Affordable Access

Forces and currents in carbon nanostructures: are we imaging atoms?

Authors
  • Ondráček, Martin
  • Pou, Pablo
  • Rozsíval, Vít
  • González, Cesar
  • Jelínek, Pavel
  • Pérez, Rubén
Type
Published Article
Journal
Physical Review Letters
Publisher
American Physical Society
Publication Date
Apr 29, 2011
Volume
106
Issue
17
Pages
176101–176101
Identifiers
PMID: 21635051
Source
Medline
License
Unknown

Abstract

First-principles calculations show that the rich variety of image patterns found in carbon nanostructures with the atomic force and scanning tunneling microscopes can be rationalized in terms of the chemical reactivity of the tip and the distance range explored in the experiments. For weakly reactive tips, the Pauli repulsion dominates the atomic contrast and force maxima are expected on low electronic density positions as the hollow site. With reactive tips, the interaction is strong enough to change locally the hybridization of the carbon atoms, making it possible to observe atomic resolution in both the attractive and the repulsive regime although with inverted contrast. Regarding STM images, we show that in the near-contact regime, due to current saturation, bright spots correspond to hollow positions instead of atomic sites, providing an explanation for the most common hexagonal pattern found in the experiments.

Report this publication

Statistics

Seen <100 times