A ferroelectric ceramic material with a large dielectric constant in a wide temperature range and a preparation method thereof

Abstract

The present invention provides a ferroelectric ceramic material with a large dielectric constant over a wide temperature range and a preparation method thereof. The ferroelectric ceramic material is prepared by laminating and compounding BZT-xBST ceramic green bodies containing six components (x is 0.1, 0.2, 0.3, 0.4, 0.6, and 0.8, respectively) that undergo critical ferroelectric phase transitions. The ferroelectric ceramic material is prepared by laminating and compounding the six BZT-xBST ceramic green bodies with different components, and successfully achieves high dielectric properties over a wide temperature range of 5°C to 55°C. This high dielectric constant (ε>21448) over a wide temperature range enables the ferroelectric ceramic material to exhibit excellent performance in a variety of application scenarios, such as capacitors, sensors, and energy storage devices, filling a gap in the current ferroelectric ceramic materials where both a wide temperature range and a high dielectric constant are difficult to achieve.

Description

Technical Field

[0001] The invention belongs to the technical field of capacitors and relates to a ferroelectric ceramic material with a large dielectric constant in a wide temperature range and a preparation method thereof. Background Art

[0002] High-k capacitors are made from materials with a high dielectric constant. The dielectric constant describes a material's ability to store electrical energy in an electric field. A high dielectric constant means the material can store energy more efficiently. High-k capacitors typically offer advantages such as high capacitance, compact size, low leakage current, high operating voltage, and good thermal stability. High-k capacitors achieve high capacitance within a compact size, thus meeting the high energy density requirements of electronic devices. They also offer excellent stability and temperature resistance, enabling them to maintain stable performance in harsh environments. Despite their many advantages, high-k capacitors are relatively complex and costly to manufacture. Furthermore, their dielectric constant and capacitance may change with temperature or voltage, potentially impacting circuit performance. Therefore, when selecting and using high-k capacitors, factors such as their temperature and voltage characteristics must be carefully considered.

[0003] To further optimize the performance of high-k capacitors, it is necessary to develop ferroelectric ceramic materials that possess both high k and high temperature stability. However, achieving both high k and good temperature stability is often difficult because high k is typically achieved at the phase transition temperature and decreases dramatically as the temperature moves away from the transition temperature, resulting in poor temperature stability. Therefore, high k and temperature stability are often incompatible.

[0004] High-k capacitors primarily use barium titanate materials, which exhibit temperature characteristics such as X5R / X7R, meaning their capacitance varies significantly with temperature. Other materials with high dielectric constants, such as ceramics, polymers, and thin-film materials, are also used in the manufacture of high-k capacitors.

[0005] In recent years, experiments have shown that at the four-phase junction of the BaTiO3-based binary ferroelectric solid solution system phase diagram, the paraelectric cubic phase (C), ferroelectric tetragonal phase (T), orthorhombic phase (O), and rhombohedral phase (R) converge. This quadruple point exhibits a critical ferroelectric phase transition. Since the phase transition energy barrier of the critical ferroelectric phase transition is close to zero, the dielectric constant of these critical quadruple points is very large. However, the high dielectric constant of the critical quadruple point is difficult to be applied in practice because their temperature stability is very low. When the temperature rises or falls, their dielectric constant drops sharply. Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a material having a large dielectric constant within a large temperature range, so that the material has both a high dielectric constant and temperature stability.

[0007] The present invention is achieved through the following technical solutions:

[0008] A ferroelectric ceramic material with a large dielectric constant in a wide temperature range, comprising six BZT-xBST ceramic bodies with different additive components laminated and composited to obtain the ferroelectric ceramic material;

[0009] The chemical formula of the BZT-xBST ceramic body is (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 O3

[0010] Here, x is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 respectively.

[0011] A method for preparing a ferroelectric ceramic material having a large dielectric constant in a wide temperature range, comprising:

[0012] S1, based on (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 The x in O3 is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 in different component ratios. A mixture of raw materials including BaCO3, TiO2, BaZrO3 and SnO2 is weighed and mixed by ball milling once, and then pre-sintered to obtain a bulk material. The bulk material is ground into powder and then ball milled twice, and then dried to obtain BZT-xBST ceramic powders with different component ratios.

[0013] S2, mixing BZT-xBST ceramic powders with different component ratios with a solvent, a dispersant, a plasticizer, and a binder to obtain casting slurries with different component ratios;

[0014] S3, vacuum degassing the tape casting slurries with different component ratios, and then tape casting and drying to obtain BZT-xBST ceramic bodies with different component ratios;

[0015] S4. The BZT-xBST ceramic bodies with different component ratios are heated and laminated to obtain ferroelectric ceramic green bodies, and then the binder is removed and high-temperature sintered in sequence to obtain ferroelectric ceramic materials with a large dielectric constant in a wide temperature range.

[0016] Preferably, in S2, the mass ratio of BZT-xBST ceramic powder to solvent, dispersant, binder and plasticizer is 55.0wt%:39.5wt%:0.5wt%:4.0wt%:1.0wt%.

[0017] Preferably, the specific process of S1 is:

[0018] Based on (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 The x in O3 is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 in different component ratios. A mixture of BaCO3, TiO2, BaZrO3 and SnO2 is weighed as raw materials, and the mixture of BaCO3, TiO2, BaZrO3 and SnO2: anhydrous ethanol: zirconium balls = 1:2:1 is ball-milled for 12 hours; the material after the first ball milling is washed out and dried, and then pre-fired at 1300°C for 2 hours. The pre-fired block material is ground into powder, and then ball-milled for a second time for 12 hours according to the mass ratio of powder: anhydrous ethanol = 1:2. After drying, BZT-xBST ceramic powders with different component ratios are obtained.

[0019] Preferably, the specific process of S2 is:

[0020] BZT-xBST ceramic powders with different component ratios were mixed with solvents and dispersants and ball-milled for 12 h. Then, binders and plasticizers were added and the mixture was mixed and ball-milled for another 12 h to obtain tape casting slurries with different component ratios.

[0021] Preferably, the solvent is ethanol and ethyl acetate mixed in a volume fraction ratio of 3:7; the dispersant is oleic acid; the binder is polyvinyl butyral; and the plasticizer is at least one of polyethylene glycol and butyl phthalate.

[0022] Preferably, the specific process of S3 is:

[0023] The tape-casting slurries with different component ratios were subjected to vacuum degassing for 20 min, and then poured into the trough of the tape-casting machine and cast at a thickness of 400 μm at a rate of 3 cm / min and dried at 70°C for 24 h to obtain BZT-xBST ceramic bodies with different component ratios.

[0024] Preferably, the specific process of S4 is:

[0025] The BZT-xBST ceramic bodies with six different component ratios were cut into the same size and heated and laminated at a temperature of 80°C and a pressure of 5-10 MPa for 5-10 minutes to obtain ferroelectric ceramic green bodies; wherein the number of laminated layers was 16-32;

[0026] The ferroelectric ceramic green body is heated to 550°C at a heating rate of 1-3°C / min under normal pressure and air atmosphere and kept warm for 30 minutes for debinding treatment to obtain a ferroelectric ceramic body; after the ferroelectric ceramic body is debinded, it is pressed with a zirconium plate and heated to 1460~1500°C at a heating rate of 3-5°C / min under air atmosphere and kept warm for 2 hours to complete high-temperature sintering, thereby obtaining a ferroelectric ceramic material with a large dielectric constant in a wide temperature range.

[0027] Preferably, when testing the dielectric constant of the ferroelectric ceramic material with a large dielectric constant in a wide temperature range, the ferroelectric ceramic material is ground and polished, and then the single-sided smooth surface is gold-sprayed using a plasma magnetron sputtering coating apparatus, and plated with a Pt point electrode with an electrode diameter of 1 mm.

[0028] Preferably, the ferroelectric ceramic material with a large dielectric constant in a wide temperature range undergoes a critical ferroelectric phase transition at a Curie temperature of 5° C. to 55° C.;

[0029] The ferroelectric ceramic material with a large dielectric constant in a wide temperature range has a high dielectric performance in a wide temperature range of 5°C to 55°C.

[0030] Compared with the prior art, the present invention has the following beneficial technical effects:

[0031] The present invention provides a ferroelectric ceramic material with a large dielectric constant in a wide temperature range and a preparation method thereof. The ferroelectric ceramic material is prepared by laminating and compounding BZT-xBST ceramic bodies containing six components (x is 0.1, 0.2, 0.3, 0.4, 0.6, and 0.8) that undergo critical ferroelectric phase transitions. The chemical formula of the BZT-xBST ceramic body is (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 O3, by designing a layered structure on the critical line, a ferroelectric ceramic material was prepared by stacking and compounding BZT-xBST ceramic green bodies of 6 different components, successfully achieving high dielectric properties in a wide temperature range of 5°C to 55°C. This high dielectric constant (ε>21448) in a wide temperature range enables the ferroelectric ceramic material to exhibit excellent performance in a variety of application scenarios, such as capacitors, sensors, energy storage devices, etc., filling the blank area where existing ferroelectric ceramic materials are difficult to achieve both a wide temperature range and a high dielectric constant.

[0032] In the preparation method of the present invention, by precisely adjusting (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 The x values ​​in O3 (0.1, 0.2, 0.3, 0.4, 0.6, and 0.8) enable precise control of the ferroelectric ceramic material's composition. This precise ratio helps optimize the material's ferroelectric and dielectric properties, resulting in a stable and excellent high dielectric constant over a wide temperature range. Heating and laminating ceramic bodies with different composition ratios achieves a uniform distribution of the various components within the material, improving the overall performance and maintaining stable dielectric properties across a wide temperature range. This preparation method not only enhances the dielectric properties of the ferroelectric ceramic material but also reduces production costs and increases the material's application value by optimizing the process steps and composition ratios. The present invention further fabricates a multilayer ferroelectric ceramic material with multiple critical phase transition components by designing a laminated structure of six components that undergo critical ferroelectric phase transitions. This ingeniously utilizes the fact that the six components undergo critical ferroelectric phase transitions at different Curie temperatures within the range of 5-55°C. By rationally designing and combining ceramic bodies with different compositions, phase transitions can be induced within a specific temperature range, significantly improving the material's dielectric properties.

[0033] Furthermore, the present invention successfully prepared (1-x)BaZr using a casting method. 0.12 Ti 0.88 O3-xBaSn 0.115 Ti 0.885 O3 binary system BZT-xBST ceramic green body thick film.

[0034] Furthermore, the process steps of primary ball milling, pre-sintering, grinding into powder, secondary ball milling, and drying ensure the uniformity and purity of the ceramic powder. This optimized powder preparation process helps to improve the density and performance stability of ceramic materials.

[0035] Furthermore, after debinding and high-temperature sintering, the ceramic material obtains a dense microstructure and excellent performance. The high-temperature sintering process helps eliminate pores and defects inside the material and improves the mechanical strength and dielectric properties of the ceramic material. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a flow chart of the preparation method of the ferroelectric ceramic material of the present invention;

[0037] Figure 2 is (1-x)BaZr 0.12 Ti 0.88 O3-xBaSn0.115 Ti 0.885 Schematic diagram of ceramic material design for the O3(BZT-xBST) binary system;

[0038] Figure 3 The dielectric temperature spectra of the multi-layer multi-component ceramic sheets of Example 1 and Example 2 with sintering and holding times of 1 h and 2 h, respectively; Figure (a) is Example 1, and Figure (b) is Example 2;

[0039] Figure 4 This is a comparison chart of the maximum dielectric constant and temperature range of the ferroelectric ceramic material of the present invention and other ferroelectric materials; DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0041] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0042] Example 1

[0043] According to (1-x)BaZr 0.12 Ti 0.88 O3-xBaSn 0.115 Ti 0.885 The x in O3 is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 respectively. The mass of BaCO3, TiO2, BaZrO3 and SnO2 raw materials is calculated and weighed to generate a 40g BZT-xBST ceramic body. The mass addition ratio of BaCO3, TiO2, BaZrO3 and SnO2 raw materials is shown in Table 1.

[0044]

[0045] The mixtures of BaCO3, TiO2, BaZrO3 and SnO2 with different component ratios in Table 1 were weighed and subjected to a first planetary ball milling for 12 h at a mass ratio of mixture: anhydrous ethanol: zirconium ball = 1:2:1; the materials after the first ball milling were washed out into a glass petri dish, placed in an oven for drying, poured into a quartz crucible, compacted, and placed in a muffle furnace for pre-calcination at 1300°C for 2 h; the pre-calcined block material was simply ground into powder with a mortar, and then subjected to a second ball milling for 12 h at a mass ratio of powder: anhydrous ethanol = 1:2; the materials after the second ball milling were washed into a glass petri dish and dried to obtain 6 BZT-xBST ceramic powders with different component ratios.

[0046] Six different BZT-xBST ceramic powders were mixed with a solvent (ethanol and ethyl acetate in a volume fraction ratio of 3:7 to achieve azeotropic properties at the same temperature) and a dispersant, and then ball-milled for 12 hours. Binders and plasticizers were then added and ball-milled for another 12 hours to obtain uniformly distributed and stable tape-cast slurries. The tape-cast slurries were then placed in a vacuum degassing machine for 20 minutes of stirring and degassing. The mass fraction ratios of the six different BZT-xBST ceramic powders to the solvent, dispersant, binder, and plasticizer were 55.0wt%: 39.5wt%: 0.5wt%: 4.0wt%: 1.0wt%; the plasticizers were 0.5wt% polyethylene glycol and 0.5wt% butyl phthalate; the dispersant was oleic acid; and the binder was polyvinyl butyral.

[0047] Six different component ratio casting slurries after vacuum degassing treatment were poured into the casting machine trough and cast at a rate of 3 cm / min with a thickness of 400 μm and dried at 70°C for 24 h to obtain BZT-xBST ceramic green bodies with different component ratios; the dried BZT-xBST ceramic green bodies with different component ratios were cut into appropriate specifications as required, and the BZT-xBST ceramic green bodies were heated and laminated at 80°C and 5 MPa for 10 min using a flat heating hydraulic press to obtain ferroelectric ceramic green bodies, wherein the number of laminated layers was 16. The mature BZT-xBST ceramic green bodies were cut or cut into small rectangles of 10 mm*10 mm as required.

[0048] The ferroelectric ceramic green body was placed in a high-temperature muffle furnace, and the temperature was increased to 550°C at a heating rate of 1°C / min under normal pressure and air atmosphere, and the temperature was kept for 30 minutes for debinding treatment, and then the ferroelectric ceramic body was obtained by cooling with the furnace; the debinding sample was placed in a high-temperature muffle furnace again, pressed with a small piece of zirconium plate to prevent deformation, and heated to 1460°C at a heating rate of 3°C / min under air atmosphere and kept for 1 hour to complete sintering, thereby obtaining a ferroelectric ceramic material with a large dielectric constant in a wide temperature range; after the ferroelectric ceramic material with a large dielectric constant in a wide temperature range was polished, the single-sided smooth surface was gold-sprayed using a plasma magnetron sputtering coating instrument, and plated with a Pt point electrode with an electrode diameter of 1 mm for subsequent testing.

[0049] Example 2

[0050] The difference compared with Example 1 is that after the ferroelectric ceramic body is debinded, the temperature is increased to 1460° C. at a heating rate of 3° C. / min in an air atmosphere and kept at this temperature for 2 hours to complete sintering, thereby obtaining a ferroelectric ceramic material with a large dielectric constant in a wide temperature range;

[0051] The rest of the preparation process is the same;

[0052] Example 3

[0053] The difference compared with Example 1 is that the mass fraction ratio of the BZT-xBST ceramic powder with six different component ratios to the solvent, dispersant, binder and plasticizer is 55.0wt%:39.5wt%:0.5wt%:4.0wt%:1.0wt%; wherein the plasticizer uses 0.2wt% polyethylene glycol and 0.8wt% butyl phthalate;

[0054] The rest of the preparation process is the same, and a ferroelectric ceramic material with a large dielectric constant in a wide temperature range is obtained;

[0055] Example 4

[0056] The difference compared with Example 1 is that the mass fraction ratio of the BZT-xBST ceramic powder with six different component ratios to the solvent, dispersant, binder and plasticizer is 55.0wt%:39.5wt%:0.5wt%:4.0wt%:1.0wt%; wherein the plasticizer uses 1.0wt% of butyl phthalate;

[0057] The rest of the preparation process is the same, and a ferroelectric ceramic material with a large dielectric constant in a wide temperature range is obtained;

[0058] Example 5

[0059] The difference compared with Example 1 is that the BZT-xBST ceramic bodies with different component ratios are cut into the same size and heated and laminated at a temperature of 80° C. and a pressure of 10 MPa for 10 minutes to obtain a ferroelectric ceramic green body; wherein the number of laminated layers is 32;

[0060] The ferroelectric ceramic green body was heated to 550°C at a heating rate of 3°C / min under normal pressure and air atmosphere and kept at that temperature for 30 minutes for debinding treatment to obtain a ferroelectric ceramic body. After the ferroelectric ceramic body was debinded, it was pressed with a zirconium plate and sintered at a heating rate of 5°C / min to 1500°C in air atmosphere and kept at that temperature for 1 hour to obtain a ferroelectric ceramic material with a large dielectric constant in a wide temperature range.

[0061] The rest of the preparation process is the same, and a ferroelectric ceramic material with a large dielectric constant in a wide temperature range is obtained;

[0062] Example 6

[0063] The difference compared with Example 1 is that the BZT-xBST ceramic bodies with different composition ratios of the six components are cut into the same size and heated and laminated for 8 minutes at a temperature of 80° C. and a pressure of 8 MPa to obtain a ferroelectric ceramic green body; wherein the number of laminated layers is 24;

[0064] The ferroelectric ceramic green body was heated to 550°C at a heating rate of 2°C / min under normal pressure and air atmosphere and kept at that temperature for 30 minutes for debinding treatment to obtain a ferroelectric ceramic body. After the ferroelectric ceramic body was debinded, it was pressed with a zirconium plate and sintered at a heating rate of 4°C / min to 1480°C in air atmosphere and kept at that temperature for 1 hour to obtain a ferroelectric ceramic material with a large dielectric constant in a wide temperature range.

[0065] The rest of the preparation process is the same, and a ferroelectric ceramic material with a large dielectric constant in a wide temperature range is obtained;

[0066] Figure 3 (a) and Figure 3 (b) shows the dielectric constant-temperature spectra of two multi-layered multi-component samples of Example 1 and Example 2 with sintering times of 1 hour and 2 hours respectively. Figure 3 (a) It can be seen that the sample sintered for 1 hour has a significant dielectric peak platform in the temperature range of 5℃-55℃, and its dielectric constant is greater than 21448 in this temperature range. Figure 3 (b) The sample sintered for 2 hours exhibits a high dielectric constant within the 20°C-48°C temperature range, exceeding 34087. These results demonstrate that the designed material maintains a high dielectric response over a wide temperature range, achieving high dielectric performance across this wide temperature range.

[0067] Figure 4 Comparisons were made between the maximum dielectric constant and temperature range (defined as the temperature range where the dielectric constant exceeds 90% of the maximum dielectric constant) of other ferroelectric ceramic materials and the two samples designed in Examples 1 and 2. The results show that the laminated sample designed in this paper exhibits a dielectric constant ε > 21448 over a temperature range of 50K, demonstrating both a wide temperature range and a high dielectric constant, filling a gap in the current ferroelectric ceramic materials, where both a wide temperature range and a high dielectric constant are difficult to achieve.

[0068] The preferred embodiments of the present invention are described in detail above. 0.12 Ti 0.88 O3-xBaSn 0.115 Ti 0.885 By designing a layered structure on the critical line of O3 (BZT-xBST), a large dielectric constant is achieved in a wide temperature range of 5 to 55°C (ε>21448), filling the blank area where existing ferroelectric ceramic materials are difficult to achieve both a wide temperature range and a high dielectric constant.

[0069] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in this industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A ferroelectric ceramic material having a large dielectric constant over a wide temperature range, characterized in that: Ferroelectric ceramic materials were prepared by laminating and compounding BZT-xBST ceramic bodies with 6 different component ratios. The chemical formula of the BZT-xBST ceramic body is (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 O3 Among them, x is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 respectively; The method for preparing a ferroelectric ceramic material having a large dielectric constant in a wide temperature range comprises: S1, based on (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 The x in O3 is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 in different component ratios. A mixture of raw materials including BaCO3, TiO2, BaZrO3 and SnO2 is weighed and mixed by ball milling once, and then pre-sintered to obtain a bulk material, which is ground into powder and then ball milled twice. After drying, BZT-xBST ceramic powders with different component ratios are obtained. S2, mixing BZT-xBST ceramic powders with different component ratios with a solvent, a dispersant, a plasticizer, and a binder to obtain casting slurries with different component ratios; S3, vacuum degassing the tape casting slurries with different component ratios, and then drying the tape casting slurries to obtain BZT-xBST ceramic bodies with different component ratios; S4. The BZT-xBST ceramic bodies with different component ratios are heated and laminated to obtain ferroelectric ceramic green bodies, and then the binder is removed and high-temperature sintered in sequence to obtain ferroelectric ceramic materials with a large dielectric constant in a wide temperature range.

2. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, wherein: In S2, the mass ratio of BZT-xBST ceramic powder to solvent, dispersant, binder and plasticizer is 55.0wt%:39.5wt%:0.5wt%:4.0wt%:1.0wt%.

3. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, characterized in that: The specific process of S1 is: Based on (1-x)BaZr 0.12 Ti 0.88 O 3- xB 0.115 Ti 0.885 The x in O3 is 0.1, 0.2, 0.3, 0.4, 0.6 and 0.8 in different component ratios. A mixture of BaCO3, TiO2, BaZrO3 and SnO2 is weighed as raw materials, and the mixture of BaCO3, TiO2, BaZrO3 and SnO2: anhydrous ethanol: zirconium balls = 1:2:1 is ball-milled for 12 hours; the material after the first ball milling is washed out and dried, and then pre-fired at 1300°C for 2 hours. The pre-fired block material is ground into powder, and then ball-milled for a second time for 12 hours according to the mass ratio of powder: anhydrous ethanol = 1:

2. After drying, BZT-xBST ceramic powders with different component ratios are obtained.

4. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, characterized in that: The specific process of S2 is: BZT-xBST ceramic powders with different component ratios were mixed with solvents and dispersants and ball-milled for 12 h, and then binders and plasticizers were added and the mixture was continued to be ball-milled for 12 h to obtain casting slurries with different component ratios.

5. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 4, characterized in that: The solvent is prepared by mixing ethanol and ethyl acetate in a volume fraction ratio of 3:

7.

6. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, characterized in that: The dispersant is oleic acid; the binder is polyvinyl butyral; and the plasticizer is at least one of polyethylene glycol and butyl phthalate.

7. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, characterized in that: The specific process of S3 is: The tape-casting slurries with different component ratios were vacuum degassed for 20 min, poured into the trough of the tape-casting machine and cast at a rate of 3 cm / min with a thickness of 400 μm and dried at 70°C for 24 h to obtain BZT-xBST ceramic bodies with different component ratios.

8. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 1, characterized in that: The specific process of S4 is: Six BZT-xBST ceramic bodies with different component ratios were cut into the same size and heated and laminated at a temperature of 80°C and a pressure of 5-10 MPa for 5-10 minutes to obtain ferroelectric ceramic green bodies; the number of laminated layers was 16-32; The ferroelectric ceramic green body is heated to 550°C at a heating rate of 1-3°C / min under normal pressure and air atmosphere and kept warm for 30 minutes for debinding treatment to obtain a ferroelectric ceramic green body; after the ferroelectric ceramic green body is debinded, it is pressed with a zirconium plate and heated to 1460~1500°C at a heating rate of 3-5°C / min under air atmosphere and kept warm for 2 hours to complete high-temperature sintering, thereby obtaining a ferroelectric ceramic material with a large dielectric constant in a wide temperature range.

9. The ferroelectric ceramic material having a large dielectric constant in a wide temperature range according to claim 2, wherein: The ferroelectric ceramic material with a large dielectric constant in a wide temperature range undergoes a critical ferroelectric phase transition at a Curie temperature of 5°C to 55°C; the temperature range of the wide temperature range high dielectric performance of the ferroelectric ceramic material with a large dielectric constant in a wide temperature range is 5°C to 55°C.

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