Effect of BaO₂addition on superconducting properties of melt-processed (Sm,Eu,Gd)Ba₂Cu₃O₇superconductors

Abstract

We fabricated large c-axis-oriented single-grain (Sm,Eu,Gd)Ba2Cu3O7−δ bulk superconductors with BaO2 addition under 1% O2 partial pressure in Ar. The experiment showed that BaO2 addition significantly reduced RE–Ba substitution, slightly hindered the coarsening of (Sm,Eu,Gd)2BaCuO5 inclusion, and improved the superconducting properties. An optimum addition amount was around 0.1–0.18 mol−1 RE123. At 77 K, the critical current density reached 83 000 A cm−2 in zero field. A disc 3.5 cm in diameter trapped a field of 1.27 T at 77 K.