Improvement of superconducting properties in YBa₂Cu₃O_x

Abstract

The superconducting properties (superconducting temperature Tc and critical current density Jc) in bulk YBa₂Cu₃O_x ceramics have been investigated in terms of their microstructural dependence with regard to especially grain size and relative sintered density. Two kinds of experiments were conducted in this study; (1) the grain size dependence of Jc in YBa₂Cu₃O_x ceramic and (2) preparation of high-density YBa₂Cu₃O_x ceramics using hot-pressing under controlled atmosphere. In these experiments Tc and Jc in the materials appeared to be much improved, associated with some findings such as a characteristic behavior of Jc with grain size between 1·0 and 25 μm and an interesting oxygenation characteristics in high-density YBa₂Cu₃O_x ceramics with a relative sintered density >97%.