OPTICAL-PROPERTIES OF PD2SI

Near-normal reflectivity measurements with polarized light have been performed on good quality single crystals of Pd2Si in the spectral range from 0.05 to 4 eV. Moreover, spectral ellipsometry from 1.4 to 5 eV and nonpolarized reflectivity from 3 to 12 eV have been used in order to Kramers-Kronig analyze the data and to obtain the dielectric functions. The results show strong anisotropy in the optical response for the polarization along the crystallographic c axis, or in the basal plane, of the hexagonal cell, according to the transport measurements. The optical properties of Pd2Si have been calculated within the local-density approximation using the semirelativistic linear-muffin-tin-orbital method. The band structure, the l-projected densities of states, the complex dielectric function, the optical conductivity, the optical reflectivity, and the electron-energy-loss spectrum have been obtained in the energy range from 0 to 5 eV. The agreement with the experimental data is rather good.