VUV spectral properties of GdPO4 : Tm3+ and Sr3Gd(PO4)3 : TM3+

GdPO4 : Tm3+ and Sr3Gd(PO4)(3) : Tm3+ samples were prepared by solid state reaction. The properties of structure, VUV excitation and luminescence under VUV excitation were studied. GdPO4 : Tm3+ belongs to the monoclinic space group, and the crystal structure does not change as the crystal lattice is doped with Tm ions. The excitation spectra of GdPO4 : Tm3+ show strong absorption at 164 and 210 nm due the to host and the S-8(7/2)-6G(J) transition of Gd3+, respectively. The emission spectra of GdPO4 : Tm3+ reveal two intense and sharp emission peaks (453 nm and 363 rim) under 166 nin. VUV excitation. The chief emission is at 453 rim from the typical Tm3+1 D-2 -> H-3(4) (22, 123 cm(-1)) transition. The emission spectra of Sr3Gd(PO4)(3) Tn(3+) at 363 rim is weakened while the blue emission at 453 rim is strengthened because the excitation spectra of Sr3Gd(PO4)3 Tm3+ at 166 rim are higher than that of GdPO4 : Tm3+.