| With the ongoing miniaturization of Si-based electronic devices, one-dimensional Si-based materials have attracted much attention. Two kinds of one-dimensional Si-based materials,β-SiC nanowires and'O'junctions of amorphous silicon oxide microwires, were obtained by simple but effective process in this thesis. Their growth mechanisms were also investigated. Furthermore, amorphous silicon oxide nanowires were used as template to produce open-ended CNTs.β-SiC nanowires were directly synthesized by heating single-crystal silicon wafer and graphite without metal catalysts. The diameter of SiC nanowires is in the range of 10-30 nm, and the length is up to a few millimeters. Two kinds of SiC nanowires, namely pure SiC nanowires and SiC/SiO2 composite nanowires, formed at higher temperature (the holding stage) and lower temperature (the cooling stage), respectively. A multiple-reaction model was proposed to explain the formation of SiC nanowires.'O'junctions of amorphous silicon oxide microwires were synthesized for the first time by thermal evaporation of silicon wafer covered with micrometer-sized metallic Fe catalysts, which is simple but effective. The growth of microwires follows a solid-liquid-solid (SLS) mechanism. The formation of'O'junctions is attributed to the segregation and congregation of nucleation points in Fe-Si droplets. The thermal evaporation method is simple and effective to synthesize a large amount of silicon oxide microwires with a length up to millimeter scale. Silica microwires with fantastic'O'structure have high potential on the future industrial applications.A new method was proposed to produce open-ended CNTs where amorphous silicon oxide nanowires were used as template. The process contained two steps. At first, carbon-coated silicon oxide nanowires were synthesized by using the amorphous silicon oxide nanowires as template; next, open-ended CNTs were obtained by immersing the carbon-coated silicon oxide nanowires in hydrofluoric acid. |
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