| 摘要 |
PURPOSE:To easily produce the superconducting ceramics having high critical temp., critical current value, and critical magnetic field value with good reproducibility by using a ceramics having a specified K2NiF4-type crystal structure as the component. CONSTITUTION:The superconducting ceramics has the K2NiF4-type crystal structure shown by the formula. In the formula, A is a rare-earth metal and a trivalent ion element, B is bivalent alkaline-earth metal ion, M is a tetravalent ion element, 0.6<=alpha<=2, 0<=beta<=2, and 0<=y<=0.2. In the crystal structure of the superconducting ceramic, trivalent Y, La, etc., or the ions of Bi, Tl, etc., are replaced by a tetravalent ion to increase the number of valences, and hence the mean number of valences of 2.1-2.3 of the Cu ion is changed to the ideal bivalent ion state. The amt. of the tetravelent ion to be replaced to obtain such an effect is such that a trace amt. of trivalent ion is converted to bivalent ion, and only the trace amt. is used. |
