Synthesis, structure and luminescent properties of Lu(PO3)3

A new structural type of rare earth metaphosphate, Lu(PO3)3, was prepared from high-temperature solution, of which the crystal structure was solved in S.G. of Cc (No.9) and Z = 4 with unit cell dimensions of a = 13.972(3) Å, b = 6.6710(13) Å, c = 9.958(2) Å and β = 127.36(3)°. In Lu(PO3)3, [LuO6] octahedra connect with the non-bridging oxygens on (PO3)n infinite zigzag chains that extended along c-axis. The VUV and X-ray excited luminescent properties of undoped and Ln3+ (Ln = Ce, Eu, Tb) doped samples were examined, from which the optical band gap was estimated to be 8.3 eV. Besides, in the undoped sample a STE emission within 320–480 nm was observed, which probably be related to oxygen defects. However, in the Lu(PO3)3:Ce sample the Ce3+ emission was weak and STE emission was totally quenched under hard X-ray excitation.