Energetics of Mg and B adsorption on polar zinc oxide surfaces from first principles

Abstract

We have performed first-principles density-functional projector augmented-wave calculations to investigate the energetics of Mg and B adsorption on polar zinc oxide (ZnO) surfaces, thereby to understand the origin of the peculiar affinities between an epitaxial Mg B2 film and the ZnO substrate. We found that the (0001) Zn surface is relatively inert, while the (000 1̄) O surface is very reactive in the adsorption of atomic species, where a triplaner B O3 (a hump of Mg O3) binding unit is formed as a consequence of the B (Mg) atom adsorption on the surface. These binding units would be formed at an early stage in the epitaxial growth of Mg B2 film on the ZnO substrate, and subsequently lead to the formation of the reaction products that were recently found in the interface between the Mg B2 film and the ZnO substrate. © 2008 The American Physical Society.