| 摘要 |
PURPOSE:To obtain a superconducting material, consisting of perovskite-type oxides, capable of utilizing liquid N2 as a cooling medium and having the high critical temperature (TC), by blending oxides and salts of Ba, La and Cu, previously sintering the blend, pulverizing the sintered blend, pressing the resultant pulverized blend and normally sintering the obtained pressed compact at a temperature within a specific range. CONSTITUTION:Powders of oxides, carbonates, sulfates or nitrates of Ba, La and Cu having respective <=20mum, especially <=5mum average particle diameter are blended. The resultant blended powder then previously sintered at 700-1,000 deg.C and the sintered blend is pulverized to <=5mum, especially <=3mum average particle diameter and subsequently pressed at 60-80% relative density. The above-mentioned pressed compact is then normally sintered at a tempera ture within the range of (melting point of aforementioned fired compact) - (melting point of the above-mentioned fired compact-100 deg.C). Thereby the aimed superconducting material consisting of a perovskite-type or pseudo-perovskite- type oxide, expressed by the formula and having <=10mum average crystal grain diameter is obtained. The aforementioned superconducting material has the high TC and TCF and characteristics thereof stabilized for a long period. |
