Iron-deficient soft magnetic mn-zn ferrite material and its preparation method and application

Abstract

This invention discloses an iron-deficient soft magnetic manganese-zinc ferrite material, its preparation method, and its applications. The iron-deficient soft magnetic manganese-zinc ferrite material of this invention comprises a main component and secondary components. The main component, by molar percentage, includes the following components: Fe₂O₃ at 43.5–48.5 mol%, MnO at 30–35 mol%, with the balance being ZnO. The secondary components include CaCO₃, CuO, ZrO₂, Bi₂O₃, and MoO₃. In this iron-deficient soft magnetic manganese-zinc ferrite material, a low molar percentage (<50%) of Fe₂O₃ is combined with MnO and ZnO as the main component to increase the cutoff frequency of the manganese-zinc ferrite material's permeability, thereby improving its permeability attenuation in the high-frequency range. Simultaneously, the combination of CaCO₃, CuO, ZrO₂, Bi₂O₃, and MoO₃ promotes grain growth, thereby increasing the permeability of the manganese-zinc ferrite material while ensuring it possesses high saturation magnetic induction and a high Curie temperature.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, and more specifically, to an iron-deficient soft magnetic manganese-zinc ferrite material, its preparation method, and its application. Background Technology

[0002] With the continuous development of the electronics industry, the performance requirements for electronic components are becoming increasingly stringent. Ferrite cores, as one of the core components of electronic devices, are undergoing continuous improvement and optimization of their electromagnetic characteristics. High-permeability manganese-zinc ferrite materials, due to their high initial permeability and low loss, are widely used in pulse transformers in fields such as electromagnetic interference (EMI) filters, ISDN, LAN, WAN, and automotive electronics. However, the cores in these fields are limited by the cutoff frequency of the high-permeability materials themselves, generally operating under low-frequency, weak-field conditions, making them unsuitable for high-frequency environments. Currently, ferrite cores for high-frequency environments generally use nickel-zinc ferrite materials, but nickel-zinc ferrite materials are relatively expensive, and their initial permeability and Curie temperature are both relatively low.

[0003] To address the issue of low permeability in nickel-zinc ferrite materials, continuous improvements have been made to enhance their permeability. For example, existing technology discloses a high-permeability, broadband, high-impedance nickel-zinc soft magnetic ferrite material, comprising a main component and additives. The main component, by molar percentage, includes: Fe₂O₃ 45–55 mol%, ZnO 25–35 mol%, NiO 10–20 mol%, and CuO 5–10 mol%. The additives, by molar percentage, include: MgO 0.5–5 mol%, Co₂O₃ 0.5–9.5 mol%, and CaCO₃ 0.5–5 mol%. By increasing the ZnO content in the main component, controlling the molar ratio of Fe₂O₃ to ZnO, and combining it with CuO, the permeability of the ferrite is improved. However, its permeability only reaches 952–968, requiring further improvement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of existing high permeability manganese zinc ferrite materials that cannot be applied to high frequency bands and wideband high impedance nickel zinc ferrite materials with poor permeability, and to provide an iron-deficient soft magnetic manganese zinc ferrite material.

[0005] Another objective of this invention is to provide a method for preparing an iron-deficient soft magnetic manganese-zinc ferrite material.

[0006] Another object of the present invention is to provide the application of the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material in the preparation of electronic components.

[0007] Another object of the present invention is to provide a pulse transformer.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution:

[0009] This invention protects a soft magnetic manganese-zinc ferrite material with an iron-deficient formulation, comprising a main component and secondary components. The main component, in molar percentage, comprises the following components:

[0010] Fe2O3 is 43.5–48.5 mol%, MnO is 30–35 mol%, and the balance is ZnO;

[0011] Relative to the total weight of the principal components, the secondary components, by weight percentage, include the following components:

[0012] CaCO3 is 0.3–0.7 wt%, CuO is 0.2–0.4 wt%, ZrO2 is 0–0.08 wt%, Bi2O3 is 0.03–0.1 wt%, and MoO3 is 0.03–0.1 wt%.

[0013] The inventors discovered through research that reducing the molar percentage of Fe2O3 in manganese-zinc ferrite materials to below 50% can significantly increase the cutoff frequency of its magnetic permeability, thereby improving the attenuation of its magnetic permeability in the high-frequency range. At the same time, combining specific amounts of CaCO3 and ZrO2 can reduce the temperature coefficient of manganese-zinc ferrite materials, increase the grain boundary resistivity to reduce the loss of manganese-zinc ferrite materials, and also make the grain growth more uniform, thereby improving the electrical properties of manganese-zinc ferrite materials.

[0014] Preferably, the main components, by molar percentage, include 46.5–47.9 mol% Fe2O3, 31.8–33.7 mol% MnO, and the balance being ZnO.

[0015] Specifically, the main components can be: 46.5 mol% Fe2O3, 33.7 mol% MnO, with the balance being ZnO; or 47.0 mol% Fe2O3, 32.7 mol% MnO, with the balance being ZnO; or 47.3 mol% Fe2O3, 32.3 mol% MnO, with the balance being ZnO; or 47.90 mol% Fe2O3, 31.8 mol% MnO, with the balance being ZnO.

[0016] Specifically, the iron-deficient soft magnetic manganese-zinc ferrite material has an impedance Z≥20Ω at 1MHz, an impedance Z≥80Ω at 25MHz, and an impedance Z≥150Ω at 100MHz at 25℃. The test conditions are H25*15*8, 1TsФ0.5mm, and L=160mm.

[0017] Specifically, the initial permeability μi of the iron-deficient soft magnetic manganese-zinc ferrite material is ≥3000 under the conditions of 5℃, 10KHz, and 0.05V; the density ρ of the iron-deficient soft magnetic manganese-zinc ferrite material is ≥4.9g / cm³. 3 The Curie temperature Tc > 130℃; the saturation magnetic flux density Bs ≥ 400mT of the iron-deficient soft magnetic manganese-zinc ferrite material at 25℃.

[0018] This invention also protects a method for preparing the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material, comprising the following steps:

[0019] S1. Measure the content of the main components and mix them evenly;

[0020] S2. The main components mixed in S1 are placed into a pre-firing furnace for pre-firing treatment to form pre-fired material;

[0021] S3. Mix the pre-burned material from S2 with the by-products, add water, and perform a second ball milling to obtain a fine powder with a particle size of 1.00 to 1.40 μm;

[0022] S4. The finely ground powder from S3 is granulated and pressed into shape to obtain a density of 3.00–3.05 g / cm³. 3 raw blanks;

[0023] S5. Place the green blank from S4 in an atmosphere furnace and sinter it at 1250-1350℃ to obtain the iron-deficient soft magnetic manganese-zinc ferrite material.

[0024] Preferably, the pre-firing treatment in S2 is carried out at a temperature of 850–950°C for a time of 2.5–3.5 h.

[0025] Specifically, the oxygen partial pressure in the sintering atmosphere described in S5 is 2.0% to 4.5%, with the balance being the nitrogen partial pressure.

[0026] The application of the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material in the preparation of electronic components is also within the scope of protection of this invention.

[0027] This invention also protects a pulse transformer made from the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The iron-deficient soft magnetic manganese-zinc ferrite material of the present invention uses Fe2O3 with a low molar percentage (<50%) combined with MnO and ZnO as the main components to increase the cutoff frequency of the magnetic permeability of the manganese-zinc ferrite material and improve its magnetic permeability attenuation in the high-frequency range; at the same time, it combines CaCO3, CuO, ZrO2, Bi2O3 and MoO3 to promote grain growth, thereby increasing the magnetic permeability of the manganese-zinc ferrite material while ensuring that it has a high saturation magnetic induction intensity and a high Curie temperature. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0031] Example 1

[0032] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 46.5 mol%; MnO 33.4 mol%; ZnO 20.1 mol%; and secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.25 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0033] The above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material can be prepared by the following method:

[0034] S1. Weigh the main component raw materials and place them in a sand mill. Add a certain proportion of deionized water for mixing and crushing. Run the planetary ball mill for 30 minutes and dry the material at 180°C after discharge.

[0035] S2. First, pass the dried powder through a 40-mesh sieve, then put it into a pre-firing furnace, and then pre-fire it at 880℃ for 2.5 hours to form pre-fired material;

[0036] S3. Add the secondary components to the pre-burned material, then place it in a sand mill and add deionized water for secondary sand milling. The planetary ball milling time is 80 minutes, and the powder particle size is controlled at 1.00~1.40μm.

[0037] S4. Laboratory manual granulation followed by molding into standard sample rings with a diameter of 25.00 × 15.00 × 7.50 mm. The green density of the sample rings is 3.10 g / cm³. 3 about;

[0038] S5. Sinter at 1320℃ for 6 hours in an atmosphere of oxygen and nitrogen in a certain proportion, with an oxygen partial pressure of 3.5% during sintering. Cool to room temperature under appropriate oxygen partial pressure (the industry default is conventional oxygen partial pressure).

[0039] Example 2

[0040] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 46.5 mol%; MnO 33.7 mol%; ZnO 19.8 mol%; and the following secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.25 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0041] The above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material can be prepared by the following method:

[0042] S1. Weigh the main component raw materials and place them in a sand mill. Add a certain proportion of deionized water for mixing and crushing. Run the planetary ball mill for 30 minutes and dry the material at 180°C after discharge.

[0043] S2. First, pass the dried powder through a 40-mesh sieve, then put it into a pre-firing furnace, and then pre-fire it at 880℃ for 2.5 hours to form pre-fired material;

[0044] S3. Add the secondary components to the pre-burned material, then place it in a sand mill and add deionized water for secondary sand milling. The planetary ball milling time is 80 minutes, and the powder particle size is controlled at 1.00~1.40μm.

[0045] S4. Laboratory manual granulation followed by molding into standard sample rings with a diameter of 25.00 × 15.00 × 7.50 mm. The green density of the sample rings is 3.10 g / cm³. 3 about;

[0046] S5. Sinter at 1320℃ for 6 hours in an atmosphere of oxygen and nitrogen in a certain proportion, with an oxygen partial pressure of 3.5% during sintering. Cool to room temperature under appropriate oxygen partial pressure (the industry default is conventional oxygen partial pressure).

[0047] Example 3

[0048] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 47.0 mol%; MnO 33.5 mol%; ZnO 19.5 mol%; and secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.25 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0049] The above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material can be prepared by the following method:

[0050] S1. Weigh the main component raw materials and place them in a sand mill. Add a certain proportion of deionized water for mixing and crushing. Run the planetary ball mill for 30 minutes and dry the material at 180°C after discharge.

[0051] S2. First, pass the dried powder through a 40-mesh sieve, then put it into a pre-firing furnace, and then pre-fire it at 880℃ for 2.5 hours to form pre-fired material;

[0052] S3. Add the secondary components to the pre-burned material, then place it in a sand mill and add deionized water for secondary sand milling. The planetary ball milling time is 80 minutes, and the powder particle size is controlled at 1.00~1.40μm.

[0053] S4. Laboratory manual granulation followed by molding Standard sample ring, green body density of sample ring is 3.10 g / cm³. 3 about;

[0054] S5. Sinter at 1320℃ for 6 hours in an atmosphere of oxygen and nitrogen in a certain proportion, with an oxygen partial pressure of 3.5% during sintering. Cool to room temperature under appropriate oxygen partial pressure (the industry default is conventional oxygen partial pressure).

[0055] Example 4

[0056] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 47.2 mol%; MnO 33.5 mol%; ZnO 19.3 mol%; and secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.25 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0057] The above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material can be prepared by the following method:

[0058] S1. Weigh the main component raw materials and place them in a sand mill. Add a certain proportion of deionized water for mixing and crushing. Run the planetary ball mill for 30 minutes and dry the material at 180°C after discharge.

[0059] S2. First, pass the dried powder through a 40-mesh sieve, then put it into a pre-firing furnace, and then pre-fire it at 880℃ for 2.5 hours to form pre-fired material;

[0060] S3. Add the secondary components to the pre-burned material, then place it in a sand mill and add deionized water for secondary sand milling. The planetary ball milling time is 80 minutes, and the powder particle size is controlled at 1.00~1.40μm.

[0061] S4. Laboratory manual granulation followed by molding Standard sample ring, green body density of sample ring is 3.10 g / cm³. 3 about;

[0062] S5. Sinter at 1320℃ for 6 hours in an atmosphere of oxygen and nitrogen in a certain proportion, with an oxygen partial pressure of 3.5% during sintering. Cool to room temperature under appropriate oxygen partial pressure (the industry default is conventional oxygen partial pressure).

[0063] Example 5

[0064] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 47.2 mol%; MnO 33.5 mol%; ZnO 19.3 mol%; and secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.50 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0065] The above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material can be prepared by the following method:

[0066] S1. Weigh the main component raw materials and place them in a sand mill. Add a certain proportion of deionized water for mixing and crushing. Run the planetary ball mill for 30 minutes and dry the material at 180°C after discharge.

[0067] S2. First, pass the dried powder through a 40-mesh sieve, then put it into a pre-firing furnace, and then pre-fire it at 880℃ for 2.5 hours to form pre-fired material;

[0068] S3. Add the secondary components to the pre-burned material, then place it in a sand mill and add deionized water for secondary sand milling. The planetary ball milling time is 80 minutes, and the powder particle size is controlled at 1.00~1.40μm.

[0069] S4. Laboratory manual granulation followed by molding into standard sample rings with a diameter of 25.00 × 15.00 × 7.50 mm. The green density of the sample rings is 3.10 g / cm³. 3 about;

[0070] S5. Sinter at 1320℃ for 6 hours in an atmosphere of oxygen and nitrogen in a certain proportion, with an oxygen partial pressure of 3.5% during sintering. Cool to room temperature under appropriate oxygen partial pressure (the industry default is conventional oxygen partial pressure).

[0071] Example 6

[0072] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 43.5 mol%; MnO 35 mol%; ZnO 21.5 mol%; and the following secondary components relative to the total weight of the main components: CaCO3 0.1 wt%, CuO 0.4 wt%, ZrO2 0.08 wt%, Bi2O3 0.1 wt%, and MoO3 0.1 wt%.

[0073] The preparation method of the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material is the same as that in Example 1.

[0074] Comparative Example 1

[0075] A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation comprises the following main components: Fe2O3 40 mol%; MnO 33.4 mol%; ZnO 26.6 mol%; and the following secondary components relative to the total weight of the main components: CaCO3 0.55 wt%, CuO 0.25 wt%, ZrO2 0.04 wt%, Bi2O3 0.04 wt%, and MoO3 0.04 wt%.

[0076] The preparation method of the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material is the same as that in Example 1.

[0077] Comparative Example 2

[0078] A soft magnetic manganese-zinc ferrite material comprises the following main components: 50 mol% Fe2O3; 33.4 mol% MnO; and 16.6 mol% ZnO. The material also comprises the following secondary components relative to the total weight of the main components: 0.55 wt% CaCO3, 0.25 wt% CuO, 0.04 wt% ZrO2, 0.04 wt% Bi2O3, and 0.04 wt% MoO3.

[0079] The preparation method of the above-mentioned iron-deficient soft magnetic manganese-zinc ferrite material is the same as that in Example 1.

[0080] Result detection

[0081] (1) The iron-deficient soft magnetic manganese zinc ferrite materials in Examples 1-6 and Comparative Examples 1-2 were tested for density using the liquid draining method. At the same time, their Curie temperature, initial permeability and saturation magnetic flux density were also tested. The specific test results are shown in Table 1.

[0082] Table 1 Curie temperature, density, initial permeability, and saturation flux density of the iron-deficient soft magnetic manganese-zinc ferrite materials in Examples 1-6 and Comparative Examples 1-2.

[0083]

[0084] (2) The iron-deficient soft magnetic manganese-zinc ferrite materials in Examples 1-6 and Comparative Examples 1-2 were subjected to impedance testing using an HP4192A instrument (test coil: 10Ts), the specific test results are shown in Table 2:

[0085] Table 2 shows the impedance of the iron-deficient soft magnetic manganese-zinc ferrite materials under different conditions in Examples 1-6 and Comparative Examples 1-2.

[0086]

[0087] According to the data in Tables 1 and 2, the Curie temperature of the iron-deficient soft magnetic manganese-zinc ferrite material of this invention reaches 102-134℃, the initial permeability μi reaches 3007-3892, and the Z value is 238-278Ω under 100MHz conditions. It not only has excellent initial permeability, but can also be applied in the high-frequency band, which has obvious advantages over existing manganese-zinc ferrite materials and nickel-zinc ferrite materials.

[0088] Comparative Examples 1 and 2 show that when the Fe2O3 content in the main component of the soft magnetic manganese zinc ferrite material is too low, although it can broaden its application frequency band and improve the initial permeability to a certain extent, it will cause the Curie temperature to drop sharply. When the Fe2O3 content in the main component of the soft magnetic manganese zinc ferrite material is too high, although the Curie temperature is high, the initial permeability is low and it cannot be applied to the high frequency band.

[0089] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A soft magnetic manganese-zinc ferrite material with an iron-deficient formulation, comprising a main component and secondary components, characterized in that, The principal component, expressed as a molar percentage, consists of the following components: Fe2O3 content was 43.5–47.2 mol%, MnO content was 33.4–35 mol%, and ZnO content was 19.3–21.5 mol%. Relative to the total weight of the principal components, the secondary components, by weight percentage, consist of the following components: CaCO3 is 0.55~0.1wt%, CuO is 0.25~0.40wt%, ZrO2 is 0.04~0.08wt%, Bi2O3 is 0.04~0.1wt%, and MoO3 is 0.04~0.1wt%.

2. The iron-deficient soft magnetic manganese-zinc ferrite material according to claim 1, characterized in that, The iron-deficient soft magnetic manganese-zinc ferrite material has an impedance Z≥20Ω at 1MHz, an impedance Z≥80Ω at 25MHz, and an impedance Z≥150Ω at 100MHz at 25℃.

3. The iron-deficient soft magnetic manganese-zinc ferrite material according to claim 2, characterized in that, The iron-deficient soft magnetic manganese-zinc ferrite material has an initial permeability µi ≥ 3000 under the conditions of 25℃, 10KHz, and 0.05V.

4. The iron-deficient soft magnetic manganese-zinc ferrite material according to claim 1, characterized in that, The density ρ of the iron-deficient soft magnetic manganese-zinc ferrite material is ≥ 4.9 g / cm³. 3 .

5. A method for preparing an iron-deficient soft magnetic manganese-zinc ferrite material according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Measure the proportions of the main components and mix thoroughly; S2. The main components mixed in S1 are placed into a pre-firing furnace for pre-firing treatment to form pre-fired material; S3. Mix the pre-burned material from S2 with the by-products, add water, and perform a second ball milling to obtain a fine powder with a particle size of 1.00~1.40μm; S4. The finely ground powder from S3 is granulated and pressed into shape to obtain a density of 3.00~3.05 g / cm³. 3 raw blanks; S5. Place the green blank from S4 in an atmosphere furnace and sinter it at 1250~1350℃ to obtain the iron-deficient soft magnetic manganese-zinc ferrite material.

6. The preparation method according to claim 5, characterized in that, The pre-firing treatment described in S2 is performed at a temperature of 850~950℃ for 2.5~3.5h.

7. The preparation method according to claim 5, characterized in that, The oxygen partial pressure in the sintering atmosphere described in S5 is 2.0%~4.5%, with the balance being nitrogen partial pressure.

8. The application of the iron-deficient soft magnetic manganese-zinc ferrite material according to any one of claims 1 to 4 in the preparation of electronic components.

9. A pulse transformer, characterized in that, Includes the iron-deficient soft magnetic manganese-zinc ferrite material as described in any one of claims 1 to 4.

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