中国物理B ›› 2016, Vol. 25 ›› Issue (6): 67403-067403.doi: 10.1088/1674-1056/25/6/067403

所属专题: Virtual Special Topic — High temperature superconductivity

• SPECIAL TOPIC—Non-equilibrium phenomena in soft matters • 上一篇    下一篇

Superconductivity in Sm-doped CaFe2As2 single crystals

Dong-Yun Chen(陈东云), Bin-Bin Ruan(阮彬彬), Jia Yu(于佳), Qi Guo(郭琦), Xiao-Chuan Wang(王小川), Qing-Ge Mu(穆青隔), Bo-Jin Pan(潘伯津), Tong Liu(刘通), Gen-Fu Chen(陈根富), Zhi-An Ren(任治安)   

  1. 1 Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
  • 收稿日期:2016-04-22 修回日期:2016-04-26 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: Zhi-An Ren E-mail:renzhian@iphy.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11474339), the National Basic Research Program of China (Grant Nos. 2010CB923000 and 2011CBA00100), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB07020100).

Superconductivity in Sm-doped CaFe2As2 single crystals

Dong-Yun Chen(陈东云)1, Bin-Bin Ruan(阮彬彬)1, Jia Yu(于佳)1, Qi Guo(郭琦)1, Xiao-Chuan Wang(王小川)1, Qing-Ge Mu(穆青隔)1, Bo-Jin Pan(潘伯津)1, Tong Liu(刘通)1, Gen-Fu Chen(陈根富)1, 2, Zhi-An Ren(任治安)1,2   

  1. 1 Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
  • Received:2016-04-22 Revised:2016-04-26 Online:2016-06-05 Published:2016-06-05
  • Contact: Zhi-An Ren E-mail:renzhian@iphy.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11474339), the National Basic Research Program of China (Grant Nos. 2010CB923000 and 2011CBA00100), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB07020100).

摘要:

In this article, the Sm-doping single crystals Ca1-xSmxFe2As2 (x=0~0.2) were prepared by the CaAs flux method, and followed by a rapid quenching treatment after the high temperature growth. The samples were characterized by structural, resistive, and magnetic measurements. The successful Sm-substitution was revealed by the reduction of the lattice parameter c, due to the smaller ionic radius of Sm3+ than Ca2+. Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping. The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples. Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x >0.10. The doping dependences of the c-axis length and onset Tc were summarized. The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.

关键词: superconductivity, Sm-doping, CaFe2As2, collapsed structure

Abstract:

In this article, the Sm-doping single crystals Ca1-xSmxFe2As2 (x=0~0.2) were prepared by the CaAs flux method, and followed by a rapid quenching treatment after the high temperature growth. The samples were characterized by structural, resistive, and magnetic measurements. The successful Sm-substitution was revealed by the reduction of the lattice parameter c, due to the smaller ionic radius of Sm3+ than Ca2+. Superconductivity was observed in all samples with onset Tc varying from 27 K to 44 K upon Sm-doping. The coexistence of a collapsed phase transition and the superconducting transition was found for the lower Sm-doping samples. Zero resistivity and substantial superconducting volume fraction only happen in higher Sm-doping crystals with the nominal x >0.10. The doping dependences of the c-axis length and onset Tc were summarized. The high-Tc observed in these quenched crystals may be attributed to simultaneous tuning of electron carriers doping and strain effect caused by lattice reduction of Sm-substitution.

Key words: superconductivity, Sm-doping, CaFe2As2, collapsed structure

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.70.-b (Superconducting materials other than cuprates) 74.72.Ek (Electron-doped)