Properties of resistive- and superconducting-joints in Bi-Pb-Sr-Ca-Cu-O tape

We evaluated the electrical properties of BSCCO jointed tapes processed by both resistive- and superconducting-joint methods. For resistive-joints, filler materials of wood's metal, Pb-Sn, In and silver paste were used, whereas, for superconducting-joints, the lap joint method was used. In the resistive-joint tape, critical transport property, n-value, and contact resistance were observed to be in the range of 10% to 77%, 1.0 to 8.9, and 0.71×10^-6 to 0.13×10^-6 Ω, respectively, depending on the filler materials used. The electrical properties of resistive-joint tape seemed to be significantly related to the resistivity of the filler materials. On the other hand, the critical transport property of superconducting-joint tape varied from 55% to 85% with uniaxial pressure. The contact resistance for the superconducting-joint tape was obtained to be 1.74×10^-12 Ω by measuring field decay from the closed superconducting loop. Higher critical transport property and lower contact resistance for the superconducting-jointed tapes seemed to be a result of the direct connection between superconducting cores.