Crystal Field Analysis and Electron-phonon Coupling in Sc2O3:Cr3+

Crystal field analysis of the energy level structure of the Cr3+ ion in the Sc2O3 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 C3i 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 Sc2O3: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 S = 4.32 and the energy of the phonons effectively interacting with an impurity center h̅ω = 499 cm−1 are derived from the experimental spectra of absorption and emission