Ab initio study of surface stress response to charging

¹  Institut für Zuverlässigkeit von Bauteilen und Systemen, University of Karlsruhe - Karlsruhe, Germany
²  Institute of Industrial Science, The University of Tokyo - Tokyo, Japan
³  Fraunhofer-Institut für Werkstoffmechanik IWM - Freiburg, Germany
⁴  Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum - Bochum, Germany
⁵  Institut für Nanotechnologie, Forschungszentrum Karlsruhe - Karlsruhe, Germany
⁶  Technische Physik, Universität des Saarlandes - Saarbrücken, Germany
⁷  Institut für Theorie der Kondensierten Materie, Universität Karlsruhe - Karlsruhe, Germany

Received: 28 October 2006
Accepted: 13 February 2007

Abstract

We explore an efficient way to numerically evaluate the response of the surface stress of a metal to changes in its superficial charge density by analysis of the strain-dependence of the work function of the uncharged surface. As an application we consider Au(111), (110) and (100) sur- faces, employing density functional theory (DFT) calculations. The sign of the calculated response parameter can be rationalized with the dependence of the surface dipole and the Fermi energy on strain. The numerical value falls within the range indicated by experiment. The magnitude can explain the experimentally observed volume changes of nanoporous materials upon charging.