Dresden 2006 – wissenschaftliches Programm
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O: Oberflächenphysik
O 26: Particles and clusters I
O 26.4: Vortrag
Dienstag, 28. März 2006, 16:30–16:45, WIL A317
Oxidation of mass-selected Aun clusters (n=2-9) on SiO2/Si — •Rainer Dietsche, Dong Chan Lim, Moritz Bubek, Young Dok Kim, and Gerd Ganteför — Fachbereich Physik, Universität Konstanz, 78464 Konstanz
Mass-selected Au cluster anions consisting of less than 9 atoms were deposited on etched Si wafer surfaces covered with native oxide layers. Oxidation and reduction of the Au clusters were studied using X-ray Photoelectron Spectroscopy (XPS). For n=2,4,6,8 exposures of the clusters to atomic oxygen environments result in the appearance of additional peaks at the Au 4f level, which are characteristic for the Au-oxide formation.
For the odd numbered clusters, the Au-oxide formation is much less pronounced. In particular, it can be observed that there is no characteristic feature of the Au-oxide formation for Au7. This result suggests that each additional atom can drastically change chemical proporties of the deposited clusters consisting of the less than 9 atoms. Moreover, the even-odd pattern indicate that chemistry of the clusters correlates with electronic structures rather than with specific adsorption/reaction sites.