Angular Dependence of Spin-Valves Using Antiferromagnetic Epitaxial YFeO₃

Abstract

Spin-valves using epitaxial orthoferrite (YFeO₃) as an antiferromagnetic layer were prepared on SrTiO₃(100), (110), and (111) substrates, and their properties were investigated. Each spin-valve showed a markedly different MR property according to the plane of the SrTiO₃ substrate. The highest MR ratio was observed in a spin-valve with a-axis-oriented epitaxial YFeO₃ on the SrTiO₃ substrate with a (110) plane, while a trace amount of MR was visible in a spin-valve with c-axis-oriented YFeO₃ on (100) SrTiO₃. The MR properties of the spin-valve on (110) SrTiO₃ exhibited strong angular dependence under an in-plane magnetic field. The exchange coupling in these spin-valves seems to have some relation with the direction of parasitic ferromagnetism in the antiferromagnetic epitaxial YFeO₃ layer.