Optical Functions of Chromium Disilicide Epitaxial Films in the 0.35-6.2-eV Energy Range: The Semiempirical Simulation

摘要

The real and imaginary parts of the dielectric function ε(E) = ε_1(E) + iε_2(E) were calculated from reflection spectra of chromium disilicide epitaxial films with the use of the Kramers-Kronig integral relations in the 0.35- to 6.2-eV energy range at room temperature. A semiempirical model of the dielectric function for the A-type CrSi_2 epitaxial films was derived on the basis of the available theoretical calculations of the energy-band structure of CrSi_2 single crystals and the data of the optical reflection spectroscopy. The integrated spectra of the dielectric function were decomposed into the contributions from seven noninteracting harmonic oscillators and the parameters of these oscillators were evaluated. A satisfactory agreement was obtained between the experimental spectra and the spectra of complex refractive index and reflection coefficient as calculated on the basis of the model suggested.