Electron irradiation-induced change of structure and damage mechanisms in multi-walled carbon nanotubes
Electron irradiation-induced change of structure and damage mechanisms in multi-walled carbon nanotubes
复制标题
电子辐照引起的多壁碳纳米管结构变化和损伤机制
DOI：
10.1088/1674-1056/24/11/116103
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Gao Feng
中科院分区：
文献类型：
--
作者：
Yang Jian-Qun;Li Xing-Ji;Liu Chao-Ming;Ma Guo-Liang;Gao Feng
碳纳米管具有独特的结构和优异的电学性能，是制造未来电子元件的理想候选材料，具有巨大的应用潜力。为了满足电子元件空间应用的要求，有必要研究多壁碳纳米管(MWCNTs)在70和110keV电子束辐照下的结构变化和损伤机制。本文研究了70和110keV电子辐照引起的多壁碳纳米管的结构变化和损伤机制。用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、拉曼光谱、X射线衍射仪(XRD)和电子顺磁共振(EPR)对辐照后MWCNT薄膜的表面形貌和结构的变化进行了表征。研究发现，由于损伤机制的不同，MWCNTs在70keV和110keV电子辐照后表现出不同的结构变化行为。扫描电子显微镜结果表明，70keV的电子辐照并没有改变多壁碳纳米管薄膜的表面形态，而高能注量为5×1015 cm−2的110keV电子辐照引起了明显的表面变化，如粗糙表面的形成、纳米管的缠绕和纳米管的收缩。拉曼光谱、XPS和X射线衍射谱分析表明，70keV电子辐照增加了多壁碳纳米管的层间距，并通过电子激发和电离效应使其结构紊乱，而110keV电子辐照则通过原子碰撞位移显著减小了多壁碳纳米管的层间距，改善了其石墨化有序性。110keV电子对多壁碳纳米管性能的改善归因于碰撞原子位移引起的缺陷位重组。EPR谱分析表明，多壁碳纳米管在70keV电子和110keV电子作用下均受到不同程度的电离损伤。
Owing to their unique structure and excellent electrical property, carbon nanotubes (CNTs) as an ideal candidate for making future electronic components have great application potentiality. In order to meet the requirements for space application in electronic components, it is necessary to study structural changes and damage mechanisms of multi-walled carbon nanotubes (MWCNTs), caused by the irradiations of 70 and 110 keV electrons. In the paper, the changes of structure and damage mechanisms in the irradiated MWCNTs, induced by the irradiations of 70 and 110 keV electrons, are investigated. The changes in surface morphology and structure of the irradiated MWCNT film are characterized using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, x-ray diffraction analysis (XRD), and electron paramagnetic resonance (EPR) spectroscopy. It is found that the MWCNTs show different behaviors in structural changes after 70 and 110 keV electron irradiation due to different damage mechanisms. SEM results reveal that the irradiation of 70 keV electrons does not change surface morphology of the MWCNT film, while the irradiation of 110 keV electrons with a high fluence of 5 × 1015 cm−2 leads to evident morphological changes, such as the formation of a rough surface, the entanglement of nanotubes and the shrinkage of nanotubes. Based on Raman spectroscopy, XPS, and XRD analyses, it is confirmed that the irradiation of 70 keV electrons increases the interlayer spacing of the MWCNTs and disorders their structure through electronic excitations and ionization effects, while the irradiation of 110 keV electrons obviously reduces the interlayer spacing of the MWCNTs and improves their graphitic order through knock-on atom displacements. The improvement of the irradiated MWCNTs by 110 keV electrons is attributed to the restructuring of defect sites induced by knock-on atom displacements. EPR spectroscopic analyses reveal that the MWCNTs exposed to both 70 keV electrons and 110 keV electrons suffer ionization damage to some extent.
DOI：
10.5772/18140
发表时间：
2007
期刊：
MRS Proceedings
影响因子：
--
作者：
Satoru Suzuki
通讯作者：
Satoru Suzuki