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O: Fachverband Oberflächenphysik

O 101: Particles and clusters II

O 101.4: Vortrag

Freitag, 18. März 2011, 12:00–12:15, WIL C107

Using STM-Lithography to study interface properties: Footprints of Cu-clusters on single crystalline ZnO(1010) — •Martin Kroll and Ulrich Köhler — Institut für Experimentalphysik IV / AG Oberflächen, Ruhr-Universität Bochum

As model systems in heterogeneous catalysis Cu clusters on single ZnO crystals grown under UHV conditions are used as a first step to understand complex reactions under real catalytical conditions. STM and STS were used to study the annealing behaviour of Cu clusters deposited by MBE on the nonpolar ZnO(1010) surface. As already found for the polar ZnO(0001)-Zn surface [1], separated Cu clusters are formed at room temperature and a partial entrenching of Cu into the ZnO substrate at elevated temperatures of T > 670K was found. To investigate what happens at the Cu-ZnO interface in more detail Cu clusters were removed from the ZnO surface after different annealing steps using STM-tip induced diffusion. The remaining footprints of the Cu clusters on the undisturbed ZnO substrate were analysed with STM and STS. The results point to a pure thermally driven interaction of the Cu-clusters with ZnO at the borderline between the cluster and the free ZnO substrate surface.

[1] Kroll, M.; Köhler, U.; Surf. Sci. 601 (2007) 2182