Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 56: Symposium: The Solid-Liquid Interface: A Challenge for Theoreticians I
O 56.2: Hauptvortrag
Donnerstag, 29. März 2007, 16:15–16:45, H36
Electric field effects at metal surfaces — •Ali Alavi1 and Alexander Lozovoi2 — 1Department of Chemistry, Cambridge CB2 1EW — 2School of Mathematics and Physics, Queen's University, Belfast Bt7 1NN
We review our recent work on electric field effects at metal surfaces, concentrating on (a) the relation between first-principles theory and the thermodynamics of charged surfaces [1] (held either at constant charge or constant potential), (b) a practical implementation of suitable for periodic slabs, and (c) new results on the stark effect for CO on Pt(111)[2]. Regarding (a), by generalising Koopman's theorem, we derive expressions for the surface (excess) free energy as a function of charge (or potential) in terms of the neutral surface energy, the workfunction and the position of the image plane. This is used to investigate potential-induced surface reconstructions. We show that a remarkable type of phase-coexistence in which charge-separation occurs. If time permits, we will show results on field effects on surface-relaxation, and adatom diffusion.
[1] A.Y. Lozovoi and A. Alavi, Phys. Rev. B 68 , 245416, (2003).
[2] A.Y. Lozovoi and A. Alavi, J. Electroanalytical. Chem., to appear.