Synthesis, Crystal Structure and Photoluminescence Property of Potassium Terbium Polyphosphate KTb(PO3)4

The potassium terbium polyphosphate crystal KTb(PO3)(4) has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P2(1)/n with a = 10.3182(6), b = 8.9129(5), c = 10.7940(6) angstrom, beta = 105.993(1)degrees, V = 954.3 angstrom(3), Z = 4, M-r = 513.91, D-c = 3.577 g/cm(3), mu = 8.585 mm(-1), F(000) = 960, S = 0.955, (Delta rho)(max) = 1.380, (Delta rho)(min) = -3.428 e/angstrom(3), the final R = 0.0301 and wR = 0.0400 for 2301 observed reflections with I > 2 sigma(I). In addition, pure powder of isostructural RbTb(PO3)(4) was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb(PO3)(4) (A = K (1), Rb (2)) are promising candidates to become solid-state visible green light-emitting sources.