Stability and Migration of Charged Oxygen Interstitials in ThO₂ and CeO₂

Journal Article · Mon Sep 30 04:00:00 EDT 2013 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2013.09.001· OSTI ID:1120098

Xiao, Haiyan Y.; Zhang, Yanwen; Weber, William J.

Density functional theory calculations have been carried out to study the stability and migration of charged oxygen interstitials 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 and singly positive O–O (1 1 0) split interstitials, and doubly negative octahedral (O^2-_octa.) oxygen interstitial are found to be the lowest-energy configurations within a certain Fermi energy range. In both oxides, the 0⁰_split is the most mobile, and the migration energies of the split oxygen interstitials in ThO₂ are lower than in CeO₂, indicating higher oxygen interstitial mobility in ThO₂ than in CeO₂.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1120098
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 20 Vol. 61; ISSN 1359-6454
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory