Stacking nature of graphene layers in carbon nanotubes and nanofibres
Stacking nature of graphene layers in carbon nanotubes and nanofibres
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DOI：
10.1016/s0022-3697(97)00055-3
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发表时间：
1997-11-01
影响因子：
4
通讯作者：
Dresselhaus, MS
中科院分区：
文献类型：
--
作者：
Endo, M;Takeuchi, K;Dresselhaus, MS
多层碳纳米管的结构进行了研究，使用数字图像分析解释高分辨率TEM晶格图像包含002和100条纹，在与非常薄的气相生长的碳纤维与纳米尺寸的直径（纳米纤维）相比。结果表明，在多层纳米管中，石墨烯壳层的堆叠相对于彼此滑动，这与三维石墨的堆叠保真度相反。从晶格图像的快速傅立叶变换导出的衍射图案产生相对于理想100方向的100晶格平面的0度-17度的角度。还通过使用100间距作为内标来表征碳纳米管之间的中值壳层间距d（002），并且d（002）范围为3.4埃至3.6埃。壳层间距d（002）随着碳纳米管直径的增加而减小，这可能是由于尺寸效应。所谓的气相生长碳纤维（VGCF），通过碳氢化合物的热解分解获得，通过碳层在最初形成的纳米管上的自发沉积而生长。为了阐明层堆叠的尺寸效应，将直径类似于500埃的非常薄的VGCF（称为纳米纤维以及亚微米直径VGCF）与碳纳米管进行比较，并且讨论与石墨烯层的曲率的关系。一些轻微粉碎的VGCF与nm以及μ m尺寸的直径具有暴露的碳纳米管在核心的断裂部分，这表明在中心核心纳米管和外部热解部分之间的石墨烯层的堆叠结构的差异。(C)1997 Elsevier Science Ltd.
The structure of multilayer carbon nanotubes is studied using digital image analysis to interpret high resolution TEM lattice images containing 002 and 100 fringes, in comparision with very thin vapour-grown carbon fibres with nanometer-sized diameter (nanofibres). The results show that the stacking of graphene shells in a multilayer nanotube glide with respect to one another, which is in contrast to th: stacking fidelity of three-dimensional graphite. The diffraction patterns derived from the fast Fourier transform of the lattice images yield angles of 0 degrees-17 degrees for the 100 lattice planes relative to the ideal 100 direction. The median inter-shell spacing d(002) between carbon nanotubes is also characterized, by using the 100 spacing as an internal standard, and d(002) range from 3.4 to 3.6 Angstrom. The inter-shell spacing d(002) decreases with increasing carbon nanotube diameter, which could be due to a size effect. The so-called vapour-grown carbon fibres (VGCFs), obtained by pyrolytic decomposition of hydrocarbon, are grown through spontaneous deposition of carbon layers on primarily formed nanotubes. In order to clarify the size effect for layer stacking, very thin VGCFs with diameter similar to 500 Angstrom, named nanofibers as well as submicron diameter VGCFs, are compared with carbon nanotubes, and are discussed in relation with the curvature of graphene layers. Some gently pulverized VGCFs with nm as well as mu m size diameters possess an exposed carbon nanotube at the core of the broken portion, suggesting a difference in the stacking structure of the graphene layers between the central core nanotube and the outer pyrolytic sections. (C) 1997 Elsevier Science Ltd.