Synthesis and photoluminescence of  -Al₂O₃nanowires

α-Al 2 O 3 nanowires have been synthesized in bulk quantity by using simple physical evaporation of mixture of pure Al powders and nanometre-sized TiO 2 powders at 1150 °C. Scanning electron microscopy and transmission electron microscopy observations show that α-Al 2 O 3 nanowires have diameters ranging from 20 to 60 nm and lengths up to several tens of micrometres. The growth of α-Al 2 O 3 nanowires is controlled by the vapour–liquid–solid (VLS) mechanism. Photoluminescence measurements revealed a blue luminescence band in the wavelength range of 400–500 nm with two peaks at 415 and 440 nm, which could be attributed to the F + centres in the α-Al 2 O 3 nanowires.