Zhang Guangqiang, Wei Guodong, Zheng Kezhi, Li Liang, Xu Dapeng, Wang Deyong, Xue Yanfeng, Su Wenhui
College of Physics, Jilin University, Changchun 130023, China.
J Nanosci Nanotechnol. 2010 Mar;10(3):1951-5. doi: 10.1166/jnn.2010.2062.
We succeeded in the synthesis of single-phase beta-SiC nanoparticles via simple and low-cost high-energy mechanical ball milling of a silicon and graphite mixture at ambient temperature. The synthesis products were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The results show that starting graphite and silicon mixture reacted completely into beta-SiC nanoparticles with an average grain size of approximately 8 nm after being milled for 20 h, and the grain size gradually decreased as milling time increased from 20 to 60 h but remained basically unchanged above 60 h. The agglomeration problem of the beta-SiC nanoparticles synthesized by ball milling was resolved to a great extent by the introduction of 2 wt% NH4Cl to the initial Si-C mixture. Under 325 nm excitation, a stable and intensive broad emission peak at 387 nm was observed in the photoluminescence (PL) spectrum of the synthetic nanoparticles, and this emission shows an obvious blueshift of bandgap.
我们通过在室温下对硅和石墨混合物进行简单且低成本的高能机械球磨，成功合成了单相β - 碳化硅纳米颗粒。采用X射线衍射（XRD）、傅里叶变换红外（FTIR）光谱、透射电子显微镜（TEM）和选区电子衍射（SAED）对合成产物进行了表征。结果表明，起始的石墨和硅混合物在球磨20小时后完全反应生成平均粒径约为8纳米的β - 碳化硅纳米颗粒，随着球磨时间从20小时增加到60小时，粒径逐渐减小，但在60小时以上基本保持不变。通过向初始Si - C混合物中引入2 wt%的NH4Cl，很大程度上解决了球磨合成的β - 碳化硅纳米颗粒的团聚问题。在325纳米激发下，合成纳米颗粒的光致发光（PL）光谱中在387纳米处观察到一个稳定且强烈的宽发射峰，并且该发射显示出明显的带隙蓝移。
