Defect cluster formation in M 2O 3-doped CeO 2

Abstract

Atomistic simulation calculations based on energy minimisation techniques have been used to study the energetics associated with M 2O 3 solution in CeO 2. Results show that the binding energy of an oxygen vacancy to one or two substitutional cations is a strong function of dopant cation radius; small dopant ions prefer to occupy first neighbour sites, large dopant ions prefer second neighbour sites. The crossover occurs at approximately Gd 3 +, which also exhibits the smallest binding energy. These results are used to predict lattice parameter as a function of defect concentration and comparison is made to experimental values.