JPH063765B2 - Superconducting coil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thin film ceramic-based superconducting (also referred to as superconducting, herein referred to as superconducting) material.

The present invention provides a non-superconducting material by covering a material formed into a thin film on a gas, thereby allowing multilayer wiring of the superconducting material, and using such a configuration, a superconducting device, preferably a superconducting coil (for energy storage or It is intended to be used for magnets, etc.).

"Background of the Invention" Conventionally, superconducting materials metallic material Nb-Ge (e.g. Nb ₃ Ge) is used. Since this material is a metal, it has high ductility and malleability, and it was possible to perform coil winding for a superconducting magnet.

However, the superconducting materials using these metallic materials have a small Tc (superconducting water temperature is simply referred to as Tc hereinafter) and are only 23K or less. On the other hand, when considering industrial applications, it is more effective that the Tc is 77K, preferably room temperature or higher.

“Conventional Problems” For this reason, ceramic-based materials, particularly oxide ceramic-based materials, are attracting attention as materials with high Tc, rather than metals. However, despite the high Tc, this ceramic superconducting material, which has been attracting attention, has poor bendability, ductility, and malleability, and even if it is bent a little. Iwanya 0.1-30μ
It has been considered completely impossible to form a thin film having a thickness of m on a cylindrical or disk-shaped substrate and selectively remove a part or all of this thin film. In particular, it has been completely impossible to perform multi-layer wiring using the same photosonography technology as that for semiconductor integrated circuits or to make new electronic devices using this thin film superconductivity.

Furthermore, when trying to provide multilayer wiring, especially coils etc.,
In order to prevent cracks and the like, it is important to match the coefficient of thermal expansion by making the entire assembly the same main component. Therefore, using the substrate itself as a different material from the oxide superconducting material and actually using it under a long-term use condition causes a great problem in reliability.

"Means for Solving the Problem" The present invention is intended to form an electronic device, preferably a superconducting coil, using a thin film of such an oxide superconducting material and an interlayer separation film of an oxide non-superconducting material of the same main component that sandwiches the thin film. It was done.

In the present invention, a non-superconducting material having the same main component material as that of the oxide superconducting material is previously formed on the formation surface of a matrix having a desired shape, for example, a cylindrical or disk-shaped matrix. This material is used as a base. Further, by removing the original matrix after the formation, only the non-superconducting material can be used as the gas.
The present invention provides a starting material having superconducting properties after annealing in an oxide superconducting material or an oxidizing atmosphere on a substrate having a surface on which such an oxide non-superconducting material is formed (these are collectively referred to as oxide superconducting material or simply Film) is formed by a sputtering method, a printing method such as a screen printing method, a spray method, a plasma spray method, an electron beam evaporation method, a plasma CVD method, or another method.

For example, magnetron sputtering method with substrate temperature 650 ° C, Ar
It is formed in an atmosphere containing 20% oxygen. At this time, the ab plane of the oxide superconducting material (the c plane, that is, the plane perpendicular to the c axis) on the formation surface
Are formed so that they are parallel to each other.

Therefore, when forming a film on the substrate, this surface to be formed
A magnetic field is applied in the vertical direction to the (tangential surface of the circle if it is cylindrical). Then, the modified perovskite structure oxide superconducting material used in the present invention has an ab which an electric current flows easily.
The surface parallel to the surface is configured to be parallel to the surface to be formed. This magnetic field is applied to the film formed by the sputtering method in oxygen at 850 ° C for 8 hours,
During slow cooling at a rate of 4 ° C / min, it is also added during annealing at 400 ° C for 2 hours.

The present invention experimentally found that such an oxide superconducting material has a subliming property and can be easily scribed (cut) by an excimer laser or a YAG laser. For this reason, the present invention selectively irradiates the formed superconducting thin film with a laser beam before or after firing, and further scans (scans) as necessary to give a predetermined region,
For example, the oxide superconducting material is removed in a band shape having a certain width. Then, the band of the superconducting thin film having a constant Tc can be formed only in the portion other than the groove formed by the laser irradiation.

For the film formed by the sputtering method, adjust the target,
The oxide superconducting material after formation is, for example, (A _1-x Bx) yCuzOw, where x = 0.1-1, preferably 0.6-0.7, y = 2.0-4.0, preferably 2.5-3.5, z = 0.1-4.0, preferably 1.5- 3.5, w = 4.
0 to 10.0, preferably 6 to 8, A is the periodic table of elements III
One or more elements selected from group a, especially yttrium (Y) or lanthanoids, B is the periodic table IIa
One or more elements selected from the group Ba (barium), Sr (strontium) or Ca (calcium), for example, barium (Ba).

Further, the interlayer insulating film is ((A'pA " _1-P ) _1-x (B'qB" _1-q )
x) y (CurX _1-r ) zOw x = 0 to 1.0, y = 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 10.
Has 0, A ′ is Y (yttrium), Gd (gadolinium), Yb
(Ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm
(Thulium), Lu (Lutetium), Sc (Scandium) and other lanthanoids, consisting of one or more elements, B'is selected from Ba (Barium), Sr (Strontium), Ca (Calcium) A ″, B ″, X are Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), An oxide superconducting material composed of one or more kinds of elements selected from Ti (titanium), Mn (manganese) and Zr (zirconium) was used. At this time, 1 to 20% by volume (the value of p, q or r is 0.99 to 0.80) was added as an additive for forming the non-superconducting material. In particular, Mg and Al, which have a large degree of becoming an oxide insulator, are convenient because the addition amount thereof is as small as 1 to 5%.

In addition, the periodic table of elements in this specification is based on a dictionary of physics and chemistry (Iwanami Shoten, published April 1, 1963).

When laser scribing using an excimer laser is performed to form the insulating region, the pulse width is as small as 20 nsec. Therefore, it becomes easier to control the region to be removed in the depth direction.
The present invention can make a laser beam of a circle (diameter 10 to 100 μm) by squeezing an excimer laser with an optical system,
The substrate or the substrate and the laser beam light are moved while irradiating the oxide superconducting film with this laser beam. Then, the oxide superconducting thin film at a desired position is removed by sublimation or flying.

For this region to be removed, Mg (magnesium), Be (beryllium), Al (aluminum), Fe used in the present invention
Insulation by selectively implanting one or more species selected from (iron), Co (cobalt), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese) by ion implantation method, etc. May be turned into. Thus, although the upper surfaces of the insulating region and the superconducting region can be made smooth and flat, the amount of implantation is large and the productivity is not sufficient.

As described above, the present invention uses the oxide superconducting material and the oxide non-superconducting material having the same main component as the substrate or the upper portion thereof and the interlayer insulating material, so that the oxide superconducting material has substantially the same thermal expansion coefficient as that of the oxide superconducting material. A non-superconducting material is used as an interlayer film for electrical isolation. Then, after this, a second oxide superconducting material was laminated, and again, like the first oxide superconducting material, unnecessary substances were selectively removed by a laser scribing method or the like. This was repeated to form a coil wound in multiple layers.

In the present invention, when it is left as a substrate material thereafter, alumina, YSZ (yttria stabilized zircon), magnesium oxide (MgO), zirconia, yttria, strontium titanate (SrTiO ₃ ), glass or oxide superconducting material A non-superconducting material having the same main component material as was used. Alternatively, a composite substrate may be used by forming an oxide non-superconducting thin film on a substrate such as metal.

When the substrate was provided on the base and removed after the substrate was formed, an organic resin that was soluble in an organic solvent was used.

[Operation] Conventionally, when a metallic superconducting material is used, a wire is first used as a process. A coil was constructed by spreading this on a predetermined substrate.

However, for the coil using the oxide superconductor of the present invention, a substrate having a final shape, such as a disc or a cylinder,
(Bobbin) structure is used. After band-shaped superconducting heat treatment is performed on this substrate, an oxide superconducting material that exhibits superconducting properties is formed into a film. Then, by selectively performing the first patterning on this film, a strip-shaped coil is constituted by the remaining region of the other portion. Further, an oxide non-superconducting material having the same main component material as the oxide superconducting material is formed on the upper surface thereof. Then, since the main components are the same, cracks are less likely to occur, and high reliability can be obtained. Further, the second oxide superconducting thin film is formed while connecting at the connecting portion of the oxide non-superconducting material. Second patterning is performed on this thin film. The thermal annealing or oxidation treatment of the oxide superconducting material and the non-superconducting material may be performed after performing all the steps, or may be performed in each step.

The present invention will be described below with reference to examples.

"Example 1" Fig. 1 shows an example of the present invention. In Fig. 1 (A), the matrix (1) is a material that can be removed later,
For example, a material in which the superconducting material does not dissolve and the matrix can be removed may be used. Further on that, on the material (1), ((A'pA " _1-P ) _1-x (B'qB" _1-q )
x) y (CurX _1-r ) zOw x = 0.1 to 1.0, y = 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 1.
Has 0.0, A'is Y (yttrium), Gd (gadolinium), Y
b (ytterbium), Eu (europium), Tb (terbium),
Dy (dysprosium), Ho (holmium), Er (erbium), T
Consists of one or more elements selected from m (thulium), Lu (lutetium), Sc (scandium) and other lanthanoids. B'is derived from Ba (barium), Sr (strontium) and Ca (calcium). In addition to having selected elements, A ″, B ″ or X is Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium). 1 to 1 or more kinds of elements selected from, Ti (titanium), Mn (manganese), and Zr (zirconium)
About 10-5000 μm of oxide non-superconducting film (1 ') containing 20% by volume
For example, the one formed to a thickness of 20 μm was used. Then,
A difference in the coefficient of thermal expansion of the same degree (within ± 50%) as that of the oxide superconducting thin film can be created on the upper surface. If this difference is too large, there is stress strain after annealing, the temperature at which superconductivity is exhibited is low, and cracks that occur in the film prevent superconductivity from being observed. In this embodiment, a disk-shaped substrate
An oxide superconducting thin film (2) having a thickness of 0.1 to 50 μm, for example 20 μm, was formed on (1) by a sputtering method or a printing method such as a screen printing method.

It was heat-treated in an oxygen atmosphere. It was carried out at 500 to 1000 ° C, for example 900 ° C for 15 hours. Then, the temperature was lowered to 200 ° C / min or less, for example, slow cooling was performed at 10 ° C / min, and the product was further stored at 450 ° C for 1 hour for oxidation treatment. Thus, an oxide superconducting film was formed. Then, an excimer laser (254 nm) (4) was irradiated for laser scribing. In Fig. 1, this laser light is scanned from the left end to the center (11), and the disk-shaped substrate is rotated.
(12) I did. Thus, the open groove (3) was prepared. The laser light had a peak output of 10 ⁶ to 10 ⁸ W / sec. If this is made too strong, the bases (1), (1) 'will also be damaged, so care must be taken.

FIG. 1 (B) shows that ((A'pA " _1-P ) _1-x (B'qB" _1-q ) is formed on the entire surface after the single-layer wiring of FIG. 1 (A).
x) y (CurX _1-r ) zOw x = 0 to 1.0, y = 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 10.
Has 0, A ′ is Y (yttrium), Gd (gadolinium), Yb
(Ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm
(Thulium), Lu (Lutetium), Sc (Scandium) and other lanthanoids, consisting of one or more elements, B'is selected from Ba (Barium), Sr (Strontium), Ca (Calcium) In addition to having the above elements, A ″, B ″ or X is Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), 1 to 1 or more kinds of elements selected from Ti (titanium), Mn (manganese) and Zr (zirconium)
An oxide non-superconducting film (6) containing 20% by volume is formed, and the second (A _1-x Bx) yCuzOw x = 0 to 1.0, y = 2.0 to 4.0,
z = 1.0 to 4.0, w = 4.0 to 10.0, A is Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), Dy (dysprosium), Ho (holmium). ), Er (erbium), Tm (thulium), Lu (lutetium), Sc (scandium) and one or more elements selected from other lanthanoids, and B is Ba
(Barium), Sr (strontium), Ca (calcium) one or more elemental oxide superconducting thin film (7)
Were laminated. It corresponds to the cross section of AA ′ in FIG. 1 (A).

As is clear from the drawing, the first oxide superconducting thin film remains in the form of strips (5-1), (5-2) ... And constitutes a coil. The second oxide superconducting thin film is connected to the laser-scribed coils (7-1), (7-2) ... At the connecting portion (8).

Thus, it becomes possible to wire the strip-shaped wire in a disc shape and to perform the multi-layer winding.

A multi-layer film in which a metal such as silver is provided on or under the first and second strip-shaped superconducting thin films may be used.

Second Embodiment FIG. 2 shows another embodiment of the present invention.

In the drawing, the substrate (1) has a cylindrical shape (bobbin shape). Here, as in Example 1, a film-shaped oxide superconducting material was formed.
Form (2).

This preparation was carried out by spraying on the matrix (50) of this cylinder ((A'pA " _1-P ) _1-x (B'qB" _1-q )
x) y (CurX _1-r ) zOw x = 0.1 to 1.0, y = 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 1.
Has 0.0, A'is Y (yttrium), Gd (gadolinium), Y
b (ytterbium), Eu (europium), Tb (terbium),
Dy (dysprosium), Ho (holmium), Er (erbium), T
Consists of one or more elements selected from m (thulium), Lu (lutetium), Sc (scandium) and other lanthanoids. B'is derived from Ba (barium), Sr (strontium) and Ca (calcium). In addition to having selected elements, A ″, B ″, and X are Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium). An oxide non-superconducting material composed of one or more elements selected from Ti, Tn, Mn, and Zr was prepared as a substrate. After this, the mother body (50) was removed to obtain a cylindrical substrate. Furthermore this substrate
The deposit may be made while rotating (1) as shown by the arrow (12).

In this spray method, the nitrates, bromates or hydrochlorides of the elements constituting the superconducting material are sufficiently mixed with water to form ultrafine particles neutralized with ammonia. The surface to be coated is coated with these, dried and then baked.

It is effective to lower the temperature by performing this firing in ozone. Further, this spraying work may be formed on the surface to be coated in ozone or active oxygen to which a magnetic field is applied to form a film.

Next, after annealing these films by thermal annealing, while irradiating this film with a YAG laser (3) beam (diameter 50 μm),
Gradually move in the direction of (11). Simultaneously with the arrow on the cylindrical substrate (1)
Rotate in the direction of (12). Then, one continuous strip-shaped scribe line (3) can be formed on this cylindrical substrate. By this groove, each oxide superconducting material is formed into a band shape as (5-1) and (5-2), and each is electrically separated to form a superconducting region. Here, this superconducting region had a coil shape, and a superconducting magnet coil could be substantially constituted.

In this example, after these steps, the whole of these was baked in oxygen, and (A _1-x Bx) yCuzOw x = 0.1 to 1.0, y = 2.0 to 4.0, z =
1.0 to 4.0, w = 4.0 to 10.0, A is Y (yttrium),
Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc
Consists of one or more elements selected from (scandium) and other lanthanoids, and B is composed of one or more elements selected from Ba (barium), Sr (strontium) and Ca (calcium) It was transformed into an oxide superconducting material. And I was able to make it a superconducting magnet. An energy storage device can be obtained by connecting the start point and the end point of this coil with a superconducting wire.

FIG. 2 (B) corresponds to the cross-sectional view of AA ′ in FIG. 2 (A). FIG. 2 (A) shows only the first layer in order to avoid complication of the drawing. The present invention has a multilayer structure. Fig. 2
In (B), ((A'pA " _1-P ) _1-x (B'qB" _1-q )
x) y (CurX _1-r ) zOw x = 0 to 1.0, y = 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 10.
Has 0, A ′ is Y (yttrium), Gd (gadolinium), Yb
(Ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm
(Thulium), Lu (Lutetium), Sc (Scandium) and other lanthanoids, consisting of one or more elements, B'is selected from Ba (Barium), Sr (Strontium), Ca (Calcium) A ″, B ″, X are Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), As shown in FIG. 2 on the substrate (1) having the oxide non-superconducting thin film (1) ′ composed of one or more kinds of elements selected from Ti (titanium), Mn (manganese) and Zr (zirconium).
The oxide superconducting material is formed into a strip shape as shown in (A). Further, an oxide non-superconducting thin film containing the same element is formed on the whole by a spray method of the same method. Connection
After making holes in (8), a second oxide superconducting thin film is formed on all of them. Further, similarly to the first superconducting thin film, laser scribing is performed to form strips (7-1), (7-2) .... Further, a second oxide superconducting thin film (6 ') was formed and further connected by a third oxide superconducting material (8') to form a strip. External extraction is done in (10) and (11). By repeating this, it is possible to form not only three layers but also arbitrary layers.

Others are the same as in the first embodiment.

"Effect" The present invention makes it possible to selectively leave the oxide superconducting material, which has been heretofore impossible at all, substantially in the form of a coil on the substrate.

Thus, the ceramic superconducting material that would be easily bent can be isolated to form a conductor, an electrode or a superconducting element, and can be formed into a film or strip.

The present invention may be applied to the field of microelectronics to form a superconducting thin film, and then, using a known photolithography technique, predetermined patterning may be performed to form a superconducting element or a superconducting wiring. However, the method of the present invention is excellent because it easily deteriorates depending on the liquid used in this step.

[Brief description of drawings]

1 and 2 show examples of superconducting coils using the oxide superconducting material of the present invention. DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Oxide superconducting material 3 ... Open groove 4 ... Laser light 5 ... Region which exhibits superconductivity 6,9 / Interlayer separation film 7 ... Second oxide superconductivity material

Claims (2)

[Claims] _1. (A _1-X Bx) y CUzOwx = 0.1 to 1.0, y on a substrate
= 2.0 to 4.0, z = 1.0 to 4.0, w = 4.0 to 10.0, and A is Y
(Yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), L
consisting of one or more elements selected from u (lutetium), Sc (scandium) and other lanthanoids,
B is a band-shaped oxide superconducting material containing one or more elements selected from Ba (barium), Sr (strontium), and Ca (calcium), and ((A'pA " _1-P ) _1-x (B'qB" _1-q )
x) y (CurX _1-r ) zOwx = 0 to 1.0, y = 2.0 to
4.0, z = 1.0 to 4.0, w = 4.0 to 10.0, A ′ is Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu
(Europium), Tb (Terbium), Dy (Dysprosium), H
O (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc (scandium) and one or more selected from other lanthanoids, B'is Ba ( It has one or more elements selected from barium), Sr (strontium) and Ca (calcium), and A ″, B ″ or X is Mg (magnesium), Be
(Beryllium), Al (aluminum), Fe (iron), Co (cobalt),
Ni (nickel), Cr (chrome), Ti (titanium), Mn (manganese), Zr
A material having non-superconducting properties, to which one or more elements selected from (zirconium) are added, is provided in a laminated manner, and is connected to one end of the oxide superconducting material on the material, (A _1-x Bx) yCuzOw x = 0.1 to 1.0, y = 2.0 to 4.
0, z = 1.0 to 4.0, W = 4.0 to 10.0, A is Y (yttrium), (gadolinium) Yb (ytterbium), Eu (europium), Tb (terribium), Dy (dysprosium), Ho (holmium). ), Er (erbium), Tm (thulium), Lu (lutetium), S
Consists of one or more elements selected from c (scandium) and other lanthanoids, and B is one or more elements selected from Ba (barium), Sr (strontium), and Ca (calcium). A superconducting coil, characterized in that the oxide superconducting material has a strip shape. 2. The substrate according to claim 1, wherein the substrate is ((A'pA " _1-P ) _1-x (B'qB" _1-q ).
x) y (CurX _1-r ) zOw x = 0 to 1.0, y = 2.0 to 4.0, Z = 1.0 to 4.0, W = 4.0 to 10.0
And A ′ is Y (yttrium), Gd (gadolinium), Yb
(Ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm
(Thulium), Lu (lutetium), Sc (scandium) and other lanthanoids, consisting of one or more elements, B'is Ba (barium), Sr (strontium), C
In addition to having one or more elements selected from a (calcium), A ″, B ″ or X is Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt). ), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese), Zr (zirconium), or a superconducting coil containing one or more kinds of elements.