| 摘要 |
PURPOSE:To provide a Bi-Sr-Ca-Cu-O-based oxide superconductor of specified composition, capable of giving critical current density with small anisotropy, having polycrystalline structure. CONSTITUTION:The objective oxide superconductor of formula I or II (x satisfies the relationship: 0.5<=x<=0.8); delta represents oxygen defect, being -0.2-0.4), having polycrystalline structure. The reason why the value of x determining the ratio Sr/Ca is defined as 0.5-0.8 is that if <0.5, anisotropy will get remarkable, resulting in significant decrease in critical current density in terms of polycrystalline form; on the contrary, if >0.8, phase other than superconductive phase will be separated, resulting in adverse effects on superconducting characteristics. The reason why the value of y determining the ratio Sr/Ca is defined as 0.5-0.8 is that if <=0.5, anisotropy will get remarkable, resulting in significant decrease in critical current density in terms of polycrystalline form; on the contrary, if >0.8, phases other than superconductive phase will be separated, resulting in adverse effects on superconducting characteristics. |
