Synthesis and Sinterability of YAG Nanopowders by Microwave Homogeneous Precipitation

The low-agglomerated single-phase YAG nanopowders were synthesized by the microwave homogeneous precipitation in the presence of urea. The composition and transformations during calcination of YAG precursor were analyzed by IR, DTA/TG and XRD. The size and morphology of YAG powders were characterized by LD and TEM. Results show that the amorphous precursor crystallizes directly to single-phase YAG powders upon calcining to 900℃ that was synthesized under [urea]/[metal ions] molar ratio of 15. The size distribution and sinterability of YAG powders are obviously improved by adding (NH4)2SO4 into the reaction solution. YAG powders obtained from the precursor with the (NH4)2SO4 content of 8% have good sinterability and can be highly densified at 1500℃.