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arXiv · 1807.01609

U 5$f$ crystal-field ground state of UO$_2$ probed by directional dichroism in nonresonant inelastic x-ray scattering

Martin Sundermann·Gerrit van der Laan·Andrea Severing·Laura Simonelli·Gerry Lander·Maurits Haverkort·Roberto Caciuffo
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Abstract

Nonresonant inelastic x-ray scattering (NIXS) has been performed on single crystals of UO$_2$ to study the direction dependence of higher-order-multipole scattering from the uranium $O_{4,5}$ edges (90--110 eV). By comparing the experimental results with theoretical calculations the symmetry of the ground state is confirmed directly as the crystal-field (CF) $\Gamma_5$ triplet state within the $J$ = 4 manifold. The results also demonstrate that the directional dichroism of the NIXS spectra is sensitive to the CF strength and establish NIXS as a tool for probing CF interactions quantitatively.

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Martin Sundermann, Gerrit van der Laan, Andrea Severing, Laura Simonelli, Gerry Lander, Maurits Haverkort, Roberto Caciuffo. 2018-07-04. U 5$f$ crystal-field ground state of UO$_2$ probed by directional dichroism in nonresonant inelastic x-ray scattering. https://doi.org/10.1103/physrevb.98.205108

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