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

Chris M Fancher; Matthew J Burch; Srikanth Patala; Elizabeth C Dickey

doi:10.1111/jmi.13077

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

J Microsc. 2022 Feb;285(2):85-94. doi: 10.1111/jmi.13077. Epub 2022 Jan 4.

Authors

Chris M Fancher¹, Matthew J Burch², Srikanth Patala², Elizabeth C Dickey³

Affiliations

¹ Material Science and Technology Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee.
² Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina.
³ Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania.

PMID: 34873694
DOI: 10.1111/jmi.13077

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.

Keywords: EBSD; TKD; gnomonic distortions.