Optical Spectroscopy of Ce3+, Eu3+ and Pr3+ in (M2+)9M3+(PO4)7 (M2+=Ca, Sr) (M3+=Al, Ga, In, Sc, Y, Lu, Gd, La)

Optical properties of Ce³⁺, Pr³⁺ and Eu³⁺ in the compound (M²⁺)₉M³⁺(PO₄)₇ (M²⁺=Ca, Sr) (M³⁺=Al, Ga, In, Sc, Y, Lu, Gd, La) are reported and discussed. The M³⁺ ion is octahedrally coordinated in this structure. The crystal field splitting, the centroid shift and the Stokes shift of the Ce³⁺ ion are reported in these compounds (Figure 1). The optical data is connected with the structural aspects of the host lattice and compared with those that have been reported in the literature.