First-principles study of thermal conductivities of uranium aluminides

Journal Article · 13 November 2018 · Materialia

DOI: https://doi.org/10.1016/j.mtla.2018.11.007 · OSTI ID:1489801

Mei, Zhi -Gang  ^[1]; Kim, Yeon Soo ^[1]; Yacout, Abdellatif M. ^[1]; Yang, Jiong ^[2]; Li, Xin ^[2]; Cao, Yan ^[2]

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1. Argonne National Lab. (ANL), Lemont, IL (United States)
2. Shanghai Univ., Shanghai (China)

Here, we investigate the lattice and electronic thermal conductivities of uranium aluminide compounds, i.e., UAl₂, UAl₃ and UAl₄, by density functional theory calculations. The lattice and electronic contributions to the total thermal conductivity of uranium aluminides are compared, and the contributions of phonons with different mean free times and modes to the lattice thermal conductivity of UAl₃ are analyzed from the calculated cumulative and spectral thermal conductivities. The effect of Mo alloying and U vacancy on the thermal conductivity of UAl₃ and UAl₄ is studied by considering the elastic phonon scattering due to mass difference. Both Mo alloying and U vacancy are found to significantly reduce the thermal conductivities of ideal UAl₃ and UAl₄ even with very low concentrations. The currently predicted thermal conductivities of uranium aluminide compounds are expected to be useful to the evaluation of the effective thermal conductivity of the interaction layer formed in U-Mo/Al dispersion fuel.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20). Office of Material Management and Minimization (NA-23) Reactor Conversion Program
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1489801
• Journal Information: Materialia, Journal Name: Materialia Journal Issue: C Vol. 4; ISSN 2589-1529
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English