MAGNETOOPTICAL KERR-EFFECT OF RARE EARTH-TRANSITION METAL AMORPHOUS ALLOY AND MULTILAYER FILMS

Magneto-optical Kerr rotation theta(K) spectra are shown for the amorp hous alloy films of R(0.30)(Fe0.89Co0.11)(0.70) with R = La, Pr, Nd, S m, Eu, Gd, Tb, and Dy, and they are compared with those for R(similar to 0.2)Co(similar to 0.8) films. On the whole, one of the most remarka ble differences is that theta(K) greatly depends on the species of R f or a series of RFeCo in infrared regions, while theta(K) for RCo scarc ely depends on R. This difference is explained by a change in Curie te mperature with the R species. Based on this model, spectral subnetwork contributions of R to theta K are estimated. In ultraviolet regions, large negative contributions can be expected for R = Pr, smaller negat ive ones for Nd and Gd, with large positive ones for R = Tb and Dy, an d almost zero for R = Sm. Although experiments are done only on a rest ricted number of films, the Kerr spectra change only slightly for mult ilayers from alloy films with corresponding compositions.