Angular dependence of magnetization reversal in exchange-biased Co∕Pt multilayer with perpendicular magnetic anisotropy

Abstract

The magnetization reversal in exchange-biased (Co∕Pt)5∕Co∕FeMn multilayer with perpendicular magnetic anisotropy has been studied depending on the angle between an applied field and the easy axis (the normal of the film plane). The results show different characters from that in most in-plane exchange bias systems. In a large angular range, the magnetization rotates first toward the adjacent direction of easy axis for both descending and ascending branches because perpendicular magnetic anisotropy is much larger than unidirectional exchange anisotropy. With increasing the angle from 0° to 90°, the magnitude of the exchange bias field decreases, but the coercivity increases due to domain nucleation and propagation included in the magnetization reversal process. The angular dependence of magnetization reversal shows no hysteresis between clockwise and counterclockwise rotations.