一维单原子链在碳纳米管研究中的应用  

Applications of the one-dimensional monatomic chain in the study of carbon nanotube

作　　者：常旭[1] 

机构地区：[1]商丘师范学院物理与电气信息学院,河南商丘476000

出　　处：《大学物理》2013年第2期13-17,共5页College Physics

基　　金：河南省基础与前沿技术研究项目(102300410278);河南省教育厅科学技术研究重点项目(12B140012);商丘师范学院青年科研基金资助(2011QN13)项目

摘　　要：以一维单原子链为模型,讨论了五边形和原子空位两种缺陷对碳管振动性质的影响,定性地解释了这两种缺陷产生局域模式的原因.计算结果表明,由于五边形周围碳碳键的缩短使得力常数变大;与此类似,当原子空位存在时,空位处有效质量变小,且碳碳键长变短,这些都相当于在晶格中掺入了"轻杂质",会使得在完整晶格的振动模式的外侧出现一个新的局域振动模式.Using the one-dimensional monatomic chain as a model, the vibrational properties of the carbon nanotube with pentagon and atomic vacancy have been investigated respectively. It explains qualitatively the reason that the two defects can induce the localized defective modes. From the calculations, it＇s found that the bond length on the pentagon rings is shorter than that of the hexagon rings, meaning that the force constants on the pentagon de- fect should be larger relative to those on the hexagon rings, A similar result is proved for the atomic vacancy. The effective mass of the vacancy is smaller than the normal carbon atom, at the same time, the bond length around the vacancy is shorter than the hexagon ring＇s. Therefore, the two kinds of defects may be considered as the ＇ light- mass impurity＇ , which can cause a new localized defect mode out of the vibrational modes of the perfect lattice, re- spectively.

关 键 词：一维单原子链 晶格振动 拓扑缺陷 原子空位 局域模式 

分 类 号：O481[理学—固体物理]