Strain dependence of Berry-phase-induced anomalous Hall effect in the non-collinear antiferromagnet Mn3NiN

Johnson, F., Boldrin, D. , Zemen, J., Pesquera, D., Kim, J., Moya, X., Zhang, H., Singh, H. K., Samathrakis, I. and Cohen, L. F. (2021) Strain dependence of Berry-phase-induced anomalous Hall effect in the non-collinear antiferromagnet Mn3NiN. Applied Physics Letters, 119(22), 222401. (doi: 10.1063/5.0072783)

Abstract

The anomalous Hall effect (AHE) has been shown to be present in certain non-collinear antiferromagnets due to their symmetry-breaking magnetic structure, and its magnitude is dependent primarily on the non-zero components of the Berry curvature. In the non-collinear antiferromagnet Mn3NiN, the Berry phase contribution has been predicted to have strong strain dependence, although in practice, direct observation may be obscured by other strain-related influences—for instance, magnetic phase transitions mediated by strain. To unravel the various contributions, we examine the thickness and temperature dependence of the AHE for films grown on the piezoelectric substrate BaTiO3. We observe a systematic reduction in TN due to increased compressive strain as film thickness is reduced and a linear decrease in the AHE magnitude as the films are cooled from their ferrimagnetic phase above TN to their antiferromagnetic phase below. At 190 K, we applied an electric field across a 0.5 mm thick BaTiO3 substrate with a 50 nm thick Mn3NiN film grown on top and we demonstrate that at the coercive field of the piezoelectric substrate, the tensile in-plane strain is estimated to be of the order of 0.15%, producing a 20% change in AHE. Furthermore, we show that this change is, indeed, dominated by the intrinsic strain dependence of the Berry curvature.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Boldrin, Dr David
• Authors: Johnson, F., Boldrin, D., Zemen, J., Pesquera, D., Kim, J., Moya, X., Zhang, H., Singh, H. K., Samathrakis, I., and Cohen, L. F.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Applied Physics Letters
• Publisher: AIP Publishing
• ISSN: 0003-6951
• ISSN (Online): 1077-3118
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Applied Physics Letters 119(22): 222401
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
307066		New Caloric Materials for Energy Efficient Refrigeration	Donald Maclaren	Leverhulme Trust (LEVERHUL)	ECF-2019-351	P&S - Physics & Astronomy