Large-scale fast synthesis of single-crystalline alpha-alumina nanotubes

Large-scale single-crystalline α-Al2O3 nanotubes were synthesized by fast evaporation of pure Al powders using induction heating. The morphology and structure of the nanotubes were investigated by field emission scanning electron microscopy and transmission electron microscopy. The nanotubes exhibit a broad diameter-scale from about 20 nm to 150 nm and length up to more than 10 μm. The possible formation mechanism of the nanotubes was discussed. Phase transformation accompanied void generation might result in the α-Al2O3 tubular structure.