Patent ID: 6301774
Filing Date: 2001-10-16
Classification: H01L,Y10S,Y10T

Abstract:
A process for producing a composite wire having a core of compound oxide superconductor having a crystal structure of perovskite and an outer metal pipe surrounding said core, characterized in thatsaid compound oxide is selected from the group consisting of:(I) a compound oxide including a IIa group element .alpha., a IIIa group element .beta. and copper, and(II) a compound oxide including at least two elements .alpha.1 and .alpha.2 selected from IIa group elements, an element .delta. selected from Va group elements and copper, andsaid outer metal pipe being made of at least one of metals selected from a group comprising gold, silver, platinum metals and their alloys,said process comprising the steps of preparing at least one material powder selected from the group of:(i) a powder mixture of compounds each containing at least one of constituent elements of said compound oxide, and(ii) a sintered powder prepared by sintering a powder mixture of compounds each containing at least one of constituent elements of said compound oxide and then by pulverizing obtained sintered mass,compacting said material powder in said outer metal pipe,subjecting said metal pipe filled with said material powder to wire-drawing, and then,heating the resulting wire-drawn metal pipe filled with said material powder at a temperature ranging between an upper limit which is defined by a melting point which corresponds to the lowest melting point of any one of constituent components in said material powder and a lower limit which is lower by 100.degree. C. than said upper limit to sinter said material powder inside said outer metal pipe; and wherein said wire-drawing and heat-treatment are repeated for more than two times so as to improve superconductivity relative to the superconductivity which would result from a single wire-drawing and a single heat-treatment.