TEMPERATURE-DEPENDENT CRITICAL CURRENT-DENSITY OF BI(PB)-SR-CA-CU-O TAPES IN FIELDS UP TO 20 TESLA

The transport critical current density (J(c)) of silver-sheathed polycrystalline Bi(Pb)-Sr-Ca-Cu-O (BPSCCO) tapes has been measured at approximately 10 K intervals from 4.2 K up to 77 K in fields of 1-20 T. The tapes produced by swaging, drawing, and multiple final pressing and sintering steps, which developed a preferred orientation of the basal planes of the predominantly 2223 BPSCCO phase within the tape. J(c) values greater than 10(4) A cm-2 at 4.2 K were obtained, and these decreased smoothly as the field and temperature were increased. No evidence of any catastrophic change in J(c)(H) was seen at any temperature, thus suggesting that flux line lattice melting is not controlling the J(c) of these tapes.