scholarly journals Determination of Dislocation Density and Correlation Length of Si, Ti, Au and Zno on Ge by Peak Profile

2021 ◽  
Author(s):  
Ahmet Kürşat Bilgili ◽  
Rabia ÇAĞATAY ◽  
Hasan Celal DERVİŞOĞLU ◽  
Mustafa Kemal ÖZTÜRK
Keyword(s):  
Dislocation Density ◽  
Correlation Length ◽  
Iteration Step ◽  
X Ray Diffraction ◽  
Dense Region ◽  
X Ray ◽  
Good Accordance ◽  
Gauss Function ◽  
Diffraction Peaks

Abstract In this study, X-ray diffraction peaks of Si, Ti, Au and ZnO grown on Ge substrate with thickness of 500 nm by using sputtering method are analyzed to determine correlation length and dislocation density. It is seen that in most dense region of peaks, peak behaviour is in accordance with Gauss function. Right and left tails of peaks are in good accordance with q3 law. For randomized dislocations, obeying q3 law is typical and they can be monitored with w-scans by using open detectors. Whole profile is fitted with a limited dislocation dispersion. Edge dislocation density and correlation length are determined in the degree of 1010cm-2 and 103 nm, respectively. In order to gain these values, semi-experimental equations in Kragner method are used. For making a good fit, fit iteration step is taken as 9x106.

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.

Techniques for the Determination of Particle Size and Texture in Retained Austenite / Martensite Microstructures and Interpretation of the Measurements

1995 ◽  
Vol 39 ◽  
pp. 473-479
Author(s):  
J. D. Makinson ◽  
W. N. Weins ◽  
Y. Xu ◽  
D. J. Medlin ◽  
R. V. Lawrence
Keyword(s):  
Particle Size ◽  
Retained Austenite ◽  
Quantitative Information ◽  
Manufacturing Processes ◽  
X Ray Diffraction ◽  
Steel Component ◽  
X Ray ◽  
Other Information ◽  
Diffraction Peaks

The measurement of retained austenite is important in the analysis and quality control of asmanufactured steel components, as well as to the evaluation of components returned from service. The amounts of retained austenite are most accurately measured using x-ray diffraction techniques where the integrated area under the austenite and martensite diffraction peaks from a sample are determined. In addition to quantitative information about the amount of each phase, however, the raw x-ray diffraction data contains other information that may be useful in evaluating the condition of a steel component. The diffracting particle size of both the martensite and austenite phases, and the presence and degree of preferred orientation in both phases can be calculated from the basic four peak retained austenite x-ray scan. This information, in conjunction with knowledge of the amount of retained austenite present, may be used to determine information about variations in materials and manufacturing processes as well as changes due to service. If the residual stress in both phases is also measured, additional conclusions can be made regarding changes due to processing and service. The theoretical and experimental aspects of these measurements are reviewed data from a case history in which these types of measurements were used to determine changes due to processing and service are presented.

A fast methodology to determine the characteristics of thousands of grains using three-dimensional X-ray diffraction. I. Overlapping diffraction peaks and parameters of the experimental setup

2012 ◽  
Vol 45 (4) ◽  
pp. 693-704 ◽  
Author(s):  
Hemant Sharma ◽  
Richard M. Huizenga ◽  
S. Erik Offerman
Keyword(s):  
Data Analysis ◽  
Three Dimensional ◽  
Experimental Setup ◽  
Centre Of Mass ◽  
X Ray Diffraction ◽  
X Ray ◽  
Overlapping Peaks ◽  
Diffraction Peaks ◽  
Mass Position

A data-analysis methodology is presented for the characterization of three-dimensional microstructures of polycrystalline materials from data acquired using three-dimensional X-ray diffraction (3DXRD). The method is developed for 3DXRD microscopy using a far-field detector and yields information about the centre-of-mass position, crystallographic orientation, volume and strain state for thousands of grains. This first part deals with pre-processing of the diffraction data for input into the algorithms presented in the second part [Sharma, Huizenga & Offerman (2012).J. Appl. Cryst.45, 705–718] for determination of the grain characteristics. An algorithm is presented for accurate identification of overlapping diffraction peaks from X-ray diffraction images, which has been an issue limiting the accuracy of experiments of this type. The algorithm works in two stages, namely the identification of overlapping peaks using a seeded watershed algorithm, and then the fitting of the peaks with a pseudo-Voigt shape function to yield an accurate centre-of-mass position and integrated intensity for the peaks. Regions consisting of up to six overlapping peaks can be successfully fitted. Two simulations and an experiment are used to verify the results of the algorithms. An example of the processing of diffraction images acquired in a 3DXRD experiment with a sample consisting of more than 1600 grains is shown. Furthermore, a procedure for the determination of the parameters of the experimental setup (global parameters) without the need for a calibration sample is presented and validated using simulations. This is immensely beneficial for simplifying experiments and the subsequent data analysis.

scholarly journals Determining the Degree of [001] Preferred Growth of Ni(OH)2 Nanoplates

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 991 ◽  
Author(s):  
Taotao Li ◽  
Ning Dang ◽  
Wanggang Zhang ◽  
Wei Liang ◽  
Fuqian Yang
Keyword(s):  
Shape Function ◽  
Complex Anion ◽  
Practical Importance ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Accordance ◽  
Low Dimensional ◽  
Low Dimensional Materials

Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results measured by SEM and TEM imaging. The method using the shape function of crystallites is not suitable for the determination of the preferred growth degree of the Ni(OH)2 nanoplates. The method using the March parameter and the expression given by Zolotoyabko can be extended to the analysis of block materials.

The X-Ray Diffraction Characteristics of Different Materials

2010 ◽  
Vol 638-642 ◽  
pp. 2434-2439 ◽  
Author(s):  
Yi Liang Zhang ◽  
Zhao Miao Liu ◽  
Jin Yan Liu
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Accurate Determination ◽  
X Ray Diffraction ◽  
Ray Method ◽  
X Ray ◽  
Real Change ◽  
Diffraction Peaks ◽  
Aluminum Titanium Alloy

The x-ray diffraction characteristics of different materials are discussed in this paper. It is found that the accurate determination of real stress is not easy to obtain when two diffraction peaks with low diffraction intensity are shown and the residual stress of stainless steel, aluminum, titanium alloy materials etc are determined by X-ray method. Five kinds of uniform intensity girders made from common carbon steel (Q235), austenite stainless steel (1Cr18Ni9Ti), martensitic stainless steel(A335P92), aluminium alloy(LY12) and titanium alloy(TA15) are determined repeatedly using uniform intensity girder demarcation method. It is proved by experiment results that X-ray diffraction peaks at some angles can’t well reflect the real change of stress.

scholarly journals Refining bimodal microstructure of materials with MSTRUCT

2014 ◽  
Vol 29 (S2) ◽  
pp. S35-S41 ◽  
Author(s):  
Z. Matěj ◽  
A. Kadlecová ◽  
M. Janeček ◽  
L. Matějová ◽  
M. Dopita ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Copper Sample ◽  
Bimodal Microstructure ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Angular Pressing ◽  
Crystallite Sizes ◽  
Diffraction Peaks

The possibilities of modelling the diffraction profiles from bimodal microstructure in computer program MSTRUCT are demonstrated on two examples. A special “Double Component” profile effect can be utilized for such problems. At first it was applied to an analysis of a mixture of two nanocrystalline anatase powders with different crystallite sizes and the relative ratio of both components was determined from X-ray diffraction data. In the second case study, diffraction peaks from a pure polycrystalline copper sample treated by equal channel angular pressing were fitted using a two-phase model of large recrystallized defect-free grains and ultrafine crystallites with high dislocation density. The method is shown to be suitable for determination of the relative fraction of the microstructural components as well as other parameters (e.g. dislocation density).

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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