A high saturation magnetization yttrium iron garnet ferrite material and a preparation method thereof

Abstract

This invention discloses a high-saturation magnetization, low-loss yttrium iron garnet ferrite material and its preparation method. The aim is to address the shortcomings of existing YIG ferrite materials, which have a saturation magnetization of approximately 1750 Gs, making it difficult to meet the diverse requirements of high-frequency microwave devices for wide bandwidth and low loss performance. Furthermore, simply increasing saturation magnetization through ion substitution often results in increased magnetic loss and broadened ferromagnetic resonance linewidth. This invention proposes a high-saturation magnetization, low-loss yttrium iron garnet ferrite material and its preparation method. This invention achieves a relative permittivity ε through Sr-Zr ion synergistic substitution. r The ferromagnetic resonance linewidth ΔH is 90~105 Oe, and the saturation magnetization is 4π M. s A high-saturation magnetization and low-loss yttrium iron garnet ferrite material with a magnetization range of 1800~1900 Gs has been developed, achieving synergistic optimization of high saturation magnetization and low loss, and providing a material basis for the expanded application of devices such as microwave circulators and isolators.

Description

Technical Field

[0001] This invention belongs to the field of microwave device technology, specifically relating to a high saturation magnetization yttrium iron garnet ferrite material and its preparation method, which is mainly used in microwave ferrite devices such as microwave circulators and isolators. Background Technology

[0002] Among numerous microwave ferrite materials, yttrium iron garnet (YIG) is highly favored due to its unique comprehensive properties. Compared to spinel and magnetoplumb ferrites, YIG has a narrower ferromagnetic resonance linewidth (ΔH), which can minimize energy attenuation during signal transmission. Furthermore, YIG's high resistivity and good chemical and temperature stability enable it to maintain reliable performance even in harsh environments. These characteristics make it an ideal material basis for low-loss, high-stability microwave devices (such as isolators, circulators, and phase shifters) and emerging spin-wave devices.

[0003] As 5G communication, radar systems, and satellite communication expand into higher frequency bands, microwave devices place higher demands on the saturation magnetization of ferrite materials. Higher saturation magnetization (4πMs) helps broaden the operating bandwidth of devices, reduce insertion loss, and achieve better impedance matching in specific frequency bands. However, the saturation magnetization of pure-phase YIG is approximately 1750 Gs, which is insufficient to meet the diverse needs of different application scenarios. Therefore, directional control of the saturation magnetization of YIG through ion substitution has become a key approach to expanding its high-frequency application range.

[0004] Ion doping is the main method for controlling the magnetic properties of YIG, but the choice of different doping ions and their occupancy mechanisms have significantly different effects on the material properties. Divalent ions (such as Ca) 2+ 、Sr 2+ ) and tetravalent ions (such as Zr) 4+ Sn 4+ The joint substitution of Sr has attracted widespread attention due to its excellent charge compensation effect. 2+ With Zr 4+ There are relatively few studies on co-doped systems of YIG, and the mechanisms by which they affect ion radius matching, site occupancy tendency, and saturation magnetization and magnetic loss performance are still unclear, making them of significant research value. Summary of the Invention

[0005] The purpose of this invention is to address the problem that the saturation magnetization of existing YIG ferrite materials is about 1750 Gs, which is difficult to meet the differentiated requirements of high-frequency microwave devices for broadband and low-loss performance, and that simply increasing the saturation magnetization by ion substitution often leads to increased magnetic loss and broadening of the ferromagnetic resonance linewidth. The invention proposes a yttrium iron garnet ferrite material with high saturation magnetization and low magnetic loss, as well as its preparation method.

[0006] To achieve the above-mentioned objectives, the following technical solutions are mainly adopted:

[0007] A high-saturation magnetization yttrium iron garnet ferrite material and its preparation method are characterized in that: the YIG ferrite material is composed of multi-ion substituted YIG material, and its chemical formula is Yi. 3-x Sr x Fe 5-x Zr x O 12 , 0.1≤x≤0.4.

[0008] Furthermore, the ferrite material has a garnet structure and is formed by pre-sintering raw materials Y2O3, SrCO3, ZrO2, and Fe2O3 at 1100℃~1200℃, followed by sintering at 1350℃~1400℃.

[0009] Furthermore, the relative permittivity ε of the ferrite material r The ferromagnetic resonance linewidth ΔH is 90~105 Oe, and the saturation magnetization is 4π M. s It is 1800~1900Gs.

[0010] Furthermore, the preparation method of the high saturation magnetization and low loss yttrium iron garnet ferrite material is characterized by comprising the following steps:

[0011] Step 1: Using Y₂O₃, SrCO₃, ZrO₂, and Fe₂O₃ as raw materials, according to the molecular formula Y 3-x Sr x Fe 5-x Zr x O 12 Weigh the raw materials in a stoichiometric ratio of 0.1 ≤ x ≤ 0.4 to obtain a mixed raw material;

[0012] Step 2: Wet ball milling is performed on the mixed raw materials from Step 1. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain the first mixed slurry.

[0013] Step 3: Dry the first mixed slurry obtained in Step 2, and then grind and sieve the dried mixed material to obtain the dried first mixed powder;

[0014] Step 4: The first mixed powder obtained in step 3 is pre-sintered at 1100℃~1200℃ for 3~5 hours to obtain pre-sintered powder.

[0015] Step 5: The pre-calcined powder obtained in Step 4 is subjected to wet ball milling again. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain a second mixed slurry.

[0016] Step 6: Dry the second mixed slurry obtained in step 5, and then grind and sieve the dried mixed material to obtain a dried second mixed powder;

[0017] Step 7: Granulate and shape the second mixed powder obtained in step 6 to obtain a green body;

[0018] Step 8: Place the green blank obtained in step 7 into a high-temperature furnace and sinter at 1350℃~1400℃ for 5~7 hours to prepare a yttrium iron garnet ferrite material with high saturation magnetization and low loss.

[0019] Furthermore, in steps 2 and 5, the wet ball milling uses deionized water as a dispersant and zirconium dioxide balls as the milling medium. The mass ratio of raw material: zirconium balls: pure water is 1:(4~5):(3~4), the ball mill speed is 200~280 rpm, and the ball milling time is 12~16 hours.

[0020] Furthermore, in steps 3 and 6, the slurry drying temperature is 80°C;

[0021] Furthermore, in step 4, the heating rate is 1~2℃ / min;

[0022] Furthermore, in step 6, the granulating agent is a polyvinyl alcohol solution (PVA), the mass fraction of which is 15%, to obtain powder particles with a particle size between 40 and 100 mesh.

[0023] Furthermore, in step 8, the sintering process is as follows: the temperature is increased to 400-450℃ at a rate of 1-2℃ / min, held for 3 hours for debinding, then the temperature is increased to 1350℃-1400℃ at a rate of 1-2℃ / min and held for 5-7 hours; the temperature is then cooled to 800℃ at a rate of 0-1℃ / min, and finally air-cooled to room temperature.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] This invention provides a high-saturation magnetization yttrium iron garnet ferrite material and its preparation method. The method involves multi-ion co-substitution of YIG, pre-sintering at 1100℃~1200℃, and then sintering at 1350℃~1400℃, meeting the requirements for circulators and phase shifters. The saturation magnetization of YIG is 4πM. sThe yttrium iron garnet ferrite material achieves a magnetization of 1800-1900 Gs, a relative permittivity of 15.5-16.5, and maintains a ferromagnetic resonance linewidth ΔH of 90-105 Oe, enabling device miniaturization and on-chip integration. Furthermore, this invention provides a method for preparing this yttrium iron garnet ferrite material. The process is simple, cost-effective, and the composition ratio is easily controlled, making it suitable for large-scale industrial production. These characteristics make it an ideal material basis for high-saturation magnetization, low-loss microwave devices (such as isolators, circulators, and phase shifters) and emerging spin-wave devices. Attached Figure Description

[0026] Figure 1 The XRD patterns of the microwave dielectric ceramic materials prepared in Examples 1-4 of this invention are shown. Left image: Sintered at 1360℃, Y... 3-x Sr x Fe 5-x Zr x O 12 The XRD patterns of (x = 0.1, 0.2, 0.3, 0.4) are shown in the right image, which is a magnified view of the left image at 32° to 34°. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] The embodiments provide yttrium iron garnet ferrite materials with high saturation magnetization. These YIG ferrite materials are composed of multi-ion substituted YIG materials, with the chemical formula Yi. 3-x Sr x Fe 5-x Zr x O 12 , 0.1≤x≤0.4.

[0029] In some embodiments, preferably, the ferrite material has a garnet structure and is formed by pre-sintering raw materials Y2O3, SrCO3, ZrO2, and Fe2O3 at 1100℃~1200℃, and then sintering at 1350℃~1400℃.

[0030] In some embodiments, preferably, the relative permittivity ε of the ferrite material is... r The ferromagnetic resonance linewidth ΔH is 90~105 Oe, and the saturation magnetization is 4π M. s It is 1800~1900Gs.

[0031] In some embodiments, preferably, the method for preparing the high saturation magnetization yttrium iron garnet ferrite material includes the following steps:

[0032] Step 1: Using Y₂O₃, SrCO₃, ZrO₂, and Fe₂O₃ as raw materials, according to the molecular formula Y 3-x Sr x Fe 5-x Zr x O 12 Weigh the raw materials in a stoichiometric ratio of 0.1 ≤ x ≤ 0.4 to obtain a mixed raw material;

[0033] Step 2: Wet ball milling is performed on the mixed raw materials from Step 1. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain the first mixed slurry.

[0034] Step 3: Dry the first mixed slurry obtained in Step 2, and then grind and sieve the dried mixed material to obtain the dried first mixed powder;

[0035] Step 4: The first mixed powder obtained in step 3 is pre-sintered at 1100℃~1200℃ for 3~5 hours to obtain pre-sintered powder.

[0036] Step 5: The pre-calcined powder obtained in Step 4 is subjected to wet ball milling again. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain a second mixed slurry.

[0037] Step 6: Dry the second mixed slurry obtained in step 5, and then grind and sieve the dried mixed material to obtain a dried second mixed powder;

[0038] Step 7: Granulate and shape the second mixed powder obtained in step 6 to obtain a green body;

[0039] Step 8: Place the green blank obtained in step 7 into a high-temperature furnace and sinter at 1350℃~1400℃ for 5~7 hours to prepare a yttrium iron garnet ferrite material with high saturation magnetization and low loss.

[0040] In some embodiments, preferably, in steps 2 and 5, the wet ball milling uses deionized water as a dispersant and zirconium dioxide balls as the milling medium. The mass ratio of raw material: zirconium balls: pure water is 1:(4~5):(3~4), the ball mill speed is 200~280 rpm, and the ball milling time is 12~16 hours.

[0041] In some embodiments, preferably, the slurry drying temperature in steps 3 and 6 is 80°C.

[0042] In some embodiments, preferably, the heating rate in step 4 is 1~2℃ / min.

[0043] In some embodiments, preferably, in step 6, the granulating agent is a polyvinyl alcohol solution (PVA) with a mass fraction of 15%, to obtain powder particles with a particle size between 40 and 100 mesh.

[0044] In some embodiments, preferably, in step 8, the sintering process is as follows: heating to 400-450°C at a rate of 1-2°C / min, holding at that temperature for 3 hours for debinding, then heating to 1350-1400°C at a rate of 1-2°C / min and holding at that temperature for 5-7 hours; cooling to 800°C at a rate of 0-1°C / min, and finally air cooling to room temperature.

[0045] Example 1

[0046] Press Y 3-x Sr x Fe 5-x Zr x O 12 With a stoichiometric ratio of 0.1 ≤ x ≤ 0.12, 40 g of raw materials were weighed. The weighed oxide raw materials were placed in a planetary ball mill, and zirconium balls and deionized water were added at a mass ratio of raw material: zirconium balls: pure water = 1:(4~5):(3~4), where the ratio of large, medium, and small balls was 2:2:1. The mixture was thoroughly mixed at 200~280 rpm for 12~16 hours to obtain a first mixed slurry. The first mixed slurry was then dried in an 80℃ oven. After drying, the powder was sieved through a 100-mesh sieve to obtain a dried first mixed powder. This powder was then pre-sintered at 1100℃~1200℃ for 3~5 hours and cooled with the furnace to obtain a pre-sintered powder. The pre-sintered powder was then placed back into the ball mill for a second ball milling at the same speed and time to obtain a second mixed slurry. The slurry after secondary ball milling was dried and sieved to obtain a dry second mixed powder. This powder was then thoroughly mixed with an appropriate amount of 15% PVA solution, ground and granulated in a mortar, and the particles with good flowability and a particle size between 40 and 100 mesh were screened and pressed into green bodies. Finally, the green bodies were sintered at 1350℃~1400℃ for 5~7 hours, then slowly cooled to 800℃ and allowed to cool naturally. This yielded a yttrium iron garnet ferrite material with high saturation magnetization.

[0047] Example 2

[0048] Press Y 3-x Sr x Fe 5-x Zr x O 12With a stoichiometric ratio of 0.18 ≤ x ≤ 0.22, 40 g of raw materials were weighed. The weighed oxide raw materials were placed in a planetary ball mill, and zirconium balls and deionized water were added at a mass ratio of raw material: zirconium balls: pure water = 1:(4~5):(3~4), where the ratio of large, medium, and small balls was 2:2:1. The mixture was thoroughly mixed at 200~280 rpm for 12~16 hours to obtain a first mixed slurry. The first mixed slurry was then dried in an 80℃ oven. After drying, the powder was sieved through a 100-mesh sieve to obtain a dried first mixed powder. This powder was pre-sintered at 1100℃~1200℃ for 3~5 hours and cooled with the furnace to obtain a pre-sintered powder. The pre-sintered powder was then placed back into the ball mill for a second ball milling at the same speed and time to obtain a second mixed slurry. The slurry after secondary ball milling was dried and sieved to obtain a dry second mixed powder. This powder was then thoroughly mixed with an appropriate amount of 15% PVA solution, ground and granulated in a mortar, and the particles with good flowability and a particle size between 40 and 100 mesh were screened and pressed into green bodies. Finally, the green bodies were sintered at 1350℃~1400℃ for 5~7 hours, then slowly cooled to 800℃ and allowed to cool naturally. This yielded a yttrium iron garnet ferrite material with high saturation magnetization.

[0049] Example 3

[0050] Press Y 3-x Sr x Fe 5-x Zr x O 12 With a stoichiometric ratio of 0.28 ≤ x ≤ 0.32, 40 g of raw materials were weighed. The weighed oxide raw materials were placed in a planetary ball mill, and zirconium balls and deionized water were added at a mass ratio of raw material: zirconium balls: pure water = 1:(4~5):(3~4), where the ratio of large, medium, and small balls was 2:2:1. The mixture was thoroughly mixed at 200~280 rpm for 12~16 hours to obtain a first mixed slurry. The first mixed slurry was then dried in an 80℃ oven. After drying, the powder was sieved through a 100-mesh sieve to obtain a dried first mixed powder. This powder was then pre-sintered at 1100℃~1200℃ for 3~5 hours and cooled with the furnace to obtain a pre-sintered powder. The pre-sintered powder was then placed back into the ball mill for a second ball milling at the same speed and time to obtain a second mixed slurry. The slurry after secondary ball milling was dried and sieved to obtain a dry second mixed powder. This powder was then thoroughly mixed with an appropriate amount of 15% PVA solution, ground and granulated in a mortar, and the particles with good flowability and a particle size between 40 and 100 mesh were screened and pressed into green bodies. Finally, the green bodies were sintered at 1350℃~1400℃ for 5~7 hours, then slowly cooled to 800℃ and allowed to cool naturally. This yielded a yttrium iron garnet ferrite material with high saturation magnetization.

[0051] Example 4

[0052] Press Y 3-x Sr x Fe 5-x Zr x O 12 With a stoichiometric ratio of 0.38 ≤ x ≤ 0.4, 40 g of raw materials were weighed. The weighed oxide raw materials were placed in a planetary ball mill, and zirconium balls and deionized water were added at a mass ratio of raw materials: zirconium balls: pure water = 1:(4~5):(3~4), where the ratio of large, medium, and small balls was 2:2:1. The mixture was thoroughly mixed at 200~280 rpm for 12~16 hours to obtain a first mixed slurry. The first mixed slurry was then dried in an 80℃ oven. After drying, the powder was sieved through a 100-mesh sieve to obtain a dried first mixed powder. This powder was then pre-sintered at 1100℃~1200℃ for 3~5 hours and cooled with the furnace to obtain a pre-sintered powder. The pre-sintered powder was then placed back into the ball mill for a second ball milling at the same speed and time to obtain a second mixed slurry. The slurry after secondary ball milling was dried and sieved to obtain a dry second mixed powder. This powder was then thoroughly mixed with an appropriate amount of 15% PVA solution, ground and granulated in a mortar, and the particles with good flowability and a particle size between 40 and 100 mesh were screened and pressed into green bodies. Finally, the green bodies were sintered at 1350℃~1400℃ for 5~7 hours, then slowly cooled to 800℃ and allowed to cool naturally. This yielded a yttrium iron garnet ferrite material with high saturation magnetization.

[0053] The Y prepared in Examples 1 to 4 above 3-x Sr x Fe 5-x Zr x O 12 The ferrite material underwent XRD and magnetoelectric property testing. The XRD pattern is shown below. Figure 1 As shown in Table 1, the microwave dielectric properties test results are as follows.

[0054] Table 1

[0055] serial number <![CDATA[ε r ]]> ΔH <![CDATA[4πM s ]]> Example 1 15.9 103 1774 Example 2 16.5 91 1901 Example 3 16.2 105 1902 Example 4 15.4 106 1801

[0056] In summary, this invention discloses a high saturation magnetization yttrium iron garnet ferrite material and its preparation method. By introducing Sr-Zr ion substitution, the saturation magnetization of YIG is increased to above 1800~1900 Gs while maintaining low magnetic loss, which meets the requirements of microwave devices (such as circulators, phase shifters, etc.) to increase the operating bandwidth.

[0057] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A yttrium iron garnet ferrite material with high saturation magnetization, characterized in that: The YIG ferrite material is composed of a YIG material substituted by multiple ions, and has a chemical formula of Y 3-x Sr x Fe 5-x Zr x O 12 , 0.1≤x≤0.

4.

2. The yttrium iron garnet ferrite material with high saturation magnetization as described in claim 1, characterized in that: The ferrite material has a garnet structure and is formed by pre-sintering raw materials Y2O3, SrCO3, ZrO2, and Fe2O3 at 1100℃~1200℃, followed by sintering at 1350℃~1400℃.

3. The yttrium iron garnet ferrite material with high saturation magnetization as described in claim 1, characterized in that: The relative permittivity ε of the ferrite material r The ferromagnetic resonance linewidth ΔH is 90~105 Oe, and the saturation magnetization is 4π M. s It is 1800~1900Gs.

4. The method for preparing the high saturation magnetization yttrium iron garnet ferrite material according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Using Y₂O₃, SrCO₃, ZrO₂, and Fe₂O₃ as raw materials, according to the molecular formula Y 3-x Sr x Fe 5-x Zr x O 12 Weigh the raw materials in a stoichiometric ratio of 0.1 ≤ x ≤ 0.4 to obtain a mixed raw material; Step 2: Wet ball milling is performed on the mixed raw materials from Step 1. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain the first mixed slurry. Step 3: Dry the first mixed slurry obtained in Step 2, and then grind and sieve the dried mixed material to obtain the dried first mixed powder; Step 4: The first mixed powder obtained in step 3 is pre-sintered at 1100℃~1200℃ for 3~5 hours to obtain pre-sintered powder. Step 5: The pre-calcined powder obtained in Step 4 is subjected to wet ball milling again. The mixed raw materials, ball milling media and dispersant are placed in a ball mill and ball milled to obtain a second mixed slurry. Step 6: Dry the second mixed slurry obtained in step 5, and then grind and sieve the dried mixed material to obtain a dried second mixed powder; Step 7: Granulate and shape the second mixed powder obtained in step 6 to obtain a green body; Step 8: Place the green blank obtained in step 7 into a high-temperature furnace and sinter at 1350℃~1400℃ for 5~7 hours to prepare a yttrium iron garnet ferrite material with high saturation magnetization and low loss.

5. The preparation method according to claim 4, characterized in that: In steps 2 and 5, the wet ball milling uses deionized water as the dispersant and zirconium dioxide balls as the milling medium. The mass ratio of raw material: zirconium balls: pure water is 1:(4~5):(3~4). The ball mill speed is 200~280 rpm, and the milling time is 12~16 hours.

6. The preparation method according to claim 4, characterized in that: In steps 3 and 6, the slurry drying temperature is 80℃.

7. The preparation method according to claim 4, characterized in that: In step 4, the heating rate is 1~2℃ / min.

8. The preparation method according to claim 4, characterized in that: In step 6, the granulating agent is polyvinyl alcohol solution (PVA), with a mass fraction of 15%, to obtain powder particles with a particle size between 40 and 100 mesh.

9. The preparation method according to claim 4, characterized in that: In step 8, the sintering process is as follows: heat up to 400-450℃ at a rate of 1-2℃ / min, hold for 3 hours for debinding, then heat up to 1350-1400℃ at a rate of 1-2℃ / min and hold for 5-7 hours; cool down to 800℃ at a rate of 0-1℃ / min, and finally air cool to room temperature.

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