Oxygen vacancy formation and migration in CexTh1-xO2 (0≤x≤1) solid solution...

A DFT+U method has been employed to investigate oxygen vacancy formation and migration in CexTh1-xO2. The addition of CeO2 into ThO2 significantly decreases the oxygen vacancy formation and migration energies. ThO2 doped with 50% CeO2 exhibits the lowest formation energy and when doped with 75% CeO2 exhibits the lowest migration energy, suggesting that introducing CeO2 into ThO2 promotes the formation of mobile oxygen vacancies. If the ceria content is less than 25%, the reduced CexTh1-xO2 becomes antiferromagnetic; whereas the ferromagnetic state dominates for x>25%, which may allow the manipulation of magnetic properties by varying the CeO2 concentration.