Method for producing magnetic body, and magnetic body

Abstract

A plurality of magnetic nanoparticles (30) are mixed with a solvent (111). An external magnetic field is applied to the solvent in which the plurality of magnetic nanoparticles are mixed. By doing so, the plurality of magnetic nanopowders are linearly connected, and a plurality of thread-like magnetic powders (100), in which a plurality of magnetic nanopowders are magnetically oriented along an extension thereof, are generated. The solvent is vaporized to take out the plurality of thread-like magnetic powders. Extrusion molding is performed in a state in which the plurality of thread-like magnetic powders and a liquid molding resin are mixed. By doing so, the plurality of thread-like magnetic powders are extended in the pressing direction, and a magnetic body in which the plurality of thread-like magnetic powders are arranged in a direction orthogonal to the pressing direction is produced.

Description

Method for manufacturing a magnetic material, and magnetic material Cross-reference of related applications

[0001] This application is based on Japanese Patent Application No. 2024-184997, filed in Japan on October 21, 2024, and incorporates the contents of the basic application by reference in whole.

[0002] The disclosures described herein relate to methods for manufacturing magnetic materials and magnetic materials.

[0003] Patent Document 1 discloses a method for producing a composite magnetic material comprising a nanoparticle aggregate containing magnetic metal nanoparticles containing a magnetic metal and an intervening phase containing a non-magnetic metal.

[0004] Patent No. 6230513

[0005] Patent Document 1 describes that it is preferable for magnetic metal nanoparticles to form a nanoparticle texture in which they are in contact at points or on a surface, and that this nanoparticle texture is mainly oriented in one direction within the particle aggregate.

[0006] Patent Document 1 describes coating and drying in a magnetic field as means of orientation. However, it does not provide any further specific details. It is unclear whether nano-sized magnetic metal nanoparticles can be effectively oriented using these methods.

[0007] This disclosure aims to provide a method for producing a magnetic material in which magnetic nanoparticles are oriented, and a magnetic material.

[0008] A method for manufacturing a magnetic material according to the disclosed embodiment involves mixing a plurality of magnetic nanoparticles in a solvent, applying an external magnetic field to the solvent containing the plurality of magnetic nanoparticles so that the plurality of magnetic nanoparticles are linearly linked and multiple filamentous magnetic powders are formed in which the plurality of magnetic nanoparticles are oriented along the extension of the linear linkage, removing the solvent to extract the plurality of filamentous magnetic powders, and extruding the mixture of the plurality of filamentous magnetic powders and a liquid molding resin in a first direction so that the plurality of filamentous magnetic powders are extended and oriented in the first direction, and the plurality of filamentous magnetic powders are aligned in a second direction perpendicular to the first direction.

[0009] The disclosed embodiment of the magnetic material comprises a plurality of filamentous magnetic powders, each having a plurality of magnetic nanoparticles linearly linked together, and a molding resin connecting the plurality of filamentous magnetic powders, wherein the plurality of filamentous magnetic powders extend and are oriented in a first direction, and the plurality of filamentous magnetic powders are aligned in a second direction perpendicular to the first direction.

[0010] According to this, the application of mechanical pressure makes it easier for multiple filamentous magnetic particles to orient themselves in the direction of their own extension. Therefore, a magnetic material in which multiple filamentous magnetic particles are oriented can be obtained. In other words, a magnetic material in which multiple magnetic nanoparticles are oriented can be obtained.

[0011] The reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

[0012] This is a perspective view of a magnet. This is an enlarged view of region A enclosed by the dashed line in Figure 1. This is a perspective view showing a single magnetic nanoparticle. This is a cross-sectional view of a single magnetic nanoparticle. This is a schematic diagram showing the unit cell of an FeNi ordered alloy. This is a schematic diagram showing the unit cell of FeNiN. This is a flowchart for manufacturing an FeNi ordered alloy. This is an SEM image showing filamentous magnetic powder. This is a flowchart for manufacturing filamentous magnetic powder. This is a schematic diagram for explaining the manufacturing method shown in Figure 9. This is a flowchart for manufacturing a magnetic material. This is a schematic diagram for explaining the manufacturing method shown in Figure 11. This is a schematic diagram showing filamentous magnetic powder containing magnetic microparticles.

[0013] This description will explain embodiments for implementing this disclosure with reference to the drawings. In later embodiments, parts corresponding to those described in earlier embodiments may be given the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the description of the earlier embodiment may be applied to the other parts of the configuration.

[0014] It is possible to combine parts that are explicitly shown to be combinable in each form. In particular, if there are no problems with the combination, it is also possible to partially combine multiple forms with each other, a form with a modified form, and multiple modified forms with each other, even if it is not explicitly shown that they can be combined.

[0015] Furthermore, in the following, the three directions that are orthogonal to each other will be referred to as the X direction, Y direction, and Z direction. The X, Y, and Z directions are linear directions. In the drawings, the term "direction" is omitted, and they are simply shown as X, Y, and Z.

[0016] <First Embodiment> <Magnet> Figure 1 shows a magnet 10. The magnet 10 of this embodiment has six faces. Two of the six faces are aligned in the X direction, two of the remaining four faces are aligned in the Y direction, and the last two faces are aligned in the Z direction. The magnet 10 has a rectangular parallelepiped shape.

[0017] Of course, the shape of the magnet 10 is not particularly limited. For example, the magnet 10 may be arc-shaped. The shape of the magnet 10 can be changed as appropriate depending on the application.

[0018] <Magnetic Section> Figure 2 shows a magnified view of the inside of the magnet 10. A part of the magnet 10 shown in this magnified view is referred to as the magnetic section 20. The magnetic section 20 contains magnetic nanoparticles 30 and molding resin 40. The magnetic nanoparticles 30 are arranged in the Y direction. The magnetic nanoparticles 30 are also arranged in a direction perpendicular to the Y direction. In Figure 2, multiple magnetic nanoparticles 30 are clearly separated by lines and shown individually.

[0019] <Magnetic Nanoparticles> The term "single particle" above refers to a state in which the particles are primary particles that are not aggregated or fixed to each other, and exist independently without being supported by a substrate or other support. The magnetic part 20 includes at least one of the single magnetic nanoparticles 30 themselves, a powder as an aggregate of single magnetic nanoparticles 30, granular form of the powder, and a molded mass of the powder. The magnetic part 20 also includes filamentous magnetic powder 100, in which a plurality of magnetic nanoparticles 30 are linked together in a linear manner, as will be described later.

[0020] <Magnetic Nanoparticles> As shown in Figures 3 and 4, the magnetic nanoparticles 30 of this embodiment are individually flattened. The magnetic nanoparticles 30 have a flattened surface 30a and a side surface 30b. The two flattened surfaces 30a are spaced apart and side by side. The side surface 30b is located between the two flattened surfaces 30a. The side surface 30b extends around the direction in which the two flattened surfaces 30a are aligned, forming an annular shape. The side surface 30b connects the two flattened surfaces 30a.

[0021] The long axis 31 is aligned along the flattened surface 30a, and the short axis 32 is aligned along the side surface 30b. The long axis 31 and the short axis 32 intersect. The short axis 32 is aligned in the direction of the two flattened surfaces 30a. The length of the long axis 31 of the magnetic nanoparticle 30 is longer than the length of the short axis 32. The area of ​​the side surface 30b is smaller than that of the flattened surface 30a. Thus, the magnetic nanoparticle 30 is flattened in its own form. In the magnetic nanoparticle 30, the easy magnetization axis 33 is aligned along the flattened surface 30a.

[0022] In the following, for the sake of simplicity, the length of the major axis 31 will be referred to as the major axis length, and the length of the minor axis 32 will be referred to as the minor axis length. The major axis length refers to the longest length in the direction along the flattened plane 30a. The minor axis length refers to the longest length in the direction along the side surface 30b and intersecting the major axis 31.

[0023] As shown in Figure 4, the magnetic nanoparticles 30 have alloy particles 34 and an insulating coating 35. The surface of the alloy particles 34 is covered with the insulating coating 35.

[0024] As for the alloy particles 34, L1 ０ FeNi magnetic powder having a structure, ferrite magnetic powder, etc. can be used. The alloy particles 34 in this embodiment are L1 ０ It contains an FeNi ordered alloy with a type ordered structure. In addition to Fe and Ni, the alloy particles 34 may contain additives such as sulfur or unavoidable impurities. The alloy particles 34 determine the magnetic properties of the magnetic nanoparticles 30.

[0025] The alloy particles 34 form the shape of the magnetic nanoparticles 30. The alloy particles 34 are flattened in shape. The alloy particles 34 have two main surfaces 34a and an annular surface 34b connecting these two main surfaces 34a.

[0026] As its name suggests, the insulating coating 35 has insulating properties. The thickness of the insulating coating 35 is expected to be uniform. The thickness of the insulating coating 35 covering the main surface 34a is expected to be the same as the thickness of the insulating coating 35 covering the annular surface 34b.

[0027] The flattened surface 30a and side surface 30b of the magnetic nanoparticle 30 are formed by an insulating coating 35. However, the shape of the flattened surface 30a is determined by the main surface 34a of the alloy particle 34, and the shape of the side surface 30b is determined by the annular surface 34b of the alloy particle 34. The long axis 31 and the easy magnetization axis 33 are along the main surface 34a, and the short axis 32 intersects the long axis 31 and is along the annular surface 34b. If the magnetic nanoparticle 30 does not have an insulating coating 35, the main surface 34a of the alloy particle 34 corresponds to the flattened surface 30a, and the annular surface 34b corresponds to the side surface 30b.

[0028] The insulating coating 35 functions to disrupt the magnetic coupling between alloy particles 34 contained in multiple adjacent magnetic nanoparticles 30 located near each other within the magnetic portion 20. The magnetic coupling between multiple alloy particles 34 refers to the exchange interaction, which is a quantum mechanical effect that occurs between particles of the same kind. The insulating coating 35 may also be called a "magnetic separation layer" or "magnetic separation coating layer."

[0029] <Unit cell> In Figure 5, L1 ０ The unit cell of the FeNi ordered alloy with a type ordered structure is shown as an FeNi superlattice 50. In the FeNi superlattice 50, Fe and Ni are arranged in layers in the (001) direction, based on a face-centered cubic lattice. The FeNi superlattice 50 has I sites 51 located at the edges and II sites 52 located in the middle of the stacked structure of the (001) plane of the face-centered cubic lattice. In Figure 5, the locations of atoms in the I sites 51 are shown as white circles, and the locations of atoms in the II sites 52 are shown as black circles.

[0030] In the crystal structure described above, the a-axis 53 is in the (010) direction, and the c-axis 54 is in the (001) direction. The c-axis 54 is the easy magnetization axis 33. In the FeNi superlattice 50 with a degree of order of 1.0 described later, only Ni atoms are present at the I-site 51, and only Fe atoms are present at the II-site 52, among the Fe atoms and Ni atoms.

[0031] Magnetic nanoparticles 30 are nanoparticles. Their major axis length is 1000 nm or less and several hundred nm or less. Their minor axis length is 100 nm or less and several tens of nm or less. "nm" stands for "nanometer".

[0032] When a plurality of magnetic nanoparticles 30 are included in the magnetic part 20, it is presumed that not all of these plurality of magnetic nanoparticles 30 necessarily exist individually, and at least a part of them are in a state of being connected to each other. However, even in such a connected state, it is presumed that the properties of the plurality of magnetic nanoparticles 30 do not become heterogeneous when there is no fundamental change in the L1 ０ type regular structure.

[0033] <Degree of regularity> In the present embodiment, the magnetic part 20 is manufactured such that the degree of regularity measured by the powder X-ray diffraction method is more than 0.7, preferably 0.76 or more, and more preferably 0.8 or more. The "degree of regularity" is an index indicating the degree of regularization in the FeNi superlattice 50, as described in Japanese Patent No. 6528865 and the like.

[0034] The degree of regularity is evaluated based on the XRD pattern. Let J be the ratio of the integrated intensity of the superlattice diffraction peak to the integrated intensity of the fundamental diffraction peak in the measured X-ray diffraction pattern. Let K be the ratio of the integrated intensity of the superlattice diffraction peak to the integrated intensity of the fundamental diffraction peak in the FeNi regular alloy with a degree of regularity "1" estimated from the Rietveld simulation. Then, the degree of regularity is evaluated by (J / K) ０．５ .

[0035] When the ratio of metal A present at the I site 51 shown in FIG. 5 is x and the ratio of metal B present is 1 - x, the ratio of metal A and metal B present at the I site 51 is A ｘ B １－ｘ and is expressed as. When the ratio of metal B present at the II site 52 is x and the ratio of metal A present is 1 - x, the ratio of metal A and metal B present at the II site 52 is A １－ｘ B ｘ and is expressed as. When the degree of regularity is OP, it is expressed as OP = 2x - 1. x is a value between 0.5 and 1.0.

[0036] <FeNiN> FeNiN is a precursor material for FeNi ordered alloys. In FIG. 6, the unit cell of FeNiN is shown as FeNiN lattice 60. The crystal structure including this unit cell can be identified from the XRD diffraction pattern. XRD is an abbreviation for X-ray diffraction.

[0037] The FeNiN lattice 60 has III site 61, IV site 62, and V site 63. The III site 61 corresponds to the I site 51 in the FeNi superlattice 50. The IV site 62 corresponds to the II site 52 in the FeNi superlattice 50. The V site 63 is located in the middle between two adjacent III sites 61 in the stacking direction. In FeNiN50, it is expected that Ni atoms exist at the III site 61, Fe atoms exist at the IV site 62, and N atoms exist at the V site 63.

[0038] <Method for manufacturing magnetic material> Next, the method for manufacturing the magnetic nanoparticles 30 will be outlined based on FIG. 7.

[0039] [[ID=⑨]] In step S10, FeNiN, which is a precursor material of the FeNi ordered alloy, is synthesized. In freshly synthesized FeNiN, many FeNiN particles are aggregated or adhered.

[0040] In step S20, FeNiN is coarsely pulverized. By doing so, FeNiN particles smaller in size than FeNiN are obtained.

[0041] In step S30, mechanical forces such as mechanical shear force are applied to the FeNiN particles. By doing so, the shape of the FeNiN particles is flattened. There is a particle size distribution in the plurality of flattened FeNiN particles obtained at this point.

[0042] In step S40, flattened FeNiN particles within a desired particle size range are selected from among the plurality of flattened FeNiN particles having a particle size distribution. The flattened FeNiN particles are classified.

[0043] In step S50, the surface of the classified, flattened FeNiN particles is coated with the constituent material of the insulating film 35. The constituent material of the insulating film 35 is silica or the like.

[0044] In step S60, the flattened FeNiN particles coated with the constituent material of the insulating film 35 are heat-treated (annealed). This repairs any defects that may have occurred in the flattened FeNiN particles due to previously performed processes such as coarse grinding and flattening.

[0045] In step S70, the heat-treated flattened FeNiN particles are subjected to a denitrification treatment. This removes nitrogen from the flattened FeNiN particles, thereby producing flattened magnetic nanoparticles 30.

[0046] Next, the method for producing the magnetic nanoparticles 30 shown in Figure 7 will be described in detail.

[0047] <FeNiN Synthesis> For the synthesis of FeNiN, a precursor material, techniques described in, for example, Japanese Patent Publication No. 6230513 and Japanese Patent Publication No. 6627818 can be used.

[0048] Specifically, FeNiN is synthesized by nitriding FeNi disorder alloy powder produced by methods such as thermal plasma, flame spray, or coprecipitation. FeNiN can also be obtained by reduction and nitriding of FeNi oxide. The FeNi oxide used in the reduction process may contain Fe oxide or Ni oxide, or an oxide containing both Fe and Ni.

[0049] The Fe oxide is not particularly limited, but for example, FeO, Fe ２ O ３ Fe ３ O ４ These include, among others. Fe oxides include oxides obtained by oxidizing raw materials such as metallic iron, iron hydroxide, iron carbonate, iron chloride, iron iodide, iron bromide, iron sulfate, iron nitrate, iron phosphate, and iron oxalate.

[0050] Ni oxides are not particularly limited, but examples include NiO. Ni oxides include oxides obtained by oxidizing raw materials such as metallic nickel, nickel hydroxide, nickel carbonate, nickel chloride, nickel iodide, nickel bromide, nickel sulfate, nickel nitrate, nickel phosphate, and nickel oxalate.

[0051] An oxide containing Fe and Ni can be produced by carrying out the following precipitation and oxidation steps. In the precipitation step, a solution containing Fe and Ni is mixed with a precipitating agent to obtain a precipitate containing Fe and Ni. Next, in the oxidation step, the precipitate is heat-treated to obtain an oxide containing Fe and Ni. According to the above production method, it is easy to control the average particle size and particle size distribution of the obtained oxide containing Fe and Ni, and the distribution of Fe and Ni in the oxide containing Fe and Ni tends to be uniform.

[0052] The Fe and Ni raw materials are not limited as long as they can be dissolved in an acidic solution. Examples of Fe raw materials include metallic iron, iron oxide, iron hydroxide, iron carbonate, iron chloride, iron iodide, iron sulfate, iron nitrate, iron phosphate, and iron oxalate. Examples of Ni raw materials include metallic nickel, nickel oxide, nickel hydroxide, nickel carbonate, nickel chloride, nickel iodide, nickel sulfate, nickel nitrate, nickel phosphate, and nickel oxalate. Examples of acidic solutions include sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid. The concentration of the solution containing Fe and Ni can be appropriately adjusted within the range in which the Fe and Ni raw materials are substantially soluble in the acidic solution.

[0053] To react a solution containing Fe and Ni with a precipitating agent, the precipitating agent may be added to the solution containing Fe and Ni, or the solution containing Fe and Ni may be added to the precipitating agent. The solution containing Fe and Ni referred to here only needs to be a solution containing Fe and Ni when reacting with the precipitating agent; the Fe and Ni raw materials may be prepared as separate solutions, and each solution may be added to react with the precipitating agent. Even when the Fe and Ni raw materials are prepared as separate solutions, the range can be adjusted as appropriate so that each raw material is substantially soluble in the acidic solution.

[0054] The precipitating agent mentioned above is not limited to any agent that reacts with a solution containing Fe and Ni to produce a precipitate. Examples of precipitating agents include alkaline solutions such as oxalic acid, sodium hydroxide aqueous solution, sodium bicarbonate aqueous solution, potassium hydroxide aqueous solution, and lithium hydroxide aqueous solution. Alternatively, a precipitate can be obtained by blowing carbon dioxide into a solution containing Fe and Ni. The precipitates produced may include oxalates, carbonates, and hydroxides.

[0055] To give a specific example, FeNiN can be obtained by firing iron nickel oxalate powder in air, hydrogen reduction, and nitriding.

[0056] <Coarse Grinding> For coarse grinding of FeNiN, general grinding methods such as ball milling can be used.

[0057] <Flattening> Flattening of FeNiN particles is not particularly limited, but can be achieved, for example, by applying mechanical shear force to the FeNiN particles. Specifically, a wet bead mill is performed on a slurry containing FeNiN particles. In this way, mechanical shear force is applied to the FeNiN particles, and their shape can be flattened.

[0058] The slurry containing the FeNiN particles described above can be prepared by dispersing coarsely ground FeNiN particles in a solvent containing a surfactant. A surfactant that provides good coating properties for the FeNiN particles can be used. Examples of surfactants include nitrogen-containing surfactants such as oleylamine and trioctylamine, and sulfur-containing surfactants such as octanthiol and triazinedithiol. Polymeric surfactants such as polyvinyl alcohol, polyacrylic acid, polyethyleneimine, and polyvinylpyrrolidone can also be used. As a solvent, a liquid that allows for stable dispersion of the surfactant-coated FeNiN particles can be used. Examples of solvents include pure water, alcohols such as ethanol and isopropyl alcohol, and nonpolar solvents such as toluene and cyclohexane.

[0059] As an example, a slurry containing 5% by weight of FeNiN particles in ethanol is introduced into a bead mill apparatus together with zirconia media with a diameter of 0.1 mm and processed at 600 rpm for 30 minutes. This process yields a slurry containing flattened FeNiN particles. The bead mill apparatus used is a planetary ball mill, PL-7, manufactured by Fritsch.

[0060] <Classification> The slurry containing flattened FeNiN particles is centrifuged. This allows for particle size classification. For example, centrifugation is performed in the following order: 500G for 10 min, 4000G for 10 min, and 4000G for 120 min. This allows the flattened FeNiN particles with larger particle sizes to settle first. These particles are then collected. To obtain high coercivity, the flattened FeNiN particles with smaller particle sizes are extracted. This coercivity is evaluated as the strength of the magnetic field when a magnetic field is applied to the magnetic nanoparticles 30 and the magnetization direction of the FeNi ordered alloy is switched by the influence of the magnetic field.

[0061] <Coating> As described above, the insulating film 35 plays a role in disrupting the magnetic bonds between multiple magnetic nanoparticles 30 located in close proximity within the magnetic portion 20. For this reason, the constituent material of the insulating film 35 must be a non-magnetic material. Furthermore, the constituent material of the insulating film 35 must be a substance that can be subjected to heat treatment and denitrification treatment, and that does not react with the alloy particles 34.

[0062] As constituent materials for the insulating coating 35 that satisfy the above requirements, for example, oxides of Group III to VII and Group XIII to XVI elements such as silica, titania, zirconia, yttria, and alumina can be used. In addition, insulating materials such as nitride films can be used as constituent materials for the insulating coating 35. The thickness of the insulating film constituting the insulating coating 35 is preferably 1 nm or more.

[0063] In this example, the classified flattened FeNiN particles were coated with silica (silica coating). When silica is used as the insulating film 35 in this way, the powdered flattened FeNiN particles are mixed with a solvent of water or ethanol to which tetraethoxysilane has been added, and then an aqueous ammonia solution is poured in. As a result, silica is produced by the hydrolysis and condensation of tetraethoxysilane. The flattened FeNiN particles are covered with silica. The flattened FeNiN particles are coated with the insulating film 35.

[0064] As explained above, the coating treatment on the flattened FeNiN particles is performed before the heat treatment and denitrification. This suppresses the sintering of the flattened FeNiN particles during the subsequent heat treatment and denitrification. In addition, it suppresses the bonding of the alloy particles 34 contained in the magnetic part 20 during the molding of the magnet 10. This suppresses the deterioration of the magnetic properties of the magnet 10.

[0065] <Heat Treatment> The heat treatment performed on the flattened FeNiN particles is carried out, for example, in an ammonia gas environment. Specifically, as an example, the flattened FeNiN particles are placed in an electric furnace capable of introducing ammonia gas. The ambient temperature is set to 300 to 450°C, and the treatment time is set to 4 to 48 hours. This arranges the atomic structure of the flattened FeNiN particles.

[0066] Flattened FeNiN particles contain sulfur as an impurity or additive. After grinding, the stabilizing effect of sulfur on the FeNiN particles weakens, making them more susceptible to decomposition at high temperatures. Therefore, the optimal heat treatment conditions vary depending on the amount of sulfur present in the flattened FeNiN particles and their particle size. The temperature for this heat treatment should preferably be lower than the nitriding temperature used in the FeNiN synthesis process.

[0067] <Denitrification> Flattened FeNiN particles, whose atomic arrangement has been aligned by heat treatment, are subjected to denitrification treatment. This denitrification treatment removes nitrogen from the flattened FeNiN particles. At the same time, the atomic arrangement is corrected. Flattened FeNi particles with a regular atomic arrangement and increased coercivity are obtained. Alloy particles 34 containing an FeNi ordered alloy, covered with an insulating coating 35, are manufactured.

[0068] The denitrification treatment can be carried out using the apparatus and method described in Japanese Patent Publication No. 6230513 and Japanese Patent Publication No. 6627818. Specifically, the denitrification treatment can be carried out, for example, by heat treatment under a hydrogen atmosphere. The hydrogen flow rate can be, for example, 0.01 to 10 liters / min per 1 g of flattened FeNiN particles. Preferably, the hydrogen flow rate can be 0.1 to 5 liters / min. The heat treatment temperature can be, for example, 100 to 400°C. Preferably, the heat treatment temperature can be 200 to 350°C. The heat treatment time can be, for example, 1 to 24 hours. Preferably, the heat treatment time can be 2 to 10 hours.

[0069] <Long axis length and short axis length> The method for measuring the long axis length and short axis length of magnetic nanoparticles 30 is described below. The length can be measured using image analysis software.

[0070] The shapes of the multiple magnetic nanoparticles 30 visible in the image captured by the scanning electron microscope (SEM image) are varied. From these, magnetic nanoparticles 30 that make it easy to determine the longest length on the flattened plane 30a are selected. For example, particles whose flattened plane 30a has an elliptical shape, making it easy to determine the major axis length, are selected, while particles whose flattened plane 30a has a U-shape or J-shape, making it difficult to determine the major axis length, are not selected. For example, 100 such magnetic nanoparticles 30 are selected. Then, the longest length on the flattened plane 30a of these nanoparticles is measured, and the average value is calculated. In this way, the major axis length (average particle size) can be determined. The standard deviation of the measured values ​​for the major axis length of the 100 magnetic nanoparticles 30 can be evaluated as the measurement error of the major axis length.

[0071] From among several magnetic nanoparticles 30 with varying shapes displayed in the SEM image, a magnetic nanoparticle 30 is selected that makes it easy to determine the longest thickness between two flattened surfaces 30a on the side surface 30b. Similarly to the long axis length, for example, 100 magnetic nanoparticles 30 that make it easy to determine the longest thickness between two flattened surfaces 30a are selected. Then, the longest thickness on the side surface 30b of these nanoparticles is measured, and the average value is calculated. In this way, the short axis length can be determined. The standard deviation of the measured thicknesses of the 100 magnetic nanoparticles 30 can be evaluated as the thickness measurement error.

[0072] Of course, the number of magnetic nanoparticles 30 suitable for measuring the long axis length and short axis length is not particularly limited. For example, it is preferable to select at least 30 or more.

[0073] As described above, magnetic nanoparticles 30 suitable for measuring the long axis length and short axis length are selected. Therefore, the magnetic nanoparticles 30 used to measure the long axis length and the magnetic nanoparticles 30 used to measure the short axis length are different, meaning the objects of measurement for the long axis length and short axis length are different. However, as described above, 100 magnetic nanoparticles 30 are selected for each measurement of the long axis length and short axis length. The average values ​​of the long axis length and short axis length are calculated. Therefore, although the objects of measurement for the long axis length and short axis length are different, it is considered that the influence of the difference in measurement objects on the calculated long axis length and short axis length is small.

[0074] More precisely, when actually measuring the long axis length and short axis length as described above, it is better to measure the long axis length and short axis length of the flattened FeNiN particles before denitrification, rather than the long axis length and short axis length of the magnetic nanoparticles 30 after denitrification. The reason for this is as follows.

[0075] As shown in the manufacturing method in Figure 7, the coating treatment in step S50 is performed before the denitrification treatment in step S70. Therefore, in the magnetic nanoparticles 30 obtained by denitrification, the outer surface of the alloy particles 34 is covered with an insulating film 35. The insulating film 35 is electrically insulating. Therefore, it becomes difficult to obtain a clear SEM image due to charge-up. As a result, it becomes difficult to measure the long axis length and short axis length of the magnetic nanoparticles 30. For this reason, it is preferable to measure the long axis length and short axis length of the flattened FeNiN particles before they are covered with the insulating film 35, rather than the long axis length and short axis length of the magnetic nanoparticles 30.

[0076] Furthermore, it is presumed that the size of the alloy particles 34 of the magnetic nanoparticles 30 shrinks to some extent due to the denitrification treatment compared to the flattened FeNiN particles. It is presumed that the lattice constant decreases by about 10% due to the change from the FeNiN lattice 60 to the FeNi superlattice 50. However, this change in size is within the range of the measurement error (standard deviation) mentioned above. In addition, it is presumed that the particle shape and size distribution do not change much before and after denitrification. The thickness of the insulating coating 35 is about 1 nm, which is also within the range of measurement error. For these reasons, the major axis length and minor axis length based on the measurement results from the SEM image of the flattened FeNiN particles can be considered as the major axis length and minor axis length of the magnetic nanoparticles 30. In the magnetic nanoparticles 30 of Examples 1 to 3 described later, their major axis length and minor axis length are considered to be the major axis length and minor axis length based on the measurement results from the SEM image of the flattened FeNiN particles.

[0077] <Evaluation of Examples> In the classification process of step S40, magnetic nanoparticles 30 of Example 1 were produced by centrifugal separation under the conditions of 500 G and 10 min. In the classification process of step S40, magnetic nanoparticles 30 of Example 2 were produced by centrifugal separation under the conditions of 4000 G and 10 min. In the classification process of step S40, magnetic nanoparticles 30 of Example 3 were produced by centrifugal separation under the conditions of 4000 G and 120 min. It was confirmed that the shape of these magnetic nanoparticles 30 of Examples 1 to 3 was flattened.

[0078] In contrast, the nanoparticles of Comparative Example 1 were produced by omitting steps S30, S40, and S50 from the manufacturing method described in Figure 7. The shape of the nanoparticles of Comparative Example 1 was not flattened.

[0079] The major axis length and minor axis length of the magnetic nanoparticles 30 in the above-described examples, and the particle size of Comparative Example 1 were measured. Furthermore, their orderliness and coercivity were measured. Although Comparative Example 1 is not flattened, the method for measuring the major axis length and minor axis length of the magnetic nanoparticles 30 can be used to measure its length.

[0080] The measured length of the long axis of the magnetic nanoparticles 30 in Example 1 was 640 nm, with a measurement error (standard deviation) of 205 nm. The measured length of the short axis was 49 nm, with a measurement error of 15 nm. The degree of order was 0.80, with a measurement error of 0.04. The coercivity was 160 kA / m.

[0081] The measured length of the long axis of the magnetic nanoparticles 30 in Example 2 was 221 nm, with a measurement error of 82 nm. The measured length of the short axis was 33 nm, with a measurement error of 8 nm. The orderness was 0.81, with a measurement error of 0.04. The coercivity was 220 kA / m.

[0082] The measured length of the long axis of the magnetic nanoparticles 30 in Example 3 was 96 nm, with a measurement error of 40 nm. The measured length of the short axis was 20 nm, with a measurement error of 4 nm. The orderness was 0.89, with a measurement error of 0.05. The coercivity was 380 kA / m.

[0083] Furthermore, the particle size of the nanoparticles in Comparative Example 1 was 182 nm, with a measurement error of 64 nm. The orderliness was 0.63, with a measurement error of 0.03. The coercivity was 120 kA / m.

[0084] As shown above, the order of the nanoparticles in Comparative Example 1 could not exceed 0.7. In contrast, the order of the magnetic nanoparticles 30 in Examples 1 to 3 exceeded 0.7. The expected range of possible values ​​for the order of the nanoparticles is 0.76 or higher and 0.94 or lower. In Comparative Example 1, the coercivity was 120 kA / m, while in Examples 1 to 3, the coercivity was 160 to 380 kA / m.

[0085] Furthermore, the degree of regularity tended to increase as the minor axis length decreased. It is expected that a degree of regularity of 0.7 or higher can be achieved by setting the minor axis length to 100 nm or less, or to a few tens of nm or less. A possible range for minor axis lengths of 0.76 or higher is a few nanometers or more, and 50 nm or less.

[0086] Furthermore, the shorter the major axis length, the greater the coercivity tended to be. A range of major axis lengths that yield good coercivity is considered to be between several tens of nanometers and 350 nm.

[0087] As shown above, it was confirmed that Examples 1 to 3 showed improved regularity and greater coercivity compared to Comparative Example 1.

[0088] When diffraction spots were observed in flattened FeNiN particles using electron diffraction, diffraction spots indicating the presence of the c-axis 54 within the flattened plane were observed. Furthermore, it was found that some flattened FeNiN particles had a structure in which multiple regions with different c-axis orientations were arranged along the long axis. This orientation of the c-axis 54 is similar in the FeNi ordered alloy after denitrification.

[0089] Furthermore, a correlation was observed where the azimuthal distribution became smaller as the length of the major axis decreased. It is thought that as the length of the major axis decreased, the distribution in the c-axis direction narrowed, the degree of regularity increased, and the coercivity increased.

[0090] In Comparative Example 2, the nanoparticles produced by performing steps S30 and S40 of the manufacturing method described in Figure 7 after step S70 were flattened in shape. However, although the shape of Comparative Example 2 was flattened, the orderliness and coercivity were lower than those of Comparative Example 1.

[0091] Specifically, the measured length of the long axis of the nanoparticles in Comparative Example 2 was 245 nm, with a measurement error of 101 nm. The measured length of the short axis was 38 nm, with a measurement error of 8 nm. The orderliness was 0.30, with a measurement error of 0.02. The coercivity was 25 kA / m.

[0092] Furthermore, analysis of the electron diffraction pattern of Comparative Example 2 revealed that while a diffraction pattern typical of polycrystalline particles was observed, no spots corresponding to {001} or {002}, which appear when the c-axis 54 is located within a flattened plane, were observed. Therefore, it was confirmed that Comparative Example 2 is polycrystalline and does not have a specific crystal orientation direction.

[0093] In the magnetic nanoparticle 30 described above, which has a flattened shape with a long axis 31 and a short axis 32, and in which the easy magnetization axis 33 is aligned with the flattened surface 30a along the long axis 31, the easy magnetization axis 33 is oriented inward towards the flattened surface 30a. As a result, it is less susceptible to the influence of the demagnetizing field, and it is possible to increase the coercivity.

[0094] <Thread-like Magnetic Powder> As described above, the magnetic part 20 contains magnetic nanoparticles 30 and molding resin 40. As shown in Figure 2, the multiple magnetic nanoparticles 30 are arranged in the Y direction. At the same time, the multiple magnetic nanoparticles 30 are connected in the Y direction. Hereafter, a mass in which multiple magnetic nanoparticles 30 are connected linearly in the Y direction in this manner will be referred to as thread-like magnetic powder 100. Figure 8 shows an SEM image of the thread-like magnetic powder 100.

[0095] The multiple magnetic nanoparticles 30 contained in the filamentous magnetic powder 100 are flattened as described above. The flattened surfaces 30a of these multiple magnetic nanoparticles 30 are aligned in the Y direction. The multiple magnetic nanoparticles 30 are oriented in the Y direction. As a result, the easy magnetization axis of the filamentous magnetic powder 100 is aligned in the Y direction.

[0096] The filamentous magnetic particles 100 having these properties are arranged in the Y direction. Furthermore, the filamentous magnetic particles 100 are arranged in a direction perpendicular to the Y direction. Due to this configuration, the magnetic part 20 is oriented in parallel. The magnet 10 is oriented in parallel. The magnet 10 has a configuration in which a plurality of magnetic nanoparticles 30 are oriented in the Y direction.

[0097] <Method for Manufacturing Filamentous Magnetic Powder> First, in step S110 shown in Figure 9, magnetic nanoparticles 30 manufactured by the manufacturing method shown in Figure 7 are prepared. At this preparation stage, the magnetic nanoparticles 30 may be aggregated or fixed together, as shown in Figure 10.

[0098] In step S120, the magnetic nanoparticles 30 are mixed with the solvent 111. This produces the first mixture 110. Specifically, the first mixture 110 contains 0.025% by weight of magnetic nanoparticles 30. The first mixture 110 may contain several times the amount of magnetic nanoparticles 30, such as 0.01% by weight.

[0099] In step S130, a static external magnetic field is applied to the first mixed liquid 110. A static external magnetic field is a magnetic field with a spatial magnetic field gradient close to zero. For example, the magnetic field inside a coil corresponds to a static magnetic field. Due to this external magnetic field, the easy magnetization axes 33 of the multiple magnetic nanoparticles 30 are aligned along the direction in which the external magnetic field is applied. The multiple magnetic nanoparticles 30 are then arranged in a linear or thread-like manner in this direction. These multiple magnetic nanoparticles 30 are connected to each other. As a result, thread-like magnetic powder 100 is produced. Note that instead of applying a static, continuous external magnetic field as described above, a dynamic, continuous external magnetic field may be applied to produce the thread-like magnetic powder 100. Furthermore, thread-like magnetic powder 100 may also be produced by applying an intermittent external magnetic field.

[0100] Furthermore, in the magnetic nanoparticles 30 contained in the first mixture 110, there is a possibility that multiple particles are aggregated or stuck together. Therefore, it may be difficult to produce the filamentous magnetic powder 100 by simply applying a static external magnetic field in step S130.

[0101] To avoid such problems, a dispersion treatment may be performed on the first mixture 110 to break the bonds of aggregated or stuck particles. For example, ultrasonic waves may be generated in the first mixture 110. This will generate bubbles in the first mixture 110. These bubbles may break the bonds of aggregated or stuck particles, causing them to separate.

[0102] Alternatively, for example, a high-viscosity substance may be mixed with the first mixture 110 and mechanically stirred. The viscous force of the high-viscosity substance and the force of mechanical stirring may break the bonds of aggregated or stuck particles. Or, more simply, a jet mill may be used to break the bonds of aggregated or stuck particles. The method of dispersion treatment for breaking such bonds is not particularly limited. Figure 10 illustrates the first mixture 110 containing a plurality of dispersed magnetic nanoparticles 30.

[0103] A static external magnetic field is applied to the first mixture 110 containing magnetic nanoparticles 30 whose particle size has been reduced by the dispersion treatment described above. This generates torque in the magnetic nanoparticles 30. The magnetic nanoparticles 30 rotate in the solvent 111 without changing their position. The easy magnetization axis 33 of the magnetic nanoparticles 30 is aligned with the direction in which the external magnetic field is applied. As a result, the flattened surfaces 30a of the multiple magnetic nanoparticles 30 are aligned with the direction of application. Multiple magnetic nanoparticles 30 in this aligned position are placed next to each other. These multiple adjacent magnetic nanoparticles 30 are connected to each other. This produces filamentous magnetic powder 100.

[0104] The easy magnetization axes 33 of the multiple magnetic nanoparticles 30 contained in the filamentous magnetic powder 100 are aligned along the extension direction of the filamentous magnetic powder 100. The multiple magnetic nanoparticles 30 contained in the filamentous magnetic powder 100 are oriented in the extension direction of the filamentous magnetic powder 100. In Figure 10, the multiple magnetic nanoparticles 30 contained in one filamentous magnetic powder 100 are shown without being separated by lines.

[0105] Next, in step S140, the solvent 111 is removed from the first mixture 110. This extracts multiple filamentous magnetic particles 100. Methods for removing the solvent 111 include vaporization and filtration.

[0106] <Method for Manufacturing Magnetic Material> First, in step S210 shown in Figure 11, the magnetic nanoparticles 30 manufactured by the manufacturing method shown in Figure 9 are mixed with the molten molding resin 40. This generates a liquid second mixture 120.

[0107] A thermosetting resin can be used as the molding resin 40. This thermosetting resin can be a high-heat-resistant engineering plastic. Examples of high-heat-resistant engineering plastics include Teflon (registered trademark) and PEEK. The molding resin 40 has a higher melting point than the two-color molding resin. A thermoplastic resin is used as the two-color molding resin. Examples of thermoplastic resins include nylon, polypropylene, and PPS.

[0108] Next, in step S220, the second mixture 120 is placed into the mold 200 shown in Figure 12. The mold 200 has an internal space. This internal space is formed by an inner wall 200a. The internal space extends from the inlet 200b towards the outlet 200c. The size of the internal space in the direction perpendicular to this extension decreases as it moves from the inlet 200b towards the outlet 200c. The internal space has a shape that gradually narrows as it moves from the inlet 200b towards the outlet 200c. Note that in Figure 12, multiple magnetic nanoparticles 30 contained in one filamentous magnetic powder 100 are shown without being separated by lines.

[0109] The second mixed liquid 120 is introduced into the internal space of the mold 200 from the inlet 200b. Then, it is pressed from the inlet 200b towards the outlet 200c. The second mixed liquid 120 is pressed and molded. In this way, the extension direction of the filamentous magnetic powder 100 contained in the second mixed liquid 120 is aligned with this pressing direction. The filamentous magnetic powder 100 is oriented in the pressing direction. At the same time, multiple filamentous magnetic powders 100 are aligned in a direction perpendicular to the pressing direction. Then, the molding resin 40 contained in the second mixed liquid 120 is solidified. In this way, a magnet 10 is manufactured as shown in Figure 12. Alternatively, pellets 300, which are the raw material for this magnet 10, are manufactured. The direction from the inlet 200b towards the outlet 200c corresponds to the first direction, and the direction perpendicular to this corresponds to the second direction.

[0110] Whether to manufacture the magnet 10 or the pellet 300 can be appropriately selected by selecting the size of the mold 200 used in the press molding in step 220. The magnet 10 and the pellet 300 correspond to magnetic materials.

[0111] <Effects> Flat-shaped magnetic nanoparticles 30 can be manufactured by the manufacturing method shown in Figure 7. Furthermore, filamentous magnetic powder 100 containing these magnetic nanoparticles 30 can be manufactured by the manufacturing method shown in Figure 9.

[0112] Because the filamentous magnetic powder 100 is used, the application of mechanical pressure during press molding makes it easier for multiple filamentous magnetic powders 100 to orient in the direction of their own extension. As a result, a magnet 10 or pellet 300 in which multiple filamentous magnetic powders 100 are oriented can be obtained. In other words, a magnetic material in which multiple magnetic nanoparticles 30 are oriented can be obtained.

[0113] The magnetic nanoparticles 30 have a flattened shape. Therefore, it is easier to extend the filamentous magnetic powder 100. The aspect ratio of the filamentous magnetic powder 100, obtained by dividing the long axis by the short axis, tends to be large. Therefore, when pressed and molded, the flattened surfaces 30a of the multiple magnetic nanoparticles 30 contained in the filamentous magnetic powder 100 tend to follow the direction of the pressing. The multiple filamentous magnetic powders 100 tend to be oriented in the direction of the pressing.

[0114] The alloy particles 34 contained in the magnetic nanoparticles 30 have an order degree of 0.76 to 0.94 and a coercivity of 160 to 380 kA / m, L1 ０ It contains an FeNi ordered alloy with a type ordered structure. The alloy particles 34 are contained in the magnetic material and are also oriented. ０ FeNi ordered alloys with a type ordered structure possess high heat resistance properties.

[0115] Therefore, the magnetic material containing the alloy particles 34 has high coercivity and high heat resistance. The magnetic properties of the magnetic material are less likely to deteriorate due to the heat generated during two-color molding. In addition, a resin with a high melting point can be used as the constituent material of the molding resin 40. Specifically, the melting point of the resin can be 300°C or higher. Therefore, it is a magnetic material that is easy to apply.

[0116] <Variations> The disclosure of this specification is not limited to the exemplary embodiments. The disclosure includes the exemplary embodiments and modifications made by those skilled in the art based on those exemplary embodiments. The disclosure is not limited to combinations of parts and elements shown in the embodiments, but can be implemented in various modifications. The disclosure can be implemented in a variety of combinations. The disclosure may have parts that can be added to the embodiments. The disclosure includes embodiments in which parts and elements have been omitted. The disclosure includes substitutions of parts, substitutions of elements, combinations of parts, or combinations of elements between one embodiment and another. The technical scope of the disclosure is not limited to the descriptions of embodiments. The technical scope of the disclosure is indicated by the description of the claims. The technical scope of the disclosure should be understood to include the description of the claims and equivalents, and all modifications within the claims.

[0117] The applications of the filamentous magnetic powder 100 are not limited to the manufacture of magnets 10, but can also be applied to the manufacture of magnetic recording media, etc. Furthermore, the expression "regularity measured by powder X-ray diffraction" does not necessarily mean that the regularity is directly measured by powder X-ray diffraction, but includes regularity that can be calculated using various patterns, waveforms, values, etc., measured by powder X-ray diffraction. For this reason, "regularity measured by powder X-ray diffraction" can also be rephrased as "regularity obtained by measurement using powder X-ray diffraction."

[0118] In this embodiment, an example of manufacturing filamentous magnetic powder 100 containing one type of magnetic nanoparticle 30 is shown. However, filamentous magnetic powder 100 containing multiple types of magnetic nanoparticles 30 may be manufactured. Alternatively, multiple types of filamentous magnetic powder 100 containing different types of magnetic nanoparticles 30 may be manufactured, and magnets 10 may be manufactured using these different types of filamentous magnetic powder 100.

[0119] Furthermore, as simply shown in Figure 13, filamentous magnetic powder 100 may be manufactured containing not only nanoscale magnetic nanoparticles 30 but also microscale magnetic microparticles 70. In this case, in step S120, the first mixed solution 110 is produced by mixing the magnetic nanoparticles 30 and magnetic microparticles 70 in the solvent 111. In Figure 13, the difference between the magnetic nanoparticles 30 and magnetic microparticles 70 is represented by the size difference. The bonding state of these two particles is not limited to the example shown in Figure 13. The number of magnetic nanoparticles 30 bonded to one magnetic microparticle 70 is not particularly limited. The shape of the magnetic microparticles 70 contained in the filamentous magnetic powder 100 is not particularly limited.

[0120] The magnet 10 may be manufactured using filamentous magnetic powder 100 containing the magnetic microparticles 70. Alternatively, the magnet 10 may be manufactured using filamentous magnetic powder 100 containing magnetic nanoparticles 30 and magnetic microparticles 70 not contained in the filamentous magnetic powder 100. In this case, the shape of the magnetic microparticles 70 may be the same as or different from that of the filamentous magnetic powder 100.

[0121] <Disclosure of Technical Ideas> This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0122] <Technical Concept 1> A method for manufacturing a magnetic material comprising: mixing a plurality of magnetic nanoparticles (30) in a solvent (111); applying an external magnetic field to the solvent containing the plurality of magnetic nanoparticles so that the plurality of magnetic nanoparticles are linearly connected and a plurality of thread-like magnetic powders (100) are formed in which the plurality of magnetic nanoparticles are oriented along the extension of the linear connection; removing the solvent to extract the plurality of thread-like magnetic powders; and extruding the mixture of the plurality of thread-like magnetic powders and a liquid molding resin (40) in a first direction so that the plurality of thread-like magnetic powders are extended and oriented in the first direction, and the plurality of thread-like magnetic powders are aligned in a second direction perpendicular to the first direction.

[0123] <Technical Concept 2> The method for manufacturing a magnetic material according to Technical Concept 1, wherein each magnetic nanoparticle has a flattened shape in which a long axis (31) and a short axis (32) shorter than the long axis intersect, and the flattened plane (30a) along the long axis is wider than the side surface (30b) along the short axis, and the easy magnetization axis (33) is along the flattened plane, and by applying the external magnetic field to the solvent in which a plurality of the magnetic nanoparticles are mixed, the plurality of magnetic nanoparticles are linearly connected, and the easy magnetization axes of the plurality of magnetic nanoparticles are aligned along the extension of this, thereby forming a plurality of thread-like magnetic powders in which the plurality of magnetic nanoparticles are oriented.

[0124] <Technical Concept 3> The magnetic nanoparticles are L1 ０ Includes a FeNi ordered alloy with a type ordered structure, the L1 ０ A method for manufacturing a magnetic material according to technical concept 2, wherein the easy magnetization axis of the type-ordered structure is aligned with the flattened plane.

[0125] <Technical Idea 4> A method for producing a magnetic material according to any one of Technical Ideas 1 to 3, wherein a plurality of magnetic microparticles (70) are mixed with a plurality of magnetic nanoparticles in the solvent.

[0126] <Technical Concept 5> A magnetic material comprising a plurality of filamentous magnetic powders (100) in which a plurality of magnetic nanoparticles (30) are linearly linked, and a molding resin (40) that connects the plurality of filamentous magnetic powders, wherein the plurality of filamentous magnetic powders extend and are oriented in a first direction, and the plurality of filamentous magnetic powders are aligned in a second direction perpendicular to the first direction.

[0127] <Technical Idea 6> The magnetic material according to Technical Idea 5, wherein each magnetic nanoparticle has a flattened shape in which a long axis (31) and a short axis (32) shorter than the long axis intersect, and the flattened plane (30a) along the long axis is wider than the side surface (30b) along the short axis, and the easy magnetization axis (33) is along the flattened plane, and in the filamentous magnetic powder, the easy magnetization axes of the multiple magnetic nanoparticles are aligned on the extension of the filamentous magnetic powder, thereby orienting the multiple magnetic nanoparticles.

[0128] <Technical Concept 7> The magnetic nanoparticles are L1 ０ Includes a FeNi ordered alloy with a type ordered structure, the L1 ０ A magnetic material according to technical concept 6, wherein the easy magnetization axis of the type-ordered structure is aligned with the flattened plane.

Claims

1. A method for manufacturing a magnetic material, comprising: mixing a plurality of magnetic nanoparticles (30) in a solvent (111); applying an external magnetic field to the solvent containing the plurality of magnetic nanoparticles so that the plurality of magnetic nanoparticles are linearly linked and a plurality of thread-like magnetic powders (100) are formed in which the plurality of magnetic nanoparticles are oriented along the extension of the linear linkage; removing the solvent to extract the plurality of thread-like magnetic powders; and extruding the plurality of thread-like magnetic powders with a liquid molding resin (40) in a mixed state in a first direction so that the plurality of thread-like magnetic powders are extended and oriented in the first direction, and the plurality of thread-like magnetic powders are aligned in a second direction perpendicular to the first direction.

2. The method for manufacturing a magnetic material according to claim 1, wherein each magnetic nanoparticle has a flattened shape in which a long axis (31) and a short axis (32) shorter than the long axis intersect, and the flattened plane (30a) along the long axis is wider than the side surface (30b) along the short axis, and the easy magnetization axis (33) is along the flattened plane, and by applying the external magnetic field to the solvent in which a plurality of the magnetic nanoparticles are mixed, the plurality of magnetic nanoparticles are linearly connected, and the easy magnetization axes of the plurality of magnetic nanoparticles are aligned along the extension of this, thereby forming a plurality of thread-like magnetic powders in which the plurality of magnetic nanoparticles are oriented.

3. The magnetic nanoparticles are L1 ０ Includes a FeNi ordered alloy with a type ordered structure, the L1 ０ A method for manufacturing a magnetic material according to claim 2, wherein the easy magnetization axis of the type-ordered structure is aligned with the flattened plane.

4. A method for producing a magnetic material according to any one of claims 1 to 3, wherein a plurality of magnetic microparticles (70) are mixed with a plurality of magnetic nanoparticles in the solvent.

5. A magnetic material comprising a plurality of filamentous magnetic powders (100) in which a plurality of magnetic nanoparticles (30) are linearly linked, and a molding resin (40) that connects the plurality of filamentous magnetic powders, wherein the plurality of filamentous magnetic powders extend and are oriented in a first direction, and the plurality of filamentous magnetic powders are arranged in a second direction perpendicular to the first direction.

6. The magnetic material according to claim 5, wherein each magnetic nanoparticle has a flattened shape in which a long axis (31) intersects with a short axis (32) shorter than the long axis, and the flattened plane (30a) along the long axis is wider than the side surface (30b) along the short axis, and the easy magnetization axis (33) is along the flattened plane, and in the filamentous magnetic powder, the easy magnetization axes of the plurality of magnetic nanoparticles are aligned on the extension of the filamentous magnetic powder, thereby orienting the plurality of magnetic nanoparticles.

7. The magnetic nanoparticles are L1 ０ Includes a FeNi ordered alloy with a type ordered structure, the L1 ０ The magnetic material according to claim 6, wherein the easy magnetization axis of the type-ordered structure is aligned with the flattened plane.

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