中国物理B ›› 2013, Vol. 22 ›› Issue (8): 87412-087412.doi: 10.1088/1674-1056/22/8/087412

所属专题: TOPICAL REVIEW — Iron-based high temperature superconductors

• TOPICAL REVIEW—Iron-based high temperature superconductors • 上一篇    下一篇

Exploring FeSe-based superconductors by liquid ammonia method

应天平, 王刚, 金士锋, 申士杰, 张韩, 周婷婷, 赖晓芳, 王皖燕, 陈小龙   

  1. Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2013-06-08 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 90922037, 51072226, and 51202286), the Chinese Academy of Sciences, the International Center for Diffraction Data (ICDD), and the Beijing Nova Program, China (Grant No. 2011096).

Exploring FeSe-based superconductors by liquid ammonia method

Ying Tian-Ping (应天平), Wang Gang (王刚), Jin Shi-Feng (金士锋), Shen Shi-Jie (申士杰), Zhang Han (张韩), Zhou Ting-Ting (周婷婷), Lai Xiao-Fang (赖晓芳), Wang Wan-Yan (王皖燕), Chen Xiao-Long (陈小龙)   

  1. Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2013-06-08 Online:2013-06-27 Published:2013-06-27
  • Contact: Chen Xiao-Long E-mail:chenx29@iphy.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 90922037, 51072226, and 51202286), the Chinese Academy of Sciences, the International Center for Diffraction Data (ICDD), and the Beijing Nova Program, China (Grant No. 2011096).

摘要: Our recent progress on the preparation of a series of new FeSe-based superconductors and the clarification of SC phases in potassium-intercalated iron selenides are reviewed here. By the liquid ammonia method, metals Li, Na, Ca, Sr, Ba, Eu, and Yb are intercalated in between FeSe layers and form superconductors with transition temperatures of 30 K~46 K, which cannot be obtained by high-temperature routes. In the potassium-intercalated iron selenides, we demonstrate that at least two SC phases exist, KxFe2Se2(NH3)y (x ≈ 0.3 and 0.6), determined mainly by the concentration of potassium. NH3 has little, if any, effect on superconductivity, but plays an important role in stabilizing the structures. All these results provide a new starting point for studying the intrinsic properties of this family of superconductors, especially for their particular electronic structures.

关键词: superconductivity, iron-based superconductor, liquid ammonia, critical temperature

Abstract: Our recent progress on the preparation of a series of new FeSe-based superconductors and the clarification of SC phases in potassium-intercalated iron selenides are reviewed here. By the liquid ammonia method, metals Li, Na, Ca, Sr, Ba, Eu, and Yb are intercalated in between FeSe layers and form superconductors with transition temperatures of 30 K~46 K, which cannot be obtained by high-temperature routes. In the potassium-intercalated iron selenides, we demonstrate that at least two SC phases exist, KxFe2Se2(NH3)y (x ≈ 0.3 and 0.6), determined mainly by the concentration of potassium. NH3 has little, if any, effect on superconductivity, but plays an important role in stabilizing the structures. All these results provide a new starting point for studying the intrinsic properties of this family of superconductors, especially for their particular electronic structures.

Key words: superconductivity, iron-based superconductor, liquid ammonia, critical temperature

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.25.-q (Properties of superconductors) 74.62.Bf (Effects of material synthesis, crystal structure, and chemical composition) 74.25.Dw (Superconductivity phase diagrams)