A large-size single-phase cu1245 superconductor and a preparation method thereof

Abstract

The present application relates to a kind of large size single-phase Cu1245 superconductor and its preparation method, belong to superconducting material technical field, to solve at least one of the problems such as low yield of single-phase Cu1245 superconductor prepared by existing method, high process requirement, cannot mass production etc..The present application uses Cu1234 superconductor material as precursor, through Ca2CuO3 and CuO as intercalation source, under high temperature and high pressure, through intercalation reaction, make intercalation source diffusion into Cu1234 lattice, in-situ reaction generates Cu1245 superconductor, obtains large size single-phase Cu1245 superconductor.The present application uses industrial grade cubic press as the device of high pressure and high temperature synthesis, provides centimeter level Cu1234 superconductor, ensures the preparation of centimeter level Cu1245 superconductor.

Description

Technical Field

[0001] This invention relates to the field of superconducting materials technology, and in particular to a large-size single-phase Cu1245 superconductor and its preparation method. Background Technology

[0002] Superconducting materials, due to their zero resistance and perfect diamagnetism, hold revolutionary application prospects in fields such as energy, medicine, transportation, and scientific research. Although thousands of types of superconducting materials have been discovered to date, including elemental superconductors, alloy superconductors, heavy fermion superconductors, copper-based superconductors, iron-based superconductors, and hydrogen-rich compound superconductors, copper oxide (copper-based) superconductors remain the only material system that can exceed the liquid nitrogen temperature range under normal pressure conditions. They are also the main carrier for superconducting applications in this temperature range and possess significant application value.

[0003] The copper-based superconductor family includes multiple material systems, including "copper-based" superconductors (general formula: CuBa2Ca). n-1 Cu n O 2n+2+δ The [CuO6] superconductor (n=1,2,3…, abbreviated as Cu12(n-1)n) exhibits advantages in terms of being environmentally friendly and cost-effective due to its composition being limited to copper, oxygen, and alkaline earth metals, while other systems generally contain toxic or rare earth elements. This system possesses a fully perovskite crystal structure, with the [CuO6] octahedrons in its charge pool exhibiting a compressed coordination configuration, leading to shorter interlayer spacing and enhanced interlayer coupling. This structural feature reduces superconducting anisotropy, improves flux pinning capability, and optimizes the stability of the critical current density under varying magnetic fields and temperatures. This gives the "copper-based" superconductor excellent high-temperature, high-field current-carrying performance in the liquid nitrogen temperature range, making it one of the potential mainstream application materials for the future.

[0004] "Copper-based" superconductors include several structurally similar members, such as Cu1212, Cu1223, Cu1234, Cu1245, and Cu1256. These members share similar crystal structures and superconducting properties, differing primarily in the number of copper-oxygen planes within the unit cell. This structural gradient makes the "copper-based" system a valuable resource for studying superconductivity mechanisms and exploring the superconducting transition temperature (T0). c It is an important platform for regulating the mechanism of copper-based superconductivity. Among them, Cu1245, as a member with a high number of copper-oxygen layers, may exhibit unique physical properties. Systematic research on it is of great significance for understanding the mechanism of copper-based superconductivity and developing new high-performance superconducting materials.

[0005] However, in the synthesis of Cu1245, due to the identical constituent elements and highly similar crystal structures, the thermodynamic stability regions of different components overlap, leading to a common co-occurrence phenomenon in traditional synthesis methods (high-temperature and high-pressure methods). Existing literature indicates that during the preparation of Cu1245, the product often contains impurities such as Cu1223, Cu1234, CaCuO2, and other unknown impurity phases. This phenomenon has long existed in the research of copper-based superconducting materials, seriously affecting the phase purity of the target material and hindering the practical application of the material.

[0006] Although CN 118851742 A discloses a method for preparing single-phase Cu1245, this method employs a one-step high-temperature, high-pressure synthesis, which has high requirements for the process window, especially the oxygen partial pressure. It necessitates the addition of CrO3 to release oxygen and uses a sandwich structure assembly method, requiring silver foil sealing. However, due to the toxicity of CrO3, this method restricts its large-scale preparation and application. Furthermore, during the preparation of Cu1245, the product often contains impurities such as Cu1223, Cu1234, and other unknown impurities. This phenomenon has long existed in copper-based superconducting material research, making it difficult to obtain large-size single-phase Cu1245 in a one-step process, hindering the material's practical application, and requiring even stricter preparation standards for large-size single-phase Cu1245. Summary of the Invention

[0007] In view of the above analysis, the present invention aims to provide a large-size single-phase Cu1245 superconductor and its preparation method, so as to solve at least one of the problems of low yield, high process requirements and inability to mass-produce single-phase Cu1245 superconductors prepared by existing methods.

[0008] In a first aspect, the present invention provides a method for preparing a large-size single-phase Cu1245 superconductor, comprising the following steps: (1) Cu1234 superconductor material was selected as the precursor, and Ca2CuO3 and CuO were used as intercalation sources; (2) After the Cu1234 superconductor material, Ca2CuO3 and CuO are mixed evenly, a mixture is obtained. The mixture is pre-pressed into a cylindrical material and the cylindrical material is sealed to obtain an assembled sample. (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction; (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

[0009] Furthermore, in step (1), the molar ratio of the precursor to the intercalation source is m:1, where 0.8 ≤ m ≤ 1.2.

[0010] Furthermore, the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:1.

[0011] Furthermore, in step (1), the Cu1234 superconductor material is a single phase.

[0012] Furthermore, in step (2), the pre-compression pressure is 5~10 MPa.

[0013] Furthermore, in step (2), the height of the cylindrical material is 0.5~1.5cm and the diameter is 0.5~1.5cm.

[0014] Furthermore, in step (2), the sealing involves sequentially wrapping the cylindrical material with a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve, and a graphite heating sleeve to obtain the assembled sample.

[0015] Furthermore, in step (3), the intercalation reaction is carried out at a pressure of 3~3.5 GPa and a temperature of 950~1100℃ for 0.5~2h.

[0016] Furthermore, in step (4), the large-size single-phase Cu1245 superconductor is a cylinder with a height of 0.5-1.5cm and a diameter of 0.5-1.5cm.

[0017] Secondly, the present invention provides a large-size single-phase Cu1245 superconductor prepared by the above method.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention uses Cu1234 superconductor material as a precursor and Ca2CuO3 and CuO as intercalation sources. Under high temperature and pressure, the intercalation sources diffuse into the Cu1234 lattice, generating Cu1245 superconductors in situ, resulting in large-size single-phase Cu1245 superconductors. This invention employs an industrial-grade six-sided press as the high-pressure, high-temperature synthesis apparatus, providing centimeter-scale Cu1234 superconductors and ensuring the preparation of centimeter-scale Cu1245 superconductors.

[0019] 2. In the sealing process of this invention, the magnesium oxide sleeve is used to prevent the sample from reacting with the platinum metal. The platinum sleeve is used to better seal the sample and prevent internal oxygen from leaking out, which would reduce the purity of the sample. The boron nitride is used to transfer heat and ensure that the heat is concentrated for heating the sample. The graphite heating sleeve is the outermost heat source and provides high-temperature conditions for the experiment.

[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0022] Figure 1 This is a schematic diagram illustrating the principle of the intercalation reaction of the present invention; Figure 2 This is a schematic diagram of the assembled sample in the method of the present invention; Figure 3 The X-ray diffraction pattern of the Cu1245 superconductor prepared in Example 1 of this invention; Figure 4 The X-ray diffraction pattern of the Cu1245 superconductor prepared in Example 1 of this invention is analyzed and fitted. Figure 5 Standard XRD patterns of Cu1223 superconductor, Cu1245 superconductor and Cu1234 superconductor; Figure 6 XRD pattern of single-phase Cu1245 superconductor in the prior art; Figure 7 The image shows the magnetic susceptibility test result of the Cu1245 superconductor prepared in Example 1 of this invention. Figure 8 The images show the XRD patterns of the Cu1245 superconductors prepared in Example 1 and Comparative Examples 1-4 of this invention. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0024] A specific embodiment of the present invention discloses a method for preparing a large-size single-phase Cu1245 superconductor, comprising the following steps: (1) Cu1234 superconductor material was selected as the precursor, and Ca2CuO3 and CuO were used as intercalation sources; (2) After the Cu1234 superconductor material, Ca2CuO3 and CuO are mixed evenly, a mixture is obtained. The mixture is pre-pressed into a cylindrical material. The cylindrical material is then wrapped with a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve and a graphite heating sleeve in sequence to obtain the assembled sample. (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction; (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

[0025] Compared with existing technologies, this invention uses Cu1234 superconductor material as a precursor and Ca2CuO3 and CuO as intercalation sources. Under high temperature and pressure, the intercalation sources diffuse into the Cu1234 lattice, generating Cu1245 superconductors in situ, resulting in large-size single-phase Cu1245 superconductors. This invention employs an industrial-grade six-sided press as the high-pressure, high-temperature synthesis apparatus, providing centimeter-scale Cu1234 superconductors and ensuring the preparation of centimeter-scale Cu1245 superconductors.

[0026] The intercalation principle in this invention is as follows: Figure 1 As shown, the crystal structure of Cu1234 can be considered as an alternating stack of "charge reservoir layers" (containing Ba, Cu, etc.) and "copper oxide layer units". To generate Cu1245 on this basis means inserting a new set of CuO layers into the existing four copper oxide layers, resulting in Cu1245 with five copper oxide layers. During the insertion process, the c-axis lengthens, causing a change in the lattice volume. This must be carried out under external high pressure (such as a six-sided press), otherwise it is prone to collapse or the generation of numerous defects.

[0027] Specifically, in step (1), the Cu1234 superconductor material is single-phase. It should be noted that the Cu1234 superconductor material in this invention can be a single-phase superconducting bulk or polycrystalline powder. The Cu1234 superconductor material in this invention is prepared using existing methods, such as the method described in CN 118894719 A. After the sample of this invention is assembled, as shown... Figure 2 As shown.

[0028] Specifically, in step (1), the molar ratio of the precursor to the intercalation source is m:1, where 0.8≤m≤1.2, for example, m is 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, and the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:1.

[0029] It should be noted that due to the presence of defective copper-oxygen surfaces in copper-based "copper-system" superconductors, the Cu atom content in the unit cell varies. Numerous experiments have shown that when the proportion of Cu1234 precursor is 0.8≤m≤1.2, this proportion range yields a single-phase Cu1245.

[0030] Specifically, in step (2), the pre-compression pressure is 5~10 MPa, the height of the cylindrical material is 0.5~1.5 cm, for example, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, and the diameter is 0.5~1.5 cm, for example, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm.

[0031] It should be noted that the magnesium oxide sleeve is used to prevent the sample from reacting with the platinum metal, the platinum sleeve is used for better sealing to prevent internal oxygen from leaking out and reducing the purity of the sample, the boron nitride is used to transfer heat and ensure that the heat is concentrated for heating the sample, and the graphite heating jacket is the outermost heat source to provide high temperature conditions for the experiment.

[0032] Specifically, in step (3), the pressure of the intercalation reaction is 3~3.5 GPa, for example, 3 GPa, 3.05 GPa, 3.1 GPa, 3.15 GPa, 3.2 GPa, 3.25 GPa, 3.3 GPa, 3.35 GPa, 3.4 GPa, 3.45 GPa, 3.5 GPa, and the temperature is 950~1100℃, for example, 950℃, 960℃, 970℃, 980℃, 990℃, 100℃. React at 0℃, 1010℃, 1020℃, 1030℃, 1040℃, 1050℃, 1060℃, 1070℃, 1080℃, 1090℃, and 1100℃ for 0.5~2h, for example, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, and 2h.

[0033] It should be noted that the synthesis temperature mentioned above was chosen in this invention because excessively high temperatures lead to the decomposition of Cu1234, while excessively low temperatures hinder the reaction. During intercalation, the lattice expands, increasing the C-axis; excessively high pressure results in volume compression, leaving a significant amount of Cu1234 phase remaining, while excessively low pressure makes intercalation difficult. Within this time range, the larger the volume of the cylindrical sample, the more complete the reaction will be with extended time.

[0034] Another specific embodiment of the present invention discloses a large-size single-phase Cu1245 superconductor prepared by the above method.

[0035] Specifically, the chemical formula of the large-size single-phase Cu1245 superconductor is Cu. x Ba2Ca4Cu5O 12+δ , where 0.6≤x≤0.9, 0≤δ≤1.

[0036] Specifically, the large-size single-phase Cu1245 superconductor is a cylinder with a height of 0.5-1.5 cm, for example, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, or 1.5 cm, and a diameter of 0.5-1.5 cm (for example, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, or 1.5 cm).

[0037] The technical solution of the present invention will be further explained below with reference to specific embodiments. The Cu1234 superconductor material involved in the following embodiments and comparative examples is a single-phase Cu1234 superconductor prepared according to the method of Example 1 in patent CN 118894719 A.

[0038] The specific method is as follows: A method for preparing a single-phase Cu1234 superconductor includes the following steps: (1) In an inert gas argon atmosphere glove box, BaO and CuO are used as raw materials. After BaO and CuO are mixed evenly in a molar ratio of 1:1, they are pre-pressed into discs so that the powder particles can fully contact each other to participate in the solid-phase reaction. The mixture is sintered at 700℃ for 96h to obtain sample A. After taking out sample A, it is fully ground, pressed into discs again, and sintered again. This process is repeated 3 times to obtain single-phase BaCuO2. (2) In an inert gas argon atmosphere glove box, CaO and CuO are used as raw materials. After CaO and CuO are mixed evenly in a molar ratio of 2:1, they are pre-pressed into discs so that the powder particles can fully contact each other and participate in the solid-phase reaction. The mixture is sintered at 800°C for 36 hours to obtain sample B. After taking out sample B, it is fully ground, pressed into discs again, and sintered again. This process is repeated 3 times to obtain single-phase Ca2CuO3. (3) In an inert gas argon atmosphere glove box, single-phase BaCuO2 and single-phase Ca2CuO3 are mixed with CuO, CaO and CaO2 as precursors to obtain mixed powder, wherein the molar ratio of BaCuO2, Ca2CuO3, CuO, CaO and CaO2 is 2:1:x:(1-y):y, x=1.6, y=1.0; (4) Press the mixed powder into a disc, seal the disc inside a gold cylinder, place the mixed powder wrapped in the gold cylinder into the cavity of a six-sided press, and perform high-pressure synthesis for 10 minutes at a pressure of 5 GPa, a temperature of 1150℃, and a heating rate of 1200℃ / min. After the high-pressure synthesis is completed, take out the sample, peel off the gold cylinder sealed outside the sample, and obtain a single-phase Cu1234 superconductor.

[0039] The molecular formula of the single-phase Cu1234 superconductor is Cu 0.6 Ba2Ca3Cu4O 10 .

[0040] Example 1 This embodiment describes a method for preparing a large-size single-phase Cu1245 superconductor, comprising the following steps: (1) Cu1234 superconductor material was selected as the precursor, and Ca2CuO3 and CuO were used as intercalation sources; Wherein, the molar ratio of the precursor to the intercalation source is 1:1, and the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:1; (2) After uniformly mixing the Cu1234 superconductor material, Ca2CuO3, and CuO, a mixture is obtained. The mixture is pre-pressed into a cylindrical material with a height of 0.5 cm and a diameter of 1.5 cm. The pre-pressing pressure is 5 MPa. The cylindrical material is then wrapped in a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve, and a graphite heating sleeve in sequence to obtain the assembled sample, such as... Figure 2 As shown; (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction; The intercalation reaction was carried out at a pressure of 3.25 GPa and a temperature of 1020 °C for 1.25 h. (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

[0041] The large-size single-phase Cu1245 superconductor prepared in this embodiment has the chemical formula Cu. 0.6 Ba2Ca4Cu5O 13The single-phase Cu1245 superconductor has a height of 0.5 cm and a diameter of 1.5 cm. The Cu1245 superconductor prepared in this embodiment was ground into powder, and X-ray diffraction was tested as follows: Figure 3 As shown, the X-ray diffraction pattern of the Cu1245 superconductor prepared in this embodiment was analyzed and fitted, and the results are as follows. Figure 4 As shown. The standard XRD patterns of Cu1223 superconductors, Cu1245 superconductors, and Cu1234 superconductors are shown below. Figure 5 As shown, the XRD pattern of the Cu1245 superconductor in patent CN 118851742 A is as follows: Figure 6 As shown. According to Figure 3-4 and Figure 5-6 This indicates that the Cu1245 superconductor synthesized in this invention corresponds completely with the standard XRD peak positions and is consistent with the X-ray diffraction pattern results in patent CN 118851742 A. The above two comparisons confirm that the Cu1245 prepared in this invention is a single phase and does not contain Cu1223 and Cu1234.

[0042] The magnetic properties of the Cu1245 superconductor prepared in this embodiment were tested, and the results are as follows: Figure 7 As shown, the results indicate that the superconducting transition temperature is 89K. Furthermore, no superconducting transitions at other temperatures were observed in the magnetic tests, indirectly proving that the sample does not contain the Cu1234 and Cu1223 phases.

[0043] Example 2 This embodiment describes a method for preparing a large-size single-phase Cu1245 superconductor, comprising the following steps: (1) Cu1234 superconductor material was selected as the precursor, and Ca2CuO3 and CuO were used as intercalation sources; Wherein, the molar ratio of the precursor to the intercalation source is 0.8:1, and the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:1; (2) After the Cu1234 superconductor material, Ca2CuO3 and CuO are mixed evenly, a mixture is obtained. The mixture is pre-pressed into a cylindrical material with a height of 1 cm and a diameter of 1 cm. The pre-pressing pressure is 7.5 MPa. The cylindrical material is then wrapped with a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve and a graphite heating sleeve in sequence to obtain the assembled sample. (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction; The intercalation reaction was carried out at a pressure of 3 GPa and a temperature of 1100℃ for 0.5 h. (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

[0044] The large-size single-phase Cu1245 superconductor prepared in this embodiment has the chemical formula Cu. 0.6 Ba2Ca4Cu5O 13 The height of the single-phase Cu1245 superconductor is 1 cm and the diameter is 1 cm.

[0045] The Cu1245 superconductor prepared in this embodiment was tested in Example 1, and the results were basically the same. Due to space limitations, they will not be listed one by one.

[0046] Example 3 This embodiment describes a method for preparing a large-size single-phase Cu1245 superconductor, comprising the following steps: (1) Cu1234 superconductor material was selected as the precursor, and Ca2CuO3 and CuO were used as intercalation sources; Wherein, the molar ratio of the precursor to the intercalation source is 1.2:1, and the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:1; (2) After the Cu1234 superconductor material, Ca2CuO3 and CuO are mixed evenly, a mixture is obtained. The mixture is pre-pressed into a cylindrical material with a height of 1.5cm and a diameter of 0.5cm. The pre-pressing pressure is 10MPa. The cylindrical material is then wrapped with a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve and a graphite heating sleeve in sequence to obtain the assembled sample. (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction; The intercalation reaction was carried out at a pressure of 3.5 GPa and a temperature of 950 °C for 2 hours. (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

[0047] The large-size single-phase Cu1245 superconductor prepared in this embodiment has the chemical formula Cu. 0.6 Ba2Ca4Cu5O 13 The height of the single-phase Cu1245 superconductor is 1.5 cm and the diameter is 0.5 cm.

[0048] The Cu1245 superconductor prepared in this embodiment was tested in Example 1, and the results were basically the same. Due to space limitations, they will not be listed one by one.

[0049] Comparative Example 1 The preparation method of the Cu1245 superconductor in this comparative example is similar to that in Example 1, except that in step (1), the intercalation source is replaced with BaCuO2 and CuO.

[0050] Comparative Example 2 The preparation method of the Cu1245 superconductor in this comparative example is similar to that in Example 1, except that in step (2), the mixture is wrapped with a platinum sleeve and a graphite heating sleeve in sequence.

[0051] Comparative Example 3 The preparation method of the Cu1245 superconductor in this comparative example is similar to that in Example 1, except that the intercalation reaction pressure in step (3) is 2.5 GPa.

[0052] Comparative Example 4 The preparation method of the Cu1245 superconductor in this comparative example is similar to that in Example 1, except that the temperature of the intercalation reaction in step (3) is 1200℃.

[0053] Experimental Example 1 1. The XRD patterns of the Cu1245 superconductors prepared in Example 1 and Comparative Examples 1-4 were tested respectively, as follows: Figure 8 As shown in the figure, it can be seen that the samples prepared in Comparative Examples 1-3 all contain a large number of impurity phases (* in the figure indicates impurity phases), and the main phase of the sample prepared in Comparative Example 4 has been decomposed.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a large-size single-phase Cu1245 superconductor, characterized in that, Includes the following steps: (1) Select Cu1234 superconductor material as precursor, and Ca2CuO3 and CuO as intercalation source. The molar ratio of the precursor to the intercalation source is m:1, where 0.8≤m≤1.2, and the molar ratio of Ca2CuO3 to CuO in the intercalation source is 1:

1. (2) After the Cu1234 superconductor material, Ca2CuO3 and CuO are mixed evenly, a mixture is obtained. The mixture is pre-pressed into a cylindrical material and then sealed. The sealing is done by wrapping the cylindrical material with a magnesium oxide sleeve, a platinum sleeve, a boron nitride sleeve and a graphite heating sleeve in sequence to obtain the assembled sample. (3) The assembled sample is placed in a six-sided press for high-temperature and high-pressure intercalation reaction. The intercalation reaction pressure is 3~3.5GPa, the temperature is 950~1100℃, and the reaction is kept at temperature and pressure for 0.5~2h. (4) After the reaction is complete, stop heating, cool to room temperature, release pressure, and obtain a large-size single-phase Cu1245 superconductor.

2. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (1), the molar ratio of the precursor to the intercalation source is m:1, where 0.85≤m≤1.

15.

3. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (1), the Cu1234 superconductor material is a single phase.

4. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (2), the pre-compression pressure is 5~10 MPa.

5. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (2), the height of the cylindrical material is 0.5~1.5cm and the diameter is 0.5~1.5cm.

6. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (3), the intercalation reaction is carried out at a pressure of 3.05~3.45GPa and a temperature of 960~1090℃ for 0.6~1.9h.

7. The method for preparing a large-size single-phase Cu1245 superconductor according to claim 1, characterized in that, In step (4), the large-size single-phase Cu1245 superconductor is a cylinder with a height of 0.5-1.5cm and a diameter of 0.5-1.5cm.

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