Quantitative atom-resolved force gradient imaging using noncontact atomic force microscopy

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Oral A., GRIMBLE R., ÖZER H. Ö., HOFFMANN P., PETHICA J.

APPLIED PHYSICS LETTERS, vol.79, no.12, pp.1915-1917, 2001 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 79 Issue: 12
  • Publication Date: 2001
  • Doi Number: 10.1063/1.1389785
  • Journal Name: APPLIED PHYSICS LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1915-1917
  • Middle East Technical University Affiliated: No

Abstract

Quantitative force gradient images are obtained using a sub-angstrom amplitude, off-resonance lever oscillation method during scanning tunneling microscopy imaging. We report the direct observation of short-range bonds, and the measured short-range force interaction agrees well in magnitude and length scale with theoretical predictions for single bonds. Atomic resolution is shown to be associated with the presence of a prominent short-range contribution to the total force interaction. It is shown that the background longer-range interaction, whose relative magnitude depends on the tip structure, has a significant effect on the contrast observed at the atomic scale. (C) 2001 American Institute of Physics.