Dependence of microstructure and magneto-optical properties on deposition angle in evaporated TbFe and TbFeCo films

Abstract

We have investigated the effects of deposition angle on growth morphology and magneto-optical properties in TbFe and TbFeCo films, which were prepared by coevaporation of Tb and Fe (or FeCo) on tilted substrates. Cross-sectional scanning electron microscopy revealed that the films had columnar structure and the growth orientations of columns generally followed the ‘‘tangent rule’’ [Dirks and Leamy, Thin Solid Films 47, 219 (1977)]. Measurements of the polar Kerr hysteresis loops revealed that with increasing the angle of incidence of the vapor beam from the substrate normal, the squareness of the hysteresis loop deteriorated, and also the Kerr rotation angle and the coercivity decreased. The results of the present study clearly demonstrate the importance of normal growth of columns with respect to a film plane to achieve perpendicular magnetic anisotropy in evaporated rare-earth transition-metal alloy films.