Effect of lead oxide compounds on microstructure and critical current density of (Bi,Pb)-2223/Ag tapes

Abstract

The effect of lead oxide compounds on microstructure and critical current density of (Bi,Pb)-2223/Ag tapes has been investigated. Precursor powders containing different types of lead-rich phases were prepared by controlling the calcination temperature and atmosphere. Monofilament (Bi,Pb)-2223/Ag tapes were fabricated using these powders. Experimental results show that both the microstructure and critical current density depended strongly on the nature of the lead oxide compounds. The lead-rich phases in precursor powders played an important role on the formation of the (Bi,Pb)-2223 phase, the microstructure and critical current of Bi-2223/Ag tapes. The Ca2PbO4 and Pb3(Sr,Bi)3Ca2CuOy (3321) phases had different influences on the formation of (Bi,Pb)-2223 phase. Therefore, the critical currents of Bi-2223/Ag tapes containing different lead oxide compounds were various.