Defect cluster arrangements and oxygen vacancy migration in Gd doped ceria for different interatomic potentials

Pair potential simulations have been used to study the defect configurations and the oxygen vacancy migration in Gd doped CeO2 (GDC). The increasing number of parameter values used in the literature leads to different conclusions concerning the defect arrangement and the oxygen vacancy migration. It is then necessary to study the influence of those parameters on the structure and properties of GDC. We have thus employed six different parameter sets for the description of the short range interaction based on the Buckingham function. The most stable configurations of the (GdCeV(O) over dot)(center dot) defect pair and the (2Gd(Ce)V((O) over dot))(x) trimer have been calculated and clearly depend on the parameter set used. The linear trajectory for the oxygen vacancy jump is not evident for all the parameter sets and for a same jump the highest calculated energy barrier could be as high as third time the lowest one. The results have been compared with the available experimental data and two parameter sets are more adapted for the description of the oxygen vacancy migration inside the Gd doped ceria structure. (C) 2015 Elsevier B.V. All rights reserved.