A novel microwave combustion approach for single step synthesis of α-Al2O3 nanopowders

A novel method for synthesis of nano-sized α-Al2O3 particles in a single step using microwave is being reported for the first time. The sol of aluminum nitrate with urea mixed in the stoichiometric ratios in accordance with jet propellant chemistry, when combusted in a microwave oven gave fine single phase α-Al2O3 nanoparticles. The resultant oxide powder was characterized by TGA (Thermo-Gravimetric Analysis), FTIR (Fourier Transform Infra-Red Spectroscopy), XRD (X-ray Diffraction) and TEM (Transmission Electron Microscopy). The XRD analysis of the microwave combusted powder showed complete formation single phase α-Al2O3 without contamination of other phases of alumina. In comparison to the well known furnace combustion method for the direct synthesis of α-Al2O3, microwave combustion gave finer particles with very small agglomerate size as revealed by TEM analysis.