Bi-2223/Ag tapes prepared by high temperature sintering

Heat treatments of Bi-2223/Ag tapes were performed through the continuous cooling sintering (CCS) method, by which the tapes are heated to high temperatures above the 2223 single-phase region, then cooled with a slow rate. The results indicated that the tapes prepared at higher temperature exhibit higher grain packing density and less porosity than those prepared at lower temperatures. As a result, the critical current density is improved. On the other hand, the tapes sintered at high temperatures contain more Pb-rich phases than those sintered at low temperatures. This drawback may be solved by controlling overall Pb concentration in precursor powders.