中国物理B ›› 2016, Vol. 25 ›› Issue (6): 67401-067401.doi: 10.1088/1674-1056/25/6/067401

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

Critical current density behaviors across a grain boundary inclined to current with different angles in YBa2Cu3O7-δ bicrystal junctions

Tao Hua(花涛), Wei-Wei Xu(许伟伟), Zheng-Ming Ji(吉争鸣), Da-Yuan Guo(郭大元), Qing-Yun Wang(王青云), Xiang-Rong Ma(马湘蓉), Rui-Yu Liang(梁瑞宇)   

  1. 1 School of Communication Engineering, Nanjing Institute of Technology, Nanjing 211167, China;
    2 Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
  • 收稿日期:2015-10-31 修回日期:2016-02-01 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: Tao Hua E-mail:huataonju@163.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61501222, 61371036, and 61571219) and the School Scientific Research Fund of Nanjing Institute of Technology, China (Grant Nos. YKJ201418).

Critical current density behaviors across a grain boundary inclined to current with different angles in YBa2Cu3O7-δ bicrystal junctions

Tao Hua(花涛)1,2, Wei-Wei Xu(许伟伟)2, Zheng-Ming Ji(吉争鸣)2, Da-Yuan Guo(郭大元)2, Qing-Yun Wang(王青云)1, Xiang-Rong Ma(马湘蓉)1, Rui-Yu Liang(梁瑞宇)1   

  1. 1 School of Communication Engineering, Nanjing Institute of Technology, Nanjing 211167, China;
    2 Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
  • Received:2015-10-31 Revised:2016-02-01 Online:2016-06-05 Published:2016-06-05
  • Contact: Tao Hua E-mail:huataonju@163.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 61501222, 61371036, and 61571219) and the School Scientific Research Fund of Nanjing Institute of Technology, China (Grant Nos. YKJ201418).

摘要:

The critical current density behaviors across a bicrystal grain boundary (GB) inclined to the current direction with different angles in YBa2Cu3O7-δ bicrystal junctions in magnetic fields are investigated. There are two main reasons for the difference in critical current density in junctions at different GB inclined angles in the same magnetic field: (i) the GB plane area determines the current carrying cross section; (ii) the vortex motion dynamics at the GB affects the critical current value when the vortex starts to move along the GB by Lorentz force. Furthermore, the vortex motion in a bicrystal GB is studied by investigating transverse (Hall) and longitudinal current-voltage characteristics (I-Vxx and I-Vxy). It is found that the I-Vxx curve diverges from linearity at a high driving current, while the I-Vxy curve keeps nearly linear, which indicates the vortices inside the GB break out of the GB by Lorentz force.

关键词: grain boundary, bicrystal Josephson junction, inclined angle, high temperature superconductor

Abstract:

The critical current density behaviors across a bicrystal grain boundary (GB) inclined to the current direction with different angles in YBa2Cu3O7-δ bicrystal junctions in magnetic fields are investigated. There are two main reasons for the difference in critical current density in junctions at different GB inclined angles in the same magnetic field: (i) the GB plane area determines the current carrying cross section; (ii) the vortex motion dynamics at the GB affects the critical current value when the vortex starts to move along the GB by Lorentz force. Furthermore, the vortex motion in a bicrystal GB is studied by investigating transverse (Hall) and longitudinal current-voltage characteristics (I-Vxx and I-Vxy). It is found that the I-Vxx curve diverges from linearity at a high driving current, while the I-Vxy curve keeps nearly linear, which indicates the vortices inside the GB break out of the GB by Lorentz force.

Key words: grain boundary, bicrystal Josephson junction, inclined angle, high temperature superconductor

中图分类号:  (Transport properties)

  • 74.25.F-
74.62.Dh (Effects of crystal defects, doping and substitution) 74.25.Sv (Critical currents)