Inhomogeneous transport properties in Ag/Bi2223 tapes

Abstract

In order to elucidate the influence of weak link on the E– J characteristics in the silver sheathed Bi2223 tape, the weak link path model has been applied by using three different stochastic regimes. In general, the growth of non-SC chains proceeds at the low current density region and at the high current density region, the coagulation among non-SC chains takes place and the fast growth rate of percolation network is realized. Comparing three cases, the generating rate of the percolation path becomes lowest for the Markov process. When the correlation becomes stronger, the initial rate of generation of percolated columns becomes faster. The theoretical E– J curves can reproduce the experimental results qualitatively. It is clear that the power-law relationship, E∝ J n , does not hold over the whole range of current. The n value becomes smaller in sequence when the I c decreases for three cases.