Berlin 2008 – scientific programme

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O: Fachverband Oberflächenphysik

O 6: Metal Substrates: Clean Surfaces

O 6.1: Talk

Monday, February 25, 2008, 11:15–11:30, MA 005

Imaging phonon excitation with atomic resolution — •Heiko Gawronski and Karina Morgenstern — Institute of Solid State Physics, Department of Surface Science, Leibniz University Hannover, Appelstr. 2, D-30167 Hannover, Germany

Scanning tunneling microscopy (STM), inelastic tunneling spectroscopy (IETS), and d²I/dV²-mapping at low temperature are used to investigate vibrations of Au(111) and Cu(111). The low energy peaks in the IET-spectra at 9meV on Au(111) and 21meV on Cu(111) are attributed to phonons at surfaces. This phonon energy on Au(111) is not influenced by the different stacking of the surface atoms, but it is considerably influenced by different atomic distances within the surface layer. In addition, the spatial variation of the phonon excitation is measured in d²I/dV²-maps on Au(111). These display a novel type of atomic resolution that is explained in terms of site specific phonon excitation probabilities.