Influence of internal magnetostriction on the formation of periodic magnetization configurations

Using a general argument which enables the stresses due to a magnetic configuration to be described by effective dislocation densities, it is shown that isolated non-180° walls in infinite media are not stable, but that periodic configurations of such walls have a very small magnetostriction energy and are thus not forbidden. Such structures are described for iron (walls parallel to {100} planes) and nickel (walls parallel to {110} planes). The variation of the periodicity and the energy is calculated as a function of the maximum angular amplitude of the magnetization. It is suggested that such periodic configurations are related to the so-called stripe domains observed in thin foils above a critical thickness.