Torque measurements of textured Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ sintered pellets

The authors present at 4.2 K magnetic torque balance study of a textured sintered YBCO sample produced by pyrolysis using in the thermal treatments an ozone-enriched oxygen atmosphere. The shape of the torque signal as a function of the angle and of the measuring field shows features that are intermediate between those of a standard sintered pellet and those of a single crystal. The anisotropic experimental values of the lower critical field H/sub c1/ compare rather well to those previously found on YBCO single crystals. The intensity of the remaining magnetization, measured after a field cycling procedure, suggests the existence of a strong pinning for H>or=H/sub c1//sup (c)/ along the c-axis. >