Optical properties of tantalum disilicide thin films

${\mathrm{TaSi}}_2$ polycrystalline films, grown by sputtering and subjected to a preliminary chemical and structural characterization, were studied by reflectance from 0.01 to 6 eV and thermoreflectance from 1 to 9 eV. The data were Kramers-Kronig transformed to obtain the dielectric functions. Low-energy response is discussed in terms of the Drude model; some indications concerning the interband structures are drawn on the basis of calculated density of states and of photoemission results. A comparison is made with the optical properties of isoelectronic pure refractory metals and their disilicides.