Critical current density for filamentary (Nd, Eu, Gd)Ba2Cu3Oy superconductors

In order to study the effect of matrix composition in the filamentary (Nd, Eu, Gd)Ba2Cu3Oy ((Nd, Eu, Gd)123) superconductors on critical current density, we prepared three samples with various rare-earth ratios: (Nd0.33Eu0.38Gd0.28)123 (sample A), (Nd0.33Eu0.33Gd0.33)123 (sample B), (Nd0.33Eu0.08Gd0.58)123 (sample C). The filamentary precursor was prepared by a solution-spinning method and partially melted in flowing 0.1%O-2 + Ar and 1%O-2 + Ar. The samples had well aligned texture along the filamentary diameter as well as the length except sample C processed in flowing 1%O-2 + Ar. The T, value for the samples processed in flowing 0.1%O-2 + Ar is higher than that for 1%O-2 + Ar. The high J(c) value more than 101 A/cm(2) at 77 K and self-field is attained for samples A and B. The field dependence of J(c) for the samples was measured at 77 K up to 14 T by changing the angle along the filament diameter. The anisotropic behavior of the J(c)-B curve was detected. The J(c) values and irreversibility field for the samples processed in flowing 0.1%O-2 + Ar are higher than those for 1%O-2 + Ar. By optimizing the angle for the samples, the highest J(c) value of 3400 A/cm(2) at 14 T was attained for sample A. (C) 2004 Elsevier B.V. All rights reserved.