Synthesis and luminescent properties of Eu3+-doped phosphate-sulfate fluorapatites Ca10−xNax(PO4)6−x(SO4)xF2

A series of phosphate-sulfate fluorapatites Ca10−xNax(PO4)6−x(SO4)xF2:Eu3+(2%) (x = 0, 3, 6) has been synthesized by the solid-state reaction at high temperature. The samples were characterized by X-ray diffraction, Infrared spectroscopy and Raman scattering spectroscopy. Eu3+ luminescence properties were investigated at 77 K using site selective and time-resolved spectroscopy. Lifetimes and the color points were calculated. The emission spectra and luminescence decays of Eu3+ ions indicate that there is an energy transfer between different sites occupied by Eu3+.