High-temperature superconducting material filaring method based on decomposable template and step-by-step annealing, structure and power equipment

Abstract

The application discloses a high-temperature superconducting material filarization method, structure and power equipment based on a decomposable template and step-by-step annealing. A specific pattern of a heat-decomposable polymer template is ink-jet printed on a metal substrate with a buffer layer. After solidification, a REBCO precursor film is deposited, amorphous template destroys the epitaxial condition to form a superconducting interruption area. Finally, two-stage annealing is performed: first, the polymer template is completely decomposed into CO2 and H2O in a flowing oxygen-containing atmosphere and is discharged with the gas flow, and then the REBCO is crystallized into a phase, in-situ forming an isolated groove with an exposed buffer layer at the bottom, and a plurality of electrically isolated superconducting filaments are obtained. The application realizes non-contact, non-damage and flexible pattern filarization processing, completely avoids the pollution of the decomposition products of the template to the superconducting layer, the critical current retention rate is greater than or equal to 95%, the alternating current loss is effectively inhibited, the process is simple, green and environmentally friendly, and is suitable for large-scale manufacturing of superconducting power equipment.

Description

Technical Field

[0001] This invention relates to the field of high-temperature superconducting material preparation technology, specifically to a filamentation structure for reducing AC loss in second-generation high-temperature superconducting tapes (REBCO) and its preparation method, and more particularly to a filamentation method, structure, and power device for high-temperature superconducting materials based on a decomposable template and stepwise annealing. Background Technology

[0002] Second-generation high-temperature superconducting tapes (REBCO, such as YBCO) possess high critical current densities in the liquid nitrogen temperature range, showing broad application prospects in high-voltage fields such as superconducting cables, transformers, and current limiters. However, when transmitting alternating current or operating in an alternating magnetic field, wide superconducting layers exhibit significant AC losses, severely limiting their economic viability. Dividing the wide superconducting layer into multiple electrically insulated filaments (filamentization) is one of the most effective ways to suppress AC losses.

[0003] Currently, the mainstream technologies for achieving filamentation include laser scribing, photolithography and chemical etching, and ion irradiation. However, these methods all have significant drawbacks: laser scribing uses lasers to directly ablate the superconducting layer to form trenches, which generates a heat-affected zone, damages the superconducting layer and buffer layer, and causes a significant decrease in the critical current (Ic); photolithography and chemical etching processes are complex, use a large number of chemical reagents (such as photoresist, developer and etchant), are costly and pollute the environment, and have poor pattern flexibility; ion irradiation equipment is expensive, has low processing efficiency, and may introduce lattice defects.

[0004] Furthermore, some studies have attempted to utilize sacrificial layer technology. However, ensuring the complete and clean removal of the sacrificial layer without contaminating atmosphere-sensitive superconducting materials (e.g., avoiding the reaction of CO2 with barium in YBCO to form barium carbonate) remains a well-solved technical challenge. For instance, the known approach of using inkjet-printed BTO (barium titanate) insulating wires as permanent insulators achieves filament thinning, but BTO itself reduces the effective area of ​​the superconducting layer and cannot be removed. On the other hand, the approach using water-soluble sacrificial layers is incompatible with high-temperature MOCVD (metal-organic chemical vapor deposition) deposition processes and does not involve filament thinning patterns.

[0005] Therefore, developing a new filamentation method that is non-destructive, simple in process, flexible in patterning, and can ensure the purity of the superconducting layer has important practical value. Summary of the Invention

[0006] The purpose of this invention is to provide a method, structure, and power device for filamentation of high-temperature superconducting materials based on a decomposable polymer template and stepwise annealing, so as to overcome the defects of physical damage, chemical pollution, complex process, or inflexible pattern in the prior art, and to achieve high-quality filamentation preparation that is non-contact, non-damaging, flexible in pattern, and can completely avoid template residue pollution.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for filamentizing high-temperature superconducting materials based on a decomposable template and stepwise annealing, comprising the following steps: S1: Provides a metal substrate with a buffer layer; S2: On the buffer layer, a polymer template is prepared according to a predetermined pattern. The polymer template is made of a polymer with a residual carbon rate of less than 1% after thermal decomposition in an oxygen-containing atmosphere, and the polymer template is amorphous at the deposition temperature. S3: The polymer template is cured to shape it into a raised structure with clear boundaries; S4: Deposit a precursor film of the second-generation high-temperature superconducting material REBCO on a substrate with a solidified template using at least one of the following deposition processes: metal-organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), radio frequency magnetron sputtering deposition (RF-MS), electron beam evaporation deposition (EBE), trifluoroacetate metal-organic solution deposition (TFA-MOD), or sol-gel deposition (Sol-Gel), at a deposition temperature of 700℃-850℃; S5: The deposited sample undergoes a two-stage annealing process, including: S5a: In the first temperature range T1, in a flowing oxygen-containing atmosphere, the polymer template is completely decomposed into gaseous products and discharged from the reaction zone with the gas flow. The first temperature range T1 is 300°C to 450°C, and the gas flow rate of the oxygen-containing atmosphere is not less than 100 sccm. S5b: In the second temperature range T2, in an oxygen-containing atmosphere, the REBCO precursor film is crystallized into a c-axis oriented REBCO superconducting thin film, where the second temperature range T2 is 500°C to 700°C. The decomposition process in step S5a is completed before the crystallization process in step S5b begins, thereby transforming the polymer template into isolation trenches in situ, resulting in a filamentary structure composed of multiple superconducting filaments, and the bottom of the isolation trenches is an exposed buffer layer surface.

[0009] Furthermore, in step S5, the heating rate between T1 and T2 is 2-10℃ / min; the holding time in step S5a is 10-60 minutes, and the holding time in step S5b is 30-180 minutes.

[0010] Furthermore, after step S5a is completed and before step S5b begins, the residual carbon content in the reaction chamber is less than 10 ppm.

[0011] Further, in step S2, the polymer template is prepared by one of inkjet printing, aerosol jet printing or micro-contact printing; the predetermined pattern is a straight line, wave or grid pattern with a width of 1μm to 20μm.

[0012] Furthermore, the polymer template material is selected from one or more combinations of polyethylene glycol, polyvinylpyrrolidone, and polyethylene oxide, and the molecular weight of the polymer is 2000~100000.

[0013] Further, in step S3, the curing treatment method is thermal curing or photocuring: the thermal curing is carried out in air or inert atmosphere at 150℃~350℃ for 1~10 minutes; the photocuring is irradiated with ultraviolet light with wavelength of 200nm~400nm and intensity of 10mW / cm²~500 mW / cm² for 10 seconds~10 minutes.

[0014] Furthermore, in step S4, the thickness of the deposited precursor film is 0.5 μm to 3.0 μm.

[0015] Secondly, the present invention provides a high-temperature superconducting material filament structure based on a decomposable template and stepwise annealing, which is prepared by the above method and includes a metal substrate, a buffer layer disposed on the metal substrate, and a REBCO superconducting layer disposed on the buffer layer, which is composed of multiple electrically isolated superconducting filaments. The superconducting filaments are separated by isolation trenches, the bottom of the isolation trenches is the exposed surface of the buffer layer, and the REBCO superconducting layer on the sidewall of the trenches has a clear boundary without a heat-affected zone.

[0016] Furthermore, the width of the superconducting filament is 10μm~100μm, and the width of the isolation trench is 1μm~20μm; the critical current retention rate of the superconducting filament is not less than 95%.

[0017] Thirdly, the present invention provides a superconducting power device comprising the above-mentioned filamentation structure of high-temperature superconducting material based on a decomposable template and stepwise annealing, wherein the superconducting power device is a superconducting cable, a superconducting transformer, or a superconducting current limiter.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. High retention of superconducting properties: This invention forms a natural isolation zone by destroying the epitaxial growth conditions of the deposition process using an amorphous polymer template, eliminating the need for physical etching such as lasers and ion beams, thus avoiding heat-affected zones and lattice damage, and achieving a critical current (Ic) retention rate of over 95%.

[0019] 2. No Chemical Pollution: This invention employs a two-stage "time-decoupled" annealing process. First, the polymer template is completely decomposed into CO2 and H2O in flowing oxygen at 300-450℃ and forcibly discharged, ensuring that the residual carbon content in the reaction chamber is below 10ppm. Then, the temperature is raised to 500-700℃ to allow REBCO to crystallize. This design completely avoids the reaction of decomposition products (especially CO2) with barium in REBCO to form barium carbonate impurities, solving the long-standing pollution problem in the field of sacrificial layer technology.

[0020] 3. Extremely flexible pattern design: This invention uses digital additive manufacturing technologies such as inkjet printing to prepare polymer templates, which can easily achieve rapid switching of various complex patterns such as straight lines, curves, and grids, meeting the personalized needs of different application scenarios for AC loss suppression.

[0021] 4. Simple process and environmentally friendly: This invention eliminates many complex processes such as photolithography and etching, greatly simplifying the process flow and increasing production efficiency; the polymer decomposition products are only CO2 and H2O, with no toxic chemical waste liquid, which is in line with the concept of green manufacturing.

[0022] 5. Integrity of structure and absence of heat-affected zone: The bottom of the resulting isolation trench is an exposed buffer layer with clear sidewall boundaries and no residual stress or recrystallization layer, ensuring reliable electrical isolation between superconducting filaments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the preparation process in an embodiment of the present invention; Figure 2 This is a schematic diagram of the filamentized superconducting tape structure prepared according to an embodiment of the present invention.

[0025] In the figure: 1-metal substrate, 2-buffer layer, 3-polymer template, 4-precursor film, 5-superconducting filament, 6-isolation trench, 7-silver layer, 8-copper layer. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Example 1: Preparation of YBCO tape with straight filaments This embodiment provides a method for filamentizing high-temperature superconducting materials based on a decomposable template and stepwise annealing, combined with... Figure 1 The method described in this embodiment includes the following steps: S1: Substrate preparation This step provides a metal substrate 1 with a buffer layer 2. Specifically, a second-generation superconducting substrate (such as a Hastelloy substrate) prepared using commercial RABiTS or IBAD technology is selected as the metal substrate 1. The substrate has a buffer layer 2 deposited on it, which has a structure of NiW alloy / Al2O3 buffer layer / LaMnO3 epitaxial layer (total thickness of approximately 100 μm).

[0029] S2: Polymer template preparation In this step, a polymer template 3 is prepared on the buffer layer 2 according to a predetermined pattern. The polymer template 3 is made of a polymer with a residual carbon rate of less than 1% after thermal decomposition in an oxygen-containing atmosphere, and the polymer template 3 is amorphous at the deposition temperature. The preparation process of the polymer template 3 is one of inkjet printing, aerosol jet printing, or micro-contact printing. The predetermined pattern is a straight line, wavy line, or grid pattern with a width of 1μm to 20μm. The material of the polymer template 3 is selected from one or a combination of polyethylene glycol, polyvinylpyrrolidone, and polyethylene oxide, and the molecular weight of the polymer is 2000 to 100000. Specifically, in this embodiment, polyethylene glycol (PEG-10000) with a molecular weight of 10000 is selected, and its residual carbon rate is 0.3% as determined by thermogravimetric analysis. The polymer is dissolved in deionized water to prepare an 8 wt% solution, which is then filtered through a 0.2μm filter membrane. A piezoelectric inkjet printing system was used to print a set of parallel straight lines with a width of 10μm and a spacing of 150μm on the surface of the buffer layer.

[0030] S3: Curing process This step involves curing the polymer template 3 to shape it into a raised structure with clear boundaries. The curing method is either thermosetting or photosetting: thermosetting is performed at 150℃~350℃ in air or an inert atmosphere for 1~10 minutes; photosetting involves irradiating the sample with ultraviolet light at a wavelength of 200nm~400nm and an intensity of 10 mW / cm²~500 mW / cm² for 10 seconds~10 minutes. Specifically, this embodiment uses thermosetting: the printed sample is placed in a rapid annealing furnace and treated in an air atmosphere at 250℃ for 3 minutes to cure the PEG filaments, forming a raised template with clear boundaries to prevent deformation in subsequent processes.

[0031] S4: Pre-deposited membrane This step employs at least one of the following deposition processes: metal-organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), radio frequency magnetron sputtering deposition (RF-MS), electron beam evaporation deposition (EBE), trifluoroacetate metal-organic solution deposition (TFA-MOD), or sol-gel deposition (Sol-Gel) to deposit a precursor film 4 of the second-generation high-temperature superconducting material REBCO on a substrate with a solidified template. The deposition temperature is 700℃-850℃, and the thickness of the deposited precursor film 4 is 0.5μm~3.0μm.

[0032] This embodiment uses metal-organic chemical vapor deposition (MOCVD) for illustration. Specifically, the sample is fed into an MOCVD apparatus, and under conditions of 780°C and appropriate oxygen partial pressure, organometallic precursors of Y, Ba, and Cu (such as β-diketone complexes) are introduced to deposit a 1.0 μm thick YBCO precursor film (i.e., a superconducting layer). Above the PEG template, due to the amorphous template disrupting the epitaxial growth conditions, the YBCO grows non-epitaxically or polycrystallinely and does not possess superconducting properties. Specifically, the polymer template 3, due to its amorphous structure, disrupts the lattice matching conditions for the epitaxial growth of the superconducting material, preventing the formation of high-performance superconducting grains in the region above the template, thus creating a superconducting performance interruption region.

[0033] S5: Two-stage annealing process The deposited samples were subjected to a two-stage annealing process, including S5a and S5b.

[0034] S5a (Template Decomposition): In the first temperature range T1, under a flowing oxygen-containing atmosphere, the polymer template 3 is completely decomposed into gaseous products and discharged from the reaction zone with the gas flow. The first temperature range T1 is 300℃ to 450℃, the heating rate is 2-10℃ / min, and the holding time is 10-60 minutes; the gas flow rate of the oxygen-containing atmosphere is not less than 100 sccm. Specifically, in this embodiment, the sample is transferred to a tubular annealing furnace, heated to 400℃ at a rate of 5℃ / min in pure oxygen at a flow rate of 200 sccm, and held for 30 minutes. During this stage, the PEG template is fully decomposed into CO2 and H2O, which are carried out of the reaction zone by the gas flow. Gas chromatography detection shows that after step S5a and before step S5b, the residual carbon content in the reaction chamber is less than 10 ppm (the measured value is 3 ppm).

[0035] S5b (REBCO Crystallization): In the second temperature range T2, under an oxygen-containing atmosphere, the REBCO precursor film 4 is crystallized into a c-axis oriented REBCO (YBCO) superconducting thin film. The second temperature range T2 is 500℃ to 700℃, the heating rate is 2-10℃ / min, and the holding time is 30-180 minutes. Specifically, in this embodiment, the furnace temperature is further increased to 600℃ at the same heating rate (5℃ / min), and annealed at this temperature for 120 minutes to fully oxidize and crystallize the YBCO into a c-axis oriented high-performance superconducting thin film.

[0036] In this process, the decomposition process in step S5a is completed before the crystallization process in step S5b begins, thereby transforming the polymer template 3 into an isolation trench 6 in situ, resulting in a filamentous structure composed of multiple superconducting filaments 5, and the bottom of the isolation trench 6 is the exposed surface of the buffer layer 2.

[0037] In the resulting filamentized superconducting tape, an isolation trench 6 with a width of approximately 10 μm is formed at the original PEG template location, with the bottom of the trench being the exposed surface of the buffer layer 2; the width of the adjacent superconducting filament 5 is approximately 140 μm. Scanning electron microscopy observation shows that the REBCO superconducting layer on the trench sidewall has a clear boundary with no heat-affected zone. The critical current retention rate of the superconducting filament 5 (i.e., the ratio of the critical current after filamentization to the critical current of the original tape) measured using the standard four-wire method is not less than 95% (96.5% in this example), and X-ray photoelectron spectroscopy (XPS) analysis did not detect any carbon or barium carbonate residues, confirming that the residual carbon content is less than 10 ppm.

[0038] Example 2 The difference between this embodiment and Embodiment 1 is that: Polymer template 3 is made of polyvinylpyrrolidone (PVP K30, molecular weight approximately 40,000), and the solvent is ethanol, with a molecular weight in the range of 2,000 to 100,000. The residual carbon content of this polymer was tested to be 0.5%.

[0039] The predetermined pattern is a periodic wavy filament with a width of 5μm and a spacing of 100μm.

[0040] The curing process uses light curing: ultraviolet light wavelength 300nm, intensity 200 mW / cm², irradiation for 5min.

[0041] In the two-stage annealing process, the temperature of S5a is 350℃ and the holding time is 20 minutes; the temperature of S5b is 620℃ and the holding time is 90 minutes; the heating rate is 8℃ / min and the gas flow rate is 150 sccm.

[0042] The resulting wavy superconducting filament also exhibited excellent superconducting properties, with a critical current retention rate of 95.8%, a residual carbon content of 4 ppm in the reaction chamber, and clear trench sidewalls without a heat-affected zone. The wavy filament structure further reduced AC losses.

[0043] Example 3 This embodiment changes the precursor film thickness and annealing parameters, following the basic steps of Embodiment 1, only adjusting the following parameters: The thickness of the MOCVD deposited precursor film is 2.5 μm (in the range of 0.5 μm to 3.0 μm).

[0044] S5a: Temperature 400℃, hold for 45 minutes, oxygen flow rate 300 sccm.

[0045] S5b: Temperature 650℃, hold for 150 minutes, heating rate 3℃ / min.

[0046] In the obtained filamentary structure, the width of the superconducting filament 5 is 100 μm, and the width of the isolation trench 6 is 15 μm (the width of the superconducting filament is 10 μm to 100 μm, and the width of the isolation trench is 1 μm to 20 μm). The critical current retention rate is 97.2%, and the residual carbon content is 2 ppm. The REBCO superconducting layer on the trench sidewall has a clear boundary without a heat-affected zone.

[0047] Comparative example: To verify the effectiveness of this invention, trenches with a width of 10 μm were fabricated on the same YBCO tape using a conventional laser scribing method. The results showed that a significant heat-affected zone existed at the edge of the laser-etched area, the critical current of the superconducting filament decreased by approximately 25%, the critical current retention rate was only about 75%, and reconstituted layers and microcracks were present on the trench sidewalls. In contrast, Example 1 of this invention achieved a critical current retention rate as high as 96.5%, and the trench sidewalls were clear and free of thermal damage, demonstrating significant advantages.

[0048] Example 4 This embodiment provides a high-temperature superconducting material filament structure based on a decomposable template and stepwise annealing prepared according to the above method, as well as a superconducting power device, such as... Figure 2 As shown, the filamentary structure includes a metal substrate 1 (Hastelloy alloy substrate), a buffer layer 2 disposed on the metal substrate 1, and a REBCO superconducting layer disposed on the buffer layer 2, consisting of multiple electrically isolated superconducting filaments 5. The superconducting filaments 5 are separated by isolation trenches 6, the bottom of which is the exposed surface of the buffer layer 2, and the REBCO superconducting layer on the sidewalls of the trenches has a clear boundary with no heat-affected zone. The width of the superconducting filaments 5 is 10 μm to 100 μm, and the width of the isolation trenches 6 is 1 μm to 20 μm; the critical current retention rate of the superconducting filaments 5 is not less than 95%.

[0049] like Figure 2 As shown, in practical applications of high-temperature superconducting tapes, a silver layer 7 and a copper layer 8 can be disposed below the metal substrate 1, and a silver layer 7 and a copper layer 8 can be disposed above the superconducting layer. These silver and copper layers serve as conventional stabilizing and protective layers, providing overcurrent shunt channels and mechanical protection.

[0050] This filamentary structure is applied to superconducting power devices, such as superconducting cables, superconducting transformers, or superconducting current limiters. Because the superconducting layer is divided into multiple electrically isolated filaments, AC losses are significantly reduced, and the operational stability of the equipment is improved. Tests show that a superconducting cable model incorporating the filamentary structure of this invention exhibits approximately 70% lower AC losses at 50Hz compared to the non-filamentary tape.

[0051] In summary, the high-temperature superconducting material filamentation method based on decomposable templates and stepwise annealing provided in this invention is simple, low-cost, pollution-free, has a high critical current retention rate, and offers flexible patterns. It is suitable for large-scale manufacturing of high-performance filamentized tapes required for superconducting power equipment and has significant industrial applicability.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for filamentizing high-temperature superconducting materials based on decomposable templates and stepwise annealing, characterized in that, Includes the following steps: S1: Provide a metal substrate (1) with a buffer layer (2); S2: On the buffer layer (2), a polymer template (3) is prepared according to a predetermined pattern. The material of the polymer template (3) is a polymer with a carbon residue rate of less than 1% after thermal decomposition in an oxygen-containing atmosphere, and the polymer template (3) is amorphous at the deposition temperature. S3: The polymer template (3) is cured to shape it into a raised structure with clear boundaries; S4: Deposit a precursor film of second-generation high-temperature superconducting material REBCO on a substrate with a solidified template using at least one of the following deposition processes: metal-organic chemical vapor deposition, pulsed laser deposition, radio frequency magnetron sputtering deposition, electron beam evaporation deposition, trifluoroacetate metal-organic solution deposition or sol-gel deposition (4). S5: The deposited sample undergoes a two-stage annealing process, including: S5a: In the first temperature range T1, in a flowing oxygen-containing atmosphere, the polymer template (3) is completely decomposed into gaseous products and discharged from the reaction zone with the gas flow. The first temperature range T1 is 300°C to 450°C, and the gas flow rate of the oxygen-containing atmosphere is not less than 100 sccm. S5b: In the second temperature range T2, in an oxygen-containing atmosphere, the REBCO precursor film (4) is crystallized into a c-axis oriented REBCO superconducting film, where the second temperature range T2 is 500°C to 700°C. The decomposition process in step S5a is completed before the crystallization process in step S5b begins, thereby transforming the polymer template (3) into an isolation trench (6) in situ, resulting in a filamentous structure composed of multiple superconducting filaments (5), and the bottom of the isolation trench (6) is the exposed surface of the buffer layer (2).

2. The method according to claim 1, characterized in that, In step S5, the heating rate between T1 and T2 is 2-10℃ / min; the holding time in step S5a is 10-60 minutes, and the holding time in step S5b is 30-180 minutes.

3. The method according to claim 1, characterized in that, After step S5a is completed and before step S5b begins, the residual carbon content in the reaction chamber is less than 10 ppm.

4. The method according to claim 1, characterized in that, In step S2, the polymer template (3) is prepared by one of inkjet printing, aerosol jet printing or micro-contact printing; the predetermined pattern is a straight line, wave or grid with a width of 1μm to 20μm.

5. The method according to claim 1, characterized in that, The polymer template (3) is made of one or more of polyethylene glycol, polyvinylpyrrolidone, and polyethylene oxide, and the molecular weight of the polymer is 2,000 to 100,000.

6. The method according to claim 1, characterized in that, In step S3, the curing method is thermal curing or photocuring: thermal curing is carried out in air or inert atmosphere at 150℃~350℃ for 1~10 minutes; photocuring is carried out by irradiation with ultraviolet light with wavelength of 200nm~400nm and intensity of 10 mW / cm²~500 mW / cm² for 10 seconds~10 minutes.

7. The method according to claim 1, characterized in that, In step S4, the thickness of the deposited precursor film (4) is 0.5 μm to 3.0 μm.

8. A high-temperature superconducting material filament structure based on a decomposable template and stepwise annealing, prepared by the method described in any one of claims 1-7, characterized in that, The device includes a metal substrate (1), a buffer layer (2) disposed on the metal substrate (1), and a REBCO superconducting layer disposed on the buffer layer (2) consisting of multiple electrically isolated superconducting filaments (5), wherein the superconducting filaments (5) are separated by isolation trenches (6), the bottom of the isolation trenches (6) is the exposed surface of the buffer layer (2), and the REBCO superconducting layer on the sidewall of the trench has a clear boundary without a heat-affected zone.

9. The structure according to claim 8, characterized in that, The width of the superconducting filament (5) is 10μm to 100μm, and the width of the isolation trench (6) is 1μm to 20μm; the critical current retention rate of the superconducting filament (5) is not less than 95%.

10. A superconducting power device, characterized in that, The device comprises the high-temperature superconducting material filament structure based on a decomposable template and stepwise annealing as described in claim 8 or 9, wherein the superconducting power device is a superconducting cable, a superconducting transformer, or a superconducting current limiter.

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