Satishkumar B C, Paulson S, Johnson A T, Luzzi D E
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
J Nanosci Nanotechnol. 2006 May;6(5):1350-6. doi: 10.1166/jnn.2006.188.
Electron beam induced structural transformations are investigated in single-wall carbon nanotubes (SWNTs), double-wall carbon nanotubes (DWNTs) and crossed nanotube junctions. The nanotubes studied here are synthesized by the chemical vapor deposition method. The response of the nanotubes to an electron beam is found to be influenced by the presence of coatings of amorphous carbon, graphene fragments and structural defects on the tube surface. The dependence of structural modifications on electron beam irradiation dose is measured. While nanotubes with amorphous carbon, graphene fragment coverage and/or defects undergo rapid transformation leading to structure disintegration, those without such coverage or defects are more resistant to beam damage. In addition, it is shown that the amorphous carbon coverage on the double-wall nanotubes can be transformed into graphene layers during electron beam irradiation of coated nanotubes. Finally, the relative stability of nanotube side-wall and end-walls are investigated through sub-threshold energy and above threshold energy irradiation of a model system, C60-filled nanotubes (Peapods). The data indicates that electron beams could be used to join nanotubes end-to-end without damaging the side-walls.
研究了单壁碳纳米管（SWNTs）、双壁碳纳米管（DWNTs）和交叉纳米管结中的电子束诱导结构转变。这里研究的纳米管是通过化学气相沉积法合成的。发现纳米管对电子束的响应受管表面非晶碳涂层、石墨烯碎片和结构缺陷的影响。测量了结构改性对电子束辐照剂量的依赖性。虽然具有非晶碳、石墨烯碎片覆盖和/或缺陷的纳米管会经历快速转变导致结构解体，但没有这种覆盖或缺陷的纳米管对束损伤更具抗性。此外，研究表明，在对涂覆纳米管进行电子束辐照期间，双壁纳米管上的非晶碳覆盖层可转变为石墨烯层。最后，通过对模型系统C60填充纳米管（豆荚状结构）进行亚阈值能量和高于阈值能量的辐照，研究了纳米管侧壁和端壁的相对稳定性。数据表明，电子束可用于端对端连接纳米管而不损坏侧壁。
