LiZnFe ferrite materials with high saturation magnetization Ms and low ferromagnetic resonance linewidth, their preparation methods and applications

Abstract

This invention relates to the field of ferrite materials technology, and discloses a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth. It utilizes a combination of main and auxiliary materials. The main materials are Li₂CO₃, Fe₂O₃, ZnO, MnCO₃, and TiO₂, with a molar ratio of 13-14:75-77:6-7.5:1.5-2.8:0.55-0.95. The auxiliary materials are CaCO₃ and Bi₂O₃, added at 0.5-2 wt% and 0.3-1.8 wt% of the total main materials, respectively. This invention solves the problems of insufficient magnetization Ms and low resonance linewidth in existing technologies by addressing both the formulation and preparation process, ensuring the material performance meets the requirements. The Ms can reach 5000 Gs, and the resonance linewidth can be within 200 Oe.

Description

Technical Field

[0001] This invention relates to a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth, its preparation method and application, belonging to the field of ferrite material technology. Background Technology

[0002] Ferrite is a ferromagnetic metal oxide. Electrically, ferrite has a much higher resistivity than metallic and alloy magnetic materials, and also possesses high dielectric properties. Ferrite's magnetic properties are further demonstrated by its high permeability at high frequencies. Therefore, ferrite has become a widely used non-metallic magnetic material in high-frequency, low-power applications. However, because ferrite stores relatively low magnetic energy per unit volume and has a low saturation magnetization (typically only 1 / 3 to 1 / 5 that of pure iron), its application in low-frequency, high-power applications requiring high magnetic energy density is limited.

[0003] Circulators, isolators, and other ferromagnetic ferrite devices are crucial components of electronic systems in radar, satellite, and communication equipment, directly impacting the performance and reliability of the entire system. Ferromagnetic ferrite materials are the core of these devices; their bandwidth, insertion loss, isolation, and high power handling capacity largely depend on the performance of the ferromagnetic ferrite material. Therefore, against the backdrop of accelerated domestic production and a maturing market for specialized communication equipment, the demand for specialized circulators / isolators is robust, and the RF front-end device market will continue to grow rapidly. Simultaneously, ferromagnetic ferrite materials are key raw materials for various RF front-end devices, and their properties determine the performance of the final product. Driven by the RF front-end device market, the demand for ferromagnetic ferrite materials will increase rapidly, and the industry will maintain rapid growth.

[0004] A search revealed that CN201410064998.1 describes a lithium ferrite material composed of main components and additives. The main components consist of Fe2O3, Li2CO3, TiO2, ZnO, MnCO3, and Bi2O3. The preparation method involves ball milling and drying each component, followed by calcination. The calcined components are then ball milled again and granulated using a spray granulator. The resulting granules are pressed into shape using a dry powder press, then pressed into blanks using an isostatic press. Finally, the blanks are sintered in a furnace. The lithium ferrite material for phase shifters prepared using this method exhibits excellent properties such as low coercivity, low dielectric loss, and high densification. Its saturation magnetization is 2200-2600 Gs, and its saturation magnetization Ms is a crucial magnetic parameter for permanent magnet materials. Higher Ms is generally preferred for permanent magnet materials. The saturation magnetization is determined by the number of magnetic atoms, atomic magnetic moments, and temperature of the constituent materials.

[0005] Therefore, the invention of a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is of great significance and market value in practical use and production. Summary of the Invention

[0006] This invention addresses the aforementioned problems by proposing a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth, along with its preparation method. This solves the problems of insufficient magnetization Ms and low resonance linewidth in existing technologies, and improves the material performance by addressing both the formulation and the preparation process.

[0007] The technical means adopted by this invention to solve the above problems is as follows: A LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is disclosed, which combines main materials and auxiliary materials. The main materials are Li2CO3, Fe2O3, ZnO, MnCO3, and TiO2, with a molar percentage (mol%) of 13-14:75-77:6-7.5:1.5-2.8:0.55-0.95. The auxiliary materials are CaCO3 and Bi2O3, with addition amounts of 0.5-2wt% and 0.3-1.8wt% of the total main materials, respectively.

[0008] This invention relates to a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth. The material employs an innovative composition, combining various metal oxides and carbonates as the main components, with Fe2O3 as the primary element. It exhibits a honeycomb crystal structure, strong chemical reactivity, well-developed solid-state reaction, and low levels of chemical impurities and soluble salts. It is applicable to the solid-state reaction of oxides, hydroxides, carbonates, or oxalates of other metal elements to form ferrite magnetic materials. The addition of ZnO increases the initial permeability, lowers the saturation magnetic induction Bs and Curie temperature, and the ZnO in this formulation exhibits excellent frequency characteristics. TiO2 reduces lattice defects, prevents porosity formation, and reduces stress near grain boundaries, thus reducing material loss. The appropriate addition of Li2CO3 contributes to obtaining fine, uniform grains, reducing power loss, and shifting the temperature profile towards higher temperatures. 2+ It can replace Fe at the a-site of the octahedron 3+ Reduce the impact of conductive ions on Fe 2+ -Fe 3+ This improves grain resistivity and reduces eddy current loss. In the auxiliary materials, CaCO3 forms a high-resistivity layer at the grain boundaries, increasing the resistivity of the grain boundaries and reducing eddy current loss; Bi2O3 can also form a liquid-phase sintering layer, lowering the sintering temperature, increasing the sintering density, and reducing the porosity between grains and grain boundaries. In summary, the formulation of this invention can effectively ensure the high saturation magnetization Ms of the ferrite material.

[0009] Furthermore, the auxiliary material CaCO3 is nano-light calcium carbonate with a particle size of 100-300 nanometers. The principle and advantages of choosing nano-light calcium carbonate are as follows: the nano-calcium carbonate auxiliary material is located at the grain boundaries, and its fine nanoparticle size can increase the activation energy, forming a grain boundary layer with high resistivity, which is beneficial to reducing ferrite loss. The particle radius of nanomaterials is very small; for the same amount of impurities of different particle sizes, the total volume of nanomaterials is larger, making it easier to disperse uniformly into the ferrite material, which helps the ferrite material's grains grow uniformly. Therefore, adding nano-auxiliary materials can yield high-performance LiZnFe ferrite with uniform grains.

[0010] Another objective of this invention is to provide a method for preparing a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth, comprising the following steps:

[0011] S1. Pre-calcination of Mixed Materials: First, the main component materials are prepared and wet-mixed evenly. The water-to-grinding ball ratio is 4-6:1:0.8-1.2. After mixing for 4-12 hours, the mixture is discharged and dried at 160℃-200℃, then sieved. Next, the pre-calcination temperature is increased to 800℃-950℃ at a heating rate of 2℃ / min-4℃ / min, and the holding time is 2-6 hours. If the temperature exceeds 950℃, the ferrite will be over-calcined, making it difficult to grind to the required particle size later. If the pre-calcination temperature is below 800℃, preliminary crystallization will not be achieved, leading to deformation during subsequent sintering. Excessive pre-calcination time will cause rapid grain growth, resulting in uneven grain size; conversely, insufficient time will result in insignificant grain growth and failure of preliminary crystallization, both affecting subsequent sintering.

[0012] S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind for 12h-24h until the particle size reaches 1.5±0.2μm. Then add 7wt%-10wt% of binder, which is the total amount of main materials and auxiliary materials.

[0013] S3. Spray granulation: The wet-mixed mixture is placed in an atomizing device at 150℃-270℃ for spray granulation;

[0014] S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape. The sieve mesh size is 50-260 mesh, the forming pressure is 120Mpa-200Mpa, and the holding time is 40s-80s.

[0015] S5. Low-temperature sintering: Remove the binder in the low-temperature section, raise the temperature from 20℃ to 650℃ at a rate of 0.7℃ / min to 1.5℃ / min, then hold at 600℃ for 120min to 240min; raise the temperature to the highest temperature at a rate of 2℃ / min to 2.5℃ / min; sinter at 900℃ to 1000℃ for 240min to 600min, with a sintering pressure of 0.01MPa to 1MPa.

[0016] Furthermore, the grinding rate in step S1 is 200rpm-280rpm, and the grinding time is 10h-15h; the grinding rate in step S2 is 240rpm-300rpm, and the grinding time is 10h-15h.

[0017] Further, the adhesive in step S2 is an 8%-10% PVA glue. Polyvinyl alcohol (PVA) increases the viscosity of the glue. After adding PVA to the glue, its molecular chains interact with other components to form a three-dimensional network structure. This structure increases the viscosity of the glue, making it more viscous when applied or coated, thus improving its adhesive properties. PVA also promotes the adhesive properties of the glue. The PVA molecular chains in the glue have a certain polarity, allowing them to interact with many material surfaces through hydrogen bonds or other chemical bonds, thereby enhancing the adhesion between the glue and the adhered materials. In this way, the glue can better adhere to the surface of the bonded materials during the bonding process, improving the bond strength.

[0018] Furthermore, the particle size of the particulate material produced by spray granulation in step S3 is 60μm-200μm.

[0019] Another object of the present invention is to disclose the application of the above-mentioned LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth in high-frequency isolators / circulators.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention synthesizes a new LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth by using a combination of main formulation (Li2CO3, Fe2O3, ZnO, TiO2 and MnCO3) and auxiliary materials (CaCO3 and Bi2O3), employing a suitable pre-calcination temperature (800℃-950℃) and grinding process, and a relatively low sintering temperature (900℃-1000℃); its Ms can reach 5000Gs and its resonance linewidth can be within 200Oe.

[0022] 2. The synthesis method of this invention is novel. First, the main components are mixed uniformly. Then, a suitable pre-firing process is used in a conventional kiln at a temperature of 800℃-950℃ for 2-6 hours. Next, appropriate auxiliary materials are added and ground during batching, followed by the addition of a binder. The mixture is then spray-granulated into granules. These granules are dry-pressed into suitable shapes, and finally, a low-temperature sintering process is performed to prepare LiZnFe microwave ferrite with high saturation magnetization Ms and low ΔH. This method is suitable for commercial application. Attached Figure Description

[0023] Figure 1 This is a SEM image of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth described in Example 1.

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto.

[0026] Density was measured using the water displacement method, saturation magnetization Ms was measured using a magnetic balance, Curie temperature Tc was measured using a vibrating sample magnetometer, and saturation magnetic induction Bs, remanent magnetic induction Br, and coercivity He were measured using an SMT-600 hysteresis loop tester. The ferromagnetic resonance linewidth, dielectric constant, and dielectric loss of the material were tested according to GB / T9633-1998 "Test Methods for the Properties of Rotary Magnetite Ferrite Materials for Microwave Frequency Applications". Example 1

[0027] This embodiment uses the proportions of the components in Table 1, combining the main materials and auxiliary materials. Specifically, the preparation method of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is as follows:

[0028] S1. First, prepare the main component materials, wet mix them evenly, and grind the balls with a water ratio of 4:1:0.8. After mixing for 12 hours, discharge and dry the material at a temperature of 160℃-170℃. Then sieve the material and raise the pre-calcination temperature to 800℃ at a heating rate of 2℃ / min-3℃ / min. The holding time is 4 hours.

[0029] S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind them at a grinding rate of 240 rpm for 12 hours. When the particle size reaches 1.5 ± 0.2 μm, add 9 wt%-10 wt% of adhesive to the total amount of main materials and auxiliary materials. In this embodiment, the adhesive is preferably 8%-10% PVA glue.

[0030] S3. Spray granulation: At 150℃-180℃, the wet-mixed mixture is placed in an atomizing device for spray granulation. The particle size of the spray-granulated material is 60μm-70μm.

[0031] S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape. The sieve mesh size is 50-100 mesh, the forming pressure is 120Mpa-150Mpa, and the holding time is 40s-60s.

[0032] S5. Low-temperature sintering: Remove the binder in the low-temperature section, raise the temperature from 20℃ to 650℃ at a rate of 0.7℃ / min to 1.0℃ / min, hold at 600℃ for 120 to 180 min; then raise the temperature to the highest temperature at a rate of 2 to 2.5℃ / min; sinter at 1000℃ for 440 to 600 min, with a sintering pressure of 0.06 MPa to 1 MPa.

[0033] The LiZnFe ferrite material with high saturation magnetization (Ms) and low ferromagnetic resonance linewidth prepared using the method of this embodiment is shown in Table 2 for its performance testing structure. Figure 1 The image shows the SEM morphology of a LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth. The microstructure shows a porous structure. This is because sintering Li2CO3 and TiO2 produces an appropriate amount of pores, which is beneficial for obtaining fine and uniform grains and resulting in a material with low linewidth. Example 2

[0034] This embodiment uses the proportions of the components in Table 1, combining the main materials and auxiliary materials. Specifically, the preparation method of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is as follows:

[0035] S1. First, prepare the main component materials, wet mix them evenly, and grind the balls with a water ratio of 6:1:1.2. After mixing for 8 hours, discharge and dry the material at a temperature of 180℃-200℃. Then sieve the material and raise the pre-calcination temperature to 900℃ at a heating rate of 3℃ / min-4℃ / min. The holding time is 2 hours.

[0036] S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind them at a grinding speed of 300 rpm for 10 hours. When the particle size reaches 1.5 ± 0.2 μm, add 7-10 wt% of adhesive to the total amount of main materials and auxiliary materials. In this embodiment, the adhesive is preferably 8%-10% PVA glue.

[0037] S3. Spray granulation: At 230-270℃, the wet-mixed mixture is placed in an atomizing device for spray granulation. The particle size of the spray-granulated material is 90μm-100μm.

[0038] S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape. The sieve mesh size is 200-260 mesh, the forming pressure is 180-200 MPa, and the holding time is 60-80 seconds.

[0039] S5. Low-temperature sintering: Remove the binder in the low-temperature section, with a heating rate of 1.2℃ / min-1.5℃ / min from 20℃ to 650℃, and hold at 600℃ for 210min-240min; then heat to the highest temperature at a rate of 2-2.5℃ / min; sinter at 950℃ for 240min-300min, with a sintering pressure of 0.01MPa-0.05MPa.

[0040] The performance test structure of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth prepared by the method of this embodiment is shown in Table 2. Example 3

[0041] This embodiment uses the proportions of the components in Table 1, combining the main materials and auxiliary materials. Specifically, the preparation method of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is as follows:

[0042] S1 First, the main component materials are prepared and wet-mixed evenly. The ratio of grinding balls to water is 5:1:1. After mixing for 4 hours, the material is discharged and dried at a temperature of 180℃-200℃. Then, it is sieved. The pre-calcination temperature is then raised to 950℃ at a heating rate of 3℃ / min-4℃ / min and a holding time of 6 hours.

[0043] S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind them at a grinding rate of 240 rpm for 15 h. When the particle size reaches 1.5 ± 0.2 μm, add 8 wt% of the total amount of the main materials and auxiliary materials as binder. In this embodiment, the binder is preferably 8%-10% PVA glue.

[0044] S3. Spray granulation: At 180℃-210℃, the wet-mixed mixture is placed in an atomizing device for spray granulation. The particle size of the spray-granulated material is 60μm-200μm.

[0045] S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape. The sieve mesh size is 210-260 mesh, the forming pressure is 120-200 MPa, and the holding time is 40-80 seconds.

[0046] S5. Low-temperature sintering: Remove the binder in the low-temperature section, raise the temperature from 20℃ to 650℃ at a rate of 1.0℃ / min to 1.2℃ / min, then hold at 600℃ for 160 to 210 min; then raise the temperature to the highest temperature at a rate of 2℃ / min to 2.5℃ / min; sinter at 950℃ for 500 to 600 min at a sintering pressure of 0.01MPa to 0.04MPa.

[0047] The performance test structure of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth prepared by the method of this embodiment is shown in Table 2. Example 4

[0048] In this embodiment, the components are proportioned according to Table 1, and the main materials and auxiliary materials are used in combination. Specifically, the preparation method of the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth is the same as in Example 1.

[0049] Comparative Examples 1-13

[0050] Comparative Examples 1-13 were prepared according to the composition ratios in Table 1, using the main and auxiliary materials in combination to produce LiZnFe system polycrystalline ferrite materials. The preparation method was the same as that in Example 1. Their performance test structures are shown in Table 2. Comparative Example 14

[0051] Comparative Example 14 was prepared by combining the main and auxiliary materials according to the proportions in Table 1. The preparation method used was a conventional ceramic process. The performance test results are shown in Table 2. The preparation method of the LiZnFe polycrystalline ferrite material was as follows: 1) S1. Mixing and pre-firing; 2) S2. Batching and grinding; 3) S3. Spray granulation; 4) S4. Dry pressing; 5) S5. Low-temperature sintering.

[0052] The specific process steps are as follows: 1) Weigh and mix the main and auxiliary materials according to their weights and proportions, and mix them evenly using wet or dry methods. After mixing for several hours, the particle size should reach the required material size before discharging for post-processing; 2) Add adhesive: Mix evenly using wet methods, with a grinding ball:material:adhesive:water ratio of 2-6:1:0.08-0.12:0.7-1.2. After mixing for 2-12 hours, the material should be discharged as slurry B1. 3) Spray granulation: At 150-270℃, the wet-mixed material is placed in an atomizing device for spray granulation to obtain granules with certain flowability; 4) Dry pressing: The granules from the previous step are sieved and then pressed into shape; the sieve mesh size is 50-260 mesh, the forming pressure is 20-100 MPa, and the holding time is 40-80 s; 5) Sintering: The temperature is increased to the maximum temperature at a heating rate of 2-3℃ / min; sintering is carried out at the maximum temperature of 900-1500℃ for 240-600 min, and the sintering pressure is 0.01-1 MPa. Such ordinary ceramic processes cannot produce high-performance ferrite materials.

[0053] The performance test structure is shown in Table 2.

[0054]

[0055]

[0056] The amount of Li2CO3 added in Comparative Examples 1 and 2 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large, which did not meet the process requirements.

[0057] The amount of Fe2O3 added in Comparative Examples 3 and 4 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs decreased, the remanence ratio Rs was lower, and the ferromagnetic resonance linewidth ΔH was larger; which did not meet the process requirements.

[0058] The amount of ZnO added in Comparative Examples 5 and 6 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0059] The amount of MnCO3 added in Comparative Examples 7 and 8 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0060] The amount of TiO2 added in Comparative Examples 9 and 10 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0061] The amount of CaCO3 added in Comparative Examples 11 and 12 differed from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0062] In Comparative Example 13, the amount of Bi2O3 added was different from that in Examples 1-4, while the other components were all within the range of Examples 1-4. The test results showed that the sintering density and saturation magnetization 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0063] The composition ratio of Comparative Example 14 was the same as that of Example 1, and a conventional ceramic process was used. The test results showed that the sintering density and saturation magnetization intensity 4πMs were significantly reduced; the ferromagnetic resonance linewidth ΔH was large and the remanence ratio Rs was low, which did not meet the process requirements.

[0064] In summary, the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth of the present invention adopts an innovative compositional approach, setting the main materials as a combination of various metal oxides and carbonates, and combined with the low-temperature sintering process of the present invention, to achieve excellent performance.

[0065] Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the protection scope of the present invention, which should be defined by the claims.

Claims

1. A LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth, characterized in that, The main materials and auxiliary materials are used in combination. The main materials are Li2CO3, Fe2O3, ZnO, MnCO3, and TiO2, with a molar ratio of 13-14:75-77:6-7.5:1.5-2.8:0.55-0.

95. The auxiliary materials are CaCO3 and Bi2O3, with addition amounts of 0.5wt%-2wt% and 0.3wt%-1.8wt% of the total amount of the main materials, respectively. The preparation method includes the following steps: S1. Mixing and pre-firing: First, the main component materials are prepared and wet-mixed evenly. The ratio of grinding balls to water is 4-6:1:0.8-1.

2. After mixing for 4-12 hours, the material is discharged and dried at a temperature of 160℃-200℃. Then, it is sieved. The pre-firing temperature is then increased to 800℃-950℃ at a heating rate of 2℃ / min-4℃ / min and a holding time of 2-6 hours. S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind for 12h-24h until the particle size reaches 1.5±0.2μm. Then add 7wt%-10wt% of binder, which is the total amount of main materials and auxiliary materials. S3. Spray granulation: The wet-mixed mixture is placed in an atomizing device at 150℃-270℃ for spray granulation; S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape; the sieve mesh size is 50-260 mesh, the forming pressure is 120Mpa-200Mpa, and the holding time is 40s-80s. S5. Low-temperature sintering: Remove the binder in the low-temperature section, raise the temperature from 20℃ to 650℃ at a rate of 0.7℃ / min to 1.5℃ / min, then hold at 600℃ for 120min to 240min; raise the temperature to the highest temperature at a rate of 2-2.5℃ / min; sinter at 900℃ to 1000℃ for 240min to 600min, with a sintering pressure of 0.01MPa to 1MPa.

2. The LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth according to claim 1, characterized in that, The auxiliary material CaCO3 is nano-light calcium with a particle size of 100-300nm.

3. A method for preparing the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth as described in claim 1, characterized in that, Includes the following steps: S1. Mixing and pre-firing: First, the main component materials are prepared and wet-mixed evenly. The ratio of grinding balls to water is 4-6:1:0.8-1.

2. After mixing for 4-12 hours, the material is discharged and dried at a temperature of 160℃-200℃. Then, it is sieved. The pre-firing temperature is then increased to 800℃-950℃ at a heating rate of 2℃ / min-4℃ / min and a holding time of 2-6 hours. S2. Ingredients: Add appropriate amount of auxiliary materials to the main materials of step S1 and grind for 12h-24h until the particle size reaches 1.5±0.2μm. Then add 7wt%-10wt% of binder, which is the total amount of main materials and auxiliary materials. S3. Spray granulation: The wet-mixed mixture is placed in an atomizing device at 150℃-270℃ for spray granulation; S4. Dry pressing: The spray-granulated granules from step S3 are sieved and then pressed into shape; the sieve mesh size is 50-260 mesh, the forming pressure is 120Mpa-200Mpa, and the holding time is 40s-80s. S5. Low-temperature sintering: Remove the binder in the low-temperature section, raise the temperature from 20℃ to 650℃ at a rate of 0.7℃ / min to 1.5℃ / min, then hold at 600℃ for 120min to 240min; raise the temperature to the highest temperature at a rate of 2-2.5℃ / min; sinter at 900℃ to 1000℃ for 240min to 600min, with a sintering pressure of 0.01MPa to 1MPa.

4. The method for preparing the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth according to claim 3, characterized in that, The grinding rate in step S1 is 200rpm-280rpm, and the grinding time is 10h-15h; the grinding rate in step S2 is 240rpm-300rpm, and the grinding time is 10h-15h.

5. The method for preparing the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth according to claim 3, characterized in that, The adhesive used in step S2 is a PVA adhesive with a concentration of 8%-10%.

6. The method for preparing the LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth according to claim 3, characterized in that, The particle size of the particulate material produced by spray granulation in step S3 is 60μm-200μm.

7. The LiZnFe ferrite material with high saturation magnetization Ms and low ferromagnetic resonance linewidth as described in claim 1 is applied to high-frequency isolators / circulators.

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