Prediction of potential pseudo‐symmetry issues in the indexing of electron backscatter diffraction patterns. Issue 5 (23rd September 2019)

• Record Type: Journal Article
• Authors: Lenthe, William; Singh, Saransh; De Graef, Marc
• Is Part Of: Journal of applied crystallography. Volume 52:Issue 5(2019)
• Page Start: 1157
• Page End: 1168
• Publication Date: 2019-09-23
• Subjects: electron backscatter diffraction -- EBSD -- pseudo‐symmetry -- autocorrelation -- spherical harmonic transform; Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S1600576719011233
• Languages: English
• ISSNs: 0021-8898

Abstract

Abstract : Using the recently proposed spherical indexing algorithm for EBSD patterns, a novel methodology to automatically predict potential pseudo‐symmetric or systematically mis‐indexed orientations for an arbitrary crystal structure is proposed. Abstract : A new methodology to predict potential pseudo‐symmetric or systematically mis‐indexed orientations for an arbitrary crystal structure is presented. The method leverages the recently proposed spherical indexing algorithm to index electron backscatter diffraction patterns. Potential pseudo‐symmetric orientations are interpreted as secondary peaks in the autocorrelation of the Kikuchi sphere. The generality of the method is illustrated using a number of crystal systems, ranging from nickel, where no significant pseudo‐symmetric issues are expected, to SrTiO3, with mild occurrence of such issues, to the olivine series, γ‐TiAl and U‐6%Nb systems, where the traditional Hough method systematically mis‐indexes the pseudo‐symmetric variants. Furthermore, the method predicts the severity of potential pseudo‐symmetric matches and ranks all variants using a normalized autocorrelation coefficient.