Crystal structures and luminescence properties of Eu2+-activated new NaBa0.5Ca0.5PO4 and Na3Ba2Ca(PO4)3†
Abstract
NaBa1−xCaxPO4:Eu2+ were synthesized using polymerizable complex method. New phases were observed at x = 1/3 and 0.5, which were identified by single-crystal XRD analysis as Na3Ba2Ca(PO4)3 and NaBa0.5Ca0.5PO4 with a trigonal system. Though both phases pretend to be solid solutions between NaBaPO4 and NaCaPO4, they have different coordination environments and PO4 orderings. 1 mol% Eu2+-activated NaBaPO4, Na3Ba2Ca(PO4)3, and NaBa0.5Ca0.5PO4 exhibited an emission maximum at 435 nm, 458 nm, and 460 nm, respectively. The shift of the emission maximum might be due to a change in the Eu–O bond length.