A method for preparing near-pure single-domain REBa2Cu3O y Methods using superconducting crystals

Abstract

The application provides a method for preparing a near-pure single-domain superconducting crystal, comprising the following steps: S1: preparing a nano-powder; S2: preparing a near-pure single-domain (RE is a rare earth element) superconducting crystal; by doping the nano-powder, changing a method for preparing a single-domain superconducting bulk material in a traditional TSMTG and TSIG method, and changing a distribution of a sub-domain structure and a non-superconducting second-phase micro-nano particle, a new four-prism sub-domain area is grown in the single-domain REBCO superconducting bulk material for the first time, and the sub-domain area is a near-pure single-domain superconducting crystal which almost does not contain the second-phase micro-nano particle. The nano-powder is prepared by a solid-state sintering method; the near-pure single-domain superconducting crystal is prepared by using a RE+011 TSIG method, and a solid-phase precursor block component is RE+011TSIG, wherein the value range of RE is 0<=x<=10.

Description

Technical Field

[0001] This invention belongs to the technical field of high-temperature copper oxide superconducting materials, specifically relating to a method for preparing near-pure single domains. Methods for using superconducting crystals. Background Technology

[0002] High-temperature superconductors have been known for over 30 years. They possess higher critical current densities and superconducting transition temperatures, superior superconducting properties, and enormous application potential, especially... ( , The series of superconducting materials (referring to rare earth elements) have very important scientific research and practical value. Superconducting bulk materials are commonly used in strong magnetic field permanent magnets, superconducting magnetic bearings, superconducting energy storage flywheels, motors, generators, and magnetic levitation systems. The extent of these applications depends on their superconducting properties. Therefore, to meet application requirements, the introduction of non-superconducting second-phase micro / nano particles is crucial for improving... The properties of superconducting bulk materials are of great significance. However, in research... The physical properties of superconducting crystals, as well as the preparation of superconducting thin films and tapes, require pure crystals. Superconducting single crystal or single domain Superconducting crystals. However, single-domain superconducting crystals prepared using the conventional top-seeded melt textured growth method (TSMTG) and top-seeded melt infiltration growth method (TSIG) have limitations. In superconducting samples, there is a non-uniformly distributed second phase. The existence of non-superconducting micro- and nano-particles is a challenge that current methods cannot overcome. So far, only the addition of platinum (Pt) has enabled the preparation of such particles. Content less than 2% Single crystal. Therefore, there are no reports on the preparation of near-pure single domains using TSMTG and TSIG methods by doping compounds other than platinum Pt. Reports on superconducting crystals.

[0003] In research The physical properties of superconducting crystals, as well as the preparation of superconducting thin films and tapes, require pure crystals. Superconducting single crystal or single domain Superconducting crystals. Preparation. Common methods for growing superconducting single crystals include flux methods, zone melting, top-seeded Czochralski (TLS) methods, and tip nucleation methods. The first two methods are low-cost but can only produce very small crystals. The latter two methods require sophisticated equipment, are difficult to control technically, have long and complex preparation processes, and also produce relatively small crystals. Therefore, exploring the growth of near-pure superconducting single crystals is crucial. New methods for superconducting crystals are crucial.

[0004] Both the traditional TSMTG and TSIG methods can be used to prepare centimeter-scale single domains. Superconducting crystals, but this method produces... The crystal contains 10% to 40% non-superconducting phase. The presence of these non-uniformly distributed second-phase micro- and nano-particles will severely affect the purity of single domains without impurities. The study of the preparation and physical properties of superconducting bulk materials is crucial; these properties significantly affect the crystal uniformity and superconducting performance uniformity of superconducting thin films and tapes, thus impacting their overall performance. Therefore, how to prepare pure single domains is essential. Superconducting crystals have become one of the key issues that urgently need to be addressed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing near-pure single domains. The method for producing superconducting crystals involves doping. Nanoparticles, modified traditional TSMTG and TSIG methods for preparing single domains A method for subdomain structure and distribution of non-superconducting second-phase micro / nano particles in superconducting bulk materials.

[0006] To achieve the above objectives, the present invention provides a method for preparing near-pure single domains. The method for superconducting crystals includes the following steps: S1: Preparation containing Nanoparticles; S2: Preparation of near-pure single domains Superconducting crystals.

[0007] Furthermore, S1: the prepared containing The chemical formula of the nanopowder is ,in The range of values ​​for is , It is a single rare earth element or a mixture of multiple rare earth elements.

[0008] Furthermore, the containing The molar ratio of reagents used in the preparation of nanopowders is: 1 mole of a single rare earth element oxide, Moore's , Moore's 1 mole 1 mole Or: 1 mole of mixed rare earth element oxides, Moore's , Moore's 1 mole 1 mole .

[0009] Furthermore, the containing The preparation method of nanopowder is as follows: S101, Preparation of mixed powder: For single rare earth elements: analytically pure , , , , according to Mixing in a molar ratio; or: To prepare a mixture of multiple rare earth elements: different RE2O3s were mixed uniformly in a molar ratio of 1:1:1... to prepare a mixed rare earth oxide powder; the mixed rare earth oxide powder, , , , according to Mix in the specified molar ratio; S102. Place the mixed powder from S101 into a zirconium oxide container, add an appropriate amount of anhydrous ethanol, and ball mill it in a planetary ball mill for 4 hours. S103. Pour the well-mixed powder from S102 into a glass dish and dry it in an oven. S104. Place the dried powder from step S103 into a high-temperature furnace and sinter it at high temperature for 24 hours. Then, ball mill the sintered powder using a planetary ball mill for 4 hours. S105. Repeat step S104 three times to obtain nanoparticles. .

[0010] Furthermore, S2: preparing near-pure single domains The process of superconducting crystal formation is as follows: S201, Preparation of Nd123 Powder: Preparation of Nd123 Powder , and The three powders were mixed uniformly in a molar ratio of 1:4:6, sintered at 910℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain... (Nd123) powder, in which Preparation of Nd211 powder: , and The three powders were mixed uniformly in a molar ratio of 1:1:1, sintered at 915℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (Nd211) powder; Nd123 powder and Nd211 powder are mixed at a mass ratio of 3:1, and then 8wt% of [a specific ingredient] is added. The powder is mixed evenly, pressed into Nd:barium copper oxide precursor blocks, and sintered in a high-temperature crystal growth furnace to obtain Nd:barium copper oxide bulk material; small cubes of Nd:barium copper oxide with natural cleavage are taken as seed crystals. S202, Preparation of solid precursor block: Preparation of 011 powder: ... and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: Mix the above powders evenly, weigh out 8g to 15g and press them into cylindrical solid precursor blocks; S203, Preparation of liquid phase precursor block: ... 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 19g to 30g of the mixture was weighed and pressed into cylindrical liquid phase precursor blocks. S204, weigh out 4g to 5g Press the support block into a diameter equal to that of the S203 liquid phase precursor block, and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate; S205, weigh out 6.5g Pressed into cylindrical precursor blocks, then cut into several 4×4×2mm pieces. 3 The transport layer; S206, Assembly Pioneer Block: Several... The single crystal block (6) is placed Place the support block (5) on the plate (7). On the single crystal block (6), the liquid phase precursor block (4) is placed on the support block (5), several transport layers (3) are placed on the liquid phase precursor block (4) at intervals, the solid phase precursor block (2) is placed on the transport layer (3), and the neodymium barium copper oxide seed crystal (1) is placed on the solid phase precursor block (2). S207. Place the precursor block assembled in S206 into a high-temperature crystal growth furnace for growth to obtain a single domain. Blocks; S208, Oxygen permeation treatment: This process removes the single domains of S207. The bulk material is placed in a quartz tube oxygen infiltration furnace and oxygenated according to the appropriate program to obtain single-domain oxygen infiltration. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0011] Furthermore, the single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, increased to 1051℃ at a rate of 50–60℃ / h, held at 1051℃ for 2.5 hours, decreased to 1028℃ at a rate of 45℃ / h, and slowly cooled to 1011℃ at a rate of 0.2–0.4℃ / h. The material is then allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

[0012] Furthermore, the single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, then increased to 1045℃ at a rate of 130℃ / h, held at 1045℃ for 2 hours, and then decreased to 1020℃ at a rate of 60℃ / h. The temperature is then lowered in two steps: first rapidly decreased to 1012℃ at a rate of 1℃ / h, and then slowly cooled to 990℃ at a rate of 0.2℃ / h. Finally, the material is allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

[0013] Furthermore, the near-pure single domains in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0014] Furthermore, the near-pure single domains in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 440℃ at a rate of 90℃ / h, then slowly cooled to 410℃ at a rate of 0.15℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0015] The advantages of this invention are: this invention provides a method for preparing near-pure single domains. The method of superconducting crystals, through doping Nanoparticles, modified traditional TSMTG and TSIG methods for preparing single domains The method for subdomain structure and non-superconducting second-phase micro / nano particle distribution in superconducting bulk materials is first applied to single-domain materials. A new tetragonal prism-shaped subdomain region was grown in the superconducting bulk material. This subdomain region is a near-pure single domain that contains almost no second-phase micro / nano particles. Superconducting crystals were prepared by solid-state sintering. Nanoparticles, where the range of values ​​for 'a' is... , It consists of a single rare earth element and a mixture of multiple rare earth elements. Near-pure single domains were prepared using the RE+011TSIG method. Superconducting crystals have the following solid-phase precursor bulk composition: ,in The range of values ​​for x is 0 ≤ x ≤ 10. It is doped with... Single domains of nanopowders Superconducting bulk materials are superior to traditional single-domain materials. The superconducting bulk material grows an additional quadrangular prism-shaped c-axis growth domain region, and the volume V of the c-axis growth domain region is... c Compared to traditional single domain V of superconducting bulk materials c Significantly increased, and physical properties significantly improved. Furthermore, the c-axis growth domains, shaped like square prisms, contain almost no [materials / resources]. Particles and Particles, for well-textured pure This subdomain is a near-pure single domain. Superconducting crystals. Therefore, doping. Nanoparticles can yield near-pure single domains. Superconducting crystals are used, and this method is easy to operate and requires minimal equipment. Furthermore, it is suitable for high-quality... Preparation and doping of superconducting thin films and tapes Near-pure single domains prepared from nanoparticles Superconducting crystals are high-quality target crystal materials. This method prepares near-pure single domains. Superconducting crystals are important for the study of... The crystal structure and physical property variation patterns of superconducting crystals can provide high-quality crystal materials; this is crucial for the preparation of high-quality... Superconducting thin films and superconducting tapes can provide high-quality target crystal materials.

[0016] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 It is doping Single domains of nanopowders Crystal subdomain structure diagram of superconducting bulk materials.

[0018] Figure 2 It is a pilot block assembly drawing.

[0019] Figure 3 It is a single domain in Example 2 Macroscopic morphology of the upper surface of the superconducting bulk sample.

[0020] Figure 4 It is a single domain in Example 3 Macroscopic morphology of the upper surface of the superconducting bulk sample.

[0021] Figure 5 It is a single domain in Example 4 Macroscopic morphology of the upper surface of the superconducting bulk sample.

[0022] Figure 6 The XRD patterns are those of the precursor powder in Example 5 after sintering at temperatures of 1090°C, 1120°C, 1150°C, 1180°C, and 1210°C.

[0023] Figure 7 The images are SEM images of the precursor powder in Example 5 after sintering at 1090℃, 1120℃, 1150℃, 1180℃ and 1210℃.

[0024] Figure 8 It is a single domain in Example 5 Macroscopic morphology of the upper surface of the superconducting bulk sample.

[0025] Figure 9 This is a magnetic levitation force diagram between the sample in Example 5 and a permanent magnet (20mm) with a surface magnetic field of 0.5T.

[0026] Figure 10 This is a magnetic field distribution diagram of the sample after being magnetized by an electromagnet with a magnetic field strength of 0.5T in Example 5.

[0027] Figure 11 This is a macroscopic topographic image of the sample cross-section in Example 6.

[0028] Figure 12 It is a conventional single domain in Example 6. Crystal subdomain structure diagram of superconducting bulk materials.

[0029] Figure 13 yes Figure 11 The region containing the non-superconducting phase impurity layer in the sample was magnified to obtain a SEM image of that region.

[0030] Explanation of reference numerals in the attached figures: 1. Neodymium barium copper oxide seed crystal; 2. Solid phase precursor block; 3. Transport layer; 4. Liquid phase precursor block; 5. Support block; 6. MgO single crystal block; 7. Al2O3 plate. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Example 1

[0036] The purpose of this embodiment is to provide a method for preparing near-pure single domains. The method for producing superconducting crystals involves doping. Nanoparticles, modified traditional TSMTG and TSIG methods for preparing single domains A method for subdomain structure and distribution of non-superconducting second-phase micro / nano particles in superconducting bulk materials.

[0037] Specifically, this embodiment provides a method for preparing near-pure single domains. The method for superconducting crystals includes the following steps: S1: Preparation containing Nanoparticles; S2: Preparation of near-pure single domains Superconducting crystals.

[0038] Furthermore, S1: the prepared containing The chemical formula of the nanopowder is ,in The range of values ​​for is , It is a single rare earth element or a mixture of multiple rare earth elements.

[0039] Furthermore, the containing The molar ratio of reagents used in the preparation of nanopowders is: 1 mole of a single rare earth element oxide, Moore's , Moore's 1 mole 1 mole Or: 1 mole of mixed rare earth element oxides, Moore's , Moore's 1 mole 1 mole .

[0040] Furthermore, the single rare earth element oxide is , , , Any one of the following; the mixed rare earth element oxide is , , , Any two, three, four... of the above can be mixed together; Furthermore, the containing The preparation method of nanopowder is as follows: S101, Preparation of mixed powder: Single rare earth element: analytically pure , , , , according to Mixing in a molar ratio; or: To prepare a mixture of multiple rare earth elements: different RE2O3s were mixed uniformly in a molar ratio of 1:1:1... to prepare a mixed rare earth oxide powder; the mixed rare earth oxide powder, , , , according to Mix in the specified molar ratio; S102. Place the mixed powder from S101 into a zirconium oxide container, add 100ml-150ml of anhydrous ethanol, and ball mill it in a planetary ball mill for 4 hours. S103. Pour the well-mixed powder from S102 into a glass dish and dry it in an oven. S104. Place the dried powder from step S103 into a high-temperature furnace and sinter it at 1135℃~1150℃ for 24 hours. Then, ball mill the sintered powder using a planetary ball mill for 4 hours. S105. Repeat step S104 three times to obtain nanoparticles. .

[0041] Furthermore, S2: preparing near-pure single domains The process of superconducting crystal formation is as follows: S201, Preparation of Nd123 Powder: Preparation of Nd123 Powder , and The three powders were mixed uniformly in a molar ratio of 1:4:6, sintered at 910℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain... (Nd123) powder, in which Preparation of Nd211 powder: , and The three powders were mixed uniformly in a molar ratio of 1:1:1, sintered at 915℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (Nd211) powder; Nd123 powder and Nd211 powder are mixed at a mass ratio of 3:1, and then 8wt% of [a specific ingredient] is added. The powder is mixed evenly, pressed into Nd:barium copper oxide precursor blocks, and sintered in a high-temperature crystal growth furnace to obtain Nd:barium copper oxide bulk material; small cubes of Nd:barium copper oxide with natural cleavage are taken as seed crystals. S202, Preparation of solid precursor block: Preparation of 011 powder: ... and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: Mix the above powders evenly, weigh out 8g to 15g and press them into cylindrical solid precursor blocks; S203, Preparation of liquid phase precursor block: ... 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 19g to 30g of the mixture was weighed and pressed into cylindrical liquid phase precursor blocks. S204, Weigh out 4g to 5g Press the support block into a diameter equal to that of the S203 liquid phase precursor block, and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate; S205, weigh out 6.5g Pressed into cylindrical precursor blocks, then cut into several 4×4×2mm pieces. 3 The transport layer; S206, Assembly Pioneer Block: Combining several... Single crystal block 6 is placed Place the support block 5 on plate 7. On the single crystal block 6, the liquid phase precursor block 4 is placed on the support block 5, several transport layers 3 are placed on the liquid phase precursor block 4 at intervals, the solid phase precursor block 2 is placed on the transport layer 3, and the neodymium barium copper oxide seed crystal 1 is placed on the solid phase precursor block 2. S207. Place the precursor block assembled in S206 into a high-temperature crystal growth furnace for growth to obtain a single domain. Blocks; S208, Oxygen permeation treatment: This process removes the single domains of S207. The bulk material is placed in a quartz tube oxygen infiltration furnace and oxygenated according to the appropriate program to obtain single-domain oxygen infiltration. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0042] Furthermore, the single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, increased to 1051℃ at a rate of 50–60℃ / h, held at 1051℃ for 2.5 hours, decreased to 1028℃ at a rate of 45℃ / h, and slowly cooled to 1011℃ at a rate of 0.2–0.4℃ / h. The material is then allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

[0043] Furthermore, the single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, then increased to 1045℃ at a rate of 130℃ / h, held at 1045℃ for 2 hours, and then decreased to 1020℃ at a rate of 60℃ / h. The temperature is then lowered in two steps: first rapidly decreased to 1012℃ at a rate of 1℃ / h, and then slowly cooled to 990℃ at a rate of 0.2℃ / h. Finally, the material is allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

[0044] Furthermore, the near-pure single domains in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials; for single domains Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0045] Furthermore, the near-pure single domains in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 440℃ at a rate of 90℃ / h, then slowly cooled to 410℃ at a rate of 0.15℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials; for single domains Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0046] Furthermore, near-pure single domains are obtained in S208. Superconducting crystals are tetragonal prisms; the tetragonal prism-shaped subdomains refer to: doped... Single domains of nanopowders The subdomain region unique to superconducting bulk materials, compared with traditional single domains Compared to superconducting bulk materials, containing Single domains of nanopowders Pyramid-shaped protrusions appear on the upper surface of the superconducting bulk material, and a square prism-shaped c-axis growth region without non-superconducting phases grows below the seed crystal, forming a well-textured pure superconducting material. This subdomain is a near-pure single domain. Superconducting crystal. This prism-shaped pure c-axis single domain... The superconducting crystal region and the four adjacent a-axis growth regions are separated by impurity layers such as Zr-containing non-superconducting phase compounds.

[0047] Furthermore, the near-pure single domain Superconducting crystals are prepared by melt infiltration growth.

[0048] Furthermore, the near-pure single domain Superconducting crystals are a type of high-quality target crystal material.

[0049] In summary, this embodiment provides a method for preparing near-pure single domains. The method of superconducting crystals, through doping Nanoparticles, modified traditional TSMTG and TSIG methods for preparing single domains The method for subdomain structure and non-superconducting second-phase micro / nano particle distribution in superconducting bulk materials is first applied to single-domain materials. A new tetragonal prism-shaped subdomain region was grown in the superconducting bulk material. This subdomain region is a near-pure single domain that contains almost no second-phase micro / nano particles. Superconducting crystals were prepared by solid-state sintering. Nanoparticles, where the range of values ​​for 'a' is... , It consists of a single rare earth element and a mixture of multiple rare earth elements. Near-pure single domains were prepared using the RE+011TSIG method. Superconducting bulk material, its solid-phase precursor bulk composition is as follows: ,in The range of values ​​for x is 0 ≤ x ≤ 10. It is doped with... Single domains of nanopowders Superconducting bulk materials are superior to traditional single-domain materials. The superconducting bulk material grows an additional quadrangular prism-shaped c-axis growth domain region, and the volume V of the c-axis growth domain region is... c Compared to traditional single domain V of superconducting bulk materials c Significantly increased, and physical properties significantly improved. Furthermore, the c-axis growth domains, shaped like square prisms, contain almost no [materials / resources]. Particles and Particles, for well-textured pure This subdomain is a near-pure single domain. Superconducting crystals. Therefore, doping. Nanoparticles can yield near-pure single domains. Superconducting crystals are used, and this method is easy to operate and requires minimal equipment. Furthermore, it is suitable for high-quality... Preparation and doping of superconducting thin films and tapes Near-pure single domains prepared from nanoparticles Superconducting crystals are high-quality target crystal materials. This method prepares near-pure single domains. Superconducting crystals are important for the study of... The crystal structure and physical property variation patterns of superconducting crystals can provide high-quality crystal materials; this is crucial for the preparation of high-quality... Superconducting thin films and superconducting tapes can provide high-quality target crystal materials.

[0050] Example 2 , When a=0, Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials: 1) Preparation Nanoparticles: (1) Analytical purity , , and The powder was prepared in a molar ratio of 1:4:1:1 and placed into a zirconium oxide container.

[0051] (2) Pour 150ml of anhydrous ethanol into a zirconium oxide jar, stir it with a spoon, and then put the zirconium oxide jar into a planetary ball mill for 4 hours.

[0052] (3) Pour the wet-mixed powder into a glass dish and put it in an oven to dry.

[0053] (4) The dried powder is placed in a high-temperature furnace and sintered at 1135°C for 24 hours. The sintered powder is then ball-milled for 4 hours.

[0054] (5) Repeat step (4) 3 times to obtain a purer product. Powder.

[0055] 2) Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials (1) Preparation of neodymium barium copper oxide seed crystals.

[0056] (2) Preparation of solid precursor blocks: and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: Mix the above powders evenly, weigh out 8g and press them into solid precursor blocks with a diameter of 20mm.

[0057] (3) Preparation of liquid phase precursor block: 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 19g of the mixture was weighed and pressed into a liquid phase precursor block with a diameter of 32mm.

[0058] (4) Weigh out 4.5g Press the support block into a diameter equal to that of the liquid phase precursor block in step (3), and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate.

[0059] (5) Weigh out 6.5g The precursor block is pressed into a diameter of 40mm and then cut into several 4mm×4mm×2mm transport layers. (6) Assembling the precursor blocks: Place several MgO single crystal blocks 6 on the Al2O3 plate 7, place the support block 5 on the MgO single crystal blocks 6, place the liquid phase precursor block 4 on the support block 5, place several transport layers 3 at intervals on the liquid phase precursor block 4, place the solid phase precursor block 2 on the transport layer 3, and place the neodymium barium copper oxide seed crystal 1 on the solid phase precursor block 2; Figure 2 As shown.

[0060] (7) Place the assembled precursor block from step (6) in a high-temperature crystal growth furnace, heat it to 910°C at a rate of 90-120°C / h, hold it at 910°C for 10h, heat it to 1045°C at a rate of 130°C / h, hold it at 1045°C for 2h, cool it to 1020°C at a rate of 60°C / h, and then cool it in two steps: first, rapidly cool it to 1012°C at a rate of 1°C / h, and then slowly cool it to 990°C at a rate of 0.2°C / h. Then, allow it to cool naturally to room temperature with the furnace to obtain a single domain. Block.

[0061] (8) The single domain of step (7) The bulk material was placed in a quartz tube oxygen infiltration furnace and heated to 440℃ at a rate of 90℃ / h, then slowly cooled to 410℃ at a rate of 0.15℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature with the furnace to obtain a single domain. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0062] Figure 3 It is a single domain Macroscopic morphology of the upper surface of the superconducting bulk sample. Obvious pyramidal protrusions appear on the upper surface of the sample.

[0063] Example 3 When MRE=Gd, a=0 Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials: 1) Preparation Nanoparticles: (1) Analytical purity , , and Weigh out 8.017g, 17.457g, 1.799g and 2.725g respectively in a molar ratio of 1:4:1:1 and put them into a zirconium oxide jar.

[0064] (2) Pour anhydrous ethanol into a zirconium oxide container, stir it with a spoon, and then put the zirconium oxide container into a planetary ball mill for 4 hours.

[0065] (3) Pour the wet-mixed powder into a glass dish and put it in an oven to dry.

[0066] (4) Place the dried powder into a high-temperature furnace and sinter at 1140℃ for 24 hours. Then ball mill the sintered powder for 4 hours.

[0067] (5) Repeat step (4) 3 times to obtain a purer product. Powder.

[0068] 2) Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials (1) Preparation of neodymium barium copper oxide seed crystals.

[0069] (2) Preparation of solid precursor blocks: and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. Powder; the composition of solid-phase precursor powder is as follows Mix the above powders evenly, weigh out 14g and press them into solid precursor blocks with a diameter of 20mm.

[0070] (3) Preparation of liquid phase precursor block: 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 25g of the mixture was weighed and pressed into a liquid phase precursor block with a diameter of 32mm.

[0071] (4) Weigh out 4.5g Press the support block into a diameter equal to that of the liquid phase precursor block in step (3), and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate.

[0072] (5) Weigh out 6.5g The precursor block is pressed into a diameter of 40mm and then cut into several 4mm×4mm×2mm transport layers. (6) Assemble the precursor blocks: Place several MgO single crystal blocks 6 on the Al2O3 plate 7, place the support block 5 on the MgO single crystal blocks 6, place the liquid phase precursor block 4 on the support block 5, place several transport layers 3 at intervals on the liquid phase precursor block 4, place the solid phase precursor block 2 on the transport layer 3, and place the neodymium barium copper oxide seed crystal 1 on the solid phase precursor block 2.

[0073] (7) Place the assembled precursor block in a high-temperature crystal growth furnace, heat it to 910℃ at a rate of 90-120℃ / h, hold it at 910℃ for 10h, heat it to 1051℃ at a rate of 50-60℃ / h, hold it at 1051℃ for 2.5h, cool it to 1028℃ at a rate of 45℃ / h, and slowly cool it to 1011℃ at a rate of 0.2-0.4℃ / h. Then let it cool naturally to room temperature with the furnace to obtain a single domain. Block.

[0074] (8) The single domain of step (7) The bulk material was placed in a quartz tube oxygen infiltration furnace and heated to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature with the furnace to obtain a single domain. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0075] Figure 4 It is a single domain Macroscopic morphology of the upper surface of the superconducting bulk sample. Obvious pyramidal protrusions appear on the upper surface of the sample.

[0076] Example 4 When MRE=Gd, a=2 Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials: 1) Preparation Nanoparticles: (1) Analytical purity , , , and Weigh out 8.65g, 9.41g, 7.046g, 1.94g and 2.94g respectively in a molar ratio of 1:2:2:1:1 and put them into a zirconium oxide jar.

[0077] (2) Pour anhydrous ethanol into a zirconium oxide container, stir it with a spoon, and then put the zirconium oxide container into a planetary ball mill for 4 hours.

[0078] (3) Pour the wet-mixed powder into a glass dish and put it in an oven to dry.

[0079] (4) Place the dried powder into a high-temperature furnace and sinter at 1140℃ for 24 hours. Then ball mill the sintered powder for 4 hours.

[0080] (5) Repeat step (4) 3 times to obtain a purer product. Powder.

[0081] 2) Nanoparticles for single domains Influence of macroscopic morphology on superconducting bulk materials (1) Preparation of neodymium barium copper oxide seed crystals.

[0082] (2) Preparation of solid precursor blocks: and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: Mix the above powders evenly, weigh out 14g and press them into solid precursor blocks with a diameter of 20mm.

[0083] (3) Preparation of liquid phase precursor block: 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 25g of the mixture was weighed and pressed into a liquid phase precursor block with a diameter of 32mm.

[0084] (4) Weigh out 4.5g Press the support block into a diameter equal to that of the liquid phase precursor block in step (3), and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate.

[0085] (5) Weigh out 6.5g It is pressed into a precursor block with a diameter of 40mm and cut into several transmission layers of 4mm×4mm×2mm.

[0086] (6) Assemble the pilot block: Assemble several The single crystal block 6 is placed on the Al2O3 plate 7, and the support block 5 is placed on... On the single crystal block 6, the liquid phase precursor block 4 is placed on the support block 5, several transport layers 3 are placed on the liquid phase precursor block 4 at intervals, the solid phase precursor block 2 is placed on the transport layer 3, and the neodymium barium copper oxide seed crystal 1 is placed on the solid phase precursor block 2.

[0087] (7) Place the assembled precursor block from step (6) in a high-temperature crystal growth furnace, heat it to 910°C at a rate of 90–120°C / h, hold it at 910°C for 10 h, heat it to 1051°C at a rate of 50–60°C / h, hold it at 1051°C for 2.5 h, cool it to 1028°C at a rate of 45°C / h, and slowly cool it to 1011°C at a rate of 0.2–0.4°C / h. Then allow it to cool naturally to room temperature with the furnace to obtain a single domain. Block.

[0088] (8) The single domain of step (7) The bulk material was placed in a quartz tube oxygen infiltration furnace and heated to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature with the furnace to obtain a single domain. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0089] Figure 5 It is a single domain Macroscopic morphology of the upper surface of the superconducting bulk sample. Obvious pyramidal protrusions appear on the upper surface of the sample.

[0090] Example 5: When MRE=YGd, a=2 Nanopowder Pair Influence of superconducting bulk material physical properties: 1) Preparation Nanoparticles: (1) Analytical purity , , , , and Weigh out 30.5422g, 66.5080g, 13.4081g, 49.7558g, 20.7642g and 19.0256g respectively in a molar ratio of 1:1:4:4:2:2 and place them into a zirconium oxide jar.

[0091] (2) Pour 150ml of anhydrous ethanol into a zirconium oxide jar, stir it with a spoon, and then put the zirconium oxide jar into a planetary ball mill for 4 hours.

[0092] (3) Pour the wet-mixed powder into a glass dish and put it in an oven to dry.

[0093] (4) The dried powder was divided into five groups and placed in a high-temperature furnace. The powder was sintered at 1090℃, 1120℃, 1150℃, 1180℃ and 1210℃ for 24 hours respectively. The sintered powder was then ball-milled for 4 hours.

[0094] (5) Repeat step (4) 3 times to obtain a purer powder.

[0095] (6) Use X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze which temperature produces the purest powder with the smallest particle size. Figure 6 These are the XRD patterns of the precursor powder after sintering at temperatures of 1090℃, 1120℃, 1150℃, 1180℃ and 1210℃. Figure 7The images are SEM images of the precursor powder after sintering at 1090℃, 1120℃, 1150℃, 1180℃ and 1210℃, where (a) 1090℃, (b) 1120℃, (c) 1150℃, (d) 1180℃, and (e) 1210℃.

[0096] (7) From step (6), it is found that the powder sintered at 1150℃ is the purest and has the smallest particle size.

[0097] 2) Nanopowder Pair Influence of physical properties of superconducting bulk materials (1) Preparation of neodymium barium copper oxide seed crystals.

[0098] (2) Preparation of solid precursor blocks: and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: ,in x =0, 1, 2, 3, 4, 5, 6, 7, 9. Mix the above powders evenly, weigh out 15g and press them into solid precursor blocks with a diameter of 20mm.

[0099] (3) Preparation of liquid phase precursor block: 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 30g of the mixture was weighed and pressed into a liquid phase precursor block with a diameter of 32mm.

[0100] (4) Weigh out 4.5g Press the support block into a diameter equal to that of the liquid phase precursor block in step (3), and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate.

[0101] (5) Weigh out 6.5g The precursor block is pressed into a diameter of 40mm and then cut into several 4mm×4mm×2mm transport layers. (6) Assemble the pilot block: assemble several Single crystal block 6 is placed in step (4) Place the support block 5 on plate 7. On the single crystal block 6, the liquid phase precursor block 4 is placed on the support block 5, several transport layers 3 are placed on the liquid phase precursor block 4 at intervals, the solid phase precursor block 2 is placed on the transport layer 3, and the neodymium barium copper oxide seed crystal 1 is placed on the solid phase precursor block 2.

[0102] (7) Place the assembled precursor block from step (6) in a high-temperature crystal growth furnace, heat it to 910°C at a rate of 90–120°C / h, hold it at 910°C for 10 h, heat it to 1051°C at a rate of 50–60°C / h, hold it at 1051°C for 2.5 h, cool it to 1028°C at a rate of 45°C / h, and slowly cool it to 1011°C at a rate of 0.2–0.4°C / h. Then allow it to cool naturally to room temperature with the furnace to obtain a single domain. Block.

[0103] (8) The single domain of step (7) The bulk material was placed in a quartz tube oxygen infiltration furnace and heated to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature with the furnace to obtain a single domain. Superconducting bulk materials. For single domains. Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

[0104] Figure 8 It is a single domain Macroscopic morphology of the upper surface of the superconducting bulk sample, where (a) x =0, (b) x =1, (c) x =2, (d) x =3, (e) x =4, (f) x =5, (g) x =6, (h) x =7, (i) x =9. As the doping concentration increases, increasingly wider pyramidal protrusions appear on the upper surface of the sample. Figure 9 It is the magnetic levitation force between the sample and a permanent magnet (20mm) with a surface magnetic field of 0.5T. Figure 10 This is a magnetic field distribution diagram of the sample after being magnetized by an electromagnet with a magnetic field strength of 0.5T.

[0105] Doped with 3wt% When nanoparticles are used, the magnetic levitation force of the sample reaches 46N, and the trapping magnetic field reaches 0.443T.

[0106] Example 6 When MRE=YGd, a=2 Nanopowder Influence of crystal structure on superconducting bulk materials: 1) Cut the sample of Example 5 along its diameter with a diamond saw blade, first smooth the cross section with 100-2000 grit sandpaper, and then remove the fine scratches on the cross section with alumina polishing liquid. Figure 11This is a macroscopic topography diagram of the sample cross-section; the area marked with a red box represents the net single domain. Superconducting crystal region, where (a) x =0, (b) x =1, (c) x =2, (d) x =3, (e) x =4, (f) x =5, (g) x =6, (h) x =7, (i) x When x = 9 and x ≥ 6, the GdBCO superconducting bulk material no longer exhibits a single-domain morphology, therefore it is not labeled. Net Single Domain The dimensions of the superconducting crystal region are approximately 3.9 mm × 3.9 mm × 2.4 mm. x =1), 5.2mm×5.2mm×2.8mm ( x =2), 5.7mm×5.7mm×2.8mm ( x =3), 7.8mm×7.8mm×3.5mm ( x =4), 8.0mm×8.0mm×3.5mm ( x =5).

[0107] 2) Draw a three-dimensional crystal structure diagram. Figure 12 It is a traditional single domain Crystal subdomain structure diagram of superconducting bulk materials. Figure 1 It is mixed with Single domains of nanopowders Subdomain structure diagram of superconducting bulk crystal. The gray transparent areas represent the a-axis growth domains, and the blue areas represent the c-axis growth domains. Figure 1 The blue prismatic regions are doped Subdomains grown from nanoparticles, these are prismatic pure c-axis single domains The crystal region and the four adjacent a-axis growth regions are separated by impurity layers such as Zr-containing non-superconducting phase compounds. Figure 1 Black layered area). Figure 1 The area of ​​the c-axis growth domain is significantly larger than that of the c-axis growth domain. Figure 12 The area of ​​the c-axis growth domain region.

[0108] 3) Figure 11 A magnified view of the region containing the non-superconducting phase impurity layer in the sample was obtained, as shown in the SEM image. Figure 13 As shown, it was found that there were almost no [specific characteristics] in the prismatic c-axis growth domain region. Particles and Particles exhibiting well-textured purity Phase. Therefore, it can be concluded that this prismatic subdomain region is a near-pure single domain. Superconducting crystals. Therefore, doping. Near-pure single-domain superconducting crystals (#imgpt403#) can be prepared.

[0109] 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 method for preparing near-pure single domains The method for using superconducting crystals is characterized by: Includes the following steps: S1: Preparation containing Nanoparticles; S2: Preparation of near-pure single domains Superconducting crystals.

2. The method for preparing near-pure single domains as described in claim 1 The method for using superconducting crystals is characterized by: S1: The prepared containing The chemical formula of the nanopowder is ,in The range of values ​​is , It is a single rare earth element or a mixture of multiple rare earth elements.

3. The method for preparing near-pure single domains as described in claim 2 The method for using superconducting crystals is characterized by: The containing The molar ratio of reagents used in the preparation of nanopowders is: 1 mole of a single rare earth element oxide, Moore's , Moore's 1 mole 1 mole ; Or: 1 mole of mixed rare earth element oxides, Moore's , Moore's 1 mole 1 mole .

4. The method for preparing near-pure single domains as described in claim 3 The method for using superconducting crystals is characterized by: The containing The preparation method of nanopowder is as follows: S101, Preparation of mixed powder: For single rare earth elements: analytically pure , , , , according to Mix in the specified molar ratio; Or: To prepare a mixture of multiple rare earth elements: different RE2O3s were mixed uniformly in a molar ratio of 1:1:1... to prepare a mixed rare earth oxide powder; the mixed rare earth oxide powder, , , , according to Mix in the specified molar ratio; S102. Place the mixed rare earth oxide powder from S101 into a zirconium oxide container, add an appropriate amount of anhydrous ethanol, and place it in a planetary ball mill for 4 hours. S103. Pour the well-mixed powder from S102 into a glass dish and dry it in an oven. S104. Place the dried powder from step S103 into a high-temperature furnace and sinter it at high temperature for 24 hours. Then, ball mill the sintered powder using a planetary ball mill for 4 hours. S105. Repeat step S104 three times to obtain nanoparticles. .

5. The method for preparing near-pure single domains as described in claim 1 The method for using superconducting crystals is characterized by: S2: Preparation of near-pure single domains The preparation process of superconducting crystals is as follows: S201, Preparation of Nd123 Powder: Preparation of Nd123 Powder , and The three powders were mixed uniformly in a molar ratio of 1:4:6, sintered at 910℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain... (Nd123) powder, in which ; Preparation of Nd211 powder: , and The three powders were mixed uniformly in a molar ratio of 1:1:1, sintered at 915℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (Nd211) powder; Nd123 powder and Nd211 powder were mixed at a mass ratio of 3:1, and then 8 wt% of [a specific ingredient] was added. The powder is mixed evenly, pressed into Nd:barium copper oxide precursor blocks, and sintered in a high-temperature crystal growth furnace to obtain Nd:barium copper oxide bulk material; small cubes of Nd:barium copper oxide with natural cleavage are taken as seed crystals. S202, Preparation of solid precursor block: Preparation of 011 powder: ... and The two powders were mixed uniformly at a molar ratio of 1:1, sintered at 900℃ for 24 hours using a solid-state sintering method, and then ball-milled for 4 hours. The sintering and ball-milling processes were repeated three times to obtain the desired product. (011) Powder; the composition of the solid-phase precursor powder is as follows: Mix the above powders evenly, weigh out 8g to 15g and press them into cylindrical solid precursor blocks; S203, Preparation of liquid phase precursor block: ... 011 powder and The three powders were mixed evenly in a molar ratio of 1:10:6, and 19g to 30g of the mixture was weighed and pressed into cylindrical liquid phase precursor blocks. S204, weigh out 4g to 5g Press the support block into a diameter equal to that of the liquid phase precursor block of S203, and prepare several blocks of the same height. Single crystal block, prepare one with a diameter larger than the liquid phase precursor block. plate; S205, weigh out 6.5g Pressed into cylindrical precursor blocks, then cut into several 4×4×2mm pieces. 3 The transport layer; S206, Assembly Pioneer Block: Combining several... The single crystal block (6) is placed Place the support block (5) on the plate (7). On the single crystal block (6), the liquid phase precursor block (4) is placed on the support block (5), several transport layers (3) are placed on the liquid phase precursor block (4) at intervals, the solid phase precursor block (2) is placed on the transport layer (3), and the neodymium barium copper oxide seed crystal (1) is placed on the solid phase precursor block (2). S207. Place the precursor block assembled in S206 into a high-temperature crystal growth furnace for growth to obtain a single domain. Blocks; S208, Oxygen permeation treatment: This process removes the single domains of S207. The bulk material is placed in a quartz tube oxygen infiltration furnace and oxygenated according to the appropriate program to obtain single-domain oxygen infiltration. Superconducting bulk materials; for single domains Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

6. The method for preparing near-pure single domains as described in claim 5 The method for using superconducting crystals is characterized by: The single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, increased to 1051℃ at a rate of 50–60℃ / h, held at 1051℃ for 2.5 hours, decreased to 1028℃ at a rate of 45℃ / h, and slowly cooled to 1011℃ at a rate of 0.2–0.4℃ / h. The material is then allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

7. The method for preparing near-pure single domains as described in claim 5 The method for using superconducting crystals is characterized by: The single domain obtained in S207 The bulk is a single domain The bulk material preparation process is as follows: The temperature is increased to 910℃ at a rate of 90–120℃ / h, held at 910℃ for 10 hours, then increased to 1045℃ at a rate of 130℃ / h, held at 1045℃ for 2 hours, and then decreased to 1020℃ at a rate of 60℃ / h. The temperature is then lowered in two steps: first rapidly decreased to 1012℃ at a rate of 1℃ / h, and then slowly cooled to 990℃ at a rate of 0.2℃ / h. Finally, the material is allowed to cool naturally to room temperature in the furnace to obtain a single domain. Block.

8. A method for preparing near-pure single domains as described in claim 5, 6, or 7. The method for using superconducting crystals is characterized by: The near-pure single domain in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 430℃ at a rate of 90℃ / h, then slowly cooled to 350℃ at a rate of 0.4℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials; for single domains Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

9. A method for preparing near-pure single domains as described in claim 5, 6, or 7. The method for using superconducting crystals is characterized by: The near-pure single domain in S208 Superconducting crystals are near-pure single domains The oxygen permeation process for superconducting crystals is as follows: The temperature is increased to 440℃ at a rate of 90℃ / h, then slowly cooled to 410℃ at a rate of 0.15℃ / h, held at that temperature for 24 hours, and then allowed to cool naturally to room temperature in the furnace to obtain single-domain crystals. Superconducting bulk materials; for single domains Near-pure single domains were obtained by cutting away superconducting bulk material. Superconducting crystals.

Images