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.
| Original language | English |
|---|---|
| Article number | 081106 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 94 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2016 Aug 17 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Localized and mixed valence state of Ce 4f in superconducting and ferromagnetic CeO1-x FxBiS2 revealed by x-ray absorption and photoemission spectroscopy. / Sugimoto, T.; Ootsuki, D.; Paris, E.; Iadecola, A.; Salome, M.; Schwier, E. F.; Iwasawa, H.; Shimada, K.; Asano, T.; Higashinaka, R.; Matsuda, T. D.; Aoki, Y.; Saini, N. L.; Mizokawa, Takashi.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 94, No. 8, 081106, 17.08.2016.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Localized and mixed valence state of Ce 4f in superconducting and ferromagnetic CeO1-x FxBiS2 revealed by x-ray absorption and photoemission spectroscopy
AU - Sugimoto, T.
AU - Ootsuki, D.
AU - Paris, E.
AU - Iadecola, A.
AU - Salome, M.
AU - Schwier, E. F.
AU - Iwasawa, H.
AU - Shimada, K.
AU - Asano, T.
AU - Higashinaka, R.
AU - Matsuda, T. D.
AU - Aoki, Y.
AU - Saini, N. L.
AU - Mizokawa, Takashi
PY - 2016/8/17
Y1 - 2016/8/17
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevB.94.081106
DO - 10.1103/PhysRevB.94.081106
M3 - Article
AN - SCOPUS:84985990095
VL - 94
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 8
M1 - 081106
ER -