A Gd2(Ba 4-r Sr r )CuZrO y Nanopowder and method of manufacture and single domain bulk gadolinium barium copper oxide superconductor and method of manufacture

Abstract

This invention provides a Gd2(Ba 4‑r Sr r CuZrO y Nanoparticles and a method for improving the properties of single-domain gadolinium barium copper oxide superconducting bulk materials using the same, wherein the nanoparticles, based on 100 moles, have the following molar ratios: 1 mole of Gd₂O₃, 0-4 moles of BaCO₃, 0-4 moles of SrCO₃, 1 mole of CuO, and 1 mole of ZrO₂; the chemical formula of the nanoparticles is Gd₂(Ba 4‑r Sr r CuZrO y Where r takes values ​​in the range 0 ≤ r ≤ 4, and y is in Gd2(Ba 4‑r Sr r CuZrO y The oxygen content in the powder; this invention replaces RE2Ba4CuMO with Sr element. y A method for extracting Ba from phases (M = U, Mo, Zr, Bi, Nb, W, ...) has led to the development of a chemically stable Gd2(Ba) phase. 4‑r Sr r CuZrO y (r=0, 1, 2, 3, 4) nanoparticles and their complete preparation method, using Gd2(Ba 4‑r Sr r CuZrO y Nanoparticle doping improves the flux pinning ability and superconducting performance of GdBCO superconducting bulk materials.

Description

Technical Field

[0001] This invention belongs to the technical field of high-temperature copper oxide superconducting materials, specifically relating to a Gd2(Ba) superconducting material. 4-r Sr r CuZrO y Nanoparticles and their manufacturing methods, as well as single-domain gadolinium barium copper oxide superconducting bulk materials and their manufacturing methods. Background Technology

[0002] In 1987, Y-Ba-Cu-O (YBCO) superconductors with critical transition temperatures higher than liquid nitrogen were discovered. Subsequently, by replacing Y with elements such as Gd, Yb, and Sm, it was found that the critical transition temperatures of these superconductors were also around 90K. These superconductors are called rare-earth copper-based oxide superconductors, generally written as RE-Ba-Cu-O (REBCO). Among them, single-domain GdBCO superconducting bulk materials are one of the most widely used high-temperature superconducting bulk materials. Single-domain REBCO superconducting bulk materials have broad application prospects in magnetic bearings, current leads, wastewater purification, and magnetic levitation trains due to their high critical temperature, large critical current density, strong flux trapping ability, large magnetic levitation force, and good self-stabilizing magnetic levitation performance. These superconducting properties gradually decay over time; therefore, improving the flux pinning ability, superconducting performance, and stability of REBCO bulk materials is of great significance.

[0003] In terms of preparation methods, the process has evolved from solid-state sintering, melting, top-seeded crystal melting and texturing, to top-seeded crystal infiltration (TSIG), and the preparation methods have now become relatively mature. In the exploration of superconductors, it has been discovered that certain defects in the crystal itself can enhance pinning, such as dislocations and twins. The magnetic flux pinning ability can be enhanced in the following ways: 1. Optimizing the heat treatment process to reduce Y2BaCuO5 (Y211) particles; 2. Using particle bombardment and high-energy particle radiation to generate tiny intrinsic defects; 3. Doping and injecting fine second-phase particles. Introducing even finer non-superconducting phase particles to improve magnetic flux pinning force and superconducting performance has always been a hot research topic. Babu et al. discovered a new type of fine-grained non-superconducting second-phase particle, Y2Ba4CuUO, in textured YBCO samples doped with UO2. y Building upon this, Babu and Cardwell et al. investigated RE₂Ba₄CuMO by substituting U. yThe effects of REM2411 (M = Bi, Nb, U, Ta, Mo, W…) particle doping on the microstructure and superconducting properties of REBCO superconductors were investigated. Results showed that single-phase REM2411 particles could be prepared via a solid-state reaction method. During the melting and growth of the REBCO superconductor, REM2411 particles did not chemically react with the Ba-Cu-O liquid phase, exhibiting good chemical stability and no particle coarsening. This method effectively introduced REM2411 particles into the REBCO superconductor without complex chemical preparation methods or lengthy ball milling processes. The particle size ranged from approximately 20 to 500 nm, and the artificial flux pinning centers evolved from RE211 to RE2411. Compared to RE211, RE2411 particles were significantly smaller. The morphology of REM2411 particles included dot-like, needle-like, and rice-grain-like forms, with the specific shape depending on the RE and M elements. Doping with appropriate amounts of REM2411 particles can significantly improve the magnetic flux pinning force, critical current density, trapping magnetic flux density, and magnetic levitation force of REBCO superconductors.

[0004] REBCO superconducting bulk materials have attracted much attention due to their excellent superconducting properties, such as superior flux trapping ability, large magnetic levitation force, and good self-stabilizing magnetic levitation characteristics. However, these superconducting properties gradually decay over time under environmental influences. Increasing the number of flux pinning centers can mitigate this problem. Many artificial flux pinning centers are known, but their application is limited, mainly due to two reasons: their high cost and the potential negative impact on the superconducting performance of the bulk material. RE2411 particles are small and stable, do not chemically react with the Ba-Cu-O liquid phase, exhibit good chemical stability, and do not show particle coarsening. They can effectively introduce nano- to submicron-sized RE2411 particles into REBCO superconductors without complex chemical preparation methods or lengthy ball milling processes, forming effective flux pinning centers in the REBCO superconducting bulk material. However, how to optimize RE2Ba4CuMO... y The research and development of novel nanomaterials capable of serving as effective flux pinning centers has been ongoing. How can the critical current density, magnetic levitation force, and trapping magnetic field of REBCO superconducting bulk materials be improved by doping with these novel nanoparticles? These questions have remained largely unanswered since the discovery of RE2411 phase nanoparticles, significantly limiting the development of REBCO superconducting bulk materials. By replacing Ba in the RE2411 phase with Sr, we have invented a Gd2(Ba) nanoparticle... 4-r Sr r CuZrO y(r=0, 1, 2, 3, 4) nanoparticles were obtained, and the effect of their doping on the performance of GdBCO superconducting bulk materials was studied. This is of great significance for further improving the performance of GdBCO superconducting bulk materials. Summary of the Invention

[0005] By replacing the Ba element in the RE2411 phase with the Sr element, we invented a Gd2(Ba) 4-r Sr r CuZrO y (r=0, 1, 2, 3, 4) nanoparticles were used, and the effect of their doping on the properties of GdBCO superconducting bulk materials was investigated.

[0006] The purpose of this invention is to provide a nanopowder with the following molar ratio: 1 mole of Gd₂O₃, 0 to 4 moles of BaCO₃, 0 to 4 moles of SrCO₃, 1 mole of CuO, and 1 mole of ZrO₂; the chemical formula of the nanopowder is Gd₂(Ba 4-r Sr r CuZrO y Where r takes values ​​in the range 0 ≤ r ≤ 4, and y is in Gd2(Ba 4-r Sr r CuZrO y The oxygen content in the powder.

[0007] Furthermore, the Sr element can be replaced with any one of La, Nd, Sm, Eu, and Pr, and the element can also be replaced with any one of U, Mo, Bi, Nb, and W.

[0008] Furthermore, the method for preparing the nanopowder includes the following steps:

[0009] S1: Prepare Gd2O3, BaCO3, SrCO3, CuO, and ZrO2 with a purity of 99.0% and mix them in a molar ratio;

[0010] S2: The mixed powder from step S1 is placed in a zirconium oxide container, alcohol is added, and after wet mixing, it is placed in a planetary ball mill and ball-milled for 4 hours.

[0011] S3: Pour the wet-mixed powder into a glass dish and let it stand until it dries. Then, put it into a mortar and grind it by hand.

[0012] S4: The dried powder is placed in a high-temperature furnace and sintered three times at temperatures T (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃).

[0013] S5: The powder from step 4 is subjected to three sintering processes and four ball milling processes to obtain Gd2(Ba4-r Sr r )CuZrO y powder

[0014] Furthermore, a single-domain gadolinium barium copper oxide superconducting bulk material, wherein the doping amount of Gd2Ba4CuZrO y is between 0 < x ≤ 6 wt%.

[0015] Furthermore, a single-domain gadolinium barium copper oxide superconducting bulk material, wherein the Gd2Ba 4-r Zr r The doping amount of CuZrOy is between 0 < x ≤ 4 wt%, where the value of r is 1, 2, 3, 4.

[0016] Furthermore, the preparation method of the above-mentioned single-domain gadolinium barium copper oxide superconducting bulk material includes the following steps:

[0017] M1: Prepare a neodymium barium copper oxide seed crystal;

[0018] M2: Prepare BaCuO2 powder: Mix BaCO3 and CuO evenly in a molar ratio of 1:1, and use the solid-state reaction method to sinter three times and ball-mill four times at 897 °C, 900 °C, and 903 °C respectively to prepare BaCuO2 powder;

[0019] M3: Prepare a solid-phase precursor block;

[0020] M4: Prepare a liquid-phase precursor block;

[0021] M5: Weigh 5 g of Y2O3 and press it into a support block with the same diameter as the liquid-phase precursor block, prepare several MgO single-crystal blocks, and prepare Al2O3 gaskets;

[0022] M6: Assemble the blank: Arrange multiple MgO single-crystal blocks at intervals on the Al2O3 gasket, and place the corresponding precursor blocks in the order of the support block, liquid-phase precursor block, and solid-phase precursor block from bottom to top on the surface layer of the upper part of the MgO single crystal. Place the neodymium barium copper oxide seed crystal at the center position of the upper surface of the solid-phase precursor block, and make its ab plane parallel to the surface of the solid-phase precursor block;

[0023] M6: Put the assembled blank into a high-temperature furnace. First, raise the temperature to 910 °C at a speed of 150 °C / h and maintain this temperature for 10 h; then heat it to 1062 °C at a rate of 120 °C / h and keep it warm for 2 h to fully melt the liquid-phase source block and infiltrate it into the solid-phase precursor block; then quickly lower the temperature to 1043 °C at a speed of 30 °C / h, and then slowly lower it to 1021 °C at a speed of 0.44 °C / h; then gradually lower the temperature to room temperature at a speed of 145 °C / h to complete the growth process of the single-domain gadolinium barium copper oxide bulk material induced by the seed crystal;

[0024] M7: Oxygen permeation treatment: The single-domain gadolinium barium copper oxide block is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 410℃~440℃ in a flowing oxygen atmosphere to obtain the single-domain gadolinium barium copper oxide superconducting block.

[0025] Furthermore, the specific process for preparing the Nd:barium copper oxide seed crystal in M1 is as follows:

[0026] M11: Preparation of Nd2O3 powder: Nd2O3, BaCO3, and CuO powders were mixed evenly in a molar ratio of 1:4:6. The mixture was then subjected to three sintering processes at 910℃ using a solid-state reaction method, followed by four ball milling processes to produce NdBa2Cu3O3. 7-δ (Nd123) powder; in the above formula, 0≤δ≤1;

[0027] M12: Preparation of Nd211 powder: Nd2O3, BaCO3 and CuO powders were mixed evenly in a molar ratio of 1:1:1, and Nd2BaCuO5(Nd211) powder was generated by solid-state reaction at 920℃ after three sinterings and four ball millings.

[0028] M13: Nd123 powder and Nd211 powder are mixed at a mass ratio of 3:1, and then 8.6wt% MgO powder is added and mixed evenly. 34g of the evenly mixed powder is weighed and pressed into NdBarium Copper Oxide precursor blocks with a diameter of 32mm. The blocks are then grown in a crystal growth furnace to obtain NdBarium Copper Oxide bulk materials. Naturally cleaved NdBarium Copper Oxide cubes (2×2×2mm) are then taken. 3 It serves as a neodymium barium copper oxide seed crystal.

[0029] Furthermore, the specific process for preparing the solid precursor block, M3, is as follows: the solid source powder is composed of the following components: (100-x)(Gd2O3+1.2BaCuO2)+xGd2(Ba 4-r Sr r CuZrO y The powder of (where x=0, 1, 2, 3, 4, 5, 6, 8, 10wt% and r=1, 2, 3, 4)+1wt%CeO2 was mixed evenly with a ball mill and a mortar to serve as a solid phase source precursor powder; 14g of the above solid phase source precursor powder was weighed and pressed into solid phase precursor blocks with a diameter of 20mm.

[0030] Furthermore, the specific process for preparing the liquid phase precursor block is as follows: the liquid phase source powder is formed by uniformly mixing Y2O3, BaCuO2 and CuO2 powder in a ratio of 1:10:6. After uniform mixing, 25g of the mixture is pressed into a cylindrical blank with a diameter of 30mm, and the liquid phase precursor block is prepared.

[0031] The advantages of this invention are:

[0032] This invention replaces RE2Ba4CuMO with Sr. y A method for identifying the Ba element in a phase (M = U, Mo, Zr, Bi, Nb, W, ...) led to the development of a chemically stable Gd2(Ba) alloy. 4-r Sr r CuZrO y (r=0, 1, 2, 3, 4) nanoparticles and their complete preparation method, using Gd2(Ba 4-r Sr r CuZrO y Nanoparticle doping improves the flux pinning ability and superconducting performance of GdBCO superconducting bulk materials.

[0033] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0034] Figure 1 Example 2: Gd2Ba4CuZrO y XRD patterns of powder sintered at different temperatures.

[0035] Figure 2 Example 2: Gd2Ba4CuZrO y SEM images of powder sintered at different temperatures.

[0036] Figure 3 It is Example 2 with different doping ratios of Gd2Ba4CuZrO y A schematic diagram of the upper surface morphology of a single-domain GdBCO superconducting bulk material.

[0037] Figure 4 It is Example 2 with different doping ratios of Gd2Ba4CuZrO y Magnetic levitation force curve of single-domain GdBCO superconducting bulk material.

[0038] Figure 5 It is Example 2 with different doping ratios of Gd2Ba4CuZrO y The trapping magnetic field distribution of a single-domain GdBCO superconducting bulk material.

[0039] Figure 6 It is Gd2(Ba3Sr)CuZrO from Example 3 y XRD patterns of powder sintered at different temperatures.

[0040] Figure 7 It is Gd2(Ba3Sr)CuZrO from Example 3 y SEM images of powder sintered at different temperatures.

[0041] Figure 8It is Example 3 with different proportions of Gd2(Ba3Sr)CuZrO y A schematic diagram of the upper surface morphology of a single-domain GdBCO superconducting bulk material.

[0042] Figure 9 It is Example 3 with different proportions of Gd2(Ba3Sr)CuZrO y Magnetic levitation force curve of single-domain GdBCO superconducting bulk material.

[0043] Figure 10 It is Example 3 with different proportions of Gd2(Ba3Sr)CuZrO y The trapping magnetic field distribution of a single-domain GdBCO superconducting bulk material.

[0044] Figure 11 It is Gd2(Ba2Sr2)CuZrO from Example 4 y XRD patterns of powder sintered at different temperatures.

[0045] Figure 12 It is Gd2(Ba2Sr2)CuZrO from Example 4 y SEM images of powder sintered at different temperatures.

[0046] Figure 13 It is Example 4, which is a Gd2(Ba2Sr2)CuZrO doped with different proportions. y Top surface morphology of single-domain GdBCO superconducting bulk material.

[0047] Figure 14 It is Example 4, which is a Gd2(Ba2Sr2)CuZrO doped with different proportions. y Magnetic levitation force curve of single-domain GdBCO superconducting bulk material.

[0048] Figure 15 It is Example 4, which is a Gd2(Ba2Sr2)CuZrO doped with different proportions. y The trapping magnetic field distribution of single-domain GdBCO superconducting bulk material.

[0049] Figure 16 It is Gd2(BaSr3)CuZrO from Example 5 y XRD patterns of powder sintered at different temperatures.

[0050] Figure 17 It is Gd2(BaSr3)CuZrO from Example 5 y SEM images of powder sintered at different temperatures.

[0051] Figure 18 It is Gd2(BaSr3)CuZrO from Example 5 yMacroscopic morphology of the upper surface of a sample with a doping concentration of 4 wt%.

[0052] Figure 19 It is Gd2(BaSr3)CuZrO from Example 5 y Magnetic levitation force curve of single-domain GdBCO superconducting bulk material with a doping ratio of 4 wt%.

[0053] Figure 20 It is Gd2(BaSr3)CuZrO from Example 5 y Three-dimensional trapping magnetic flux density distribution on the surface of a single-domain GdBCO superconducting bulk material with a doping ratio of 4 wt%.

[0054] Figure 21 It is Gd2Sr4CuZrO from Example 6 y XRD patterns of powder sintered at different temperatures.

[0055] Figure 22 It is Gd2Sr4CuZrO from Example 6 y SEM images of powder sintered at different temperatures.

[0056] Figure 23 It is Gd2Sr4CuZrO from Example 6 y Macroscopic morphology of the upper surface of a sample with a doping concentration of 4 wt%.

[0057] Figure 24 It is Gd2Sr4CuZrO from Example 6 y Magnetic levitation force curve of single-domain GdBCO superconducting bulk material with a doping ratio of 4 wt%.

[0058] Figure 25 It is Gd2(BaSr3)CuZrO from Example 6 y Three-dimensional trapping magnetic flux density distribution on the surface of a single-domain GdBCO superconducting bulk material with a doping ratio of 4 wt%. Detailed Implementation

[0059] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the specific implementation methods, structural features and effects of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "aligned", "overlapping", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0063] Example 1

[0064] A nanopowder, with the following molar ratio: 1 mole of Gd₂O₃, 0-4 moles of BaCO₃, 0-4 moles of SrCO₃, 1 mole of CuO, and 1 mole of ZrO₂; the chemical formula of the nanopowder is Gd₂(Ba 4-r Sr r CuZrO y Where r takes values ​​in the range 0 ≤ r ≤ 4, and y is Gd2(Ba 4-r Sr r CuZrO y The oxygen content in the powder.

[0065] Furthermore, the Sr element can be replaced with any one of La, Nd, Sm, Eu, and Pr, and the element can also be replaced with any one of U, Mo, Bi, Nb, and W.

[0066] Furthermore, the method for preparing the nanopowder includes the following steps:

[0067] S1: Prepare Gd2O3, BaCO3, SrCO3, CuO, and ZrO2 with a purity of 99.0% and mix them in a molar ratio;

[0068] S2: The mixed powder from step S1 is placed in a zirconium oxide container, alcohol is added, and after wet mixing, it is placed in a planetary ball mill and ball-milled for 4 hours.

[0069] S3: Pour the wet-mixed powder into a glass dish and let it stand until it dries. Then, put it into a mortar and grind it by hand.

[0070] S4: Put the dried powder into a high-temperature furnace and conduct three sinterings at temperatures T (T = 1050 °C, 1100 °C, 1120 °C, 1140 °C, 1160 °C, 1180 °C).

[0071] S5: Conduct three sinterings and four ball millings on the powders in Step 4 to obtain Gd2(Ba 4-r Sr r )CuZrO y powders.

[0072] Furthermore, for a single-domain gadolinium barium copper oxide superconducting bulk, the doping amount of Gd2Ba4CuZrO y is between 0 < x ≤ 6 wt%.

[0073] Furthermore, for a single-domain gadolinium barium copper oxide superconducting bulk, the doping amount of Gd2Ba 4-r Zr r CuZrOy is between 0 < x ≤ 4 wt%, where the value of r is 1, 2, 3, 4.

[0074] Furthermore, the preparation method of the single-domain gadolinium barium copper oxide superconducting bulk includes the following steps:

[0075] M1: Prepare a neodymium barium copper oxide seed crystal;

[0076] M2: Prepare BaCuO2 powders: Mix BaCO3 and CuO evenly at a molar ratio of 1:1, and use the solid-state reaction method to conduct three sinterings and four ball millings at 897 °C, 900 °C, and 903 °C respectively to prepare BaCuO2 powders;

[0077] M3: Prepare a solid-phase precursor bulk;

[0078] M4: Prepare a liquid-phase precursor bulk;

[0079] M5: Weigh 5 g of Y2O3 and press it into a support block with the same diameter as the liquid-phase precursor bulk, prepare several MgO single-crystal blocks, and prepare Al2O3 gaskets;

[0080] M6: Assemble the green body: Arrange multiple MgO single-crystal blocks at intervals on the Al2O3 gasket, and place the corresponding precursor blocks in the order of the support block, liquid-phase precursor bulk, and solid-phase precursor bulk from bottom to top on the upper surface of the MgO single crystal. Place the neodymium barium copper oxide seed crystal at the center position of the upper surface of the solid-phase precursor bulk, and make its ab plane parallel to the surface of the solid-phase precursor bulk;

[0081] M6: The assembled billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, it is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, it is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain gadolinium barium copper oxide bulk material based on seed crystal induction.

[0082] M7: Oxygen permeation treatment: The single-domain gadolinium barium copper oxide block is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 410℃~440℃ in a flowing oxygen atmosphere to obtain the single-domain gadolinium barium copper oxide superconducting block.

[0083] Furthermore, the specific process for preparing the Nd:barium copper oxide seed crystal in M1 is as follows:

[0084] M11: Preparation of Nd2O3 powder: Nd2O3, BaCO3, and CuO powders were mixed evenly in a molar ratio of 1:4:6. The mixture was then subjected to three sintering processes at 910℃ using a solid-state reaction method, followed by four ball milling processes to produce NdBa2Cu3O3. 7-δ (Nd123) powder; in the above formula, 0≤δ≤1;

[0085] M12: Preparation of Nd211 powder: Nd2O3, BaCO3 and CuO powders were mixed evenly in a molar ratio of 1:1:1, and Nd2BaCuO5(Nd211) powder was generated by solid-state reaction at 920℃ after three sinterings and four ball millings.

[0086] M13: Nd123 powder and Nd211 powder are mixed at a mass ratio of 3:1, and then 8.6wt% MgO powder is added and mixed evenly. 34g of the evenly mixed powder is weighed and pressed into NdBarium Copper Oxide precursor blocks with a diameter of 32mm. The blocks are then grown in a crystal growth furnace to obtain NdBarium Copper Oxide bulk materials. Naturally cleaved NdBarium Copper Oxide cubes (2×2×2mm) are then taken. 3 It serves as a neodymium barium copper oxide seed crystal.

[0087] Furthermore, the specific process for preparing the solid precursor block, M3, is as follows: the solid source powder is composed of the following components: (100-x)(Gd2O3+1.2BaCuO2)+xGd2(Ba 4-r Sr r CuZrO yThe powder of (where x=0, 1, 2, 3, 4, 5, 6, 8, 10wt% and r=1, 2, 3, 4)+1wt%CeO2 was mixed evenly with a ball mill and a mortar to serve as a solid phase source precursor powder; 14g of the above solid phase source precursor powder was weighed and pressed into solid phase precursor blocks with a diameter of 20mm.

[0088] Furthermore, the specific process for preparing the liquid phase precursor block, M4, is as follows: the liquid phase source powder is formed by uniformly mixing Y2O3, BaCuO2, and CuO2 powder in a ratio of 1:10:6. After uniform mixing, 25g of the mixture is pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block remains on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is now complete.

[0089] In summary, by replacing RE2Ba4CuMO with Sr, y A method for identifying the Ba element in a phase (M = U, Mo, Zr, Bi, Nb, W, ...) led to the development of a chemically stable Gd2(Ba) alloy. 4-r Sr r CuZrO y (r=0, 1, 2, 3, 4) nanoparticles and their complete preparation method, using Gd2(Ba 4-r Sr r CuZrO y Nanoparticle doping improves the flux pinning ability and superconducting performance of GdBCO superconducting bulk materials.

[0090] Example 2

[0091] I. Preparation of Gd₂Ba₄CuZrO y powder

[0092] Step 1: Commercially purchased Gd₂O₃, BaCO₃, CuO, and ZrO₂ (purity 99.0%) are mixed in a molar ratio of Gd:Ba:Cu:Zr = 2:4:1:1. 8.017 g, 17.457 g, 1.799 g, and 2.725 g of each are weighed and mixed to obtain Gd₂Ba₄CuZrO₂. y Initial powder.

[0093] Step 2: Place the mixed powder from Step 1 into a zirconium oxide container and add alcohol. After wet mixing, place it in a planetary ball mill and ball mill for 4 hours. After ball milling, pour it into a clean glass dish and let it stand until it dries. Then, place it in a mortar and pestle for hand grinding.

[0094] Step 3: Place the dried and hand-ground mixed powder into a high-temperature furnace and sinter it at temperatures T℃ (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃). Repeat the sintering process three times at each temperature point.

[0095] Step 4: Perform three sinterings and four ball millings on the powders from Step 3 to obtain relatively pure powders.

[0096] Step 5: Select Gd2Ba4CuZrO by X-ray diffraction (XRD) and scanning electron microscopy (SEM). y The optimal sintering temperature for powder with the smallest and most uniform particle size distribution. Figure 1 These are XRD patterns of the mixed powder after sintering at different temperature points: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃. Figure 2 SEM images of the mixed powder after sintering at different temperatures: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃.

[0097] Depend on Figure 1 It can be seen that at lower temperatures, the peak intensity is weaker, and there are obvious unreacted compounds, resulting in many impurity peaks. When the temperature reaches around 1140℃, the diffraction peak positions match the standard spectrum more closely, and the diffraction peaks are sharper, the phase is relatively pure, and the phase structure is stable. When the sintering temperature reaches 1180℃, it was found that the powder shrinks severely and has high hardness, making further grinding and ball milling very difficult. Therefore, the sintering temperature should not be too high. Figure 2 It is evident that the microstructure of the particles varies significantly at different temperatures. At lower temperatures, the particle size is larger, and agglomeration is pronounced. As the temperature increases, the particle size gradually decreases, reaching its smallest size and most uniform distribution at 1140℃. Ultimately, Gd₂Ba₄CuZrO₂ was selected for sintering at 1140℃. y Nanoparticles were doped into the sample, and superconducting bulk materials were prepared by top seeded infiltration growth (TSIG).

[0098] II. Preparation of Solid-Liquid Phases

[0099] (1) Preparation of solid precursor blocks

[0100] Solid source powder composition: The composition is (100-x)(Gd2O3+1.2 BaCuO2)+x Gd2Ba4CuZrO yA mixture of 1 wt% CeO2 (where x = 0, 1, 2, 3, 4, 5, 6, 8, 10 wt%) powders was mixed evenly using a ball mill and a mortar. Then, 14 g of the powder was weighed out as the solid precursor powder and pressed into a cylindrical blank with a diameter of 20 mm. The solid precursor block preparation was then completed.

[0101] (2) Preparation of liquid phase precursor blocks

[0102] Composition of liquid phase source powder: Y2O3, BaCuO2 and CuO2 powders are uniformly mixed in a ratio of 1:10:6. After mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block is always on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is completed.

[0103] III. Assembly of Solid and Liquid Phases

[0104] 1) In order to avoid sample deformation due to liquid phase loss, about 5g of Y2O3 powder should be pressed into a cylindrical blank with a diameter of 30mm as a support block.

[0105] 2) Prepare several MgO single crystal blocks and Al2O3 spacers;

[0106] 3) Overlap the above precursor blocks in an axially symmetrical manner: First, place an appropriate number of MgO single crystals in the Al2O3 substrate to separate them from the sample (MgO single crystals can not only prevent the Al2O3 substrate from contaminating the sample, but also reduce the loss of liquid phase). Second, place the corresponding precursor blocks on the surface of the upper part of the MgO single crystals in the order of support block, liquid phase, and solid phase from bottom to top. Third, place the prepared NdBCO seed crystal at the center of the upper surface of the solid phase precursor block, and make its ab plane parallel to the surface of the solid phase precursor block.

[0107] IV. Sample growth and oxygen permeation

[0108] Growth process: The prepared billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain GdBCO bulk material based on seed crystal induction.

[0109] Oxygen permeation treatment: The single-domain GdBCO block material is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 440-410℃ in a circulating oxygen atmosphere to obtain the single-domain GdBCO superconducting block material.

[0110] V. Sample Morphology and Properties

[0111] A. Macroscopic morphology of the sample

[0112] Figure 3 It has different Gd2Ba4CuZrO y The macroscopic morphology of the upper surface of the doped samples is shown in the figure. The sample diameter is d=20mm. As shown in the figure, for samples with different doping levels, all nine samples have the characteristics of single-domain samples, with clear cross-shaped patterns on the surface, smooth and flat four sectors, metallic luster, and no random nucleation phenomenon. The difference is that as the doping level increases, more and more raised square stripe patterns appear around the seed crystal.

[0113] Figure 3 Doping with different proportions of Gd2Ba4CuZrO y Top surface morphology of single-domain GdBCO superconducting bulk material: (a) x=0 wt%; (b) x=1 wt%; (c) x=2 wt%; (d) x=3 wt%; (e) x=4 wt%; (f) x=5 wt%; (g) x=6 wt%; (h) x=8 wt%; (i) x=10 wt%

[0114] B. Sample performance

[0115] like Figure 4 Different Gd2Ba4CuZrO under zero field cooling conditions at 77 K y Magnetic levitation force curves of single-domain GdBCO superconducting bulk materials with different doping ratios, with insets showing Gd₂Ba₄CuZrO doped in different ratios. y The corresponding maximum magnetic levitation force is shown in the line graph. The magnet used in the test had a diameter of 20 mm and a surface magnetic field strength of 0.5 T. The maximum levitation force of each sample was obtained at the minimum interval of 0.5 mm between the sample and the permanent magnet. As can be seen from the graph, with the increase of doping amount, the overall change of the magnetic levitation force of the sample is first increased and then decreased. When undoped, i.e., x = 0 wt%, the magnetic levitation force of the sample is 32.870 N. yThe addition of powder initially increased the magnetic levitation force, reaching 32.890 N at x=1 wt%, a negligible difference compared to the undoped state. As x=1 wt%, the magnetic levitation forces increased to 34.850 N, 36.040 N, 43.250 N, and 43.550 N at x=2 wt%, 36.040 N, 43.250 N, and 43.550 N respectively. The magnetic levitation force increased slowly, reaching a maximum of 45.190 N at x=6 wt%. Further increasing the doping amount to 8 wt% resulted in a magnetic levitation force of 39.640 N. At 10 wt%, the force was 32.000 N, lower than the undoped state. This indicates that an appropriate amount of Gd₂Ba₄CuZrO₂... y Doping can appropriately enhance the magnetic levitation force of GdBCO conductor materials. In this group of experiments, the optimal doping ratio was x = 6 wt%, at which point the sample was able to grow a complete single-domain morphology and the magnetic levitation force reached its maximum value of 45.190 N.

[0116] Superconductors, once magnetized, can trap magnetic flux. The magnitude of this trapping flux reflects the strength of the magnetic flux pinning ability within the superconductor. For trapping field measurements, a GdBCO single-domain superconductor was cooled to 77 K and held for 5 minutes under a magnetic field (NdFeB, Φ=40 mm) perpendicular to the surface. Data was then acquired at a depth of 0.5 mm on the upper surface of the superconductor using a Hall probe following a pre-defined path. Figure 5 To dope Gd2Ba4CuZrO in different proportions y The three-dimensional trapping magnetic field distribution on the surface of the GdBCO sample shows a symmetrical single-peak structure in the trapping magnetic flux density, indicating good single-domain characteristics. The trapping magnetic field also initially increases and then decreases. In the undoped state (x = 0 wt%), the maximum trapping magnetic field is 0.3357 T. With the increase of Gd₂Ba₄CuZrO₄... y The addition of powder initially increases the trapping magnetic field. When the doping concentration gradually increases from x=1 wt% to x=2 wt%, x=3 wt%, x=4 wt%, and x=5 wt%, the trapping magnetic fields are 0.3799 T, 0.3936 T, 0.3955 T, 0.4214 T, and 0.4268 T, respectively, with a relatively slow increase. The trapping magnetic field reaches its maximum of 0.4291 T when the doping concentration reaches x=6 wt%. With further increases in doping concentration, the trapping magnetic field shows a decreasing trend, reaching 0.4111 T at x=8 wt% and 0.3787 T at x=10 wt%, with a significant decrease. This indicates that Gd₂Ba₄CuZrO₄... yDoping can indeed affect the sample’s trapping magnetic flux, and appropriate doping can appropriately enhance the trapping magnetic field of GdBCO superconducting bulk material. In this group of experiments, the effect was best when x=6 wt%, which is consistent with the trend of magnetic levitation force, and the maximum trapping magnetic field was 0.4291T.

[0117] Example 3

[0118] I. Preparation of Gd2(Ba3Sr)CuZrO y powder

[0119] Step 1: Commercially purchased Gd₂O₃, BaCO₃, SrCO₃, CuO, and ZrO₂ (purity 99.0%) are mixed in a molar ratio of Gd:Ba:Sr:Cu:Zr = 2:3:1:1:1. 8.322 g, 13.591 g, 3.389 g, 1.868 g, and 2.828 g of these mixtures are weighed out and mixed to obtain Gd₂(Ba₃Sr)CuZrO₂. y Initial powder;

[0120] Step 2: Place the mixed powder from Step 1 into a zirconium oxide container and add alcohol. After wet mixing, place it in a planetary ball mill and ball mill for 4 hours. After ball milling, pour it into a clean glass dish and let it stand until it dries. Then, place it in a mortar and pestle for hand grinding.

[0121] Step 3: Place the dried and hand-ground mixed powder into a high-temperature furnace and sinter it at temperatures T℃ (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃). Repeat the sintering process three times at each temperature point.

[0122] Step 4: Perform three sinterings and four ball millings on the powders from Step 3 to obtain relatively pure powders.

[0123] Step 5: Select Gd2(Ba3Sr)CuZrO by X-ray diffraction (XRD) and scanning electron microscopy (SEM). y The optimal sintering temperature for powder with the smallest and most uniform particle size distribution. Figure 6 These are XRD patterns of the mixed powder after sintering at different temperature points: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃. Figure 7 SEM images of the mixed powder after sintering at different temperatures: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃.

[0124] Depend on Figure 6It can be seen that at lower temperatures, the peak intensity is weaker, and there are obvious unreacted compounds, resulting in many impurity peaks. When the temperature reaches around 1140℃, the diffraction peak positions match the standard spectrum more closely, and the diffraction peaks are sharper, the phase is relatively pure, and the phase structure is stable. When the sintering temperature reaches 1180℃, it was found that the powder shrinks severely and has high hardness, making further grinding and ball milling very difficult. Therefore, the sintering temperature should not be too high. Figure 7 It is evident that the microstructure of the particles varies significantly at different temperatures. At lower temperatures, the particle size is larger, and agglomeration is pronounced. As the temperature increases, the particle size gradually decreases, reaching its smallest size and most uniform distribution at 1140℃. Ultimately, Gd2(Ba3Sr)CuZrO was selected for sintering at 1140℃. y Nanoparticles were incorporated into the sample, and superconducting bulk materials were prepared by top seeded infiltration growth (TSIG).

[0125] II. Preparation of Solid-Liquid Phases

[0126] (1) Preparation of solid precursor blocks

[0127] Solid source powder composition: The composition is (100-x)(Gd2O3+1.2 BaCuO2)+x Gd2(Ba3Sr)CuZrO y A mixture of +1 wt% CeO2 (where x = 0, 1, 2, 3, 4, 5, 6, 8, 10 wt%) powders was mixed evenly using a ball mill and a mortar. Then, 14g was weighed out as the solid precursor powder and pressed into a cylindrical blank with a diameter of 20 mm, thus completing the preparation of the solid precursor block.

[0128] (2) Preparation of liquid phase precursor blocks

[0129] Composition of liquid phase source powder: Y2O3, BaCuO2 and CuO2 powders are uniformly mixed in a ratio of 1:10:6. After mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block is always on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is completed.

[0130] III. Assembly of Solid and Liquid Phases

[0131] 1) In order to avoid sample deformation due to liquid phase loss, about 5g of Y2O3 powder should be pressed into a cylindrical blank with a diameter of 30mm as a support block.

[0132] 2) Prepare several MgO single crystal blocks and Al2O3 spacers;

[0133] 3) Overlap the above precursor blocks in an axially symmetrical manner: First, place an appropriate number of MgO single crystals in the Al2O3 substrate to separate them from the sample (MgO single crystals can not only prevent the Al2O3 substrate from contaminating the sample, but also reduce the loss of liquid phase). Second, place the corresponding precursor blocks on the surface of the upper part of the MgO single crystals in the order of support block, liquid phase, and solid phase from bottom to top. Third, place the prepared NdBCO seed crystal at the center of the upper surface of the solid phase precursor block, and make its ab plane parallel to the surface of the solid phase precursor block.

[0134] IV. Sample growth and oxygen permeation

[0135] Growth process: The prepared billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain GdBCO bulk material based on seed crystal induction.

[0136] Oxygen permeation treatment: The single-domain GdBCO block material is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 440-410℃ in a circulating oxygen atmosphere to obtain the single-domain GdBCO superconducting block material.

[0137] V. Sample Morphology and Properties

[0138] A. Macroscopic morphology of the sample

[0139] Figure 8 It is different from Gd2(Ba3Sr)CuZrO y The macroscopic morphology of the upper surface of the samples with different doping concentrations is shown in the following cases: (a) x = 0 wt%; (b) x = 1 wt%; (c) x = 2 wt%; (d) x = 3 wt%; (e) x = 4 wt%; (f) x = 5 wt%; (g) x = 6 wt%; (h) x = 8 wt%; (i) x = 10 wt%. The sample diameter is d = 20 mm. The macroscopic morphology varies for samples with different doping concentrations. When the doping concentration is relatively small, i.e., x... At 6 wt%, the surface exhibits a clear cross-shaped pattern, with all four sectors being smooth and flat, possessing a metallic luster, and showing no random nucleation. When the doping concentration x... At 8 wt%, as the doping concentration increases, random nucleation becomes more severe, and the single-domain region becomes smaller.

[0140] B. Sample performance

[0141] like Figure 9 It is different from Gd2(Ba3Sr)CuZrO y Magnetic levitation force curves of single-domain GdBCO superconducting bulk materials with different doping ratios under zero-field cooling conditions at 77 K, with insets showing Gd2(Ba3Sr)CuZrO doped with different ratios. y The corresponding maximum magnetic levitation force is plotted in a line graph. The magnet used in the test had a diameter of 20 mm and a surface magnetic field strength of 0.5 T. The maximum levitation force of each sample was obtained at the minimum interval of 0.5 mm between the sample and the permanent magnet. As can be seen from the graph, the trend of magnetic levitation force changes with increasing doping concentration is the same as in the previous experiment. When undoped (x = 0 wt%), the magnetic levitation force of the sample is 32.870 N. y The addition of powder initially increased the magnetic levitation force, reaching 38.430 N at x = 1 wt%, showing a significant improvement compared to Gd₂Ba₄CuZrO₄. y The increase in magnetic levitation force is significant when the doping concentration is small. As the doping concentration increases from 1 wt% to 2 wt% and then to 3 wt%, the magnetic levitation force corresponds to 42.500 N and 43.260 N respectively, showing a slow increase. When the doping concentration reaches 4 wt%, the magnetic levitation force of the sample reaches 48.669 N. This indicates that with the addition of Sr, an appropriate amount of Gd2(Ba3Sr)CuZrO... y The doping effect is better than Gd2Ba4CuZrO y Doping showed a better effect. When x=5 wt% and x=6 wt%, the magnetic levitation forces were 40.950 N and 40.830 N, respectively, indicating that the magnetic levitation force of the sample decreased with increasing doping concentration, and the decrease was significant. When x increased to x=8 wt% and x=10 wt%, the magnetic levitation forces were only 14.670 N and 11.600 N, respectively, which were far lower than the magnetic levitation force without doping. The optimal doping ratio in this experiment was x=4 wt%, at which point the maximum magnetic levitation force reached 48.669 N.

[0142] Superconductors, once magnetized, can trap magnetic flux. The magnitude of this trapping flux reflects the strength of the magnetic flux pinning ability within the superconductor. For trapping field measurements, a GdBCO single-domain superconductor was cooled to 77 K and held for 5 minutes under a magnetic field (NdFeB, Φ=40 mm) perpendicular to the surface. Data was then acquired at a depth of 0.5 mm on the upper surface of the superconductor using a Hall probe following a pre-defined path. Figure 10 Gd2(Ba3Sr)CuZrO yThree-dimensional trapping magnetic field distributions on the surface of GdBCO samples with different doping concentrations are shown in the figures: (a) x = 0 wt%; (b) x = 1 wt%; (c) x = 2 wt%; (d) x = 3 wt%; (e) x = 4 wt%; (f) x = 5 wt%; (g) x = 6 wt%; (h) x = 8 wt%; and (i) x = 10 wt%. The figures show that the trapping magnetic fields of the samples exhibit a symmetrical single-peak structure, indicating that the samples possess good single-domain characteristics. With increasing doping concentration, the trapping magnetic field of the samples initially increases and then decreases. In the undoped state (x = 0 wt%), the maximum trapping magnetic flux is 0.3357 T. With increasing doping concentration, the trapping magnetic field of the Gd2(Ba3Sr)CuZrO sample decreases. y The addition of powder initially increases the trapping field. When the powder content gradually increases from x=1 wt% to x=2 wt% and x=3 wt%, the trapping magnetic fields increase more slowly to 0.4015 T, 0.4224 T, and 0.4289 T, respectively. However, the doping effect is still better than that of Gd₂Ba₄CuZrO₄. y The doping effect is better. When the doping amount reaches x=4 wt%, the trapping magnetic field reaches its maximum of 0.4308 T, and the change in the trapping magnetic field is relatively small, indicating that the trapping magnetic field of the sample is good. The effect of lower doping amount on the trapping magnetic field is small, but it does enhance the trapping magnetic field. When the doping amount is further increased, the trapping field shows a decreasing trend. When x=5 wt% and x=6 wt%, the values ​​are 0.4224 T and 0.420 T, respectively. When x=8 wt% and x=10 wt%, the values ​​decrease to 0.1839 T and 0.1022 T, respectively. The decrease is relatively large, so excessive doping will actually weaken the trapping magnetic field. This indicates that an appropriate amount of Gd2(Ba3Sr)CuZrO y Doping can appropriately improve the trapping magnetic field characteristics of GdBCO superconducting materials. In this group of experiments, the effect was the best when the doping amount was x=4 wt%, and the maximum trapping magnetic field was 0.4308 T.

[0143] Example 4

[0144] I. Preparation of Gd2(Ba2Sr2)CuZrO y powder

[0145] Step 1: Commercially purchased Gd₂O₃, BaCO₃, SrCO₃, CuO, and ZrO₂ (purity 99.0%) are mixed in a molar ratio of Gd:Ba:Sr:Cu:Zr = 2:2:2:1:1. The resulting mixtures of 8.65g, 9.41g, 7.046g, 1.94g, and 2.94g are weighed and mixed to obtain Gd₂(Ba₂Sr₂)CuZrO₂. y Initial powder;

[0146] Step 2: Place the mixed powder from Step 1 into a zirconium oxide container and add alcohol. After wet mixing, place it in a planetary ball mill and ball mill for 4 hours. After ball milling, pour it into a clean glass dish and let it stand until it dries. Then, place it in a mortar and pestle for hand grinding.

[0147] Step 3: Place the dried and hand-ground mixed powder into a high-temperature furnace and sinter it at temperatures T℃ (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃). Repeat the sintering process three times at each temperature point.

[0148] Step 4: Perform three sinterings and four ball millings on the powders from Step 3 to obtain relatively pure powders.

[0149] Step 5: Select Gd2(Ba2Sr2)CuZrO by X-ray diffraction (XRD) and scanning electron microscopy (SEM). y The optimal sintering temperature for powder with the smallest and most uniform particle size distribution. Figure 11 These are XRD patterns of the mixed powder after sintering at different temperature points: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃. Figure 12 SEM images of the mixed powder after sintering at different temperatures: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃.

[0150] Depend on Figure 11 It can be seen that at lower temperatures, the peak intensity is weaker, and there are obvious unreacted compounds, resulting in many impurity peaks. When the temperature reaches around 1140℃, the diffraction peak positions match the standard spectrum more closely, and the diffraction peaks are sharper, the phase is relatively pure, and the phase structure is stable. When the sintering temperature reaches 1180℃, it was found that the powder shrinks severely and has high hardness, making further grinding and ball milling very difficult. Therefore, the sintering temperature should not be too high. Figure 12 It is evident that the microstructure of the particles varies significantly at different temperatures. At lower temperatures, the particle size is larger, and agglomeration is pronounced. As the temperature increases, the particle size gradually decreases, reaching its smallest size and most uniform distribution at 1140℃. Ultimately, Gd2(Ba2Sr2)CuZrO was selected for sintering at 1140℃. y Nanoparticles were incorporated into the sample. Scanning electron microscopy analysis showed that the particle size of this group of powders was smaller than that of the previous two groups, indicating that by continuously replacing Ba, the particle size of the corresponding powders would also decrease, and the doping effect on improving the performance of the superconducting bulk material would be better. The superconducting bulk material was prepared by top seeded infiltration growth (TSIG).

[0151] II. Preparation of Solid-Liquid Phases

[0152] (1) Preparation of solid precursor blocks

[0153] Solid-phase source powder composition: The composition is (100-x)(Gd2O3+1.2 BaCuO2)+xGd2(Ba2Sr2)CuZrO y A mixture of +1 wt% CeO2 (where x = 0, 1, 2, 3, 4, 5, 6, 8, 10 wt%) powders was mixed evenly using a ball mill and a mortar. Then, 14 g of the powder was weighed out as the solid precursor powder and pressed into a cylindrical blank with a diameter of 20 mm. The solid precursor block preparation was completed.

[0154] (2) Preparation of liquid phase precursor blocks

[0155] Composition of liquid phase source powder: Y2O3, BaCuO2 and CuO2 powders are uniformly mixed in a ratio of 1:10:6. After mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block is always on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is completed.

[0156] III. Assembly of Solid and Liquid Phases

[0157] 1) In order to avoid sample deformation due to liquid phase loss, about 5g of Y2O3 powder should be pressed into a cylindrical blank with a diameter of 30mm as a support block.

[0158] 2) Prepare several MgO single crystal blocks and Al2O3 spacers;

[0159] 3) Overlap the above precursor blocks in an axially symmetrical manner: First, place an appropriate number of MgO single crystals in the Al2O3 substrate to separate them from the sample (MgO single crystals can not only prevent the Al2O3 substrate from contaminating the sample, but also reduce the loss of liquid phase). Second, place the corresponding precursor blocks on the surface of the upper part of the MgO single crystals in the order of support block, liquid phase, and solid phase from bottom to top. Third, place the prepared NdBCO seed crystal at the center of the upper surface of the solid phase precursor block, and make its ab plane parallel to the surface of the solid phase precursor block.

[0160] IV. Sample growth and oxygen permeation

[0161] Growth process: The prepared billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain GdBCO bulk material based on seed crystal induction.

[0162] Oxygen permeation treatment: The single-domain GdBCO block material is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 440-410℃ in a circulating oxygen atmosphere to obtain the single-domain GdBCO superconducting block material.

[0163] V. Sample Morphology and Properties

[0164] A. Macroscopic morphology of the sample

[0165] Figure 13 It is different from Gd2(Ba2Sr2)CuZrO y The macroscopic morphology of the upper surface of the samples with different doping concentrations is shown in the following cases: (a) x = 0 wt%; (b) x = 1 wt%; (c) x = 2 wt%; (d) x = 3 wt%; (e) x = 4 wt%; (f) x = 5 wt%; (g) x = 6 wt%; (h) x = 8 wt%; (i) x = 10 wt%. The macroscopic morphology varies considerably for samples with different doping concentrations. At 5 wt%, the surface exhibits a clear cross-shaped pattern, with all four sectors being smooth and flat, possessing a metallic luster, and showing no random nucleation. When the doping concentration x... At 6 wt%, random nucleation becomes increasingly severe with increasing doping concentration, and the single-domain region also becomes smaller, indicating that the higher the doping concentration, the more severe the sample deformation. Due to the increased substitution of Ba by Sr, the proportion of random nucleation begins to form compared to Gd2(Ba3Sr)CuZrO. y The doping concentration of the powder was reduced from x=8 wt% to x=6 wt%, indicating that the degree of Sr substitution for Ba affects the growth structure inside the superconducting bulk material. Overall, with the increase of doping concentration, more and more raised square stripe patterns appear around the seed crystal.

[0166] B. Sample performance

[0167] like Figure 14 It is different from Gd2(Ba2Sr2)CuZrO yMagnetic levitation force curves of single-domain GdBCO superconducting bulk materials with different doping ratios under zero-field cooling conditions at 77 K, with insets showing Gd2(Ba2Sr2)CuZrO doped with different ratios. y The corresponding maximum magnetic levitation force line graph shows that the magnet used in the test had a diameter of 20 mm and a surface magnetic field strength of 0.5 T. The maximum levitation force of each sample was obtained at the minimum interval of 0.5 mm between the sample and the permanent magnet. The graph shows that as the doping concentration increases, the overall change in the magnetic levitation force of the sample is consistent with the previous two sets of experiments. In the undoped state (x = 0 wt%), the magnetic levitation force of the sample is 32.870 N. With increasing doping concentration, the magnetic levitation force of the Gd2(Ba2Sr2)CuZrO... y The addition of powder improves its magnetic levitation force. At x = 1 wt%, the magnetic levitation force increases to 38.720 N, showing a significant improvement compared to Gd₂Ba₄CuZrO₄. y The improvement is significant when the doping ratio of the powder is small. As x=1 wt% increases to x=2 wt% and x=3 wt%, the magnetic levitation forces are 42.930 N and 43.280 N, respectively. The magnetic levitation force increases slowly, reaching a maximum of 49.440 N when the doping ratio reaches x=4 wt%. Overall, the effect of small doping ratios is similar to that of Gd2(Ba3Sr)CuZrO. y Doping at small ratios produces similar effects, but in terms of the effect of the doping ratio, when the doping ratio is the same, for example, the doping amount is x=4 wt%, Gd2(Ba2Sr2)CuZrO y The doping effect of Gd2Ba4CuZrO on improving magnetic levitation force is better than that of Gd2Ba4CuZrO. y and Gd2(Ba3Sr)CuZrO y The doping effect is better, indicating that the continuous addition of Sr also optimizes the particle size of the powder. Further increasing the doping amount, when x=5 wt% and x=6 wt%, the magnetic levitation forces are 32.450 N and 22.360 N respectively, indicating that the magnetic levitation force of the sample decreases with increasing doping amount, and the decrease is significant. When x increases to x=8 wt% and x=10 wt%, the magnetic levitation force is only 11.500 N and 9.800 N, respectively, which is far lower than the magnetic levitation force without doping. The optimal doping ratio in this experiment is x=4 wt%, at which point the sample can grow a complete single-domain morphology and the magnetic levitation force reaches its maximum value of 49.440 N.

[0168] Magnetizing a superconductor allows it to trap magnetic flux, and the magnitude of this trapping flux reflects the strength of the superconductor's internal flux pinning ability. For trapping field measurements, a GdBCO single-domain superconductor was cooled to 77 K and held for 5 minutes under a magnetic field (NdFeB, Φ=40 mm) perpendicular to the surface. Data was then acquired at a depth of 0.5 mm on the upper surface of the superconductor using a Hall probe following a pre-defined path. Figure 15 To dop Gd2(Ba2Sr2)CuZrO with different proportions y The three-dimensional trapping magnetic field distribution on the surface of the GdBCO sample is shown in the figure, where (a) x=0 wt%; (b) x=1 wt%; (c) x=2 wt%; (d) x=3 wt%; (e) x=4 wt%; (f) x=5 wt%; (g) x=6 wt%; (h) x=8 wt%; and (i) x=10 wt%. The figure shows that the trapping magnetic field of the sample exhibits a symmetrical single-peak structure, indicating that the sample has good single-domain characteristics. The trapping magnetic field of the sample also increases first and then decreases. The maximum value of the trapping magnetic field is 0.3357 T when the sample is undoped (x=0 wt%). With the increase of Gd2(Ba2Sr2)CuZrO y With the addition of powder, the trapping magnetic field gradually increases. When the doping concentration increases from x=1 wt% to x=2 wt% and x=3 wt%, the trapping magnetic fields are 0.4052 T, 0.4152 T, and 0.4264 T, respectively. The trapping field reaches its maximum of 0.4344 T when the doping concentration reaches x=4 wt%. At lower doping concentrations, the trapping magnetic field increases slowly with increasing doping concentration, and is more potent than that of doped Gd2(Ba3Sr)CuZrO. y The effect is better. With further increasing the doping amount, the trapping field shows a decreasing trend. When x=5wt% and x=6wt%, the trapping magnetic field is 0.3832 T and 0.1908 T respectively. When x=8wt% and x=10wt%, the trapping magnetic field of the sample decreases to 0.1136 T and 0.0658 T respectively. This means that when the doping ratio is high, the magnetic flux pinning ability decreases significantly, indicating that more doping is not necessarily better. This suggests that an appropriate amount of Gd2(Ba2Sr2)CuZrO... y Doping can better improve the magnetic flux trapping ability of GdBCO conductor materials. In this group of experiments, the effect was the best when the doping amount was x=4 wt%, and the maximum trapping magnetic field was 0.4344 T.

[0169] Example 5

[0170] I. Preparation of Gd2(BaSr3)CuZrO y powder

[0171] Step 1: Commercially purchased Gd₂O₃, BaCO₃, SrCO₃, CuO, and ZrO₂ (purity 99.0%) are mixed in a molar ratio of Gd:Ba:Sr:Cu:Zr = 2:1:3:1:1. The following amounts are weighed out: 9.00g, 4.903g, 11.005g, 2.022g, and 3.061g respectively. After mixing, the resulting mixture is Gd₂(BaSr₃)CuZrO₂. y Initial powder.

[0172] Step 2: Place the mixed powder from Step 1 into a zirconia container and add alcohol. After wet mixing, place it in a planetary ball mill and ball mill for 4 hours. After ball milling, pour it into a glass dish and let it stand until it dries. Then, place it in a mortar and pestle for hand grinding.

[0173] Step 3: Place the dried and hand-ground mixed powder into a high-temperature furnace and sinter it at temperatures T℃ (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃). Repeat the sintering process three times at each temperature point.

[0174] Step 4: Perform three sinterings and four ball millings on the powders from Step 3 to obtain relatively pure powders.

[0175] Step 5: Select the optimal sintering temperature for Gd2(BaSr3)CuZrOy powder with the smallest and most uniform particle size by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Figure 16 These are XRD patterns of the mixed powder after sintering at different temperature points: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃. Figure 17 SEM images of the mixed powder after sintering at different temperatures: 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃.

[0176] Depend on Figure 16 It can be seen that at lower temperatures, the peak intensity is weaker, and there are obvious unreacted compounds, resulting in many impurity peaks. When the temperature reaches around 1140℃, the diffraction peak positions match the standard spectrum more closely, and the diffraction peaks are sharper, the phase is relatively pure, and the phase structure is stable. When the sintering temperature reaches 1180℃, it was found that the powder shrinks severely and has high hardness, making further grinding and ball milling very difficult. Therefore, the sintering temperature should not be too high. Figure 17It is evident that the microstructure of the particles varies significantly at different temperatures. At lower temperatures, the particle size is larger, and agglomeration is pronounced. As the temperature increases, the particle size gradually decreases, reaching its smallest and most uniform distribution at 1140℃. Ultimately, Gd2(BaSr3)CuZrOy nanoparticles sintered at 1140℃ were selected for doping the sample. Scanning electron microscopy analysis was used to examine the particle size of this powder and its relationship with Gd2(Ba2Sr2)CuZrOy. y The powder particle size actually shows a trend of increasing, indicating that by continuously replacing Ba, the particle size of the powder first decreases and then increases, meaning there is an optimal ratio for Ba replacement. Superconducting bulk materials were prepared using the topseeded infiltration growth (TSG) method.

[0177] II. Preparation of Solid-Liquid Phases

[0178] (1) Preparation of solid precursor blocks

[0179] Solid source powder composition: Similar to the previous two experiments, the ratio that yielded the best results after doping was selected, i.e., when the doping amount was 4 wt%. The composition was 96 wt% (Gd2O3 + 1.2 BaCuO2) + 4 wt% Gd2(BaSr3)CuZrO y The mixed powder of +1wt%CeO2 was mixed evenly using a ball mill and a mortar. Then, 14g was weighed out as solid precursor powder and pressed into a cylindrical blank with a diameter of 20 mm. The solid precursor block preparation was completed.

[0180] (2) Preparation of liquid phase precursor blocks

[0181] Composition of liquid phase source powder: Y2O3, BaCuO2 and CuO2 powders are uniformly mixed in a ratio of 1:10:6. After mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block is always on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is completed.

[0182] III. Assembly of Solid and Liquid Phases

[0183] 1) In order to avoid sample deformation due to liquid phase loss, about 5g of Y2O3 powder should be pressed into a cylindrical blank with a diameter of 30mm as a support block.

[0184] 2) Prepare several MgO single crystal blocks and Al2O3 spacers;

[0185] 3) Overlap the above precursor blocks in an axially symmetrical manner: First, place an appropriate number of MgO single crystals in the Al2O3 substrate to separate them from the sample (MgO single crystals can not only prevent the Al2O3 substrate from contaminating the sample, but also reduce the loss of liquid phase). Second, place the corresponding precursor blocks on the surface of the upper part of the MgO single crystals in the order of support block, liquid phase, and solid phase from bottom to top. Third, place the prepared NdBCO seed crystal at the center of the upper surface of the solid phase precursor block, and make its ab plane parallel to the surface of the solid phase precursor block.

[0186] IV. Sample growth and oxygen permeation

[0187] Growth process: The prepared billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain GdBCO bulk material based on seed crystal induction.

[0188] Oxygen permeation treatment: The single-domain GdBCO block material is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 440-410℃ in a circulating oxygen atmosphere to obtain the single-domain GdBCO superconducting block material.

[0189] V. Sample Morphology and Properties

[0190] A. Macroscopic morphology of the sample

[0191] Figure 18 It is Gd2(BaSr3)CuZrO y The macroscopic morphology of the upper surface of the sample with a doping concentration of 4 wt% and a sample diameter of d = 20 mm is shown in the figure. The sample surface has a clear cross pattern, the four sectors are smooth and flat with a metallic luster, and there is no random nucleation phenomenon. Obvious square stripes are visible around the seed crystals.

[0192] B. Sample performance

[0193] like Figure 19 It is Gd2(BaSr3)CuZrO yThe magnetic levitation force curves of 4 wt% single-domain GdBCO superconducting bulk material under zero-field cooling at 77 K were obtained. The magnet used in the test had a diameter of 20 mm and a surface magnetic field strength of 0.5 T. The maximum levitation force of each sample was obtained at the minimum interval of 0.5 mm between the sample and the permanent magnet, with a maximum magnetic levitation force of 45.5 N. Superconductors can trap magnetic flux after magnetization, and the magnitude of the trapped magnetic flux reflects the strength of the magnetic flux pinning ability within the superconductor. For trapping field measurement, the GdBCO single-domain superconductor was cooled to 77 K and held for 5 minutes under a magnetic field (NdFeB, Φ=40 mm) perpendicular to the surface. Data was then acquired at a distance of 0.5 mm from the upper surface of the superconductor using a Hall probe along a pre-set path. Figure 20 The figure shows the three-dimensional trapping magnetic flux density distribution on the sample surface. As can be seen from the figure, the trapping magnetic flux density of the sample exhibits a symmetrical single-peak structure, indicating that the sample has good single-domain characteristics, and the maximum trapping magnetic field is 0.4284T.

[0194] Example 6

[0195] I. Preparation of Gd₂Sr₄CuZrO y powder

[0196] Step 1: Commercially purchased Gd₂O₃, SrCO₃, CuO, and ZrO₂ (purity 99.0%) are mixed in a molar ratio of Gd:Sr:Cu:Zr = 2:4:1:1. The following amounts are weighed out: 9.394g, 15.303g, 2.108g, and 3.193g respectively. After mixing, Gd₂Sr₄CuZrO₂ is obtained. y Initial powder.

[0197] Step 2: Place the mixed powder from Step 1 into a zirconia container and add alcohol. After wet mixing, place it in a planetary ball mill and ball mill for 4 hours. After ball milling, pour it into a glass dish and let it stand until it dries. Then, place it in a mortar and pestle for hand grinding.

[0198] Step 3: Place the dried and hand-ground mixed powder into a high-temperature furnace and sinter it at temperatures T℃ (T=1050℃, 1100℃, 1120℃, 1140℃, 1160℃, 1180℃). Repeat the sintering process three times at each temperature point.

[0199] Step 4: Perform three sinterings and four ball millings on the powders from Step 3 to obtain relatively pure powders.

[0200] Step 5: Select the optimal sintering temperature for Gd2Sr4CuZrOy powder with the smallest and most uniform particle size by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Figure 21These are XRD patterns of the mixed powder after sintering at temperatures of 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃. Figure 22 SEM images of the mixed powder after sintering at temperatures of 1050℃, 1100℃, 1120℃, 1140℃, 1160℃, and 1180℃.

[0201] Depend on Figure 21 It can be seen that at lower temperatures, the peak intensity is weaker, and there are obvious unreacted compounds, resulting in many impurity peaks. When the temperature reaches around 1140℃, the diffraction peak positions match the standard spectrum more closely, and the diffraction peaks are sharper, the phase is relatively pure, and the phase structure is stable. When the sintering temperature reaches 1180℃, it was found that the powder shrinks severely and has high hardness, making further grinding and ball milling very difficult. Therefore, the sintering temperature should not be too high. Figure 22 It is evident that the microstructure of the particles varies significantly at different temperatures. At lower temperatures, the particle size is larger, and agglomeration is pronounced. As the temperature increases, the particle size gradually decreases, reaching its smallest and most uniform distribution at 1140℃. Ultimately, Gd₂Sr₄CuZrOy nanoparticles sintered at 1140℃ were selected for doping the sample. Scanning electron microscopy analysis revealed that the particle size of this powder group was larger than that of the previous three groups, indicating an optimal Ba replacement ratio. The optimal ratio was Ba:Sr = 1:1, resulting in the smallest particle size and the best doping effect. Superconducting bulk materials were then prepared using the top-seeded infiltration growth (TSG) method.

[0202] II. Preparation of Solid-Liquid Phases

[0203] (1) Preparation of solid precursor blocks

[0204] Solid source powder composition: 96 wt% (Gd₂O₃ + 1.2 BaCuO₂) + 4 wt% Gd₂Sr₄CuZrO y The mixed powder of +1wt% CeO2 was mixed evenly using a ball mill and a mortar. Then, 14g was weighed out as solid precursor powder and pressed into a cylindrical blank with a diameter of 20 mm. The solid precursor block preparation was completed.

[0205] (2) Preparation of liquid phase precursor blocks

[0206] Composition of liquid phase source powder: Y2O3, BaCuO2 and CuO2 powders are uniformly mixed in a ratio of 1:10:6. After mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. This ensures that the solid phase block is always on top of the liquid phase block during the heat treatment process, preventing it from tilting to one side or collapsing. The preparation of the liquid phase precursor block is completed.

[0207] III. Assembly of Solid and Liquid Phases

[0208] 1) In order to avoid sample deformation due to liquid phase loss, about 5g of Y2O3 powder should be pressed into a cylindrical blank with a diameter of 30mm as a support block.

[0209] 2) Prepare several MgO single crystal blocks and Al2O3 spacers;

[0210] 3) Overlap the above precursor blocks in an axially symmetrical manner: First, place an appropriate number of MgO single crystals in the Al2O3 substrate to separate them from the sample (MgO single crystals can not only prevent the Al2O3 substrate from contaminating the sample, but also reduce the loss of liquid phase). Second, place the corresponding precursor blocks on the surface of the upper part of the MgO single crystals in the order of support block, liquid phase, and solid phase from bottom to top. Third, place the prepared NdBCO seed crystal at the center of the upper surface of the solid phase precursor block, and make its ab plane parallel to the surface of the solid phase precursor block.

[0211] IV. Sample growth and oxygen permeation

[0212] Growth process: The prepared billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. The purpose is to ensure that the solid phase reacts fully to generate the Gd211 phase. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain GdBCO bulk material based on seed crystal induction.

[0213] Oxygen permeation treatment: The single-domain GdBCO block material is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 440-410℃ in a circulating oxygen atmosphere to obtain the single-domain GdBCO superconducting block material.

[0214] The morphology and properties of the five samples;

[0215] A. Macroscopic morphology of the sample

[0216] Figure 23 It is Gd2Sr4CuZrO y The macroscopic morphology of the upper surface of the sample with a doping amount of 4 wt% and a sample diameter of d=20 mm is shown in the figure. The sample surface has a clear cross pattern, the four sectors are smooth and flat with a metallic luster, and there is no random nucleation phenomenon. Obvious square stripes can be seen around the seed crystal.

[0217] B. Sample performance

[0218] like Figure 24 It is Gd2Sr4CuZrO y The magnetic levitation force curves of 4 wt% single-domain GdBCO superconducting bulk material under zero-field cooling at 77 K were obtained. The magnet used in the test had a diameter of 20 mm and a surface magnetic field strength of 0.5 T. The maximum levitation force of each sample was obtained at the minimum interval of 0.5 mm between the sample and the permanent magnet, with a maximum magnetic levitation force of 41.50 N. Superconductors can trap magnetic flux after magnetization, and the magnitude of the trapped magnetic flux reflects the strength of the magnetic flux pinning ability within the superconductor. For trapping field measurement, the GdBCO single-domain superconductor was cooled to 77 K and held for 5 minutes under a magnetic field (NdFeB, Φ=40 mm) perpendicular to the surface. Data was then acquired at a distance of 0.5 mm from the upper surface of the superconductor using a Hall probe along a pre-set path. Figure 25 The figure shows the three-dimensional trapping magnetic flux density distribution on the sample surface. As can be seen from the figure, the trapping magnetic flux density of the sample exhibits a symmetrical single-peak structure, indicating that the sample has good single-domain characteristics, and the maximum trapping magnetic field is 0.4056T.

[0219] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A nanopowder, characterized in that: The molar ratio is: 1 mole of Gd₂O₃, 0-3 moles of BaCO₃, 1-4 moles of SrCO₃, 1 mole of CuO, and 1 mole of ZrO₂; the chemical formula of this nanopowder is Gd₂(Ba 4-r Sr r CuZrO y Where r takes the values ​​1, 2, 3, and y is in Gd2(Ba 4-r Sr r CuZrO y Oxygen content in powder; The method for preparing the nanopowder includes the following steps: S1: Prepare Gd2O3, BaCO3, SrCO3, CuO, and ZrO2 with a purity of 99.0% and mix them in a molar ratio; S2: The mixed powder from step S1 is placed in a zirconium oxide container, alcohol is added, and after wet mixing, it is placed in a planetary ball mill and ball-milled for 4 hours. S3: Pour the wet-mixed powder into a glass dish and let it stand until it dries. Then, put it into a mortar and grind it by hand. S4: Place the dried powder into a high-temperature furnace and sinter it three times at a temperature of T=1140℃; S5: The powder from step 4 is subjected to three sintering processes and four ball milling processes to obtain Gd2(Ba 4-r Sr r CuZrO y Powder.

2. A single-domain gadolinium barium copper oxide superconducting bulk material, characterized in that: The Gd2(Ba 4-r Sr r )CuZrO y The doping amount is between 0 < x ≤ 4 wt%, where the value of r is 1, 2, or 3.

3. The method for preparing a single-domain gadolinium barium copper oxide superconducting bulk material as described in claim 2, characterized in that, Includes the following steps: M1: Preparation of neodymium barium copper oxide seed crystals; M2: Preparation of BaCuO2 powder: BaCO3 and CuO are mixed evenly in a molar ratio of 1:1, and BaCuO2 powder is prepared by solid-state reaction method after sintering three times at 897℃, 900℃ and 903℃ and ball milling four times. M3: Preparation of solid-phase precursor blocks, the specific process is as follows: the solid-phase source powder is composed of the following components: (100-x)(Gd2O3+1.2BaCuO2)+xGd2(Ba 4-r Sr r CuZrO y +1wt%CeO2, wherein x=1, 2, 3, 4wt% and r=1, 2, 3 powders are mixed evenly using a ball mill and a mortar to serve as solid phase source precursor powders; 14g of the above solid phase source precursor powders are weighed and pressed into solid phase precursor blocks with a diameter of 20mm. M4: Preparation of liquid phase precursor block; The specific process is as follows: The liquid phase source powder is formed by uniformly mixing Y2O3, BaCuO2 and CuO2 powder in a ratio of 1:10:

6. After uniform mixing, 25g is taken and pressed into a cylindrical blank with a diameter of 30mm. The preparation of liquid phase precursor block is completed. M5: Weigh 5g of Y2O3 and press it into a support block with the same diameter as the liquid phase precursor block. Prepare several MgO single crystal blocks and prepare Al2O3 gaskets. M6: Assembly blank: Multiple MgO single crystal blocks are arranged at intervals on the Al2O3 pad. On the surface of the upper part of the MgO single crystal, the corresponding precursor blocks are arranged from bottom to top in the order of support block, liquid phase precursor block, and solid phase precursor block. The Nd:barium copper oxide seed crystal is placed at the center of the upper surface of the solid phase precursor block, and its ab plane is parallel to the surface of the solid phase precursor block. M6: The assembled billet is placed in a high-temperature furnace. First, the temperature is raised to 910℃ at a rate of 150℃ / h and maintained at this temperature for 10h. Then, it is heated to 1062℃ at a rate of 120℃ / h and held for 2h to allow the liquid phase source block to fully melt and infiltrate into the solid phase precursor block. Next, the temperature is rapidly reduced to 1043℃ at a rate of 30℃ / h, followed by a slow reduction to 1021℃ at a rate of 0.44℃ / h. Finally, the temperature is gradually reduced to room temperature at a rate of 145℃ / h to complete the growth process of single-domain gadolinium barium copper oxide bulk material based on seed crystal induction. M7: Oxygen permeation treatment: The single-domain gadolinium barium copper oxide block is placed in a quartz tube furnace and slowly cooled for 200 hours in a temperature range of 410℃~440℃ in a flowing oxygen atmosphere to obtain the single-domain gadolinium barium copper oxide superconducting block.

4. The method for preparing a single-domain gadolinium barium copper oxide superconducting bulk material as described in claim 3, characterized in that, The process for preparing Nd:barium copper oxide seed crystals, specifically for M1, is as follows: M11: Preparation of Nd2O3 powder: Nd2O3, BaCO3, and CuO powders were mixed evenly in a molar ratio of 1:4:

6. The mixture was then subjected to three sintering processes at 910℃ using a solid-state reaction method, followed by four ball milling processes to produce NdBa2Cu3O3. 7-δ , i.e., Nd123 powder; in the above formula, 0≤δ≤1; M12: Preparation of Nd211 powder: Nd2O3, BaCO3 and CuO powders were mixed evenly in a molar ratio of 1:1:

1. The mixture was then sintered three times and ball-milled four times at 920℃ using a solid-state reaction method to produce Nd2BaCuO5, i.e. Nd211 powder. M13: Nd123 powder and Nd211 powder are mixed at a mass ratio of 3:1, and then 8.6 wt% MgO powder is added and mixed evenly. 34 g of the evenly mixed powder is weighed and pressed into NdBarium Copper Oxide precursor blocks with a diameter of 32 mm. The blocks are then grown in a crystal growth furnace to obtain NdBarium Copper Oxide bulk materials. 2×2×2 mm NdBarium Copper Oxide cubes with natural cleavage are then taken. 3 As a neodymium barium copper oxide seed crystal.

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