OPTICAL AND ELECTRONIC-PROPERTIES MODIFICATIONS IN PD-NI MULTILAYERS

The optical and electronic properties of compositionally modulated Pd(m)-Ni(n) multilayers (CMMs), for modulation period up to 20 monolayers, have been studied by conventional and synchrotron radiation ellipsometry. A broad structure around 4.6 eV was found to depend strongly on the composition modulation period (m + n) whereas the plasma energy depended on both Pd-layer thickness m and modulation period. In higher energies (about 7 eV) additional features were observed to occur in the dielectric function spectra of Pd-Ni CMMs depending on the layer thicknesses. These effects are discussed in terms of the coherency strains and influence of the layer thickness on the electronic structure.