【作者】 魏剑； 李克智； 李贺军； 李正佳； 付前刚；

【Author】 Wei Jian Li Kezhi Li Hejun Li Zhengjia Fu Qiangang (C/C Composites Technology Research Center,Northwestern Polytechnical University,Xi’an 710072)

【机构】 西北工业大学碳／碳复合材料工程技术研究中心；

【摘要】 利用碳热还原方法,以正硅酸乙酯(TEOS)和蔗糖(C12H22O11)分别作为凝胶的硅源和碳源,在1500℃氩气气氛条件下制备了六棱柱状的SiC纳米线。借助扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射(XRD)等测试手段分析和表征SiC纳米线的形貌和晶体结构。研究结果表明:制备的产物为六棱柱状β-SiC纳米线,直径为50～100 nm,纳米线内部含有较多的堆垛层错;产物中的SiC微米/纳米颗粒和六棱柱状的SiC纳米线是通过气-固(VS)反应机制形成的;一些SiC晶粒表面存在着自由能较低的六角形小晶面,其对SiC纳米线六棱柱状形貌的形成具有明显的诱导作用。更多还原

【Abstract】 Hexagonal silicon carbide (SiC) nanowires had been synthesized through carbothermal reduction of SiO2 xerogels containing carbon, within a graphite crucible at 1500℃ . Scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to characterize the as-received products. The B-SiC nanowires experience a typical hexagonal section and diameters in the range of 50 - 100 nm. A high stacking faults density exists in the nanowires. The growth mechanism of the as-received nanowires and particals is considered to involve a vapor-solid (VS) process. The formation of hexagonal morphology of the B-SiC nanowires may own to the memory effect of some hexagonal facets with lower free energy of the SiC paticals.更多还原