| 摘要 |
PURPOSE:To provide the title composite oxide extremely stable in the air and having low carrier density and a higher Tc than liquefied He by specifying the composition in the Sr-Bi-Cu-O based composite oxide. CONSTITUTION:The superconductive composite oxide has the chemical composition of SrxBi1-xCuyOz where 0.1<=x<=0.9, 0.4<=y<=3, and 1.4<=z<=4.5. When the value for (x) is lower than 0.1 or higher than 0.9, the oxide forms an insulator, and a superconductor is not obtained. When the value for (y) is lower than 0.4 or higher than 3, superconductivity is not exhibited even at a temp. which can be reached by the cooling with liquefied He. When the value for (z) is lower than 1.4 or higher than 4.5, a superconductor is not obtained. The oxygen amt. can be controlled by adjusting the atmosphere in sintering, and sintering is carried out in a reducing atmosphere to reduce the oxygen amt. below the stoichiometric amt. |
