JPH0621011B2 - Method for producing superconducting thin film and transfer material for producing the superconducting thin film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a superconducting thin film and a transfer material for producing the superconducting thin film used therein.

(Prior Art) Conventionally, there is known a method of obtaining a predetermined superconducting object by press-molding a material obtained by kneading a powder of a non-superconducting material which becomes superconducting by firing and firing it.

(Problems to be Solved by the Invention) However, in the conventional method, although a superconducting object having a desired three-dimensional shape could be obtained, in particular, a non-superconducting material powder which becomes superconducting by firing is a metallic material. However, when it is a ceramics-based material, there are many difficult points in processing work such as kneading, press molding, and firing of non-superconducting material powder. It was not easy to obtain a superconducting thin film having a desired shape such as a sheet, a surface or a sheet.

The present invention eliminates the above-mentioned drawbacks and makes it possible to obtain a superconducting thin film having a desired shape such as a point, a line, a surface or a sheet very easily, and a method for producing a superconducting thin film, and a transfer material for producing the superconducting thin film. Is provided.

(Means for Solving Problems) The present invention is to coat a non-superconducting material mixed on a resin that decomposes and disappears non-superconducting material powder, which becomes superconducting by firing, with non-superconducting material on one surface of a substrate. The transfer material for forming a superconducting thin film, which has a conductive transfer layer, is placed on the substrate so that the non-superconducting transfer layer side is in contact with the substrate, and heated from the base material side with a mold of a desired shape such as a mold. Pressing, then peeling off the base material to transfer the non-superconducting transfer layer onto the substrate into a desired shape corresponding to the mold, and then firing the non-superconducting transfer layer having the desired shape in an oxidizing atmosphere. It is a method for producing a characteristic superconducting thin film.

Further, according to the present invention, the non-superconducting transfer layer is formed on the entire surface of one side of the base material by coating the coating material mixed in the resin that decomposes and disappears the non-party conductive material powder that becomes superconducting by firing. Is a transfer material for producing a superconducting thin film.

The non-superconducting material powder which becomes superconducting by firing is, for example, Y-Ba-Cu-O system or La-Ba-Cu-O.
-Based, La-Sr-Cu-O-based, Ho-Ba-Cu-O-based, or other ceramic-based non-superconducting material powder that becomes superconducting by firing, or metallic-based non-superconducting material powder that becomes superconducting by firing Etc., various things can be used.

The non-superconducting material powder that becomes superconducting by firing is as fine as possible because the finer the powder, the more dense and more uniform the superconducting thin film can be obtained in the desired shape such as dots, lines, planes or sheets. Is preferred.

The non-superconducting material powder which becomes superconducting by firing is a powder of a material which becomes superconducting by having a predetermined composition after firing.

The resin that decomposes and disappears by firing, in which the non-superconducting material powder that becomes superconducting by firing is mixed, is a resin that decomposes and disappears during firing.

The resin that decomposes and disappears by firing is specifically selected depending on the firing conditions and the like, and examples thereof include butyral resin resins.

To mix the non-superconducting material powder that becomes superconducting by firing into the resin that decomposes and disappears by baking to form a paint, the non-superconducting material powder that becomes superconducting by baking in the resin that decomposes and disappears by baking Blended as an ingredient,
Knead into paint.

When a non-superconducting material powder that becomes superconducting by firing is blended as a main component and kneaded into a paint, the non-superconducting material powder that becomes superconducting by firing used may be one type, or two or more types. But it's okay.

A coating material mixed with a resin that decomposes and disappears non-superconducting material powder that becomes superconducting by firing, and forms a non-superconducting transfer layer by coating the entire surface of one side of the base material. To get

As the base material, a plastic film or the like can be used.

When the substrate has releasability, it can be used as it is, and if necessary, a substrate having a release layer formed on the surface can be used as the substrate.

The thickness of the non-superconducting transfer layer is not particularly limited, and specifically, it varies depending on the kind of the non-superconducting material powder that becomes superconducting by firing used, the amount used, the size of the powder, the application, and the like.

The non-superconducting material powder, which becomes superconducting by firing the non-superconducting transfer layer, is a material which reacts and fuses with the non-superconducting material powder by firing to be electrically conductive.

The transfer material for producing a superconducting thin film is placed on the substrate such that the non-superconducting transfer layer side is in contact with the substrate, and is heated and pressed from the base material side with a die having a desired shape such as a die.

As a mold having a desired shape such as a mold, a mold having a desired shape such as a dot, a line, a surface or a sheet is used.

The surface of the substrate on which the transfer material for superconducting thin film production is placed may be a flat surface or a curved surface.

When it is desired to leave the substrate as it is as a unit with the superconducting thin film obtained after firing the non-superconducting transfer layer, about 10
It needs to be a heat resistant substrate that can withstand firing at 00 ° C.
Examples thereof include ceramics such as oxides such as alumina, silica and zirconia, nitrides and borides.

Further, the substrate, if it is not necessary to remain as it is as a unit with the superconducting thin film obtained after firing of the non-superconducting transfer layer, for example, an appropriate plastic film or the like may be one that decomposes and disappears during firing, When such a material is used as the substrate, only a superconducting thin film having no substrate can be obtained after firing.

As will be described later, in baking the non-superconducting transfer layer, the non-superconducting transfer layer having a desired shape and the substrate on which the transfer is performed may be baked as they are, or the non-superconducting transfer layer having a desired shape may be baked. Since the non-superconducting transfer layer may be baked by peeling the conductive transfer layer from the transferred substrate, in the latter case, the substrate is a mold from the base material side of the transfer material for superconducting thin film production. It suffices as long as it can withstand the heat of heating and pressing with a mold having a desired shape such as.

After placing the transfer material for superconducting thin film production on the substrate so that the non-superconducting transfer layer side is in contact with the substrate and heating and pressurizing from the base material side with a mold of a desired shape such as a die, The base material of the transfer material for thin film production is peeled off, and the non-superconducting transfer layer is transferred onto the substrate into a desired shape corresponding to the mold.

The transfer of the desired shape of the non-superconducting transfer layer corresponding to the mold onto the substrate may be performed once, but the desired shape of the non-superconducting transfer layer is transferred once and then the desired shape of the non-superconducting transfer layer is further transferred. The transfer layer may be transferred to overlap the non-superconducting transfer layers, and the transfer may be performed by stacking a plurality of non-superconducting transfer layers having a desired shape by a plurality of transfers, and in the case of such a plurality of transfers, It is possible to obtain a more dense and uniform superconducting thin film than in the case of one-time transfer.

After the transfer, the non-superconducting transfer layer having a desired shape is fired in an oxidizing atmosphere.

Firing is performed in an oxidizing atmosphere, that is, in oxygen or air in about 1
Bake at 000 ° C. In this case, it is necessary to smoothly promote the decomposition and disappearance of the resin in the non-superconducting transfer layer due to heat.

The firing may be performed by firing the non-superconducting transfer layer having a desired shape and the substrate on which it is transferred as it is, or by peeling the non-superconducting transfer layer having a desired shape from the substrate on which it is transferred, Only the non-superconducting transfer layer may be baked.

By firing, the non-superconducting transfer layer having a desired shape becomes a superconducting thin film. That is, by firing, a superconducting thin film having a desired shape such as dots, lines, planes or sheets can be obtained.

After firing, the non-superconducting transfer layer having a desired shape and the substrate on which the layer is laminated are fired as they are, and when the substrate remains, the superconducting thin film and the substrate can be used as they are as a unit. Of course, if necessary, the superconducting thin film may be peeled from the substrate and only the superconducting thin film may be used.

Further, when only the non-superconducting transfer layer having a desired shape is fired or when the substrate is decomposed and disappeared during firing to obtain only the superconducting thin film having the desired shape, the superconducting thin film having the desired shape can be used as it is.

(Example) Example 1 (1) Non-superconducting material powder (oxide type superconducting material powder) which becomes superconducting by firing of a ceramics-based material composed of the following three components was sufficiently stirred and mixed in a mortar.

Yttrium oxide Y ₂ O ₃ powder about 112.9 g Barium carbonate BaCo ₃ powder about 394.7 g Cupric oxide CuO powder about 238.6 g Next, a non-superconducting material powder that becomes superconducting by firing of these ceramics is A paint in which 1700 PHR is blended into a butyral resin-based resin that decomposes and disappears by firing, kneaded for one day in a ball mill, and non-superconducting material powder that becomes superconducting by firing of a ceramics is mixed in the resin that decomposes and disappears by firing. Was produced.

The prepared coating material is coated on a single surface of a polyester film having a thickness of 25 μm with a bar coater to form a non-superconducting transfer layer having a thickness of 21 μm. Obtained.

Next, an alumina green sheet with a purity of 98% (125
On the heat resistant substrate (for μm IC substrate), place the transfer material for superconducting thin film production so that the non-superconducting transfer layer side is in contact with the alumina green sheet, and heat it with a die of the desired shape from the polyester film side. After pressurizing, the polyester film was peeled off, and the non-superconducting transfer layer of the wiring circuit having a line width of 3.5 mm was transferred onto the alumina green sheet.

(2) Next, the non-superconducting transfer layer of the wiring circuit having a line width of 3.5 mm is baked together with the alumina green sheet in a laboratory baking furnace at 920 ° C. for 5 hours, and then at 200 ° C.
It was gradually cooled to a superconducting thin film of a wiring circuit.

The superconducting thin film of the obtained wiring circuit had a line width of 2.8 mm and a thickness of 15 μm and was firmly adhered to the alumina green sheet.

(3) It was confirmed by X-ray diffraction that the superconducting thin film of the obtained wiring circuit had a YBa ₂ Cu ₃ O _7-8 herovskite structure.

The electric resistance was several Ω to several tens Ω in room temperature measurement, but no electric resistance was felt in the four-terminal method measurement at liquid nitrogen temperature,
It showed sufficient superconductivity.

As for the Meissner effect, it was difficult to confirm the floating directly in the magnetic field due to the large weight of the alumina green sheet.

Example 2 (1) The same transfer material for producing a superconducting thin film as in Example 1 was used, and the non-superconducting transfer layer was formed on a polyester film coated with a silicon resin as a substrate in the same manner as in Example 1. Transfer, and then the transferred non-superconducting transfer layer is gently peeled off from the polyester film coated with silicon resin to obtain a single 3.5 m film without a substrate.
A flat linear non-superconducting transfer layer having an m line width was obtained.

(2) Next, a flat linear non-superconducting transfer layer having a substrate-free 3.5 mm line width is fired in the same manner as in Example 1,
After cooling, a linear superconducting thin film was obtained.

The obtained linear superconducting thin film has a line width of 3.0 mm and a thickness of 16
It had a linear shape of μm and was slightly curled.

(3) The obtained linear superconducting thin film was analyzed by X-ray diffraction to obtain YB.
It was confirmed that the structure was a herbskite structure of a ₂ Cu ₃ O _7-8 .

The electric resistance was several Ω to several tens Ω in room temperature measurement, but no electric resistance was felt in the four-terminal method measurement at liquid nitrogen temperature,
It showed sufficient superconductivity.

Regarding the Meissner effect, it floated lighter than the permanent magnet at liquid nitrogen temperature, and it was confirmed from this Meissner effect that it was superconducting.

Example 3 (1) The transfer in Example 2 was repeated three times,
A non-superconducting transfer layer in which three layers of non-superconducting transfer layers are laminated is the same as in Example 2, and a flat linear non-superconducting transfer of 3.5 mm line width without a substrate in which three layers are laminated is performed. Layers were obtained.

(2) Next, a flat linear non-superconducting transfer layer having a line width of 3.5 mm and having no substrate laminated in three layers is baked and cooled in the same manner as in Example 1 to obtain linear superconductivity. A thin film was obtained.

The resulting linear superconducting thin film has a line width of 3.0 mm and a thickness of 45.
It had a linear shape of μm and was slightly curled.

(3) The obtained linear superconducting thin film was analyzed by X-ray diffraction to obtain YB.
It was confirmed that the structure was a perovskite structure of a ₂ Cu ₃ O _7-8 .

The electric resistance was several Ω to several tens Ω in room temperature measurement, but no electric resistance was felt in the four-terminal method measurement at liquid nitrogen temperature,
It showed sufficient superconductivity.

Regarding the Meissner effect, it floated lighter than the permanent magnet at liquid nitrogen temperature, and it was confirmed from this Meissner effect that it was superconducting.

(Effects of the Invention) The present invention has effects.

(1) A non-superconducting transfer layer is transferred onto a substrate into a desired shape corresponding to the shape of a mold to be used, and then the non-superconducting transfer layer having the desired shape is baked in an oxidizing atmosphere. A desired shape of superconducting object, that is, a point,
A superconducting thin film having a desired shape such as a line, a surface or a sheet can be obtained very easily.

(2) Since the non-superconducting transfer layer is transferred to a desired shape corresponding to the shape of the mold and then baked to obtain a superconducting thin film, the superconducting thin film having the desired shape can be manufactured and molded at the same time. It can be carried out, so that the manufacturing and forming process of the superconducting thin film is very efficient.

(3) Since the non-superconducting transfer layer is transferred, the non-superconducting transfer layer and the substrate are strongly adhered to each other by heating and pressing with a mold having a desired shape during the transfer.

(4) The non-superconducting transfer layer is formed by using a non-superconducting material powder that becomes superconducting by firing, and is heated and pressed by a mold having a desired shape during the transfer,
The superconducting thin film obtained after firing has a very dense and uniform structure, and the superconducting thin film is very excellent in denseness and uniformity.

(5) The obtained superconducting thin film has very excellent compactness and uniformity, so that the superconducting property is stable, zero electric resistance and diamagnetic Meissner effect can be easily confirmed.
It has sufficient reproducibility as a superconducting thin film and can be stably reproduced.

That is, the superconducting thin film obtained by the present invention is very excellent in denseness, uniformity, stability and reproducibility, and has both of them.

(6) The transfer of the non-superconducting transfer layer can be performed not only on the flat surface of the substrate but also on the curved surface, and can be applied to a necessary part or place as appropriate, so that the superconducting thin film can be applied to a very wide range.

(7) Since the thickness of the non-superconducting transfer layer can be freely controlled, the degree of freedom in application development and design of the superconducting thin film is high.

(8) When the transfer of the non-superconducting transfer layer having a desired shape corresponding to the mold on the substrate is a transfer in which a plurality of non-superconducting transfer layers having a desired shape are laminated by a plurality of transfers, one transfer is performed. Since a denser and more uniform superconducting thin film can be obtained than in the case of (1), a superconducting thin film which is more excellent in denseness, uniformity, stability and reproducibility than in the case of one-time transfer can be obtained.

(9) By selecting the substrate, not only the superconducting thin film integrated with the substrate can be obtained after firing, but also the superconducting thin film can be peeled from the substrate after firing, and depending on the material of the substrate. The substrate is decomposed and disappeared by heat during firing, and consists of only superconducting thin film without substrate.
Points, lines, planes or sheets etc. are obtained.

(10) When the non-superconducting transfer layer is peeled off from the substrate and only the non-superconducting transfer layer having a desired shape is baked, a point, a line, a surface, a sheet, etc., which is made of only the superconducting thin film without the substrate, can be obtained. .

(11) The superconducting thin film obtained by the present invention is extremely excellent in denseness, uniformity, stability, and reproducibility, so that its application field is expanded, and the present invention is applied to electronics, medical treatment, measurement, energy, etc. It greatly contributes to the manufacture and processing of various elements and devices used in many fields, and their applications can be further expanded.

Claims (5)

[Claims] 1. A superconducting material in which a non-superconducting transfer layer is formed on the entire surface of one side of a base material by coating a coating material mixed with a resin which decomposes and disappears by firing the non-superconducting material powder which becomes superconducting by firing. The transfer material for producing a conductive thin film is placed on the substrate so that the non-superconducting transfer layer side is in contact with the substrate, heated and pressed from the base material side with a mold having a desired shape such as a mold, and then the base material is peeled off. Method for producing a superconducting thin film, characterized in that a non-superconducting transfer layer is transferred onto a substrate into a desired shape corresponding to the mold, and then the non-superconducting transfer layer having the desired shape is baked in an oxidizing atmosphere. . 2. The transfer of a non-superconducting transfer layer having a desired shape corresponding to a mold onto a substrate is a transfer in which a plurality of non-superconducting transfer layers having a desired shape are laminated by a plurality of transfers. Manufacturing method of superconducting thin film. 3. The superconducting material according to claim 1, wherein the non-superconducting transfer layer having a desired shape is baked by integrally firing the non-superconducting transfer layer having a desired shape and the substrate onto which the transfer is made. Of thin film. 4. The non-superconducting transfer layer having a desired shape is baked by peeling the non-superconducting transfer layer having a desired shape from the substrate onto which the non-superconducting transfer layer is transferred and baking only the non-superconducting transfer layer. Or the method for producing a superconducting thin film according to 2. 5. A non-superconducting transfer layer is formed on the entire surface of one side of a base material by coating a coating material mixed with a resin which decomposes and disappears by firing the non-superconducting material powder which becomes superconducting by firing. A transfer material for producing a superconducting thin film, characterized by: