MAGNETOOPTICAL EFFECTS IN AU/CO/AU ULTRATHIN-FILM SANDWICHES

This paper deals with the study of magneto-optical effects exhibited in perfect Au/Co/Au ultrathin films structures as a function of magnetic field and photon energy. They stand as ideal basic structures to test theories describing the magneto-optical effects in multilayers. In both optical transmission and polar Kerr rotation dispersion spectra, the main feature is a prominent peak centered near the photon energy of 2.5 eV, which corresponds to the plasma edge and reflectivity minimum in gold. The observed trends in magneto-optical effects are explained using the electromagnetic wave theory starting from the published optical and magneto-optical constants values in gold and cobalt thick films. The polar Kerr effect in our samples is a sum of one independent plus one linearly dependent term on the Co film thickness. The nonzero value of the thickness-independent term indicates the presence of a contribution not accounted for by the employed electromagnetic wave model.