Nothing moves a surface: vacancy mediated surface diffusion
Abstract
We report scanning tunneling microscopy observations, which imply that all atoms in a close-packed copper surface move frequently, even at room temperature. Using a low density of embedded indium `tracer' atoms, we visualize the diffusive motion of surface atoms. Surprisingly, the indium atoms seem to make concerted, long jumps. Responsible for this motion is an ultra-low density of surface vacancies, diffusing rapidly within the surface. This interpretation is supported by a detailed analysis of the displacement distribution of the indium atoms, which reveals a shape characteristic for the vacancy mediated diffusion mechanism that we propose.
Cite
@article{arxiv.cond-mat/0009436,
title = {Nothing moves a surface: vacancy mediated surface diffusion},
author = {R. van Gastel and E. Somfai and S. B. van Albada and W. van Saarloos and J. W. M. Frenken},
journal= {arXiv preprint arXiv:cond-mat/0009436},
year = {2007}
}
Comments
4 pages; for associated movie, see http://www-lion.leidenuniv.nl/sections/cm/groups/interface/projects/thermo