Magnetization reversal of Tb-Co/Fe19Ni81 films with a unidirectional anisotropy

Conditions have been found for the realization of induced in-plane uniaxial anisotropy of the amorphous Tb31Co69 films and of unidirectional anisotropy in the Permalloy layers in the composite two-layered Tb31Co69/Fe19Ni81 films. The mechanisms of magnetization reversal in such film structures have been studied in a temperature range of 5–300 K. It has been found that a decrease in temperature leads to a transformation of hysteresis loops, a significant increase in the field of unidirectional anisotropy, and a nonmonotonic change in the coercive force of the Permalloy layer. The regularities found are interpreted taking into account the variation in the properties of the amorphous layer Tb31Co69 with temperature under the assumption on a temperature-induced change in the localization of the interlayer magnetic boundary, which is formed upon a layer-by-layer magnetization reversal of the film structure.