Magnetic responses of a high-T-c semi-reversible YBCO superconductor

We report the magnetic responses of a YBCO superconducting sample prepared by solid-state reaction method, in terms of d.c. magnetization, and a.c. su sceptibility. Hysteresis loops have been analyzed in the framework of criti cal state model including the Meissner current. The critical current as a f unction of temperature and the volume fraction of the grains have been esti mated from the a.c. susceptibility data. The zero resistance temperature an d diamagnetic onset temperature were found to be 90 and 91.5 K respectively . (C) 1999 Elsevier Science S.A. All rights reserved.