Preparation of melt-textured NdBa2Cu3Oy bulk with Nd4Ba2Cu2O10 addition

The NdBa₂Cu₃O_y (Nd123) bulk superconductor, to which Nd₄Ba₂Cu₂O₁₀ (Nd422) particles were intentionally added, was prepared through the so-called MMTG process in Ar (99% purity) flowing atmosphere at an ambient pressure. The quasi-single crystal thus grown was about 1 cm × 1 cm × 1 cm in dimension. It turned out that the Nd422 particles were uniformly distributed in the Nd123-phase matrix in a fashion similar to the distribution of the intentionally added Y211 particles in the Y123 phase matrix. The superconducting transition temperature T_c for the sample subjected to post-annealing in oxygen atmosphere was 94 K. The critical current density J_c was determined to be 45 000 A/cm² at 77 K and 1 T, when the field was applied parallel to the c-axis of the sample. To the best of our knowledge, the J_c value is the highest and the size of the quasi-single crystal is the largest in the melt-textured Nd123 bulk superconductors so far reported.