First-principles study of Mg(0001)/MgO(1-11) interfaces

Abstract

By means of first-principles density-functional calculations, we studied the surface energy of a nonstoichiometric MgO(1-11) slab, the interfacial energy and interfacial bonding characteristics of Mg-terminated and O-terminated Mg/MgO(1-11) interfaces with three stacking-site (TOP, HCP and FCC sites) models, and the effect of the thickness of Mg films on the O-terminated MgO(1-11) surface. The results indicate that the surface energies of the nonstoichiometric MgO(1-11) slab and interfacial energies of Mg/Mg(1-11) interface depend on Mg chemical potential. We found that the Mgterminated MgO(1-11) surface is more stable than the O-terminated MgO(1-11) surface at high Mg chemical potential, and Mg/MgO(1-11) with FCC stacking-site model is the most stable configuration in the Mg/MgO(1-11) interfaces. The results of the electronic structure reveals that the interfacial bonding of Mg-terminated interface with FCC site model mainly consists of metallic bond and of the O-terminated interface with FCC site model is mainly ionic with a small degree of σ-type covalent bond. Although the interfacial energy of Mg-terminated Mg/MgO interface with FCC stacking-site model is slightly higher than that of O-terminated Mg/MgO interface, the molten Mg would epitaxially grow on the FCC sites of the Mg-terminated MgO(1-11) surface because of the high evaporation pressure of Mg at high temperature.

Prenucleation at the Interface Between MgO and Liquid Magnesium: An Ab Initio Molecular Dynamics Study

“…This suggests that fcc MgO can act as sites for heterogeneous nucleation of hcp a-Mg. First-principles approaches were used to explore mainly the wetting and adhesion for different crystal orientations between solid a-Mg and MgO. [20][21][22] In order to understand the structural effect on prenucleation at atomic level, Men and Fan [23,24] performed atomistic molecular dynamics (MD) simulations on the atomic ordering in a liquid metal adjacent to a smooth substrate of different lattice misfits. Their simulations showed that the structural effect is strong on the in-plane atomic ordering but weak on the atomic layering in the liquid adjacent to the substrate.…”