Method of manufacturing oxide superconducting films by peritectic reaction

A method of manufacturing an oxide superconductor comprising the steps of:

• (a) dispersing a powder of a raw material for an oxide superconductor comprising M.sub.2 O.sub.3, BaCO.sub.3 and CuO, where M represents at least a single element selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, in a dispersion medium to form a dispersion;
• (b) then applying the dispersion onto a substrate;
• (c) then heating dispersion under an oxygen atmosphere to a temperature from 0.degree. to 100.degree. C. higher than the peritectic reaction temperature of said powder to form a molten solution, wherein said peritectic reaction temperature is within a range .+-.30.degree. C. of a rise temperature of a differential thermal peak of said powder;
• (d) then cooling the molten solution to the peritectic temperature,
• (e) then maintaining said molten solution at said peritectic temperature for about 1 to 20 hours;
• and
• (f) then cooling said molten solution at a rate not more than 300.degree. C./hour to room temperature.

A method of manufacturing an oxide superconductor comprising the steps of:

• (a) heating a mixture of BaCuO.sub.2 and CuO under an oxygen atmosphere to a temperature above the peritectic solidification temperature at which the following reaction proceeds
• M.sub.2 BaCuO.sub.5 (solid phase)+Ba-Cu oxides (liquid phase) .fwdarw.MBa.sub.2 Cu.sub.3 O.sub.7-.delta. (solid phase)
• to form a molten solution, wherein M represents at least a single element selected from the group consisting of Y, Nd, Sm, Eu, Gd, Ho, Er, Tm, Yb and Lu, and said peritectic solidification temperature is measured by differential thermal analysis;
• (b) then dipping a substrate composed of M.sub.2 BaCuO.sub.5, in the molten solution;
• (c) then cooling the molten solution to a temperature 0.degree. to 100.degree. C. below said peritectic solidification temperature and maintaining said temperature for 5 minutes to 10 hours;
• (d) then cooling the substrate to room temperature at a rate of 5.degree.-150.degree. C./hour to form an oxide superconductor MBa.sub.2 Cu.sub.3 O.sub.7-.delta..