Magnetization processes of storage and back layers in double-layered perpendicular magnetic recording media observed using anomalous and planar Hall effects

Abstract

An anomalous Hall effect (AHE) and a planar Hall effect (PHE) represent a perpendicular component and an in-plane component of the magnetization in the double-layered media. Since AHE and PHE have different symmetries regarding to the applied magnetic field H, it is easy to distinguish the AHE component, which is proportional to M, and PHE component, which is proportional to M2, from the measured Hall voltage VH. The Hall voltage of the double-layered film composed of Co–Cr–Ta and Ni–Fe layers was observed when the magnetic field is applied at an angle (α) of 30° from the normal to the film plane. The perpendicular and the in-plane components, which are regarded as the magnetization process of Co–Cr–Ta and that of the Ni–Fe layer, respectively, can be easily determined from these characteristics. The Hall measurement is useful to study the magnetization characteristics in the double-layered media.