Improvement of the superconducting properties of an infiltrated YBCO bulk superconductor by a BaCeO3 addition

Single grain YBa₂Cu₃O_7−x (Y123) bulk superconductors with Y₂BaCuO₅ (Y211) and various amounts of BaCeO₃ (5–45 wt.% by an increment of 10 wt.%) were fabricated by a seeded infiltration process. The addition of BaCeO₃ was found to be effective for a modification of the microstructure and an improvement of the superconducting properties. The refinement effect for Y211 particles within an entire superconducting YBa₂Cu₃O_7−x (Y123) matrix was achieved by BaCeO₃ additions. The critical current density (J_c) values were increased as the BaCeO₃ contents were increased (maximum J_c at 35 wt.% BaCeO₃ addition). The J_c improvement by BaCeO₃ additions might be due to the microstructure modifications associated with the finely distributed Y211 and BaCeO₃ particles. With the addition of BaCeO₃ the onset T_c values decreased slightly, indicating highly limited Ce substitution for Y site. It can be concluded that the BaCeO₃ addition has a beneficial effect on the morphology, the size and the distribution of the Y211 inclusions and the microstructure regarding pinning improvement.