Thermal decomposition of Y3Al5O12 precursor synthesized by urea homogeneous co-precipitation

Yttrium aluminum garnet (YAG) nano-precursors were synthesized by urea homogeneous co-precipitation. The morphology and crystalline phase, particularly the in situ evolved gases of as-synthesized precursors during the thermal decomposition, were characterized and verified. The evolved NH3, H2O, and CO2 gases can be observed below 600 °C. The released NO2 gas was observed at 202 °C, 500 °C and 885 °C, which suggests that N O 3 − existed in the precursor with three different forms. Furthermore, the evolved SO2 gas was detected above 850 °C due to desulfurization. Phase-pure YAG can be obtained when the precursor was calcined at 900 °C. The particle size increases with increasing calcination temperature. The powders calcined at 1100 °C were well dispersed and had an average grain size of 100 nm owing to the decomposition of S O 4 2 − at high temperatures.