Orbital-free ab-initio study of the structure of liquid Al on a model fcc metallic wall: the influence of surface orientation.

Abstract

It is well known that liquids on a wall adopt layered structures, even for simple atom-atom and atom-wall interactions. Liquid metals, moreover, also stratify when a free surface is exposed. In this contribution we analyse the structure of 2000 atoms of liquid Al in contact with a metallic wall described atomistically (not in an integrated way), and modeled as an array of Al atoms fixed at the sites of an fcc lattice, somehow simulating a metallic material with a much higher melting temperature. We analyse how the liquid structure is affected by the orientation of the wall surface (100, 110 and 111), finding large differences in the liquid properties for the different surface setups. Specifically, for the 100 surface we find a ‘normal’ solid-liquid interface, for the 110 orientation we observe a preferential positioning of the liquid atoms along the solid surface channels, whereas for the 111 setup an induced crystallisation of the liquid takes place.