Element Substitution Effect on Superconductivity in BiS2-Based NdO1-xFxBiS2
Element Substitution Effect on Superconductivity in BiS2-Based NdO1-xFxBiS2
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元素替代对 BiS2 基 NdO1-xFxBiS2 超导性的影响
DOI：
10.1007/s10948-014-2852-1
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Yoshikazu Mizuguchi
中科院分区：
文献类型：
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作者：
Takafumi Hiroi;Joe Kajitani;Atsushi Omachi;Osuke Miura;Yoshikazu Mizuguchi
最近，已经发现了具有BiS 2型导电层的新的层状超导体。NdO 1 − xFxBiS 2是一种典型的BiS 2基超导体，最大Tc为5.4 K。在这项研究中，在BiS 2基NdO0.5F0.5BiS2超导层内的元素替代的效果进行了研究。采用两步固相反应法系统地合成了NdO0.5F0.5Bi（S1−xSex）2和NdO0.5F0.5Bi1− ySbyS 2两种多晶样品。用X射线衍射分析了相纯度和晶格常数的变化。通过磁化率和电阻率测量研究了其超导性能。结果表明，Se部分取代S导致了晶格沿着a轴的单轴膨胀。超导转变温度随着NdO0.5F0.5Bi（S1−xSex）2中Se浓度的增加而逐渐降低。当Sb部分取代Bi时，在NdO 0.5F 0.5Bi 1 − ySbyS 2中观察到沿轴向沿着的单轴晶格收缩。在Sb取代的系统中，观察到的金属-绝缘体的转变，随着Sb浓度的增加。
Recently, new layered superconductors having a BiS2-type conduction layer have been discovered. NdO1−xFxBiS2is a typical BiS2-based superconductor with a maximumTcof 5.4 K. In this study, the effect of element substitution within the superconducting layer of BiS2-based NdO0.5F0.5BiS2was investigated. We systematically synthesized two kinds of polycrystalline samples of NdO0.5F0.5Bi(S1−xSex)2and NdO0.5F0.5Bi1−ySbyS2by a two-step solid-state reaction method. The phase purity and the changes in lattice constants were investigated by X-ray diffraction. The superconducting properties were investigated by magnetic susceptibility and electrical resistivity measurements. It was found that the partial substitution of S by Se resulted in the uniaxial lattice expansion along thea-axis. The superconducting transition temperature were gradually degraded with increasing Se concentration in NdO0.5F0.5Bi(S1−xSex)2. When Bi was partially substituted by Sb, the uniaxial lattice contraction along thec-axis was observed in NdO0.5F0.5Bi1−ySbyS2. In the Sb-substituted system, a metal-insulator transition was observed with increasing Sb concentration.