Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 66: Nanostructures at surfaces III

O 66.7: Vortrag

Donnerstag, 29. März 2012, 12:00–12:15, MA 042

Scanning tunneling microscopy study of antimony clusters on Si(111)7x7 — •Stephan Appelfeller, Martin Franz, and Mario Dähne — Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin

The growth regime of surface clusters is located between single atom adsorption processes and long range surface reconstructions. These surface clusters are interesting structures to analyze not only because of their possible use in nanocatalysis and the miniaturization of nanodevices but also for their unique physical properties. Here, clusters were grown on heated, 7x7 reconstructed Si(111) substrates by molecular beam epitaxy with submonolayer antimony coverages. Several different cluster appearances were found depending on the exact preparation conditions using a scanning tunneling microscope. The structural and electronic properties of the dominant cluster types were studied with a focus on antimony clusters which appear ring like in empty state images. These ring clusters form preferentially at an edge of a faulted half unit cell and represent up to 75% of all clusters observed in the measurements. A structure model that explains the experimental results well was developed for these ring clusters. This work was supported by the DFG through FOR 1282 project D.