The effect of density on critical current and oxygen stoichiometry of YBa2Cu3O(x) superconductors

The factors controlling the critical current density Jc in sintered bulk ceramics that display no preferred orientation are reported. The relation between sintered density, oxygen content, and Jc is examined, and it is shown how Jc is strongly dependent on both the volume fraction of solid and on the oxygen stoichiometry, which are in turn both strongly influenced by ceramic density. The problem of optimizing the solid connectivity and simultaneously maintaining a high oxygen content, thereby maximizing Jc in anisotropic bulk ceramics, is addressed.