Berlin 2015 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 15: Scanning Probe Techniques: STM/AFM
O 15.8: Talk
Monday, March 16, 2015, 16:45–17:00, MA 043
Mapping intra-molecular charge distribution by distortions in high-resolution AFM/STM microscopy — •Prokop Hapala1, Martin Ondracek1, 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
Distribution of electron charge in molecules is a central property for chemistry since it indicates nature of bonding. Ionic bonds, polar covalent and non-polar covalent bonds of different bond order distinguish from each other by different charge distribution. At the same time, the internal charge transfer in molecules caused by presence of atoms with different electronegativity can help with identification of these atoms. In this work, we extend our simple mechanical model [1] for simulation of high-resolution AFM and STM images by incorporation of electrostatic potential obtained from DFT calculation. We will demonstrate that distortions observed in high-resolution STM/AFM experiments, including STM images of PTCDA, IETS images of CoPc [2,3] and bond order discrimination in C60 [4], are considerably affected by electrostatic force between local charge density in sample and atomic probe-particle (CO or Xe) attached to tip. [1] Hapala, P. et al., Phys. Rev. B 90, 085421 (2014). [2] Chiang, C. et al., Science 344, 885-8 (2014). [3] Hapala, P. et al., Phys. Rev. Lett. 113, 226101 (2014). [4] Gross, L. et al., Science 337, 1326-9 (2012).