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O: Fachverband Oberflächenphysik

O 61: Nanostructures at Surfaces III

O 61.5: Vortrag

Mittwoch, 2. April 2014, 17:00–17:15, WIL B321

Truly monodisperse clusters on boron nitride films and self-assembled monolayers — •Fabian Knoller, Sarah Wieghold, Michael König, Friedrich Esch, and Ulrich Heiz — Technische Universität München, Catalysis Research Center, Chair of Physical Chemistry, Lichtenbergstr. 4, 85748 Garching, Germany

Matter in the non-scalable size regime displays unique, size-dependent chemical and physical properties. We study truly monodisperse supported clusters for catalytic applications, by characterizing their behavior under harsh conditions by Scanning Tunneling Microscopy (STM).
For this purpose, we soft-land size-selected PdN clusters first on epitaxial boron nitride films on Rh(111) for the study at elevated temperatures and under controlled dosage of reaction gases. It can be shown that the clusters are located at specific sites of the Moiré-structure and that these adsorption sites change upon ripening.
Second, we soft-land the clusters on self-assembled monolayers of n-dodecylthiole on Au(111) for studies in liquid ambients. Heating of the SAM sample under UHV conditions leads to long-range ordering of the film on which the PdN clusters are deposited. Their structure is conserved upon transfer into aqueous ambient (0.1M KClO₄) and imaging by electrochemical STM.