Enhancing Spin–Orbit Torque Through Octahedral Tilt/Rotation Relaxation in CaRuO3 Films for Efficient Magnetization Switching

Abstract

Transition metal oxides with strong spin–orbit coupling exhibit efficient charge-to-spin interconversion. The modification of crystal structure provides a promising platform for enhancing the spin–orbit torque (SOT) efficiency, which potentially leads to energy-efficient spintronic devices. Here, efficient switching of perpendicular magnetization driven by SOT in CaRuO₃ films is reported. By precisely tuning octahedral tilt/rotation, the enhancement of SOT efficiency is achieved, and the corresponding spin Hall conductivity can be increased from the value of 2.48 to 7.56 × (ℏ/2e) × 10⁴ Ω⁻¹ m⁻¹. The thickness dependence of spin Hall conductivity indicates that SOT originates from the bulk spin Hall effect. Moreover, this large SOT efficiency contributes to the reduction of power consumption in current-induced switching of magnetization. The results provide a route to further enhance the SOT efficiency and verify CaRuO₃ as a very promising candidate material for efficient spintronics devices.