Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5425410 | Surface Science | 2007 | 7 Pages |
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.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
A.S. Dalton, E.G. Seebauer,