Stripes in thin ferromagnetic films with out-of-plane anisotropy

We examine the T=0 phase diagram of a thin ferromagnetic film with a strong out-of-plane anisotropy (e.g., Co∕Pt multilayers) in the vicinity of the reorientation phase transition. The phase diagram in the anisotropy–applied-field plane is universal in the limit in which the film thickness is the shortest length scale. It contains uniform fully magnetized and canted phases, as well as periodically nonuniform states: weakly modulated spin-density waves and strongly modulated stripes. We determine the boundaries of metastability of these phases and point out the existence of a critical point at which the difference between the spin-density wave and striped phases vanishes. Out-of-plane magnetization curves exhibit hysteresis loops caused by the coexistence of one or more phases. Additionally, we study the effect of a system edge on the orientation of nearby stripes. We compare our results with recent experiments.