Process study on the formation of nanocrystalline α-alumina with novel morphology at 1000 °C

Abstract

We have reported in a short communication that nanocrystalline α-alumina with novel morphology was synthesized at a relatively low temperature of 1000 °C without any seed material. The α-alumina nanocrystallites at a size of 5 nm were observed for the first time, and more interestingly the nanocrystallites organized themselves into nanorods having widths of about 15 nm and lengths of about 50–250 nm. In this follow up full paper, detailed processing parameters of such nanocrystalline α-alumina are reported and more characterizations are carried out in order to study the mechanism of the synthesis. The formation scheme of the novel morphology of such nanocrystalline α-alumina is illustrated and the phase transformation from transition aluminas to α-alumina is discussed.