摘要
Influence of doping and oxygen vacancy concentrations on oxygen ion or oxygen vacancy（V） migration energies of SmxCe1-xO2-δ（x = 0.0625, 0.125, 0.25 and δ = 0.0625, 0.125） systems using a GGA+U method are studied. Calculated results show that advantage migration types change from V?O2- to O2- ?V as x and δ increase. For V?O2- migrations of the Sm0.0625Ce0.9375O1.9375 and Sm0.125Ce0.875O1.9375 systems, electrostatic attractions between Sm3+ and V, defect associations between Ce3+ and V, and steric hindrances of Sm3+ affect the migration energies. For O2- ?V migrations of the Sm+（0.125）Ce0.875O1.875 and Sm0.25Ce0.75O1.875 systems, migration energies of O2- are affected by electrostatic repulsions between Sm3+ and O2- and defect associations between Ce3+ and V. Increases of the oxygen vacancy and Sm3+ doping concentrations benefit the oxygen ion and vacancy migrations, respectively.
基金
Supported by the National Natural Science Foundation of China(No.51474133)
Inner Mongolia Natural Science Foundation(No.2016MS0513)
