CRITICAL CURRENT DENSITY OF Y-Ba-Cu-Sn-O SUPERCONDUCTORS

The magnetic curves of bulk Y-Ba-Cu-Sn-O have been studied in the temperature range 60-77 K and in fields up to 2.4 T. The results indicate that Jc varies with the magnetic field as a power law and decreases exponentially with temperature. The critical current density Jc can be improved by the substitution of Sn for Cu.