Ultra long SiC nanowires with fluctuating diameters synthesized in a polymer pyrolysis CVD route

摘要

Large areas of millimeters long beta-SiC nanowires with fluctuating diameters were synthesized in a poly-mer pyrolysis CVD (PPCVD) route. Polycarbosilane was used as the raw material. The morphology and structure of the nanowires were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the nanowires had non-periodically fluctu-ating diameters in the range of 100-250 nm along the axial direction, and were composed of well crystalline beta-SiC along the <111> direction. The vapor-solid (VS) mechanism was employed to interpret the nanowires growth procedure, and the diameter fluctuation was resulted from the varying concen-tration of the local silane fragments.