Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 45: Metal Substrates II
O 45.4: Vortrag
Mittwoch, 13. März 2013, 11:15–11:30, H42
Kinetics of Single D2O Molecules and Dimers on Cu(111) — •Cord Bertram and Karina Morgenstern — Lehrstuhl für Physikalische Chemie 1, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum
Water is well-known to form hydrogen-bonded networks on metal surfaces with a high structure variety, even at low temperature. Previous work on Cu(111) explored this variety by observing different amorphous and crystalline phases (Mehlhorn et al., Phys. Rev. Lett. 99 (2007), 246101). For further understanding of these networks, it is useful to analyse the kinetics of single molecules and the formation of nanoclusters. In this talk, we will discuss the diffusion of single D2O molecules and dimers on Cu(111) measured by low temperature time-lapsed scanning tunneling microscopy. We deposit D2O onto the surface below a temperature of 15 K with fluxes below 1.54·10−4 molecules/nm2s. The diffusion of monomers, the formation of dimers, and the subsequent diffusion of dimers is recorded between 19 K and 29 K. The height of the diffusion barrier and the prefactors are determined via the Arrhenius law. Surprisingly both species show similarities to the diffusion via tunneling of hydrogen. The results will be compared to previous works on e.g. Pd(111), Pt(111), and Ag(111) (Mitsui et al., Science 297 (2002) 1850; Motobayashi et al., Surf. Sci. 602 (2008) 3136).