Deformation state extraction from electron backscatter diffraction patterns via simulation-based pattern-matching

Kikuchi pattern simulations of backscattered and transmitted electrons

“…These values can result in similar changes of absolute lattice parameters and strain when these are determined based on simulations that neglect E/D effect. Results of some recent numerical simulation studies concerning a potentially very high precision projection centre and strain determination 14,30,125 are thus difficult to transfer directly to a correspondingly high precision in realistic experimental situations because excess-deficiency effects have not been accounted for in the underlying theoretical model of these studies. Optical distortions will be an additional source of error that would need to be treated in highresolution pattern matching studies.…”

“…Kikuchi diffraction simulations are also applied to estimate continuous parameters from experimental patterns. This includes the calibration of the geometrical setup, 17–20 the indexing and refinement of crystal orientations 8,21–27 and the quantification of local changes in lattice parameters, 28–31 including the possible role of defects 32 …”

“…Kikuchi diffraction simulations are also applied to estimate continuous parameters from experimental patterns. This includes the calibration of the geometrical setup, [17][18][19][20] the indexing and refinement of crystal orientations 8,[21][22][23][24][25][26][27] and the quantification of local changes in lattice parameters, [28][29][30][31] including the possible role of defects. 32 To improve the simulation-based pattern matching approaches, it is necessary to understand which experimental effects are relevant to be included in the theoretical models used in Kikuchi diffraction pattern simulations.…”

“…We demonstrate that systematic errors in the order of at least 1% in the relative position of the projection centre can be introduced by not including E/D effects in the simulations, which has corresponding effects for a quantitative determination of lattice parameters and strain states via simulated Kikuchi patterns. Several existing estimations of the absolute precision of pattern matching approaches for projection centre and strain determination have been based on analyses of simulated synthetic data without E/D effects, 19,30,73 which thus potentially introduces a corresponding bias. Finally, we will show that the refined simulation model is able to reproduce contrast formation under various different conditions which are relevant for both SEM as well as TEM Kikuchi diffraction patterns.…”