Electric Field-Current Characteristics of Ag Sheathed (Bi,Pb)(2)Sr2Ca2Cu3O10 (Bi-2223) Tapes.

Bi-2223 tapes have been investigated by transport and magnetization measurements. At high temperatures, where the critical current j(c) is governed by thermally activated motion of pancake vortices a good agreement was found between the j(c) obtained by transport and magnetization measurements. Characteristic changes in the electric field-current characteristics and the j(c)(B) dependence at low temperatures are interpreted in the framework of the 'brick wall' model by c axis weak links between the grains. The transport j(c) at low temperatures is limited by the critical Josephson current of weakly coupled grains for which we determined values between 3000 and 6000 A/cm(2). In the low temperature region the j(c) derived from magnetization loops is considerably lower than that of transport measurements.