Synthesis and Analysis of a New Silica Nanowire Periodically Wrapped by Nano-spheres

Lawn-like nanowire arrays silica nanowires were grown on graphite substrate by thermal evaporation of silicon powders using vapor from melted CaCl2 as carrier at 1300 degrees C. A series of analysis technique were employed to investigate the as-grown nanowires. The results show that the as-grown silica nanowires are in length of several micron-meters with the diameter ranging from 50-400 nm, which is identified to be face-centered cubic structure. Systematic analyses reveal that the growth models such as classic vapor-liquid-solid(VLS) model are not applicable to explain the growth of silica nanowire periodically wrapped by nano-spheres. Hereby, an extended VLS model is proposed which can perfectly interpret the silica nanowires' growth on graphite surface