Effect of barrier configuration on the superconducting properties of Bi2223 multifilamentary tapes with Sr-V-O oxide barriers

We prepared Ag-sheathed Bi2223 multifilamentary tapes having 19 filaments w ith three different barrier configurations by using the powder-in-tube meth od. The layers of Sr-V-O (SVO) barrier are arranged inside and/or outside o f each filament. For the tapes with barriers the transport critical current Ic and its density Jc at 77K are higher than those of the non-barrier tape s for all the barrier configurations. This can be due to the reduction in o xygen partial pressure during the heat-treatment and the enhancement of Bi2 223 phase formation by the reaction of the inside-coated SVO with a Bi-base d oxide core in the inside-barrier tapes. Furthermore, for an the barrier t apes the transport sc. losses at 77K in self field are lower than those of the non-barrier tapes. This results suggest that SVO will be one of the mos t important candidates for resistive barrier with the view of the a.c. appl ications. In particular, due inside-barrier tapes give us an excellent poss ibility to improve the overall Jc and ease the fabrication of tape. For the tapes, however, SrCO3 contaminated in the process of SVO preparation must be eliminated