Magnetic anisotropy of thin metallic film tapes deposited at oblique incidence

The origin of magnetic anisotropy of thin films deposited at oblique incidence is investigated. Electron micrographs of such films prepared at various incident angles demonstrate a characteristic particle structure. A model of the film developed on this basis is composed of identical elongated rotation ellipsoids whose long axes are oriented parallel to the beam direction. The energy density is calculated for all orientations of magnetization, taking into account the shape anisotropy of the particles and the interaction of their stray fields. Hence the anisotropic properties of the film are obtained. The comparison of calculated and experimental results verifies the assumption that anisotropy is caused preferably by effects of shape induced by technological processes. The parameters of films with optimal storage properties (maximum energy product) can be determined theoretically by the suggested method.