Ferrite material, preparation method thereof and magnetic converter containing ferrite material

Abstract

The invention belongs to the technical field of magnetic materials, and provides a ferrite material, a preparation method thereof and a magnetic converter containing the same, the ferrite material comprises a main component and an additive component; the main component comprises the following components in parts by weight: 71.20 to 72.50 parts of Fe2O3, 2.00 to 4.80 parts of ZnO and 22.7 to 26.8 parts of Mn3O4, and the additive component comprises the following components in parts by weight: CaO, Li2O, CoO, CuO and Nb2O5. According to the present invention, the main components comprise the high Fe2O3 content and the low ZnO content, and the specific additive components are matched, such that the obtained ferrite material has characteristics of high Curie temperature and high saturation magnetic flux density, can have the low loss characteristic under the conditions of wide temperature range (25-120 DEG C) and high frequency (1-4 MHz), and can effectively support the high frequency and miniaturization development of the converter.

Description

Technical Field

[0001] This invention belongs to the field of magnetic materials technology, and relates to a ferrite material, its preparation method, and a magnetic transducer containing it. Background Technology

[0002] With the continuous development of technology, the level of digitalization and intelligence in various industries is getting higher and higher. The development of "digitalization and intelligence" cannot be separated from the strong support provided by power supply devices. As a result, higher technical requirements are placed on manganese zinc soft magnetic ferrite, which is a core component of power supplies. At present, in accordance with the trend of improving power supply efficiency and ensuring device miniaturization, the overall development of power-type manganese zinc soft magnetic ferrite materials needs to gradually move towards wide temperature range and low loss, and high frequency and low loss. However, the loss of manganese zinc soft magnetic ferrite materials in the frequency range of 1MHz to 4MHz is generally too high, which limits the development progress of devices towards high frequency applications. Summary of the Invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a ferrite material, a method for preparing the same, and a magnetic converter containing the same, wherein the ferrite material has the characteristics of wide temperature range, high frequency range, and low loss, thereby supporting the miniaturization of the magnetic converter and enabling it to operate in a higher temperature and wider frequency range.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides a ferrite material comprising a main component and additive components; the main component, based on 100 parts by weight, comprises 71.20 to 72.50 parts of Fe2O3, 2.00 to 4.80 parts of ZnO, and 22.7 to 26.8 parts of Mn3O4; the additive components, based on 100 parts by weight of the main component, comprise 0.055 to 0.11 parts of CaO, 0.05 to 0.07 parts of Li2O, 0.25 to 0.35 parts of CoO, 0.01 to 0.06 parts of CuO, and 0.01 to 0.04 parts of Nb2O5.

[0006] The ferrite material provided by this invention has a formula with high Fe2O3 content and low ZnO content as the main components, which can reduce the Curie temperature T of the ferrite material. c At temperatures above 290℃ and with a high saturation magnetic flux density B sThis facilitates the acquisition of ferrite materials with low permeability and permeability-temperature (or power dissipation-temperature) stability, supporting better applications in high-frequency environments. Among the additives, CaO can be derived from the decomposition of CaCO3, forming a high-resistivity layer at the grain boundaries to increase grain boundary resistivity and suppress eddy currents. Li2O and CoO can be derived from LiCoO2, which has a melting point above 1000℃, while CuO has a melting point of 1046℃. At certain sintering temperatures, both can promote solid-state reactions in the ferrite in liquid phase. The combined effect of CuO and LiCoO2 is beneficial for solid-state reactions at low-temperature sintering, while also increasing the saturation magnetic flux density B. s The function of Cu; in addition, Cu 2+ It can enter the spinel phase to form copper ferrite CuFe2O4, and Li in LiCoO2 + It can enter the spinel phase to form lithium ferrite (Li). 0.5 Fe 2.5 O4, Cu 2+ With Li + It can promote Fe 2+ Fe 3+ To improve the resistivity of ferrite and effectively reduce high-frequency eddy current losses, the reaction of Co in LiCoO2 with Fe2O3 to form CoFe2O4, whose K1 (magnetocrystalline anisotropy constant) is positive, can adjust the final K1-T of the ferrite material, effectively improving the power dissipation-temperature characteristics of the material and reducing high-frequency losses. Nb2O5 promotes mass exchange and synthesis during its solid-state reaction, but ultimately distributes itself at the grain boundaries, inhibiting disordered grain growth and promoting full and uniform grain growth, thus reducing high-frequency losses. Through these methods, the resistivity of ferrite grain boundaries and the interior of the grains can be effectively improved, ensuring that the densification of the material at low sintering temperatures meets the product's requirements, ultimately resulting in a practically valuable high-frequency, low-loss ferrite material.

[0007] Therefore, the ferrite material and the magnetic converter formed therefrom provided by the present invention can work in various complex temperature environments, and have a wide standby and working temperature range. The standby no-load loss is small and the working loss is low. It can meet the power loss requirements in a wider design temperature range. That is, the characteristics of wide temperature, high frequency and low loss are conducive to the miniaturization of the device and enable the device to work well in a higher temperature and a wider frequency range.

[0008] For example, in the main component, the weight percentage of Fe2O3 is 71.20 parts to 72.50 parts, such as 71.2 parts, 71.3 parts, 71.4 parts, 71.5 parts, 71.6 parts, 71.7 parts, 71.8 parts, 71.9 parts, 72 parts, 72.1 parts, 72.2 parts, 72.3 parts, 72.4 parts, or 72.5 parts, etc.; the weight percentage of ZnO is 2.00 parts to 4.80 parts, such as 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, etc. 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, or 4.8 parts, etc.; the weight percentage of Mn3O4 is 22.7 parts to 26.8 parts, for example, it can be 22.7 parts, 23 parts, 23.3 parts, 23.5 parts, 23.8 parts, 24 parts, 24.3 parts, 24.5 parts, 24.8 parts, 25 parts, 25.3 parts, 25.5 parts, 25.8 parts, 26 parts, 26.3 parts, 26.5 parts, or 26.8 parts, etc.

[0009] For example, relative to 100 parts by weight of the main component, the weight percentage of CaO can be 0.055 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.1 parts, or 0.11 parts, etc.; the weight percentage of Li2O can be 0.05 parts, 0.055 parts, 0.06 parts, 0.065 parts, or 0.07 parts, etc.; and the weight percentage of CoO can be 0.25 parts to 0.35 parts. The weight percentages of CuO can be 0.25, 0.28, 0.30, 0.32, or 0.35, etc.; the weight percentages of CuO can be 0.01, 0.02, 0.03, 0.04, 0.05, or 0.06, etc.; the weight percentages of Nb2O5 can be 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, or 0.04, etc.

[0010] In some embodiments of the present invention, the average diameter of the cross-sectional grains of the ferrite material is <8 μm. Exemplarily, the average diameter of the cross-sectional grains can be 7.9 μm, 7.6 μm, 7.2 μm, 7 μm, 6.8 μm, 6.5 μm, 6.3 μm, 6 μm, 5.5 μm, 5.2 μm, or 5 μm, etc. Exemplarily, the size of the cross-sectional grains can be obtained by cross-sectional SEM testing and analysis using a scanning electron microscope. The formulation of the ferrite material of the present invention is beneficial for obtaining smaller grain sizes, which is beneficial for improving loss characteristics at high frequencies.

[0011] In some embodiments of the present invention, the maximum applied magnetic induction intensity B is between 22°C and 28°C. m Under test conditions of <0.25mT, the initial permeability μ of the ferrite material is... i The value is 580 to 880. For example, μ...i It can be 580, 600, 620, 640, 660, 680, 700, 720, 740, 760, 780, 800, 820, 840, 860, or 880, etc.

[0012] In some embodiments of the present invention, the maximum applied magnetic field strength H is between 22°C and 28°C. m Under test conditions of 1194 A / m and frequency f = 1 kHz, the saturation magnetic flux density B of the ferrite material is... s >520mT. For example, B s It can be 521mT, 522mT, 525mT, 528mT, 530mT, 532mT, or 535mT, etc.

[0013] In some embodiments of the present invention, at the applied maximum magnetic induction intensity B m Under test conditions of <0.25mT, the Curie temperature T of the ferrite material is... c >290℃.

[0014] In some embodiments of the present invention, the maximum applied magnetic induction intensity B is between 25°C and 120°C. m Under test conditions of 50mT and frequency f=1MHz, the volumetric magnetic loss P of the ferrite material is... cv <100kW / m 3 .

[0015] In some embodiments of the present invention, the maximum applied magnetic induction intensity B is between 25°C and 120°C. m Under test conditions of 36mT and frequency f=4MHz, the volume magnetic loss P of the ferrite material is... cv <1000kW / m 3 .

[0016] In a second aspect, the present invention provides a method for preparing the ferrite material described in the first aspect, including the design and selection of raw materials, the design of a formula containing main components and additives, weighing, mixing, pre-firing, grinding, granulation, pressing and molding, and sintering.

[0017] It should be noted that the selection of raw materials and the design of the formula containing main components and additives are not in any particular order.

[0018] Preferably, the preparation method includes:

[0019] The main raw materials are weighed, mixed, and then pre-fired to obtain pre-fired material;

[0020] The pre-fired material and the raw materials of the additive components are sequentially ground, granulated and pressed to obtain a blank;

[0021] The blank is sintered to obtain a ferrite material.

[0022] In some embodiments of the present invention, the raw materials of the main components include Fe2O3 with a purity > 99.3%, ZnO with a purity > 99.7%, and Mn3O4 with a purity > 71.4%. The raw materials of the additive components include CaCO3, LiCoO2, CuO, and Nb2O5.

[0023] Preferably, based on 100 parts by weight of the main component raw material, the additive components include 0.08 to 0.15 parts of CaCO3, 0.35 to 0.45 parts of LiCoO2 (melting point exceeding 1000°C), 0.01 to 0.06 parts of CuO, and 0.01 to 0.04 parts of Nb2O5. For example, CaCO3 can be 0.08 parts, 0.09 parts, 0.1 parts, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts, or 0.15 parts, etc.; LiCoO2 can be 0.35 parts, 0.36 parts, 0.37 parts, 0.38 parts, 0.39 parts, 0.4 parts, 0.41 parts, 0.42 parts, 0.43 parts, 0.44 parts, or 0.45 parts, etc.; CuO can be 0.01 parts, 0.02 parts, 0.03 parts, 0.04 parts, 0.05 parts, or 0.06 parts, etc.; Nb2O5 can be 0.01 parts, 0.015 parts, 0.02 parts, 0.025 parts, 0.03 parts, 0.035 parts, or 0.04 parts, etc.

[0024] It is understandable that ferrite materials require a process of mixing and sintering various raw materials, during which reactions occur to generate new substances and form a complete material system to obtain the final ferrite material. However, the components and their contents in the ferrite material can still be described using the form of metal oxides. Therefore, the composition and content characteristics of the obtained ferrite material can be clearly defined using the formulation ratio of the raw materials. Specifically, when raw materials that undergo decomposition and reaction, such as CaCO3, are used, the calcium component in the ferrite material can be described in the form of the oxide CaO, and its content can be specified.

[0025] In some embodiments of the present invention, the method of mixing the raw materials of the main component includes wet ball milling, obtaining ball milling material by wet ball milling, and then drying the ball milling material before pre-calcination.

[0026] In this invention, pre-firing helps control the activity of the powder and reduces the shrinkage rate after sintering.

[0027] In some embodiments of the present invention, the pre-firing is carried out in an oxygen-containing atmosphere.

[0028] In some embodiments of the present invention, the pre-firing temperature is 780°C to 880°C. Exemplarily, the pre-firing temperature may be 780°C, 790°C, 800°C, 820°C, 840°C, 860°C, or 880°C, etc.

[0029] In some embodiments of the present invention, the pre-firing holding time is 100 min to 180 min. Exemplarily, the pre-firing holding time can be 100 min, 115 min, 130 min, 145 min, 150 min, 165 min, or 180 min, etc.

[0030] As an example, the pre-firing can be carried out in an air atmosphere inside a high-temperature furnace. Generally, the higher the pre-firing temperature, the shorter the holding time should be, and the two should be selected appropriately.

[0031] In some embodiments of the present invention, the grinding includes wet grinding, in which a slurry is obtained by wet grinding, and the slurry is dried before granulation.

[0032] In this invention, the raw materials of the additive components are mixed by grinding or other crushing methods, which helps to improve the accuracy of dosage control and the uniformity of mixing and dispersion.

[0033] As an example, the wet grinding can be carried out in a micron-level sand mill, and the grinding media can be a single Φ2.0mm or Φ3.0mm, or a mixture of Φ2.0mm and Φ3.0mm stainless steel balls in a certain proportion, and the grinding solvent can be pure water.

[0034] In some embodiments of the present invention, the average particle size of the slurry obtained by wet milling is 0.6 μm to 1.0 μm. Exemplarily, the average particle size of the slurry can be 0.6 μm, 0.65 μm, 0.7 μm, 0.75 μm, 0.8 μm, 0.85 μm, 0.9 μm, 0.95 μm, or 1 μm, etc. This facilitates control over the activity of the powder and the consistency of its activity.

[0035] In some embodiments of the present invention, the granulation includes spray granulation, wherein the water content of the spray granulation is controlled to be 0.01wt%~0.03wt%. Exemplarily, the water content of the spray granulation can be 0.01wt%, 0.015wt%, 0.02wt%, 0.025wt%, 0.03wt%, etc. This is beneficial for improving the processing quality of subsequent processes and reducing problems such as sticking to the mold and cracking.

[0036] In some embodiments of the invention, the granulation also uses a dry lubricant for granulation.

[0037] In some embodiments of the present invention, the granulation yields normally distributed granules of 60-200 mesh, which are then subjected to the pressing molding process.

[0038] In some embodiments of the present invention, the density of the blank obtained by compression molding is 2.95 g / cm³. 3 ~3.25g / cm 3 For example, the density of the blank can be 2.95 g / cm³. 3 3.00g / cm 3 3.13 g / cm 3 3.15g / cm 3 3.18 g / cm 3 3.20g / cm 3 3.22g / cm 3 Or 3.25g / cm 3 wait.

[0039] In this invention, when pressing to form a blank, under the premise of no defects, the higher the pressing density, the lower the pressing density shrinkage rate, the less likely the product is to deform. At the same time, the lower the internal porosity of the product can improve the electromagnetic properties of the final material. However, excessively high pressing density can easily generate stress or cracks, and should be reasonably controlled and adjusted.

[0040] As an example, compression molding can be carried out in a fully automatic dry powder press, and can be pressed into ring-shaped blanks.

[0041] In some embodiments of the present invention, the sintering process includes heating, densification sintering within the heating range, holding sintering, and then lowering the temperature under balanced oxygen partial pressure conditions.

[0042] In some embodiments of the present invention, the holding sintering temperature (final firing temperature) is 1130℃~1160℃, and the time is 3.5h~6h. For example, the holding sintering temperature can be 1130℃, 1135℃, 1140℃, 1145℃, 1150℃, 1155℃, or 1160℃, etc.; the time can be 3.5h, 4h, 4.5h, 5h, 6h, etc.

[0043] In the sintering process described in this invention, densification sintering can be achieved during the heating stage, allowing excess oxygen to be released during the solid-state reaction of the raw materials, which helps reduce the porosity inside the ferrite grains and at the grain boundaries. Holding the sinter at a relatively low temperature helps control the grain size, supporting the obtaining of smaller, but fully and uniformly grown grains, which is beneficial for improving loss characteristics at high frequencies.

[0044] Thirdly, the present invention provides a magnetic transducer containing the ferrite material described in the first aspect, or containing the ferrite material obtained by the preparation method described in the second aspect.

[0045] In some embodiments of the present invention, the magnetic transducer includes a transducer made of the ferrite material.

[0046] The converter made using the ferrite material provided by this invention can be applied to the power supply of electronic devices with high-frequency characteristics, so that when the electronic device is used in the range of 25℃~120℃, the converter has high-frequency (frequency greater than 1MHz) low-loss performance and high conversion efficiency.

[0047] It should be noted that, due to space limitations and to avoid redundancy, this invention does not exhaustively list all point values ​​within the above numerical range, but it is not limited to the listed values ​​either; other unlisted values ​​within the above numerical range are also applicable.

[0048] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0049] The ferrite material provided by this invention has a formula with high Fe2O3 content and low ZnO content as the main components, and is combined with specific additive components CaO, Li2O, CuO and Nb2O5, so that the resulting ferrite material has both high Curie temperature and high saturation magnetic flux density, and can have low loss characteristics under wide temperature (25℃~120℃) and high frequency (1MHz~4MHz) conditions, effectively supporting the development of converter devices towards high frequency and miniaturization. Attached Figure Description

[0050] Figures 1 to 4 These are cross-sectional microstructure diagrams of the ferrite materials obtained in Example 1, Comparative Example 8, Comparative Example 10, and Comparative Example 11, respectively. Detailed Implementation

[0051] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0052] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0053] Example 1

[0054] This embodiment provides a ferrite material, the raw materials of which include a main component and additive components; based on 100 parts by weight of the main component, the main component includes 71.87 parts of Fe2O3, 3.67 parts of ZnO, and 24.46 parts of Mn3O4; the additive components include 0.11 parts of CaCO3, 0.42 parts of LiCoO2, 0.04 parts of CuO, and 0.04 parts of Nb2O5.

[0055] like Figure 1 The image shown is a cross-sectional microstructure obtained by SEM (scanning electron microscope) testing of the ferrite material obtained in this embodiment. Statistical calculations show that the average diameter of the cross-sectional grains of the ferrite material is <8μm.

[0056] This embodiment also provides a method for preparing the ferrite material, including the following steps:

[0057] (1) Take Fe2O3 with a purity of >99.3%, ZnO with a purity of >99.7%, and Mn3O4 with a purity of >71.4% as the raw materials for the main components; take CaCO3, LiCoO2, CuO, and Nb2O5 as the raw materials for the additive components.

[0058] (2) Calculate the mass of the raw materials of the main component required based on the content of each component in the formulation of the ferrite material and the purity of the raw materials. Then weigh the raw materials of the main component and mix them by wet ball milling to obtain the ball milling material.

[0059] (3) After the ball milling material is dried, it is placed in a high-temperature furnace for pre-firing in an air atmosphere. The pre-firing temperature is 850℃ and the holding time is 135min to obtain the pre-fired material.

[0060] (4) Based on the content of each component in the ferrite material formula and the purity of the raw materials, calculate the mass of the raw materials of the required additive components, mix them with the pre-calcined material, and perform wet grinding in a micron-level sand mill. The grinding media can be stainless steel balls with a certain ratio of Φ2.0mm and Φ3.0mm. The grinding solvent is pure water. Control the average particle size of the slurry obtained by wet grinding to be 0.91μm.

[0061] (5) After drying the obtained slurry, spray granulation is carried out in a spraying equipment. During granulation, the water content can be controlled at 0.025wt%, and an appropriate amount of dry lubricant is added for granulation. After granulation, granules between 60 mesh and 200 mesh are taken.

[0062] (6) The granules are pressed into ring-shaped blanks in a fully automatic dry powder press. The density of the blanks is controlled at 3.10±0.15g / cm³. 3 ;

[0063] (7) The blanks are sintered sequentially. The sintering process includes: heating up, densifying sintering within the heating range, holding sintering at the final sintering temperature of 1150°C for 4 hours, and then reducing the temperature to less than or equal to 200°C under the condition of balanced oxygen partial pressure to obtain ferrite material.

[0064] Examples 2 to 7 and Comparative Examples 1 to 11

[0065] Examples 2 to 7 and Comparative Examples 1 to 11 all provide a ferrite material and a method for preparing the same. Compared with Example 1, at least one of the following was adjusted: the proportion of components in the ferrite material, the pre-firing temperature in the preparation method, and the final firing temperature of the heat preservation sintering, as shown in Table 1.

[0066] Table 1

[0067]

[0068] Characterization and testing:

[0069] The ferrite materials obtained in each embodiment and comparative example were tested:

[0070] The results are shown in Tables 2, 3, and 4. Microscopic measurements of the cross-sections of the ferrite materials obtained in Example 1, Comparative Example 8, Comparative Example 10, and Comparative Example 11 are also shown. Figures 1 to 4 As shown.

[0071] Table 2

[0072]

[0073] Table 3

[0074]

[0075] Table 4

[0076]

[0077] Combine Tables 1 to 4 and Figures 1 to 4 It can be seen that:

[0078] The relevant data from Examples 1 to 7 demonstrate that the ferrite material provided by the present invention meets the electromagnetic properties under various conditions. The power consumption of the sample in the examples is low in a wide temperature range (25℃~120℃) and high frequency (1MHz~4MHz) conditions. The average grain diameter of the cross section of the sample in Example 1 is <8μm.

[0079] In comparison, Comparative Example 1 had a low iron oxide content, while Comparative Example 3 had a low iron oxide content and an excessively high zinc oxide content, resulting in low Curie temperatures, insufficient saturation magnetization, and poor high-frequency power consumption characteristics. Comparative Example 2 had an excessively high iron oxide content, leading to low permeability and unacceptable high-temperature power consumption. Comparative Example 4 had the same main component as Example 1, but the lack of Nb2O5 prevented the suppression of CuO-induced grain growth, resulting in insufficient grain refinement, increased high-frequency eddy current losses, and severely deteriorated high-frequency power consumption characteristics. Comparative Example 5 had insufficient CaCO3 addition, resulting in inadequate grain refinement and reduced grain boundary resistivity, further worsening high-frequency eddy current losses. Comparative Example 6 had excessive CaCO3 addition, increasing the non-magnetic phase content and reducing permeability, leading to increased high-frequency power consumption. Comparative Example 7 had insufficient LiCoO2 addition, resulting in insufficient flatness of the K1-T curve and an increased K1 value, while Li... + Decreased content inhibits Fe 2+ The reduced effect of the copper oxide content leads to increased high-frequency power consumption. In Comparative Example 8, the excessive addition of LiCoO2 is due to two main reasons: firstly, it results in excessive compensation for the matrix K1, causing the overall K1-T curve of the ferrite to increase, thus increasing the high-frequency power consumption; secondly, the excessive addition enhances the sintering effect, leading to excessive grain growth within the material and worsening the high-frequency power consumption. In Comparative Example 9, the insufficient addition of copper oxide results in a lower power consumption-temperature valley point, leading to an overall higher high-frequency power consumption. In Comparative Example 10, the excessive addition of copper oxide leads to an increase in non-magnetic phases and an excessively strong sintering effect, resulting in excessive grain growth within the material and worsening the high-frequency power consumption. In Comparative Example 11, the excessive addition of Nb2O5 leads to uneven grain growth, resulting in increased power consumption.

[0080] In summary, the ferrite material provided by this invention, through a specific composition and sintering at a relatively low temperature, achieves low-loss characteristics (f=1MHz, B) over a wide temperature range (25℃~120℃) and high frequency range (1MHz~4MHz). This ferrite material possesses a high Curie temperature and high saturation magnetic flux density. m =50mT, P under conditions of 25℃~120℃ cv Less than 100kW / m 3 f=4MHz, B m =36mT, P under conditions of 25℃~120℃ cv Less than 1000kW / m 3 The performance is shown in Table 5 below, which can support the development of devices towards higher frequency and smaller size.

[0081] Table 5

[0082]

[0083] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0084] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A ferrite material, characterized in that, Including main ingredients and additives; Based on 100 parts by weight of the main component, the main component includes 71.20 to 72.50 parts of Fe2O3, 2.00 to 4.80 parts of ZnO, and 22.7 to 26.8 parts of Mn3O4; Based on 100 parts by weight relative to the main component, the additive components include 0.055 to 0.11 parts of CaO, 0.05 to 0.07 parts of Li2O, 0.25 to 0.35 parts of CoO, 0.01 to 0.06 parts of CuO, and 0.01 to 0.04 parts of Nb2O5.

2. The ferrite material according to claim 1, characterized in that, The average diameter of the cross-sectional grains of the ferrite material is <8μm.

3. The ferrite material according to claim 1, characterized in that, The ferrite material satisfies at least one of the following conditions: (2a) The maximum magnetic induction intensity B applied at 22℃~28℃ m Under test conditions of <0.25mT, the initial permeability μ of the ferrite material is... i The range is 550~850; (2b) The maximum magnetic field strength H applied at 22℃~28℃ m Under test conditions of 1194 A / m and frequency f = 1 kHz, the saturation magnetic flux density B of the ferrite material is... s >520mT; (2c) At the maximum applied magnetic induction intensity B m Under test conditions of <0.25mT, the Curie temperature T of the ferrite material is... c >290℃; (2d) The maximum applied magnetic induction intensity B at 25℃~120℃ m Under test conditions of 50mT and frequency f=1MHz, the volumetric magnetic loss P of the ferrite material is... cv <100kW / m 3 ; (2e) The maximum applied magnetic induction intensity B at 25℃~120℃ m Under test conditions of 36mT and frequency f=4MHz, the volumetric magnetic loss P of the ferrite material is... cv <1000kW / m 3 .

4. A method for preparing the ferrite material according to any one of claims 1-3, characterized in that, The preparation method includes: raw material design and selection, formulation design including main components and additives, weighing, mixing, pre-firing, grinding, granulation, pressing and molding, and sintering.

5. The method for preparing ferrite material according to claim 4, characterized in that, The raw materials for the main components include Fe2O3 with a purity > 99.3%, ZnO with a purity > 99.7%, and Mn3O4 with a purity > 71.4%.

6. The method for preparing ferrite material according to claim 4, characterized in that, The raw materials for the additive components include CaCO3, LiCoO2, CuO, and Nb2O5.

7. The method for preparing ferrite material according to claim 4, characterized in that, The average particle size of the primary particles obtained by grinding is 0.6 μm to 1.0 μm.

8. The method for preparing ferrite material according to claim 4, characterized in that, The final firing temperature for sintering is 1130℃~1160℃.

9. The method for preparing ferrite material according to claim 4, characterized in that, The holding time for sintering is 3.5h to 6h.

10. A magnetic transducer, characterized in that, The magnetic converter contains the ferrite material according to any one of claims 1-3, or the ferrite material obtained by the preparation method according to any one of claims 4-9.

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