SOL–GEL COMBUSTION SYNTHESIS AND LUMINESCENT PROPERTIES OF NANOCRYSTALLINE Y3Al5O12:Eu3+ PHOSPHORS

Nanosized YAG:Eu3+ powder samples were synthesized by using co-precipitation method and combining stoichiometric ratios of Y(NO3)3 · 6H2O, Eu(NO3)3 · 5H2O, Al(OR)3. After sintering at the temperature of 900°C for 3 h, YAG:Eu3+ nanoparticles with single phase were obtained. In comparison with the conventional solid-state reaction process, this sol–gel process not only decreased the temperature required for synthesizing YAG:Eu3+ powder, but also reduced their particle size to the nanometer range. The crystallinity, surface morphology and photoluminescent characteristics of phosphors were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectrophotometer, respectively. The size of the nanocrystalline materials was found to increase from 33.66 to 51.70 nm with the annealing temperature increasing from 900° to 1100°C. The photoluminescence spectra shows the emissions radiated by the transitions from 5D0 excited states to 7FJ (J = 1, 2) states of Eu3+ ions. The crystallinity, surface morphology and photoluminescence spectra of phosphors were highly dependent on the sintering temperature.