JP2011009098A - Superconducting wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting wire for stabilizing a superconducting layer and reducing alternating-current loss, and for manufacturing it easily.SOLUTION: In the superconducting wire 1, an intermediate layer 12 made from metal oxide, a superconducting layer 13 and a first metal stabilizing layer 14 are laminated in this order on a surface 11c side of a metal base material 11, a first groove 18 and a second groove 19 reaching to the intermediate layer 12 and dividing the first metal stabilizing layer 14 and the superconducting layer 13 in a width direction are integrally formed on the first metal stabilizing layer 14 and the superconducting layer 13 along a length direction, a second metal stabilizing layer 16 are laminated on a rear surface 11d side of the metal base material 11, and the second metal stabilizing layer 16 is electrically connected with the superconducting layer 13.

Description

  The present invention relates to a superconducting wire in which peeling of a metal stabilizing layer for stabilizing a superconductor is suppressed.

A superconductor such as an yttrium (Y) oxide is maintained in a superconducting state within a range of conditions defined by a critical temperature, a critical current, and a critical magnetic field. On the other hand, depending on the state of the superconductor, it is known that a part of the region becomes a normal conduction state during energization and generates heat, and further, a so-called quench phenomenon occurs in which the whole superconductor is changed to a normal state. ing. When the quench phenomenon occurs, the superconductor burns out. Therefore, in order to prevent this, a stabilizing layer (metal stabilizing layer) made of a metal having good conductivity is placed in contact with the superconducting layer to be compounded. By providing the stabilization layer, even if a partial region of the superconducting layer becomes a normal conduction state during energization, the superconducting layer is stabilized by passing a current through the stabilization layer (energization).
As a method of providing a stabilization layer, a method of forming a stabilization layer (silver stabilization layer) made of silver (Ag) by a physical method such as sputtering or vapor deposition (see Patent Document 1), or via solder A method of forming a stabilization layer (copper stabilization layer) made of inexpensive copper (Cu) on a silver stabilization layer (see Patent Document 2) is disclosed.

On the other hand, in order to use a superconductor for practical use such as a cable and a transformer, it is necessary to reduce AC loss. On the other hand, in a coil using a superconducting wire, a groove reaching the metal substrate is formed in the superconducting layer, and the superconducting layer is divided into a plurality of thin lines, so that AC is inversely proportional to the number of divisions. It is known that loss can be reduced (see Patent Document 3 and Non-Patent Document 1). Laser irradiation, photolithography, etching, etc. are usually applied as the thinning technique.
Thus, in a superconducting wire provided with a metal stabilizing layer in order to stabilize the superconducting layer and prevent burnout, it is important to make the superconducting layer thin in order to reduce AC loss.

JP 2006-236652 A JP 2008-60074 A JP 2007-141688 A

Supercond. Soc. Technol. , 20, 822-826 (2007)

However, as described above, in a superconducting wire provided with a silver stabilizing layer by physical vapor deposition such as sputtering or vapor deposition, the thickness of the silver stabilizing layer needs to be approximately 100 μm or more in order to stabilize the superconducting layer. There was a problem that the cost would increase.
In addition, the superconducting wire having a copper stabilizing layer on the silver stabilizing layer via solder has a problem that it is difficult to make the wire thin. Specifically, when thinning is performed by laser irradiation, the laser irradiation portion becomes high temperature, so that the solder may melt and the copper stabilization layer may be peeled off. Further, when thinning by photolithography, since the entire stabilizing layer is thick, thinning itself is difficult, and the configuration of the apparatus for that is complicated. In addition, when thinning is performed by etching, the solder may be etched and the copper stabilization layer may be peeled off.
Thus, conventionally, there has been no actual superconducting wire that can be easily manufactured and can be put to practical use.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the superconducting wire which can stabilize a superconducting layer and can reduce alternating current loss, and can be manufactured simply.

To solve the above problem,
In the present invention, an intermediate layer made of a metal oxide, a superconducting layer, and a first metal stabilizing layer are laminated in this order on the surface side of a metal substrate, and reach the intermediate layer to reach the first metal stabilizing layer and A groove for dividing the superconducting layer in the width direction is formed integrally with the first metal stabilizing layer and the superconducting layer along the longitudinal direction, and the second metal stabilizing layer is laminated on the back side of the metal substrate. The second metal stabilizing layer is electrically connected to the superconducting layer. A superconducting wire is provided.
In the superconducting wire of the present invention, it is preferable that the second metal stabilizing layer is laminated on the back surface of the metal substrate via a conductive bonding layer.
In the superconducting wire of the present invention, the second metal stabilization layer has extra length portions at both ends in the longitudinal direction, and the extra length portions are folded back to the surface side of the metal base, It is preferable to be electrically connected to the formation layer.

  ADVANTAGE OF THE INVENTION According to this invention, the superconducting wire which can stabilize a superconducting layer and reduce alternating current loss, and can be manufactured simply is obtained.

It is the schematic which illustrates the superconducting wire of this invention, (a) is sectional drawing of a direction substantially perpendicular | vertical with respect to a longitudinal direction, (b) is a longitudinal cross-sectional view of a longitudinal direction, (c) is a top view. It is the schematic for demonstrating the manufacturing method of the superconducting wire of this invention, and is a longitudinal cross-sectional view of the longitudinal direction of a superconducting wire.

In the superconducting wire of the present invention, an intermediate layer made of a metal oxide (hereinafter abbreviated as an intermediate layer), a superconducting layer, and a first metal stabilizing layer are laminated in this order on the surface side of the metal substrate, And a groove for dividing the first metal stabilizing layer and the superconducting layer in the width direction is integrally formed along the longitudinal direction in the first metal stabilizing layer and the superconducting layer. A second metal stabilizing layer is laminated on the back side, and the second metal stabilizing layer is electrically connected to the superconducting layer.
Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view illustrating a superconducting wire according to the present invention, in which (a) is a sectional view in a direction substantially perpendicular to the longitudinal direction, (b) is a longitudinal sectional view in the longitudinal direction, and (c) is a plan view. FIG.
In the superconducting wire 1, the intermediate layer 12, the superconducting layer 13, and the first metal stabilizing layer 14 are laminated on the surface 11 c of the metal substrate 11 in this order. Further, the bonding layer 15 and the second metal stabilization layer 16 are laminated in this order on the back surface 11 d of the metal base 11.

  The metal substrate 11 may be any material that can be used as a substrate for ordinary superconducting wires, and is preferably plate-shaped or sheet-shaped, and is preferably made of a heat-resistant metal. Among heat resistant metals, an alloy is preferable, and a nickel (Ni) alloy or a copper (Cu) alloy is more preferable. Among them, Hastelloy (trade name, manufactured by Haynes Co., Ltd.) is suitable for commercial products, and has different amounts of components such as molybdenum (Mo), chromium (Cr), iron (Fe), cobalt (Co), etc. Any type of C, G, N, W, etc. can be used.

  What is necessary is just to adjust the thickness of the metal base material 11 suitably according to the objective, Usually, it is preferable that it is 10-500 micrometers, and it is more preferable that it is 20-200 micrometers. By setting it to the lower limit value or more, the strength can be further improved, and by setting the upper limit value or less, the critical current density can be further improved.

  The surface 11c of the metal substrate 11 (lamination surface of the intermediate layer 12) preferably has a surface roughness (Ra) of 0 to 30 nm, and more preferably 0 to 5 nm. By setting it to the upper limit value or less, the crystal orientation of the superconducting layer 13 can be controlled better. The surface roughness may be adjusted by polishing the surface of the metal substrate 11 by a known method.

The intermediate layer 12 controls the crystal orientation of the superconducting layer 13 and prevents diffusion of metal elements in the metal substrate 11 into the superconducting layer 13. Then, it functions as a buffer layer that alleviates the difference in physical properties (thermal expansion coefficient, lattice constant, etc.) between the metal substrate 11 and the superconducting layer 13, and the material has physical properties such as the metal substrate 11 and the superconducting conductor. A metal oxide showing an intermediate value with respect to the film 13 is preferable. Specifically, preferred materials for the intermediate layer 12 are Gd ₂ Zr ₂ O ₇ , MgO, ZrO ₂ —Y ₂ O ₃ (YSZ), SrTiO ₃ , CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , Gd _2. Examples thereof include metal oxides such as O ₃ , Zr ₂ O ₃ , Ho ₂ O ₃ , and Nd ₂ O ₃ .

  The intermediate layer 12 may be a single layer or a plurality of layers. For example, the layer made of the metal oxide (metal oxide layer) preferably has crystal orientation, and when it is a plurality of layers, the outermost layer (layer closest to the superconducting layer 13) is at least It preferably has crystal orientation.

  The intermediate layer 12 may have a multi-layer structure in which a cap layer is further laminated on the metal oxide layer. The cap layer has a function of controlling the orientation of the superconducting layer 13, diffuses the elements constituting the superconducting layer 13 into the intermediate layer 12, and reacts the gas used when the superconducting layer 13 is laminated with the intermediate layer 12. It has a function to suppress. The orientation is controlled by the metal oxide layer.

The cap layer is formed through a process of epitaxially growing on the surface of the metal oxide layer, and then growing the grains in the lateral direction (plane direction) (overgrowth) and selectively growing the crystal grains in the in-plane direction. The ones made are preferred. Such a cap layer has a higher degree of in-plane orientation than the metal oxide layer.
The material of the cap layer is not particularly limited as long as it can exhibit the above functions, but specifically, preferred examples include CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , Gd ₂ O ₃ , and Zr ₂ O. ₃ , Ho ₂ O ₃ , Nd ₂ O _{3 and the} like. When the material of the cap layer is CeO ₂ , the cap layer may contain a Ce—M—O-based oxide in which part of Ce is substituted with another metal atom or metal ion.

The thickness of the intermediate layer 12 may be appropriately adjusted according to the purpose, but is usually preferably 0.1 to 5 μm, and more preferably 0.3 to 3 μm. By setting it to the lower limit value or more, a higher effect of controlling the orientation of the superconducting layer 13 can be obtained. By setting the upper limit value or less, it can be formed in a short time, and the surface roughness is further reduced, so that the superconducting layer 13 is reduced. The critical current density of can be further increased.
When the intermediate layer 12 has a multi-layer structure in which a cap layer is laminated on the metal oxide layer, the thickness of the cap layer is usually preferably 0.1 to 1.5 μm. More preferably, it is 0.3-1 micrometer. By setting it in such a range, a higher effect can be obtained.

The intermediate layer 12 is formed by physical vapor deposition such as sputtering, vacuum vapor deposition, laser vapor deposition, electron beam vapor deposition, ion beam assisted vapor deposition (hereinafter abbreviated as IBAD), chemical vapor deposition (CVD). Method: Thermal coating decomposition method (MOD method); It can be laminated by a known method for forming an oxide thin film such as thermal spraying. In particular, the metal oxide layer formed by the IBAD method is preferable in that the crystal orientation is high and the effect of controlling the crystal orientation of the superconducting layer 13 and the cap layer is high. The IBAD method is a method of orienting crystal axes by irradiating an ion beam at a predetermined angle with respect to a crystal deposition surface during deposition. Usually, an argon (Ar) ion beam is used as the ion beam. For example, the intermediate layer 12 made of Gd ₂ Zr ₂ O ₇ , MgO, or ZrO ₂ —Y ₂ O ₃ (YSZ) can reduce the value of ΔΦ (FWHM: full width at half maximum) that is an index representing the degree of orientation in the IBAD method. Therefore, it is particularly suitable.

The superconducting layer 13 is formed with a first groove 18 and a second groove 19 along the longitudinal direction, and the superconducting layer 13 has a width direction (a direction substantially parallel to the surface 11c of the metal substrate). Further, it is divided into three divided layers 131, 132 and 133. That is, the first groove 18 and the second groove 19 reach the intermediate layer 12.
In these divided layers of the superconducting layer 13, the widths W ₁₃₁ , W ₁₃₂ and W _{133 in the} direction substantially parallel to the surface 11c of the metal substrate (lamination surface of the intermediate layer 12) may be the same or different from each other. Good but usually the same.
Further, the width S ₁₃₁ of the first groove 18 and the width S ₁₃₂ of the second groove 19 in the direction substantially parallel to the surface 11c of the metal substrate (lamination surface of the intermediate layer 12) are the same or different from each other. Usually, it is almost the same.
The thickness of the superconducting layer 13 is preferably 0.5 to 9 μm, and more preferably 1 to 5 μm.

The superconducting layer 13 may be a known one, and is preferably made of an oxide superconductor. Specifically, REBa ₂ Cu ₃ O _y (RE is a rare earth element such as Y, La, Nd, Sm, Er, Gd, etc.). Can be exemplified.
The superconducting layer 13 can be laminated by a physical vapor deposition method such as sputtering, vacuum vapor deposition, laser vapor deposition, electron beam vapor deposition, chemical vapor deposition (CVD), or thermal coating decomposition (MOD). Of these, laser vapor deposition is preferred.

  The first metal stabilizing layer 14 is a main component that stabilizes the superconducting layer 13 and prevents burning by energizing when a partial region of the superconducting layer 13 is in a normal conducting state. A first groove 18 and a second groove 19 are formed along the longitudinal direction, and the first metal stabilizing layer 14 is divided into three divided layers 141, 142, and 143. That is, the first metal stabilizing layer 14 and the superconducting layer 13 are integrally formed with the first groove 18 and the second groove 19 along the longitudinal direction.

In these divided layers of the first metal stabilizing layer 14, the widths W ₁₄₁ , W _142, and W _{143 in the} direction substantially parallel to the surface 11 c of the metal substrate (lamination surface of the intermediate layer 12) are the same as each other. However, they may be different, but are usually almost the same.
In addition, the width S ₁₄₁ of the first groove 18 and the width S ₁₄₂ of the second groove 19 in the direction substantially parallel to the surface 11c of the metal substrate (lamination surface of the intermediate layer 12) may be the same as each other. Although they may be different, they are usually almost the same.
As described above, the widths of the first groove 18 and the second groove 19 are generally substantially equal between the superconducting layer 13 and the first metal stabilizing layer 14.
The thickness of the first metal stabilization layer 14 is preferably 3 to 10 μm. By setting it to the lower limit value or more, a higher effect of stabilizing the superconducting layer 13 can be obtained, and by setting the upper limit value or less, the superconducting wire 1 can be thinned.

The first metal stabilization layer 14 is preferably made of a metal having good conductivity, and specifically, can be made of silver or a silver alloy.
The first metal stabilizing layer 14 can be laminated by a known method, and among these, the sputtering method is preferable. In addition, it is preferable to perform oxygen heat treatment in the final step of forming the first metal stabilization layer 14.

  As described above, the first metal stabilizing layer 14 and the superconducting layer 13 are integrally formed with grooves along the longitudinal direction, and the superconducting layer 13 is divided and thinned to thereby reduce the AC loss of the superconducting wire 1. Is reduced.

The bonding layer 15 is for bonding and fixing the second metal stabilizing layer 16 to the metal substrate 11.
The bonding layer 15 is preferably conductive, and more preferably silver paste or solder.
The thickness of the bonding layer 15 is preferably 1 to 5 μm. By setting the lower limit value or more, a higher adhesion fixing effect can be obtained, and by setting the upper limit value or less, the superconducting wire 1 can be thinned.

  The second metal stabilization layer 16 stabilizes the superconducting layer 13 in the same manner as the first metal stabilization layer 14, but is not necessarily conductive as in the first metal stabilization layer 14. May be. Preferred examples of the second metal stabilizing layer 16 include copper (Cu); copper-nickel (Cu-Ni) alloy; nickel (Ni) alloy such as nickel-chromium (Ni-Cr) alloy; stainless steel; silver alloy What consists of either etc. can be illustrated. By forming the second metal stabilization layer 16 with a material cheaper than the first metal stabilization layer 14, a high stabilization effect can be obtained at a low cost.

The second metal stabilization layer 16 includes a bonding layer 15, a metal base 11, an intermediate layer 12, a superconducting layer 13, and a first metal stabilization layer that have a length in the longitudinal direction laminated above the second metal stabilization layer 16. Longer than 14, and has extra length portions 160 and 160 in the vicinity of the end portions 16a and 16a, respectively. The surplus length portion 160 has a first notch portion 161 and a second notch portion 162 at positions corresponding to the first groove 18 and the second groove 19 in a direction substantially perpendicular to the longitudinal direction. Is formed.
Further, each of the surplus length portions 160 is folded back to the base material surface 11c side with the folding start portion 160a as a base point and the portion on the end portion 16a side in the longitudinal direction. As described above, the extra length portion 160 of the second metal stabilizing layer 16 is folded back to the base material surface 11c side by a total angle of about 180 °, and is located on the end portion 16a side. A surface 160 c facing the stabilization layer 14 is laminated on the first metal stabilization layer 14 via the end bonding layer 17 so as to be in contact with the end bonding layer 17. In this state, the first notch part 161 and the second notch part 162 are arranged at the same positions as the first groove 18 and the second groove 19.

Here, in the surplus length portion 160, an example is shown in which the position of the folding start portion 160a in the longitudinal direction substantially coincides with the end portion 15a of the bonding layer 15. However, the present invention is not limited to this. Alternatively, it may be positioned on the end 16a side (not shown).
Further, here, the extra length portion 160 includes the end portion 15a of the bonding layer 15 positioned above the end portion 15a, the end portion 11a of the metal substrate 11, the end portion 12a of the intermediate layer 12, and the end portion 13a of the superconducting layer 13. , And an example in which the first metal stabilizing layer 14 is folded in half or curved without contacting any of the end portions 14a, but is not limited to this in the present invention. It may be folded back so as to contact any one or more of the end portions 11a to 15a (not shown).

The end bonding layer 17 adheres and fixes the facing surface 160 c of the second metal stabilization layer 16 to the first metal stabilization layer 14.
The end bonding layer 17 is conductive and is preferably solder.
Thus, the second metal stabilization layer 16 is electrically connected to the first metal stabilization layer 14 and the superconducting layer 13, and stabilizes the superconducting layer 13 together with the first metal stabilization layer 14. The thickness of the one end bonding layer 17 may be the same as or different from each other, and is preferably 1 to 5 μm for the same reason as in the bonding layer 15.
The length L of the end bonding layer 17 in the longitudinal direction of the superconducting wire 1 (the length of the adhesive fixing portion of the extra length portion 160 in the longitudinal direction) L may be the same as or different from each other. Although it will not specifically limit if the metal stabilization layer 16 can be stably bonded and fixed, It is preferable that it is 30-200 mm. By setting the lower limit value or more, the second metal stabilization layer 16 can be more stably bonded and fixed to the first metal stabilization layer 14, and by setting the upper limit value or less, the superconducting wire 1 can be manufactured at a lower cost. Can be manufactured.

The second metal stabilization layer 16 can be laminated in the same manner as the first metal stabilization layer 14. Further, when a metal sheet or an alloy sheet is available, it may be used for lamination.
What is necessary is just to adjust the thickness of the 2nd metal stabilization layer 16 suitably according to a material. For example, when formed of copper or the like having lower conductivity than silver, the thickness is preferably 40 to 300 μm. By setting it to the lower limit value or more, a higher effect of preventing burning of the superconducting layer 13 can be obtained. By setting the upper limit value or less, the superconducting wire 1 can be thinned.

The superconducting wire 1 may further be entirely covered with an insulating coating layer (not shown). By covering with a coating layer, the grooved portion is particularly protected, and a superconducting wire with stable performance can be obtained.
The coating layer may be made of known materials such as various resins and oxides that are usually used for insulating coatings such as superconducting wires.
Specific examples of the resin include polyimide resin, polyamide resin, epoxy resin, acrylic resin, phenol resin, melamine resin, polyester resin, silicon resin, silicon resin, alkyd resin, and vinyl resin. Moreover, an ultraviolet curable resin is preferable.
As the _{oxide, CeO 2, Y 2 O 3} , Gd 2 Zr 2 O 7, Gd 2 O 3, ZrO 2 -Y 2 O 3 (YSZ), Zr 2 O 3, Ho 2 O 3 or the like can be mentioned .
The thickness of the coating by the coating layer is not particularly limited, and may be appropriately adjusted according to the portion to be coated.
The coating layer may be formed by a known method according to the material, for example, a raw material may be applied and cured. Moreover, when a sheet-like thing is available, you may laminate | stack using this.

The superconducting wire of the present invention is not limited to what has been described so far, and within a range not impairing the effects of the present invention, a part of the configuration may be changed, added or deleted,
For example, the number of grooves formed in the first metal stabilizing layer 14 and the superconducting layer 13 is not limited to two, but may be one or three or more, and may be adjusted as appropriate according to the purpose. .
In addition, for example, the second metal stabilizing layer 16 may not have the first notch 161 and the second notch 162 formed therein.
Furthermore, the second metal stabilization layer 16 does not necessarily have the connection form shown in FIG. 1 as long as it is electrically connected to the superconducting layer 13.

The superconducting wire 1 can be manufactured, for example, by the following method. FIG. 2 is a schematic view for explaining the method of manufacturing a superconducting wire of the present invention, and is a longitudinal sectional view in the longitudinal direction of the superconducting wire.
First, as shown in FIG. 2A, the intermediate layer 12, the superconducting layer 13, and the first metal stabilizing layer 14 are laminated in this order on the surface 11c of the metal substrate.

Next, a first groove 18 and a second groove 19 are formed in the first metal stabilizing layer 14 and the superconducting layer 13 from one end to the other end along the longitudinal direction thereof, and the intermediate layer 12 is exposed. In addition, the first metal stabilizing layer 14 is divided into three divided layers 141, 142, and 143, and the superconducting layer 13 is divided into three divided layers 131, 132, and 133 to be thinned. At this time, the first groove 18 and the second groove 19 may be formed by the same means in the first metal stabilizing layer 14 and the superconducting layer 13 or may be formed by different means. In the case where the S ₁₄₁ and S ₁₃₁ and the S ₁₄₂ and S ₁₃₂ are substantially equal to each other, it is preferable that they are formed by the same means.

  Next, as shown in FIG. 2B, the bonding layer 15 and the second metal stabilizing layer 16 are laminated in this order on the back surface 11d of the metal substrate. At this time, extra length portions 160 and 160 are provided in the vicinity of the end portions 16a and 16a of the second metal stabilizing layer 16, respectively. At this time, a first notch 161 and a second notch 162 are formed in the extra length 160 as necessary.

  Next, as shown in FIG. 2 (c), the surplus length portions 160 of the second metal stabilization layer 16 are folded back to the base material surface 11c side by an angle of about 180 ° from the folding start portion 160a. The facing surface 160 c is bonded and fixed to the first metal stabilizing layer 14 through the end bonding layer 17. Note that the end bonding layer 17 may be provided before or after the surplus portion 160 is folded. As described above, the superconducting wire 1 is obtained.

According to such a manufacturing method, the first groove 18 and the second groove 19 are formed in the first metal stabilizing layer 14 and the superconducting layer 13 to be thinned, and then the end bonding layer 17 is laminated. In addition, since the second metal stabilization layer 16 is bonded and fixed to the first metal stabilization layer 14, the end bonding layer 17 does not exist at the time of thinning, and the end bonding layer 17 deteriorates at the time of thinning. There is no. Therefore, the second metal stabilizing layer 16 can be stably bonded and fixed to the first metal stabilizing layer 14, and a stabilizing effect for preventing a quenching phenomenon or the like can be stably obtained. Further, since the thickness of the first metal stabilizing layer 14 does not need to be increased, it can be easily thinned without using a special apparatus. Furthermore, even if the first metal stabilizing layer 14 is a silver stabilizing layer, the thickness can be reduced by providing the second metal stabilizing layer 16, so that the superconducting wire 1 can be manufactured at a low cost. The wire can be made thinner.
Therefore, a superconducting wire capable of stabilizing the superconducting layer and reducing AC loss can be manufactured easily and at low cost.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples.

[Examples 1 to 5]
The superconducting wire 1 shown in FIG. 1 was manufactured by the manufacturing method shown in FIG. Specifically, it is as follows.
A Gd ₂ Zr ₂ O ₇ layer having a thickness of 1 μm was laminated as an intermediate layer on the surface of a metal substrate having a width of 5 mm, a length of 10 m, and a thickness of 0.1 mm made of Hastelloy C276, and further, A CeO ₂ layer having a thickness of 0.5 μm was laminated by a pulsed laser deposition method (hereinafter referred to as PLD method). Then, a superconducting layer having a composition of 1 μm thickness was laminated on the CeO ₂ layer by a PLD method, and a first metal stabilizing layer made of silver having a thickness of 7 μm was laminated on the superconducting layer by a sputtering method.
Next, the first carbide stabilizing layer and the superconducting layer are formed by forming a first groove and a second groove having a width of 100 μm in the first metal stabilizing layer and the superconducting layer with the rotated carbide blade. Divided.
Next, a silver paste serving as a bonding layer is applied on the back surface of the substrate, and a copper tape having a thickness of 0.1 mm is placed on the silver paste at a speed of 5 m / hour under the conditions shown in Table 1, and the silver paste is applied. A second metal stabilization layer made of copper was laminated by laminating while being cured by heating. At this time, an extra length portion having a length of 100 mm was left at both ends of the second metal stabilizing layer. The heat curing was performed by placing a copper tape on the silver paste on the back surface of the base material and passing it through a heating furnace and sandwiching it with a heated roll.
Next, a first cutout portion and a second cutout portion that are aligned so as to overlap the first groove and the second groove are formed in the surplus length portion, and the surplus length portion is folded back to the substrate surface side. Then, the superconducting wire was obtained by laminating on the first metal stabilizing layer via the solder which becomes the end bonding layer.
About the obtained superconducting wire, the external appearance was confirmed whether there was any deterioration of a joining layer and an edge part joining layer. Moreover, the presence or absence of the deterioration of the superconducting characteristic before and behind formation of the joining layer and the 2nd metal stabilization layer on a base-material back surface was confirmed. Furthermore, the degree of stabilizing effect of the superconducting layer was confirmed. The results are shown in Table 1.

[Example 6]
A second metal stabilization layer made of copper is obtained by bringing the copper tape into contact with the silver paste, pressing it for 1 minute with a press heated to 150 to 200 ° C., heat-curing the silver paste, and laminating the copper tape. A superconducting wire was obtained in the same manner as in Examples 1 to 5 except that the layers were laminated.
As a result, the obtained superconducting wire has no deterioration of the bonding layer and the end bonding layer as in Examples 1 to 5, the appearance is good, the bonding layer on the back surface of the base material, and the second metal stability. There was no deterioration of the superconducting properties before and after the formation of the chemical layer. The stabilizing effect of the superconducting layer was good up to 100K.

[Comparative Examples 1-5]
The same as in Examples 1 to 5 except that no extra length was left at both ends of the second metal stabilization layer and the second metal stabilization layer was not laminated on the first metal stabilization layer. A superconducting wire was obtained. The results are shown in Table 2.

[Comparative Example 6]
A second metal stabilization layer made of copper is obtained by bringing the copper tape into contact with the silver paste, pressing it for 1 minute with a press heated to 150 to 200 ° C., heat-curing the silver paste, and laminating the copper tape. Example, except that the second metal stabilization layer was not laminated on the first metal stabilization layer, and the second metal stabilization layer was not laminated on the first metal stabilization layer. Superconducting wires were obtained as in 1-5.
As a result, the obtained superconducting wire has no deterioration of the bonding layer and the end bonding layer as in Examples 1 to 5, the appearance is good, the bonding layer on the back surface of the base material, and the second metal stability. There was no deterioration of the superconducting properties before and after the formation of the chemical layer. The stabilizing effect of the superconducting layer was good up to 95K.

  The present invention can be used in the fields of energy storage, transformers, motors, generators and the like.

  DESCRIPTION OF SYMBOLS 1 ... Superconducting wire, 11 ... Metal base material, 11c ... The surface of a metal base material, 11d ... The back surface of a metal base material, 12 ... Intermediate | middle layer, 13 ... Superconducting layer, 14 ... 1st metal stabilization layer, 15 ... Bonding layer, 16 ... 2nd metal stabilization layer, 16a ... End of 2nd metal stabilization layer, 18 ... 1st One groove, 19 ... second groove, 160 ... extra length of second metal stabilizing layer

Claims (3)

  An intermediate layer made of a metal oxide, a superconducting layer, and a first metal stabilizing layer are laminated in this order on the surface side of the metal substrate, and reach the intermediate layer to extend the width of the first metal stabilizing layer and the superconducting layer. A groove that is divided in a direction is formed integrally with the first metal stabilization layer and the superconducting layer along the longitudinal direction, and a second metal stabilization layer is laminated on the back side of the metal substrate. A superconducting wire, wherein the second metal stabilizing layer is electrically connected to the superconducting layer.   The superconducting wire according to claim 1, wherein the second metal stabilizing layer is laminated on the back surface of the metal substrate via a conductive bonding layer.   The second metal stabilization layer has extra length portions at both ends in the longitudinal direction, the extra length portions are folded back to the surface side of the metal base material, and are electrically connected to the first metal stabilization layer. The superconducting wire according to claim 1, wherein the superconducting wire is formed.

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