Wire for Nb.sub.3 X superconducting wire

A wire for an Nb.sub.3 X multifilamentary superconducting wire being formed by a number of superconducting filamentary wires being embedded in a matrix, each said superconducting filamentary wire comprising:

• a wire being prepared by superposing and winding up a first sheet consisting of pure Nb or an Nb alloy and a second sheet consisting of an X alloy such as that of metal atoms X reacting with said Nb for forming a compound exhibiting superconductivity;
• a stabilizing material layer being so provided as to enclose said wire;
• and
• a diffusion barrier layer being provided between an outer surface of said wire and an inner surface of said stabilizing material layer for preventing said metal atoms X from being diffused in said stabilizing material layer,
• said diffusion barrier layer being made of a metal material having larger tensile strength than that of said first sheet wherein said metal material includes an Nb alloy.

A wire for an Nb.sub.3 X superconducting wire, comprising:

• a wire being prepared by superposing and winding up a first sheet consisting of pure Nb or an Nb alloy and a second sheet consisting of an X alloy such as that of metal atoms X reacting with said Nb for forming a compound exhibiting superconductivity;
• a stabilizing material layer being so provided as to enclose said wire;
• and
• a diffusion barrier layer being provided between an outer surface of said wire and an inner surface of said stabilizing material layer for preventing said metal atoms X from being diffused in said stabilizing material layer,
• said diffusion barrier layer being made of a Nb alloy having larger tensile strength than that of said first sheet,
• the interface between said first sheet and said second sheet being so densely zigzagged as to increase the contact area therebetween.

A wire for an Nb.sub.3 X multifilamentary superconducting wire being formed by a number of superconducting filamentary wires being embedded in a matrix, each said superconducting filamentary wire comprising:

• a wire being prepared by superposing and winding up a first sheet consisting of pure Nb or an Nb alloy and a second sheet consisting of an X alloy such as that of metal atoms X reacting with said Nb for forming a compound exhibiting superconductivity;
• stabilizing material layer being so provided as to enclose said wire;
• and
• a diffusion barrier layer being provided between an outer surface of said wire and an inner surface of said stabilizing material layer for preventing said metal atoms X from being diffused in said stabilizing material layer,
• said diffusion barrier layer being made of a Nb alloy having larger tensile strength than that of said first sheet,
• the interface between said first sheet and said second sheet being so densely zigzagged as to increase the contact area therebetween.