Crystal structure and luminescent properties of europium-activated Ca10−x M x (PO4)6F2 (M = Pb, Mg) prepared via precipitation from aqueous solutions

Phase-pure polycrystalline fluorapatites with the general formula Ca10-x M x (PO4)6F2:Eu(M = Pb, Mg) have been prepared by precipitation from aqueous solutions, and the effects of the Pb and Mg ions, differing markedly in ionic radius, on the structure, morphology, and luminescence spectra of the fluorapatites have been investigated. The Pb and Mg contents are shown to influence the Eu distribution over inequivalent sites in the crystal structure of Ca10-x M x (PO4)6F2.