First principles assessment of metal/oxide interface adhesion

Adhesion at the interface between metals and oxides is strongly affected by the presence of impurities and dopants. We report a strategy for characterizing the influence of such species on adhesion through systematic first principles calculations. This is demonstrated for a technologically important interface that between a gamma-Ni(Al) alloy and alpha-Al(2)O(3). The effects on adhesion of stoichiometry, Al activity, impurities, and dopants are thoroughly examined, both in the bulk and at the interface. A surprising discovery is that doping with Hf provides several concurrent benefits, including an increase in the work of separation of the clean stoichiometric interface by a factor of 3. (C) 2008 American Institute of Physics.