Improvement in Superconducting Properties of Air Processed SmBa₂Cu₃O_y with Ag₂O Addition

We have investigated the influence of combined additions of Ag₂O and BaO₂ with the aim of producing good- quality single-grain SmBa₂Cu₃O_y "Sm-123" material in air, and have characterized its superconducting performance with a SQUID magnetometer. The quality of the Sm-123 material was improved with increasing the Ag₂O content from 0 wt% to 20 wt%. Magnetization measurements indicated that the T_c (onset) increases with Ag₂O concentration i.e. from 86 K to 92 K for Ag₂O addition of 10 wt% to 20 wt%. At 77 K, the critical current density of 10 kA/cm² was achieved at 0 T (self-field). These results indicate that high-performance bulk Sm-123 materials can be fabricated even in air when optimum quantity of BaO₂ and silver is added.