1999/03/09 by Nicola Marzari, David Vanderbilt, Alessandro De Vita +1 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.82.3296
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
arxiv created 1999/03/09 · arxiv updated 2009/11/30
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.