Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 29: Poster session II (Nanostructures, Magnetism, Particles and clusters, Scanning probe techniques, Time-resolved spectroscopy, Structure and dynamics, Semiconductor surfaces and interfaces, Oxides and insulators, Solid-liquid interfaces)
O 29.34: Poster
Mittwoch, 29. März 2006, 14:30–17:30, P2
Manipulation of nanometer-scale metallic islands in ultrahigh vacuum by dynamic force microscopy techniques — •Dirk Dietzel1, Andre Schirmeisen1, Harald Fuchs1, and Udo Schwarz2 — 1Institute of Physics, University of Münster, Münster, Germany — 2Department of Mechanical Engineering, Yale University, New Haven CT, USA
The fundamentals of friction are still insufficiently understood on the nanometer-scale. Recently, a new technique for systematic island manipulation using dynamic force microscopy (DFM) in air has been introduced by Ritter et al. [1], which allows the correlation between contact area, energy dissipation during motion, and crystalline structure. However, under ambient conditions, oxidation and contamination might influence the frictional properties of the interface. To avoid this, experiments have been performed entirely under UHV conditions. Metallic islands with diameters between 10-50 nm have been grown by thermal evaporation of aluminum on highly oriented pyrolytic graphite (HOPG). The experimental protocol by Ritter et al. was adapted to UHV conditions and frequency modulation detection by gradually reducing the frequency shift setpoint. This allows determining the threshold value for energy dissipation necessary to initiate manipulation. In addition, information about the dissipated energy can be obtained even during the lateral movement. First results show that the manipulation of the islands strongly depends on their size and on the strength of the interaction between the oscillating cantilever tip and the islands.
[1] Ritter et al., Phys. Rev. B 71, 085405 (2005)