Journal of Asian Ceramic Societies (Sep 2014)

Exhaust gas analysis and formation mechanism of SiC nanowires synthesized by thermal evaporation method

  • Noppasint Jiraborvornpongsa,
  • Sae Enomoto,
  • Masamitsu Imai,
  • Katsumi Yoshida,
  • Toyohiko Yano

DOI
https://doi.org/10.1016/j.jascer.2014.05.004
Journal volume & issue
Vol. 2, no. 3
pp. 235 – 240

Abstract

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Silicon carbide nanowires (SiCNWs) are a set of promising reinforcement materials due to their superior properties. However, formation mechanism of the SiCNWs synthesized by the thermal evaporation method without metal catalyst is still unclear. To understand the formation mechanism, SiCNWs were synthesized by the thermal evaporation method at 1350 °C using a pre-oxidized Si powder and CH4 gas as precursors. SiCNWs obtained by this method were β-SiC/SiO2 core–shell nanowires with average diameter about 55 nm and with a length up to 1 mm. The exhaust gases during the SiCNWs synthesis process were examined by gas chromatography and the photographs of growth activity of SiCNWs inside the furnace were captured. CO gas was detected during the active formation of SiCNWs. It was clarified that CO gas was one of the byproducts from SiCNWs synthesis process, and the formation reaction of SiCNWs should be 3SiO(g) + 3C(s) → 2SiC(s) + SiO2(s) + CO(g). The formation of SiCNWs was discussed based on the oxide-assisted-growth mechanism.

Keywords