一种链珠状SiO_2纳米线的制备及分析

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

实验通过硅粉和氯化钙盐高温处理,以熔融CaCl_2高温下产生的蒸气作为特殊的蒸发载体,在1300℃条件下通过热蒸发法在石墨基板表面获得了具有草坪状排列的特殊形状的纳米线。系列测试分析表明,该纳米线的直径为50~400 nm,长度约为几个微米,且为面心立方结构。另外,系统分析显示传统的纳米线生长模型如气–液–固（VLS）生长机制不能很好地解释该二氧化硅纳米线在石墨纸上的生长过程,本文提出的一种增强的气–液–固生长机制,可以很好地解释上述纳米线的生长过程。

Lawn-like nanowire arrays silica nanowires were grown on graphite substrate by thermal evaporation of silicon powders using vapor from melted CaCl_2 as carrier at 1300℃. 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.