CONCENTRATION AND THE TEMPERATURE-DEPENDENCE OF THE INPLANE UNIAXIAL ANISOTROPY IN AMORPHOUS COZRDY THIN-FILMS

Amorphous transition metal-rare-earth thin films of composition (Co0.9 5Zr0.05)100-x(Dy)x were prepared by rf sputtering. During deposition a dc magnetic field of 700 Oe was applied parallel to the film plane, s o the films exhibit a very well defined in-plane uniaxial anisotropy K (u). The variations of K(u) were investigated as a function of Dy cont ent for the concentration range 9 less-than-or-equal-to x less-than-or -equal-to 26 and in the temperature range 4K<T<300K. The experimental data were analyzed by considering the possible contributions of pair o rdering and/or of the single ion anisotropy to K(u). It is shown that the experimental data can not be explained if one suppose that K(u) is essentially connected with a dipolar anisotropy. The overall result c an be well explained, and the experimental curves well fitted by as ca lculated curves based on a mean field analysis, if one assumes that th e dominant mechanism arises from single-ion anisotropy.