Dresden 2003 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 12: Postersitzung (Struktur und Dynamik reiner Oberfl
ächen, Grenzfl
äche fest-flüssig, Nanostrukturen, Teilchen und Cluster, Halbleiteroberfl
ächen und Grenzfl
ächen, Zeitaufgelöste Spektroskopie, Rastersondentechniken, Methodisches)
O 12.24: Poster
Montag, 24. März 2003, 18:00–21:00, P1
Multi Stable Switching of a Single Molecule — •Stefan Griessl1, Markus Lackinger2, Michael Hietschold2, and Wolfgang Heckl1 — 1LMU Muenchen, Therseienstr. 41, 80333 Muenchen — 2TU Chemnitz, Reichenhainer Str. 70, 09107 Chemnitz
The adsorption of Trimesic Acid (TMA) to a single crystal graphite surface has been studied under Ultra High Vacuum conditions. This work focuses on initiating a particular self-assembly structure by OMBE (Organic Molecular Beam Epitaxy). The structure is characterized by periodic non-dense-packing of the molecules. Two coexisting phases could be imaged by STM with sub-molecular resolution. Induced by directed hydrogen bonding, the organic molecules built in both cases a two-dimensional grid architecture with molecular caves. This two-dimensional host structure can accept single trimesic acid guest molecules at different positions. Furthermore the switching process of a single guest molecule within the molecular grid structure is demonstrated. STM induced movement of a single molecule to six stable positions was observed. These states of the molecular switch have a distance of 0.15 nm. The calculated energy barriers indicating that the switch is stable at room temperature are consistent with the experiment.