Preparation of amorphous magnetic thin film by two source r.f. magnetron sputtering

Abstract

Magnetic properties of rare earth-transition metal amorphous films deposited by the multiple target r.f. magnetron sputtering method were studied. These films have microscopically multi-layered structure, because rare earth element and transition metal element deposit alternately onto a substrate. So, the magnetic spin interaction is supposed to be different from that of the film made by other conventional deposition technique, for example sputtering from mosaic target or vacuum evaporation from the alloy target. The results of torque measurement showed that the easy axis of Gd-Fe film and Tb-Fe film declined from the film normal. Uniformity of compensation temperature, Curie temperature and coercivity over a wide area was fairly good under the insertion of the window, which was designed to maintain constant the film composition and to decrease the oblique incidence of sputtered atom onto substrate. The critical deposition rate per revolution was about 10 Å/rev, where the transition of electrical resistivity occurs, and the change of magnetic anisotropy occurs at 8 Å/rev for Gd-Fe and 12 Å/rev for Tb-Fe.