High-power and low-loss gyromagnetic ferrite and preparation method thereof

Abstract

The high-power and low-loss rotating ferrite of the present invention is formulated according to Y 3‑x‑p‑w Ca x Gd p Dy w Ge x In y Mn z Co q Fe 4.97‑x‑y‑z‑q O 12 proportion; wherein, 0.05 ≤ x ≤ 0.3, 0.01 ≤ y ≤ 0.1, 0.001 ≤ z ≤ 0.1, 0.05 ≤ p ≤ 0.7, 0.002 ≤ w ≤ 0.01, 0.002 ≤ q ≤ 0.005. The present invention uses the Y, Gd series as the basic formula, improves the rectangularity of the hysteresis loop through the micro-doping of Mn; realizes high power by the combined substitution of Gd and Dy to increase the self-selection wave linewidth ΔHk; reduces the resonance linewidth ΔH to achieve small loss through the small substitution of In and Mn; regulates the saturation magnetization intensity 4πMs through the combined substitution of Gd, Ca and Ge; to suit the selection of different frequency devices. It has both a high self-selection wave linewidth ΔHk, a high remanence ratio Rs and low electromagnetic loss.

Description

Technical Field

[0001] The invention relates to a high-power and low-loss gyromagnetic ferrite and a preparation method thereof, belonging to the technical field of magnetic materials. Background Art

[0002] Miniaturization and high power are the main development trends of communication technology. Microwave ferrite materials, as the core of devices, should make some contribution to meet this development trend. The requirements for microwave ferrite materials for circulators and isolators used in base stations are as follows: 1) The saturation magnetization intensity 4πMs must be suitable for the requirements of the system's operating frequency upward shift. Accordingly, the device requires the 4πMs value of microwave ferrite materials to be 1800G-5000G; 2) The ferromagnetic resonance linewidth (ΔH) / effective linewidth (ΔHeff) is narrow; 3) The dielectric constant (ε′) is high and the dielectric loss (tanδε) is low; 4) The 4πMs temperature coefficient (αT) is low / and the Curie temperature (Tc) is high; 5) The power bearing capacity meets the use requirements / has a higher spin wave linewidth (ΔHk), etc. Among them, ΔHeff / ΔH reflects the microwave magnetic loss of the material, which is closely related to the device insertion loss; the increase in the dielectric constant ε is the only way to miniaturize the device; and the spin wave linewidth ΔHk limits the power bearing capacity of the device. The technical difficulty of microwave ferrite materials lies in the fact that these technical indicators are mutually restricted, especially low-loss ΔHeff / ΔH and high ΔHk are two pairs of parameters that contradict each other.

[0003] The general solution is to innovate in both the formulation and the process. A new formulation is used to introduce fast-relaxing impurity ions. A suitable sintering temperature is used in the process to refine the grains. The method of adding fast-relaxing impurity ions is simple and easy, but it increases the line width ΔH and the effective line width ΔHeff while increasing ΔHk. The amount of fast-relaxing ions added to the formulation needs to be controlled. Dy is usually used as the rare earth fast-relaxing impurity ion. 3+ Because it has a higher figure of merit, Dy 3+ However, due to its large ion radius, it will cause the magnet grain size to become larger, which will affect the change of sintering density.

[0004] The "ultra-high dielectric constant garnet" disclosed in CN106242547A has a chemical formula of Bi x Ca y G z Y 3-x-y-z Zr y O 12Etc. This patent is characterized by high Bi content (1.4-2.5 / mol) and high dielectric constant (ε≥31). However, the 4πMs range of high ε′ materials with smaller line width is very narrow, which is difficult to meet the requirements of 5G communications. To avoid high-power nonlinear effects, the key measure is to increase the high-power critical field hc or spin wave linewidth ΔHk of the material (hc∝ΔHk). There are two ways to increase ΔHk, one is to incorporate fast-relaxing impurity ions, and the other is to refine the grains. Grain refinement is often accompanied by the generation of pores, which increases ΔH, and hot pressing sintering is inconvenient to use. The method of incorporating fast-relaxing impurity ions is simple and easy, but while increasing ΔHk, it also increases the line width ΔH and the effective line width ΔHeff.

[0005] CN110981461 A discloses a yttrium iron garnet ferrite material and a preparation method thereof, wherein the chemical formula is Y 3-x-y-z G x Ca y Cu z Fe 5-a-b-c In a V b Al c O 12 Its main feature is that the prepared ferrite material has fine and uniform grains, which helps to obtain a dense microstructure, thereby improving the material's high-power bearing capacity and is suitable for use in various high-power isolators in communication base stations. 2+ Doping appropriately reduces the sintering temperature of the material, which is conducive to mass production of the material. However, it does not involve its loss and resonance line width.

[0006] CN112430080A provides a garnet ferrite material with high power and high remanence ratio, the chemical formula of which is Y 3-a-b-(c+d) G a Dy b Ca (c+d) Ge c Zr d In e Mn f Al g Fe 5-c-d-e-f-g-δ O 12 , where 0≤a≤1.5, 0.01≤b≤0.1, 0≤c≤0.3, 0≤d≤0.3, 0≤e≤0.3, 0≤f≤0.15, 0≤g≤0.5, 0≤δ≤0.3, and a and b are not 0 at the same time, δ is the iron deficiency of the process. Its patented material has high self-selected wave line width ΔHk, high remanence ratio Rs and low electromagnetic loss, which can meet the needs of various microwave devices including locked microwave ferrite devices for high-power materials. However, its resonance line width ΔH is too large, and the saturation magnetization intensity 4πMs is less than 1900Gs.

[0007] The chemical composition of the microwave ferrite described in CN1719658A is (Y a G b Ca x )Fe 8-a-b-x-y-z In y V z O 12 , 3.01≤a+b+x≤3.03; 0.25≤b≤0.55; 0.02≤y≤0.12; 0≤z≤0.15; 1.8≤x / z≤2; the lowest insertion loss tested is 0.37dB, which is a relatively large loss value.

[0008] CN111116193A provides a microwave ferrite material and a preparation method and device thereof. The chemical formula of the microwave ferrite material is Y 2.95-x Bi 0.04 Ce 0.01 Ca x Co 0.02 Sn x Fe 4.83-x O 12 , 0.25≤x≤0.35, the 4πMs of the microwave ferrite material invented by the inventor is controlled at 1850-1950Gs, and has a small line width (△H<20Oe) and low loss (tanδ<2*10 -4 ), which meets the application of microwave ferrite devices; but the value of the self-selected wave line width ΔHk is not given, which cannot meet the high power requirements.

[0009] At present, the main preparation method of yttrium iron garnet ferrite used in industrial production is the oxide method, which uses solid oxide as raw material and produces ferrite through basic steps such as batching, ball milling, drying, molding, and sintering. The sintered grains are coarse and the uniformity is poor, which limits the high-power performance of ferrite materials.

[0010] In summary, how to invent a gyromagnetic ferrite that has high self-selected wave line width ΔHk, high remanence ratio Rs (tested under 20Oe external field) and low electromagnetic loss has great significance and market value in practical use and production. Summary of the invention

[0011] In view of the above problems, the present invention proposes a high-power and low-loss gyromagnetic ferrite and a preparation method thereof. In order to meet the requirements of high power, high remanence ratio and low loss, a new formula is provided, which has high self-selected wave line width ΔHk, high remanence ratio Rs (tested under 20Oe external field) and low electromagnetic loss, wherein the dielectric loss tanδe≤2×10 -4, resonance linewidth ΔH≤30Oe, self-selected wave linewidth ΔHk≥15Oe, saturation magnetization intensity 4πM is adjustable in 1800Gs-1950Gs, which can not only meet the needs of circulators and isolators that withstand high peak power in low field operation, but also meet the needs of locking devices (phase shifters and switches, etc.) working under high power for high-power materials with high remanence ratio. The material saturation magnetization intensity 4πMs is serialized to provide high-power devices for SX frequency band selection.

[0012] The technical means adopted by the present invention to solve the above problems are: to disclose a high-power and low-loss gyromagnetic ferrite, the chemical composition of which is as follows: 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 Formula design; wherein, 0.05≤x≤0.3, 0.01≤y≤0.1, 0.001≤z≤0.1, 0.05≤p≤0.7, 0.002≤w≤0.01, 0.002≤q≤0.005.

[0013] The present invention adopts Y and Gd series as the basic formula in raw material design and improves the rectangularity (remanence ratio) of the hysteresis loop by micro-doping of Mn; improves the self-selected wave line width ΔHk by joint substitution of Gd and Dy to achieve high power characteristics; reduces the resonance line width ΔH by small amount substitution of In and Mn to achieve low loss characteristics; and regulates the saturation magnetization intensity 4πMs by combined substitution of Gd, Ca and Ge to suit the selection of devices with different frequencies. 2+ -Ge 4+ After doping, the saturation magnetization of the material decreases, but the material's self-selected wave line width ΔHk does not change much, and high power characteristics can be achieved; Gd 3+ After YIG is doped, the saturation magnetization of the material is significantly reduced; however, its 4πMs can be increased by adding Ge, Dy, and In.

[0014] Another object of the present invention is to disclose a method for preparing the high-power and low-loss gyromagnetic ferrite according to Y 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12The method is prepared by selecting initial raw material ingredients, mixing the ingredients by ball milling twice, spray granulating and pressing into shape, and finally performing a sintering process.

[0015] Furthermore, the initial raw material is Gd 2 O 3 、CaCO 3 , Y 2 O 3 、Dy 2 O 3 ,GeO 2 、In 2 O 3 、MnCO 3 、Co 2 O 3 , Fe 2 O 3 It is made of mixed proportions. It uses innovative ingredients combined with CaCO 3 It can form a high resistance layer at the grain boundary, increase the resistivity of the grain boundary and reduce eddy current loss; 3+ After ion doping, it can enter the ferrite lattice, and the appropriate amount of Y 2 O 3 Doping is beneficial to increase the saturation magnetization and initial magnetic permeability of the sample, reduce the coercive force, and improve the magnetic properties of ferrite materials. 2 O 3 As the main component, its crystal form is preferably honeycomb, with strong chemical activity, perfect solid phase reaction, and less chemical impurities and soluble salts. It is suitable for other one or more metal elements of oxides, hydroxides, carbonates or oxalates to form ferrite magnetic materials by solid phase reaction composite oxides. Mn 2+ Can replace octahedral a-site Fe 3+ , reducing the conductive ions to Fe 2+ -Fe 3+ , thereby increasing the grain resistivity and reducing losses. 2 O 3 Function: Use In 3+ Plasma substitution of octahedral Fe 3+ It can effectively reduce K1 and resonance line width ΔH. The principle is that after ion substitution, Fe at position A 3+ The number of ions decreases, causing K1 and θ f The decrease in the room temperature K1 value can eliminate the anisotropic broadening ΔHα. 3 The role is to reduce Fe 2+ The generation of Co 2 O 3 Role: Fast relaxing ion Co 3+ It is adjustable to increase the spin wave line width so that its ΔHk reaches above 15Oe.

[0016] The additive nano calcium carbonate is located on the grain boundary. The nanometer particle size is fine, which can increase the activation energy and form a grain boundary layer with high resistivity, which is beneficial to reduce the loss of ferrite. The particle radius of nano materials is very small. The total volume of nano materials is larger for the same impurities of different particle sizes. It is easier to evenly disperse into the ferrite material, which helps the grains of ferrite material to grow evenly. Therefore, adding nano additives can obtain high-performance ferrite with uniform grains.

[0017] Furthermore, the raw materials are all analytically pure. 2 andIn 2 O 3 It is nanometer-sized, with a median particle size of 200nm-400nm.

[0018] Furthermore, the method specifically includes the following steps:

[0019] S1. Wet first ball milling: The initial raw material is placed in a ball mill for the first ball milling, and the mass ratio is 1:3-5:1-3 for initial raw material: zirconium ball: pure water. After uniform mixing for 2h-6h, the material is sieved to obtain a mixed oxide slurry;

[0020] S2. Drying and sieving: The mixed oxide slurry obtained in step S1 is placed at 130°C-180°C, dried for 8h-12h and then sieved to obtain a mixed oxide powder;

[0021] S3 pre-sintering: The mixed oxide powder obtained in step S2 is pre-sintered at 900 ℃ -1250 ℃;

[0022] S4. Wet second ball milling: The powder pre-sintered in step S3 is put into a ball mill for a second ball milling, according to the mass ratio of raw material: zirconium ball: pure water = 1:4-6:1-2, and ground to a median particle size = 1.1-1.5μm to obtain a finely ground slurry;

[0023] S5. Spray granulation: The ground slurry of step S4 is prepared in a mass ratio of raw materials: PVA glue: dispersant: defoamer = 1000: 70-120: 1-3: 1-2, and spray granulation is performed to obtain spray granulation powder;

[0024] S6. Green billet production: The spray granulation powder obtained in step S5 is placed in a mold to press a green billet of a specified shape. The green billet molding density is maintained at 3.2-3.9 g / cm 3 above;

[0025] S7. Sintering the green compact formed in step S6 at 1350°C-1480°C.

[0026] Further, in step S3, the pre-firing is a staged pre-firing: the temperature is raised from room temperature to 400°C at a rate of 1°C / min-1.5°C / min, kept at 400°C for 1.5h-3h, then raised to a maximum pre-firing temperature of 1050°C-1250°C at a rate of 2°C / min-4°C / min, kept at the maximum pre-firing temperature of 1050°C-1250°C for 4h-6h, and then cooled with the furnace. In the low temperature stage, this heating rate is convenient for removing moisture, and the high temperature stage is kept at 1050°C-1250°C for 4h-6h. This process is the initial crystallization to prevent the generation of heterogeneous phases different from the garnet crystal phase.

[0027] Furthermore, in step S7, the sintering is segmented sintering: the temperature is raised from room temperature to 600°C at a rate of 1°C / min-2°C / min, kept at this temperature for 1.5h-3h, and then raised to the maximum sintering temperature of 1150°C-1480°C at a rate of 2°C / min-5°C / min, kept at this temperature for 5h-10h at the maximum pre-firing temperature, and then cooled with the furnace. Low-temperature debinding requires a slow heating rate, and keeping at 600°C is a large amount of oxidation and exhaust gas of PVA, so it needs to be kept at this temperature for 2 hours; then the temperature is raised to the maximum sintering temperature at a rate of 2°C / min, which can generate materials with low dielectric loss and low resonance line width. The highest temperature of 1150°C-1480°C is kept at this temperature for 5h-10h, so that the continuous growth of the grains is uniform, and the final average grain size is not large. The resonance line width of the microwave ferrite prepared in this way is not higher than 30Oe, and the spin wave line width will be higher than 15Oe.

[0028] Furthermore, the dispersant is ammonium polyacrylate and the defoaming agent is tributyl phosphate. Ammonium polyacrylate is convenient for dispersing YIG microwave ferrite with high efficiency; while tributyl phosphate is a kind of defoaming agent, which can easily eliminate the ball-milling bubbles of ferrite.

[0029] Furthermore, the air inlet temperature of the spray dryer is 250°C-270°C, and the air outlet temperature is 125°C-150°C.

[0030] Furthermore, the rotation speed of the first ball milling is 240rpm-260rpm; the rotation speed of the second ball milling is 280rpm-300rpm.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The high-power and low-loss gyromagnetic ferrite of the present invention is prepared by solid phase reaction method. 3-x-p- w Ca x G p Dy w Ge x In y Mn z Co q Fe4.97-x-y-z-q O 12 , providing a new formula that combines high self-selected wave linewidth ΔHk, high remanence ratio Rs (tested under 20Oe external field) and low electromagnetic loss.

[0033] 2. The present invention adopts Y and Gd series as the basic formula in raw material design and improves the rectangularity (remanence ratio) of the hysteresis loop by micro-doping of Mn; increases the self-selected wave line width ΔHk by joint substitution of Gd and Dy to achieve high power characteristics; reduces the resonance line width ΔH by small amounts of substitution of In and Mn to achieve low loss characteristics; and regulates the saturation magnetization intensity 4πMs by combined substitution of Gd, Ca and Ge to suit the selection of devices with different frequencies. 2+ -Ge 4+ After doping, the saturation magnetization of the material decreases, but the material's self-selected wave line width ΔHk does not change much, and high power characteristics can be achieved; Gd 3+ After YIG is added, the saturation magnetization of the material is significantly reduced, but by adding Ge, Dy, and In, its 4πMs can be increased. It is suitable for commercial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] In the attached picture:

[0036] Figure 1 This is the SEM morphology of the high-power and low-loss gyromagnetic ferrite described in Example 1. DETAILED DESCRIPTION

[0037] The high-power and low-loss gyromagnetic ferrite of the present invention has a raw material chemical composition according to Y 3-x-p- w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 Formula design; wherein, 0.05≤x≤0.3, 0.01≤y≤0.1, 0.001≤z≤0.1, 0.05≤p≤0.7, 0.002≤w≤0.01, 0.002≤q≤0.005.

[0038] The preparation method of the high-power and low-loss gyromagnetic ferrite of the present invention comprises the following steps: the initial raw material is Gd 2 O 3 、CaCO3 , Y 2 O 3 、Dy 2 O 3 ,GeO 2 、In 2 O 3 、MnCO 3 、Co 2 O 3 , Fe 2 O 3 Mixed in proportion, GeO 2 andIn 2 O 3 It is nanometer-sized, with a median particle size of 200nm-400nm. 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 The material is formulated by ball milling the ingredients twice, spray granulating and pressing them into shape, and finally sintering them.

[0039] Example 1

[0040] The high-power and low-loss gyromagnetic ferrite of this embodiment is prepared by weighing the contents of each compound according to the composition ratio in Table 1. 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 , a method for preparing a high-power and low-loss gyromagnetic ferrite comprises the following steps:

[0041] S1. Wet first ball milling: put the raw materials into a ball mill for ball milling, add corresponding zirconium balls and deionized water in the ratio of raw materials: zirconium balls: pure water = 1:4:1.5, mix evenly at a speed of 260 rpm for 4 hours, and sieve the material to obtain a mixed oxide slurry;

[0042] S2 drying and sieving: The mixed oxide slurry obtained in step S1 is placed in an oven at 180°C for drying once, and then dried for 12 hours and crushed once;

[0043] S3 pre-burning: The mixed oxide powder obtained in step S2 is loaded into a corundum mullite sagger and placed in a box furnace for pre-burning; the pre-burning temperature is 1150 ℃, and the heat is kept for 3h;

[0044] S4. Wet second ball milling: put the powder pre-sintered in step S3 into a crusher for secondary crushing to obtain crushed material A; add corresponding zirconium balls and pure water in a ratio of crushed material A: zirconium balls: pure water = 1:5:2, mix evenly at a speed of 260rpm for 8h, grind to D50 = 1.1-1.5μm, and obtain finely ground slurry B; perform particle size test, and when D50 meets the requirements, proceed to the next step of ball milling slurry preparation;

[0045] S5. Spray granulation: Mix the ground slurry B and PVA aqueous solution, dispersant and defoamer, stir evenly, ball mill for 6 hours, filter out the slurry, wherein the dispersant is ammonium polyacrylate, the defoamer is tributyl phosphate, and the ingredients are prepared in the ratio of crushed material A: PVA aqueous solution: dispersant: defoamer = 1000: 80: 3: 1.5. Then spray granulate in a spray dryer to obtain spray granulation powder C, wherein the air inlet temperature of the spray dryer is 250℃-270℃, and the air outlet temperature is 125-150℃;

[0046] S5. Green body preparation: The obtained spray granulated powder C is placed into a mold to press a green body of a specified shape. The green body molding density is maintained at 3.2 g / cm 3 The above; molding method: use the granular material to press with an oil press to obtain a cylindrical product (120MPa, holding time 60s) and a dry pressed magnetic strip (45*20*3mm), 80Mpa, holding time 30s; the above pressed green body is placed in an alumina sagger and placed in a box furnace for sintering at 1350℃-1400℃.

[0047] Test method: The sintering density is tested by the buoyancy method using the automatic density meter GF-300D, and the dielectric properties are tested by the Agilent 4991 impedance analyzer; the ferromagnetic resonance line width is tested by the Dahua Instrument 811B; the spin wave line width ΔHk is tested by the Chengdu Enchi microwave equipment; the performance test results are as follows; the dielectric loss is tested by the Dahua 406B at a frequency of 9.2GHz; its performance test is performed by grinding and cutting after sintering the formed round rod (20cm*diameter φ5mm), the dielectric loss performance test is tested by the IEC60556 standard test (resonant cavity perturbation method, test frequency: 10.7GHZ, sample size: cylinder with a diameter of 1.6±0.01mm), the ferromagnetic resonance line width is tested by the transmission resonant cavity method, the sample size is a small ball with a diameter of 0.6-0.8mm, and the saturation magnetization intensity 4πMs is tested by KJS The sample size is a small ball with a diameter of 1.0-2.5 mm. The density is tested by the drainage method, and the sample size is 25.4 mm × 25.4 mm × 0.8 mm.

[0048] The performance test results of the product of this embodiment are shown in Table 2. The SEM morphology of Example 1 is as follows Figure 1 .

[0049] Example 2

[0050] The high-power and low-loss gyromagnetic ferrite of this embodiment is prepared by weighing the contents of each compound according to the composition ratio in Table 1. 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 , a method for preparing a high-power and low-loss gyromagnetic ferrite comprises the following steps:

[0051] S1. Wet first ball milling: put the raw materials into a ball mill for ball milling, add corresponding zirconium balls and deionized water in the ratio of raw materials: zirconium balls: pure water = 1:5:1.2, mix evenly at a speed of 240 rpm for 6 hours, and sieve the material to obtain a mixed oxide slurry;

[0052] S2 drying and sieving: The mixed oxide slurry obtained in step S1 was placed in an oven at 150 ° C for drying, and after drying for 8h, it was crushed once;

[0053] S3 pre-burning: The mixed oxide powder obtained after crushing in step S2 is loaded into a corundum mullite sagger and placed in a box furnace for pre-burning; the pre-burning temperature is 1200 ℃, and the temperature is kept for 3h;

[0054] S4. Wet second ball milling: put the pre-burned powder into a crusher for secondary crushing to obtain crushed material A; add corresponding zirconium balls and pure water in the ratio of crushed material A: zirconium balls: pure water = 1:5.5:1.2, mix evenly at a speed of 300rpm for 8h, grind to D50 = 1.1-1.5μm, and obtain finely ground slurry B; perform particle size test, and when D50 meets the requirements, proceed to the next step of ball milling;

[0055] S5. Spray granulation: The ground slurry B and the PVA aqueous solution, dispersant and defoamer are mixed and stirred evenly, and after ball milling for 5 hours, the slurry is filtered out, wherein the dispersant is ammonium polyacrylate, and the defoamer is tributyl phosphate, and the ingredients are prepared in a ratio of crushed material A: PVA aqueous solution: dispersant: defoamer = 1000:100:2:1; and then spray granulation is performed in a spray dryer to obtain spray granulation powder C, wherein the air inlet temperature of the spray dryer is 260°C, and the air outlet temperature is 130°C;

[0056] S6. Green body preparation: The obtained spray granulated powder C is placed into a mold to press a green body of a specified shape. The green body molding density is maintained at 3.429 g / cm 3 The above; molding method: use the granular material to press with an oil press to obtain a cylindrical product (120MPa, holding time 60s) and a dry pressed magnetic strip (45*20*3mm), 80Mpa, holding time 30s; the green compacts pressed above are placed in an alumina sagger and placed in a box furnace for sintering at 1440℃. The performance test results are shown in Table 2 below.

[0057] Example 3

[0058] The high-power and low-loss gyromagnetic ferrite of this embodiment is prepared by weighing the contents of each compound according to the composition ratio in Table 1. 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 The preparation method of high-power and low-loss gyromagnetic ferrite is substantially the same as that in the embodiment. The difference is that in step S1, wet first ball milling: the raw material is put into a ball mill for a first ball milling, and corresponding zirconium balls and deionized water are added in a ratio of raw material: zirconium balls: pure water = 1:3:3.

[0059] In step S3, the pre-sintering temperature is 1250°C and the temperature is kept for 2 hours. In step S4, the second ball milling is carried out according to the ratio of raw materials: zirconium balls: pure water = 1:6:2.

[0060] The raw materials in step S5 are prepared in a ratio of PVA glue: dispersant: defoamer = 1000:120:1:2, and the rest is the same as in Example 1. The performance test results are shown in Table 2 below.

[0061] Example 4

[0062] Use the formula table to calculate the content of each substance and the corresponding raw material Gd 2 O 3 、CaCO 3 , Y 2 O 3 、Dy 2 O 3 ,GeO 2 、In 2 O 3 、MnCO 3 、Co 2 O 3 , Fe 2 O 3 , weigh the material, and the subsequent process steps are the same as those in Example 2. The performance test results are shown in Table 2 below.

[0063] Comparative Example 1-Comparative Example 6

[0064] Comparative Examples 1 to 6 use the formula table to calculate the content of each substance, and the corresponding raw material Gd 2 O 3 、CaCO 3 , Y 2 O 3 、Dy 2 O 3 ,GeO 2 、In 2 O 3 、MnCO 3 、Co 2 O 3 , Fe 2 O 3 , weigh the material, and the various process steps of its preparation are the same as those of Example 1. Its performance test adopts the grinding and cutting of the formed round rod (20cm*diameter φ5mm) after sintering, the dielectric loss performance test adopts the IEC60556 standard test (resonant cavity perturbation method, test frequency: 10.7GHZ, sample size: cylinder with a diameter of 1.6±0.01mm), the ferromagnetic resonance line width adopts the transmission resonant cavity method, the sample size: a small ball with a diameter of 0.6-0.8mm, the saturation magnetization intensity 4πMs is measured by KJS SMT-600 BH hysteresis loop tester, the sample size: a small ball with a diameter of 1.0mm-2.5mm; the density is tested by the drainage method, and the sample size is 25.4mm×25.4mm×0.8mm. Its performance test results are shown in Table 2 below.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069] The above scheme and test results show that the high-power and low-loss gyromagnetic ferrite of the present invention has high self-selected wave line width ΔHk, high remanence ratio Rs (tested under 20Oe external field) and low electromagnetic loss. Among them, the dielectric loss tanδe≤2×10 -4 , resonance linewidth ΔH≤30Oe, self-selected wave linewidth ΔHk≥15Oe, saturation magnetization intensity 4πM adjustable in 1800Gs-1950Gs.

[0070] Those skilled in the art may 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, and the protection scope of the present invention should be defined by the claims.

Claims

1. A high-power, low-loss gyromagnetic ferrite. It is characterized in that The chemical composition of the raw materials is 3-x-p- w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 Formula design; wherein, 0.05≤x≤0.3, 0.01≤y≤0.1, 0.001≤z≤0.1, 0.05≤p≤0.7, 0.002≤w≤0.01, 0.002≤q≤0.

005.

2. A method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 1, It is characterized in that Follow Y 3-x-p-w Ca x G p Dy w Ge x In y Mn z Co q Fe 4.97-x-y-z-q O 12 The method is prepared by selecting initial raw material ingredients, mixing the ingredients by ball milling twice, spray granulating and pressing into shape, and finally performing a sintering process.

3. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 2, It is characterized in that The initial raw material is Gd 2 O 3 、CaCO 3 , Y 2 O 3 、Dy 2 O 3 ,GeO 2 、In 2 O 3 、MnCO 3 、Co 2 O 3 , Fe 2 O 3 mix.

4. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 3, It is characterized in that The GeO 2 andIn 2 O 3 It is nanometer-sized, with a median particle size of 200nm-400nm.

5. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 4, It is characterized in that The following steps are involved: S1. Wet first ball milling: The initial raw material is placed in a ball mill for the first ball milling, and the mass ratio is 1:3-5:1-3 for initial raw material: zirconium ball: pure water. After uniform mixing for 2h-6h, the material is sieved to obtain a mixed oxide slurry; S2. Drying and sieving: The mixed oxide slurry obtained in step S1 is placed at 130°C-180°C, dried for 8h-12h and then sieved to obtain a mixed oxide powder; S3 pre-sintering: The mixed oxide powder obtained in step S2 is pre-sintered at 900 ℃ -1250 ℃; S4. Wet second ball milling: The powder pre-sintered in step S3 is put into a ball mill for a second ball milling, according to the mass ratio of raw material: zirconium ball: pure water = 1:4-6:1-2, and ground to a median particle size = 1.1-1.5μm to obtain a finely ground slurry; S5. Spray granulation: The ground slurry of step S4 is prepared in a mass ratio of raw materials: PVA glue: dispersant: defoamer = 1000:70-120:1-3:1-2, and then mixed and stirred evenly, and then spray granulated to obtain spray granulated powder; S6. Green billet production: The spray granulation powder obtained in step S5 is placed in a mold to press a green billet of a specified shape. The green billet molding density is maintained at 3.2-3.9 g / cm 3 above; S7. Sintering the green compact formed in step S6 at 1350°C-1480°C.

6. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 5, It is characterized in that In step S3, the pre-firing is a staged pre-firing: the temperature is increased from room temperature to 400°C at a rate of 1°C / min-1.5°C / min, kept at 400°C for 1.5h-3h, then increased to a maximum pre-firing temperature of 1050°C-1250°C at a rate of 2°C / min-4°C / min, kept at the maximum pre-firing temperature of 1050°C-1250°C for 4h-6h, and then cooled with the furnace.

7. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 6, It is characterized in that In step S7, the sintering is staged sintering: the temperature is increased from room temperature to 600°C at a rate of 1°C / min-2°C / min, kept at this temperature for 1.5h-3h, then increased to the maximum sintering temperature of 1150°C-1480°C at a rate of 2°C / min-5°C / min, kept at the maximum pre-firing temperature for 5h-10h, and then cooled with the furnace.

8. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 5, It is characterized in that The dispersant is ammonium polyacrylate, and the defoamer is tributyl phosphate.

9. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 5, It is characterized in that The air inlet temperature of the spray dryer is 250°C-270°C, and the air outlet temperature is 125°C-150°C.

10. The method for preparing the high-power and low-loss gyromagnetic ferrite according to claim 5, It is characterized in that The rotation speed of the first ball milling is 240-260rpm; the rotation speed of the second ball milling is 280-300rpm.

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