Observation of bulk forbidden defects during the oxidation of $\mathrm{NiAl}\mathrm{}\left(110\right)\mathrm{}$

Selective oxidation of alloys can induce a restructuring of the oxide-alloy interface by the attraction of specific point defects which are not observed in the alloy bulk phase diagram. This phenomenon is elucidated in the case of the oxidation of NiAl(110) by surface x-ray-diffraction experiments. In this model system the strong ordering tendency of NiAl competes with the formation of ${\mathrm{Al}}_2{\mathrm{O}}_3,$ which is one of the most stable oxides. This leads to the formation of bulk forbidden Al antisite atoms at the oxide-alloy interface, which in turn has an important impact on the interfacial bonding and all related applications.