5d-5f Electric-multipole Transitions in Uranium Dioxide Probed by Non-resonant Inelastic X-ray Scattering

TL;DR

This study uses non-resonant inelastic x-ray scattering to investigate 5d-5f electronic transitions in uranium dioxide, revealing multipolar transition structures and demonstrating NIXS as a powerful bulk-sensitive technique for actinide electronic characterization.

Contribution

It provides detailed insights into multipolar electronic transitions in uranium dioxide using NIXS, highlighting its effectiveness for actinide material analysis.

Findings

Identification of multipolar transition structures at high q values

Demonstration of NIXS as a bulk-sensitive technique

Correlation of spectral features with atomic multiplet calculations

Abstract

Non-resonant inelastic x ray scattering (NIXS) experiments have been performed to probe the 5d-5f electronic transitions at the uranium O(4,5) absorption edges in uranium dioxide. For small values of the scattering vector q, the spectra are dominated by dipole-allowed transitions encapsulated within the giant resonance, whereas for higher values of q the multipolar transitions of rank 3 and 5 give rise to strong and well-defined multiplet structure in the pre-edge region. The origin of the observed non-dipole multiplet structures is explained on the basis of many-electron atomic spectral calculations. The results obtained demonstrate the high potential of NIXS as a bulk-sensitive technique for the characterization of the electronic properties of actinide materials.