MICROMAGNETIC CALCULATIONS OF 180-DEGREES SURFACE DOMAIN-WALLS

We compare quantitative results from two methods of solving the micromagnetics equations for 180-degrees domain walls. The first method solves the Landau-Lifshitz-Gilbert equation by time integration of the stiff differential equations. The second method uses a relaxation scheme to determine the equilibrium domain wall magnetization configuration. We compare results from these calculations for various damping parameters and discretization mesh densities, and also compare our results with domain wall measurements made using scanning electron microscopy with polarization analysis. We conclude that equilibrium domain wall microstructure is insensitive to the damping parameter used in the time method of solution for domain walls in magnetically soft iron and Permalloy. For large damping parameters, the approach to equilibrium is the same for the time method and the relaxation method. Further, we can obtain metastable equilibrium states with both methods.