Amplitude response of multiwalled carbon nanotube probe with controlled length during tapping mode atomic force microscopy
Amplitude response of multiwalled carbon nanotube probe with controlled length during tapping mode atomic force microscopy
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DOI：
10.1021/jp804481g
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发表时间：
2008-10-09
影响因子：
3.7
通讯作者：
Chen, Q.
中科院分区：
文献类型：
--
作者：
Jiang, A. N.;Gao, S.;Chen, Q.
利用扫描电子显微镜中的纳米操纵器制备了长度可控的多壁碳纳米管原子力显微镜(AFM)探针。实验系统地研究了多壁碳纳米管原子力显微镜探针的幅度-距离响应。观察到了碳纳米管原子力显微镜探头的一些特殊特性，如幅度跳跃到零，在探头已经接触表面后反弹，以及在回缩过程中的大滞后。当碳纳米管较长且幅度较大时，也观察到从吸引区到排斥区的转变。攻丝模式幅值-距离曲线随碳纳米管长度及其相对于衬底表面法线的倾斜角呈规律性变化。这一结果与之前的理论预测具有可比性。通过电子显微镜的直接观察，发现MWCNT AFM探针在接触到衬底表面后，即使在向SiO_2晶片推进数百纳米时也能均匀弯曲。通过分析几种探头的测量结果，发现在合适的长度和工作条件下，处于攻丝模式的多壁碳纳米管原子力显微镜探头应适合于稳定工作。
Multiwalled carbon nanotube (MWCNT) atomic force microscope (AFM) probes were fabricated with controlled length using nanomanipulators inside scanning electron microscope. The amplitude-distance responses of MWCNT AFM probes were systematically studied experimentally. Several special characteristics of CNT AFM probes were observed, such as amplitude jump-into-zero, rebounds after the probe already touched the surface and large hysteresis during retraction. Transition from attractive to repulsive regions was also observed when the CNT is long and the amplitude is large. Tapping mode amplitude-distance curves were found to change regularly with the length of the carbon nanotubes and their tilting angle relative to the substrate surface normal. The results were comparable with previous theoretical predictions. Through direct observations by electron microscopes, MWCNT AFM probes were found to bend homogenously even when they were pushed toward the SiO2 wafer for several hundred nanometers after they had touched the surface of the substrate. By analyzing the results obtained from several probes it was found that the MWCNT AFM probes in tapping mode should be suitable for stable operation with proper length and working condition.