Title :
E-J characteristics and n value of melt-textured REBa2Cu3Ox (RE: Nd, Y)
Author :
Inoue, Kazuo ; Sakai, Naomichi ; Murakami, Masato
Author_Institution :
Int. Supercond. Technol. Center, Supercond. Res. Lab., Tokyo, Japan
fDate :
6/1/2003 12:00:00 AM
Abstract :
Melt-textured NdBa2Cu3Ox (Nd123) exhibits the secondary peak effect on the magnetic field dependence of the critical current density (Jc), which is attributed to the field-induced pinning. The electric field (E)-the current density (J) characteristics will be affected by the field-induced pinning. With the aim of clarifying this effect, we have investigated the E-J characteristics for melt-textured Nd123 with the secondary peak and YBa2Cu3Ox (Y123) with smaller secondary peak through dc magnetization and ac susceptibility. The n value was estimated on the assumption that E follows the power law: E=Ec(J/Jc)n. The n value was about 30 at 77 K for Y123. In the case of Nd123, the peak structure was observed on the magnetic field dependence of the n value, which exceeded 60 at 77 K. This suggests that the n value is increased by the field-induced pinning.
Keywords :
barium compounds; critical current density (superconductivity); flux pinning; high-temperature superconductors; magnetic susceptibility; magnetisation; neodymium compounds; yttrium compounds; 77 K; E-J characteristics; Nd123; NdBa2Cu3O; Y123; YBa2Cu3O; ac susceptibility; critical current density; dc magnetization; field-induced pinning; magnetic field dependence; melt-textured REBa2Cu3Ox; secondary peak effect; Atmosphere; Critical current density; Current density; High temperature superconductors; Magnetic field measurement; Magnetic fields; Magnetic susceptibility; Magnetization; Neodymium; Superconductivity;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812116
