Weak flux pinning at grain boundaries in Ag sheathed Ba2YCu3O6+xtapes

摘要

This letter is concerned with the mechanism controlling the transport critical current measured at 4.2 K. The current densities increased with decreasing the oxide layer thickness of Ag sheathed tapes and reached 1010 A/cm2at 15 T for the tape with a 15hyphen;mgr;mhyphen;thick layer. The magnetic field dependence of critical current density in the region between 0.5 and 15 T can be explained in terms of a modified model of the theory by E. J. Kramer lsqb;J. Appl. Phys.44, 1360 (1973)rsqb;, based on the weak flux pinning along grain boundaries.