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Implications of gnomonic distortion on electron backscatter diffraction and transmission Kikuchi diffraction.

Authors :
Fancher, Chris M.
Burch, Matthew J.
Patala, Srikanth
Dickey, Elizabeth C.
Source :
Journal of Microscopy. Feb2022, Vol. 285 Issue 2, p85-94. 10p.
Publication Year :
2022

Abstract

The effect of gnomonic distortion on orientation indexing of electron backscatter diffraction patterns is explored through simulation of electron diffraction patterns for sample‐to‐detector geometries associated with transmission Kikuchi diffraction (TKD) and electron backscatter diffraction (EBSD). Simulated data were analysed by computing a similarity index for both Hough transformed data and simulated patterns to determine the sensitivity of each method for detecting subtle differences in the effect of gnomonic distortions on electron diffraction patterns. These results indicate that the increased gnomonic distortions in electron diffraction patterns for a TKD geometry enhance the sensitivity for detecting subtle differences in interband angles. Additionally, the utilisation of a Hough transform‐based indexing approach further enhances the sensitivity. Electron backscatter diffraction (EBSD) and transmission Kikuchi diffraction (TKD) have become vital tools for studying materials. These probes provide information about how locally arranged. EBSD and TKD utilise different experimental configurations that have impacts the measured data. The projection of the electron diffraction Ewald's sphere onto the face of the detectors results in Gnomonic distortions, and the selection of experimental configuration affects the magnitude of these distortions. In this work we used simulated dynamical electron diffraction patterns (EDPs) to understand the how differences in the EBSD and TKD experimental configurations impacts Gnomonic distortions and how these distortions effect the sensitivity of each method for detecting subtle differences in interband angles. These results indicate that the increased gnomonic distortions in electron diffraction patterns for a TKD geometry enhance the sensitivity for detecting subtle differences in interband angles. These results also suggest that a traditional Hough transform approach for indexing EDP data is less sensitive to detecting slight deviations than direct analysis of EDPs. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00222720
Volume :
285
Issue :
2
Database :
Academic Search Index
Journal :
Journal of Microscopy
Publication Type :
Academic Journal
Accession number :
154959609
Full Text :
https://doi.org/10.1111/jmi.13077