Effect of Gd₂Ba₄CuMoO_y addition on the band structure and spatial variation of superconducting properties in GdBa ₂Cu₃O_7-δ single domains

Gd₂Ba₄CuMoO_y (Gd2411) single phase was synthesized in air and added into GdBa₂Cu₃O _7-δ (Gd123) bulk superconductors with the addition amount ranging from 0.2% to 20%, in molar ratio to Gd123. Both microstructure and superconducting properties of each bulk were investigated from the seed position to the boundary of a single domain. Although a band structure with the alternative distribution of Gd₂BaCuO₅ (Gd211) and Gd2411 appeared in all samples, the range of this inhomogeneity only appeared within 5 mm from each side of the seed. The critical current density (J_c) shows that Gd2411 plays an important role in the control of the local superconducting properties. The highest J_c reached 84 500 A cm ^-2 at 77 K under the self-field in the sample with 0.4% addition of Gd2411.