Domain wall structures in thin magnetic films

Abstract

A review of recent theoretical experimental results on domain walls in thin magnetic films both of prallel anisotropy (permalloy films) and of perpendicular anisotropy (bubble film) is given. For the case of parallel anisotropy good agreement is achieved between theoretical predictions and experimental observations of the three wall types, symmetric and asymmetric Néel walls and asymmetric Bloch walls. We show pictures of asymmetric Néel walls in NiFe single crystal foils. In general, the calculation of a domain wall in a thin film means the calculation of a two-dimensional vector field of unit length under the influence of a long-range, dipolar interaction. Theoretical methods to do this are still clumsy and only very few rigorous calculations have been published. Even models Which avoid the dipolar interaction (stray field free models) cannot be computed straightforwardly. Recent efforts are reviewed together with a proposal for a new approach.