INTERFACIAL OXIDE LAYERS AT THE METAL–OXIDE PHASE BOUNDARY

The nature of oxide phases at metal–oxide interfaces, i.e. of oxide layers in the proximity of a metal surface, is assessed by critically examining the available data in the literature. The data reveal a trend towards the formation of reduced oxide phases with lower oxidation states in the vicinity of the interface with a metal. The physical origin of these interface-stabilized oxide layers is discussed and the possible causes include strong metal–metal bonding, high oxygen affinity of the substrate metal, reduction of the interfacial strain, and the stability of two-dimensional oxide phases.