Effect of Heat Treatment on Transport Critical Current Densities in Ag-Clad Bi-Based Superconducting Tapes
Silver-clad Bi-based superconducting monocore tapes (BPSCCO) were fabricated by the conventional powder-in-tube method. The influence of heat-treatment conditions as well as mechanical treatments was studied. The dependence of J c on critical temperature, T c , transport critical current density, J c , orthogonal transport critical current density, J cn , and applied magnetic field, B, was measured under various conditions. After more than 150 h total sintering time, little of the low-Ta phase remained, and also, the value of 4 depended strongly on the total heat-treatment time. The contact surface resistivity, R c , was also measured to evaluate the quality of the interface between the Ag and the superconducting core. The uniformity of the superconducting tape along its 65-cm length was determined by short-interval voltage terminals (60 taps). The lack of uniformity in the long tape was due more to the mechanical deformation than to heat-treatment conditions.
KeywordsCritical Current Density Core Thickness Composite Tape Transport Critical Current Density Tape Surface
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