The effect of edge roughness on magnetization reversal in micron-sized permalloy thin films

Abstract

The effect of edge roughness on the reproducibility of hysteresis loops and the magnetization reversal time of rectangular micron-sized permalloy thin films was studied using a dynamic micromagnetic simulation. Edge roughness was found to change the local equilibrium magnetization patterns, and the transition between these local equilibrium magnetization patterns was shown to induce steps in the hysteresis loops and to strongly affect the magnetization reversal time. In rectangular films, fast magnetization reversals and clean hysteresis loops are more likely to result when N-type magnetization patterns are stable in positive and negative saturation. A rough estimate of the hard-axis bias field required to eliminate edge-roughness-induced irreproducibility was determined.