pycotem: An open source toolbox for online crystal defect characterization from TEM imaging and diffraction

J Microsc. 2021 Apr;282(1):84-97. doi: 10.1111/jmi.12982. Epub 2020 Nov 30.

Abstract

We present a series of tools working together that facilitate the determination of dislocation Burgers vectors and slip planes, interface plane normals and misorientation between two crystals from a series of Transmission Electron Microscopy (TEM) micrographs and diffraction patterns. To that purpose, we developed graphical user interface programs that allow crystal orientation determination from spot diffraction patterns taken at various tilt angles or from Kikuchi patterns crystal representation from stereographic projection plots and determination of geometrical features from series of conventional images taken at different tilt angles. We present working examples that allow a faster and easier way to analyse data that can especially be retrieved during in situ straining experiments where dislocations and grain boundaries need to be characterized. More generally, these tools target material scientists interested in daily microstructural characterization in TEM.

Keywords: crystal orientation; defect analysis; electron diffraction; stereographic projection.