AVS 50th International Symposium
    Surface Science Monday Sessions
       Session SS2-MoM

Invited Paper SS2-MoM5
Medard W. Welch Award Address: Get Real ! --- The Importance of Complexity for Understanding the Function of Surfaces

Monday, November 3, 2003, 9:40 am, Room 327

Session: Catalysis I: Adsorption and Reactions of Small Molecules at Surfaces
Presenter: M. Scheffler, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany
Correspondent: Click to Email
Knowledge of the surface composition and atomic geometry is a prerequisite for understanding the physical and chemical properties of (most) modern materials as for example hardness, electronic and magnetic properties, and chemical activity. In this talk I will emphasize that to understand the function of surfaces it is important to "get real !", i.e. to go out of the vacuum and to take into account the influence of environmental gas and liquid phases at finite (possibly high) temperature and pressure.@footnote 1@ We employ ab initio, atomistic thermodynamics to construct a phase diagram of surface structures in the (T, p)-space from ultra-high vacuum to technically-relevant pressures and temperatures.@footnote 2-4@ The value of such phase diagrams as well as the importance of the reaction kinetics that may be crucial e.g. close to phase boundaries will be emphasized. -- We also calculated reaction pathways and energy barriers and use this information for a long time-scale modeling of surface diffusion, island nucleation, crystal growth, and oxidation catalysis. Examples in this talk are: semiconductor quantum-dot formation,@footnote 5@ the function of transition metals and transition-metal oxides, and heterogeneous catalysis.@footnote 6@ @FootnoteText@ @footnote 1@ C. Stampfl, et al., Catalysis and Corrosion: The Theoretical Surface-Science Context, Surf. Sci. 500, 368 (2002). @footnote 2@ X.-G. Wang, et al., Phys. Rev. Lett. 81, 1038 (1998). @footnote 3@ K. Reuter and M. Scheffler, Phys. Rev. Lett. 90, 046193 (2003); and Phys. Rev. B, in print. @footnote 4@ W. X. Li, C. Stampfl, and M. Scheffler, Phys. Rev. Lett., in print (June 2003); and Phys. Rev. B, in print. @footnote 5@ P. Kratzer and M. Scheffler, Surface Knowledge: Toward a Predictive Theory of Materials, Computing in Science & Engineering 3, 16 (2001); and Phys. Rev. Lett. 88, 036102 (2002). @footnote 6@ K. Reuter and M. Scheffler, to be published.