| 摘要 |
PROBLEM TO BE SOLVED: To obtain the principal phase of a superconductor acting at a relatively high temp. which can be attained using N2 as a low-cost refrigerant by selecting a rhombic-crystallized principal phase in a black crystalline material having a specified chemical compsn. and a specified superconduction critical temp. SOLUTION: A rhombic-crystallized principal phase in a black crystalline material having a chemical compsn. represented by the formula Bia (Sr,Ca)b Cu6 Ox and 60 deg. K superconduction critical temp. is used. In the formula, (a) is 3-12, (b) is 6-12, the atomic ratio of Bi:(Sr+Ca) is 0.3:1 to 1.3:1 and the atomic ratio of Sr:Ca is 1:9 to 9:1, but when the atomic ratio of Bi:(Sr+Ca):Cu is 3:6:6, the atomic ratio of Sr:Ca is other than 1:1. A superconducting material contg. the principal phase can be used in the state of a coil through which electric current flows in a cable, a lead wire, etc., in the energy industry. |
