INFLUENCE OF THE COLD DEFORMATION PROCEDURES ON THE CRITICAL-CURRENT DISTRIBUTION IN AG-(BI,PB)2SR2CA2CU3OX TAPES

Dramatic differences are reported between the transversal and longitudinal in-plane transport critical current of the Ag-(Bi,Pb)2Sr2Ca2Cu3Ox tape form conductor for longitudinally rolled, uniaxially pressed, and transversely rolled tapes. An explanation is given of the physical origin of such differences based on the observation of modulations of the superconducting core coinciding with microcracks in the Ag-(Bi,Pb)2Sr2Ca2Cu3Ox tape form conductor. The data presented provide an explanation of why, when considering the critical current of conductors, combination of (a) pressing with conventional longitudinal rolling and (b) transversal rolling with conventional longitudinal rolling give superior results compared to conventional rolling alone.