Wide-temperature low-loss manganese-zinc ferrite and preparation method thereof

Abstract

This invention discloses a wide-temperature, low-loss manganese-zinc ferrite and its preparation method, belonging to the technical field of ferrite soft magnetic materials. The manganese-zinc ferrite comprises a main component, a first additive, and a second additive; the main component includes Fe2O3, ZnO, and MnO; the first additive includes one or more of SnO2, TiO2, Cr2O3, Co3O4, and CuO; the second additive includes one or more of SiO2, CaCO3, ZrO2, Nb2O5, and Ta2O5. The preparation method includes the following steps: primary ball milling; primary sintering; secondary ball milling; granulation; molding; and secondary sintering. This invention optimizes the preparation process by adding additives with different functions in batches during the primary and secondary ball milling processes, and makes simple adjustments to the primary and secondary sintering processes, thereby effectively reducing the core loss of the manganese-zinc ferrite and improving its temperature stability.

Description

Technical Field

[0001] This invention belongs to the field of ferrite soft magnetic materials technology, specifically relating to a wide-temperature, low-loss manganese-zinc ferrite and its preparation method. Background Technology

[0002] With the development of modern electronic technology, especially the rapid development of the new generation of GaN electronic technology, the demand for switching power supplies will inevitably move towards smaller size and higher efficiency. However, the core loss of manganese zinc ferrite materials is difficult to reduce, which has become a major obstacle.

[0003] Numerous studies indicate that the core loss of manganese-zinc ferrites can be divided into three main components: hysteresis loss Ph, eddy current loss Pe, and residual loss Pr. Among these, Pr is more significant at high frequencies, so for low-frequency power ferrites, the focus is on reducing Ph and Pe. Forming a uniform grain structure free of lattice defects and pores to reduce the resistance to domain wall movement is crucial for reducing Ph and can also lower the total loss. Pe and grain size have the following relationship: Pe ∝ D 2 / ρ, where ρ is the material resistivity and D is the grain size. It can be seen that the influence of Pe can be effectively reduced by increasing the material resistivity or reducing the grain size.

[0004] Although the application of additives such as Co3O4, Ti2O3, CaCO3, and SiO2 in traditional production processes has improved the temperature stability and loss characteristics of manganese-zinc ferrites, structural defects such as abnormal grain growth and excessive voids are often encountered during production, hindering further improvement in the performance of manganese-zinc ferrites. Secondly, although the manganese-zinc ferrites produced by this method have increased grain boundary resistivity and reduced eddy current losses, hysteresis losses have not decreased significantly, resulting in still high core losses. Summary of the Invention

[0005] The purpose of this invention is to provide a wide-temperature, low-loss manganese-zinc ferrite and its preparation method to address the above problems, thereby solving the issues of poor temperature stability and high core loss in manganese-zinc ferrite.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A wide-temperature, low-loss manganese-zinc ferrite comprises the following raw materials: main component, first additive, and second additive.

[0008] The main components include Fe2O3, ZnO, and MnO;

[0009] The first additive includes one or more of SnO2, TiO2, Cr2O3, Co3O4, and CuO;

[0010] The second additive includes one or more of SiO2, CaCO3, ZrO2, Nb2O5, and Ta2O5.

[0011] Furthermore, the purity of the raw materials for the main component should be no less than 98 mol%.

[0012] Furthermore, the ratio of the main components is 51-59 mol% Fe2O3, 5-10 mol% ZnO, and the remainder is MnO.

[0013] Furthermore, Co3O4 and TiO2 in the first additive need to be added simultaneously, with the amount of Co3O4 being 200-4000 ppm and the amount of TiO2 being 50-800 ppm.

[0014] Furthermore, SiO2 and CaCO3 in the second additive need to be added simultaneously, with SiO2 added at 10-150 ppm and CaCO3 added at 200-1500 ppm.

[0015] A method for preparing a wide-temperature, low-loss manganese-zinc ferrite includes the following steps:

[0016] First ball milling; first sintering; second ball milling; granulation; molding; second sintering.

[0017] Furthermore, the specific steps of the first ball milling are as follows:

[0018] Weigh the main component and the first additive according to the required ratio, put them into a ball mill, and ball mill for 3-10 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0019] Furthermore, the specific steps of the first sintering are as follows:

[0020] The ball-milled powder is heated to 900-1200℃ in air at a heating rate of 200-300℃ / h, held for 1-3 hours, and then cooled in the furnace to obtain the primary sintered powder.

[0021] Furthermore, the specific steps of the secondary ball milling are as follows:

[0022] A second additive is added to the sintered powder in a certain proportion, and the powder is put into a ball mill again and milled for 1-5 hours to obtain a slurry. The slurry is then dried to obtain the secondary ball-milled powder.

[0023] Furthermore, the specific steps of the granulation are as follows:

[0024] Based on the total weight of the secondary ball milled powder, add 6-15 wt% of a polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 5-10% wt%, and granulate by high-speed centrifugation to obtain particles.

[0025] Furthermore, the specific steps of the molding process are as follows:

[0026] The granulated particles are pressed into magnetic rings of size T25×15×7.5.

[0027] Furthermore, the specific steps of the secondary sintering are as follows:

[0028] The magnetic rings were sintered in a bell-shaped furnace using a balanced oxygen partial pressure. The temperature was raised from room temperature to 1100-1450℃ over 1-6 hours, and held at the highest temperature for 0.5-5 hours. The oxygen partial pressure in the sintering atmosphere was controlled within the range of 0.5-5%. After the holding period, the temperature was lowered to 300-600℃ over 1-6 hours to obtain manganese-zinc ferrite.

[0029] Furthermore, the maximum temperature of the first sintering can be appropriately increased to 1100-1200℃ to promote the participation of the first additive in the crystal lattice formation process, while reducing the activity of the powder and preventing abnormal grain growth during the second sintering process.

[0030] Furthermore, the holding time at the highest temperature during the secondary sintering can be appropriately shortened to 0.5-1h, allowing the second additive to react fully while further refining the grain size.

[0031] The beneficial effects of this invention are:

[0032] (1) The present invention adopts a reasonable main component ratio and improves the temperature stability of manganese zinc ferrite by first additives such as Co3O4 and TiO2, and improves the core loss of manganese zinc ferrite by introducing second additives such as SiO2 and CaCO3.

[0033] (2) This invention optimizes the preparation process so that the additives enter the spinel structure of the ferrite. In the first ball milling, ions that can affect the performance of manganese zinc ferrite by occupying ferrite ion vacancies (i.e., the first additive) are added, and the first sintering temperature is appropriately increased. In the second ball milling, ions that can gather near the grain boundary and improve the product performance by affecting the formation of grain boundary and magnetic domain wall (i.e., the second additive) are added. At the same time, the second sintering time is shortened, thereby effectively reducing the magnetic core loss of manganese zinc ferrite and improving the temperature stability of manganese zinc ferrite. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a wide-temperature, low-loss manganese-zinc ferrite, which is prepared through the following steps:

[0037] (1) First ball milling: Weigh 1 kg of the main component, which contains 53 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Weigh 2000 ppm Co3O4 and 200 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0038] (2) Primary sintering: The primary ball milled powder is heated to 1100℃ in air at a heating rate of 5℃ / min, held for 3h, and cooled in the furnace to obtain primary sintered powder.

[0039] (3) Secondary ball milling: Add 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0040] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0041] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0042] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.5%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 500℃ in 6 hours to obtain manganese-zinc ferrite.

[0043] Example 2

[0044] This embodiment provides a wide-temperature, low-loss manganese-zinc ferrite, which is prepared through the following steps:

[0045] (1) First ball milling: Weigh 1 kg of the main component, which contains 53 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Weigh 2000 ppm Co3O4 and 200 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0046] (2) Primary sintering: The primary ball milled powder is heated to 1100℃ in air at a heating rate of 10℃ / min, held for 3 hours, and then cooled in the furnace to obtain primary sintered powder.

[0047] (3) Secondary ball milling: Add 25ppm SiO2 and 350ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0048] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0049] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0050] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1150℃ in 3 hours and held at the highest temperature for 1.5 hours. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.5%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1150℃ to 500℃ in 6 hours to obtain manganese-zinc ferrite.

[0051] Example 3

[0052] This embodiment provides a wide-temperature, low-loss manganese-zinc ferrite, which is prepared through the following steps:

[0053] (1) First ball milling: Weigh 1 kg of the main component, which contains 52.75 mol% Fe2O3, 7.75 mol% ZnO, and the remainder is MnO. Weigh 2000 ppm Co3O4 and 200 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0054] (2) Primary sintering: The primary ball milled powder is heated to 1000℃ in air at a heating rate of 5℃ / min, held for 3h, and cooled in the furnace to obtain primary sintered powder.

[0055] (3) Secondary ball milling: Add 50ppm SiO2 and 400ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0056] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0057] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0058] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1350℃ in 3 hours and held at the highest temperature for 3 hours. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.4%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1350℃ to 600℃ in 5 hours to obtain manganese-zinc ferrite.

[0059] Example 4

[0060] This embodiment provides a wide-temperature, low-loss manganese-zinc ferrite, which is prepared through the following steps:

[0061] (1) First ball milling: Weigh 1 kg of the main component, which contains 52.75 mol% Fe2O3, 7.75 mol% ZnO, and the remainder is MnO. Weigh 3000 ppm Co3O4 and 400 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0062] (2) Primary sintering: The primary ball milled powder is heated to 1200℃ in air at a heating rate of 5℃ / min, held for 2 hours, and then cooled in the furnace to obtain primary sintered powder.

[0063] (3) Secondary ball milling: Add 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 5 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0064] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0065] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0066] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.5%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 600℃ in 5 hours to obtain manganese-zinc ferrite.

[0067] Example 5

[0068] This embodiment provides a wide-temperature, low-loss manganese-zinc ferrite, which is prepared through the following steps:

[0069] (1) First ball milling: Weigh 1 kg of the main component, which contains 53.5 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Weigh 3000 ppm Co3O4 and 400 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0070] (2) Primary sintering: The primary ball milled powder is heated to 1200℃ in air at a heating rate of 5℃ / min, held for 1h, and cooled in the furnace to obtain primary sintered powder.

[0071] (3) Secondary ball milling: Add 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 5 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0072] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0073] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0074] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.4%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 400℃ in 4 hours to obtain manganese-zinc ferrite.

[0075] Comparative Example 1

[0076] This comparative example provides a manganese-zinc ferrite, which is prepared by the following steps:

[0077] (1) First ball milling: Weigh 1 kg of the main component, which contains 53 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Put it into a ball mill and ball mill for 1 hour to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0078] (2) Primary sintering: The primary ball milled powder is heated to 800°C in air at a heating rate of 5°C / min, held for 3 hours, and then cooled in the furnace to obtain primary sintered powder.

[0079] (3) Secondary ball milling: Add 2000ppm Co3O4, 200ppm TiO2, 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0080] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0081] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0082] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.4%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 500℃ in 7 hours to obtain manganese-zinc ferrite.

[0083] Comparative Example 2

[0084] This comparative example provides a manganese-zinc ferrite, which is prepared by the following steps:

[0085] (1) First ball milling: Weigh 1 kg of the main component, which contains 53 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Weigh 2000 ppm Co3O4 and 200 ppm TiO2, put them into a ball mill, and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0086] (2) Primary sintering: The primary ball milled powder is heated to 800°C in air at a heating rate of 5°C / min, held for 3 hours, and then cooled in the furnace to obtain primary sintered powder.

[0087] (3) Secondary ball milling: Add 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0088] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0089] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0090] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.4%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 500℃ in 6 hours to obtain manganese-zinc ferrite.

[0091] Comparative Example 3

[0092] This comparative example provides a manganese-zinc ferrite, which is prepared by the following steps:

[0093] (1) First ball milling: Weigh 1 kg of the main component, which contains 53 mol% Fe2O3, 7.5 mol% ZnO, and the remainder is MnO. Put it into a ball mill and ball mill for 3 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder.

[0094] (2) Primary sintering: The primary ball milled powder is heated to 1100℃ in air at a heating rate of 5℃ / min, held for 3h, and cooled in the furnace to obtain primary sintered powder.

[0095] (3) Secondary ball milling: Add 2000ppm Co3O4, 200ppm TiO2, 20ppm SiO2 and 300ppm CaCO3 to the obtained primary sintered powder, put it into the ball mill again, and ball mill for 3 hours to obtain slurry. Dry the slurry to obtain secondary ball milled powder.

[0096] (4) Granulation: Based on the total weight of the secondary ball milled powder, add 10 wt% of polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 10% wt%, and granulate by high-speed centrifugation to obtain granules;

[0097] (5) Molding: The granulated particles are pressed into magnetic rings of T25×15×7.5;

[0098] (6) Secondary sintering: The magnetic ring is sintered in a bell furnace with balanced oxygen partial pressure. The temperature is raised from room temperature to 1250℃ in 3 hours and held at the highest temperature for 1 hour. The oxygen partial pressure in the sintering atmosphere is controlled within the range of 0.5%. After the holding period, the cooling stage begins. During the cooling stage, the atmosphere is maintained at the balanced oxygen partial pressure at different temperatures. The temperature is lowered from 1250℃ to 500℃ in 6 hours to obtain manganese-zinc ferrite.

[0099] Performance tests were conducted on Examples 1-5 and Comparative Examples 1-3, and the results are shown in Table 1:

[0100] Table 1

[0101]

[0102] As can be seen from Table 1, the manganese-zinc ferrites prepared in Examples 1-5 have low core losses at 25-140℃ and high saturation magnetic flux density at 25-100℃, exhibiting good temperature stability and low loss performance.

[0103] The conventional method for preparing manganese-zinc ferrite involves sintering the main component at a relatively low temperature in a single operation, while additives are added during a secondary ball milling process (refer to Comparative Example 1). Comparative Example 1, compared to Example 1, shows that with consistent main and additive compositions, optimizing the preparation process by adding additives with different functions in batches, and making simple adjustments to the primary and secondary sintering processes, can improve the temperature stability and saturation magnetic flux density of manganese-zinc ferrite while reducing its losses. Comparative Examples 2 and 3, compared to Example 1, show that simply adjusting the order of additive addition or only adjusting the sintering process not only fails to reduce core losses and increase saturation magnetic flux density but may even degrade performance. A balance must be struck, i.e., adjusting both the order of additive addition and the sintering process simultaneously, to maximize the advantages of the process.

[0104] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0105] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a wide-temperature, low-loss manganese-zinc ferrite, characterized in that, Includes the following steps: First ball milling; first sintering; second ball milling; granulation; molding; second sintering; The specific steps of the first ball milling are as follows: Weigh the main component and the first additive according to the required proportion, put them into a ball mill, and ball mill for 3-10 hours to obtain a slurry. Dry the slurry to obtain the first ball milled powder. The specific steps of the secondary ball milling are as follows: A second additive is added to the sintered powder in a certain proportion, and the powder is put into a ball mill again and milled for 1-5 hours to obtain a slurry. The slurry is then dried to obtain the secondary ball-milled powder. The first additives are Co3O4 and TiO2, with the amount of Co3O4 added being 200-4000ppm and the amount of TiO2 added being 50-800ppm. The second additives are SiO2 and CaCO3, with SiO2 added at 10-150 ppm and CaCO3 added at 200-1500 ppm. The ferrite main component is composed of 51-59 mol% Fe2O3, 5-10 mol% ZnO, and the remainder is MnO.

2. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The purity of the raw materials for the main component should be no less than 98 mol.

3. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The specific steps of the first sintering are as follows: The ball-milled powder is heated to 900-1200℃ in air at a heating rate of 200-300℃ / h, held for 1-3 hours, and then cooled in the furnace to obtain the primary sintered powder.

4. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The specific steps of the granulation process are as follows: Based on the total weight of the secondary ball milled powder, add 6-15 wt% of a polyvinyl alcohol aqueous solution of the total mass of the secondary ball milled powder, wherein the concentration of the polyvinyl alcohol aqueous solution is 5-10% wt%, and granulate by high-speed centrifugal granulation to obtain granules.

5. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The specific steps of the molding process are as follows: The granulated particles are pressed into magnetic rings of size T25×15×7.

5.

6. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The specific steps of the secondary sintering are as follows: The magnetic rings were sintered in a bell-shaped furnace using a balanced oxygen partial pressure. The temperature was raised from room temperature to 1100-1450℃ over 1-6 hours, and held at the highest temperature for 0.5-5 hours. The oxygen partial pressure in the sintering atmosphere was controlled within the range of 0.4-5%. After the holding period, the temperature was lowered to 300-600℃ over 1-6 hours to obtain manganese-zinc ferrite.

7. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The highest temperature for the first sintering is 1100-1200℃, which promotes the participation of the first additive in the crystal lattice formation process, while reducing the activity of the powder and preventing abnormal grain growth during the second sintering process.

8. The method for preparing a wide-temperature, low-loss manganese-zinc ferrite according to claim 1, characterized in that, The holding time at the highest temperature during the second sintering is 0.5-1h, which allows the second additive to react fully while further refining the grain size.

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