Optical properties of gadolinium in the condensed state

The optical properties of gadolinium in liquid and solid states have been studied. The optical constants are measured by the Beatty ellipsometry method in the range of $0.48$–$2.6\,\mu$m. The dispersion dependences of light conductivity $\sigma$, reflectivity $R$, the imaginary and real parts of dielectric permittivity $\varepsilon_1$ and $\varepsilon_2$, and the function $\rm Im(\varepsilon)^{-1}$ of the characteristic electron energy losses are calculated from the measured values of the refractive index and the absorption coefficient. The electronic characteristics of gadolinium in solid and liquid states are calculated on the basis of a two-band conductivity model with measurement results in the infrared spectral region.