Synthesis and characterization of silicon carbide whisker arrays prepared by thermal evaporation method

SiC whiskers arrays were prepared by thermal evaporation of Si onto two carbon templates: graphite plate and PAN-carbon fiber at 1600℃ in different levels of vacuum. The XRD analyses and FESEM observations reveal that the products are 3C-SiC whisker arrays: whisker forests standing on the graphite plate and tube brush shaped whisker arrays around the carbon fibers, respectively. The dimensions of the whiskers grown on the two templates are about 100nm in diameter and 50μm in length. Due to the quantum confinement effect of nano-materials, a photoluminescence peak locating around 468nm is observed under 380nm excitation at room temperature. The multi-place selected area electron diffraction (SAED) demonstrates that the SiC whiskers are single crystals, growing in 111 direction. Based on the fact that the silicon melt and carbon templates were separated throughout the whole process, the vapor-solid reaction growth mechanism of the SiC whiskers is discussed.