Evaluation of crystallographic strain, rotation and defects in functional oxides by the moiré effect in scanning transmission electron microscopy

Naden, A.B., O'Shea, K.J. and MacLaren, D.A. (2018) Evaluation of crystallographic strain, rotation and defects in functional oxides by the moiré effect in scanning transmission electron microscopy. Nanotechnology, 29(16), 165704. (doi: 10.1088/1361-6528/aaae50)

Abstract

Moiré patterns in scanning transmission electron microscopy (STEM) images of epitaxial perovskite oxides are used to assess strain and defect densities over fields of view extending over several hundred nanometers. The patterns arise from the geometric overlap of the rastered STEM electron beam and the samples' crystal periodicities and we explore the emergence and application of these moiré fringes for rapid strain analysis. Using the epitaxial functional oxide perovskites BiFeO3 and Pr1−x Ca x MnO3, we discuss the impact of large degrees of strain on the quantification of STEM moiré patterns, identify defects in the fringe patterns and quantify strain and lattice rotation. Such a wide-area analysis of crystallographic strain and defects is crucial for developing structure-function relations of functional oxides and we find the STEM moiré technique to be an attractive means of structural assessment that can be readily applied to low dose studies of damage sensitive crystalline materials.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacLaren, Dr Donald and O'Shea, Miss Kerry
• Authors: Naden, A.B., O'Shea, K.J., and MacLaren, D.A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nanotechnology
• Publisher: IOP Publishing
• ISSN: 0957-4484
• ISSN (Online): 1361-6528
• Published Online: 27 February 2018
• Copyright Holders: Copyright © 2018 IOP Publishing Ltd
• First Published: First published in Nanotechnology 29(16):165704
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
58486	1	EPSRC Doctoral Training Grant 2011-2015	Mary Beth Kneafsey	Engineering and Physical Sciences Research Council (EPSRC)	EP/J500434/1	VPO VICE PRINCIPAL RESEARCH & ENTERPRISE
53072	1	Integrating advanced nanomaterials into transformative technologies	Donald Maclaren	Engineering and Physical Sciences Research Council (EPSRC)	EP/I00419X/1	P&A - PHYSICS & ASTRONOMY