Method for preparing superconducting block through top seed crystal melt texture growth and superconducting block
By using a top-seeded melt textured growth method and only one type of powder, BaCuO2, combined with a heat treatment process, the problems of complex processes and high costs in existing technologies have been solved, and high-performance REBCO superconducting bulk materials have been prepared efficiently.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEST JIAOTONG UNIV
- Filing Date
- 2026-01-19
- Publication Date
- 2026-05-08
AI Technical Summary
Existing technologies require two or more types of powder to prepare REBCO superconducting bulk materials, which is complex, costly, and results in powder waste.
Superconducting bulk materials are prepared by using a mixture of RE2O3, BaCuO2, and CuO pressed precursor blocks, combined with a top seed crystal melt texture growth method, and by controlling the heat treatment process. Only one type of powder, BaCuO2, is required, which simplifies the process and reduces costs.
This technology enables the efficient preparation of high-performance superconducting bulk materials, improving preparation efficiency, reducing costs, and optimizing superconducting performance.
Smart Images
Figure CN122000129A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of superconducting materials technology, specifically relating to a method for preparing superconducting bulk materials by top seed crystal melting texture growth and the superconducting bulk materials themselves. Background Technology
[0002] RE-Ba-Cu-O (REBCO, where RE represents rare earth elements such as Y, Gd, Sm, and Nd) series high-temperature superconducting bulk materials possess properties such as high magnetic levitation force, high critical transition temperature, and large unhindered current carrying capacity, showing great promise for applications in superconducting magnetic levitation, superconducting motors, and superconducting flywheel energy storage. In the preparation of REBCO superconducting bulk materials, the previously used top-seeded crystal infiltration growth method (TSIG) required the pre-preparation of two or more powders, such as REBa2Cu3O. 6.5 The processes of refining RE2BaCuO5 and Ba3Cu5O8 consume a lot of time and are quite complicated, while also causing some waste of powder.
[0003] While existing technologies enable the preparation of REBCO superconducting bulk materials using only one type of powder (BaCuO2), they employ a melt infiltration growth method, which requires pressing two precursors—solid and liquid phases—resulting in a complex and costly process. Therefore, there is an urgent need to develop a melt texture growth method that requires only one type of powder to prepare superconducting bulk materials, thereby simplifying the process and reducing costs. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing superconducting bulk materials through top seed crystal melt texture growth, and the superconducting bulk material itself, to improve the aforementioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows:
[0005] This application provides a method for preparing superconducting bulk materials by top seed crystal melt texture growth, including:
[0006] A precursor block was obtained by mixing RE2O3, BaCuO2, and CuO and pressing the mixture; RE represents rare earth elements; the molar ratio of RE2O3:BaCuO2:CuO was 1:x:1; and x was 2.3-3.0.
[0007] Support pads are obtained by pressing Yb2O3 or Y2O3 powder;
[0008] Al2O3 plate, MgO single crystal, support pad, precursor block and NdBCO seed crystal doped with MgO are stacked sequentially from bottom to top to assemble the embryo.
[0009] The preform is heated to 900℃-910℃ at a rate of 80-110℃ / h and held at this temperature for 8-10 hours. Then, it is heat-treated according to the preset temperature control program for preparing superconducting bulk materials corresponding to rare earth elements. Finally, it is cooled to room temperature with the furnace temperature to obtain REBCO superconducting bulk material.
[0010] Oxygen permeation treatment was performed on REBCO superconducting bulk material to obtain superconducting bulk material with single-domain texture.
[0011] Optionally, the method includes:
[0012] Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 4-5 hours to obtain a mixed powder.
[0013] The mixed powder was calcined and then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
[0014] Optionally, the calcination conditions are calcination at 900℃-920℃ for 24-28 hours.
[0015] Optionally, the oxygen permeation treatment includes: cooling the REBCO superconducting block material from 430°C to 350°C in a circulating oxygen environment and annealing for 195-205 hours.
[0016] Optionally, the RE2O3 is a rare earth oxide, including any one of Y2O3, Gd2O3, Sm2O3, etc.
[0017] Optionally, when RE is Gd, the preset temperature control program is as follows: increase the temperature to 1050-1058℃ at a rate of 60-70℃ / h, hold for 1.5-2.5 hours, then decrease the temperature to 1030℃-1035℃ at a rate of 18-28℃ / h, and then decrease the temperature to 1005℃-1018℃ at a rate of 0.2-0.4℃ / h.
[0018] Optionally, when RE is Y, the preset temperature control program is as follows: increase the temperature to 1035-1042℃ at a rate of 60-70℃ / h, maintain the temperature for 1.5-2.5 hours, then decrease the temperature to 993℃-1000℃ at a rate of 18-28℃ / h, and then decrease the temperature to 968℃-983℃ at a rate of 0.2-0.4℃ / h.
[0019] Optionally, when RE is Sm, the preset temperature control program is as follows: increase the temperature to 1065-1073℃ at a rate of 60-70℃ / h, hold for 1.5-2.5 hours, then decrease the temperature to 1050℃-1058℃ at a rate of 18-28℃ / h, and then decrease the temperature to 1030℃-1040℃ at a rate of 0.2-0.4℃ / h.
[0020] Optionally, the diameter of the front drive block and the support pad are the same.
[0021] Optionally, the height of the MgO single crystal is 2-10 mm.
[0022] Optionally, the number of MgO single crystals is three or more (as long as the support is stable, there are no special requirements), and the MgO single crystals are distributed in a circumferential array at the bottom of the support pad.
[0023] Optionally, the size of the MgO-doped NdBCO seed crystal is 1×1×1 mm. 3 -2×2×2mm 3 .
[0024] This application also provides a superconducting bulk material, which is prepared by the above-described method.
[0025] The beneficial effects of this invention are as follows:
[0026] This invention provides a melt-textured growth method for preparing superconducting bulk materials using only one type of powder: RE₂O₃ + xBaCuO₂ + CuO (RE₂O₃ can be Y₂O). 3、 Gd2O 3、 By using appropriate mixing ratios of Sm2O3 and other materials, high-performance superconducting bulk materials such as YBCO, GdBCO, and SmBCO can be successfully prepared. This significantly improves preparation efficiency, reduces costs, and optimizes superconducting performance.
[0027] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. Attached Figure Description
[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0029] Figure 1 This is an assembly diagram of the embryo from Example 1;
[0030] Figure 2 Images of the GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7;
[0031] Figure 3 The magnetic levitation force test curves of the GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7 are shown.
[0032] Figure 4The magnetic levitation force density test results are for the GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0035] Example 1:
[0036] A method for preparing superconducting bulk materials by top seed crystal melt texture growth: including:
[0037] Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 4 hours to obtain a mixed powder.
[0038] The mixed powder was calcined at 900℃ for 26 hours, then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
[0039] A precursor block was obtained by mixing RE₂O₃, BaCuO₂, and CuO and pressing the mixture; RE represents the rare earth element Gd; the molar ratio of RE₂O₃:BaCuO₂:CuO was 1:x:1; x was 2.5; and the diameter of the precursor block was 30 mm.
[0040] The support pad was obtained by pressing Y2O3 powder; the support pad was 2mm thick and 30mm in diameter.
[0041] The Al2O3 plate, MgO single crystal, support pad, precursor block, and MgO-doped NdBCO seed crystal are stacked sequentially from bottom to top to assemble the preform; see [link to documentation]. Figure 1 This is the assembly diagram of the embryo;
[0042] The number of MgO single crystals is three, arranged in a circular array at the bottom of the support pad; the height of the MgO single crystal is 5 mm; the NdBCO seed crystals doped with MgO are commercially available, with a size of 1.5 × 1.5 × 1 mm. 3 ;
[0043] The assembled preform is placed in a high-temperature furnace and heated to 900°C at a rate of 105°C / h, and held at this temperature for 10 hours. Then, it is raised to 1050°C at a rate of 60°C / h and held for 2.0 hours. Then, it is cooled to 1030°C at a rate of 18°C / h, and then cooled to 1010°C at a rate of 0.2°C / h. Finally, it is cooled to room temperature along with the furnace temperature to obtain GdBCO superconducting bulk material.
[0044] GdBCO superconducting bulk material was subjected to oxygen permeation treatment, and then slowly cooled from 430℃ to 350℃ in a circulating oxygen environment and annealed for 200 hours to obtain superconducting bulk material with single-domain texture.
[0045] Example 2:
[0046] A method for preparing superconducting bulk materials by top seed crystal melt texture growth: including:
[0047] Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 4 hours to obtain a mixed powder.
[0048] The mixed powder was calcined at 900℃ for 26 hours, then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
[0049] A precursor block was obtained by mixing RE2O3, BaCuO2, and CuO and pressing them together; RE represents the rare earth element Gd; the molar ratio of RE2O3:BaCuO2:CuO was 1:x:1; x was 2.6; and the diameter of the precursor block was 30 mm.
[0050] The support pad was obtained by pressing Y2O3 powder; the support pad was 2mm thick and 30mm in diameter.
[0051] Al2O3 plate, MgO single crystal, support pad, precursor block and NdBCO seed crystal doped with MgO are stacked sequentially from bottom to top to assemble the embryo.
[0052] The number of MgO single crystals is three, arranged in a circular array at the bottom of the support pad; the height of the MgO single crystal is 2 mm; the NdBCO seed crystals doped with MgO are commercially available, with a size of 1.5 × 1.5 × 1 mm. 3 ;
[0053] The assembled preform is placed in a high-temperature furnace and heated to 900°C at a rate of 105°C / h, and held at this temperature for 10 hours. Then, it is raised to 1050°C at a rate of 60°C / h and held for 2.0 hours. Then, it is cooled to 1030°C at a rate of 18°C / h, and then cooled to 1010°C at a rate of 0.2°C / h. Finally, it is cooled to room temperature along with the furnace temperature to obtain GdBCO superconducting bulk material.
[0054] GdBCO superconducting bulk material was subjected to oxygen permeation treatment, and then slowly cooled from 430℃ to 350℃ in a circulating oxygen environment and annealed for 200 hours to obtain superconducting bulk material with single-domain texture.
[0055] Example 3:
[0056] A method for preparing superconducting bulk materials by top seed crystal melt texture growth: including:
[0057] Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 5 hours to obtain a mixed powder.
[0058] The mixed powder was calcined at 900℃ for 26 hours, then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
[0059] A precursor block was obtained by mixing RE2O3, BaCuO2, and CuO and pressing them together; RE represents rare earth element Y; the molar ratio of RE2O3:BaCuO2:CuO is 1:x:1; x is 2.8; the diameter of the precursor block is 30 mm.
[0060] The support pad was prepared by pressing Yb2O3 powder; the support pad was 2mm thick and 30mm in diameter.
[0061] Al2O3 plate, MgO single crystal, support pad, precursor block and NdBCO seed crystal doped with MgO are stacked sequentially from bottom to top to assemble the embryo.
[0062] The MgO single crystals consist of 16 crystals arranged in a circular array at the bottom of the support pad; the height of each MgO single crystal is 10 mm; the NdBCO seed crystals doped with MgO are commercially available and have a size of 1×2×2 mm. 3 ;
[0063] The assembled preform is placed in a high-temperature furnace and heated to 905°C at a rate of 100°C / h, and held at this temperature for 9 hours. Then, it is raised to 1035°C at a rate of 65°C / h and held for 2 hours. Then, it is cooled to 1000°C at a rate of 28°C / h, and then cooled to 980°C at a rate of 0.4°C / h. Finally, it is cooled to room temperature along with the furnace temperature to obtain YBCO superconducting bulk material.
[0064] The YBCO superconducting bulk material was subjected to oxygen permeation treatment, and then slowly cooled from 430℃ to 350℃ in a circulating oxygen environment and annealed for 205 hours to obtain a single-domain textured superconducting bulk material.
[0065] Example 4:
[0066] A method for preparing superconducting bulk materials by top seed crystal melt texture growth: including:
[0067] Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 4 hours to obtain a mixed powder.
[0068] The mixed powder was calcined at 900℃ for 26 hours, then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
[0069] A precursor block was obtained by mixing RE2O3, BaCuO2, and CuO and pressing them together; RE represents the rare earth element Sm; the molar ratio of RE2O3:BaCuO2:CuO is 1:x:1; x is 3.0; the diameter of the precursor block is 30 mm.
[0070] The support pad was prepared by pressing Yb2O3 powder; the support pad was 2mm thick and 30mm in diameter.
[0071] Al2O3 plate, MgO single crystal, support pad, precursor block and NdBCO seed crystal doped with MgO are stacked sequentially from bottom to top to assemble the embryo.
[0072] The number of MgO single crystals is 12, arranged in a circular array at the bottom of the support pad; the height of the MgO single crystal is 8 mm; the NdBCO seed crystals doped with MgO are commercially available, with a size of 1.5 × 1.5 × 1.5 mm. 3 ;
[0073] The assembled preform is placed in a high-temperature furnace and heated to 902°C at a rate of 105°C / h, and held at this temperature for 8.5 hours. Then, it is raised to 1070°C at a rate of 62°C / h and held for 2 hours. Then, it is lowered to 1055°C at a rate of 20°C / h, and then cooled to 1035°C at a rate of 0.3°C / h. Finally, it is cooled to room temperature along with the furnace temperature to obtain SmBCO superconducting bulk material.
[0074] SmBCO superconducting bulk material was subjected to oxygen permeation treatment, and then slowly cooled from 430℃ to 350℃ in a circulating oxygen environment and annealed for 198 hours to obtain a single-domain textured superconducting bulk material.
[0075] Example 5:
[0076] GdBCO superconducting bulk material was prepared using Gd2O3+xBaCuO2+CuO, and the preparation method was the same as in Example 2, except that x was 3.0.
[0077] Example 6
[0078] GdBCO superconducting bulk material was prepared using Gd2O3+xBaCuO2+CuO, and the preparation method was the same as in Example 2, except that x was 2.8.
[0079] Example 7
[0080] GdBCO superconducting bulk material was prepared using Gd2O3+xBaCuO2+CuO, and the preparation method was the same as in Example 2, except that x was 2.3.
[0081] Figure 2 The GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7 have a diameter of 25 mm and a thickness of 9 mm.
[0082] Figure 3 The magnetic levitation force test results are for the GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7; Test environment: using a magnet with a diameter of 30 mm and a thickness of 30 mm, with a surface magnetic field of 0.5 T.
[0083] Figure 4 The magnetic levitation force density test results are for the GdBCO superconducting bulk materials prepared in Examples 1, 2, 5, 6 and 7.
[0084] from Figure 4 It can be seen that when x reaches 2.5, the magnetic levitation force density is significantly improved. When x = 3.0, the magnetic levitation force density of the superconducting bulk GdBCO reaches 15.0971 N / cm². 2 .
[0085] It is evident that the superconducting bulk material prepared by the novel top seed melt textured growth method (TSMTG) provided by this invention has excellent magnetic levitation performance, and the preparation process is simple, requiring only the pre-preparation of one powder (BaCuO2) and the pressing of one precursor, which significantly improves efficiency and reduces production costs.
[0086] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for preparing superconducting bulk materials by top seed crystal melt texture growth, characterized in that, include: A precursor block was obtained by mixing RE2O3, BaCuO2, and CuO and pressing the mixture; RE represents rare earth elements; the molar ratio of RE2O3:BaCuO2:CuO was 1:x:1; and x was 2.3-3.
0. Support pads are obtained by pressing Yb2O3 or Y2O3 powder; Al2O3 plate, MgO single crystal, support pad, precursor block and NdBCO seed crystal doped with MgO are stacked sequentially from bottom to top to assemble the embryo. The preform is heated to 900℃-910℃ at a rate of 80-110℃ / h and held at this temperature for 8-10 hours. Then, it is heat-treated according to the preset temperature control program for preparing superconducting bulk materials corresponding to rare earth elements. Finally, it is cooled to room temperature with the furnace temperature to obtain REBCO superconducting bulk material. Oxygen permeation treatment was performed on REBCO superconducting bulk material to obtain superconducting bulk material with single-domain texture.
2. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, The method includes: Barium carbonate and copper oxide were mixed in a molar ratio of 1:1 and ball-milled for 4-5 hours to obtain a mixed powder. The mixed powder was calcined and then ball-milled again. The calcination and ball-milling were repeated at least three times to obtain BaCuO2 powder.
3. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 2, characterized in that, The calcination conditions are calcination at 900℃-920℃ for 24-28 hours.
4. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, The oxygen permeation treatment includes: cooling the REBCO superconducting bulk material from 430°C to 350°C in a circulating oxygen environment, and annealing for 195-205 hours.
5. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, The RE2O3 is a rare earth oxide, including any one of Y2O3, Gd2O3, and Sm2O3.
6. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, When RE is Gd, the preset temperature control program is as follows: increase the temperature to 1050-1058℃ at a rate of 60-70℃ / h, hold for 1.5-2.5 hours, then decrease the temperature to 1030℃-1035℃ at a rate of 18-28℃ / h, and then decrease the temperature to 1005℃-1018℃ at a rate of 0.2-0.4℃ / h.
7. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, When RE is Y, the preset temperature control program is as follows: increase the temperature to 1035-1042℃ at a rate of 60-70℃ / h, maintain the temperature for 1.5-2.5 hours, then decrease the temperature to 993℃-1000℃ at a rate of 18-28℃ / h, and then decrease the temperature to 968℃-983℃ at a rate of 0.2-0.4℃ / h.
8. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, When RE is Sm, the preset temperature control program is as follows: increase the temperature to 1065-1073℃ at a rate of 60-70℃ / h, hold for 1.5-2.5 hours, then decrease the temperature to 1050℃-1058℃ at a rate of 18-28℃ / h, and then decrease the temperature to 1030℃-1040℃ at a rate of 0.2-0.4℃ / h.
9. The method for preparing superconducting bulk materials by top seed crystal melt texture growth according to claim 1, characterized in that, The size of the MgO-doped NdBCO seed crystal is 1×1×1 mm. 3 -2×2×2mm 3 .
10. A superconducting bulk material, characterized in that, The superconducting bulk material is prepared by the method described in any one of claims 1-9.