Electronic Structure and Luminescence Spectroscopy of MIBi(MoO4)2 (MI = Li, Na, K), LiY(MoO4)2 and NaFe(MoO4)2 Molybdates

The mechanisms of intrinsic luminescence in the set of molybdate crystals of (MMIII)-M-I(MoO4)(2) (M-I = Li, Na, K; M-III = Bi, Y, Fe) type are revealed in complex experimental and theoretical studies. The luminescence spectroscopy under vacuum ultraviolet (VUV) synchrotron excitations is applied together with the electronic structure calculations carried out by the FLAPW method. The energy gaps (E-g) values of the crystals are determined in simultaneous analysis of diffuse reflectance and luminescence excitation spectra. It is found that the molybdate groups MoO42- play a dominant role in the processes of intrinsic luminescence in studied molybdate compounds.