CaLaPrNdGdFeO perovskite high-entropy ferrite wave-absorbing material as well as preparation method and application thereof

Abstract

The invention discloses a CaLaPrNdGdFeO perovskite high-entropy ferrite wave-absorbing material as well as a preparation method and application thereof, and belongs to the technical field of electromagnetic wave absorbing materials. The chemical composition of the material is (Ca < 0.2 > La < 0.2 > Pr < 0.2 > Nd < 0.2 > Gd < 0.2 >) FeO3. The preparation method comprises the following steps: dissolving metal nitrate and a complexing agent in water, adjusting to alkalescence to obtain a metal ion-complexing agent solution, heating to obtain gel, aging, drying and carrying out self-propagating reaction to obtain precursor xerogel; and then grinding, pre-sintering and carrying out heat treatment. The ferrite wave-absorbing material composed of the equimolar high-entropy components fully solves the disadvantages of narrow effective wave-absorbing frequency band and poor low-frequency performance stability of the traditional ferrite, has the advantages of strong synthesis stability, good oxidation resistance, high absorption efficiency and stable performance, can absorb electromagnetic waves in the microwave band of 2-18 GHz, and has a wide application prospect. And the material can be used in the fields of stealth coatings, electromagnetic shielding, 5G communication devices and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic wave absorbing materials, and in particular relates to a CaLaPrNdGdFeO perovskite high-entropy ferrite absorbing material, a preparation method thereof, and an application thereof. Background Art

[0002] Ferrite, a typical representative of traditional microwave absorbing materials, remains indispensable in the field of microwave absorbing materials, thanks to its low cost and excellent weather resistance, even after years of upgrading. However, its narrow effective absorption bandwidth and poor low-frequency performance stability have gradually made it lose its competitiveness in meeting market demand. High-entropy (HE) materials are an emerging class of materials composed of multiple primary metal elements and are defined as solid solutions of five or more cationic or anionic sublattices with high configurational entropy. In recent years, high-entropy oxides have also been used in the field of electromagnetic wave absorption. In highly disordered multicomponent systems, high entropy produces desirable properties, including a preference for single-phase solid solutions with simple crystal structures, slow kinetics, lattice distortion, and a performance ensemble that exceeds that of the constituent materials. Furthermore, short-range element distribution, lattice distortion, oxygen defects, and shear strain are major factors influencing electromagnetic wave absorption properties. The cocktail effect of high-entropy components can also be exploited, providing an effective approach for designing efficient microwave absorbing materials. Due to their unique crystal structure and high degree of controllability, perovskite oxides can achieve fine-tuning of electromagnetic parameters through doping or ion substitution at the A (or B) site, thereby adapting to the absorption requirements of different frequency bands and providing broad space for high-entropy strategies to optimize electromagnetic wave absorption performance. Therefore, the design and introduction of high-entropy components into ferrites to construct perovskite high-entropy ferrite absorbers breaks through the performance bottlenecks caused by traditional ferrite materials such as low absorption efficiency, narrow frequency band, poor stability, and single function. This helps to improve the inherent disadvantages of traditional ferrites and significantly enhance their competitiveness in the field of wave absorption. Summary of the Invention

[0003] In order to solve the above problems in the prior art, the present invention provides a CaLaPrNdGdFeO perovskite high entropy ferrite wave absorbing material and its preparation method and application. Through the design of multiple main components, the entropy stabilization effect, lattice distortion effect and slow diffusion effect of the material are significantly improved, aiming to solve the key performance defects of traditional ferrite in the field of wave absorption. Perovskite high entropy ferrite (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 has strong wave absorption ability in the 2-18GHz frequency band, wide absorption bandwidth, stable performance, strong thermal stability, and good antioxidant ability. The preparation process is simple and easy to achieve large-scale industrial production.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a CaLaPrNdGdFeO perovskite high entropy ferrite absorbing material, wherein the chemical composition of the perovskite high entropy ferrite absorbing material is (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3.

[0006] The present invention also provides a method for preparing the CaLaPrNdGdFeO perovskite high-entropy ferrite absorbing material according to the above-mentioned method, comprising the following steps: weighing a metal nitrate according to the molar ratio of the metal elements Ca, La, Pr, Nd, Gd and Fe in the chemical formula, dissolving the metal nitrate and a complexing agent in water, adjusting the solution to a weak alkalinity to obtain a metal ion-complexing agent solution, heating the solution to obtain a gel, aging the solution, drying the solution and causing a self-propagating reaction to obtain a precursor dry gel; and then grinding, pre-calcining and heat treating the solution to obtain the CaLaPrNdGdFeO perovskite high-entropy ferrite absorbing material.

[0007] As a preferred embodiment of the present invention, the metal nitrate is calcium nitrate, lanthanum nitrate, praseodymium nitrate, neodymium nitrate, gadolinium nitrate and ferric nitrate, and the purity of the metal nitrate is ≥99.9%. The complexing agent is citric acid and ethylenediaminetetraacetic acid, and the purity of the complexing agent is ≥99.5%.

[0008] The complexing agents of citric acid and EDTA ensure the formation of gel.

[0009] As a preferred embodiment of the present invention, the molar ratio of the total molar amount of metal ions in the metal nitrate to the complexing agent is 1:(2.5-3.5), and the molar ratio of citric acid to ethylenediaminetetraacetic acid is (1.5-2.5):1. Preferably, the molar ratio of the total molar amount of metal ions in the metal nitrate to citric acid and ethylenediaminetetraacetic acid is 1:2:1.

[0010] As a preferred embodiment of the present invention, the volume ratio of the total mass of the solute (metal nitrate and complexing agent) to water is (8.9-10.7) g:50 mL.

[0011] As a preferred embodiment of the present invention, the metal nitrate and the complexing agent are dissolved in water under stirring conditions at a stirring rate of 200 to 250 r / min; the adjustment to weak alkalinity specifically adjusts the pH to 7.5 to 8, the pH adjusting agent is ammonia water, and the ammonia water concentration is 25 to 28 wt%; the heating is carried out under stirring at a stirring rate of 400 to 450 r / min.

[0012] As a preferred embodiment of the present invention, the heating temperature is 75-85°C and the time is 3-4 hours; the gel aging temperature is 18-30°C and the time is 5-7 hours; the drying and self-propagating reaction temperature is 170-190°C and the time is 8-10 hours.

[0013] As a preferred embodiment of the present invention, the dry gel is ground using an agate mortar, the pre-firing temperature is 200°C to 300°C, and the time is 10 to 15 minutes; the heat treatment temperature is 800 to 1000°C, and the time is 6 to 12 hours.

[0014] The present invention also provides a use of the above-mentioned CaLaPrNdGdFeO perovskite high-entropy ferrite absorbing material in the preparation of absorbing devices and equipment.

[0015] As a preferred embodiment of the present invention, the absorbing devices and equipment include stealth coatings, electromagnetic shielding and 5G communication devices.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The CaLaPrNdGdFeO perovskite high entropy ferrite absorbing material provided by the present invention has the molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3, the ferrite absorbing material composed of this equimolar high entropy component fully solves the disadvantages of traditional ferrites, such as narrow effective absorption band and poor low-frequency performance stability, and has strong synthetic stability, strong thermal stability, good oxidation resistance, high absorption efficiency and stable performance. It can absorb electromagnetic waves in the 2-18GHz microwave band, and the absorption bandwidth (the bandwidth of existing oxides at RL<-10dB is generally less than 2GHz) is greater than 4.2GHz, and the absorption efficiency is extremely high (greater than 99.99%), and can be used in stealth coatings, electromagnetic shielding and 5G communication devices and other fields.

[0018] The invention provides a CaLaPrNdGdFeO perovskite high-entropy ferrite absorbing material. The CaLaPrNdGdFeO absorbing material can be prepared through a sol-gel reaction, and the process is simple and suitable for high-throughput production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 The (Ca) prepared in Example 1 at a heat treatment temperature of 800°C and calcination times of 6h, 8h, 10h and 12h respectively 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) XRD pattern of FeO3 perovskite high entropy ferrite absorber;

[0021] Figure 2 The (Ca) prepared in Example 2 at a heat treatment temperature of 900°C and calcination times of 6h, 8h, 10h and 12h respectively 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) XRD pattern of FeO3 perovskite high entropy ferrite absorber;

[0022] Figure 3 The (Ca) prepared in Example 3 at a heat treatment temperature of 1000°C and calcination times of 6h, 8h, 10h and 12h respectively 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) XRD pattern of FeO3 perovskite high entropy ferrite absorber;

[0023] Figure 4 In Example 2, the calcination time is 10h (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) SEM image of FeO3 perovskite high entropy ferrite absorber material at ×9000 magnification;

[0024] Figure 5 In Example 2, the calcination time is 10h (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) SEM image of FeO3 perovskite high entropy ferrite absorber material at a magnification of ×18000;

[0025] Figure 6 For Examples 1, 2 and 3 (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber with a thickness d of 2 mm;

[0026] Figure 7 For Examples 1, 2 and 3 (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber with a thickness d of 2.2 mm;

[0027] Figure 8 The heat treatment temperature of Example 1 is 800℃, the calcination time is 6h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0028] Figure 9 The heat treatment temperature of Example 1 is 800℃, the calcination time is 8h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0029] Figure 10 The heat treatment temperature of Example 1 is 800℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0030] Figure 11 The heat treatment temperature of Example 1 is 800℃, the calcination time is 12h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0031] Figure 12 The heat treatment temperature of Example 2 is 900℃, the calcination time is 6h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0032] Figure 13 The heat treatment temperature of Example 2 is 900℃, the calcination time is 8h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0033] Figure 14 The heat treatment temperature of Example 2 is 900℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0034] Figure 15 The heat treatment temperature of Example 2 is 900℃, the calcination time is 12h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0035] Figure 16 The heat treatment temperature of Example 3 is 1000℃, the calcination time is 6h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0036] Figure 17 The heat treatment temperature of Example 3 is 1000℃, the calcination time is 8h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0037] Figure 18The heat treatment temperature of Example 3 is 1000℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0038] Figure 19 The heat treatment temperature of Example 3 is 1000℃, the calcination time is 12h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber material.

[0039] Figure 20 The heat treatment temperature of Example 4 is 800℃, the calcination time is 12h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0040] Figure 21 The heat treatment temperature of Example 5 is 1000℃, the calcination time is 6h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0041] Figure 22 For comparative example 1, the heat treatment temperature is 800℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.1 La 0.3 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0042] Figure 23 For comparative example 2, the heat treatment temperature is 800℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.25 Pr 0.25 Nd 0.25 Gd 0.25 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0043] Figure 24 For comparative example 3, the heat treatment temperature is 900℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber;

[0044] Figure 25 For comparative example 4, the heat treatment temperature is 900℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber material. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0046] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0047] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0048] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0049] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0050] The raw materials used in the following examples are all commercially available, without particular limitation. The purity of citric acid and EDTA is ≥99.5%. The process of combining the complexing agents is not particularly limited, and any method known to those skilled in the art can be used to uniformly mix the raw materials. In the examples of the present invention, citric acid and EDTA are specifically added to a metal nitrate solution. In the following examples, room temperature refers to 18-30°C. This description will not be repeated.

[0051] Example 1

[0052] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Preparation of FeO3 perovskite high entropy ferrite absorbing material, the steps are as follows:

[0053] 1) Calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% were prepared according to the material molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=1:1:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent orange.

[0054] 2) 3.3033 g of citric acid and 2.5757 g of EDTA were weighed and added to the nitrate solution, with the total molar weight of the metal ions in the metal nitrate being in a 1:2:1 ratio to the molar weight of the citric acid and EDTA complexing agent combination. The mixture was stirred on a magnetic stirrer for 10 minutes until dissolved. A 27 wt% aqueous ammonia solution was slowly added dropwise to the nitrate-complexing agent solution. The solution was observed to change from transparent orange to transparent green and finally to transparent deep red. The pH of the solution was measured with pH paper. The addition was stopped when the pH reached 7.5.

[0055] 3) The beaker containing the nitrate-complexing agent solution was placed in a water bath maintained at 80°C for gelation. The gelation reaction was carried out with stirring at 420 rpm for 3.5 hours. During the gelation reaction, the metal nitrate, under the complexing action of the complexing agent, formed a deep red, viscous gel through hydrogen bonding. The beaker containing the gel was then slowly cooled to room temperature and aged at room temperature for 6 hours to obtain a red, solidified gel.

[0056] 4) The gel obtained in step 3) was placed in a constant-temperature forced air drying oven set at 180°C and dried for 9 hours. This constant-temperature drying and self-propagating reaction of the gel took place for 9 hours. This drying not only dried out the moisture in the gel, causing it to expand, but also caused the self-propagating reaction at 180°C to preliminarily remove the organic complexing agent from the gel, ultimately yielding an expanded, dark-gray foamy xerogel.

[0057] 5) The dry gel in the beaker was ground with an agate mortar and pre-fired in a resistance wire heating furnace at 250°C for 13 minutes. After cooling to room temperature, the dry gel was placed in four corundum crucibles and calcined at 800°C for 6 hours, 8 hours, 10 hours, and 12 hours, respectively. The (Ca) 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material.

[0058] Example 2

[0059] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Preparation of FeO3 perovskite high entropy ferrite absorbing material, the steps are as follows:

[0060] 1) Calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% were prepared according to the material molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2)FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=1:1:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent orange.

[0061] 2) 3.3033 g of citric acid and 2.5757 g of EDTA were weighed and added to the nitrate solution, with the total molar weight of the metal ions in the metal nitrate being in a 1:2:1 ratio to the molar weight of the citric acid and EDTA complexing agent combination. The mixture was stirred on a magnetic stirrer for 10 minutes until dissolved. A 27 wt% aqueous ammonia solution was slowly added dropwise to the nitrate-complexing agent solution. The solution was observed to change from transparent orange to transparent green and finally to transparent deep red. The pH of the solution was measured with pH paper. The addition was stopped when the pH reached 7.5.

[0062] 3) The beaker containing the nitrate-complexing agent solution was placed in a water bath maintained at 80°C for gelation. The gelation reaction was carried out with stirring at 420 rpm for 3.5 hours. During the gelation reaction, the metal nitrate, under the complexing action of the complexing agent, formed a deep red, viscous gel through hydrogen bonding. The beaker containing the gel was then slowly cooled to room temperature and aged at room temperature for 6 hours to obtain a red, solidified gel.

[0063] 4) The gel obtained in step 3) was placed in a constant-temperature forced air drying oven set at 180°C and dried for 9 hours. This constant-temperature drying and self-propagating reaction of the gel took place for 9 hours. This drying not only dried out the moisture in the gel, causing it to expand, but also caused the self-propagating reaction at 180°C to preliminarily remove the organic complexing agent from the gel, ultimately yielding an expanded, dark-gray foamy xerogel.

[0064] 5) The dry gel in the beaker was ground with an agate mortar and pre-fired in a resistance wire heating furnace at 250°C for 13 minutes. After cooling to room temperature, the dry gel was placed in four corundum crucibles and calcined at 900°C for 6 hours, 8 hours, 10 hours, and 12 hours, respectively. The (Ca) 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material.

[0065] Example 3

[0066] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Preparation of FeO3 perovskite high entropy ferrite absorbing material, the steps are as follows:

[0067] 1) Calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% were prepared according to the material molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=1:1:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent orange.

[0068] 2) 3.3033 g of citric acid and 2.5757 g of EDTA were weighed and added to the nitrate solution, with the total molar weight of the metal ions in the metal nitrate being in a 1:2:1 ratio to the molar weight of the citric acid and EDTA complexing agent combination. The mixture was stirred on a magnetic stirrer for 10 minutes until dissolved. A 27 wt% aqueous ammonia solution was slowly added dropwise to the nitrate-complexing agent solution. The solution was observed to change from transparent orange to transparent green and finally to transparent deep red. The pH of the solution was measured with pH paper. The addition was stopped when the pH reached 7.5.

[0069] 3) The beaker containing the nitrate-complexing agent solution was placed in a water bath maintained at 80°C for gelation. The gelation reaction was carried out with stirring at 420 rpm for 3.5 hours. During the gelation reaction, the metal nitrate, under the complexing action of the complexing agent, formed a deep red, viscous gel through hydrogen bonding. The beaker containing the gel was then slowly cooled to room temperature and aged at room temperature for 6 hours to obtain a red, solidified gel.

[0070] 4) The gel obtained in step 3) was placed in a constant-temperature forced air drying oven set at 180°C and dried for 9 hours. This constant-temperature drying and self-propagating reaction of the gel took place for 9 hours. This drying not only dried out the moisture in the gel, causing it to expand, but also caused the self-propagating reaction at 180°C to preliminarily remove the organic complexing agent from the gel, ultimately yielding an expanded, dark-gray foamy xerogel.

[0071] 5) The dry gel in the beaker was ground with an agate mortar and pre-fired in a resistance wire heating furnace at 250°C for 13 minutes. After cooling to room temperature, the dry gel was placed in four corundum crucibles and calcined at 1000°C for 6 hours, 8 hours, 10 hours, and 12 hours, respectively. The (Ca) 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material.

[0072] Example 4

[0073] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Preparation of FeO3 perovskite high entropy ferrite absorbing material, the steps are as follows:

[0074] 1) Calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% were prepared according to the material molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=1:1:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent orange.

[0075] 2) Based on a molar ratio of 1:1.5:1 between the total molar amount of metal ions in the metal nitrate and the combined molar amount of citric acid and EDTA, the corresponding amounts of citric acid and EDTA were weighed and added to the nitrate solution. Stir on a magnetic stirrer for 10 minutes until dissolved. A 25 wt% aqueous ammonia solution was slowly added dropwise to the nitrate-complexing agent solution. The solution was observed to change from transparent orange to transparent green and finally to transparent deep red. The pH of the solution was measured using pH paper. The addition was stopped when the pH reached 7.7.

[0076] 3) The beaker containing the nitrate-complexing agent solution was placed in a water bath maintained at 75°C for gelation. The gelation reaction was carried out with stirring at 450 rpm for 4 hours. During the gelation reaction, the metal nitrate, under the complexing action of the complexing agent, formed a deep red, viscous gel through hydrogen bonding. The beaker containing the gel was then slowly cooled to room temperature and aged at room temperature for 7 hours to obtain a red, solidified gel.

[0077] 4) The gel obtained in step 3) was placed in a constant-temperature forced air drying oven set at 170°C and dried for 10 hours. This constant-temperature drying and self-propagating reaction of the gel took place for 10 hours. This drying not only dried out the moisture in the gel, causing it to expand, but also caused the self-propagating reaction at 170°C to preliminarily remove the organic complexing agent from the gel, ultimately yielding an expanded, dark-gray foamy xerogel.

[0078] 5) The dry gel in the beaker was ground with an agate mortar and placed on a resistance wire heating furnace for pre-sintering at 200°C for 15 minutes. After cooling to room temperature, it was placed in a corundum crucible and calcined at 800°C for 12 hours to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material.

[0079] Example 5

[0080] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Preparation of FeO3 perovskite high entropy ferrite absorbing material, the steps are as follows:

[0081] 1) Calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% were prepared according to the material molecular formula (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=1:1:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent orange.

[0082] 2) Based on a molar ratio of 1:2.5:1 between the total molar amount of metal ions in the metal nitrate and the combined molar amount of citric acid and EDTA, the corresponding amounts of citric acid and EDTA were weighed and added to the nitrate solution. Stir on a magnetic stirrer for 10 minutes until dissolved. A 28 wt% aqueous ammonia solution was slowly added dropwise to the nitrate-complexing agent solution. The solution was observed to change from transparent orange to transparent green and finally to transparent deep red. The pH of the solution was measured using pH paper. The addition was stopped when the pH reached 8.0.

[0083] 3) The beaker containing the nitrate-complexing agent solution was placed in a water bath maintained at 85°C for gelation. The gelation reaction was carried out with stirring at 400 rpm for 3 hours. During the gelation reaction, the metal nitrate, under the complexing action of the complexing agent, formed a deep red, viscous gel through hydrogen bonding. The beaker containing the gel was then slowly cooled to room temperature and aged at room temperature for 5 hours to obtain a red, solidified gel.

[0084] 4) The gel obtained in step 3) was placed in a constant-temperature forced-air drying oven set at 190°C and dried for 8 hours. This constant-temperature drying and self-propagating reaction of the gel took place for 8 hours. This drying not only dried out the moisture in the gel, causing it to expand, but also caused the self-propagating reaction at 190°C to preliminarily remove the organic complexing agent from the gel, ultimately yielding an expanded, dark-gray foamy xerogel.

[0085] 5) The dry gel in the beaker was ground with an agate mortar and placed on a resistance wire heating furnace for pre-sintering at 300°C for 10 minutes. After cooling to room temperature, it was placed in a corundum crucible and calcined at a heat treatment temperature of 1000°C for 6 hours to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material.

[0086] Comparative Example 1

[0087] Same as Example 1, except that in step 1), the amount of metal nitrate used is different, and the other steps are the same as Example 1. In this comparative example, step 1) is: calcium nitrate tetrahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate with a purity of ≥99.9% are mixed according to the material molecular formula (Ca 0.1 La 0.3 Pr 0.2 Nd 0.2 Gd 0.2)FeO3 with a stoichiometric ratio of metal elements (Ca:La:Pr:Nd:Gd:Fe=0.5:1.5:1:1:1:5) was weighed into a 250mL beaker filled with 50mL of deionized water and stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution turned transparent reddish orange.

[0088] Comparative Example 2

[0089] The same as Example 1, except that, in step 1), the types of metal nitrates are reduced. In this comparative example, step 1) is: calcium nitrate tetrahydrate, praseodymium nitrate hexahydrate, neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate and ferric nitrate nonahydrate, all of which have a purity of ≥99.9%, are mixed according to the material molecular formula (Ca 0.25 Pr 0.25 Nd 0.25 Gd 0.25 ) FeO3 metal element stoichiometric ratio (Ca:Pr:Nd:Gd:Fe=1:1:1:1:4) was weighed 0.2588g, 0.4767g, 0.4804g, 0.4948g, and 1.4168g, respectively, and dissolved in a 250mL beaker filled with 50mL of deionized water. The mixture was stirred under a magnetic stirrer for 5 minutes until the metal nitrate was completely dissolved and the solution became transparent green-orange. The other steps were the same as in Example 1.

[0090] Comparative Example 3

[0091] The same as Example 2, except that the pre-calcination step is omitted in step 5). Step 5) of this comparative example is as follows: the dry gel in the beaker is ground with an agate mortar, placed in a corundum crucible, and calcined for 10 hours at a heat treatment temperature of 900°C to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) FeO3 perovskite high entropy ferrite absorbing material. The other steps are the same as those in Example 2.

[0092] Comparative Example 4

[0093] The same as Example 2, except that in step 2), only EDTA is used as the complexing agent. Step 2) of this comparative example is as follows: 5.8790 g of EDTA is weighed and added to the nitrate solution, with a molar ratio of the total molar amount of metal ions in the metal nitrate to the EDTA complexing agent of 1:3. The mixture is stirred on a magnetic stirrer for 10 minutes until dissolved. A 27 wt% aqueous ammonia solution is slowly added dropwise to the nitrate-complexing agent solution. The solution is observed to change from a transparent purple-red to a transparent green and finally to a transparent deep red. The pH of the solution is measured with pH paper; addition is stopped when the pH reaches 7.5. All other steps are the same as in Example 2.

[0094] In the present invention, in order to verify the 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 high entropy structure, if the mixing entropy of a system (ΔS mix ) is greater than 1.5R, then the system is a high entropy material. The configurational entropy is calculated by formula (I):

[0095]

[0096] where ΔS mix is the entropy of mixing, R is the gas constant, x i is the mole fraction of the i-th component in HEO.

[0097] ΔS mix ((Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3)=-R(0.2ln 0.2+0.2ln 0.2+0.2ln 0.2+

[0098] 0.2ln 0.2+0.2ln 0.2)=1.61R>1.5R.

[0099] When the mixing entropy increases, the Gibbs free energy decreases and the solid solution becomes more stable. This means that the mixing entropy increases with the increase of element type N, while promoting the equiatomic (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )The formation of a single-phase solid solution in FeO3.

[0100] In the present invention, in order to verify the 0.2 La 0.2 Pr0.2 Nd 0.2 Gd 0.2 )FeO3's structural stability is used to verify its strong synthetic stability. 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The Goldschmid tolerance factor t of FeO3 is calculated. When the value of t is greater than 0.75 and less than 1, the perovskite structure is stable. The formula is shown in formula (II):

[0101]

[0102] where R A 、R B and R0 refer to the radii of the A-site cation, B-site cation, and oxygen anion, respectively.

[0103] A position is composed of Ca 2+ 、La 3+ 、Pr 3+ 、Nd 3+ 、Gd 3+ The mole fraction is 0.2.

[0104] According to the Shannon ionic radius table (twelve coordination), see Table 1:

[0105] Table 1 Shannon ionic radius table (twelve coordination)

[0106]

[0107]

[0108] Weighted average:

[0109] B position is Fe 3+ (six-coordinated, high spin), radius

[0110] Substitute into the formula to calculate:

[0111]

[0112] The tolerance factor t≈0.931 is within the perovskite stability range (0.8~1.0) and close to the ideal value (0.9~1.0), indicating that the high-entropy perovskite structure has high stability.

[0113] For the (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd0.2 ) FeO3 perovskite high entropy ferrite absorbing material was subjected to XRD test, and the test results are as follows Figure 1 、 2 As shown in Figure 3, the molar ratio of high entropy components (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 exists stably in the form of a single-phase solid solution, and with the increase of heat treatment temperature and the extension of calcination time, the crystallinity and structure of the material do not change significantly, which once again verifies the stability of the perovskite high-entropy ferrite structure.

[0114] For the (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) FeO3 perovskite high entropy ferrite absorbing material was tested by SEM. Figure 4 and Figure 5 The SEM images of the material calcined for 10 h in Example 1 are magnified by ×9000 and ×18000 respectively. It can be clearly seen from the figure that the sol-gel method (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 The FeO3 perovskite high-entropy ferrite absorber is a woven structure composed of uniform, dumbbell-shaped particles approximately 330 nm in size. This unique structure not only creates a large number of pores, reducing the absorber's mass density, but also provides more transmission paths for electromagnetic waves incident on its surface, optimizing impedance matching performance.

[0115] Performance Testing

[0116] For the (Ca 0..2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The performance test of the FeO3 perovskite high entropy ferrite absorbing material was carried out according to the powder: paraffin = 2:1 (mass ratio) fully mixed to make a coaxial ring test sample with an outer diameter and inner diameter of 7mm and 3.04mm respectively, and a thickness of about 3mm. The complex dielectric constant and complex magnetic permeability of the test sample in the 2-18GHz frequency band were measured using an N5230C microwave vector network analyzer, and then the reflectivity R of the single-layer absorbing material was calculated and simulated. The simulation formula is shown in formula (III):

[0117]

[0118] Where, ε r 、μ r and d are the relative dielectric constant, relative magnetic permeability and thickness of the absorbing material, respectively; f is the frequency of the electromagnetic wave; c is the propagation speed of the electromagnetic wave in free space (i.e., the speed of light); and j is an imaginary unit.

[0119] In Examples 1 to 3, the heat treatment temperatures were 800, 900°C, and 1000°C, and the calcination times were 6h, 8h, 10h, and 12h to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The reflection loss values ​​of FeO3 absorbing materials in the range of 2-18GHz with thicknesses of 2mm and 2.2mm are as follows: Figures 6-7 shown.

[0120] In Example 1, the heat treatment temperature was 800°C, and the calcination time was 6h, 8h, 10h, and 12h to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The reflection loss value of FeO3 absorbing material in the range of 2-18GHz and with a thickness of 1-5mm is as follows Figures 8-11 In Example 2, the heat treatment temperature was 900°C, and the calcination time was 6h, 8h, 10h, and 12h to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The reflection loss value of FeO3 absorbing material in the range of 2-18GHz and with a thickness of 1-5mm is as follows Figures 12-15 In Example 3, the heat treatment temperature was 1000°C, and the calcination time was 6h, 8h, 10h, and 12h to obtain (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) The reflection loss value of FeO3 absorbing material in the range of 2-18GHz and with a thickness of 1-5mm is as follows Figures 16-19 The best absorbing performance results are shown in Table 2.

[0121] Table 2 (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2) Test data of the best absorbing performance of FeO3 absorbing material in the range of 2-18GHz and with a thickness of 1-5mm

[0122]

[0123]

[0124] The above data show that the absorbent has excellent absorption bandwidth and strong absorption performance in the 2-18 GHz frequency band, and has high absorption efficiency (> 99.99%). The most preferred one is (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material, it is at d=2mm,EAB max =7.23GHz,f=6.10GHz,RL min =-53.80dB, achieving more than 80% coverage of the X-band and full coverage of the Ku-band

[0125] (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3 perovskite high entropy ferrite absorbing material fully solves the disadvantages of traditional ferrite, such as narrow effective absorption band and poor low-frequency performance stability. Moreover, under certain heat treatment temperature and sintering time, it has an innovative trend of achieving minimum reflection loss and maximum absorption bandwidth at the same thickness.

[0126] The performance tests were carried out on the products prepared in Examples 4 to 5 and Comparative Examples 1 to 4. Figure 20 The heat treatment temperature of Example 4 is 800℃, the calcination time is 12h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber; Figure 21 The heat treatment temperature of Example 5 is 1000℃, the calcination time is 6h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber; Figure 22For comparative example 1, the heat treatment temperature is 800℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.1 La 0.3 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber; Figure 23 For comparative example 2, the heat treatment temperature is 800℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.25 Pr 0.25 Nd 0.25 Gd 0.25 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber; Figure 24 For comparative example 3, the heat treatment temperature is 900℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 ) Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber; Figure 25 For comparative example 4, the heat treatment temperature is 900℃, the calcination time is 10h, and the thickness range is 1~5mm (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )Reflection loss diagram of FeO3 perovskite high entropy ferrite absorber material.

[0127] The performance test results show that in comparative example 1, when f = 5.12 GHz, the minimum reflection loss RL min =-30.06dB, when the matching thickness d = 2mm, the maximum effective absorption bandwidth EAB max =2.8GHz, the minimum reflection loss value is 29.54dB higher than that in Example 1, resulting in a decrease in absorption efficiency and a significant decrease in the maximum effective absorption bandwidth by 35%. In Comparative Example 2, when f=6GHz, the minimum reflection loss RL min =-18.49dB, when the matching thickness d = 2mm, the maximum effective absorption bandwidth EAB max =3.72GHz, the minimum reflection loss value is increased by 41.11dB compared with Example 1, and only 90% of the absorption efficiency is maintained, resulting in a serious decrease in the absorption performance. In Comparative Example 3, when f = 5.44GHz, the minimum reflection loss RL min =-15.59dB, when the matching thickness d = 5mm, the maximum effective absorption bandwidth EAB max=3.2GHz, which is more than the optimal matching thickness of Example 2, which goes against the development trend of absorbing materials to be "light, thin, strong and wide" and will greatly increase production costs. In Comparative Example 4, when f=12.4GHz, the minimum reflection loss RL min =-28.41dB, when the matching thickness d = 2.2mm, the maximum effective absorption bandwidth EAB max =4.56 GHz, which is still within the medium and high frequency range compared to the minimum reflection loss value in Example 2. This fails to solve the problem of narrow absorption frequency band of traditional ferrite materials, and the maximum absorption bandwidth is reduced by 2.67 GHz, thus losing the broadband advantage.

[0128] Excellent wave absorption performance is related to both structure and composition. By constructing a high-entropy component with equimolar main group elements and four rare earth elements (Ca, La, Pr, Nd, Gd), the dielectric constant and magnetic permeability of the material are regulated, the reflection of electromagnetic waves on the surface of the material is reduced, and the efficiency of energy entering the interior of the material is enhanced. The lattice distortion and structural defects caused by the high-entropy effect increase the polarization relaxation and magnetic domain wall displacement resistance, thereby increasing dielectric loss and magnetic loss, and efficiently converting electromagnetic energy into heat energy. Multi-element doping introduces multiple resonance modes such as electron relaxation and interface polarization, forming loss peaks in multiple frequency bands, achieving wider bandwidth electromagnetic wave absorption, and adapting to the needs of complex electromagnetic environments. The high configurational entropy of the high-entropy system inhibits element diffusion and phase change, allowing the material to maintain structural stability at high temperatures, avoiding the degradation of wave absorption performance of traditional ferrites due to temperature increases. The sol-gel preparation method forms a woven structure composed of uniform nanoscale particles. This unique structure not only produces a large number of porous structures, but also easily forms a rich heterogeneous interface, greatly improving interfacial polarization and enhancing dielectric loss. It can also provide more transmission paths for electromagnetic waves irradiated on its surface, optimizing impedance matching performance. The intrinsic low density of the perovskite structure combined with the efficient wave absorption ability of high-entropy ferrite can reduce the thickness or amount of material while maintaining the same performance, meeting the demand for lightweight wave-absorbing materials in fields such as aerospace. This innovative design comprehensively improves the absorption efficiency, environmental adaptability, and engineering applicability through the coordinated regulation of material composition and structure, providing new ideas for the next generation of high-performance electromagnetic stealth and shielding materials.

[0129] The above description is only a preferred specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention within the technical scope disclosed in the present invention, and these changes should be covered by the scope of protection of the present invention.

Claims

1. A CaLaPrNdGdFeO perovskite high entropy ferrite absorbing material, characterized in that: The chemical composition of the perovskite high entropy ferrite absorbing material is (Ca 0.2 La 0.2 Pr 0.2 Nd 0.2 Gd 0.2 )FeO3.

2. A method for preparing the CaLaPrNdGdFeO perovskite high entropy ferrite absorbing material according to claim 1, characterized in that: The following steps are involved: According to the molar ratio of the metal elements Ca, La, Pr, Nd, Gd and Fe in the chemical formula, metal nitrates are weighed, the metal nitrates and the complexing agent are dissolved in water, the solution is adjusted to be weakly alkaline to obtain a metal ion-complexing agent solution, the solution is heated to obtain a gel and aged, and the solution is dried and a self-propagating reaction occurs to obtain a precursor xerogel; Then, grinding, pre-sintering and heat treatment are performed to obtain the CaLaPrNdGdFeO perovskite high entropy ferrite wave absorbing material.

3. The preparation method according to claim 2, characterized in that The metal nitrates are calcium nitrate, lanthanum nitrate, praseodymium nitrate, neodymium nitrate, gadolinium nitrate and ferric nitrate, and the complexing agents are citric acid and ethylenediaminetetraacetic acid.

4. The preparation method according to claim 2, characterized in that The molar ratio of the metal ion to the complexing agent is 1:(2.5-3.5), and the molar ratio of the citric acid to the ethylenediaminetetraacetic acid is (1.5-2.5):

1.

5. The preparation method according to claim 2, characterized in that The volume ratio of the total mass of the metal nitrate and the complexing agent to water is (8.9-10.7) g:50 mL.

6. The preparation method according to claim 2, characterized in that: The metal nitrate and the complexing agent are dissolved in water under stirring conditions at a stirring rate of 200 to 250 r / min; the adjustment to weak alkalinity specifically adjusts the pH to 7.5 to 8, and the heating is carried out under stirring at a stirring rate of 400 to 450 r / min.

7. The preparation method according to claim 2, characterized in that: The heating temperature is 75-85° C. and the time is 3-4 hours; the gel aging temperature is 18-30° C. and the time is 5-7 hours; the drying and self-propagating reaction temperature is 170-190° C. and the time is 8-10 hours.

8. The preparation method according to claim 2, characterized in that: The pre-firing temperature is 200-300° C., and the time is 10-15 minutes; the heat treatment temperature is 800-1000° C., and the time is 6-12 hours.

9. Use of the CaLaPrNdGdFeO perovskite high entropy ferrite absorbing material according to claim 1 in the preparation of absorbing devices and equipment.

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