R. Rosei

The optical properties of some alkali metal tungsten bronzes from 0.1 to 38 eV

Abstract The optical properties of the alkali metal tungsten bronzes are investigated. A review of existing data and the interpretation thereof is presented. Our absorptivity or reflectivity data for two cubic Na bronzes and for a tetragonal K bronze in the energy range 0.1 to 38 eV are displayed; the data are Kramers-Kronig analyzed and the optical constants are obtained. When feasible, comparisons are made with the existing data for the bronzes as well as for ReO 3 , which is structurally similar. The interpretation of optical constants is based on an existing band structure for ReO 3 and modifications thereto are suggested.

Thermoreflectance of V, Nb, and paramagnetic Cr

Thermoreflectance measurements of V, Nb, and Cr films were performed near 80 and 340 K to investigate the electronic properties of these metals. The thermoreflectance spectra ..delta..R/R were Kramers-Kronig analyzed to determine the temperature dependence of the dielectric functions. The results were compared with previous derivative measurements of Mo and with static measurements of the optical reflectance of the bcc metals. Interpretation of the structures was guided by recent band calculations. It was shown that the observed features reflect the behavior of large volumes of the Brillouin zone rather than well-defined singularities. (AIP)