YBCO 초전도체의 효과적인 플럭스 피닝 센터로서의 나노 크기 BaCeO₃ 합성

Abstract

In this work, nano size BaCeO3, which is a possible flux pinning medium of melt processed YBa₂Cu₃Ox superconductor, was synthesized by the conventional solid state reaction method using powders. BaCO₃ and CeO₂ were mixed thoroughly using a ball milling for 24 hours and calcined at 1200℃ for 5 hours for the formation BaCeO₃ powder. The obtained BaCeO3 powder was attrition milled at various milling times of 60 min, 120 min and 240 min. The BaCeO3 powders of various milling times were mixed with YBa₂Cu3Ox powder. Seed melt processed YBa₂Cu₃Ox-BaCeO₃ (15wt.%) superconductors were prepared and the superconducting properties were investigated. It was found that Tc of Y1.5Ba₂Cu₃Ox samples was not significantly affected by BaCeO₃ addition, but Jc of samples was increased by BaCeO₃ addition. The Jc improvement by fine BaCeO₃ powder (120 min attrition-milled) was effective at low magnetic fields less than 2 T.