Direct synthesis of 2H–SiC nanowhiskers

We report here the first synthesis of 2H-polytype silicon carbide (SiC) nanowhiskers by the reaction of silicon monoxide (SiO) with methane. The diameter of the 2H–SiC nanowhiskers was less than 200 nm and the length was over 2 μm. Energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), high resolution TEM (HRTEM) and Raman scattering spectroscopy were used to characterize the nanowhiskers. Electron diffraction and HRTEM confirmed that the nanowhiskers were composed of the rare-occurring 2H–SiC polytype with a 3C–SiC polytype tip. The growth direction of the nanowhiskers was along the hexagonal [0 0 0 1] orientation. The nanowhiskers had many stacking faults and micro-twins, which possibly caused the downshift of the Raman scattering peaks. The SiC nanowhiskers are believed to form via the oxide-assisted growth process.