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.