Synthesis of YAG powders by the co-precipitation method

YAG (Y3Al5O12) powders have been prepared by co-precipitation technique in which NH4HCO3 is used as a precipitant and Y2O3, A1((NO3)3·9H2O—as raw materials. Two kinds of surfactant are added into the solution, i.e. Polyethylene glycol (PEG10000) as steric stabilizer and (NH4)2SO4 as electrical stabilizer. The composition of YAG precursor, the phase formation process of YAG and the properties of the powders were investigated by means of differential scanning calorimetry and thermogravimetry analysis (DSC–TG), X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM). The results of XRD show that phase YAG crystallite can be obtained as precursors when heated at 900 °C for 2 h. The powders loosely dispersed with narrow size distribution and spherical shapes could be observed by SEM. It has been found that the presence of PEG and (NH4)2SO4 is beneficial for the dispersion of the resulting YAG powder. In the presence of surfactants, the synthesized product consists of highly dispersed nano-sized particles.