JP2007179827A - Method of manufacturing metal base material for oxide superconductive conductoor and method of manufacturing oxide superconductive conductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an oxide superconductive conductor using a manufacturing method of a metal base material for an oxide superconductive conductor and the metal base material which is capable of producing an oxide superconductive conductor being made of a Ni-base alloy containing Mo and excellent in surface smoothness, and further having excellent superconductive properties in a case that an oxide superconductive thin film is formed on a polycrystal oriented intermediate thin film. <P>SOLUTION: The method includes the steps of operating annealing procedures at least one-time and also rolling procedures at least one-time at a higher temperature than 1,100°C on a mother material which is made of a Ni-base alloy containing Mo, and after the final rolling, making it electropolish. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is used as a base material for oxide superconducting conductors that are being developed and applied in fields such as superconducting power cables, superconducting magnets, superconducting energy storage devices, superconducting power generation devices, medical MRI devices, and superconducting current leads. The present invention relates to a method for producing a metal substrate for an oxide superconducting conductor, and a method for producing an oxide superconducting conductor obtained by forming an oxide superconducting thin film on a metal substrate via a polycrystalline oriented intermediate thin film.

In order to use an oxide superconductor as a practical superconductor, it is necessary to form a thin film of an oxide superconductor with good crystal orientation on a substrate. In general, the metal substrate itself is polycrystalline, and its crystal structure is also very different from that of the oxide superconductor. Therefore, a thin film of an oxide superconductor with good crystal orientation is directly formed on the metal substrate. Is difficult. Therefore, a polycrystalline orientation intermediate thin film such as Gd ₂ Zr ₂ O ₇ having excellent crystal orientation is formed on a metal substrate such as Hastelloy having a tape shape with a smooth surface, and this polycrystalline orientation intermediate thin film Attempts have been made to form a thin film of a Y ₁ Ba ₂ Cu ₃ O _x- based oxide superconductor. For the thin film formation of the Y ₁ Ba ₂ Cu ₃ O _x- based oxide superconductor, a pulse laser deposition method (PLD) or the like capable of forming a thin film uniformly on a tape substrate is used. . The polycrystalline oriented intermediate thin film is formed by an ion beam assisted deposition (hereinafter referred to as IBAD method) so that the crystal grains are c-axis oriented in advance and are also oriented in the a-axis and b-axis. In the Y ₁ Ba ₂ Cu ₃ O _x- based oxide superconductor thin film, each crystal axis, c-axis, a-axis, and b-axis are epitaxially grown and crystallized so as to match the crystal of the polycrystalline oriented intermediate thin film. As a result, a Y ₁ Ba ₂ Cu ₃ O _x- based oxide superconductor thin film with good crystal orientation can be obtained.

The metal substrate is required to have high strength, oxidation resistance, heat resistance, etc., but it is desirable that the metal substrate has a thermal expansion coefficient close to that of the oxide material. One of the promising candidates for the metal tape base material found so far is a Ni-based alloy containing Cr, Mo, Fe and the like as components.
By the way, one of the important elements in the base material for a superconducting tape conductor is the smoothness of the tape surface. The superconducting properties of oxide superconducting thin films are highly dependent on the degree of crystal orientation, and it is known that if there are irregularities on the surface of the substrate, the orientation of the crystals will be disturbed accordingly and the properties will be greatly reduced. Yes. For this reason, attempts have been made to improve the smoothness of the tape substrate surface. As one of the attempts, a method of performing roll rolling is considered (for example, refer to Patent Document 1).
In this method, since the hardness is increased, annealing is performed before the rolling process. The annealing temperature at this time is 1000 to 1050 ° C. This is because the softness is not sufficiently softened below 1000 ° C., and the smoothness of the base metal surface is remarkably lowered due to recrystallization of the metal crystal above 1050 ° C. . When this method is used, the smoothness of the surface of the metal tape substrate after the final rolling can be reduced to R _max = 0.2 μm or less. Further, by performing polishing with an abrasive having a particle size of 28 μm or less before the final rolling step, it is possible to smoothen to R _max = 0.1 μm.
JP-A-10-245661 Applied Metallurgy 6 128-145 Stainless Steel Handbook 3rd Edition Stainless Steel Association 710-711

In the prior art described in Patent Document 1, since the smoothness of the surface of the metal tape substrate can only be smoothed to about R _max = 0.1 μm, the metal tape substrate after the final rolling process is electropolished. Further, it is necessary to obtain a smoother surface by performing chemical polishing. In order to smooth the surface to be polished by electrolytic polishing or chemical polishing, it is desirable that the surface to be polished be a uniform solid solution. If there is a noble part and a base part, the elution rates at the noble part and the base part are different, and smoothing cannot be performed, and a good surface cannot be obtained as a substrate for film formation. In particular, it is known that a Ni-based alloy containing Mo as a component is difficult to be heat-treated, and a compound rich in Mo is precipitated by the heat-treatment (see, for example, Non-Patent Document 1). Further, Mo is deficient in the vicinity of the Mo-rich precipitate. The Mo-rich compound is precious, and the Mo-deficient substrate portion near the Mo is a base. Therefore, it becomes a base material that is not suitable for electrolytic polishing or chemical polishing.
It is known that a Ni-based alloy containing Mo precipitates a compound rich in Mo at a temperature of 650 to 1090 ° C. (see, for example, Non-Patent Document 2). Therefore, annealing at 1000 ° C. to 1050 ° C. performed in Patent Document 1 is a temperature at which a compound rich in Mo is expected to be precipitated.

  The present invention has been made in view of the above circumstances, is made of a Ni-based alloy containing Mo, has a very low surface smoothness, and is good when an oxide superconducting thin film is formed on a polycrystalline oriented intermediate thin film thereon. It is an object of the present invention to provide a method for producing a metal substrate for an oxide superconducting conductor capable of producing an oxide superconducting conductor having superconducting properties, and a method for producing an oxide superconducting conductor using the metal substrate.

  In order to achieve the above object, the present invention performs at least one annealing at a temperature of 1100 ° C. or more and rolling at least once on a base material made of a Ni-based alloy containing Mo, and after the final rolling Provided is a method for producing a metal substrate for an oxide superconducting conductor, which is obtained by performing electropolishing to obtain a metal substrate for an oxide superconducting conductor.

  In the present invention, a base material made of a Ni-based alloy containing Mo is subjected to at least one annealing at a temperature of 1100 ° C. or more and at least one rolling, and is subjected to electrolytic polishing after final rolling to oxidize. A metal base material for a superconductor is prepared, and then a polycrystalline oriented intermediate thin film is formed on the metal base material for oxide superconducting conductor by an IBAD method, and then an oxide superconducting material is formed on the polycrystalline oriented intermediate thin film. Provided is a method for producing an oxide superconducting conductor characterized in that a thin film is formed to obtain an oxide superconducting conductor.

  According to the present invention, when the annealing temperature of the Ni-based alloy containing Mo is set to 1100 ° C. or higher, the Mo-rich compound does not precipitate, and the surface of the metal substrate for the oxide superconducting conductor is subjected to subsequent electrolytic polishing treatment. Smoothness can be improved, and high-performance oxide superconductivity with high critical current density can be obtained by depositing an oxide superconducting thin film on the metal substrate for oxide superconducting conductor via a polycrystalline oriented intermediate thin film. A conductor can be provided.

  FIG. 1 is a sectional view showing an embodiment of the oxide superconducting conductor of the present invention. The oxide superconducting conductor 1 of this embodiment is provided with a first polycrystalline oriented intermediate thin film 3 on a metal substrate 2 for an oxide superconducting conductor having a tape shape, and the first polycrystalline oriented intermediate thin film. 2 is provided with a second polycrystalline oriented intermediate thin film 4, an oxide superconducting thin film 5 is provided on the second polycrystalline oriented intermediate thin film 4, and an Ag protective layer 6 is provided on the oxide superconducting thin film 5. It is a provided configuration.

  The metal substrate for the oxide superconducting conductor is subjected to at least one annealing and rolling at least once at a temperature of 1100 ° C. or more on a base material made of a Ni-based alloy containing Mo, and electrolysis is performed after the final rolling. Manufactured by polishing.

  As a particularly preferred example of the Ni-based alloy containing Mo, which is a material of the metal substrate 2 for oxide superconducting conductor, there is Hastelloy (trade name of Haynes Stellite). This Hastelloy is divided into several types such as Hastelloy A, Hastelloy C and Hastelloy D depending on the kinds and amounts of elements contained. In the present invention, among these Hastelloys, those containing Mo in particular, for example Hastelloy A and Hastelloy C, can be suitably used. The elements contained in various hastelloys and their ratios are as follows: C is 0 to 0.15%, Si is 1.0 to 10.0%, Mn is 1.0 to 2.0%, and Cr is 1.0 to 23 0.0%, Co 0-2.5%, Mo 0-30%, W 0-5.0%, Al 0-2.0%, Fe 0-20.0%, Cu 0 It is in the range of ˜3.0%, and the balance is Ni. Table 1 shows the types and ratios of the elements contained in Hastelloy A and Hastelloy C.

  The base material of the Ni-based alloy containing Mo is annealed at a temperature of 1100 ° C. or higher and then rolled. As described above, it is known that a Ni-based alloy containing Mo precipitates a compound rich in Mo at a temperature of 650 to 1090 ° C. When annealing is performed at a temperature of 1090 ° C. or lower, A compound rich in Mo is deposited on the surface, and a region having a composition deficient in Mo is formed in the vicinity thereof. When the base material in which the Mo component is unevenly distributed is electropolished, a difference occurs in the polishing state between the chemically rich Mo-rich region and the base Mo-deficient portion. Even if electrolytic polishing is performed, the smoothness cannot be improved, and the surface smoothness may deteriorate.

  On the other hand, in the manufacturing method of the present invention, by setting the temperature during annealing to 1100 ° C. or higher, precipitation of a compound rich in Mo can be suppressed, whereby the surface of the substrate after final rolling is electrolyzed. It can be processed extremely smoothly by polishing.

The roll used when processing the annealed Ni-base alloy base material into the tape-shaped metal substrate 2 for oxide superconducting conductor may be a so-called normal roll such as a cast iron roll or a steel roll. hardness is about 70～100Hs, Young's modulus and forged steel rolls about 21500kgf / mm ² is about 120Hs hardness, Young's modulus to use so-called carbide roll such 66000kgf / mm ² approximately tungsten carbide sintered roll Thereby, the smoothness of the surface of the metal substrate 2 for an oxide superconducting conductor can be further improved. Although it is not necessary to make all the rolls used in the rolling process a cemented carbide roll, it is preferable to use a cemented carbide roll particularly in the final rolling process. Moreover, it is preferable that the cemented carbide roll used for the last rolling process is grind | polished so that the unevenness | corrugation of the surface may be 0.1 micrometer or less.

  As a rolling mill suitably used in the rolling process, as shown in FIG. 2 (a), a double rolling mill 10A provided with a pair of upper and lower drive rolls 8 and 8 for rolling with a Ni-based alloy base material 7 interposed therebetween, A triple rolling mill 10B further provided with a driving roll 8 above the double rolling mill as shown in FIG. 2 (b), and a roll further above and below the pair of upper and lower driving rolls 8 and 8 as shown in FIG. 2 (c). A quadruple rolling mill 10C provided with 9, 9 can be exemplified. The rolling conditions here are a temperature of room temperature to 300 ° C., a rolling reduction of 5 to 20%, and a rolling speed of about 1 to 10 m / min.

  In the annealing step performed before the rolling step, the substrate may be annealed using a heating device that can obtain a desired annealing temperature. Examples of the heating device include a batch electric furnace and a continuous firing furnace. In particular, when the substrate is in the form of a tape, for example, as shown in FIG. 3, a heating device 13 is provided at an arbitrary position between the supply bobbin 11 and the take-up bobbin 12, and the tape-shaped metal for an oxide superconducting conductor is provided. While the substrate is wound up and the bobbin 12 is slowly wound up, the heating device 13 can perform the annealing by heating the metal substrate for the oxide superconducting conductor. At this time, the annealing time can be adjusted by changing the rotation speed of the winding bobbin 12.

  During the production of the metal substrate 2 for oxide superconductor, the number of annealing and rolling is not limited to far away, and is necessary for obtaining the metal substrate 2 for oxide superconductor having a desired thickness by the final rolling process. Can be repeated a number of times. Moreover, before the final rolling step, the surface of the metal substrate 2 for oxide superconducting conductor can be polished with an abrasive to improve the smoothness of the surface.

  The particle size of the abrasive used in this polishing step is preferably 28 μm (# 600) or less, and more preferably in the range of 10 to 28 μm (# 1600 to # 600). Even when an abrasive having a particle size of less than 10 μm (# 1600) is used, no significant improvement in surface smoothness is observed. An abrasive having a particle size exceeding 28 μm (# 600) is not preferable because it tends to deteriorate the smoothness of the surface.

  After the final rolling step, electrolytic polishing is performed to further smooth the surface of the metal substrate 2 for oxide superconducting conductor. As a method of this electropolishing, conventionally, using the same method and conditions as the electropolishing method performed by metal surface treatment or the like, or according to the material of the metal substrate 2 for an oxide superconductor, The polishing liquid composition, pH, applied voltage and the like can be changed as appropriate. As an example, if conditions suitable for electropolishing the metal substrate 2 for oxide superconducting conductors using Hastelloy are exemplified, a mixed solution mainly composed of phosphoric acid and sulfuric acid is used as an electrolytic solution, and a reference electrode is used. As the silver-silver chloride, there is a method of electrolytic polishing the substrate surface after the final rolling step by applying a potential of 1.2 V or more.

In the present embodiment, the surface smoothness _{R max} of oxide superconductor metal substrate 2 obtained after electrolytic polishing process, 0.05 .mu.m or less, preferably 0.03μm or less, and more preferably not more than 0.02μm Is desirable. When the surface smoothness R _max of the metal substrate 2 for oxide superconductor is 0.05 μm or more, the effect of improving the critical current density of the obtained oxide superconductor 1 cannot be sufficiently obtained.

In this embodiment, the first polycrystalline oriented intermediate thin film 3 and the second polycrystalline oriented intermediate thin film 4 excellent in crystal orientation are formed on the metal substrate 2 for the oxide superconducting conductor, An oxide superconductor thin film 5 is formed on the second polycrystalline oriented intermediate thin film 4. The polycrystalline oriented intermediate thin films 3 and 4 are formed with Gd ₂ Zr ₂ O ₇ while irradiating an ion beam from an oblique direction of the base film forming surface simultaneously with sputtering when forming the polycrystalline oriented intermediate thin film by a sputtering apparatus. The film is formed by an ion beam assist method (IBAD method) or the like for forming one or two or more polycrystallized intermediate thin films 3 and 4 made of CeO ₂ , YSZ or the like and having excellent crystal orientation.

The polycrystalline oriented intermediate thin films 3 and 4 are formed by integrating a large number of fine crystal grains in which crystals having a cubic crystal structure are joined together via a grain boundary. The c-axis of the crystal axis is oriented substantially perpendicular to the upper surface (deposition surface) of the metal substrate 2 for oxide superconducting conductors, and the a-axis and the b-axis of each crystal grain are the same. Oriented in-plane and oriented. The thickness per layer of the polycrystalline oriented intermediate thin films 3 and 4 is about 0.1 to 1.0 μm. Even if the thickness per layer of the polycrystalline oriented intermediate thin films 3 and 4 exceeds 1.0 μm, the effect of improving the superconducting characteristics of the oxide superconducting thin film 5 due to the orientation can no longer be expected. Is also disadvantageous. On the other hand, if the thickness per layer of the polycrystalline oriented intermediate thin films 3 and 4 is less than 0.1 μm, the oxide superconducting thin film 5 may not be sufficiently supported because it is too thin. In addition to Gd ₂ Zr ₂ O ₇ , CeO ₂ , and YSZ, Sm ₂ Zr ₂ O ₇ , MgO, SrTiO _{3, and the} like can be used as constituent materials for the polycrystalline oriented intermediate thin films 3 and 4.

The oxide superconducting thin film _{5, Y 1 Ba 2 Cu 3} O x, Gd 1 Ba 2 Cu 3 O x, Yb 1 Ba 2 Cu 3 O x, Ho 1 Ba 2 Cu 3 O x having a composition, (Bi, Pb) _{2 Ca 2 Sr 2 Cu 3 O} x, (Bi, Pb) 2 Ca 2 Sr 3 Cu 4 O x having a composition, or _{Tl 2 Ba 2 Ca 2 Cu 3} O x, Tl 1 Ba 2 Ca 2 Cu 3 O x, It is made of an oxide superconductor having a high critical temperature typified by a composition such as Tl ₁ Ba ₂ Ca ₃ Cu ₄ O _x . The oxide superconducting thin film 5 has a thickness of about 0.5 to 5 μm and a uniform thickness in the longitudinal direction. The oxide superconducting thin film 5 has a uniform film quality and is epitaxially grown so that the c-axis, a-axis and b-axis of the oxide superconducting thin film 5 are aligned with the crystals of the polycrystalline oriented intermediate thin films 3 and 4. It is crystallized and has excellent crystal orientation.

A method for forming the oxide superconducting thin film 5 is not limited, but a laser deposition method or the like is preferable. The laser light source used for the laser vapor deposition method is not particularly limited, and for example, any of excimer lasers such as Ar-F (193 nm) and Kr-F (248 nm), YAG lasers, and CO ₂ lasers may be used. good.

  The oxide superconducting conductor 1 according to the present embodiment deposits a Mo-rich compound by setting the annealing temperature of a Ni-based alloy containing Mo to 1100 ° C. or higher when the metal base 2 for an oxide superconducting conductor is manufactured. Then, the surface smoothness of the metal substrate 2 for oxide superconducting conductor can be improved by the subsequent electropolishing treatment, and the polycrystalline oriented intermediate thin films 3 and 4 are formed on the metal substrate 2 for oxide superconducting conductor. By forming the oxide superconducting thin film 5 through, a high-performance oxide superconducting conductor 1 having a high critical current density can be provided.

  In accordance with the steps shown in Table 2, a Hastelloy (C276) base material was processed into a tape-shaped metal substrate for an oxide superconducting conductor having a thickness of 100 μm. The annealing was performed at the temperatures shown in Table 3 (1020 ° C, 1050 ° C, 1070 ° C, 1090 ° C, 1100 ° C, 1150 ° C, 1200 ° C). Among these, three of 1100 ° C., 1150 ° C., and 1200 ° C. are examples according to the present invention, and the others are comparative examples.

  As shown in Table 3, the smoothness of the base material after the final rolling when annealing was performed at each temperature was about the same.

Thereafter, each substrate is subjected to electrolytic polishing using a mixed solution mainly composed of phosphoric acid and sulfuric acid as an electrolytic solution, and the surface smoothness R _max of the metal substrate for an oxide superconducting conductor after electrolytic polishing is measured. did. As a result, the metal base material for oxide superconducting conductors annealed at a temperature of 1090 ° C. or lower had a surface that was not smoothed because the Mo-rich compound was precipitated, and the surface became rough. On the other hand, the metal substrate for oxide superconducting conductor annealed at a temperature of 1100 ° C. or higher had no Mo-rich compound precipitated, so that by performing electropolishing after final rolling, R _max = 0.01 μm A good degree of smoothness was obtained.

Next, a thickness of Gd ₂ Zr ₂ O _{7 is} formed on the metal substrate (thickness: 100 μm) for these oxide superconducting conductors using an ion beam assisted sputtering apparatus having a configuration as shown in FIG. A 1 μm first polycrystalline oriented intermediate thin film was deposited. Specifically, a base material delivery bobbin 22 around which a tape-shaped metal substrate 21 for an oxide superconductor is wound is disposed in a film forming treatment vessel 23, and the metal base for an oxide superconductor is provided from the base material delivery bobbin 22. The material 21 was continuously fed onto the substrate holder 24, and the metal substrate 21 for oxide superconducting conductor after the formation of the polycrystalline orientation intermediate layer was set to be wound up by the substrate winding bobbin 25. Here, Gd ₂ Zr ₂ O ₇ was used as the target 26 to form a film. And the inside of the film-forming treatment container 23 of this ion beam assisted sputtering apparatus is evacuated by a cryopump 27 and a rotary pump 28 to reduce the pressure to 3.0 × 10 ⁻⁴ Torr, and a metal substrate for an oxide superconducting conductor 21 was negatively charged.

Further, when a mixed ion beam of argon ions and oxygen ions having a sputtering voltage of 1200 V and a sputtering current of 240 mA is generated from the first filament ion source 29, the ionization voltage value applied between the filament and the anode is set to 50 V, while assisting. When a mixed ion beam of argon ions and oxygen ions having a voltage of 200 V and an assist current of 100 mA is generated from the second filament ion source 30, the ionization voltage value applied between the filament and the anode is 50 V, and the metal for the oxide superconductor By depositing the particles of the target 26 on the film forming surface of the base material 21 and simultaneously irradiating with an ion beam, the film is processed to form Gd ₂ Zr ₂ on the metal base material for oxide superconductor having a thickness of 100 μm. first polycrystalline orientation intermediate thin film having a thickness of 1μm consisting O ₇ It was formed. Here, the incident angle of the mixed ion beam generated from the second filament type ion source 30 was set to 55 degrees.

Next, the metal substrate for the oxide superconducting conductor on which the first polycrystalline orientation intermediate thin film is formed is set in a laser deposition apparatus, laser deposition is performed using CeO ₂ as a target, and the first polycrystalline orientation intermediate thin film is formed. A _second polycrystalline oriented intermediate thin film made of CeO ₂ was formed. Next, laser deposition is performed by changing the target to Y ₁ Ba ₂ Cu ₃ O _x , and a ₁ μm thick oxide superconducting thin film made of Y ₁ Ba ₂ Cu ₃ O _{x is formed} on the second polycrystalline oriented intermediate thin film. Was deposited. Further, an Ag protective layer having a thickness of 10 μm was formed on this oxide superconducting thin film, thereby producing an oxide superconducting conductor having the structure shown in FIG.

  The critical current density (Jc) of the oxide superconductors manufactured using the respective metal substrates for oxide superconductors with different annealing temperatures was measured, and the results are shown in Table 2. As described in Table 3, it was found that the oxide superconducting conductor manufactured using the metal substrate for oxide superconducting conductor annealed at 1100 ° C. or higher clearly has higher Jc.

  Also, after the final rolling of the metal substrate for oxide superconducting conductor, without performing electrolytic polishing, a polycrystalline oriented intermediate thin film, an oxide superconducting thin film, and an Ag protective layer were sequentially formed, and the resulting oxide superconducting conductor was obtained. The critical current density (Jc) of was measured. The results are shown in Table 4. From Table 4, it can be seen that when each layer is formed without subjecting the substrate to electropolishing, the Jc value is comparable even if the substrate is annealed at any temperature.

  From the results of Tables 3 and 4, the base material annealed at a temperature of 1090 ° C. or less has poor smoothness when subjected to electrolytic polishing after the final rolling, and for that reason, a polycrystalline oriented intermediate thin film is interposed on the base material. Thus, Jc of the oxide superconducting conductor obtained by forming the oxide superconducting thin film is low. On the other hand, the base material according to the present invention annealed at a temperature of 1100 ° C. or higher becomes smoother when the electrolytic polishing is performed after the final rolling, so that the oxide is formed on the base material through a polycrystalline oriented intermediate thin film. Jc of the oxide superconducting conductor obtained by forming the superconducting thin film is high.

It is sectional drawing which shows one Embodiment of the oxide superconductor of this invention. It is a schematic block diagram which illustrates the structure of the roll rolling apparatus used in the manufacturing method of this invention. It is a schematic block diagram which illustrates the annealing apparatus used in the manufacturing method of this invention. It is a block diagram which illustrates the ion beam assist sputtering apparatus used in the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Oxide superconducting conductor, 2, 21 ... Metal base material for oxide superconducting conductor, 3 ... 1st polycrystalline orientation intermediate thin film, 4 ... 1st polycrystalline orientation intermediate thin film, 5 ... Oxide superconducting thin film, 6 DESCRIPTION OF SYMBOLS ... Ag protective layer, 7 ... Ni base alloy base material, 8 ... Drive roll, 9 ... Roll, 10A ... Double rolling mill, 10B ... Triple rolling mill, 10C ... Quadruple rolling mill, 11 ... Supply bobbin, 12 ... Winding Take-up bobbin, 13 ... heating device, 22 ... substrate delivery bobbin, 23 ... substrate delivery bobbin, 24 ... substrate holder, 25 ... substrate take-up bobbin, 26 ... target, 27 ... cryopump, 28 ... rotary pump, 29 ... 1st filament type ion source, 30 ... 2nd filament type ion source.

Claims (2)

  A base material made of a Ni-based alloy containing Mo is subjected to at least one annealing at a temperature of 1100 ° C. or more and at least one rolling, and after the final rolling, electrolytic polishing is performed to provide a metal for an oxide superconducting conductor A method for producing a metal substrate for an oxide superconducting conductor, comprising obtaining a substrate. A base material made of a Ni-based alloy containing Mo is subjected to at least one annealing at a temperature of 1100 ° C. or more and at least one rolling, and after the final rolling, electrolytic polishing is performed to provide a metal for an oxide superconducting conductor Make the substrate,
Next, a polycrystalline oriented intermediate thin film is formed on the metal substrate for the oxide superconductor by an ion beam assist method,
Then, an oxide superconducting thin film is formed on the polycrystalline oriented intermediate thin film to obtain an oxide superconducting conductor.

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