| 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, Er and Cu, previous ly calcining the blend, pulverizing the calcined 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, Er and Cu having respective <=20mum, especially <=5mum average particle diameter are blended. The resultant blended powder is then previously calcined at 700-1,000 deg.C and the calcined 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 the aforementioned calcined compact) - (melting point of the above-mentioned calcined compact -100 deg.C). Thereby the aimed superconducting material consisting of perovskite-type or pseudo- perovskite-type oxides, 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. |
