Effect of growth temperature on superconducting properties of YBa2Cu3Oy bulk superconductors grown by seeded infiltration

Abstract

We investigated the effect of growth temperature on the characteristics of YBa2Cu3Oy (Y-123) bulk superconductor prepared by seeded infiltration process. Homemade Y2BaCuO5 “Y-211” particles and liquid phase of Ba3Cu5O8 were used to produce Y-123 bulks in air such that the liquid phase infiltrates into a Y-211 block. Y-123 samples of 20mm diameter and 8mm thickness were produced at different growth temperatures, i.e., 990, 985, 983, 980 and 978°C with the same holding time of 25h. We found that single grain growth without multi-nucleation occurred at 980°C. Further, magnetization measurements indicated a sharp superconducting transition with Tc (onset) around 93.2K. Trapped field measurements showed that the samples are single domain, and the sample 27mm in diameter and 5mm in thickness showed the maximum trapped field of around 0.45T on the sample surface at 77K. The critical current density (Jc) at 77K and zero field was determined to be 175kA/cm2, which is the highest value ever reported in the literature.