Large-scale synthesis and characterization of hexagonal prism-shaped SiC nanowires

Abundant hexagonal prism-shaped SiC nanowires were synthesized on graphite substrate via heating silicon in a graphite crucible. The products were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The characterization first showed that the product was nanowires of beta-SiC with almost a perfect hexagonal cross section. The growth was determined along [111] direction. The six side surfaces look smooth under low magnification microscopy, but faceted at high magnification. Based on the characterization results, a formation mechanism combining vapor-solid (VS) growth mechanism and the lowest surface energy principle is proposed.