Electronic structure and ionicity of actinide oxides from first principles
- Aarhus Univ. (Denmark); Daresbury Lab. (United Kingdom)
- Aarhus Univ. (Denmark)
- Daresbury Lab. (United Kingdom)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
The ground-state electronic structures of the actinide oxides AO , A2 O3 , and AO2 (A=U , Np, Pu, Am, Cm, Bk, and Cf) are determined from first-principles calculations, using the self-interaction corrected local spin-density approximation. Emphasis is put on the degree of f -electron localization, which for AO2 and A2 O3 is found to follow the stoichiometry, namely, corresponding to A4+ ions in the dioxide and A3+ ions in the sesquioxides. In contrast, the A2+ ionic configuration is not favorable in the monoxides, which therefore become metallic. The energetics of the oxidation and reduction in the actinide dioxides is discussed, and it is found that the dioxide is the most stable oxide for the actinides from Np onward. Our study reveals a strong link between preferred oxidation number and degree of localization which is confirmed by comparing to the ground-state configurations of the corresponding lanthanide oxides. The ionic nature of the actinide oxides emerges from the fact that only those compounds will form where the calculated ground-state valency agrees with the nominal valency expected from a simple charge counting.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Defect Physics in Structural Materials (CDP)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1064724
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 81, Issue 4; Related Information: CDP partners with Oak Ridge National Laboratory (lead); Ames Laboratory; University of California, Berkeley; Carnegie Mellon University; University of Georgia; University of Illinois, Urbana-Champaign; Ohio State University; University of Tennessee; ISSN 1098-0121
- Publisher:
- American Physical Society (APS)
- Country of Publication:
- United States
- Language:
- English
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