Thermal Contraction and Disordering of the Al(110) Surface
Abstract
Al(110) has been studied for temperatures up to 900 K via ensemble density-functional molecular dynamics. The strong anharmonicity displayed by this surface results in a negative coefficient of thermal expansion, where the first interlayer distance decreases with increasing temperature. Very shallow channels of oscillation for the second-layer atoms in the direction perpendicular to the surface support this anomalous contraction, and provide a novel mechanism for the formation of adatom-vacancy pairs, preliminary to the disordering and premelting transition. Such characteristic behavior originates in the free-electron-gas bonding at a loosely packed surface.
Keywords
Cite
@article{arxiv.cond-mat/9903147,
title = {Thermal Contraction and Disordering of the Al(110) Surface},
author = {Nicola Marzari and David Vanderbilt and Alessandro De Vita and M. C. Payne},
journal= {arXiv preprint arXiv:cond-mat/9903147},
year = {2009}
}
Comments
4 pages, two-column style with 5 PostScript figures embedded. Uses RevTeX and epsf macros. To appear in Phys. Rev. Lett. Also available at http://www.physics.rutgers.edu/~marzari/preprints/index.html#al110