Ab-initio thermodynamics at surfaces: Relaxation, segregation, substitutional ordering and adsorption

Stefan Müller 

University Erlangen-Nürnberg, Lehrstuhl für Festkörperphysik, Staudtstr. 7, Erlangen 91058, Germany

Abstract

A prerequisite for studying catalytic processes at surfaces is a detailed knowledge of the surfaces' structural properties. Thereby the subject "structure" cannot be restricted to atomic relaxations alone, but also must consider substitutional ordering phenomena which often take place on a mesoscopic scale. Two examples whose modelling is fundamental for studying chemical processes at surfaces, are surface segregation and multi-site adsorption. It will be shown that today it is possible to study these properties using a first-principles based Hamiltonian constructed form the energetics of geometrically fully relaxed structures. This Hamiltonian can then be used for Monte-Carlo simulations in order to investigate the temperature-dependence of the surface properties. It will be shown that our new UNCLE code allows for a quantitative prediction of segregation, adsorption. and short-range order in excellent agreement with experimental data. Our focus will be on segregation at metal alloy surfaces and nanostructures stabilized by hydrogen adsorption.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/7586 must be provided.

 

Related papers
  1. Ab-initio statistical physics of precipitate evolution in metal alloys
  2. Ab-initio thermodynamics of metal alloys: From the atomic to the mesoscopic scale

Presentation: Invited oral at E-MRS Fall Meeting 2006, Symposium B, by Stefan Müller
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-11 14:38
Revised:   2009-06-07 00:44
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine