Molecular model of fused salts near an electrode

Abstract

We study the charged–hard-sphere model of a fused salt near a planar electrode, using a density-functional theory of inhomogeneous electrolytes. The results at relatively high temperatures show an oscillating charge distribution near the electrode, suggesting that near solid-liquid coexistence, the electrode is ‘‘coated’’ by a few atomic layers of the solid phase, analogous to wetting phenomena at liquid-vapor coexistence. At lower temperatures, we observe the growth of a macroscopically large ordered (solidlike) phase that is separated from the bulk fluid by an interface that extends over many molecular layers. Among other things this result shows, for the first time in the literature, that a density-functional theory is capable of producing a thermodynamically stable, ordered phase without the need of putting in any crystallographic symmetry at forehand.