Publication Date:
2012-03-01
Description:
Pressure has an essential role in the production and control of superconductivity in iron-based superconductors. Substitution of a large cation by a smaller rare-earth ion to simulate the pressure effect has raised the superconducting transition temperature T(c) to a record high of 55 K in these materials. In the same way as T(c) exhibits a bell-shaped curve of dependence on chemical doping, pressure-tuned T(c) typically drops monotonically after passing the optimal pressure. Here we report that in the superconducting iron chalcogenides, a second superconducting phase suddenly re-emerges above 11.5 GPa, after the T(c) drops from the first maximum of 32 K at 1 GPa. The T(c) of the re-emerging superconducting phase is considerably higher than the first maximum, reaching 48.0-48.7 K for Tl(0.6)Rb(0.4)Fe(1.67)Se(2), K(0.8)Fe(1.7)Se(2) and K(0.8)Fe(1.78)Se(2).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Liling -- Chen, Xiao-Jia -- Guo, Jing -- Gao, Peiwen -- Huang, Qing-Zhen -- Wang, Hangdong -- Fang, Minghu -- Chen, Xiaolong -- Chen, Genfu -- Wu, Qi -- Zhang, Chao -- Gu, Dachun -- Dong, Xiaoli -- Wang, Lin -- Yang, Ke -- Li, Aiguo -- Dai, Xi -- Mao, Ho-kwang -- Zhao, Zhongxian -- England -- Nature. 2012 Feb 22;483(7387):67-9. doi: 10.1038/nature10813.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22367543" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
