Antiferromagnetic NiO thickness dependent sign of the spin Hall magnetoresistance in gamma-Fe2O3/NiO/Pt epitaxial stacks
Date issued
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
License
Abstract
We study the spin Hall magnetoresistance (SMR) in epitaxial γ–Fe2O3/NiO(001)/Pt stacks, as a function of temperature and thickness of the antiferromagnetic insulating NiO layer. Upon increasing the thickness of NiO from 0 nm to 10 nm, we detect a sign change of the SMR in the temperature range between 10 K and 280 K. This temperature dependence of the SMR in our stacks is different compared to that of previously studied yttrium iron garnet/NiO/Pt, as we do not find any peak or sign change as a function of temperature. We explain our data by a combination of spin current reflection from both the NiO/Pt and γ-Fe2O3/NiO interfaces and the thickness-dependent exchange coupling mode between the NiO and γ-Fe2O3 layers, comprising parallel alignment for thin NiO and perpendicular alignment for thick NiO.
Description
Keywords
Citation
Published in
Applied physics letters, 114, 10, American Inst. of Physics, Melville, NY, 2019, https://doi.org/10.1063/1.5080766