Direct synthesis and strong cathodoluminescence of Al2O3 nanotubes

alpha-Al2O3 nanotubes were synthesized in bulk quantity by using simple physical evaporation of pure aluminum powders at 1000 degrees C. Field emission scanning electron microscopy and transmission electron microscopy observations show that the nanotubes have diameters smaller than nm and lengths up to several microns. Cathodoluminescence measurements revealed a strong luminescence band in the wavelength range of 280-380 nm centered at 330 nm, which could be attributed to the oxygen vacancies in the alpha-Al2O3 nanotubes. Sacrificial template model is regarded as the possible formation mechanism of the nanotubes. (c) 2009 Elsevier B.V. All rights reserved.