be higher, and the lattice spacing D{sub 10}, larger. These differences are consistent with the idea that under a wide range of conditions, a greater fraction of cross-bridges is weakly bound to actin in the myocardium.

Xu,S.; Martyn, D.; Zaman, J.; Yu, L.

2007-01-01

425

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

426

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 µm down to 10 µm 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

427

X-ray diffraction imaging of metal-oxide 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–oxide tunnel junctions made by optical lithography, with lateral sizes ranging from 150?µm down to 10?µm 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.

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

2013-01-01

428

Diffraction theory applied to X-ray imaging with clessidra prism array lenses.  

PubMed

Clessidra (hourglass) lenses, i.e. two large prisms each composed of smaller identical prisms or prism-like objects, can focus X-rays. As these lenses have a periodic structure perpendicular to the incident radiation, they will diffract the beam like a diffraction grating. Refraction in the prisms is responsible for blazing, i.e. for the concentration of the diffracted intensity into only a few diffraction peaks. It is found that the diffraction of coherent radiation in clessidra lenses needs to be treated in the Fresnel, or near-field, regime. Here, diffraction theory is applied appropriately to the clessidra structure in order to show that blazing in a perfect structure with partly curved prisms can indeed concentrate the diffracted intensity into only one peak. When the lens is entirely composed of identical perfect prisms, small secondary peaks are found. Nevertheless, the loss in intensity in the central peak will not lead to any significant widening of this peak. Clessidras with perfect prisms illuminated by full coherent X-ray radiation can then provide spatial resolutions, which are consistent with the increased aperture, and which are far below the height of the single small prisms. PMID:18296785

De Caro, Liberato; Jark, Werner

2008-03-01

429

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

PubMed

Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. PMID:24209602

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

2014-08-01

430

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

431

Spectroscopic and X-ray Diffraction Study of Structural Disorder in Cryomilled and Amorphous Griseofulvin  

SciTech Connect

Structural disorder induced by cryogenic milling and by heating to the amorphous phase in the active pharmaceutical ingredient Griseofulvin has been studied using Raman spectroscopy, X-ray powder diffraction (XRPD), and fluorescence spectroscopy. A broad, exciting-frequency-independent scattering background in the Raman spectra and changes in intensities and splitting of some of the Raman lines due to lattice and molecular modes have been observed. In the cryomilled samples this strong background is deconvoluted into two components: one due to lattice disorder induced by cryomilling and the other due to Mie scattering from nanosized crystallites. A single-component background scattering attributed to lattice disorder is seen in the Raman spectrum of the amorphous sample. Fluorescence measurements showed an intrinsic fluorescence signal in as-received Griseofulvin that does not correspond to the inelastic background in the Raman spectra and, moreover, decreases in intensity upon cryomilling, thus excluding an assignment of the Raman background intensity to impurity- or molecular-defect-induced fluorescence. Wide-angle XRPD measurements on cryomilled Griseofulvin shows a broad two-component background consistent with the background-scattering component in the Raman data associated with lattice disorder, but at longer correlation lengths. Persistence of this disorder to even longer lengths is evident in small-angle synchrotron XRPD data on micronized Griseofulvin taken as a function of temperature from the crystalline to the amorphous phase.

A Zarow; B Zhou; X Wang; R Pinal; Z Iqbal

2011-12-31

432

Measuring Strain field of Multi-Component Material Systems Using X-Ray Bragg- Surface Diffraction  

NASA Astrophysics Data System (ADS)

We investigated the strain field of the ?-FeSi2 semiconductor on a Si(001) substrate, where FeSi in a grain form coexists with ?-FeSi2 during the growth of ?-FeSi2. The lattice-parameter variations of silicon, ?-FeSi2, FeSi and the grain boundary were detected using x-ray Bragg-Surface Diffraction (BSD). With the penetration depth calculated by the dynamical theory of x-ray diffraction, the strain field versus depth of Si-substrate near the interface is determined with the resolution of 0.002 å. The largest strain detected is about 0.4% up to 8˜12 å below the interfaces.

Chu, Chia-Hung; Tsai, Yi-Wei; Chou, Li-Jen; Tang, Mau-Tsu; Stetsko, Yuriy P.; Chang, Shih-Lin

2010-03-01

433

Structural investigation of GaInP nanowires using X-ray diffraction  

PubMed Central

In this work the structure of ternary GaxIn1 ? xP nanowires is investigated with respect to the chemical composition and homogeneity. The nanowires were grown by metal–organic vapor-phase epitaxy. For the investigation of ensemble fluctuations on several lateral length scales, X-ray diffraction 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.

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

2013-01-01

434

Experimental Approaches for Solution X-Ray Scattering And Fiber Diffraction  

SciTech Connect

X-ray scattering and diffraction from non-crystalline systems have gained renewed interest in recent years, as focus shifts from the structural chemistry information gained by high-resolution studies to the context of structural physiology at larger length scales. Such techniques permit the study of isolated macromolecules as well as highly organized macromolecular assemblies as a whole under near-physiological conditions. Time-resolved appr