Dependence of the strain diffraction line broadening on (hkl) and sample direction in textured polycrystals

2013 ◽  
Vol 46 (2) ◽  
pp. 391-395 ◽  
Author(s):  
Nicolae C. Popa ◽  
George Adrian Lungu
Keyword(s):  
Phenomenological Approach ◽  
Diffraction Line ◽  
Line Broadening ◽  
New Model ◽  
Anisotropic Strain ◽  
Diffraction Patterns

A new phenomenological approach describing the dependence of the strain diffraction line breadth on direction in both crystal and sample is presented. For a negligibly small dependence on the direction in the sample, these models reduce to those for anisotropic strain broadening that already exist in the literature and which are implemented in popular Rietveld codes. The new model is appropriate for implementation in the Rietveld programs able to process simultaneously diffraction patterns recorded in multiple directions in a sample.

Notes on the order-of-reflection dependence of microstrain broadening

2010 ◽  
Vol 43 (5) ◽  
pp. 981-989 ◽  
Author(s):  
A. Leineweber ◽  
E. J. Mittemeijer
Keyword(s):  
Phenomenological Approach ◽  
Nonlinear Dependence ◽  
Line Broadening ◽  
Diffraction Vector ◽  
Integral Breadth ◽  
Lorentzian Line ◽  
Diffraction Angle ◽  
Diffraction Patterns ◽  
Lattice Planes ◽  
Insight Into

In order to obtain systematic insight into the different manifestations of microstrain broadening in powder diffraction patterns, the consequences of the breakdown of the Stokes–Wilson approximation (negligible strain gradient in a stack of lattice planes) were investigated. To this end, a phenomenological approach for the decay of the variance of the microstrain with increasing correlation distanceL, 〈∊L2〉, was adopted, as well as a Gaussian microstrain distribution for eachL. For the case of anL-independent 〈∊L2〉 (i.e.the Stokes–Wilson approximation) the (Gaussian) microstrain distribution directly shows up (is affinely mapped) on the diffraction angle scale as well as on the length of the diffraction vector scale. Furthermore, the integral breadth (on the length of the diffraction vector scale) then increases linearly with the order of reflection or, expressed another way, with the length of the diffraction vector (i.e.the integral breadth increases with tanθ on the diffraction angle 2θ scale). For the case of a decay of 〈∊L2〉 withL, deviations from such simple behaviour of the integral breadth occur. In particular, Lorentzian line broadening and nonlinear dependence of the integral breadth on the length of the diffraction vector scale (i.e.non-tanθ dependence on the 2θ scale) are induced. It is argued that the approaches used for the description of microstrain broadening in many procedures (integral breadth and Rietveld refinement) are of limited validity,i.e.they do not warrant general unverified application.

Investigation of diffraction line broadening due to compositional fluctuations in L-alanine-doped triglycine sulfate

2003 ◽  
Vol 59 (5) ◽  
pp. 647-652 ◽  
Author(s):  
Rajul Ranjan Choudhury ◽  
R. Chitra ◽  
M. Ramanadham
Keyword(s):  
Powder Diffraction ◽  
Triglycine Sulfate ◽  
Diffraction Line ◽  
Line Broadening ◽  
X Ray ◽  
Alanine Substitution ◽  
Anisotropic Strain ◽  
Diffraction Peaks ◽  
Compositional Disorder ◽  
Hall Method

Broadening of X-ray powder diffraction peaks as a result of compositional disorder in L-alanine-doped triglycine sulfate crystals is investigated using the Williamson–Hall method. The analysis indicates that L-alanine substitution in triglycine sulfate crystals leads to anisotropic strain in the crystal.

Microstrain-like diffraction-line broadening as exhibited by incommensurate phases in powder diffraction patterns

2007 ◽  
Vol 40 (6) ◽  
pp. 1027-1034 ◽  
Author(s):  
Andreas Leineweber ◽  
Vaclav Petricek
Keyword(s):  
Powder Diffraction ◽  
Diffraction Line ◽  
Line Broadening ◽  
Modulated Phase ◽  
Diffraction Patterns ◽  
Incommensurate Phases

Variations of lattice and modulation parameters of an incommensurately modulated phase as well as the resulting line broadening arising in powder diffraction patterns were theoretically analysed. The resulting line broadening is in principle microstrain-like. For the case that only the modulation parameters vary, only the satellite reflections are broadened, and for constant-order satellite reflections, the line broadening can then be regarded as size-like.

X-Ray Diffraction Study of Hep Metals. I. Line Broadening in Polycrystalline Cd Powder

1974 ◽  
Vol 29 (12) ◽  
pp. 1771-1777 ◽  
Author(s):  
N. C. Haider ◽  
S. H. Hunter
Keyword(s):  
Room Temperature ◽  
Small Deformation ◽  
Correction Factors ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Fault Probability ◽  
Large Particle Size ◽  
X Ray ◽  
Melting Temperatures ◽  
Diffraction Patterns

Powder Cd of 99.999% purity was prepared at room temperature (25 °C) and x-ray diffraction patterns were obtained using CuKaα radiation with Ni-filter. The line broadening was analyzed after incorporating the appropriate correction factors. At room temperature Cd was found to have large particle size (653 A), small root mean square strain (.001), small deformation fault probability a (.003). and negligible growth fault probability β(0). Compared to other hep metals which have been studied earlier and which have higher melting temperatures, metal Cd is much less affected by mechanical deformation at room temperature.

X-ray diffraction line broadening on vibrating dry-milled Two Crows sepiolite

2006 ◽  
Vol 54 (3) ◽  
pp. 390-401 ◽  
Author(s):  
Joaquin Bastida ◽  
Marek A. Kojdecki ◽  
Pablo Pardo ◽  
Pedro Amorós
Keyword(s):  
Diffraction Line ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals In Situ Synchrotron X-ray Study of the Mechanical Properties of Pure Mg Produced by Powder Metallurgy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1198
Author(s):  
Li Li ◽  
Leyun Wang ◽  
Jie Wang ◽  
Huan Zhang ◽  
Qingchun Zhu ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Tensile Deformation ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Scattering ◽  
Type Dislocation ◽  
Diffraction Patterns ◽  
Saxs Analysis ◽  
Ray Scattering

In this study, in situ synchrotron X-ray experiments with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) detectors were performed on two pure magnesium materials produced by powder metallurgy. According to SAXS analysis, each of the two materials has a porosity of less than 0.5%. Line broadening analysis was performed on diffraction patterns collected by WAXS to analyze the dislocation evolution during material deformation. In both materials, <a>-type dislocation activities dominate the tensile deformation. The influence of grain size and texture on the different tensile behaviors of these two materials is also discussed.

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