The Irreversibility Lines Of Silver-Sheathed Bi2223 Superconducting Tapes

A study of the irreversibility lines of a silver-sheathed Bi2223 superconducting tape with a critical temperature of 108 K is presented for H parallel-to c and H perpendicular-to c. The irreversibility lines can be fitted to an exponential form and appear at higher temperature in comparison with those of sintered polycrystalline Bi2223. The irreversibility line of this material depends on flux pinning properties. The reversible magnetization increases linearly with temperature from irreversibility temperature T* to T(c) and can be described by Abrikosov's theory for classical type-II superconductors.