Dresden 2014 – scientific programme
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O: Fachverband Oberflächenphysik
O 48: Scanning Probe Methods I
O 48.8: Talk
Wednesday, April 2, 2014, 12:15–12:30, GER 38
Origin of sharp apparent intermolecular bonds in AFM and STM experiments — •Prokop Hapala1, Georgy Kichin2, Stefan Tautz2, Ruslan Temirov2, and Pavel Jelinek1 — 1Institute of Physics , Academy of Sciences of the Czech Republic, Cukrovarnická 10, Prague, 16253, Czech Republic — 2Institut fur Bio- und Nanosysteme 3, Forschungszentrum Julich, 52425 Julich, Germany
In recent years sub-molecular resolution in STM and AFM was achieved and enabled visualization of individual bonds between atoms. These techniques are based on usage of functionalized probe consisting a simple molecule or atom (such as CO, CH3, Xe, H2, Cl-) attached to the tip apex. Recently, several groups also reported direct observation of intermolecular bonds between molecules by the same technique [1],[2],[3]. In literature this observations used to be explained as visualization of electron density in the bond due to Pauli repulsion. It was already shown, that the measured images are strongly distorted and sharpened by relaxation of molecular probe [4]. Here we show, that sharp features measured in these experiments, especially apparent intermolecular bonds, can be explained almost exclusively by simple geometrical model using pairwise potential (Lennard-Jones, Morse) when relaxation of probe position is considered.
1. J.Zhang, et al., Science 342, 611-4 (2013).
2. C.Weiss, et al., J. Am. Chem. Soc. 132, 11864-5 (2010).
3. G.Kichin, et al., J. Am. Chem. Soc. 133, 16847-51 (2011).
4. L.Gross, et al., Science 337, 1326-9 (2012).