Micromagnetic investigation of periodic cross-tie/vortex wall geometry
Michael J. Donahue
A systematic series of micromagnetic simulations on periodic cross-tie/vortex wall structures in an ideal soft film at various width, thickness, and period lengths is performed. For each width and thickness a natural period length is found which has minimal energy density for walls of this type. For each width a critical thickness is determined below which the natural period length is infinite; for films thinner than this the pure Neel wall has lower energy than any cross-tie/vortex wall. Details of the origin of the energy reduction in cross-tie/vortex walls as compared to Neel walls is also examined, and canting inside cross-tie and vortex structures in films thicker than 1 exchange length is explained.