A low-dielectric gallium, germanium-based high-quality factor microwave dielectric material and a preparation method thereof

Abstract

The application relates to the technical field of ceramic dielectric materials, in particular to a novel low-dielectric gallium and germanium-based high-quality factor microwave dielectric material and a preparation method thereof. Ga2O3, GeO2 and MgO are weighed according to a proportion, ball-mixed, dried and sintered to obtain pre-sintered ceramic powder, the ceramic powder is put into a ball mill for secondary ball milling, the ceramic powder after the secondary ball milling is granulated, pressed into a cylindrical green body, and finally the green body is sintered after glue removal. Compared with the prior art, the novel low-dielectric gallium and germanium-based high-quality factor microwave dielectric material has not only a dielectric constant but also a high quality factor, can be used in different devices such as filters, resonators and dielectric antennas, and can ensure the stability of the devices, so the novel low-dielectric gallium and germanium-based high-quality factor microwave dielectric material has a wide market prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic dielectric materials, in particular to a preparation method of a new low-dielectric gallium and germanium-based high-quality factor microwave dielectric material. BACKGROUND

[0002] Microwave dielectric ceramics refer to ceramic materials applied in microwave frequency bands (300MHz-300GHz) circuits to complete specific functions. As key materials for devices such as filters, resonators, and dielectric antennas, microwave dielectric ceramic materials have appropriate dielectric constants (ε r ) to meet different use occasions, high quality factors (Qxf) to reduce the insertion loss of devices, and near-zero resonance frequency temperature coefficients (τ f ) to ensure the stability of devices.

[0003] However, with the development of 5G / 6G communication technology, the signal transmission rate has increased significantly. According to , the signal transmission rate is inversely proportional to the dielectric constant, which requires ceramic materials to have a low dielectric constant to ensure the transmission rate, and a high quality factor to reduce the insertion loss of devices. Therefore, it is an inevitable trend to develop microwave dielectric materials with low dielectric constant and high quality factor.

[0004] At present, many low-dielectric constant microwave dielectric ceramic materials are commonly found in Si-based, Ga-based, and Ge-based materials. However, these materials generally have low quality factors. For example, the microwave dielectric properties of LiYbSiO4 are ε r = 7.4, Qxf = 25276GHz, the microwave dielectric properties of Li2GeO3 are ε r = 6.36, Qxf = 29000GHz, and the microwave dielectric properties of CaLaGaO4 are ε r = 11.23, Qxf = 63900GHz. Therefore, there is an urgent need to develop a microwave dielectric ceramic material with low dielectric constant and high quality factor. SUMMARY

[0005] In view of the deficiencies of the above background technology, the present application provides a preparation method of a new low-dielectric gallium and germanium-based high-quality factor microwave dielectric material, which solves the problem of low quality factor of existing gallium and germanium-based ceramic materials.

[0006] In one aspect, the present application provides a preparation method of a new low-dielectric gallium and germanium-based high-quality factor microwave dielectric material, which comprises the following steps:

[0007] S1. Mix high-purity Ga2O3, GeO2, and MgO in a certain proportion, and then put them into a ball mill for primary ball milling;

[0008] S2. drying and sintering the ball-mixed material of S1 to obtain a pre-sintered ceramic powder;

[0009] S3. putting the pre-sintered ceramic powder of S2 into a ball mill to perform secondary ball-milling;

[0010] S4. drying and granulating the ball-mixed material of S3 to obtain a ceramic powder with a particle size of 80-120 mesh;

[0011] S5. sintering the ceramic powder green body of S4 to obtain a finished product.

[0012] Preferably, in S1, the raw materials are weighed and mixed according to the molecular formula Mg2Ga4GeO 10 The raw materials are weighed and mixed.

[0013] Preferably, the ball-milling conditions of S2 and S3 are as follows: the mass ratio of raw materials, grinding balls and ball-milling medium is 1:5:1.4, wherein the ball-milling medium is anhydrous ethanol and deionized water with a mass ratio of 6:4; the ball-milling time is 10-14 h.

[0014] Preferably, the pre-sintering conditions of S2 are as follows: sintering at 1100℃ in an air atmosphere for 4 h.

[0015] Preferably, in S4, the granulation conditions are as follows: adding a polyvinyl alcohol aqueous solution for granulation, and screening the ceramic powder after granulation through a 80-120 mesh screen.

[0016] Preferably, the polyvinyl alcohol aqueous solution comprises the following components: 8-17%wt of polyvinyl alcohol, 0.2%wt of citric acid, and the balance of water.

[0017] Preferably, in S5, the green body forming conditions are as follows: pressing into a cylindrical green body block with a diameter of 15 mm and a height of 8 mm under a pressure of 200 Mpa.

[0018] Preferably, in S5, the sintering conditions are as follows: heating at a rate of 0.5℃ / min to 700℃, holding for 3 h, then heating at a rate of 2℃ / min to 1100℃, then heating at a rate of 5℃ / min to 1280-1360℃, holding for 4 h, then cooling at a rate of 3℃ / min to 1000℃, then cooling at a rate of 5℃ / min to 700℃, and finally cooling to room temperature in the furnace.

[0019] In another aspect, the present application provides a new type of low dielectric gallium and germanium-based high quality factor microwave dielectric material prepared by the above-mentioned method, the key being that the dielectric constant ε of the material is 9.33-9.84, and the quality factor Qxf value is 150000-190000 GHz.

[0020] Beneficial effects: Compared with the prior art, the novel low-dielectric gallium and germanium-based high-quality factor microwave dielectric material prepared by the present invention not only has dielectric constant but also high quality factor. It can be used in various devices such as filters, resonators, and dielectric antennas, and ensures the stability of the devices, thus having broad market prospects.

[0021] Instruction manual illustrations

[0022] Figure 1 This is a scanning electron microscope image of the dielectric material of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0024] Example 1: Preparation of Low-Dielectric Gallium and Germanium-Based High-Quality Factor Microwave Dielectric Materials

[0025] (1) Ga2O3, GeO2, and MgO are synthesized using a solid-state synthesis method according to their molecular formula Mg2Ga4GeO 10 Weigh and prepare the ingredients;

[0026] (2) The raw materials weighed in step (1), the agate grinding ball, the mixture of anhydrous ethanol and deionized water, wherein the ratio of anhydrous ethanol to deionized water is 6:4, are placed in the agate grinding jar at a mass ratio of 1:5:1.4. The mixture is ball-milled for 12 hours. The resulting slurry is then dried and sieved.

[0027] (3) The powder obtained in step (2) is pre-fired in air at a sintering temperature of 1100℃ for 4 hours;

[0028] (4) The powder obtained in step (3), the agate grinding ball, the mixture of anhydrous ethanol and deionized water are ball-milled and mixed for 12 hours at a mass ratio of 1:5:1.4, then dried and passed through a 120-mesh sieve, wherein the ratio of anhydrous ethanol to deionized water is 6:4.

[0029] (5) The powder obtained in step (4) is added to the polyvinyl alcohol aqueous solution for granulation. After mixing evenly, it is first passed through an 80-mesh sieve and then through a 120-mesh sieve to obtain a uniform powder. The polyvinyl alcohol aqueous solution includes the following components: 8-17% wt of polyvinyl alcohol, 0.2% wt of citric acid, and the balance water.

[0030] (6) The powder obtained in step (5) is dry-pressed into a cylinder with a diameter of 15 mm and a height of 8 mm under a pressure of 200 MPa.

[0031] (7) Put the cylinder obtained in step (6) on a crucible, and then put the crucible into a sintering furnace, and heat at a rate of 0.5°C / min to 700°C, keep for 3 hours to remove polyvinyl alcohol, then heat at a rate of 2°C / min to 1100°C, then heat at a rate of 5°C / min to 1280°C, keep for 4 hours, then heat at a rate of 3°C / min to 1000°C, then heat at a rate of 5°C / min to 700°C, and then cool to room temperature, to obtain a ceramic microwave dielectric material.

[0032] Performance test: dielectric constant is 9.33, and quality factor is 151023 GHz.

[0033] Preparation of low-dielectric gallium and germanium-based high-quality factor microwave dielectric material

[0034] (1) Ga2O3, GeO2, MgO are weighed and prepared according to the molecular formula Mg2Ga4GeO 10

[0035] (2) Put the weighed raw materials in step (1), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 into an agate ball mill tank, and mix for 12 hours. Dry the obtained slurry and sieve;

[0036] (3) Sinter the powder obtained in step (2) at a sintering temperature of 1100°C in air for 4 hours;

[0037] (4) Ball mill mix the powder obtained in step (3), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 for 12 hours, and then dry and sieve through a 120 mesh screen;

[0038] (5) Add the powder obtained in step (4) to a polyvinyl alcohol aqueous solution, mix uniformly, and then sieve through an 80 mesh screen and then a 120 mesh screen to obtain uniform powder; the polyvinyl alcohol aqueous solution comprises the following components: 8-17%wt polyvinyl alcohol, 0.2%wt citric acid, and the balance water;

[0039] (6) Dry-press the powder obtained in step (5) to obtain a cylinder with a diameter of 15 mm and a height of 8 mm under a pressure of 200 MPa.

[0040] ​(7) Put the cylinder obtained in step (6) on a crucible, and then put the crucible into a sintering furnace, and heat at a rate of 0.5°C / min to 700°C, keep for 3 hours to remove polyvinyl alcohol, then heat at a rate of 2°C / min to 1100°C, and then heat at a rate of 5°C / min to 1300°C, keep for 4 hours, then heat at a rate of 3°C / min to 1000°C, and then heat at a rate of 5°C / min to 700°C, and then cool to room temperature in the furnace, to obtain the ceramic microwave dielectric material.

[0041] Performance test: dielectric constant is 9.46, and quality factor is 167431 GHz.

[0042] Preparation of low-dielectric gallium and germanium-based high-quality factor microwave dielectric material

[0043] (1) Ga2O3, GeO2, MgO are weighed and prepared according to their molecular formula Mg2Ga4GeO 10

[0044] (2) Put the weighed raw materials in step (1), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 into an agate ball mill tank, and mix for 12 hours. Dry the obtained slurry and sieve;

[0045] (3) Sinter the powder obtained in step (2) at a sintering temperature of 1100°C in air for 4 hours;

[0046] (4) Ball mill mix the powder obtained in step (3), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 for 12 hours, and then dry and sieve through a 120 mesh screen;

[0047] (5) Add the powder obtained in step (4) to a polyvinyl alcohol aqueous solution, mix uniformly, and then sieve through an 80 mesh screen and then a 120 mesh screen to obtain uniform powder; the polyvinyl alcohol aqueous solution comprises the following components: 8-17%wt polyvinyl alcohol, 0.2%wt citric acid, and the balance water;

[0048] (6) Dry-press the powder obtained in step (5) to obtain a cylinder with a diameter of 15 mm and a height of 8 mm under a pressure of 200 MPa.

[0049] ​(7) Put the cylinder obtained in step (6) on a crucible, and then put the crucible into a sintering furnace, and heat at a rate of 0.5°C / min to 700°C, keep for 3 hours to remove polyvinyl alcohol, then heat at a rate of 2°C / min to 1100°C, then heat at a rate of 5°C / min to 1320°C, keep for 4 hours, then heat at a rate of 3°C / min to 1000°C, then heat at a rate of 5°C / min to 700°C, and then cool to room temperature in the furnace, to obtain a ceramic microwave dielectric material.

[0050] Performance test: dielectric constant is 9.75, and quality factor is 173374 GHz.

[0051] Preparation of low-dielectric gallium and germanium-based high-quality factor microwave dielectric material

[0052] (1) Ga2O3, GeO2, MgO are weighed and prepared according to the molecular formula Mg2Ga4GeO 10

[0053] (2) Put the weighed raw materials in step (1), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 into an agate ball mill tank, and mix for 12 hours. Dry the obtained slurry and sieve;

[0054] (3) Sinter the powder obtained in step (2) at a sintering temperature of 1100°C in air for 4 hours;

[0055] (4) Ball mill mix the powder obtained in step (3), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 for 12 hours, and then dry and sieve through a 120 mesh screen;

[0056] (5) Add the powder obtained in step (4) to a polyvinyl alcohol aqueous solution, mix uniformly, and then sieve through an 80 mesh screen and then a 120 mesh screen to obtain uniform powder; the polyvinyl alcohol aqueous solution comprises the following components: 8-17%wt polyvinyl alcohol, 0.2%wt citric acid, and the balance water;

[0057] (6) Dry-press the powder obtained in step (5) to obtain a cylinder with a diameter of 15 mm and a height of 8 mm under a pressure of 200 MPa.

[0058] ​(7) Put the cylinder obtained in step (6) on a crucible, and then put the crucible into a sintering furnace, and heat at a rate of 0.5°C / min to 700°C, keep for 3 hours to remove polyvinyl alcohol, then heat at a rate of 2°C / min to 1100°C, and then heat at a rate of 5°C / min to 1340°C, keep for 4 hours, then heat at a rate of 3°C / min to 1000°C, and then heat at a rate of 5°C / min to 700°C, and then cool to room temperature in the furnace, to obtain the ceramic microwave dielectric material.

[0059] Performance test: dielectric constant is 9.84, and quality factor is 185213 GHz.

[0060] Example 5 Preparation of low-dielectric gallium and germanium-based high-quality factor microwave dielectric material

[0061] (1) Ga2O3, GeO2, MgO are weighed and prepared according to the molecular formula Mg2Ga4GeO 10

[0062] (2) Put the weighed raw materials in step (1), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 into an agate ball mill tank, and mix for 12 hours. Dry the obtained slurry and sieve;

[0063] (3) Sinter the powder obtained in step (2) at a sintering temperature of 1100°C in air for 4 hours;

[0064] (4) Ball mill mix the powder obtained in step (3), agate grinding balls, a mixture of anhydrous ethanol and deionized water (anhydrous ethanol: deionized water = 6:4) in a mass ratio of 1:5:1.4 for 12 hours, and then dry and sieve through a 120 mesh screen;

[0065] (5) Add the powder obtained in step (4) to a polyvinyl alcohol aqueous solution, mix uniformly, and then sieve through an 80 mesh screen and then a 120 mesh screen to obtain uniform powder; the polyvinyl alcohol aqueous solution comprises the following components: 8-17%wt polyvinyl alcohol, 0.2%wt citric acid, and the balance water;

[0066] (6) Dry-press the powder obtained in step (5) to obtain a cylinder with a diameter of 15 mm and a height of 8 mm under a pressure of 200 MPa.

[0067] ​(7) The cylinder obtained in step (6) is placed on a crucible, and the crucible is placed in a sintering furnace, and heated to 700°C at a rate of 0.5°C / min, and kept for 3 hours to remove polyvinyl alcohol, and then heated to 1100°C at a rate of 2°C / min, and then heated to 1360°C at a rate of 5°C / min, and kept for 4 hours, and then cooled to 1000°C at a rate of 3°C / min, and then cooled to 700°C at a rate of 5°C / min, and then cooled to room temperature in the furnace, to obtain a microwave dielectric material which is sintered.

[0068] Performance test: dielectric constant is 9.81, and quality factor is 179267 GHz.

[0069] Finally, it should be noted that the above description is only the preferred embodiments of the present application, and those skilled in the art can make various similar expressions under the inspiration of the present application without departing from the purpose and claims of the present application, and such changes fall within the protection scope of the present application.

Claims

1. A method for preparing a low dielectric gallium, germanium based high quality factor microwave dielectric material, characterized in that, The method comprises the following steps: S1. After Ga2O3, GeO2, MgO are mixed in proportion, put into a ball mill for one-time ball milling, wherein Ga2O3, GeO2, MgO are in the formula Mg2Ga4GeO 10 Carry out weighing and batching; S2. Drying the ball-mixed material of S1, and sintering at 1100℃ in air for 4h to obtain a pre-sintered ceramic powder; S3. Putting the pre-sintered ceramic powder of S2 into a ball mill for secondary ball-milling; S4. Drying and granulating the ball-mixed material of S3 to obtain a ceramic powder with a particle size of 80-120 mesh; S5. Preparing a green body from the ceramic powder of S4 and sintering to obtain a finished product, wherein the sintering conditions are as follows: heating at a rate of 0.5℃ / min to 700℃, maintaining for 3h, then heating at a rate of 2℃ / min to 1100℃, then heating at a rate of 5℃ / min to 1280-1360℃, maintaining for 4h, then cooling at a rate of 3℃ / min to 1000℃, then cooling at a rate of 5℃ / min to 700℃, and finally cooling to room temperature in the furnace.

2. The method of claim 1, wherein the low dielectric gallium, germanium based high quality factor microwave dielectric material is prepared by the steps of: preparing a solution by dissolving gallium (Ga), germanium (Ge), and a fluxing agent in a solvent; and crystallizing the solution to obtain a low dielectric gallium, germanium based high quality factor microwave dielectric material. The ball-milling conditions of S2 and S3 are as follows: the mass ratio of raw materials, grinding balls and ball-milling medium is 1:5:1.4, wherein the ball-milling medium is anhydrous ethanol and deionized water with a mass ratio of 6:4; the ball-milling time is 10-14h.

3. The method of claim 1, wherein the low dielectric gallium, germanium based high quality factor microwave dielectric material is prepared by the steps of: preparing a solution by dissolving gallium (Ga), germanium (Ge), and a fluxing agent in a solvent; and crystallizing the solution to obtain a low dielectric gallium, germanium based high quality factor microwave dielectric material. In S4, the granulation conditions are as follows: granulating by adding a polyvinyl alcohol aqueous solution, and screening the ceramic powder after granulation through a 80-120 mesh screen.

4. The method of claim 3, wherein the low dielectric gallium, germanium based high quality factor microwave dielectric material is prepared by the steps of: preparing a solution by dissolving gallium (Ga), germanium (Ge), and a fluxing agent in a solvent; and crystallizing the solution to obtain a low dielectric gallium, germanium based high quality factor microwave dielectric material. The polyvinyl alcohol aqueous solution comprises the following components: 8-17wt% of polyvinyl alcohol, 0.2wt% of citric acid, and the balance of water.

5. The method of claim 1, wherein the low dielectric gallium, germanium based high quality factor microwave dielectric material is prepared by the steps of: preparing a solution by dissolving gallium (Ga), germanium (Ge), and a fluxing agent in a solvent; and crystallizing the solution to obtain a low dielectric gallium, germanium based high quality factor microwave dielectric material. In S5, the green body preparation conditions are as follows: pressing into a cylindrical green body block with a diameter of 15mm and a height of 8mm under a pressure of 200Mpa.

6. A low dielectric gallium, germanium based high quality factor microwave dielectric material prepared by the method of any one of claims 1 to 5, characterized in that: The dielectric constant εr of the material is 9.33-9.84, and the quality factor Qxf value is 150000-190000GHz.

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