Comparison of irreversibility lines of silver-sheathed Bi-2223, Tl-1223 and Tl-1234 superconducting tapes

Abstract

The irreversibility lines of silver-sheathed (Bi,Pb)(2)Sr2Ca2Cu3O10 (Bi-2223), (Tl,Pb,Bi)(Sr,Ba)(2)Ca2Cu2O9 (T1-1223) and (Tl,Pb)Sr2Ca3Cu4O11 (T1-1234) superconducting tapes were investigated and compared with those of other superconducting systems. We have demonstrated that the shape of the irreversibility lines of T1-1223 and T1-1234 superconducting tapes are similar in behavior to those of YBa2Cu3O7 (Y-123) and (Tl,Pb)Sr-2(Ca,Y)Cu2O7 (T1-1212) systems and better than those of Tl2Ba2Ca2Cu3O10 (T1-2223) and (Bi,Pb)(2)Sr2Ca2Cu5O10 (Bi-2223) superconductors. This means that the flux pinning ability of T1-1223 and T1-1234 superconducting tapes was stronger than that of Bi-2223 and T1-2223 superconductors. The possible reason for controlling flux pinning can be attributed to the intrinsic crystal structure difference in the materials.