New Series of Red-Light Phosphor Ca(9−)(x)Zn(x)Gd(0.9)(PO(4))(7):0.1Eu(3+) (x = 0–1)

In this study, a new series of phosphors, Ca(9−x)Zn(x)Gd(0.9)(PO(4))(7):0.1Eu(3+) (x = 0.00–1.00, step dx 0.05), was synthesized, consisting of centro- and non-centrosymmetric phases with β-Ca(3)(PO(4))(2)-type structure. Crystal structures with space groups R3c (0.00 ≤ x < 0.35) and R [Formula: see text] c (x > 0.8) were determined using X-ray powder diffraction and the method of optical second harmonic generation. In the region 0.35 ≤ x ≤ 0.75, phases R3c and R [Formula: see text] c were present simultaneously. Refinement of the Ca(8)ZnGd(PO(4))(7) crystal structure with the Rietveld method showed that 71% of Gd(3+) ions are in M3 sites and 29% are in M1 sites. A luminescent spectroscopy study of Ca(9−x)Zn(x)Gd(0.9)(PO(4))(7):0.1Eu(3+) indicated the energy transfer from the crystalline host to the Gd(3+) and Eu(3+) luminescent centers. The maximum Eu(3+) luminescence intensity corresponds to the composition with x = 1.