Critical current density for filamentary (Eu, Gd, Ho)123 superconductors

We have studied a fabrication of filamentary ternary RE123 superconductors by changing the RE element for pinning enhancement. In this paper, the J _c of the filamentary (Eu, Gd, Ho)123 superconductors prepared by solution spinning and partial melting under various atmospheres was examined. As the oxygen partial pressure decreased, the optimum melting temperature decreased. The T_c of the samples melted in flowing 0.1%O₂ + Ar and 1%O₂+Ar was around 92 K and the T_c for the samples melted in flowing 20%O₂ + Ar was low such as 83 K. The transport J_c values for the samples were measured at 77 K in applied magnetic fields up to 14 T by rotating the sample in a direction of the filament diameter. Anisotropic behavior of the field dependence of J_c along the filament diameter was detected. The highest J_c value of 4100 A/cm² at 77 K and 14 T was detected for the sample melted in flowing 0.1%O₂ + Ar. By the rotating the angle for 90°, the superconductivity at 77 K was disappeared by applying the field more than 8 T.