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The NaCl(100) Surface: Why Does it Not Melt?

2005/11/19 by T. Zykova-Timan, U. Tartaglino, Zykova-Timan, T. +5
Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci

paper · pdf · doi:10.48550/arxiv.cond-mat/0511485

9 pages, 3 figures; to appear in: "Highlights in the quantum theory of condensed matter", a volume in honour of M. P. Tosi on his 72th birthday, ed. Scuola Normale Superiore di Pisa

arxiv created 2005/11/19 · arxiv updated 2009/12/01

Abstract

The high temperature surface properties of alkali halide crystals are very unusual. Through molecular dynamics simulations based on Tosi-Fumi potentials, we predict that crystalline NaCl(100) should remain stable without any precursor signals of melting up to and even above the bulk melting point Tm. In a metastable state, it should even be possible to overheat NaCl (100) by at least 50 K. The reasons leading to this lack of surface self-wetting are investigated. We will briefly discuss the results of calculations of the solid-vapor and liquid-vapor interface free energies, showing that the former is unusually low and the latter unusually high, and explaining why. Due to that the mutual interaction among solid-liquid and liquid-vapor interfaces, otherwise unknown, must be strongly attractive at short distance, leading to the collapse of any liquid film attempting to nucleate at the solid surface. This scenario naturally explains the large incomplete wetting angle of a drop of melt on NaCl(100).

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