Iso-coverage diffusion zones observed with LEEM during annealing of Ag on Si(001)

ORAL

Abstract

During high temperature annealing of 3D Ag islands grown on Si(001) PEEM images reveal the emergence of a bright zone surrounding the decaying islands. Microdiffraction patterns from these bright areas display a (2x3) Ag reconstruction. The decaying Ag islands act as sources of Ag adatoms which then diffuse on the surface. The (2x3) reconstruction spreads away from the island to a distance determined by the interplay of diffusion and desorption, and by the local coverage of Ag: the outer boundary of the imaged diffusion zones constitutes an ``iso-coverage boundary.'' We describe the time and temperature behavior of these iso-coverage zones, and present a simple continuum model that describes the iso-zone size as a function of the diffusion and desorption rates.

*Financial support from the National Science Foundation through grants DMR-0203097 and DMR-0320908, and from Deutsche Forschungsgemeinschaft through SFB616 "Energy Dissipation at Surfaces" is gratefully acknowledged.

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Authors

  • Kelly Roos

    • Department of Physics, Bradley University

  • Kimberly Roos

    • Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign

  • Frank Meyer zu Heringdorf

  • Michael Horn-von Hoegen

    • Institute for Experimetnal Physics, University of Duisburg-Essen

  • Joachim Krug

    • Institute for Theoretical Physics, University of Cologne