An improved theory for temperature-dependent Arrhenius parameters in mesoscale surface diffusion

A. S. Dalton, E. G. Seebauer

Research output: Contribution to journalArticle

Abstract

Experiments on metals typically show an abrupt change in the Arrhenius behavior of surface self-diffusion at temperatures near 60-75% of the bulk melting point. To explain this phenomenon, we propose based on correlational evidence that the most common mechanism for surface self-diffusion is one in which adatoms dominate low-temperature transport, while surface vacancies dominate at high temperatures. The high-temperature dominance of vacancies results from their substantially higher entropy of diffusion, which is a consequence of the large vibrational displacements of surface atoms relative to the bulk. This phenomenon may also explain the Arrhenius behavior on some non-metal surfaces.

Original languageEnglish (US)
Pages (from-to)728-734
Number of pages7
JournalSurface Science
Volume601
Issue number3
DOIs
StatePublished - Feb 1 2007

Keywords

  • Composition, segregation
  • Defects and impurities
  • Diffusion
  • Diffusion of adsorbates, kinetics of coarsening and aggregation
  • Interface formation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

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