火焰法制备的非晶态“实心”炭纳米纤维内部原子排列无序紊乱,依靠常规的表征手段,难以得到其三维原子构型分布。根据非晶态“实心”炭纳米纤维的XRD图谱提供的衍射强度数据,采用逆向蒙特卡罗法,重构了非晶态“实心”炭纳米纤维的微观原子构型,并对获得的模型进行充分的误差分析。计算得到了非晶态炭纳米纤维的费米能级及其导电机制,认为其具有半导体特征;实验测量单根非晶态“实心”炭纳米纤维的电输运行为发现,其I_V曲线呈现对称和非线性特征,且电阻随着温度的升高而下降,进一步证明非晶态“实心”炭纳米纤维的原子构型具有一定的真实性。
The microstructures of amorphous solidˉcore carbon nanofibers ( CNFs) synthesized in flames show longˉrange disorˉ der, which makes it difficult to reconstruct their threeˉdimensional atom configurations by popular characterization methods. Using a reverse Monte Carlo method, the atom configurations of CNFs were derived from Xˉray diffraction data, and these were used to calˉ culate the Fermi levels, density of electronic states and electrical conductivity of the CNFs. The calculated electronic structures of CNFs indicate that the amorphous CNFs are semiconducting. Experimentally, the I_V curve of the CNFs was investigated and shown to be symmetrical and nonlinear, indicating the semiconductivity of the CNFs, which is good agreement with calculated results.
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