On the origin of differential phase contrast at a locally charged and globally charge-compensated domain boundary in a polar-ordered material

MacLaren, I. , Wang, L., McGrouther, D. , Craven, A. J., McVitie, S. , Schierholz, R., Kovács, A., Barthel, J. and Dunin-Borkowski, R. E. (2015) On the origin of differential phase contrast at a locally charged and globally charge-compensated domain boundary in a polar-ordered material. Ultramicroscopy, 154, pp. 57-63. 25837677. (doi: 10.1016/j.ultramic.2015.03.016)

Abstract

Differential phase contrast (DPC) imaging in the scanning transmission electron microscope is applied to the study of a charged antiphase domain boundary in doped bismuth ferrite. A clear differential signal is seen, which matches the expected direction of the electric field at the boundary. However, further study by scanned diffraction reveals that there is no measurable deflection of the primary diffraction disc and hence no significant free E-field in the material. Instead, the DPC signal arises from a modulation of the intensity profile within the primary diffraction disc in the vicinity of the boundary. Simulations are used to show that this modulation arises purely from the local change in crystallographic structure at the boundary and not from an electric field. This study highlights the care that is required when interpreting signals recorded from ferroelectric materials using both DPC imaging and other phase contrast techniques.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McGrouther, Dr Damien and McVitie, Professor Stephen and MacLaren, Dr Ian and Wang, Ms Liqiu and Craven, Professor Alan
• Authors: MacLaren, I., Wang, L., McGrouther, D., Craven, A. J., McVitie, S., Schierholz, R., Kovács, A., Barthel, J., and Dunin-Borkowski, R. E.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Ultramicroscopy
• Publisher: Elsevier B.V.
• ISSN: 0304-3991
• ISSN (Online): 1879-2723
• Copyright Holders: Copyright © 2015 The Authors
• First Published: First published in Ultramicroscopy 154:57-63
• Publisher Policy: Reproduced under a Creative Commons License