A MAGNETOOPTICAL STUDY OF THE INTERFACES IN EVAPORATED CO/PT MULTILAYERS

Co/Pt multilayer films have been prepared by evaporation under UHV conditions. For samples with Co layer thickness below 0.8 nm rectangular loops are observed. While the polar Kerr rotation decreases with the Co layer thickness, the Faraday rotation, on the contrary, is seen to increase strongly. This increase has been attributed to the presence of Co-Pt alloy layer formed by mixing at the interfaces and whose thickness has been estimated to be about 0.3 nm. Furthermore this layer is thought to play a crucial role in the origin of the uniaxial anisotropy. Faraday rotation study is thus shown to be an useful tool to characterize the multilayers.