Effect of nanoscopic ZrO₂ particles on flux pinning in (Nd, Eu, Gd)-123/Gd-211 composites

We investigated the effect of ZrO₂ addition on superconducting and magnetic properties of oxygen-controlled-melt-growth- (OCMG-) processed (Nd_0.33Eu_0.33Gd_0.33)Ba₂Cu ₃O), (NEG-123) bulk material. The purpose of this study was to ascertain whether the ZrO₂ particles are able to improve flux pinning even without entering into reaction with NEG-123 and Gd₂BaCuO ₅ (Gd-211) phases. We observed the expected effect but only at a relatively low concentration of ZrO₂. The best flux pinning was observed in the sample with 0.29 wt% ZrO₂. No trace of Zr was found in the NEG-123 matrix. Our study demonstrates the potential of ZrO₂ particles in enhancing flux pinning in melt-processed REBa₂Cu ₃O_y, (RE-123).