Effect of pre-aging pH on the formation of yttrium aluminum garnet powder (YAG) via the solid state reaction method

Yttrium aluminum garnet (YAG) powder was successfully synthesized by a novel solid state reaction method. The starting materials including: yttrium oxide (Y2O3), boehmite (AlOOH) and cerium chloride (CeCl3·7H2O) are pre-aged at pH 1, 2 and 3, respectively, before calcining. According to the experimental results, the case of pre-aging at pH 1 is the best condition for the formation of YAG powder. The particle size of Y2O3 and AlOOH are reduced by the pre-aging at pH 1. It induces to shorten the diffusion distance of the solid state reaction. The pre-aging at pH 1 process leads the formation of YAG powder via solid state reaction more easily. The emission intensity of the product was increased by the decrease of the pre-aging pH, the increase of the calcination temperature and the increase of the heating time.