| 摘要 |
PURPOSE:To obtain a Tl-based oxide superconductor excellent in composition stability by monitoring the thermogravimetric change of a raw material and controlling the composition of the starting raw material on the basis of the monitored value so that the composition of the Tl-based oxide superconductor to be synthesized is regulated to the proper composition and performing calcination in the case of calcining the starting raw material having the prescribed composition ratio. CONSTITUTION:The raw materials such as Tl2O3, BaO2, CuO and CaO are mixed at such ratio wherein the aimed Tl-based oxide superconductor is obtained. This mixture is molded to produce the starting raw material having the prescribed composition ratio. Then this starting raw material is calcined and also the thermogravimetric change of the raw material is monitored by a differential thermobalance. The vaporized amount of Tl is calculated on the basis of this data. Tl2O3 correspondent to the calculated amount is added to the starting raw material and calcination is performed. Thereby the Tl-based oxide superconductor having a stabilized composition is obtained. Further the starting raw material is calcined under such conditions wherein calcination is performed while monitoring the thermogravimetric change of the starting raw material and vaporization of Tl is not made remarkable. |
