Structure,stability,and motion of dislocations in double-wall carbon nanotubes

• Published in: Chinese physics B 2012-10, Vol.21 (10), p.327-334
• Main Author: 张凯旺 李中秋 吴建 彭向阳 谭新君 孙立忠 钟建新
• Format: Article
• Language: English
• Subjects: Carbon nanotubes; Chairs; Dislocation loops; Dislocations; Edge dislocations; Melting; Molecular structure; Screw dislocations; 双壁碳纳米管; 热稳定性; 熔化温度; 结构; 自我修复能力; 螺型位错; 运动; 透射电子显微镜
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/21/10/106102

In this paper,a novel double-wall carbon nanotube（DWCNT） with both edge and screw dislocations is studied by using the molecular dynamics（MD） method.The differences between two adjacent tubule indexes of armchair and zigzag nanotubes are determined to be 5 and 9,respectively,by taking into account the symmetry,integrality,and thermal stability of the composite structures.It is found that melting first occurs near the dislocations,and the melting temperatures of the dislocated armchair and zigzag DWCNTs are around 2600 K-2700 K.At the premelting temperatures,the shrink of the dislocation loop,which is comprised of edge and screw dislocations,implies that the composite dislocation in DWCNTs has self-healing ability.The dislocated DWCNTs first fracture at the edge dislocations,which induces the entire break in axial tensile test.The dislocated DWCNTs have a smaller fracture strength compared to the perfect DWCNTs.Our results not only match with the dislocation glide of carbon nanotubes（CNTs） in experiments,but also can free from the electron beam radiation under experimental conditions observed by the high resolution transmission electron microscope（HRTEM）,which is deemed to cause the motion of dislocation loop.