The determination of dislocation density depth profiles in surface layers from broadening of X-ray diffraction profiles

1990 ◽  
Vol 50 (1) ◽  
pp. 107-109 ◽  
Author(s):  
Liu Yang ◽  
Hongnian Yao
Keyword(s):  
Dislocation Density ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Depth Profiles

Experimental Method of Determination of Structural Correlations in Surface Layers of Oxide Glass

1990 ◽  
Vol 216 ◽  
Author(s):  
Zenon BochyŃski
Keyword(s):  
Structural Changes ◽  
Lattice Models ◽  
Molecular Size ◽  
Oxide Glass ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
The Real ◽  
Inorganic Glasses

ABSTRACTA new method of X-ray diffraction analysis of structural inhomogeneities in the quartz/Si02/n based inorganic glasses is presented. The method enables the determination of structural changes occuring in the real nodal lattice in the regions of 10…20 Å or more as well as substructural changes in the regions 5…15 Å comparable to the molecular size of SiO2…SiO4. In consequence these changes can be correlated with approximate nodal lattice models of different degree of ordering. The applied method provided the possibility of constructing structural models of nodal lattices describing the surface and inner layers of the real glasses, changes in the local inhomogeneities as well as boundaries in water-gel associates.

scholarly journals RaDMaX online: a web-based program for the determination of strain and damage profiles in irradiated crystals using X-ray diffraction

2020 ◽  
Vol 53 (2) ◽  
pp. 587-593
Author(s):  
A. Boulle ◽  
V. Mergnac
Keyword(s):  
Web Application ◽  
The Internet ◽  
Programming Environment ◽  
X Ray Diffraction ◽  
Web Browser ◽  
Web Based ◽  
X Ray ◽  
Depth Profiles ◽  
User Friendly

RaDMaX online is a major update to the previously published RaDMaX (radiation damage in materials analysed with X-ray diffraction) software [Souilah, Boulle & Debelle (2016). J. Appl. Cryst. 49, 311–316]. This program features a user-friendly interface that allows retrieval of strain and disorder depth profiles in irradiated crystals from the simulation of X-ray diffraction data recorded in symmetrical θ/2θ mode. As compared with its predecessor, RaDMaX online has been entirely rewritten in order to be able to run within a simple web browser, therefore avoiding the necessity to install any programming environment on the users' computers. The RaDMaX online web application is written in Python and developed within a Jupyter notebook implementing graphical widgets and interactive plots. RaDMaX online is free and open source and can be accessed on the internet at https://aboulle.github.io/RaDMaX-online/.

Processing of Ultrafine Grained Cu-30%Zn Alloy through Severe Plastic Deformation Using Accumulative Roll Bonding

2010 ◽  
Vol 667-669 ◽  
pp. 571-576
Author(s):  
Sayed Ghafar Hashemi ◽  
Beitallah Eghbali
Keyword(s):  
Dislocation Density ◽  
Size Distribution ◽  
Profile Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrafine Grained ◽  
Average Contrast ◽  
Log Normal ◽  
Zn Alloy

In the present research, the microstructural features of ultrafine grained Cu-30 Zn alloy via ARB at room temperature were investigated by X-ray diffraction peak profile analysis. The character of dislocations was determined by analyzing the dislocation contrast factors. The average contrast factors for the different reflections obtained by determination of the type of dislocations and Burgers vectors in crystals. Also, using the modified Williamson–Hall and Warren–Averbach procedure size parameters, the effective outer cut-off radius and density of dislocations were determined. Assuming that the grain size distribution is log-normal, the median and the variance of the size distribution of sub grains were obtained. It was found that the crystallite size is reduced substantially, while the dislocation density increases up to 2 cycles of ARB. After 2nd cycle, dislocation density decreases. This is attributed to the occurrence of dynamic restoration process which takes place during next ARB cycles.

scholarly journals RaDMaX: a graphical program for the determination of strain and damage profiles in irradiated crystals

2016 ◽  
Vol 49 (1) ◽  
pp. 311-316 ◽  
Author(s):  
M. Souilah ◽  
A. Boulle ◽  
A. Debelle
Keyword(s):  
Spline Functions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Diffraction Model ◽  
Calculated Curve ◽  
Fitting Procedures ◽  
Damage Depth ◽  
User Friendly

RaDMaX(radiation damage in materials analysed with X-ray diffraction) is a user-friendly graphical program that allows the determination of strain and damage depth profiles in ion-irradiated crystals. This task is achieved by fitting experimental X-ray diffraction data, recorded in symmetrical θ–2θ geometry, with a dynamical diffraction model parametrized with variable strain and damage profiles based onB-spline functions. The strain and damage profiles can be graphically manipulated so as to fit the calculated curve to the experimental data. Automatic fitting procedures (generalized simulated annealing and conventional least squares) are also implemented.RaDMaXis free and open source (CeCILL licence) and can be downloaded from http://aboulle.github.io/RaDMaX.

Determination of Crystal Structure and Cation Distribution in Thin Films

1991 ◽  
Vol 35 (A) ◽  
pp. 151-157
Author(s):  
G. Will ◽  
T. C. Huang ◽  
F. Sequeda
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Grazing Incidence ◽  
High Tech ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Scanning Geometry

The structural characterization of thin films is important for research development and manufacturing of electronic, magnetic, optical, and other high-tech materials. The grazing incidence X-ray diffraction technique has bean used successfully for the determination of crystalline phases, structural-depth profiles, crystallite size, and strain, etc. of thin films with thickness's down to a few tens of Å, If the crystal structure, e.g. the distribution of atoms in the unit cell, or the crystallinity and texture (or preferred orientation) of a film is of interest, the conventional Bragg-Brentano diffractometer technique with the θ-2θ scanning geometry has been found to be appropriate.

Determination of depth profiles from X-ray diffraction data

1993 ◽  
Vol 8 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Paul Predecki
Keyword(s):  
Diffraction Data ◽  
Direct Method ◽  
Sample Surface ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
Depth Profiles ◽  
A Direct Method

A direct method is described for determining depth profiles (z-profiles) of diffraction data from experimentally determined τ-profiles, where z is the depth beneath the sample surface and τ is the 1/e penetration depth of the X-ray beam. With certain assumptions, the relation between these two profile functions can be expressed in the form of a Laplace transform. The criteria for fitting experimental τ-data to functions which can be utilized by the method are described. The method was applied to two τ-data sets taken from the literature: (1) of residual strain in an A1 thin film and (2) of residual stress in a surface ground A12O3/5vol% TiC composite. For each data set, it was found that the z-profiles obtained were of two types: oscillatory and nonoscillatory. The nonoscillatory profiles appeared to be qualitatively consistent for a given data set. The oscillatory profiles were considered to be not physically realistic. For the data sets considered, the nonoscillatory z-profiles were found to lie consistently above the corresponding τ-profiles, and to approach the τ-profiles at large z, as expected from the relation between the two.

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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