CdCoNb ternary substituted CCTO modified dielectric ceramic material and preparation method thereof

Abstract

The invention discloses a CdCoNb ternary substituted CCTO modified dielectric ceramic material, and relates to the technical field of dielectric functional ceramics. The chemical formula of the CdCoNb ternary substituted CCTO modified dielectric ceramic material is Ca < 0.95 > Cd < 0.05 > Cu < 3-x > Co < x > Ti < 3.99 > Nb < 0.01 > O < 12 >, xlt; and 0.05%. 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 limiting its application scenarios by providing a CdCoNb ternary-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 CdCoNb ternary substituted CCTO modified dielectric ceramic material, whose chemical formula is Ca0.95Cd0.05Cu3-xCoxTi3.99Nb0.01O12, wherein 0 <x<0.05。

[0006] Further optimization of this technical solution, the preparation method of CdCoNb ternary substituted CCTO modified dielectric ceramic material includes the following steps: S1. Accurately weigh calcium nitrate, cadmium nitrate, cobalt 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 appropriate mass of tetrabutyl titanate and niobium oxalate, dissolve them thoroughly 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 Ca0.95Cd0.05Cu3-xCoxTi3.99Nb0.01O12 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, Cd, Cu, Co, Ti, and Nb in the precursor solution C obtained in step S3 is 0.95:0.05:(2.993-2.97):(0.007-0.03):3.99:0.01.

[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. In terms of performance, the performance of the material is significantly optimized by ternary substitution of Cd, Co and Nb. The dielectric constant can reach up to 40217, the dielectric loss is as low as 0.0248, and the dielectric loss at 1kHz is 0.0252. The breakdown field strength is increased to 1003V / cm. At the same time, the dielectric constant changes by 0±15% in the range of -125℃ to +125℃. It has good frequency stability and can maintain stable dielectric performance in a wide range of temperature and frequency, effectively overcoming the defects of traditional CCTO with high dielectric loss but low breakdown field strength. 2. In terms of material structure, the multi-substitution did not change the perovskite cubic phase structure of CCTO. Each substituent element can enter the A-site or B-site of the main crystal phase of CCTO and achieve effective modification through mechanisms such as charge compensation, thus ensuring the stability of the material's basic structure. 3. In terms of preparation process, the sol-gel method is adopted, combined with water bath heating and the addition of polyethylene glycol as a dispersant. This allows for precise control and uniform mixing of components. The process is flexible and easy to control. By adjusting parameters such as the substitution amount of Co2+ and Cd2+, the material properties can be further optimized, which facilitates its industrial production and application, enabling this modified dielectric ceramic material to meet the application needs of more scenarios. Attached Figure Description

[0016] Figure 1 The xRD patterns of the CCTO, CCN5071, CCN511, and CCN531 modified dielectric ceramic materials of the present invention are shown below. Figure 2 The graphs show the dielectric constant of the CCTO, CCN5071, CCN511, and CCN531 modified dielectric ceramic materials of the present invention as a function of frequency. Figure 3 The dielectric loss curves of the CCTO, CCN5071, CCN511, and CCN531 modified dielectric ceramic materials of the present invention are as follows: Figure 4The JE characteristic curves of the CCTO, CCN5071, CCN511, and CCN531 modified dielectric ceramic materials of the present invention are shown. Figure 5 The graphs show the grain resistance (Rg) and grain boundary resistance (Rgb) values ​​of the CCTO, CCN5071, CCN511, and CCN531 ceramics of the present invention. Figure 6 The grain boundary barrier spectra of the CCN5071, CCN511, and CCN531 modified dielectric ceramic materials of the present invention are shown. Figure 7 The variation of Δε' of the CCN511 ceramic of the present invention in the range of -55 to 125°C at 1 kHz; Figure 8 XPS spectra of CCTO and CCN511 ceramics of the present invention; Figure 9 The dielectric properties of the CCTO, CCN5071, CCN511, and CCN531 ceramics of the present invention are described. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example 1

[0018] A method for preparing a CdCoNb ternary substituted CCTO modified dielectric ceramic material includes the following steps: S1. Using chemometric methods, accurately weigh calcium nitrate (Ca(NO3)2•4H2O) with a concentration of 98.0%, copper nitrate (Cu(NO3)2•3H2O) with a concentration of 98.0%, cadmium nitrate (CdN2O6•4H2O) with a concentration of 99.0%, cobalt nitrate (Co(NO3)2•6H2O) with a concentration of 99.5%, and dissolve them completely 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 mass of 99.0% tetrabutyl titanate ([CH3(CH2)3O]Ti) and 98.0% niobium oxalate (C10H5NbO20), dissolve them completely in an appropriate amount of anhydrous ethanol solvent, and 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, Cd, Cu, Co, Ti, and Nb in the precursor solution C is 0.95:0.05:2.993:0.007:3.99:0.01. S4. Place the beaker containing 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 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, a Ca0.95Cd0.05Cu2.993Co0.007Ti3.99Nb0.01O12 ceramic sample is obtained. Then, a portion of the sample is polished and silver paste is applied to the sample. The sample is then placed back into the sintering furnace and fired at 620℃ for 30 minutes to obtain Ca0.95Cd0.05Cu2.993Co0.007Ti3.99Nb0.01O12 ceramic material (abbreviated as CCN5071). After cooling to room temperature, the sample is removed to complete the processing of the ceramic sample for electrical performance testing. Example 2

[0019] Unlike Example 1, in step S3 of Example 2, the molar ratio of Ca, Cd, Cu, Co, Ti, and Nb in the precursor solution C is 0.95:0.05:2.99:0.01:3.99:0.01, resulting in a Ca0.95Cd0.05Cu2.99Co0.01Ti3.99Nb0.01O12 ceramic material (abbreviated as CCN511). Example 3

[0020] 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 0.95:0.05:2.97:0.03:3.99:0.01, resulting in Ca0.95Cd0.05Cu2.99Co0.03Ti3.99Nb0.01O12 ceramic material (abbreviated as CCN531).

[0021] Test 1 After polishing the ceramic material samples obtained in Examples 1-3, 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=0.007, x=0.01, and x=0.03 represent the improved dielectric ceramic materials of Examples 1-3, respectively. As can be seen from the figure, the xRD spectra of all samples are highly matched with the standard diffraction peaks of CCTO (perovskite structure), and no obvious impurity phase peaks are observed. With the increase of the substitution amount of Co2+, no new impurity phases are introduced, and the integrity of the original perovskite structure is maintained.

[0022] Test 2 The ceramic samples after the electrical performance testing in Examples 1-3 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=0.007, x=0.01, and x=0.03 represent the improved dielectric ceramic materials of Examples 1-3, respectively. As can be seen from the figure, the dielectric constant first increases and then decreases with the increase of the substitution amount of Co2+. When the substitution amount reaches 0.01, the dielectric constant increases, and when the substitution amount reaches 0.03, the dielectric constant shows a decreasing trend. In addition, all ceramic samples show good frequency stability.

[0023] 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=0.007, x=0.01, and x=0.03 represent the improved dielectric ceramic materials of Examples 1-3, respectively. As can be seen from the figure, the dielectric loss of ceramic materials with different Co2+ substitution amounts is significantly different. The material with a substitution amount of 0.007 has the lowest dielectric loss of 0.0153 and a dielectric constant of 32893 at 1kHz. The material with a substitution amount of 0.01 has the highest dielectric constant of 40217 at 1kHz and a dielectric loss of 0.0248.

[0024] Test 4 The ceramic samples after electrical performance testing in Examples 1-3 were measured and analyzed using a high-resistivity meter (KEITHLEY, 6517B) to obtain the JE characteristic curves of the ceramic samples in Examples 1-4. Their structures are shown below. Figure 4 As shown, Figure 4 In the figure, x=0.007, x=0.01, and x=0.03 represent the improved dielectric ceramic materials of Examples 1-3, respectively. As can be seen from the figure, the breakdown field strength first decreases and then increases with the increase of the substitution amount of Co2+.

[0025] In summary: the ionic radius of Cd²⁺ (0.97 Å) is similar to that of Ca²⁺ (0.99 Å), the ionic radius of Co²⁺ (0.74 Å) is similar to that of Cu²⁺ (0.72 Å), and the ionic radius of Nb⁵⁺ (0.70 Å) is similar to that of Ti⁴⁺ (0.68 Å). Meanwhile, the ionic radius of Co³⁺ (0.63 Å) is slightly smaller than that of Ti⁴⁺. When the substitution amount is low, a small amount of Co²⁺ will transform into Co³⁺, with little impact on lattice disruption. However, when the substitution amount is excessive, the amount of Co³⁺ increases, leading to crystal instability, exacerbating lattice distortion, and affecting dielectric properties.

[0026] When the Co²⁺ substitution amount is small (x=0.007 to x=0.01), Co²⁺ replaces Cu²⁺ in the crystal lattice, causing minor lattice distortion, increasing the number and mobility of dipoles, and thus increasing the dielectric constant. Simultaneously, an appropriate amount of Co²⁺ may promote uniform grain growth, increase the number of grain boundaries, and form more "micro-capacitor" structures, contributing to an increase in the dielectric constant. Furthermore, some Co²⁺ will transform into Co³⁺, which will then replace Ti⁴⁺. Co³⁺ and Nb⁵⁺ form donor substitution, and through a charge compensation mechanism, they further increase the carrier concentration, further improving the dielectric constant. However, when the substitution amount increases further (x=0.03), excessive Co²⁺ leads to excessive lattice distortion, disrupting the original crystal structure stability. Simultaneously, defect aggregation occurs at grain boundaries, hindering effective charge storage and conduction, resulting in a decrease in the dielectric constant. When the Co²⁺ substitution amount is further increased, excessive Co²⁺ will transform into Co³⁺, which will then replace Ti⁴⁺, creating more defects and leading to a decrease in the dielectric constant. When the Co²⁺ substitution amount is 0.007, an appropriate amount of Co²⁺ fills the vacancy defects in the crystal lattice, reducing the leakage conduction path of charge and thus reducing dielectric loss. As the substitution amount increases, excess Co²⁺ leads to the generation of new defects in the crystal lattice, such as interstitial ions or dislocations. These defects increase charge mobility, resulting in an increase in dielectric loss.

[0027] As the Co2+ substitution amount increases, the grain size of the sample first increases and then decreases. According to the IBLC model, the dielectric constant of the sample is proportional to the grain size, which is consistent with the experimental results. Therefore, appropriate Co2+ is beneficial to promote grain growth, while excessive Co2+ will further exacerbate lattice distortion, inhibit grain growth, and thus affect dielectric properties.

[0028] Impedance spectroscopy analysis was performed to obtain the grain resistivity (Rg) and grain boundary resistivity (Rgb) values ​​for CCTO, CCN5071, CCN511, and CCN531 ceramics. Rgb can be determined by the intersection of the large 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. Figure 5 It can be seen that with the increase of Co2+ substitution, the Rgb tends to increase, while the Rg tends to decrease. The larger Rgb of the samples with x=0.007 and x=0.030 may be related to the enhanced grain boundary density. A larger Rgb can suppress carrier crossing of grain boundaries, reduce leakage current, and lower dielectric loss, but an excessively high Rgb may reduce its dielectric properties. The increase in εr is also related to Rg. When the Rgb to Rg ratio is large, it will increase its polarization intensity, keeping εr at a high level. Among them, the sample with x=0.010 has good electrical heterogeneity due to its appropriate Rgb and Rg, thus having a higher dielectric constant and lower dielectric loss.

[0029] Depend on Figure 6 Analysis revealed that the grain boundary barriers for x=0.007, 0.010, and 0.030 were 1.063, 0.709, and 0.807 eV, respectively, which is largely consistent with the variation in Rgb. A higher barrier height increases the resistance of charge carriers crossing the grain boundary, resulting in lower leakage current and improved resistance to electric field breakdown, thus increasing the breakdown field strength.

[0030] Figure 7 The variation of Δε' of CCN511 ceramic in the range of -55 to 125°C at 1 kHz is shown. According to the temperature stability requirements of ceramic capacitors, the CCN511 in this study meets the x7R (55-125°C, Δε'≤±15%) standard.

[0031] The valence structure and charge compensation mechanism of CCTO and CCN511 ceramics were systematically studied using xPS technology. Figure 8 As shown, the Cu2p3 / 2 peaks of CCTO and CCN511 ceramics were reproduced using Gaussian-Lorentz line fitting techniques. 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 CCTO and CCN511 ceramics were 9.88% / 90.12% and 25.48% / 74.52%, respectively. The xPS spectra of Ti2p in CCTO and CCN511 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 CCTO and CCN511 ceramics are 8.77% / 91.23% and 14.02% / 85.98%, respectively. This indicates that Cd, Co, and Nb substitution reduces some Cu2+ and Ti4+ to Cu+ and Ti3+. The oxygen vacancy ratio increases from 13.61% to 26.97%, due to the local charge imbalance caused by substitution, which leads to the formation of oxygen vacancies to compensate for the charge. In summary, substitution increases the number of defects, promotes carrier migration and crystal polarization, and thus improves the dielectric constant.

[0032] Figure 9Table 1 systematically presents the dielectric properties of CCTO, CCN5071, CCN511, and CCN531 ceramics in this study. The comparison shows that, under the same test conditions, replacing the ceramic samples with Cd, Co, or Nb significantly improves the dielectric properties. Among them, CCN511, due to its high dielectric constant and low dielectric loss, has great application potential in practical devices.

Claims

1. A CdCoNb ternary substituted CCTO modified dielectric ceramic material, characterized in that: The chemical formula of the CdCoNb ternary substituted CCTO modified dielectric ceramic material is Ca. 0.95 Cd 0.05 Cu 3-x Co x Ti 3.99 Nb 0.01 O 12 , of which 0 <x<0.05。 2. The preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material according to claim 1, characterized in that: Includes the following steps: S1. Accurately weigh calcium nitrate, cadmium nitrate, cobalt 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 appropriate mass of tetrabutyl titanate and niobium oxalate, dissolve them thoroughly 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. 0.95 Cd 0.05 Cu 3-x Co x Ti 3.99 Nb 0.01O12 Ceramic materials.

3. The preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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 method for preparing the CdCoNb ternary substituted CCTO modified dielectric ceramic material according to claim 2, characterized in that: The molar ratio of Ca, Cd, Cu, Co, Ti, and Nb in the precursor solution C prepared in step S3 is 0.95:0.05:(2.993-2.97):(0.007-0.03):3.99:0.

01.

5. The preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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 preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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 preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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 method for preparing the CdCoNb ternary substituted CCTO modified dielectric ceramic material according to claim 2, characterized in that: The concentration of the PVA adhesive in step S7 is 5%.

9. The preparation method of the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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 method for preparing the CdCoNb ternary substituted CCTO modified dielectric ceramic material 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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