Impact of valence fluctuations on the electronic properties of R O1-x FxBiS2 (R=Ce and Pr)

S. Dash, T. Morita, K. Kurokawa, Y. Matsuzawa, N. L. Saini, N. Yamamoto, Joe Kajitani, R. Higashinaka, T. D. Matsuda, Y. Aoki, Takashi Mizokawa

    Research output: Contribution to journalArticle


    We have investigated the electronic properties of BiS2-based superconductors by using x-ray photoemission spectroscopy (XPS). In going from x=0.3 to 0.5 in PrO1-xFxBiS2, the Pr 3d and Pr 4d peaks are shifted by ∼0.10±0.05 eV from the Fermi level, partially consistent with the electron doping. In PrO1-xFxBiS2, the Pr3+-Pr4+ mixed valence remains unchanged with the electron doping from x=0.3 to 0.5. In CeO1-xFxBiS2, the doped electrons for x=0.5 almost suppress the Ce3+-Ce4+ valence fluctuation. Although the core-level peaks are also shifted by ∼0.10±0.05 eV towards the higher-binding-energy side with the electron doping from x=0 to 0.5 in CeO1-xFxBiS2, the Bi 4f7/2 binding-energy shift is higher in the Pr system compared with the Ce system. The present results suggest that the doped electrons increase orbital occupations in the rare-earth 4f orbitals at the valence band and show valence fluctuations differently in the two systems.

    Original languageEnglish
    Article number144501
    JournalPhysical Review B
    Issue number14
    Publication statusPublished - 2018 Oct 1


    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics

    Cite this

    Dash, S., Morita, T., Kurokawa, K., Matsuzawa, Y., Saini, N. L., Yamamoto, N., Kajitani, J., Higashinaka, R., Matsuda, T. D., Aoki, Y., & Mizokawa, T. (2018). Impact of valence fluctuations on the electronic properties of R O1-x FxBiS2 (R=Ce and Pr). Physical Review B, 98(14), [144501].