PURPOSE: To produce a new T' type superconductor having a critical temp. Tc of max. 30K which is high as compared with a conventional T' type.
CONSTITUTION: The superconductor is expressed by a general formula (La1-xCex)2CuO4 (x is a number within a range of 0-1) and a crystalline structure of Cu oxide has the same type crystal structure with that of N' type Nd2CuO4. This oxide superconductor is produced by the following three stage. (1) A sintered compact consisting of La-Ce-Cu-O is produced at high temp. in an inert gas. (2) This sintered compact is oxidized at low temp. (3) This oxidized sintered compact is heat treated at an intermediate temp. between above described high temp. and low temp. in the inert gas. In this three stage, it is preferable that the first stage is executed at 1000-1040°C, the second stage is executed at 250-300°C and the third stage is executed at 600-700°C. As a starting material, La2O3, CeO2 and Cu2O are used preferably.
KINOSHITA KYOICHI
SHIBATA HIROYUKI
