Abstract: Rare earth silicophosphates with a general formula RE₂O₃·0.10SiO₂·0.95P₂O₅ were synthesized and developed as good host materials. This paper reports a systematic investigation on the luminescence properties of Ce³⁺-activated silicophosphates of lanthanum and gadolinium. Samples of definite composition and single phase were prepared by solid state reactions. Their crystal stuctures were determined by high resolution X-ray diffractometer D/maxra (4okV, 150mA) to be monodinic and isostructural with GdPO₄(ASTM 26-660) (Fig. 2). The latice parameters were calculated(Table 1).The emission, excitation and diffuse reflectance spectra of these two phosphors are determined(Fig. 4, Fig.5).The temperature effect from 77 to 423Kon the luminescence of these phosphors has been studied. These appears the thermal shifts of sublevels of ²F_7/2 of Ce³⁺(Fig,6, Fig.7)From the concentration dependence of Ce³⁺ emission Igx-lgI/x a conclusion may be drown, that the concentration quenching of Ce³⁺ in the LSPand GSPcomes from the dipole-dipole interaction(Fig.10, Fig.11).

Key words: Cerium, Rare Earth, Luminescence phosphor, Silicophospate