JPH08190816A - Oxide super conducting wire and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a high superconducting critical current density at the liquid nitrogen temperature range by compounding a metallic body having a cubic aggregate structure and an oxide superconducting substance. CONSTITUTION: Pure silver is rolled at 220 deg.C so as to obtain 0.05mm thickness, and the same is annealed at 800 deg.C for two hours so as to form a silver tape board 10 in which crystal planes 100} of 80% or more are in parallel with a tape plane and orientation <100> is arranged in parallel with a rolling direction. Solution composed of 11 of water, 0.01mol of thallium nitrate, 0.02mol of barium nitrate, 0.02mol of calcium nitrate, 0.03mol of copper nitrate, 0.05mol of glycine is atomized by ultrasonic so as to deposit on the silver board 10 of 800 deg.C in 3μm thickness. The same is annealed at 850 deg.C for 50 hours in an atmosphere of oxygen and Tl2 O vapour so as to form a superconducting substance 11. The (c) axis orientation of the crystal of 80% or more stay within 1 degree against the normal line of the board 10, the (a) axis thereof coincides with the rolling direction of the silver tape, and critical current density of 80kA/cm<2> is obtained at a temperature of 77K and in a magnetic field of 1T.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a freezing point 63 of liquid nitrogen.
By flowing a high superconducting critical current density (Jc) even in a magnetic field by forming a complex with an oxide-based superconducting material that exhibits superconductivity by cooling to K and a metal body whose crystal orientation is controlled. The present invention relates to a structure of a superconducting wire or a superconductor that can be manufactured and a manufacturing method thereof. Further, by using the superconducting wire or the superconductor according to the present invention, a superconducting magnet, a superconducting NMR apparatus, a superconducting MRI apparatus, a superconducting power generating apparatus, a superconducting energy storage apparatus, which has a great economic merit compared to the conventional ones, The present invention relates to devices such as a magnetic shield device, a synchrotron radiation generation device, a magnetic separation device, and an elementary particle accelerator.

The present invention also relates to a silver tape having a cubic texture invented in the process of developing a superconducting wire or superconductor having a high Jc even in a magnetic field, and a method for producing the same.

[0003]

2. Description of the Related Art Since the discovery of the first oxide high temperature superconducting material in 1986, more than several tens of oxide superconducting materials have been discovered. Among them, the stability of matter,
Oxide superconducting materials, which are still being researched for practical use because of their ease of synthesis, are (1) (Tl _1-X1-X2 Pb _X1 Bi _X2 ) (Sr _{1- X3} Ba _X3 ) ₂ C
a _n-1 Cu _n O _{2n + 3} where 0 ≦ X1 ≦ 0.9, 0 ≦ X2 ≦ 0.5, 0 ≦ X1 + X2 ≦ 1, 0 ≦ X3 ≦ 1, n = 1,2,3,4 , 5 (hereinafter referred to as Tl-1-layer _{system) (2) Tl 2 Ba 2} Ca n _over 1 Cu _n O _{2n + 4} where, n = 1,2,3,4,5 (hereinafter, Tl-2 abbreviated as layer system) (3) (Bi _{1 over X1 Pb X1) 2 Sr 2 Ca} n _over 1 Cu _n O _{2n + 4} where, 0 ≦ X1 ≦ 0.4, n = 1,2,3 ( hereinafter, Bi-2 layer system) (4) LnBa ₂ Cu ₃ O _{7 + X1} where Ln is Y or a rare earth element of −0.5 ≦ X1 ≦ 0.1 (hereinafter abbreviated as Y system). It has been almost squeezed by the material system.

Among these, the Bi-2 layer type material is easy to orient the crystal (to align the crystal in a specific direction), and the superconducting flow at the grain boundary portion is good, so that the magnetic field is large. The superconducting transport current density (transport Jc) is high when it is not applied (Japa
nese Journal Of Applied Physics, vol. 30, 1991, p
p.L2083-L2084). However, this material system has a fatal problem that the pinning force becomes extremely weak in the temperature range where it can be cooled by liquid nitrogen due to the essential problem derived from its crystal structure (Physica C, vol. 177, 1
991, pp.431-437). Therefore, it is possible to produce a superconducting wire having very good characteristics for use in a temperature range of about 40K or lower, but it was not possible to use it for a wire used in a temperature range of 60K or higher. .

On the other hand, the Tl-1 layer system, the Tl-2 layer system and the Y system material can exhibit a high pinning force up to the vicinity of their critical temperature (Tc), but the crystal orientations should be aligned. Is difficult, and therefore the flow of superconducting current at the grain boundaries is poor, and the transport Jc at a temperature of 77K and a magnetic field of 1T, which is considered to be a tentative standard required for practical use, exceeds 10,000 A / cm ² . No superconducting wire has been obtained (Physica C, vol.220, 1994, pp.310−322, Hitachi
Review, vol. 39, 1990, p.55, Japanese Journal Of
Applied Physics, vol. 27, 1988, pp. L185-L187).

Recently, the crystal orientations of the Tl-1 layer system and the Y system materials having a strong pinning force at 77K have been aligned to 77
Research aiming at producing a superconducting wire capable of obtaining a high Jc even in a magnetic field at K has been conducted in various places. For example, Iijima et al. "Proceedings of 5th
International Symposium on Superconductivity, Nove
mber 16-19, 1992, Kobe, Japan, pp.661-664 "on a polycrystalline Ni-based alloy.
Yttria-Stabilized-with the crystal orientation aligned by the position method
Zirconia is prepared and pulsed laser deposition is performed on it.
A method for producing a Y-based superconducting material by the method is disclosed. Also, Deluca et al. "Physica C vol. 205, 1993, pp.21-31"
On top of the polycrystalline Yttria-Stabilized-Zirconia
Disclosed is a method for producing a Tl-1 layer type superconducting substance by a spray pyrolysis method. Also, Tatsuyoshi Yoshino, in JP-A-3-9311, uses a silver tape in which (100) or (110) crystal planes are arranged in parallel with a rolling surface.
Disclosed is a method for producing a superconductor in which the directions of crystals are aligned. In addition, Yoshino and others are `` Abstracts of 6th Internat
ional Symposium on Superconductivity, October26-2
3, 1992, Hiroshima, Japan. P. 119 ”discloses a method for producing a Y-based superconducting substance by the ionized-cluster-beam-deposition method on a silver tape in which (110) planes of silver crystals are arranged in parallel with the tape surface.

Further, until now, it has been impossible to produce a superconducting wire having a performance that can withstand practical use in a temperature range above the temperature at which it can be cooled by liquid nitrogen, so a refrigerant having a boiling point higher than that of liquid helium such as liquid nitrogen. There was no superconducting device that could operate by cooling with.

Further, a silver tape having a so-called cubic texture in which the {100} planes of the crystals are aligned in the <100> direction has not been obtained until now (for example, “texture” by Shinichi Nagashima, Maruzen Co., Ltd.). Company).

[0009]

Among the above-mentioned conventional techniques,
The technology using the Bi-2 layer superconducting material is 77K.
There is a problem that the pinning power is weak in 6
In the temperature range of 0 K or higher, there is a problem that the critical current density is greatly reduced when a magnetic field is applied to the Bi-2 layer system superconducting material, which greatly limits the use in superconducting equipment that operates by liquid nitrogen cooling. That was a problem.

According to the technique of Iijima et al., Yt in which crystal directions are aligned
The process Ion-Beam-Assisted Deposition, which requires a vacuum, must be used in making the tria-Stabilized-Zirconia. However, when it is assumed that a long wire (for example, 1 km) is to be produced, such a process is expected to be very economical. Therefore, Yttria-Stabilized-Zirc with the crystal orientation aligned on the Ni-based alloy
It is considered that it is difficult to produce a long superconducting wire as a product by a technique of producing onia and then producing a Y-based superconducting substance on it.

Deluca's technology is ceramics Yt
It is expected that there will be great difficulty in producing tria-Stabilized-Zirconia as a long product, and it will be difficult to produce a long superconducting wire as a product.

[0012] According to Yoshino's technique, c of a crystal of a superconducting substance is used.
Since only attention is paid to aligning the directions of the axes, and the directions of the a-axes of the crystals are not aligned, the critical current density at 77K remains as low as 10,000 A / cm ² .

According to Yoshino et al.'S technology, silver crystal (110)
The sides are parallel to the tape surface. In order to obtain a high Jc, it is necessary to align the directions of the (001) plane of the superconducting crystal in parallel. However, the matching of the (110) plane of the silver crystal and the (001) plane of the superconducting crystal is not so good, so Yosh
The technology of ino et al. has not yet fully aligned the orientation of the superconducting crystals, and as a result, the Jc value is 77K, 0T, 45,000A.
It is not so high as / cm ² .

In the conventional technique disclosed by Iijima et al., Deluca et al., And Yoshino et al., Since the property of the base material to be composited with the superconducting substance is not sufficiently considered, a long superconducting wire is produced as a product. Was difficult.

An object of the present invention is to provide a base material suitable for aligning crystals of an oxide superconducting material in a preferred direction, and by compounding the base material and the oxide superconducting material, it is possible to achieve high magnetic field. It is to provide a superconductor and a superconducting wire having a critical current density. In addition, the use of the superconducting wire according to the present invention makes it possible for the first time to operate a superconducting magnet, an NMR apparatus, an MRI apparatus, a magnetic levitation train, a superconducting generator, an energy storage apparatus that operates in a temperature range higher than the temperature that can be cooled by liquid nitrogen. It is also an object of the present invention to provide an application device utilizing superconductivity such as a magnetic shield device, a synchrotron radiation device, and an elementary particle accelerator.

[0016]

The above object can be achieved by compounding an oxide superconducting material with a metal body having a cubic texture to form a superconducting wire or a superconductor. The cubic texture is, for example, a texture having a {100} <001> orientation as described in “Texture” published by Maruzen Co., Ltd., edited by Shinichi Nagashima, pages 133 and 185.

When the {100} plane of the metal crystal of the metal body having a cubic texture is aligned parallel to the interface between the metal body and the oxide superconducting substance, the superconductor is a composite of the two. The superconducting critical current density (Jc) can be increased.

When the {100} plane of the metal crystal of the metal body having a cubic texture and the (001) plane of the oxide superconducting substance are made parallel to each other, the crystal grains of the oxide superconducting substance are The crystal orientation can be easily aligned, and Jc can be increased. Here, parallel means that both directions are aligned within 10 degrees. The direction of the {100} plane of the metal crystal and the angle of the interface, and the angle of the {100} plane of the metal crystal and the (001) plane of the oxide superconducting material are variously changed to obtain Jc.
Was measured, it was 10% when it was 5 degrees or more, 1
The Jc dropped sharply at 0 degrees or more.

It is the highest when all the crystal axes of a, b and c of the metal crystal of the metal body having the cubic texture and all the crystal axes of a, b and c of the oxide superconducting material are parallel to each other. Give Jc. By aligning only one axis in parallel,
Although the value of Jc can be improved to some extent, it is insufficient when considering practical use.

99% of the crystal {100} planes are parallel and the <001> orientation is aligned (having a cubic texture) to prepare a silver tape, on which an oxide superconducting material is formed. Was manufactured by varying the degree of aligning the crystal orientations, and the change in Jc was investigated. Metal crystal {100}
In the range where the angle between the plane and the (001) plane of the oxide superconducting material is within 10 degrees, the Jc value higher than the Jc of the conventional superconducting wire or superconducting wire can be obtained within the range of not less than 60%. Has been. However, when the angle between the {100} plane of the metal crystal and the (001) plane of the oxide superconducting material is within 10 degrees, when less than 80% of the whole, Jc sharply decreases. From the (100) plane of the metal crystal and the (001) plane of the oxide superconducting material.
80% of the total angle is within 10 degrees
The above is preferable. In addition, metal crystals <
In the range where the 110> direction and the [110] direction of the oxide superconducting substance crystal are within 10 degrees, the Jc value higher than the Jc value of the superconducting wire or the superconducting wire according to the prior art is not exceeded. Has been obtained. However, when the <110> direction of the metal crystal and the [110] direction of the oxide superconducting material crystal are within 10 degrees, when less than 80% of the whole, Jc sharply decreases. Therefore, it is preferable that the <110> direction of the metal crystal and the [110] direction of the oxide superconducting material crystal are within 10 degrees, which is 80% or more of the whole. In addition, in the range where the <100> direction of the metal crystal and the [100] direction of the oxide superconducting material crystal are within 10 degrees within 60% of the whole, the superconducting wire or the superconducting wire according to the conventional technique is A Jc value higher than Jc is obtained. However, when the <100> direction of the metal crystal and the [100] direction of the oxide superconducting material crystal are within 10 degrees, when less than 80% of the whole, Jc sharply decreases. From <100> of metal crystals
It is preferable that the direction and the [100] direction of the crystal of the oxide superconducting material are within 10 degrees, which is 80% of the whole.

A silver tape having {100} planes parallel to the tape surface and varying the proportion of crystals whose <110> direction is aligned with the tape longitudinal direction was prepared, and an oxide superconducting material layer was carefully formed thereon. Formed and examined for changes in Jc. {1
The ratio of crystals in which the {00} planes are aligned in the <110> direction is 8
It has been found that Jc drops sharply when it falls below 0%.

The metal tape having a cubic texture may be composed of any element other than silver as long as it does not impair the properties of the oxide superconducting material used during the heat treatment of the superconductor. It doesn't matter. For example, pure silver, an alloy of silver and gold, an alloy of silver and palladium, an alloy of silver and copper, and a dispersion strengthening alloy in which an oxide such as MgO is dispersed in a silver matrix phase may be used. A metal having an FCC structure is preferable because a cubic texture can be easily obtained. However, since a cubic texture can be obtained even with a metal having a BCC structure, a BCC metal may be used, but a superconductor having good characteristics cannot be obtained with a metal having an HCP structure.

In order to obtain a high critical current density as a superconducting wire, it is needless to say that the superconducting critical current density flowing through the superconducting portion should be high, but the composition ratio of the superconducting substance and the non-superconducting substance is also important. Become a factor. As a matter of course, the higher the proportion of the superconducting material, the higher the Jc of the superconducting wire. In the method according to the invention, the thinner the metal tape, the better, while the thicker the superconducting material layer, the better. However, their thickness is naturally limited. In consideration of economic efficiency, the metal tape needs to be manufactured by rolling, but in that case, it was very difficult to manufacture the metal tape having a thickness of less than 5 microns. Further, the crystal of the superconducting material is influenced by the crystal of the base material, so that the directions thereof are aligned, so that the crystal direction is disturbed when the superconducting material layer exceeds 3 microns. For this reason, it is difficult to make the ratio S1 / S2 of the area S1 of the metal body and the area S2 of the oxide superconducting material in the cross section perpendicular to the longitudinal direction larger than 0.6.
If the value of S1 / S2 is too small, the critical current density of the entire superconducting wire will be too low, which is not preferable. From an economical point of view, the value of S1 / S2 must be at least 0.01.

Although the metal body is often in the form of a tape, a superconducting wire having a high Jc can be obtained by the same principle regardless of whether the metal body is in the shape of a wire, a tube or the like.

The oxide superconducting material has an irreversible magnetic field (the minimum magnetic field that produces a finite resistance above the magnetic field) higher than the magnetic field required in the region above the temperature where it can be cooled with liquid nitrogen. It is necessary to use existing superconducting materials. For example, superconducting materials synthesized on the basis of Tl, Sr, Ca, Cu, O are preferable because of their high Tc and high irreversible magnetic field Hc *. This superconducting substance group is rich in flexibility, and element substitution of crystal sites is very likely to occur. A specific composition formula is (Tl _X1 Pb _X2 Bi _X3 Hg _X4 Cu _X5 ) (Sr _1-X6 Ba _X6 ) ₂
C _n-1 Cu _n O _{2n + 3 + X7} (where 0 ≦ X1 ≦ 1.0, 0 ≦ X2 ≦ 1.0, 0 ≦ X
3 ≦ 0.5, 0 ≦ X4 ≦ 1.0, 0 ≦ X5 ≦ 1.0, 0.0.
5 ≦ X1 + X2 + X3 + X4 + X5 ≦ 1,0 ≦ X6 ≦
1, -0.5 ≦ X7 ≦ 0.5, n = 1, 2, 3, 4, 5)
Is. Further, the oxide superconducting substance group represented by the composition formula of LnBa ₂ Cu ₃ O _{7 + X1} (where Ln is Y or a rare earth element, −0.5 ≦ X1 ≦ 0.1) also has a high irreversible magnetic field. Therefore, it is a preferable substance for the present invention. Also,
The composition is (Tl _1-X1-X2-X3 Pb _X1 Bi _X2 Hg _X3 ) ₂ (Sr _1-X4 B
_{a X4) 2 Ca n-1} Cu n O 2n + 3 + X5 ( where n = 2,3,4,5,6,0 ≦ X1 ≦ 0.8,
0 ≦ X2 ≦ 0.5, 0 ≦ X3 ≦ 1.0, 0 ≦ X1 + X2 +
X3 ≦ 1,0 ≦ X4 ≦ 1, −0.5 ≦ X5 ≦ 0.5) has a slightly smaller irreversible magnetic field than the above Tl-1 layer system or Y system superconducting substance group. However, such a substance group may be used.

Compositional formula, (Bi _{1 -X1} Pb _X1 ) ₂ Sr ₂ Ca _{n -1}
Cu _n O _{2n + 4} (where 0 ≦ X1 ≦ 0.4, n = 1, 2,
The superconducting material group represented by 3) does not have such a high irreversible magnetic field in the temperature range where liquid nitrogen can be cooled, so it is slightly outside the scope of the present invention, but even when such a superconducting material is used, a cubic assembly is used. By forming a complex with a metal body having a tissue, Jc (in a magnetic field below the irreversible magnetic field) can be increased.
Also, lower temperature range (for example, cooling with liquid helium)
When used in, the Jc is greatly improved.

The superconducting substance to which the present invention can be applied is not limited to these, but is a technique that can be applied to all substances whose characteristics are generally improved by aligning the crystal directions.

Since all the conventional superconducting equipment uses a superconducting substance which is in a superconducting state only in a temperature range of 30 K or less, liquid helium is required for its operation, which is very costly. In order to solve this point, the present invention uses a superconducting wire or a superconductor made of a substance that becomes sufficiently in a superconducting state by cooling with liquid nitrogen, so that the cost for cooling can be greatly reduced. Furthermore, when a superconducting applied device is manufactured using the superconducting wire or the superconducting wire manufactured by the present invention, quenching (for some reason, the superconducting When a part changes to the normal conduction state, it rapidly propagates and the entire superconductor changes to the normal conduction state, and at that time, a large amount of heat is suddenly generated. In the first place, a superconducting device in which quenching does not substantially occur can be provided. Therefore, it is not necessary to take a quenching measure that has been necessary in the past, and a significant cost reduction can be achieved.

Silver is most preferable as a metal body having a cubic texture when the present invention is applied to a practical product, but a silver polycrystal having a cubic texture has not been present so far. Therefore, we have succeeded in finally obtaining a silver cubic texture by examining various factors such as the purity of silver, the workability, rolling temperature, heat treatment temperature and time. Specifically, silver with a purity of 99.0% or more is drawn or rolled at a temperature of 100 ° C. or higher and 300 ° C. or lower, preferably 150 ° C. or higher and 200 ° C. or lower so that the workability is 80% or higher. After that, a silver cube texture can be obtained by performing heat treatment at a temperature of 400 ° C. or higher for 5 minutes or longer. Since silver having this cubic texture has no anisotropy in addition to being used in combination with an oxide superconducting material, it is better than conventional silver wires when used for conducting wires that carry currents and signals. The characteristics are obtained. Further, when it was used as a substrate for a GaAs semiconductor device, the same characteristics as the performance of a GaAs semiconductor device formed on a GaAs single crystal substrate were confirmed. From this, it is understood that the silver having the cubic texture of the present invention can be used as a substrate which is cheaper than the GaAs single crystal. Further, when it is necessary to prepare some substances by aligning the crystal orientations thereof, silver having a cubic texture according to the present invention can be used for a substrate to obtain a large area at low cost.

[0030]

We have found that a superconducting material having a crystal structure as shown in FIGS. 1, 2 and 3 (two unit lattices in FIGS. 1 and 2 and a unit lattice in FIG. 3) has a high irreversible magnetic field ( The value of the maximum applied magnetic field that allows a superconducting current with zero electric resistance to flow through the sample at a certain temperature. When a magnetic field higher than this value is applied to the sample, the sample can generate resistance. We have made possible a method for producing a superconductor with a high irreversible magnetic field by introducing a pinning center into the superconducting material. In the process, when a superconducting wire is produced with a polycrystalline body (that is, not a single crystal but a superconductor in which crystal grain boundaries exist) using a superconducting material capable of increasing the irreversible magnetic field, c of the crystal of the superconducting material is used. It is possible to make a superconductor with a higher Jc when the axes are oriented in the same direction (c-axis orientation). The a, b and c axes of the crystal of the superconducting material are all oriented in the same direction. It was found that a superconductor having a higher Jc can be obtained by performing (triaxial orientation). Therefore, this time, by aligning a superconducting material that can have a high irreversible magnetic field
A structure and a manufacturing method of a superconducting wire or a superconductor having c have been devised.

Y-based, Tl-
Even if a superconducting substance such as a one-layer system or a T1-2 layer system is produced, the crystal orientation of the oxide superconducting substance is not sufficiently aligned, and the temperature is 77
K and Jc in a magnetic field of 1 T cannot be as high as several thousand A / cm ² . In addition, on the silver tape in which the {110} planes of the crystals are aligned parallel to the surface, Y system, Tl-1 layer system, Tl-
Even if a superconducting material such as a two-layer system is produced, the crystal orientations of the oxide superconducting material are not sufficiently aligned, and the temperature is 77K and the magnetic field is J.
c = J, tens of thousands A / cm ² , temperature 77K, magnetic field 1T
c is a value of several thousand A / cm ^2, which is not sufficiently high. Also, the {100} of the crystals are aligned parallel to the surface, but <1
00> Y direction, Tl-
Even if a superconducting substance such as a one-layer system or a T1-2 layer system is produced, the crystal orientation of the oxide superconducting substance is not sufficiently aligned, and the temperature is 77
K, Jc = tens of thousands A / cm ² without magnetic field, temperature 77K, magnetic field 1
The value of Jc in T is about several thousand A / cm ^2, which is not sufficiently high. However, when an oxide superconducting material was produced on a silver tape having a cubic texture, a superconducting wire with a Jc of 10,000 A / cm ² or more at a temperature of 77 K and a magnetic field of 1 T was obtained. did it. There are various possible reasons for this, but it is likely that the arrangement of silver atoms on the surface of the silver tape having a cubic texture is favorable for the triaxial orientation, which is the ideal crystal orientation of the superconducting material. It is thought that it is because there is.

In addition, an alloy of silver and gold having a cubic texture, an alloy of silver and palladium, an alloy of silver and copper, a dispersion-strengthened alloy in which MgO is dispersed in a silver matrix phase, and an intermetallic material in the silver matrix phase. Even when the dispersion-strengthened alloy in which the compound was dispersed was used, a high Jc was obtained as in the case of producing the oxide superconducting material on the silver tape having the cubic texture. In addition, N having a cubic texture
Even when i, Ni-Fe alloy, Cu, or Cu-Al alloy is used, it is considered that a high Jc can be obtained as in the case of producing an oxide superconducting material on a silver tape having a cubic texture. To be

The composition of the superconducting substance, non-superconducting substance and other substances described in the present invention is not strictly limited to this value. Actually, these oxides have some composition indefiniteness, and the content ratio of each constituent element may deviate from about a dozen percent to about 30 percent. Therefore, even if the composition of the substance described in the present invention is slightly different, if the crystal structure is basically the same,
It is the same as the substance described in the present invention.

By using the superconductor produced by the present invention, it becomes possible to produce a superconducting magnet which operates with liquid nitrogen cooling and has good characteristics. By using this magnet, it is possible to fabricate an NMR apparatus, a SQUID apparatus, an MRI apparatus, a magnetic levitation train, etc. that operate by cooling with liquid nitrogen. It is possible to replace all of the devices using the superconducting magnet with the superconducting material using the wire material using the superconducting material of the present invention, whereby it is possible to operate with liquid nitrogen cooling. By operating with liquid nitrogen cooling, the reliability of the superconducting device (suppressing a phenomenon called rapid quenching of superconductivity) is suppressed beyond the merit of simply lowering the operating cost (price difference between liquid helium and liquid nitrogen). In addition, the cost for securing various measures), the cost for the refrigerator, and the cost for heat insulation are significantly reduced. Therefore, by manufacturing a superconducting device using the superconducting wire and coil according to the present invention, the cost of the device can be significantly reduced.

[0035]

Embodiments of the present invention will be described below.

[Example 1] First, a silver tape having a cubic texture was prepared. A block of commercially available silver (99.99%) with a width of 10 mm, a thickness of 5 mm and a length of 50 mm is heated to 220 ° C.
Rolled 5 times while keeping the thickness at 0,5 mm thickness
I made it thin. At this time, the annealing process should not be inserted in the middle. This tape was annealed at 800 ° C. for 2 hours to obtain a silver tape substrate. When the orientation of silver crystals was examined by X-ray diffraction measurement, the {100} plane of about 80% of the crystal grains was parallel to the tape surface, and the <100> orientation was aligned parallel to the rolling direction. I was able to confirm that.

Next, a superconducting substance was prepared on the silver tape having the cubic texture prepared above. To 1 liter of distilled water, 0.01 mol of thallium nitrate having a purity of 98% or more, 0.02 mol of barium nitrate and 0.02 mol of calcium nitrate were added.
02 mol, copper nitrate 0.03 mol, glycine 0.05
A raw material solution was prepared by melting the moles. Using an ultrasonic oscillator, this solution was made into droplets having a diameter of several microns and sprayed onto a silver tape substrate to deposit a precursor having a thickness of 3 microns. The substrate temperature at this time was 800 ° C. This was annealed at 850 ° C. for 50 hours in an atmosphere in which oxygen gas and Tl ₂ O vapor coexist to obtain a superconducting material. FIG. 4 shows the structure of the completed superconductor. 10
Is a silver tape substrate having a cubic texture, and 11 is an oxide superconducting material.

When the superconducting critical temperature of the finished superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 107K. The measured critical current density of 77K, the magnetic field 500,000A / cm ^2, 1T in zero magnetic field when applied perpendicular to the substrate was 80,000 A / cm ^2.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 1 degree with respect to the normal to the substrate. Was there. In addition, the a-axis (or b) of the crystal of the superconducting material
80% when the axis is in line with the rolling direction of the silver tape
It was confirmed that there was above.

[Comparative Example 1] The same commercially available ingot of silver used in Example 1 was rolled 5 times at room temperature,
The thickness was reduced to 0.05 mm and then annealed at 800 ° C. for 5 hours to obtain a silver tape substrate for comparison. When the orientation of silver crystals was examined by X-ray diffraction measurement, the {110} planes were aligned parallel to the tape surface. On this substrate, Example 1
A superconducting material was prepared in exactly the same manner as in. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 107K. The measured critical current density of 77K, the magnetic field of 48,000A / cm ^2, 1T in zero magnetic field when applied perpendicular to the substrate was 5,000 A / cm ^2.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 degrees with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

[Comparative Example 2] A superconducting material was prepared in exactly the same manner as in Example 1 on the same commercially available mass of silver as that used in Example 1. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 107K. When the critical current density of 77K was measured, it was 35,000A / cm ² at zero magnetic field,
1,000 when a 1T magnetic field is applied vertically to the substrate
It was A / cm ² .

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 degrees with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

As described above, from the results of Examples 1 and Comparative Examples 1 and 2, by combining a metal body having a cubic texture and an oxide superconducting substance into a superconductor, it is possible to obtain a very high Jc. It can be seen that a superconductor or a superconducting wire having a high conductivity can be obtained.

[Example 2] A superconducting substance was prepared on the silver tape having a cubic texture used in Example 1. In 1 liter of distilled water, 0.005 mol of thallium nitrate having a purity of 98% or more, 0.005 mol of lead nitrate, 0.02 mol of strontium nitrate and 0.02 mol of calcium nitrate were added.
A raw material solution was prepared by dissolving 2 mol, 0.03 mol of copper nitrate and 0.04 mol of glycine. Using an ultrasonic oscillator, this solution was made into droplets having a diameter of several microns and sprayed onto a silver tape substrate to deposit a precursor having a thickness of 3 microns. The substrate temperature at this time was 800 ° C. This was annealed at 860 ° C. for 50 hours in an atmosphere in which oxygen gas and Tl ₂ O vapor coexist to obtain a superconductor.

When the superconducting critical temperature of the finished superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 121K. The measured critical current density of 77K, the magnetic field 800,000A / cm ^2, 1T in zero magnetic field when applied perpendicular to the substrate was 100,000 A / cm ^2.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 1 degree with respect to the normal to the substrate. Was there. In addition, the a-axis (or b) of the crystal of the superconducting material
80% when the axis is in line with the rolling direction of the silver tape
It was confirmed that there was above.

[Comparative Example 3] The same commercial silver lump as used in Example 1 was thinned to a thickness of 0.05 mm by rolling five times while keeping it at 20 ° C, and then 800 ℃
It was annealed for 2 hours to prepare a silver tape substrate for comparison.
A superconducting substance was produced on this substrate in exactly the same manner as in Example 2. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 121K. The measured critical current density of 77K, the magnetic field of 30,000A / cm ^2, 1T in zero magnetic field when applied perpendicular to the substrate 2,000 A / cm ²
Met.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 degrees with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

[Comparative Example 4] A superconducting material was prepared in exactly the same manner as in Example 2 on the same commercially available mass of silver as that used in Example 1. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 121K. When the critical current density of 77K was measured, it was 25,000A / cm ² at zero magnetic field,
1,000 when a 1T magnetic field is applied vertically to the substrate
It was A / cm ² .

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 ° with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

As described above, from the results of Examples 2, Comparative Examples 3 and 4, by combining a metal body having a cubic texture and an oxide superconducting substance into a superconductor, it is possible to obtain a very high Jc. It can be seen that a superconductor or a superconducting wire having a high conductivity can be obtained.

[Example 3] A superconducting substance was prepared on the silver tape having a cubic texture used in Example 1. In 1 liter of distilled water, 0.01 mol of yttrium nitrate having a purity of 98% or more and 0.02 mol of barium nitrate were added.
A raw material solution was prepared by dissolving 0.03 mol of copper nitrate and 0.02 mol of glycine. Using an ultrasonic oscillator, this solution was made into droplets having a diameter of several microns and sprayed onto a silver tape substrate to deposit a precursor having a thickness of 3 microns. The substrate temperature at this time was 800 ° C. In an oxygen gas atmosphere
A superconductor was obtained by annealing at 870 ° C. for 50 hours.

When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 92K. The measured critical current density of 77K, the magnetic field 400,000A / cm ^2, 1T in zero magnetic field when applied perpendicular to the substrate was 80,000 A / cm ^2.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 1 degree with respect to the normal to the substrate. Was there. In addition, the a-axis (or b) of the crystal of the superconducting material
80% when the axis is in line with the rolling direction of the silver tape
It was confirmed that there was above.

[Comparative Example 5] The same commercial silver ingot as used in Example 1 was thinned to a thickness of 0.05 mm by rolling five times while keeping it at 20 ° C, and then 800 ℃
It was annealed for 2 hours to prepare a silver tape substrate for comparison.
A superconducting substance was produced on this substrate in the same manner as in Example 3. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 83K. When the critical current density of 77K was measured, it was 800 A / cm ² when a magnetic field of 10,000 A / cm ² at a zero magnetic field and a magnetic field of 1 T was applied perpendicularly to the substrate.

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 degrees with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

[Comparative Example 6] A superconducting substance was prepared in exactly the same manner as in Example 3 on the same commercially available mass of silver as that used in Example 1. When the superconducting critical temperature of the completed superconductor was measured by the DC 4-terminal method, it was confirmed that the electric resistance became zero at 83K. When the critical current density of 77K was measured, it was 9,000 A / cm ² at zero magnetic field,
900 A / m when a magnetic field of 1 T is applied vertically to the substrate
It was cm ² .

When the direction of the c-axis of the crystal of the superconducting material was examined by X-ray diffraction measurement, 80% of the c-axis of the crystal entered within 5 degrees with respect to the normal to the substrate. Was there. However, the orientation of the a-axis (or b-axis) of the crystal of the superconducting material has not been particularly aligned.

As described above, from the results of Examples 3 and Comparative Examples 5 and 6, by combining a metal body having a cubic texture and an oxide superconducting substance into a superconductor, it is possible to obtain a very high Jc. It can be seen that a superconductor or a superconducting wire having a high conductivity can be obtained.

Example 4 Instead of the silver tape substrate having the cubic texture used in Examples 1, 2, and 3, Ag was used.
-40% Au, Ag-20% Au, Ag-10% Pd,
An Ag-10% Cu alloy and an oxide dispersion type alloy in which MgO having a grain size of 0.1 micron is dispersed at a deposition rate of 0.1% in an Ag matrix to have a cubic texture by rolling + heat treatment. As a metal tape, a superconducting substance was produced thereon in the same manner as in Examples 1, 2, and 3 to obtain a superconducting tape. In any case, the performance of the same level (Jc within 90%) as that obtained in Examples 1, 2, and 3 was obtained.

Example 5 In the same manner as in Example 1, a silver tape having a cube texture having a thickness of 5 μm, a width of 1 cm and a length of 100 m was produced. On this, a superconducting wire rod having a length of 100 m was manufactured in the same manner as in Example 3. Outer diameter 30c
The tape-shaped superconducting wire was wound around a bobbin of m and heat treated, and then Jc over the entire length of the wire was measured and found to be Jc (all) = 50,000A / cm ² at zero magnetic field (this Jc (all) Is the critical current value divided by the cross-sectional area of the entire wire including silver). Jc (al in a magnetic field
In order to measure l), 10 pieces of 10 cm long sample pieces were randomly cut from a 100 m wire and Jc (all) was measured by a DC 4-terminal method. The measurement result of the sample piece with the worst characteristics was 0.
When the magnetic fields of 01T, 0.1T, 1T, and 5T are applied in the direction perpendicular to the longitudinal direction of the sample, Jc (all) is 50,000, 38,000, 23,000, 11,000, 10,000A / cm, respectively.
^{Was 2} .

[Example 6] Two SrTiO ₃ (100) single crystal substrates were prepared, the [001] directions of these single crystals were kept parallel, and the angle (a
2 sheets of SrTiO 3 with various degrees
_A (100) single crystal substrate was bonded to produce a bicrystal substrate. A superconducting material was produced on this bicrystal substrate in the same manner as in Example 1. The crystal orientation of the superconducting material was examined by X-ray diffraction measurement.
[001] and [100] of rTiO ₃ (100) single crystal
It was confirmed that 98% or more of all the crystals had the [010] direction and the [001] direction of the superconducting crystal, and the [100] and [010] directions thereof coincided with each other. Therefore, the crystal of the superconducting material formed on the bicrystal substrate may be in a state in which the [100] direction is deviated by a degree (the c-axis direction is the same) at a position just above the crystal grain boundary of the bicrystal substrate. Recognize. That is, it can be seen that if a superconducting material is produced on a bicrystal substrate with variously changed angles a, it is possible to produce various samples with different angles formed by the a-axis directions with the c-axis directions aligned. .

In FIG. 5, TlB with the c-axis direction aligned.
In the a ₂ Ca ₂ Cu ₃ O ₉ superconducting material film, the critical current density Jc (a) flowing through a grain boundary whose angle with the a-axis direction is a is
The value is divided by the critical current density Jc (0) flowing through the crystal grain boundary where the angle formed by the a-axis direction is 0. As can be seen from the figure, when the angle formed by the a-axis direction is 10 degrees or more, the value of the critical current density that can flow beyond the crystal grain boundary suddenly decreases. Therefore, in order to produce a superconducting wire having good characteristics, it is understood that not only the c-axis of the crystal of the superconducting substance must be aligned, but also the direction of the a-axis must be aligned within 10 degrees.

Example 7 A silver tape having a cubic texture changed by changing rolling and heat treatment conditions was prepared, and a superconducting substance was prepared thereon by the same method as in Example 1. did. The proportion of silver crystals in which the {100} plane was parallel to the tape surface and the <100> direction was parallel to the rolling direction was examined by X-ray diffraction measurement. Further, the critical current density of the produced superconductor (TlBa ₂ Ca ₂ Cu ₃ O ₉ ) sample was measured by the DC 4-terminal method.

FIG. 6 shows the relationship between the two. As can be seen from the figure, when the ratio of silver crystals whose {100} plane is parallel to the tape surface and <100> direction is parallel to the rolling direction (cubic texture ratio) is 80% or less, It can be seen that the value of the critical current density is significantly reduced. Therefore, in order to produce a superconducting wire with good characteristics, the {100} plane is parallel to the tape surface and <
It can be seen that a silver tape in which the ratio of silver crystals having 100> directions parallel to each other (the ratio of cubic texture) is 80% or more must be used.

Further, when the [100] direction of the superconducting crystal was within 10 degrees with respect to the <100> direction of the silver crystal forming the cubic texture by X-ray diffraction measurement, the proportion was estimated. It was 80%.

[Embodiment 8] Ten superconducting tape wire rods similar to those produced in Embodiment 5 were produced. This wire rod 10
10 bundled into a bundle and have a sectional structure shown in FIG.
A superconducting wire having a length of 0 m was produced. Alumina was coated on the surface of this superconducting wire to a thickness of about 5 μm and wound in a pancake shape to prepare a superconducting coil.
Eight such coils are produced and stacked in the vertical direction, as shown in FIG.
The superconducting magnet shown in was produced. When the coil was immersed in liquid nitrogen and an electric current was applied to generate a magnetic field, a maximum magnetic field of 2.6 Tesler could be generated.

Example 9 Superconducting conductors having various cross-sectional structures were produced using the superconducting tape wire produced according to the production method of Example 1. Its sectional structure is shown in FIG.
This is shown in FIGS. Alumina was coated on the surface of this superconducting wire to a thickness of about 5 μm and wound in a pancake shape to prepare a superconducting coil. Eight such coils were produced and laminated in the longitudinal direction to produce a superconducting magnet having the structure shown in FIG. When the coil was immersed in liquid nitrogen and an electric current was applied to generate a magnetic field, a maximum magnetic field of 2.1 to 2.8 Tesler could be generated regardless of which superconducting conductor was used.

[Embodiment 10] Using the superconducting magnet prepared in Embodiment 8, NMR having the structure shown in FIG.
A device was produced and it was confirmed that nuclear magnetic resonance of hydrogen atoms could be measured. The manufacturing cost is 10 because the heat insulation can be simplified as compared with the commercially available He-cooled type.
It turns out that it can be reduced by more than%. It was also found that operating costs can be significantly reduced because expensive liquid helium is not required.

Since the basic operation principle of the NMR apparatus and the MRI apparatus is the same, the M using the superconducting magnet using the superconducting wire produced by using the superconductor according to the present invention is used.
It can be seen that the RI device can be manufactured. Estimating the manufacturing cost, instead of a helium refrigerator, a nitrogen refrigerator with a much simpler structure and cheaper cost, a single heat insulation, an operating temperature of 77K and an operating temperature of a conventional MRI device 4. Since it is much higher than 2K, there is no concern about quenching because the specific heat of the superconducting wire is about 100, and there is no need to take measures against it, so at least 20% cost reduction is possible. I knew it was.

[Embodiment 11] A magnetic shield using the superconductor produced in the present invention was produced. A cube is made of a superconducting plate with a thickness of 3 cm and cooled with nitrogen gas of 78K,
A shielded superconducting state was applied and a magnetic field of 50 gauss was applied from the outside. When the internal magnetic field was measured with the Hall element placed inside, it was a small magnetic field below the detectable limit of the Hall element. When the external magnetic field was set to 3000 gauss, the internal magnetic field was about 1 gauss. It was confirmed that the magnetic shield manufactured using the superconductor according to the present invention has sufficient characteristics.

[Embodiment 12] A large particle accelerator, for example, a quadrupole electromagnet for converging a particle beam to be attached to an accelerator ring having a diameter of 1 km is manufactured by a magnet using a superconducting wire according to the present invention. It was estimated how much the cost would be reduced compared to the case where the superconducting magnet cooled by liquid helium was used. A nitrogen refrigerator that has a much simpler structure and is cheaper than a helium refrigerator can be used, heat insulation is simple and good, and liquid nitrogen with a large specific heat makes it possible to greatly simplify the system for supplying the refrigerant to the superconducting magnet. Therefore, it was found that the cost could be reduced by 20% or more.

[Example 13] As an oxide superconducting material, (Tl _X1 Pb _X2 Bi _X3 Hg _X4 Cu _X5 ) (Sr _{1 -X6} Ba _X6 ) ₂
C _n-1 Cu _n O _{2n + 3 + X7} (where 0 ≦ X1 ≦ 1.0, 0 ≦ X2 ≦ 1.0, 0 ≦ X
3 ≦ 0.5, 0 ≦ X4 ≦ 1.0, 0 ≦ X5 ≦ 1.0, 0.0.
5 ≦ X1 + X2 + X3 + X4 + X5 ≦ 1,0 ≦ X6 ≦
1, -0.5 ≦ X7 ≦ 0.5, n = 1, 2, 3, 4, 5)
The same results as in Examples 1 to 9 were obtained by using.
Table 1 shows the results.

[0075]

[Table 1]

Example 14 As an oxide superconducting substance,
Even if LnBa ₂ Cu ₃ O _{7 + X1} (where Ln is Y or a rare earth element, −0.5 ≦ X1 ≦ 0.1) is used,
The results are almost the same as those of Nos. 1 to 9, but it is necessary to make the angle of the a-axis of the crystal of the superconducting substance within 6 degrees.

Example 15 As an oxide superconducting material, (Tl _1-X1-X2-X3 Pb _X1 Bi _X2 Hg _X3 ) ₂ (Sr _1-X4 B
_{a X4) 2 Ca n-1} Cu n O 2n + 3 + X5 ( where n = 2,3,4,5,6,0 ≦ X1 ≦ 0.8,
0 ≦ X2 ≦ 0.5, 0 ≦ X3 ≦ 1.0, 0 ≦ X1 + X2
It can be confirmed that even if + X3 ≦ 1,0 ≦ X4 ≦ 1, −0.5 ≦ X5 ≦ 0.5), a critical current density about twice as high as that of the conventional superconducting wire or superconductor can be obtained. It was

Example 16 As an oxide superconducting substance,
(Bi _1-X1 Pb _X1 ) ₂ Sr ₂ C _n-1 C _n O _{2n + 4} (where
It was confirmed that even with 0 ≦ X1 ≦ 0.4, n = 1, 2, 3), a critical current density about twice as high as that of the conventional superconducting wire or superconductor can be obtained. Example 17 A silver plate having a purity of 99.99% was rolled at various temperatures and annealed at 800 ° C. for 10 hours to find out what proportion of the crystal had a cubic orientation (rolled surface and {10
0 plane was parallel and the rolling direction was parallel to the <100> direction. The plate thickness before rolling was 3 mm and the plate thickness after rolling was 0.1 mm. The results are shown in Fig. 13. From the figure, to obtain a cubic texture, 100 ℃
Above 300 ℃, preferably above 150 ℃ 200 ℃
It turns out that rolling at the following temperatures is preferable.

Example 18 A silver plate having a purity of 99.99% was rolled at 160 ° C. and annealed at various temperatures for 10 hours to find out what proportion of crystals had a cubic orientation (rolled surface and { It was examined whether or not it was within 10 degrees from the (100) plane being parallel and the rolling direction being parallel to the <100> direction. The plate thickness before rolling was 3 mm and the plate thickness after rolling was 0.1 mm. The results are shown in Fig. 14. From the figure, it can be seen that it is preferable to anneal at a temperature of 400 ° C. or higher and a melting point of silver or lower in order to obtain a cubic texture.

[0080]

According to the present invention, a superconductor, a superconducting wire, a superconducting magnet, and a superconducting material which have a high superconducting critical current density even in a high magnetic field are operated by cooling with liquid helium as well as with liquid nitrogen. Equipment is obtained. Since the superconducting device using the superconductor and the superconducting wire according to the present invention can be operated by cooling with liquid nitrogen, the superconducting portion is simply a conventional superconductor and a superconducting wire when viewed as a whole device. Not only the replacement, but also the cooling system, heat insulation structure, quenching measures (measures for suppressing the phenomenon of rapid superconducting destruction) can be greatly simplified, and there are further cost advantages.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a crystal structure of a superconducting substance.

FIG. 2 is a schematic view showing a crystal structure of a T1-2 layer system superconducting material.

FIG. 3 is a schematic diagram showing a crystal structure of a superconducting substance.

FIG. 4 is a schematic diagram showing the structure of a superconducting wire according to the present invention.

FIG. 5 is a characteristic diagram of a TlBa ₂ Ca ₂ Cu ₃ O ₉ superconducting material film with the c-axis directions aligned.

FIG. 6 is a diagram showing a relationship between a ratio of a crystal of a silver tape used as a base material having a cubic texture and a critical current density of a superconducting substance film formed thereon.

FIG. 7 is a cross-sectional view of a 100 m long superconducting wire according to the present invention.

FIG. 8 is a schematic diagram of a superconducting magnet according to the present invention.

FIG. 9 is an enlarged cross-sectional view of a superconducting conductor according to the present invention.

FIG. 10 is an enlarged cross-sectional view of a superconducting conductor according to the present invention.

FIG. 11 is an enlarged cross-sectional view of a superconducting conductor according to the present invention.

FIG. 12 is a schematic diagram of an NMR apparatus according to the present invention.

FIG. 13 is a relationship diagram between the rolling temperature of silver and the ratio of cubic texture used in the description of Example 17 for explaining the present invention.

FIG. 14 is a diagram showing the relationship between the annealing temperature of silver after rolling and the proportion of cubic texture, which was used in the description of Example 18 to explain the present invention.

[Explanation of symbols]

1 ... Tl atom or Pb atom or Bi atom or Hg atom, 2 ... Sr atom or Ba atom, 3 ... Ca
Atom, 4, 6 ... Cu atom, 5, 9 ... Oxygen atom, 7 ... Ba
Atom, 8 ... Y atom or rare earth atom, 10 ... Metal having cubic texture, 11, 14 ... Oxide superconducting substance,
12 ... Silver tape having cubic texture, 13 ... Silver coating material, 15 ... Excitation power supply, 16 ... Service port, 17 ...
Refrigerant body discharge port, 18 ... Heat reflection plate, 19 ... Liquid nitrogen, 20
… Stacked superconducting coils, 21… Cryostat.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C01G 21/00 ZAA 29/00 ZAA H01B 13/00 565 D H01L 39/20 ZAA (72) Inventor Kazutoshi Higashiyama 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory

Claims (50)

[Claims] 1. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal body and 60% or more of the metal crystals constituting the metal body {100}.
The surface is 1 with respect to the interface between the metal body and the oxide superconducting material.
A superconducting wire which is parallel within 0 degree and has 60% or more <100> directions of the metal crystals aligned with each other within 10 degrees. 2. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal body and 70% or more of the metal crystals constituting the metal body {100}.
The surface is 1 with respect to the interface between the metal body and the oxide superconducting material.
A superconducting wire which is parallel within 0 degree and has 70% or more <100> directions of the metal crystals aligned with each other within 10 degrees. 3. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal body and 80% or more of the metal crystals constituting the metal body {100}.
The surface is 1 with respect to the interface between the metal body and the oxide superconducting material.
A superconducting wire which is parallel within 0 degree, and 80% or more of the <100> directions of the metal crystals are aligned within 10 degrees. 4. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal body, and 60% or more of the metal crystals constituting the metal body {100}.
A surface of the superconducting wire is parallel to the longitudinal direction of the superconducting wire within 10 degrees, and 60% or more of <100> directions of the metal crystals are aligned within 10 degrees in the longitudinal direction. 5. A superconducting wire containing at least a metal body and an oxide superconducting substance, wherein the metal body is a polycrystal body and 70% or more of the metal crystals constituting the metal body {100}.
A superconducting wire whose surfaces are parallel to the longitudinal direction of the superconducting wire within 10 degrees and 70% or more of the <100> directions of the metal crystals are aligned within 10 degrees in the longitudinal direction. 6. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal body and 80% or more of the metal crystals constituting the metal body {100}.
A superconducting wire whose surfaces are parallel to the longitudinal direction of the superconducting wire within 10 degrees and 80% or more of the <100> directions of the metal crystals are aligned within 10 degrees in the longitudinal direction. 7. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal metal tape, and 60% of the metal crystals constituting the metal tape.
The above {100} plane is parallel to the surface of the metal tape within 10 degrees, and 60% or more of the metal crystal <100.
> A superconducting wire whose direction is aligned within 10 degrees in the longitudinal direction of the metal tape. 8. A superconducting wire containing at least a metal body and an oxide superconducting material, wherein the metal body is a polycrystal metal tape, and 70% of the metal crystals constituting the metal tape.
The above {100} plane is parallel to the surface of the metal tape within 10 degrees, and 70% or more of the metal crystal <100.
> A superconducting wire whose direction is aligned within 10 degrees in the longitudinal direction of the metal tape. 9. A superconducting wire containing at least a metal body and an oxide superconducting substance, wherein the metal body is a polycrystal metal tape, and 80% of the metal crystals constituting the metal tape.
The {100} plane is parallel to the surface of the metal tape within 10 degrees, and 80% or more of the metal crystals <100.
> A superconducting wire whose direction is aligned within 10 degrees in the longitudinal direction of the metal tape. 10. The superconducting wire according to claim 1, 4 or 7, wherein 60% or more of the crystals of the oxide superconducting material have (001) faces of {100} of the crystal of the metal.
A superconducting wire that is parallel to the surface within 10 degrees. 11. The superconducting wire according to claim 2, 5 or 8, wherein the (001) plane of 70% or more of the oxide superconducting material has {100} of the metal crystal.
A superconducting wire that is parallel to the surface within 10 degrees. 12. The superconducting wire according to claim 3, 6 or 9, wherein 80% or more of the (001) crystal faces of the oxide superconducting material have {100} crystal faces of the metal.
A superconducting wire that is parallel to the surface within 10 degrees. 13. The superconducting wire according to claim 1, 4 or 7, wherein 60% or more of the crystals of the oxide superconducting material have a [110] direction of <110.
> A superconducting wire which is parallel to the direction within 10 degrees. 14. The superconducting wire according to claim 2, 5 or 8, wherein 70% or more of crystals of the oxide superconducting material have a [110] direction of <110.
> A superconducting wire which is parallel to the direction within 10 degrees. 15. The superconducting wire according to claim 3, 6 or 9, wherein the [110] direction of 80% or more of the oxide superconducting material has <110 direction of the crystal of the metal.
> A superconducting wire which is parallel to the direction within 10 degrees. 16. The superconducting wire according to claim 1, 4 or 7, wherein the (001) plane of 60% or more of the oxide superconducting substance crystal is the {100} plane of the crystal of the metal. The superconductivity is parallel within 10 degrees, and the [110] direction of 60% or more of the crystals of the oxide superconducting substance is parallel within 10 degrees with the <110> direction of the metal crystal. line. 17. The superconducting wire according to claim 2, 5 or 8, wherein the (001) plane of 70% or more of the oxide superconducting material is the {100} plane of the crystal of the metal. The superconductivity is parallel within 10 degrees, and the [110] direction of 70% or more of the crystals of the oxide superconducting material is parallel within 10 degrees with the <110> direction of the metal crystal. line. 18. The superconducting wire according to claim 3, 6 or 9, wherein the (001) plane of 80% or more of the oxide superconducting material is the {100} plane of the crystal of the metal. Superconductivity that is parallel within 10 degrees, and the [110] direction of 80% or more of the crystals of the oxide superconducting material is parallel within 10 degrees with the <110> direction of the metal crystal. line. 19. The superconducting wire according to claim 1, wherein the area S1 of the metal body or the metal tape and the oxide superconductivity in a cross section perpendicular to the interface between the metal body and the oxide superconducting substance. A superconducting wire rod characterized in that the ratio of the area S2 of the substance portion satisfies 0.01 ≦ S2 / S1 ≦ 0.6. 20. The superconducting wire according to claim 1, wherein the metal body is silver. 21. The superconducting wire according to claim 1, wherein the metal body is an alloy containing silver, a dispersion of an oxide in silver, or a dispersion of an oxide in an alloy containing silver. A superconducting wire, characterized in that it is an alloy containing silver or an alloy containing silver in which an intermetallic compound is dispersed. 22. The superconducting wire according to any one of claims 1 to 19, wherein the metal has a FCC structure or F.
A superconducting wire characterized by being an alloy of CC structure. 23. The superconducting wire according to claim 1, wherein the metal has a BCC structure or B.
A superconducting wire characterized by being an alloy of CC structure. 24. The superconducting wire according to claim 1, wherein the oxide superconducting material has a chemical composition of (Tl _X1 Pb _X2 Bi _X3 Hg _X4 Cu _X5 ) (Sr _{1 -X6} Ba _X6 ). ₂
C _n-1 C _n O _{2n + 3 + X7} where 0 ≦ X1 ≦ 1.0, 0 ≦ X2 ≦ 1.0, 0 ≦ X3 ≦ 0.5, 0 ≦ X4 ≦ 1.0, 0 ≦ X5 ≦ 1.0, 0.5 ≦ X1 + X2 + X3 + X4 + X5 ≦ 1, 0 ≦ X6 ≦ 1, −0.5 ≦ X7 ≦ 0.5 n = 1,2,3,4,5 line. 25. The superconducting wire according to claim 1, wherein the oxide superconducting substance has a chemical composition of (Tl _{1 -X1-X2-X3} Pb _X1 Bi _X2 Hg _X3 ) ₂ (Sr _{1 -X4} B
a _{X4) 2} Ca _{n over 1 Cu n O 2n + 4 +} X5 where, 0 ≦ X1 ≦ 0.9, 0 ≦ X2 ≦ 0.1, 0 ≦ X3 ≦ 0.5, 0 ≦ X1 + X2 + X3 ≦ 1, 0 ≦ X4 ≦ 1, −0.5 ≦ X5 ≦ 0.5 n = 1, 2, 3, 4, 5 A superconducting wire characterized by the following. 26. A superconducting wire according to any one of claims 1 to 23, the chemical composition of the oxide superconducting material, (Bi _{1 over X1 Pb X1) 2 Sr 2 Ca} n _over 1 Cu _n O _{2n + 4 + X2} where 0 ≦ X1 ≦ 0.4, −0.5 ≦ X2 ≦ 0.5 n = 1, 2, 3 A superconducting wire characterized by the following. 27. The superconducting wire according to claim 1, wherein the oxide superconducting material has a chemical composition of LnBa ₂ Cu ₃ O _{7 + X1,} where Ln is selected from Y or a rare earth element. One or more. -0.5≤X1≤0.2 A superconducting wire characterized by being represented by n = 1, 2, 3. 28. A silver tape having a purity of 99.0% or more, in which 80% or more of crystals have a cubic texture, and a chemical composition is (Tl _X1 Pb _X2 Bi _X3 Hg _X4 Cu _X5 ) (Sr _1-X6 Ba). _X6 ) ₂
C _n-1 C _n O _{2n + 3 + X7} where 0 ≦ X1 ≦ 1.0, 0 ≦ X2 ≦ 1.0, 0 ≦ X3 ≦ 0.5, 0 ≦ X4 ≦ 1.0, 0 ≦ X5 ≦ 1.0, 0.5 ≦ X1 + X2 + X3 + X4 + X5 ≦ 1, 0 ≦ X6 ≦ 1, −0.5 ≦ X7 ≦ 0.5 An oxide superconducting material represented by n = 1, 2, 3, 4, 5 A superconducting wire containing at least the constituents thereof, wherein the silver tape and the oxide superconducting material are in direct contact with each other, and the area S1 of the silver tape layer in a cross section perpendicular to the longitudinal direction and the oxide superconducting material layer. The ratio of the area S2 satisfies 0.01 ≦ S2 / S1 ≦ 0.6, and the silver crystals forming the cubic texture <
80> direction and 80% or more of the [110] direction of the oxide superconducting material crystal are parallel within 10 degrees. 29. A silver tape having a purity of 99.0% or more in which 80% or more of crystals have a cubic texture, and a chemical composition is LnBa ₂ Cu ₃ O _{7 + X1,} wherein Ln is Y or a rare earth element. One or more selected. -0.5≤X1≤0.2 A superconducting wire containing an oxide superconducting material represented by n = 1,2,3 as at least one of its constituent elements, wherein the silver tape and the oxide superconducting material are directly connected to each other. A ratio of the area S1 of the silver tape layer and the area S2 of the oxide superconducting material layer in a cross section perpendicular to the longitudinal direction in contact with each other satisfies 0.01 ≦ S2 / S1 ≦ 0.6, and the cube is Of the silver crystals forming the texture <
80> direction and 80% or more of the [110] direction of the oxide superconducting material crystal are parallel within 10 degrees. 30. A silver tape having a purity of 99.0% or more in which 80% or more of crystals have a cubic texture, and a chemical composition of (Tl _{1 -X1-X2 -X3} Pb _X1 Bi _X2 Hg _X3 ) ₂ ( Sr _1-X4 B
a _{X4) 2} Ca _{n over 1 Cu n O 2n + 4 +} X5 where, 0 ≦ X1 ≦ 0.9, 0 ≦ X2 ≦ 0.1, 0 ≦ X3 ≦ 0.5, 0 ≦ X1 + X2 + X3 ≦ 1, 0 ≤X4 ≤1, -0.5 ≤X5 ≤0.5 A superconducting wire containing an oxide superconducting material represented by n = 1,2,3,4,5 as at least one of its constituents, wherein the silver The tape and the oxide superconducting material are in direct contact, and the ratio of the area S1 of the silver tape layer to the area S2 of the oxide superconducting material layer in a cross section perpendicular to the longitudinal direction is 0.01 ≦ S2 / S1 ≦ 0. <1 of the silver crystals that satisfy the requirement of .6 and form the cubic texture.
A superconducting wire, wherein 80% or more of the 10> direction and the [110] direction of the oxide superconducting substance crystal are parallel within 10 degrees. 31. More than 80% of the crystals and silver tape over 99.0% purity and has a cubic texture, chemical composition (Bi _{1 over X1 Pb X1) 2 Sr 2 Ca} n _over 1 Cu _n O _{2n + 4 + X2} where 0 ≦ X1 ≦ 0.4, −0.5 ≦ X2 ≦ 0.5 superconductivity containing at least an oxide superconducting material represented by n = 1, 2, 3 as its constituent element A line in which the silver tape and the oxide superconducting material are in direct contact, and the ratio of the area S1 of the silver tape layer to the area S2 of the oxide superconducting material layer in a cross section perpendicular to the longitudinal direction is 0. 01 ≦ S2 / S1 ≦ 0.6 and <1 of silver crystals forming the cubic texture.
A superconducting wire, wherein 60% or more of the 10> direction and the [110] direction of the oxide superconducting substance crystal are parallel within 10 degrees. 32. A silver tape having a purity of 99.0% or more in which 80% or more of crystals have a cubic texture, and a chemical composition of (Bi _{1 -X1} Pb _X1 ) ₂ Sr ₂ Can _-1 Cu _n O. _{2n + 4 + X2} where 0 ≦ X1 ≦ 0.4, −0.5 ≦ X2 ≦ 0.5 superconductivity containing at least an oxide superconducting material represented by n = 1, 2, 3 as its constituent element A line in which the silver tape and the oxide superconducting material are in direct contact, and the ratio of the area S1 of the silver tape layer to the area S2 of the oxide superconducting material layer in a cross section perpendicular to the longitudinal direction is 0. 01 ≦ S2 / S1 ≦ 0.6 and <1 of silver crystals forming the cubic texture.
A superconducting wire, wherein 70% or more of the 10> direction and the [110] direction of the oxide superconducting substance crystal are parallel within 10 degrees. 33. More than 80% of the crystals and silver tapes 99.99% pure and has a cubic texture, chemical composition (Bi _{1 over X1 Pb X1) 2 Sr 2 Ca} n _over 1 Cu _n O _{2n + 4 + X2} where 0 ≦ X1 ≦ 0.4, −0.5 ≦ X2 ≦ 0.5 superconductivity containing at least an oxide superconducting material represented by n = 1, 2, 3 as its constituent element A line in which the silver tape and the oxide superconducting material are in direct contact, and the ratio of the area S1 of the silver tape layer to the area S2 of the oxide superconducting material layer in a cross section perpendicular to the longitudinal direction is 0. 01 ≦ S2 / S1 ≦ 0.6 and <1 of silver crystals forming the cubic texture.
A superconducting wire, wherein 80% or more of the 10> direction and the [110] direction of the oxide superconducting substance crystal are parallel within 10 degrees. 34. A continuous deposition step of continuously depositing an oxide superconducting substance or a raw material of an oxide superconducting substance on the surface of a metal tape in which 80% or more of metal crystals have a cubic texture. A method for producing a superconducting wire, comprising a heating step of heating it to a temperature of 700 ° C. or higher. 35. A continuous deposition step of continuously depositing an oxide superconducting substance or a raw material of an oxide superconducting substance on the surface of a metal tape in which 80% or more of metal crystals have a cubic texture. It is characterized by including an assembling step of collecting a plurality of them into an aggregate, a heating step of heating the aggregate to a temperature of 700 ° C. or higher, and an insulating layer forming step of forming an insulator on the surface of the aggregate. And a method for producing a superconducting wire. 36. A part of a metal tape in which 80% or more of metal crystals have a cubic texture is locally heated to a temperature of 400 ° C. or more, and a surface of the metal tape is used as a raw material of an oxide superconducting substance. A method for producing a superconducting wire, which comprises a continuous heating deposition step of continuously producing a superconducting material by continuously depositing. 37. A part of a metal tape, in which 80% or more of metal crystals have a cubic texture, is locally heated to a temperature of 400 ° C. or more, and the surface of the metal tape is used as a raw material of an oxide superconducting substance. A continuous heating deposition step of continuously producing a superconducting material by continuously depositing, an assembly step of collecting a plurality of them into an aggregate, and an insulating layer forming step of forming an insulator on the surface of the aggregate. A method for producing a superconducting wire, comprising: 38. A part of a metal tape, in which 80% or more of metal crystals have a cubic texture, is locally heated to a temperature of 400 ° C. or more, and the surface of the metal tape is used as a raw material of an oxide superconducting substance. A continuous heating deposition step of continuously producing a superconducting material by continuously depositing, an assembly step of collecting a plurality of them into an assembly, and the assembly at 700 ° C.
A method for producing a superconducting wire, comprising a heating step of heating to the above temperature and an insulating layer forming step of forming an insulator on the surface of the aggregate. 39. A method for producing a superconducting wire, wherein the metal tape according to any one of claims 34 to 38 is silver. 40. A superconducting magnet using the superconducting wire according to any one of claims 1 to 33. 41. An NMR apparatus using a magnet using the superconducting wire produced by using the superconducting wire according to any one of claims 1 to 33. 42. An MRI apparatus using a magnet using the superconducting wire produced by the method according to any one of claims 34 to 39. 43. A synchrotron radiation light generator using a magnet using the superconductor according to any one of claims 1 to 31. 44. A magnetic separation device using a magnet using the superconductor according to any one of claims 1 to 31. 45. A silver tape having a cubic texture. 46. A silver tape comprising a large number of crystals, 8
0% or more of the {100} face of the crystal is 1 on the surface of the silver tape.
Parallel within 0 degree and 80% or more of the crystals <1
The 00> direction is aligned within 10 degrees in the longitudinal direction of the silver tape. 47. A silver plate composed of a large number of crystals, which is 80%
The {100} plane of the crystal is parallel to the surface of the silver plate within 10 degrees, and 80% or more of <100> of the crystal.
A silver plate having a direction aligned within 10 degrees in the longitudinal direction of the silver plate. 48. Silver having a purity of 99.0% or more is plastically deformed at a temperature of 100 ° C. or higher and 300 ° C. or lower, and then 400 ° C.
Silver characterized by being heat-treated at a temperature not higher than the melting point of silver. 49. Silver having a purity of 99.0% or more is plastically deformed at a temperature of 100 ° C. or more and 300 ° C. or less, and then 400 ° C.
A silver tape which is heat-treated at a temperature not higher than the melting point of silver. 50. Rolling silver having a purity of 99.0% or more at a temperature of 100 ° C. or more and 300 ° C. or less until the final tape thickness becomes 1/10 or less of the initial silver thickness, and thereafter. 40
A silver tape which is heat-treated at a temperature of 0 ° C. or more and a melting point of silver or less.