Magneto-optical Kerr spectra of non-equilibrium Au-Co alloy films and Au/Co multilayer films

The magneto-optical Kerr effect was measured for non-equilibrium Au-Co alloy films prepared by rf magnetron sputtering. From the result of XRD and TEM, it was confirmed that the Au-Co alloy films with Co contents below 48 at% consist of a single fcc phase. The spectra of the Kerr rotation /spl theta//sub K/ of the films showed two peaks, which were observed at E=1.4 and 3.4 eV. The shape of /spl theta//sub K/ spectra was very different from that obtained from a calculation using an effective dielectric tensor of the film consisting of Co clusters dispersed in Au matrices. It approached the calculated one after annealing.