| AVS 66th International Symposium & Exhibition | |
| Actinides and Rare Earths Focus Topic | Tuesday Sessions |
| Session AC+AS+LS-TuA |
| Session: | Forensics, Science and Processing for Nuclear Energy |
| Presenter: | Dominik Legut, Technical University of Ostrava, Ostrava, Czechia |
| Authors: | D. Legut, Technical University of Ostrava, Ostrava, Czechia L. Kývala, Technical University of Ostrava, Ostrava, Czechia U.D. Wdowik, Technical University of Ostrava, Ostrava, Czechia G. Jaglo, Technical University of Ostrava, Ostrava, Czechia P. Piekarz, Technical University of Ostrava, Ostrava, Czechia L. Havela, Charles University, Prague, Czechia |
| Correspondent: | Click to Email |
Actinides and especially their carbides as prospective nuclear fuel
materials for the generation IV reactors were investigated using the
density functional theory. We demonstrate that their electronic,
magnetic, elastic, and thermal properties can be at present well
described if the spin-orbit interaction and partial delocalization 5f
electrons is properly included in the computational approaches. One
can well reproduce not only basic electronic structure but also
elastic constants, phonon dispersions, and their density of states,
provided by XPS, UPS, BIS, and inelastic
neutron scattering data [1-4]. The localization of the 5f electrons
could be captured using a moderate value of the on-site Coulomb
interaction parameter. The case studies include a realistic
description of the ground-state properties of elemental metals as Th,
U and their monocarbides ThC and UC. The realistic description of the
electronic structure and lattice dynamics (phonons) explains much
higher thermal expansion and heat capacity in pure actinides (as Th)
comparing with respective actinide monocarbides. The modelling also
gives an insight up to which temperature the heat transport depends on
lattice vibrations and where the electron transport starts to
dominate. We can identify the vibration modes influencing the heat
transport most. Carbides are compared with actinide oxides, where the
major role is played by optical phonon branches [3]. The phase
stability and elastic properties have been explored in a cascade of
uranium hydrides [5], for which the requirement to reproduce the
ferromagnetic moments gives an important feedback for the choice of
on-site Coulomb U and Hund's exchange J.
1. U. D. Wdowik, P. Piekarz, D. Legut, and G. Jaglo, Phys. Rev. B 94, 054303 (2016).
2. L. Kyvala and D. Legut (submitted to PRB April 2019)
3. P. Maldonado, L. Paolasini, P. M. Oppeneer, T. R. Forrest, A. Prodi, N. Magnani, A. Bosak, G. H. Lander, and R. Caciuffo, Phys. Rev. B 93, 144301 (2016).
4. Y. Yun, D. Legut and P. M. Oppeneer, J. Nucl. Mat. 426, 109 (2012).
5. L. Havela, M. Paukov, M. Dopita, L. Horak, D. Drozdenko, M. Divis, I. Turek, D. Legut, L. Kyvala, T. Gouder, A. Seibert, F. Huber, Inorg. Chem. 57, 14727 (2018).