High-power garnet ferrite and preparation method thereof

Abstract

The invention belongs to the field of magnetic materials, particularly relates to a high-power garnet ferrite and a preparation method thereof, and provides a high-power garnet ferrite and a preparation method thereof aiming at the defects that high residual magnetism ratio, low resonance line width, high spin wave line width and high Curie temperature of the garnet ferrite in the prior art are difficult to consider at the same time, and the high-power garnet ferrite is obtained through Co < 2 + >-Ge < 4 + > or Co < 2 + >-Si < 4 + > ion combined substitution. The garnet ferrite with high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature can be obtained by reasonably designing the doping amount of Co < 2 + > ions and Mn < 3 + > ions and matching with proper Dy < 3 + > doping. Aiming at the defect that low resonance line width, high spin wave line width and high Curie temperature of garnet ferrite are difficult to consider at the same time, the invention provides a Co < 2 + > ion and Dy < 3 + > ion combined substitution method, so that the garnet ferrite can have low resonance line width, high spin wave line width and high Curie temperature at the same time.

Description

Technical Field

[0001] The invention belongs to the field of magnetic materials, and in particular relates to a high-power garnet ferrite and a preparation method thereof. Background Art

[0002] Ferrite phase shifters, switches, polarizers and other locked microwave ferrite devices widely used in radar systems require spin-torque ferrite materials with low loss, high remanence ratio, low coercivity and low temperature coefficient. Especially in high-power devices, garnet ferrite is widely used due to its low resonance linewidth and high spin wave linewidth. However, the low loss and high power requirements of ferrite cannot be taken into account at the same time. High spin wave linewidth means high resonance linewidth. How to increase the spin wave linewidth of garnet ferrite while controlling the resonance linewidth to a smaller value, while maintaining high remanence ratio, low coercivity, high Curie temperature and low temperature coefficient, is an important research topic.

[0003] In order to improve the remanence ratio of garnet ferrite materials, in addition to reducing the porosity and controlling the grain size in the process, two solutions are usually adopted in the formulation design. One is a garnet ferrite material and preparation method for high-power phase shifters described in patent CN 201510802358.0, which mainly uses Mn 3+ Ion doping makes the magnetostriction coefficient of the material approach zero, thereby increasing the remanence ratio of the material. 3+ Ion doping can also achieve the same effect. Another solution is to use Co 2+ -Si 4+ Combined substitution to increase the magnetocrystalline anisotropy constant K1 to increase the remanence ratio of the material;

[0004] Disadvantages of the existing technology:

[0005] Main disadvantage 1: In order to reduce the loss of high-power garnet, non-magnetic ions In are usually used 3+ Sn 4+ Equal doping reduces the magnetocrystalline anisotropy constant K1 of the material, thereby reducing the ferromagnetic resonance line width of the material. However, In 3+ Sn 4+ The non-magnetic ion substitution will seriously reduce the Curie temperature of garnet ferrite, thereby deteriorating the high and low temperature performance of the material. 3+ The effect of ion doping on reducing the magnetostriction coefficient of the material and increasing the remanence ratio of the material is not significant.

[0006] Main disadvantage 2: Patent CN 108191423 B through Co 2+ -Si 4+The combined substitution method has an obvious effect on improving the remanence ratio of the material and can also simultaneously improve the spin wave line width of the material. However, it also has the disadvantages of large resonance line width and low Curie temperature when the substitution amount is large. 2+ -Si 4+ When the substitution amount is 0.03, the ferromagnetic resonance line width is 150 oersteds, and the Curie temperature is theoretically only about 200°C, which is difficult to meet the requirements for device use.

[0007] Ferrite circulators, isolators and other constant-field microwave ferrite devices widely used in radar systems require low-loss, high-power, and low-temperature-coefficient spin-magnetic ferrite materials. Garnet ferrites are widely used in high-power devices because of their low resonance linewidth and high spin wave linewidth. However, the low-loss and high-power requirements of ferrites cannot be taken into account at the same time. High spin wave linewidth means high resonance linewidth. How to increase the spin wave linewidth of garnet ferrites while controlling the resonance linewidth to a smaller value, while maintaining a high Curie temperature and a low temperature coefficient, is an important research direction.

[0008] In order to improve the spin wave line width of garnet ferrite materials, in addition to refining the grains through hot pressing sintering process, the main method is to dope Co in the formula design. 2+ 、Dy 3+ , Gd 3+ 、Ho 3+ Isofast relaxing ions.

[0009] The shortcomings of the prior art mainly include:

[0010] Main disadvantage 1: The hot pressing sintering process is complicated, the equipment is expensive, the production efficiency is low, and the use is limited.

[0011] Main disadvantage 2: Doping with fast-relaxing ions will greatly increase the resonance linewidth of the material while increasing the spin wave linewidth. This can be achieved by simultaneously doping with In 3+ Sn 4+ Non-magnetic ions such as Co can reduce the magnetocrystalline anisotropy constant K1 of the material, thereby reducing the ferromagnetic resonance line width of the material, but this will reduce the Curie temperature of garnet ferrite, thereby deteriorating the high and low temperature performance of the material. In 1970, the research of Jean Nicolas et al. in France showed that by using an appropriate amount of Co 2+ Doping to adjust the anisotropy constant K1 of garnet ferrite can reduce the resonance line width. However, in order to obtain a higher spin wave line width, excessive doping with Co 2+ ions will rapidly increase the resonance line width, and in order to balance the charge, Co 2+ The ions must be non-magnetic Si 4+ Or Ge 4+ The combined substitution of ions will reduce the Curie temperature of the material, which leads to the2+ Ion doping has limited use in high-power garnet materials. Summary of the invention

[0012] In view of this, the present invention aims at the disadvantages of the prior art that garnet ferrite has high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature, and proposes a method of using Co 2+ -Ge 4+ or Co 2+ -Si 4+ ion replacement, through rational design of Co 2+ Ions and Mn 3+ The doping amount of ions, combined with appropriate Dy 3+ By doping, a garnet ferrite is obtained which has high remanence ratio, low resonance linewidth, high spin wave linewidth and high Curie temperature.

[0013] The present invention aims to solve the problems of low resonance line width, high spin wave line width and high Curie temperature of garnet ferrite in the prior art, and proposes a method to obtain a garnet ferrite by using Co 2+ Ions and Dy 3+ The method of ion combined substitution enables garnet ferrite to have low resonance linewidth, high spin wave linewidth and high Curie temperature at the same time.

[0014] The technical solution of the present invention is:

[0015] A high-power garnet ferrite, the garnet ferrite is applied to microwave ferrite devices; the chemical formula of the ferrite is:

[0016] Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12

[0017] Where: 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1; or,

[0018] 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, θ is the process iron deficiency.

[0019] Furthermore, when 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1,

[0020] The garnet ferrite utilizes the gyromagnetic properties of the birefringence effect and the Faraday rotation effect, and the magnetic property of high remanence specific moment, and is applied to the modulation of the microwave phase / polarization and transmission direction of the locked microwave ferrite device.

[0021] Furthermore, the locked microwave ferrite device includes a phase shifter, a polarizer and a switch.

[0022] Furthermore, when 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, and 0.005≤ξ≤0.1, the garnet ferrite utilizes the non-reciprocal transmission characteristics to modulate the transmission direction of microwaves and is applied to constant-field microwave ferrite devices.

[0023] Furthermore, the constant-field microwave ferrite device includes a circulator or an isolator.

[0024] In some embodiments, the present invention further provides a method for preparing the above-mentioned garnet ferrite, comprising the following steps:

[0025] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 Calculate and weigh raw materials;

[0026] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0027] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0028] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0029] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0030] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0031] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0032] Beneficial effects of the present invention:

[0033] The present invention dopes an appropriate amount of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, adjusting the magnetocrystalline anisotropy constant K1 of the basic formula YGd garnet ferrite from a negative value to a positive value of 100-400 J / m 3 About, while doping with appropriate amount of Mn 3+ ions, adjust the magnetostriction coefficient of the material to close to zero, and then dope an appropriate amount of Dy according to the spin wave line width requirements of the material. 3+ Ions are added to obtain garnet ferrite having high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature. The ferrite material of the present invention is produced by traditional ceramic process.

[0034] The present invention dopes an appropriate amount of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, the magnetocrystalline anisotropy constant K1 of the basic formula YGd garnet ferrite is adjusted from negative to zero, and then an appropriate amount of Dy is added according to the spin wave line width requirements of the material. 3+ ions to obtain garnet ferrite with low resonance linewidth, high spin wave linewidth and high Curie temperature. DETAILED DESCRIPTION

[0035] The embodiments of the present disclosure are described in detail below in conjunction with the solutions.

[0036] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0037] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0038] It should also be noted that the schemes provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The schemes only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0039] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0040] The embodiment of the present invention provides a high-power garnet ferrite, which is applied to microwave ferrite devices; the chemical formula of the ferrite is:

[0041] Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ Gx Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12

[0042] Where: 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1; or,

[0043] 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, θ is the process iron deficiency.

[0044] In some embodiments, when 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1,

[0045] The garnet ferrite utilizes the gyromagnetic properties of the birefringence effect and the Faraday rotation effect, and the magnetic property of high remanence specific moment, and is applied to the modulation of the microwave phase / polarization and transmission direction of the locked microwave ferrite device.

[0046] In some embodiments, the locked microwave ferrite device includes a phase shifter, a polarizer, and a switch.

[0047] In the above embodiment, Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 When 0≤x≤2.5, 0.05≤y≤0.1, 0.01≤z≤0.02, and 0.01≤ξ≤0.1, the garnet ferrite has a high remanence ratio, a low resonance linewidth, a high spin wave linewidth, and a high Curie temperature.

[0048] In the above embodiment, Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ Gx Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 When 0≤x≤2.5, 0.02≤y≤0.05, 0.005≤z≤0.02, and 0.01≤ξ≤0.1, the garnet ferrite has a low resonance linewidth, a high spin wave linewidth, and a high Curie temperature.

[0049] In some embodiments, the present invention further provides a method for preparing garnet ferrite, which is described below with multiple embodiments according to different contents of each component.

[0050] Embodiment 1:

[0051] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.95, y = 0.05, z = 0.019, ξ = 0.015;

[0052] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0053] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0054] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0055] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0056] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0057] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0058] Embodiment 2:

[0059] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.95, y = 0.05, z = 0.019, ξ = 0.015;

[0060] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0061] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0062] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0063] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0064] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0065] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0066] Embodiment 3:

[0067] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.3, y = 0.05, z = 0.02, ξ = 0.02;

[0068] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0069] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0070] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0071] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of a polyvinyl alcohol aqueous solution and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0072] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0073] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0074] Embodiment 4:

[0075] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.6, y = 0.05, z = 0.019, ξ = 0.015;

[0076] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0077] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0078] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0079] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0080] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0081] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0082] Embodiment 5:

[0083] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.6, y = 0.05, z = 0.012, ξ = 0.03;

[0084] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0085] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0086] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0087] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of a polyvinyl alcohol aqueous solution and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0088] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0089] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0090] In the above embodiment, by doping an appropriate amount of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, combined with appropriate amount of Mn 3+ions, the material can take a smaller magnetocrystalline anisotropy constant K1 under the condition of meeting a certain remanence ratio requirement, so that the material has a smaller resonance line width, while avoiding the existing technology by using In 3+ Sn 4+ The disadvantage of the material Curie temperature being greatly reduced due to non-magnetic ion doping is that Co 2+ Ion doping has the best figure of merit in improving the spin wave linewidth of garnet ferrite materials. 3+ Ion doping will not reduce the Curie temperature of the material. In high-spin wave linewidth and high-power garnet ferrite, the combined substitution of the two can achieve the best effect;

[0091] The high-power torque garnet ferrite material of the above embodiment can be widely used in locked ferrite devices such as high-power microwave ferrite phase shifters, switches, polarizers, etc., especially in the military field with high requirements for adaptability to high and low temperature environments.

[0092] Comparative Example 1:

[0093] (1) According to chemical formula Y 3-x-z-ξ G x Ca z Sn z Mn y Dy ξ Fe 5-y-z-θ O 12 , calculate and weigh the raw materials, where x = 1.5, y = 0.06, z = 0.3, ξ = 0.03;

[0094] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0095] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0096] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0097] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0098] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0099] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0100] Comparative Example 2:

[0101] (1) According to chemical formula Y 3-x G x Mn y Co z Ge z Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x=0.6, y=0.05, z=0.025;

[0102] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0103] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0104] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0105] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0106] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0107] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0108] Comparative Example 3:

[0109] (1) According to chemical formula Y 3-x-z G x Ca z Sn z Mn y Co w Ge w Fe 5-y-z-2w-θ O 12 , calculate and weigh the raw materials, where x=0.6, y=0.05, z=0.3, w=0.03;

[0110] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0111] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours;

[0112] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0113] (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0114] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0115] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0116] The data comparison of the above embodiments and comparative examples is shown in Table 1

[0117] Table 1: The first set of data comparison table

[0118]

[0119] Through the analysis of the above embodiments and comparative examples, it can be seen that by doping with non-magnetic ions Ca 2+ -Sn 4+ While reducing the ferromagnetic resonance line width, the Curie temperature and remanence ratio of the material will be significantly reduced. 2+ Ions can increase the remanence ratio, but its essence is to change the magnetocrystalline anisotropy constant K1 from negative to positive and reach a certain value, losing the remanence ratio obtained by doping with Ca 2+ -Sn 4+ The original intention of reducing the magnetocrystalline anisotropy constant K1 and thus reducing the ferromagnetic resonance line width by ions was not to reduce the line width, but to reduce the Curie temperature of the material. 2+ Ion doping, when the spin wave line width requirement is high, Co 2+ A larger ion doping amount introduces a larger magnetocrystalline anisotropy line width and also reduces the Curie temperature of the material. 2+ With Dy 3+Ion co-doping can simultaneously take into account the material's requirements for high remanence ratio, low resonance linewidth, high spin wave linewidth, and high Curie temperature.

[0120] In some embodiments, when 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, and 0.005≤ξ≤0.1, the garnet ferrite utilizes non-reciprocal transmission characteristics to modulate the transmission direction of microwaves and is applied to constant-field microwave ferrite devices.

[0121] In some embodiments, the constant-field microwave ferrite device includes a circulator or an isolator.

[0122] The above embodiment is doped with an appropriate amount of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, and then doped with an appropriate amount of Dy 3+ ions can make the magnetocrystalline anisotropy constant K1 of the material approach zero, so that the material has a smaller resonance line width, while avoiding the existing technology by using In 3+ Sn 4+ The Curie temperature of the material caused by non-magnetic ion doping is greatly reduced. 2+ Ion doping has the best figure of merit in improving the spin wave linewidth of garnet ferrite materials. 3+ Ion doping will not reduce the Curie temperature of the material. In high-spin wave linewidth and high-power garnet ferrites, the combined substitution of the two can achieve very good results.

[0123] The high-power garnet ferrite material of the above-mentioned embodiment can be widely used in ferrite devices such as high-power microwave ferrite circulators and isolators, especially in the military field with high requirements for adaptability to high and low temperature environments.

[0124] In some embodiments, the present invention further provides a method for preparing garnet ferrite, which is described below with multiple embodiments according to different contents of each component.

[0125] Embodiment 6:

[0126] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0, y = 0.02, z = 0.018, ξ = 0.025;

[0127] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0128] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0129] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0130] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to mix, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0131] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0132] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0133] Embodiment 7:

[0134] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.5, y = 0.02, z = 0.012, ξ = 0.035;

[0135] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0136] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0137] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0138] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to the slurry, mixing the mixture evenly, and sieving the mixture through a 20-60 mesh sieve to obtain a powder;

[0139] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0140] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0141] Embodiment 8:

[0142] (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.5, y = 0.02, z = 0.012, ξ = 0.035;

[0143] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0144] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0145] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0146] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to the slurry, mixing the mixture evenly, and sieving the mixture through a 20-60 mesh sieve to obtain a powder;

[0147] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0148] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0149] Embodiment 9:

[0150] (1) According to chemical formula Y 3-x-ξ Gx Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x=1, y=0.02, z=0.015, ξ=0.02;

[0151] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0152] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0153] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0154] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to mix, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0155] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0156] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0157] Comparative Example 4:

[0158] (1) According to chemical formula Y 3-x-z-ξ G x Ca z Sn z Mn y Dy ξ Fe 5-y-z-θ O 12 , calculate and weigh the raw materials, where x = 0, y = 0.02, z = 0.15, ξ = 0.05;

[0159] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0160] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0161] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0162] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to the slurry, mixing the mixture evenly, and sieving the mixture through a 20-60 mesh sieve to obtain a powder;

[0163] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0164] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0165] Comparative Example 5:

[0166] (1) According to chemical formula Y 3-x G x Mn y Co z Ge z Fe 5-y-2z-θ O 12 , calculate and weigh the raw materials, where x = 0.6, y = 0.02, z = 0.025;

[0167] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0168] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0169] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0170] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to the slurry, mixing the mixture evenly, and sieving the mixture through a 20-60 mesh sieve to obtain a powder;

[0171] (6) Molding: pressing the powder obtained in step (5) into a green body;

[0172] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0173] Comparative Example 6:

[0174] (1) According to chemical formula Y 3-x-z-ξ G x Ca z Sn z Mn y Dy ξ Fe 5-y-z-θ O 12 , calculate and weigh the raw materials, where x = 0, y = 0.02, z = 0, ξ = 0.05;

[0175] (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry;

[0176] (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100° C. to 1300° C. for 4 to 6 hours;

[0177] (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained;

[0178] (5) Granulation: drying the slurry obtained in step (4), adding 5 wt% to 15 wt% of polyvinyl alcohol-water solution to mix, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder;

[0179] (6) Molding: Pressing the powder obtained in step (5) into a green body;

[0180] (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400° C. to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

[0181] The data comparison of the above embodiments and comparative examples is shown in Table 2

[0182] Table 2: Comparison table of the first set of data

[0183]

[0184] Through the analysis of the above embodiments and comparative examples, it can be seen that by doping with non-magnetic ions Ca 2+ Sn 4+While reducing the ferromagnetic resonance line width, the Curie temperature of the material will be significantly reduced. 2+ Ion ratio Co 2+ Ions and Dy 3+ The joint doping has a higher resonance line width and a lower Curie temperature. 3+ Although the Curie temperature of Co ions is the highest, the ferromagnetic resonance line width is too large. 2+ With Dy 3+ Ion co-doping can simultaneously take into account the material's low resonance linewidth, high spin wave linewidth, and high Curie temperature index requirements.

[0185] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A high power garnet ferrite, characterized in that , the garnet ferrite is applied to microwave ferrite devices; the chemical formula of the ferrite is: Y 3-x-ξ Gd x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ Gd x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 Where: 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, θ is the process iron deficiency.

2. The high power garnet ferrite according to claim 1, characterized in that , when 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, 0.005≤ξ≤0.1, The garnet ferrite utilizes the gyromagnetic properties of the birefringence effect and the Faraday rotation effect, and the magnetic property of high remanence specific moment, and is applied to the modulation of the microwave phase / polarization and transmission direction of the locked microwave ferrite device.

3. The high power garnet ferrite according to claim 2, characterized in that ,The locked microwave ferrite device includes a phase shifter, a polarizer and a switch.

4. The high power garnet ferrite according to claim 1, characterized in that When 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, the garnet ferrite utilizes the non-reciprocal transmission characteristics to modulate the transmission direction of microwaves and is applied to constant-field microwave ferrite devices.

5. The high power garnet ferrite according to claim 4, characterized in that , the constant-field microwave ferrite device includes a circulator or an isolator.

6. The method for preparing garnet ferrite according to any one of claims 1 to 5, comprising the following steps: (1) According to chemical formula Y 3-x-ξ G x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ G x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 Calculate and weigh raw materials; (2) primary ball milling: various raw materials weighed in step (1) are placed in a ball milling jar, and grinding balls and ball milling media are added, and ball milling is performed for 18 to 30 hours to obtain a ball milled slurry; (3) Pre-calcination: The ball-milled slurry obtained in step (2) is dried, crushed, sieved, pressed into round cakes, and then pre-calcined at a temperature of 1100 to 1300° C. for 4 to 6 hours; (4) Secondary ball milling: the pre-sintered material obtained in step (3) is placed in a ball mill, and grinding balls and ball milling media are added. After ball milling for 18 to 30 hours, a secondary ball milling slurry is obtained; (5) Granulation: drying the slurry obtained in step (4), adding a polyvinyl alcohol aqueous solution at a ratio of 5 wt% to 15 wt% and mixing, and after mixing evenly, passing through a 20-60 mesh sieve to obtain a powder; (6) Molding: pressing the powder obtained in step (5) into a green body; (7) Sintering: The green body obtained in step (6) is placed in a sintering furnace for sintering at a temperature of 1400 to 1500° C. for 4 to 10 hours to obtain the garnet ferrite.

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