Micromagnetic simulation of random anisotropy model

Abstract The random anisotropy model was simulated by micromagnetic calculations performed on a 450 nm×72 nm×72 nm computational box, periodic in y and z directions, which consists of iron nanograins. The diminishing of effective anisotropy as a function of grain size was followed through the domain wall width. The domain wall structures have been calculated as a function of average grain sizes 10, 12, 15, 20 nm and for single-crystal, using direct integration of the Landau–Lifshitz–Gilbert equation. The domain wall width was found to increase with 1/ D 3 as predicted by the Herzer model.