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).

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 Hc and Hc. 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 Hc and Hc 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 Hc than for Hc 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 Hc and Hc. 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 Hc and Hc 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 Hc than for Hc 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)