SUPERCONDUCTING MATERIAL AND ITS PRODUCTION

摘要

PURPOSE:To provide the superconducting material which becomes a superconductor at the remarkably high critical temp. as compared to the conventional superconducting material by incorporating specific >=7 kinds of multielement oxides expressed by specific formula into said material. CONSTITUTION:The above-mentioned superconducting material is the multielement oxide having the compsn. expressed by general formula I and is the oxide of a so-called pseudo perovskite type structure. The tendency with which desirable characteristics are obtainable at about X=0.3-0.4 in formula I is admitted. While the ratio of (gamma) to Ba in particular can take a 1-90atomic% range, the characteristics are improved preferably in a 1-50atomic% range. Said superconducting material is preferably heat-treated at 500-900 deg.C in an O2-contg. atmosphere after sintering or film formation. The structure is homogenized by this heat treatment and the critical temp. is improved by this heat treatment; in addition, the phase transition end temp. at which the electric resistance is completely zero approximates remarkably to the critical temp. The compd. expressed by the above-mentioned formula is exemplified by, for example, the compd. expressed by formula II.