Optical properties and electronic structure of copper-manganese solid solutions

Abstract

Optical properties of Cu—Mn alloys with Mn concentrations of 2 %, 5 %, 10 % and 17.5 % (which corresponds to γ -solid solutions) were studied in a wide spectral range of 0.23—2.8 $mu;m (0.44—5.39 eV). Real and imaginary parts of the refractive index were measured and other optical properties such as dielectric constant, optical conductivity and the coefficient of specular reflectance at normal incidence were calculated based on them. Based on the analysis of the dispersion dependences ε(ν), R(ν) and σ(ν) the electronic structure model of these alloys was proposed. According to this model, the electronic spectra (dependence of the density of electronic states on energy N(E)) of alloys with the indicated concentrations of components are the superposition of electronic spectra of Cu host, with weights equal to Cu concentrations, and the density of states within the impurity band, calculated basing on the experimental data.