Low field magnetization reversal behavior in GaMnAs films

Abstract

The magnetization reversal process of a GaMnAs film has been investigated by using the planar Hall effect. The angle-dependent measurements of the planar Hall resistance that were performed with a field smaller than 60 Oe displayed new intermediate stable resistance values during the rotation of the external field direction over 360A degrees. This phenomenon was understood by considering the formation of the multi-domain, whose magnetizations lie along two magnetic easy axes, and the differences in the domain-pinning fields that required for the transition between two easy axes. We further showed that the relative populations of the magnetic domains corresponding to the two orthogonal easy axes can be controlled by the value of the applied field during the process of magnetization reversal.