中国物理B ›› 2001, Vol. 10 ›› Issue (6): 531-536.doi: 10.1088/1009-1963/10/6/313

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ELECTRONIC PROPERTIES OF CARBON NANOTUBES WITH A PENTAGON-HEPTAGON PAIR DEFECT

胡慧芳1, 周维亚2, 唐东升2, 李义兵3   

  1. (1)Department of Fundamental Courses, Changsha Railway University, Changsha 410075, China; Materials Research Institute, Changsha Railway University, Changsha 410075, China; (2)Institute of Physics and Center of Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; (3)Materials Research Institute, Changsha Railway University, Changsha 410075, China
  • 收稿日期:2000-12-26 修回日期:2001-02-06 出版日期:2001-06-15 发布日期:2005-06-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 69890227), by the Natural Science Foundation of Hunan Province, China (Grant No. 99JJY2083), and by the Fok Ying-Tong Foundation, Hong Kong, China.

ELECTRONIC PROPERTIES OF CARBON NANOTUBES WITH A PENTAGON-HEPTAGON PAIR DEFECT

Hu Hui-fang (胡慧芳)ab, Li Yi-bing (李义兵)b, Zhou Wei-ya (周维亚)c, Tang Dong-sheng (唐东升)c    

  1. a Department of Fundamental Courses, Changsha Railway University, Changsha 410075, China; b Materials Research Institute, Changsha Railway University, Changsha 410075, China; c Institute of Physics and Center of Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Received:2000-12-26 Revised:2001-02-06 Online:2001-06-15 Published:2005-06-12
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 69890227), by the Natural Science Foundation of Hunan Province, China (Grant No. 99JJY2083), and by the Fok Ying-Tong Foundation, Hong Kong, China.

摘要: The features of energetics and electronic properties of carbon nanotubes, containing a pentagon-heptagon pair (5/7) topological defect in the hexagonal network of the zigzag configuration, are investigated using the extended Su-Schriffer-Heeger model based on the tight binding approximation in real space. Our calculations show that this pentagon-heptagon pair defect in the nanotube structures is not only responsible for a change in nanotube diameter, but also governs the electronic behaviour around Fermi level. Furthermore, we have calculated the densities of states of the (9,0)-(8,0) and (8,0)-(7,0) systems. For the (9,0)-(8,0) system, a narrow gap exists in the vicinity of the Fermi energy. In contrast, for the (8,0)-(7,0) system, a little peak of the density of states occurs at the Fermi energy. These can be attributed to the addition of a pair of pentagon-heptagon defects in the interface between two isolated carbon nanotubes.

Abstract: The features of energetics and electronic properties of carbon nanotubes, containing a pentagon-heptagon pair (5/7) topological defect in the hexagonal network of the zigzag configuration, are investigated using the extended Su-Schriffer-Heeger model based on the tight binding approximation in real space. Our calculations show that this pentagon-heptagon pair defect in the nanotube structures is not only responsible for a change in nanotube diameter, but also governs the electronic behaviour around Fermi level. Furthermore, we have calculated the densities of states of the (9,0)-(8,0) and (8,0)-(7,0) systems. For the (9,0)-(8,0) system, a narrow gap exists in the vicinity of the Fermi energy. In contrast, for the (8,0)-(7,0) system, a little peak of the density of states occurs at the Fermi energy. These can be attributed to the addition of a pair of pentagon-heptagon defects in the interface between two isolated carbon nanotubes.

Key words: carbon nanotubes, pentagon-heptagon pair defect, electronic properties, densities of states

中图分类号:  (Electronic structure of nanoscale materials and related systems)

  • 73.22.-f
71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.))