JP2012018870A - Oxide superconductor base material, oxide superconductor using the material, and method for manufacturing the material and the superconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an oxide superconductor base material having a cross section preferable for the application to a superconducting coil or the like; an oxide superconductor using the material; and a method for manufacturing the material and the superconductor.SOLUTION: An oxide superconductor base material comprises: a long base material having a columnar shape including a flat portion in at least one part of an outer circumferential part in a circumferential direction and a circumferential surface portion in at least the other part of the outer circumferential part in the circumferential direction, with the flat portion and the circumferential surface portion being continuously formed over an entire length; and an intermediate layer having a good crystalline orientation, being laminated on the circumferential surface of the base material so as to cover at least one of the flat portion and the circumferential surface portion, by an ion beam assist deposition method.

Description

  The present invention relates to a substrate for an oxide superconducting conductor having an intermediate layer with good orientation on the peripheral surface of a substrate having a cross-sectional shape similar to a circular shape, an oxide superconducting conductor having the substrate, and production thereof Regarding the method.

Rare earth oxide superconductors (REBa ₂ Cu ₃ O _{7-X, where} RE is a rare earth element) are super promising materials at liquid nitrogen temperatures and are considered to be extremely promising materials for practical use. Therefore, it is desired to be used as a power supply conductor. Among them, a superconducting wire using a Y-based oxide superconductor (YBa ₂ Cu ₃ O _7-X ) is strong against an external magnetic field and can maintain a high current density even in a strong magnetic field. In addition to its use as a conductor or a power supply cable, research and development as a conductor for a superconducting fault current limiter is underway.
In any of these research and development applications, it is necessary to use an alignment substrate for the production of rare earth oxide superconducting conductors. As an example of a method for preparing an alignment substrate, an ion beam assisted film formation method (IBAD method) is used. : Ion-Beam-Assisted Deposition).

As one structural example of a rare earth oxide superconducting conductor, a tape-shaped metal substrate, an intermediate layer formed thereon by an IBAD method through a bed layer or a diffusion prevention layer, and a cap formed thereon An oxide superconducting wire comprising a layer and an oxide superconducting layer is known (see, for example, Patent Document 1).
This type of rare earth oxide superconductor is known to exhibit high superconducting properties by being biaxially oriented on an oriented substrate. The higher the crystal orientation of the rare earth oxide superconductor, the higher the critical current. Further, superconducting properties such as critical magnetic field and critical temperature can be obtained.

A structure shown in FIG. 8 is known as an example of an oxide superconducting conductor in which an intermediate layer is formed on a tape-like metal substrate and an oxide superconducting layer is laminated thereon according to the IBAD method described above.
The oxide superconducting conductor T shown in FIG. 8 has a diffusion prevention layer 101 made of Al ₂ O ₃ , a bed layer 102 made of Y ₂ O ₃ , an IBAD on a base material 100 made of a Ni-based heat-resistant alloy tape. An intermediate layer 103 made of MgO or Gd ₂ Zr ₂ O ₇ by a method, a cap layer 104 made of CeO ₂ , a rare earth-based oxide superconducting layer 105, a stabilizing base layer 106 made of Ag, and a stabilization made of Cu The layer 107 is stacked.

JP 2004-71359 A

  When manufacturing the oxide superconducting conductor T having the above-described structure, it is an important technique to adjust the crystal orientation of the intermediate layer 103 by the IBAD method, and the in-plane direction crystal axis used as an index of the crystal orientation degree of the intermediate layer 103 By setting the value of the half width of dispersion (Δφ) to 20 ° or less, the cap layer 104 formed thereon can be self-oriented to make the value of Δφ about 4 to 10 °. By forming an oxide superconducting layer 105 epitaxially on 104, an oxide superconducting conductor T exhibiting excellent superconducting properties can be obtained.

By the way, attempts have been made to use the oxide superconducting conductor T as a conductor for various electric and energy-related electrical equipment, and as a potential development application, a superconducting magnet, a superconducting current limiter, a superconducting transformer, a superconducting generator. Etc. are being considered. In addition, the structure of superconducting coils to be applied to these superconducting devices is known to have a structure in which a long superconducting conductor is wound around a winding drum or a structure in which a superconducting winding circuit is formed on a disk-shaped substrate. Research and development are underway.
In these backgrounds, when an oxide superconducting conductor T as shown in FIG. 8 is wound around a winding drum to form a superconducting coil, the substrate 100 has a thin tape shape, and various films are formed thereon. Even if the film is formed, the film thickness of each film is about several tens of nm to 1 μm, so that the obtained oxide superconducting conductor T is formed in a thin tape shape as a whole.

For this reason, in order to wind this kind of oxide superconducting conductor T around the winding drum, the base material 100 side of the tape-shaped oxide superconducting conductor T is placed along the circumferential surface of the winding drum, and the upper layer from the lower layer side of the winding drum. However, as long as the thin tape-shaped oxide superconducting conductor T is used, it is not easy to perform multi-layer winding on the circumferential surface of the winding drum. That is, in the case of the tape-shaped oxide superconducting conductor T, the direction in which it can be bent is limited, so that it is difficult to align and wind around the winding cylinder, and as long as it is tape-shaped, processing into a free shape is difficult. There is.
Further, if the thin tape-shaped oxide superconducting conductor T is used as an AC superconducting device, the occurrence of AC loss tends to be a problem. For example, it is difficult to twist a thin tape-shaped superconducting conductor T even if it is going to adopt a twisted wire structure or a transition structure for alternating current use. Therefore, there is a problem that a twisted wire structure or a transition structure for reducing AC loss cannot be easily adopted.

Considering one of the reasons why the oxide superconducting conductor T is in the form of a tape, in order to form an intermediate layer having a good crystal orientation by the IBAD method, the substrate 100 is formed by a film forming method such as a sputtering method. While the particles constituting the intermediate layer are deposited on the film forming surface, the incident angle is ± 10 ° from a specific direction such as 45 ° or 55 ° obliquely to the normal of the film forming surface. It is necessary to irradiate the assist ion beam in a narrow range, and a flat surface is desirable as the film formation surface of the base material 100. In order to manufacture a long superconductor, the tape-shaped base material 100 is selected. This is because it is natural.
However, in consideration of application to the above-described superconducting coil, AC use, etc., it is not a tape-shaped oxide superconducting conductor T, but an intermediate layer with good crystal orientation using the IBAD method, and a winding drum, etc. It is desired to provide an oxide superconducting conductor having a shape suitable for winding on a metal. In addition, it is desired to provide an oxide superconducting conductor having a shape that is not a thin tape shape from the viewpoint of reducing AC loss and that can adopt a twisted wire structure or a transition structure.

The present invention has an intermediate layer excellent in crystal orientation by the IBAD method, and is easier to handle than a thin tape-shaped oxide superconducting conductor in the case of application as a superconducting coil or assuming an AC application, An object of the present invention is to provide a base material for an oxide superconducting conductor that can provide an oxide superconducting conductor having a structure that can be easily wound around a winding drum and that can easily suppress the occurrence of AC loss.
Another object of the present invention is to provide an oxide superconducting conductor having such an excellent base material for oxide superconducting conductors and a method for producing them.

The base material for an oxide superconducting conductor of the present invention is a columnar shape having a flat surface portion in at least a part in the circumferential direction of the outer peripheral portion and a circumferential surface portion in at least another portion in the circumferential direction of the outer peripheral portion. And a long base material in which the circumferential surface portion is continuously formed over the entire length, and a crystal laminated on the outer peripheral surface of the base material by at least one of the planar portion and the circumferential surface portion by an ion beam assisted film formation method And an intermediate layer with good orientation.
The base material for an oxide superconducting conductor of the present invention is characterized in that the half-value width (Δφ) of in-plane direction crystal axis dispersion of the intermediate layer laminated by the ion beam assisted film-forming method is 16 ° or less. To do.
The base material for an oxide superconducting conductor according to the present invention is characterized in that the intermediate layer is laminated on the base material through at least one of a bed layer and a diffusion prevention layer.

The base material for an oxide superconducting conductor according to the present invention is characterized in that the outer peripheral portion of the base material is formed in a substantially polygonal cross section in which a plane portion and a circumferential surface portion are alternately arranged in the circumferential direction. To do.
The oxide superconductor of the present invention is characterized in that a cap layer and an oxide superconductor layer are laminated on the intermediate layer of the base material for an oxide superconductor described above.

  The method for manufacturing a base material for an oxide superconducting conductor according to the present invention is a columnar shape having a flat surface portion at least in a circumferential direction of an outer peripheral portion and a circumferential surface portion in at least another portion in the circumferential direction of the outer peripheral portion. A long base material in which the flat surface portion and the circumferential surface portion are continuously formed over the entire length, and at least one of the flat surface portion and the circumferential surface portion is covered on the outer peripheral surface of the base material by an ion beam assisted film formation method. In producing a base material for an oxide superconducting conductor comprising an intermediate layer having a good crystal orientation, the intermediate layer is rolled out from one reel and wound around the other reel. The constituent particles are deposited to pass through a film formation region in which an intermediate layer is formed, and while the substrate passes through the film formation region, an assist ion beam is applied to the substrate from a specific direction simultaneously with the deposition of the particles. Ion beam assisted deposition for irradiation To form an intermediate layer, and when forming the intermediate layer by performing the ion beam assisted film formation method, using a shield plate having a slit-shaped passage hole narrower than the substrate, the passage A hole is disposed along the center in the extending direction of the base material fed between the reels, and covers the both side portions in the width direction of the base material fed between the reels. When depositing and forming the intermediate layer by performing the ion beam assisted film formation method, the constituent particles of the intermediate layer are passed through the passage holes of the shield plate while rotating the base material by a predetermined angle around its circumference. The film is deposited on the flat surface portion or the circumferential surface portion of the base material while sequentially changing the position where the metal is deposited in the circumferential direction of the base material.

In the method for manufacturing a base material for an oxide superconducting conductor according to the present invention, when forming the film by depositing the constituent particles of the intermediate layer on the circumferential surface portion of the base material through the slit-shaped passage hole, The inclination angle of the tangent line of the circumferential surface portion defined at the position where the edge in the width direction of the passage hole is projected onto the circumferential surface portion of the substrate is 30 ° or less as the inclination angle with respect to the surface of the shield plate including the passage hole. It is characterized in that film formation is performed.
In the method for manufacturing a base material for an oxide superconducting conductor according to the present invention, with respect to the width of the slit-shaped passage hole, the incident angle of an assist ion beam incident from an oblique direction on the circumferential surface portion of the base material through the passage hole However, at any position within the irradiation range of the assist ion beam with respect to the circumferential surface portion, the film is formed so as to have a width within a range of ± 10 ° with respect to the incident angle of the specific assist ion beam. Thus, an intermediate layer is formed.

The method for producing a base material for an oxide superconducting conductor according to the present invention is characterized in that the intermediate layer is laminated on the base material through at least one of a bed layer and a diffusion prevention layer.
The method for producing a base material for an oxide superconducting conductor according to the present invention includes a base material having a substantially polygonal cross section in which a planar portion and a circumferential surface portion are alternately arranged in the circumferential direction on the outer peripheral portion as the base material. It is characterized by using.
The method for producing an oxide superconducting conductor of the present invention is characterized in that a cap layer and an oxide superconducting layer are laminated on the intermediate layer described in any one of the preceding items.

Since an intermediate layer with a good crystal orientation by an ion beam assisted film formation method is provided on a column-shaped long base material having a flat surface part at least at a part of the outer peripheral part and a circumferential surface part at the other part, By forming an oxide superconducting layer on the surface, an oxide superconducting conductor with good superconducting characteristics can be obtained, and when coiling for applications such as superconducting coils, an oxide using a tape-like substrate Compared to a superconducting conductor, the degree of freedom in the direction in which bending can be performed is improved, so that there is an effect that coil processing is facilitated. Therefore, if it is an oxide superconducting conductor to which the substrate according to the present invention is applied, it becomes easy to manufacture a superconducting coil applied to a superconducting magnet, a superconducting current limiter, a superconducting transformer, a superconducting generator, etc. The AC loss can be reduced as compared with a structure using a tape-shaped oxide superconducting conductor.
Oxidation with excellent superconducting properties can be achieved by setting the value of the half-value width Δφ of the in-plane direction crystal axis dispersion of the intermediate layer to 16 ° or less so that an oxide superconducting layer is formed thereon via a cap layer. It is possible to provide an oxide superconducting conductor having a structure in which an object superconducting layer is provided on a plane portion or a circumferential surface portion.

Applying the ion beam assisted film-forming method to a columnar long base material having a flat surface part at least in the outer peripheral part and a circumferential surface part in the other part, and utilizing the shield plate having a through hole, the outer peripheral part of the base material The intermediate layer with good crystal orientation is formed by depositing particles in the intermediate layer while irradiating the assist ion beam with the appropriate incident angle only to the necessary area of the crystal. A good intermediate layer can be formed. Therefore, it is possible to obtain a substrate for an oxide superconducting conductor having an intermediate layer excellent in crystal orientation even if it is a columnar substrate having a circumferential surface portion. An excellent oxide superconductor can be obtained.
In order to form an intermediate layer having excellent crystal orientation by the ion beam assisted film formation method on the circumferential surface portion of the base material, the width of the slit-shaped passage hole of the shield plate is important, and the edge of the passage hole is By making the inclination of the tangent passing through the position projected on the circumferential surface portion of the base material to be 30 ° or less, the incident angle of the assist ion beam passing through the through hole and reaching the circumferential surface portion can be within an allowable range. Thus, a base material for an oxide superconducting conductor provided with an intermediate layer having a good crystal orientation on the circumferential surface portion can be provided.

The block diagram which shows an example of the oxide superconducting conductor provided with 1st Embodiment of the base material for oxide superconducting conductors which concerns on this invention. The perspective view which shows an example of the film-forming apparatus used in order to implement an ion beam assist sputtering method. Schematic which shows an example structure of the ion source provided in the film-forming apparatus shown in FIG. Process explanatory drawing which shows an example of the process of manufacturing the base material for oxide superconducting conductors of 1st Embodiment using the film-forming apparatus shown in FIG. The principal part expanded sectional view in the case of implementing the process shown in FIG. The block diagram which shows an example of the oxide superconducting conductor provided with 2nd Embodiment of the base material for oxide superconducting conductors which concerns on this invention. The block diagram which shows an example of the oxide superconductor provided with 3rd Embodiment of the base material for oxide superconductors which concerns on this invention. Explanatory drawing which shows an example of the conventional structure of the oxide superconducting conductor provided with the intermediate | middle layer obtained based on IBAD method.

FIG. 1 is a partial cross-sectional view schematically showing an example of an oxide superconducting conductor including a base material for an oxide superconducting conductor according to the first embodiment of the present invention.
The oxide superconducting conductor A of this embodiment is composed of a diffusion preventing layer 2 made of Al ₂ O _{3 and the} like, Y ₂ O _{3 and the} like on the outer peripheral surface of a long metal base 1 having a substantially circular cross section. Bed layer 3, intermediate layer 4 by IBAD method, cap layer 5 made of CeO ₂ , oxide superconducting layer 6 made of rare earth or the like, stabilization base layer 7 made of Ag, etc., stabilization made of Cu, etc. The layer 8 is sequentially laminated. In this embodiment, the base material 9 for oxide superconducting conductors is configured by laminating the diffusion preventing layer 2, the bed layer 3, and the intermediate layer 4 on the base material 1.
In addition, in the structure of the base material 9 for the oxide superconducting conductor, the diffusion prevention layer 2 and the bed layer 3 are not essential structures, and one or both may be omitted.

The base material 1 has a substantially circular cross-sectional structure in which a flat portion 1A is provided at least in the circumferential direction of the outer peripheral portion of a circular wire having a circular cross section, and the remaining portion in the circumferential direction of the outer peripheral portion serves as a circumferential surface portion 1B. The flat portion 1A is continuously formed over the entire length of the substrate 1.
The base material 1 applicable to the base material A for oxide superconducting conductors can be used as a base material for ordinary superconducting wires and has only to be high strength and heat resistance, and is used for long superconducting cables and superconducting coils. In view of heat resistance, those made of metal are preferable. For example, various heat-resistant metal materials such as stainless steel, copper alloy or nickel alloy, or those in which ceramics are arranged on these various metal materials can be used. Among various heat-resistant metals, nickel alloys are preferable, and if it is a commercial product, Hastelloy (trade name manufactured by Haynes, USA) is suitable, and the amount of components such as molybdenum, chromium, iron, cobalt, etc. is different as Hastelloy. Any kind of Hastelloy B, C, G, N, W, etc. can be used.

The diffusion prevention layer 2 is formed for the purpose of preventing the diffusion of the constituent elements of the base material 1, 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.
If the thickness of the diffusion preventing layer 2 is less than 10 nm, there is a possibility that the diffusion of the constituent elements of the substrate 1 cannot be sufficiently prevented. On the other hand, when the thickness of the diffusion preventing layer 2 exceeds 400 nm, the internal stress of the diffusion preventing layer 2 increases, and this tends to cause the whole including the other layers to be easily peeled off from the substrate 2. Further, since the crystallinity of the diffusion preventing layer 2 is not particularly limited, it may be formed by a film forming method such as a normal sputtering method.

The bed layer 3 has high heat resistance and is used for reducing interfacial reactivity, and is used for obtaining the orientation of a film disposed thereon. Such a bed layer 3 is, for example, a rare earth oxide such as yttria (Y ₂ O ₃ ), and is represented by a composition formula (α ₁ O ₂ ) _2x (β ₂ O ₃ ) _(1-x). It can be illustrated. More _{specifically, Er 2 O 3, CeO 2} , Dy 2 O 3, Er 2 O 3, Eu 2 O 3, Ho 2 O 3, can be exemplified _La 2 _{O 3} and the like. The bed layer 3 is formed by a film forming method such as a sputtering method, and has a thickness of 10 to 200 nm, for example.

The intermediate layer 4 may have either a single layer structure or a multi-layer structure, and is formed of a biaxially oriented material for controlling crystal orientation such as a cap layer 5 laminated thereon. Specific examples of the intermediate layer 4 include 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 O ₃ , Metal oxides such as Zr ₂ O ₃ , Ho ₂ O ₃ , and Nd ₂ O ₃ can be selected.
If the intermediate layer 4 is formed with a good crystal orientation (for example, a crystal orientation of 16 ° or less) by the IBAD method, the crystal orientation of the cap layer 5 formed thereon has a good value (for example, in the cap layer). An oxide superconducting layer capable of exhibiting excellent superconducting properties with a good crystal orientation of the oxide superconducting layer 6 formed on the cap layer 5. The provided oxide superconducting conductor A can be obtained.

The thickness of the intermediate layer 4 may be appropriately adjusted according to the purpose, but can usually be in the range of 5 to 300 nm.
The intermediate layer 4 is laminated by an ion beam assisted sputtering method (IBAD method). The intermediate layer 4 formed by the IBAD method is preferable in that it has a high crystal orientation and a high effect of controlling the crystal orientation of the oxide superconducting layer 6 and the cap layer 5. The IBAD method is a method of orienting a crystal axis of a target thin film by assisting irradiation of an ion beam at a predetermined angle with respect to a base film-forming surface during film formation as described above. Usually, an argon (Ar) ion beam is used as the assist ion beam. For example, the intermediate layer 4 made of MgO or Gd ₂ Zr ₂ O ₇ is particularly preferable because the value of the half-value width ΔΦ (FWHM: full width at half maximum) of crystal axis dispersion, which is an index representing the degree of crystal orientation in the IBAD method, can be reduced. It is.

The cap layer 5 is formed through a process of epitaxial growth with respect to the surface of the intermediate layer 4 and then grain growth (overgrowth) in the lateral direction (plane direction) and selective growth of crystal grains in the in-plane direction. The ones made are preferred. Such a cap layer 5 has a higher in-plane orientation degree than the intermediate layer 4 made of the metal oxide layer.
The material of the cap layer 5 is not particularly limited as long as it can exhibit the above functions, but specific examples of preferable materials include CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , Gd ₂ O ₃ , and Zr _2. Examples thereof include O ₃ , Ho ₂ O ₃ and Nd ₂ O ₃ . When the material of the cap layer 5 is CeO ₂ , the cap layer 5 may include a Ce—M—O-based oxide in which part of Ce is substituted with another metal atom or metal ion.

The CeO ₂ cap layer 5 can be formed by a PLD method (pulse laser deposition method), a sputtering method, or the like, but it is desirable to use the PLD method in that a high film formation rate can be obtained. The film formation conditions for the CeO ₂ cap layer by the PLD method can be performed in an oxygen gas atmosphere at a substrate temperature of about 500 to 1000 ° C. and about 0.6 to 100 Pa.
The thickness of the CeO ₂ cap layer 5 may be 50 nm or more, but is preferably 100 nm or more in order to obtain sufficient orientation. However, if it is too thick, the crystal orientation deteriorates, so that it can be in the range of 50 to 5000 nm, more preferably in the range of 100 to 5000 nm.

The oxide superconducting layer 6 may be a known one, and specifically, a material made of REBa ₂ Cu ₃ O _y (RE represents a rare earth element such as Y, La, Nd, Sm, Er, Gd) is exemplified. it can. Examples of the oxide superconducting layer 6 include Y123 (YBa ₂ Cu ₃ O _7-X ) or Gd123 (GdBa ₂ Cu ₃ O _7-X ).
The oxide superconducting layer 6 is 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). In particular, from the viewpoint of productivity, it is preferable to use the TFA-MOD method (organic metal deposition method using trifluoroacetate, coating pyrolysis method), PLD method or CVD method.
This MOD method is a method in which a metal organic acid salt is applied and then thermally decomposed. After a solution in which a metal component organic compound is uniformly dissolved is applied onto a substrate, the substrate is heated and thermally decomposed. This is a method of forming a thin film on top, and is suitable for the production of a long tape-shaped oxide superconducting conductor because it does not require a vacuum process and enables high-speed film formation at low cost.

  The stabilizing base layer 7 laminated on the oxide superconducting layer 6 is formed as a layer made of a metal material having good conductivity such as Ag and low contact resistance with the oxide superconducting layer 6 and is compatible with Cu. It is set as the laminated structure which compounded the stabilization layer 8 of the highly conductive metal material of this. The stabilizing base layer 7 can be formed by a film forming method such as sputtering, and the stabilizing layer 8 can be formed by a plating method or a foil attaching method.

FIG. 2 shows an example of the structure of a film forming apparatus for carrying out the above-described IBAD method.
The ion beam assisted sputtering apparatus 50 shown in FIG. 2 is arranged in the film forming chamber 51 in a state where the target 52 is supported by the target holder 55 so as to face downward to the film forming region K where the long base material 1 is arranged. The sputter ion source source 54 is disposed so as to face the target 52 in an oblique direction, and a predetermined incident angle with respect to the normal of the installation surface of the substrate 1 installed in the film formation region K. (For example, the incident angle θ = 45 °), the assist ion source source 53 is arranged so as to face each other from an oblique direction.
The ion beam assisted sputtering apparatus 50 of this example is a film forming apparatus in which various devices are provided in a film forming chamber 51 that constitutes a vacuum chamber. When the base material is a long base material 1, The substrate 1 is moved so as to be fed out from one reel 60 to the second reel 61 side so that the substrate 1 can move horizontally in the film formation region K.
The ion source sources 53 and 54 applied in this embodiment include an extraction electrode 57 and a filament 58 inside a container 56 as shown in FIG. 3, and an introduction tube 59 such as Ar gas outside the container 56. It is comprised and can irradiate ion from the front-end | tip of the container 56 parallel to a beam form.

  The vacuum chamber constituting the ion beam assisted sputtering apparatus 50 used in the present embodiment is a container that partitions the outside and the film formation space, and has airtightness and pressure resistance because the inside is in a high vacuum state. It is said. The vacuum chamber is connected to a gas supply means for introducing a carrier gas and a reactive gas into the vacuum chamber, and an exhaust means for exhausting the gas in the vacuum chamber. In FIG. For brevity, only the arrangement relationship of each device is shown. The target 52 used here can be a target having a composition commensurate with the material constituting the intermediate layer 4 described above.

  In the ion beam assisted sputtering apparatus 50, a rectangular shield plate 62 covers the substrate 1 fed between the reels 60 and 61 at a position between the target 52 and the ion source source 53 and the film formation space K. Are arranged horizontally. The shield plate 62 is made of a metal rectangular plate material such as JIS standard SUS304 (stainless steel), and is formed to have a width and length that can substantially cover the film formation space K between the reels 60 and 61. A slit-shaped passage hole 62 a that is slightly narrower than the base material 1 is formed at the center in the width direction.

As shown in FIG. 5, the passage hole 62a of the shield plate 62 arranges the base material 1 horizontally below the passage hole 62a, and the uppermost portion 1C of the circumferential surface portion 1B of the base material 1 is located on the center side of the passage hole 62a. And the angle of inclination θ of the tangent S of the circumferential surface portion 1B defined at a position where the edge 62b in the width direction of the slit-shaped passage hole 62a is projected onto the circumferential surface portion 1B of the substrate 1. The inclination angle θ) with respect to the surface of the shield plate 62 is set to be 30 ° or less, for example, 5 to 30 °. The condition of 30 ° or less is one of setting examples when the incident angle θ2 of the assist ion beam with respect to the surface of the shield plate 62 is 45 °.
The reason why the inclination angle θ is set to 30 ° or less is to prevent the ion beam from hitting a portion (region) where the angle of the substrate surface with respect to the ion beam deviates from an appropriate angle.

Further, as a more preferable width of the slit-shaped passage hole 62a, an assist ion beam incident from an oblique direction to the circumferential surface portion 1B of the substrate 1 through the passage hole 62a is assisted ions with respect to the circumferential surface portion 1B. It is preferable that the width is set to be within a range of ± 15 ° with respect to the incident angle of the specific assist ion beam at any position within the beam irradiation range.
However, if the inclination angle is too small, the width of the passage hole of the shield plate becomes too small, and the number of steps when the intermediate layer is sequentially formed in the circumferential direction by rotating the substrate 1 may increase unnecessarily. Considering this, the range of the practical inclination angle θ is preferably in the range of 15 to 20 °.

In the ion beam assisted sputtering apparatus 50 shown in FIG. 2, as a mechanism for rotating the substrate 1, a rotation mechanism is incorporated in a mechanism that supports the central axis C of the reels 60 and 61. collectively substrate 1 which is fed between them are configured to be rotated in the direction of arrow E _1, E ₂ of Figure 2. As an example of the rotation mechanism, if a C-shaped or Y-shaped shaft support member that supports both ends of the central axis C of the reels 60 and 61 is configured to rotate synchronously, the reels 60 and 61 are extended between the reels 60 and 61. The substrate 1 can be rotated around its circumference.

By using the ion beam assisted sputtering apparatus 50 having the structure shown in FIG. 2, the IBAD method can be performed, and the target intermediate layer 4 can be formed on the outer peripheral surface of the substrate 1.
When the intermediate layer 4 is formed by the IBAD method, a source gas such as Ar gas or oxygen gas is introduced into the vacuum chamber containing the target 52, the ion source sources 53 and 54, and the substrate 1 shown in FIG. For example, the inside is adjusted to a desired degree of vacuum and then adjusted to a mixed gas atmosphere (source gas atmosphere) such as Ar: O ₂ = 9: 1.
The vacuum chamber used in the present embodiment can be adjusted to a desired degree of vacuum in the range of 0.008 Pa to 0.00008 Pa in a reduced pressure atmosphere using a vacuum pump, for example, with back pressure. The degree of vacuum in this range can be reached by appropriately adjusting the time required for pressure reduction by the vacuum pump.

  And in order to form the intermediate | middle layer 4 on the bed layer 3 of the base material 1, after setting the back pressure of the film-forming atmosphere at the time of pressure reduction with a vacuum pump to the target value, the said source gas is introduce | transduced, The target 52 is irradiated with an ion beam from the sputter ion source 54 to eject and eject target particles, and the particles of the intermediate layer 4 are deposited on the bed layer 3 and at the same time oblique to the film formation surface of the bed layer 3. An ion beam assisted sputtering method for forming a film while irradiating an ion beam from the assist ion source 53 from the 45 ° direction is performed. The film forming temperature at the time of performing the ion beam assisted sputtering method may be normal temperature.

  In order to form the intermediate layer 4 on the entire outer peripheral portion of the substrate 1 by performing the ion beam assisted sputtering method, as shown in FIG. When depositing the constituent particles of the intermediate layer while concealing, only the sputtered particles that fly from the target 52 and pass through the passage hole 62a are deposited while being irradiated with an assist ion beam from an oblique direction of 45 °, for example. The intermediate layer 4 is formed only on the circumferential surface portion 1B in the lower region of 62a. Here, since the aforementioned inclination angle θ is set to 30 ° or less, the assist ion beam irradiated at an incident angle of 45 ° in the oblique direction is directed to the circumferential surface portion 1B of the base material 1 positioned below the passage hole 62a. As a result of being incident at an incident angle of an appropriate allowable range, the intermediate layer 4 formed on the circumferential surface portion 1B on the lower side of the passage hole 62a is in a state where the crystal orientation is in order, and the intermediate layer having the target crystal orientation is obtained. 4 can be formed on the circumferential surface portion 1B.

  If the intermediate layer 4 having a desired film thickness is formed on the circumferential surface portion 1B of the base material 1, the base material 1 is turned clockwise by a predetermined angle as shown in FIG. 4 (B) from the state shown in FIG. 4 (A). When the intermediate layer 4 is rotated and held for a predetermined time, the intermediate layer 4 is formed at a position adjacent to the previously formed intermediate layer 4 by depositing particles through the passage holes 62a at other positions on the circumferential surface portion 1B of the base material 1. it can. When this particle deposition process is performed at predetermined angles as shown in FIGS. 4B to 4E, the intermediate layer 4 is sequentially formed along the circumferential direction on the outer peripheral portion of the circumferential surface portion 1B of the substrate 1. Therefore, the intermediate layer 4 can be formed on the entire circumference including the circumferential surface portion 1B and the flat surface portion 1A of the substrate 1 by sequentially performing the particle deposition and the rotation operation of the substrate 1. 4 (A) to 4 (E), an area where the film is first formed on the circumferential surface portion 1B of the base material 1 is indicated by an arrow F. In FIGS. 4 (A) to (E), the base material 1 is shown. It is displayed so that the rotation angle when rotating can be easily understood.

About the plane part 1A formed in the outer peripheral part of the base material 1, as shown to FIG. 4 (A)-(E), it can utilize as a mark of the rotation angle in the case of rotating the base material 1 by a predetermined angle. In the present embodiment, the planar portion 1A is also a surface on which the intermediate layer 4 is formed in a state where the planar portion 1A is positioned below the passage hole 62a. The intermediate layer 4 may be deposited only on the entire peripheral surface of the circumferential surface portion 1B of the substrate 1 by omitting the deposition of the intermediate layer 4 on the flat surface portion 1A.
If the intermediate layer 4 is formed on the entire peripheral surface of the base material 1, the part of the base material 1 where the intermediate layer 4 is formed by being positioned below the shield plate 62 is moved to the reel 61 side to start from the reel 60 side. After the base material 1 without the intermediate layer is fed out and the base material 1 without the intermediate layer is positioned below the passage hole 62a of the shield plate 62, the base material 1 is again formed as shown in FIGS. While rotating the material 1, an operation for forming the intermediate layer 4 on the entire circumferential surface is performed. By repeatedly performing the rotation operation of the base material 1 and the operation of feeding the base material 1 from the reel 60 side to the reel 61 side, the intermediate layer 4 can be formed over the entire circumference of the base material 1.

When the intermediate layer 4 is formed on the entire length and the entire peripheral surface of the base material 1, the cap layer 5 is formed on the intermediate layer 4 of the base material 1 according to the PLD method or the sputtering method described above. When the cap layer 5 is formed on the entire peripheral surface of the substrate 1, the reel described above is formed in the film forming apparatus when the film is formed by the PLD method, and in the film forming apparatus when the film is formed by the sputtering method. A mechanism equivalent to 60 and 61 is incorporated, and the base material 1 is sequentially formed while rotating, and the base material 1 is drawn out from one reel to the other reel in the length direction on the intermediate layer 4 of the base material 1. The cap layer 5 may be formed.
When the cap layer 5 is formed as a layer made of the above-mentioned material, it exhibits a better crystal orientation than the crystal orientation of the intermediate layer 4 due to the self-orientation effect. For example, the value of Δφ is about 5 °. Excellent crystal orientation can be obtained.

Thereafter, the oxide superconducting layer 6 is formed on the cap layer 5 of the substrate 1. Here, when the oxide superconducting layer 6 is formed on the cap layer 5 having good orientation as in the structure shown in FIG. 1, the oxide superconducting layer 6 laminated on the cap layer 5 is also formed of the cap layer 5. Crystallize to match the orientation. When the oxide superconducting layer 6 is formed, similarly to the formation of the cap layer 5, the substrate 1 is fed from one reel provided in the film forming apparatus to the other reel side and is formed while rotating. Thus, the oxide superconducting layer 6 can be formed on the entire circumference of the substrate 1.
The oxide superconducting layer 6 formed on the cap layer 5 has almost no disorder in the crystal orientation. In each of the crystal grains constituting the oxide superconducting layer 6, the radial direction of the base material 1 is used. The c-axis is difficult to pass electricity to, and the a-axis or the b-axis is biaxially oriented in the length direction of the substrate 1. Therefore, the obtained oxide superconducting layer 6 is excellent in quantum connectivity at the crystal grain boundary, and hardly deteriorates in the superconducting characteristics at the crystal grain boundary. An oxide superconducting conductor A having an outer diameter circular cross-sectional structure exhibiting a very high critical current density is obtained.

In the case of the oxide superconducting conductor A having the structure shown in FIG. 1, the oxide superconducting layer 6 is provided on the outer peripheral surface of the substrate 1 close to a circular cross section, and the oxide superconducting conductor A as a whole is similar to the circular cross section. Since it has a shape, unlike the conventional tape-shaped oxide superconducting conductor, it has a high degree of freedom in bending, so that workability in the case of forming a superconducting coil by winding it around a winding drum is improved. Moreover, when winding around a winding drum, it can be set as the standard of a winding direction by winding so that the plane part 1A may face the winding drum surrounding surface side. Further, if the conductor structure has the oxide superconducting layer 6 on the outer peripheral surface of the substrate 1 having a substantially circular cross section, when the oxide superconducting conductor A is wound around a winding drum to form a superconducting coil, the AC loss is reduced. Contributes to suppression.
In addition, if it is a structure which has the oxide superconducting layer 6 in the whole outer peripheral surface, when it is set as a superconducting coil, there exists the characteristic which is hard to be influenced by the directionality of a magnetic field. That is, in the region where the vector component of the magnetic field generated by the superconducting coil is perpendicular to the oxide superconducting layer 6, the superconducting characteristics of that region may deteriorate due to the influence of the magnetic field. If the oxide superconducting layer 6 is formed on the entire surface, even if the superconducting property of the region is partially deteriorated due to the influence of the magnetic field in a region of the substrate 1 in the circumferential direction. Since the oxide superconducting layer 6 in other regions in the circumferential direction of the substrate 1 maintains the superconducting characteristics, deterioration of the superconducting characteristics can be reduced when viewed as a whole of the oxide superconducting conductor A.
In this regard, if a superconducting coil is formed using an oxide superconducting conductor having a structure having a band-shaped oxide superconducting layer along only a part of the outer peripheral surface of the substrate 1, the superconducting coil generates a magnetic field. In addition, there is a possibility that the entire oxide superconducting layer at any part in the length direction of the long oxide superconducting conductor may deteriorate in characteristics, which may lead to deterioration in superconducting characteristics. Therefore, the oxide superconducting conductor A having the above-described configuration has an effect of suppressing deterioration of characteristics when coiled.

FIG. 6 is a partial cross-sectional view schematically showing an example of an oxide superconducting conductor provided with the base material for oxide superconducting conductor according to the second embodiment of the present invention.
The oxide superconducting conductor B of this embodiment has a diffusion prevention layer 12, a bed layer 13, an intermediate layer 14 by IBAD method on the outer peripheral surface of a long metal base 11 having a substantially rectangular cross section, The cap layer 15, the oxide superconducting layer 16, the stabilization base layer 17, and the stabilization layer 18 are sequentially stacked. In this embodiment, the base material 19 for oxide superconducting conductors is configured by laminating the diffusion prevention layer 12, the bed layer 13, and the intermediate layer 14 on the base material 11.
The metal base 11 has a substantially quadrangular shape in which four planar portions 11A and four circumferential surface portions 11B are alternately arranged in the circumferential direction. Therefore, the oxide superconducting conductor B is formed in a substantially quadrangular shape as a whole.

Even in the oxide superconducting conductor B of this embodiment, the oxide superconducting material is formed on the circumferential surface portion 11B by using the shield plate 62 having the passage hole 62a as in the oxide superconducting conductor A of the first embodiment. Layer 16 can be deposited. When the film is formed on the circumferential surface portion 11B, the width of the passage hole 62a of the shield plate 62 is slightly narrower than the width of the circumferential surface portion 11B, and the film is formed on the circumferential surface portion 11B. In addition, it is preferable that no film is formed on the planar portions 11A on both sides.
Further, when the film is formed on the portion of the flat portion 11A, the width of the passage hole 62a of the shield plate 62 is slightly narrower than the width of the flat portion 11A, and adjacent to the case where the film is formed on the flat portion 11A. More preferably, no film is formed on the circumferential surface portion 11B. Further, the width of the passage hole 62a of the shield plate 62 is allowable regardless of the position of the circumferential surface portion 11B through the passage hole 62a, as in the case of the first embodiment. The same is true for setting the incident angle of the ion beam within a range.

  Even in the oxide superconducting conductor B having the cross-sectional structure shown in FIG. 6, it is possible to obtain the same effects as the oxide superconducting conductor A of the first embodiment.

FIG. 7 is a partial cross-sectional view schematically showing an example of an oxide superconducting conductor provided with the base material for an oxide superconducting conductor according to the third embodiment of the present invention.
The oxide superconducting conductor C of this embodiment has a substantially rectangular cross section and each outer peripheral surface of the columnar long metal substrate 11 spirally swung at a predetermined pitch over the entire length. Further, the diffusion prevention layer 22, the bed layer 23, the intermediate layer 24 by the IBAD method, the cap layer 25, the oxide superconducting layer 26, the stabilization base layer 27, and the stabilization layer 28 are sequentially laminated. ing. In this embodiment, the base material 29 for oxide superconducting conductors is configured by laminating the diffusion prevention layer 22, the bed layer 23, and the intermediate layer 24 on the base material 21.
The metal base material 21 has a substantially quadrangular shape in which four plane portions 21A and four circumferential surface portions 21B are alternately arranged in the circumferential direction, and the four planar portions 21A and the circumferential surface portion 21B. Are formed in a spiral shape at a predetermined pitch over the entire length of the substrate 21.
Even in the oxide superconducting conductor C having the cross-sectional structure shown in FIG. 7, it is possible to obtain the same effects as the oxide superconducting conductor A of the first embodiment.

  In order to manufacture the oxide superconducting conductor C of this embodiment, the planar portion 21A is formed so as to spirally spiral at a predetermined pitch in the length direction of the substrate 21, so that the film formation of the film forming apparatus is performed. The passage hole 62c provided in the shield plate disposed in the region has a width and length shape corresponding to the planar portion 21A having a predetermined length of the base material 21. Here, the predetermined length and width of the passage hole 62c ensure the allowable range of the incident angle of the assist ion beam with respect to the plane portion 21 of the predetermined length range of the base material 21 as in the previous embodiment. The shield plate is configured as a configuration that can be concealed by the shield plate.

While the passage hole 62c of the shield plate is opposed to the flat surface portion 21A of the predetermined length range of the base material 21, the base material 21 is rotated little by little around its circumference from the one reel in the longitudinal direction of the base material 21. By forming the film while moving the base material 21 to the other reel, the intermediate layer 24 is formed on one continuous plane portion 21A spirally arranged at a predetermined pitch in the length direction of the base material 21. Therefore, by sequentially forming the film on the remaining three flat portions 21A, the intermediate layer 24 can be formed on each of the four flat portions 21A arranged in a spiral shape over the entire length of the base material 21.
As an example, the outline of the passage hole 62c of the shield plate is shown by a two-dot chain line in FIG. 7, and the range in which particles are deposited along the passage hole 62c is set at a predetermined angle in the length direction of the base material 21. The intermediate layer 24 corresponding to the planar portion 21A having a predetermined spiral pitch can be formed by moving while rotating each time.

  In addition, in order to form a film in a spiral range of a predetermined pitch along the circumferential surface portion 21B of the base material 21, a shield plate provided with a passage hole 62d surrounded by a two-dot chain line in FIG. By rotating the base material 21 by a predetermined angle while moving the base material 21 in the length direction, it is possible to form the intermediate layer 24 corresponding to the circumferential surface portion 21B having a predetermined spiral shape.

In the oxide superconducting conductor C of the present embodiment, the intermediate layer 24 is formed only along the plane portion 21A without forming the intermediate layer 24 on the circumferential surface portion 21B, and only on the intermediate layer 24. The cap layer 25, the oxide superconducting layer 26, the stabilizing base layer 27, and the stabilizing layer 28 may be configured. In that case, since the oxide superconducting layer 26 is not formed on the circumferential surface portion 21B, a stranded wire structure in which four oxide superconducting layers 26 are spirally formed at a predetermined pitch on the circumferential surface of the base material 21. An oxide superconductor can be obtained.
In the case of the oxide superconducting conductor of this example, the oxide superconducting layer can be provided on the outer peripheral surface of the substrate 21 as a twisted wire structure (spiral structure). Obtainable. If it is an oxide superconducting conductor of this structure, there exists an effect which can obtain the oxide superconducting conductor which can suppress an alternating current loss.

As mentioned above, although each embodiment of the base materials A, B, and C for oxide superconducting conductors according to the present invention has been described, in these embodiments, each part constituting the superconducting conductor is an example, and the scope of the present invention is within the scope of the present invention. Changes can be made as appropriate without departing from the scope.
For example, the cross-sectional shape of the base material is not limited to the shape of the previous form, but a substantially elliptical base material in which a flat surface portion is provided in at least one place of the elliptical cross-sectional shape, a circumferential surface portion at a corner of the polygonal base material Needless to say, the present invention can be applied to a substantially polygonal base material provided with the.

Specific examples of the present invention will be described below, but the present invention is not limited to these examples.
On a base material having a substantially circular cross section shown in FIG. 1, which is made of a long Hastelloy C276 (trade name of US Haynes Co., Ltd.) having a circular cross section with a diameter of 10 mm and a flat portion with a width of 2 mm on the outer peripheral surface with a total length of 20 m. Then, an Al ₂ O ₃ diffusion prevention layer (thickness 150 nm) and a Y ₂ O ₃ bed layer (thickness 20 nm) were laminated by sputtering. In order to form the diffusion prevention layer and the bed layer on the entire outer peripheral surface of the base material, the film is formed on the entire peripheral surface by rotating the base material inside the sputtering apparatus used to form these layers. Filmed.
An intermediate layer of MgO was formed on this laminate by ion beam assisted sputtering using the film forming apparatus shown in FIG.
In carrying out the ion beam assisted sputtering method, the base material is wound around one reel member, the other end of the base material is wound around the other reel member, and the base material is fed between both reels. It was arranged in the film forming space of the film forming apparatus.

A base plate in which a rectangular plate shield plate made of stainless steel (SUS304) made of stainless steel (SUS304) having a slit-like passage hole having a width of 5 mm smaller than the width of the base material is arranged along the base material, and is drawn out between the reel members. The width direction both ends were covered up. In this state, the base material positioned between both reels was exposed to the MgO target, and in this state, an ion beam assisted sputtering method was performed to form a MgO intermediate layer.
In the passage hole of the shield plate, the inclination angle θ of the tangent to the circumferential surface portion at a position where the edge in the width direction is projected onto the circumferential surface portion of the base material below is 15 °.

In carrying out the ion beam assisted sputtering method, a film forming apparatus having the structure shown in FIG. 2 is used, and the incident direction of the assist ion beam is set in a direction inclined by 45 ° with respect to the normal of the shield plate surface, and the film forming temperature is set to 30 An ion beam assisted sputtering method was performed using a mixed gas of Ar gas: O ₂ gas = 9: 1 as a source gas in a film formation atmosphere at a temperature of 0 ° C. (room temperature) and using an MgO target. The film was formed by setting the acceleration voltage of the assist ion beam to 1400 V, the current density to 90 μA / cm ^2, and the back pressure of the film formation atmosphere to 0.00008 Pa.

  After performing ion beam assisted sputtering and forming a MgO intermediate layer with a thickness of about 20 nm on the base material, both the pair of reels and the base material fed between the reels are rotated by 15 ° as shown in FIG. By depositing the film 24 times, after depositing an MgO intermediate layer with a thickness of about 20 nm on the entire circumference of the substrate, the substrate that has not been deposited between the pair of reels is fed out and formed again on the entire circumference. This operation was sequentially repeated over the entire length of the substrate to form a MgO intermediate layer with a thickness of about 20 nm over the entire length of the substrate.

  Next, the irradiation of the assist ion beam was stopped and switched to the ion beam sputtering method, and an epitaxial MgO layer (Epi-MgO) having a film thickness of about 400 nm and a film thickness of 300 ° C. was laminated on one end in the length direction of the substrate. . This epitaxial MgO layer having a thickness of about 400 nm is formed in order to measure the crystal orientation of the IBAD-MgO intermediate layer by performing X-ray measurement. Since the MgO intermediate layer having a thickness of 20 nm is too thin and X-ray measurement is difficult or impossible, after the epitaxial MgO layer is formed, the base material in the film forming portion is cut out, and the circumferential direction of the base material 4 An MgO (220) positive electrode point measurement was performed by X-ray measurement at the location, and the average value of the half-value width Δφ of the crystal axis dispersion, which is an index of crystal orientation, was obtained.

  Since the epitaxial MgO layer is oriented so as to follow the orientation of the 20 nm thick MgO intermediate layer formed by the IBAD method, the excellent Δφ of the epitaxial MgO layer is equivalent to the MgO layer of the underlying IBAD method as well. It means that it has a good orientation. From this measurement result, it was found that an MgO layer formed on a substrate having a circular cross section by the IBAD method exhibits good crystal orientation.

A CeO ₂ cap layer having a film thickness of 500 nm was formed at 800 ° C. on the IBAD-MgO layer formed over almost the entire length of the substrate by a pulse laser deposition method (PLD method). The cap layer was also formed on the entire circumference of the substrate by rotating the substrate inside the laser deposition apparatus. When Δφ was measured at four locations on the peripheral surface of the base material of the cap layer, the average Δφ was 5 °, indicating good orientation.
Next, a RE123-based oxide superconducting layer having a thickness of 1.0 μm is formed on the cap layer by pulse laser deposition, and further, Ag (stabilizing layer) having a thickness of 10 μm is sputtered on the oxide superconducting layer. Then, a 0.1 mm thick copper layer (stabilization layer) was laminated to produce an oxide superconducting conductor. The oxide superconducting layer was formed using a target obtained by sintering a powder of GdBa ₂ Cu ₃ O _y (GdBCO) at a temperature of 800 ° C., a pressure of 80 Pa, a laser output of 180 W, and an oxygen of 80%. went. Regarding the formation of this oxide superconducting layer, the substrate was rotated inside the laser vapor deposition apparatus to form a film on the entire circumference of the substrate.

  When the obtained superconducting oxide was immersed in liquid nitrogen and the superconducting characteristics were measured, the critical current was 100A. As a result, an oxide superconducting wire having an oxide superconducting layer with excellent superconducting properties having good crystal orientation on the entire surface of the outer peripheral portion of the substrate close to a circular cross section could be obtained.

Next, in the passage hole of the shield plate, the inclination angle θ of the tangent to the circumferential surface portion at a position where the edge in the width direction is projected onto the circumferential surface portion of the lower substrate is 35 °, 25 °, 20 °. The intermediate layer is formed at 15 ° to obtain base materials for oxide superconducting conductors, and the same cap layer, oxide superconducting layer, stabilizing base layer, and stabilizing layer are laminated on each base material. An oxide superconductor was prepared, and the critical current value of each superconductor was measured. As a result, when the tilt angle θ = 35 °, the critical current value 60A, when the tilt angle θ = 25 °, the critical current value 68A, when the tilt angle θ = 20 °, the critical current value 74A, the tilt angle θ = 15. In the case of °, a critical current value of 100 A was shown.
For this reason, it is desirable that the inclination angle θ is 30 ° or less, but it is considered that a preferable range is 15 ° or less. However, if the inclination angle is too small, the width of the passage hole of the shield plate becomes too small, so the number of steps when the intermediate layer is sequentially formed in the circumferential direction by rotating the substrate is unnecessarily increased. A range of 15 to 20 ° is practically preferable.

  A, B: oxide superconducting conductor, K: film forming region, S: tangential, θ: incident angle, 1, 11: base material, 1A ... plane portion, 1B ... circumferential surface portion, 2, 12 ... diffusion preventing layer, 3, 13 ... Bed layer, 4, 14 ... Intermediate layer, 5, 15 ... Cap layer, 6, 16 ... Oxide superconducting layer, 7, 17 ... Stabilizing base layer, 8, 18 ... Stabilizing layer, 50 ... Film formation Equipment: 51 ... Film formation chamber, 52 ... Target, 53, 54 ... Ion source, 60, 61 ... Reel, 62 ... Shield plate, 62a ... Pass-through hole, 62b ... Edge.

Claims (11)

  The flat portion and the circumferential surface portion are continuously formed over the entire length, with a columnar shape having a planar portion at least in the circumferential direction of the outer circumferential portion and a circumferential surface portion in at least another portion of the circumferential direction of the outer circumferential portion. A long base material, and an intermediate layer having a good crystal orientation, which is laminated on the outer peripheral surface of the base material by at least one of the planar portion and the peripheral surface portion and laminated by an ion beam assisted film forming method. A base material for an oxide superconducting conductor.   2. The oxide superconducting conductor according to claim 1, wherein a half-value width (Δφ) of in-plane direction crystal axis dispersion of the intermediate layer laminated by the ion beam assisted deposition method is 16 ° or less. Base material.   The base material for an oxide superconducting conductor according to claim 1 or 2, wherein the intermediate layer is laminated on the base material via at least one of a bed layer and a diffusion prevention layer.   The outer peripheral part of the said base material is formed in the cross-sectional substantially polygonal shape formed by alternately arranging a plane part and a circumferential surface part in the circumferential direction, The any one of Claims 1-3 characterized by the above-mentioned. The base material for oxide superconducting conductors as described.   An oxide superconducting conductor comprising a cap layer and an oxide superconducting layer laminated on an intermediate layer of the base material for an oxide superconducting conductor according to claim 1. It is a columnar shape having a flat portion at least in the circumferential direction of the outer peripheral portion and a circumferential surface portion in at least another portion of the outer peripheral portion in the circumferential direction, and the flat portion and the circumferential surface portion are continuously formed over the entire length. A long base material, and an intermediate layer having a good crystal orientation, which is laminated on the outer peripheral surface of the base material by covering the at least one of the flat surface portion and the peripheral surface portion by an ion beam assisted film formation method. When manufacturing a substrate for an oxide superconducting conductor,
While the base material is fed from one reel and wound on the other reel, the constituent particles of the intermediate layer are deposited to pass through the film formation region where the intermediate layer is formed, and the base material passes through the film formation region. While performing the ion beam assisted film formation method of irradiating the substrate with an assist ion beam from a specific direction simultaneously with the deposition of the particles, forming an intermediate layer,
When forming the intermediate layer by performing the ion beam assisted film forming method, a shield plate having a slit-like passage hole narrower than the substrate is used, and the passage hole is drawn out between the reels. The material is deposited along the center of the extending direction of the material, and the particles constituting the intermediate layer are deposited while covering both sides in the width direction of the base material fed between the reels.
When the intermediate layer is formed by performing the ion beam assisted film formation method, a position where the constituent particles of the intermediate layer are deposited through the passage hole of the shield plate while rotating the base material by a predetermined angle around the circumference thereof. A method for producing a base material for an oxide superconducting conductor, comprising forming a film on a flat surface portion or a circumferential surface portion of the base material while sequentially changing in a circumferential direction of the base material.   When forming the film by depositing the constituent particles of the intermediate layer on the circumferential surface portion of the base material through the slit-shaped passage hole, the edge in the width direction of the slit-shaped passage hole is defined as the circumferential surface portion of the base material. 7. The film is formed by setting an inclination angle of a tangential line of the circumferential surface portion defined at a position projected onto the surface to 30 ° or less as an inclination angle with respect to the surface of the shield plate including the passage hole. The manufacturing method of the base material for oxide superconducting conductors of description.   Regarding the width of the slit-shaped passage hole, the incident angle of the assist ion beam incident from the oblique direction with respect to the circumferential surface portion of the base material through the passage hole is within the irradiation range of the assist ion beam with respect to the circumferential surface portion. The intermediate layer is formed by forming a film so as to have a width within a range of ± 10 ° with respect to an incident angle of the specific assist ion beam at any position. 8. A method for producing a base material for an oxide superconducting conductor according to 6 or 7.   The base material for an oxide superconducting conductor according to any one of claims 6 to 8, wherein the intermediate layer is laminated on the base material through at least one of a bed layer and a diffusion prevention layer. Production method.   The base material according to any one of claims 6 to 9, wherein a base material having a substantially polygonal cross section formed by alternately arranging a flat surface portion and a circumferential surface portion in the circumferential direction is used as the base material. The manufacturing method of the base material for oxide superconductors as described in an item.   A method for producing an oxide superconducting conductor comprising laminating a cap layer and an oxide superconducting layer on the intermediate layer according to any one of claims 6 to 10.

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