Rare earth barium copper oxide superconducting target material and preparation method thereof

Abstract

The invention discloses a rare earth barium copper oxide superconducting target material and a preparation method thereof. The preparation method comprises the following steps: S1, mixing rare earth salt, barium salt and copper salt to obtain a rare earth barium copper oxide precursor; wherein the purity of the rare earth salt, the barium salt and the copper salt is greater than 99.9%, and the molar ratio of the rare earth metal to the barium to the copper is 1: 2: 3; s2, performing microwave calcination on the rare earth barium copper oxide precursor to obtain rare earth barium copper oxide single-phase powder; wherein the power of the microwave calcination is 100-2000W, and the time of the microwave calcination is within 30min; s3, carrying out mold pressing and cold isostatic pressing on the rare earth barium copper oxide single-phase powder to obtain a rare earth barium copper oxide superconducting target material blank; wherein the mold pressing pressure ranges from 10 MPa to 20 MPa, and the cold isostatic pressing pressure ranges from 100 MPa to 300 MPa; and S4, carrying out microwave sintering on the rare earth barium copper oxide superconducting target material green body to obtain the rare earth barium copper oxide superconducting target material. Wherein the frequency of the microwave sintering is 2.45 GHz, the power of the microwave sintering is 100-1000 W, and the time is within 25 min.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting sputtering target materials, and in particular relates to a rare earth barium copper oxide superconducting target material and a preparation method thereof. Background Art

[0002] Rare earth barium copper oxide (REBCO), also known as rare earth barium copper oxide, is composed of rare earth, barium, copper, and oxygen elements. It has the advantages of excellent mechanical properties, strong current carrying capacity, high irreversible field, and large cost reduction space. It is a high-temperature superconducting material with great industrial application prospects. REBCO is mainly used as a multi-layer composite structure strip, which consists of a metal base strip, a buffer layer, a superconducting layer, a protective layer, etc. The superconducting layer is the core of the REBCO strip and determines its performance. It is mainly prepared by pulsed laser deposition of REBCO superconducting targets. Therefore, the rapid and low-cost preparation of REBCO superconducting targets is of great significance for the commercial application of high-temperature superconducting strips.

[0003] At present, the common preparation methods of REBCO superconducting target materials are mainly atmospheric sintering and pressure sintering, but the preparation time is generally long. For example, patent CN114105631A discloses a method for preparing YBCO target materials by atmospheric sintering, and the sintering time is 12 to 29 hours; patent CN116606131A discloses a method for preparing europium barium copper oxide superconducting target materials by atmospheric sintering after slip casting, and the sintering time is 44 to 62 hours; patent CN111943674B discloses a method for preparing REBCO superconducting target materials by non-vacuum pressure sintering, and the sintering time is 30 to 1000 minutes. Although it is much shorter than the atmospheric pressure sintering time, it needs to apply a large pressure for sintering, generally 50 to 150 tons.

[0004] In summary, how to prepare REBCO superconducting target materials quickly and at low cost has become an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] In view of this, some embodiments disclose a method for preparing a rare earth barium copper oxide superconducting target material, comprising:

[0006] S1. Mixing rare earth salt, barium salt and copper salt to obtain rare earth barium copper oxide precursor; wherein the purity of rare earth salt, barium salt and copper salt is greater than 99.9%, and the molar ratio of rare earth metal, barium and copper is 1:2:3;

[0007] S2, calcining the rare earth barium copper oxide precursor by microwave to obtain a single-phase rare earth barium copper oxide powder; wherein the microwave calcination power is 100 to 2000 W and the time is within 30 minutes;

[0008] S3, molding and cold isostatic pressing the rare earth barium copper oxide single-phase powder to obtain a rare earth barium copper oxide superconducting target material blank; wherein the molding pressure is 10 to 20 MPa, and the cold isostatic pressing pressure is 100 to 300 MPa;

[0009] S4. The rare earth barium copper oxide superconducting target material blank is subjected to microwave sintering to obtain a rare earth barium copper oxide superconducting target material; wherein the frequency of the microwave sintering is 2.45 GHz, the power of the microwave sintering is 100 to 1000 W, and the time is within 25 minutes.

[0010] In some embodiments, the method for preparing a rare earth barium copper oxide superconducting target material disclosed in step S1 specifically comprises:

[0011] The rare earth salt, the barium salt and the copper salt are mixed with the acid solution respectively to prepare a rare earth salt solution, a barium salt solution and a copper salt solution;

[0012] Mixing rare earth salt solution, barium salt solution and copper salt solution in a set ratio, adding a precipitant and a pH adjuster, heating and stirring to obtain a uniform mixed solution;

[0013] The mixed solution is heated and aged, and then the aged mixed solution is centrifuged to obtain a rare earth barium copper oxide precursor, wherein the aging heating temperature is 70-90° C. and the time is 8-15 hours.

[0014] In the preparation method of rare earth barium copper oxide superconducting target material disclosed in some embodiments, the acid solution is one or a combination of hydrochloric acid, sulfuric acid, and nitric acid; the precipitant is oxalic acid; and the pH regulator is ammonia water.

[0015] In some embodiments, the method for preparing a rare earth barium copper oxide superconducting target material disclosed in step S1 specifically comprises:

[0016] The rare earth salt, barium salt, copper salt and zirconium oxide grinding balls are mixed by ball milling to obtain a rare earth barium copper oxide precursor; wherein the ball-to-material ratio is 0.6-1.5:1.

[0017] In some embodiments of the method for preparing a rare earth barium copper oxide superconducting target material, the rare earth salt is a rare earth oxide, a rare earth chloride or a rare earth nitrate.

[0018] In some embodiments of the method for preparing a rare earth barium copper oxide superconducting target material, the barium salt is barium oxide, barium chloride or barium nitrate.

[0019] In some embodiments of the method for preparing a rare earth barium copper oxide superconducting target material, the copper salt is copper oxide, copper chloride or copper nitrate.

[0020] In the preparation method of rare earth barium copper oxide superconducting target material disclosed in some embodiments, the rare earth element in the rare earth salt is a combination of one or more of lanthanum, cerium, praseodymium and neodymium.

[0021] In some embodiments of the method for preparing a rare earth barium copper oxide superconducting target material, the rare earth element in the rare earth salt is a combination of one or more of terbium, dysprosium, and holmium.

[0022] Some embodiments disclose a rare earth barium copper oxide superconducting target material, which is obtained by the preparation method of the rare earth barium copper oxide superconducting target material.

[0023] The method for preparing a rare earth barium copper oxide superconducting target disclosed in an embodiment of the present invention comprises mixing rare earth salt, barium salt and copper salt to prepare a rare earth barium copper oxide precursor by a coprecipitation method or a direct mixing method; microwave calcining the rare earth barium copper oxide precursor to obtain a rare earth barium copper oxide single-phase powder; molding and cold isostatic pressing the rare earth barium copper oxide single-phase powder, and then microwave sintering to obtain a rare earth barium copper oxide superconducting target. Compared with the traditional pressure sintering technology and the normal pressure sintering technology, the method for preparing a rare earth barium copper oxide superconducting target disclosed in an embodiment of the present invention is time-consuming and simple to operate, and the prepared rare earth barium copper oxide superconducting target has excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 XRD pattern of EBCO target material in Example 2. DETAILED DESCRIPTION

[0025] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0026] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0027] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0028] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0029] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0030] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be arbitrarily combined, and the obtained technical solutions belong to the contents disclosed in the embodiments of the present application. It should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like mentioned in the present application indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the technical features and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention, unless it conflicts with the context. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance, unless it conflicts with the context.

[0031] In some embodiments, a method for preparing a rare earth barium copper oxide superconducting target comprises:

[0032] S1. Mixing rare earth salt, barium salt and copper salt to obtain rare earth barium copper oxide precursor; wherein the purity of rare earth salt, barium salt and copper salt is greater than 99.9%, and the molar ratio of rare earth metal, barium and copper is 1:2:3;

[0033] S2, calcining the rare earth barium copper oxide precursor by microwave to obtain a single-phase rare earth barium copper oxide powder; wherein the microwave calcination power is 100 to 2000 W and the time is within 30 minutes;

[0034] S3, molding and cold isostatic pressing the rare earth barium copper oxide single-phase powder to obtain a rare earth barium copper oxide superconducting target material blank; wherein the molding pressure is 10-20 MPa, and the cold isostatic pressing pressure is 100-300 MPa; generally, the molding mold is an alloy steel mold, the molding holding time is 5 minutes, and the cold isostatic pressing mold is a polyurethane mold, and the cold isostatic pressing holding time is 10 minutes;

[0035] S4. The rare earth barium copper oxide superconducting target material blank is subjected to microwave sintering to obtain a rare earth barium copper oxide superconducting target material; wherein the frequency of the microwave sintering is 2.45 GHz, the power of the microwave sintering is 100 to 1000 W, and the time is within 25 minutes.

[0036] In some implementations, step S1 specifically includes:

[0037] The rare earth salt, the barium salt and the copper salt are mixed with the acid solution respectively to prepare the rare earth salt solution, the barium salt solution and the copper salt solution; usually, the concentration of the rare earth salt solution, the barium salt solution and the copper salt solution is 0.5-1 mol / L;

[0038] A rare earth salt solution, a barium salt solution, and a copper salt solution are mixed in a rare earth, barium, and copper atomic ratio of 1:2:3, a precipitant is added, a pH regulator is added, and the mixture is heated and stirred to promote the dissolution of the rare earth salt, the barium salt, and the copper salt to obtain a uniform mixed solution; generally, the temperature of heating and stirring is 60°C; generally, an excess of 10% of the precipitant is added, and the addition is made in small amounts and multiple times to ensure full contact of the molecules and promote complete reaction of the metal ions; the pH regulator is added dropwise to achieve uniform pH of the solution, and generally, the pH value of the mixed solution is adjusted to about 5 and kept unchanged for 1 hour, and then the addition of the pH regulator is stopped; in the mixed solution, a complex chelating reaction occurs among the rare earth ions, the barium ions, and the copper ions;

[0039] The mixed solution is placed in a water bath for heating aging, and then the aged mixed solution is centrifuged, and the centrifugal product is repeatedly washed with deionized water and alcohol for 4 times to obtain a rare earth barium copper oxide precursor, wherein the heating temperature is 70-90° C. and the time is 8-15 hours.

[0040] In some embodiments, the acid solution is one or a combination of hydrochloric acid, sulfuric acid, and nitric acid; the precipitant is oxalic acid; and the pH adjuster is aqueous ammonia.

[0041] In some implementations, step S1 specifically includes:

[0042] Rare earth salt, barium salt, copper salt and zirconium oxide grinding balls are placed in a three-dimensional mixer and ball-milled to obtain a rare earth barium copper oxide precursor; wherein the ball-to-material ratio is 0.6-1.5:1. Generally, the swing speed of the three-dimensional mixer is 15rpm and the time is 10h; the three-dimensional mixer can ensure the uniform mixing of rare earth salt, barium salt and copper salt, disperse the agglomerated powder, and thus improve the quality of the product.

[0043] In some embodiments, a rare earth barium copper oxide precursor is prepared by co-precipitation of a rare earth salt solution, a barium salt solution, and a copper salt solution, and is usually microwave calcined once to obtain a rare earth barium copper oxide single-phase powder.

[0044] In some embodiments, a rare earth barium copper oxide precursor prepared by directly mixing a rare earth salt, a barium salt, and a copper salt is typically repeatedly microwave calcined three times to allow the rare earth barium copper oxide precursor to react fully and thoroughly to obtain a single-phase rare earth barium copper oxide powder.

[0045] In some embodiments, the rare earth salt is a rare earth oxide, a rare earth chloride, or a rare earth nitrate.

[0046] In some embodiments, the barium salt is barium oxide, barium chloride, or barium nitrate.

[0047] In some embodiments, the copper salt is copper oxide, copper chloride, or copper nitrate.

[0048] In some embodiments, the rare earth salt is a rare earth oxide, the barium salt is barium oxide, and the copper salt is copper oxide.

[0049] In some embodiments, the rare earth salt is a rare earth chloride, the barium salt is barium chloride, and the copper salt is copper chloride.

[0050] In some embodiments, the rare earth salt is a rare earth nitrate, the barium salt is barium nitrate, and the copper salt is copper nitrate.

[0051] In some embodiments, the rare earth element in the rare earth salt is one or more of light rare earth elements.

[0052] In some embodiments, the rare earth element in the rare earth salt is one or more heavy rare earth elements.

[0053] In some embodiments, the rare earth element in the rare earth salt is a combination of one or more of lanthanum, cerium, praseodymium, and neodymium.

[0054] In some embodiments, the rare earth element in the rare earth salt is a combination of one or more of terbium, dysprosium, and holmium.

[0055] In some embodiments, it is obtained by the above-mentioned method for preparing the rare earth barium copper oxide superconducting target.

[0056] The technical details are further illustrated below in conjunction with embodiments.

[0057] Example 1

[0058] Example 1 discloses a method for preparing a YBCO target material, which specifically includes:

[0059] Dissolve yttrium oxide, barium oxide and copper oxide powders with a purity of 99.9% in nitric acid solution to prepare yttrium nitrate solution, barium nitrate solution and copper nitrate solution, respectively; wherein the molar ratio of yttrium, barium and copper is 1:2:3;

[0060] Yttrium nitrate solution, barium nitrate solution and copper nitrate solution were mixed in the atomic ratio of rare earth, barium and copper of 1:2:3, heated and stirred at 60°C, 10% excess oxalic acid was added and stirred for 30 minutes, then ammonia water was added dropwise, the pH of the solution was adjusted to 5 and kept unchanged for 1 hour to obtain a uniform mixed solution;

[0061] The mixed solution was placed in a water bath for constant temperature heating aging at 80°C for 8 hours, and then the aged mixed solution was centrifuged to obtain a precipitate, and the precipitate was repeatedly washed with deionized water and alcohol for 4 times to obtain a YBCO precursor;

[0062] The YBCO precursor was placed in an oven at 100°C for 4 hours for drying, and then placed in a microwave sintering furnace for microwave calcination to obtain a YBCO single-phase powder, wherein the microwave calcination power was 500W and the time was 10 minutes;

[0063] After ball milling, the YBCO single-phase powder is molded in an alloy steel mold at a molding pressure of 15 MPa and a holding time of 5 min, and then cold isostatic pressing is performed in a polyurethane mold at a cold isostatic pressing pressure of 200 MPa and a holding time of 10 min to obtain a YBCO target material blank;

[0064] The YBCO target material blank is placed in a microwave sintering furnace and subjected to microwave sintering to obtain a single-phase YBCO target material, wherein the microwave sintering frequency is 2.45 GHz, the microwave sintering power is 400 W, and the microwave sintering time is 20 min.

[0065] Example 2

[0066] Example 2 discloses a method for preparing an EBCO target, which specifically includes:

[0067] According to the molar ratio of europium, barium and copper of 1:2:3, europium nitrate, barium nitrate and copper nitrate powders with a purity of 99.9% are placed in a three-dimensional mixer, and then zirconium oxide grinding balls with diameters of 10 mm, 5 mm and 3 mm are added according to a ball-to-material ratio of 1:1, and mixed to obtain an EBCO precursor; wherein the swing speed of the three-dimensional mixer is 15 rpm, and the time is 10 hours;

[0068] The EBCO precursor was placed in a microwave sintering furnace for calcination at a microwave calcination power of 500 W for 10 min; the calcined EBCO precursor was ball-milled and then placed in a microwave sintering furnace for secondary calcination at a microwave calcination power of 400 W for 15 min; the EBCO precursor after the second calcination was ball-milled and then placed in a microwave sintering furnace for a third microwave calcination at a microwave calcination power of 300 W for 20 min to obtain EBCO single-phase powder;

[0069] After ball milling, the EBCO single-phase powder is molded in an alloy steel mold at a molding pressure of 18 MPa and a holding time of 5 min, and then cold isostatic pressing is performed in a polyurethane mold at a cold isostatic pressing pressure of 220 MPa and a holding time of 10 min to obtain an EBCO target blank;

[0070] The EBCO target material blank is placed in a microwave sintering furnace and subjected to microwave sintering to obtain a single-phase EBCO target material, wherein the microwave sintering frequency is 2.45 GHz, the microwave sintering power is 500 W, and the microwave sintering time is 15 min.

[0071] The XRD pattern of the single-phase EBCO target prepared in Example 2 is as follows: Figure 1 As shown, a single-phase superconducting phase of EuBaCu3O7 was formed.

[0072] The method for preparing a rare earth barium copper oxide superconducting target disclosed in an embodiment of the present invention comprises mixing rare earth salt, barium salt and copper salt to prepare a rare earth barium copper oxide precursor by a coprecipitation method or a direct mixing method; microwave calcining the rare earth barium copper oxide precursor to obtain a rare earth barium copper oxide single-phase powder; molding and cold isostatic pressing the rare earth barium copper oxide single-phase powder, and then microwave sintering to obtain a rare earth barium copper oxide superconducting target. Compared with the traditional pressure sintering technology and the normal pressure sintering technology, the method for preparing a rare earth barium copper oxide superconducting target disclosed in an embodiment of the present invention is time-consuming and simple to operate, and the prepared rare earth barium copper oxide superconducting target has excellent performance.

[0073] The technical solutions disclosed in the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the present invention. Any conventional changes, substitutions or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a rare earth barium copper oxide superconducting target, characterized in that: include: S1. Mixing rare earth salt, barium salt and copper salt to obtain rare earth barium copper oxide precursor; wherein the purity of rare earth salt, barium salt and copper salt is greater than 99.9%, and the molar ratio of rare earth metal, barium and copper is 1:2:3; S2, calcining the rare earth barium copper oxide precursor by microwave to obtain a single-phase rare earth barium copper oxide powder; wherein the microwave calcination power is 100 to 2000 W and the time is within 30 minutes; S3, molding and cold isostatic pressing the rare earth barium copper oxide single-phase powder to obtain a rare earth barium copper oxide superconducting target material blank; wherein the molding pressure is 10 to 20 MPa, and the cold isostatic pressing pressure is 100 to 300 MPa; S4. The rare earth barium copper oxide superconducting target material blank is subjected to microwave sintering to obtain a rare earth barium copper oxide superconducting target material; wherein the frequency of the microwave sintering is 2.45 GHz, the power of the microwave sintering is 100 to 1000 W, and the time is within 25 minutes.

2. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: Step S1 specifically includes: The rare earth salt, the barium salt and the copper salt are mixed with the acid solution respectively to prepare a rare earth salt solution, a barium salt solution and a copper salt solution; Mixing rare earth salt solution, barium salt solution and copper salt solution in a set ratio, adding a precipitant and a pH adjuster, heating and stirring to obtain a uniform mixed solution; The mixed solution is heated and aged, and then the aged mixed solution is centrifuged to obtain a rare earth barium copper oxide precursor, wherein the aging heating temperature is 70-90° C. and the time is 8-15 hours.

3. The method for preparing a rare earth barium copper oxide superconducting target according to claim 2, characterized in that: The acid solution is one of hydrochloric acid, sulfuric acid and nitric acid or a combination of two thereof; the precipitant is oxalic acid; and the pH regulator is ammonia water.

4. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: Step S1 specifically includes: The rare earth salt, barium salt, copper salt and zirconium oxide grinding balls are mixed by ball milling to obtain a rare earth barium copper oxide precursor; wherein the ball-to-material ratio is 0.6-1.5:

1.

5. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: The rare earth salt is rare earth oxide, rare earth chloride or rare earth nitrate.

6. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: The barium salt is barium oxide, barium chloride or barium nitrate.

7. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: The copper salt is copper oxide, copper chloride or copper nitrate.

8. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: The rare earth element in the rare earth salt is a combination of one or more of lanthanum, cerium, praseodymium and neodymium.

9. The method for preparing a rare earth barium copper oxide superconducting target according to claim 1, characterized in that: The rare earth element in the rare earth salt is a combination of one or more of terbium, dysprosium and holmium.

10. Rare earth barium copper oxide superconducting target, characterized in that: The superconducting target is obtained by the method for preparing the rare earth barium copper oxide superconducting target according to any one of claims 1 to 9.

Images