Effect of defects on the stability of heteroepitaxial ceramic interfaces studied by computer simulation

Static simulation techniques have been used to examine the defect chemistry in heteroepitaxial ceramic interfaces. Reduced ion density at the interface is seen to enhance the interfacial stability. The energetics of defect formation are shown to be substantially modified at the interface. In particular, we find that the energy of oxygen vacancy formation is lower at the interface between ${\mathrm{CeO}}_2$ thin films on α-${\mathrm{Al}}_2$ ${\mathrm{O}}_3$ compared with its value on the pure ${\mathrm{CeO}}_2$ surface. This effect of the interface may influence the catalytic activity of several systems.