Temperature-Induced Atomic Reconstruction At Au/MgAl₂O₄ Interfaces

The metal–oxide interaction, associated with intermingling delocalization of bonding electrons in metals and ionic bonds in oxides, may cause reconstruction of interface structure and accordingly affect physical properties of heterogeneous materials. This Communication reports reconstructions of (111) interface between gold and magnesium aluminate spinel according to experimental observation and theoretical prediction. Three interfacial structures are evidenced with respect to the arrangement of gold atoms: perfect Au (111) interface, atoms missing in the first Au (111) plane, and atoms mixing in the two adjacent atomic planes. Such atomic arrangements in the reconstructed interfaces are similar to those of metal cations in the spinel lattice, thus providing new insights into the chemistry and structure of metal–oxide interfaces and highlighting new pathways toward metal–oxide interface engineering.