Magnetisation and Critical Currents in High Tc Powders

ABSTRACTMagnetisation curves have been measured on powders of various sizes. The hysteresis decreases with size for articles smaller than 20μ showing that barriers to current flow are at least this far apart. The current density is 6×106 amps/cm2 at 1.5T and this is consistent with theoretical calculations of Jc. Inductive transitions are consistent with a penetration depth of about 0.5μ at 78K. The results of Hot Isostatic Pressing are also discussed.