SiC Nanowires by Silicon Carburization

ABSTRACTPolycrystalline SiC nanowires and composite Si nanowire-SiC nanograin structures have been synthesized using a combined catalytic chemical vapor deposition and carburization method. Si nanowires are grown at low temperature (550-650 C) and subsequently carburized at 1100-1200 C in a methane/hydrogen or propane/hydrogen environment. Thermochemical calculations showed that the Si carburization is thermodynamically favorable over a wide tempareture range, whereas our studies showed that the Si nanowire carburization is kinetically limited below ∼1100 °C. Partially carburized nanowires contained distinct SiC nanosized grains on the Si nanowire surface, whereas fully carburized nanowires were polycrystalline 3C SiC with grain sizes of ∼ 50-100 nm.