Modified dielectric ceramic material based on niobium-zirconium double metal element doped copper calcium titanate and preparation method of modified dielectric ceramic material

Abstract

The invention provides a modified dielectric ceramic material based on niobium-zirconium double metal element doped copper calcium titanate and a preparation method thereof, and the preparation method comprises the following steps: drying a raw material to obtain the raw material; putting the raw materials into a zirconium oxide ball milling tank, and adding zirconium oxide milling balls in proportion for dry milling to obtain mixed powder; pre-sintering the mixed powder to form a perovskite precursor phase, and naturally cooling the perovskite precursor phase to room temperature to obtain pre-sintered powder; carrying out wet ball milling on the pre-sintered powder and absolute ethyl alcohol to obtain slurry, drying the slurry, and sieving to obtain powder; adding the powder into a polyvinyl alcohol adhesive, uniformly mixing, and performing cold isostatic pressing to obtain a wafer; and putting the wafer into a high-temperature furnace for first-stage and second-stage treatment in sequence, and then cooling to room temperature along with the furnace to obtain a sample. The mixed oxide ceramic with good crystallinity, strong component uniformity and high phase purity is obtained through sintering, and the obtained ceramic is improved in density, not easy to decompose and enhanced in mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of dielectric functional ceramic materials, and in particular to a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate and a preparation method thereof. Background Art

[0002] From miniaturized chip components to high-performance energy storage devices, dielectric materials with high dielectric constant, low dielectric loss and excellent stability have become key factors in promoting the miniaturization, integration and high performance of electronic devices. In this context, calcium copper titanate ( As a new type of dielectric material with great potential, CCTO has attracted much attention due to its unique physical properties.

[0003] However, despite CCTO's many advantages, it still faces some limitations in practical applications. When the dielectric loss of CCTO increases significantly within this critical frequency band, the dielectric loss of CCTO increases significantly. This increase in dielectric loss not only wastes energy and reduces the efficiency of electronic devices, but can also cause device heating, affecting their stability and reliability. This in turn limits CCTO's application in electronic circuits such as audio circuits and some communication circuits, which have strict requirements for low dielectric loss within this frequency band. Summary of the Invention

[0004] In view of the above situation, the main purpose of the present invention is to propose a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with copper calcium titanate and a preparation method thereof to solve the above technical problems.

[0005] The present invention proposes a preparation method of a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with copper calcium titanate, the preparation method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide to obtain dried raw materials, and cooling the dried raw materials in a dryer to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls in proportion, seal the ball mill, fill it with nitrogen, and dry-grind in a planetary ball mill in a forward and reverse rotation mode to obtain a mixed powder; S3, lightly compacting the mixed powder and placing it in a corundum crucible, and then placing it in a muffle furnace for pre-sintering to form a perovskite precursor phase, and then naturally cooling it to room temperature and breaking up the agglomerates by grinding to obtain a pre-sintered powder; S4, adding anhydrous ethanol to the calcined powder and wet-milling it to obtain a slurry, adding a titanate coupling agent to the slurry and stirring it at a certain temperature to obtain a treated slurry, performing ultrasonic dispersion treatment on the treated slurry, drying it in an oven, and sieving it to obtain an intermediate powder; S5, uniformly mixing the polyvinyl alcohol binder and the intermediate powder, aging, and then cold isostatic pressing to obtain a disc; S6, placing the wafer in a pulsed magnetic field to perform a gradient magnetic field assisted burn-in treatment to obtain a gradient magnetic field treated wafer; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high temperature furnace for the first stage treatment to obtain a first stage sintered product, performing a second stage annealing treatment on the first stage sintered product to obtain a second stage product, and then cooling it to room temperature in the furnace to obtain Ceramic samples, among which .

[0006] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention obtains nanoparticles with good crystallinity, strong composition uniformity and high phase purity through sintering, which can easily prepare uniform mixed oxide ceramics. The obtained ceramics have increased density, are not easy to decompose, and have enhanced mechanical properties; 2. The present invention coordinates and modifies the microstructure and electrical properties of CCTO by co-doping elements to achieve the dielectric ceramic material required for a specific frequency.

[0007] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Schematic diagram of the dielectric constant and dielectric loss change curves of the modified dielectric ceramic material samples prepared in Example 1, Example 2, Example 3 and Example 4; Figure 2 Schematic diagram of the dielectric constant and dielectric loss change curves of the modified dielectric ceramic material samples prepared in Example 5, Example 6, Example 7 and Example 8. DETAILED DESCRIPTION

[0009] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0010] These and other aspects of the embodiments of the present invention will become clear with reference to the following description and accompanying drawings. In these descriptions and accompanying drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to illustrate some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not limited thereto.

[0011] Example 1 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 100° C. for 3 hours to obtain dried raw materials, and cooling the dried raw materials in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 8:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 250 rpm for 6 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 800°C at 4°C / min for 4 hours for pre-sintering to form a perovskite precursor phase, and then naturally cooled to room temperature and crushed by grinding to obtain a pre-sintered powder; S4. The calcined powder was added to anhydrous ethanol at a solid-liquid ratio of 1:2 and wet-milled at 200 rpm for 4 hours to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 hours to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 70° C. for 12 hours. The slurry was then passed through a 180-mesh sieve to obtain an intermediate powder. S5, mixing 5wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 150MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high-temperature furnace, heating it to 1100°C at a heating rate of 5°C / min and keeping it warm for 1 hour to perform a first-stage sintering treatment to obtain a first-stage sintered product, cooling the first-stage sintered product to 950°C at a cooling rate of 1°C / min and keeping it warm for 8 hours to obtain a second-stage annealing treatment, and then cooling it to room temperature with the furnace to obtain Ceramic samples.

[0012] Example 2 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 120° C. for 4 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 10:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 8 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 850°C at 5°C / min and kept at this temperature for 6 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added with anhydrous ethanol at a solid-liquid ratio of 1:3 and wet-milled at 250 rpm for 6 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 80° C. for 24 h. The slurry was then sieved through a 200-mesh sieve to obtain an intermediate powder. S5, mixing 6 wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 200 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high-temperature furnace, heating it to 1100°C at a heating rate of 8°C / min and keeping it warm for 2 hours to perform a first-stage sintering treatment to obtain a first-stage sintered product, cooling the first-stage sintered product to 950°C at a cooling rate of 2°C / min and keeping it warm for 10 hours to obtain a second-stage annealing treatment, and then cooling it to room temperature with the furnace to obtain Ceramic samples.

[0013] Example 3 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 150° C. for 6 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 12:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 10 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 900°C at 6°C / min and kept at this temperature for 8 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added to anhydrous ethanol at a solid-liquid ratio of 1:4 and wet-milled at 300 rpm for 8 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 90° C. for 36 h. The slurry was then passed through a 220-mesh sieve to obtain an intermediate powder. S5, mixing 7 wt% of polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 250 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high-temperature furnace, heating it to 1100°C at a heating rate of 10°C / min and keeping it warm for 3 hours to perform a first-stage sintering treatment to obtain a first-stage sintered product, cooling the first-stage sintered product to 950°C at a cooling rate of 2°C / min and keeping it warm for 12 hours to obtain a second-stage annealing treatment, and then cooling it to room temperature with the furnace to obtain Ceramic samples.

[0014] Example 4 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 120° C. for 4 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 10:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 8 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 850°C at 5°C / min and kept at this temperature for 6 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added with anhydrous ethanol at a solid-liquid ratio of 1:3 and wet-milled at 250 rpm for 6 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 80° C. for 24 h. The slurry was then sieved through a 200-mesh sieve to obtain an intermediate powder. S5, mixing 6 wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 200 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high-temperature furnace, heating it to 1100°C at a heating rate of 8°C / min and keeping it warm for 2 hours to perform a first-stage sintering treatment to obtain a first-stage sintered product, cooling the first-stage sintered product to 950°C at a cooling rate of 2°C / min and keeping it warm for 10 hours to obtain a second-stage annealing treatment, and then cooling it to room temperature with the furnace to obtain Ceramic samples.

[0015] Example 5 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 120° C. for 4 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 10:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 8 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 850°C at 5°C / min and kept at this temperature for 6 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added with anhydrous ethanol at a solid-liquid ratio of 1:3 and wet-milled at 250 rpm for 6 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 80° C. for 24 h. The slurry was then sieved through a 200-mesh sieve to obtain an intermediate powder. S5, mixing 6 wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 200 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high-temperature furnace, heating it to 1100°C at a heating rate of 8°C / min and keeping it warm for 2 hours to perform a first-stage sintering treatment to obtain a first-stage sintered product, cooling the first-stage sintered product to 1050°C at a cooling rate of 2°C / min and keeping it warm for 10 hours to obtain a second-stage annealing treatment, and then cooling it to room temperature with the furnace to obtain Ceramic samples.

[0016] Example 6 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 120° C. for 4 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 10:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 8 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 850°C at 5°C / min and kept at this temperature for 6 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added with anhydrous ethanol at a solid-liquid ratio of 1:3 and wet-milled at 250 rpm for 6 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 80° C. for 24 h. The slurry was then sieved through a 200-mesh sieve to obtain an intermediate powder. S5, mixing 6 wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 200 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S6. Place the disc after gradient magnetic field treatment on an alumina pad, put it into a high-temperature furnace, heat it to 1100°C at a heating rate of 8°C / min and keep it at that temperature for 2 hours to perform the first stage sintering treatment to obtain the first stage sintered product. Cool the first stage sintered product to 1050°C at a cooling rate of 2°C / min and keep it at that temperature for 10 hours to obtain the second stage product. Then cool it to room temperature with the furnace to obtain Ceramic samples.

[0017] Example 7 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 100° C. for 3 hours to obtain dried raw materials, and cooling the dried raw materials in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 8:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 250 rpm for 6 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 800°C at 4°C / min for 4 hours for pre-sintering to form a perovskite precursor phase, and then naturally cooled to room temperature and crushed by grinding to obtain a pre-sintered powder; S4. The calcined powder was added to anhydrous ethanol at a solid-liquid ratio of 1:2 and wet-milled at 200 rpm for 4 hours to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 hours to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 70° C. for 12 hours. The slurry was then passed through a 180-mesh sieve to obtain an intermediate powder. S5, mixing 5wt% polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 150MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S6. Place the disc after gradient magnetic field treatment on an alumina pad, put it into a high-temperature furnace, heat it to 1100°C at a heating rate of 8°C / min and keep it at that temperature for 2 hours to perform the first stage sintering treatment to obtain the first stage sintered product. Cool the first stage sintered product to 1050°C at a cooling rate of 2°C / min and keep it at that temperature for 10 hours to obtain the second stage product. Then cool it to room temperature with the furnace to obtain Ceramic samples.

[0018] Example 8 This embodiment provides a method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, the method comprising the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide at 150° C. for 6 hours to obtain a dried raw material, and cooling the dried raw material in a desiccator to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls at a ball-to-material ratio of 12:1, seal the ball mill, fill it with nitrogen, and dry-mill in a planetary ball mill at 300 rpm for 10 h using alternating forward and reverse rotations to obtain a mixed powder; S3, the mixed powder is lightly pressed and densely placed in a corundum crucible, and then placed in a muffle furnace and heated to 900°C at 6°C / min and kept at this temperature for 8 hours to pre-sinter to form a perovskite precursor phase, and then naturally cooled to room temperature and then ground to break up agglomerates to obtain a pre-sintered powder; S4. The calcined powder was added to anhydrous ethanol at a solid-liquid ratio of 1:4 and wet-milled at 300 rpm for 8 h to obtain a slurry. 0.75% wt of a titanate coupling agent was added to the slurry and stirred at a constant temperature of 60° C. for 2 h to obtain a treated slurry. The treated slurry was subjected to ultrasonic dispersion treatment and then dried in an oven at 90° C. for 36 h. The slurry was then passed through a 220-mesh sieve to obtain an intermediate powder. S5, mixing 7 wt% of polyvinyl alcohol binder with the intermediate powder, aging, and then cold isostatic pressing at 250 MPa to obtain a φ10 mm × 1 mm disc; S6, placing the wafer in a pulsed magnetic field with an intensity of 1.5 T, raising the temperature to 600° C. at a heating rate of 5° C. / min and holding the temperature for 1 hour, and performing a gradient magnetic field assisted sintering treatment to obtain a wafer treated with a gradient magnetic field, wherein the angle between the magnetic field direction and the axial direction of the wafer is 45°; S6. Place the disc after gradient magnetic field treatment on an alumina pad, put it into a high-temperature furnace, heat it to 1100°C at a heating rate of 8°C / min and keep it at that temperature for 2 hours to perform the first stage sintering treatment to obtain the first stage sintered product. Cool the first stage sintered product to 1050°C at a cooling rate of 2°C / min and keep it at that temperature for 10 hours to obtain the second stage product. Then cool it to room temperature with the furnace to obtain Ceramic samples.

[0019] Example 9 The present invention further proposes a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, wherein the modified dielectric ceramic material is prepared by the preparation method of the above-mentioned embodiment 2.

[0020] The present invention also studies the dielectric constant and dielectric loss of the modified dielectric ceramic material under different annealing temperature conditions.

[0021] The present invention's research shows that: metal zirconium and titanium are elements of the same family. Replaced by CCTO ceramics The site is to provide stability and the lowest energy configuration. Doping into CCTO can effectively reduce the dielectric loss tangent tanδ by inhibiting grain growth while maintaining a high dielectric constant. .in, Dielectric ceramics have excellent dielectric properties. The results show that CCTO ceramics doped , can refine the grains and improve the uniformity of grain size. However, in the medium and high frequency range, the dielectric loss still cannot meet the actual demand. Therefore, in the doping Based on this, bimetallic element doping modification is carried out.

[0022] because The valence is higher than This high-valent ion substitution will break the original charge balance. In order to maintain electrical neutrality, the dielectric material will reduce oxygen vacancies and inhibit Towards low price The restoration, The extra electrons need to be compensated by oxygen vacancies, that is, the source of carriers (free electrons) is reduced. The moderate introduction of oxygen vacancies can optimize the charge accumulation state at the grain boundary, by improving the grain conductivity, stabilizing the grain boundary barrier, inhibiting defect migration and optimizing the microstructure, so that it can be used at a specific frequency. The dielectric constant is kept high within a certain range while suppressing the dielectric loss caused by disordered charge migration. In this way, the microstructure of CCTO is regulated to improve its dielectric properties.

[0023] By referring to Figures 1 to 2 It can be seen that the dielectric constant of the modified dielectric ceramic materials under different annealing temperature conditions will decrease with the increase of frequency. This is because the change rate of the high-frequency electric field exceeds the response capacity of some polarization mechanisms in the material, resulting in a decrease in the mechanism participating in the polarization and a decrease in the total polarization intensity, which ultimately manifests as a decrease in the dielectric constant. The experimental results show that under the same annealing temperature conditions, the ceramic samples after doping will decrease with the increase of Nb 5+ As the doping amount increases, the dielectric constant will show an overall upward trend.

[0024] Figure 1 It shows that after annealing at 950℃, the Ceramic samples in It has a minimum loss tangent of 0.073 and a dielectric constant of 367; Figure 2 It shows that after annealing at 1050℃, the Ceramic samples in It has a minimum loss tangent of 0.08 and a dielectric constant of 1616; It should be noted that Figures 1 to 2 The descriptions in the figure legends are independent; Figure 1 All ceramic samples annealed at 950℃ are shown in In this frequency range, the dielectric constant can only reach Magnitude, Figure 2 All ceramic samples annealed at 1050℃ can still maintain low dielectric loss. Dielectric constant of the order of magnitude.

[0025] The results show that the doping of niobium-zirconium bimetallic elements can significantly improve the dielectric response of calcium copper titanate. Under the same annealing temperature, the appropriate amount of Doping can effectively enhance the dielectric response, making it At the same time, temperature has a great influence on it. Different annealing temperatures affect its microstructure and thus change the dielectric response mechanism. Comparative analysis shows that the dielectric properties are better under the condition of annealing at 1050℃. In summary, this experiment obtained the ideal required dielectric properties after annealing at the target temperature of 1050℃. Ceramic samples in It has a minimum loss tangent of 0.08, a dielectric constant of 1616, and a 40Hz-10 6 Hz dielectric constant is greater than 10 3 Magnitude.

[0026] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0027] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with copper calcium titanate, characterized in that: The preparation method comprises the following steps: S1. Drying calcium carbonate, copper oxide, titanium dioxide, niobium pentoxide, and zirconium dioxide to obtain dried raw materials, and cooling the dried raw materials in a dryer to room temperature to obtain a raw material; S2. Place the raw materials in a zirconia ball mill, add zirconia grinding balls in proportion, seal the ball mill, fill it with nitrogen, and dry-grind in a planetary ball mill in a forward and reverse rotation mode to obtain a mixed powder; S3, lightly compacting the mixed powder and placing it in a corundum crucible, and then placing it in a muffle furnace for pre-sintering to form a perovskite precursor phase, and then naturally cooling it to room temperature and breaking up the agglomerates by grinding to obtain a pre-sintered powder; S4, adding anhydrous ethanol to the calcined powder and wet-milling it to obtain a slurry, adding a titanate coupling agent to the slurry and stirring it at a certain temperature to obtain a treated slurry, performing ultrasonic dispersion treatment on the treated slurry, drying it in an oven, and sieving it to obtain an intermediate powder; S5, uniformly mixing the polyvinyl alcohol binder and the intermediate powder, aging, and then cold isostatic pressing to obtain a disc; S6, placing the wafer in a pulsed magnetic field to perform a gradient magnetic field assisted burn-in treatment to obtain a gradient magnetic field treated wafer; S7, placing the disc after gradient magnetic field treatment on an alumina pad, placing it in a high temperature furnace for the first stage treatment to obtain a first stage sintered product, performing a second stage annealing treatment on the first stage sintered product to obtain a second stage product, and then cooling it to room temperature in the furnace to obtain Ceramic samples, among which .

2. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 1, characterized in that: In S1, the drying temperature is 100-150° C., the drying time is 3-6 hours, the purity of calcium carbonate and titanium dioxide is ≥99.8%, and the purity of copper oxide, niobium pentoxide and zirconium dioxide is ≥99.5%.

3. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 2, characterized in that: In step S2, the ball-to-material ratio is 8:1-12:1, the ball milling speed is 250-350 rpm, and the ball milling time is 6-10 h.

4. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 3, characterized in that: In step S3, the pre-firing heating rate is 4-6°C / min, the pre-firing target temperature is 800-900°C, and the holding time is 4-8h.

5. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 4, characterized in that: In step S4, the solid-liquid ratio of the calcined powder to anhydrous ethanol is 1:2-1:4, the ball mill speed is 200-300 rpm, the ball milling time is 4-8 hours, the addition amount of the titanate coupling agent is 0.75%wt, the stirring temperature is a constant temperature of 60°C, the stirring time is 2 hours, the drying temperature is 70-90°C, the drying time is 12-36 hours, and the sieve mesh size is 180-220 mesh.

6. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 5, characterized in that: In step S5, the amount of polyvinyl alcohol added is 5-7 wt %, and the molding pressure is 150-250 MPa.

7. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 6, characterized in that: In step S6, the intensity of the pulsed magnetic field is 1.5 T, the heating rate of the auxiliary pre-burning is 5°C / min, the target temperature of the auxiliary pre-burning is 600°C, the holding time is 1 hour, and the angle between the magnetic field direction and the wafer axis is 45°.

8. The method for preparing a modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate according to claim 7, characterized in that: In S6, the heating rate of the sintering treatment in the first stage is 5-10°C / min, the target temperature of the sintering in the first stage is 1050-1150°C, the holding time after sintering in the first stage is 1-3h, the cooling rate in the second stage annealing treatment is 1-3°C / min, the target temperature in the second stage annealing treatment is 900-1050°C, and the holding time in the second stage annealing treatment is 8-12h.

9. A modified dielectric ceramic material based on niobium-zirconium bimetallic elements doped with calcium copper titanate, characterized in that: The modified dielectric ceramic material is prepared by the preparation method according to any one of claims 1 to 8, and the chemical formula of copper calcium titanate doped with niobium zirconium bimetallic elements is ,in, .

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