A tool for automatic recognition of [110] tilt grain boundaries in zincblende-type crystals

Abstract

The local atomic structure of [110] tilt grain boundaries (GBs) formed in $100 nm-sized GaAs nanocrystals, which crystallize in the non-centrosymmetric zincblende-type structure with face-centred cubic lattice symmetry, was imaged and analysed by means of high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The nanocrystals were grown by metal-organic vapour phase epitaxy on top of (001) Si nanotips embedded in an oxide matrix. This paper introduces an automatic analysis method and corresponding processing tool for the identification of the GBs. The method comprises (i) extraction of crystallographic parameters, i.e. misorientation angles and transformation matrices for the different crystal parts (grains/ twins) observed by HAADF-STEM, and (ii) determination of their common plane(s) by modelling all possible intersections of the corresponding threedimensional reciprocal lattices. The structural unit model is also used to characterize the GB structures and to validate the data obtained by the developed algorithm. research papers 1300 Roksolana Kozak et al. A tool for automatic recognition of [110] tilt grain boundaries

Towards Generalized Noise-Level Dependent Crystallographic Symmetry Classifications of More or Less Periodic Crystal Patterns

“…Reference [36] demonstrates the application of a computational tool for the automatic extraction of the five macroscopic grain boundary parameters (geometric degrees of freedom) [43] from atomic resolution STEM images of GaAs and other materials with zinc-blende structure. Just like the proposed tool of ref.…”

“…More or less 1D periodic 2D images of crystalline materials such as aberration-corrected STEM images of plane coincidence site lattice (CSL) grain boundaries in edge-on projections which are atomically resolved [32][33][34][35][36] are known to be underlain by both predictable [37] types of frieze symmetries and 3D atomic level bi-crystal structures [38][39][40][41]. There is at present, however, no objective way to extract the parameters of grain boundary structures at the atomic level from such images.…”

Energy-dispersive Laue experiments with X-ray tube and PILATUS detector: precise determination of lattice constants

“…It is based on existing approaches for the treatment of diffraction patterns: XDS (Kabsch, 2010), EVAL-14/15 (Duisenberg et al, 2003;Schreurs et al, 2010), OSC-123 (Kim, 1989) and XMAS (Tamura, 2013). The peak search is done without image background corrections following a two-stage approach for finding local maxima within (2B + 1) Â (2B + 1) blocks (Kim, 1989;Kozak et al, 2017), where B is the size of the spotdefinition box [see Fig. 7(a)].…”

Towards Generalized Noise-level Dependent Crystallographic Symmetry Classifications of More or Less Periodic Crystal Patterns

“…Reference [36] demonstrates the application of a computational tool for the automatic extraction of the five macroscopic grain boundary parameters (geometric degrees of freedom, i.e. independent ways of variations within the physical model) [43] from atomic resolution STEM images of GaAs and other materials with zinc-blende structure.…”

“…More or less 1D periodic 2D images of crystalline materials such as aberration-corrected STEM images of plane coincidence site lattice (CSL) grain boundaries in edge-on projections which are atomically resolved [32][33][34][35][36] are known to be underlain by both predictable [37] types of frieze symmetries and 3D atomic level bi-crystal structures [38][39][40][41]. There is at present, however, no objective way to extract the parameters of grain boundary structures at the atomic level from such images.…”