CN115346744A - Magnetic refrigeration material and preparation method and application thereof - Google Patents
Magnetic refrigeration material and preparation method and application thereof Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/012—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials adapted for magnetic entropy change by magnetocaloric effect, e.g. used as magnetic refrigerating material
- H01F1/017—Compounds
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B28/00—Production of homogeneous polycrystalline material with defined structure
- C30B28/02—Production of homogeneous polycrystalline material with defined structure directly from the solid state
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
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Abstract
The invention discloses a magnetic refrigeration material and a preparation method and application thereof, belonging to the technical field of low-temperature magnetic refrigeration materials; the molecular formula of the magnetic refrigeration material provided by the invention is Eu 3 B 2 O 6 (ii) a The magnetic refrigeration material is a single-phase polycrystalline material, belongs to a hexagonal crystal system, and has a space group of R-3c (167). The magnetic refrigeration material provided by the invention has excellent giant magnetocaloric effect, the phase change temperature is 8K, and the maximum magnetic entropy change under the magnetic field change of 0-1T, 0-2T and 0-5T is respectively less than or equal to 13.0 J.kg ‑1 ·K ‑1 、22.0J·kg ‑1 ·K ‑1 And 38.6 J.kg ‑1 ·K ‑1 (ii) a In addition, the preparation method of the magnetic refrigeration material provided by the invention has simple process,The energy consumption is low, the raw materials are low in price and less in pollution, and the method is suitable for industrial production; meanwhile, the magnetic refrigeration material has excellent magnetocaloric performance under a low application magnetic field, the magnetic field can be obtained by utilizing a conventional commercial NdFeB permanent magnet, a superconducting magnet with a complex structure and a high price is not required, and the magnetic refrigeration material has a good application prospect.
Description
Technical Field
The invention belongs to the technical field of low-temperature magnetic refrigeration materials, and particularly relates to a magnetic refrigeration material and a preparation method and application thereof.
Background
In recent years, with the rapid development of human economy, environmental damage has been increasing. In this context, various green and environmentally friendly cleaning techniques are becoming popular. Among them, magnetic refrigeration technology based on the principle of magnetocaloric effect is included. Compared with the traditional vapor compression refrigeration, the magnetic refrigeration technology has the following remarkable advantages: (1) green environmental protection: the magnetic refrigeration adopts a solid or liquid refrigerant, so that the problems of ozone layer damage, greenhouse effect and the like are solved; (2) energy conservation and high efficiency: the thermodynamic process of magnetic refrigeration for generating a magnetocaloric effect is highly reversible, and the Carnot cycle efficiency can reach 60-70%; (3) stable and reliable: the magnetic refrigeration technology is realized without a gas compressor, vibration and noise are not generated, the service life of the equipment is long, and the reliability is high.
The magnetocaloric effect is a phenomenon in which when an external magnetic field is changed, the degree of magnetic moment order inside a magnetic material is changed, that is, the magnetic entropy is changed, and the material spontaneously absorbs and releases heat to the outside. In the excitation process, the magnetic moment order degree of the magnetic material is increased, the magnetic entropy is reduced, and the magnetic working medium releases heat outwards; in the demagnetizing process, the magnetic moment order degree of the magnetic material is reduced, the magnetic entropy is increased, and at the moment, the magnetic working medium absorbs heat from the outside. One of the key technologies in the implementation of the magnetic refrigeration technology is to use a large amount of permanent magnet materials or a superconducting magnet with high price and a complex structure to achieve the required magnetic field change. In addition, the required change in the magnetic fieldThe larger the size, the more demanding the weight and structure of the magnet assembly, which further increases the design difficulty and increases the operating costs. Taking a commonly used commercial cylindrical Halbach magnet as an example, when the magnetic field is changed to 0-1.5T, the volume of the magnet group is about 1.41dm 3 The weight is about 10 kg; when the magnetic field is changed to 0-1.0T, the volume of the magnet group is reduced by more than 60 percent to 0.54dm 3 Reducing weight by more than 60% to about 4.0 kg; when the magnetic field change is further reduced to 0-0.7T, the volume of the required magnet group is reduced by more than 80 percent to 0.28dm 3 The weight loss was reduced to 80%, which was reduced to about 2.1kg.
A plurality of magnetic refrigeration materials are disclosed in the prior art, for example CN111403137A discloses a rare earth-based oxide magnetic refrigeration material and a preparation method thereof, and the chemical formula of the material is RE 2 ZnMnO 6 (RE = any one or more of Gd, tb, dy, ho, er and Tm) is prepared by a sol-gel method, the phase transition temperature is 2.2-6.8K, and the isothermal magnetic entropy change is 11.53-25.26 J.kg under the change of a 0-7T magnetic field -1 ·K -1 In the meantime. CN106978576B discloses an Er-based amorphous low-temperature magnetic refrigeration material and a preparation method thereof, the material is prepared by a strip casting method, and the chemical formula of the material is as follows: er a T b Al c Wherein a is 56 to 63, b is 18 to 33, c is 16 to 28, and a + b + c =100, the magnetic transition temperature is 8 to 18K and the maximum magnetic entropy change is 12.6 to 22.5 J.kg under the change of a magnetic field of 0 to 7T -1 ·K -1 . CN105836755A discloses a gadolinium borate material and a preparation method and application thereof, and relates to gadolinium borate, wherein the magnetic entropy change of the gadolinium borate material reaches the maximum value of 47.28 J.kg at the position of T =3K under the change of a 0-7T magnetic field -1 ·K -1 (ii) a Under the change of the magnetic field of 0-3T, the magnetic entropy is changed into 18.81 J.kg -1 ·K -1 . Materials Research Bulletin 98 (2018) 173-179 reports GdBO of monoclinic structure 3 At T =2K, the magnetic entropy changes to about 7J · kg under a magnetic field change of 0-2T -1 ·K -1 (ii) a Under the magnetic field change of 0-5T, the magnetic entropy change is about 35 J.kg -1 ·K -1 。
The rare earth borate has the advantages of simple preparation process, low raw material cost and suitability for mass production and application, but the magnetic entropy change (particularly under low magnetic field, less than or equal to 1T) of the existing material is relatively small. Therefore, development of a magnetocaloric material having inexpensive raw materials and excellent magnetocaloric properties at a low driving field is not only based on ecological protection considerations but also has a very high economic benefit. And has great scientific value and strategic significance for the magnetic refrigeration technology which is applied to the terminal as early as possible, supporting low-temperature scientific research, aerospace and the like.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a rare earth borate low-temperature magnetic refrigeration material with stronger magnetocaloric effect at low temperature, in particular at low magnetic field, and a preparation method and application thereof.
In order to realize the purpose, the invention adopts the technical scheme that: a magnetic refrigeration material has a molecular formula of Eu 3 B 2 O 6 (ii) a The magnetic refrigeration material is a single-phase polycrystalline material, belongs to a hexagonal crystal system, and has a space group of R-3c (167).
The magnetic refrigeration material provided by the invention is a low-temperature rare earth borate magnetic refrigeration material with giant magnetocaloric effect, belongs to a single-phase hexagonal crystal structure, and has a space group of R-3c (167); the crystal structure is compact, the symmetry is high, and the rare earth occupation ratio is high, so that the magnetic refrigeration material has strong magnetocaloric effect at low temperature, especially under low magnetic field, and can realize very good magnetic refrigeration effect.
As a preferred embodiment of the magnetic refrigeration material of the present invention, the phase transition temperature of the magnetic refrigeration material is 8K.
As a preferred embodiment of the magnetic refrigeration material, the maximum magnetic entropy change of the magnetic refrigeration material under the change of a 0-5T magnetic field is less than or equal to 38.6 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-2T magnetic field change is less than or equal to 22.0 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-1T magnetic field change is less than or equal to 13.0 J.kg -1 ·K -1 (ii) a For example, the maximum magnetic entropy change under a 0-5T magnetic field change may be 38.6 J.kg -1 ·K -1 、37.6J·kg -1 ·K -1 Or 36.6 J.kg -1 ·K -1 Etc.; the maximum magnetic entropy change under 0-2T magnetic field variation may be 22.0 J.kg -1 ·K -1 、21.0J·kg -1 ·K -1 Or 20.0 J.kg -1 ·K -1 Etc.; the maximum magnetic entropy change under a 0-1T magnetic field variation may be 13.0 J.kg -1 ·K -1 、12.0J·kg -1 ·K -1 Or 11.0 J.kg -1 ·K -1 And so on.
As a preferred embodiment of the magnetic refrigeration material, the maximum magnetic entropy change of the magnetic refrigeration material under the magnetic field change of 0-1.5T is less than or equal to 17.9 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-0.5T magnetic field change is less than or equal to 6.8 J.kg -1 ·K -1 。
The inventor researches and discovers that the phase transition temperature of the magnetic refrigeration material provided by the invention is 8K, the magnetic refrigeration material has very good magnetocaloric performance at low temperature, and the phase transition temperature is in the range compared with other magnetic refrigeration materials (such as DyBO) 3 DyNiSi or HoCuSi) and the magnetic refrigeration material provided by the invention has more excellent magnetic refrigeration effect.
In addition, the invention also provides a preparation method of the magnetic refrigeration material, which comprises the following steps:
(1) Eu is mixed 2 O 3 、H 3 BO 3 Mixing with solvent, grinding to obtain mixture;
(2) Sealing and sintering the mixture obtained in the step (1) to obtain an intermediate product;
(3) And (3) reducing and sintering the intermediate product obtained in the step (2) in mixed gas to obtain the magnetic refrigeration material.
As a preferred embodiment of the preparation method of the present invention, in the step (1), eu 2 O 3 、H 3 BO 3 At a molar ratio of Eu 2 O 3 ：H 3 BO 3 =1: (2.1-2.4); such as Eu 2 O 3 、H 3 BO 3 May be 1:2.1, 1:2.2 or 1:2.4.
the inventor researches and discovers that when Eu is used 2 O 3 、H 3 BO 3 When the molar ratio of (A) is within the above range,can avoid H 3 BO 3 The problem that pure phase products cannot be generated due to too small addition amount, and meanwhile, on the basis of the molar ratio range of the invention, if H is further increased 3 BO 3 The amount of (B) is determined in consideration of both the effect of the reaction and the saving of resources, and it is preferable that the molar ratio of Eu to the total amount of (B) 2 O 3 ：H 3 BO 3 ＝1：(2.1～2.4)。
As a preferable embodiment of the preparation method of the present invention, in the step (1), the solvent is any one selected from the group consisting of water, ethanol, and an ethanol aqueous solution; the solvent is added for mixing and grinding, on one hand, two raw materials can be fully mixed in the grinding process, and on the other hand, friction in the grinding process is reduced, and overheating is avoided.
As a preferred embodiment of the preparation method of the present invention, in the step (1), the grinding is ball milling, and a ball milling device is selected from any one of a nano sand mill, a planetary ball mill and a high-energy ball mill; the ball milling process can ensure that the two raw materials are fully contacted, ensure uniform mixing and adjust the particle sizes of the two raw materials.
As a preferred embodiment of the preparation method of the present invention, in the step (1), the mixture has an average particle diameter of 150 μm or less, for example, 150 μm, 140 μm, 130 μm, 120 μm, 110 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 10 μm or the like.
As a preferred embodiment of the preparation method of the present invention, in the step (2), the temperature of the closed sintering is 1000 to 1200 ℃, and the time of the closed sintering is 10 to 30 hours; for example, the temperature of the closed sintering can be 1000 ℃, 1020 ℃, 1040 ℃, 1060 ℃, 1080 ℃, 1100 ℃, 1120 ℃, 1140 ℃, 1160 ℃, 1180 ℃, 1200 ℃ and the like, and the time of the closed sintering can be 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h and the like.
As a preferred embodiment of the preparation method of the present invention, in the step (2), the closed sintering is performed in a closed sintering crucible, specifically, after the mixture is added into the crucible, a crucible top cover is added for sealing; the closed sintering crucible and the crucible top cover are made of corundum.
The inventors have found that, on the one hand, sintering in a closed manner can reduce H 3 BO 3 Thereby being beneficial to the solid phase reaction and further improving the phase purity of the material; on one hand, sintering is carried out at the closed sintering temperature limited by the invention, so that the solid-phase reaction can be ensured, the serious volatilization of raw materials caused by overhigh temperature can be avoided, the phase composition and the performance of a finished product are influenced, and the energy consumption is favorably reduced; on the other hand, sintering is carried out within the closed sintering time limited by the invention, so that the solid-phase reaction can be ensured, the influence on the structure and the performance of a finished product due to overlong time can be avoided, and the production efficiency can be improved.
As a preferred embodiment of the preparation method of the present invention, in the step (3), the specific process of reduction sintering is: firstly, paving an intermediate product at the bottom of a reduction sintering crucible, then putting the intermediate product as a whole into an atmosphere furnace and carrying out reduction sintering in a sintering furnace, wherein the reduction sintering crucible is made of graphite, and the atmosphere furnace is selected from a tube furnace, a box furnace or a rotary furnace; the sintering furnace is selected from a muffle furnace, a tube furnace or a vacuum furnace.
As a preferred embodiment of the preparation method of the present invention, in the step (3), the temperature of reduction sintering is 1300-1400 ℃, and the time of reduction sintering is 18-48 h; for example, the temperature of the reduction sintering can be 1300 ℃, 1320 ℃, 1340 ℃, 1360 ℃, 1380 ℃, 1400 ℃ and the like, and the time of the reduction sintering can be 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, 48h and the like.
The inventor researches and discovers that under the temperature and time of the reduction sintering provided by the invention, the intermediate product can be ensured to be fully reduced, the phenomenon that the final product volatilizes due to overhigh temperature to influence the structure and the performance of the final product can be avoided, and the temperature and the time of the reduction sintering provided by the invention are favorable for reducing energy consumption.
As a preferable embodiment of the preparation method of the present invention, in the step (3), the mixed gas is composed of 10% hydrogen and 90% argon.
In addition, the invention also provides application of the magnetic refrigeration material in the fields of low-temperature physical research, space exploration and aerospace.
Compared with the prior art, the invention has the beneficial effects that:
firstly, the method comprises the following steps: the magnetic refrigeration material provided by the invention has excellent giant magnetocaloric effect, the phase change temperature is 8K, and the maximum magnetic entropy change under the change of a 0-5T magnetic field is less than or equal to 38.6 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-2T magnetic field change is less than or equal to 22.0 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-1T magnetic field change is less than or equal to 13.0 J.kg -1 ·K -1 (ii) a Compared with the material with the phase transition temperature close to that of the material disclosed in the prior art, such as Gd disclosed in Ceramics International 47 (2021) 18205-18212 2 CuMnO 6 The phase transition temperature is about 7.5K, and the maximum magnetic entropy under the change of 0-2T magnetic field is 1.33 J.kg -1 ·K -1 Er published by CN106978576B 57 Ni 19 Al 24 The phase transition temperature is 9.9K, and the maximum magnetic entropy under the change of 0-2T magnetic field is 20.5 J.kg -1 ·K -1 Dy disclosed in Ceramics International 47 (2021) 6290-6297 2 FeAlO 6 The phase transition temperature is about 7.8K, and the maximum magnetic entropy under the change of 0-2T magnetic field is 2.8 J.kg -1 ·K -1 The comparison of data shows that the magnetic refrigeration material provided by the invention shows obvious giant magnetocaloric effect;
secondly, the method comprises the following steps: the preparation method of the magnetic refrigeration material provided by the invention adopts a solid-phase synthesis method, and has the advantages of simple preparation process and low energy consumption; at the same time, the raw material Eu is used 2 O 3 、H 3 BO 3 Is less expensive than other rare earth oxides such as Gd, which are required for similar materials 2 O 3 、Tb 2 O 3 、Dy 2 O 3 、Ho 2 O 3 、Er 2 O 3 And the cost advantage is obvious; furthermore, H used 3 BO 3 The composite material is weak acid, has small environmental pollution and accords with the national green development concept; namely, the preparation method provided by the invention is suitable forIndustrial mass production;
thirdly, the method comprises the following steps: the magnetic refrigeration material has excellent magnetocaloric property under a low application magnetic field, particularly under a low driving field (less than or equal to 1.5T), the magnetic field can be obtained by utilizing a conventional commercial NdFeB permanent magnet, a superconducting magnet with a complex structure and a high price is not required, and the magnetic refrigeration material has a good application prospect; the method can be widely applied to the advanced fields of low-temperature physical research, space exploration, aerospace and the like, promotes the development of a magnetic refrigeration technology, and is favorable for promoting the high-added-value utilization of rare earth resources.
Drawings
FIG. 1 is a graph comparing an X-ray diffraction pattern with a theoretical pattern of an intermediate product in examples 1 to 3 of the present invention;
FIG. 2 is a comparison graph of an X-ray diffraction pattern and a theoretical pattern of a magnetic refrigeration material in examples 1 to 3 of the present invention;
FIG. 3 is a comparison of an X-ray diffraction pattern and a theoretical pattern of an intermediate product in comparative examples 1 to 2 of the present invention;
FIG. 4 is a comparison graph of an X-ray diffraction pattern and a theoretical pattern of the magnetic refrigeration material in comparative examples 3 to 4 of the present invention;
FIG. 5 is the thermomagnetic (M-T) graph of Zero Field Cooling (ZFC) and band Field Cooling (FC) of the magnetic refrigeration material in 0.01T magnetic field in the embodiment 3 of the invention;
FIG. 6 is a first derivative diagram of the Zero Field Cooling (ZFC) thermomagnetic curve of the magnetic refrigeration material in embodiment 3 of the present invention;
FIG. 7 is a graph showing isothermal magnetization curves of the magnetic refrigeration material in example 3 of the present invention at 2-30K under a magnetic field change of 0-5T;
FIG. 8 is a graph showing the relationship between the change in magnetic entropy and the temperature under the change in magnetic field of 0-1T, 0-2T, 0-3T, 0-4T and 0-5T in the magnetic refrigeration material in example 3 of the present invention.
Detailed Description
To better illustrate the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to specific examples.
The reagents, methods and equipment used in the invention are conventional in the art unless otherwise specified.
Example 1
The embodiment of the invention provides a magnetic refrigeration material, and the molecular formula of the magnetic refrigeration material is Eu 3 B 2 O 6 Belongs to a hexagonal system, and has a space group of R-3c (167); the preparation method comprises the following steps:
(1) Eu is mixed 2 O 3 、H 3 BO 3 At a molar ratio of Eu 2 O 3 ：H 3 BO 3 =1:2.4 placing the mixture and a solvent ethanol water solution in a planetary ball mill for grinding to obtain a mixture with the average grain diameter of 150 mu m;
(2) Placing the mixture in the step (1) in a crucible made of corundum, adding a crucible top cover made of corundum, and sintering in a sealed manner at the temperature of 1000 ℃ for 24 hours to obtain an intermediate product;
(3) And (3) flatly paving the intermediate product in the step (2) at the bottom of a crucible made of graphite, and then putting the crucible as a whole into a rotary furnace to be subjected to reduction sintering in a muffle furnace, wherein the reduction sintering is to be carried out for 40 hours at 1400 ℃ in mixed gas consisting of 10% of hydrogen and 90% of argon to obtain the magnetic refrigeration material.
Example 2
The embodiment of the invention provides a magnetic refrigeration material, and the molecular formula of the magnetic refrigeration material is Eu 3 B 2 O 6 Belongs to hexagonal system, and has space group of R-3c (167); the preparation method comprises the following steps:
(1) Eu is mixed 2 O 3 、H 3 BO 3 In a molar ratio of Eu 2 O 3 ：H 3 BO 3 =1:2.2 grinding the mixture and a solvent ethanol in a planetary ball mill to obtain a mixture with the average grain diameter of 100 mu m;
(2) Placing the mixture obtained in the step (1) in a crucible made of corundum, adding a crucible top cover made of corundum, and sintering in a sealed manner at 1200 ℃ for 10 hours to obtain an intermediate product;
(3) And (3) flatly paving the intermediate product in the step (2) at the bottom of a crucible made of graphite, and then putting the crucible as a whole into a rotary furnace to be subjected to reduction sintering in a muffle furnace, wherein the reduction sintering is to be carried out for 20 hours at 1300 ℃ in mixed gas consisting of 10% of hydrogen and 90% of argon, so as to obtain the magnetic refrigeration material.
Example 3
The embodiment of the invention provides a magnetic refrigeration material, wherein the molecular formula of the magnetic refrigeration material is Eu 3 B 2 O 6 Belongs to a hexagonal system, and has a space group of R-3c (167); the preparation method comprises the following steps:
(1) Eu is added 2 O 3 、H 3 BO 3 In a molar ratio of Eu 2 O 3 ：H 3 BO 3 =1:2.1 grinding the mixture and solvent ethanol in a planetary ball mill to obtain a mixture with the average grain diameter of 80 mu m;
(2) Placing the mixture obtained in the step (1) in a crucible made of corundum, adding a crucible top cover made of corundum, and sintering in a sealed manner at 1200 ℃ for 10 hours to obtain an intermediate product;
(3) And (3) flatly paving the intermediate product in the step (2) at the bottom of a crucible made of graphite, and then putting the crucible as a whole into a rotary furnace to be subjected to reduction sintering in a muffle furnace, wherein the reduction sintering is to be carried out for 40 hours at 1300 ℃ in mixed gas consisting of 10% of hydrogen and 90% of argon, so as to obtain the magnetic refrigeration material.
Comparative example 1
The invention provides a magnetic refrigeration material, and the only difference between the preparation method of the magnetic refrigeration material and the embodiment 3 is that Eu 2 O 3 、H 3 BO 3 In a molar ratio of Eu 2 O 3 ：H 3 BO 3 ＝1：1.6。
Comparative example 2
The invention provides a magnetic refrigeration material, and the only difference between the preparation method of the magnetic refrigeration material and the embodiment 3 is that Eu 2 O 3 、H 3 BO 3 At a molar ratio of Eu 2 O 3 ：H 3 BO 3 ＝1：1.8。
Comparative example 3
The invention provides a magnetic refrigeration material, and the preparation method of the magnetic refrigeration material is only different from that of the embodiment 3 in that the reduction sintering time in the step (3) is 6h.
Comparative example 4
The only difference between the preparation method of the magnetic refrigeration material and the embodiment 3 is that the reduction sintering temperature in the step (3) is 1200 ℃.
Effects of the invention
In this effect example, the magnetic refrigeration materials prepared in examples 1 to 3 and comparative examples 1 to 4 were tested, and specifically, an X-ray powder diffractometer (XRD) of type D8A A, produced by Brucker corporation, was used to perform phase analysis on the intermediate products and the magnetic refrigeration materials prepared in examples 1 to 3 and comparative examples 1 to 4 by X-ray powder diffractometry; the test results are shown in FIGS. 1 to 8;
as can be seen from FIG. 1, the intermediate products of examples 1 to 3 are of high purity and are all single EuBO 3 Phase composition; FIG. 2 shows that the magnetic refrigeration materials of examples 1 to 3 are high in purity and each of them is a single Eu 3 B 2 O 6 The phase composition belongs to a hexagonal system, and the space group is R-3c (167), wherein alpha = beta =90 DEG, and gamma =120 deg. As can be seen from FIG. 3, the X-ray diffraction patterns of the intermediate products in comparative examples 1-2 have many obvious impurity peaks at multiple angles, which indicates that the material contains more impurity phases; the results show that H 3 BO 3 Too low a content results in the intermediate EuBO 3 The normal generation cannot be realized; as can be seen from FIG. 4, the comparison of the X-ray diffraction patterns and the theoretical patterns of the magnetic refrigeration materials in the comparative examples 3 to 4 shows that the magnetic refrigeration materials obtained in the comparative examples 3 to 4 have very obvious hetero peaks at multiple angles, which indicates that the Eu with a pure phase structure can not be prepared by the heat treatment process of reducing at 1300 ℃ for 6h and at 1200 ℃ for 40h 3 B 2 O 6 . As can be seen from the above, the Eu is suitably selected in the present invention 2 O 3 And H 3 BO 3 The ratio of the amounts of substances, H 3 BO 3 Too low a content results in failure of the solid phase reaction to proceed normally, resulting in the intermediate EuBO 3 Cannot be generated. In addition, the selection of the parameters of the heat treatment process is very important, and the sintering and reduction temperature is too low or too high during sintering and reductionToo short or too long intervals can affect the phase composition of the material, so that the pure-phase magnetic refrigeration material cannot be generated.
FIG. 5 is the thermomagnetic curve of the Zero Field Cooling (ZFC) and the band Field Cooling (FC) of the magnetic refrigeration material under the magnetic field of 0.01T in the embodiment 3 of the invention; as can be seen in fig. 5, when the temperature is below 8K, significant splitting of the curve is observed, which may be related to the domain wall pinning effect; while temperatures near and above the phase transition temperature, the ZFC and FC curves almost completely overlap. Fig. 6 is the first derivative of the Zero Field Cooling (ZFC) thermomagnetic curve of the magnetic refrigeration material in embodiment 3 of the present invention; it can be seen that the phase transition temperature of the magnetic refrigeration material in example 3 is 8K, and the magnetic refrigeration material belongs to a low-temperature magnetic refrigeration material. FIG. 7 is the isothermal magnetization curve of the magnetic refrigeration material of example 3 of the present invention at 2-30K under the change of 0-5T magnetic field; it can be seen that at lower temperatures, the magnetization gradually increases with increasing magnetic field, and saturates at lower magnetic field changes, showing typical ferromagnetic behavior. At a higher temperature (>14K) It appears paramagnetic and with increasing temperature the magnetization gradually decreases, which is associated with a decrease in order due to an increase in the thermal movement of the molecules. According to isothermal magnetization curves at different temperatures, the magnitude of magnetic entropy change under different magnetic field changes can be calculated by utilizing Maxwell relation. FIG. 8 shows the relationship between the change in magnetic entropy and the temperature under the change in magnetic field of 0 to 1T, 0 to 2T, 0 to 3T, 0 to 4T and 0 to 5T in the magnetic refrigeration material in example 3 of the present invention; as can be seen from the graph, the maximum magnetic entropy change of the magnetic refrigeration material in the embodiment 3 is proportional to the magnitude of the change of the external magnetic field, and the maximum magnetic entropy change values are respectively 13.0 J.kg at the phase transition temperature of about 8K and when the magnetic field changes to 0-1T, 0-2T and 0-5T -1 ·K -1 、22.0J·kg -1 ·K -1 And 38.6 J.kg -1 ·K -1 。
The magnetic entropy change of the resulting magnetic refrigeration materials of examples 1-2 was also calculated to be 37.6 J.kg at a maximum magnetic entropy change of the magnetic refrigeration materials of examples 1 and 2 under a magnetic field change of 0-5T at a temperature around the phase transition temperature of 8K, respectively -1 ·K -1 And 36.6 J.kg -1 ·K -1 And also shows strong magnetocaloric effect.
Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (10)
1. The magnetic refrigeration material is characterized in that the molecular formula of the magnetic refrigeration material is Eu 3 B 2 O 6 (ii) a The magnetic refrigeration material is a single-phase polycrystalline material, belongs to a hexagonal system, and has a space group of R-3c (167).
2. The magnetic refrigeration material according to claim 1, wherein the phase transition temperature of the magnetic refrigeration material is 8K.
3. The magnetic refrigeration material according to claim 1, wherein the maximum magnetic entropy change of the magnetic refrigeration material under the change of a 0-5T magnetic field is less than or equal to 38.6J-kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-2T magnetic field change is less than or equal to 22.0 J.kg -1 ·K -1 (ii) a Maximum magnetic entropy change under 0-1T magnetic field change is less than or equal to 13.0 J.kg -1 ·K -1 。
4. A method for producing a magnetic refrigeration material according to any one of claims 1 to 3, characterized by comprising the steps of:
(1) Eu is mixed 2 O 3 、H 3 BO 3 Mixing with a solvent and grinding to obtain a mixture;
(2) Sealing and sintering the mixture obtained in the step (1) to obtain an intermediate product;
(3) And (3) reducing and sintering the intermediate product obtained in the step (2) in mixed gas to obtain the magnetic refrigeration material.
5. The method according to claim 4, wherein in step (1), eu 2 O 3 、H 3 BO 3 In a molar ratio of Eu 2 O 3 ：H 3 BO 3 ＝1：(2.1～2.4)。
6. The preparation method according to claim 4, wherein in the step (2), the temperature of the closed sintering is 1000-1200 ℃, and the time of the closed sintering is 10-30 h.
7. The preparation method according to claim 4, wherein in the step (3), the temperature of the reduction sintering is 1300-1400 ℃, and the time of the reduction sintering is 18-48 h.
8. The method according to claim 4, wherein in the step (3), the mixed gas consists of 10% hydrogen and 90% argon.
9. The method according to claim 4, wherein in the step (1), the solvent is any one selected from the group consisting of water, ethanol, and an aqueous ethanol solution; the average grain diameter of the mixture is less than or equal to 150 mu m.
10. Use of the magnetic refrigeration material according to any one of claims 1 to 3 in the fields of low-temperature physical research, space exploration and aerospace.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114634359A (en) * | 2022-03-01 | 2022-06-17 | 中国科学院赣江创新研究院 | Magnetic refrigeration microsphere and preparation method and application thereof |
| CN116190031A (en) * | 2023-03-14 | 2023-05-30 | 中国科学院赣江创新研究院 | Application of rare earth borate in magnetic refrigeration material and preparation method of rare earth borate |
| CN117275863A (en) * | 2023-09-06 | 2023-12-22 | 中国科学院赣江创新研究院 | Low-temperature magnetic refrigeration material and preparation method and application thereof |
| CN117586755A (en) * | 2024-01-19 | 2024-02-23 | 镧明材料技术(上海)有限公司 | Refrigerating material and preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019013095A1 (en) * | 2017-07-12 | 2019-01-17 | Ｍｅｉｊｉ Ｓｅｉｋａファルマ株式会社 | Method for producing herbicide intermediate |
| CN113035480A (en) * | 2021-02-26 | 2021-06-25 | 中国科学院江西稀土研究院 | Magnetic refrigeration material and preparation method and application thereof |
-
2022
- 2022-08-22 CN CN202211009288.XA patent/CN115346744A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019013095A1 (en) * | 2017-07-12 | 2019-01-17 | Ｍｅｉｊｉ Ｓｅｉｋａファルマ株式会社 | Method for producing herbicide intermediate |
| CN110891959A (en) * | 2017-07-12 | 2020-03-17 | 明治制果药业株式会社 | Process for producing herbicide intermediate |
| CN113035480A (en) * | 2021-02-26 | 2021-06-25 | 中国科学院江西稀土研究院 | Magnetic refrigeration material and preparation method and application thereof |
Non-Patent Citations (3)
| Title |
|---|
| H. HATA ET AL.: "Synthesis and Magnetic Property of Eu3B2O6 and Sr3B2O6", 《MAT. RES. BULL.》, vol. 12, 31 December 1977 (1977-12-31), pages 812 * |
| KEN-ICHI MACHIDA ET AL.: "The Crystal Structure and Magnetic Property of Europium(II) Orthoborate", 《THE CHEMICAL SOCIETY OF JAPAN》, vol. 54, no. 4, 31 December 1981 (1981-12-31), pages 1052 - 1055 * |
| QUANYI LIU ET AL.: "Giant low-field magnetocaloric effect in hexagonal Eu3B2O6 compound", 《JOURNAL OF ALLOYS AND COMPOUNDS》, vol. 936, 5 December 2022 (2022-12-05), pages 168372 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114634359A (en) * | 2022-03-01 | 2022-06-17 | 中国科学院赣江创新研究院 | Magnetic refrigeration microsphere and preparation method and application thereof |
| CN116190031A (en) * | 2023-03-14 | 2023-05-30 | 中国科学院赣江创新研究院 | Application of rare earth borate in magnetic refrigeration material and preparation method of rare earth borate |
| CN116190031B (en) * | 2023-03-14 | 2024-04-19 | 中国科学院赣江创新研究院 | Application of rare earth borate in magnetic refrigeration material and preparation method of rare earth borate |
| CN117275863A (en) * | 2023-09-06 | 2023-12-22 | 中国科学院赣江创新研究院 | Low-temperature magnetic refrigeration material and preparation method and application thereof |
| CN117586755A (en) * | 2024-01-19 | 2024-02-23 | 镧明材料技术(上海)有限公司 | Refrigerating material and preparation method and application thereof |
| CN117586755B (en) * | 2024-01-19 | 2024-04-09 | 镧明材料技术(上海)有限公司 | Refrigerating material and preparation method and application thereof |
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