Mechanism of high-resolution STM/AFM imaging with functionalized tips

High-resolution atomic force microscopy (AFM) and scanning tunneling microscopy (STM) imaging with functionalized tips is well established, but a detailed understanding of the imaging mechanism is still missing. We present a numerical STM/AFM model, which takes into account the relaxation of the pro...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2014-08, Vol.90 (8), Article 085421
Main Authors: Hapala, Prokop, Kichin, Georgy, Wagner, Christian, Tautz, F. Stefan, Temirov, Ruslan, Jelínek, Pavel
Format: Article
Language:English
Subjects:
Atomic force microscopy
Condensed matter
Electron density
Imaging
Mathematical models
Minima
Scanning tunneling microscopy
Tips
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:High-resolution atomic force microscopy (AFM) and scanning tunneling microscopy (STM) imaging with functionalized tips is well established, but a detailed understanding of the imaging mechanism is still missing. We present a numerical STM/AFM model, which takes into account the relaxation of the probe due to the tip-sample interaction. We demonstrate that the model is able to reproduce very well not only the experimental intra- and intermolecular contrasts, but also their evolution upon tip approach. At close distances, the simulations unveil a significant probe particle relaxation towards local minima of the interaction potential. This effect is responsible for the sharp submolecular resolution observed in AFM/STM experiments. In addition, we demonstrate that sharp apparent intermolecular bonds should not be interpreted as true hydrogen bonds, in the sense of representing areas of increased electron density. Instead, they represent the ridge between two minima of the potential energy landscape due to neighboring atoms.
ISSN:1098-0121
1550-235X
DOI:10.1103/PhysRevB.90.085421