Influence of oxygen on the microstructural growth of SiC nanowires

We examined the influence of oxygen (O2) on the growth of silicon carbide nanowires (SiC NWs) by chemical vapor deposition (CVD), because vacuum environments are susceptible to O2 leakage inflow. We investigated the effect of increasing the O2 flow rate on the microstructural changes of SiC NWs and then evaluated the effect at various growth temperatures. The O2 content was highly related to the density of NWs, which continued to increase actively at higher temperatures. High-resolution transmission electron microscopy (HR-TEM) revealed that NWs change from a single-crystalline phase to a polycrystalline phase and then to a SiC/SiO2 core–shell structure.