TY  - JOUR
AU  - Hapala, Prokop
AU  - Kichin, Georgy
AU  - Wagner, Christian
AU  - Tautz, Frank Stefan
AU  - Temirov, Ruslan
AU  - Jelínek, Pavel
TI  - Mechanism of high-resolution STM/AFM imaging with functionalized tips
JO  - Physical review / B
VL  - 90
IS  - 8
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2015-03348
SP  - 085421
PY  - 2014
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000340744200004
DO  - DOI:10.1103/PhysRevB.90.085421
UR  - https://juser.fz-juelich.de/record/201038
ER  -