场离子显微镜观测单壁碳纳米管

Field-ion Microscope Study of Single-walled Carbon Nanotube

场离子显微镜是具有原子级分辨能力的尖端表面分析工具。它适用于纳米尺度的单壁碳纳米管 (SWCNTs)末端表面原子排列的观测。利用范氏力将SWCNTs组装到钨针尖上 ,用场离子显微镜观察了这种针尖样品。在观察过程中对针尖样品进行了加热处理 ,既除掉非晶的C原子 ,也破坏了由于碳纳米管切割制造过程使用表面活化剂引起的高电阻层 ,得到了开口SWCNTs的场离子显微镜像 ,由此推断出SWCNTs束的顶端原子结构 ,估算出观察到的SWCNTs的直径 ,并且模拟了其中一个图像所代表的SWCNTs顶端开口的原子排列 ,推断出产生这个图像的SWCNTs是 (7,7)型结构。

Field-ion Microscopy (FIM),a surface probe with atomic resolution,was employed to observe the end structure of single-walled carbon nanotubes (SWCNTs).We assembled SWCNTs onto metallic tips by Van der Waals force.The amorphous carbon and the layer of high resistance were removed by heat treatment,and clear FIM image of SWCNTs could be obtained.A model of (7,7)structure of SWCNT was given on the basis of the FIM image,diameter of the SWCNT was also calculated.