Preparation of uniformly dispersed YAG ultrafine powders by coprecipitation method with SDS treatment

Abstract

Uniformly dispersed yttrium aluminum garnet (Y3Al5O12, YAG) ultrafine powders are synthesized by coprecipitating a mixed solution of aluminum and yttrium nitrates with ammonium hydrogen carbonate in the presence of sodium dodecyl sulfate (SDS) as a dispersing agent. The primary purpose of introducing SDS is to protect YAG particles from agglomeration. The evolution of phase composition and microstructure of the as-synthesized YAG powders are characterized by thermogravimetry/differential scanning calorimetry, X-ray diffraction, infrared spectra, and scanning electron microscopy. The results show that phase-pure YAG powders can be achieved by calcination of the precursor at 900°C for 2 h. Uniformly dispersed YAG powders with a particle size of approximately 90–100 nm are obtained with the optimum molar ratio of Al3+ to SDS of 2, and excessive SDS restrains good dispersion of the YAG powders. The dispersion mechanism of SDS in the preparation process is discussed.