OPTICAL-PROPERTIES OF CHROMIUM AND IRON DISILICIDE LAYERS

Results are presented on optical spectra of semiconducting CrSi2 and b eta-FeSi2 polycrystalline thin films over the spectral range from 0.02 to 24 eV. For CrSi2, indirect and direct transitions are found at 0.5 and 0.9 eV, respectively. Spectral features at higher energies are at tributed to transitions between bonding and antibonding states mediate d by energy dependent matrix elements. Simulation of the IR spectra by an oscillator model yields six TO frequencies for both CrSi2 and beta -FeSi2.