| 摘要 |
A new class of Bi-based superconductive oxides is disclosed. As do the previously known Bi-based oxide superconductors, the novel materials have a perovskite-like crystal structure. However, in contradistinction to the prior ar t materials, the inventive materials have unmixed B-site occupancy, with all substituents occupying A-sites. This tends to produce marginal stability and enhanced transition temperatures, as compared to the prior art Bi-based oxide superconductors. Materials according to the invention have composition ABiO3-.de lta., with A being Ba and at least one monovalent element (typically chosen from Na, K, Rb, and Cs) and 0 ~ .delta. ~ 0.1, and have a transition temperature T c onse t ~ 13K. The superconductive materials are advantageously produced from precursor material that contains an excess of the monovalent element(s), as compared to th e final composition. Potential uses entail all those uses for which prior art superconductors have been proposed, or in which they have been used.
|
