KR20040082610A - Method of fabricating superconductors using replication method - Google Patents

Abstract

PURPOSE: A method for fabricating a superconductor using a duplication method is provided to obtain the superconductor having a prominent characteristic by selecting freely a support layer. CONSTITUTION: A separation layer(2) is formed on an upper surface of a basic preform(1). A superconducting layer(3) is formed on an upper surface of the separation layer. A support layer(4) is formed on an upper surface of the superconducting layer. The separation layer is removed therefrom. The basic preform is formed with a continuous single crystalline metal loop. The coated superconductor obtained thereby has a shape of a tape. The separation layer and the superconducting layer are grown by using an epitaxial growth method.

Description

Manufacturing method of superconductor by replication method {Method of fabricating superconductors using replication method}

The present invention relates to a method for manufacturing a superconductor, and more particularly, to a method for easily manufacturing a high temperature superconductor such as a tape using a replication process.

Type 2 high temperature superconductors are often manufactured in the form of tapes, which typically comprise a superconducting layer, a metal support layer and a protective layer, and, if necessary, a buffer layer. In order for these superconducting tapes to have excellent properties, the superconducting layer must not only have good crystal alignment, but also be as thick as possible. In addition, the metal support layer should be as thin, strong and nonmagnetic as possible. The metal layer should be in direct contact with the superconducting layer.

Prior art methods for making superconducting tapes include Rolling-Assisted Biaxially Textured Substrate (RABiTS), Ion Beam Assisted Deposition (IBAD), Inclinated Substrate Deposition (ISD), and the like. However, when the superconducting tape is produced by this method, the alignment of the crystals in the superconducting layer is at least 8 degrees and the thickness of the metal support layer is at least tens of microns. In addition, the metal layer is not in direct contact with the superconducting layer. Therefore, it is difficult to obtain a superconducting tape that satisfies the above conditions for having excellent characteristics by the manufacturing method of the prior art.

Accordingly, the technical problem to be achieved by the present invention is to provide a method for producing a superconductor capable of making the crystal alignment of the superconducting layer close to a single crystal for good superconducting properties.

Another technical problem of the present invention is to provide a method of manufacturing a superconductor, which allows the metal layer to be in direct contact with the superconducting layer so as to bypass the transient current.

1 is a schematic view for explaining a superconductor manufacturing method according to an embodiment of the present invention;

Fig. 2 is a graph showing the X-ray diffraction measurement results for the crystallinity of the contact surface pasted at 1400 degrees with Ni single crystal tape used in the base material; And

3 is a diagram of X-ray diffraction measurement results for showing good crystallinity of the superconducting layer formed by the method of the embodiment of the present invention.

Explanation of reference numbers for the main parts of the drawings

1: base material

2: Separation layer

3: superconducting layer

4: support layer

5: separation layer removal unit

6: tape with superconducting / supporting layer

According to a first aspect of the present invention for achieving the above technical problem, a method of manufacturing a superconductor comprising: forming a separation layer on a base substrate, which is manufactured by a replication method; Forming a superconducting layer on the separation layer; Forming a support layer on the superconducting layer; Removing the separation layer.

At this time, it is preferable that the base base material is a continuous single crystal metal loop in its entirety, and the resulting superconductor is tape-shaped.

In addition, the separation layer and the superconducting layer are preferably formed by an epitaxial growth method.

In addition, a buffer layer may be further formed between the separation layer and the superconducting layer.

Furthermore, after removing the separation layer, the second superconducting layer and the support layer may be sequentially formed on the buffer layer.

In addition, if the separation layer is made of a material that can be dissolved by a predetermined solvent, it can be easily removed.

According to another aspect of the present invention, there is provided a method of manufacturing a superconductor, the method including: forming a separation layer on a base substrate, which is manufactured by a replication method; Forming a support layer on the separation layer; Removing the separation layer to separate the support layer from the base material; And sequentially forming a buffer layer, a superconducting layer, and a protective layer on the support layer.

At this time, the basic base material is a continuous single crystal metal loop in its entirety, and it is preferable that the resultant coated superconductor is tape-shaped.

In addition, if the separation layer is made of a material that can be dissolved by a predetermined solvent, it can be easily removed.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

[First Embodiment]

1 is a schematic view for explaining a superconductor manufacturing method according to an embodiment of the present invention. Referring to FIG. 1, on the base matrix 1, which is a continuous single crystal loop as a whole, a separation layer 2, a superconducting layer 3, and a support layer 4 are formed by continuous epitaxial growth. . This epitaxial growth corresponds to the cloning process for the underlying base metal. In FIG. 1, the separation layer 2, the superconducting layer 3, and the support layer 4 are shown as one layer 10 for convenience of illustration. The separation layer 2 is made of a material that is soluble in some solvent. Therefore, the superconducting layer 3 / support layer 4 is separated from the base base material 1 by adding the solvent to the separation layer 2 in the separation layer removing unit 5. This formation and separation is carried out continuously to obtain the tape 6 of the superconducting / supporting layer as long as necessary.

A detailed description of each component listed above is provided below.

(1) basic substrate

The base substrate can be manufactured in various forms and materials. For example, it is a tape made of metal such as Ni, Pt, or other alloys, and has a loop shape. The cross section may be of two or more structures for proper strength. The thickness may be somewhat thicker than 0.02 mm. It must be a cubic single crystal, which can be produced in many ways. Some long ones are commercialized in the form of rods, so you can buy them and cut them thinly. Alternatively, it can be obtained by electrodepositing or depositing Ni or Pt on sapphire or large silicon single crystal. If the total length is about 1m, it is necessary to connect several single crystal tapes together. Also, both ends must be connected to get loop form. There are several ways to connect the single crystals in a continuous manner, but they can be attached by atomic diffusion just below the melting point, for example. 2 is an X-ray diffraction (XRD) measurement result of the crystallinity of the contact surface pasted Ni single crystal tape at 1400 degrees. Referring to Figure 2, it can be seen that the crystallinity did not change at all. This metal loop consists of a totally continuous single crystal.

(2) separation layer

It is made of a material that can be crystal-grown epitaxially on a metal surface, and is made of a material that can be dissolved in an appropriate solution. For example, FIG. 3 shows XRD results of a tape separated by growing a BaO / SrTiO3 bilayer on Ni, growing a YBCO superconducting layer and a Pt support layer, and then immersing in water to dissolve BaO. Referring to FIG. 3, it can be seen that crystallinity is maintained as it is. BaO is a separation layer and SrTiO3 is a buffer layer. Although there may be no buffer layer, the drawing of FIG. 1 exemplifies that no buffer layer is formed. In FIG. 3, a superconductor is manufactured and measured after forming a buffer layer made of SrTiO 3.

(3) superconducting layer

The superconducting layer can be grown epitaxially either directly on the separation layer or using an appropriate buffer layer. Referring to FIG. 3, good crystallinity of the superconducting layer can be confirmed.

(4) support layer

The support layer is obtained by depositing a high strength nonmagnetic alloy or metal / nonmetal combination layer at low temperature. The thickness should be such that adequate strength can be obtained. In FIG. 3, the Pt layer which is a support layer also has crystal | crystallization. In general, however, the support layer does not necessarily have to be crystalline, it is stress free and should be as high strength as possible.

In this embodiment, the case where the base matrix-separating layer (buffer layer) -superconducting layer-supporting layer is laminated in order is taken as an example. In this case, the superconducting layer is a single crystal, there is no defect as long as the basic base material is perfect, the support layer can be a variety of different materials, do not need crystallinity and can be thin enough. The support layer can be variously selected from high strength nonmagnetic materials. The support layer in contact with the superconducting layer becomes the bypass passage of the overcurrent. If a buffer layer is used, the buffer layer may serve as a protective layer as it is after separation.

In the case of forming the buffer layer, the method of the present embodiment may be further developed to further include sequentially forming a secondary superconducting layer and a supporting layer on the buffer layer after the removal of the separation layer.

Second Embodiment

In the second embodiment, a separation layer and a support layer are sequentially formed on the base base material, the separation layer is removed, the support layer is separated from the base material, and then a buffer layer, a superconducting layer, and a protective layer are sequentially formed on the support layer and coated with the superconductor. To prepare.

The second embodiment is not shown by separate drawings because the structure of the finished superconductor does not show much difference from that illustrated in the first embodiment. In addition, the descriptions of the components of the superconductor structure are the same as those described in the first embodiment, and are omitted to avoid duplication.

As described with respect to the embodiments of the present invention, the present invention is not limited to the above embodiments, it is apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention. Do.

This effect of the present invention is shown below in comparison with the prior art.

1. In the prior art, since the crystal alignment effect of the long tape is applied to all parts, a defect occurs where the action is difficult. However, in the method of the present invention, the possibility of defects is in principle ruled out by replicating continuously in an ideally aligned base substrate.

2. In the prior art, since it is formed by recrystallization, charged particle collision, evaporation atomic incident angle, etc. after rolling, it is not a single crystal, but basically a polycrystal.

3. In the prior art, since the electrical contact between the support layer and the superconducting layer is not made, overcurrent bypass is not possible. However, in the method of the present invention, the overcurrent bypass is performed because it is directly contacted.

4. In the prior art, the thickness of the support layer cannot be sufficiently reduced, but in the method of the invention the thickness can be reduced as much as allowed.

5. In the method of the present invention, support layer selection is extremely free compared to the prior art.

Therefore, according to the present invention described above, a superconductor having very excellent characteristics can be obtained.

Claims (9)

In the method for producing a superconductor by the replication method, Forming a separation layer on the base substrate; Forming a superconducting layer on the separation layer; Forming a support layer on the superconducting layer; Removing the separation layer; Method for producing a superconductor characterized in that it comprises a. The method of manufacturing a superconductor according to claim 1, wherein the basic base material is a continuous single crystal metal loop in its entirety, and the resultant coated superconductor is tape-shaped. The method of manufacturing a superconductor according to claim 1, wherein the separation layer and the superconducting layer are formed by epitaxial growth. The method of manufacturing a superconductor according to claim 1, further comprising forming a buffer layer between the separation layer and the step of forming the superconducting layer. The method of manufacturing a superconductor of claim 4, further comprising sequentially forming a secondary superconducting layer and a supporting layer on the buffer layer after removing the separation layer. The method of claim 1, wherein the separation layer is made of a material that can be dissolved by a predetermined solvent. In the method for producing a superconductor by the replication method, Forming a separation layer on the base substrate; Forming a support layer on the separation layer; Removing the separation layer to separate the support layer from the base material; Sequentially forming a buffer layer, a superconducting layer, and a protective layer on the support layer; Method for producing a superconductor characterized in that it comprises a. 8. The method of claim 7, wherein the base substrate is a continuous single crystal metal loop in its entirety and the resulting coated superconductor is tape-shaped. The method of claim 8, wherein the separation layer is made of a material that can be dissolved by a predetermined solvent.