Calculation of defect formation energies in UO2. Issue 1645 (2014)

• Record Type: Journal Article
• Authors: Wiktor, Julia; Vathonne, Emerson; Freyss, Michel; Jomard, Gérald; Bertolus, Marjorie
• Is Part Of: MRS proceedings. Issue 1645:(2014)
• Publication Date: 2014
• Subjects: defects, -- electronic structure, -- actinide; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/opl.2014.119
• Languages: English
• ISSNs: 0272-9172

Abstract

ABSTRACT: We present a physically justified formalism for the calculation of defect formation energies in UO2. The accessible ranges of chemical potentials of the two components U and O are calculated using the U-O experimental phase diagram and a constraint on the formation energies of vacancies. We then apply this formalism to the DFT+ U investigation of the monovacancies and monointerstitials in UO2 . The results of the most stable charge states of these defects are consistent with a strongly ionic system. Calculations predict similarly low formation energies for $V_U^{4 - }$ and $I_O^{2 - }$ in hyperstoichiometric UO2 .