PRODUCTION OF DENSE OXIDE SUPERCONDUCTOR HAVING HIGH CRITICAL CURRENT DENSITY

摘要

PURPOSE:To obtain the title superconductor by periodically changing the partial pressure of gaseous O2 in an atmosphere in a sintering stage for producing an oxide superconductor. CONSTITUTION:Powder of an oxide such as Y-Ba-Cu-O is sintered to produce an oxide superconductor. In this sintering stage, the powder is repeatedly held in an atmosphere of only gaseous O2 under 1atm for a certain time and in an atmosphere of only an inert gas under 1atm for a certain time. The powder may be held in a mixed atmosphere consisting of gaseous O2 and an inert gas under 1atm total pressure while repeatedly keeping the partial pressure of gaseous O2 higher for a certain time and lower for a certain time. The powder may be repeatedly held in an atmosphere of only gaseous O2 under 1atm for a certain time and in an atmosphere of gaseous O2 under a reduced pressure of <1atm for a certain time. After the sintering atmosphere is periodically changed as mentioned above, the sintering stage is finished in an atmosphere of gaseous O2.