Synthesis of yttrium aluminum garnet (YAG) from an ethylenediaminetetraacetic acid precursor

Yttrium aluminum garnet was synthesized via ethylenediaminetetraacetic acid (EDTA) precursor route. The precursors and the derived oxide powders were characterized by differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy. The effect of the molar ratio of EDTA to total metal cation concentration (EDTA/M) on the crystallization behavior of YAG was investigated. For the EDTA/M = 1 precursors, YAG was found to crystallize from an amorphous precursor beginning at temperatures of 800 °C within 2 h in air and completely transformed into YAG at 950 °C; a certain amount of hexagonal-YAlO3 co-existed with the YAG phase between 800 and 900 °C. For the EDTA/M = 0.5 precursors, the phase-pure YAG was obtained at 1000 °C for 2 h.