中国物理B ›› 2013, Vol. 22 ›› Issue (8): 87415-087415.doi: 10.1088/1674-1056/22/8/087415

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

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

Interplay of superconductivity and d-f correlation in CeFeAs1-xPxO1-yFy

罗永康a, 李玉科a b, 王操a c, 林效a, 戴建辉a b, 曹光旱a, 许祝安a   

  1. a Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China;
    b Department of Physics, Hangzhou Normal University, Hangzhou 310036, China;
    c Department of Physics, School of Science, Shandong University of Technology, Zibo 255049, China
  • 收稿日期:2013-06-08 修回日期:2013-07-15 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CBA00103 and 2010CB923003) and the National Natural Science Foundation of China.

Interplay of superconductivity and d-f correlation in CeFeAs1-xPxO1-yFy

Luo Yong-Kang (罗永康)a, Li Yu-Ke (李玉科)a b, Wang Cao (王操)a c, Lin Xiao (林效)a, Dai Jian-Hui (戴建辉)a b, Cao Guang-Han (曹光旱)a, Xu Zhu-An (许祝安)a   

  1. a Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China;
    b Department of Physics, Hangzhou Normal University, Hangzhou 310036, China;
    c Department of Physics, School of Science, Shandong University of Technology, Zibo 255049, China
  • Received:2013-06-08 Revised:2013-07-15 Online:2013-06-27 Published:2013-06-27
  • Contact: Xu Zhu-An E-mail:zhuan@zju.edu.cn
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CBA00103 and 2010CB923003) and the National Natural Science Foundation of China.

摘要: The recent discovery of high-temperature superconductivity in iron-based pnictides (chalcogenides) not only triggers tremendous enthusiasm in searching for new superconducting materials, but also opens a new avenue to the study of the Kondo physics. CeFeAsO is a parent compound of the 1111-type iron-based superconductors. It shows 3d-antiferromagnetic (AFM) ordering below ~139 K and 4f-AFM ordering below ~4 K. On the other hand, the phosphide CeFePO is a ferromagnetically correlated heavy-fermion (HF) metal with Kondo scale TK~10 K. These properties set up a new platform for research of the interplay among magnetism, Kondo effect, and superconductivity (SC). In this review, we present the recent progress in the study of chemical pressure effect in CeFeAsO1-yFy (y=0 and 0.05). This P/As-doping in CeFeAsO serves as an effective controlling parameter which leads to two magnetic critical points, xc1≈0.4 and xc2≈0.92, associated with suppression of 3d and 4f magnetism, respectively. We also observe a turning point of AFM-FM ordering of Ce3+ moment at xc3≈0.37. The SC is absent in the phase diagram, which is attributed to the destruction to Cooper pair by Ce-FM fluctuations in the vicinity of xc1. We continue to investigate CeFeAs1-xPxO0.95F0.05. With the separation of xc1 and xc3, this chemical pressure results in a broad SC region 0≤x≤q 0.53, while the original HF behavior is driven away by 5% F- doping. Different roles of P and F dopings are addressed, and the interplay between SC and Ce-4f magnetism is also discussed.

关键词: superconductivity, iron-based pnictide, Kondo effect, heavy fermion, quantum critical point, chemical pressure effect

Abstract: The recent discovery of high-temperature superconductivity in iron-based pnictides (chalcogenides) not only triggers tremendous enthusiasm in searching for new superconducting materials, but also opens a new avenue to the study of the Kondo physics. CeFeAsO is a parent compound of the 1111-type iron-based superconductors. It shows 3d-antiferromagnetic (AFM) ordering below ~139 K and 4f-AFM ordering below ~4 K. On the other hand, the phosphide CeFePO is a ferromagnetically correlated heavy-fermion (HF) metal with Kondo scale TK~10 K. These properties set up a new platform for research of the interplay among magnetism, Kondo effect, and superconductivity (SC). In this review, we present the recent progress in the study of chemical pressure effect in CeFeAsO1-yFy (y=0 and 0.05). This P/As-doping in CeFeAsO serves as an effective controlling parameter which leads to two magnetic critical points, xc1≈0.4 and xc2≈0.92, associated with suppression of 3d and 4f magnetism, respectively. We also observe a turning point of AFM-FM ordering of Ce3+ moment at xc3≈0.37. The SC is absent in the phase diagram, which is attributed to the destruction to Cooper pair by Ce-FM fluctuations in the vicinity of xc1. We continue to investigate CeFeAs1-xPxO0.95F0.05. With the separation of xc1 and xc3, this chemical pressure results in a broad SC region 0≤x≤q 0.53, while the original HF behavior is driven away by 5% F- doping. Different roles of P and F dopings are addressed, and the interplay between SC and Ce-4f magnetism is also discussed.

Key words: superconductivity, iron-based pnictide, Kondo effect, heavy fermion, quantum critical point, chemical pressure effect

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.62.Fj (Effects of pressure) 74.40.Kb (Quantum critical phenomena) 75.20.Hr (Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions)