Atomistic modelling of tritium thermodynamics and kinetics in tungsten and its oxides

Autor: M. Christensen, E. Wimmer, M.R. Gilbert, C. Geller, B. Dron, D. Nguyen-Manh
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Nuclear Materials and Energy, Vol 38, Iss , Pp 101611- (2024)
Druh dokumentu: article
ISSN: 2352-1791
DOI: 10.1016/j.nme.2024.101611
Popis: Atomistic simulations using ab initio density functional theory and machine-learned potentials have been employed to map the structural, thermodynamic, and kinetic properties of the T-WOx system (x = 0 to 3). The simulations reveal that the T permeability is low in WO2, intermediate in W, and relatively high in WO3. Diffusion of T is slowest in WO2. Vacancies and self-interstitials are strong traps for T. Oxygen vacancies in WO2 are very strong traps for a few T atoms, while vacancies in bulk W can trap up to ten T atoms. Segregation to WO2 surfaces is energetically favourable. However, segregation of T to WO3 surfaces is energetically unfavourable at high surface coverage.
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