Crystal field analysis and electron-phonon coupling in Sc₂O ₃:Cr³⁺

Crystal field analysis of the energy level structure of the Cr ³⁺ ion in the 80203 crystal is performed, using the exchange charge model of the crystal field theory. The crystal field parameters acting on the optical electrons of the Cr³⁺ ion at the sites with C₂ and C_3i symmetry are calculated from the crystal structure data. On the basis of the comparison between experimental absorption and emission spectra and theoretically calculated energy levels of Sc₂O ₃:Cr³⁺, the conclusion is made that the spectroscopic properties of the title host are determined by the Cr³⁺ ion at the positions of C₂ local symmetry. The Stokes shift 5 = 4.32 and the energy of the phonons effectively interacting with an impurity center ℏω = 499 cm^-1 are derived from the experimental spectra of absorption and emission.