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

• The evolved gases of as-synthesized YAG nano-precursors during the calcination processes were verified.
• The evolved NH3, H2O, and CO2 gases can be observed below 600 °C.
• NO2 gas was observed at 202 °C, 500 °C, and 885 °C.
• SO2 gas was detected above 850 °C.
• The powders calcined at 1100 °C were well dispersed.

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 NO3− 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 SO42− at high temperatures.