JPH08106824A - Superconductive wire and its manufacture - Google Patents

Abstract

PURPOSE: To provide such a superconductive wire that fully exhibits characteristics of an oxide conductivity used for the superconductive wire without reducing critical temperature and current by processing, by mounting a conductive material around an outer circumference of a narrow wire consisting of oxide superconductivity in which silver or silver alloy is dispersed. CONSTITUTION: A superconductive wire is provided with oxide superconductivity 1, silver or silver alloy and a substance 2 added for fixing a pin dispersed in the oxide superconductivity, and a conductive material 3. The oxide superconductivity used for this heat conductive wire is generally manufactured by heat treatment, however, when a sintered body is processed into the superconductive wire, hollow hole parts are formed. Therefore, silver or silver allay which is melted to be impregnated into the hollow hole parts is dispersed in the inside of oxide conductive body for fixing the pin by using the temperature generated in impregnating. Manufacture of the superconductive wire is that, for example, powder of oxide superconductivity is filled in the silver pipe so as to be rolled into a wire material. This wire material is heated to the melting point of silver, 960 deg.C or more. Silver is impregnated and dispersed among crystal grains of oxide superconductivity by this heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting wire using an oxide superconductor and a manufacturing method thereof.

[0002]

2. Description of the Related Art Y-based, Bi-based, and other oxide superconductors exhibit superconductivity at a temperature higher than liquid nitrogen temperature. As a method for converting these materials into wire rods, a metal pipe is filled with a superconducting substance or its raw material, wire drawing is performed, and if necessary, heat treatment is performed before or after the wire drawing, or by sputtering. It is generally practiced to form an oxide superconductor on a substrate by using various thin film forming means such as a method. A method of filling a metal pipe with a superconductor is disclosed in JP-A-2-37623 or 1-27.
Japanese Patent No. 6516 and a method for forming a thin film are disclosed in Japanese Patent Laid-Open No.
They are disclosed in Japanese Patent Laid-Open No. 3-241826, respectively.

[0003]

However, since the superconducting properties of an oxide superconductor change depending on the amount of oxygen in the material, it is necessary to control the amount of oxygen in the material in order to form a wire. There is. Stabilizers are generally provided on superconducting wires, and metals such as copper are usually used for this.However, in the case of oxide superconductors, copper is generated by oxygen in the superconductor during processing. It cannot be used because it will be oxidized. In addition, since oxide superconductors do not have workability like metals, it is difficult for metal pipes to break during processing because the crystal grains are less likely to deform during wire drawing by rolling or dies. There is. There is also a problem that unless the oxide superconductor is densely and uniformly filled in the metal pipe, it cannot be used as a superconducting wire. Further, since the coefficient of thermal expansion differs between the metal and the oxide superconductor, the adhesion between the metal and the oxide superconductor during cooling is also a big problem.

In order to solve the above problems, Japanese Unexamined Patent Application Publication No.
In JP-A-37623, when an aluminum pipe is filled with an oxide superconductor and heating for sintering the superconductor is performed, aluminum is dissolved and removed, and the oxide superconductor is exposed. The amount of oxygen in the material is controlled by performing heat treatment at 900 to 1,000 ° C. Further, in Japanese Patent Laid-Open No. 1-276516, an oxide superconductor molded body is inserted into a silver pipe, and a silver powder is filled in a gap between the silver pipe and the superconductor to obtain adhesion between the metal pipe and the superconductor. Has been secured.

However, according to the method disclosed in Japanese Patent Laid-Open No. 2-37623, since the melting point of aluminum is about 660 ° C., at this temperature, before the aluminum is removed from the surface of the oxide superconductor, the oxide is superposed. There is a very high possibility that aluminum in the superconductor will be oxidized.
In particular, it is difficult to remove aluminum that has entered recesses on the surface of the oxide superconductor or crystal grain boundaries, and aluminum oxide produced by oxidation may precipitate as impurities or, in some cases, react with the oxide superconductor. Happens. Further, JP-A-2-37623 does not disclose anything about formation of a stabilizer which is essential for application to a superconducting magnet or the like. Also, Japanese Patent Laid-Open No. 1-27651
In the method described in Japanese Patent Publication No. 6, it is considered that the presence of silver powder improves the adhesion between the metal pipe and the oxide superconductor, but no attempt has been made to improve the critical current of the superconducting wire. .

Further, Japanese Patent Laid-Open No. 63-
The method described in Japanese Patent No. 241826 is to preliminarily process a wire rod, form a thin film made of a constituent element of a superconducting material on a substrate having a surface on which copper or a copper alloy is formed, and heat-treat. However, it is disclosed that the heat treatment usually requires 800 to 1000 ° C. and 1 to 100 hours depending on the kind of the superconducting material. On the other hand, in general, the faster the superconducting wire is produced, the better, and the method requiring such a long-time heat treatment has a problem that the production rate is extremely slow. Further, in the thin film forming method, it is necessary to strictly control the composition of the elements that make up the superconductor, and since the superconducting characteristics change greatly due to a slight change in the composition, a long superconducting wire can be formed. There is a fatal problem that it is difficult to manufacture. As described above, much research has been conducted on the production of superconducting wires using oxide superconductors, but at present, practical superconducting wires have not been obtained.

Therefore, an object of the present invention is to use an oxide superconductor having a high critical temperature and to put it into practical use as a superconducting wire without causing the critical temperature and the critical current to drop due to processing. To provide a superconducting wire having properties and a method for manufacturing the same.

[0008]

The above object can be achieved by the present invention described below, that is, the present invention provides a thin wire made of an oxide superconductor in which silver or a silver alloy is dispersed. A superconducting wire, characterized in that a conductive material is attached, and a manufacturing method thereof.

[0009]

According to the present invention, silver or a silver alloy is dispersed in a thin wire made of an oxide superconductor forming a superconducting wire, and the pores of the superconductor are impregnated with silver or the like. Since the reduction of the critical current is prevented and the mechanical strength is improved, and the conductive material is attached in close contact with the outer periphery of the thin wire, the function as a stabilizer is sufficiently exerted and the thermal cycle is performed. As a result, the conductive material and the superconductor do not separate even when applied to the superconducting wire. As a result, the critical temperature and the critical current do not decrease due to processing, and the critical temperature and the critical current are high. Conductive wire is obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the preferred embodiments of the present invention. The superconducting wire of the present invention is characterized in that a conductive material is attached to the outer periphery of a thin wire made of an oxide superconductor in which silver or a silver alloy is dispersed. That is, the superconducting wire of the present invention has a structure in which a fine wire made of an oxide superconductor is mixed with silver or a silver alloy to prevent a decrease in the critical current, and a specific conductive material is attached to the outer periphery thereof. have. The oxide superconductor constituting the present invention may be any oxide superconductor in which silver or a silver alloy is dispersed, and may itself be processed into a wire rod, but it is hollow. The oxide superconductor may be attached to the surface of the tube, a tape-shaped substrate, or the like.

The following materials are particularly preferable as the oxide superconductor. For example, the composition formula is represented by Ln _a Sr _b Cu _3-x M _x O _c , and 2.7 ≦
a + b ≦ 3.3, 0.8 ≦ a ≦ 1.2, 6 ≦ c ≦ 9, and 0.05 ≦ x ≦ 0.7, and Ln is selected from the Y element and the lanthanoid element group. A material having one or more elements or atomic groups, M being one or more elements or atomic groups selected from the element group of Ti, V, Ga, Ge, Mo, W and Re, and having a composition formula of Ln _a Ca _b Sr _c Cu _3-x M _x O _d , represented by 2.7 ≦ a + b + c ≦ 3.3, 0.8 ≦ a +
b ≦ 2.1, 6 ≦ d ≦ 9, 0.05 ≦ b ≦ 1.1 and 0.05 ≦ x ≦ 1.0, and Ln is selected from the Y element and lanthanoid element groups. One or more elements or atomic groups, M is Fe, Co, Ti, V, Ge, Mo, W
And a material that is one or more elements or atomic groups selected from the group of elements Re and has _a composition formula of Ln _a Ca _b Sr _c Bad _d Cu _{2 + e}
O _{6 + f} C _g , a + b + c + d = 3, 0.2 ≦ a ≦
0.8, 0.2 ≦ b ≦ 1.0, 0.5 ≦ c ≦ 2.2, 0
≦ d ≦ 1.6, 0 ≦ e ≦ 0.8, 0 <0.8f <2 and 0.2 ≦ g ≦ 1, and Ln is one selected from the group consisting of Y element and lanthanide element A material having the above elements or atomic groups and a composition formula of (Ln _1-a Ca _a ) (Sr _2-b B
_ab ) (Cu _3-c B) O _d, and 0.1 ≦ a ≦ 0.
5, 0.7 ≦ b ≦ 1.7, 0.1 ≦ c ≦ 0.5, 6.5
A material satisfying ≦ d ≦ 7.5 and Ln being one or more elements or atomic groups selected from Y element and lanthanoid element (excluding Ce and Tb),

Ln, M, Ba, Ti, Cu and O (Ln
Is Y, La, Pr, Nd, Sm, Eu, Gd, Dy, H
1 selected from the group of elements o, Er, Tm, Yb and Lu
An octahedron or a pyramid-type pentahedron made of Cu and O, and Ti, in which at least one element or atomic group, M is one or more elements or atomic groups selected from the group of elements Ca and Sr) It is a material in which both octahedrons created by and O are simultaneously provided in the basic structure and are two-dimensionally arranged. Needless to say, a material obtained by adding a trace amount of impurities to these materials may be used.

In the superconducting wire of the present invention, any conductive material may be attached to the outer periphery of an oxide superconductor in which silver or a silver alloy is dispersed, but a particularly preferable material is
Au, Al, Cu, Ni, Pd, Pt, Ti, Mo,
It is a metal or alloy of W, Nb and Mn.

By using the above materials, when silver or the like is dispersed in the oxide superconductor, the critical current is improved to some extent, and at the same time, the gaps between the crystal grains of the oxide superconductor are filled with silver or the like. The mechanical strength and the like are also improved. Further, since silver and the like on the surface portion of the oxide superconductor have good adhesion with the conductive material on the outer periphery thereof, the conductive material and the superconductor are separated even when the thermal cycle is applied to the superconducting wire. Will disappear.

The present invention also provides a method for manufacturing the above superconducting wire. That is, a superconductor or its raw material is filled in a silver or silver alloy pipe, and this is drawn by die processing, rolling or the like. The oxide superconductor may be sintered by heating before or after the drawing or during the drawing. The heating temperature is preferably about 500 to 950 ° C.
This thin wire is placed in a container such as a crucible and passed through a conductive material melt having a melting point higher than that of silver or silver alloy. The silver or silver alloy melts and partially dissolves in the oxide superconductor and the conductive material, but by winding a fine wire with a roller or the like, the surface of the oxide superconductor has the conductive material and silver or It is taken out of the melt of the conductive material with the melt of the silver alloy attached.

The melt adhered to the surface of the oxide superconductor is dispersed in the oxide superconductor because the silver or the silver alloy is in a molten state even when the conductive material is solidified, and thus the critical current is generated. Contribute to the improvement of. Further, since the melt of the silver or silver alloy or the conductive material which has not dispersed inside adheres to the surface of the oxide superconductor, even if the surface of the oxide superconductor has irregularities, it is attached without gaps. You can Oxygen in the oxide superconductor may be reduced at the stage of passing through the melt of the conductive material, but in the present invention, the released oxygen is incorporated into silver or a silver alloy, so that the conductivity is reduced. Even if the conductive material is an oxygen impermeable material, it is possible to recover the superconducting property by utilizing the oxygen taken into silver or the like by heat treatment.

The means for forming the conductive material in the present invention is not limited to passing through the above-mentioned melt. For example, in the case of a material having a high melting point such as W, not only silver or a silver alloy but also an oxide superconductor may be melted and decomposed. In the case of a material such as Al having a melting point lower than that of silver or the like, silver or the like does not melt even if it is passed through the melt. In such a case, silver or a silver alloy is melted and then a conductive material is attached. As the attachment means, an appropriate means may be selected depending on the material such as a method of applying and heat treatment, a method of utilizing a vacuum vapor deposition method, a chemical vapor deposition method or the like.

A pipe may be provided with a plurality of small holes in silver or a silver alloy to facilitate the reaction with oxygen when heat-treated in an oxidizing atmosphere, or after drawing or after solidifying a conductive material, HIP You may give a process etc. Further, it goes without saying that an insulating material may be attached to the surface of the conductive material. Although the conductive material and silver or silver alloy may form a solid solution when passing through the melt of the conductive material, the present invention does not cause any problem even if the solid solution forms a solid solution. Further, the wire drawing means, heating means, winding and feeding means, atmosphere in each step, etc. may be selected as an optimum method depending on the material used.

[0019]

EXAMPLES The present invention will be described below with reference to specific examples. Example 1 FIG. 1 shows a schematic sectional view of a superconducting wire of the present invention. 1 is an oxide superconductor, 2 is silver or a silver alloy dispersed in the oxide superconductor, and / or a substance added for pinning,
It is expressed larger than it actually is. Note that all of silver or silver alloy does not need to be dispersed inside the superconductor, and may be segregated near the surface of the oxide superconductor. 3 is a conductive material. The oxide superconductor used for the superconducting wire of the present invention is generally manufactured by a heat treatment. However, since the density of the sintered body is often lower than the theoretical density, when the superconducting wire is processed, the void portion is not formed. Occurs. The voids reduce the critical current of the superconducting wire. Therefore, silver or a silver alloy is melted and impregnated in the pores, and these substances are dispersed inside the oxide superconductor for pinning by utilizing the temperature at the time of impregnation. A conductive material is attached to the outer periphery of the superconductor as a stabilizing material.

The superconducting wire of the present invention may be manufactured by any method. For example, a silver pipe is filled with oxide superconductor powder, and this is rolled into a wire. This wire is heated to a melting point of silver of 960 ° C. or higher. By this heating, silver is impregnated into the gaps of the crystal grains of the oxide superconductor or dispersed therein. A superconducting wire can be obtained by attaching a conductive material to the outer periphery simultaneously with or after the dissolution of silver. The mounting means is not limited, but for example, it may be passed through a molten material of a conductive material, various vapor deposition methods, a method of applying an organic metal and heat treatment, or the like. The method of forming the conductive material may be selected depending on the material used.

In the superconducting wire of the present invention, as shown in FIG. 1, since silver or a silver alloy is dispersed in the oxide superconductor, these improve the critical current density. Since these melts have also entered the pores and irregularities near the surface of the conductor, they are also excellent in adhesion to the conductive material attached to the outer periphery. The combination of materials used in the present invention is not particularly limited, but in this embodiment, YSr ₂ Cu is used.
_2.8 Oxide superconductor obtained by mixing Y ₂ O ₃ , SrCO ₃ , WO ₃ and CuO so that 10 wt% of SrY ₂ O ₄ with respect to W _0.2 O _y is produced and heat-treating the mixture at 950 to 1400 ° C. And Cu was used as the conductive material provided on the outer periphery. In addition, the superconducting wire of the present invention was produced by using the same combination of materials also in the examples other than this example. The critical current density of the superconducting wire of the present example obtained by dissolving and dispersing silver using the above materials by the above method is about 10,
It was 000 A / cm ² (5K). On the other hand, even when the same oxide superconductor was used and silver was not dissolved or dispersed, the critical current density was about 2,000 A / cm ^2, which is an extremely small value as compared with that of this example. Became.
The superconducting wire of this example did not change its superconducting properties even when wound with a roller having a diameter of 30 cm, but in the case of the comparative example in which silver was not dissolved or dispersed, the same roller was used. When wound up, the energization amount dropped to 1/100 to 1/1000. These facts indicate that the superconducting wire of the present invention is excellent in mechanical strength and also in critical current density.

Example 2 FIG. 2 shows a conceptual diagram of the method for producing a superconducting wire of the present invention. First, a silver pipe is filled with an oxide superconductor, and a plurality of dies 5 (only one is shown in FIG. 2) are used to produce a silver sheath wire. Here, the outer diameter is 8 mm and the inner diameter is 6 mm.
The silver pipe was filled with a superconductor to form a thin wire 4 having an outer diameter of 0.8 mm. Reference numeral 6 is a copper melt in the crucible that is melted by a heating device (not shown), and the temperature is kept at 1,100 ° C. The silver sheath wire obtained above is put into such a copper melt and passed through the copper melt 6. At this time, since the melting point of silver is 960 ° C., it melts and a part of silver is mixed with the copper melt 6, but most of the silver is dispersed inside the oxide superconductor. Next, when the wire is wound by a roller (not shown), the wire is taken out from the crucible with copper adhered to the surface. The wire rod 10 taken out from the crucible is cooled, and copper having a high melting point first solidifies from the outer peripheral side,
The silver inside solidifies more slowly than copper. Therefore, due to the difference in the solidifying time, silver is dispersed even in the gaps of the oxide superconductor and inside the crystal. It is cooled until the solidification of silver is completed, and the superconducting wire is wound by a roller (not shown).

The critical current of the superconducting wire of this embodiment produced in this way is 10 ⁴ A / cm ² or more regardless of the composition of the superconductor material used, and the superconducting wire is wound. Even when the diameter of the roller was about 300 mm, no change was observed in the superconducting properties. However, in the case of the silver-sheathed wire in which silver is not melted, the critical current is also about 10 ² A / cm ² , and when wound with a roller having a diameter of 300 mm, the oxide superconductor is broken. Was observed.
Further, in the superconducting wire of the present invention, the critical temperature of the superconductor hardly changed before filling the silver pipe and when processing the superconducting wire.

Example 3 FIG. 3 shows a conceptual diagram of a method of manufacturing a superconducting wire of this example.
First, a raw material for synthesizing a superconductor is filled in a silver pipe having a hole with a diameter of 0.1 to 0.5 mm, and the die 5 is used.
To form a wire having a diameter of 1 mm. At this time, as shown in FIG. 3, an oxide superconductor is synthesized by heating the silver pipe with the heater 8 before and after the die processing.
Generally, drawing with a die is performed using a plurality of dice, but only one is shown in FIG. Generally, in the synthesis of oxide superconductors, carbonates, nitrates, and oxides of constituent metal elements are often used as raw materials. The hole formed in the silver pipe allows oxygen to be supplied to the central portion of the silver pipe, and at the same time, functions to release gas such as carbon dioxide produced by decomposition of these raw materials. Therefore, in this embodiment, a superconductor having excellent characteristics can be synthesized by heat treatment with the heater 8.

The wire 4 thus obtained is put into a crucible and passed through the molten gold 6. The temperature of the gold melt 6 is kept at 1,065 to 1,080 ° C. Therefore, since the melting point of silver is 960 ° C., when passing through the melt 6 of gold, silver is melted and dispersed in the oxide superconductor, and when the wire is pulled out from the crucible, the wire Gold is attached to the surface. These gold and silver are partially mixed until they solidify, and the mixing ratio thereof may be controlled by the contact time between the gold melt 6 and the wire and the winding speed. There is no problem if the mixing ratio is constant to some extent in the entire wound wire. The superconducting wire of this example manufactured in this manner is resistant to mechanical deformation, and even if the diameter of the roller 7 is 200 mm, a superconducting wire having a length of about 1,000 m can be manufactured. .

Example 4 FIG. 4 shows a conceptual diagram of a method of manufacturing a superconducting wire of this example.
An oxide superconductor is filled in an alloy pipe in which 3 wt% of palladium is added to silver, and a desired sheath wire is prepared by a die 5. This is heated by the heating device 11 to melt the silver alloy. After the molten alloy is solidified again, a conductive material is formed on the surface by the thin film device 9 to obtain the superconducting wire of this embodiment. The heating device 11 used at this time may be anything as long as it can heat the silver alloy to a temperature at which it can be melted, but in the present embodiment, infrared rays were condensed and heated. Further, the thin film device 9 may be any device as long as it can form a conductive material having a desired film thickness, but in this embodiment, organic palladium is applied and heat treated to form a palladium film. did. In the superconducting wire of this example prepared in this manner, since silver and palladium are in close contact with each other, cracks and the like are unlikely to occur even when mechanically deformed. Further, silver and palladium were dispersed in the superconductor, and the critical current density was a value that was two orders of magnitude larger than that of the superconducting wire in which the silver alloy was not dispersed.

Example 5 FIG. 5 shows a conceptual diagram of a method of manufacturing a superconducting wire of this example.
In this example, 1 wt.
% Ag-added silver alloy was filled with a mixture material that was a raw material for synthesizing an oxide superconductor. This was heat-treated with a heater 8 before being drawn with a die 5 to remove the gas released from the raw material (decomposed gas of the raw material, moisture, etc.), and the superconductor of this example was synthesized. The silver alloy pipe filled with the produced oxide superconductor is drawn into a desired size by a die 5 before being cooled to room temperature. In this example, 10 types of dies were used to lower the temperature from 500 ° C. to 100 ° C. as the wire diameter was captured, and then wire drawing was performed. For the heat treatment before and after drawing with the die 5, the atmosphere is selected according to the type of superconductor used. Also, the heat treatment conditions are set so that the oxide superconductor exhibits the most excellent superconducting properties by the heat treatment before and after drawing with the die 5. In this embodiment, the temperature is 930 ° C. Then, the heating device 11
The wire material that has been subjected to wire drawing is heated to melt the silver alloy on the surface. In this embodiment, an electric furnace having a Kanthal super wire as a heating element was used as the heating device 11. The molten silver alloy was dispersed in the oxide superconductor and then cooled, and a conductive material was formed on the surface by the thin film device 9. In this example, the conductive material was attached by inserting the wire into a crucible in which aluminum was dissolved and passing it through an aluminum solution. The superconducting wire of this example produced in this manner was strong against mechanical deformation and had a critical current density that was two orders of magnitude or more higher than that of a superconducting wire in which a silver alloy was not melted and dispersed. .

[0028]

As described above, according to the present invention, the characteristics of the oxide superconductor used for the superconducting wire can be sufficiently exhibited without lowering the critical temperature and the critical current due to processing. A superconducting wire that can be manufactured, is resistant to mechanical deformation, is highly reliable, and is practical.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a superconducting wire of the present invention.

FIG. 2 is a conceptual diagram of a method for manufacturing a superconducting wire of the present invention.

FIG. 3 is a conceptual diagram of a method for manufacturing a superconducting wire of the present invention.

FIG. 4 is a conceptual diagram of a method for manufacturing a superconducting wire of the present invention.

FIG. 5 is a conceptual diagram of a method for manufacturing a superconducting wire of the present invention.

[Explanation of symbols]

 1: Oxide superconductor 2: Dispersed substance 3: Conductive material 4: Sheath wire 5: Drawing means 6: Melt 7: Winding roller 8: Heater 9: Conductive material forming device 10: Superconducting wire 11 : Heating device

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01B 12/04 ZAA

Claims (5)

[Claims] 1. A superconducting wire, wherein a conductive material is attached to the outer periphery of a thin wire made of an oxide superconductor in which silver or a silver alloy is dispersed. 2. A silver or silver alloy pipe or a silver or silver alloy pipe having a plurality of small holes formed therein is filled with an oxide superconductor material, drawn to form a thin wire, and then the thin wire is silver. Alternatively, it is placed in a container containing a melt of a conductive material having a melting point higher than that of a silver alloy, and the solution is passed through the melt to disperse silver or a silver alloy in a wire made of an oxide superconductor and the wire. A method of manufacturing a superconducting wire, characterized in that the conductive material is attached to a surface. 3. A silver or silver alloy pipe having a plurality of small holes, filled with a raw material mixture material of an oxide superconductor,
Before and / or after the drawing process for drawing fine wires by wire drawing, the filled oxide superconductor raw material is reacted to form an oxide superconductor, and then the thin wires are made of silver or silver alloy. A conductive material having a higher melting point than that of the oxide superconductor is passed through the molten liquid to disperse silver or silver alloy in the wire made of an oxide superconductor, and the conductive material is applied to the surface of the wire. A method of manufacturing a superconducting wire, comprising: 4. A silver or silver alloy pipe or a silver or silver alloy pipe having a plurality of small holes formed therein is filled with an oxide superconductor material, drawn to form a thin wire, and then the thin wire is silver. Alternatively, a method for producing a superconducting wire, which comprises heating to a temperature higher than the melting point of a silver alloy to melt the conductive material and then attaching a conductive material to the outer periphery of the thin wire. 5. A wire drawing process in which a silver or silver alloy pipe or a silver or silver alloy pipe having a plurality of small holes is filled with a raw material mixture material of an oxide superconductor and wire drawing is performed to form fine wires. Before and / or after the reaction, the filled oxide superconductor raw material is reacted to form an oxide superconductor, and then the thin wire is heated to a temperature higher than the melting point of silver or a silver alloy to melt. A method for manufacturing a superconducting wire, characterized in that a conductive material is attached to the outer periphery of the superconducting wire.