Large melt-textured NdBa2Cu3Oy crystals with a sharp superconducting transition have been fabricated in air with Nd2BaO4 addition. Experiments show that NdBa2Cu3Oy and Nd4Ba2Cu2Oy are present in melt-textured crystals which grow in the centre of cylindrical samples while NdBa4Cu3Oy, as a stable phase, instead of the NdBa6Cu3Oy phase, which has been reported previously, has been observed in the residual liquid phase located in the edge of samples. In comparison with the effects of Nd4Ba2Cu2Oy addition, the refined Nd422 particles can be obtained in the present composition. The influence of the short-time thermal treatment in Ar before oxygenation has been discussed. Fabricated bulk samples exhibit onset Tc values of 95 K and the secondary peak effect in the M-H loop. The peak values of Jc are 2.4 x 104 A/cm2 in 0 T at 77 K and 2 x 104 A/cm2 in 1.3 T at 77 K. © 1998 Elsevier Science Ltd. All rights reserved.
|Publication status||Published - 1 Jan 1998|