Bismuth ferrite rare earth-based high-entropy ceramic material as well as preparation method and application thereof

Abstract

The invention discloses a bismuth ferrite rare earth based high-entropy ceramic material and a preparation method and application thereof, the chemical formula of the material is (Ca < 0.2 > RE < 0.6 > Bi < 0.2 >) FeO < 3 > or (Ca < 0.2 > RE < 0.6 > Bi < 0.2 >) (Fe < 0.9 > Ti < 0.1 >) O < 3 >; wherein RE is selected from at least three of Ho, La, Nd, Gd and Yb. According to the bismuth ferrite rare earth-based high-entropy ceramic material, at least three rare earth elements are added, on one hand, rare earth ions show a good gamma ray radiation effect due to a unique electronic layer of the rare earth ions; on the other hand, the bismuth ferrite rare earth-based high-entropy ceramic material has good wave-absorbing performance by applying a high-entropy lattice distortion effect and doping different rare earth elements. The bismuth ferrite rare earth-based high-entropy ceramic material disclosed by the invention has dual effects of radiation shielding and electromagnetic shielding, and has a huge application prospect in packaging protection of special nuclear power source electronic devices.

Description

Technical Field

[0001] The present invention relates to a high-entropy ceramic material, and particularly to a bismuth ferrite rare-earth-based high-entropy ceramic material, a preparation method thereof, and an application thereof. Background Art

[0002] As a low-carbon and efficient clean energy, nuclear energy has received extensive attention from various countries. Nuclear energy has diversified applications in daily life. Among them, space nuclear power sources have become ideal energy sources for space exploration due to their high specific power, long life, strong adaptability, etc. To ensure the stable operation of the power supply system, special electronic devices adapted to space reactors need to be protected by encapsulation materials with wave absorption / radiation shielding properties.

[0003] Currently, the most commonly used wave absorption materials include: ferrites, metal micropowders, silicon carbide, graphite, etc. These materials have different electromagnetic properties and have significant wave absorption effects in different electromagnetic wave bands, and can effectively absorb electromagnetic waves to reduce the harm caused by electromagnetic waves to the human body or specific electronic devices. However, traditional wave absorption materials such as ferrites and metal powders often have a high density, which limits the application of traditional wave absorption materials in fields where low-density design is required (such as aerospace, mobile communication devices, etc.). High density not only increases the weight of the equipment, but also may affect the overall performance and cost of the equipment. Lead and concrete are currently commonly used γ-radiation shielding materials, but lead is highly toxic and the density and weight of concrete are too large, and both are not the optimal materials for shielding γ-rays.

[0004] Currently, the research and development of materials with integrated wave absorption and radiation shielding functions is still lacking. Therefore, developing materials with integrated wave absorption and radiation shielding functions is of great significance for the long-term safe operation of space nuclear power sources.

[0005] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a bismuth ferrite rare-earth-based high-entropy ceramic material, a preparation method thereof, and an application thereof. This material solves the problem of the lack of integrated wave absorption and radiation shielding functions in existing materials. The bismuth ferrite rare-earth-based high-entropy ceramic material of the present invention has dual functions of radiation shielding and electromagnetic shielding, and has great application prospects in the encapsulation and protection of special nuclear power electronic devices.

[0007] To achieve the above purpose, the present invention provides a bismuth ferrite rare-earth-based high-entropy ceramic material, and the chemical formula of this material is: (Ca 0.2 RE 0.6 Bi0.2 )(FeO3 or (Ca 0.2 RE 0.6 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3; wherein, RE is selected from at least three of Ho, La, Nd, Gd, and Yb.

[0008] By adding at least three rare earth metals, the invented bismuth ferrite rare earth-based high-entropy ceramic material has dual functions of radiation shielding and electromagnetic shielding, and has great application prospects in the packaging protection of special nuclear power electronic devices. In addition, it is impossible to stably synthesize bismuth ferrite rare earth-based high-entropy materials doped with one or two REs.

[0009] Preferably, the bismuth ferrite rare earth-based high-entropy ceramic material has a perovskite structure.

[0010] Preferably, the wave absorption performance of the bismuth ferrite rare earth-based high-entropy ceramic material is: the absolute value of the minimum reflection loss is 20 - 50 dB, and the effective absorption bandwidth is 1 - 3 GHz.

[0011] Preferably, the chemical formula of the bismuth ferrite rare earth-based high-entropy ceramic material is: (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3, (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3, (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 or (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3.

[0012] The second object of the present invention is to provide a preparation method of the bismuth ferrite rare earth-based high-entropy ceramic material, which includes: heating and stirring and mixing the RE source, Fe source, Ca source, Bi source, and Ti source with a chelating agent, a dispersing agent, and a solvent, drying and then grinding, and then calcining at 600 °C to obtain the bismuth ferrite rare earth-based high-entropy ceramic material.

[0013] Preferably, the chelating agent is selected from citric acid; and / or, the dispersant is selected from ethylene glycol; and / or, the solvent is selected from water; and / or, the molar ratio of the chelating agent to the metal ion is 1.2:1; and / or, the molar ratio of the dispersant to the chelating agent is 1.2:1.

[0014] Preferably, for the calcination, the heat preservation time is 3 h and / or the heating rate is 5 °C / min.

[0015] Preferably, for the heating and stirring, the temperature is 80 °C and / or the stirring speed is 500 rpm.

[0016] Preferably, the RE source is selected from at least three of neodymium hexahydrate nitrate, gadolinium hexahydrate nitrate, holmium pentahydrate nitrate, lanthanum hexahydrate nitrate, ytterbium pentahydrate nitrate; the Fe source is selected from iron(III) nitrate nonahydrate; the Bi source is selected from bismuth(V) nitrate pentahydrate; the Ca source is selected from calcium oxalate hydrate; the Ti source is selected from tetrabutyl titanate.

[0017] The third object of the present invention is to provide the application of the bismuth ferrite rare earth-based high-entropy ceramic material in wave absorption and / or radiation shielding.

[0018] Preferably, the thickness of the bismuth ferrite rare earth-based high-entropy ceramic material is 1-5 mm. Specifically, the thickness can be 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm.

[0019] The bismuth ferrite rare earth-based high-entropy ceramic material, its preparation method and application of the present invention solve the problem of the lack of integration of wave absorption and radiation shielding functions in existing materials, and have the following advantages: (1) The bismuth ferrite rare earth-based high-entropy ceramic material of the present invention has the chemical formula (Ca 0.2 RE 0.6 Bi 0.2 )FeO3 or (Ca 0.2 RE 0.6 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3, wherein RE is selected from at least three of Ho, La, Nd, Gd, and Yb. On the one hand, rare earth ions exhibit good γ-ray radiation effects due to their unique electron layers; on the other hand, by applying the lattice distortion effect of high entropy, the bismuth ferrite rare earth-based high-entropy ceramic material has good wave absorption performance by doping different rare earth elements. The invented bismuth ferrite rare earth-based high-entropy ceramic material has dual functions of radiation shielding and electromagnetic shielding, and has great application prospects in the packaging protection of special nuclear power electronic devices;

[0020] (2) The present invention prepares a bismuth ferrite rare earth-based high-entropy ceramic material by a sol-gel method. The preparation process of the present invention is simple, with high synthesis purity and can be applied on a large scale. Description of the Drawings

[0021] Figure 1 XRD pattern of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention.

[0022] Figure 2 Absorbing wave reflection loss diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention.

[0023] Figure 3 EDS diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention.

[0024] Figure 4 XRD pattern of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention.

[0025] Figure 5 Absorbing wave reflection loss diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention.

[0026] Figure 6 EDS diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention.

[0027] Figure 7 XRD pattern of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention.

[0028] Figure 8 Absorbing wave reflection loss diagram of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention.

[0029] Figure 9 EDS diagram of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention.

[0030] Figure 10 XRD pattern of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention.

[0031] Figure 11 Absorbing wave reflection loss diagram of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention.

[0032] Figure 12 EDS diagram of bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention.

[0033] Figure 13 For the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention, the γ-ray linear attenuation coefficient diagram. Specific embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0035] It should be noted that: for those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified in the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0036] In the present invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of the numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0037] The features mentioned in the present invention can be combined arbitrarily, as long as there is no contradiction in the combination of these features, all possible combinations should be considered as the scope described in this specification. Each feature disclosed in the specification can be replaced by any alternative feature that provides the same, equivalent or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equivalent or similar features.

[0038] The present invention provides a bismuth ferrite rare earth-based high-entropy ceramic material, and the chemical formula of the material is: (Ca 0.2 RE 0.6 Bi 0.2 )FeO3 or (Ca 0.2 RE 0.6 Bi 0.2 )(Fe 0.9 Ti 0.1)O3; wherein, RE is selected from at least three of Ho, La, Nd, Gd, and Yb. Rare earth elements can be used as doping elements to replace traditional toxic elements because of their good chemical stability, low toxicity, polychromatism, and unique optical and magnetic properties. Some elements in rare earth elements, such as neodymium and samarium, have strong magnetism and are ideal raw materials for making microwave absorption materials. At the same time, adding alkaline earth element calcium to the bismuth ferrite matrix can improve the microwave absorption performance of the material. The K-edge absorption of rare earth elements can cover all weak absorption regions of lead radiation shielding materials, making up for the shortcoming of lead plates as radiation shielding materials. At the same time, the concept of high entropy is introduced, and the properties of ceramic materials are adjusted by regulating the chemical composition of the materials, so that ferrites with different structures have high selectivity in both microwave absorption and radiation shielding to meet the specific packaging material requirements of space nuclear power sources.

[0039] The following will detail the bismuth ferrite rare earth-based high-entropy ceramic materials provided by the present invention, their preparation methods, and applications through Examples 1 to 4.

[0040] Example 1 A bismuth ferrite rare earth-based high-entropy ceramic material, and its preparation method includes the following steps: (1) Weigh 0.002 mol of C2CaO4·xH2O, NdN3O9·6H2O, GdN3O9·6H2O, YbN3O9·5H2O, and BiN3O9·5H2O and 0.01 mol of FeN3O9·9H2O respectively and add them to a 250 mL beaker. Then add 0.024 mol of citric acid as a chelating agent and 0.0288 mol of ethylene glycol as a dispersant. Finally, add 100 mL of ultrapure water as a solvent, and stir at 80 °C and 500 rpm for three hours.

[0041] (2) Place the stirred mixture in an oven and dry it at 110 °C for 24 h. Then grind the mixture for 30 min, and then put the sample into a muffle furnace for calcination. The calcination temperature is 600 °C, the heating rate is 5 °C / min, and the holding time is 3 h to obtain the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3; (3) Perform secondary grinding on the obtained bismuth ferrite rare earth-based high-entropy ceramic material to obtain a bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 with more uniform particles.

[0042] As shown Figure 1 in the figure, it is the XRD pattern of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention, Figure 1 indicating that the obtained bismuth ferrite rare-earth-based high-entropy ceramic material has a perovskite structure, without extra peaks, the product crystal form is complete, and the synthesis purity is 100%.

[0043] As shown Figure 2 in the figure, it is the wave absorption reflection loss diagram of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention. The 5 curves in the figure are the curve diagrams of the material with thicknesses of 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively. From Figure 2 it can be seen that the minimum reflection loss value of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 with a thickness of 5 mm within the frequency range of 2 - 18 GHz is -24.21 dB, and the effective absorption bandwidth is 1.22 GHz.

[0044] As shown Figure 3 in the figure, it is the EDS element distribution diagram of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3 prepared in Example 1 of the present invention. From Figure 3 it can be seen that the rare-earth ions are uniformly distributed on the ceramic body, realizing the uniform doping of rare-earth metals.

[0045] Example 2 A bismuth ferrite rare-earth-based high-entropy ceramic material, the preparation method of which is basically the same as that of Example 1, the difference is that in step (1), LaN3O9·6H2O is used to replace YbN3O9·5H2O.

[0046] The bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi0.2 )FeO3。

[0047] As Figure 4 shown, the XRD pattern of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention, Figure 4 shows that the obtained bismuth ferrite rare earth-based high-entropy ceramic material has a perovskite structure, no extra impurity peaks appear, the product crystal form is complete, and the synthesis purity is 100%.

[0048] As Figure 5 shown, the wave absorption reflection loss diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention. The 5 curves in the figure are the curve diagrams when the thickness of the material is 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively. From Figure 5 it can be seen that the minimum reflection loss value of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 with a thickness of 5 mm within the frequency range of 2 - 18 GHz is -26.17 dB, and the effective absorption bandwidth is 1.44 GHz.

[0049] As Figure 6 shown, the EDS element distribution diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3 prepared in Example 2 of the present invention. From Figure 6 it can be seen that the rare earth ions are uniformly distributed on the ceramic body, realizing the uniform doping of rare earth metals.

[0050] Example 3 A bismuth ferrite rare earth-based high-entropy ceramic material, the preparation method of which is basically the same as that of Example 1, the difference is that: In step (1), HoN3O9·5H2O is used to replace YbN3O9·5H2O.

[0051] The bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd0.2 Ho 0.2 Bi 0.2 )FeO3。

[0052] As Figure 7 shown, the XRD pattern of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention, Figure 7 indicates that the obtained bismuth ferrite rare-earth-based high-entropy ceramic material has a perovskite structure, no extra peaks appear, the product crystal form is complete, and the synthesis purity is 100%.

[0053] As Figure 8 shown, the wave absorption reflection loss diagram of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention. The 5 curves in the figure are the curve diagrams of the material with thicknesses of 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively. From Figure 8 it can be seen that the minimum reflection loss value of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 within the frequency range of 2 - 18 GHz is -26.54 dB, and the effective absorption bandwidth is 1.60 GHz.

[0054] As Figure 9 shown, the EDS element distribution diagram of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 prepared in Example 3 of the present invention. From Figure 9 it can be seen that the rare-earth ions are evenly distributed on the ceramic body, realizing the uniform doping of rare-earth metals.

[0055] Example 4 A bismuth ferrite rare-earth-based high-entropy ceramic material, the preparation method of which is basically the same as that of Example 3, except that: In step (1), 0.009 mol of FeN3O9·9H2O and 0.001 mol of TiC 16 H 16O4 replaces 0.01 mol of FeN3O9·9H2O.

[0056] Example 4 obtained the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3.

[0057] As Figure 10 shown, it is the XRD pattern of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention. Figure 10 It shows that the obtained bismuth ferrite rare earth-based high-entropy ceramic material has a perovskite structure, no extra peaks appear, the product crystal form is complete, and the synthesis purity is 100%.

[0058] As Figure 11 shown, it is the microwave absorption reflection loss diagram of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention. The 5 curves in the figure are the curve diagrams of the material with thicknesses of 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm respectively. From Figure 11 it can be seen that the minimum reflection loss value of the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 within the frequency range of 2~18 GHz is -46.94 dB, and the effective absorption bandwidth is 2.92 GHz.

[0059] As Figure 12 shown, it is the bismuth ferrite rare earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9Ti 0.1 ) EDS elemental distribution map of O3. It can be seen from Figure 12 that the rare earth ions are evenly distributed on the ceramic body, realizing the uniform doping of rare earth metals.

[0060] In order to test the γ-radiation shielding performance of the material, the obtained bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 and polypropylene material were melted at a high temperature of 190 °C in a torque rheometer, mixed evenly, and then the mixed material was pressed into sheets by a flat vulcanizer to obtain four composite materials with different doping gradients. Among them, the doping ratios of the high-entropy powder are 0%, 15%, 30% and 45% respectively. The four samples are named PP, PP / B1, PP / B2 and PP / B3 respectively. The results are shown in Figure 13 .

[0061] As Figure 13 shown, it is the γ-ray attenuation coefficient diagram of the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 prepared in Example 4 of the present invention. It can be seen from Figure 13 that when the doping ratio of the high-entropy powder is 45%, the linear attenuation coefficient of PP / B3 is more than 16 times that of the blank sample PP. This proves that the bismuth ferrite rare-earth-based high-entropy ceramic material (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3 has the performance of integrated radiation shielding and electromagnetic shielding.

[0062] Although the content of the present invention has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A bismuth ferrite rare earth-based high-entropy ceramic material, characterized in that, The chemical formula of the material is: (Ca 0.2 RE 0.6 Bi 0.2 )FeO3 or (Ca 0.2 RE 0.6 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3; Among them, RE is selected from at least three of Ho, La, Nd, Gd, and Yb.

2. The bismuth ferrite rare earth-based high-entropy ceramic material according to claim 1, characterized in that The bismuth ferrite rare earth-based high-entropy ceramic material has a perovskite structure.

3. The bismuth ferrite rare earth-based high-entropy ceramic material according to claim 1, characterized in that, The wave absorption performance of the bismuth ferrite rare earth-based high-entropy ceramic material is as follows: the absolute value of the minimum reflection loss is 20 - 50 dB, and the effective absorption bandwidth is 1 - 3 GHz.

4. The bismuth ferrite rare earth-based high-entropy ceramic material according to claim 1, characterized in that, The chemical formula of the bismuth ferrite rare earth-based high-entropy ceramic material is: (Ca 0.2 Nd 0.2 Gd 0.2 Yb 0.2 Bi 0.2 )FeO3, (Ca 0.2 La 0.2 Nd 0.2 Gd 0.2 Bi 0.2 )FeO3, (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )FeO3 or (Ca 0.2 Nd 0.2 Gd 0.2 Ho 0.2 Bi 0.2 )(Fe 0.9 Ti 0.1 )O3.

5. The preparation method of the bismuth ferrite rare earth-based high-entropy ceramic material according to any one of claims 1 to 4, characterized in that, This method includes: Mixing the RE source, Fe source, Ca source, Bi source, and Ti source with a chelating agent, a dispersing agent, and a solvent by heating and stirring, drying, grinding, and then calcining at 600 °C to obtain the bismuth ferrite rare earth-based high-entropy ceramic material.

6. The preparation method according to claim 5, wherein The chelating agent is selected from citric acid; Or / and, the dispersing agent is selected from ethylene glycol; Or / and, the solvent is selected from water; Or / and, the molar ratio of the chelating agent to the metal ion is 1.2:1; Or / and, the molar ratio of the dispersing agent to the chelating agent is 1.2:

1.

7. The preparation method according to claim 5, characterized in that, For the calcination, the holding time is 3 h or / and the heating rate is 5 °C / min.

8. The preparation method according to claim 5, characterized in that, For the heating and stirring, the temperature is 80 °C or / and the stirring speed is 500 rpm.

9. The preparation method according to any one of claims 5 to 8, characterized in that, The RE source is selected from at least three of neodymium nitrate hexahydrate, gadolinium nitrate hexahydrate, holmium nitrate pentahydrate, lanthanum nitrate hexahydrate, and ytterbium nitrate pentahydrate; The Fe source is selected from iron(III) nitrate nonahydrate; The Bi source is selected from bismuth nitrate pentahydrate; The Ca source is selected from calcium oxalate hydrate; The Ti source is selected from tetrabutyl titanate.

10. Application of the bismuth ferrite rare earth-based high-entropy ceramic material according to any one of claims 1 - 4 in wave absorption or / and radiation shielding.

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