Synthesis of α-alumina powder with internal nanostructures from Al13-cluster

Nanostructured α-alumina powder was synthesized by precipitation and calcination of Al13-clusters that were formed by the hydrolysis of Al3+ions with hydroxide. The Al13-clusters were precipitated with oxalic acid by two-stage and one-stage precipitation techniques. The precipitates were calcined in air at 1100 °C. The resulting α-alumina particles were characterized using particle size analyzer, X-ray diffraction (XRD) and transmission electron microscope (TEM). The pH and precipitation technique were found to influence the microstructural features of the α-alumina powder produced. Alumina with more extensive nanostructures inside the grain can be produced through the two-stage precipitation technique.