E–J characteristics of melt-textured RE123 (RE: Nd, Y) superconductors

Abstract We have investigated the E – J characteristics for melt-textured NdBa 2 Cu 3 O 7− δ (Nd123) with the secondary peak and Y123 with no secondary peak over a wide range of the electric field by measuring the ac susceptibility and the dc magnetization. In the case of Y123, the E – J characteristics exhibited normal behavior in that the convex curve changed to the concave with increasing magnetic field. In contrast the E – J characteristics of Nd123 were complicated and the convex curve changed to the concave with decreasing electric field near the secondary peak field. This shows that the E – J characteristics are affected by the field-induced pinning.