Reversible relaxation at charged metal surfaces: An ab initio study

¹  Institut für Zuverlässigkeit von Bauteilen und Systemen, Universität Karlsruhe - Karlsruhe, Germany
²  Institute of Industrial Science, The University of Tokyo - Tokyo, Japan
³  Fraunhofer-Institut für Werkstoffmechanik IWM - Freiburg, Germany
⁴  Interdisziplinäres Zentrum für Molekulare Materialien ICMM, Universität Erlangen-Nürnberg Erlangen, Germany
⁵  Institut für Nanotechnologie, Forschungszentrum Karlsruhe - Karlsruhe, Germany
⁶  Technische Physik, Universität des Saarlandes - Saarbrücken, Germany

Corresponding author: Joerg.Weissmueller@int.fzk.de

Received: 30 June 2008
Accepted: 22 August 2008

Abstract

Results of an ab initio density functional theory study of atomic and electronic relaxation at electrically charged surfaces of Au suggest that the outward relaxation of the top layer at negative excess charge is driven by electrostatic forces on the surface atoms due to the incomplete screening of the external electric field. The relaxation amplitude agrees well with experiments on Au(111) in electrolyte. Electron redistribution between bonding and antibonding states in the plane containing the surface atoms may contribute to the charge response of the surface stress.