Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide
Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide
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DOI：
10.1038/s43246-020-00085-z
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发表时间：
2020-10
影响因子：
7.8
通讯作者：
M. Kamminga;M. Batuk;J. Hadermann;S. Clarke
中科院分区：
文献类型：
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作者：
M. Kamminga;M. Batuk;J. Hadermann;S. Clarke
拓扑超导电性是当代的一大兴趣，并已提出在掺杂的Bi 2Se 3，其中给电子原子，如Cu，Sr或Nb已插入到Bi 2Se 3结构中。对于Nb_xBi_2Se_3，在Tc ~ 3 K时，文献中假定Nb插入在货车德瓦耳斯能隙中。然而，在这项工作中，在Nb掺杂的Bi 2 Se 3的超导性的替代起源建立。与以前的报道相比，推断Nb在Bi_2Se_3中没有发生嵌入。相反，名义成分为NbxBi 2Se 3的样品中的超导行为是由（BiSe）1.10NbSe2失配相引起的，该相在小x（0.01 ≤x≤ 0.10）时作为杂质相存在于样品中，在大x（x= 0.50）时作为主相存在于样品中。使用X射线衍射和透射电子显微镜技术相结合，详细研究了这种失配相的结构。
Topological superconductivity is of great contemporary interest and has been proposed in doped Bi2Se3, in which electron-donating atoms such as Cu, Sr or Nb have been intercalated into the Bi2Se3structure. For NbxBi2Se3, withTc~ 3 K, it is assumed in the literature that Nb is inserted in the van der Waals gap. However, in this work an alternative origin for the superconductivity in Nb-doped Bi2Se3is established. In contrast to previous reports, it is deduced that Nb intercalation in Bi2Se3does not take place. Instead, the superconducting behaviour in samples of nominal composition NbxBi2Se3results from the (BiSe)1.10NbSe2misfit phase that is present in the sample as an impurity phase for smallx(0.01 ≤x≤ 0.10) and as a main phase for largex(x= 0.50). The structure of this misfit phase is studied in detail using a combination of X-ray diffraction and transmission electron microscopy techniques.