中国物理B ›› 2014, Vol. 23 ›› Issue (12): 127402-127402.doi: 10.1088/1674-1056/23/12/127402

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Magneto-resistance and vortex phase diagram of BaNi0.1Fe1.9As2 single crystal

鲁俊超a, 于一b, 皮雳c, 张裕恒c   

  1. a College of Science, Henan University of Technology, Zhengzhou 450001, China;
    b School of Physics and Material Science, Anhui University, Hefei 230601, China;
    c High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2014-04-23 修回日期:2014-06-12 出版日期:2014-12-15 发布日期:2014-12-15
  • 基金资助:

    Project supported by the Foundation of Henan Educational Committee, China (Grant No. 13B140951) and the Foundation of Henan University of Technology, China (Grant Nos. 11JCYJ15 and 2011BS030).

Magneto-resistance and vortex phase diagram of BaNi0.1Fe1.9As2 single crystal

Lu Jun-Chao (鲁俊超)a, Yu Yi (于一)b, Pi Li (皮雳)c, Zhang Yu-Heng (张裕恒)c   

  1. a College of Science, Henan University of Technology, Zhengzhou 450001, China;
    b School of Physics and Material Science, Anhui University, Hefei 230601, China;
    c High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei 230026, China
  • Received:2014-04-23 Revised:2014-06-12 Online:2014-12-15 Published:2014-12-15
  • Contact: Lu Jun-Chao E-mail:jchlu@mail.ustc.edu.cn
  • Supported by:

    Project supported by the Foundation of Henan Educational Committee, China (Grant No. 13B140951) and the Foundation of Henan University of Technology, China (Grant Nos. 11JCYJ15 and 2011BS030).

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摘要：

The transition from vortex glass to a liquid phase is studied in BaNi0.1Fe1.9As2 single crystal with Tc=19.4 K by magneto-resistance measurements. The resistivity curves are measured in magnetic fields in a range of 0 T–13 T for H‖c and H⊥c. Good scalings for all values of resistivity ρ(H,T) and the effective pinning potential U0(H,T) are obtained with the modified vortex glass theory by using the critical exponents s and H0. Phase diagrams for H‖c and H⊥c are determined based on the obtained vortex glass temperature Tg, the vortex dimensionality crossover temperature T*, and the upper critical magnetic field Hc2. Our results suggest that both below and above 5 T, single vortex pinning co-exists with collective creep, and collective creep is dominant. There is a narrower vortex liquid region for H⊥c than for H‖c in the vortex phase diagram, which may originate from a stronger pinning force.

关键词: Fe-based superconductor, magneto-resistance, pinning, phase transition

Abstract:

The transition from vortex glass to a liquid phase is studied in BaNi0.1Fe1.9As2 single crystal with Tc=19.4 K by magneto-resistance measurements. The resistivity curves are measured in magnetic fields in a range of 0 T–13 T for H‖c and H⊥c. Good scalings for all values of resistivity ρ(H,T) and the effective pinning potential U0(H,T) are obtained with the modified vortex glass theory by using the critical exponents s and H0. Phase diagrams for H‖c and H⊥c are determined based on the obtained vortex glass temperature Tg, the vortex dimensionality crossover temperature T*, and the upper critical magnetic field Hc2. Our results suggest that both below and above 5 T, single vortex pinning co-exists with collective creep, and collective creep is dominant. There is a narrower vortex liquid region for H⊥c than for H‖c in the vortex phase diagram, which may originate from a stronger pinning force.

Key words: Fe-based superconductor, magneto-resistance, pinning, phase transition

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.25.Uv (Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses)) 74.25.Op (Mixed states, critical fields, and surface sheaths)