Localized and mixed valence state of Ce 4f in superconducting and ferromagnetic CeO1−xFxBiS2 revealed by x-ray absorption and photoemission spectroscopy
T. Sugimoto, D. Ootsuki, E. Paris, A. Iadecola, M. Salome, E. F. Schwier, H. Iwasawa, K. Shimada, T. Asano, R. Higashinaka, T. D. Matsuda, Y. Aoki, N. L. Saini, T. Mizokawa
DOI 10.1103/PhysRevB.94.081106 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We have performed Ce L3-edge x-ray absorption spectroscopy (XAS) and Ce 4d−4f resonant photoemission spectroscopy (PES) on single crystals of CeO1−xFxBiS2 for x=0.0 and 0.5 in order to investigate the Ce 4f electronic states. In Ce L3-edge XAS, a mixed valence of Ce was found in the x=0.0 sample, and F doping suppressed it, which is consistent with the results on polycrystalline samples. As for resonant PES, we found that the Ce 4f electrons in both x=0.0 and 0.5 systems respectively formed a flat band at 1.0 and 1.4 eV below the Fermi level and there was no contribution to the Fermi surfaces. Interestingly, Ce valence in CeOBiS2 deviates from Ce3+ even though Ce 4f electrons are localized, indicating the Ce valence is not in a typical valence fluctuation regime. We assume that localized Ce 4f in CeOBiS2 is mixed with unoccupied Bi 6pz, which is consistent with a previous local structural study. Based on the analysis of the Ce L3-edge XAS spectra using Anderson's impurity model calculation, we found that the transfer integral becomes smaller, increasing the number of Ce 4f electrons upon the F substitution for O.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| CeOBiS2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| CeO0.5F0.5BiS2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Fermi surfaces and orbital polarization in superconducting CeO0.5F0.5BiS2 revealed by angle-resolved photoemission spectroscopy
similarity 0.96T. Sugimoto et al.
Source status unknown — claims are unverified
Localized and mixed valence state of Ce in superconducting and ferromagnetic CeOFBiS revealed by x-ray absorption and photoemission spectroscopy
similarity 0.94T. Sugimoto et al. · 2016 · arXiv:1604.01880
Source status unknown — claims are unverified
Role of the Ce valence in the coexistence of superconductivity and ferromagnetism of CeO1−xFxBiS2 revealed by Ce L3-edge x-ray absorption spectroscopy
similarity 0.93T. Sugimoto et al.
Source status unknown — claims are unverified
Superconducting gap symmetry of the BiS2-based superconductor LaO0.5F0.5BiSSe elucidated through specific heat measurements
similarity 0.91Naoki Kase et al.
Source status unknown — claims are unverified
Two-dimensional phase-fluctuating superconductivity in bulk crystalline NdO0.5F0.5BiS2
similarity 0.90C. S. Chen et al.
Source status unknown — claims are unverified
CeFePO: f−d Hybridization and Quenching of Superconductivity
similarity 0.90M. G. Holder et al.
Source status unknown — claims are unverified