A first-principles study of the formation of atomically rough {111} MgO surface and its effect on prenucleation of Mg

Abstract

Based on the recent studies of the effects of lattice misfit and substrate chemistry on prenucleation, we investigate the interface between liquid Mg and MgO{111} using an ab initio molecular dynamics simulation (AIMD) technique. Our study reveals the formation of an atomically rough Mg layer on the {111}MgO surface when MgO is in contact with Mg melt. This atomically rough substrate surface deteriorates significantly the atomic ordering in the liquid adjacent to the liquid/substrate interface. Consequently, it reduces the potency of MgO as a substrate for heterogeneous nucleation.