Modeling of electron-vibrational 4fn-4fn − 15d spectra in LiYF4:RE3+ crystals

In the present work, the low temperature absorption band shapes of the impurity Ce3+ (4f-5d) and Lu3+ (4f14-4f135d) ions in LiYF4 crystals have been simulated within adiabatic approximation on the basis of a derived microscopic model of electron-phonon interaction and phonon spectrum of the host lattice. Crystal field parameters and electron-phonon coupling constants were treated in the framework of the exchange charge model. Results of simulations of the spectral envelopes agree satisfactorily with the experimental data available from the literature.