Effect of mechanical grinding on the transport critical current density and the flux pinning force of a YBa sub 2 Cu sub 3 O sub y -Ag composite superconductor

The effect of mechanical grinding (MG) on the physical properties, especially the transport critical current density J sub c and the global pinning force F sub p , of a YBa sub 2 Cu sub 3 O sub y -Ag composite superconductor was examined. J sub c and F sub p increase with the addition of Ag. J sub c of the samples not exposed to MG treatment (no-MG-sample) shows a maximum value at about 4 wt.% Ag, while that of the samples which are exposed to MG treatment (MG-sample) is almost constant, independent of Ag content. F sub p of the MG-sample is larger than that of the no-MG-sample. The density of the grain boundary and the configuration of Ag in the samples seem to be much affected by MG treatment. Copyright (c) 1996 Elsevier Science S.A. All rights reserved.