THE BI BASED SUPERCONDUCTORS DOPED WITH B2O3

The influence of the addition of B2O3 on the properties of the oxide c eramic materials Bi-Pb-Sr-Ca-Cu-O was investigated. The samples with n ominal composition BiaPbbBcSr2Ca2Cu3Ox (a = 0.8-1.6, b = 0.06-0.26, c = 0.05-1.0) were prepared and studied by the measurement of the temper ature dependence of the electrical resistivity and critical current de nsity. The addition of a small amount of B2O3(C = 0.05, a = 1.8, b = 0 .26) had positive influence on the critical current density. On the ot her hand, a high content of boron (c > 0.6, b = 0.26, a + b = 1.8) rev ersed the superconductor to an insulator. (C) 1997 Academic Press Limi ted.