Stability and migration of charged oxygen interstitials in ThO2 and CeO2

Journal Article · Tue Jan 01 04:00:00 EST 2013 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2013.09.001· OSTI ID:1097489

Xiao, Haiyan ^[1]; Zhang, Yanwen ^[2]; Weber, William J ^[2]

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1. University of Tennessee, Knoxville (UTK)
2. ORNL

Density functional theory calculations have been carried out to study the stability and migration of charged oxygen interstitial in ThO2 and CeO2. The calculations demonstrate that the oxygen interstitial is likely to lose electrons under p-type conditions and gain electrons under n-type conditions. Neutral (Osplit0) and singly positive (Osplit+) O-O<110> split interstitials, and doubly negative octahedral (Oocta.2-) oxygen interstitial are found to be the lowest-energy configurations within a certain Fermi energy range. In both oxides, the Osplit+ is the most mobile, and the migration energies of the split oxygen interstitials in ThO2 are lower than in CeO2, indicating high oxygen interstitial mobility in ThO2 than in CeO2.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1097489
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 20 Vol. 61; ISSN 1359-6454
• Country of Publication: United States
• Language: English

Related Subjects

Ceria
Density Functional Theory
Interstitials
Thoria