Transition from symmetric to asymmetric local coercivity distribution in CoCrPt alloy films

Abstract

The local coercivity distribution of CoCrPt alloy films prepared by dc magnetron sputtering has been investigated by means of magneto-optical microscope magnetometer, capable of simultaneously measuring the local magnetic properties on a submicrometer spatial resolution. We find that with increasing Pt concentration the local coercivity distribution becomes asymmetric and the average local coercivity as well as the width of the distribution increases. Transmission electron microscopy studies, together with a theoretical explanation, reveal that the results are closely correlated with the grain size distribution dependent on the Pt concentration.