A new approach to the determination of atomic-architecture of amorphous zeolite precursors by high-energy X-ray diffraction technique

2006 ◽  
Vol 8 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Toru Wakihara ◽  
Shinji Kohara ◽  
Gopinathan Sankar ◽  
Seijiro Saito ◽  
Manuel Sanchez-Sanchez ◽  
...  
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Zeolite Precursors

X-ray diffraction cell for studying solid–gas reactions under gas pressures to 100 bar

2006 ◽  
Vol 39 (6) ◽  
pp. 850-855 ◽  
Author(s):  
E. MacA. Gray ◽  
D. J. Cookson ◽  
T. P. Blach
Keyword(s):  
Phase Transformation ◽  
Heat Flow ◽  
Real Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Determination ◽  
Gas Reactions ◽  
Gas Pressures

A pressure cell designed for high-energy X-ray diffraction in transmission mode is described. The cell is intended for use at temperatures up to 573 K with samples that are large enough to permit the real-time determination of the amount of absorbed gas by measuring the gas pressure. The design is driven by the need to ensure that the sample temperature is constant and uniform, despite the heat flow accompanying the reaction between the gas and the sample. The use of the cell is illustrated by its application to elucidating the hydriding phase transformation in the LaNi5–H2system.

Experimental determination of residual stress in silicon nitride diffusion bonds obtained by high-energy X-ray diffraction

2004 ◽  
Vol 148 (1) ◽  
pp. 60-63 ◽  
Author(s):  
M. Vila ◽  
M.L. Martínez ◽  
C. Prieto ◽  
P. Miranzo ◽  
M.I. Osendi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Silicon Nitride ◽  
Experimental Determination ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Bonds

Oxford HEXameter: Laboratory High Energy X-Ray Diffractometer for Bulk Residual Stress Analysis

2006 ◽  
Vol 524-525 ◽  
pp. 743-748 ◽  
Author(s):  
Alexander M. Korsunsky ◽  
Shu Yan Zhang ◽  
Daniele Dini ◽  
Willem J.J. Vorster ◽  
Jian Liu
Keyword(s):  
Accurate Determination ◽  
High Energy ◽  
Energy Dispersive ◽  
Detector Response ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Instrument ◽  
Synchrotron Beamlines

Diffraction of penetrating radiation such as neutrons or high energy X-rays provides a powerful non-destructive method for the evaluation of residual stresses in engineering components. In particular, strain scanning using synchrotron energy-dispersive X-ray diffraction has been shown to offer a fast and highly spatially resolving measurement technique. Synchrotron beamlines provide best available instruments in terms of flux and low beam divergence, and hence spatial and measurement resolution and data collection rate. However, despite the rapidly growing number of facilities becoming available in Europe and across the world, access to synchrotron beamlines for routine industrial and research use remains regulated, comparatively slow and expensive. A laboratory high energy X-ray diffractometer for bulk residual strain evaluation (HEXameter) has been developed and built at Oxford University. It uses a twin-detector setup first proposed by one of the authors in the energy dispersive X-ray diffraction mode and allows simultaneous determination of macroscopic and microscopic strains in two mutually orthogonal directions that lie approximately within the plane normal to the incident beam. A careful procedure for detector response calibration is used in order to facilitate accurate determination of lattice parameters by pattern refinement. The results of HEXameter measurements are compared with synchrotron X-ray data for several samples e.g. made from a titanium alloy and a particulate composite with an aluminium alloy matrix. Experimental results are found to be consistent with synchrotron measurements and strain resolution close to 2×10-4 is routinely achieved by the new instrument.

scholarly journals A new approach for the determination of multiple cation locations and ordering, using the example of natural and heat-treated columbites

2011 ◽  
Vol 44 (4) ◽  
pp. 738-746 ◽  
Author(s):  
E. J. Kinast ◽  
O. Isnard ◽  
J. B. M. da Cunha ◽  
M. A. Z. de Vasconcellos ◽  
C. A. dos Santos
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
X Ray Diffraction ◽  
Rietveld Refinements ◽  
New Approach ◽  
X Ray ◽  
Type Compound ◽  
Natural Minerals ◽  
Heat Treated

A new approach is proposed to determine unambiguously the location of four cations within the crystal structure of a naturalAB2O6columbite-type compound and derivatives, when submitted to order–disorder transitions caused by heat treatments. This method is based on the successive use of electron microprobe analysis to determine the cation concentration, Mössbauer spectroscopy to identify the Fe occupation, and a crystal structure determination of the samples combining Rietveld refinements of both neutron and X-ray diffraction. This approach is tested successfully to investigate (Fe, Mn, Nb, Ta) natural minerals as well as oxides obtained by heat treatment of the initialAB2O6columbite-type compound.

scholarly journals In situ high-energy X-ray diffraction of precipitation and dissolution reactions during heating of Al alloys

2021 ◽  
Author(s):  
Hannes Fröck ◽  
Christian Rowolt ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Wolfgang Kowalski ◽  
...  
Keyword(s):  
High Energy ◽  
Al Alloys ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Zero Crossing ◽  
New Approach ◽  
X Ray ◽  
Common Technique ◽  
Equilibrium Phases

AbstractDuring heating of Al alloys, typically a sequence of precipitation and dissolution reactions occurs and the single (partly opposing) reactions superimpose. Differential scanning calorimetry (DSC) is one common technique to analyse the kinetic development of precipitation and dissolution in Al alloys, but the superposition of the exothermic precipitation and endothermic dissolution reactions complicates the DSC signal interpretation, as DSC measures the sum of any heat effect. Synchrotron high-energy X-ray diffraction (HEXRD) allows the kinetic development of phase transformations to be obtained and can support the separation of superimposed DSC signals. HEXRD results from this work offer a new approach to separate part of the superimposed reactions and their kinetic development for the equilibrium phases β-Mg2Si in EN AW-6082 and η-Mg(Zn,Cu,Al)2 in EN AW-7150. Comparing DSC and HEXRD results confirms serious overlap issues. Common DSC evaluation methods alone, using zero crossing between endothermic and exothermic heat flow or peak positions can be misleading regarding individual reaction start and finish temperatures as well as regarding reaction intensities, which can be unambiguously determined by in situ HEXRD.

Twenty Years of Progress in X-Ray Diffraction Techniques

1961 ◽  
Vol 5 ◽  
pp. 1-12
Author(s):  
Andre Guinier
Keyword(s):  
Electron Microscopy ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
Rational Utilization ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Near Future

AbstractAlthough no revolutionary advance has been achieved in the last two decades, X-ray diffraction is not to be considered as a quiescent field of physics. Actually many improvements, in theory as well as in experiment, slight by themselves but very numerous, have considerably increased the efficiency of techniques such as the determination of crystal structures, the analysis of crystalline phases, and the applications of X-rays to various problems of the physics of solids. Only the two last points will be dealt with here:1.Crystalline phase analysis. The development of a satisfactory atlas of powder patterns has been too slow, and the data are not yet complete and precise enough to permit a rational utilization of the modern diffractometers. A very interesting new approach is the systematic indexing of the powder patterns which would be possible with computers. In the near future, anyone should be able to analyze a powder at any temperature as an easy routine experiment.2.The study of lattice defects. X-ray techniques are now in competition with electron microscopy, the development of which has been very successful in recent years. Now we have a better understanding of the possibilities of both techniques. X-rays give better results to determine the statistics of an extended disorder even if it is slight (e.g., degrees of order in a solid solution), and the microscope is more powerful for the detection of large but rare defects (e.g., dislocations).

Quantitative determination of fragmentation kinetics and thermodynamics of colloidal silver nanowires by in situ high-energy synchrotron X-ray diffraction

Nanoscale ◽  
2014 ◽  
Vol 6 (1) ◽  
pp. 365-370 ◽  
Author(s):  
Zheng Li ◽  
John S. Okasinski ◽  
Jonathan D. Almer ◽  
Yang Ren ◽  
Xiaobing Zuo ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Silver Nanowires ◽  
High Energy ◽  
Colloidal Silver ◽  
X Ray Diffraction ◽  
Kinetics And Thermodynamics ◽  
X Ray

Microstructural Evolution of Monolithic Fuel Foils During Processing

2014 ◽  
Vol 70 (a1) ◽  
pp. C729-C729
Author(s):  
Donald Brown ◽  
Maria Okuniewski ◽  
Bjorn Clausen ◽  
Thomas Sisneros ◽  
Levente Balogh
Keyword(s):  
Dislocation Density ◽  
Residual Stresses ◽  
Weight Percent ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bonded Materials ◽  
Processing Step ◽  
Phase Stresses

Residual stresses are expected in monolithic, aluminum clad uranium 10 weight percent molybdenum (U-10Mo) nuclear fuel plates because of the large mismatch in thermal expansion between the two bonded materials. Previous high energy x-ray diffraction measurements successfully profiled the residual stresses in the U-10Mo, but were unable to probe either the Al cladding or the 15micron Zr diffusion prevention barrier due to poor grain statistics. Neutron diffraction, with its inherently more divergent incident be alleviates this problem and, moreover, allowed for the determination of the dislocation density and texture in all three phases. Several samples were examined as a function of processing step and the phase stresses, dislocation density and texture are monitored with respect to the processing conditions.

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