Transport critical current density JcJ is investigated as a function of the external magnetic field perpendicular to a sample surface, and the trapped magnetic field and magnetization in a remanent state after removal of external field are also investigated at 77K on screen-printed Ag-Bi2223 composite tape. The hysteresis behavior in JcJ between increasing and decreasing fields is observed in a zero-field-cooled sample and explained by the influence of trapped magnetic flux in the grains on intergranular (transport) current. Such hysteresis in JcJ causes decreases in the trapped field and in magnetization with increasing Bex, defined as the maximum field in a field loop for measuring JcJ values. The experimental results give the full flux penetration field Bp for the grains to be nearly equal to 9mT. The use of a critical state model and the value of Bp=9mT results in the intragranular critical current density JcG being-5, 000A/mm2, which is about 50 times higher than the transport critical current density (-85A/mm2 at 77K and self-field) of the sample. The study shows that strong pinning in the grains does not lead to a high transport critical current density unless further improvements for grain connectivity are made.
