YTa7O19 doped with Tm3+ was prepared by a solid state reaction of co-decomposition nitrates as starting materials. The substitution of Tm3+ for Y3+ in Yi_xTmxTa7O19 was performed in the full compositional region on calcinating at 1200°C for 24 24 in air. The solid solution was isomorphous of CeTa7O19 which involved a network of (Ce3+, Ta5+)-O2- polyhedra inter-stratified in a double layer of Ta5+-O2- polyhedra. The samples were identified by XRD and the optical measurement was carried out. According to the results of excitation and emission spectra, the intense blue emission of Tm3+ was observed near 460 nm corresponding to twice the intensity of YA103 doped with Tm3+. The unique concentration dependence of emission intensity in Y1-zTmzTa7O19 was observed. The maximum of relative intensity was obtained at x=0.2. This profile revealed the concentration quenching of emission. The energy migration of excited Tm3+ was discussed in relation to the low-dimensionality of substituting sites for Tm3+.
ASJC Scopus subject areas
- Chemical Engineering(all)