JP2008270796A - Magnetic material and magnet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic material having satisfactory magnetic characteristics with a small content of rare earth elements, capable of easily forming a magnet having a bulk shape, and to provide a magnet that uses the material. <P>SOLUTION: This magnet contains a magnetic material constituted of a plurality of particles 2, and a binder 4 for binding the particles 2. The particles 2 are constituted of main phase particles 6 which are constituted mainly of Fe, and a coating layer 8 that covers these main phase particles 6 and is constituted of an intermetallic compound, having a CaCu<SB>5</SB>-type crystal structure that is made of at least rare-earth elements. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic material and a magnet using the same.

  Rare earth magnets containing rare earth elements are used in various applications as magnets having high magnetic properties. For example, an R—Fe—B rare earth magnet having a predetermined composition as described in Patent Document 1 below is known to exhibit excellent magnetic properties.

  In rare earth magnets, it is desired to obtain high characteristics while minimizing the amount of rare earth elements used. As a rare earth magnet capable of reducing the amount of rare earth element used, for example, a composite rare earth magnet in which a phase containing a rare earth element and a phase not containing a rare earth element are combined can be considered. According to such a composite rare earth magnet, since it has a phase that does not contain a rare earth element, the amount of rare earth element can be reduced as compared with a rare earth magnet composed of a single intermetallic compound.

As a composite type rare earth magnet, for example, a hard magnetic phase having a composition of Sm (Co, Cu) ₅ and a soft magnetic phase made of Fe as described in Patent Document 2 below are alternately and repeatedly laminated. Nanocomposite magnets having a multilayer structure are known.
JP 2000-234151 A JP 2006-173210 A

  However, the conventional nanocomposite magnet is a thin film magnet having a multilayer film structure, and it has been difficult to form a bulk-shaped magnet such as a bonded magnet or a sintered magnet applicable to a wide range of applications. Further, compared with a conventional Nd—Fe—B rare earth magnet composed of a single material, sufficient magnetic properties have not been obtained yet.

  Therefore, the present invention has been made in view of such circumstances, and has a sufficient magnetic property with a small content of rare earth elements, and can easily form a magnet having a bulk shape. An object is to provide a material and a magnet using the same.

In order to achieve the above object, the magnetic material of the present invention covers main phase particles mainly composed of Fe and at least a part of the periphery of the main phase particles, and contains at least a rare earth element and is of the CaCu ₅ type. It includes particles having a coating layer made of an intermetallic compound having a crystal structure.

  Since the magnetic material of the present invention has a composite structure of main phase particles containing Fe as a main component and a coating layer containing a rare earth element, the amount of rare earth elements is larger than that of a rare earth magnet composed of a single material. Can be reduced. In addition, since the main phase particles include particles coated with a coating layer, a magnet having a bulk shape can be easily formed as compared with the conventional multilayer film structure. Furthermore, since the magnetic material of the present invention has a composite structure in which the main phase particles are coated with a coating layer as described above, it has excellent magnetic properties despite its low content of rare earth elements. It becomes.

Here, although it is not necessarily clear that the magnetic material of the present invention has excellent magnetic properties, it is considered to be due to the following factors. That is, in the magnetic material of the present invention, the coating layer covering the main phase particles is composed of an intermetallic compound having a CaCu ₅ type crystal structure. This CaCu ₅ type crystal structure has an anisotropic structure in which rare-earth elements are densely layered and layered in layers, and the rare-earth elements are arranged in a hexagonal c-axis direction. Therefore, it is considered that large anisotropy is expressed. Therefore, the coating layer constituted by such an intermetallic compound has a very large anisotropic magnetic field. Since the magnetic material of the present invention has a structure in which such a coating layer covers the main phase particles, when a magnet is formed, exchange coupling between the phases constituted by these strongly occurs. Can do. Therefore, even if there are few rare earth elements (including intermetallic compounds) that affect the coercive force, a high coercive force can be obtained. Further, since the main phase particles are coated, it is possible to avoid instability of these single magnetic domain structures due to the close proximity of the main phase particles, and this also tends to maintain a high coercive force. Due to these factors, it is considered that the magnetic material of the present invention can form a magnet having excellent magnetic properties even if the amount of rare earth elements is small.

  In the magnetic material of the present invention, the main phase particles preferably have an acicular shape. When the main phase particles have a needle-like shape, the particles covered with the coating layer also have a needle-like shape as a whole, and may have a large anisotropic energy in the axial direction due to the shape. it can. Therefore, a magnetic material composed of such particles can exhibit further excellent magnetic properties. On the other hand, in the case of the multilayer film structure as in the above-described prior art, the anisotropic energy derived from such a shape cannot be sufficiently utilized, so that the high magnetic characteristics as in the present invention cannot be obtained. It is done.

The present invention also provides a suitable magnet using the magnetic material of the present invention. That is, the magnet of the present invention covers main phase particles mainly composed of Fe and at least part of the periphery of the main phase particles, and includes at least a rare earth element and has a CaCu ₅ type crystal structure. It is characterized by including particles having a coating layer consisting of.

  Such a magnet of the present invention is composed of a magnetic material having a composite structure similar to that of the present invention, so that it can easily have a bulk shape and has a reduced rare earth element content. Also have high magnetic properties.

  In the magnet of the present invention, the main phase particles preferably have a needle shape. A magnet including such main phase particles has more excellent magnetic properties for the same reason as described above.

  More specifically, the magnet of the present invention preferably has a configuration further including a binder that binds the particles composed of the main phase particles and the coating layer. When the particles have a structure in which the particles are bound by the binder as described above, the bulking is further facilitated, and the magnet of the present invention can have a shape suitable for various applications.

  According to the present invention, there are provided a magnetic material that has sufficient magnetic properties with a small content of rare earth elements and can easily form a magnet having a bulk shape, and a magnet using the same. It becomes possible.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an enlarged cross-sectional configuration of a magnet according to a preferred embodiment. As shown in FIG. 1, the magnet 1 has a structure composed of a large number of particles 2 and a binder 4 that fills the spaces between the particles 2 and binds them. As described above, the magnet 1 is configured by binding magnetic powder (magnetic material) composed of a large number of particles 2 with the binder 4.

  The particle 2 is composed of a main phase particle 6 having an acicular shape and a coating layer 8 formed so as to cover the surface of the main phase particle 6, and has an acicular shape as a whole. ing. Here, the needle-like shape is a shape in which a cross section along a specific uniaxial axis (long axis) is flat in the long axis direction, and a shape like a spheroid is shown here. Applicable. Specifically, for example, a shape in which the major axis is three times or longer than the axis (short axis) in a direction substantially orthogonal to the major axis can be mentioned.

  The main phase particle 6 in the particle 2 is a magnetic phase containing iron (Fe) as a main component. This main phase particle 6 may be comprised only from Fe, and may contain combining elements other than Fe. Examples of elements other than Fe contained in the main phase particles 6 include cobalt (Co) and nitrogen (N), and it is more preferable to have a composition containing 20 to 50% of Co. By containing Co in addition to Fe, the saturation magnetic flux density of the particles 2 tends to be improved.

  Further, the main phase particles 6 may contain aluminum (Al) or yttrium (Y) for the purpose of preventing sintering during the reduction treatment. That is, by containing Al and Y, sintering can be prevented from occurring during the reduction treatment performed when forming the main phase particles 6 as described later. The main phase particles 6 may further contain other metals as necessary, and may contain components that are inevitably mixed. As a specific composition of the main phase particle 6, a composition of Fe-20% Co-3% Al-2.8% Y can be exemplified.

The covering layer 8 in the particle 2 is a magnetic phase made of an intermetallic compound containing at least a rare earth element and having a CaCu ₅ type crystal structure. Whether or not this intermetallic compound has a CaCu ₅ type structure can be confirmed by X-ray diffraction (XRD). The intermetallic compound constituting the coating layer 8 is a compound in which a rare earth element and another metal element are bonded by a metal bond.

Examples of the rare earth element contained in the intermetallic compound include samarium (Sm), erbium (Er), and thulium (Tm), and Sm is preferable. In addition, examples of other metal elements to be combined with rare earth elements include iron group elements (Fe, Co, or nickel (Ni)), and cobalt (Co) is particularly preferable. Examples of such intermetallic compounds include Sm—Co compounds. Sm is the CaCu ₅ type structure, can be given a large anisotropy in the c-axis direction, also, Co is considered to have a characteristic that can be stabilized CaCu ₅ type structure. Specifically, as the Sm—Co based intermetallic compound, SmCo ₅ is preferable. Intermetallic compounds having a composition of SmCo ₅ tend to have a particularly large anisotropic magnetic field.

Further, the intermetallic compound is more preferably an Sm—Co—B based compound in which a part of Co is substituted with boron (B) in the Sm—Co based. By substituting part of Co with B in this way, since B has a smaller atomic radius than Co, the distance between Sm in the c-axis direction can be reduced in the CaCu ₅ type structure. It is thought that a isotropic magnetic field is obtained. Examples of the Sm—Co—B-based intermetallic compound include Sm _N Co _{3N + 2} B _2N-2 (N, such as SmCo ₄ B, SmCo ₃ B ₂ , Sm ₂ Co ₇ B ₃ , and Sm ₃ Co ₁₁ B _4. Are those having a composition represented by 2 or more).

  Further, as the intermetallic compound, a compound having an Sm—Co—Fe—B composition in which a part of Co is substituted with Fe in the Sm—Co—B composition is more preferable. Thus, by replacing part of Co with Fe, the Curie temperature can be sufficiently increased while increasing the anisotropic magnetic field of the intermetallic compound. By having the coating layer 8 made of an intermetallic compound having a high Curie temperature, the magnet 1 can maintain excellent magnetic properties even at high temperatures. From the viewpoint of achieving both sufficiently high Tc and Hc, the ratio of Co to Fe with respect to the Sm—Co—B composition (based on the number of atoms) is preferably 75% or less, and is preferably 25 to 75%. Is more preferable.

  In the particle 2 having such a configuration, the size of the main phase particle 6 is such that the acicular long axis is preferably 0.05 to 3 μm, more preferably 0.1 to 2 μm. It is preferable. Moreover, the coating layer 8 has coat | covered the main phase particle 6 uniformly, and the thickness is preferable in it being 0.01-0.2 micrometer, and it is more preferable in it being 0.02-0.1 micrometer. When the main phase particles 6 and the coating layer 8 satisfy such conditions, exchange interaction is likely to occur between these phases, and the coercive force of the magnet 1 tends to be improved.

  The binder 4 in the magnet 1 is a component that bonds the particles 2 to each other, and is composed of a material having a saturation magnetic flux density lower than that of the particles 2 and is nonmagnetic (paramagnetic, diamagnetic) or antiferromagnetic material. It is more preferable that it consists of. Specifically, the binder 4 may be made of a rare earth metal (Sm or La), a simple metal such as Mn, Zn, or Cu, an alloy such as NiO, FeMn, or FeAl, or a resin.

  Among these, Sm can suppress a decrease in anisotropy due to disorder of the structure of the particle 2 and the like, Zn is suitable for dispersing the particle 2 because of its low melting point, and Cu is malleable. Further, since it is excellent in ductility, it is suitable as a binder, and also has an advantage that formation by plating and the like are easy. Further, NiO and FeMn are inexpensive and can be easily used as the binder 4, and the resin has advantages such as easy melting and easy dispersion of the particles 2. As the binder 4, it is preferable to appropriately select and use the above components according to desired characteristics.

The magnet of the present invention is not limited to the structure described above, and may be appropriately selected as long as it includes particles having main phase particles mainly composed of Fe and a coating layer made of an intermetallic compound having a CaCu ₅ type crystal structure. It may have a different structure.

  For example, the main phase particles 6 may be a single phase mainly composed of Fe, but may be composed of a plurality of phases. When the main phase particles 6 are composed of a plurality of phases, they may be distributed so that the phases are mixed in the particles, and the structure is such that the surroundings of a certain phase are covered with other phases. May be. In the magnet 1, main phase particles 6 composed of a single phase and main phase particles 6 composed of a plurality of phases may be mixed.

The covering layer 8 need not be composed of a single phase as long as it is made of an intermetallic compound having a CaCu ₅ type crystal structure, and may be formed of a plurality of phases. When the coating layer 8 is composed of a plurality of phases, the coating layer 8 may be formed so that each phase covers a part of the main phase particle 6, and one phase is It may be a multilayer structure formed so as to cover the other phase, and these structures may be mixed. Further, the magnet 1 may include both the particles 2 on which the coating layer 8 composed of a single phase is formed and the particles 2 on which the coating layer 8 composed of a plurality of phases is formed.

  When the main phase or the coating layer is composed of a plurality of phases, particularly a multilayer structure, the main phase and the coating layer are magnetically transferred in a stepwise manner, and these interactions occur more strongly. As a result, the combination of the main phase and the coating layer may improve the magnetic characteristics. Such a structure including a plurality of phases is obtained by a method of mixing and reacting a raw material mainly composed of iron for the main phase and a raw material for the intermetallic compound for the coating layer as described later. Especially, it tends to be easily formed.

  As an example, FIG. 2 shows a cross-sectional configuration of a magnet having a multilayer structure in which a coating layer is composed of a plurality of phases. As shown in FIG. 2, the magnet 10 in this form includes a plurality of particles 12 and a binder 14 between the particles 12. In the particle 12, the coating layer 18 covers the periphery of the main phase particle 16. The coating layer 18 includes a first coating layer 18 a that covers the main phase particle 16, and the first coating layer 18 a. Furthermore, it has a two-layer structure with a second covering layer 18b covering it.

  Furthermore, the magnet 1 does not necessarily have to have the binder 4 described above. The binder 4 may have the same composition as that of the coating layer 8. In this case, since the binder 4 also becomes a ferromagnetic material, it is preferable that a nonmagnetic or antiferromagnetic material is mixed in the binder 4.

  Next, a preferred example of a method for manufacturing the magnet 1 having the above-described configuration will be described.

  In manufacturing the magnet 1, first, acicular particles mainly containing iron for forming the main phase particles 6 in the particles 2 are prepared. For example, the needle-shaped particles react with a ferrous salt aqueous solution and an alkaline aqueous solution, and then a gas containing oxygen such as air is passed through the suspension after the reaction to cause an oxidation reaction. A goethite particle powder is produced. Thereafter, the goethite powder is heated and dehydrated, and then reduced at a high temperature (about 500 ° C.) in a hydrogen atmosphere to obtain needle-like particles containing iron as a main component.

  Next, particles 2 are formed by coating the surface of needle-like particles containing iron as a main component with an intermetallic compound constituting the coating layer 8. Coating with an intermetallic compound is a method of depositing an intermetallic compound raw material on the surface of acicular particles by a PVD method such as vapor deposition or sputtering, a method of mixing acicular particles and fine particles of an intermetallic compound, It can be performed by a method of immersing needle-like particles in a raw material solution.

  Further, the needle-like particles can be coated with the intermetallic compound by mixing and reacting the needle-like particles containing iron as a main component with the raw material of the intermetallic compound. According to such a method, since manufacture of the particle | grains 2 becomes easy, it is more preferable. Examples of such a method include a method using a eutectic reaction by a short heat treatment, a method using a rare earth hydride as a raw material particle of an intermetallic compound, removing hydrogen by a vacuum heat treatment, or an intermetallic compound. For example, a rare earth oxide is used as the raw material particles, and the reaction is performed by reduction with Ca.

  For example, in the method based on the PVD method described above, when the acicular particles are coated with the Sm—Co—B intermetallic compound by the laser ablation method, first, raw material compounds of Sm, Co, and B are desired. Weigh so that the composition of By performing high frequency melting of these, casting into a mold to make a cast product, cutting and polishing so as to have a desired size, and performing a solution treatment at about 1100 ° C. for about 60 hours, A target used for sputtering is obtained.

  Next, the target is set on the target holder, and the above-mentioned needle-like particles are put into a sample container or the like arranged on the vibration mechanism, and the inside of the apparatus is adjusted to a vacuum. At this time, it is preferable to prepare the acicular particles so as not to touch the atmosphere. Then, the surface of the acicular particles is obtained by irradiating the target with laser while intermittently vibrating the acicular particles under high vacuum conditions, and depositing the Sm-Co-B clusters generated thereby on the acicular particles. A layer made of an Sm—Co—B intermetallic compound is formed. As a result, a magnetic powder (magnetic material) including main phase particles 6 made of needle-like particles and particles 2 covering the surface and having a coating layer 8 made of an intermetallic compound is obtained.

  In the production of the magnet 1, the magnetic powder thus obtained is then bonded by the binder 4 to obtain the bulk magnet 1. This bulking is performed by, for example, a method in which the particles 2 constituting the magnetic powder are covered with the binder 4 and then molded, or a method in which the particles 2 are dispersed in the binder 4. Can do.

  For example, when using Zn as the binder 4, first, a container containing Zn is heated to about 500 ° C. to melt Zn, and then the above magnetic powder is added and dispersed therein. Next, the temperature of the mixture is gradually raised, and Zn is evaporated while forming in a magnetic field, thereby obtaining a bulk magnet 1. In order to obtain a desired product shape, the magnet 1 once obtained may be roughly pulverized and then further shaped in a magnetic field.

As described above, the magnet 1 of the present embodiment described above is mainly configured by the particles 2 including the main phase particles 6 and the covering layer 8 covering the main phase particles 6. The particle 2 having such a composite structure is a nanocomposite in which the coating layer 8 has a CaCu ₅ type crystal structure having a high magnetic anisotropy, and the main phase particles 6 and the coating layer 8 cause exchange interaction. Since it has a structure, it can exhibit excellent magnetic properties (residual magnetic flux density and coercive force).

  The magnet 1 is easy to be bulked because the magnetic material composed of the particles 2 is bound by the binder 4, and the binder 4 is non-magnetic or diamagnetic. For this reason, the excellent magnetic properties of the particles 2 are sufficiently maintained without being inhibited. Therefore, such a magnet 1 has excellent magnetic properties even though the content of rare earth elements is small as compared with a conventional rare earth magnet constituted by a single intermetallic compound.

  The magnetic material or magnet of the present invention is not necessarily limited to that of the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, in the above-described embodiment, only the main phase particles 6 (and particles 2) having an acicular shape have been described. However, in the present invention, the main phase particles and particles are not necessarily acicular. They may not be spherical and may have other shapes. However, from the viewpoint of obtaining excellent magnetic anisotropy, these preferably have a needle shape.

  In the above description, the particle 2 having a structure in which the entire surface of the main phase particle 6 is covered with the coating layer 8 is illustrated. However, for example, the coating layer 8 only needs to cover at least a part of the main phase particle 6. Furthermore, the magnet of the present invention only needs to contain the magnetic material of the present invention, and may not necessarily contain the binder as described above as long as the shape of the magnet can be maintained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples.

[Comparative test 1]
The raw material compounds of each element of Sm, Co, and B were weighed so that a composition of 37.9Sm-59.4Co-2.7B (the numerical value was wt%) was obtained, and high frequency dissolution of these was performed. The obtained alloy was treated at 1100 ° C. for 72 hours in an Ar flow to form a solution. About the sample obtained in this way, the phase was identified by X-ray diffraction. The obtained results are shown in FIG. From FIG. 3, it was confirmed that the obtained sample was an SmCo ₄ B phase having a CaCu ₅ type crystal structure. When the magnetic properties of this sample were measured by VSM, the coercive force (HcJ) was 3.6 (kOe), the saturation magnetization (Ms) was 3.4 (kG), and the residual magnetic flux density (Br) was 3 .3 (kG).

[Test 1]
The alloy of SmCo ₄ B produced in the same manner as in Comparative Test 1 was occluded at 250 ° C. and coarsened by hydrogen pulverization. The obtained coarse powder was jet milled in a nitrogen atmosphere to obtain fine powder having an average particle size of 4 μm. The fine powder obtained was mixed with 100 μm spherical Fe to obtain a mixed powder. In Test 1, various mixed powders were obtained by changing SmCo ₄ B: Fe to have a weight ratio of 95: 5, 99: 1, and 100: 0, respectively.

  Subsequently, each obtained mixed powder was molded in a magnetic field under a condition of 50 kN in a 3T magnetic field to obtain a molded body. Then, the obtained compacts were subjected to rapid temperature increase and sintering for a short time to obtain sintered bodies. At this time, the conditions for rapid temperature increase were 0.5 ° C./second from 0 ° C. to 850 ° C., and 1 ° C./second from 850 ° C. to sintering temperature. Sintering was performed by holding the molded bodies having different component ratios of the mixed powder for 5 seconds under three temperature conditions of 1200 ° C, 1250 ° C, and 1280 ° C. After sintering, it was cooled to room temperature in Ar for 30 minutes to produce various rare earth magnets.

  About each obtained rare earth magnet, it carried out similarly to the comparative test 1, and measured the magnetic characteristic. The obtained results are shown in Table 1.

From Table 1, be mixed Fe in SmCo ₄ B (sample SmCoB ₄ is 95% and 99%), when not mixed Fe (SmCoB ₄ 100% of the sample) in comparison with sufficiently high It was confirmed that the magnetic characteristics were maintained or exceeded. “> 19.5” in the table means that the maximum applied magnetic field of the VSM apparatus used this time was 19.5 kOe, and the HcJ of the sample was more than that.

[Comparison Test 2]
Comparative test 1 except that the raw material compounds of each element of Sm, Co and B were weighed and used so as to obtain a composition of 39.5Sm-56.7Co-3.8B (numerical value was% by weight). A sample was prepared in the same manner as described above. About the obtained sample, the phase was identified by X-ray diffraction. The obtained results are shown in FIG. From FIG. 4, it was confirmed that the obtained sample was mainly composed of the Sm ₃ Co ₁₁ B ₄ phase having a CaCu ₅ type derived structure. When the magnetic properties of this sample were measured by VSM, HcJ was 3.1 (kOe), Ms was 2.1 (kG), and Br was 2.0 (kG).

[Test 2]
Using an alloy of Sm ₃ Co ₁₁ B ₄ produced in the same manner as in Comparative Test 2, the ratio of Sm ₃ Co ₁₁ B ₄ : Fe by weight ratio was 95: 5, 99: 1 and Various rare earth magnets were manufactured when sintering was performed at three temperature conditions of 1200 ° C, 1250 ° C, and 1280 ° C.

  About each obtained rare earth magnet, it carried out similarly to the comparative test 1, and measured the magnetic characteristic. The results are shown in Table 2.

From Table _2, even when mixed with Fe in _{Sm 3 Co 11 B 4 (Sm} 3 Co 11 B 4 is 95% and 99% samples), when not mixed Fe _{(Sm 3 Co} 11 _{B 4} 100 It was confirmed that sufficiently high magnetic characteristics were maintained or higher than that of the samples (%).

[Test 3]
First, commercially available iron oxide (Fe ₂ O ₃ ) having a needle-like shape was prepared, and this was subjected to reduction treatment at 500 ° C. for 3 hours in a hydrogen flow to obtain needle-like Fe powder. Then, various rare earth magnets having different ratios of SmCo ₄ B and Fe and sintering temperatures were obtained in the same manner as in Test 1 except that this Fe powder was used instead of spherical Fe.

About each obtained rare earth magnet, it carried out similarly to the comparative test 1, and measured the magnetic characteristic. The obtained results are shown in Table 3.

From Table 3, when using a needle-like Fe particles, whatever value the ratio of SmCo ₄ B and Fe have been obtained high HcJ, also when mixed with SmCo ₄ B and Fe ( It was confirmed that the samples having SmCoB ₄ of 95% and 99%) obtained Br equal to or higher than the case where Fe was not mixed (sample having SmCoB ₄ of 100%).

It is a schematic diagram which expands and shows the cross-sectional structure of the magnet which concerns on suitable embodiment. It is a figure which shows typically the cross-sectional structure of the magnet which has a multilayer structure which a coating layer consists of a some phase. It is a figure which shows the result of the X-ray diffraction of the sample of the comparative test 1. It is a figure which shows the result of the X-ray diffraction of the sample of the comparative test 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10 ... Magnet, 2,12 ... Particle | grains, 4,14 ... Binder, 6,16 ... Main phase particle | grains, 8,18 ... Coating layer.

Claims (5)

A main phase particle mainly composed of Fe, and a coating layer that covers at least a part of the periphery of the main phase particle and is made of an intermetallic compound having a CaCu ₅ type crystal structure including at least a rare earth element. A magnetic material comprising particles having the same.   The magnetic material according to claim 1, wherein the main phase particles have a needle-like shape. A main phase particle mainly composed of Fe, and a coating layer that covers at least a part of the periphery of the main phase particle and is made of an intermetallic compound having a CaCu ₅ type crystal structure including at least a rare earth element. A magnet comprising particles having the same.   The magnet according to claim 3, wherein the main phase particles have a needle-like shape.   The magnet according to claim 3, further comprising a binder that binds the particles.

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