Fabrication and transport properties in Bi2-xPbxSr2Ca2Cu3Oy monocore and multicore superconductors

Bi-2223 high Tc superconductors have been fabricated by the powder-in-tube technique to yield long lengths of flexible silver clad composites. Short samples sectioned from the long lengths were characterized by measuring their transport properties and evaluating their microstructure. The dc transport critical current densities measured on short monotape samples which were prepared using an optimum processing schedule were greater than 105 A/cm2 at zero field in liquid helium (4.2 K) and liquid hydrogen (20.2 K), and exceeded 3×104 A/cm2 at liquid nitrogen (77 K) temperature. Measurements with applied magnetic fields up to 20 Tesla on tape samples are also reported. Problems associated with fabricating long lengths of both the monotape and multifilament wire are discussed.