OPTICAL-PROPERTIES OF POLYCRYSTALLINE NICKEL SILICIDES

The near-normal reflectivity of polycrystalline Ni3Si, Ni2Si, NiSi, and NiSi2 from 0.01 to 6 eV and the dielectric functions obtained by Kramers-Kronig analysis are presented. The effect of an oxide overlayer on the optical properties is also considered. The low-energy response is discussed in terms of the Drude model and compared with the transport measurements. The higher-energy interband spectrum is interpreted on the basis of the calculated density of states and photoemission results. In particular, the optical structures of NiSi2 are correlated to interband transitions using the joint density of states obtained by band-structure calculations. © 1990 The American Physical Society.