Description
Spin-orbit torque (SOT) is an effective approach for electrical manipulation of magnetization and for probing angular-momentum transport. In this work, high-quality RuO₂(101) epitaxial films were grown on Al₂O₃(1-102) substrates and fabricated into RuO₂/FM heterostructures, where FM = Ni or Fe. Using harmonic Hall voltage measurements, we quantitatively extracted the SOT effective fields. The results show that the SOT is dominated by field-like torque, while the damping-like torque is much weaker. The σᵧ-induced field-like torque exhibits opposite signs in RuO₂/Ni and RuO₂/Fe, indicating strong sensitivity to the ferromagnetic layer and the RuO₂/FM interface. In addition, the SOT efficiency remains unsaturated up to 6 nm RuO₂, suggesting possible long-range spin/orbital transport.
