A comparison of a direct electron detector and a high-speed video camera for a scanning precession electron diffraction phase and orientation mapping

MacLaren, I. et al. (2020) A comparison of a direct electron detector and a high-speed video camera for a scanning precession electron diffraction phase and orientation mapping. Microscopy and Microanalysis, 26(6), pp. 1110-1116. (doi: 10.1017/S1431927620024411) (PMID:32867871)

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Abstract

A scanning precession electron diffraction system has been integrated with a direct electron detector to allow the collection of improved quality diffraction patterns. This has been used on a two-phase α–β titanium alloy (Timetal® 575) for phase and orientation mapping using an existing pattern-matching algorithm and has been compared to the commonly used detector system, which consisted of a high-speed video-camera imaging the small phosphor focusing screen. Noise is appreciably lower with the direct electron detector, and this is especially noticeable further from the diffraction pattern center where the real electron scattering is reduced and both diffraction spots and inelastic scattering between spots are weaker. The results for orientation mapping are a significant improvement in phase and orientation indexing reliability, especially of fine nanoscale laths of α-Ti, where the weak diffracted signal is rather lost in the noise for the optically coupled camera. This was done at a dose of ~19 e−/Å2, and there is clearly a prospect for reducing the current further while still producing indexable patterns. This opens the way for precession diffraction phase and orientation mapping of radiation-sensitive crystalline materials.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McGrouther, Dr Damien and Frutos Myro, Mr Enrique and McFadzean, Dr Sam and MacLaren, Dr Ian
Authors: MacLaren, I., Frutos-Myro, E., McGrouther, D., McFadzean, S., Weiss, J. K., Cosart, D., Portillo, J., Robins, A., Nicolopoulos, S., Nebot del Busto, E., and Skogeby, R.
College/School:College of Science and Engineering > School of Engineering
College of Science and Engineering > School of Physics and Astronomy
Journal Name:Microscopy and Microanalysis
Publisher:Cambridge University Press
ISSN:1431-9276
ISSN (Online):1435-8115
Published Online:01 September 2020
Copyright Holders:Copyright © 2020 Microscopy Society of America
First Published:First published in Microscopy and Microanalysis 26(6): 1110-1116
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
171131Fast Pixel Detectors: a paradigm shift in STEM imagingIan MacLarenEngineering and Physical Sciences Research Council (EPSRC)EP/M009963/1P&S - Physics & Astronomy
190531Impact Acceleration Account (IAA - EPSRC)Jonathan CooperEngineering and Physical Sciences Research Council (EPSRC)EP/K503903/1Research and Innovation Services
304896EPSRC-IAA: Early Stage Commercialisation of a PET Imaging Agent for the Detection of Cardiovascular Disease and CancerAndrew SutherlandEngineering and Physical Sciences Research Council (EPSRC)EP/R511705/1Chemistry
300756NPIF EPSRC Doctoral - University of Glasgow 2017Neil BoweringEngineering and Physical Sciences Research Council (EPSRC)EP/R512266/1S&E - Research Administration