2009/06/19 by Takashi Hotta
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.80.024408
published as Phys. Rev. B 80, 024408 (2009), · 8 pages, 4 figures. To appear in Phys. Rev. B
arxiv created 2009/06/19 · openalex publication_date 2009/07/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
By evaluating multipole susceptibility of a seven-orbital impurity Anderson model with the use of a numerical renormalization group method, we discuss possible multipole states of actinide dioxides at low temperatures. In particular, here we point out a possible scenario for multipole ordering in americium dioxide. For Am4+ ion with five 5f electrons, it is considered that the ground state is \ensuremathΓ7^\ensuremath- doublet and the first-excited state is \ensuremathΓ8^\ensuremath- quartet, but we remark that the f5 ground state is easily converted due to the competition between spin-orbit coupling and Coulomb interactions. Then, we find that the \ensuremathΓ8^\ensuremath- quartet can be the ground state of AmO2 even for the same crystalline electric-field potential. In the case of \ensuremathΓ8^\ensuremath- quartet ground state, the numerical results suggest that high-order multipoles such as quadrupole and octupole can be relevant to AmO2.