Switching of Co Magnetization Driven by Antiferromagnetic-Ferromagnetic Phase Transition of FeRh Alloy in Co/FeRh Bilayers

We show that Co spins in Co/FeRh epitaxial bilayers grown on W(110) switch reversibly between the two orthogonal in-plane directions as the FeRh layer undergoes temperature-driven antiferromagnetic-ferromagnetic (AFM-FM) phase transition. The switching of Co magnetization is characterized by a hysteretic behavior owing to a temperature hysteresis of the AFM-FM transition in FeRh. The spin reorientation of Co is driven by the evolution interfacial exchange coupling to the FeRh system across the AFM-FM process. Our results provide a method of writing information purely by a local temperature change.