Effects of initial, intermediate and final sinterings in preparation of Ag-sheathed Bi-2223 tapes

Effects of initial, intermediate and final sintering on superconducting properties, morphology, and critical current density, J/sub c/, were studied in Ag-sheathed Bi(Pb)-Sr-Ca-Cu-O tapes prepared using the powder-in-tube method and repetitions of a combined process of pressing and sintering. The variables in the repetitive process were a history by which the calcined constituent powders were heat treated before filled into Ag-tubes, and duration periods of the intermediate and final sinterings. The effects are discussed in terms of conversion of 2212 phase to 2223 and vice versa, the formation mechanism of 2223 phase, and alignment and connection of the 2223 grains. In the present study, a J/sub c/ on the order to 10/sup 4/ A/cm/sup 2/ at 77 K and 0 T was obtained.<>