Preparation of Er, Tm:Yb3Al5O12 nanopower by gel method and their luminescence properties

Er, Tm:Yb3Al5O12(Er, Tm:YbAG) nanopowder was synthesized by a gel method with citric acid as a combustion agent. The optimal preparation conditions for the sample obtained are Er3+ and Tm3+ doped mole fractions of 2% and 1%, the mole ratio of citric acid to metal nitrate total number of atoms of 1.7:1, and calcination temperature and time of 950℃ and 2 h, respectively. The well-dispersed particles prepared appear spherical with the narrow size distribution, and the average particle size is 45nm. The emission spectra of Er, Tm:YbAG nanopowder at room temperature were analyzed. The results show that the luminous properties of the 2%Er, 1%Tm: YbAG samples is optimum, and the intensive emission peaks are located at 1587, 1658 nm and 1711 nm, which are corresponding to the 4I13/2→4I15/2 level transition of Er3+ and the 3F4→3H6 level transition of Tm3+, respectively. It is indicated that the upconversion fluorescence peaks include blue, green and red lights.