High-entropy ceramic as well as preparation method and application thereof

Abstract

The invention discloses high-entropy ceramic as well as a preparation method and application thereof, and relates to the technical field of high-entropy ceramic. The high-entropy ceramic is characterized in that the chemical formula of the high-entropy ceramic is Pb (ZraTibAcBdCe) O3, wherein a + b is greater than or equal to 0.4, A, B and C are tetravalent elements, and the stoichiometric ratio a + b + c + d + e is equal to 1, and a, b, c, d and e are all greater than or equal to 0. According to the invention, the problem that the current antiferroelectric material is unfavorable for a ceramic capacitor and a piezoelectric transducer which need to be operated at low voltage due to antiparallel polarization, macroscopic non-polarity, low piezoelectric response and low dielectric constant near a zero field is solved.

Description

Technical Field

[0001] This invention relates to the field of high-entropy ceramics technology, and more particularly to a high-entropy ceramic, its preparation method, and its application. Background Technology

[0002] High-entropy ceramics are a new type of multi-component ceramic material. They are characterized by the introduction of multiple elements into the crystal lattice to form a single phase or nanocomposite structure, which has unique physical, chemical and mechanical properties.

[0003] However, current antiferroelectric materials, due to their antiparallel polarization, lack macroscopic polarity, resulting in low piezoelectric response and a low dielectric constant near zero field. This makes them unsuitable for ceramic capacitors and piezoelectric transducers requiring low-voltage operation. No effective solution has yet been proposed to address these issues. Summary of the Invention

[0004] Objective of the invention: To provide a high-entropy ceramic, its preparation method, and its application, so as to at least solve one of the problems existing in the prior art.

[0005] Technical solution: A high-entropy ceramic, comprising: The chemical formula of the high-entropy ceramic is Pb(Zr). a Ti b A c B d C e O3; Where a+b≥0.4, A, B, and C are tetravalent elements and satisfy the stoichiometric ratio a+b+c+d+e=1, and a, b, c, d, and e are all ≥0.

[0006] Preferably, the tetravalent element is a combination of Sn, Hf, Ce, Si, or Ge.

[0007] Preferably, the sintering aid is also included; wherein the sintering aid is Bi2O3 and PbSiO3.

[0008] Preferably, the Bi2O3 content is 2-3 wt%, and the PbSiO3 content is 1-2 wt%.

[0009] Preferably, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c O3; Where A is Sn, a is 0.6, b is 0.2, and c is 0.2.

[0010] Preferably, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A cB d O3; Where A is Sn, B is Hf, a is 0.6, b is 0.2, c is 0.1, and d is 0.1.

[0011] Preferably, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c B d O3; Where A is Sn, B is Si, a is 0.5, b is 0.3, c is 0.1, and d is 0.1.

[0012] Preferably, the high-entropy ceramic has a crystal structure of a single crystal phase or a composite phase; The single crystal phase is of the perovskite type.

[0013] To achieve the above objectives, according to another aspect of this application, a method for preparing high-entropy ceramics is also provided.

[0014] The method for preparing high-entropy ceramics according to this application includes the high-entropy ceramics as described above; it also includes the following steps: S1. Add the mixed oxide or carbonate powder into the ball mill jar according to the preset stoichiometric ratio and ball mill for 6 hours; S2. Dry the prepared ball mill slurry and calcine the sample at 800-900℃ for 3 hours; S3. The calcined powder is ball-milled and dried again, and then pressed into a disc using polyvinyl butyral as a binder to obtain a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm. S4. Place the formed disc sample in a crucible containing lead carbonate powder and calcine it with lead carbonate at 1100-1350℃ for 3-6 hours. S5. After firing, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure.

[0015] Preferably, S1, mixing oxide or carbonate powders according to a preset stoichiometric ratio and adding them to a mixing container includes: One or more of lead carbonate, titanium oxide, zirconium oxide, tin oxide, hafnium oxide, cerium oxide, silicon oxide, or germanium oxide.

[0016] Preferably, in step S3, the calcined powder is ball-milled again, and polyvinyl butyral is used as a binder to press it into a disc, resulting in a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm, comprising: A disc sample with a diameter of 10 mm and a thickness of 1.5 mm was obtained.

[0017] Preferably, in step S5, after sintering, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure. This is followed by: The dielectric constant was tested using an LCR bridge, and the quasi-static piezoelectric coefficient was tested using a d33meter.

[0018] To achieve the above objectives, according to another aspect of this application, an application of high-entropy ceramics is also provided.

[0019] The application of high-entropy ceramics according to this application includes the preparation method of high-entropy ceramics as described above.

[0020] Beneficial effects: In this embodiment, the PbZrO3 material is modified to achieve the desired high entropy ceramic with the chemical formula Pb(ZrO3)₃. a Ti b A c B d C e O3; where a+b≥0.4, A, B, and C are tetravalent elements and satisfy the stoichiometric ratio a+b+c+d+e=1, and a, b, c, d, and e are all ≥0, achieving the goal of high dielectric constant and high entropy of piezoelectric coefficient, thus realizing the technical effect of constructing antiferroelectric-ferroelectric phase boundary, greatly improving piezoelectric and dielectric response, and solving the technical problem that current antiferroelectric materials, due to their antiparallel polarization, macroscopic lack of polarity, low piezoelectric response, and low dielectric constant near zero field, are unfavorable for ceramic capacitors and piezoelectric transducers that require low voltage operation. Attached Figure Description

[0021] Figure 1 These are graphs showing the dielectric constant test results of various embodiments of the high-entropy ceramic of the present invention; and Figure 2 The graph shows the hysteresis test results of various embodiments of the high-entropy ceramic of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figure 1-2 As shown, this application relates to a high-entropy ceramic, its preparation method, and its application. The high-entropy ceramic comprises: the high-entropy ceramic having the chemical formula Pb(Zr) a Ti b A c B d C e O3; High-entropy ceramic materials are a new type of multi-component functional ceramics that improve the material's performance, such as dielectric constant, piezoelectric properties, and sintering density, by introducing multiple component elements.

[0027] Where a+b≥0.4, A, B, and C are tetravalent elements and satisfy the stoichiometric ratio a+b+c+d+e=1, and a, b, c, d, and e are all ≥0.

[0028] Specifically, the chemical formula of high-entropy ceramics is Pb(Zr) a Ti b A c B d C e O3, its specific meaning is as follows: 1. Main crystal phase: PbZrO3 is an important antiferroelectric material, and PbTiO3 is an important ferroelectric material. The solid solution of the two in different proportions can stabilize the antiferroelectric or ferroelectric phases, providing the basic polarization and piezoelectric properties of the entire system.

[0029] a+b≥0.4: Ensure that the proportion of zirconium and titanium elements is dominant, and maintain the balance of ferroelectric / antiferroelectric properties.

[0030] 2. High-entropy components A c B d C e : These represent the introduced tetravalent elements used to achieve high-entropy design. These tetravalent elements replace part of Zr and Ti in equal or unequal proportions to form a multi-component structure.

[0031] Common tetravalent elements: A(Sn): Enhances the dielectric constant of the material and lowers the piezoelectric phase transition temperature; B(Hf): Improves high-temperature stability and durability; C(Ce): Improves dielectric properties and enhances electrical breakdown resistance within a certain range; Other options include Si, Ge, etc., for refining grains and optimizing structure.

[0032] The component constraint condition is a+b+c+d+e=1, which ensures the integrity of the stoichiometry of the components and maintains the stability of the crystal structure.

[0033] a, b, c, d, e are all ≥ 0: the proportions of all elements are non-negative.

[0034] 3. High entropy characteristics of multi-component High-entropy design introduces a variety of different tetravalent cations (such as Sn) 4+ Hf 4+ Ce 4+ (etc.), forming a random distribution at site B. This multi-component configuration has the following characteristics: Entropy effect stability: High configuration entropy significantly improves the stability of crystal structures.

[0035] Local distortion: Local distortion caused by different ion radii increases polarization, optimizes dielectric properties, and increases the carrier transport barrier, thereby improving dielectric breakdown.

[0036] 4. Component adjustment during preparation When preparing high-entropy ceramics, the ratio of a, b, c, d, and e needs to be optimized according to application requirements: For example, in low dielectric loss applications (such as high-frequency capacitors), increase the proportion of Sn and Hf and decrease the proportion of Ti.

[0037] In high-voltage response applications (such as ultrasonic transducers), the proportion of Ti is increased while the content of Ce and Si is controlled.

[0038] In high-temperature stability applications (such as high-temperature capacitors), increasing the ratio of Hf to Ce optimizes high-temperature dielectric stability.

[0039] As can be seen from the above description, this application achieves the following technical effects: In this embodiment, the PbZrO3 material is modified to produce a high-entropy ceramic with the chemical formula Pb(ZrO3) a Ti b A c B d C e O3; where a+b≥0.4, A, B, and C are tetravalent elements and satisfy the stoichiometric ratio a+b+c+d+e=1, and a, b, c, d, and e are all ≥0, achieving the goal of high dielectric constant and high entropy of piezoelectric coefficient, thus realizing the technical effect of constructing antiferroelectric-ferroelectric phase boundary, greatly improving piezoelectric and dielectric response, and solving the technical problem that current antiferroelectric materials, due to their antiparallel polarization, macroscopic lack of polarity, low piezoelectric response, and low dielectric constant near zero field, are unfavorable for ceramic capacitors and piezoelectric transducers that require low voltage operation.

[0040] Furthermore, the tetravalent element is multiple elements selected from Sn, Hf, Ce, Si, or Ge. It is understood that the ability to choose from multiple tetravalent elements facilitates easy implementation and allows for flexible use.

[0041] Specifically, Sn (tin) possesses properties that improve dielectric and piezoelectric properties; tin ions (Sn 4 +) It has small electronic polarization and medium ionic radius, resulting in low distortion of material structure.

[0042] The introduction of Sn can lower the phase transition temperature of the material and increase the temperature range of the piezoelectric effect.

[0043] Effects on materials: Increases dielectric constant and reduces dielectric loss. Optimizes low-field response, making it suitable for piezoelectric transducers or high-sensitivity sensors.

[0044] Hf (hafnium) possesses enhanced high-temperature stability; hafnium ions (Hf 4 +) has a large atomic radius, similar to that of Zr ions, so it is not easy to disrupt the lattice symmetry when replacing Zr in crystals; it also has excellent high-temperature performance and oxidation resistance.

[0045] Effects on materials: Enhances the high-temperature stability of crystals and improves high-temperature dielectric and piezoelectric properties.

[0046] Ce (cerium) possesses properties that improve polarization and dielectric properties; cerium ions (Ce)4 +) Substituting Zr or Ti in a crystal can introduce local distortion and also has strong polarization ability.

[0047] Effects on materials: Increases polarization intensity and dielectric constant.

[0048] Germanium (Ge) possesses optimized piezoelectric properties and structural stability; germanium ions (Ge 4 +) The ionic radius is similar to that of Si, and it has high polarizability; the introduction of Ge can further improve the ferroelectric behavior of the crystal.

[0049] Effects on materials: Improve the piezoelectric properties and dielectric stability of materials; optimize dielectric properties at low temperatures, making them suitable for functional devices in cold environments.

[0050] Furthermore, it also includes: sintering aids; wherein the sintering aids are Bi2O3 and PbSiO3.

[0051] Furthermore, the Bi₂O₃ content is 2-3 wt%, and the PbSiO₃ content is 1-2 wt%. It can be understood that: 1. Bi₂O₃ (bismuth oxide) addition ratio: 2-3 wt%; Mechanism of action: Lowering the sintering temperature: Bi2O3 has a low melting point (~820℃) and forms a liquid phase during the sintering process, which significantly reduces the sintering temperature of ceramics.

[0052] Liquid phase sintering promotes contact and bonding between grains, thereby improving the density of the material.

[0053] Enhanced grain boundary migration: Bi2O3 can act as a lubricant at grain boundaries, accelerating grain growth and rearrangement, and improving the microstructure.

[0054] Optimize dielectric properties: Bi in Bi2O3 3 + ions can enhance the polarization effect, thereby increasing the dielectric constant of the material, especially under low electric fields.

[0055] 2. PbSiO3 (lead silicate) addition ratio: 1-2 wt%; Mechanism of action: Promotes sintering density. PbSiO3 decomposes at high temperatures and releases PbO and SiO2. These products can fill micropores and promote intergranular bonding, thus reducing porosity.

[0056] The presence of SiO2 can also inhibit grain growth, thereby refining the grain structure and improving the mechanical properties of the material.

[0057] Enhanced thermal shock resistance: PbSiO3 helps optimize the crystal structure and improve the thermal expansion properties of the material, thereby enhancing its thermal shock resistance.

[0058] Improve piezoelectric properties: The introduction of PbSiO3 can reduce structural defects by improving the sintering process, thereby indirectly improving the piezoelectric properties and electrical stability of the material.

[0059] 3. Synergistic effect of the two Sintering optimization: The combination of Bi2O3 and PbSiO3, through liquid phase sintering and structural filling, significantly improves the sintering density of ceramic materials, enabling ceramics to achieve an ideal dense state at lower temperatures.

[0060] Balanced performance: Bi2O3 provides good polarization properties, while PbSiO3 provides good structural stability. The synergistic effect of the two ensures the material's high dielectric constant, low loss and good mechanical strength.

[0061] The introduction of 2-3 wt% Bi2O3 and 1-2 wt% PbSiO3 is to optimize the sintering process and final properties of ceramic materials. Its specific advantages include: reducing sintering temperature: reducing energy consumption in high-temperature sintering, and avoiding phase decomposition or performance degradation of materials at excessively high temperatures.

[0062] Improve density: reduce porosity and improve the dielectric, piezoelectric properties and breakdown strength of ceramics.

[0063] Optimize dielectric and piezoelectric properties: increase dielectric constant, reduce dielectric loss, and enhance the bonding force between electrodes and materials.

[0064] Furthermore, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c O3; Where A is Sn, a is 0.6, b is 0.2, and c is 0.2. It can be understood that Zr (zirconium, (Zr...) a ): The proportion of a=0.6 is the highest, and it is the main structural matrix element.

[0065] Zr 4 + ions have a large ionic radius, providing the basic lattice structure for materials and significantly affecting their resistance to electric field breakdown and dielectric properties.

[0066] Ti (titanium): with a composition of b=0.2, is introduced as a modifying element.

[0067] Ti 4 The high polarizability of + ions can enhance the ferroelectricity and piezoelectricity of materials, giving them better dielectric constant and piezoelectric response.

[0068] A (tin, Sn): with a composition of c=0.2, added as a minor modifying element.

[0069] Sn 4 The ionic radius of tin ions and Zr 4 Similar to Zr, it can partially replace it. 4 +, introduce random displacements, thereby reducing the symmetry of the system.

[0070] The introduction of Sn can also optimize phase transition characteristics, increase the dielectric constant of the material under low electric field conditions, and improve its small-signal performance in piezoelectric devices.

[0071] Furthermore, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c B d O3; Where A is Sn, B is Hf, a is 0.6, b is 0.2, c is 0.1, and d is 0.1. It is understandable that the properties of Zr, Ti, and Sn are consistent with the previous descriptions, and will not be repeated here; Sn (tin, Ac): with a proportion of c=0.1, serves as an important modifying element.

[0072] Furthermore, the high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c B d O3; Where A is Sn, B is Si, a is 0.5, b is 0.3, c is 0.1, and d is 0.1. It is understandable that the properties of Zr, Ti, and Sn are consistent with those described previously, and will not be repeated here; Si (silicon), Bd: with a partition d=0.1, is used as a second-class modifying element.

[0073] Furthermore, the crystal structure of the high-entropy ceramic is a single-crystal phase or a composite phase; The single-crystal phase is perovskite. This allows for the selection of a variety of materials.

[0074] This application also relates to a method for preparing high-entropy ceramics, including the high-entropy ceramics described above; and further includes the following steps: S1. Add the mixed oxide or carbonate powder into the ball mill jar according to the preset stoichiometric ratio and ball mill for 6 hours; S2. Dry the prepared ball mill slurry and calcine the sample at 800-900℃ for 3 hours; S3. The calcined powder is ball-milled again and pressed into a disc using polyvinyl butyral as a binder to obtain a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm. S4. Place the formed disc sample in a crucible containing lead carbonate powder and calcine it with lead carbonate at 1100-1350℃ for 3-6 hours. S5. After firing, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure.

[0075] Specifically, S1: Raw material preparation and mixing Raw material selection: Weigh the required oxide or carbonate powder as reactants according to the preset stoichiometric ratio. Commonly used raw materials include: PbO (lead oxide): providing lead ions for the perovskite structure.

[0076] ZrO2 (zirconia): As one of the main components, it provides stability to perovskites.

[0077] TiO2 (titanium oxide): Improves the dielectric and piezoelectric properties of materials.

[0078] Modified components containing tetravalent elements such as SnO2 (tin oxide), HfO2 (hafnium oxide), and SiO2 (silicon oxide).

[0079] Sintering aids: 2-3wt%Bi2O3 and 1-2wt%PbSiO3, used to lower the sintering temperature and improve density.

[0080] Mixing method: Add the raw materials evenly into a mixing container (such as a zirconium oxide or polyurethane tank) and mix using a dry or wet stirring method.

[0081] S2: Preliminary ball milling and calcination Ball milling: The mixed powder is ball milled using a ball mill. Wet ball milling (such as using water as a medium) can effectively improve the uniformity of mixing.

[0082] Time: 6-12 hours, to ensure the raw materials are fully homogenized.

[0083] Calcination: The ball-milled mixed powder is calcined in a muffle furnace at a temperature of 800-900℃ for about 3 hours.

[0084] Objective: Calcination can promote the reaction of raw materials to form a perovskite phase and eliminate volatile impurities during the mixing process.

[0085] S3: Molding Secondary ball milling: The calcined powder is ball milled again to improve the uniformity and dispersibility of the particles.

[0086] Adhesive addition: Polyvinyl butyral (PVB) is used as an adhesive to ensure the mechanical strength and dimensional accuracy of the molded samples.

[0087] Compression molding: The processed powder is loaded into a mold and pressed into a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm using a cold pressing method.

[0088] The pressing pressure is usually controlled at 100-200MPa to ensure that the sample is dense and uniform.

[0089] S4: Burial Burial environment: The pressed disc sample is placed in a crucible containing lead carbonate powder (PbCO3). Lead carbonate can decompose during the sintering process to provide PbO and prevent lead volatilization.

[0090] Sintering conditions: Temperature: 1100-1350℃; Time: 3-6 hours.

[0091] Objective: Sintering can significantly improve the density and crystal quality of materials, while forming a uniform high-entropy ceramic structure.

[0092] S5: Electrode fabrication and sintering Electrode coating: Silver paste is evenly applied to the upper and lower surfaces of the sintered ceramic sheet as electrodes.

[0093] Application methods: screen printing or brushing.

[0094] Electrode sintering: Temperature: 800℃; Time: 15 minutes.

[0095] Objective: To sinter and fix the electrodes to ensure good contact between the electrodes and the ceramic sheet, thus forming the working structure of the ceramic capacitor.

[0096] The preparation process described in this application utilizes a solid-state reaction method combined with a suitable combination of sintering aids to ensure the uniformity and density of the high-entropy ceramic. The ceramic capacitors produced through sintering and electrode bonding exhibit excellent dielectric and piezoelectric properties, as well as low losses, making them suitable for applications such as low-voltage driven capacitors and piezoelectric devices.

[0097] Further, S1, adding the mixed oxide or carbonate powder to the mixing container according to a preset stoichiometric ratio, including: One or more of lead carbonate, titanium oxide, zirconium oxide, tin oxide, hafnium oxide, cerium oxide, silicon oxide, or germanium oxide. It is understood that this allows for a variety of material options, thus enabling flexible use.

[0098] Further, in step S3, the calcined powder is ball-milled again and pressed into discs using polyvinyl butyral as a binder to obtain disc samples with a diameter of 9-11 mm and a thickness of 1-2 mm, including: A disc sample with a diameter of 10 mm and a thickness of 1.5 mm was obtained.

[0099] Furthermore, after S5 and firing, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure. This process also includes: The dielectric constant is measured using an LCR bridge, and the quasi-static piezoelectric coefficient is measured using a d33meter. The d33meter is an instrument specifically designed for testing the piezoelectric coefficient of piezoelectric materials. The d33 constant represents the displacement response of a piezoelectric material along the direction of the electric field when a z-direction electric field (voltage) is applied. This testing method is suitable for evaluating the mechanical and electrical properties of piezoelectric materials.

[0100] LCR bridge test for dielectric constant: By measuring capacitance and applying formulas, the dielectric constant of high-entropy ceramics or other piezoelectric ceramic materials can be effectively calculated. This method is suitable for routine electrical performance evaluation and helps to understand the polarization characteristics of materials.

[0101] d33meter test for piezoelectric coefficient: This method, by applying an electric field and measuring the displacement response, can accurately obtain the piezoelectric coefficient of piezoelectric materials. 33 A constant is used to evaluate the piezoelectric properties of materials and is applicable to the performance analysis of piezoelectric devices.

[0102] This application also relates to the application of high-entropy ceramics, including the preparation method of high-entropy ceramics as described above.

[0103] The following examples further illustrate this point:

[0104] Example 1 The chemical composition of high-entropy ceramics is Pb(Zr) a Ti b A c O3; where A is Sn, a is 0.6, b is 0.2, and c is 0.2.

[0105] The following process steps are adopted: Raw material preparation: Use high-purity (>99.9%) oxide or carbonate powders, including PbO, ZrO2, TiO2, and SnO2.

[0106] Mixing and ball milling: Weigh the raw materials according to the stoichiometric ratio, mix them, and then perform wet ball milling for 6-12 hours.

[0107] Calcination: Calcination at 800-900℃ for 3 hours promotes the formation of the perovskite phase.

[0108] forming: Add 2-3wt%Bi2O3 and 1-2wt%PbSiO3 sintering aid to the calcined powder, mix evenly, and then add a binder (such as PVB) to prepare a disc with a diameter of 10mm and a thickness of 1.5mm.

[0109] sintering: Burying the crystals with lead carbonate at 1100-1350℃ for 3-6 hours inhibits lead volatilization and ensures crystal integrity.

[0110] Electrode preparation: Silver paste is applied to both sides of the ceramic sheet, and it is sintered at 800℃ for 15 minutes to form a conductive electrode.

[0111] At this point, testing revealed that the high-entropy ceramic produced possesses the following characteristics: an improved dielectric constant near zero field, a wider hysteresis loop, and d... 33 The constant is 107pC / n.

[0112] Example 2 The chemical composition of high-entropy ceramics is Pb(Zr) a Ti b A c B d O3; where A is Sn, B is Hf, a is 0.6, b is 0.2, c is 0.1, and d is 0.1.

[0113] Raw material preparation: Weigh high-purity raw materials such as PbO, ZrO2, TiO2, SnO2, and HfO2 according to stoichiometric ratios.

[0114] Mixing and ball milling: Mix all powders evenly and wet ball mill for 6-12 hours to ensure the raw materials react fully.

[0115] Calcination: Pre-calcining at 800-900℃ for 3 hours promotes the formation of perovskite crystal phase.

[0116] forming: Add 2-3wt%Bi2O3 and 1-2wt%PbSiO3 sintering aid to the calcined powder, add a binder (such as PVB), and mold it into a disc with a diameter of 10mm and a thickness of 1.5mm.

[0117] sintering: PbO lead carbonate is buried and calcined at 1100-1350℃ for 3-6 hours to inhibit lead volatilization and improve sintering density.

[0118] Electrode preparation: Silver paste was applied to the surface of the ceramic sample and sintered at 800℃ for 15 minutes to form a conductive electrode.

[0119] At this point, testing revealed that the fabricated high-entropy ceramic exhibited the following characteristics: an improved dielectric constant near zero field, a wide hysteresis loop, and d... 33 The constant is 442pC / n.

[0120] Example 3 The chemical composition of high-entropy ceramics is Pb(Zr) a Ti b A c B d O3; Where A is Sn, B is Si, a is 0.5, b is 0.3, c is 0.1, and d is 0.1.

[0121] Raw material preparation: Weigh high-purity raw materials, such as PbO, ZrO2, TiO2, SnO2, and SiO2, according to stoichiometric ratios.

[0122] Mixing and ball milling: Prepare the ingredients according to the stoichiometric ratio, mix them, and then wet ball mill for 6-12 hours to ensure uniformity.

[0123] Calcination: Calcination at 800-900℃ for 3 hours promotes the formation of the perovskite phase.

[0124] Forming and sintering: After calcination, the material is pulverized and mixed with PVB binder to prepare a disc with a diameter of 10 mm and a thickness of 1.5 mm.

[0125] Sintering is carried out at 1100-1350℃ for 3-6 hours under lead carbonate burial conditions.

[0126] Electrode preparation: Silver paste was applied to the surface of the ceramic sample and sintered at 800℃ for 15 minutes to form a conductive electrode.

[0127] At this point, testing revealed that the fabricated high-entropy ceramic exhibited the following characteristics: an improved dielectric constant near zero field, a wide hysteresis loop, and d... 33 The constant is 211pC / n.

[0128] Comparative Example 1 It is prepared using traditional PbZrO3.

[0129] At this point, after testing, d 33 The constant is 33pC / n.

[0130] In summary, as can be seen from Examples 1-3 and Comparative Example 1, this application modifies PbZrO3 to give it high dielectric constant and high entropy piezoelectric coefficient, thus enabling it to be better applied to ceramic capacitors and piezoelectric transducers operating at low voltage.

[0131] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent modifications can be made to the technical solutions of the present invention, and all such equivalent modifications fall within the protection scope of the present invention. Technical Field Within this scope, various equivalent transformations can be made to the technical solution of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A high-entropy ceramic, characterized in that, include: The chemical formula of the high-entropy ceramic is Pb(Zr). a Ti b A c B d C e O3; Where a+b≥0.4, A, B, and C are tetravalent elements and satisfy the stoichiometric ratio a+b+c+d+e=1, and a, b, c, d, and e are all ≥0.

2. The high-entropy ceramic according to claim 1, characterized in that, The tetravalent element is one of Sn, Hf, Ce, Si, or Ge.

3. The high-entropy ceramic according to claim 1, characterized in that, Also includes: Sintering aid; wherein the sintering aid is Bi2O3 and PbSiO3.

4. The high-entropy ceramic according to claim 3, characterized in that, The Bi2O3 content is 2-3 wt%, and the PbSiO3 content is 1-2 wt%.

5. The high-entropy ceramic according to claim 1, characterized in that, The high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c O3; Where A is Sn, a is 0.6, b is 0.2, and c is 0.

2.

6. The high-entropy ceramic according to claim 1, characterized in that, The high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c B d O3; Where A is Sn, B is Hf, a is 0.6, b is 0.2, c is 0.1, and d is 0.

1.

7. The high-entropy ceramic according to claim 1, characterized in that, The high-entropy ceramic has the chemical composition of Pb(Zr). a Ti b A c B d O3; Where A is Sn, B is Si, a is 0.5, b is 0.3, c is 0.1, and d is 0.

1.

8. The high-entropy ceramic according to claim 1, characterized in that, The high-entropy ceramic has a crystal structure of either a single-crystal phase or a composite phase. The single crystal phase is of the perovskite type.

9. A method for preparing high-entropy ceramics, characterized in that, Including the high-entropy ceramic as described in any one of claims 1-5; further comprising the following steps: S1. Add the mixed oxide or carbonate powder into the ball mill jar according to the preset stoichiometric ratio and ball mill for 6 hours; S2. Dry the prepared ball mill slurry and calcine the sample at 800-900℃ for 3 hours; S3. The calcined powder is ball-milled again and pressed into a disc using polyvinyl butyral as a binder to obtain a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm. S4. Place the formed disc sample in a crucible containing lead carbonate powder and calcine it with lead carbonate at 1100-1350℃ for 3-6 hours. S5. After firing, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure.

10. The method for preparing high-entropy ceramics according to claim 9, characterized in that, S1. Add the mixed oxide or carbonate powders to the mixing container according to the preset stoichiometric ratio, including: One or more of lead carbonate, titanium oxide, zirconium oxide, tin oxide, hafnium oxide, cerium oxide, silicon oxide, or germanium oxide.

11. The method for preparing high-entropy ceramics according to claim 9, characterized in that, S3. The calcined powder is ball-milled again, and polyvinyl butyral is used as a binder to press it into a disc, producing a disc sample with a diameter of 9-11 mm and a thickness of 1-2 mm, including: A disc sample with a diameter of 10 mm and a thickness of 1.5 mm was obtained.

12. The method for preparing high-entropy ceramics according to claim 9, characterized in that, S5. After firing, silver is coated on the upper and lower surfaces of the ceramic sheet, and it is sintered in air at 800°C for 15 minutes to form a ceramic capacitor structure. This process also includes: The dielectric constant was tested using an LCR bridge, and the quasi-static piezoelectric coefficient was tested using a d33meter.

13. Applications of high-entropy ceramics, characterized in that, The method for preparing high-entropy ceramics as described in any one of claims 9-12.

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