JP5492681B2 - Superconducting wire and manufacturing method thereof, superconducting coil and manufacturing method thereof - Google Patents

Description

  The present invention relates to a superconducting wire, a manufacturing method thereof, a superconducting coil, and a manufacturing method thereof.

  In general, a superconductor is formed by laminating an intermediate layer and a cap layer on a long metal substrate having a wide tape shape for the purpose of controlling crystal orientation and suppressing element diffusion, and then laminating a superconducting layer. A protective layer having a good conductivity is provided. In order to use such a superconductor for practical applications such as cables and transformers, 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 1). As a method of thinning, a plurality of grooves are formed by etching using a photolithographic technique, and a superconducting layer formed on a wide tape-shaped substrate is divided in parallel in the width direction of the substrate. A method of processing into a superconducting layer, a method of physically forming and dividing a groove using a mechanical blade, a YAG laser, etc., irradiating a composition displacement in the oxide superconducting layer at the position corresponding to the previous groove Thus, a method in which the superconducting portion is made into an insulator and the oxide superconducting layer is divided into a plurality of parts by an insulator formed at a position corresponding to the groove is usually applied.
Thus, in a superconducting wire provided with a metal protective layer, it has become an important technique to make the superconducting wire thin in order to reduce AC loss.

JP 2007-141688 A

However, the dividing method using the photolithography technique has a problem that an expensive apparatus is required such that a photomask called an expensive reticle is required for exposure.
In the cutting method using a mechanical blade, it is possible to machine a plurality of grooves at a time by using a plurality of blades, and the throughput when grooving is fast, but it remains in the groove after machining. There is a problem that the material is likely to remain, and there is an influence of the residue, so that the insulation resistance between the separated superconducting layers cannot be increased, and the critical current is deteriorated. Therefore, it is necessary to remove these residues by a technique such as etching, but it is necessary to further etch after cutting with a mechanical blade, and in addition, it is necessary to protect the oxide superconducting layer other than the groove portion. Therefore, there is a problem that the process becomes complicated.

  In addition, even if the tape-shaped substrate is widened to form a film and the structure is divided, if a tape-shaped substrate that is too wide is used, twisting is likely to occur, and the broken superconducting wire breaks. There is a risk that it will lead to a restriction, and there are restrictions when winding the coil shape. Furthermore, when forming a film with a large area using a long base material, a plurality of reels are arranged so that the base material passes through the film formation area multiple times while the base material moves in a meandering manner. It is generally done. However, if the substrate width is reduced and the thin substrate is moved from reel to reel, the thin substrates spanned between the reels tend to overlap and twist easily, making it difficult to transport the thin substrate itself. There is a problem that tends to occur. From the viewpoint of production speed, it is ideally necessary that the wire is arranged and moved in the film forming area without any gap, but this is impossible in practice.

  The present invention has been made in view of the above circumstances, and is a technique capable of manufacturing a superconducting wire with little AC loss and a superconducting coil made of the superconducting wire without performing a process of subdividing the superconducting wire. The purpose is to provide. In addition, since the present invention can efficiently produce a superconducting wire with less AC loss without performing a process of subdividing the superconducting wire, the manufacturing process can be simplified and the cost can be reduced by omitting the subdividing process. The purpose is to provide technology capable of achieving the above.

The present invention has the following configuration in order to solve the above problems.
The superconducting wire of the present invention is characterized in that it comprises a crystal-oriented intermediate layer and an oxide superconducting layer on the side surfaces adjacent to the front and back surfaces of the tape-shaped metal substrate.
The superconducting wire of the present invention is characterized in that the side surface includes an intermediate layer, an oxide superconducting layer, and a protective layer.
The superconducting wire of the present invention is such that the tape-shaped metal substrate is processed so as to reduce its width, except for the side portion of the tape-shaped metal substrate on which the intermediate layer and the oxide superconducting layer are formed. Features.
The superconducting coil of the present invention is a superconducting coil formed by winding the superconducting wire described above into a roll shape, and is a portion on the side of the tape-shaped metal substrate on which an intermediate layer and an oxide superconducting layer are formed. Is a side end face.

The method for producing a superconducting wire of the present invention is characterized in that a crystal-oriented intermediate layer and an oxide superconducting layer are formed on side surfaces adjacent to the front and back surfaces of a tape-shaped metal substrate.
The superconducting wire manufacturing method of the present invention forms a roll body by winding a tape-shaped metal base material in a roll shape so that the front and back surfaces thereof are overlapped, and the roll body side formed from the side surface of the metal base material A crystal-oriented intermediate layer and an oxide superconducting layer are formed on the end face, and then a metal substrate is stretched from the roll body to obtain a tape-shaped superconducting wire.
In the method for producing a superconducting wire of the present invention, when a roll body is formed by winding the tape-shaped metal substrate into a roll shape, a tape-shaped spacer is simultaneously wound so as to overlap the tape-shaped metal substrate, thereby forming the roll body. A coil body of an oxide superconducting layer in which an intermediate layer and an oxide superconducting layer are formed on the side end face of the composite roll body, and is crystal-oriented on the intermediate layer in a state separated by a spacer on the side end face side of the composite roll body Then, a metal substrate is stretched from the roll body to obtain a tape-like superconducting wire.
The superconducting wire manufacturing method of the present invention is characterized in that an intermediate layer, an oxide superconducting layer, and a protective layer are formed on the side end face.
The method for producing a superconducting wire of the present invention is to process a tape-shaped metal substrate so as to reduce its width, except for a side portion of the tape-shaped metal substrate on which an intermediate layer and an oxide superconducting layer are formed. It is characterized by.

The method for producing a superconducting coil according to the present invention includes forming a roll body by winding a tape-shaped metal base material in a roll shape so that the front and back surfaces of the tape-shaped metal base material are overlapped, A crystal orientation-oriented intermediate layer and a crystal orientation-oriented oxide superconducting layer are formed on the end face.
In the method of manufacturing a superconducting coil according to the present invention, when forming the roll body by winding the tape-shaped metal base material into a roll shape, a tape-shaped spacer is simultaneously wound so as to overlap the tape-shaped metal base material, thereby forming A coil body of an oxide superconducting layer in which an intermediate layer and an oxide superconducting layer are formed on the side end face of the composite roll body, and is crystal-oriented on the intermediate layer in a state separated by a spacer on the side end face side of the composite roll body It is characterized by forming.
The method for manufacturing a superconducting coil of the present invention is characterized in that an intermediate layer, an oxide superconducting layer, and a protective layer are formed on the side surface.
The method for manufacturing a superconducting coil according to the present invention is to process a tape-shaped metal substrate so as to reduce its width, except for the side portion of the tape-shaped metal substrate on which an intermediate layer and an oxide superconducting layer are formed. It is characterized by.

According to the present invention, since the intermediate layer and the oxide superconducting layer crystallized on the side surface of the tape-shaped substrate are formed, the superconducting layer formed on the tape-shaped substrate is subdivided to obtain a thin wire having a small line width. A superconducting wire having a small line width and a small AC loss and a superconducting coil made of the superconducting wire can be provided without performing a step of forming a superconducting wire having a linear shape.
Further, the manufacturing process can be simplified by omitting the step of subdividing the superconducting wire, and a superconducting wire that can be manufactured at a lower cost and a method for manufacturing a superconducting coil made of the superconducting wire can be provided.
According to the present invention, a roll body is formed by winding a tape-shaped metal base material in a roll shape so that the front and back surfaces of the tape-shaped metal base material are overlapped, and oxidation is performed on the side end surface of the roll body formed from the side surface of the metal base material. Since the physical superconducting layer is formed, a superconducting coil made of a superconducting wire having a small line width and a superconducting wire having a small line width can be easily manufactured.
Further, according to the present invention, when forming a roll body, the film is formed along the side surface of the tape-shaped base material by simultaneously winding a tape-shaped spacer so as to overlap the tape-shaped metal base material. The insulation problem can be solved by forming the coil formed of the thin line-shaped oxide superconducting layer in a spiral state on the side end face of the roll body in an insulated state. Furthermore, the present invention can be further applied as a superconducting wire or a superconducting coil by processing the tape-like metal substrate after the film formation so as to reduce the width of the tape-like metal substrate except for the portion on the film-forming surface side. Preferably used.
Moreover, the orientation of the oxide superconducting layer can be made favorable by interposing an intermediate layer between the tape-shaped metal substrate and the oxide superconducting layer.

It is a figure which shows an example of the tape-shaped metal base material used for this invention. It is a schematic perspective view of the roll body formed by winding an example of the tape-shaped metal base material used for this invention in roll shape. FIG. 3A shows an example of an oxide superconducting conductor in which a superconducting layer is formed on the side surface of a tape-shaped metal substrate. FIG. 3A is a cross-sectional view after film formation, and FIG. It is a cross-sectional view after giving the process which reduces. It is a schematic perspective view of the superconducting coil obtained by processing so as to reduce the width of the tape-shaped metal substrate. It is a schematic perspective view of the composite roll body formed by winding a tape-shaped spacer at the same time so as to overlap the tape-shaped metal substrate. It is explanatory drawing for forming a groove | channel in a protective layer using a photolithographic technique. It is a schematic perspective view which illustrates the principal part of the laser vapor deposition apparatus used with the one aspect | mode of the manufacturing method of the superconducting wire of this invention.

  FIG. 1 is a view showing a tape-shaped metal substrate 21 used in the present invention. The tape-shaped metal substrate 21 includes a front surface 21a, a back surface 21b, an end surface 21c, and a side surface 21d (21d '). The end surface 21c and the side surface 21d 'are adjacent to the front surface 21a and the back surface 21b. Conventionally, the oxide superconducting layer is generally formed on the surface 21a through the intermediate layer, but in the present invention, it is formed on the side surface 21d '. Since the oxide superconducting conductor A in which the oxide superconducting layer is formed on the narrow side surface 21d ′ can function as a wire, it is not necessary to perform a subdividing step in order to reduce AC loss. .

Embodiments of the superconducting wire and superconducting coil of the present invention will be described below.
(1) 1st embodiment FIG. 2: is a schematic perspective view of the roll body 2 formed by winding the tape-shaped metal base material 21 used for this invention in roll shape so that the front and back may overlap. By winding the tape-shaped metal substrate 21 in a roll shape, a disk-shaped side end surface 21e composed of a side surface 21d 'adjacent to the front surface 21a and the back surface 21b of the tape-shaped metal substrate 21 is formed. In the first embodiment, an oxide superconducting layer is formed on the wide disk-shaped side end face 21e. In this case, it is possible to manufacture the superconducting wire and the superconducting coil easily and quickly compared to the case where the oxide superconducting layer is formed directly on the narrow 21d ′ via the intermediate layer. .

  After forming the roll body 2 by winding the tape-shaped metal substrate 21 into a roll shape, the disk-shaped side end face 21e is ground, polished, and planarized from the viewpoint of improving the crystal orientation of the intermediate layer to be formed. It is preferable to do. Next, the intermediate layer 23 and the oxide superconducting layer 37 are formed on the side end face 21e. The oxide superconducting conductor A manufactured in this way may be used as a superconducting coil as it is, or may be extended and used as a superconducting wire.

Next, the configuration of the superconducting wire and superconducting coil of this embodiment will be described with reference to FIG. FIG. 3A is a cross-sectional view of an oxide superconducting conductor A in which a superconducting layer is formed on the side surface 21d ′ of the tape-shaped metal substrate 21. FIG.
The oxide superconducting conductor A in FIG. 3A is formed on a metal substrate 21 in order, the diffusion preventing layer 12, the bed layer 22, the intermediate layer 23, the cap layer 24, the oxide superconducting layer 37, and the protective layer. 38. The oxide superconductor _{A 2} in FIG. 3 (b), the metal substrate 21 ', the diffusion preventing layer 12, the bed layer 22, intermediate layer 23, the cap layer 24, the oxide superconducting layer 37 and the protective layer 38 It will be.

  As a material constituting the metal substrate 21, metals such as Cu, Ni, Ti, Mo, Nb, Ta, W, Mn, Fe, and Ag, which are excellent in strength and heat resistance, or alloys thereof can be used. . In particular, stainless steel, Hastelloy (registered trademark), and other nickel alloys that are excellent in terms of corrosion resistance and heat resistance are preferable. Alternatively, in addition to these, a ceramic substrate, an amorphous alloy substrate, or the like may be used. In addition, the metal base material 21 is a long tape-shaped thing. In the present embodiment, for example, a long tape-shaped metal substrate having a width of 10 mm and a thickness of 0.1 mm is used.

The diffusion preventing layer 12 is formed for the purpose of preventing the diffusion of the constituent elements of the metal substrate 21, and silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ , also referred to as “alumina”), or consists _{GZO (Gd 2 Zr 2 O 7} ) or the like, a thickness of 10~400nm example.
When the thickness of the diffusion preventing film 12 is less than 10 nm, the diffusion of the constituent elements of the metal substrate 21 may not be sufficiently prevented. On the other hand, when the thickness of the diffusion preventing film 12 exceeds 400 nm, the internal stress of the diffusion preventing layer 12 increases, and each layer may be easily peeled off from the metal substrate 21.
Further, since the crystallinity of the diffusion preventing layer 12 is not particularly limited, it may be formed by a film forming method such as a normal sputtering method.
In the present invention, the diffusion preventing layer 12 may be omitted if necessary.

The bed layer 22 has high heat resistance and further reduces interfacial reactivity, and functions to obtain the orientation of the intermediate layer 23 formed thereon. As the bed layer 22, for example, a film made of a rare earth oxide or a mixture of a rare earth oxide and a metal oxide can be used.
Examples of the rare earth oxide constituting the bed layer 22 include those represented by the composition formula (α ₁ O ₂ ) _2x (β ₂ O ₃ ) _(1-X) . Here, α and β are rare earth elements belonging to 0 ≦ x ≦ 1. More _{specifically,} Y ₂ O _3, a _{CeO 2, Dy 2 O 3,} Nd 2 O 3, Pr 6 O 11, Sc 2 O 3, Sm 2 O 3, Tb 4 O 7, Tm 2 O 3 , etc. It can be illustrated. The mixture of the rare earth oxide and metal oxide constituting the bed layer 22 includes the rare earth oxide and metal oxide MO ₂ (M represents Ti, Zr, or Hf) constituting the bed layer 22 described above. And a mixture thereof.
The bed layer 22 is formed by, for example, a sputtering method, and the thickness thereof is, for example, 10 to 100 nm.

As shown in FIG. 3, when the diffusion prevention layer 12 and the bed layer 22 have a two-layer structure, a structure in which the diffusion prevention layer 12 is made of alumina and the bed layer 22 is made of Y ₂ O ₃ can be exemplified.
In the present invention, it is not limited to the two-layer structure of the diffusion prevention layer 12 and the bed layer 22, and if necessary, a one-layer structure of only the bed layer 22 or 1 of the diffusion prevention layer 12 only. A layer structure is also possible.

  As in this embodiment, the diffusion prevention layer 12 and the bed layer 22 have a two-layer structure when other layers such as the cap layer 24 and the oxide superconducting layer 37 are formed on the bed layer 22. This is to prevent diffusion of some of the constituent elements of the metal substrate 21 toward the oxide superconducting layer 37 through the bed layer 22 when receiving a thermal history as a result of inevitably heat treatment. By making it the two-layer structure of the layer 12 and the bed layer 22, the element diffusion from the metal base material 21 side can be suppressed effectively.

The intermediate layer 23 formed on the bed layer 22 is a vapor deposition film formed by an IBAD (Ion Beam Assisted Deposition) method, and is biaxially oriented on the metal substrate 21 having no orientation. Give sex.
In addition, it functions as a buffer layer that relieves differences in physical characteristics (thermal expansion coefficient, lattice constant, etc.) from the oxide superconducting layer 37 described later, and controls the crystal orientation of the cap layer 24 formed thereon. It functions as an orientation control film.

As the material constituting the intermediate layer 23, a material capable of giving biaxial orientation by the IBAD method is used. Examples of the material of the intermediate layer 23 include MgO, yttria-stabilized zirconium (YSZ), Gd ₂ Zr ₂ O ₇ , CeO _{2, and the} like. In addition, pyrochlore structure, rare earth-C structure, perovskite An appropriate compound having a mold structure or a fluorite structure can be used.
Among these, it is preferable to use MgO, YSZ, or Gd ₂ Zr ₂ O ₇ as the material of the intermediate layer 23. In particular, MgO or Gd ₂ Zr ₂ O ₇ is particularly suitable as a material for the intermediate layer 23 because it can reduce the value of ΔΦ (FWHM: full width at half maximum), which is an index representing the degree of orientation in the IBAD method.

The film thickness of the intermediate layer 23 can be in the range of 1 to 1000 nm (1.0 μm), for example, about several nm, but is not limited to these ranges and values.
When the film thickness of the intermediate layer 23 exceeds 1.0 μm, the deposition rate of the IBAD method used as the film formation method of the intermediate layer 23 is relatively low, so that the film formation time of the intermediate layer 23 becomes long and economical. Disadvantageous.
On the other hand, when the film thickness of the intermediate layer 23 is less than 1 nm, it becomes difficult to control the crystal orientation of the intermediate layer 23 itself, and it becomes difficult to control the degree of orientation of the cap layer 24 formed on the intermediate layer 23. It becomes difficult to control the degree of orientation of the oxide superconducting layer formed on 24. As a result, the oxide superconductor A may have an insufficient critical current.

The cap layer 24 has a function of controlling the orientation of the oxide superconducting layer 37 provided thereon and a function of suppressing diffusion of elements constituting the intermediate layer 23 into the oxide superconducting layer 37.
In particular, the cap layer 24 undergoes a process of epitaxial growth with respect to the surface of the intermediate layer 23, grain growth (overgrowth) in the lateral direction (plane direction), and selective growth of crystal grains in the in-plane direction. A film that is self-orientated is preferably formed. The cap layer 24 that is selectively grown in this manner can have a higher degree of in-plane orientation than the intermediate layer 23.

The material constituting the cap layer 24 is not particularly limited as long as it can exhibit such a function. For example, CeO ₂ , LaMnO ₃ , SrTiO ₃ , Y ₂ O _{3 and the} like are preferably used.
When CeO ₂ is used as the constituent material of the cap layer 24, the cap layer 24 does not need to be entirely composed of CeO ₂ , and Ce-M in which a part of Ce is substituted with another metal atom or metal ion. -O type oxide may be included.

The appropriate film thickness of the cap layer 24 varies depending on its constituent material. For example, when the cap layer 24 is composed of CeO ₂ , the range of 50 to 5000 nm, more preferably the range of 100 to 5000 nm, etc. may be exemplified. it can. If the film thickness of the cap layer 24 is out of these ranges, a sufficient degree of orientation may not be obtained.
The cap layer 24 can be formed using a pulse laser deposition method (PLD method), a sputtering method, or the like, but it is desirable to use the PLD method from the viewpoint of obtaining a high film formation rate.
Note that a configuration without the cap layer 24 is also possible.

In the present embodiment, the basic structure is such that an oxide superconducting layer 37 and a protective layer 38 are formed on the cap layer 24.
As a material of the oxide superconducting layer 37, an RE-123 oxide superconductor (REBa ₂ Cu ₃ O _7-n : RE is a rare earth element such as Y, La, Nd, Sm, Eu, Gd) is used. it can.
Among the RE-123 oxide superconductors, Y123 (YBa ₂ Cu ₃ O _7-n ) or Gd123 (GdBa ₂ Cu ₃ O _7-n ) or the like can be preferably used. In addition, other oxide superconductors, for example, those made of other oxide superconductors having a high critical temperature represented by a composition such as (Bi, Pb) ₂ Ca ₂ Sr ₃ Cu ₄ O _x may be used. . The oxide superconducting layer 37 has a thickness of about 0.5 to 5 μm and preferably a uniform thickness. The oxide superconducting layer 37 can be formed by a film forming method such as a PLD method, a sputtering method, or a TFA-MOD method (an organic metal deposition method using trifluoroacetate, a coating pyrolysis method). The film quality of the oxide superconducting layer 37 is preferably uniform, and the c-axis, a-axis, and b-axis of the crystal of the oxide superconducting layer 37 are epitaxially grown and crystallized so as to match the crystal of the cap layer 24. Thus, the crystal orientation is excellent.

  The protective layer 38 is formed for the purpose of stabilizing the superconducting characteristics of the oxide superconducting layer 37 and is made of a highly conductive metal material such as Ag, an Ag alloy, or Cu. In this embodiment, the protective layer 38 is exemplified. However, the present invention is not limited to this, and a configuration without the protective layer 38 is also possible.

As shown in FIG. 3 (b), in this embodiment, in order to suitably use the manufactured oxide superconducting conductor A as a superconducting wire or a superconducting coil, a tape-like shape in which an intermediate layer and an oxide superconducting layer are formed. It is preferable to process the tape-shaped metal base material 21 so as to reduce the width thereof, except for the portion on the side surface 21d ′ side of the metal base material 21.
FIG. 4 shows a superconducting coil obtained by processing the oxide superconducting conductor A manufactured using the roll body of FIG. 2 so as to reduce the width of the tape-like metal substrate 21 as in FIG. 3B. 3 is a schematic perspective view of FIG. The superconducting coil 3 may be used as a coil as it is, or may be extended and used as a superconducting wire.
As a processing method for reducing the width of the tape-shaped metal base material 21, a processing method by polishing such as CMP, a method by cutting, or a perforation previously placed in the tape-shaped metal base material 21 is used. For example, a method of cutting the base material 21 under the perforation in a state where the upper coil is restrained by a jig or the like is used.

  In the superconducting coil manufactured in the first embodiment, as shown in FIG. 6A, the tape-shaped metal base materials 21 are adjacent to each other. The layer 38 is formed as a unit, and there may be a problem in insulation between the oxide superconductors A. In this case, the above-mentioned problems can be solved by using the following two methods.

When forming the roll body by winding the tape-shaped metal substrate 21 in a roll shape as shown in FIG. 5, the tape-shaped spacer 50 is simultaneously wound so as to overlap the tape-shaped metal substrate 21, thereby forming the roll body. An oxide superconducting layer in which an intermediate layer and an oxide superconducting layer are formed on the side end face 4a of the composite roll body 4 and crystallized on the intermediate layer in a state separated by a spacer 50 on the side end face side of the composite roll body 4 It is preferable to form a coil body. The height of the end face of the spacer 50 is more preferably lower than the end face of the tape-shaped metal base 21. Thereby, there is little possibility that a protective layer will be formed as one.
In addition, the cap layer 24 formed on the intermediate layer 23 having excellent crystal orientation formed by the IBAD method in the structure shown in FIG. 6A shows an excellent orientation of about 5 °. The formed oxide superconducting layer 37 also exhibits excellent orientation. However, the superposed boundary portion of the tape-shaped metal substrate 21 wound in a roll shape is not in a good crystal orientation state, and the oxide insulating layer of the element constituting the oxide superconducting layer 37 is not formed in the boundary portion. Therefore, the oxide superconducting layer 37 is individually configured in a roll shape as a coil. In this regard, when the spacer 50 is coiled together as shown in FIG. 5, an insulating layer of a constituent element of the oxide superconducting layer 37 or a gap can be formed on the side surface of the spacer 50, so that the insulating property can be improved.

Further, as shown in FIG. 6B, a groove may be formed in the protective layer by a technique such as etching using a photolithography technique. Taking an example with reference to FIG. 6, the negative photosensitive resin layer 40 is formed so as to cover the surface of the protective layer 38. The photosensitive resin layer 40 is pre-baked by applying a photosensitive resin to the protective layer 38 by a coating method such as a dipping method, a spray method, or a roll coater method, and then using a hot air dryer or a far infrared irradiation device. It can obtain by performing the drying process of etc. and making it dry.
As the negative photosensitive resin 40 used here, Nippon Paint Co., Ltd., trade name OPTO-ER, N series (OPTO is a registered trademark), Kansai Paint Co., Ltd., trade name Sonne LDI series, etc. can be used. .

  Next, it exposes from the photosensitive resin layer 40 using the exposure apparatus which uses an ultrahigh pressure mercury lamp, a metal halide mercury lamp, etc. as a light source. At the time of this exposure, a photomask is used so that the boundary portion where the end faces of the tape-shaped metal substrate are adjacent to each other in the photosensitive resin layer 40 is not exposed.

From this state, development is performed for 30 seconds to 120 seconds at a liquid temperature of about 25 ° C. to 35 ° C. using a developer such as sodium carbonate, and then a rinse solution is spray applied to complete the development. By this development process, only the unexposed area in the photosensitive resin layer 40 is removed, and a groove 40a is formed in the photosensitive resin layer 40 (see FIG. 6B). After this groove 40a is formed and the surface of the photosensitive resin layer 40 is rinsed and cleaned, an etching process is performed.
After cleaning, the protective layer 38 is divided by wet etching using the photosensitive resin layer 40 as a mask. As an etchant used here, nitric acid or ammonia water + hydrogen peroxide water can be used.

  By this etching process, the protective layer 38 is divided by the separation groove 38a, so that the end surfaces of the oxide superconductor A can be insulated and separated. After completion of the etching step, the photosensitive resin layer 40 is peeled from the protective layer 38 by immersing in an aqueous sodium hydroxide solution (3 to 5%, liquid temperature 40 to 55 ° C.) for about 60 to 90 seconds (FIG. 6C). reference).

(2) Second Embodiment FIG. 7 is a schematic perspective view illustrating the main part of a laser vapor deposition apparatus used in one aspect of the method for producing a superconducting wire of the present invention. The laser vapor deposition apparatus generally used has a configuration for forming a film on the surface 21a of the tape-shaped metal substrate 21, but the laser vapor deposition apparatus used in the method of the present invention is a tape-shaped metal substrate. The film 21 is formed on the side surface 21 d ′ of the material 21.

  The laser vapor deposition apparatus 10 shown here includes a heater box 13 having an opening that surrounds and maintains a tape-shaped metal substrate 21, a backing plate 16 adjacent to the opening 14 of the heater box 13, and the backing plate 16. The target 15 to be held is provided with a laser light irradiation means 17 for irradiating laser light, and further provided with a processing container (not shown) for housing each part of the apparatus other than the laser light irradiation means 17.

  The laser light irradiation means 17 further irradiates the first laser light irradiation means 17a for irradiating the first laser light 18a and the second laser light 18b among the two kinds of laser lights having different energy densities. And a second laser light irradiation means 17b. By using the laser vapor deposition apparatus 10 and irradiating the surface of the target 15 with the first laser beam 18a and the second laser beam 18b, the vapor deposition particle group (plume) 19 struck or evaporated from the target 15 is obtained. It can be deposited on the side surface of the tape-shaped metal substrate 21 in the heater box 13.

  The laser deposition apparatus 10 further includes a delivery reel 20a around which the tape-shaped metal substrate 21 is wound, and a take-up reel 20b that accommodates the superconducting conductor A that has finished forming the oxide superconducting layer. In the heater box 13 provided between the delivery reel 20a and the take-up reel 20b, winding member groups 51a and 51b, in which a plurality of winding members for winding the tape-shaped metal substrate 1, are arranged. The tape-shaped metal base material 21 which is arranged to be spaced apart from each other and wound around the pair of winding member groups 51a and 51b circulates around the winding member groups 51a and 51b, so that the inside of the plume accumulation region Are arranged so as to constitute a plurality of lanes.

  The heater box 13 that accommodates the winding member groups 51a and 51b includes a plurality of heaters (not shown) on the inner wall surface, and energizes these heaters to uniformly heat the tape-shaped metal substrate 21. Can be kept warm. Further, an opening 14 for introducing a plume 19 generated on the surface of the target 15 into the heater box 13 is formed in the center of the bottom surface of the heater box 13.

  In the vicinity (downward) of the opening 14, a backing plate 16 to which the target 15 is fixed is provided so as to be able to reciprocate in the direction of the arrow in the drawing along a plane parallel to the opening 14. In addition, although the water channel for cooling water, another piping, etc. are attached to the backing plate 16 and it comprises as a target holder, these illustrations are abbreviate | omitted in FIG. 7, and only the backing plate 16 is drawn.

The first laser beam 18 a and the second laser beam 18 b are incident on the container 15 through a transparent window (not shown) provided at an appropriate position of the processing container, and are irradiated on the surface of the target 15. An optical system (not shown) such as a reflecting mirror or a condensing lens is provided between the laser light irradiation means 17 and the transparent window as necessary.
The irradiation output of the first laser beam 18a and the second laser beam 18b can be adjusted by the output of an amplifier (not shown) that supplies power to the laser beam irradiation means 17. The frequency is supplied intermittently to the laser beam irradiation means 17 with a constant frequency, or somewhere in the path through which the first laser beam 18a and the second laser beam 18b pass, such as a rotating sector. Adjustment is possible by providing a mechanical shutter and operating the mechanical shutter at a constant frequency.

In order to form an oxide superconducting layer on the tape-shaped metal substrate 21 using the laser deposition apparatus 10, the heater box 13 is drawn while pulling out the tape-shaped metal substrate 21 wound around the delivery reel 20a. Then, it is wound around a pair of winding member groups 51a and 51b accommodated therein, and then the leading end side is led out from the heater box 13 and attached to the take-up reel 20b so that it can be wound. As a result, the tape-shaped metal base material 21 wound around the pair of winding member groups 51 a and 51 b circulates around these winding member groups 51 a and 51 b and moves in a plurality of rows side by side at a desired position in the opening 14. It becomes like this.
Next, the target 15 is placed on the backing plate 16 adjacent to the opening 14. Thereafter, the inside of the processing container may be decompressed and oxygen gas may be introduced as necessary to create an oxygen atmosphere in the container.

  After the tape-shaped metal substrate 21 is set as described above, a pair of winding members in the heater box 13 is energized by energizing the heater provided on the inner wall of the heater box 13 before the film forming operation is started. It is preferable to heat 51a and 51b as a whole and keep the temperature constant. The temperature control of the tape-shaped metal substrate 21 in the heater box 13 is performed by installing a plurality of temperature sensors at appropriate positions in the heater box 13 so that the temperature of the tape-shaped metal substrate 21 is uniform. It is preferable to perform the above by individually controlling ON / OFF.

Next, the target 15 is irradiated with the first laser beam 18 a and the second laser beam 18 b through the transparent window from the laser beam irradiation means 17 while feeding the tape-shaped metal substrate 21 from the delivery reel 20 a.
At this time, in order to form an oxide superconducting film as uniform as possible over the entire length of the tape-shaped metal substrate 21 in the plurality of tape-shaped metal substrates 21 arranged in a lane shape, the first laser beam 18a is used. The second laser beam 18b is sequentially scanned in the width direction of the target 15 over the entire width, and a plume 19 is sequentially generated from a plurality of portions of the entire width of the target 15 to form a film. Films are formed for a long time so that they can be used. Further, by reciprocating the target 15 together with the backing plate 16 in the direction of the arrow in FIG. 7, the first laser beam 18 a and the second laser beam are also applied to the entire region in the direction perpendicular to the width direction of the target 15. As a result, the plume 19 can be sequentially generated from the entire surface of the target 15 by irradiating 18b.

  The plume 19 has an enlarged radial cross-sectional area and is introduced into the heater box 13 through the opening 14. In the vicinity of the opening 14, the tape-shaped metal base material 21 moves in a plurality of rows, so that an oxide superconducting film can be formed on the surface with a necessary thickness. The oxide superconducting conductor A obtained by forming the oxide superconducting film is led out from the heater box 13 and taken up on the take-up reel 20b.

The superconducting conductor A thus obtained can be wound into a roll shape as shown in FIG. 2 to form a superconducting coil. In addition, as described in the first embodiment, when processing to reduce the width of the tape-shaped metal substrate 21, it is better to process after forming the roll body once as shown in FIG. From the viewpoint of work efficiency, it is preferable.
Further, the superconducting conductor A thus processed may be wound in a solenoid shape to form a superconducting coil.

  As described above, the superconducting wire 3 and the superconducting coil 3 made of the superconducting wire can be obtained without performing the step of subdividing the superconducting layer formed on the surface of the wide tape-shaped substrate by the method described above. Can be obtained.

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.
Rolled so that the base material of tape-like Hastelloy C276 (trade name, manufactured by Haynes) with a width of 10 mm and a thickness of 1 mm is overlapped with a JIS standard SUS tape with a width of 8 mm and a thickness of 0.1 mm, and the front and back surfaces are stacked. By rolling into a shape, a roll body having an inner diameter of 15 cm and an outer diameter of 30 cm was formed. On the side end face of the roll body formed from the side surface of the substrate, an Al ₂ O ₃ diffusion prevention layer was formed by sputtering. The film formation temperature of the Al ₂ O ₃ layer was room temperature and the film thickness was 100 nm.
Next, a Y ₂ O ₃ bed layer was formed on the Al ₂ O ₃ diffusion prevention layer by ion beam sputtering so as to have a film thickness of 20 nm.
Subsequently, an IBAD method is used to irradiate the MgO target with an ion beam while irradiating an assist ion beam at an incident angle of 45 ° using an MgO target, and the target particle is knocked out. An intermediate layer of IBAD-MgO is formed on the bed layer. A film was formed (film thickness 5 nm).
Next, a CeO ₂ cap layer having a thickness of 500 nm was formed at 800 ° C. on the intermediate layer of IBAD-MgO by a pulse laser deposition method (PLD method).
Further, an oxide superconducting layer having a composition of Gd123 (GdBa ₂ Cu ₃ O _7-n ) was formed on the cap layer by a PLD method (pulse laser deposition method) (film thickness: 1 μm).
Subsequently, an Ag protective layer having a thickness of 5 μm was formed on the oxide superconducting layer by ion beam sputtering.
When the coil having the structure shown in FIG. 6C formed as described above was cooled with liquid nitrogen and energized, a current of 20 A could be flowed, and it was confirmed that it functions as a superconducting coil.

A, A ₂ Superconducting conductor 12 Diffusion prevention layer 21 Metal substrate 22 Bed layer 23 Intermediate layer 24 Cap layer 37 Oxide superconducting layer 38 Protective layer 40 Photosensitive resin layer 10 Laser deposition apparatus 13 Heater box 14 Opening 15 Target 16 Backing Plate 17 Laser light irradiation means 17a First laser light irradiation means 17b Second laser light irradiation means 18a First laser light 18b Second laser light 19 Plume 50 Spacer 51a, 51b Winding member group 21a Front surface 21b Back surface 21c End face 21d, 21d 'Side face 4a, 21e End face 20a Sending reel 20b Take-up reel 2 Roll body 3 Superconducting coil 4 Composite roll body

Claims (13)

  A superconducting wire comprising an intermediate layer having crystal orientation and an oxide superconducting layer on side surfaces adjacent to a front surface and a back surface of a tape-shaped metal substrate.   The superconducting wire according to claim 1, wherein the side surface includes an intermediate layer, an oxide superconducting layer, and a protective layer.   The tape-shaped metal substrate is processed so as to reduce its width except for a portion on the side surface of the tape-shaped metal substrate on which the intermediate layer and the oxide superconducting layer are formed. 2. The superconducting wire according to 2.   A superconducting coil formed by winding the superconducting wire according to any one of claims 1 to 3 in a roll shape, wherein the side surface side of the tape-shaped metal substrate on which the intermediate layer and the oxide superconducting layer are formed The superconducting coil is characterized in that the portion is a side end face.   A method for producing a superconducting wire, comprising forming a crystal-oriented intermediate layer and an oxide superconducting layer on side surfaces adjacent to the front and back surfaces of a tape-shaped metal substrate.   A roll body is formed by winding a tape-shaped metal base material in a roll shape so that the front and back surfaces are overlapped, and an intermediate layer and an oxide superconductor are formed on the side end surface of the roll body formed from the side surface of the metal base material. 6. The method for producing a superconducting wire according to claim 5, wherein after forming the layer, a metal substrate is stretched from the roll body to obtain a tape-shaped superconducting wire.   When forming the roll body by winding the tape-shaped metal substrate into a roll shape, a tape-shaped spacer is simultaneously wound so as to overlap the tape-shaped metal substrate, and an intermediate layer is formed on the side end face of the composite roll body formed thereby. And the oxide superconducting layer is formed, and the coil body of the oxide superconducting layer crystallized on the intermediate layer in a state of being separated by a spacer on the side end face side of the composite roll body, The method for producing a superconducting wire according to claim 6, wherein a tape-shaped superconducting wire is obtained by stretching a metal substrate.   The method for producing a superconducting wire according to any one of claims 5 to 7, wherein an intermediate layer, an oxide superconducting layer, and a protective layer are formed on the side end face.   9. The tape-shaped metal substrate is processed so as to reduce its width except for a portion on the side surface of the tape-shaped metal substrate on which the intermediate layer and the oxide superconducting layer are formed. The manufacturing method of the superconducting wire of any one of Claims 1.   A roll body is formed by winding a tape-shaped metal base material in a roll shape so that the front and back surfaces of the tape-shaped metal base material are overlapped, and an intermediate layer crystallized on the side end surface of the roll body formed from the side surface of the metal base material A method for producing a superconducting coil, comprising forming an oxide superconducting layer having a crystal orientation on an intermediate layer.   When forming the roll body by winding the tape-shaped metal substrate into a roll shape, a tape-shaped spacer is simultaneously wound so as to overlap the tape-shaped metal substrate, and an intermediate layer is formed on the side end face of the composite roll body formed thereby. An oxide superconducting layer is formed, and a coil body of an oxide superconducting layer is formed by crystal orientation on an intermediate layer in a state of being separated by a spacer on a side end face side of the composite roll body. 10. A method for producing a superconducting coil according to 10.   The method for manufacturing a superconducting coil according to claim 10 or 11, wherein an intermediate layer, an oxide superconducting layer, and a protective layer are formed on the side surface.   The tape-shaped metal substrate is processed so as to reduce the width thereof except for a portion on the side surface of the tape-shaped metal substrate on which the intermediate layer and the oxide superconducting layer are formed. The manufacturing method of the superconducting coil of any one of Claims 1.

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