Title :
Current-voltage characteristics of melt-textured YBCO obtained from the field-sweep rate dependence of magnetization
Author :
Yamasaki, H. ; Mawatari, Y.
Author_Institution :
Electrotech. Lab., Ibaraki, Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
We investigated current-voltage (I-V) characteristics in melt-textured YBCO sheets by measuring the field-sweep rate /spl beta/ dependence of magnetization M. We used a previously developed method that corrects for the current density distribution in the specimen [Y. Mawatari et al., Appl. Phys. Lett., vol. 70, 2300 (1997)]. For a wide temperature and field range (60-80 K, 0.2-5.0 T) the I-V curves followed a power-law behavior that often has been observed in high-T/sub c/ superconductors. We also investigated the relaxation of magnetization, flux creep. The time dependence of M also followed a power-law behavior, which was as expected because of the power-law I-V characteristics.
Keywords :
barium compounds; critical current density (superconductivity); flux creep; high-temperature superconductors; magnetic relaxation; magnetisation; yttrium compounds; 0.2 to 5.0 T; 60 to 80 K; I-V characteristics; YBa/sub 2/Cu/sub 3/O/sub 7/; current density distribution; current-voltage characteristics; field-sweep rate /spl beta/ dependence; field-sweep rate dependence; flux creep; high-T/sub c/ superconductors; magnetization; melt-textured YBCO; power-law I-V characteristics; power-law behavior; relaxation; time dependence; Creep; Current density; Current measurement; Current-voltage characteristics; Density measurement; Magnetic field measurement; Magnetization; Superconductivity; Temperature distribution; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
