FORMATION AND STABILITY OF THE 2223 PHASE IN HIGH-JC AG-SHEATHED (BI,PB)2SR2CA2CU3O10+DELTA TAPES

Powder XRD, electron microscopy and critical current measurements at 77 K were used to study phase composition, microstructure and transport properties on selected Ag-sheathed (Bi, Pb)-Sr-Ca-Cu 2223 phase-rich tapes. The selected composite tapes were put through one or several mechanical plastic deformation processes, followed by varying thermal annealing treatment cycles. The formation of 2223 and 2212 phases and the development of texture were studied after each processing cycle, concentrating on the effects arising from the sintering conditions. These included temperature, duration, the number of cycles and the cooling rate.