Center of Advanced Functional Ceramics, College of Science, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu 210023, China.
Department of Physics, Zhejiang University, Hangzhou 310027, China.
Sci Rep. 2016 Nov 22;6:37394. doi: 10.1038/srep37394.
Superconductivity within layered crystal structures has attracted sustained interest among condensed matter community, primarily due to their exotic superconducting properties. EuBiSF is a newly discovered member in the BiS-based superconducting family, which shows superconductivity at 0.3 K without extrinsic doping. With 50 at.% Ce substitution for Eu, superconductivity is enhanced with Tc increased up to 2.2 K. However, the mechanisms for the T enhancement have not yet been elucidated. In this study, the Ce-doping effect on the self-electron-doped superconductor EuBiSF was investigated by X-ray absorption spectroscopy (XAS). We have established a relationship between Ce-doping and the T enhancement in terms of Eu valence changes and nanoscale atomic displacements. The new finding sheds light on the interplay among superconductivity, charge and local structure in BiS-based superconductors.
层状晶体结构中的超导性引起了凝聚态物质领域的持续关注，主要是因为它们具有奇特的超导性质。EuBiSF 是 BiS 基超导家族中最新发现的成员，在没有外部掺杂的情况下，它在 0.3K 时表现出超导性。用 50at.%Ce 取代 Eu 后，超导性增强，Tc 提高到 2.2K。然而，Tc 增强的机制尚未阐明。在这项研究中，通过 X 射线吸收光谱（XAS）研究了 Ce 掺杂对自电子掺杂超导体 EuBiSF 的影响。我们已经建立了 Ce 掺杂与 Eu 价态变化和纳米级原子位移之间的关系，这与 Tc 增强有关。这一新发现揭示了 BiS 基超导体中超导性、电荷和局部结构之间的相互作用。
