Ce 4f electronic states of CeO1-xFxBiS2 studied by soft x-ray photoemission spectroscopy
Ce 4f electronic states of CeO1-xFxBiS2 studied by soft x-ray photoemission spectroscopy
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DOI：
10.1103/physrevb.95.085109
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发表时间：
2017-02-07
影响因子：
3.7
通讯作者：
Yokoya, Takayoshi
中科院分区：
文献类型：
--
作者：
Wakita, Takanori;Terashima, Kensei;Yokoya, Takayoshi
利用软X射线光电子能谱（SXPES）研究了新型BiS 2层状超导体CeO 1-xFxBiS 2的多晶和单晶样品的Ce 4f电子态.标称组成x = 0.7的单晶的Ce 3d光谱不具有f（0）分量，并且光谱形状非常类似于对于Ce三价绝缘化合物观察到的光谱形状，强烈地暗示CeO层即使在F掺杂之后仍然处于绝缘状态。多晶和单晶样品的Ce 3d-4f共振SXPES表明，主峰位于费米能级（E-F）以下约1 eV处，EF处的光谱强度可忽略不计。单晶价带谱的F-浓度依赖性显示了能级简并度的增加以及Ce 4f和S 3 p态之间的相互作用。这些结果提供洞察CeO 1-xFx层的性质和微观共存的磁性和超导性CeO 1-xFxBiS 2。
We use soft x-ray photoemission spectroscopy (SXPES) to investigate Ce 4f electronic states of a new BiS2 layered superconductor CeO1-xFxBiS2, for polycrystalline and single-crystal samples. The Ce 3d spectrum of the single crystal of nominal composition x = 0.7 has no f(0) component and the spectral shape closely resembles the ones observed for Ce trivalent insulating compounds, strongly implying that the CeO layer is still in an insulating state even after the F doping. The Ce 3d-4f resonant SXPES for both polycrystalline and single-crystal samples shows that the prominent peak is located around 1 eV below the Fermi level (E-F) with negligible spectral intensity at EF. The F-concentration dependence of the valence band spectra for single crystals shows the increases of the degeneracy in energy levels and of the interaction between Ce 4f and S 3p states. These results give insight into the nature of the CeO1-xFx layer and the microscopic coexistence of magnetism and superconductivity in CeO1-xFxBiS2.