Monitoring magnetization reversal and perpendicular anisotropy by the extraordinary Hall effect and anisotropic magnetoresistance.

Abstract

Simultaneous magnetotransport measurements of the extraordinary Hall effect and anisotropic magnetoresistance were used to monitor the normal and in-plane projections of magnetization in thin Co/Pd multilayers with perpendicular anisotropy. By reconstructing the magnitude and orientation of the magnetization vector we were able to track the reversal of magnetization and distinguish among the processes of coherent rotation and domain nucleation. The Stoner–Wohlfarth model was used to extract anisotropy constants from data collected during the coherent rotation. We show that magnetization reversal occurs coherently over a major part of the cycle under a canted magnetic field when the field's inclination exceeds a certain sample-dependent angle. The applicability range of the Stoner–Wohlfarth model and thus reliability of the calculated anisotropy constants is significantly improved when measurements are performed under canted fields.