Multi-element substituted CCTO modified dielectric ceramic material and preparation method thereof

Abstract

The invention discloses a multi-element substituted CCTO modified dielectric ceramic material, and relates to the technical field of dielectric functional ceramics. The multi-element substituted CCTO modified dielectric ceramic material comprises a multi-element substituted CCTO modified dielectric ceramic material, and the chemical formula of the multi-element substituted CCTO modified dielectric ceramic material is Ca < 0.993 > Na < 0.007 > Cu < 3-x > Ni < x > Ti < 3.92 > (Al < Nb >) < 0.04 > O < 12 >, xlt; 3. The modified dielectric ceramic material has the beneficial effects that the dielectric loss is effectively reduced, the dielectric constant is increased, the breakdown field strength of the CCTO is improved, and the dielectric property within a certain frequency range is kept efficient and stable.

Description

Technical Field

[0001] This invention belongs to the field of dielectric functional ceramics technology, and in particular relates to a multi-element substituted copper titanate calcium modified dielectric ceramic material and its preparation method. Background Technology

[0002] Currently, high-performance electrical equipment has become an important development goal. To meet the demands for miniaturization, intelligence, integration, flexibility, and multifunctionality of electronic devices, dielectric materials are required to have high dielectric constants (εr). At the same time, reducing the dielectric loss (tanδ) and improving the breakdown field strength (Eb) of materials can effectively reduce the energy consumption of related equipment, enabling them to be better applied in thin-film devices, high-dielectric capacitors, sensors, and other fields.

[0003] Calcium copper titanate (CaCu3Ti4O12) has become a potential material for next-generation capacitors and energy storage devices due to its high dielectric constant (>10000) and non-ferroelectric properties. However, the high tanδ and low breakdown field strength of CCTO limit its application areas. These issues severely restrict its application scenarios, making further improvement of its dielectric properties of great significance. Summary of the Invention

[0004] This invention addresses the technical problem of the high dielectric constant of calcium copper titanate (CCTO) limiting its application scenarios by providing a multi-element substituted CCTO modified dielectric ceramic material and its preparation method. The modified dielectric ceramic material effectively reduces dielectric loss, increases the dielectric constant, improves the CCTO breakdown field strength, and maintains efficient and stable dielectric performance within a certain frequency range.

[0005] The technical solution adopted in this invention is: to provide a multi-element substituted CCTO modified dielectric ceramic material, with the chemical formula Ca0.993Na0.007Cu3-xNixTi3.92(AlNb)0.04O12, wherein 0 <x<3。

[0006] Further optimization of this technical solution, the preparation method of multi-element substituted CCTO modified dielectric ceramic material includes the following steps: S1. Accurately weigh calcium nitrate, sodium nitrate, nickel nitrate, copper nitrate and citric acid using chemometric methods, and fully dissolve them in an appropriate amount of anhydrous ethanol solvent. Stir the solution evenly to obtain blue solution A. S2. Accurately weigh the corresponding mass of tetrabutyl titanate, aluminum nitrate and niobium oxalate, dissolve them completely in an appropriate amount of anhydrous ethanol solvent, and stir the solution thoroughly to obtain yellow solution B; S3. Mix blue solution A and yellow solution B in a beaker to obtain precursor solution C; S4. Place the beaker containing the precursor solution C into a water bath and heat and mix. After it is completely dissolved, add an appropriate amount of polyethylene glycol to the mixture. S5. Place the mixture with added polyethylene glycol into a water bath and stir continuously to obtain CCTO blue gel; S6. Place the blue gel in a water bath and continue heating to dry it, then place it in an evaporating dish and heat it continuously in an electric multi-functional oven until all organic matter is removed, to obtain black particles. S7. Place the black particles obtained in S6 into a crucible and sinter them in a muffle furnace to obtain precursor powder D. S8. After mixing the precursor powder D obtained in S7 with the PVA binder evenly, bake the mixture until it is slightly moist, and then press it into tablets using a tablet press to obtain round tablet samples. S9. Place the circular sample in a sintering furnace for sintering treatment. After cooling to room temperature, take out the sample and polish and silver-plat it to obtain Ca0.993Na0.007Cu3-xNixTi3.92(AlNb)0.04O12 ceramic material.

[0007] To further optimize this technical solution, the stirring time for the solution in both steps S1 and S2 is 3-5 minutes.

[0008] To further optimize this technical solution, the molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C obtained in step S3 is 0.997:0.007:(2.91-2.97):(0.03-0.09):3.92:0.04:0.04.

[0009] To further optimize this technical solution, the heating temperature of the water bath in steps S4, S5, and S6 is 80°C.

[0010] To further optimize this technical solution, the mixture containing polyethylene glycol in step S5 is stirred in a water bath for 8 hours.

[0011] To further optimize this technical solution, the sintering operation of the black particles in the crucible in step S7 in the muffle furnace is as follows: the temperature is increased from room temperature to 400 degrees Celsius at a heating rate of 5℃ / min, held for 1 hour, and then increased to 800℃ and held for 4 hours.

[0012] To further optimize this technical solution, the concentration of the PVA adhesive in step S7 is 5%.

[0013] To further optimize this technical solution, the diameter of the circular sample obtained in steps S7 and S9 is 8-9 mm and the thickness is 0.9-1.5 mm; and the sintering steps of the circular sample in the sintering furnace in step S9 are as follows: first, heat to 350℃ and hold for 1 hour, then heat to 800℃ and hold for 1 hour, and finally heat to 1100℃ and hold for 12 hours.

[0014] To further optimize this technical solution, the step of sintering the circular sample in S9 and then plating it with silver is as follows: apply silver paste to the polished circular sample and heat it at 620°C for 30 minutes.

[0015] The beneficial effects of this invention are as follows: 1. Through multi-component substitution modification with Na, Ni, Al, and Nb, the performance bottlenecks of traditional CCTO materials have been effectively overcome: core dielectric properties have been significantly optimized, with a peak dielectric constant of 61044 and a minimum dielectric loss of only 0.023 (stable below 0.0264 at 1kHz). Simultaneously, the breakdown field strength has been increased to 820V / cm, significantly enhancing electrical breakdown resistance. Furthermore, it exhibits excellent temperature and frequency stability, with the dielectric constant change rate controlled within 0±15% over a wide temperature range of -55℃ to +150℃, and good frequency adaptability, maintaining stable dielectric performance under complex temperature and frequency environments. This improvement completely overcomes the shortcomings of traditional CCTO, such as high dielectric loss and insufficient breakdown field strength, making it suitable for demanding applications with higher requirements for dielectric stability and reliability.

[0016] 2. The multi-substitution modification does not alter the inherent perovskite cubic phase main structure of CCTO, ensuring the stability of the material's basic framework. Various substituents can precisely enter the A-site or B-site of the main crystal phase and achieve effective doping through a charge compensation mechanism. This avoids performance fluctuations caused by structural distortion and enhances performance through lattice-level regulation. This characteristic of "unchanged structure and optimized performance" guarantees the structural reliability of the modified material, providing core support for its long-term stable service.

[0017] 3. The sol-gel method, combined with water bath heating and the addition of polyethylene glycol dispersant, allows for precise component proportioning and uniform mixing, effectively avoiding component segregation. The process parameters are flexible; material properties can be further optimized by adjusting key parameters such as the Ni substitution amount. The operation is simple and easily scalable. This preparation route balances performance controllability with ease of industrial production, lowering the mass production threshold and enabling this modified dielectric ceramic material to flexibly meet the application needs of various fields such as electronic devices and power equipment, significantly expanding its application scope. Attached Figure Description

[0018] Figure 1The xRD patterns of the multi-element substituted CCTO modified dielectric ceramic materials of Examples 1-4 of the present invention are shown. Figure 2 The graphs show the dielectric constant of the multi-element substituted CCTO modified dielectric ceramic materials in Examples 1-4 of the present invention as a function of frequency. Figure 3 The dielectric loss curves of the multi-element substituted CCTO modified dielectric ceramic materials in Examples 1-4 of the present invention are shown as frequency changes. Figure 4 The JE characteristic curves of the multi-element substituted CCTO modified dielectric ceramic materials of Examples 1-4 of the present invention are shown. Figure 5 Scanning electron microscope (SEM) images and grain size distribution diagrams of the multi-element substituted CCTO modified dielectric ceramic materials of Examples 1-4 of the present invention; Figure 6 The graph shows the variation of Δε' of the NiO3, NiO5, NiO7 and NiO9 ceramics of the present invention in the range of -55℃ to 125℃ at 1kHz. Figure 7 Impedance spectra of Ni03, Ni05, Ni07 and Ni09 ceramics and the relationship between grain resistance (Rg), grain boundary resistance (Rgb) and 1000 / T. Figure 8 The XPS spectra of the AN08 ceramic and Ni07 ceramic of this invention are shown below. Figure 9 This is a graph showing the dielectric properties of the CCTO sample prepared in this invention compared with existing CCTO samples. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example 1

[0020] A method for preparing a multi-element substituted CCTO modified dielectric ceramic material includes the following steps: S1. Using chemometric methods, accurately weigh calcium nitrate (Ca(NO3)2•4H2O), sodium nitrate (NaNO3), nickel nitrate (Ni(NO3)2•6H2O), copper nitrate (Cu(NO3)2•3H2O), and citric acid (C6H8O7) with concentrations of 98.0% and 99.5% respectively, and fully dissolve them in an appropriate amount of anhydrous ethanol solvent. Stir the solution evenly for 3-5 minutes to obtain blue solution A. S2. Accurately weigh the corresponding masses of 99.0% tetrabutyl titanate ([CH3(CH2)3O]Ti), 99.0% aluminum nitrate (Al(NO3)3•9H2O) and 98.0% niobium oxalate (C10H5NbO2O), and dissolve them completely in an appropriate amount of anhydrous ethanol solvent. Stir the solution evenly for 3-5 minutes to obtain yellow solution B. S3. Slowly guide the yellow solution B in the beaker to the beaker containing the blue solution A using a glass rod. Wash the remaining yellow solution B in the beaker with anhydrous ethanol and then guide it back to the beaker containing the blue solution A. Stir thoroughly to obtain the precursor solution C. The molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C is 0.997:0.007:2.97:0.03:3.92:0.04:0.04. S4. Place the beaker containing the precursor solution C into an 80°C water bath and heat and stir until it is completely dissolved. Then add an appropriate amount of polyethylene glycol to the mixture (polyethylene glycol is used as a dispersant to make the components in the mixture more dispersed and more uniformly mixed). S5. Place the mixture with added polyethylene glycol in an 80°C water bath and stir for 8 hours to obtain CCTO blue gel. S6. Place the blue gel in an 80°C water bath and continue heating to dry it, then place it in an evaporating dish and heat it continuously in an electric multi-functional oven until all organic matter is removed, to obtain black particles. S7. Place the black particles obtained in S6 into a crucible, and set the temperature in a muffle furnace to rise from room temperature to 400 degrees Celsius at a heating rate of 5℃ / min, hold for 1 hour, then raise the temperature to 800℃ and hold for 4 hours to completely remove organic matter and sinter to obtain precursor powder D. S8. Mix the precursor powder D obtained in S7 with a 5% concentration of PVA adhesive. The PVA adhesive is a 5 wt.% polyvinyl alcohol aqueous solution (using polyvinyl alcohol aqueous solution as a binder can improve the success rate of the tableting process). Stir it evenly until there is no obvious adhesion. Then bake the mixture until it is slightly moist and has fluidity. Then use an electronic balance to accurately weigh the powder and place it in a stainless steel mold with a diameter of 10 mm. Use a single-axis tablet press to apply a pressure of 300 MPa to the mold. The tableting time is about 2 minutes to obtain a round tablet with a diameter of 10 mm and a thickness of about 1 mm. S9. Place the circular sample in a sintering furnace, set the temperature to rise to 350℃ at a rate of 3℃ / min and hold for 1 hour, then rise to 800℃ and hold for 1 hour, and finally rise to 1100℃ and hold for 12 hours for sintering. After cooling to room temperature, the Ca0.993Na0.007Cu2.97Ni0.03Ti3.92(AlNb)0.04O12 ceramic material is obtained. Then, a portion of the sample is polished and coated with silver paste. The sample is then placed back into the sintering furnace and fired at 620℃ for 30 minutes to obtain the Ca0.993Na0.007Cu2.97Ni0.03Ti3.92(AlNb)0.04O12 ceramic material. After cooling to room temperature, the sample is removed to complete the processing of the ceramic sample for electrical performance testing. Example 2

[0021] Unlike Example 1, in step S3 of Example 2, the molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C is 0.997:0.007:2.95:0.05:3.92:0.04:0.04, resulting in the Ca0.993Na0.007Cu2.95Ni0.05Ti3.92(AlNb)0.04O12 ceramic material. Example 3

[0022] Unlike Example 1, in step S3 of Example 3, the molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C is 0.997:0.007:2.93:0.07:3.92:0.04:0.04, resulting in Ca0.993Na0.007Cu2.93Ni0.07Ti3.92(AlNb)0.04O12 ceramic material. Example 4

[0023] Unlike Example 1, in Example 4, the molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C in step S3 is 0.997:0.007:2.91:0.09:3.92:0.04:0.04, resulting in a Ca0.993Na0.007Cu2.91Ni0.09Ti3.92(AlNb)0.04O12 ceramic material.

[0024] Test 1 After polishing the ceramic material samples obtained in Examples 1-4, silver paste was coated onto the samples, and they were sintered in a sintering furnace at 620°C for 30 minutes. After cooling to room temperature, the electrical properties of the ceramic materials were tested, and the phase structure of the samples was characterized by X-ray diffraction (XRD, Ultima IV). The results are as follows: Figure 1 As shown, Figure 1 In the figure, x=0.03, x=0.05, x=0.07, and x=0.09 represent the improved dielectric ceramic materials of Examples 1-4, respectively. As can be seen from the figure, the diffraction peaks of all the prepared ceramic material samples are the same as those of the perovskite cubic phase CCTO.

[0025] Test 2 The ceramic samples after the electrical performance testing in Examples 1-4 were tested using a broadband dielectric spectrometer (Novocontrol, Concept 80) to measure the dielectric constant (ε) of the samples in the frequency range of 10⁻¹–10⁷ Hz. The results are as follows: Figure 2 As shown, Figure 2 In the figure, x=0.03, x=0.05, x=0.07, and x=0.09 represent the improved dielectric ceramic materials of Examples 1-4, respectively. As can be seen from the figure, the dielectric constant first increases and then decreases with the increase of Ni substitution. When the substitution amount reaches 0.07, the dielectric constant increases significantly, and when the substitution amount reaches 0.09, the dielectric constant shows a decreasing trend. In addition, all ceramic samples show good frequency stability.

[0026] Test 3 The dielectric loss (tanδ) of the sample was tested using the same broadband dielectric spectrometer in Experiment 2, and the results are as follows: Figure 3 As shown, Figure 3 In the figure, x=0.03, x=0.05, x=0.07, and x=0.09 represent the improved dielectric ceramic materials of Examples 1-4, respectively. As can be seen from the figure, the dielectric loss of ceramic materials with different Ni substitution amounts is significantly different. The material with the substitution amount of 0.05 has the lowest dielectric loss of 0.023 and a dielectric constant of 34306 at 1 kHz. The material with the substitution amount of 0.07 has the highest dielectric constant of 61044 at 1 kHz and a dielectric loss of 0.025.

[0027] Test 4 The ceramic samples from Examples 1-4, after undergoing electrical performance testing, had their current-voltage characteristics measured and analyzed using a high-resistivity meter (KEITHLEY, 6517B). The JE characteristic curves of the ceramic samples from Examples 1-4 were obtained, and their structures are shown below. Figure 4 As shown, Figure 4 In the figure, x=0.03, x=0.05, x=0.07, and x=0.09 represent the improved dielectric ceramic materials of Examples 1-4, respectively. As can be seen from the figure, the breakdown field strength first decreases and then increases with the increase of Ni element substitution.

[0028] In summary, changes in microstructure are one of the important reasons for changes in the dielectric properties of a sample, such as... Figure 5As shown, it displays SEM images of all samples, with the grain size distribution shown in the inset. Figure 5 As shown, among all co-substituted samples, the Ni07 sample has the largest and most uniform grain size. The grain size of all samples exhibits a typical normal distribution. This observation indicates that as the Ni substitution amount increases, the grain size increases. Ni substitution increases the number of oxygen vacancies, promotes carrier movement, accelerates grain boundary mobility, and thus promotes grain growth. However, excessive Ni addition affects the positron annihilation of defect states, hindering grain growth. The change in dielectric constant is consistent with the change in grain size.

[0029] As a commercial ceramic capacitor dielectric, the ε' of the ceramic also needs to exhibit good Δε' at different temperatures. Figure 6 The variation of Δε' in Ni03, Ni05, Ni07, and Ni09 ceramics over the range of -55 to 125°C at 1 kHz is shown. Based on the temperature stability requirements of ceramic capacitors, Ni05 and Ni07 in this study meet the x7R (55-125°C, Δε'≤±15%) standard.

[0030] Impedance spectroscopy analysis was performed to obtain the grain resistivity (Rg) and grain boundary resistivity (Rgb) values ​​for Ni03, Ni05, Ni07, and Ni09 ceramics. Rgb can be determined by the intersection of the semicircle in the location plot with the Z′ axis. However, the Rg value is obtained by determining the non-zero intercept point from the interpolation point when the curve intersects the Z′ axis. The impedance spectrum was then fitted. Figure 7 It can be seen that the Rgb of Ni05 and Ni07 ceramics is significantly higher than that of Ni03 and Ni09 ceramics. This is because sodium and nickel co-substitution leads to increased grain boundary density. As the Ni substitution amount increases, the grain boundary resistivity of the samples first increases and then decreases. The tanδ of Ni05 and Ni07 samples is significantly reduced; therefore, increasing Rgb can significantly reduce tanδ. The changes in Rg are shown in the figure. Figure 7 As shown, Rg also exhibits a trend of first increasing, then decreasing, and then increasing again with increasing Zn substitution. Generally, the difficulty of carrier migration increases with increasing Rg, and carrier migration is related to ε'. In this experiment, the increase of ε' is affected not only by changes in grain size but also by changes in Rg. Ni substitution leads to an increase in Egb. This is in Figure 7 As demonstrated in (b), the changes in Egb and tanδ clearly show opposite trends. Notably, the Egb of Ni05 and Ni07 ceramics is significantly increased, and the tanδ is significantly improved, indicating that the increase in Egb is also a factor in reducing tanδ; at the same time, the temperature stability of Ni05 and Ni07 ceramics is improved, which is also due to the increase in Egb.

[0031] The valence structure and charge compensation mechanism of CCTO ceramics (CaCu3NiTi3.92(AlNb)0.04O12) and NiO7 ceramics with only Al and Nb substitution were systematically studied using xPS technology. Figure 8 As shown, the Cu2p3 / 2 peaks of Ni03 and Ni07 ceramics were reproduced using Gauss-Lorentz line fitting. The asymmetric shape of the Cu2p3 / 2 peaks indicates the presence of multiple overlapping peaks, i.e., the simultaneous presence of smaller Cu+ and larger Cu2+ peaks. A smaller Cu+ peak was observed at the binding energy (BE) of 931.85–932.30 eV, while a larger Cu2+ peak was observed at 933.99–934.33 eV. The Cu+ / Cu2+ ratios of AN08 and Ni07 ceramics were 12.65% / 87.35% and 28.51% / 71.49%, respectively. The xPS spectra of Ti2p in AN08 and Ni07 ceramics are shown in the figure. In the Ti2p3 / 2 spectrum, smaller and larger peaks were detected at the BE position, corresponding to Ti3+ and Ti4+, respectively. The Ti3+ / Ti4+ ratios of AN08 and Ni07 ceramics are 7.73% / 92.27% and 20.37% / 79.27%, respectively. This indicates that Na and Ni doping alters the valence state distribution of Cu and Ti, possibly due to the different valence states of Na⁺ and the substituted Ca²⁺ ion, triggering charge compensation and leading to the reduction of Cu²⁺ and Ti℺ to Cu⁺ and Ti³⁺, respectively. After Na and Ni doping, the oxygen vacancy percentage increases from 11.15% to 28.16%. This is because Na⁺ substituting for Ca²⁺ causes a local charge imbalance, leading to O²⁻ detaching from the lattice and forming V²⁻. o ...and releases electrons to compensate for the charge; it also promotes oxygen adsorption, adsorbing O2, H2O, etc. from the air to form adsorbed oxygen. Compared with AN08, Ni07 has Ti3+, Cu+, and V... o The proportions of all these factors have increased, indicating that the number of charge carriers and defects in the lattice has increased, promoting their migration, grain boundary diffusion and interfacial polarization effects, leading to an increase in the dielectric constant.

[0032] Figure 9 Table 1 systematically presents comparative data on the dielectric properties of the CCTO sample prepared in this invention with other CCTO samples published in recent years both domestically and internationally, covering dielectric constant and dielectric loss evaluation indicators. The comparison shows that, under the same testing conditions, the dielectric constant of the CCTO sample prepared in this invention is significantly higher than that of other comparative samples, indicating a stronger performance foundation for its dielectric functions such as charge storage and signal coupling. Simultaneously, its dielectric loss is much lower than other samples, indicating that the material experiences less energy loss during energy conversion and transmission, effectively reducing problems such as localized heating and performance degradation caused by losses. This provides a more reliable performance guarantee for the stable application of this material in practical devices such as high-voltage capacitors and dielectric sensors.

Claims

1. A multi-element substituted CCTO modified dielectric ceramic material, characterized in that: The chemical formula of the multi-element substituted CCTO modified dielectric ceramic material is Ca. 0.993 Na 0.007 Cu 3-x NixTi 3.92 (AlNb) 0.04 O 12 , of which 0 <x<3。 2. The preparation method of a multi-element substituted CCTO modified dielectric ceramic material according to claim 1, characterized in that: Includes the following steps: S1. Accurately weigh calcium nitrate, sodium nitrate, nickel nitrate, copper nitrate and citric acid using chemometric methods, and fully dissolve them in an appropriate amount of anhydrous ethanol solvent. Stir the solution evenly to obtain blue solution A. S2. Accurately weigh the corresponding mass of tetrabutyl titanate, aluminum nitrate and niobium oxalate, dissolve them completely in an appropriate amount of anhydrous ethanol solvent, and stir the solution thoroughly to obtain yellow solution B; S3. Mix blue solution A and yellow solution B in a beaker to obtain precursor solution C; S4. Place the beaker containing the precursor solution C into a water bath and heat and mix. After it is completely dissolved, add an appropriate amount of polyethylene glycol to the mixture. S5. Place the mixture with added polyethylene glycol into a water bath and stir continuously to obtain CCTO blue gel; S6. Place the blue gel in a water bath and continue heating to dry it, then place it in an evaporating dish and heat it continuously in an electric multi-functional oven until all organic matter is removed, to obtain black particles. S7. Place the black particles obtained in S6 into a crucible and sinter them in a muffle furnace to obtain precursor powder D. S8. After mixing the precursor powder D obtained in S7 with the PVA binder evenly, bake the mixture until it is slightly moist, and then press it into tablets using a tablet press to obtain round tablet samples. S9. Place the circular sample in a sintering furnace for sintering. After cooling to room temperature, remove the sample and polish and silver-plat it to obtain Ca. 0.993 Na 0.007 Cu 3-x NixTi 3.92 (AlNb) 0.04 O 12 Ceramic materials.

3. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The stirring time for the solution in both steps S1 and S2 is 3-5 minutes.

4. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The molar ratio of Ca, Na, Cu, Ni, Ti, Al, and Nb in the precursor solution C prepared in step S3 is 0.997:0.007:(2.91-2.97):(0.03-0.09):3.92:0.04:0.

04.

5. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The heating temperature of the water bath in steps S4, S5, and S6 is 80°C.

6. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The mixture containing polyethylene glycol in step S5 is stirred in a water bath for 8 hours.

7. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The sintering operation of the black particles in the crucible in step S7 in the muffle furnace is as follows: the temperature is increased from room temperature to 400 degrees Celsius at a heating rate of 5℃ / min, held for 1 hour, and then increased to 800℃ and held for 4 hours.

8. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The concentration of the PVA adhesive in step S7 is 5%.

9. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The diameter of the circular sample obtained in steps S7 and S9 is 8-9 mm and the thickness is 0.9-1.5 mm. The sintering steps of the circular sample in the sintering furnace in step S9 are as follows: first, heat to 350℃ and hold for 1 hour, then heat to 800℃ and hold for 1 hour, and finally heat to 1100℃ and hold for 12 hours.

10. The multi-element substituted CCTO modified dielectric ceramic material and its preparation method according to claim 2, characterized in that: The step of sintering the circular sample in S9 and then plating it with silver is as follows: apply silver paste to the polished circular sample and heat it at 620°C for 30 minutes.

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