Optical Properties and Electronic Structure of CaO

Spectra of 11 optical functions of CaO in the ranges 6.5–7.2 eV at 2 K and 0–60 eV at 77 K were determined. A total of 14 maxima and shoulders of excitons and interband transitions were found including two distinct exciton structures at 6.9 and 11.4 eV and volume and surface plasmon maxima at ~38.3 and 33.2 eV, respectively. Their principal features and general trends were established. Variable formation efficiencies of spectra of the dielectric permittivity and characteristic electron-energy losses in different spectral ranges were analyzed. The calculations used known experimental reflectance spectra and computer programs based on the Kramers–Kronig correlations and analytical formulae for the relationship between optical functions.