A high power garnet ferrite and a method of manufacturing the same

Abstract

The application belongs to the field of magnetic materials, and particularly relates to a high-power garnet ferrite and a preparation method thereof. 2+ -Ge 4+ or Co 2+ -Si 4+ ion joint substitution, through reasonable design of Co 2+ ion and Mn 3+ ion doping amount, combined with appropriate Dy 3+ doping, a garnet ferrite capable of simultaneously having high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature is obtained. The application aims at the shortcomings that garnet ferrite is difficult to simultaneously have low resonance line width, high spin wave line width and high Curie temperature, and proposes a method of Co 2+ ion and Dy 3+ ion joint substitution, so that the garnet ferrite can simultaneously have low resonance line width, high spin wave line width and high Curie temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of magnetic materials, and particularly relates to a high-power garnet ferrite and a preparation method thereof. BACKGROUND

[0002] The spin torque ferrite material with low loss, high remanence ratio, low coercivity and low temperature coefficient is required for the lock type microwave ferrite device such as a ferrite phase shifter, a switch and a variable polarizer widely used in a radar system. In particular, in a high-power device, the garnet ferrite is widely used due to its low resonance line width and high spin wave line width. However, the low loss and high power requirements of the ferrite cannot be met at the same time. The high spin wave line width means high resonance line width. How to improve the spin wave line width of the garnet ferrite while controlling the resonance line width to a small value, and at the same time 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 the garnet ferrite material, in addition to reducing the porosity and controlling the grain size in the process, two schemes are usually adopted in the formula design. One is a garnet ferrite material applied to a high-power phase shifter and a preparation method thereof described in patent CN 201510802358.0, which mainly reduces the magnetostriction coefficient of the material by doping Mn 3+ ions to improve the remanence ratio of the material. The doping of rare earth Ce 3+ ions can also achieve the same effect. The other scheme is mentioned in patent CN 108191423 B, which improves the remanence ratio of the material by substituting Co 2+ -Si 4+ ions to increase the magnetic crystal anisotropy constant K1.

[0004] The existing problems of the prior art are:

[0005] The main problem one is that in order to reduce the loss of the high-power garnet, non-magnetic ions In 3+ , Sn 4+ are usually doped to reduce the magnetic crystal anisotropy constant K1 of the material, thereby reducing the ferromagnetic resonance line width of the material. However, the substitution of In 3+ , Sn 4+ non-magnetic ions will seriously reduce the Curie temperature of the garnet ferrite, thereby deteriorating the high and low temperature performance of the material. At the same time, the reduction of K1 also makes the effect of reducing the magnetostriction coefficient of the material by doping Mn 3+ ions to improve the remanence ratio of the material not significant.

[0006] The main problem two is that patent CN 108191423 B substitutes Co 2+ -Si 4+The method of combined substitution has obvious effect on improving the material's remanence ratio, and can also improve the material's spin wave line width, but it also has the shortcomings of wide resonance line width and low Curie temperature when the substitution amount is large. In the patent example 1, the Co 2+ -Si 4+ When the substitution amount is 0.03, the ferromagnetic resonance line width is 150 Oersted, and the Curie temperature is only about 200℃ in theory, which is difficult to meet the requirements of device use.

[0007] The spin-flop ferrite materials with low loss, high power and low temperature coefficient are needed in the constant field microwave ferrite devices such as ferrite circulator and isolator widely used in radar system. Especially in high power devices, garnet ferrite is widely used due to its low resonance line width and high spin wave line width. However, the low loss and high power requirements of ferrite cannot be met at the same time, and high spin wave line width means high resonance line width. How to improve the spin wave line width of garnet ferrite while controlling the resonance line width to a small value, maintaining high Curie temperature and low temperature coefficient is an important research direction.

[0008] In order to improve the spin wave line width of garnet ferrite material, in addition to the grain refinement by hot-pressing sintering process, the main way is to design the formula by doping Co 2+ , Dy 3+ , Gd 3+ , Ho 3+ and other fast relaxation ions.

[0009] The main shortcomings of the prior art are:

[0010] The main shortcoming one is that the hot-pressing sintering process is complex, the equipment is expensive, the production efficiency is low, and the use is limited.

[0011] The main shortcoming two is that the doping of fast relaxation ions can increase the material's resonance line width while improving the spin wave line width. Non-magnetic ions such as In 3+ , Sn 4+ can be used to reduce the material's magnetocrystalline anisotropy constant K1 to reduce the material's ferromagnetic resonance line width, but this will reduce the Curie temperature of garnet ferrite, thus deteriorating the material's high and low temperature performance. The research of Jean Nicolas et al. in France in 1970 showed that adjusting the anisotropy constant K1 of garnet ferrite by appropriate Co 2+ doping can reduce the resonance line width. However, excessive Co 2+ doping to obtain higher spin wave line width will quickly increase the resonance line width. In order to maintain electrical neutrality, Co 2+ ions must be combined with non-magnetic Si 4+ or Ge 4+ ions, which will reduce the material's Curie temperature. These lead to the simple Co2+ Ion doping is limited in the use of high-power garnet materials. SUMMARY

[0012] Therefore, the present application aims at the shortcomings of the prior art that it is difficult to simultaneously consider high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature of garnet ferrite, and proposes a method of substituting Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions in combination, by reasonably designing the doping amount of Co 2+ ions and Mn 3+ ions, and cooperating with appropriate Dy 3+ doping, a garnet ferrite capable of simultaneously having high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature is obtained.

[0013] The present application aims at the shortcomings of the prior art that it is difficult to simultaneously consider low resonance line width, high spin wave line width and high Curie temperature of garnet ferrite, and proposes a method of substituting Co 2+ ions and Dy 3+ ions in combination, so that the garnet ferrite can simultaneously have low resonance line width, high spin wave line width and high Curie temperature.

[0014] The technical scheme of the present application is as follows:

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

[0016] 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

[0017] wherein: 0<=x<=3, 0.05<=y<=0.2, 0.01<=z<=0.03, 0.005<=xi<=0.1; or,

[0018] 0<=x<=3, 0.02<=y<=0.05, 0.005<=z<=0.02, 0.005<=xi<=0.1, and theta is a process iron deficiency.

[0019] Further, 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 Faraday rotation effect and the high remanence ratio magnetic characteristic, and is applied to the microwave phase / polarization and transmission direction modulation of the lock-type microwave ferrite device.

[0021] Further, the lock-type microwave ferrite device includes a phase shifter, a polarization changer, and a switch.

[0022] Further, 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 characteristic to achieve the modulation of the transmission direction of the microwave, and is applied to the constant-field microwave ferrite device.

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

[0024] In some embodiments, the present application also proposes a preparation method of the above garnet ferrite, including the following steps:

[0025] (1) calculating and weighing raw materials according to the chemical formula 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 ;

[0026] (2) first ball milling: the weighed raw materials in step (1) are put into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0027] (3) pre-sintering: the ball milling slurry obtained in step (2) is dried, crushed and sieved, pressed into a round cake, and then pre-sintered, the pre-sintering temperature is 1100-1300℃, and the temperature is kept for 4-6 hours;

[0028] (4) second ball milling: the pre-sintered material obtained in step (3) is put into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0029] (5) granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol aqueous solution at a ratio of 5wt%-15wt%, and then sieved through a 20-60 mesh screen to obtain a powder;

[0030] (6) molding: the powder obtained in step (5) is pressed into a green body;

[0031] (7) sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering at a temperature of 1400-1500℃ for 4-10 hours to obtain the garnet ferrite.

[0032] Advantages of the present application:

[0033] The present application dopes appropriate Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, adjusts the magnetic crystal anisotropy constant K1 of the YGd garnet ferrite of the basic formula from negative to positive 100-400 J / m 3 , and cooperates with the doping of appropriate Mn 3+ ions to adjust the magnetostriction coefficient of the material to be close to zero, and according to the spin wave line width requirement of the material, dopes appropriate Dy 3+ ions to obtain a garnet ferrite with high residual magnetization ratio, low resonance line width, high spin wave line width, and high Curie temperature. The ferrite material of the present application is produced and prepared by a traditional ceramic process.

[0034] The present application dopes appropriate Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, adjusts the magnetic crystal anisotropy constant K1 of the YGd garnet ferrite of the basic formula from negative to zero, and according to the spin wave line width requirement of the material, dopes appropriate Dy 3+ ions to obtain a garnet ferrite with low resonance line width, high spin wave line width, and high Curie temperature. DETAILED DESCRIPTION

[0035] The embodiments of the present disclosure will be described in detail below in combination with the schemes.

[0036] Following, the embodiments of the present disclosure are illustrated by specific examples, and other advantages and effects of the present disclosure can be easily understood by those skilled in the art from the disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The present disclosure can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details in the specification 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 those skilled in the art without creative labor are within the scope of protection of the present disclosure.

[0037] It should be noted that various aspects of the embodiments described below are within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the teachings provided herein one skilled in the art will appreciate that one aspect described herein can be implemented independently of any other aspects and that the various aspects described herein can be combined in various ways. For example, an apparatus can be implemented and / or a method practiced using any number of the aspects set forth herein. In addition, an apparatus can be implemented and / or a method practiced using other structure and / or functionality in addition to or other than one or more of the aspects set forth herein.

[0038] It should also be noted that the figures provided in the following embodiments are only illustrative of the basic concept of the present disclosure, and only show the components related to the present disclosure, not drawn according to the number, shape and size of the components in actual implementation, and the shape, number and proportion of each component in actual implementation can be arbitrarily changed, and the layout of the components can be more complex.

[0039] In addition, in the following description, specific details are provided to facilitate a thorough understanding of examples. However, one skilled in the art will understand that the aspects described can be practiced without these specific details.

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

[0041] 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 Gdx 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 birefringence effect and Faraday rotation effect, as well as the magnetic property of high remanence specific moment, and is applied to modulation of microwave phase / polarization and transmission direction of a 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 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 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 Gd x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 or Y 3-x-ξ Gdx 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, 0.01≤ξ≤0.1, the garnet ferrite has low resonance line width, high spin wave line width and high Curie temperature.

[0049] In some embodiments, the present application also provides a preparation method of the garnet ferrite. The following embodiments are described according to different component contents.

[0050] Embodiment 1:

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

[0052] (2) First ball milling: put the various raw materials weighed in step (1) into a ball mill tank, and add grinding balls and ball milling medium. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0053] (3) Pre-sintering: dry and crush the ball milling slurry obtained in step (2), press into a disc, and then pre-sinter. The pre-sintering temperature is 1100-1300°C, and the holding time is 4-6 hours;

[0054] (4) Second ball milling: put the pre-sintered material obtained in step (3) into a ball mill tank, and add grinding balls and ball milling medium. After ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0055] (5) Granulation: dry the slurry obtained in step (4), add polyvinyl alcohol aqueous solution at a proportion of 5wt%-15wt%, mix uniformly, and then pass through a 20-60 mesh sieve to obtain a powder;

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

[0057] (7) Sintering: put the green body obtained in step (6) into a sintering furnace for sintering. The sintering temperature is 1400-1500°C, and the holding time is 4-10 hours. The garnet ferrite is obtained.

[0058] Embodiment 2:

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

[0060] (2) first ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0061] (3) pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed, pressed into a disc, and then pre-sintered, the pre-sintering temperature is 1100-1300℃, and the temperature is kept for 4-6 hours;

[0062] (4) second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0063] (5) granulation: the slurry obtained in step (4) is dried, and polyvinyl alcohol aqueous solution is added at a proportion of 5wt%-15wt% for mixing, and after uniform mixing, it is passed through a 20-60 mesh sieve to obtain a powder;

[0064] (6) forming: the powder obtained in step (5) is pressed into a green body;

[0065] (7) sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500℃, and the temperature is kept for 4-10 hours, to obtain the garnet ferrite.

[0066] Example 3:

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

[0068] (2) first ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0069] (3) pre-sintering: the ball-milled slurry obtained in step (2) is dried, crushed, sieved, and pressed into a round cake, and then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

[0070] (4) secondary ball-milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball-milling media are added, and after ball-milling for 18-30 hours, a secondary ball-milled slurry is obtained;

[0071] (5) granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol aqueous solution at a ratio of 5wt%-15wt%, and sieved through a 20-60 mesh sieve after uniform mixing, to obtain a powder;

[0072] (6) shaping: the powder obtained in step (5) is pressed into a green body;

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

[0074] Example 4:

[0075] (1) according to the chemical formula Y 3-x-ξ Gd x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , the raw materials are calculated and weighed, wherein x=0.6, y=0.05, z=0.019, and ξ=0.015;

[0076] (2) primary ball-milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball-milling media are added, and after ball-milling for 18-30 hours, a ball-milled slurry is obtained;

[0077] (3) pre-sintering: the ball-milled slurry obtained in step (2) is dried, crushed, sieved, and pressed into a round cake, and then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

[0078] (4) secondary ball-milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball-milling media are added, and after ball-milling for 18-30 hours, a secondary ball-milled slurry is obtained;

[0079] (5) granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol aqueous solution at a ratio of 5wt%-15wt%, and sieved through a 20-60 mesh sieve after uniform mixing, to obtain a powder;

[0080] (6) forming: the powder obtained in step (5) is pressed into a green body;

[0081] (7) sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500℃, and the holding time is 4-10 hours, to obtain the garnet ferrite.

[0082] Example 5:

[0083] (1) according to the chemical formula Y 3-x-ξ Gd x Mn y Co z Ge z Dy ξ Fe 5-y-2z-θ O 12 , the raw materials are calculated and weighed, wherein x=0.6, y=0.05, z=0.012, and ξ=0.03;

[0084] (2) primary ball milling: the various raw materials weighed in step (1) are loaded into a ball milling tank, and milling balls and ball milling medium are added, after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0085] (3) pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed, and then pressed into a round cake, and then pre-sintered, the pre-sintering temperature is 1100-1300℃, and the holding time is 4-6 hours;

[0086] (4) secondary ball milling: the pre-sintered material obtained in step (3) is loaded into a ball milling tank, and milling balls and ball milling medium are added, after ball milling for 18-30 hours, a secondary ball milling slurry is obtained;

[0087] (5) granulation: the slurry obtained in step (4) is dried, and polyvinyl alcohol aqueous solution is added at a proportion of 5wt%-15wt% for mixing, after uniform mixing, it is passed through a 20 mesh-60 mesh sieve to obtain a powder;

[0088] (6) forming: the powder obtained in step (5) is pressed into a green body;

[0089] (7) sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500℃, and the holding time is 4-10 hours, to obtain the garnet ferrite.

[0090] In the above examples, by doping an appropriate amount of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ion, combined with doping an appropriate amount of Mn 3+ions, can make the material take smaller magnetocrystalline anisotropy constant K1 under the condition of meeting certain residual magnetism ratio requirement, so that the material has smaller resonance line width, and at the same time avoids the disadvantage of great reduction of material Curie temperature caused by doping of non-magnetic ions such as In 3+ , Sn 4+ etc. in prior art. At the same time, since Co 2+ ion doping has the best merit factor in improving spin wave line width of garnet ferrite material, doping of Dy 3+ ion will not reduce the Curie temperature of the material, and the combined substitution of both can achieve the best effect in high spin wave line width and high power garnet ferrite.

[0091] The high power spin garnet ferrite material of the above embodiment can be widely applied to high power microwave ferrite phase shifter, switch, variable polarization device and other latching ferrite devices, especially in the military field with high requirements for high and low temperature environment adaptability.

[0092] Comparative Example 1

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

[0094] (2) First ball milling: put the various raw materials weighed in step (1) into a ball mill tank, and add milling balls and ball milling medium. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0095] (3) Pre-sintering: dry and crush the ball milling slurry obtained in step (2), press into a round cake, and then pre-sinter. The pre-sintering temperature is 1100-1300℃, and the holding time is 4-6 hours;

[0096] (4) Second ball milling: put the pre-sintered material obtained in step (3) into a ball mill tank, and add milling balls and ball milling medium. After ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0097] (5) Granulation: dry the slurry obtained in step (4), and add polyvinyl alcohol aqueous solution at a proportion of 5wt%-15wt% for mixing. After uniform mixing, pass through a 20-60 mesh sieve to obtain a powder;

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

[0099] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500°C, and the holding time is 4-10 hours, to obtain the garnet ferrite.

[0100] Comparative Example 2:

[0101] (1) According to the chemical formula Y 3-x Gd x Mn y Co z Ge z Fe 5-y-2z-θ O 12 , the raw materials are calculated and weighed, wherein x = 0.6, y = 0.05, and z = 0.025;

[0102] (2) First ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling media are added. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0103] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed, pressed into a disc, and then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

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

[0105] (5) Granulation: the slurry obtained in step (4) is dried, and a polyvinyl alcohol aqueous solution is added at a proportion of 5wt%-15wt% for mixing. After uniform mixing, the mixture is passed through a 20-60 mesh sieve to obtain a powder;

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

[0107] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500°C, and the holding time is 4-10 hours, to obtain the garnet ferrite.

[0108] Comparative Example 3:

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

[0110] (2) First ball milling: the various raw materials taken in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0111] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed and sieved, pressed into a round cake, and then pre-sintered, with a pre-sintering temperature of 1100-1300°C and a holding time of 4-6 hours;

[0112] (4) Second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0113] (5) Granulation: the slurry obtained in step (4) is dried, and a polyvinyl alcohol aqueous solution is added at a proportion of 5wt%-15wt% for mixing, and after uniform mixing, the mixture is sieved through a 20-60 mesh sieve to obtain a powder;

[0114] (6) Forming: the powder obtained in step (5) is pressed into a green body;

[0115] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, with a sintering temperature of 1400-1500°C and a holding time of 4-10 hours, to obtain the garnet ferrite.

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

[0117] Table 1: First group of data comparison table

[0118]

[0119] Through analysis of the above examples and comparative examples, it can be seen that by doping non-magnetic ions Ca 2+ -Sn 4+ While reducing the ferromagnetic resonance linewidth, the Curie temperature and the remanence ratio of the material are significantly reduced, although the remanence ratio is improved by doping a certain amount of Co 2+ ion, but its essence is to change the magnetic crystal anisotropy constant K1 from negative to positive and reach a certain value, which loses the original intention of reducing the magnetic crystal anisotropy constant K1 by doping Ca 2+ -Sn 4+ ion to reduce the ferromagnetic resonance linewidth, not only does not reduce the linewidth, but also reduces the Curie temperature of the material. By doping Co 2+ ion alone, the Co 2+ ion doping amount is large when the spin wave linewidth requirement is high, which introduces a large magnetic crystal anisotropy linewidth, and also reduces the Curie temperature of the material. By doping Co 2+ and Dy 3+The ion combined doping can simultaneously meet the requirements of high residual magnetization ratio, low resonance line width, high spin wave line width and high Curie temperature of the material.

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

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

[0122] The above embodiments can make the magnetic crystal anisotropy constant K1 of the material approach to zero by doping appropriate amounts of Co 2+ -Ge 4+ or Co 2+ -Si 4+ ions, and supplementarily doping appropriate amounts of Dy 3+ ions, so that the material has a smaller resonance line width, and meanwhile, the Curie temperature of the material is not greatly reduced due to the doping of In 3+ , Sn 4+ and other non-magnetic ions in the prior art. In addition, the doping of Co 2+ ions has the best optimal coefficient in improving the spin wave line width of the garnet ferrite material, and the doping of Dy 3+ ions does not reduce the Curie temperature of the material, and the combination of the two can achieve very good results in high spin wave line width and high power garnet ferrite.

[0123] The high-power garnet ferrite material of the above embodiments can be widely applied to high-power microwave ferrite circulators, isolators and other ferrite devices, especially in the military field which has high requirements for high and low temperature environments.

[0124] In some embodiments, the present application further provides a preparation method of the garnet ferrite. The following embodiments are described according to different contents of the components.

[0125] Embodiment 6:

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

[0127] (2) First ball milling: the various raw materials taken in step (1) are loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0128] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed and sieved, pressed into a round cake, and then pre-sintered, with a pre-sintering temperature of 1100-1300°C and a holding time of 4-6 hours;

[0129] (4) Second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0130] (5) Granulation: the slurry obtained in step (4) is dried, and a polyvinyl alcohol-water solution is added at a proportion of 5-15 wt%, and after uniform mixing, the mixture is sieved through a 20-60 mesh sieve to obtain a powder;

[0131] (6) Forming: the powder obtained in step (5) is pressed into a green body;

[0132] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, with a sintering temperature of 1400-1500°C and a holding time of 4-10 hours, to obtain the garnet ferrite.

[0133] Example 7:

[0134] (1) The raw materials are calculated and taken according to the chemical formula Y 3-x-ξ Gd x Mn y Co z Si z Dy ξ Fe 5-y-2z-θ O 12 , wherein x=0.5, y=0.02, z=0.012, and ξ=0.035;

[0135] (2) First ball milling: the various raw materials taken in step (1) are loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0136] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed and sieved, pressed into a round cake, and then pre-sintered, with a pre-sintering temperature of 1100-1300°C and a holding time of 4-6 hours;

[0137] (4) Second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0138] (5) Granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol-water solution at a ratio of 5wt%-15wt%, and then sieved through a 20-60 mesh screen to obtain a powder;

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

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

[0141] Example 8:

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

[0143] (2) First ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling media are added. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0144] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and then crushed and sieved, pressed into a round cake, and then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

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

[0146] (5) Granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol-water solution at a ratio of 5wt%-15wt%, and then sieved through a 20-60 mesh screen to obtain a powder;

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

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

[0149] Example 9:

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

[0151] (2) First ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0152] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried, crushed and sieved, pressed into a disc, and then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

[0153] (4) Second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball milling medium are added. After ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0154] (5) Granulation: the slurry obtained in step (4) is dried, mixed with polyvinyl alcohol-water solution at a ratio of 5wt%-15wt%, and then sieved through a 20-60 mesh screen to obtain a powder;

[0155] (6) Forming: the powder obtained in step (5) is pressed into a green body;

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

[0157] Comparative Example 4:

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

[0159] (2) First ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added. After ball milling for 18-30 hours, a ball milling slurry is obtained;

[0160] (3) pre-sintering: the ball-milled slurry obtained in step (2) is dried, crushed, sieved, and pressed into a round cake, which is then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

[0161] (4) secondary ball-milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball-milling medium are added, and after ball-milling for 18-30 hours, a secondary ball-milled slurry is obtained;

[0162] (5) granulation: the slurry obtained in step (4) is dried, and a polyvinyl alcohol aqueous solution is added at a proportion of 5-15 wt%, and after uniform mixing, the mixture is sieved through a 20-60 mesh sieve to obtain a powder;

[0163] (6) shaping: the powder obtained in step (5) is pressed into a green body;

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

[0165] Comparative Example 5:

[0166] (1) the raw materials are calculated and weighed according to the chemical formula Y 3-x Gd x Mn y Co z Ge z Fe 5-y-2z-θ O 12 , wherein x = 0.6, y = 0.02, and z = 0.025;

[0167] (2) primary ball-milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball-milling medium are added, and after ball-milling for 18-30 hours, a ball-milled slurry is obtained;

[0168] (3) pre-sintering: the ball-milled slurry obtained in step (2) is dried, crushed, sieved, and pressed into a round cake, which is then pre-sintered at a temperature of 1100-1300°C for 4-6 hours;

[0169] (4) secondary ball-milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball-milling medium are added, and after ball-milling for 18-30 hours, a secondary ball-milled slurry is obtained;

[0170] (5) granulation: the slurry obtained in step (4) is dried, and a polyvinyl alcohol aqueous solution is added at a proportion of 5-15 wt%, and after uniform mixing, the mixture is sieved through a 20-60 mesh sieve to obtain a powder;

[0171] (6) shaping: the powder obtained in step (5) is pressed into a green body;

[0172] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500°C, and the holding time is 4-10 hours, to obtain the garnet ferrite.

[0173] Comparative Example 6:

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

[0175] (2) First ball milling: the various raw materials weighed in step (1) are loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained;

[0176] (3) Pre-sintering: the ball milling slurry obtained in step (2) is dried and crushed, and then pressed into a disc, and then pre-sintered, the pre-sintering temperature is 1100-1300°C, and the holding time is 4-6 hours;

[0177] (4) Second ball milling: the pre-sintered material obtained in step (3) is loaded into a ball mill tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a second ball milling slurry is obtained;

[0178] (5) Granulation: the slurry obtained in step (4) is dried, and polyvinyl alcohol-water solution is added at a proportion of 5wt%-15wt% for mixing, and after uniform mixing, the mixture is passed through a 20-60 mesh sieve to obtain a powder;

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

[0180] (7) Sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, the sintering temperature is 1400-1500°C, and the holding time is 4-10 hours, to obtain the garnet ferrite.

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

[0182] Table 2: First group of data comparison table

[0183]

[0184] Through the analysis of the above examples and comparative examples, it can be seen that by doping non-magnetic ions Ca 2+ , Sn 4+The Curie temperature of the material is significantly reduced while reducing the ferromagnetic resonance linewidth. Co is doped alone 2+ The ion ratio is Co 2+ The ion ratio is Dy 3+ The combined doping resonance linewidth is higher, and the Curie temperature is lower. Dy is doped alone 3+ The ion has the highest Curie temperature, but the ferromagnetic resonance linewidth is too large. Co 2+ Dy 3+ The combined doping of the ions can simultaneously meet the requirements of low resonance linewidth, high spin wave linewidth, and high Curie temperature of the material.

[0185] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A high power garnet ferrite, characterized in that The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of: 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 wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency.

2. The high power garnet ferrite of claim 1, wherein When 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1, The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of:

3. The high power garnet ferrite of claim 2, wherein wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 4. The high power garnet ferrite of claim 1, wherein 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency.

5. The high power garnet ferrite of claim 4, wherein When 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1, The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of: (1) according to the chemical formula 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 Calculate and weigh the raw materials; wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency. When 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1, The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of: wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency. The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of: wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency. The garnet ferrite is applied to a microwave ferrite device; and the ferrite has a chemical formula of: wherein 0≤x≤3, 0.05≤y≤0.2, 0.01≤z≤0.03, and 0.005≤ξ≤0.1; or, 0≤x≤3, 0.02≤y≤0.05, 0.005≤z≤0.02, 0.005≤ξ≤0.1, and θ is a process iron deficiency. The preparation method of the garnet ferrite according to any one of claims 1-5 comprises the following steps: (2) primary ball milling: the various raw materials taken in step (1) are loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a ball milling slurry is obtained; (3) pre-sintering: the ball milling slurry obtained in step (2) is dried, crushed, and sieved, pressed into a disc, and then pre-sintered, and the pre-sintering temperature is 1100-1300 ℃, and the temperature is kept for 4-6 hours; (4) secondary ball milling: the pre-sintered material obtained in step (3) is loaded into a ball milling tank, and grinding balls and ball milling medium are added, and after ball milling for 18-30 hours, a secondary ball milling slurry is obtained; (5) granulation: the slurry obtained in step (4) is dried, and polyvinyl alcohol aqueous solution is added at a proportion of 5wt%-15wt% for mixing, and after uniform mixing, the mixture is sieved through a 20-mesh-60-mesh sieve to obtain a powder; (6) shaping: the powder obtained in step (5) is pressed into a green body; (7) sintering: the green body obtained in step (6) is loaded into a sintering furnace for sintering, and the sintering temperature is 1400-1500 ℃, and the temperature is kept for 4-10 hours, and the garnet ferrite is obtained.

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