Magnetooptical effects and Auger electron spectroscopy of two-layer NiFe-Dy and Fe-Dy films with nonuniform layers

Magnetooptical effects (magnetic circular dichroism and longitudinal Kerr e ffect) and the in-depth distribution of elements in two-layer NiFe-Dy and F e-Dy films obtained by thermal deposition of the components in an ultrahigh vacuum have been studied. It is shown that in a temperature range of 80-30 0 K dysprosium in a two-layer film gives constant contributions to both eff ects and that these contributions are approximately equal to those observed in an isolated Dy film at temperatures lower than the T-C temperature of t he Dy transition into the ferromagnetic state (similar to 100 K for the fil ms studied). It is assumed that such a behavior of the magnetooptical effec ts is due to the influence of the spin system of the NiFe layer on the magn etic state of the Dy layer enhanced by the penetration of Ni and Fe ions in to the Dy layer to a large depth, as follows from the data obtained using A uger electron spectroscopy.