JP2011195435A - Method for producing superconducting film, and calcination film and firing film obtained by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a superconducting film for obtaining large film thickness and a high orientational property at a low cost, in heat processing formation of the superconducting film with thermal decomposition of a metal organic compound.SOLUTION: In producing a superconducting film material with film thickness of nearly 0.6 to several μm, the uniformity of element distribution of a calcination film obtained at a calcination step is remarkably improved by radiation of KrCl ultraviolet excimer lamp light with illuminance of 15 mW/cmor more before the calcination step in a coating thermal decomposition method, and the superconducting film with large film thickness and the high orientational property is produced after undergoing a subsequent firing step.

Description

  The present invention relates to a method for producing a superconducting material used in the fields of electric power transportation, electric power equipment, information equipment, and the like, and more specifically, a support for the purpose of application to a current limiter, a microwave filter, a tape material, a wire, etc. The present invention relates to a method of manufacturing a superconducting material film having a superconducting material coated thereon.

Conventionally, as a method for producing a superconducting film, (1) a high-temperature superconducting oxide (hereinafter referred to as “RE123”) represented by the general formula (RE) Ba ₂ Cu ₃ O ₇ (wherein RE represents a rare earth element) (Hereinafter abbreviated as “)”, a drying step after the substrate is coated with an organic compound solution containing a rare earth element, (2) an organic component decomposition step (preliminary firing), and (3) a superconducting material formation step (main firing). There is known a method in which all of the above is performed by thermal energy, a so-called coating pyrolysis method (see Patent Document 1, etc.).
In the above steps (1) and (2), a metal trimethylacetate solution containing no fluorine is applied to the substrate and pre-baked in a humidified oxygen stream or a nitrogen stream with an oxygen partial pressure of 0.02 atm or less. Has also been proposed (Non-Patent Document 1).
Also, in the above steps (1) and (2), a superconducting film having high critical current characteristics can be obtained by using a metal organic compound containing fluorine as a starting material and including water vapor in the atmospheric gas. It is known (Non-Patent Documents 2 to 4).

Furthermore, in parallel with the above steps (2) and (3) or before the step (2), irradiation with an ultraviolet excimer laser beam or an ultraviolet excimer lamp light source using Xe or KrCl as a metal organic There is also known a manufacturing method for manufacturing a superconducting material having a thickness of about 100 nm with high efficiency and high performance by shortening the time for thermal decomposition of a compound and heat treatment formation of a superconducting substance and controlling the orientation ( Patent Document 2).
On the other hand, an epitaxially grown superconducting film having a thickness of 10 μm or more has been obtained by the pulse laser deposition (PLD) method (Non-patent Document 5), but this method is much more expensive than the coating pyrolysis method.

Japanese Patent Publication No. 7-106905 JP 2007-70216 A

Y. Xu et al. J. et al. Mater. Res. 18 (2003) 677 B. Zhao et al. Physica C386 (2003) 348 A. Gupta et al. Appl. Phys. Lett. 52 (1988) 2077 P. C. McIntyre et al. J. et al. Mater. Res. 5 (1990) 2771 Araki et al., Cryogenic Engineering 35 (2000) 516 A. Ichinose et al. Physica C468 (2008) 1627-1630

In a conventional method for producing a superconducting film material using thermal decomposition of a metal organic compound, high orientation is obtained for a film thickness of about 0.6 μm or less, while a film thickness of about 0.6 to several μm is obtained. It was difficult to control the orientation. Therefore, until now, when trying to obtain a superconducting film having a high orientation with a film thickness of about 0.6 to several μm, its manufacturing method has been limited to a high-cost pulse laser deposition method.
The present invention has been made in view of the current situation, and provides a manufacturing method for obtaining a large film thickness and orientation at low cost in the heat treatment formation of a superconducting film by thermal decomposition of a metal organic compound. It is the purpose.

  As a result of intensive studies to achieve the above object, the present inventors have identified a part of the pre-baking step in the coating pyrolysis method in the production of a superconducting film material having a thickness of about 0.6 to several μm. By substituting with an irradiation process of ultraviolet excimer lamp light having the wavelength and intensity, the uniformity of the elemental distribution of the pre-baked film obtained in the step (2) is remarkably improved, and is increased through the subsequent step (3). It was found that a superconducting film having a film thickness and orientation can be produced. Furthermore, it was also found that a superconducting film having a high critical current density can be obtained by including water vapor in the atmosphere in step (2).

The present invention has been completed based on these findings, and according to the present invention, the following inventions are provided.
<1> A step (1) of applying an organic solvent solution of a metal-containing compound blended so as to have a metal seed composition corresponding to a superconducting composite metal oxide on a support, and drying the solution (1); In producing a superconducting film epitaxially grown through a preliminary firing step (2) for thermally decomposing organic components in the formed coating film and a main firing step (3) for converting into a superconducting substance, step (2) Before the above, a method for producing a highly oriented superconducting film, wherein KrCl ultraviolet excimer lamp light is irradiated at an illuminance of 15 mW / cm ² or more.
<2> The method for producing a highly oriented superconducting film according to <1>, wherein the highly oriented superconducting film is a thick film having a thickness of 0.6 μm or more.
<3> The method for producing a highly oriented superconducting film according to <1> or <2>, wherein the step (2) is performed in an atmosphere containing water vapor having a dew point of 20 ° C. or higher.
<4> The organic solvent solution of the metal-containing compound contains each metal component composed of rare earth metal, barium, and copper as an essential component. The high value according to any one of <1> to <3> A method for producing an oriented superconducting thick film.
<5> An organic solvent solution of the metal-containing compound is mixed with a metal carboxylate having 1 to 8 carbon atoms and / or a metal acetylacetonato powder mixture of a metal species containing a rare earth element, barium, and copper, and pyridine and After adding at least one tertiary amine and at least one carboxylic acid having 1 to 8 carbon atoms to produce a metal complex and volatilizing an excess solvent, 1 having 1 to 8 carbon atoms The method for producing a highly oriented superconducting film according to any one of <1> to <4>, which is a homogeneous solution prepared by dissolving in a monovalent linear alcohol and / or water.
<6> The method for producing a highly oriented superconducting film according to <5>, wherein at least one of the metal carboxylate, metal acetylacetonate, and carboxylic acid contains halogen.
<7> A pre-baked film having a uniform element distribution obtained after the pre-baking step (2) in the method for manufacturing a superconducting film according to any one of <1> to <6>.
<8> A highly oriented main-fired film obtained after the main firing step (3) in the method for producing a superconducting film according to any one of <1> to <6>.

  According to the method for producing a superconducting film of the present invention, the uniformity of the element distribution of the pre-fired film is remarkably improved. Therefore, even when the film thickness is large, a superconducting film with excellent superconducting properties and high orientation can be obtained at low cost. Can be produced in large quantities with high production efficiency. Moreover, a superconducting film having a high critical current density can be obtained by including water vapor in the atmosphere in the step (2).

Schematic showing the manufacturing process of the superconducting film according to the present invention Cross-sectional transmission electron microscope image (left) and copper element distribution image (right) of the pre-fired film by the film forming process of the present invention (upper stage) and the conventional process using only heat (lower stage) The figure which shows typically the relationship of each process of lamp irradiation, temporary baking, and this baking, and a baking temperature in an Example. Cross-sectional transmission electron microscope image of the fired film produced by the film forming process of the present invention (Example 5) (left) and the conventional heat only process (Comparative Example 9) (right)

FIG. 1 is a schematic view showing a manufacturing process of a superconducting film according to the present invention.
As shown in FIG. 1, in the present invention, a step of applying an organic solvent solution of a metal-containing compound blended so as to have a metal seed composition corresponding to a superconducting composite metal oxide on a support and drying ( 1) When manufacturing a superconducting film through the pyrolysis pre-baking step (2) of the organic component in the coating film formed on the support and the main baking step (3) for converting it into a superconducting substance. Before the step (2), KrCl excimer lamp light is irradiated at an illuminance of 15 mW / cm ² or more, and thereby, the element distribution of the temporarily fired film obtained in the step (2) The uniformity is remarkably improved, and a superconducting film material having a large film thickness and orientation can be manufactured through the step (3). Moreover, a high critical current density is obtained by performing a process (2) in the atmosphere containing water vapor | steam whose dew point is 20 degreeC or more.

The manufacturing method of the superconducting film of this invention is demonstrated in order.
[Preparation process of organic solvent solution of metal-containing compound]
The organic solvent solution of the metal-containing compound used in the method of the present invention contains each metal component composed of rare earth metal, barium (Ba), and copper (Cu) as an essential component. This solution is used to form an oxide superconducting film, and can be used to synthesize an inorganic compound containing these metal components by performing a heat treatment.

  The essential rare earth metal elements include yttrium (Y) and lanthanoid elements, lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy). , Holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). These rare earth metals can also use a plurality of metals selected from these.

For the purpose of producing a superconducting film, in addition to the above-mentioned rare earth metal, barium and copper essential metal components, other rare earth metals such as cerium (Ce), praseodymium (Pr), terbium (Tb ) Or the like, or by containing a small amount of calcium, strontium, or the like as another component, the electrical characteristics of the resulting superconducting film can be changed.
In addition, any metal species that can be used as a metal species that can be used when forming a superconducting film can be used as appropriate.

When a superconducting film made of rare earth metal, barium, and copper is to be formed, the ratio of rare earth metal, barium, and copper is a rare earth 123 system having a ratio of 1: 2: 3 (hereinafter, for example, when the rare earth metal is yttrium, A superconducting film having a ratio of 1: 2: 4 (hereinafter referred to as Y124 when the rare earth metal is yttrium, for example). Therefore, the mixing ratio of the element species in the raw material solution is preferably a molar ratio of 1: 2: 3 to 1: 2: 4. However, for example, a preferable result can be obtained even in a composition lacking barium. , This ratio is not something that can be tied.
Also, a monovalent metal such as silver, a divalent metal such as calcium or strontium, a trivalent metal such as a rare earth metal other than the essential rare earth metal constituting the superconducting phase, or a tetravalent metal such as zirconium or hafnium is added to the above solution. Thus, it is possible to form a superconductor containing an additive element or a compound thereof. Superconductors containing additive elements such as calcium and strontium or their compounds have different electrical characteristics from superconductors that do not contain them, so by controlling the ratio of metals in the solution, It is possible to control various characteristics such as critical temperature and critical current density.

  The said solution used for the manufacturing method of this invention is a pyridine and / or at least 1 type of tertiary amine, and at least 1 type of C1-C1 with respect to the metal ion of the metal species containing rare earth elements, barium, and copper. A metal complex in which a carboxylic acid group of 8 and an acetylacetonato group are coordinated as necessary is dissolved in a linear alcohol having 1 to 8 carbon atoms and / or water to form a uniform solution.

As the “tertiary amine” which is one of the ligands in the metal complex, for example, trimethylamine, triethylamine, tripropylamine, tributylamine and the like are used, and “a carboxylic acid group having 1 to 8 carbon atoms” is used. Examples of the carboxylic acid include 2-ethylhexanoic acid, caprylic acid, butyric acid, propionic acid, acetic acid, oxalic acid, citric acid, lactic acid, benzoic acid, and salicylic acid.
Moreover, as said C1-C8 monovalent | monohydric linear alcohol, methanol, ethanol, n-propanol, n-butanol, n-pentanol etc. are raised, These mixtures can also be used.
Further, water can be used to dissolve the metal complex, and a mixture of one or more kinds of the monovalent linear alcohol having 1 to 8 carbon atoms and water can also be used.

The homogeneous solution used in the production of the present invention is preferably made into a uniform solution by further adding polyhydric alcohols after dissolving in the linear alcohol having 1 to 8 carbon atoms. Things are used. This is because the addition of polyhydric alcohols can prevent the occurrence of cracks in the above-described preliminary firing step and main firing step.
Examples of the polyhydric alcohols include ethylene glycol, hexylene glycol, octylene glycol, glycerin, diethylene glycol, triethylene glycol, tetraethylene glycol, and propylene glycol.

Specifically, the preparation of the superconducting film manufacturing solution of the present invention is performed on a metal carboxylate having 1 to 8 carbon atoms and / or a metal acetylacetonate powder mixture of rare earth elements, barium and copper. , Pyridine and / or at least one tertiary amine and at least one carboxylic acid having 1 to 8 carbon atoms to produce a metal complex and volatilizing an excess solvent, It is prepared by dissolving in 8 monovalent linear alcohol and / or water, and preferably adding a polyhydric alcohol to obtain a uniform solution.
Moreover, at least 1 sort (s) among the said metal carboxylate, metal acetylacetonate, and carboxylic acid may contain a halogen.

[Coating and drying step of raw material solution (= step (1))]
In this step, the solution is applied onto a substrate to form a solution coating film of a metal-containing compound. In this case, as the solution coating method, conventionally known methods, for example, various methods such as a dipping method, a spin coating method, a spray method, and a brush coating method can be used.
As the substrate, various materials and shapes can be used. In this case, as materials, metals and alloys such as nickel, copper, gold, silver, stainless steel, hastelloy, alumina, zirconia, titania, strontium titanate, lanthanum aluminate, neodymium gallate, yttrium aluminate, etc., Ceramics such as silicon carbide are used, and any shape such as a curved surface or a flat surface can be used. For example, any shape such as a plate shape, a wire shape, a coil shape, a fiber shape, a woven fabric shape, and a tubular shape can be adopted. The The support may be porous. Further, in order to prevent the reaction between the composite metal oxide and the base material and / or to relax the lattice mismatch between the two, a metal film or a metal oxide film such as zirconia or ceria is previously formed on the surface of the base material as an intermediate layer. Can be formed.
The solution coating film formed on the substrate in this way is dried under normal pressure or reduced pressure at room temperature or under heating. Since the drying can be completed at the initial stage of the irradiation process of the KrCl ultraviolet excimer lamp light or the preliminary baking process subsequent to the drying process, the coating film does not need to be completely dried in this drying process.

[KrCl ultraviolet excimer lamp light irradiation process]
Patent Document 2 includes a Xe excimer lamp and a KrCl excimer lamp as ultraviolet excimer lamps.
However, in the present invention, as shown in Examples and Comparative Examples described later, by using a KrCl ultraviolet excimer lamp and setting the illuminance to 15 mW / cm ² or more, the film thickness is about 0.6 to several μm for the first time. Even if it exists, a superconducting film with good orientation can be obtained, and high orientation cannot be obtained by Xe excimer lamp irradiation.
Irradiation with KrCl ultraviolet excimer lamp light is performed at room temperature and in the atmosphere under the conditions that the illuminance is 15 mW / cm ² or more, preferably ^{20 to} 50 mW / cm ² and the irradiation time is 5 minutes or more. When the illuminance is ² to 10 mW / cm ² , high orientation can be obtained until the film thickness is about 0.4 μm, but when the thickness is 1 μm, the orientation is lowered. Here, when the illuminance is increased to 10 to 15 mW / cm ² , the orientation is lowered not only at 1 μm but also at 0.4 μm or less. However, in the present invention, it has been found that unexpectedly good results can be obtained by further setting the illuminance to 15 mW / cm ² or more, preferably 20 mW / cm ² or more. Incidentally, even when the 30~50mW / cm ² is further increased the intensity, 20 mW / cm when ^two similarly good results were obtained. 50 mW / cm ² is the maximum illuminance that can be stably obtained using a commercially available excimer lamp.

[Temporary firing step (= step (2))]
In this process, the film of the metal-containing compound formed on the substrate as described above is irradiated with KrCl ultraviolet excimer lamp light and then heated and fired, and the film is oxidized with barium carbonate, rare earth metal oxide and copper oxide. This is a step of converting into a film made of a product.
As the maximum firing temperature, a temperature of 400 to 650 ° C., preferably 450 to 550 ° C. is adopted. When the temperature is gradually raised to this temperature and the equivalent film thickness is 0.5 μm or more for 20 to 600 minutes. Preferably, the temperature is lowered after holding for 150 to 300 minutes.

  Moreover, the oxygen partial pressure in temporary baking shall be 0.2 atm or more. If the oxygen partial pressure is less than this, the supply of oxygen is insufficient, so that an organic component rich in carbon is likely to remain in the film after pre-baking. The carbon-rich organic component in the pre-fired film partially makes the film reducible when the main calcination is carried out under a low oxygen partial pressure, so that Y123 is generated non-uniformly and the critical current density is also lowered. .

Furthermore, a high critical current density can be obtained by setting the pre-baking atmosphere to an atmosphere containing water vapor having a dew point of 20 ° C. or higher.
When water vapor is not contained, and when the dew point of water vapor is 20 ° C. or lower, an organic component rich in carbon tends to remain in the film after temporary baking, and the critical current density of the Y123 film after the main baking becomes low. In the calcination step, water vapor is considered to promote the removal of the carbon component in the film by the same mechanism as the gasification of the carbon component by the water gas reaction represented by the formula (1).
C + H ₂ O → CO + H ₂ (1)

[Main firing step (= step (3))]
This step is a step of reacting barium carbonate, rare earth metal oxide, and copper oxide while baking the film formed in the preliminary baking step to remove carbon dioxide from the barium carbonate. In the present invention, this firing step is preferably carried out at an oxygen partial pressure of 0.01 to 100 Pa, particularly 1 to 20 Pa.
By adopting such firing conditions, decomposition of barium carbonate in the film formed in the preliminary firing step is promoted, and a composite metal oxide film is formed. Further, in this firing step, since the conditions of low oxygen concentration or low oxygen partial pressure are adopted as described above, the decomposition of barium carbonate can be carried out smoothly at a reduced temperature. Alternatively, the reaction between the intermediate layer and the composite metal oxide can be substantially avoided. The general firing temperature in this step is 650 to 900 ° C. According to the firing conditions as described above in the present invention, it is possible to substantially prevent the reaction between the base material and / or the intermediate layer and the composite metal oxide as conventionally observed.

[Oxidation process]
This step is a step in which the composite metal oxide film formed in the main firing step is oxidized using molecular oxygen to absorb oxygen to form a composite metal oxide film having superconductivity.
In the main firing step, since the oxygen partial pressure in the atmosphere is maintained at 0.01 to 100 Pa, the superconducting properties of the obtained composite metal oxide film are unsatisfactory. It can be converted into an excellent composite metal oxide film.
The oxidation step for absorbing oxygen is preferably performed at an oxygen partial pressure of 0.2 to 1.2 atm.
As the molecular oxygen, pure oxygen or air is used. When air is used as the oxidant, the superconducting properties of the film are adversely affected by the carbon dioxide contained therein, so the carbon dioxide partial pressure in the air is reduced to 1 Pa or less, preferably 0.5 Pa or less by decarboxylation. It is good to adjust.
This oxidation step is performed at a medium to high temperature, and the reaction between the substrate and / or the intermediate layer and the composite metal oxide can be substantially avoided. The temperature of this oxidation process is generally 300 to 900 ° C. When implementing the method of this invention, the said temporary baking process, this baking process, and an oxidation process can be continuously implemented in the same apparatus.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to this Example.

Example 1
A commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) yttrium, barium and copper acetylacetonate powders are weighed so that the molar ratio of metal components is 1: 2: 3, and these are mixed to obtain a powder mixture. Got. To this mixture, pyridine and propionic acid were added in amounts until the powder mixture was completely dissolved. This was heat-treated to remove excess solvent components (pyridine and propionic acid) to obtain an amorphous dry solid of acetic acid group-propionic acid group-pyridine coordination metal complex. Next, this is dissolved in methanol, and a liquid metal complex in which the ratio of the metal element is Y: Ba: Cu = 1: 2: 3 (the three types of acetate, pyridine, and propionic acid groups as ligands). A coating solution comprising: The concentration of the solution was such that 0.1 to 0.2 mmol of rare earth metal species was contained per 1 g of the solution.
This solution was applied by spin coating on a 2 cm square strontium titanate (100) substrate on which cerium oxide was previously deposited. This coating film is irradiated with a KrCl excimer lamp at room temperature in the atmosphere (MEIR-S-1-200-222, manufactured by MDI Excimer, illuminance: 20 mW / cm ² , irradiation time: 18 minutes). Next, the sample irradiated with this lamp was heated to 500 ° C. in an oxygen stream to perform preliminary firing to remove organic components.
In addition, when an experiment was repeated on the same substrate, the spin coating application process, the lamp irradiation process, and the pre-baking process were repeated up to 3 times (maximum film thickness of 1 μm as a manufactured Y123 film), the film thickness was proportional to the number of coatings. And confirmed that it increased. Moreover, it confirmed that the coating film after repeating a process also has favorable smoothness.
That is, it was confirmed that the coating solution did not dissolve the preliminary calcination film, and that a thick film could be formed by repeating the spin coating application process, the lamp irradiation process, and the calcination process.
This pre-fired film was light brown and transparent and had good smoothness. About this temporary baking film | membrane, when the composition analysis of the cross section by a transmission electron microscope (TEM) -energy dispersive X-ray spectrometer (EDS) was conducted, it was shown that it has very uniform element distribution. The result is shown in FIG.

About these temporary baking films | membranes, after performing this baking process in 760 degreeC for 2 hours in the airflow of oxygen partial pressure 10Pa, oxygen was absorbed at atmospheric pressure and the Y123 superconducting film with a film thickness of 1 micrometer was produced.
FIG. 3 is a diagram schematically showing the relationship between the steps of lamp irradiation, preliminary firing and main firing and the firing temperature in this example.
The obtained film sample after film firing (film thickness: 1 μm) was analyzed by an X-ray diffraction method using an X-ray diffractometer MXP3 manufactured by MacScience. The film was superconductive with a Y123 structure having (001) orientation. It was confirmed to be a single body phase. Next, when the in-plane orientation of Y123 was examined by X-ray pole measurement using the same apparatus, it was confirmed that it was epitaxially grown on the single crystal substrate. Moreover, the high epitaxial orientation of the whole film was also confirmed by a cross-sectional TEM image. Furthermore, when the superconducting properties of this film were evaluated by an induction method using a cryoscan manufactured by Teva, an average critical current density (Jc) at a liquid nitrogen temperature of 0.5 MA / cm ² was obtained.

(Example 2)
A fired film having a film thickness of 1 μm was produced in the same manner as in Example 1 except that water vapor of 24 ° C. was included in the air flow during the pre-baking, and the result was high by analysis using an X-ray diffraction method (001). ) A superconductor single phase having a Y123 structure with orientation was obtained, and an average critical current density (Jc) at a liquid nitrogen temperature by an induction method was 1.2 MA / cm ² . Thus, high Jc was obtained by including water vapor | steam in the atmosphere at the time of temporary baking.

(Example 3)
When the acetylacetonate powder mixture of yttrium, barium and copper was dissolved, a fired film having a thickness of 1 μm was prepared in the same manner as in Example 2 except that tripropylamine was used instead of pyridine. Analysis using the line diffraction method yielded a superconductor single phase having a high (001) orientation and a Y123 structure, and an average critical current density (Jc) at liquid nitrogen temperature by an induction method was 1.1 MA / cm ^{2 on} average. was gotten.

Example 4
Except for adding pyridine and propionic acid in addition to pyridine and propionic acid, 0.1 mol of trifluoroacetic acid was added in the dissolution of the yttrium, barium and copper acetylacetonate powder mixture. As a result, a fired film having a film thickness of 1 μm was produced. As a result of analysis using an X-ray diffraction method, a superconductor single phase having a high (001) orientation was obtained. An average of 1.0 MA / cm ² was obtained as the critical current density (Jc).

(Comparative Examples 1 and 2)
Except that the lamp illuminance was set to 4 and 8 mW / cm ² , a fired film having a film thickness of 0.4 and 1 μm was produced in the same manner as in Example 2, respectively. In the 4 μm main fired film, a Y123-structure superconductor single phase having a high (001) orientation was obtained by analysis using the X-ray diffraction method, but in the 1 μm thick main fired film, (001) The orientation was low, and the average Jc at the liquid nitrogen temperature by the induction method was 0.1 MA / cm ² .

(Comparative Example 3)
A pre-baked film was produced by repeating the spin coat coating process, the lamp irradiation process, and the pre-baking process in the same manner as in Example 2 except that the lamp illuminance was 12 mW / cm ^2. It was. Further, these preliminary fired films were fired in the same manner as in Example 1 to produce 0.4 and 1 μm thick fired films. Both films used the X-ray diffraction method. By analysis, a superconductor single phase having a Y123 structure was not obtained.
From the results of Comparative Examples 1 and 2 and Comparative Example 3, when the lamp illuminance is 15 mW / cm ² or less in KrCl excimer lamp light irradiation, the (001) orientation is low in the fired film having a thickness of 1 μm. It can be seen that the average Jc is also low.

(Comparative Example 4)
As in Example 2, the film thickness was reduced to 0. 0, except that a Xe excimer lamp (MEIR-S-1-330, manufactured by MDI Excimer, illuminance: 20 mW / cm ² , irradiation time: 18 minutes) was used as the light source. When the fired films of 4 and 1 μm were produced, no superconductor single phase having a Y123 structure was obtained in any film by analysis using an X-ray diffraction method.

(Comparative Examples 5-7)
A fired film having a film thickness of 0.4 and 1 μm was prepared in the same manner as in Comparative Example 4 except that the lamp illuminance was changed to 4, 8, and 12 mW / cm ² . In the 4 μm main fired film, a Y123-structure superconductor single phase having a high (001) orientation was obtained by analysis using the X-ray diffraction method, but in the 1 μm thick main fired film, (001) The orientation was low.
From the results of Comparative Example 4 and Comparative Examples 5 to 7, it is understood that high orientation cannot be obtained for the fired film having a thickness of 1 μm by Xe excimer lamp light irradiation.

(Comparative Example 8)
A fired film having a film thickness of 1 μm was prepared in the same manner as in Example 2 except that lamp irradiation was not included. As a result of analysis using an X-ray diffraction method, a superconductor having a Y123 structure was included, but (001) The orientation was low.

(Example 5)
A fired film having a film thickness of 1 μm was prepared in the same manner as in Example 3 except that acetylacetonate was changed to acetate. As a result of analysis using an X-ray diffraction method, a Y123 structure having high (001) orientation was obtained. The superconductor single phase was obtained, and an average of 1.1 MA / cm ² was obtained as the critical current density (Jc) at the liquid nitrogen temperature by the induction method.

(Comparative Example 9)
A fired film having a thickness of 1 μm was produced in the same manner as in Example 5 except that lamp irradiation was not performed. As a result of analysis using an X-ray diffraction method, a superconductor having a Y123 structure was included. The orientation was low.
FIG. 4 shows cross-sectional TEM images of the fired films produced in Example 5 (with lamp irradiation) and Comparative Example 9 (without lamp irradiation).
In Example 5, epitaxial growth from the substrate surface to the film surface was observed, and high-density crystal disorder was observed in the vicinity of the interface with the substrate, whereas in Comparative Example 9, from the substrate to a thickness of 0.1 to 0.2 μm Although it is epitaxially grown, it can be seen that the orientation on the film thereon is greatly disturbed.

(Example 6)
A fired film having a film thickness of 1 μm was produced in the same manner as in Example 5 except that the yttrium salt was changed to gadolinium salt. As a result of analysis using an X-ray diffraction method, a Gd123 structure having a high (001) orientation was obtained. A superconductor single phase was obtained, and the average Jc at the liquid nitrogen temperature by the induction method was 1.0 MA / cm ² .

(Comparative Example 10)
A fired film having a film thickness of 1 μm was prepared in the same manner as in Example 6 except that lamp irradiation was not included. As a result of analysis using an X-ray diffraction method, a superconductor having a Gd123 structure was included. The orientation was low.

Claims (8)

A step (1) of applying an organic solvent solution of a metal-containing compound blended so as to have a metal seed composition corresponding to the superconducting composite metal oxide on the support, followed by drying (1), formed on the support When manufacturing the superconducting film epitaxially grown through the preliminary firing step (2) for thermally decomposing the organic component in the coating film and the main firing step (3) for conversion to a superconducting substance, before the step (2) Irradiating KrCl ultraviolet excimer lamp light with an illuminance of 15 mW / cm ² or more.   The method for producing a highly oriented superconducting film according to claim 1, wherein the highly oriented superconducting film is a thick film having a thickness of 0.6 μm or more.   The method for producing a highly oriented superconducting film according to claim 1 or 2, wherein the step (2) is performed in an atmosphere containing water vapor having a dew point of 20 ° C or higher.   The highly oriented superconductivity according to any one of claims 1 to 3, wherein the organic solvent solution of the metal-containing compound contains, as essential components, metal components composed of rare earth metals, barium, and copper. Thick film manufacturing method.   The organic solvent solution of the metal-containing compound is mixed with 1 to 8 carbon carboxylate and / or metal acetylacetonate powder of a metal species containing rare earth elements, barium and copper, pyridine and / or at least One tertiary amine and at least one carboxylic acid having 1 to 8 carbon atoms are added to produce a metal complex, and an excess solvent is volatilized. The method for producing a highly oriented superconducting film according to any one of claims 1 to 4, which is a homogeneous solution prepared by dissolving in a chain alcohol and / or water.   6. The method for producing a highly oriented superconducting film according to claim 5, wherein at least one of the metal carboxylate, metal acetylacetonate, and carboxylic acid contains halogen.   A pre-baked film having a uniform element distribution obtained after the pre-baking step (2) in the method of manufacturing a superconducting film according to any one of claims 1 to 6. A highly oriented main-fired film obtained after the main-baking step (3) in the method for producing a superconducting film according to any one of claims 1 to 6.