| 摘要 |
PURPOSE:To obtain the titled superconductor having fine crystal size and high critical current density with little lowering of critical temperature, by calcining a trivalent rare-earth element, a bivalent alkaline-earth metal element and copper in air. CONSTITUTION:The objective ceramic conductor is expressed by the formula (L is trivalent rare-earth element; M is bivalent alkaline-earth metal element; x, y and z are positive numbers) wherein M is composed of two or more kinds of bivalent alkaline-earth metals, the average ionic radius of M is larger than the average ionic radius and is 99-92% of the largest ionic radius in M. The superconductor can be produced by compounding and kneading (A) a trivalent rare-earth metal oxide (e.g. Y2O3), (B) two or more kinds of bivalent alkaline- earth metal element carbonates (e.g. BaCO3 and SrCO3) and (C) Cu and calcining the obtained mixture in air. |
