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

Journal Article · 09 December 2019 · Journal of Physical Chemistry Letters

DOI: https://doi.org/10.1021/acs.jpclett.9b02819 · OSTI ID:1671338

Chen, Bijuan ^[1]; Pärschke, Ekaterina M. ^[2]; Chen, Wei-Chih ^[2]; Scoggins, Brandon ^[3]; Li, Bing ^[1]; Balasubramanian, Mahalingam ^[4]; Heald, Steve  ^[4]; Zhang, Jianbo  ^[1]; Deng, Hongshan ^[1]; Sereika, Raimundas  ^[1]; Sorb, Yesudhas ^[1]; Yin, Xia ^[1]; Bi, Yan ^[1]; Jin, Ke ^[5]; Wu, Qiang ^[5]; Chen, Cheng-Chien  ^[2]; Ding, Yang ^[1]; Mao, Ho-kwang ^[6]

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1. Center for High-Pressure Science & Technology Advanced Research, Beijing (China)
2. Univ. of Alabama, Birmingham, AL (United States)
3. Univ. of North Georgia, Dahlonega, GA (United States)
4. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
5. Inst. of Fluid Physics, Mianyang (China)
6. Center for High-Pressure Science & Technology Advanced Research, Beijing (China); Carnegie Inst. of Science, Washington, DC (United States)

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 N_4,5-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.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1671338
• Journal Information: Journal of Physical Chemistry Letters, Vol. 10, Issue 24; ISSN 1948-7185
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
X-rays
Density functional theory
Energy
Chemical calculations
Phase transitions