WO2024106735A1 - Ferrite magnetic material, sintered ferrite magnet comprising same, and method for manufacturing sintered ferrite magnet - Google Patents

Abstract

A ferrite magnetic material according to one embodiment of the present invention comprises a compound represented by chemical formula 1. [Chemical formula 1] AFe12-x-yBxCyO19 In chemical formula 1, A is at least one selected from among calcium (Ca), strontium (Sr) and barium (Ba), each of B and C is at least one selected from 4d transition metals or 5d transition metals, and the sum of x and y is 0.5 or less.

Description

Ferrite magnetic material, sintered ferrite magnet containing the same, and method for manufacturing the sintered ferrite magnet

The present invention relates to a ferrite magnetic material, a sintered ferrite magnet containing the same, and a method of manufacturing the same.

This invention is a nanomaterial technology development project identification number: 1711158472, task number: 2020M3H4A2084418, ministry name: Ministry of Science and ICT, project management (professional) organization name: National Research Foundation of Korea, research project name: nanomaterial technology development, research project name: scarce resources It is derived from research conducted as part of the development of alternative advanced composite magnetic material material design, contribution rate: 1/1, project performing organization name: Max Planck Korea Postech Research Institute, research period: 2022.01.01 ~ 2022.12.31).

Hexagonal ferrite (Hexagonal ferrite) is one of the most important series of hard magnetic permanent magnets. Currently, the annual production of ferrite has reached 1 million tons, and various applications have been developed, including motors, recording media, high-frequency devices, etc. In particular, M-type hexagonal ferrite, which has a magnetoplumbite (M)-type crystal structure, has excellent chemical stability, corrosion resistance, and mass productivity, making it a permanent core material for small motors for automotive electronics, rotors for electrical appliances, and rotors for home appliances. It is widely used as a magnet, and much effort has been made to improve its magnetic properties.

M-type hexagonal ferrite is characterized by uniaxial crystal magnetic anisotropy, and its chemical composition is expressed as SrFe ₁₂ O ₁₉ or BaFe ₁₂ O ₁₉ , and there are 12 iron ions per molecule. The magnetic properties of the M-type ferrite are based on the magnetic moment of Fe ions, and among the 12 Fe ions, there are 8 with upward spin directions and 4 with downward spin directions, resulting in a pure water content per molecule of M-type ferrite. The sum of spins is 4. Generally, in M-type ferrite, the iron ion is trivalent (Fe ³⁺ ) and has 5 3d electrons (spin magnetic moment), for a total of 20 per molecule (5 spin moments Х sum of pure spins). The spin magnetic moment becomes the source of magnetism (saturation magnetization) of the M-type ferrite magnet. In other words, to increase the saturation magnetization value, which is the source of magnetism, by substituting an element or a non-magnetic element with a lower spin magnetic moment than the iron ion in the downward spin direction of the iron ion, the total spin magnetic moment can be increased and the saturation magnetization can be improved. there is. In general, elements with a lower spin magnetic moment than the iron ion include Co ²⁺ (spin moment = 3), Ni ²⁺ (spin moment = 2), Cu ²⁺ (spin moment = 1), etc., and are considered non-magnetic elements. There is Zn ²⁺ (spin moment = 0). It is well known that theoretically, if iron ions (Fe ³⁺ ) are replaced with Zn ²⁺ , the total spin magnetic moment can be increased the most and high saturation magnetization can be obtained. However, in the case of Zn, although high saturation magnetization can be obtained, it has a low anisotropic magnetic field and has low coercive force characteristics, making it difficult to use it as a permanent magnet.

Therefore, one of the most successful approaches to improve the magnetic performance of hexagonal ferrite is to incorporate external atoms into the lattice. Among these, it has been reported that hexagonal ferrite substituted with La-Co was successfully synthesized and improved magnetization and coercive force, and most of the important commercial products of hexagonal ferrite are based on compositions containing La-Co. However, due to the recent surge in the price of cobalt (Co), large-scale production of ferrite magnets is difficult, and there is a need to develop technology for ferrite magnets that can replace them.

In addition, when external atoms such as Co are added at a certain ratio or higher, the material phase becomes unstable, and there is a problem that a special process at ultra-high pressure is required to add external atoms at a certain ratio or higher.

One purpose of the present invention to solve the above-mentioned problems is to provide a ferrite magnetic material with improved magnetic properties, a sintered ferrite magnet containing the same, and a method of manufacturing a sintered ferrite magnet.

However, the problem to be solved by the present invention is not limited to this, and may be expanded in various ways without departing from the spirit and scope of the present invention.

A ferrite magnetic material according to an embodiment of the present invention for achieving the above-described object includes a compound represented by the following formula (1).

[Formula 1]

AFe _12-xy B _x C _y O ₁₉

In Formula 1, A is at least one selected from calcium (Ca), strontium (Sr), and barium (Ba), B and C are each at least one selected from a 4d transition metal or a 5d transition metal, and x The sum of and y is less than 0.5.

According to one aspect, in Formula 1, A may be Sr or Ba, B may be Ru, and C may be Zr.

According to one aspect, in Formula 1, x may be 0.1 to 0.4, and y may be 0.01 to 0.4.

According to one aspect, in Formula 1, B may be doped into the spin down site of Fe with an oxidation number of 4+.

According to one aspect, in Formula 1, C may be doped with a 2+ oxidation number or a 4+ oxidation number.

According to one aspect, in Formula 1, C may be doped into Fe first, and then B may be doped into Fe.

According to one aspect, C may be an element without spin.

According to one aspect, the ferrite may have magnetoplumbite-type ferrite as the main phase.

According to one aspect, the magnetoplumbite-type ferrite may contain more than 50 mol% of the total ferrite.

According to one aspect, the ferrite may further include Ca or Na.

A sintered ferrite magnet according to an embodiment may be formed by sintering the above-described ferrite magnetic material.

A method of manufacturing a sintered ferrite magnet according to an embodiment includes mixing and pulverizing SrCO ₃ , Fe ₂ O ₃ , ZrO ₂ , and RuO ₂ powder to form a pulverized product, forming and primary sintering the pulverized product. Forming a sintered body, forming a secondary sintered body by pulverizing and molding the primary sintered body and then sintering the primary sintered body, forming a tertiary sintered body by pulverizing and forming the secondary sintered body and then tertiary sintering, and It includes the step of calcining the tertiary sintered body, and the calcination may be performed at a temperature of 1300°C to 1350°C.

According to one aspect, the ferrite sintered magnet may include a compound represented by the following formula (2).

[Formula 2]

SrFe _12-xy Ru _x Zr _y O ₁₉

In Formula 2, the sum of x and y is 0.5 or less.

According to one aspect, in Formula 2, x may be 0.1, and y may be 0.01 to 0.4.

According to one aspect, the third sintering temperature may be higher than the second sintering temperature, and the second sintering temperature may be higher than the first sintering temperature.

The disclosed technology can have the following effects. However, since it does not mean that a specific embodiment must include all of the following effects or only the following effects, the scope of rights of the disclosed technology should not be understood as being limited thereby.

The ferrite magnetic material and sintered ferrite magnet according to an embodiment of the present invention described above have high magnetic saturation and magnetic anisotropy. Additionally, the method for manufacturing a sintered ferrite magnet according to an embodiment of the present invention can manufacture a sintered magnet having a high saturation magnetic susceptibility.

Figure 1 shows the thermodynamic stability of each doping site according to 4d transition metal and 5d transition metal doping.

Figure 2 predicts magnetic properties due to various 4d transition metal and 5d transition metal doping, and shows the magnetic moment for each doping site.

Figure 3 plots the energy according to the doping position when Ru and Zr are doped simultaneously.

Figure 4 shows the saturation magnetic susceptibility value according to the calcination temperature of the ferrite composite containing 4d transition metals such as Ru and Zr prepared according to Example 1.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present invention. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present application. No.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. In order to facilitate overall understanding when describing the present invention, the same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

The present invention relates to a ferrite magnetic material, a sintered ferrite magnet containing the same, and a method of manufacturing a sintered ferrite magnet.

Below, first, the ferrite magnetic material according to this embodiment will be described.

The ferrite magnetic material according to this embodiment may include a compound represented by the following formula (1).

[Formula 1]

AFe _12-xy B _x C _y O ₁₉

In Formula 1, A may be one or more selected from calcium (Ca), strontium (Sr), and barium (Ba).

Additionally, in Formula 1, B and C may each be one or more selected from a 4d transition metal or a 5d transition metal. As will be explained separately later, the ferrite magnetic material according to this embodiment can improve the magnetic properties of the ferrite magnetic material by doping Fe with two or more elements included in the 4d transition metal or 5d transition metal. At this time, the B may be doped into the spin down site of Fe. Additionally, C may be an element without spin.

In Formula 1, the sum of x and y may be 0.5 or less. That is, the maximum doping concentration of elements B and C doped in Fe may be 0.5 mol% or less. If the sum of x and y is greater than 0.5, ferrite may not maintain a single main phase. For example, x may be 0.1 and y may be 0.01 to 0.4. However, this is an example and the present invention is not limited thereto.

The ferrite according to this embodiment is characterized in that the ferrite of AFe ₁₂ O ₁₉ (A = Group 2 element, for example, Sr, Ba) is substituted with a 4d transition metal or 5d transition metal. This substitution of ferrite and the resulting effects will be described in detail later.

In one embodiment, in Formula 1, A may be Sr or Ba, B may be Ru, and C may be Zr. However, this is an example and the present invention is not limited thereto.

In Formula 1, when B is Ru, Ru may be doped into the spin down site of Fe with an oxidation number of 4+ (Ru ⁴⁺ ). Additionally, when C is Zr, Zr may be doped into Fe with a 2+ oxidation state or a 4+ oxidation state. That is, in Formula 1, Zr may be doped with an oxidation number of Zr ²⁺ or Zr ⁴⁺ .

As will be explained in detail later, ferrite may be doped with Zr first and then doped with Ru. Due to this doping order, Ru can be doped into the spin-down site and have high magnetic anisotropy. The specific doping sequence and its resulting effects will be described in detail later.

Depending on the embodiment, the compound of Formula 1 may further include Ca or Na. In this case, there may be a process advantage. According to one aspect, Ca may be substituted for Sr, and Na may be added separately.

The ferrite magnetic material according to this embodiment may have magnetoplumbite-type ferrite as the main phase. At this time, using magnetoplumbite-type ferrite as the main phase means containing magnetoplumbite-type ferrite in more than 50 mol% of the total ferrite.

Below, the effect of the ferrite magnetic material according to an embodiment of the present invention will be described. Ferrite according to this embodiment is a material for permanent magnets, and permanent magnets can express their performance through residual magnetic flux density, coercive force, and operating temperature. The greater the residual magnetic flux density, the greater the magnetic force, and the greater the coercive force, the greater the power to maintain magnetism. This residual magnetic flux density is affected by magnetic saturation, density, and alignment, and in the case of coercive force, it can be affected by magnetic anisotropy and single magnetic area ratio. These properties can be improved by appropriately controlling the chemical composition and manufacturing process of ferrite.

Hexagonal M-type ferrite based on conventional AFe ₁₂ O ₁₉ (A = Group 2 elements, for example, Sr, Ba) is a representative example of a ferrite permanent magnet. The performance of these ferrite permanent magnets can be improved through manufacturing process control such as ferrite particle size optimization, crystal grain alignment, and densification.

Improving the performance of ferrite based on changing its chemical composition rather than the manufacturing process is achieved by controlling the magnetic saturation and magnetic anisotropy of ferrite. Specifically, the magnetic performance of ferrite can be improved through optimization of chemical composition ratio and local ion substitution methods.

The ferrite magnetic material according to this embodiment has improved magnetic performance by changing its chemical composition, and can have high magnetic anisotropy by replacing ferrite with two or more compounds selected from 4d transition metals or 5d transition metals.

Typically, conventional hexagonal M-type ferrite sought to increase anisotropy and magnetic susceptibility by adding Co and Zr. In other words, when Fe ³⁺ (d ⁵ , S=5/2) ions, which have a magnetic moment oriented in the antiparallel direction, are replaced by ions with a smaller magnetic moment than the Fe ³⁺ ion or other non-magnetic elements, magnetic saturation is improved. possible. Additionally, when substituted with an ion having a larger orbital angular momentum than the Fe ³⁺ ion, greater interaction with the crystal structure can occur, resulting in greater magnetic anisotropy and improved coercive force. Additionally, when Fe ³⁺ ions are replaced with ions larger than Fe ³⁺ ions, chemical pressure may increase, resulting in lower magnetic anisotropy and improved coercive force.

Accordingly, the ferrite magnetic material and the sintered magnet containing the same according to this embodiment improve magnetic anisotropy and magnetic properties through large spin-orbital interaction by substituting 4d transition metal elements instead of existing 3d transition metal elements.

That is, in the present invention, the spin density was reduced and the magnetic anisotropy was increased by doping with a 4d transition metal or 5d transition metal, which has a relatively strong crystal field strength compared to the 3d transition metal.

Magnet performance can be improved by changing the crystal field strength of the ferrite compound. Crystal field energy (CFE) is a theory based on the technology of metal ligand-bound ions and is a simple and practical model for the electronic structure and magnetic properties of coordination compounds. The spin state of d-orbital electrons is determined depending on the crystal field strength. In other words, the low spin and high spin of d-orbital electrons can be determined depending on the crystal field strength.

For example, Fe ³⁺ (d ⁵ ) has 5 d-electrons, so for high spin, the spin moment sum is S=5/2, and for low spin, it is S=1/2. Therefore, in the case of high spin, the spin density increases and the saturation magnetization can be strengthened. The crystal field strength of transition metals tends to increase as 3d < 4d < 5d. In other words, since 4d and 5d elements are heavy elements, they can be expected to have high magnetic anisotropy.

Figure 1 shows thermodynamic stability for each doping site according to 4d transition metal and 5d transition metal doping. Figure 1 shows thermodynamic stability predicted through comparison of relative formation energies when 4d and 5d transition metal elements are doped into different Fe sites. As shown in FIG. 1, when 4d transition metal or 5d transition metal elements with high crystal field strength were doped, it was confirmed that spin-down sites were doped. Therefore, it was confirmed that spin density could be increased through spin-down site doping.

Figure 2 predicts magnetic properties due to various 4d transition metal and 5d transition metal doping, and shows the magnetic moment for each doping site. Table 1 predicts magnetic properties by 4d transition metal and 5d transition metal doping. That is, Table 1 shows MAE (magnetic anisotropy energy) values measured by varying the metal of M in the compound of SrFe _11.98 M _0.02 O ₁₉ .

	Mo	W	Rh	PD	Hg		Fe
2a	1.45	0.93	0.93	0.42	5.04	0.801
2b	1.54	4.69	4.69	6.96	2.98
4f1	0.07	0.69	0.69	0.44	0.67
4f2	0.90	2.51	1.15	0.37	2.14
12k	0.96	0.90	0.90	1.50	3.72

Referring to Table 2 and FIG. 2, it was confirmed that SrFe _11.98 M _0.02 O ₁₉ doped with a heavy transition metal with a high orbital orbit such as tungsten, palladium, and mercury had improved spin density and magnetic anisotropy.

The case where ruthenium (Ru) is doped among various 4d transition metals and 5d transition metals will be described as an example. Ru is an element belonging to the 4d transition metal, and when doping SrFe ₁₂ O ₁₉ with Ru alone, it prefers the 12k site, which is the spin-up site. This is because, although Ru is a 4th period transition metal, it belongs to the same group as Fe and prefers the Fe 12k position (spin-up), which is the position with the most Fe elements.

Table 2 shows the relative energies according to Ru doping positions in SrFe ₁₂ O ₁₉ . Referring to Table 2 below, it can be seen that the Fe-12k position (octahedral) is preferred during Ru doping.

Relative energy (unit: eV)
Fe-2a	Fe-2b	Fe-4f1	Fe-4f2	Fe-12k
Pyramidal	Octahedral	Tetragonal	Octahedral	Octahedral
0.4322	1.0865	1.4715	0.3314	0.0000

In other words, Ru belongs to the 4th period transition metal and has strong spin-orbital interaction, so an increase in coercive force can be expected by improving magnetic anisotropy. However, Ru prefers low-spin because the crystal field strength is large. Therefore, when the spin-up site is substituted, there may be a problem that the magnetic properties are impaired in terms of Tc (Curie temperature). Therefore, in order to improve magnetic properties by substitution of Ru, it is necessary to dope Ru into the spin-down site.

Accordingly, the ferrite magnetic material according to this embodiment used a method of co-doping two or more types of elements in order to dope the spin down site (tetragonal site) with an element with a large crystal field strength. Specifically, co-doping of Ru and Zr can be used, in which case Zr can be doped first and Ru can be doped later.

In the case of Zr, 4+ oxidation number is preferred during doping (d ⁰ ), and electronegativity (coordination number = 6) is 1.61. The electronegativity of Fe ³⁺ (d ⁵ ) is 1.556 (coordination number = 6, octahedral) and 1.726 (coordination number = 4, tetragonal). Therefore, when Zr ⁴⁺ is doped alone, the octahedral position is preferred.

Additionally, Ru belongs to the same family as Fe. The electronegativity of Ru ³⁺ (coordination number = 6) is 1.576, which is similar to that of Fe ³⁺ (coordination number = 6), which is 1.556. Therefore, when doping Ru alone, the Fe ³⁺ spin-up site is preferred, resulting in Ru is doped with Ru ³⁺ , which has an oxidation number of 3.

However, if Zr ⁴⁺ is doped first, the overall charge balance of SrFe ₁₂ O ₁₉ is broken. That is, if Zr is doped first, defects are induced in Fe or Sr, and therefore, when Ru is doped, it can be doped with Ru ⁴⁺ instead of Ru ³⁺ .

The electronegativity of Ru ⁴⁺ is 1.848, which is similar to the electronegativity of the spin down site of Fe ³⁺ (coordination number = 4, tetragonal site, electronegativity = 1.726), so it can be doped into the spin down site.

Figure 3 is a diagram plotting the energy according to the doping position when Ru and Zr are doped at the same time. As can be seen in Figure 3, it can be seen that after Zr is doped first, Ru prefers the 4f1 and 4f2 sites. In other words, when doping Zr first and then Ru, the charge balance of SrFe ₁₂ O ₁₉ is broken and defects are induced, and Ru can be doped to the spin-down site with similar electronegativity in the form of Ru ⁴⁺ oxidation number instead of Ru ³⁺ . there is. Therefore, an increase in coercive force can be expected due to improvement in magnetic anisotropy.

That is, the ferrite magnetic material according to this embodiment is doped with both Ru and Zr, so the magnetic anisotropy and Curie temperature can be improved.

The ferrite magnetic material according to this embodiment can be sintered to form a sintered ferrite magnet. Additionally, the ferrite magnetic material according to this embodiment may be processed and provided in the form of a powder magnet or a film film. Magnets using ferrite magnetic materials can be widely used, ranging from household electrical appliances such as switches and motors that use magnets to retail items and industrial devices.

Below, a method for manufacturing a sintered ferrite magnet will be described. However, this manufacturing method is only an example and the present invention is not limited thereto.

Example 1: Manufacturing method of ferrite sintered magnet

Prepare SrCO ₃ , Fe ₂ O ₃ , ZrO ₂ , and RuO ₂ powder as raw material powder. This raw material powder was weighed using a scale to match the molar ratio of Chemical Formula 1 above, and then mixed and ground using zirconia mortar. Subsequently, it was press molded using a metal mold and then first sintered at a temperature of 1000°C for 12 hours. The primary sintered body thus sintered was again subjected to a mixing-crushing-forming process and then secondary sintered at 1100°C for 12 hours. Afterwards, the secondary sintered body went through a mixing-crushing-molding process again and was sintered a third time at 1250°C for 12 hours. Afterwards, the third sintered body was calcined at the final calcining temperature for 24 hours. All processes were carried out in normal pressure air, and the structure of each powder phase was analyzed and the material phase was confirmed through X-ray diffraction analysis. Measurement of saturation susceptibility was carried out at a temperature of 300 K using a commercial VSM.

Figure 4 shows the saturation susceptibility values according to the calcination temperature of the ferrite composite containing 4d transition metals such as Ru and Zr prepared according to Example 1. As shown in Figure 4, when the calcination temperature was 1300°C or higher, it was confirmed that the saturation susceptibility value of the ferrite composite containing 4d ions such as Ru and Zr increased. That is, it was confirmed that the optimal calcination temperature in the manufacturing method according to this example was 1300°C or higher.

Referring to FIG. 4, it was confirmed that in the composite synthesized at the optimized final calcination temperature of 1350°C, a saturation magnetic susceptibility of up to 77 emu/g could be obtained when Ru = 0.1 and Zr = 0.2 were included. This is an improved saturation susceptibility value of about 4% compared to the maximum saturation susceptibility value of 74 emu/g of SrFe ₁₂ O ₁₉ that does not contain 4d transition metal.

Referring to FIG. 4, it was confirmed that when Ru = 0.1 and Zr = 0.3 were included, a similar maximum saturation magnetic susceptibility could be obtained as when Ru = 0.1 and Zr = 0.2 were included. However, it was confirmed that the saturation susceptibility value decreased slightly when Ru = 0.1 and Zr = 0.4 were included.

As described above, in the ferrite magnetic material and its manufacturing method according to this embodiment, ferrite with magnetoplumbite-type ferrite as the main phase is doped with two or more types of Group 4 transition metals or Group 5 transition metals. Therefore, by doping the spin-down site with a doping material, it is possible to have high magnetic anisotropy, improved Curie temperature, and high saturation susceptibility value. In other words, it is possible to form a ferrite magnetic material with improved magnetic properties.

Although it has been described above with reference to the drawings and examples, it does not mean that the scope of protection of the present invention is limited by the drawings or examples, and those skilled in the art will recognize the present invention as set forth in the claims below. It will be understood that various modifications and changes can be made to the present invention without departing from its spirit and scope.

The present invention described above is explained based on a series of functional blocks, but is not limited to the above-described embodiments and the attached drawings, and various substitutions, modifications and changes are made without departing from the technical spirit of the present invention. It will be clear to those skilled in the art that this is possible.

The combination of the above-described embodiments is not limited to the above-described embodiments, and various types of combinations in addition to the above-described embodiments may be provided depending on implementation and/or need.

In the above-described embodiments, the methods are described based on flowcharts as a series of steps or blocks, but the present invention is not limited to the order of steps, and some steps may occur in a different order or simultaneously with other steps as described above. there is. Additionally, a person of ordinary skill in the art will recognize that the steps shown in the flowchart are not exclusive and that other steps may be included or one or more steps in the flowchart may be deleted without affecting the scope of the present invention. You will understand.

The above-described embodiments include examples of various aspects. Although it is not possible to describe all possible combinations for representing the various aspects, those skilled in the art will recognize that other combinations are possible. Accordingly, the present invention is intended to include all other substitutions, modifications and changes falling within the scope of the following claims.

Claims (15)

1. Ferrite magnetic material containing a compound represented by the following formula (1):

   [Formula 1]

   AFe _12-xy B _x C _y O ₁₉

   In Formula 1,

   A is one or more selected from calcium (Ca), strontium (Sr), and barium (Ba),

   B and C are each at least one selected from a 4d transition metal or a 5d transition metal,

   The sum of x and y is 0.5 or less.
2. In paragraph 1:

   Wherein A is Sr or Ba,

   where B is Ru,

   Wherein C is Zr, a ferrite magnetic material.
3. In paragraph 2,

   The x is 0.1,

   A ferrite magnetic material where y is 0.01 to 0.4.
4. In paragraph 2,

   The B is a ferrite magnetic material doped at the spin down site of Fe with an oxidation number of 4+.
5. In paragraph 2,

   The C is a ferrite magnetic material doped with a 2+ oxidation number or a 4+ oxidation number.
6. In paragraph 1:

   After the C is first doped into Fe,

   A ferrite magnetic material in which the B is doped into Fe.
7. In paragraph 6:

   The C is a ferrite magnetic material that is an element without spin.
8. In paragraph 1:

   The ferrite is a ferrite magnetic material whose main phase is magnetoplumbite-type ferrite.
9. In paragraph 8:

   The magnetoplumbite-type ferrite is a ferrite magnetic material containing more than 50 mol% of the total ferrite.
10. In paragraph 1:

    The ferrite is a ferrite magnetic material further containing Ca or Na.
11. A sintered ferrite magnet formed by sintering the ferrite magnetic material of any one of claims 1 to 10.
12. Mixing and grinding SrCO ₃ , Fe ₂ O ₃ , ZrO ₂ , and RuO ₂ powder to form pulverized product;

    forming and primary sintering the pulverized material to form a primary sintered body;

    Forming a secondary sintered body by crushing and molding the primary sintered body and then performing secondary sintering;

    Forming a tertiary sintered body by pulverizing and molding the secondary sintered body and then tertiarily sintering the secondary sintered body; and

    Comprising the step of calcining the tertiary sintered body,

    A method of manufacturing a sintered ferrite magnet in which the calcination is performed at a temperature of 1300°C to 1350°C.
13. In paragraph 12:

    The ferrite sintered magnet is a method of manufacturing a ferrite sintered magnet containing a compound represented by the following formula (2):

    [Formula 2]

    SrFe _12-xy Ru _x Zr _y O ₁₉

    In Formula 2,

    The sum of x and y is 0.5 or less.
14. In paragraph 13:

    The x is 0.1,

    A method of manufacturing a sintered ferrite magnet where y is 0.01 to 0.4.
15. In paragraph 12:

    The third sintering temperature is higher than the second sintering temperature,

    A method of manufacturing a ferrite sintered magnet wherein the secondary sintering temperature is higher than the primary sintering temperature.

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