Probing Cerium 4 f States across the Volume Collapse Transition by X-ray Raman Scattering

Academic Article

Abstract

  • © 2019 American Chemical Society. Understanding the volume collapse phenomena in rare-earth materials remains an important challenge due to a lack of information on 4f electronic structures at different pressures. Here, we report the first high-pressure inelastic X-ray scattering measurement on elemental cerium (Ce) metal. By overcoming the ultralow signal issue in the X-ray measurement at the Ce N4,5-edge, we observe the changes of unoccupied 4f states across the volume collapse transition around 0.8 GPa. To help resolve the longstanding debate on the Anderson-Kondo and Mott-Hubbard models, we further compare the experiments with extended multiplet calculations that treat both screening channels on equal footing. The results indicate that a modest change in the 4f-5d Kondo coupling can well describe the spectral redistribution across the volume collapse, whereas the hybridization between neighboring atoms in the Hubbard model appears to play a minor role. Our study helps to constrain the theoretical models and opens a promising new route for systematic investigation of volume collapse phenomena in rare-earth materials.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Chen B; Pärschke EM; Chen WC; Scoggins B; Li B; Balasubramanian M; Heald S; Zhang J; Deng H; Sereika R
  • Start Page

  • 7890
  • End Page

  • 7897
  • Volume

  • 10
  • Issue

  • 24