CVD synthesis of Al2O3 nanotubular structures using a powder source

Alumina (Al2O3) 1D nanotubular structures were synthesized by chemical vapor deposition (CVD) using aluminum (Al) and Al2O3 powder sources at a temperature of 1300 °C and a pressure of 100 Pa. At present, no research has been published regarding the synthesis of α-phase Al2O3 nanotubes using only a powder source. In this work, we attempted to grow α-phase Al2O3 nanotubes without catalysts. As-deposited nanotubular structures had an irregular and ragged surface morphology that was related to the boundary layer thickness. Moreover, complementary nanotubular structures can be obtained via an annealing process. A model to describe the irregular nanotubular structure formation was suggested, and the effect of the boundary layer thickness was demonstrated in our experimental conditions.