H2and N2contaminated amorphous CoGd and FeGd films

O2contamination of thermally evaporated CoGd and FeGd was investigated earlier and a model which explains the origin of the observed magnetic behaviour of the rare earth transition metal films was presented. This model, based on the formation of nonmagnetic inclusions in the magnetic material, should not only be applicable to O2contaminated films which hold non-magnetic oxide inclusions, but also to films with any nonmagnetic inclusions. We, therefore, investigated the magnetic properties of H2and N2contaminated CoGd and FeGd films. We found that N2and H2contamination has qualitatively the same influence on the magnetic behaviour as O2, which strongly supports the proposed model. To obtain perpendicular anisotropy in CoGd films a critical amount of about 10^at/o Gd has to be magnetically deactivated by the influence of the contaminating gases; these perpendicular anisotropic films exhibit a common minimum electrical resistivity of 2.6 × 10^-4Ω cm. H2and N2contamination yields also similar dependencies of the magnetic properties as found for O2contamination, however, to achieve the same effects the N2and H2pressures have to be considerably larger than the O2pressure.