Magneto‐optical Kerr spectroscopy in Pt‐Ni multilayers

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