JP3157302B2 - Nitride magnetic materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth-iron-nitrogen based magnetic material having high magnetic properties and excellent oxidation resistance, and particularly to a magnetic material most suitable for use in small motors and actuators.

[0002]

2. Description of the Related Art Magnetic materials are used in a wide range of fields from home appliances, audio products, automobile parts and peripheral devices of computers, and their importance as electronic materials is increasing year by year. In particular, recently, there has been a demand for miniaturization and high efficiency of various electric and electronic devices, so that a magnetic material with higher performance is required.

[0003] In response to the demands of this era, Sm-Co based, N
The demand for rare earth magnetic materials such as d-Fe-B is rapidly increasing. However, the Sm-Co system has a problem that the supply of the material is unstable and the cost of the material is high, and the Nd-Fe-B system has a problem in that the heat resistance and the corrosion resistance are inferior. On the other hand, as a new rare earth magnetic material, a rare earth-iron-nitrogen magnetic material has been invented. This material has a high magnetization, an anisotropic magnetic field, and a high Curie point.
It is expected as a magnetic material that compensates for the drawbacks of the d-Fe-B system. However, this magnetic material has a disadvantage of poor oxidation resistance. The material having the rare earth-iron-M-nitrogen composition is disclosed in JP-A-60-14490.
6, JP-A-60-144907, JP-A-60-1449
09.

However, Japanese Patent Application Laid-Open No. Sho 60-144906-14
The material disclosed in No. 4909 becomes a material containing a large amount of iron nitride, α-iron, rare earth nitride and nitride of M from its manufacturing process and conditions, and magnetic properties such as coercive force are significantly deteriorated. These materials do not become high performance magnet materials. For this reason, rare earth-iron-M-nitrogen-based materials having a rhombohedral or hexahedral crystal structure with high magnetic properties and excellent oxidation resistance are not known at present, and their appearance has appeared. It is strongly desired.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a rare-earth-iron-nitrogen-based material having a rhombohedral or hexagonal crystal structure in which a metal element M coexists to provide high magnetic properties and excellent oxidation resistance. The present invention provides a rare earth-iron-M-nitrogen composition magnetic material having the following characteristics:

[0006]

In order to obtain a rare earth-iron-nitrogen based magnetic material having high magnetic properties and oxidation resistance, the present inventors have conducted intensive studies on a system obtained by adding various elements (M) to a mother alloy. The present inventors have found a rare earth (R) -iron (Fe) -M-nitrogen (N) -based magnetic material having a composition and a crystal structure having high magnetic properties and excellent oxidation resistance, and have accomplished the present invention.

That is, the present invention relates to (1) a magnetic material represented by the general formula R _α (Fe _(1-γ) M _γ ) _(100-α-β) N _β and having an oxidation resistance of 70% or more. Yes , R is at least one of Sm or Nd , M is Mn, C
At least one of the elements of r and Ni, α and β are atomic percentages 3 ≦ α ≦ 203 3 ≦ β ≦ 30 γ is 0.01 ≦ γ ≦ 0.2 in atomic ratio, and R, Fe , M and N are characterized in that the phase containing rhombohedral or hexagonal crystal structure is contained in the magnetic material, and (2) the content of Fe, which is a component of the magnetic material described in (1) above, is less than 0.1%.
A magnetic material characterized by having a composition in which 01 to 50 atomic% is substituted with Co; (3) a magnetic material represented by the general formula: R _α (Fe _(1-γ) M _γ ) _(100-α-β) N _β M is N
(1) The magnetic material according to (1) or (2), wherein (4) a general formula R _{α / (100-β)} (Fe _(1-γ) M _γ )
An alloy represented by _{(100-α-β) / (100-β)} , under an atmosphere containing at least one of nitrogen gas and ammonia gas,
The method for producing a magnetic material according to any one of the above (1) to (3), which is obtained by performing a heat treatment at a temperature in the range of 200 to 650 ° C.

Hereinafter, the present invention will be described in detail. Is the rare earth (R) at least one of Sm and Nd
Selected from

The R may have a purity that can be obtained by industrial production, and impurities unavoidable in production, such as O, H,
C, Al, Si, F, Na, Mg, Ca, Li and the like may be present. Iron (Fe) is the basic composition of the present magnetic material that is responsible for ferromagnetism, and up to 50 atomic% of it may be replaced by Co. Regarding the element M of Mn, Cr, and Ni, which is the point of the present invention, one or more of the elements (M) of Mn, Cr, and Ni coexist at 1 to 20 atomic% with respect to Fe + M. .

The composition of the R-Fe-MN-based magnetic material in the present invention is such that the content of the rare earth is 3 to 20 atomic%, the total of iron and M components is 50 to 94 atomic%, and the content of N is 3 to 30 atomic%. It is necessary to be in. When the R component is less than 3 atomic%,
The soft magnetic phase containing a large amount of iron component is separated, and the coercive force of the nitride is reduced, so that a practical permanent magnet cannot be obtained. The R component is 2
If it exceeds 0 atomic%, the residual magnetic flux density is undesirably reduced. The composition of the rare earth element is preferably 5 to 15 atomic%, more preferably 7 to 12 atomic%.

The M component coexisting with iron is preferably in an atomic ratio of 0.01 to 0.2 with respect to the total of iron and M component.
If it exceeds 0.2, the saturation magnetization decreases, which is not preferable.
If less, the effect of M addition on oxidation resistance is not so good
I can't. Further, when iron is substituted with 0.01 to 50 atomic% of Co, the material has a high Curie point and magnetization, and has high oxidation resistance.

In addition to Mn, Cr and Ni as M components, Li, Na, K, Mg, Ca, Sr, Ba, Ti,
Zr, Hf, V, Nb, Ta, Mo, W, Pd, Cu,
Ag, Zn, B, Al, Ga, In, C, Si, Ge,
One or more of Sn, Pb, and Bi elements (M ′ component) may be added.
The total amount of n, Cr and Ni should not exceed the total amount of Mn, C
The total amount of r and Ni must be in the range of the γ value.

[0013] The crystal structure of the main phase of the R-Fe-M-N-based magnetic material must contain at least one of hexagonal and rhombohedral in a volume fraction of 50% or more of the whole. The main phase is a phase containing R, Fe, M, and N and having a rhombohedral or hexagonal crystal structure, and a phase having another composition and crystal structure is called a sub phase. For example, as a subphase, a high magnetic nitride phase having a tetragonal structure such as an RFe _12-x M _x N _y phase may be included. The volume fraction must not exceed the volume fraction of the magnetic material of the present invention. When the volume fraction exceeds 75% by volume, it is a practically preferable material. The main phase of the R-Fe-M-N-based material obtained in the present invention has almost the same symmetry in crystal structure as the main raw material phase of the R-Fe-M alloy as the raw material, and nitrogen is generated between lattices. It penetrates or is introduced in place of the M component, and the crystal lattice expands in many cases. The main raw material phases are R, Fe,
M, and a phase having a rhombohedral or hexagonal crystal structure, having other composition and crystal structure,
A phase containing no N is called an auxiliary raw material phase.

With the expansion of the crystal lattice, at least one of the items of the oxidation resistance and the magnetic properties is improved, and the magnetic material is suitable for practical use. The magnetic properties referred to herein include the saturation magnetization (4πIs), residual magnetic flux density (Br), magnetic anisotropy magnetic field (Ha), magnetic anisotropy energy (Ea), magnetic anisotropy ratio, Curie point ( Tc), intrinsic coercive force (iHc),
Squareness ratio (Br / 4πIs), maximum energy product [(B
H) max], thermal demagnetization rate (α), and temperature change rate (β) of coercive force. Here, the magnetic anisotropy ratio refers to the ratio (a / magnetization) of the magnetization (a) in the difficult magnetization direction and the magnetization (b) in the easy magnetization direction when an external magnetic field is applied at 15 kOe.
b), the smaller the magnetic anisotropy ratio, the higher the magnetic anisotropy energy.

[0015] For example, rare earth - as an iron -M master alloy, when choosing the _{Sm 10.5 (Fe 0. 9 Ni 0.1} ) 89.5 having a rhombohedral structure, by introducing nitrogen, crystal magnetic anisotropy in-plane It changes from anisotropic to uniaxial anisotropy suitable as a hard magnetic material, and the magnetic properties such as magnetic anisotropic energy and the oxidation resistance are improved. The amount of nitrogen (N) introduced is 3
It must be ３０30 atomic%. If it exceeds 30 atomic%, the magnetization is low, and its practicality is small as a magnet material. If it is less than 3 atomic%, the performance of the raw material alloy cannot be improved much, which is not preferable. The nitrogen content is more preferably 5 to 25 atomic%, and particularly preferably 10 to 17 atomic%.
Atomic%.

Further, the R-Fe-M composition ratio of the desired R-Fe-M-N-based magnetic material, the amount ratio of the subphase, etc.
The optimal amount of nitrogen is different. The optimal amount of nitrogen at this time is
Depending on the purpose, at least one item of the oxidation resistance and the magnetic properties of the material is the optimum amount of nitrogen, and the magnetic properties are optimum when the magnetic anisotropy ratio, the demagnetization rate and the temperature change rate of the coercive force are changed. The absolute value is minimum and the others are maximum.

The R-Fe-MN based magnetic material obtained by the present invention preferably contains 0.01 to 15 atomic% of hydrogen (H) and 0.01 to 15 atomic% of oxygen (O). More preferred amounts of hydrogen and oxygen are 0.1 to 10 atomic% and 0.1 to 10 atomic%.
10 atomic%. Therefore, particularly preferred R-Fe of the present invention
The composition of the −M−N based material is represented by the general formula R _α (Fe _(1-γ) M _γ )
_{(100-α-β-δ-ε)} N _β H _δ 0 _ε , α, β,
δ and ε are atomic% and 2.4 ≦ α ≦ 20 2.4 ≦ β ≦ 30 0.1 ≦ δ ≦ 10 0.1 ≦ ε ≦ 10 γ is in the range of 0.01 ≦ γ ≦ 0.2 in atomic ratio.

The coexistence effect of the M component on the R—Fe—N magnetic material is mainly an improvement in oxidation resistance. In particular,
In the deterioration of the R-Fe-N-based magnetic material due to oxidation, a decrease in coercive force is more problematic than a decrease in magnetization. The composition of the present invention is characterized by having excellent stability of coercive force against oxidation. The source of this effect is due to the coexistence of the M component in the main phase of the R-Fe-N magnetic material, which is responsible for the ferromagnetism. The M component is contained in the soft magnetic component mainly composed of iron and affects the precipitation state, thereby contributing to preventing a decrease in the coercive force of the nitride magnetic material.

Further, depending on the method and conditions for adjusting the master alloy, R-rich nitride phase such as near the grain boundary or RFe ₃ phase and R-Fe phase such as α-Fe phase or its nitride phase may be used.
In the material of the -N composition, a large amount of the M component is distributed to the subphase exhibiting soft magnetism, and the nonmagnetic phase is formed, thereby improving the squareness ratio and coercive force of the nitride, and improving the oxidation resistance. There is also the effect of doing.

Hereinafter, the production method of the present invention will be exemplified. (1) Preparation of master alloy In the magnetic material of the present invention, R-Fe-
The main raw material phase of the M alloy has a structure in which the M component is substituted for the Fe site in the R-Fe alloy crystal structure, and / or a composition in which the auxiliary raw material phase is different from the R-Fe two-component system due to the addition of M.
It has a structure and exhibits the effects of the present invention. Therefore, it is desirable to add M at the stage of master alloy adjustment.

As a method for producing an R—Fe—M alloy, R,
High frequency melting method in which Fe and M metals are melted by high frequency and cast into molds, etc., arc melting method in which metal components are charged into a boat such as copper and melted by arc discharge, on a copper roll which rotates molten metal with high frequency melting A super-quenching method for obtaining a ribbon-shaped alloy, a gas atomizing method for spraying a high-frequency molten metal with a gas to obtain an alloy powder, Fe and / or M powder or Fe-M alloy powder, R and / or M An R / D method in which the oxide powder and the reducing agent are reacted at a high temperature to reduce R or R and M while diffusing R or R and M into Fe and / or Fe-M alloy powder. A mechanical alloying method in which a metal component alone and / or an alloy is reacted while being finely pulverized by a ball mill or the like, an alloy obtained by any of the above methods is heated in a hydrogen atmosphere, and once reacted with R and / or M hydride. Decomposed into Fe and or M or Fe-M alloy, both the may be used in the HDDR method alloying are recombined while removing hydrogen as low at a high temperature after this.

When the high frequency melting method or the arc melting method is used, a soft magnetic component mainly composed of Fe tends to precipitate from the molten state when the alloy is solidified, which causes a decrease in coercive force even after the nitriding step. Therefore, in order to eliminate the soft magnetic component or to improve the crystallinity, the temperature is set to 800 ° C. or less in an inert gas such as argon or helium or in a vacuum.
It is effective to perform annealing in a temperature range of 1300 ° C.
The alloy produced by this method has a large crystal grain size and good crystallinity, and has a high residual magnetic flux density, as compared with the case where a super-quenching method or the like is used.

When the ultra-quenching method is used, fine crystal grains are obtained, and submicron particles can be prepared depending on conditions. However, when the cooling rate is high, the alloy becomes amorphous, and magnetic properties such as magnetization are reduced even after nitriding. Also in this case, annealing after alloy preparation is effective.
The alloy obtained by the gas atomization method often takes a spherical form, and can be prepared from a fine powder to a coarse powder. Also in this case, depending on the conditions, it is necessary to perform annealing to improve the crystallinity. In addition to this method, R / D
Alloy prepared by the method, mechanical alloying method, or HDDR method can adjust fine crystal grains, have a distribution in the composition of the M component, or be a pinning type magnet material. It is possible to make the effect of the present invention more remarkable.

Incidentally, the crystal phase of the alloy may be different depending on the annealing conditions. For example, depending on the R component,
A rhombohedral system and a hexagonal system may be used depending on the case of annealing and rapid cooling. Therefore, the conditions for annealing require careful attention, and the desired crystal phase can be selected by controlling the annealing conditions. (2) Coarse pulverization and classification It is possible to directly nitride the alloy ingot produced by the above method. However, if the crystal grain size is larger than 500 μm, the nitriding treatment time becomes longer. It is efficient.

The coarse crushing is performed by using a jaw crusher, a hammer,
This is performed using a stamp mill, a rotor mill, a pin mill, a coffee mill, or the like. Further, even if a pulverizer such as a ball mill or a jet mill is used, an alloy powder suitable for nitriding can be prepared depending on conditions. Also, after coarse grinding,
Adjusting the particle size using a sieve, a vibratory or sonic classifier, a cyclone, or the like is also effective for performing more uniform nitriding.

Annealing in an inert gas or hydrogen after coarse pulverization and classification can remove structural defects, which is effective in some cases. Above, the method of preparing a powder material or an ingot material of a rare earth-iron alloy in the production method of the present invention has been exemplified.
There are differences in the following optimum conditions of nitriding depending on the microstructure, surface condition, and the like. (3) Nitriding and annealing Nitriding involves contacting a gas containing at least one of ammonia gas and nitrogen gas with the R-Fe-M alloy powder or ingot obtained in the above (1) or (1) and (2). Then, nitrogen is introduced into the crystal structure.

At this time, it is preferable to coexist a hydrogen gas in the nitriding atmosphere gas since nitriding efficiency is high and nitriding can be performed with a stable crystal structure. In addition, in order to control the reaction, an inert gas such as argon, helium, or neon may be used in some cases. The nitriding reaction can be controlled by gas composition, heating temperature, heat treatment time, and pressure. The heating temperature varies depending on the mother alloy composition and the nitriding atmosphere, but is selected in the range of 200 to 650 ° C. If the temperature is lower than 200 ° C., the rate of nitrogen penetration is low, and the reaction takes too much time, which is not preferable.

After nitriding, annealing in an inert gas and / or hydrogen gas is preferable from the viewpoint of improving magnetic properties. Examples of the nitriding / annealing apparatus include horizontal and vertical tubular furnaces, rotary reactors, and closed reactors. In any of the apparatuses, the magnetic material of the present invention can be adjusted. However, in order to obtain a powder having a uniform nitrogen composition distribution, it is preferable to use a rotary reactor.

The gas used for the reaction may be a gas flow system in which a gas stream of 1 atm or more is fed into the reaction furnace while keeping the gas composition constant, a gas sealing system in which the gas is sealed in a container at a pressure of 0.01 to 70 atm, or Supplied in combination. As a method for producing the magnetic material, a step of preparing a master alloy having an R-Fe-M composition by the method exemplified in (1) and (2) and then nitriding by the method shown in (3) is used. According to this method, the M component having a high melting point can be contained in a desired portion of the mother alloy, which is particularly effective for improving oxidation resistance.

The above is the description of the method for producing the R—Fe—MN based magnetic material of the present invention. When the magnetic material of the present invention is applied as a practical hard magnetic material, Subsequently, (4) pulverization, (5) magnetic field shaping, and (6) magnetization may be performed. Hereinafter, the example is shown simply. (4) Pulverization For example, among R-Fe-MN-based magnetic materials of a single magnetic domain type, particularly when a large crystal grain size is to be maintained and a large coercive force is desired to be developed after nitriding, Fine grinding is performed, for example, when the polycrystalline grains are kept after the treatment and anisotropic hard magnetic material is desired.

As a method of pulverization, a rotary ball mill,
A vibration ball mill, a planetary ball mill, a wet mill, a jet mill, a cutter mill, a pin mill, an automatic mortar and a combination thereof are used. The pulverization method is selected according to the adjustment of the amount of hydrogen or oxygen and the target pulverized particle size.

As a method for controlling the amounts of hydrogen and oxygen within the particularly preferred ranges of the present invention, for example, when a jet mill is used, the oxygen and water vapor concentrations in the pulverized gas are maintained at a predetermined concentration, and an attritor or the like is used. When wet pulverization is used, a method of adjusting the amount of dissolved oxygen or water in the solvent may be used. (5) Magnetic field molding For example, when the magnetic powder obtained in (3) or (4) is applied to an anisotropic bonded magnet, compression molding is performed in a magnetic field after mixing with a thermosetting resin or a metal binder, After kneading with thermoplastic resin, injection molding is performed in a magnetic field,
Form a magnetic field.

The magnetic field shaping is preferably performed at 10 kOe in order to sufficiently orient the R-Fe-MN-based magnetic material in a magnetic field.
Above, more preferably in a magnetic field of 15 kOe or more. (6) Magnetization The anisotropic bonded magnet material and sintered magnet material obtained in (5) are usually magnetized to enhance magnet performance.

Magnetization is performed, for example, by an electromagnet that generates a static magnetic field,
This is performed by a condenser magnetizer that generates a pulse magnetic field. The magnetic field strength for sufficiently magnetizing is preferably 15 kOe or more, more preferably 30 kOe or more.

[0035]

The present invention will be described below in detail with reference to examples. The evaluation method is as follows. (1) Magnetic properties An R-Fe-MN-based magnetic material having an average particle size of about 3 μm was prepared by subjecting an external magnetic field of 15 kOe to 12 ton / cm ² at 5 mm × 1.
After shaping to about 0 mm × 2 mm and pulse magnetizing at room temperature with a magnetic field of 60 kOe, the intrinsic coercive force (iHc / kOe) was measured using a vibrating sample magnetometer (VSM). (2) Nitrogen content, oxygen content and hydrogen content Using Si ₃ N ₄ (including quantitatively SiO ₂ ) as a standard sample, the nitrogen content and the oxygen content were determined by an inert gas melting method. The amount of hydrogen was determined by an inert gas melting method using high-purity hydrogen gas (99.999%) as a standard gas. (3) Average particle size It was evaluated using a Lee Nurse specific surface area meter. (4) Oxidation resistance The powder molded product having an average particle size of 3 μm evaluated in (1) was
The sample was placed in a thermostat at 10 ° C., and the intrinsic coercive force after 200 hours was measured in the same manner as in (1). The retention rate (%) of the intrinsic coercive force was determined by comparing with the result of (1). The higher the retention, the higher the oxidation resistance. (5) Oxidation test 10 mg of a coarse powder sample adjusted to an average particle size of 15 μm was placed in a thermobalance, and heated in a 50 ml / min air stream at a heating rate of 1
The rate of weight change (% by weight) from 50 ° C. to 250 ° C. was measured at 0 ° C./min. The smaller the rate of weight change, the more difficult it is to oxidize.

[0036]

Embodiment 1 Sm of 99.9% purity, Fe of 99.9% purity and Ni of 99.9% purity were melt-mixed in a high-frequency melting furnace under an argon gas atmosphere, and then the molten metal was cast into a pure iron mold. The mixture was cooled by pouring into the atmosphere, and further annealed in an argon atmosphere at 1050 ° C. for 35 hours to obtain Sm.
An alloy having a composition of _11.0 (Fe _0.9 Ni _0.1 ) _89.0 was prepared.

This alloy was pulverized by a jaw crusher and then further pulverized by a rotor mill in a nitrogen atmosphere, and the particle size was adjusted by a sieve to obtain a powder having an average particle diameter of about 50 μm. This Sm-Fe-Ni alloy powder was charged into a horizontal tubular furnace, and at 450 ° C, an ammonia partial pressure of 0.32.
Heat treatment was performed in a mixed gas flow of atm and hydrogen gas of 0.68 atm, and then annealing was performed in an argon gas flow, and then adjusted to an average particle size of about 15 μm. Next, the powder was pulverized by a jet mill to an average particle size of about 3 μm. At this time, a gas containing mainly nitrogen and partially mixed with oxygen and water vapor was used as the pulverizing gas.

The composition, oxidation resistance and oxidation test results of the obtained Sm-Fe-Ni-N powder are shown in Table 1. Further, the intrinsic coercive force of the compact of the Sm—Fe—Ni—N powder crushed to about 3 μm is 5.1 kOe, and the residual magnetic flux density is 8.7 k.
G. As a result of analysis by the X-ray diffraction method, the crystal structure of this material was mainly rhombohedral, and no diffraction line corresponding to Ni alone was found.

[0039]

Examples 2 to 5 R-F by the same operation as in Example 1 except that the composition of the mother alloy was changed to the composition ratio shown in Table 1.
An eMN-based powder was obtained. Table 1 shows the results. From the results of X-ray diffraction, the materials of Examples 2, 3 and 5 were mostly composed of substances having rhombohedral crystals, and the material of Example 4 was tetragonal with the substances having rhombohedral crystals. It was found that the substances contained were mixed.

[0040]

Comparative Example 1 Sm-F was prepared in the same manner as in Example 1 except that Fe was added by the amount (atomic%) without adding Ni.
An eN powder was obtained. Table 1 shows the results.

[0041]

Comparative Example 2 Nd-F was obtained in the same manner as in Example 2, except that Mn was not added, and Fe was added by the amount (atomic%).
eN powder was obtained. Table 1 shows the results.

[0042]

Comparative Example 3 Sm having a particle size of about 3 μm obtained in Example 3
_9.2(Fe_0.9Cr_0.1)_74.8N_13.8H_0.5O _1.7Composition of powder
The body is 2ton / cm^Two, 15kOe magnetic field molding
After that, under argon atmosphere, at 800 ° C for 1 hour
The heat treatment was performed. The characteristic of the compact when it is quenched
The coercive force was 0.06 kOe. This compact is again
The inherent coercive force of the powder ground to 3 μm is 0.07 kOe
there were. The crystal structure of this material was analyzed by X-ray diffraction
As a result, diffraction lines corresponding to α-iron and iron nitride are mainly detected
Was done.

[0043]

[Table 1]

[0044]

As described above, according to the present invention, a rare earth-iron-nitrogen based magnetic material having excellent oxidation resistance and high magnetic properties can be provided.

Claims (4)

(57) [Claims] 1. The general formula R _α (Fe _(1-γ) M _γ ) _(100-α-β) N
expressed in _beta, and a magnetic material of oxidation resistance is 70% or more, at least one of R is Sm or Nd, M is at least one kind of Mn, Cr, Ni elements, alpha, beta atomic percent 3 ≦ α ≦ 20 3 ≦ β ≦ 30 γ is 0.01 ≦ γ ≦ 0.2 in atomic ratio, and the phase containing R, Fe, M and N is rhombohedral or hexagonal. A magnetic material having a crystal structure. 2. A magnetic material having a composition in which 0.01 to 50 atomic% of Fe, which is a component of the magnetic material according to claim 1, is substituted with Co. 3. The general formula R _α (Fe _(1-γ) M _γ )
_(100-α-β) N _β Wherein M is Ni.
3. The magnetic material according to claim 1 or 2. 4. The general formula R _{α / (100-β)} (Fe
_(1-γ) M _γ ) An alloy represented by _{(100-α-β) / (100-β)}
The method for producing a magnetic material according to any one of claims 1 to 3 , wherein the heat treatment is performed in an atmosphere containing at least one of nitrogen gas and ammonia gas at a temperature of 200 to 650 ° C.