Defect cluster formation in M2O3-doped CeO2

Atomistic simulation calculations based on energy minimisation techniques h ave been used to study the energetics associated with M2O3 solution in CeO2 . Results show that the binding energy of an oxygen vacancy to one or two s ubstitutional cations is a strong function of dopant cation radius; small d opant ions prefer to occupy first neighbour sites, large dopant ions prefer second neighbour sites. The crossover occurs at approximately Gd3+. which also exhibits the smallest binding energy. These results are used to predic t lattice parameter as a function of defect concentration and comparison is made to experimental values. (C) 1999 Published by Elsevier Science B.V. A ll rights reserved.