VARIATIONS OF THE LOCAL ANISOTROPY VERSUS TB CONTENT IN AMORPHOUS COZRTB THIN-FILMS

The magnetic properties of rf sputtered amorphous (Co93Zr7)100-xTbx th in films were investigated as a function of Th content for 0 less-than -or-equal-to x less-than-or-equal-to 2 by transverse biased initial su sceptibility measurements. The deposition was performed in a magnetic field. This films exhibit a very well-defined in-plane anisotropy with negligible long-range fluctuations and a small coercive field H(c), i n accordance with the experimental data. The overall variations of the transverse susceptibility are related to the ripple, and the variatio ns of the structure factor S with composition was measured. The local anisotropy K(loc) deduced from S, increases with the increasing amount of Tb in the layers. The results are discussed in terms of the single -ion anisotropy of the rare earth.