Influence of microstructure on superconductivity in KxFe₂-ySe₂ and evidence for a new parent phase K₂Fe₇Se₈.
Influence of microstructure on superconductivity in KxFe₂-ySe₂ and evidence for a new parent phase K₂Fe₇Se₈.
复制标题
DOI：
10.1038/ncomms2913
复制
发表时间：
2013
影响因子：
16.6
通讯作者：
中科院分区：
文献类型：
--
作者：
铁基超导体的发现刺激了对新超导材料的探索，铁基超导体的结构和组成与铜酸盐有质的不同。对临界温度为32 K的KxFe 2 − ySe 2的研究变得更加困难，因为它分为两相-主要的反铁磁绝缘相K2 Fe 4Se 5和少数超导相，其精确结构尚不清楚。在这里，我们对在不同淬火工艺下制备的KxFe 2 − ySe 2晶体进行电学和磁化测量，扫描电子显微镜和微观分析，X射线衍射和扫描隧道显微镜，以更好地了解其微观结构与超导相之间的关系。我们确定了一个三维网络的超导细丝在这种材料和目前的证据表明，超导相由一个单一的Fe空位，每八个Fe-网站安排在一个108 x 1010的结构。 铁基超导体KxFe 2 − ySe 2的超导相结构很难确定，因为它与主要的绝缘相共存。丁等人确定了超导细丝，为超导性的母相结构提供了线索。
The search for new superconducting materials has been spurred on by the discovery of iron-based superconductors whose structure and composition is qualitatively different from the cuprates. The study of one such material, KxFe2−ySe2 with a critical temperature of 32 K, is made more difficult by the fact that it separates into two phases—a dominant antiferromagnetic insulating phase K2Fe4Se5, and a minority superconducting phase whose precise structure is as yet unclear. Here we perform electrical and magnetization measurements, scanning electron microscopy and microanalysis, X-ray diffraction and scanning tunnelling microscopy on KxFe2−ySe2 crystals prepared under different quenching processes to better understand the relationship between its microstructure and its superconducting phase. We identify a three-dimensional network of superconducting filaments within this material and present evidence to suggest that the superconducting phase consists of a single Fe vacancy for every eight Fe-sites arranged in a √8 x √10 parallelogram structure. The structure of the superconducting phase of iron-based superconductor KxFe2−ySe2 is difficult to determine because it coexists with an predominant insulating phase. Ding et al. identify the superconducting filaments that provide clues to the structure of the parent phase of superconductivity.
登录
查看更多内容
影响因子：
8.6
作者：
Li, Wei;Ding, Hao;Xue, Qi-Kun
通讯作者：
Xue, Qi-Kun
影响因子：
3.7
作者：
Guo, Jiangang;Jin, Shifeng;Chen, Xiaolong
通讯作者：
Chen, Xiaolong
空位有序硒化铁K0.5Fe1.75Se2的电子结构
影响因子：
3.7
作者：
Cao, Chao;Zhang, Fuchun
通讯作者：
Zhang, Fuchun
影响因子：
3.6
作者：
Speller, S. C.;Britton, T. B.;Grovenor, C. R. M.
通讯作者：
Grovenor, C. R. M.
影响因子：
8.6
作者：
Wang, Limin;Berlijn, Tom;Ku, Wei
通讯作者：
Ku, Wei