Synthesis of SiO2 covered SiC nanowires with milled Si,C nanopowders

SiO2 covered β-SiC nanowires were directly synthesized with a novel method, annealing the milled Si,C nanopowders at 900–1100 °C on Si wafer or Al2O3 substrate, and there is no any metal catalysts used. The diameters of the nanowires are range of 20 to 50 nm, and the lengths of the nanowires are up to several hundreds of microns. There is a uniform SiO2 amorphous layer on the surface of SiC nanowires. The axial direction of SiC nanowires is < 111>, and there are stacking faults and twin lamellae in the SiC nanowires. The synthetic mechanism of SiC nanowires includes two solid–solid reactions and one gas–solid reaction between SiO, Si, C and CO.

► SiO2 covered β-SiC nanowires were synthesized with the milled Si, C nanopowders.
► No metal catalyst was used in this process.
► The nanowires grow along < 111> direction, stacking faults and twin were found.
► The synthetic mechanism of SiC nanowires was discussed.