Crystal field analysis of the absorption spectra and electron-phonon interaction in Ca3Sc2Ge3O12:Ni2+

Exchange charge model of crystal field [B.Z. MaLkin, in: A.A. Kaplyanskii, B.M. Macfarlane (Eds.), Spectroscopy of Solids Containing Rare-earth Ions, North-Holland, Amsterdam, 1987, pp. 33-50.] was used to analyze the energy level schemes of Ni2+ ion at both possible positions (octahedral and tetrahedral) in Ca3Sc2Ge3O12. The crystal field parameters were calculated from the crystal structure data; the crystal field Hamiltonian was diagonalised in the complete basis consisting of 25 wave functions of all LS terms of the Ni2+ ion. Results of calculations are in a good agreement with experimental data. From the experimental spectra available in the literature, the Huang-Rhys parameter S = 3.5 and effective phonon energy h omega = 200 cm(-1) were evaluated for the octahedral Ni2+ ion. (c) 2005 Elsevier Ltd. All rights reserved.