Yttrium aluminum garnet nanoparticles synthesized by nitrate decomposition and their low temperature densification behavior

A simple method for synthesizing yttrium aluminum garnet (YAG) powder based on a mixed precursor solution of yttrium nitrate and aluminum nitrate is proposed. At a temperature below 850 °C, the pure YAG phase can be obtained by simply calcining the precursors in air. Uniform granular YAG nanoparticles of about 20–30 nm in diameter are obtained. The YAG granules can be densified to become a nanoceramic fraction by calcination at 900 °C, and can be sintered at 1000 °C to become a very dense ceramic with well crystallized grains of diameter from 1 μm to 2 μm. This result indicates that YAG nanoceramics can be obtained at 900 °C without a stringent sintering process, and that transparent YAG ceramics may be obtained below 1000 °C by this simple and novel synthesis method. Based on X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), and scanning electron microscopy analysis, a chemical mechanism for the densification of the ceramic is proposed.