Magnetism and spin-dependent transport phenomena across Verwey and Morin transitions in iron oxide/Pt bilayers

Abstract

Understanding the influence of phase coexistence and transitions on spin transport properties in a ferromagnet/heavy metal (FM/HM) system is utmost importance for spintronics. Here, we report comprehensive investigation magnetic biphase iron oxide (BPIO = α-Fe2O3 + Fe3O4)/Pt films over wide temperature range, 10K≤T≤300K. In-plane (IP) out-of-plane (OOP) magnetometry radio frequency transverse susceptibility measurements confirm characteristic features Verwey Morin at TV ∼ 120 K TM 200 K, respectively. Anisotropic magnetoresistance (AMR) observed BPIO film, which arises mainly from polarized tunneling conduction electrons between neighboring uniformly magnetized grains through resistive grain boundary. Spin Hall (SMR) anomalous effect (SH-AHE) are detected BPIO/Pt films. Around TV, evolution SMR shows sharp maximum, while SH-AHE exhibits steep decrease. Both strongly susceptible to transition but transition, indicating that interfacial magnetism our film dominated by Fe3O4 rather than phase.