Multiconfigurational nature of 5f orbitals in uranium and plutonium intermetallics

Abstract

Uranium and plutonium's 5f electrons are tenuously poised between strongly bonding with ligand spd-states and residing close to the nucleus. The unusual properties of these elements and their compounds (eg. the six different allotropes of elemental plutonium) are widely believed to depend on the related attributes of f-orbital occupancy and delocalization, for which a quantitative measure is lacking. By employing resonant x-ray emission spectroscopy (RXES) and x-ray absorption near-edge structure (XANES) spectroscopy and making comparisons to specific heat measurements, we demonstrate the presence of multiconfigurational f-orbital states in the actinide elements U and Pu, and in a wide range of uranium and plutonium intermetallic compounds. These results provide a robust experimental basis for a new framework for understanding the strongly-correlated behavior of actinide materials.

30 pages, concatenated article and supporting information, 10 figures

References in corpus (4)

• Nature of the 5f states in actinide metals
• What is the valence of a correlated solid? The double life of delta-plutonium
• Electronic Duality in Strongly Correlated Matter
• Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20

Cited by in corpus (8)

• Resonant x-ray spectroscopy of uranium intermetallics at the U $M_{4,5}$ edges
• Chemical Design of Electronic and Magnetic Energy Scales in Tetravalent Praseodymium
• Probing 5f-state configurations in URu2Si2 with U L3-edge resonant x-ray emission spectroscopy
• Synchrotron Radiation Techniques and their Application to Actinide Materials
• Quasiparticle multiplets and 5f electronic correlation in prototypical plutonium borides
• Valence instability across magnetostructural transition in USb${}_2$
• Thermal Equation of State of U${}_6$Fe from Experiments and Calculations
• UCd${}_{11}$: A strongly localized 5$f^3$ material