%0 Journal Article
%A Sundermann, Martin
%A Hahn, Henrik
%A Christovam, Denise S.
%A Haverkort, Maurits W.
%A Caciuffo, Roberto
%A Keimer, Bernhard
%A Tjeng, Liu Hao
%A Severing, Andrea
%A Gretarsson, Hlynur
%T Resonant inelastic x-ray scattering at the actinide M<sub>4,5</sub> -edges
%J Physical review research
%V 7
%N 4
%@ 2643-1564
%C College Park, MD
%I APS
%M PUBDB-2025-04556
%P 043081
%D 2025
%X Understanding the electronic structure of actinide materials is crucial for both fundamental research and nuclear applications. The partially filled 5⁢𝑓shells exhibit complex behavior due to strong correlations and ligand hybridization, requiring advanced spectroscopic techniques. Here, we report on the development and application of high-resolution valence band resonant inelastic x-ray spectroscopy (VB-RIXS) experiments at the uranium 𝑀<sub>4,5</sub> edges (3551 and 3725 eV). We present data of UO<sub>2</sub>, a well-established model actinide compound. VB-RIXS is particularly well suited for probing the 5⁢𝑓-shell electronic structure, as it probes, in contrast to core-to-core RIXS, excitations without leaving a high-energy core hole in the final state. In VB-RIXS, we achieve energy resolutions of 50 meV (𝑀<sub>5</sub>) and 90 meV (𝑀<sub>4</sub>), enabling the resolution of multiplet excitations and crystal-field effects, as well as charge-transfer and fluorescencelike features with unprecedented clarity. As such, high-resolution VB-RIXS offers direct insights into both low-energy, near-ground-state properties and high-energy hybridization and covalency effects. Our results demonstrate the power of VB-RIXS as a versatile and powerful tool for probing the strongly correlated electronic structure of actinide materials, providing essential input for quantitative modeling and the validation of theoretical concepts. 
%F PUB:(DE-HGF)16
%9 Journal Article
%R 10.1103/twsv-xh5j
%U https://bib-pubdb1.desy.de/record/639470