Interband Transitions and Critical Points of Single‐Crystal Thoria Compared with Urania

• Published in: Physica Status Solidi B. Basic Solid State Physics Vol. 259; no. 11
• Main Authors: Dugan, Christina, Wang, Lu, Zhang, Kai, Mann, James Matthew, Kimani, Martin M., Mei, Wai-Ning, Dowben, Peter A., Petrosky, James
• Format: Journal Article
• Language: English
• Published: United States Wiley-Blackwell 01-11-2022
• Subjects: cathode luminescence; interband transitions; Physics; thoria; urania
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202200238

The interband transitions of UO2 are validated independently through cathode luminescence. A picture emerges consistent with density functional theory. While theory is generally consistent with experiment, it is evident from the comparison of UO2 and ThO2 that the choice of functional can significantly alter the bandgap and some details of the band structure, in particular at the conduction band minimum. Strictly ab initio predictions of the optical properties of the actinide compounds, based on density functional theory alone, continue to be somewhat elusive.
Both thoria ThO2 and urania, UO2, adopt the cubic fluorite phase and this is reproduced in theory.