Crystallization of Yttrium Aluminum Garnet (YAG) from a Gel Obtained by a Glycothermal Method

The crystallization of yttrium aluminum garnet (YAG) was investigated for the gelatinous product obtained by the reaction of yttrium acetate with aluminum isopropoxide in ethylene glycol at 280 °C under spontaneous vapor pressure of the glycol (glycothermal method). Crystallization of YAG started at 880 °C and completed at 1000 °C. During these temperatures, a small amount of YAlO3 (hexagonal), was also detected. The crystallization temperature was as low as the reported temperatures for the products prepared by the alkoxide processes (Refs.5 and 6). Therefore, glycothermal method provides a new route to prepare a gel for the preparation of mixed oxides.