THE EFFECT OF INITIAL PACKING DENSITY OF THE OPIT METHOD ON THE PHASE-FORMATION, ELECTRICAL-TRANSPORT AND MECHANICAL-PROPERTIES OF BI-(PB)-SR-CA-CU-O MONOCORE SUPERCONDUCTING TAPES

This paper presents the effect of powder density by various means during the oxide-powder-in-tube (OPIT) method on the critical current density, mechanical properties and high-T-c phase formation in Bi(Pb)-2223 monocore superconducting tapes. A higher initial packing density of OPIT monocore short tapes was found to give higher J(c) values as well as a higher rate of the high-T-c phase formation, while lower initial packing density samples gave better mechanical performance. Critical strains for bend tests show a dependence on the core thickness and the silver/oxide volume ratio.