ENHANCED FLUX-PINNING AND CRITICAL CURRENTS IN OXYGEN-RICH YBA2(CU1-XFEX)(3)O-Z SYSTEM

Oxygen rich YBa2(Cu1-xFex)(3)O-2 (x = 0.01 to 0.04) samples prepared u nder identical conditions have been characterized by de magnetization and thermogravimetric analysis measurements. Detailed magnetization me asurements on randomly oriented powdered samples as a function of temp erature and field exhibit pronounced M(H) hysteresis loop, indicatives of extensive flux pinning. It is believed that the flux pinning arise s due to the preferential substitution of Fe on the Cu-site, which act s as a pinning center. The critical current density J(c) has been dedu ced from hysteresis data.