Strain-driven switching between antiferromagnetic states in frustrated antiferromagnet UO2 probed by exchange bias effect

• Main Authors: Tereshina-Chitrova, E. A, Pourovskii, L. V, Khmelevskyi, S, Horak, L, Bao, Z, Mackova, A, Malinsky, P, Gouder, T, Caciuffo, R
• Format: Journal Article
• Language: English
• Published: 24-10-2023
• Subjects: Physics - Materials Science; Physics - Other Condensed Matter
• DOI: 10.48550/arxiv.2310.15696

Frustrated antiferromagnets offer a captivating platform to study the
intricate relationship of magnetic interactions, geometric constraints, and
emergent phenomena. By controlling spin orientations, these materials can be
tailored for applications in spintronics and quantum information processing.
The research focuses on the interplay of magnetic and exchange anisotropy
effects in artificial heterostructures based on a canonical frustrated
antiferromagnet, UO2. The potential to manipulate the spin directions in this
material and switch between distinct antiferromagnetic states is investigated
using substrate-induced strain. The phenomenon is probed using exchange bias
(EB) effects in stoichiometric UO2/Fe3O4 bilayers. By employing many-body
first-principles calculations magnetic configurations in the UO2 layers are
identified. Even a minor tetragonal distortion triggers a transition between
antiferromagnetic states of different symmetries, driven by a robust alteration
of single-ion anisotropy due to the distortion. Consequently, this change
influences the arrangement of magnetic moments at the UO2/Fe3O4 interface,
affecting the magnitude of exchange bias. The findings showcase how epitaxial
strain can effectively manipulate the antiferromagnetic states in frustrated
antiferromagnets by controlling single-site anisotropy.