Conduction of flux at high frequencies by a charge-free magnetization distribution

A charge-free, analytically tractable model for flux conduction by pure rotation in Permalloy strips at high frequencies is proposed. An expression for the magnetization rotation versus applied field is presented. The model is extended to give important qualitative results for shapes other than simple strips. In particular, the region where the narrow pole tip joins an abruptly widened yoke in a thin film recording head is considered. It is shown that the desired flux spreading in this region can only be achieved with accompanying wall motion