A method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect

Abstract

The present invention belongs to the field of microwave dielectric ceramic materials, and specifically provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect, so that the prepared zinc-magnesium-titanium microwave dielectric ceramic material has low dielectric loss and low resonant frequency temperature coefficient, and is suitable for manufacturing ceramic substrates with excellent performance. 0.7 Mg 0.3 TiO3 system, by introducing Mn element, makes the material produce Jan-Taylor effect, distorts the crystal structure, hinders ion migration, and enhances the structural stability of the ceramic; finally, the present invention improves the Zn 0.7 Mg 0.3 The dielectric properties of TiO3 microwave ceramics have obtained a microwave dielectric ceramic material with a dielectric constant of 20.689, Q×f=50807.9, and a resonant frequency temperature stability coefficient of ‑22.3ppm / ℃, which is expected to be used in the manufacture of ceramic substrates.

Description

Technical Field

[0001] The invention belongs to the field of microwave dielectric ceramic materials, and provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect. The prepared microwave dielectric ceramic material has a low dielectric constant and high stability, and is suitable for manufacturing a ceramic substrate with excellent performance. Background Art

[0002] Low Temperature Co-fired Ceramic (LTCC) is an ideal technology to achieve miniaturization, integration, lightweight and multifunctionality of electronic devices. However, LTCC substrates have a series of special requirements for materials, such as low sintering temperature (≤950℃), low dielectric constant, high Q×f value and near-zero τ. f Value, etc.

[0003] Zn 0.7 Mg 0.3 As a new type of electronic material, TiO3 exhibits excellent performance and high reliability, but it has problems such as high sintering temperature and poor sintering properties, and its stability needs to be improved to meet higher standards of industrialization. This makes it an inevitable trend to explore new improvement methods or conduct material design.

[0004] In the field of functional oxides, JT distortion is an excellent tool to establish the unique relationship between structure and electronic properties. Manganese is usually in Mn 3+ and Mn 4+ Mixed valence states, where Mn 4+ It can form an undistorted [MnO6] octahedral structure. In contrast, high-spin Mn 3+ The 3d orbital electron configuration is (t 2g ) 3 (e g ) 1 When the two longer and two shorter Mn-O axial bonds are distorted, a Jan-Taylor distortion is generated. This geometric distortion of two longer and two shorter Mn-O axial bonds usually reduces the symmetry and energy of nonlinear molecular systems and leads to structural disorder and strong strain in the structure. Deviations from the ideal crystal structure often produce variants that are anisotropic and exhibit new properties.

[0005] At present, Zn synthesized by conventional solid phase method 0.7 Mg 0.3 TiO3 microwave dielectric ceramic material has high dielectric loss and high resonant frequency temperature coefficient; in order to improve its dielectric properties, the present invention introduces Mn element to make the material produce the Jan-Taylor effect and distort the crystal structure, so that it has more excellent performance. Summary of the invention

[0006] The object of the present invention is to provide a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jahn-Teller effect, so that the prepared zinc-magnesium-titanium microwave dielectric ceramic material has low dielectric loss and low temperature coefficient of resonant frequency, and is suitable for manufacturing ceramic substrates with excellent performance. The present invention uses Zn 0.7 Mg 0.3 TiO3 system. By introducing Mn element, the Jahn-Teller effect occurs in the material, the crystal structure is distorted, the ion migration is hindered, and the structural stability of the ceramic is enhanced; finally, the present invention uses the Jahn-Teller effect to improve the dielectric properties of Zn 0.7 Mg 0.3 TiO3 microwave ceramics, and obtains a microwave dielectric ceramic material with a dielectric constant of 20.689, Q×f = 50807.9, and a temperature stability coefficient of resonant frequency of -22.3 ppm / °C, which is expected to be used for manufacturing ceramic substrates.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jahn-Teller effect, which is characterized by comprising the following steps:

[0009] a. Using zinc oxide powder, magnesium oxide powder, manganese dioxide and titanium dioxide powder as raw materials, weighing and mixing the raw materials according to the composition of Zn 0.7 Mg 0.3 Ti 1- x Mn x O3 (0 < x ≤ 0.12); wherein, each raw material consists of the same content of zinc oxide and magnesium oxide powder and different contents of titanium dioxide and manganese dioxide powder, which are 0.96% titanium dioxide and 0.04% manganese dioxide powder, 0.92% titanium dioxide and 0.08% manganese dioxide powder, 0.88% titanium dioxide and 0.12% manganese dioxide powder respectively;

[0010] b. Ball-milling the mixed raw materials for the first time. After the ball-milling is completed, drying and grinding the slurry to obtain a precursor powder;

[0011] c. Calcining the precursor powder at 850°C - 950°C for 2 - 4 hours to obtain a pre-sintered material;

[0012] d. Ball-milling the pre-sintered material for the second time. After the ball-milling is completed, drying and grinding the slurry to obtain Zn 0.7 Mg 0.3 Ti 1-x Mn x O3 (0 < x ≤ 0.12) powder;

[0013] e. Zn 0.7 Mg 0.3 Ti1-x Mn x The MnO3(0 < x ≤ 0.12) powder is granulated with a polyvinyl alcohol binder, and after sieving, it is pressed into a compact to obtain a green body;

[0014] f. Sinter the green body at 1150°C - 1200°C for 4 - 6 hours to fully generate the Jahn - Teller distortion inside the material, and obtain the zinc - magnesium - titanium - manganese microwave ceramic material.

[0015] Furthermore, in step a, for the three raw materials, the content of manganese dioxide powder is different, resulting in different degrees of Jahn - Teller effect in the ceramic.

[0016] Furthermore, in steps b and d, both the first - stage ball milling and the second - stage ball milling adopt the same wet ball milling method. The wet ball milling is carried out in a planetary ball mill, using deionized water and absolute ethanol as solvents and agate beads as ball - milling media. Among them, the mass ratio of the raw materials to the solvents is 1:1.5, the volume ratio of deionized water to absolute ethanol in the solvents is 1:1, and the ball - milling time is 12 hours.

[0017] Furthermore, in steps b and d, the drying temperature is 85°C and the drying time is 24 hours.

[0018] Furthermore, in step e, the dosage of the binder is 10 - 15 ml; the sieving process is as follows: sieve through 40 - mesh and 100 - mesh in sequence, and take the particles between 40 - mesh and 100 - mesh; the pressure for pressing into a compact is 15 - 20 Kg / cm 2 , and the time is 2 - 3 minutes, and a cylindrical green body is pressed.

[0019] Based on the above - mentioned technical solutions, the beneficial effects of the present invention are as follows:

[0020] The present invention provides a method for improving the performance of zinc - magnesium - titanium microwave ceramics based on the Jahn - Teller effect. Using the solid - phase method, through batching, first - stage ball milling, pre - sintering, second - stage ball milling, granulation and high - temperature sintering, Zn 0.7 Mg 0.3 Ti 1-x Mn x O3(0 < x ≤ 0.12) microwave dielectric ceramics are prepared; by introducing Mn element in the present invention, the material undergoes the Jahn - Teller effect, the crystal structure is distorted, the ion migration is hindered, and the structural stability of the ceramic is enhanced; finally, the present invention utilizes the Jahn - Teller effect to improve the Zn 0.7 Mg 0.3The dielectric properties of TiO3 microwave ceramics are specifically as follows: adding different contents of manganese dioxide powder (0.04-0.12%) induces the Jan-Taylor effect, causing different degrees of distortion of the crystal structure, which can greatly hinder ion migration and enhance the structural stability of the ceramics; ultimately, the present invention obtains a microwave dielectric ceramic material with a dielectric constant of 20.689, Q×f=50807.9, and a resonant frequency temperature stability coefficient of -22.3ppm / °C, which is expected to be used to manufacture ceramic substrates with excellent performance; and the microwave dielectric ceramic material prepared by the present invention has stable performance and good consistency, which is conducive to the industrial production of ceramic substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the X-ray diffraction pattern of the zinc-magnesium-titanium-manganese microwave dielectric ceramic in Example 1 of the present invention.

[0022] Figure 2 Graph showing the dielectric properties of the zinc-magnesium-titanium-manganese microwave dielectric ceramics in Example 1, Example 2 and the comparative example of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1

[0025] This embodiment provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect. The chemical expression of the zinc-magnesium-titanium-manganese microwave dielectric ceramics is: Zn 0.7 Mg 0.3 Ti 0.92 Mn 0.08 O3, specifically includes the following steps:

[0026] a. Using zinc oxide powder, magnesium oxide powder and titanium dioxide powder as raw materials, according to Zn 0.7 Mg 0.3 Ti 0.92 Mn 0.08 Composition: Weigh zinc oxide powder, magnesium oxide powder, titanium dioxide and manganese dioxide powder respectively and mix them; wherein each raw material is composed of the same content of zinc oxide and magnesium oxide powder and different content of titanium dioxide and manganese dioxide powder, respectively containing 0.92% titanium dioxide and 0.08% manganese dioxide powder;

[0027] b. Put the mixed raw materials into a planetary ball mill, and perform wet ball milling with deionized water and anhydrous ethanol as solvents and agate beads as ball milling media, wherein the mass ratio of the raw materials to the solvent is 1:1.5, the volume ratio of deionized water to anhydrous ethanol in the solvent is 1:1, and the ball milling time is 12 hours; after the ball milling, the obtained slurry is dried in an oven at 85°C, and the precursor powder is obtained after grinding;

[0028] c. calcining the precursor powder at 850°C for 2 hours to obtain a pre-calcined material;

[0029] d. The pre-sintered material is subjected to secondary ball milling, and the secondary ball milling adopts the same wet ball milling as in step b. After the ball milling, the obtained slurry is dried in an oven at 85°C, and Zn is obtained after grinding. 0.7 Mg 0.3 Ti 0.92 Mn 0.08 Powder;

[0030] e. Zn 0.7 Mg 0.3 Ti 0.92 Mn 0.08 The powder was granulated with polyvinyl alcohol (PVA, 10%) adhesive and sieved. The amount of adhesive was 12 ml. The sieving process was: 40 mesh and 100 mesh in turn, and the particles between 40 mesh and 100 mesh were taken; the obtained particles were then sieved at 15 kg / cm 2 The briquetting was carried out under a pressure of 2000 mm / s for 2 minutes, and a cylindrical green body (Φ×h: 12 mm×6 mm) was formed.

[0031] f. Sinter the green body at 1150°C for 4 hours to fully produce the Jiang Taylor distortion inside the material to obtain the zinc-magnesium-titanium-manganese microwave ceramic material.

[0032] The zinc-magnesium-titanium-manganese microwave dielectric ceramic material prepared in this embodiment was tested, wherein the X-ray diffraction spectrum is as follows: Figure 1 As shown in the figure, it can be seen that the microwave dielectric ceramic material Zn 0.7 Mg 0.3 Ti 0.92 Mn 0.08 O3 has good crystallinity; in addition, the dielectric constant of the zinc-magnesium-titanium-manganese microwave dielectric ceramic material is 20.689, Q×f=50807.9, and the resonant frequency temperature stability coefficient is -22.3ppm / ℃.

[0033] Example 2

[0034] This embodiment provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect. The chemical expression of the zinc-magnesium-titanium-manganese microwave dielectric ceramics is: Zn 0.7 Mg0.3 Ti 0.88 Mn 0.12 O3, the only difference between it and Example 1 is that in step a, each raw material is composed of the same content of zinc oxide and magnesium oxide powder and different contents of titanium dioxide and manganese dioxide powder, respectively containing 0.88% titanium dioxide and 0.12% manganese dioxide powder.

[0035] The zinc-magnesium-titanium-manganese microwave dielectric ceramic material prepared in this embodiment was tested, and its dielectric constant was 20.596, Q×f=34452.5, and the temperature stability coefficient of the resonant frequency was -27.9 ppm / °C.

[0036] Comparative Example

[0037] This comparative example provides a method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect. The chemical expression of the zinc-magnesium-titanium-manganese microwave dielectric ceramics is: Zn 0.7 Mg 0.3 Ti 0.96 Mn 0.04 O3, the only difference between it and Example 1 is that in step a, each raw material is composed of the same content of zinc oxide and magnesium oxide powder and different contents of titanium dioxide and manganese dioxide powder, respectively containing 0.96% titanium dioxide and 0.04% manganese dioxide powder.

[0038] The dielectric properties of the zinc-magnesium-titanium-manganese microwave dielectric ceramics in the above examples 1 and 2 are compared with those in the comparative example. The results are as follows: Figure 2 As shown in the figure, it can be seen that Example 1 and Example 2 have better dielectric properties. This is because the different contents of manganese dioxide powder are introduced to induce the Jan-Taylor effect, causing the crystal structure to be distorted to varying degrees, which can greatly hinder ion migration and enhance the structural stability of the ceramic.

[0039] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect, characterized in that: The following steps are involved: a. Using zinc oxide powder, magnesium oxide powder, manganese dioxide and titanium dioxide powder as raw materials, weigh and mix the raw materials according to the composition of Zn 0.7 Mg 0.3 Ti 1-x Mn x O3 (0 < x ≤ 0.12). Among them, each raw material consists of the same content of zinc oxide and magnesium oxide powder and different contents of titanium dioxide and manganese dioxide powder, which are x = 0.04, or x = 0.08, or x = 0.12 respectively; b. Ball milling the mixed raw materials. After the ball milling, the slurry is dried and ground to obtain a precursor powder; c. Calcine the precursor powder at 850°C-950°C for 2-4 hours to obtain a pre-calcined material; d. Secondarily ball-mill the pre-sintered material. After the ball-milling is completed, dry and grind the slurry to obtain Zn 0.7 Mg 0.3 Ti 1-x Mn x O3 (0 < x ≤ 0.12) powder; e. Granulate the Zn 0.7 Mg 0.3 Ti 1-x Mn x O3 (0 < x ≤ 0.12) powder with a polyvinyl alcohol binder, and compact it into a green body after sieving; f. Sinter the green body at 1150°C-1200°C for 4-6 hours to fully produce the Jan-Taylor distortion inside the material to obtain the zinc-magnesium-titanium-manganese microwave ceramic material.

2. The method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect according to claim 1, characterized in that: In step b and step d, the first ball milling and the second ball milling are both carried out by the same wet ball milling, and the wet ball milling is carried out in a planetary ball mill, with deionized water and anhydrous ethanol as solvents and agate beads as ball milling media, wherein the mass ratio of the raw material to the solvent is 1:1.5, the volume ratio of deionized water to anhydrous ethanol in the solvent is 1:1, and the ball milling time is 12 hours.

3. The method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect according to claim 1, characterized in that: In step b and step d, the drying temperature is 85° C. and the drying time is 24 hours.

4. The method for improving the performance of zinc-magnesium-titanium microwave ceramics based on the Jan-Taylor effect according to claim 1, characterized in that: In step e, the amount of binder is 10-15 ml; the sieving process is: 40 mesh and 100 mesh in turn, and the particles between 40 mesh and 100 mesh are taken; the pressure for briquetting is 15-20 Kg / cm 2 , time is 2-3 minutes, and pressed into a cylindrical green body.

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