Dresden 2006 – wissenschaftliches Programm

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O: Oberflächenphysik

O 4: Nanostructures I

O 4.6: Vortrag

Montag, 27. März 2006, 12:30–12:45, PHY C213

Direct Observation of Individual Defects on Carbon Nanotubes by Dynamic Force Microscopy — •Makoto Ashino and Roland Wiesendanger — Institute of Applied Physics and Microstructure Research Center, University of Hamburg, Jungiusstr. 11, D-20355 Hamburg

Single-walled carbon nanotubes (SWNTs) have attracted much attention due to their unusual mechanical and unique electronic properties, which can provide great opportunity for fabricating nanoscale devices. Actual implementation of the SWNT devices demands a thorough understanding of the structural and electronic properties not only of perfect SWNTs but also of defective SWNTs because some kinds of defects are naturally included and can cause drastic changes of their properties. Recently, we have successfully achieved atomic resolution for imaging SWNTs by dynamic force microscopy (DFM) in ultrahigh vacuum and at low temperature [1]. The DFM, operated by the frequency modulation technique in non-contact regime, has enabled “true” atomic resolution for imaging non-periodic features and point defects. Here, we present atomic resolution imaging of individual defects in the SWNTs. As in the case of Ref. 1, we observed the SWNTs on a graphite substrate under feedback control to maintain a constant frequency shift of the cantilever oscillation with a constant amplitude operation. The images obtained suggest the existence of localized defects. Through detailed analysis of the image contrasts, we will topologically characterize those defects.

[1] M. Ashino, et al., Phys. Rev. Lett. 93, 136101 (2004).