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

作　　者：花涛 许伟伟 吉争鸣 郭大元 王青云 马湘蓉 梁瑞宇 

机构地区：[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

出　　处：《Chinese Physics B》2016年第6期500-503,共4页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.61501222,61371036,and 61571219);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.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 

分 类 号：O511.3[一般工业技术—材料科学与工程]