Author(s)

Yu Hasegawa, Takahiro Maehira, Takashi Hotta

1Department of Physics, Tokyo Metropolitan University, Tokyo, Japan 2Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan.
Department of Physics, Tokyo Metropolitan University, Tokyo, Japan.
Faculty of Science, University of the Ryukyus, Okinawa, Japan.

In order to promote our understanding on electronic structure of actinide dioxides, we construct a tight-binding model composed of actinide 5f and oxygen 2p electrons, which is called f-p model. After the diagonalization of the f-p model, we compare the eigen-energies in the first Brillouin zone with the results of relativistic band-structure calculations. Here we emphasize a key role of f-p hybridization in order to understand the electronic structure of actinide dioxides. In particular, it is found that the position of energy levels of Г₇ and Г₈ states determined from crystalline electric field (CEF) potentials depends on the f-p hybridization. We investiagte the values of the Slater-Koster integrals for f-p hybridization, (fpσ) and (fpπ), which reproduce simultaneously the local CEF states and the band-structure calculation results. Then, we find that the absolute value of (fpπ) should be small in comparison with (fpσ) = 1 eV. The small value of |(fpπ)| is consistent with the condition to obtain the octupole ordering in the previous analysis of the f-p model.

Tight-Binding Approximation; Actinide Dioxides; f-p Hybridization; Crystalline Electric Field Potential

Y. Hasegawa, T. Maehira and T. Hotta, "Key Role of Hybridization between Actinide 5f and Oxygen 2p Orbitals for Electronic Structure of Actinide Dioxides," Journal of Modern Physics, Vol. 4 No. 12, 2013, pp. 1574-1582. doi: 10.4236/jmp.2013.412194.