Method of manufacturing oxide superconductor containing ag and having

Abstract

An oxide superconductor which has high mechanical strength and exhibits favorable magnetic properties and high resistance to environment. Further, a method of manufacturing this oxide superconductor, namely, a method of manufacturing a RE--Ba--Cu--O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than the melting point of a raw material mixture containing a RE-compound raw material, a Ba-compound raw material and a Cu-compound raw material, on the aforesaid raw material mixture. This method further comprises the addition step of adding 1 to 30 in percent by weight (wt %) of Ag to the raw material mixture, and the crystallization step of melting the raw material mixture, to which Ag is added, at a temperature that is not lower than a temperature at which the raw material mixture is decomposed and fused into the RE.sub.2 BaCuO.sub.5 phase and a liquid layer, and then lowering the temperature of the aforesaid raw material mixture to a temperature close to a temperature, at which a REBa.sub.2 Cu.sub.3 O.sub.7-X phase crystallizes, and subsequently bringing a seed crystal, which meets the following condition: (the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-X phase of the seed crystal)>(the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-X phase of the aforesaid raw material to which Ag is added), into contact with the aforesaid raw material mixture and then performing crystallization by using this seed crystal as a starting point.