Domain structures due to induced anisotropy and stresses in film heads

The local anisotropy near the backgap closure of inductive-film heads is generally the result of two superimposed anisotropies. One is the anisotropy induced during deposition of the magnetic yoke in the presence of a magnetic field, and the other is a stress anisotropy whose magnitude and direction depend on the sign and magnitude of the stress-magnetostriction product. The authors present a simple model for these combined anisotropies and the associated domain wall patterns, assuming that the stress-magnetostriction product falls off as r^-2, where r is the distance from the center of the backgap closure, which in this case is assumed to be circular. One of the features of the predicted domain wall patterns is a three-wall intersection occurring where the two anisotropies cancel, i.e. where the yoke material is isotropic. Examples of domain walls in the vicinity of a backgap closure of an experimental film head are shown and discussed