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...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.展开更多
基金Supported by the National Natural Science Foundation of China(No.51474133)Inner Mongolia Natural Science Foundation(No.2016MS0513)
文摘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.
