INTERNATIONAL JOURNAL OF CHEMICAL AND PHYSICAL SCIENCES

12-22

Authors: YADAV P.J., MESHRAM N.D., JOSHI C.P.1, MOHARIL S.V.

In Y2O3–Al2O3 system, compounds Y3Al5O12 (yttrium aluminum garnet-YAG), YAP (yttrium aluminum perovskite-YAlO3,) and Y4Al2O9 (yttrium aluminate monoclinic- YAM,) are well known. YAG and YAP are of considerable technological importance. The conventional solid-state reaction techniques require high sintering temperatures (above 1800°C) to prepare phase pure compounds. Though several soft chemical routes have been explored for synthesis of YAG, YAP and YAM, most of these methods are complex. Moreover, phase pure materials are not obtained in one step, but prolonged annealing at temperatures around 1000 C is necessary. One step combustion synthesis of these compounds is reported in this paper using a modified procedure and employing mixed (glycine + urea) fuel. Phosphors based on Eu3+ activation were also prepared which exhibited characteristic photoluminescence. The emission spectrum of Eu3+ doped YAG phosphor is dominated by orange emission due to 5D0-7F1 transition with inversion symmetry. However, the emission spectrum of Eu3+ doped YAP phosphor is dominated by red emission due to 5D0-7F2 transition without inversion symmetry. The PL spectrum of Eu3+ doped YAM phosphor consists of similar emission intensities for both 5D0-7F1 (590 nm) and 5D0-7F2 (607 nm) transitions.