Apparent diameter of carbon nanotubes in scanning tunnelling microscopy measurements

L. Tapasztó, G. I. Mrk, A. A. Koós, P. Lambin, L. P. Biró

Research output: Contribution to journalArticle

10 Citations (Scopus)


Geometric effects influencing scanning tunnelling microscopy (STM) image formation of single wall carbon nanotubes (SWCNTs) were studied within the framework of a simple model potential. We focused on the geometrical effects which may influence the tunnelling probabilities and lead to discrepancies between the apparent height of the nanotubes measured by STM and their real geometrical diameter. We found that there are two main factors responsible for the underestimation of nanotubes diameter by measuring their height in STM images: (1) the curvature of the nanotube affects the cross sectional shape of the tunnelling channel; (2) the decay rate of tunnelling probabilities inside the tunnel gap increases with increasing curvature of the electrodes. For a nanotube with 1nm diameter an apparent flattening of about 10%, due to these geometry-related effects, is predicted. Furthermore these effects are found to be dependent on the diameter of the tubes and tip-sample distances: an increasing flattening of the tubes is predicted for decreasing tube diameter and increasing tip-sample distance.

Original languageEnglish
Article number001
Pages (from-to)5793-5805
Number of pages13
JournalJournal of Physics Condensed Matter
Issue number26
Publication statusPublished - Jul 5 2006

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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