Electronic structure and adhesion on metal-aluminum-oxide interfaces

This paper reports on the results of the systematic analysis of the atomic and electronic structure of the Me/alpha-Al2O3(0001) interfaces for two series of isoelectronic metals (Me = Cu, Ag, Au and Ni, Pd, Pt), depending on the termination of the oxide substrate and the configuration of oxide films. The calculations have been performed by the pseudopotential method in the plane-wave basis set. The adhesion energy of metal films has been calculated depending on the cleavage plane. It has been shown that the adhesion energy is maximum at the oxygen interface, which is caused by the ion component in chemical bonding at this interface. The aluminum and aluminum-enriched interfaces are characterized by the metallic type of bonding. The local densities of states and the charge distribution near the interface have been analyzed. It has been demonstrated that oxygen vacancies at the interface substantially weaken the adhesion due to the partial breaking of Me-O bonds.