Low ferromagnetic resonance linewidth and high dielectric constant ferrite thick film material and preparation method thereof

Abstract

The present invention belongs to the field of electronic materials and provides a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant and a preparation method thereof. Firstly, a YIG ferrite material substituted with Bi-Ca-Sn-Zr ions is used as a basis, and a YIG ferrite is prepared by a traditional solid phase sintering method. 2.0‑x Bi 1.0 Ca x Fe 5‑2x Sn x Zr x O 12 Ferrite materials, Bi-Ca ion substitution in the composition can increase the dielectric constant of the material, making the material have high dielectric constant characteristics (dielectric constant ε' ≥ 20) in the frequency band of 1MHz to 500MHz. Sn-Zr ion substitution in the composition promotes the material to reduce magnetocrystalline anisotropy and loss, and improves the influence of internal stress and pores on the ferromagnetic resonance linewidth of the material, reducing the magnetic loss of the ferrite in the high frequency band, so that the material has a lower ferromagnetic resonance linewidth (ΔH ≤ 100Oe); however, the ferrite thick film material is prepared by a spinning process, and annealing and forming under magnetic field orientation to obtain a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant, which meets the needs of microwave devices.

Description

Technical Field

[0001] The present invention belongs to the field of electronic materials, and specifically provides a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant and a preparation method thereof. Background Art

[0002] With the rapid development of high-frequency wireless communications and big data, microwave high-frequency devices for wireless communications have become a key component. Driven by the demands of integrated microwave systems, microwave devices are increasingly demanding high integration, chip-based design, and high performance. Research on microwave device substrate materials and the design of miniaturized microwave devices have become internationally recognized topics. The use of materials with low ferromagnetic resonance linewidth and high dielectric constant as microwave device substrates is driven by the influence of these materials' electromagnetic parameters on device size and performance. As transmission efficiency increases, the transmission loss requirements for microwave devices are becoming increasingly lower. From a fundamental material perspective, the requirements for ferromagnetic resonance linewidth are becoming increasingly stringent. Lower ferromagnetic resonance linewidths enable microwave devices to achieve lower microwave losses and higher transmission efficiency. High dielectric constants meet the application requirements of miniaturized microwave devices. Furthermore, to meet the integration and space requirements of microwave systems, devices are increasingly being developed in a chip-based format.

[0003] For substrate materials with low ferromagnetic resonance linewidth and high dielectric constant, many studies have focused on yttrium iron garnet (Y3Fe5O 12, YIG) materials; for example, the patent document with patent number 202110239907.3 discloses a high dielectric constant microwave ferrite material and its preparation method and application, which adopts Sn-Al-Sm collaborative ion substitution to improve the dielectric constant of YIG ferrite (above 18) while maintaining good magnetic properties, and adopts Bi element ion substitution to maintain large grain size and reduce the ferromagnetic resonance line width; for example, the patent document with patent number 202210164462.1 discloses a medium saturation magnetization intensity power type high dielectric constant garnet material and its preparation method , using Bi-Ca-Dy-Zr-Sn-In-Sb and other ions to regulate the dielectric constant of YIG materials (dielectric constant is 25-26), while maintaining good magnetic properties such as saturation magnetization; for example, the patent document with patent number 202110324952.9 discloses a low-temperature sintered YIG gyromagnetic ferrite material and its preparation method, using Bi-Zn-V plasma to regulate the sintering temperature and magnetic properties of YIG, and obtaining a YIG material sintered below 960°C, which has certain saturation magnetization, low coercive force and low loss characteristics. However, the YIG materials prepared in the above patent documents are all YIG powders. In order to meet the high integration requirements of microwave systems, the present invention is based on ferromagnetic resonance linewidth and high dielectric constant ferrite, and forms thick film materials through a spinning process to further meet the higher demands of microwave devices. Summary of the Invention

[0004] The purpose of the present invention is to provide a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant and a preparation method thereof. First, Y3Fe5O 12 (YIG) ferrite material is used as the basis, and YIG is prepared by traditional solid phase sintering method according to the stoichiometric ratio. 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 Ferrite materials, Bi-Ca ion substitution in the composition can improve the dielectric constant of the material, making the material have high dielectric constant characteristics (dielectric constant ε' ≥ 20) in the frequency band of 1MHz to 500MHz. Sn-Zr ion substitution in the composition promotes the material to reduce magnetocrystalline anisotropy and loss, and improves the influence of internal stress and pores on the ferromagnetic resonance linewidth of the material, thereby reducing the magnetic loss of the ferrite in the high frequency band as a whole, so that the material has a lower ferromagnetic resonance linewidth (ΔH ≤ 100Oe); however, a spinning process is used to prepare a thick film of ferrite material to prepare a ferrite thick film material with uniform thickness; finally, a magnetic field orientation annealing molding is used to prepare a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant, which meets the needs of microwave devices.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A ferrite thick film material with low ferromagnetic resonance line width and high dielectric constant, characterized in that the ferrite thick film material is composed of Y 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 The ferrite material is formed on a carrier substrate through a spinning process and is annealed and formed under magnetic field orientation, wherein x=0.1-0.5.

[0007] Furthermore, the thickness of the ferrite thick film material is 10-50 μm.

[0008] Furthermore, the method for preparing the ferromagnetic resonance linewidth high dielectric constant ferrite thick film material is characterized by comprising the following steps:

[0009] Step 1. Follow Y 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 The reactants of the ferrite material are weighed in a stoichiometric ratio, wherein the reactants are: yttrium oxide (Y2O3), bismuth oxide (Bi2O3), calcium carbonate (CaCO3), tin dioxide (SnO2), zirconium oxide (ZrO2) and ferric oxide (Fe2O3), wherein x = 0.1 to 0.5;

[0010] Step 2: Prepare Y by solid phase sintering the raw materials of step 1 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 Ferrite powder, the sintering temperature of the solid phase sintering method is 900℃~1100℃, and the holding time is 1~6 hours;

[0011] Step 3: Mixing the ferrite powder obtained in step 2 with toluene, ethanol, a dispersant, and a plasticizer to form a slurry; wherein the mass ratio of toluene: ethanol: dispersant: plasticizer: ferrite powder is 4:6:1:1:15, and stirring for 3 to 5 hours to obtain a slurry; then weighing 8 to 12 wt% of the ferrite powder and adding a PVA adhesive to the slurry, and continuing to stir for 1 hour to obtain a slurry;

[0012] Step 4, placing the slurry obtained in step 3 in a slurry spinning machine, using a silicon substrate, a glass substrate or a silicon dioxide substrate as a carrier, and spinning the coating on the carrier for slurry spinning. The speed of the slurry spinning machine is 500 to 1500 rpm. After 20-40 seconds of slurry spinning, the sample is removed and heat treated. The heat treatment is specifically kept at 250°C for 10 to 15 minutes and kept at 800°C to 1000°C for 10 minutes. After taking out the sample, the slurry is slurried again, and the process is repeated several times to obtain a preliminary sample of the ferrite thick film.

[0013] Step 5: anneal the preliminary sample of the ferrite thick film obtained in step 4 under a magnetic field, specifically: set the magnetic field to 300-1000 Oe, keep it at 600°C-700°C for 0.5-3 hours under nitrogen protection, and obtain a low ferromagnetic resonance linewidth high dielectric ferrite thick film material.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The low ferromagnetic resonance line width and high dielectric constant ferrite thick film material of the present invention is Y 2.0-x Bi 1.0 Ca x Fe 5- 2x Sn x Zr x O 12 Ferrite is the basic material. Through the design of material components, the ferromagnetic resonance line width and dielectric constant of the material can be adjusted to meet the application requirements of microwave devices.

[0016] 2. The low ferromagnetic resonance linewidth and high dielectric constant ferrite thick film material of the present invention has a high dielectric constant characteristic (dielectric constant ε' ≥ 20) in the frequency band of 1 MHz to 500 MHz and a low ferromagnetic resonance linewidth (ΔH ≤ 100 Oe);

[0017] 3. The low ferromagnetic resonance linewidth and high dielectric constant ferrite thick film material in the present invention is used as a substrate for microwave devices. Based on the characteristics of low ferromagnetic resonance linewidth and high dielectric constant, compared with ordinary powder substrates, it has the advantages of small size and large bias magnetic field, which can improve the high transmission efficiency of microwave devices and provide new materials for the application of high-frequency and integrated small-size communication equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of the preparation method of the low ferromagnetic resonance linewidth high dielectric ferrite thick film material of the present invention.

[0019] Figure 2 These are XRD test patterns of the low ferromagnetic resonance linewidth and high dielectric ferrite thick film materials of Examples 1, 2 and 3 of the present invention.

[0020] Figure 3 This is a dielectric constant test diagram of the low ferromagnetic resonance linewidth and high dielectric ferrite thick film material of Examples 1, 2 and 3 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions 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.

[0022] Example 1

[0023] This embodiment provides a low ferromagnetic resonance linewidth high dielectric ferrite thick film material, and its preparation method is as follows Figure 1 As shown, the specific steps include:

[0024] Step 1. Follow Y 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 The reactants were weighed in the stoichiometric ratio of ferrite, with x = 0.1, and yttrium oxide (Y2O3) 10.73 g, bismuth oxide (Bi2O3) 11.65 g, calcium carbonate (CaCO3) 0.5 g, tin dioxide (SnO2) 0.75 g, zirconium oxide (ZrO2) 0.62 g, and ferric oxide (Fe2O3) 19.16 g were weighed;

[0025] Step 2: Prepare ferrite powder by solid phase sintering method using the raw materials of step 1, adopt conventional ball milling method, sintering temperature is 1030℃, holding time is 3 hours, obtain Y 1.9 Bi 1.0 Ca 0.1 Fe 4.8 Sn 0.1 Zr 0.1 O 12 Ferrite powder;

[0026] Step 3, the powder obtained in step 2 is mixed with toluene, ethanol, a dispersant and a plasticizer to form a slurry, wherein the mass ratio of toluene: ethanol: dispersant (M1135 type): plasticizer (M1125 type): ferrite powder is 4:6:1:1:15, and the slurry is obtained by stirring for 4 hours; then, 10 wt% of the mass ratio of B74001 type PVA adhesive of the ferrite component is weighed and added to the above slurry, and stirring is continued for 1 hour to obtain a slurry;

[0027] Step 4, the step 3 obtained by throwing glue slurry is placed in a throwing glue machine, using a silicon substrate, a glass substrate or a silicon dioxide substrate as a carrier, and spin coating is performed to throw glue. The spinning glue machine speed is 800 rpm. After throwing glue for 30 seconds, the sample is removed and heat treated. The heat treatment is kept at 250 ° C for 12 minutes and kept at 900 ° C for 10 minutes. The sample is taken out for secondary throwing glue. The above parameters are consistent. The method of throwing glue-heat treatment is repeated three times to obtain a preliminary sample of ferrite thick film.

[0028] Step 5: Anneal the preliminary sample of the ferrite thick film obtained in step 4 in a magnetic field, under nitrogen protection, with a magnetic field of 800 Oe, and keep it at 650°C for 1 hour to obtain a ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant with a thickness of 30 μm.

[0029] Example 2

[0030] The difference between this embodiment and embodiment 1 is that the process of step 1 is: 2.0-x Bi 1.0 Ca x Fe 5- 2x Sn x Zr x O 12 The reactants are weighed in the stoichiometric ratio of ferrite, and x=0.3 is selected. 9.60g of yttrium oxide (Y2O3), 11.65g of bismuth oxide (Bi2O3), 1.5g of calcium carbonate (CaCO3), 2.26g of tin dioxide (SnO2), 1.85g of zirconium oxide (ZrO2) and 17.57g of ferrite trioxide (Fe2O3) are weighed to prepare the ferrite material. The remaining steps are the same as in Example 1.

[0031] Example 3

[0032] The difference between this embodiment and embodiment 1 is that the process of step 1 is: 2.0-x Bi 1.0 Ca x Fe 5- 2x Sn x Zr x O 12 The reactants are weighed in the stoichiometric ratio of ferrite, and x=0.5 is selected. 8.47g of yttrium oxide (Y2O3), 11.65g of bismuth oxide (Bi2O3), 2.5g of calcium carbonate (CaCO3), 3.77g of tin dioxide (SnO2), 3.08g of zirconium oxide (ZrO2) and 15.97g of ferrite trioxide (Fe2O3) are weighed to prepare the ferrite material. The remaining steps are the same as in Example 1.

[0033] The ferrite thick film materials prepared in Example 1, Example 2 and Example 3 were subjected to XRD testing. The XRD patterns are shown in FIG. Figure 2 As shown, Figure 2 (a), (b), and (c) correspond to Examples 1, 2, and 3, respectively. As can be seen from the figures, the ferrite material prepared by the present invention has a single phase without the presence of other impurity phases, and maintains the garnet structure of the YIG ferrite.

[0034] The ferrite thick film materials prepared in Example 1, Example 2 and Example 3 were tested for ferromagnetic resonance line width and dielectric constant. The ferromagnetic resonance line width test results are shown in Table 1, and the dielectric constant test results are shown in Table 2. Figure 3 As shown, Figure 3 (a), (b), and (c) correspond to Examples 1, 2, and 3, respectively. The ferromagnetic resonance linewidth of the ferrite thick film material was measured at 9.56 GHz using a waveguide resonant cavity method, and the dielectric constant was measured at 1 MHz to 1 GHz. The results show that the ferrite thick film material provided by the present invention has a low ferromagnetic resonance linewidth and a high dielectric constant, making it suitable as a substrate material for microwave devices.

[0035] Table 1

[0036] sample Example 1 Example 2 Example 3 Ferromagnetic resonance linewidth ΔH=87.85Oe ΔH=86.37Oe ΔH=83.41Oe

[0037] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A ferrite thick film material with low ferromagnetic resonance linewidth and high dielectric constant, characterized in that: The ferrite thick film material is made of Y 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 The ferrite material is formed on a carrier substrate by a spinning process and annealed under a magnetic field orientation, wherein x=0.1-0.5; The specific glue throwing process is: Ferrite powder is mixed with toluene, ethanol, dispersant and plasticizer to form a slurry; wherein the mass ratio of toluene: ethanol: dispersant: plasticizer: ferrite powder is 4:6:1:1:15, and the slurry is obtained after stirring for 3 to 5 hours; then, 8 to 12 wt% of the ferrite powder weight of PVA adhesive is weighed and added to the slurry, and stirring is continued for 1 hour to obtain a slurry; The slurry is placed in a slurry spinning machine, and a silicon substrate, a glass substrate or a silicon dioxide substrate is used as a carrier, and the slurry is spin-coated on the carrier for slurry spinning. The speed of the slurry spinning machine is 500 to 1500 revolutions per minute. After slurry spinning for 20 to 40 seconds, the sample is removed and heat-treated. The heat treatment is specifically heat-insulating at 250° C. for 10 to 15 minutes and heat-insulating at 800° C. to 1000° C. for 10 minutes. After the sample is removed, the slurry is slurried again, and the process is repeated multiple times to obtain a preliminary sample of the ferrite thick film. The annealing molding under magnetic field orientation is specifically as follows: The magnetic field is set to 300-1000 Oe, and the material is kept at 600-700° C. for 0.5-3 hours under nitrogen protection to obtain a low ferromagnetic resonance linewidth and high dielectric ferrite thick film material.

2. The low ferromagnetic resonance linewidth and high dielectric constant ferrite thick film material according to claim 1, characterized in that: The thickness of the ferrite thick film material is 10-50 μm.

3. The method for preparing the ferromagnetic resonance linewidth high dielectric constant ferrite thick film material according to claim 1, characterized in that: The following steps are involved: Step 1. Follow Y 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 The reactants of the ferrite material are weighed in a stoichiometric ratio, wherein the reactants are: yttrium oxide (Y2O3), bismuth oxide (Bi2O3), calcium carbonate (CaCO3), tin dioxide (SnO2), zirconium oxide (ZrO2) and ferric oxide (Fe2O3), wherein x = 0.1 to 0.5; Step 2: Prepare Y by solid phase sintering the raw materials of step 1 2.0-x Bi 1.0 Ca x Fe 5-2x Sn x Zr x O 12 Ferrite powder, the sintering temperature of the solid phase sintering method is 900℃~1100℃, and the holding time is 1~6 hours; Step 3: Mixing the ferrite powder obtained in step 2 with toluene, ethanol, a dispersant, and a plasticizer to form a slurry; wherein the mass ratio of toluene: ethanol: dispersant: plasticizer: ferrite powder is 4:6:1:1:15, and stirring for 3 to 5 hours to obtain a slurry; then weighing 8 to 12 wt% of the ferrite powder and adding a PVA adhesive to the slurry, and continuing to stir for 1 hour to obtain a slurry; Step 4, placing the slurry obtained in step 3 in a slurry spinning machine, using a silicon substrate, a glass substrate or a silicon dioxide substrate as a carrier, and spinning the coating on the carrier for slurry spinning. The speed of the slurry spinning machine is 500 to 1500 rpm. After 20-40 seconds of slurry spinning, the sample is removed and heat treated. The heat treatment is specifically kept at 250°C for 10 to 15 minutes and kept at 800°C to 1000°C for 10 minutes. After taking out the sample, the slurry is slurried again, and the process is repeated several times to obtain a preliminary sample of the ferrite thick film. Step 5: anneal the preliminary sample of the ferrite thick film obtained in step 4 under a magnetic field, specifically: set the magnetic field to 300-1000 Oe, keep it at 600°C-700°C for 0.5-3 hours under nitrogen protection, and obtain a low ferromagnetic resonance linewidth high dielectric ferrite thick film material.

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