LAUSR

Abstract For the first time, rare-earth phosphate compound Cs4PbTb2(PO3)12 was prepared using molten salt method and structurally characterized by single-crystal X-ray diffraction (XRD). Its structure features a three-dimensional (3D) open framework constructed by P4O12 cyclotetraphosphate groups and (Pb|Tb)O8 polyhedra, with large holes filling with Cs+ ions. The P4O12 groups in this structure are isolated and each P4O12 is surrounded by four (Pb|Tb)O8 polyhedra by sharing terminal O atoms. Furthermore, the powder XRD, infrared (IR) spectrum, Ultraviolet–visible (UV–Vis) spectroscopy and photoluminescence (PL) properties for title compound were studied. Under near-UV excitation (378 nm), the emission colour turns from green through yellow to pure red by simply adjusting the Eu3+ concentration due to the efficient Tb3+→Eu3+ energy transfer mechanism.