Theoretical Simulation and Synchrotron Excitation Spectra of Lanthanide Ions in Hexafluoroelpasolite Lattices

Vacuum ultraviolet (VUV) excitation spectra at 10 K have been recorded for the lanthanide ions, Ln 3+ = Nd 3+, Ho 3+, Tm 3+, and Yb 3+, situated at octahedral site symmetry in hexafluoroelpasolite Cs 2 NaLnF 6 lattices. The corresponding VUV/UV/visible/near-infrared emission spectra have also been recorded. The 4f N −1 5d energy levels and 4f N −4f N -1 5d spectral intensities have been calculated by judicious selection of parameters, without detailed fittings, when employing the M. F. Reid suite of programs. The simulations are in reasonable agreement with experimental data. Some additional spectral features for these systems have been assigned to charge transfer (CT) transitions, and CT emission is reported for the case of Tm 3+ . A comparison of the results with the spectra of LiYF 4:Ln 3+ has been included and the major difference lies in the greater crystal-field strengths for Ln 3+ in the hexafluoroelpasolite lattices.