Charge transfer at oxygen/zirconia interface at elevated temperatures: Part 3: Segregation induced interface properties

The present paper considers segregation of lattice elements, including dopants and impurities, in oxide materials and its effect on the formation of concentration gradients within the interface layer. Segregation is discussed in terms of the effect of temperature and oxygen partial pressure on segregation induced enrichment of interfaces in oxide materials and related local properties. The phenomenon of segregation and its impact on surface composition is outlined for yttria-stabilised zirconia (YSZ), where it impacts upon the performance of zirconia at elevated temperatures. The difference between equilibrium segregation and non-equilibrium segregation is discussed. In the former case, the segregation induced data represent specific materials properties. In the latter case, non-equilibrium segregation leads to a complex distribution of concentration gradients and structures, which are a reflection of the applied experimental procedures rather than of material properties.