A manganese-zinc ferrite material and a method for producing the same

Abstract

The application provides a manganese-zinc ferrite material and a preparation method thereof. The manganese-zinc ferrite material comprises main components Fe2O3 51.30-51.78 mol%, ZnO 11.42-11.64 mol%, MnO 36.58-37.27 mol%, CoO 0.02-0.1 mol%; and auxiliary components CaCO3 200-2000 ppm, Bi2O3 200-2000 ppm, MoO 200-2000 ppm, NbO 200-2000 ppm, ZrO 200-2000 ppm. The material has a high Curie temperature greater than 230 DEG C, a Bs (25 DEG C) higher than 530 mT, and a high permeability and a low temperature coefficient in a temperature range of 0-230 DEG C. The manganese-zinc ferrite material provided by the application can realize stable work in a wider and more extreme environment, and greatly widens the application of the manganese-zinc ferrite in the field of electronic devices.

Description

Technical Field

[0001] This invention relates to the field of ferrite materials technology, and more specifically, to a manganese-zinc ferrite material and its preparation method. Background Technology

[0002] Currently, high-permeability manganese-zinc ferrites are widely used in electronic signal transmission, electromagnetic interference suppression technology, and environmental protection and energy conservation. However, when applied to electronic devices, manganese-zinc ferrites often require improved overall performance, such as maintaining stable high permeability over a wide temperature range. Generally, the commonly used operating temperature range is around -40 to 90°C, but military electronic products and civilian electronic products operating in extreme environments often require higher temperatures, sometimes reaching 0 to 230°C, meaning the electronic products must maintain a stable high permeability state within this temperature range. Currently, there are no reports of mass-producing products within this temperature range. Therefore, it is necessary to develop manganese-zinc ferrite materials with high Bs, high permeability, high Curie temperature, and low temperature coefficient characteristics to achieve applicability in the electronic signal field.

[0003] The current development of Mn-Zn ferrite technology in the field of high permeability manganese-zinc ferrite materials with a wide temperature range mainly focuses on effectively controlling parameters such as the range of main component formulations, the types and amounts of additives, molding density, and sintering process for different properties. These are all mentioned in existing invention patents.

[0004] For example, CN101863657B discloses a Mn-Zn ferrite with a magnetic permeability of over 5000 in a temperature range of -60 to 130°C. Its main components are iron oxide in the range of 51 to 56 mol% and zinc oxide in the range of 16 to 26 mol%. However, the temperature coefficient of magnetic permeability is relatively high in its temperature range, and its Curie temperature is low.

[0005] CN101560091A discloses a Mn-Zn ferrite material with a low temperature coefficient of magnetic permeability in the temperature range of -25 to 150°C. The main components of this material are iron oxide in the range of 52.5 to 55 mol% and zinc oxide in the range of 10 to 18 mol%. However, this patent does not explain how to achieve high magnetic permeability in the temperature ranges of -40 to -25°C and 150 to 230°C.

[0006] CN103588471B discloses a Mn-Zn ferrite material with a magnetic permeability of over 5000 in a temperature range of -55℃ to 125℃, wherein the main components are iron oxide in the range of 54 to 55 mol% and zinc oxide in the range of 14 to 15.9 mol%.

[0007] CN104961450A discloses a Mn-Zn ferrite material with a magnetic permeability of over 2900 in the temperature range of -40 to 85℃, wherein the main components are iron oxide in the range of 47.5 to 54.5 mol% and zinc oxide in the range of 15 to 24 mol%. The magnetic permeability of this invention is much lower than 5000.

[0008] As can be seen, there are currently no reports of Mn-Zn ferrite materials with a permeability exceeding 5000 within a temperature range of -55 to 230℃. Therefore, there is an urgent need to prepare a manganese-zinc ferrite material with high Bs, high permeability, high Curie temperature, and low temperature coefficient. Summary of the Invention

[0009] The main objective of this invention is to provide a manganese-zinc ferrite material and its preparation method, so as to solve the problem that manganese-zinc ferrite materials in the prior art are difficult to achieve high Bs, high permeability, high Curie temperature and low temperature coefficient characteristics at the same time.

[0010] To achieve the above objectives, according to one aspect of the present invention, a manganese-zinc ferrite material is provided, characterized in that the manganese-zinc ferrite material comprises a main component and auxiliary components; wherein the main component comprises Fe2O3: 51.30-51.78 mol%, ZnO: 11.42-11.64 mol%, MnO: 36.58-37.27 mol%, CoO: 0.02-0.1 mol%; and the content of each component of the auxiliary components, based on the total weight of the main component, is CaCO3: 200-2000 ppm, Bi2O3: 200-2000 ppm, MoO: 200-2000 ppm, NbO: 200-2000 ppm, and ZrO: 200-2000 ppm.

[0011] Further, the main components include Fe2O3: 51.02-51.63 mol%, ZnO: 11.30-11.60 mol%, CoO: 0.02-0.1 mol%, and the remainder being MnO; preferably, based on the total weight of the main components, the contents of each auxiliary component are CaCO3: 200-1000 ppm, Bi2O3: 200-1000 ppm, MoO: 200-800 ppm, NbO: 200-2000 ppm, and ZrO: 200-2000 ppm.

[0012] According to another aspect of the present invention, a method for preparing a manganese-zinc ferrite material is provided, characterized in that the method includes the following steps: (1) pre-calcination: weigh each component raw material of the main component, wet ball mill and dry them, and then pre-calcinate them to obtain a pre-calcined material; (2) mixing: wet ball mill the pre-calcined material and each component raw material of the auxiliary component to obtain a mixed slurry; (3) tempering: dry the mixed slurry and then temper it to obtain a tempered material; (4) granulation: dry the tempered material to obtain a dried material, then mix the dried material with a binder, grind and granulate it to obtain granules; (5) pressing: press the granules into a molded body to obtain a molded body; (6) sintering: sinter the molded body to obtain a manganese-zinc ferrite material.

[0013] Furthermore, the sintering temperature is 1250–1300℃, and the sintering time is 5–7 h; preferably, the oxygen content in the sintering atmosphere is 3–5 vol%, and the atmosphere other than oxygen is an inert gas.

[0014] Furthermore, prior to the sintering process, the preparation method also includes a heating process, which includes: firstly, heating the molded body to 600-800°C and holding it at that temperature for 2-3 hours under a sintering atmosphere with an oxygen content of 19-21 vol%; secondly, heating it to 1100-1300°C within 6-10 hours and holding it at that temperature for 5-8 hours.

[0015] Furthermore, after the sintering process, the preparation method also includes a cooling process, which is carried out under equilibrium oxygen partial pressure.

[0016] Furthermore, the pre-firing process is carried out in an air atmosphere; the pre-firing temperature is 650–800℃, and the time is 2–3 hours.

[0017] Furthermore, the tempering temperature is 650–800℃.

[0018] Furthermore, the wet ball milling time is 70–90 minutes.

[0019] Furthermore, the particle size of the granules is 1.0–1.05 μm.

[0020] Furthermore, the binder accounts for 10-12 wt% of the dried material; the binder includes one or more of PVA, adhesive, and epoxy resin.

[0021] Using the technical solution of this invention, a manganese-zinc ferrite material was prepared. This material has a high Curie temperature greater than 230°C, a Bs value higher than 530 mT (25°C), and achieves high permeability and a low temperature coefficient within a temperature range of -55°C to 230°C. The manganese-zinc ferrite material provided by this invention can achieve stable operation under wider and more extreme environmental conditions, greatly expanding the application of manganese-zinc ferrite in the field of electronic devices. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0023] To address the aforementioned technical problems, according to one aspect of the present invention, a manganese-zinc ferrite material is provided, comprising a main component and auxiliary components; wherein the main component comprises Fe2O3: 51.30–51.78 mol%, ZnO: 11.42–11.64 mol%, MnO: 36.58–37.27 mol%, and CoO: 0.02–0.1 mol%; and the auxiliary components, based on the total weight of the main component, contain the following amounts: CaCO3: 200–2000 ppm, Bi2O3: 200–2000 ppm, MoO: 200–2000 ppm, NbO: 200–2000 ppm, and ZrO: 200–2000 ppm. Using the technical solution of the present invention, a manganese-zinc ferrite material was prepared. This material exhibits a high Curie temperature greater than 230°C, a Bs value exceeding 530 mT (25°C), and achieves high permeability and a low temperature coefficient within a temperature range of 0–230°C. The manganese-zinc ferrite material provided by this invention enables stable operation under wider and more extreme environmental conditions, greatly expanding the application of manganese-zinc ferrite in the field of electronic devices.

[0024] In manganese-zinc ferrite materials, the magnetic permeability increases with increasing zinc oxide content, while the impedance decreases accordingly. Therefore, within a certain range, increasing the zinc oxide content is beneficial for improving the magnetic permeability of manganese-zinc ferrites. However, excessive zinc oxide can reduce the Curie temperature and temperature stability of the material, making it unsuitable for applications over a wide temperature range. Therefore, selecting the composition ratio of the main component based on the working environment and application is crucial. In this invention, the zinc oxide content is 11.42–11.64 mol%.

[0025] In manganese-zinc ferrite materials, CoO is added as a main component. Its anisotropy constant (K1) is greater than 0, and the value of K1 decreases sharply with the increase of temperature. CoO is combined with other main components to adjust K1 to move towards lower temperatures. The curve is flatter in the range of 0 to 230℃ and the magnetic permeability μi (0 to 230℃) is between 5000 and 5500.

[0026] Meanwhile, the auxiliary components doped in the technical solution provided by this invention can also improve the magnetic permeability of the material and maintain a low temperature coefficient. Furthermore, the main and auxiliary components also have a synergistic effect, thereby improving the temperature characteristics of the material.

[0027] In summary, it is precisely because of the main and auxiliary components and their range values ​​provided in the technical solution of the present invention as described above that the manganese-zinc ferrite material provided by the present invention has a Curie temperature greater than 230°C, can be used in the range of 0 to 230°C, and has good properties such as magnetic permeability, saturation magnetic flux, and temperature coefficient within this range.

[0028] To further improve the Curie temperature and temperature stability of the manganese-zinc ferrite material, in a preferred embodiment, the main components of the above-mentioned manganese-zinc ferrite material include Fe2O3: 51.02-51.63 mol%, ZnO: 11.30-1160 mol%, CoO: 0.02-0.1 mol%, and the remainder being MnO; preferably, based on the total weight of the main components, the contents of each auxiliary component are CaCO3: 200-1000 ppm, Bi2O3: 200-1000 ppm, MoO: 200-800 ppm, NbO: 200-2000 ppm, and ZrO: 200-2000 ppm.

[0029] According to another aspect of the present invention, a method for preparing the above-mentioned manganese-zinc ferrite material is provided, comprising the following steps: (1) pre-calcination: weighing each component raw material of the main component, wet ball milling and drying them, and then pre-calcining them to obtain pre-calcined material; (2) mixing: wet ball milling the pre-calcined material and each component raw material of the auxiliary component to obtain a mixed slurry; (3) tempering: drying the mixed slurry and then tempering it to obtain tempered material; (4) granulation: drying the tempered material to obtain dried material, then mixing the dried material with a binder, grinding and granulating it to obtain granules; (5) pressing: pressing the granules into a molded body to obtain a molded body; (6) sintering: sintering the molded body to obtain the manganese-zinc ferrite material. Using the technical solution of the present invention, a manganese-zinc ferrite material was prepared. This material has a high Curie temperature greater than 230°C, a Bs (25°C) greater than 530 mT, and achieves high permeability and low temperature coefficient in the temperature range of 0–230°C. The manganese zinc ferrite material provided by this invention can achieve stable operation under a wider range of more extreme environmental conditions, which greatly expands the application of manganese zinc ferrite in the field of electronic devices.

[0030] As mentioned above, in the manganese-zinc ferrite material provided by this invention, CoO is added as the main component. Therefore, in the preparation method of this invention, the CoO component undergoes multiple processes including ball milling, pre-firing, tempering, and sintering. Through the above processes, CoO can be... 2+The uniform distribution of elements results in the manganese-zinc ferrite material prepared according to the method of the present invention exhibiting excellent properties such as high initial permeability, low temperature coefficient, and wide temperature range. In particular, while there are reports in the prior art of improving the overall performance of ferrites by pre-calcining the main components, such as in CN114195500A, where a secondary tempering process is performed on the ball-milled powder after pre-calcination, Co2O3 is present as an auxiliary component in that patent, and therefore Co2O3, as an auxiliary material, is not pre-calcined. In contrast, in the technical solution of the present invention, a larger amount of CoO is added, and it is innovatively pre-calcined together with Fe2O3, ZnO, and MnO as the main component. This results in a more uniform elemental distribution, and as the main component, it can better adjust the K1 to shift towards lower temperatures with other components, making the permeability μi (0~230℃) between 5000 and 5500, exhibiting an excellent temperature coefficient, and achieving unexpectedly beneficial technical effects.

[0031] To further improve the temperature characteristics of manganese-zinc ferrite materials, in a preferred embodiment, the sintering temperature is 1250–1300°C, and the sintering time is 5–7 hours. Preferably, the oxygen content in the sintering atmosphere is 3–5 vol%, and the atmosphere other than oxygen is an inert gas. In actual operation, the inert gas can be nitrogen, argon, or other inert gases that do not react with manganese-zinc ferrite. A lower sintering temperature is preferred, as it allows for higher grain density and more uniform ion distribution in the ferrite, resulting in manganese-zinc ferrite materials with high Curie temperature, high Bs, and high initial permeability.

[0032] To further improve the temperature characteristics of manganese-zinc ferrite materials, in a preferred embodiment, the preparation method further includes a heating process before the sintering process. This heating process includes: first, heating the molded body to 600–700°C and holding it at that temperature for 2–3 hours in a sintering atmosphere with an oxygen content of 19–21 vol%; then, heating it to 1100–1300°C within 6–10 hours and holding it at that temperature for 5–8 hours. Through this preferred series of heating and holding processes, low-temperature gradient sintering is achieved, which can better improve lattice defects, thereby obtaining a material with better overall magnetic properties.

[0033] In practice, preferably, after the sintering process, the preparation method also includes a cooling process, which is carried out under equilibrium oxygen partial pressure.

[0034] To further enhance the magnetic properties of manganese-zinc ferrite materials, in a preferred embodiment, the pre-firing process is carried out in an air atmosphere; the pre-firing temperature is 650–800°C, and the time is 2–3 hours.

[0035] To further improve the stability of the material's internal structure and make the distribution of its components more uniform, in a preferred embodiment, the tempering temperature is 650–800°C.

[0036] The process conditions for wet ball milling can be conventional in the art, but for the purpose of further ensuring thorough mixing of the components, the wet ball milling time is preferably 70 to 90 minutes.

[0037] To further ensure uniform mixing of all components and uniform ion distribution, the particle size of the granules is preferably 1.0 to 1.05 μm.

[0038] In order to better mix the tempering material, in a preferred embodiment, the binder accounts for 10-12 wt% of the weight of the dried material; the binder includes one or more of PVA, adhesive, and epoxy resin.

[0039] In practice, the granules are preferably pressed in a press. The dimensions of the pressed body are preferably H25×15×8.

[0040] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0041] Example 1

[0042] The four main components of the designed formula, Fe2O3: 51.63 mol%, MnO: 36.3 mol%, ZnO: 11.60 mol%, and CoO: 0.47 mol%, were accurately weighed and ball-milled until homogeneous. After drying in an oven, the mixture was pre-calcined at 700℃ for 3 hours to obtain a pre-calcined material. Then, auxiliary components (based on the total amount of the main components) were added to the pre-calcined material: Bi2O3: 400 ppm, CaCO3: 400 ppm, MoO: 200 ppm, NbO: 200 ppm, and ZrO: 200 ppm. The mixture was ball-milled for 70 minutes, dried, and then tempered at 750℃. Finally, 10 wt% PVA was added to granulate the mixture to obtain ferrite particles, which were then sieved. Ferrite granules were pressed into blanks with dimensions of H25×15×8 using a press. These blanks were then sintered at 600℃ for 2 hours under N2 conditions with an oxygen content of 21 vol%. Next, they were sintered at 1100℃ for 8 hours under N2 conditions with an oxygen content of 21 vol%. Finally, they were sintered at 1290℃ for 7 hours under N2 conditions with an oxygen content of 4 vol%. The blanks were then cooled under balanced oxygen partial pressure to obtain powder cores for testing.

[0043] Example 2

[0044] The four main components of the designed formula, Fe2O3: 51.44 mol%, MnO: 36.60 mol%, ZnO: 11.49 mol%, and CoO: 0.47 mol%, were accurately weighed and ball-milled until uniformly mixed. After drying in an oven, the mixture was pre-calcined at 800℃ for 3 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components): CaCO3: 400 ppm, Bi2O3: 400 ppm, MoO: 200 ppm, NbO: 300 ppm, and ZrO: 200 ppm were added to the pre-calcined material and ball-milled for 80 minutes. Then, the mixture was dried and tempered at 800℃. Finally, 10 wt% PVA was added to granulate the mixture to obtain ferrite granules, which were then sieved. Ferrite granules were pressed into blanks with dimensions of H25×15×8 using a press. These blanks were then sintered at 650°C for 3 hours under N2 conditions with an oxygen content of 21 vol%. Next, they were sintered at 1120°C for 5 hours under N2 conditions with an oxygen content of 21 vol%. Finally, they were sintered at 1290°C for 5 hours under N2 conditions with an oxygen content of 3 vol%. The blanks were then cooled under balanced oxygen partial pressure to obtain powder cores for testing.

[0045] Example 3

[0046] The four main components of the designed formula, Fe2O3: 51.24 mol%, MnO: 36.81 mol%, ZnO: 11.49 mol%, and CoO: 0.55 mol%, were accurately weighed and ball-milled until uniformly mixed. After drying in an oven, the mixture was pre-calcined at 800℃ for 2 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components) were added to the pre-calcined material: CaCO3: 200 ppm, Bi2O3: 600 ppm, MoO: 200 ppm, NbO: 200 ppm, and ZrO: 250 ppm. The mixture was then ball-milled for 100 min and then again for 80 min. After drying, it was tempered at 850℃. Finally, 10 wt% PVA was added to granulate the mixture to obtain ferrite granules, which were then sieved. Ferrite granules were pressed into blanks with dimensions of H25×15×8 using a press. These blanks were then sintered at 700°C for 2 hours under N2 conditions with an oxygen content of 21 vol%. Next, they were sintered at 1100°C for 8 hours under N2 conditions with an oxygen content of 21 vol%. Finally, they were sintered at 1280°C for 7 hours under N2 conditions with an oxygen content of 5 vol%. The blanks were then cooled under balanced oxygen partial pressure to obtain powder cores for testing.

[0047] Example 4

[0048] The four main components of the designed formula, Fe2O3: 51.03 mol%, MnO: 36.81 mol%, ZnO: 11.40 mol%, and CoO: 0.47 mol%, were accurately weighed and ball-milled until uniformly mixed. After drying in an oven, the mixture was pre-calcined at 650°C for 3 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components) were added to the pre-calcined material: CaCO3: 600 ppm, Bi2O3: 600 ppm, MoO: 200 ppm, NbO: 250 ppm, and ZrO: 250 ppm. The mixture was then ball-milled for 90 minutes, dried, and tempered at 750°C. Finally, 10 wt% PVA was added to granulate the mixture to obtain ferrite granules, which were then sieved. Ferrite granules were pressed into blanks with dimensions of H25×15×8 using a press. These blanks were then sintered at 700°C for 2 hours under N2 conditions with an oxygen content of 21 vol%. Next, they were sintered at 1100°C for 8 hours under N2 conditions with an oxygen content of 21 vol%. Finally, they were sintered at 1300°C for 5 hours under N2 conditions with an oxygen content of 5 vol%. The blanks were then cooled under balanced oxygen partial pressure to obtain powder cores for testing.

[0049] Example 5

[0050] The four main components of the designed formula, Fe2O3: 51.58 mol%, MnO: 36.35 mol%, ZnO: 11.52 mol%, and CoO: 0.55 mol%, were accurately weighed and ball-milled until uniformly mixed. After drying in an oven, the mixture was pre-calcined at 650℃ for 3 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components) were added to the pre-calcined material: CaCO3: 400 ppm, Bi2O3: 800 ppm, MoO: 300 ppm, NbO: 400 ppm, and ZrO: 400 ppm. The mixture was then ball-milled for 90 minutes, dried, and tempered at 850℃. Finally, 12 wt% PVA was added to granulate the mixture to obtain ferrite granules, which were then sieved. Ferrite granules were pressed into blanks with dimensions of H25×15×8 using a press. These blanks were then sintered at 700°C for 2 hours under N2 conditions with an oxygen content of 19 vol%. Next, they were sintered at 1120°C for 6 hours under N2 conditions with an oxygen content of 21 vol%. Finally, they were sintered at 1260°C for 7 hours under N2 conditions with an oxygen content of 5 vol%. The blanks were then cooled under balanced oxygen partial pressure to obtain powder cores for testing.

[0051] Comparative Example 1

[0052] The three main components of the designed formula, Fe2O3: 49.7mol%, MnO: 38.9mol%, and ZnO: 11.4mol%, were accurately weighed, ball-milled and mixed evenly, dried in an oven, and pre-calcined at 800℃ for 3 hours to obtain pre-calcined material. Auxiliary components (based on the total amount of main components) were added to the pre-calcined material: CaCO3: 400ppm, Bi2O3: 400ppm, CoO: 2000ppm, and MoO: 200ppm. The mixture was ball-milled for 80 minutes, and then 10wt% PVA was added to granulate the material to obtain ferrite granules, which were then sieved. Ferrite powder is pressed into blank samples of H25×15×8 by a press, and sintered at 1100℃ for 6 hours under N2 control with oxygen content of 21 vol%. Then, it is sintered at 1330℃ for 2 hours under N2 control with oxygen content of 5 vol%. The cooling stage is carried out under balanced oxygen partial pressure, and the magnetic core can be obtained for testing.

[0053] Comparative Example 2

[0054] The three main components of the designed formula, Fe2O3: 53.0 mol%, MnO: 35.4 mol%, and ZnO: 11.6 mol%, were accurately weighed and ball-milled until uniformly mixed. The mixture was then pre-calcined at 750℃ for 3 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components) were added to the pre-calcined material: CaCO3: 400 ppm, Bi2O3: 400 ppm, CoO: 1000 ppm, and MoO: 200 ppm. The mixture was ball-milled for 70 minutes, and then spray-granulated to obtain ferrite particles, which were then sieved. The ferrite powder was pressed into H25×15×8 blank samples and sintered at 1100℃ for 6 hours under N2 control with an oxygen content of 21 vol%. Then, it was sintered at 1300℃ for 2 hours under N2 control with an oxygen content of 5 vol%. The cooling stage was carried out under equilibrium oxygen partial pressure, yielding the magnetic core for testing.

[0055] Comparative Example 3

[0056] The three main components, Fe2O3: 52.0 mol%, MnO: 36.3 mol%, and ZnO: 11.7 mol%, were precisely weighed and ball-milled until uniformly mixed. The mixture was then dried in an oven and pre-calcined at 700℃ for 3 hours to obtain a pre-calcined material. Auxiliary components (based on the total amount of the main components): CaCO3: 400 ppm, Bi2O3: 400 ppm, and MoO: 200 ppm were added to the pre-calcined material and ball-milled for 100 minutes. The resulting ferrite particles were then obtained by spray granulation and sieved. The ferrite powder was pressed into H25×15×8 blank samples and sintered at 1110℃ for 6 hours under N2 conditions with an oxygen content of 21 vol%. Then, it was sintered at 1310℃ for 2 hours under N2 conditions with an oxygen content of 5 vol%. The cooling stage was carried out under balanced oxygen partial pressure to obtain the magnetic core for testing.

[0057] The performance indicators of the manganese-zinc ferrite materials prepared by the above method are shown in Table 1 and Table 2.

[0058] Table 1

[0059]

[0060] Table 2

[0061]

[0062]

[0063] As can be seen from the examples, the main component within the scope of this invention, with CoO as the main component, achieves the target value in magnetic permeability and has an extremely low temperature coefficient, thus meeting the target requirements.

[0064] As can be seen from Comparative Examples 1 to 3, manganese-zinc ferrites with main and auxiliary components added in amounts outside the scope of the present invention, and those with CoO used only as an auxiliary component and not pre-calcined, have relatively high temperature coefficients of magnetic permeability in the range of 0 to 230°C, and their magnetic permeability changes significantly with temperature. Therefore, it is difficult to ensure that electronic devices operate normally within this temperature range.

[0065] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0066] Using the technical solution of this invention, a manganese-zinc ferrite material was prepared. This material has a high Curie temperature greater than 230°C, a Bs value higher than 530 mT (25°C), and achieves high permeability and a low temperature coefficient within a temperature range of 0–230°C. The manganese-zinc ferrite material provided by this invention can achieve stable operation under wider and more extreme environmental conditions, greatly expanding the application of manganese-zinc ferrite in the field of electronic devices.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A manganese-zinc ferrite material, characterized in that, The manganese-zinc ferrite material includes a main component and auxiliary components; The main components include Fe2O3: 51.02~51.63 mol%, ZnO: 11.30~11.60 mol%, CoO: 0.47 mol%, and the remainder is MnO; Based on the total weight of the main components, the contents of each auxiliary component are: CaCO3: 200~2000ppm, Bi2O3: 200~2000ppm, MoO: 200~2000ppm, NbO: 200~2000ppm, ZrO: 200~2000ppm.

2. The manganese-zinc ferrite material according to claim 1, characterized in that, Based on the total weight of the main components, the contents of each auxiliary component are as follows: CaCO3: 200~1000 ppm, Bi2O3: 200~1000 ppm, MoO: 200~800 ppm, NbO: 200~2000 ppm, ZrO: 200~2000 ppm.

3. A method for preparing the manganese-zinc ferrite material according to claim 1 or 2, characterized in that, The method Includes the following steps: S1, Pre-calcination: Weigh each component raw material of the main component separately, wet ball mill them, dry them, and then pre-calcine them to obtain pre-calcined material; S2, Mixing: The pre-calcined material and the auxiliary components are wet-milled to obtain a mixed slurry; S3, Tempering: The mixed slurry is dried and then tempered to obtain tempered material; S4, Granulation: The tempered material is dried to obtain dried material, and then the dried material is mixed with a binder, ground and granulated to obtain granules; S5, Pressing: Pressing the granules into a molded shape to obtain a molded body; S6, Sintering: The molded body is sintered to obtain the manganese-zinc ferrite material.

4. The method for preparing the manganese-zinc ferrite material according to claim 3, characterized in that, The sintering process is carried out at a temperature of 1250~1300℃ for 5~7 hours.

5. The method for preparing the manganese-zinc ferrite material according to claim 4, characterized in that, The oxygen content in the sintering atmosphere during the sintering process is 3-5 vol%, and the atmosphere other than oxygen is an inert gas.

6. The method for preparing the manganese-zinc ferrite material according to claim 3, characterized in that, Before the sintering process, the preparation method further includes a heating process, which includes: firstly heating the molded body to 600-800°C and holding it at that temperature for 2-3 hours under a sintering atmosphere with an oxygen content of 19-21 vol%; secondly, heating the body to 1100-1300°C within 6-10 hours and holding it at that temperature for 5-8 hours.

7. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, Following the sintering process, the preparation method further includes a cooling process, which is carried out under equilibrium oxygen partial pressure.

8. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, The pre-firing process is carried out in an air atmosphere; the pre-firing temperature is 650~800℃ and the time is 2~3h.

9. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, The tempering temperature is 650~800℃.

10. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, The wet ball milling time is 70-90 minutes.

11. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, The particle size of the granules is 1.0~1.05μm.

12. The method for preparing the manganese-zinc ferrite material according to any one of claims 3 to 6, characterized in that, The binder accounts for 10-12 wt% of the weight of the dried material; the binder includes one or more of PVA, adhesive, and epoxy resin.

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