2025/10/16 by Yongjian Tang, Pratap Kumar Pal, Tang, Yongjian +17
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Multiferroics and related materials #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2510.15091
openalex publication_date 2025/10/16 · openalex created_date 2025/10/21 · openalex updated_date 2026/07/28
Spin Hall magnetoresistance (SMR) measurements provide a way to probe the surface spin structure of insulating magnetic materials. Such measurements produce resistance signals of the form ΔR ∝ cos[2(α-α0)], where α is the angle between the current and the external in-plane magnetic field. Previous experiments on a wide range of materials have found α0 = 0° for ferromagnets and α0 = 90° for antiferromagnets. Here we investigate SMR in bilayers of Pt with monodomain BiFeO3 multiferroic epitaxial thin films. We observe signals of the form ΔR ∝ cos[2(α-α0)] but surprisingly the angle α0 can take values very different from 90° or 0°, with large variations from sample to sample. The aim of the paper is to report this striking departure from the expected magnetic field dependence of SMR and to encourage consideration of possible microscopic mechanisms.