Racah materials: role of atomic multiplets and intermediate valence in f-electron systems

0471344 - FZÚ 2017 RIV GB eng J - Journal Article
Lichtenstein, A.I. - Kolorenč, Jindřich - Shick, Alexander - Katsnelson, M.I.
Racah materials: role of atomic multiplets and intermediate valence in f-electron systems.
MRS Advances. Roč. 1, č. 44 (2016), s. 2967-2974. ISSN 2059-8521
R&D Projects: GA ČR GC15-05872J
Institutional support: RVO:68378271
Keywords : electronic structure * photoemission * Pu
Subject RIV: BM - Solid Matter Physics ; Magnetism

The electronic structure of PuB6 was investigated with the aid of a combination of the density functional theory (DFT), and the exact diagonalization (ED) of an auxiliary Anderson impurity model. An intermediate-valence ground state with the f-shell occupation 5.5 is found for the Pu atom. The 5f-shell magnetic moment is completely compensated by the moment carried by electrons in the conduction band. Already in DFT, PuB6 is an insulator with a small amount of holes near the X-point, and with an indirect band gap of approximately 60 meV. This gap becomes direct in DFT+ED calculations supporting the idea of topological Kondo insulator in PuB6. Connection between the electronic structure of PuB6 and δ-Pu is established. We propose that these materials belong to a new class of intermediate-valence Racah materials with a multi-orbital Kondo-like singlet ground state.
Permanent Link: http://hdl.handle.net/11104/0268730