MAGNETOOPTICAL KERR SPECTROSCOPY IN PT-NI MULTILAYERS

The magnetic multilayers consisting of ultrathin 3d-transition metal a nd Pt or Pd layers are considered for the magneto-optical storage medi a with increased information density. This paper reports on the magnet o-optical polar Kerr rotation and ellipticity spectra in Pt-Ni multila yers at photon energies from 1.5 to 5.2 eV prepared by evaporation ont o glass substrates. The thickness of individual Pt layers was kept con stant at 2 nm in all samples studied while that of Ni layers varied be tween 0.9 and 3.9 nm. The prominent feature of the Kerr rotation spect ra is a broad negative peak the amplitude of which increases with the individual Ni-layer thickness. The multilayer spectra show less struct ure than that of pure Ni. Nevertheless the trends in multilayer spectr a when the thickness of individual Ni layers changes can be reasonably simulated using the electromagnetic wave theory and permittivity spec tra in bulk (or thick film) Ni and Pt.