Detection of magnetic ordering evolution via spin Hall magnetoresistance in antiferromagnetic Cr2O3 thin films

The magnetic ordering evolution was investigated via spin Hall magnetoresistance (SMR) in antiferromagnetic Cr2O3 thin films. The SMR ratio of the Cr2O3/Pt bilayer devices exhibits a nonmonotonic temperature dependence, which peaks at a specific temperature. The peak temperature is considered to be the Néel temperature of the Cr2O3 layer, which decreases with reducing Cr2O3 thickness, as expected from finite-size effect. The nonmonotonic temperature dependence of SMR ratio is attributed to the variations in the spin current transparency at the Cr2O3/Pt interface, which reflects the magnetic ordering evolution in the Cr2O3 layer. This study highlights the promise of SMR as an electrical technique for detecting and elucidating the magnetic ordering evolution in antiferromagnetic materials.