Reexaming the ground state and magnetic properties of curium dioxide

Article

关键词: ELECTRONIC-STRUCTURE;    SUSCEPTIBILITY;    SYSTEMS;    ELEMENTS;    OXIDES;   

DOI  :  10.1103/PhysRevB.102.085127

来源: SCIE

【 摘 要 】

The ground-state electronic structure and magnetic behaviors of curium dioxide (CmO2) are controversial. In general, the formal valence of Cm ions in CmO2 should be tetravalent. The tetravalent state implies a 5f(6.0). electronic configuration and a nonmagnetic ground state. However, it is in sharp contrast to the large magnetic moment measured by painstaking experiments. In order to clarify this contradiction, we tried to study the ground-state electronic structure of CmO2 by means of a combination of density functional theory and dynamical mean-field theory. We find that CmO2 is a wide-gap charge transfer insulator with a strong 5f valence state fluctuation. It indeed belongs to a mixed-valence compound. The predominant electronic configurations for Cm ions are 5f(6.0) and 5f(7.0). The resulting magnetic moment agrees quite well with the experimental value. Therefore, the magnetic puzzle in CmO2 can be appropriately explained by the mixed-valence scenario.

【 授权许可】

Free