Enhanced Critical Current Density of FeF2 Added YBa2Cu3O7-δ

The effect of nanosized FeF2 (similar to 120 nm) addition on the critical current density, J (c), of YBa2Cu3O7-delta was studied. YBa2Cu3O7-delta superconductor was prepared by the solid-state reaction method with addition of 0 to 0.10 wt% FeF2 additions. The magnetization critical current density, J (cm) (at 77 K), was estimated from the extended Bean model by using vibrating sample magnetometer (VSM) measurements. The transport critical current density, J (ct), was measured using the four-point probe method with the 1 A mu V/cm criterion. The onset transition temperature, showed a maximal value at 92 K for 0 to 0.03 wt% additions. J (c) increased with FeF2 addition up to 0.03 wt%. Addition of FeF2 of more than 0.03 wt% suppressed and J (c). The inter-grain current density was enhanced by two orders of magnitude on 0.03 wt% FeF2 addition. In addition to the condensation energy associated with their core, the full vortex magnetic energy by addition of nanosized FeF2 enhanced J (c) in the system.