Premelting of the Al(110) surface from a local perspective

A molecular-dynamics study of premelting on the Al(110) surface has been performed. The surface atoms interact through a semiempirical many-body potential built up inside the embedded-atom scheme. The pre melting process has been studied by calculating the Debye-Waller factor, which shows anisotropic behavior above 800 K for a range of temperatures up to the melting point. Theoretical results have been compared to recent x-ray absorption fine-structure measurements. The calculations show that bonds between Al atoms are broken along the direction normal to the surface, while they remain intact on the surface. A decrease of coordination number for surface atoms is present as evidence of structural disorder for temperatures near melting.