Two-Dimensional Strain Mapping with Scanning Precession Electron Diffraction: An Investigation into Data Analysis Routines

TL;DR

This paper presents a workflow for analyzing strain in materials using scanning precession electron diffraction at small convergence angles, with a case study on Gallium Arsenide nanowires and comparison of peak finding routines.

Contribution

It introduces a systematic analysis method for small convergence angle SPED experiments and provides reproducible code and data for the community.

Findings

Comparison of three peak finding routines for SPED data

Workflow for experimental and data analysis components

Application to strained Gallium Arsenide nanowires

Abstract

Scanning precession electron diffraction (SPED) is a powerful technique for investigating strain. While extensive literature exists analysing strain under high convergence angle conditions there are few systematic studies describing work based around the use of smaller convergence angles despite this being a common set-up. We fill in some of this gap in the literature by providing a workflow for both the experimental and analysis components of such experiments. Our case study investigates strained Gallium Arsenide nanowires with a modern direct electron detector and common microscope alignments. Three peak finding routines are compared and we provide both source code and raw data to allow others to reproduce our findings.