Finite element modelling of the ionic conductivity of acceptor doped ceria

Abstract

The ionic conductivity of doped ceria is strongly influenced by temperature, oxygen partial pressure, dopant concentration and microstructure of the material. While theory and experiments generally agree on the influence of the first two parameters, the other influences are still not fully understood. A reliable simulation model of the material’s electrical conductivity is thus necessary to interpret the existing measurements.Until now, prediction of the electrical conductivity of these materials relies mainly on analytical models. This approach yields useful insights but it also has drawbacks. We implement the partial differential equations that govern charge carrier transport and electrical potential in a finite element model. This numerical approach enables us to treat grains of arbitrarily small size and to predict electrical conductivities at any applied current density. The results predicted by our model are compared to the available measurements in literature.