High-density superconducting doped rare earth barium copper oxide and preparation method and application thereof

Abstract

The invention belongs to the technical field of superconducting materials, and particularly relates to a high-density superconducting doped rare earth barium copper oxide and a preparation method and application thereof. Single-phase rare earth barium copper oxide powder and doped phase powder are mixed and subjected to ball milling and then subjected to high-pressure forming, an obtained doped rare earth barium copper oxide blank is subjected to spark plasma sintering, and the high-density superconducting doped rare earth barium copper oxide is obtained. The chemical composition of the single-phase rare earth barium copper oxide powder is ReBa < 1.9-2 > Cu < 3 > O < 6.5-7 >, and Re is Eu, Gd, Y, Dy or Yb; the chemical composition of the doped phase powder is BaMO3, and M is Hf, Zr, Sn or Ir; the heat preservation time of the spark plasma sintering is 3 to 15 minutes. The density of the prepared high-density superconductive doped rare earth barium copper oxide is greater than or equal to 99.8%, the high density is achieved, and a superconductive film prepared from the high-density superconductive doped rare earth barium copper oxide is high in grain boundary connectivity.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting materials, and in particular relates to a high-density superconducting rare earth-doped barium copper oxide and a preparation method and application thereof. Background Art

[0002] High-temperature superconducting materials have great application value in the fields of magnetic levitation, magnetic high-speed bearings, energy storage, and nuclear magnetic resonance, and have great application potential in particle accelerators and temperature-controlled nuclear fusion magnetic confinement systems. As a typical second-generation high-temperature coating conductor material, rare earth barium copper oxide has performance advantages such as high Tc, high upper critical field, and high irreversible field. It is mainly deposited on a flexible metal substrate in the form of an epitaxial thin film for application. The mainstream production process of the superconducting layer in the current commercial high-performance high-temperature superconducting tape is pulsed laser deposition of doped rare earth barium copper oxide targets.

[0003] Due to the presence of nanoscale doping phase inside the rare earth barium copper oxide superconducting target, the density of the doped target prepared by cold pressing and hot pressing is low (less than 95%). The density of the target is an important factor affecting the preparation of superconducting films by pulsed laser deposition. Low density makes the grain boundary connectivity of the superconducting film weak. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a high-density superconducting rare earth doped barium copper oxide and its preparation method and application. The high-density superconducting rare earth doped barium copper oxide prepared by the present invention has high density, density ≥ 99.8%, and the superconducting film prepared by it has strong grain boundary connectivity.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a high-density superconducting rare earth-doped barium copper oxide, comprising the following steps:

[0007] The single-phase rare earth barium copper oxide powder and the doped phase powder are mixed and ball-milled and then high-pressure molded, and the obtained doped rare earth barium copper oxide green body is subjected to spark plasma sintering to obtain a high-density superconducting doped rare earth barium copper oxide;

[0008] The chemical composition of the single-phase rare earth barium copper oxide powder is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb;

[0009] The chemical composition of the doped phase powder is BaMO3, and M is Hf, Zr, Sn or Ir;

[0010] The heat preservation time of the spark plasma sintering is 3 to 15 minutes.

[0011] Preferably, the amount of the doping phase powder is 1 to 15% of the total amount of the single-phase rare earth barium copper oxide powder and the doping phase powder.

[0012] Preferably, the vacuum degree of the spark plasma sintering is 3-10 Pa and the temperature is 800-900°C.

[0013] Preferably, before spark plasma sintering, the method further comprises: placing the rare earth-doped barium copper oxide green body in a mold for pressurization;

[0014] The pressurization is maintained during the spark plasma sintering process; the pressurization pressure is 10-40 MPa.

[0015] Preferably, the heating rate to the spark plasma sintering temperature is 50-280° C. / min.

[0016] Preferably, the particle size of the single-phase rare earth barium copper oxide powder is ≤1 μm; and the particle size of the doped phase powder is 300-500 nm.

[0017] Preferably, the high pressure forming pressure is 20-80 MPa.

[0018] The present invention also provides a high-density superconducting doped rare earth barium copper oxide prepared by the preparation method described in the above technical solution, comprising a single-phase rare earth barium copper oxide and a doped phase;

[0019] The chemical composition of the single-phase rare earth barium copper oxide is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb;

[0020] The chemical composition of the doped phase is BaMO3, and M is Hf, Zr, Sn or Ir;

[0021] The density of the high-density superconducting rare earth-doped barium copper oxide is ≥99.8%.

[0022] The present invention also provides the use of the high-density superconducting rare earth-doped barium copper oxide described in the above technical solution as a sputtering target.

[0023] The present invention also provides a method for preparing a superconducting film, comprising the following steps: sputtering the high-density superconducting rare earth-doped barium copper oxide described in the above technical solution on a metal substrate to obtain the superconducting film.

[0024] The invention provides a preparation method of high-density superconducting doped rare earth barium copper oxide, comprising the following steps: mixing single-phase rare earth barium copper oxide powder and doped phase powder, ball milling and high-pressure molding, and performing spark plasma sintering on the obtained doped rare earth barium copper oxide blank to obtain high-density superconducting doped rare earth barium copper oxide; the chemical composition of the single-phase rare earth barium copper oxide powder is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb; the chemical composition of the doped phase powder is BaMO3, M is Hf, Zr, Sn or Ir; the insulation time of the spark plasma sintering is 3 to 15 minutes. The present invention ball-mills the raw materials to refine the particle size of the raw material particles, increases the density of the doped rare earth barium copper oxide blank by high pressure molding, and then completes the solid phase sintering and diffusion between the raw material particles in a short time by spark plasma sintering, reduces grain growth, makes the grains fine, and evenly distributes the matrix elements and internal doping phases of the high-density superconducting doped rare earth barium copper oxide, thereby improving the density of the high-density superconducting doped rare earth barium copper oxide. The high-density superconducting doped rare earth barium copper oxide prepared by the present invention has a high density, the density is ≥99.8%, and the superconducting film prepared by the present invention has strong grain boundary connectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the XRD pattern of the highly dense superconducting rare earth doped barium copper oxide prepared in Example 1;

[0026] Figure 2 This is a physical picture of the highly dense superconducting rare earth-doped barium copper oxide prepared in Example 1. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a high-density superconducting rare earth-doped barium copper oxide, comprising the following steps:

[0028] The single-phase rare earth barium copper oxide powder and the doped phase powder are mixed and ball-milled and then high-pressure molded, and the obtained doped rare earth barium copper oxide green body is subjected to spark plasma sintering to obtain a high-density superconducting doped rare earth barium copper oxide;

[0029] The chemical composition of the single-phase rare earth barium copper oxide powder is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb;

[0030] The chemical composition of the doped phase powder is BaMO3, and M is Hf, Zr, Sn or Ir;

[0031] The heat preservation time of the spark plasma sintering is 3 to 15 minutes.

[0032] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0033] The invention mixes single-phase rare earth barium copper oxide powder and doped phase powder, performs ball milling and then performs high pressure molding to obtain a doped rare earth barium copper oxide blank.

[0034] As an embodiment, the chemical composition of the single-phase rare earth barium copper oxide powder is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb, and is Eu in the specific embodiment; the chemical composition of the doped phase powder is BaMO3, and M is Hf, Zr, Sn or Ir, and is Hf in the specific embodiment.

[0035] In a specific embodiment, the chemical composition of the single-phase rare earth barium copper oxide powder is EuBa2Cu3O7, and the chemical composition of the doped phase powder is BaHfO3.

[0036] As an implementation mode, the amount of the doped phase powder is 1-15% of the total amount of the single-phase rare earth barium copper oxide powder and the doped phase powder, and is 6-15% in a specific embodiment; the particle size of the single-phase rare earth barium copper oxide powder is ≤1 μm, and is 1 μm in a specific embodiment; the particle size of the doped phase powder is 300-500 nm, and is 400-500 nm in a specific embodiment; the equipment used for the mixed ball milling is a powder mixer; the time of the mixed ball milling is 5-10 hours, and is 6-8 hours in a specific embodiment; the rotation speed of the mixed ball milling is 100-500 rpm, and is 300-500 rpm in a specific embodiment; the mixed ball milling is performed to obtain a mixed powder with a particle size of ≤1.5 μm, and is 1-1.5 μm in a specific embodiment. The present invention refines the particle size of the raw material particles by mixed ball milling of the raw materials, thereby improving the density of the doped rare earth barium copper oxide blank.

[0037] As an embodiment, the preparation method of the single-phase rare earth barium copper oxide powder comprises the following steps:

[0038] Rare earth oxide powder, copper oxide powder and barium oxide powder are mixed according to a stoichiometric ratio, and tableting, sintering, crushing and ball milling are repeated in sequence to obtain the single-phase rare earth barium copper oxide powder.

[0039] As an embodiment, the rare earth oxide powder is europium oxide (Eu2O3) powder, gadolinium oxide (Gd2O3) powder, yttrium oxide (Y2O3) powder, dysprosium oxide (Dy2O3) powder or ytterbium oxide (Yb2O3) powder, and in the specific embodiment it is europium oxide powder; the particle size of the rare earth oxide powder, copper oxide powder and barium oxide powder is independently ≤1.5μm, and in the specific embodiment it is 1.5μm, and the purity is independently ≥99.99%, and in the specific embodiment it is 99.99%.

[0040] As an embodiment, the mixing device is a powder mixer; the mixing time is 5 to 10 hours, and in the specific embodiment, it is 6 to 8 hours; the tablet sintering is carried out in the air; the tablet sintering temperature is 750 to 1000°C, and in the specific embodiment, it is 800 to 950°C, the pressure is 20 to 80MPa, and in the specific embodiment, it is 40 to 60MPa, and the insulation time is 10 to 50 hours, and in the specific embodiment, it is 30 to 50 hours; the speed of the ball mill is 200 to 300rpm, and in the specific embodiment, it is 200rpm; the ball milling time is 2 to 3h, and in the specific embodiment, it is 2h; the number of repetitions is 3 to 5 times, and in the specific embodiment, it is 5 times. The present invention prevents the composition of the single-phase rare earth barium copper oxide powder from being uneven by repeatedly repeating the process of tablet sintering, crushing and ball milling.

[0041] As an implementation mode, the pressure of the high pressure forming is 20-80 MPa, and in a specific embodiment, it is 40-60 MPa, and the holding time is 5-20 min, and in a specific embodiment, it is 15-20 min; the high pressure forming is performed at room temperature using a stainless steel tool. The present invention improves the density of the rare earth doped barium copper oxide blank by high pressure forming, thereby improving the density of the high-density superconducting rare earth doped barium copper oxide.

[0042] After obtaining the rare earth-doped barium copper oxide green body, the present invention performs spark plasma sintering on the rare earth-doped barium copper oxide green body to obtain the high-density superconducting rare earth-doped barium copper oxide.

[0043] As an embodiment, before spark plasma sintering, the process further includes: placing the rare earth-doped barium copper oxide green body in a mold for pressurization; maintaining the pressurization during the spark plasma sintering process; the pressurization pressure is 10 to 40 MPa, and in a specific embodiment, 20 to 40 MPa; the mold is a graphite grinder; and the inner diameter of the mold is equal to that of the rare earth-doped barium copper oxide green body. The present invention maintains the rare earth-doped barium copper oxide green body in a formed state through the mold and pressurization, improves the densification behavior during the subsequent sintering process, and improves the density of the high-density superconducting rare earth-doped barium copper oxide.

[0044] As an implementation mode, the vacuum degree of the spark plasma sintering is 3-10Pa, 4-7Pa in a specific embodiment, the temperature is 800-900°C, 850°C in a specific embodiment; the insulation time of the spark plasma sintering is 3-15min, 5-10min in a specific embodiment. The spark plasma sintering time in the present invention is within the above range, which can avoid insufficient density due to too short spark plasma sintering time, and can also avoid high temperature decomposition of materials due to too long spark plasma sintering time.

[0045] As an implementation method, the process of spark plasma sintering is as follows: inserting a thermocouple into the mold, evacuating the sintering chamber, and when the vacuum degree is reduced to the vacuum degree of spark plasma sintering, starting to energize and heat up for spark plasma sintering. The present invention evacuates the sintering chamber to prevent oxidation of the graphite mold.

[0046] The present invention uses spark plasma sintering to complete solid-phase sintering and diffusion between raw material particles in a short time, reduce grain growth, and improve the density of the target material. The large current of spark plasma sintering is conducive to promoting diffusion between raw material particles and reducing the diffusion activation energy between particles. The sintering time is measured in minutes; while the time of traditional hot pressing and cold pressing sintering methods is measured in days. The present invention can significantly reduce the preparation cycle of high-density superconducting rare earth doped barium copper oxide.

[0047] As an implementation manner, the heating rate to the spark plasma sintering temperature is 50 to 280° C. / min, and in a specific embodiment, it is 100 to 200° C. / min.

[0048] As an embodiment, after the spark plasma sintering, the method further includes: cooling the mold and the product obtained by the spark plasma sintering to room temperature; the cooling rate is 100-300°C / min, and in a specific embodiment, 150-250°C / min.

[0049] At present, the preparation scope of rare earth barium copper oxide superconducting target materials is limited to pure rare earth barium copper oxide superconducting target materials, and the preparation methods include cold pressing sintering, hot pressing sintering and spark plasma sintering. Patent CN116606131A prepares superconducting target materials by cold isostatic pressing sintering, which inhibits the performance of thin films; Patent CN118561589A prepares superconducting target materials with a density of up to 99.6% by ball milling-cold pressing-degreasing sintering, but there are still residual CuO impurity phases. Patent CN116023127A prepares superconducting YBCO target materials by spark plasma sintering with a density of 95%. Normal pressure sintering often requires the addition of organic binders to improve the density of superconducting target materials, and the long sintering time (not less than three days) leads to larger target grain size (hundreds of microns to several millimeters). The larger the target grains, the larger the grains of the thin film prepared by it, which reduces the superconducting performance of the film.

[0050] The present invention refines the particle size of the raw material particles by mixing and ball milling the raw materials, and the obtained precursor powder has a small particle size, and the discharge plasma sintering time is short (in minutes). The middle doping phase acts as a pinning center, which can inhibit the growth of the internal grains of the target material, so that the high-density superconducting doped rare earth barium copper oxide prepared by the preparation method of the present invention has fine grains and high density. Compared with the particle size of the mixed powder obtained after mixed ball milling, the final target material has a grain size that is only increased by 1.8% (1.53μm). The organic binder will remain in the matrix during the subsequent sintering process and eventually turn into C impurities. If the impurity phase is mixed into the superconducting film, the film performance will be seriously reduced; compared with the traditional hot pressing and cold pressing sintering methods for preparing doped rare earth barium copper oxide targets, the present invention does not need to add an organic binder to prepare the target blank, eliminates the associated residual carbon in the process of preparing the target material, and the high-density superconducting doped rare earth barium copper oxide matrix prepared by the method provided by the present invention has no impurity phase, and the impurity element content is ≤100mg / kg.

[0051] The present invention also provides a high-density superconducting doped rare earth barium copper oxide prepared by the preparation method described in the above technical solution, comprising a single-phase rare earth barium copper oxide and a doped phase;

[0052] The chemical composition of the single-phase rare earth barium copper oxide is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb;

[0053] The chemical composition of the doped phase is BaMO3, and M is Hf, Zr, Sn or Ir;

[0054] The density of the high-density superconducting rare earth-doped barium copper oxide is ≥99.8%.

[0055] As an embodiment, Re is Eu, M is Hf, the chemical composition of the single-phase rare earth barium copper oxide is EuBa2Cu3O7, and the chemical composition of the doped phase is BaHfO3.

[0056] As an implementation mode, the amount of the substance of the doping phase is 1-15% of the total amount of the single-phase rare earth barium copper oxide and the doping phase, and in a specific embodiment, it is 5-10%.

[0057] As an embodiment, the density of the high-density superconducting doped rare earth barium copper oxide is ≥99.8%, and in the specific embodiment it is 99.8-99.9%, and the impurity element content is ≤100 mg / kg, and in the specific embodiment it is 100 mg / kg; the impurity elements include Al, Ca, Cr, Fe, Mg, Si and Zn, and the grain size is ≤1.53 μm, and in the specific embodiment it is 1.53 μm.

[0058] The high-density superconducting rare earth-doped barium copper oxide prepared by the invention has high density, which is ≥99.8%, and the superconducting film prepared by the oxide has strong grain boundary connectivity.

[0059] At present, most rare earth barium copper oxide target materials are prepared based on a single phase. The present invention is the first scheme for preparing doped rare earth barium copper oxide superconducting target materials for sputtering. The doped rare earth barium copper oxide superconducting target materials are transformed into doped superconducting thin films through a coating process. The internal doped phase can be used as a site for magnetic flux pinning. Increasing the sites for magnetic flux pinning can improve its superconducting performance under high magnetic fields.

[0060] The present invention also provides the use of the high-density superconducting rare earth-doped barium copper oxide described in the above technical solution as a sputtering target.

[0061] The present invention also provides a method for preparing a superconducting film, comprising the following steps: sputtering the high-density superconducting rare earth-doped barium copper oxide described in the above technical solution on a metal substrate to obtain the superconducting film.

[0062] As an embodiment, the sputtering is pulsed laser deposition.

[0063] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0064] Example 1

[0065] Europium oxide (Eu2O3) powder with a purity of 99.99% and a particle size of 1.5 μm, copper oxide (CuO) powder and barium oxide (BaO) powder are configured according to a stoichiometric ratio, mixed by a powder mixer for 6 hours, and then pressed and sintered in air at 900°C and 60 MPa for 50 hours. The obtained pressed and sintered product is crushed and ball-milled at 200 rpm for 2 hours. The process of pressing, sintering, crushing and ball-milling is repeated 5 times to obtain a single-phase rare earth barium copper oxide powder (particle size of 1 μm, chemical composition of EuBa2Cu3O7);

[0066] The doped phase powder (BaHfO3, particle size of 500nm) and the above-mentioned single-phase rare earth barium copper oxide powder were mixed and ball-milled at 500rpm for 6h by a mixer, and the particle size of the obtained mixed powder was 1μm. High-pressure molding was performed by stainless steel tools at room temperature. The pressure of high-pressure molding was 60MPa and the holding time was 20min. The obtained rare earth doped barium copper oxide green body was transferred to the inside of a graphite mold for spark plasma sintering and pressurized. The pressure of the pressurization was 30MPa. The pressurization was maintained during the spark plasma sintering process. A thermocouple was inserted into the graphite mold. The sintering chamber was evacuated, and when the vacuum degree dropped to 5 Pa, the graphite mold began to be powered on and heated up, and the temperature was raised to 850°C at 200°C / min for spark plasma sintering for 10 minutes, and then the graphite mold and the product obtained by spark plasma sintering were cooled to room temperature at 200°C / min to obtain highly dense superconducting doped rare earth barium copper oxide (density of 99.8%, impurity element content of 100 mg / kg, grain size of 1.53 μm, of which the amount of BaHfO3 was 8% of the total amount of BaHfO3 and EuBa2Cu3O7).

[0067] Example 2

[0068] The difference from Example 1 is that the amount of BaHfO3 is 4.5% of the total amount of BaHfO3 and EuBa2Cu3O7, and the rest of the contents are the same as Example 1.

[0069] Example 3

[0070] The difference from Example 1 is that the amount of BaHfO3 is 6% of the total amount of BaHfO3 and EuBa2Cu3O7, and the rest of the contents are the same as Example 1.

[0071] Comparative Example 1

[0072] The difference from Example 1 is that the doped phase powder and the single-phase rare earth barium copper oxide powder are not mixed and ball-milled, but are directly subjected to high pressure molding. The rest of the contents are the same as Example 1.

[0073] Comparative Example 2

[0074] The difference from Example 1 is that high pressure forming is not performed, and the rest of the contents are the same as Example 1.

[0075] Comparative Example 3

[0076] The difference from Example 1 is that the temperature of spark plasma sintering is 1200° C., and the rest of the contents are the same as Example 1.

[0077] Application Example 1

[0078] The high-density superconducting rare earth-doped barium copper oxide prepared in Example 1 is subjected to pulsed laser deposition on a metal substrate to obtain a superconducting film.

[0079] Comparative application example 1

[0080] The difference from Application Example 1 is that the high-density superconducting rare earth-doped barium copper oxide prepared in Example 1 is replaced by the rare earth-doped barium copper oxide superconducting target prepared in Comparative Example 1.

[0081] Performance Testing

[0082] (1) Figure 1 This is the XRD pattern of the highly dense superconducting rare earth doped barium copper oxide prepared in Example 1. Figure 1 It can be seen that the peak positions of the high-density superconducting rare earth doped barium copper oxide phase and EuBa2Cu3O7 are exactly the same and there is no peak position of the impurity phase in the XRD.

[0083] (2) Figure 2 This is a physical picture of the highly dense superconducting rare earth doped barium copper oxide prepared in Example 1. Figure 2 It can be seen that the high-density superconducting rare earth-doped barium copper oxide prepared by the present invention has a smooth surface, a complete edge, and good formability.

[0084] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a highly dense superconducting rare earth doped barium copper oxide, characterized in that: The following steps are involved: The single-phase rare earth barium copper oxide powder and the doped phase powder are mixed and ball-milled and then high-pressure molded, and the obtained doped rare earth barium copper oxide green body is subjected to spark plasma sintering to obtain a high-density superconducting doped rare earth barium copper oxide; The chemical composition of the single-phase rare earth barium copper oxide powder is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb; The chemical composition of the doped phase powder is BaMO3, and M is Hf, Zr, Sn or Ir; The heat preservation time of the spark plasma sintering is 3 to 15 minutes.

2. The preparation method according to claim 1, characterized in that: The amount of the doped phase powder is 1-15% of the total amount of the single-phase rare earth barium copper oxide powder and the doped phase powder.

3. The preparation method according to claim 1, characterized in that: The vacuum degree of the spark plasma sintering is 3-10 Pa, and the temperature is 800-900°C.

4. The preparation method according to claim 1 or 3, characterized in that: Before spark plasma sintering, the method further includes: placing the rare earth-doped barium copper oxide green body in a mold for pressurization; The pressurization is maintained during the spark plasma sintering process; the pressurization pressure is 10-40 MPa.

5. The preparation method according to claim 3, characterized in that: The heating rate to the spark plasma sintering temperature is 50 to 280° C. / min.

6. The preparation method according to claim 1 or 2, characterized in that: The particle size of the single-phase rare earth barium copper oxide powder is ≤1 μm; the particle size of the doped phase powder is 300-500 nm.

7. The preparation method according to claim 1, characterized in that: The pressure of the high pressure forming is 20-80 MPa.

8. The high-density superconducting rare earth doped barium copper oxide prepared by the preparation method according to any one of claims 1 to 7, characterized in that: It includes a single phase rare earth barium copper oxide and a doped phase; The chemical composition of the single-phase rare earth barium copper oxide is ReBa 1.9～2 Cu3O 6.5～7 , Re is Eu, Gd, Y, Dy or Yb; The chemical composition of the doped phase is BaMO3, and M is Hf, Zr, Sn or Ir; The density of the high-density superconducting rare earth-doped barium copper oxide is ≥99.8%.

9. Use of the high-density superconducting rare earth-doped barium copper oxide according to claim 8 as a sputtering target.

10. A method for preparing a superconducting thin film, characterized in that: The method comprises the following steps: sputtering the high-density superconducting rare earth-doped barium copper oxide as claimed in claim 8 on a metal substrate to obtain the superconducting film.

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