Critical currents in polycrystalline (Bi,Pb)(2)Sr2Ca2Cu3O10 systems: a comparative magnetisation study.

We report on the quasi DC magnetisation of various polycrystalline (Bi,Pb)(2)Sr2C2Cu3O10 systems. Using a vibrating sample magnetometer the magnetic response of PIT tapes, hot rolled bars and sintered pellets was measured as a function of temperature and electric field. Comparing measurements on both bulk and powdered samples, we can distinguish between the inter-and intra-granular contribution to the magnetisation. Differences and similarities in the extracted critical current density and magnetic relaxation rate of these systems are discussed in terms of grain-to-grain connectivity and intra-granular pinning properties.