| 摘要 |
PURPOSE:To produce a superconductor which functions at above the b.p. of liquid H2 and has a high critical current density by drying coprecipitate obtained from aq. soln. of water-soluble salts of a raw material compsn. then calcining in two stages. CONSTITUTION:Aq. soln. of precipitant having >=9pH is added to aq. soln. of water-soluble salts contg. La, Cu, and >=one kind of alkaline earth element selected from Ba, Sr, and Ca. After precipitating hydroxides, hydrous oxides, oxalates, carbonates or a mixture thereof in the form of coprecipitate of said salts, a solid matter is obtd. by separating the solid from liquid. Then, the solid matter is dried and calcined at 700-950 deg.C, and molded, then calcined further at 800-1,200 deg.C in oxidizing atmosphere contg. O2. By this method, a high temp. superconductor expressed by the formula: (LaxAy)2CuO2 (wherein A is at least one kind selected from Ba, Sr, and Ca; x is 0.50-0.98; y is 0.5-0.02; z is an atomic ratio <=4) is obtd. |
