Dresden 2006 – wissenschaftliches Programm

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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 29.62: Poster

Mittwoch, 29. März 2006, 14:30–17:30, P2

Jumping atom rows on Au(110) observed with video-rate STM — •Richard van Rijn, Joost W.M. Frenken, and Marcel J. Rost — Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands

When depositing gold on a Au(110) surface, we find the formation of atom rows with a width of only one atom and surprisingly large lengths up to hundreds of atoms. This length scale is roughly a factor ten larger than we expect on the basis of two-dimensional equilibrium shape theory (Wulff construction). In addition we observe a large spread in row lengths. Next to the unusual island form, we also find that these atom rows are mobile at room temperature. Using standard STM imaging speeds, we observe atom rows with lots of kinks. But at video rate it seems, as if the whole atom row jumps back and forth in the [001] direction via a collective movement of all (hundreds of) atoms. As this collective movement is highly unlikely, we suggest that the basic mechanism for the jumps is given by the creation and the diffusion of an individual kink within the row, but on a very fast time scale. This system is a perfect model for one-dimensional diffusion related to the ‘classical ruin problem’. We analyze the row diffusion via the frequency and temporal correlations of kink passages, as a function of position along the row, row length and temperature.