Strain mapping using scanning precession electron diffraction - a round robin test of different methods for calculation from the raw datasets

Session

Stream 2: EMAG - Instrumentation Development (incl Detector technology)

Authors

Dr Ian MacLaren (3), Ms Emma Devine (3), Mr Hristo Gergov (3), Dr Gary Paterson (3), Dr Benjamin Savitzky (2), Dr Colin Ophus (2), Mr Renliang Yuan (4), Prof Jian-Min Zuo (4), Mr Harikrishnan K.P. (1), Prof David Muller (1), Ms Kirsten Forster (3), Ms Gaja Kobe (3), Ms Elizabeth Koppany (3), Ms Kirsten McClymont (3), Mr Anjelo Narendran (3), Mr David Riley (3)

Affiliations

1. Cornell University
2. Lawrence Berkeley National Laboratory
3. University of Glasgow
4. University of Illinois at Urbana-Champaign

Keywords

4D-STEM

Precession Electron Diffraction

Direct Electron Detectors

Strain Mapping

Abstract text

Determining the strain in crystalline structures as a function of a position has been possible for some while with scanned nanobeam diffraction and scanning precession electron diffraction.  There are a number of ways to convert the diffraction patterns to strain maps, but there has been little by way of any attempt to evaluate or compare the relative merits of these different approaches.  This work examines two scanned precession diffraction datasets using five different analysis codes, which encompass some different approaches to the determination of spot positions and strain.  Direct comparisons will be made between all of these, and the reasons for the discrepancies that are found are examined, especially by analysing the diffraction pattern fits in pixels of the dataset where the largest differences are found between the different codes.  This will lead to clear recommendations as to the most appropriate techniques for strain mapping in different structures.