Theoretical and comparative investigations of Yb3+ ion in MWO4 and M′MoO4 scheelites crystals (M=Sr, Pb, Ca, Ba) and (M′=Sr, Pb, Ca, Cd)

The crystal-field model is applied to a series of scheelites crystals (CaWO4, SrWO4, PbWO4, BaWO4, CdMoO4, CaMoO4, SrMoO4 and PbMoO4) doped with the Yb3+ ion. The calculated crystal-field parameters present a general trend of variation with M2+ ionic radius of the host cation. The maximum splitting ΔE of the 2F7/2 manifold of the Yb3+ ion is then obtained as a function of NV crystal-field strength parameters. The agreement between experimental results and theoretical predictions for all investigated systems is very satisfactory. The crystal-field effects are very important for the prediction of emission energies of the Yb3+ ion in different scheelites.