Superconducting wires, superconducting coils, superconducting magnets, superconducting motors, superconducting generators, superconducting aircraft, and superconducting equipment

Abstract

To provide a superconducting wire rod capable of reducing AC loss.SOLUTION: A superconducting wire rod according to an embodiment includes a substrate, a first region provided on the substrate and including a first rare earth element, Ba, Cu, and O, a second region provided on the substrate and including a second rare earth element, Ba, Cu, and O, and a third region provided on the substrate, between the first region and the second region, and including a third rare earth element, Pr, Ba, Cu, and O. The surface density of particles having an aspect ratio of 3 or more present on a surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surfaces of the first region and the second region.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a superconducting wire, a superconducting coil, a superconducting magnet, a superconducting motor, a superconducting generator, a superconducting aircraft, and a superconducting device. [Background technology]

[0002] For example, when a superconducting coil using superconducting wire is applied to a motor, an alternating current that reverses the direction of the current is passed through the superconducting wire that makes up the superconducting coil in order to change the magnetic field generated by the superconducting coil. This use of an alternating current passing through a superconducting wire is called an AC application of superconductivity.

[0003] In AC applications of superconductivity, energy loss occurs due to the inductance component of the superconducting wire. Energy loss due to the inductance component of the superconducting wire is also called AC loss. In AC applications of superconductivity, it is desirable to reduce AC loss in the superconducting wire.

[0004] In the following description, applications in which the current is changed without being reversed and inductance components become a problem will also be referred to as AC applications. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-48874 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a superconducting wire that can reduce AC loss. [Means for solving the problem]

[0007] The superconducting wire of the embodiment includes a substrate, and a first rare earth element provided on the substrate, the first rare earth element including at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O), and a second rare earth element provided on the surface of the substrate. a first region extending in a first direction along the substrate, the first region being provided on the substrate and including at least one second rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O); a second region extending in a direction perpendicular to the substrate; and at least one first region selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), which is provided on the substrate between the first region and the second region and in contact with the first region and the second region. a third region extending in the first direction, the third region containing three rare earth elements, praseodymium (Pr), barium (Ba), copper (Cu), and oxygen (O), wherein the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the first region, and the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the second region. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic top view of a superconducting wire according to a first embodiment. [Figure 2]1 is a schematic cross-sectional view of a superconducting wire according to a first embodiment. [Figure 3] 1 is a schematic diagram of a superconducting wire according to a first embodiment. [Figure 4] 1A to 1C are explanatory diagrams of a method for manufacturing a superconducting wire according to a first embodiment. [Figure 5] 1A to 1C are explanatory diagrams of a method for manufacturing a superconducting wire according to a first embodiment. [Figure 6] 1A to 1C are explanatory diagrams of a method for manufacturing a superconducting wire according to a first embodiment. [Figure 7] 1A to 1C are explanatory diagrams of a method for manufacturing a superconducting wire according to a first embodiment. [Figure 8] FIG. 4 is a schematic cross-sectional view of a superconducting motor according to a second embodiment. [Figure 9] FIG. 10 is a schematic top view of a superconducting aircraft according to a third embodiment. [Figure 10] FIG. 10 is a block diagram of a superconducting device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Qualitative and quantitative analyses of the chemical compositions of the components constituting the superconducting wire herein can be performed, for example, by secondary ion mass spectroscopy (SIMS) or electron probe micro analyzer (EPMA). Furthermore, measurements of the width, thickness, and distance between components constituting the superconducting wire, and identification of the continuity of the crystal structure, can be performed using, for example, a transmission electron microscope (TEM) or a scanning electron microscope. Furthermore, X-ray diffraction (XRD) can be used to identify the constituent materials of the components constituting the superconducting wire and the orientation of the crystal axes.

[0010] The "aspect ratio of particles" contained in the superconducting wire in this specification is defined as follows: When particles determined from a two-dimensional image of the superconducting wire are fitted with an ellipse, the length of the long axis is defined as the major axis, and the length of the short axis is defined as the minor axis. The ratio of the long axis to the minor axis (major axis / minor axis) is defined as the aspect ratio of the particle. For example, the shape of the particle can be determined by image processing an SEM image of the superconducting wire, and the "aspect ratio of the particle" can be calculated from the determined particle shape.

[0011] SEM images of superconducting wire are analyzed using, for example, the image processing software ImageJ. Particles with high aspect ratios are extracted as bright regions in the SEM image. Extraction is performed by binarizing the SEM image. The binarization threshold is set by comparing the original SEM image with the binarized SEM image so that particles with high aspect ratios are properly extracted. Note that if adjacent particles are in contact, they may become connected after binarization. In such cases, the particles are divided, for example, by segmentation. In addition, any other processing required for particle extraction is performed as appropriate to properly extract particles with high aspect ratios from the original SEM image.

[0012] Hereinafter, superconducting wires according to embodiments will be described with reference to the drawings.

[0013] (First embodiment) The superconducting wire of the first embodiment includes a substrate and at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), provided on the substrate. a first region including an earth element, barium (Ba), copper (Cu), and oxygen (O), extending in a first direction parallel to a surface of the substrate; and a second region provided on the substrate and including yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium ( a second region extending in a first direction along the surface of the substrate, the second region including at least one second rare earth element selected from the group consisting of Yb, and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O); and a third region provided on the substrate, between the first region and the second region and in contact with the first region and the second region, the third region including at least one third rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), and oxygen (O), and extending in the first direction. The surface density of particles with an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles with an aspect ratio of 3 or more present on the surface of the first region, and the surface density of particles with an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles with an aspect ratio of 3 or more present on the surface of the second region.

[0014] Fig. 1 is a schematic top view of a superconducting wire of a first embodiment. Fig. 2 is a schematic cross-sectional view of the superconducting wire of the first embodiment. Fig. 1 is a top view of Fig. 2 with a protective layer removed. Fig. 2 is a cross-section taken along line AA' of Fig. 1.

[0015] The superconducting wire of the first embodiment is a superconducting wire 100.

[0016] As shown in FIG. 2, the superconducting wire 100 includes a substrate 10, an intermediate layer 20, an oxide superconducting layer 30, and a protective layer 40. The substrate 10 increases the mechanical strength of the oxide superconducting layer 30. The intermediate layer 20 is a so-called orientation intermediate layer. The intermediate layer 20 is provided to orient the oxide superconducting layer 30 when the oxide superconducting layer 30 is formed. The protective layer 40 protects the oxide superconducting layer 30.

[0017] The length of superconducting wire 100 in a first direction parallel to the surface of substrate 10 is, for example, not less than 0.1 m and not more than 500 m.

[0018] The substrate 10 is made of a metal such as a nickel-tungsten alloy. The intermediate layer 20 is made of, for example, yttrium oxide (Y2O3), yttria-stabilized zirconia (YSZ), and cerium oxide (CeO2) from the substrate 10 side. The layer structure of the substrate 10 and the intermediate layer 20 is, for example, nickel-tungsten alloy / yttrium oxide / yttria-stabilized zirconia / cerium oxide. In this case, the oxide superconducting layer 30 is formed on the cerium oxide.

[0019] The substrate 10 may be, for example, a single crystal layer that is lattice-matched to the oxide superconducting layer 30. The single crystal layer is, for example, lanthanum aluminate (LaAlO3, hereinafter also referred to as LAO). When lanthanum aluminate is used for the substrate 10, the intermediate layer 20 may be omitted.

[0020] The protective layer 40 is made of a metal such as silver (Ag) or copper (Cu), or is made of an alloy. The protective layer 40 may also be an oxide layer.

[0021] The oxide superconducting layer 30 is provided between the substrate 10 and the protective layer 40. The oxide superconducting layer 30 is provided between the intermediate layer 20 and the protective layer 40. The oxide superconducting layer 30 is provided on and in contact with the intermediate layer 20.

[0022] The oxide superconducting layer 30 includes a first superconducting region 31a, a second superconducting region 31b, a third superconducting region 31c, a fourth superconducting region 31d, a first non-superconducting region 32a, a second non-superconducting region 32b, and a third non-superconducting region 32c.

[0023] The first superconducting region 31a is an example of a first region, the second superconducting region 31b is an example of a second region, and the first non-superconducting region 32a is an example of a third region.

[0024] The first superconducting region 31a, the second superconducting region 31b, the third superconducting region 31c, the fourth superconducting region 31d, the first non-superconducting region 32a, the second non-superconducting region 32b, and the third non-superconducting region 32c extend in a first direction along the surface of the substrate 10. The first direction is, for example, the longitudinal direction of the substrate 10.

[0025] The first non-superconducting region 32a is provided between the first superconducting region 31a and the second superconducting region 31b, and is in contact with the first superconducting region 31a and the second superconducting region 31b.

[0026] The second non-superconducting region 32b is provided between the second superconducting region 31b and the third superconducting region 31c, and is in contact with the second superconducting region 31b and the third superconducting region 31c.

[0027] The third non-superconducting region 32c is provided between the third superconducting region 31c and the fourth superconducting region 31d, and is in contact with the third superconducting region 31c and the fourth superconducting region 31d.

[0028] Hereinafter, for ease of explanation, the first superconducting region 31a, the second superconducting region 31b, the third superconducting region 31c, and the fourth superconducting region 31d may be collectively referred to simply as superconducting region 31. Furthermore, the first non-superconducting region 32a, the second non-superconducting region 32b, and the third non-superconducting region 32c may be collectively referred to simply as non-superconducting region 32.

[0029] The second direction is perpendicular to the first direction and is a direction along the surface of substrate 10. The second direction is a direction from non-superconducting region 32 toward superconducting region 31. The second direction is, for example, the short-side direction of substrate 10. A direction perpendicular to the first and second directions is a third direction. The third direction is the thickness direction of substrate 10 and is approximately perpendicular to the surface of substrate 10.

[0030] The oxide superconducting layer 30 includes a non-superconducting region 32 and a superconducting region 31. The oxide superconducting layer 30 is divided into a plurality of superconducting regions 31 with the non-superconducting regions 32 sandwiched between them. In the case of FIGS. 1 and 2, the oxide superconducting layer 30 is divided into four superconducting regions 31. The oxide superconducting layer 30 may be divided into, for example, two or three regions. The oxide superconducting layer 30 may also be divided into, for example, five or more regions.

[0031] Superconducting region 31 has superconducting properties. Non-superconducting region 32 does not have superconducting properties. Non-superconducting region 32 electrically separates superconducting regions 31. Non-superconducting region 32 functions as an insulator when a current flows through superconducting wire 100.

[0032] The length in the first direction of the oxide superconducting layer 30 (L in FIG. 1) is, for example, 0.1 m or more. The length in the first direction of the superconducting region 31 is, for example, 0.1 m or more. The length in the first direction of the non-superconducting region 32 is, for example, 0.1 m or more.

[0033] The width W1 of superconducting region 31 in the second direction is, for example, 5 μm or more and 10 mm or less. The width W2 of non-superconducting region 32 in the second direction is, for example, 1 μm or more and 2 mm or less. For convenience, superconducting regions 31a, 31b, 31c, and 31d are all shown with the same width W1 in FIG. 1, but in reality, their widths may be different. Here, the median value of the widths of superconducting regions 31a, 31b, 31c, and 31d is represented as W1. Similarly, the widths of non-superconducting regions 32a, 32b, and 32c may be different, and the median value of the widths of non-superconducting regions 32a, 32b, and 32c is represented as W2.

[0034] The width in the second direction of the oxide superconducting layer 30 (Wx in FIG. 1) is, for example, 1 mm or more and 20 mm or less. The width in the second direction of the non-superconducting region 32 (W2 in FIG. 1) is, for example, not more than the width in the second direction of the superconducting region 31 (W1 in FIG. 1). The width in the second direction of the non-superconducting region 32 (W2 in FIG. 1) is, for example, smaller than the width in the second direction of the superconducting region 31 (W1 in FIG. 1).

[0035] The boundary between the superconducting region 31 and the non-superconducting region 32 can be determined, for example, by mapping and point-analyzing the surface of the oxide superconducting layer 30 using an EPMA, and determining that the region where the concentration of praseodymium (Pr) in the rare earth element RE is less than 1% is the superconducting region 31, and the region where the concentration of praseodymium (Pr) in the rare earth element RE is 1% or more is the non-superconducting region 32.

[0036] The thickness of the oxide superconducting layer 30 in the third direction is, for example, not less than 100 nm and not more than 10 μm.

[0037] The oxide superconducting layer 30 is an oxide containing a rare earth element. The oxide containing a rare earth element contained in the oxide superconducting layer 30 has a perovskite structure. The crystal structure of the oxide containing a rare earth element contained in the oxide superconducting layer 30 is, for example, an orthorhombic crystal.

[0038] The oxide containing a rare earth element contained in the oxide superconducting layer 30 is, for example, REBa A Cu B O7-C The oxide superconducting layer 30 has a chemical composition of (1.8≦A≦2.2, 2.7≦B≦3.3, −0.2≦C≦1). The oxide containing a rare earth element contained in the oxide superconducting layer 30 is, for example, REBa2Cu3O 7-y It contains oxides with a chemical composition of (-0.2≦y≦1), where RE is the rare earth site.

[0039] The superconducting region 31 contains at least one rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O).

[0040] The concentration of praseodymium (Pr) in the rare earth element RE in the superconducting region 31 is, for example, less than 1 atomic %. The concentration of praseodymium (Pr) in the superconducting region 31 is lower than the concentration of praseodymium (Pr) in the non-superconducting region 32.

[0041] The oxide containing a rare earth element contained in the superconducting region 31 is, for example, REBa D Cu E O 7-F The superconducting region 31 has a chemical composition of (1.8≦D≦2.2, 2.7≦E≦3.3, −0.2≦F≦1). 7-y It includes oxides having a chemical composition of (-0.2≦y≦1).

[0042] The superconducting region 31 has, for example, a perovskite structure. The superconducting region 31 is, for example, a single crystal having a perovskite structure.

[0043] The superconducting region 31 is, for example, c-axis oriented. D Cu E O 7-FThe c-axis of the crystal (1.8≦D≦2.2, 2.7≦E≦3.3, −0.2≦F≦1) is aligned, for example, in the thickness direction of the oxide superconducting layer 30, that is, in a direction substantially perpendicular to the surface of the substrate 10, that is, in a third direction.

[0044] The non-superconducting region 32 contains at least one rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), and oxygen (O).

[0045] The non-superconducting region 32 does not exhibit superconducting properties due to the inclusion of praseodymium (Pr). The concentration of praseodymium (Pr) in the rare earth element RE in the non-superconducting region 32 is, for example, 10 atomic % or more and 50 atomic % or less. The concentration of praseodymium (Pr) in the rare earth element RE in the non-superconducting region 32 is more preferably 15 atomic % or more and 45 atomic % or less, and even more preferably 20 atomic % or more and 40 atomic % or less.

[0046] The oxide containing a rare earth element contained in the non-superconducting region 32 is, for example, REBa G Cu H O 7-I The non-superconducting region 32 has a chemical composition of (1.8≦G≦2.2, 2.7≦H≦3.3, −0.2≦I≦1). 7-y It includes oxides having a chemical composition of (-0.2≦y≦1).

[0047] The non-superconducting region 32 has, for example, a perovskite structure.

[0048] At least one rare earth element selected from the above group contained in each of the first superconducting region 31a, the second superconducting region 31b, the third superconducting region 31c, the fourth superconducting region 31d, the first non-superconducting region 32a, the second non-superconducting region 32b, and the third non-superconducting region 32c is, for example, the same.

[0049] For example, the first superconducting region 31a contains at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and the second superconducting region 31b contains at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), It is assumed that the first non-superconducting region 32a contains at least one second rare earth element selected from the group consisting of holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and the first non-superconducting region 32b contains at least one third rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0050] For example, the first rare earth element, the second rare earth element, and the third rare earth element are the same element, for example, the first rare earth element, the second rare earth element, and the third rare earth element are all yttrium (Y).

[0051] At least one rare earth element selected from the above group contained in each of the first superconducting region 31a, the second superconducting region 31b, the third superconducting region 31c, the fourth superconducting region 31d, the first non-superconducting region 32a, the second non-superconducting region 32b, and the third non-superconducting region 32c may be different.

[0052] For example, the first rare earth element, the second rare earth element, and the third rare earth element are different elements, for example, the first rare earth element is yttrium (Y), the second rare earth element is samarium (Sm), and the third rare earth element is dysprosium (Dy).

[0053] For example, any one or all of the first rare earth element, the second rare earth element, and the third rare earth element may be two or more kinds of rare earth elements, or any one or all of the first rare earth element, the second rare earth element, and the third rare earth element may be three or more kinds of rare earth elements.

[0054] Figures 3(a) and 3(b) are schematic diagrams of the superconducting wire of the first embodiment. Figure 3(a) is a schematic diagram of the surface of the superconducting region 31. Figure 3(b) is a schematic diagram of the surface of the non-superconducting region 32. Figures 3(a) and 3(b) are top views of the oxide superconducting layer 30 after the protective layer 40 on the oxide superconducting layer 30 has been removed.

[0055] 3(a) and 3(b), the surface density of the high-aspect-aspect particles 36 present on the surface of the non-superconducting region 32 is greater than the surface density of the high-aspect-aspect-particles 36 present on the surface of the superconducting region 31. The aspect ratio of the high-aspect-aspect-particles 36 is 3 or greater.

[0056] The high-aspect ratio particles 36 are, for example, rod-shaped or needle-shaped particles. The long axis direction of the high-aspect ratio particles 36 is considered to be the c-axis direction of the rare-earth element-containing oxide having an orthorhombic perovskite structure. Therefore, the high-aspect ratio particles 36 are not c-axis oriented relative to the surface of the substrate 10.

[0057] The degree of c-axis orientation decreases as the surface density of the high aspect ratio particles 36 increases. Therefore, at least on the surface of the oxide superconducting layer 30, the degree of c-axis orientation of the non-superconducting region 32 is lower than the degree of c-axis orientation of the superconducting region 31.

[0058] For example, the areal density of high aspect ratio particles 36 present on the surface of first non-superconducting region 32a is greater than the areal density of high aspect ratio particles 36 present on the surface of first superconducting region 31a. Also, for example, the areal density of high aspect ratio particles 36 present on the surface of first non-superconducting region 32a is greater than the areal density of high aspect ratio particles 36 present on the surface of second superconducting region 31b.

[0059] For example, the areal density of high aspect ratio particles 36 present on the surface of non-superconducting region 32 is at least two times but not more than 1000 times the areal density of high aspect ratio particles 36 present on the surface of superconducting region 31. For example, the areal density of high aspect ratio particles 36 present on the surface of first non-superconducting region 32a is at least two times but not more than 100 times the areal density of high aspect ratio particles 36 present on the surface of first superconducting region 31a. Furthermore, for example, the areal density of high aspect ratio particles 36 present on the surface of first non-superconducting region 32a is at least two times but not more than 1000 times the areal density of high aspect ratio particles 36 present on the surface of second superconducting region 31b.

[0060] The surface density of the high aspect particles 36 is the number of high aspect particles 36 present per unit area. The unit area used to calculate the surface density of the high aspect particles 36 is, for example, 1 μm 2 is.

[0061] When determining the surface density of high aspect ratio particles 36 present on the surface of the superconducting region 31 or non-superconducting region 32, for example, the number of high aspect ratio particles 36 is counted in multiple 10 μm square areas to determine the surface density, and the average value is used.

[0062] The surface density of the high aspect ratio particles 36 in the superconducting region 31 is, for example, 0.1 particles / μm 2 The surface density of the high aspect ratio particles 36 in the non-superconducting region 32 is, for example, 0.1 particles / μm 2 More than 1 piece / μm 2 The following is the result.

[0063] For example, the areal density of high-aspect particles 36 present inside the non-superconducting region 32 is smaller than the areal density of high-aspect particles 36 present on the surface of the non-superconducting region 32. For example, the interior of the non-superconducting region 32 refers to a cross section along the surface of the non-superconducting region 32 at a position closer to the substrate 10 than the surface of the non-superconducting region 32. For example, the interior of the non-superconducting region 32 refers to a cross section at a position closer to the substrate 10 than a position halfway through the thickness of the non-superconducting region 32 in the third direction. The areal density of high-aspect particles 36 present inside the non-superconducting region 32 can be measured, for example, by removing the surface of the non-superconducting region 32 by polishing or the like. The surface of the non-superconducting region 32 refers, for example, to the vicinity of the interface between the non-superconducting region 32 and the protective layer 40. The areal density of high-aspect particles 36 present on the surface of the non-superconducting region 32 can be measured, for example, by removing the protective layer 40 by peeling or the like.

[0064] The oxide superconducting layer 30 may contain impurity elements other than, for example, yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), oxygen (O), aluminum (Al), and carbon (C). Two or more types of impurity elements may be contained.

[0065] For example, the atomic concentration of the impurity element contained in the non-superconducting region 32 is higher than the atomic concentration of the impurity element contained in the superconducting region 31 .

[0066] An example of a method for manufacturing the superconducting wire 100 of the first embodiment will be described below.

[0067] In one example of a method for manufacturing the superconducting wire 100 of the first embodiment, the intermediate layer 20 is formed on the substrate 10, the oxide superconducting layer 30 is formed on the intermediate layer 20, and the protective layer 40 is formed on the oxide superconducting layer 30. The oxide superconducting layer 30 is formed by the Trifluoroacetates Metal Organic Deposition method (TFA-MOD method).

[0068] Fig. 4 is an explanatory diagram of the method for producing a superconducting wire according to the first embodiment, and is a flow chart showing an example of preparation of a coating solution in the production method according to the first embodiment.

[0069] First, the preparation of the first coating solution and the second coating solution will be described.

[0070] As shown in Figure 4, metal acetates of yttrium (Y), barium (Ba), and copper (Cu) are prepared (a1). Trifluoroacetic acid is also prepared (a2). Next, the prepared metal acetates are dissolved in water to prepare an aqueous solution (b). The resulting aqueous solution is mixed with the prepared trifluoroacetic acid (c). The resulting solution is reacted and purified (d) to obtain a first gel containing impurities (e). The first gel is then dissolved in methanol (f) to create a solution containing impurities (g). The resulting solution is reacted and purified to remove impurities (h) to obtain a second gel containing the solvent (i). The second gel is then dissolved in methanol (j) to prepare a coating solution (k). The method of incorporating a solvent into a gel to reduce impurities, as shown in Figure 4, is called the Solvent-Into-Gel (SIG) method.

[0071] The coating solution containing yttrium (Y), barium (Ba), and copper (Cu) serves as a first coating solution, which will be hereinafter referred to as a coating solution for forming a superconducting region.

[0072] Next, the preparation of the second coating solution will be described.

[0073] As shown in Figure 4, metal acetates of praseodymium (Pr), yttrium (Y), barium (Ba), and copper (Cu) are prepared (a1). Trifluoroacetic acid is also prepared (a2). Next, the prepared metal acetates are dissolved in water to prepare an aqueous solution (b). The resulting aqueous solution is mixed with the prepared trifluoroacetic acid (c). The resulting solution is reacted and purified (d) to obtain a first gel containing impurities (e). The first gel is then dissolved in methanol (f) to create a solution containing impurities (g). The resulting solution is reacted and purified to remove impurities (h) to obtain a second gel containing the solvent (i). The second gel is then dissolved in methanol (j) to prepare a coating solution (k).

[0074] The coating solution containing praseodymium (Pr), yttrium (Y), barium (Ba), and copper (Cu) serves as the second coating solution, which will be hereinafter referred to as the non-superconducting region forming coating solution.

[0075] Fig. 5 is an explanatory diagram of a method for producing a superconducting wire according to the first embodiment, and is a flow chart showing an example of a method for forming a superconducting film from a coating solution.

[0076] As shown in Figure 5, first, the previously prepared coating solution is prepared (a). The coating solution is applied to a substrate, for example, by inkjet printing, to form a film (b), resulting in a gel film (c). The resulting gel film is then subjected to a primary heat treatment, calcination, to decompose the organic matter (d), resulting in a calcined film (e). This calcined film is then subjected to a secondary heat treatment, firing (f), and then, for example, pure oxygen annealing is performed (g), resulting in a superconducting film (h).

[0077] Figures 6(a) and 6(b) are explanatory diagrams of a method for manufacturing a superconducting wire according to the first embodiment. Figures 6(a) and 6(b) are explanatory diagrams of forming a gel film on a substrate by the inkjet method according to the first embodiment. Figure 6(a) is a diagram of the substrate 10 as seen from above, and Figure 6(b) is a diagram of the substrate 10 as seen from the side.

[0078] 6(a) and 6(b), a coating solution 35a for forming a superconducting region and a coating solution 35b for forming a non-superconducting region are ejected from a nozzle 34 toward a substrate 10. As shown in FIG. 6(a), the coating solution 35a for forming a superconducting region and the coating solution 35b for forming a non-superconducting region are ejected onto the substrate 10 so that the coating solution 35b for forming a non-superconducting region is sandwiched between the coating solutions 35a for forming a superconducting region and so that the coating solutions 35a for forming a superconducting region and the coating solutions 35b for forming a non-superconducting region are in contact with each other.

[0079] The substrate 10 moves in a first direction relative to the nozzle 34. The coating solution 35a for forming a superconducting region and the coating solution 35b for forming a non-superconducting region ejected onto the substrate 10 extend in the first direction.

[0080] The average diameter of droplets of coating solution 35b for forming non-superconducting regions ejected onto substrate 10 when it reaches substrate 10 is, for example, 5 μm or less.

[0081] It is also possible to use, for example, a die coating method instead of the ink jet method.

[0082] Fig. 7 is an explanatory diagram of the method for manufacturing a superconducting wire according to the first embodiment. Fig. 7 is an explanatory diagram of the relationship between the firing conditions for calcination or firing when manufacturing a superconducting wire 100 and the surface density of high aspect ratio particles 36.

[0083] 7, the relationship between the firing conditions and the surface density of high aspect ratio particles 36 differs between superconducting region 31 and non-superconducting region 32. The firing conditions include, for example, firing temperature, firing time, or oxygen partial pressure.

[0084] For example, under condition X, by setting the oxygen partial pressure during firing to a value intermediate between the optimum value for the superconducting region and the optimum value for the non-superconducting region, the surface density of high aspect ratio particles 36 is reduced in both the superconducting region 31 and the non-superconducting region 32. In other words, under condition X, a high degree of c-axis orientation is obtained in both the superconducting region 31 and the non-superconducting region 32.

[0085] On the other hand, under condition Y, when the oxygen partial pressure during firing is shifted slightly higher than the optimum value for the superconducting region, the superconducting region only deviates slightly from the optimum value, while the non-superconducting region deviates more significantly from the optimum value than the superconducting region. As a result, the surface density of high aspect ratio particles 36 in superconducting region 31 is low, but the surface density of high aspect ratio particles 36 in non-superconducting region 32 is high. In other words, under condition Y, the degree of c-axis orientation in superconducting region 31 is high, but the degree of c-axis orientation in non-superconducting region 32 is low.

[0086] For example, in the method for manufacturing the superconducting wire 100 of the first embodiment, by selecting a condition equivalent to condition Y as the firing condition, it is possible to make the areal density of the high-aspect ratio particles 36 in the non-superconducting region 32 greater than the areal density of the high-aspect ratio particles 36 in the superconducting region 31. Furthermore, for example, by initially setting the oxygen partial pressure during firing to condition X and then changing it to condition Y midway through, it is possible to change the areal density of the high-aspect ratio particles in the non-superconducting region 32 whose crystals have grown from the substrate side, and to control the areal density of the high-aspect ratio particles so that they are low inside the non-superconducting region 32 and high on the surface of the non-superconducting region 32.

[0087] By the above manufacturing method, superconducting wire 100 of the first embodiment including oxide superconducting layer 30 is manufactured.

[0088] In the superconducting wire 100 of the first embodiment, the oxide superconducting layer 30 is divided into a plurality of superconducting regions 31 by the non-superconducting regions 32. In other words, the oxide superconducting layer 30 is thinned into a plurality of superconducting regions 31.

[0089] Therefore, according to the superconducting wire 100, it is possible to reduce energy loss due to inductance components when used in AC applications, and therefore, according to the superconducting wire 100, it is possible to reduce AC loss.

[0090] One method for dividing the oxide superconducting layer of a superconducting wire is to ablate it from above using a laser scribing method. However, this method has the risk of deteriorating the superconducting properties due to thermal damage caused by the laser scribing method, and of reducing the mechanical strength of the oxide superconducting layer due to the voids that form between the divided oxide superconducting layers.

[0091] In the superconducting wire 100 of the first embodiment, the oxide superconducting layer 30 is divided into a plurality of superconducting regions 31 by non-superconducting regions 32. The non-superconducting regions 32 can be formed by injecting or applying a coating solution. Therefore, the superconducting properties of the superconducting regions 31 are less likely to deteriorate. Furthermore, the non-superconducting regions 32 exist between the divided superconducting regions 31. Therefore, the mechanical strength of the oxide superconducting layer 30 is improved.

[0092] In the superconducting wire 100 of the first embodiment, the areal density of the high-aspect ratio particles 36 present on the surface of the non-superconducting region 32 is greater than the areal density of the high-aspect ratio particles 36 present on the surface of the superconducting region 31. The high density of high-aspect ratio particles 36 present on the surface of the non-superconducting region 32 is thought to allow the surface of the non-superconducting region 32 to function as a gettering site for impurities. In other words, the surface of the non-superconducting region 32 can function as a region that captures impurities that are unintentionally introduced during the manufacture of the superconducting wire 100.

[0093] For example, if impurities are unintentionally introduced and enter the superconducting region 31, there is a risk of degrading the superconducting properties of the superconducting region 31. In the superconducting wire 100 of the first embodiment, the surface of the non-superconducting region 32 functions as a gettering site for the impurities, thereby preventing the impurities from entering the superconducting region 31. Therefore, a superconducting wire 100 with excellent superconducting properties can be realized.

[0094] The surface density of high aspect ratio particles 36 present on the surface of non-superconducting region 32 is preferably at least twice, more preferably at least five times, and even more preferably at least ten times the surface density of high aspect ratio particles 36 present on the surface of superconducting region 31. Exceeding the lower limit further promotes the capture of impurities on the surface of non-superconducting region 32. This makes it possible to achieve superconducting wire 100 with even better superconducting properties.

[0095] From the viewpoint of promoting the capture of impurities at the surface of the non-superconducting region 32, the areal density of the high-aspect ratio particles 36 present inside the non-superconducting region 32 is preferably higher than the areal density of the high-aspect ratio particles 36 present inside the superconducting region 31. For example, the inside of the superconducting region 31 refers to a cross section along the surface of the superconducting region 31 at a position closer to the substrate 10 than the surface of the superconducting region 31. The inside of the superconducting region 31 refers to a cross section closer to the substrate 10 than a position halfway through the thickness of the superconducting region 31 in the third direction. The areal density of the high-aspect ratio particles 36 present inside the superconducting region 31 can be measured, for example, by removing the surface of the superconducting region 31 by polishing or the like. The surface of the superconducting region 31 refers, for example, to the vicinity of the interface between the superconducting region 31 and the protective layer 40. The areal density of the high-aspect ratio particles 36 present on the surface of the superconducting region 31 can be measured, for example, by removing the protective layer 40 by peeling or the like.

[0096] On the other hand, from the viewpoint of improving the mechanical strength of the oxide superconducting layer 30, it is preferable that the areal density of the high-aspect ratio particles 36 present inside the non-superconducting region 32 is smaller than the areal density of the high-aspect ratio particles 36 present on the surface of the non-superconducting region 32. This improves the degree of c-axis orientation inside the non-superconducting region 32, and improves the continuity of the perovskite structure at the interface between the superconducting region 31 and the non-superconducting region 32. As a result, the mechanical strength of the interface between the superconducting region 31 and the non-superconducting region 32 is improved.

[0097] In superconducting wire 100 of the first embodiment, from the viewpoint of making superconducting wire 100 function as a wire, the length in the first direction of superconducting region 31 and non-superconducting region 32 is preferably 0.1 m or more.

[0098] In the superconducting wire 100 of the first embodiment, from the viewpoint of reducing AC loss, it is preferable that the width in the second direction of the non-superconducting region 32 (W2 in Figure 1) is smaller than the width in the second direction of the superconducting region 31 (W1 in Figure 1).

[0099] In superconducting wire 100 of the first embodiment, in order not to impair the superconducting properties, the width in the second direction of superconducting region 31 (W1 in FIG. 1) is, for example, preferably 5 μm or more, and more preferably 10 μm or more.

[0100] In the superconducting wire 100 of the first embodiment, from the viewpoint of reducing AC loss, the width in the second direction of the superconducting region 31 (W1 in Figure 1) is, for example, preferably 1 mm or less, more preferably 50 μm or less, and even more preferably 10 μm or less.

[0101] In the superconducting wire 100 of the first embodiment, from the viewpoint of ensuring insulation, the width in the second direction of the non-superconducting region 32 (W2 in FIG. 1) is preferably, for example, 5 μm or more, and more preferably 10 μm or more.

[0102] In the superconducting wire 100 of the first embodiment, from the viewpoint of reducing AC loss, the width in the second direction of the non-superconducting region 32 (W2 in Figure 1) is, for example, preferably 1 mm or less, more preferably 50 μm or less, and even more preferably 10 μm or less.

[0103] In the superconducting wire 100 of the first embodiment, the concentration of praseodymium (Pr) contained in the non-superconducting region 32 is preferably 10 atomic % or more, and more preferably 20 atomic % or more, in order to prevent the non-superconducting region 32 from exhibiting superconducting properties.

[0104] In the superconducting wire 100 of the first embodiment, the concentration of praseodymium (Pr) contained in the superconducting region 31 is preferably less than 1 atomic % in order not to impair the superconducting properties of the superconducting region 31, and more preferably less than 0.1 atomic %.

[0105] As described above, according to the first embodiment, it is possible to provide a superconducting wire that can reduce AC loss. Furthermore, by providing an impurity gettering site, it is possible to provide a superconducting wire that has excellent superconducting properties.

[0106] (Second embodiment) The superconducting motor of the second embodiment includes a superconducting coil having the superconducting wire of the first embodiment and a superconducting magnet having the superconducting coil. Hereinafter, some of the description overlapping with the first embodiment may be omitted.

[0107] Figures 8(a) and 8(b) are schematic cross-sectional views of a superconducting motor according to the second embodiment, and Figure 8(b) is a cross-section taken along line BB' in Figure 8(a).

[0108] The superconducting motor 200 of the second embodiment is a fully superconducting motor that uses superconducting coils in both the rotor and the stator.

[0109] The superconducting motor 200 includes a case 50, a stator 52, a rotor 54, and a shaft 56. The stator 52 includes a stator coil 52a, and the rotor 54 includes a rotor coil 54a.

[0110] The stator coil 52a uses the superconducting wire 100 of the first embodiment. The rotor coil 54a uses the superconducting wire 100 of the first embodiment. The stator coil 52a and the rotor coil 54a are examples of superconducting coils.

[0111] An AC magnetic field is generated when an AC current flows through the stator coil 52a of the stator 52. The stator 52 is an example of a superconducting magnet.

[0112] According to the second embodiment, a superconducting coil, a superconducting magnet, and a superconducting motor with reduced AC loss can be realized by using the superconducting wire 100 of the first embodiment. Furthermore, by using the superconducting wire 100 with excellent superconducting properties, a superconducting coil, a superconducting magnet, and a superconducting motor with excellent properties can be realized.

[0113] (Third embodiment) The superconducting aircraft of the third embodiment includes the superconducting motor of the second embodiment. Hereinafter, some of the description that overlaps with the first or second embodiment may be omitted.

[0114] 9 is a schematic top view of a superconducting aircraft according to the third embodiment. A superconducting aircraft 300 according to the third embodiment uses a superconducting motor 200 as a power source.

[0115] The superconducting aircraft 300 includes a fuselage 60 , a wing 62 , a gas turbine 64 , a superconducting generator 66 , and a plurality of superconducting motors 200 .

[0116] A plurality of superconducting motors 200 are provided on the main wing 62. The superconducting motor 200 includes a superconducting coil using the superconducting wire 100 of the first embodiment.

[0117] Each of the multiple superconducting motors 200 rotates a propulsion fan (not shown), generating thrust for the superconducting aircraft 300 .

[0118] The gas turbine 64 and the superconducting generator 66 are provided inside the body 60. The superconducting generator 66 includes a superconducting coil using the superconducting wire 100 of the first embodiment.

[0119] The gas turbine 64 is driven by, for example, liquid hydrogen as fuel. The superconducting generator 66 is directly connected to the gas turbine 64, and generates electricity when the gas turbine 64 is driven. The electricity generated by the superconducting generator 66 drives a plurality of superconducting motors 200.

[0120] According to the third embodiment, a superconducting generator and a superconducting aircraft with reduced AC loss can be realized by using the superconducting wire 100 of the first embodiment. Furthermore, by using the superconducting wire 100 with excellent superconducting properties, a superconducting generator and a superconducting aircraft with excellent properties can be realized.

[0121] (Fourth embodiment) The superconducting device of the fourth embodiment is a superconducting device including a superconducting coil using the superconducting wire of the first embodiment. Hereinafter, some of the description overlapping with the first embodiment will be omitted.

[0122] 10 is a block diagram of a superconducting device according to a fourth embodiment. The superconducting device according to the fourth embodiment is a heavy ion beam therapy device 400. The heavy ion beam therapy device 400 is an example of a superconducting device.

[0123] The heavy ion beam therapy device 400 includes an injection system 70 , a synchrotron accelerator 72 , a beam transport system 74 , an irradiation system 76 , and a control system 78 .

[0124] The injection system 70 has a function of generating, for example, carbon ions to be used in therapy and pre-accelerating the ions to be injected into the synchrotron accelerator 72. The injection system 70 has, for example, an ion generation source and a linear accelerator.

[0125] The synchrotron accelerator 72 has a function of accelerating the carbon ion beam injected from the injection system 70 to an energy suitable for treatment. A superconducting coil using the superconducting wire 100 of the first embodiment is applied to the synchrotron accelerator 72.

[0126] The beam transport system 74 has a function of transporting the carbon ion beam injected from the synchrotron accelerator 72 to the irradiation system 76. The beam transport system 74 has, for example, a bending electromagnet.

[0127] The irradiation system 76 has a function of irradiating a patient, who is an irradiation target, with the carbon ion beam injected from the beam transport system 74. The irradiation system 76 has, for example, a rotating gantry that enables the carbon ion beam to be irradiated from any direction. A superconducting coil using the superconducting wire 100 of the first embodiment is applied to the rotating gantry.

[0128] The control system 78 controls the injection system 70, the synchrotron accelerator 72, the beam transport system 74, and the irradiation system 76. The control system 78 is, for example, a computer.

[0129] In the heavy ion beam therapy device 400 of the fourth embodiment, a superconducting coil using the superconducting wire 100 of the first embodiment is used in the synchrotron accelerator 72 and the rotating gantry. Therefore, according to the fourth embodiment, a heavy ion beam therapy device with excellent characteristics is realized.

[0130] In the fourth embodiment, a heavy ion beam therapy device 400 has been described as an example of a superconducting device, but the superconducting device may also be, for example, a nuclear magnetic resonance device (NMR), a magnetic resonance imaging device (MRI), a magnetic field application type single crystal pulling device, or a superconducting magnetic levitation railway vehicle.

[0131] Examples will be described below. [Example]

[0132] Example 1 A superconducting wire similar to the superconducting wire 100 of the first embodiment was manufactured according to the flowcharts shown in Figures 4 and 5. Yttrium (Y) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region. The coating solution was applied onto the substrate using an inkjet method.

[0133] The firing conditions for the gel film and calcined film were selected to reduce the surface density of high-aspect-aspect particles in the superconducting region and increase the surface density of high-aspect-aspect-particles in the non-superconducting region: specifically, a firing temperature of 790°C and an oxygen partial pressure of 850 ppm.

[0134] Example 2 A superconducting wire was produced in the same manner as in Example 1, except that the firing conditions for the gel film and the calcined film were selected so that the surface density of high aspect ratio particles in the non-superconducting region was smaller than that in Example 1. Specifically, the firing conditions were a firing temperature of 790°C and an oxygen partial pressure of 800 ppm.

[0135] Example 3 A superconducting wire was produced in the same manner as in Example 1, except that the firing conditions for the gel film and the calcined film were selected so that the surface density of high aspect ratio particles in the non-superconducting region was smaller than in Example 2. Specifically, the firing conditions were a firing temperature of 790°C and an oxygen partial pressure of 750 ppm.

[0136] Example 4 A superconducting wire was produced in the same manner as in Example 1, except that gadolinium (Gd) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 80 ppm.

[0137] Example 5 A superconducting wire was produced in the same manner as in Example 1, except that europium (Eu) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 35 ppm.

[0138] Example 6 A superconducting wire was produced in the same manner as in Example 1, except that lanthanum (La) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 0.2 ppm.

[0139] Example 7 A superconducting wire was produced in the same manner as in Example 1, except that neodymium (Nd) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 3.5 ppm.

[0140] Example 8 A superconducting wire was produced in the same manner as in Example 1, except that samarium (Sm) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 20 ppm.

[0141] Example 9 A superconducting wire was produced in the same manner as in Example 1, except that dysprosium (Dy) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 300 ppm.

[0142] Example 10 A superconducting wire was produced in the same manner as in Example 1, except that holmium (Ho) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 510 ppm.

[0143] Example 11 A superconducting wire was produced in the same manner as in Example 1, except that erbium (Er) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 920 ppm.

[0144] Example 12 A superconducting wire was produced in the same manner as in Example 1, except that thulium (Tm) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 1600 ppm.

[0145] Example 13 A superconducting wire was produced in the same manner as in Example 1, except that ytterbium (Yb) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 2000 ppm.

[0146] Example 14 A superconducting wire was produced in the same manner as in Example 1, except that lutetium (Lu) was selected as the rare earth element for the superconducting region and the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 2400 ppm.

[0147] Example 15 A superconducting wire was produced in the same manner as in Example 1, except that yttrium (Y) was selected as the rare earth element for the superconducting region, gadolinium (Gd) was selected as the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 760 ppm.

[0148] Example 16 A superconducting wire was produced in the same manner as in Example 1, except that yttrium (Y) was selected as the rare earth element for the superconducting region, europium (Eu) was selected as the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 755 ppm.

[0149] Example 17 A superconducting wire was produced in the same manner as in Example 1, except that gadolinium (Gd) was selected as the rare earth element for the superconducting region, europium (Eu) was selected as the rare earth element for the non-superconducting region, and the sintering conditions for the gel film and calcined film were selected so that the surface density of high aspect ratio particles in the superconducting region was small and the surface density of high aspect ratio particles in the non-superconducting region was large. Specifically, the sintering conditions were a sintering temperature of 790°C and an oxygen partial pressure of 80 ppm.

[0150] (Comparative Example) A superconducting wire was produced in the same manner as in Example 1, except that the firing conditions for the gel film and the calcined film were selected so that the areal density of the high-aspect-aspect particles in the superconducting region and the areal density of the high-aspect-aspect-particles in the non-superconducting region were similarly small. Specifically, the firing conditions were a firing temperature of 790°C and an oxygen partial pressure of 700 ppm.

[0151] Table 1 shows the evaluation results of the superconducting wires of Examples 1 to 17 and the comparative example. Elements other than yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), oxygen (O), aluminum (Al), and carbon (C) were counted as impurities. EPMA measurements showed that in Examples 1 to 17, the surface density of particles with an aspect ratio of 3 or greater present on the surface of the non-superconducting region was greater than the surface density of particles with an aspect ratio of 3 or greater present on the surface of the superconducting layer region. It was also revealed that chlorine (Cl) segregated in the non-superconducting region. From Table 1, it can be seen that in Examples 1 to 17, the critical current density is increased compared to the comparative example, and the superconducting properties are improved.

[0152] [Table 1]

[0153] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. For example, components of one embodiment may be replaced or changed with components of another embodiment. These embodiments and modifications thereof are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0154] The technical solution of the present invention is described below.

[0155] (Technical proposal 1) A substrate; a first region provided on the substrate, the first region including at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O), and extending in a first direction along a surface of the substrate; a second region provided on the substrate, the second region including at least one second rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O), and extending in the first direction; a third region provided on the substrate, between the first region and the second region and in contact with the first region and the second region, the third region including at least one third rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), and oxygen (O), and extending in the first direction; the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the first region; A superconducting wire, wherein the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the second region.

[0156] (Technical proposal 2) The superconducting wire according to Technical Solution 1, wherein the concentration of praseodymium (Pr) contained in the first region and the second region is lower than the concentration of praseodymium (Pr) contained in the third region.

[0157] (Technical proposal 3) A superconducting wire according to Technical Proposal 1 or Technical Proposal 2, wherein the concentration of praseodymium (Pr) among the rare earth elements contained in the first region and the second region is less than 1 atomic %, and the concentration of praseodymium (Pr) among the rare earth elements contained in the third region is 10 atomic % or more.

[0158] (Technical proposal 4) the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is at least twice the surface density of particles having an aspect ratio of 3 or more present on the surface of the first region, A superconducting wire described in any one of Technical Proposals 1 to 3, wherein the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is at least twice the surface density of particles having an aspect ratio of 3 or more present on the surface of the second region.

[0159] (Technical proposal 5) a width of the first region in a second direction perpendicular to the first direction and along the surface of the substrate is 5 μm or more and 10 mm or less; The width of the second region in the second direction is 5 μm or more and 10 mm or less, A superconducting wire according to any one of Technical Schemes 1 to 4, wherein the width of the third region in the second direction is 1 μm or more and 2 mm or less.

[0160] (Technical proposal 6) A superconducting wire described in any one of Technical Solutions 1 to 5, wherein the width of the third region in a second direction perpendicular to the first direction and along the surface of the substrate is less than or equal to the width of the first region in the second direction and the width of the first region in the second direction.

[0161] (Technical proposal 7) A superconducting wire described in any one of Technical Solutions 1 to 6, wherein the surface density of particles with an aspect ratio of 3 or more present in a cross section along the surface of the third region at a position closer to the substrate than the surface of the third region is smaller than the surface density of particles with an aspect ratio of 3 or more present on the surface of the third region.

[0162] (Technical proposal 8) the atomic concentration of the impurity element contained in the third region is higher than the atomic concentration of the impurity element contained in the first region; A superconducting wire according to any one of Technical Schemes 1 to 7, wherein the atomic concentration of the impurity element contained in the third region is higher than the atomic concentration of the impurity element contained in the second region.

[0163] (Technical proposal 9) A superconducting coil comprising the superconducting wire according to any one of Technical Schemes 1 to 8.

[0164] (Technical proposal 10) A superconducting magnet equipped with the superconducting coil described in Technical Proposal 9.

[0165] (Technical proposal 11) A superconducting motor equipped with the superconducting coil described in Technical Proposal 9.

[0166] (Technical proposal 12) A superconducting generator equipped with the superconducting coil described in Technical Proposal 9.

[0167] (Technical proposal 13) A superconducting aircraft equipped with a superconducting motor as described in Technical Proposal 11.

[0168] (Technical proposal 14) A superconducting device equipped with the superconducting wire according to any one of Technical Schemes 1 to 8. [Explanation of symbols]

[0169] 10 Substrate 20 Middle Class 30 Oxide superconducting layer 31a First superconducting region (first region) 31b Second superconducting region (second region) 32a First non-superconducting region (third region) 40 protective layer 52 Stator (superconducting magnet) 52a Stator coil (superconducting coil) 54a Rotor coil (superconducting coil) 66 Superconducting generator 100 Superconducting wire 200 Superconducting Motor 300 superconducting aircraft 400 Heavy particle beam therapy equipment (superconducting equipment)

Claims

1. A substrate; a first region provided on the substrate, the first region including at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O), and extending in a first direction along a surface of the substrate; a second region provided on the substrate, the second region including at least one second rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), barium (Ba), copper (Cu), and oxygen (O), and extending in the first direction; a third region provided on the substrate, between the first region and the second region and in contact with the first region and the second region, the third region including at least one third rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), praseodymium (Pr), barium (Ba), copper (Cu), and oxygen (O), and extending in the first direction; the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the first region; A superconducting wire, wherein the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is greater than the surface density of particles having an aspect ratio of 3 or more present on the surface of the second region.

2. 2. The superconducting wire according to claim 1, wherein the concentrations of praseodymium (Pr) contained in the first region and the second region are lower than the concentration of praseodymium (Pr) contained in the third region.

3. 2. The superconducting wire according to claim 1, wherein the concentration of praseodymium (Pr) among the rare earth elements contained in the first region and the second region is less than 1 atomic %, and the concentration of praseodymium (Pr) among the rare earth elements contained in the third region is 10 atomic % or more.

4. the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is at least twice the surface density of particles having an aspect ratio of 3 or more present on the surface of the first region, 2. The superconducting wire according to claim 1, wherein the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region is at least twice the surface density of particles having an aspect ratio of 3 or more present on the surface of the second region.

5. a width of the first region in a second direction perpendicular to the first direction and along the surface of the substrate is 5 μm or more and 10 mm or less; The width of the second region in the second direction is 5 μm or more and 10 mm or less, 2. The superconducting wire according to claim 1, wherein the width of the third region in the second direction is 1 μm or more and 2 mm or less.

6. 2. The superconducting wire according to claim 1, wherein the width of the third region in a second direction perpendicular to the first direction and along the surface of the substrate is less than or equal to the width of the first region in the second direction and the width of the first region in the second direction.

7. 2. The superconducting wire according to claim 1, wherein the surface density of particles having an aspect ratio of 3 or more present in a cross section along the surface of the third region at a position closer to the substrate than the surface of the third region is smaller than the surface density of particles having an aspect ratio of 3 or more present on the surface of the third region.

8. the atomic concentration of the impurity element contained in the third region is higher than the atomic concentration of the impurity element contained in the first region; 2. The superconducting wire according to claim 1, wherein the atomic concentration of the impurity element contained in the third region is higher than the atomic concentration of the impurity element contained in the second region.

9. A superconducting coil comprising the superconducting wire according to any one of claims 1 to 8.

10. A superconducting magnet comprising the superconducting coil according to claim 9.

11. A superconducting motor comprising the superconducting coil according to claim 9.

12. A superconducting generator comprising the superconducting coil according to claim 9.

13. A superconducting aircraft comprising the superconducting motor according to claim 11.

14. A superconducting device comprising the superconducting wire according to any one of claims 1 to 8.

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