A carbonate precursor of yttrium aluminum garnet (YAG) with an approximate composition of NH4AlY0.6(CO3)1.9(OH)2·0.9H2O was synthesized via a coprecipitation method from a mixed solution of ammonium aluminum sulfate and yttrium nitrate, using ammonium hydrogen carbonate as the precipitant. The precursor precipitate was characterized using chemical analysis, differential thermal analysis/thermogravimetry, X-ray diffractometry, and scanning electron microscopy. The sinterability of the YAG powders was evaluated by sintering at a constant rate of heating in air and vacuum sintering. The results showed that the precursor completely transforms to YAG at approximately 1000 °C via the formation of a yttrium aluminate perovskite (YAP) phase. YAG powders obtained by calcining the precursor at temperatures of ≤1200 °C were highly sinterable and could be densified to transparency under vacuum at 1700 °C in 1 h without additives.
|Number of pages||3|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 2000 Jan 1|
ASJC Scopus subject areas
- Ceramics and Composites