JP7258646B2 - Plural flat magnetic metal particles, compacted powder materials and rotating electric machines - Google Patents

Description

An embodiment of the present invention relates to a plurality of flat magnetic metal particles, a compacted powder material, and a rotating electric machine.

Currently, soft magnetic materials are very important materials that are applied to parts of various systems and devices such as rotary electric machines (e.g. motors, generators, etc.), transformers, inductors, transformers, magnetic inks, and antenna devices. is. In these parts, since the real part of magnetic permeability (real part of relative magnetic permeability) μ′ of the soft magnetic material is used, it is preferable to control μ′ according to the frequency band used in actual use. . Also, in order to realize a highly efficient system, it is preferable to use a material with as low a loss as possible. That is, it is preferable to make the imaginary part of magnetic permeability (imaginary part of relative magnetic permeability) μ″ (corresponding to loss) as small as possible. The smaller the μ″ relative to μ′, the smaller the loss factor tan δ, which is preferable. For this purpose, it is preferable to reduce the iron loss under actual operating conditions, namely, eddy current loss, hysteresis It is preferable to minimize loss, ferromagnetic resonance loss, and residual loss (other loss).In order to reduce eddy current loss, electrical resistance may be increased, the size of metal parts may be reduced, and the magnetic domain structure may be reduced. To reduce the hysteresis loss, it is effective to reduce the coercive force and increase the saturation magnetization.To reduce the ferromagnetic resonance loss, , It is effective to increase the ferromagnetic resonance frequency by increasing the anisotropic magnetic field of the material.In addition, in recent years, the demand for handling high-power electric power has increased, so in particular, high current and high voltage For this reason, it is desirable that the saturation magnetization of the soft magnetic material is as large as possible so as not to cause magnetic saturation. In recent years, the use of higher frequency bands for systems and devices has been progressing because higher frequencies have made it possible to downsize devices, and magnetic fields with excellent characteristics, such as high magnetic permeability and low loss at high frequencies, have been developed. There is an urgent need to develop materials.

In recent years, due to the growing awareness of energy conservation and environmental issues, there is a demand to improve system efficiency as much as possible. In particular, since motor systems are responsible for much of the power consumption in the world, it is very important to improve the efficiency of motors. Among them, the core and the like that constitute the motor are made of soft magnetic material, and it is required that the magnetic permeability and saturation magnetization of the soft magnetic material be increased as much as possible, and that the loss be made as small as possible. Also, a magnetic wedge used in a part of the motor is required to have a loss as small as possible. A system using a transformer also requires the same. As for motors and transformers, there is a great demand for miniaturization as well as high efficiency. In order to achieve miniaturization, it is important to increase the magnetic permeability and saturation magnetization of the soft magnetic material as much as possible. Also, in order to prevent magnetic saturation, it is important to increase the saturation magnetization as much as possible. Furthermore, there is a great demand for higher system operating frequencies, and development of low-loss materials in high-frequency bands is required.

Soft magnetic materials with high magnetic permeability and low loss are also used for inductance elements, antenna devices, etc. Among them, in recent years, in particular, attention has been paid to their application to power inductance elements used in power semiconductors. In recent years, the importance of energy saving and environmental protection has been actively advocated, and there has been a demand for reducing _CO2 emissions and reducing dependence on fossil fuels. As a result, development of electric vehicles and hybrid vehicles to replace gasoline vehicles is vigorously advanced. In addition, technology for using natural energy such as solar power generation and wind power generation is said to be a key technology for an energy-saving society, and developed countries are actively promoting the development of technology for using natural energy. Furthermore, as eco-friendly power saving systems, HEMS (Home Energy Management System) and BEMS ( (Building and Energy Management System) The importance of construction has been vigorously advocated. Power semiconductors play an important role in this trend of energy saving. Power semiconductors are semiconductors that control high power and energy with high efficiency.In addition to individual power semiconductors such as IGBTs (insulated gate bipolar transistors), MOSFETs, power bipolar transistors, and power diodes, linear regulators, switching - Includes power supply circuits such as regulators, and power management logic LSIs for controlling these. Power semiconductors are widely used in all types of equipment, including home appliances, computers, automobiles, and railways. Significant market growth is expected. For example, most of the inverters installed in home appliances use power semiconductors, which enables significant energy savings. Power semiconductors are currently mainly made of Si, but the use of SiC and GaN is believed to be effective in achieving higher efficiency and downsizing of devices. SiC and GaN have a larger bandgap and dielectric breakdown field than Si, and can have a higher breakdown voltage, so that the device can be made thinner. Therefore, the on-resistance of the semiconductor can be lowered, which is effective in reducing loss and improving efficiency. In addition, since SiC and GaN have high carrier mobility, it is possible to increase the switching frequency, which is effective in miniaturizing the device. Furthermore, since SiC has a higher thermal conductivity than Si, it has a high heat dissipation capability and can operate at high temperature, which is effective for miniaturization because the cooling mechanism can be simplified. From the above point of view, the development of SiC and GaN power semiconductors is being vigorously pursued. However, in order to realize this, it is essential to develop power inductor elements used with power semiconductors, that is, to develop high permeability soft magnetic materials (high permeability and low loss). At this time, the properties required for the magnetic material are high magnetic permeability and low magnetic loss in the drive frequency band, and high saturation magnetization that can handle a large current is preferable. When the saturation magnetization is high, even if a high magnetic field is applied, magnetic saturation is unlikely to occur, and a decrease in effective inductance value can be suppressed. This improves the DC superposition characteristics of the device and improves the efficiency of the system.

Magnetic materials with high magnetic permeability and low loss at high frequencies are also expected to be applied to devices of high-frequency communication equipment such as antenna devices. As a method to reduce the size and power consumption of the antenna, an insulating substrate with high magnetic permeability (high magnetic permeability and low loss) is used as the antenna substrate, and the radio waves reaching the electronic parts and substrates in the communication equipment from the antenna are involved, and the electronic parts There is also a method of transmitting and receiving without allowing radio waves to reach the substrate. This makes it possible to reduce the size and power consumption of the antenna, and at the same time, it is possible to widen the band of the resonance frequency of the antenna, which is preferable.

Other characteristics required when incorporated into each of the above systems and devices include high thermal stability, high strength, high toughness, and the like. Also, in order to apply to complex shapes, compacts are preferable to plate or ribbon shapes. However, it is generally known that when it is made into a compact, its properties deteriorate in terms of saturation magnetization, magnetic permeability, loss, strength, toughness, hardness, etc. Therefore, it is preferable to improve the properties.

Next, types and problems of existing soft magnetic materials will be described.

An existing soft magnetic material for systems below 10 kHz is silicon steel (FeSi). Silicon steel sheets have a long history and are used for most core materials of rotating electric machines and transformers that handle high power. Improvements in characteristics have been made from non-oriented silicon steel sheets to oriented silicon steel sheets, and progress has been made compared to when they were first discovered, but in recent years, the improvement in characteristics has reached a plateau. As characteristics, it is particularly important to satisfy high saturation magnetization, high magnetic permeability, and low loss at the same time. In the world, studies on materials that surpass silicon steel sheets are being actively conducted, centering on amorphous and nanocrystalline compositions, but no material composition that surpasses silicon steel sheets in all aspects has yet been found. Research is also being conducted on green compacts that can be applied to complex shapes, but green compacts have the disadvantage of being inferior to plates and ribbons in terms of characteristics.

Existing soft magnetic materials for 10 kHz to 100 kHz systems include Sendust (Fe--Si--Al), nanocrystalline Finemet (Fe--Si--B--Cu--Nb), and Fe- or Co-based amorphous glasses. A ribbon, compact, or MnZn-based ferrite material can be used. However, none of them completely satisfy high magnetic permeability, low loss, high saturation magnetization, high thermal stability, high strength, high toughness and high hardness, and are insufficient.

NiZn-based ferrite, hexagonal ferrite, etc. can be cited as existing soft magnetic materials of 100 kHz or higher (MHz band or higher), but their magnetic properties at high frequencies are insufficient.

In view of the above, it is desirable to develop magnetic materials with high saturation magnetization, high magnetic permeability, low loss, high thermal stability, and excellent mechanical properties.

JP 2017-059816 A

The problem to be solved by the present invention is to provide a plurality of flat magnetic metal particles having excellent magnetic properties, and a compacted powder material and rotating electric machine using the same.

A plurality of flat magnetic metal particles according to an embodiment have flat surfaces and a magnetic metal phase containing Fe, Co, and Si and having an average crystal grain size of 1 μm or more . The amount of Co is 0.001 at % or more and 80 at % or less with respect to the total amount of Fe and Co. The amount of Si is 0.001 at % or more and 30 at % or less with respect to the entire magnetic metal phase. The average thickness of the plurality of flat magnetic metal particles is 10 nm or more and 100 μm or less. The average value of the ratio of the average length in the flat plane to the thickness is 5 or more and 10,000 or less. Within the flat plane, there is a coercive force difference depending on the direction.

Further, the plurality of flat magnetic metal particles of the embodiment have flat surfaces and a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and additional elements. The additive element contains B and Hf. The total amount of the additive elements is 0.002 at % or more and 80 at % or less with respect to the entire magnetic metal phase. The average thickness of the plurality of flat magnetic metal particles is 10 nm or more and 100 μm or less. The average value of the ratio of the average length in the flat plane to the thickness is 5 or more and 10,000 or less. Within the flat plane, there is a coercive force difference depending on the direction.

FIG. 4 is a conceptual diagram showing an example of how to determine the thickness of the flat magnetic metal particles of the first embodiment. FIG. 2 is a conceptual diagram for explaining how to obtain the maximum length and the minimum length in the flat plane of the flat magnetic metal particles of the first embodiment. FIG. 4 is a conceptual diagram for explaining how to obtain another example of the maximum length and the minimum length in the flat plane of the flat magnetic metal particles of the first embodiment. FIG. 4 is a schematic diagram showing directions when coercive force is measured by changing the direction every 22.5 degrees with respect to an angle of 360 degrees in the flat plane of the flat magnetic metal particles of the first embodiment. 1 is a graph showing saturation magnetization and coercive force of flat magnetic metal particles having (FeCo) ₉₀ (BHf) ₁₀ composition and (FeCo) ₉₀ (BHfY) ₁₀ composition. 1 is a schematic perspective view of flat magnetic metal particles according to a first embodiment; FIG. FIG. 2 is a schematic view of the flat magnetic metal particles of the first embodiment as viewed from above; FIG. 2 is a schematic diagram of flat magnetic metal particles according to a second embodiment; It is a schematic diagram of the powder material of 3rd Embodiment. FIG. 10 is a schematic diagram showing an angle between a plane parallel to the flat surface of the flat magnetic metal particles and a plane of the compacted powder material in the third embodiment. FIG. 11 is a conceptual diagram of a motor system according to a fourth embodiment; FIG. FIG. 11 is a conceptual diagram of a motor according to a fourth embodiment; FIG. 11 is a conceptual diagram of a motor core (stator) according to a fourth embodiment; FIG. 11 is a conceptual diagram of a motor core (rotor) according to a fourth embodiment; It is a conceptual diagram of the transformer of 4th Embodiment. FIG. 11 is a conceptual diagram of an inductor (ring-shaped inductor, rod-shaped inductor) according to a fourth embodiment; FIG. 11 is a conceptual diagram of an inductor (chip inductor, planar inductor) according to a fourth embodiment; It is a conceptual diagram of the generator of 4th Embodiment. FIG. 2 is a conceptual diagram showing the relationship between the direction of magnetic flux and the arrangement direction of powder material.

Embodiments will be described below with reference to the drawings. In addition, the same or similar reference numerals are attached to the same or similar portions in the drawings.

(First embodiment)
The plurality of flat magnetic metal particles of the present embodiment have flat surfaces and a magnetic metal phase containing Fe, Co, and Si, and the amount of Co is 0.001 at% or more and 80 att with respect to the total amount of Fe and Co. %, the amount of Si is 0.001 at % or more and 30 at % or less with respect to the entire magnetic metal phase, the average thickness of the plurality of flat magnetic metal particles is 10 nm or more and 100 μm or less, and The plurality of flat magnetic metal particles have an average length ratio in the flat plane of 5 or more and 10000 or less, and have a coercive force difference depending on the direction in the flat plane.

Further, the plurality of flat magnetic metal particles of the present embodiment have flat surfaces and a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and an additive element, and the additive The elements include B and Hf, the total amount of the additional elements is 0.002 at% or more and 80 at% or less with respect to the entire magnetic metal phase, and the average thickness of the plurality of flat magnetic metal particles is 10 nm or more and 100 μm or less. and the average value of the ratio of the average length in the flat plane to the thickness is 5 or more and 10000 or less, and the plurality of flat magnetic metal particles have a coercive force difference depending on the direction in the flat plane.

A flat magnetic metal particle is a flaky particle (flattened particle) having a flaky shape (flaky shape, flattened shape).

The thickness refers to the average thickness of one flat magnetic metal particle. Any method can be used to determine the thickness, as long as the method can determine the average thickness of one flat magnetic metal particle. For example, a cross section perpendicular to the flat surface of the flattened magnetic metal particles is observed with a transmission electron microscope (TEM), a scanning electron microscope (SEM), an optical microscope, or the like, and the observed flattened magnetic metal particles It is also possible to use a method of selecting 10 or more arbitrarily selected points in the direction of the flat plane in the cross section, measuring the thickness at each selected point, and adopting the average value. In addition, in the cross section of the observed flat magnetic metal particles, 10 or more points are selected at equal intervals from one end to another end in the direction in the flat plane (at this time, the end and the other end are special (It is preferable not to select this location because it is a difficult location.) Alternatively, a method of measuring the thickness at each selected location and adopting the average value may be used. FIG. 1 is a conceptual diagram showing an example of how to determine the thickness of the flat magnetic metal particles of the first embodiment. FIG. 1 specifically shows how to obtain the thickness in this case. In any case, it is preferable to measure as many points as possible because average information can be obtained. In addition, if the contour line of the cross section is highly uneven or has a rough surface, and it is difficult to obtain an average thickness as it is, the contour line is an average straight line or curve. It is preferable to perform the above method after appropriately smoothing according to the situation.

Also, the average thickness refers to the average value of the thicknesses of a plurality of flat magnetic metal particles, and is distinguished from the mere "thickness" described above. When determining the average thickness, it is preferable to adopt the average value for 20 or more flat magnetic metal particles. In addition, it is preferable to obtain as many flat magnetic metal particles as possible because average information can be obtained. Moreover, when 20 or more flat magnetic metal particles cannot be observed, it is preferable to observe as many flat magnetic metal particles as possible and adopt the average value for them. The average thickness of the flat magnetic metal particles is preferably 10 nm or more and 100 μm or less. It is more preferably 10 nm or more and 1 μm or less, and still more preferably 10 nm or more and 100 nm or less. The flat magnetic metal particles preferably have a thickness of 10 nm or more and 100 μm or less, more preferably 10 nm or more and 1 μm or less, still more preferably 10 nm or more and 100 nm or less. This is preferable because eddy current loss can be sufficiently reduced when a magnetic field is applied in a direction parallel to the flat surface. Also, a smaller thickness is preferable because the magnetic moment is confined in the direction parallel to the flat plane, and the magnetization tends to progress by rotational magnetization. When the magnetization proceeds by rotational magnetization, the magnetization tends to proceed reversibly, so the coercive force is reduced, which is preferable because the hysteresis loss can be reduced.

The average length of the flat magnetic metal particles is defined as (a+b)/2 using the maximum length a and the minimum length b in the flat plane. The maximum length a and minimum length b can be obtained as follows. For example, consider the rectangle with the smallest area among the rectangles circumscribing the flat plane. Then, let the length of the long side of the rectangle be the maximum length a, and the length of the short side be the minimum length b. FIG. 2 is a conceptual diagram for explaining how to determine the maximum length and minimum length in the flat plane of the flat magnetic metal particles of the first embodiment. FIG. 2 is a schematic diagram showing the maximum length a and the minimum length b determined by the above method, taking some flat magnetic metal particles as examples. The maximum length a and the minimum length b can be obtained by observing the flat magnetic metal particles with a TEM, SEM, or an optical microscope, like the average thickness. It is also possible to perform image analysis of the micrograph on a computer and obtain the maximum length a and the minimum length b. In any case, it is preferable to target 20 or more flat magnetic metal particles. In addition, it is preferable to obtain as many flat magnetic metal particles as possible because average information can be obtained. In addition, when 20 or more flat magnetic metal particles cannot be observed, it is preferable to observe as many flat magnetic metal particles as possible and adopt an average value for them. In addition, since it is preferable to obtain an average value as much as possible at this time, in a state where the flat magnetic metal particles are uniformly dispersed (a plurality of flat magnetic metal particles with different maximum lengths and minimum lengths are dispersed as randomly as possible) ), preferably observation or image analysis. For example, a plurality of flat magnetic metal particles are sufficiently mixed and then pasted on the tape, or a plurality of flat magnetic metal particles are dropped from above and dropped down and pasted on the tape, Observation or image analysis is preferably performed by

However, depending on the flat magnetic metal particles, when the maximum length a and the minimum length b are determined by the above method, the method of determination may not capture the essence. FIG. 3 is a conceptual diagram for explaining how to obtain another example of the maximum length and the minimum length in the flat plane of the flat magnetic metal particles of the first embodiment. For example, in the case shown in FIG. 3, the flat magnetic metal particles are elongated and curved. In this case, the maximum and minimum lengths of the flat magnetic metal particles are essentially is the length of a and b shown in . In this way, it is not possible to determine the maximum lengths a and b in a completely unambiguous way. The length of the long side of the rectangle is the maximum length a, and the length of the short side is the minimum length b. It is obtained as the maximum length a and the minimum length b that can capture the essence. The thickness t is defined as the length perpendicular to the flat plane. The ratio A of the average length in the flat plane to the thickness is defined as A=((a+b)/2)/t, with maximum length a, minimum length b, and thickness t.

The average value of the ratio of the average length in the flat plane to the thickness of the flat magnetic metal particles is preferably 5 or more and 10,000 or less. This is because the magnetic permeability increases as a result. Also, since the ferromagnetic resonance frequency can be increased, the ferromagnetic resonance loss can be reduced.

The average value is adopted as the ratio of the average length in the flat plane to the thickness. Preferably, a value averaged for 20 or more flat magnetic metal particles is adopted. In addition, it is preferable to obtain as many flat magnetic metal particles as possible because average information can be obtained. In addition, when 20 or more flat magnetic metal particles cannot be observed, it is preferable to observe as many flat magnetic metal particles as possible and adopt an average value for them. For example, when there are particles Pa, particles Pb, and particles Pc, and their respective thicknesses Ta, Tb, and Tc, and the average lengths in the flat plane La, Lb, and Lc, the average thickness is (Ta+Tb+Tc)/3 and the average value of the ratio of the average length in the flat plane to the thickness is calculated as (La/Ta+Lb/Tb+Lc/Tc)/3.

The flat magnetic metal particles preferably have a coercive force difference depending on the direction within the flat plane. The ratio of the coercive force difference depending on the direction is preferably as large as possible, and is preferably 1% or more. More preferably, the coercive force difference ratio is 10% or more, still more preferably 50% or more, and even more preferably 100% or more. The ratio of the coercive force difference here means (Hc (max) - Hc (min)) using the maximum coercive force Hc (max) and the minimum coercive force Hc (min) in the flat plane. /Hc (min) x 100 (%). The coercive force can be evaluated using a vibrating sample magnetometer (VSM) or the like. If the coercivity is low, coercivities below 0.1 Oe can also be measured by using a low field unit. Measurement is performed by changing the direction in the flat plane with respect to the direction of the measurement magnetic field.

It should be noted that "has a coercive force difference" means the direction in which the coercive force is maximized and the direction in which the coercive force is minimized when a magnetic field is applied in the 360-degree direction in the flat plane and the coercive force is measured. and exist. For example, when the coercive force is measured by changing the direction every 22.5 degrees with respect to the angle of 360 degrees in the flat plane, the coercive force difference appears, that is, the angle at which the coercive force becomes larger and the coercive force If there appears an angle at which is smaller than , it shall be said to "has a coercive force difference". FIG. 4 is a schematic diagram showing the direction when the coercive force is measured by changing the direction every 22.5 degrees with respect to the angle of 360 degrees in the flat plane in the flat magnetic metal particles of the first embodiment. It is a diagram. By having a coercive force difference in the flat plane, the minimum coercive force value is smaller than in an isotropic case where there is almost no coercive force difference, which is preferable. A material having magnetic anisotropy in a flat plane has a difference in coercive force depending on the direction in the flat plane, and the minimum coercive force value is smaller than that of a magnetically isotropic material. This reduces the hysteresis loss and improves the magnetic permeability, which is preferable.

Coercive force is related to magnetocrystalline anisotropy, Hc=αHa-NMs (Hc: coercive force, Ha: magnetocrystalline anisotropy, Ms: saturation magnetization, α, N: changes depending on value). That is, generally, the larger the crystal magnetic anisotropy, the larger the coercive force, and the smaller the crystal magnetic anisotropy, the smaller the coercive force. However, the α and N values in the above approximation are values that vary greatly depending on the composition, structure, and shape of the material. or a large N value), the coercive force becomes a relatively large value even if the magnetocrystalline anisotropy is small (if the α value is large or the N value is small). In other words, the magnetocrystalline anisotropy is a property unique to a substance determined by the composition of the material, but the coercive force is a property that is not determined only by the composition of the material and can vary greatly depending on the structure, shape, and the like. The magnetocrystalline anisotropy is not a factor that directly affects the hysteresis loss, but it is a factor that affects it indirectly. (corresponding to ), it is a factor that almost directly determines the magnitude of the hysteresis loss. That is, the coercive force can be said to be a very important factor that directly greatly affects the hysteresis loss, unlike the magnetocrystalline anisotropy.

Further, even if the flat magnetic metal particles have magnetic anisotropy including magnetocrystalline anisotropy, it does not necessarily mean that a coercive force difference occurs depending on the flat surface direction of the flat magnetic metal particles. This is because, as described above, the coercive force is not a value uniquely determined by magnetocrystalline anisotropy, but is a characteristic that varies depending on the composition, structure, and shape of the material. As described above, the factor that directly and greatly affects the hysteresis loss is not the magnetic anisotropy but the coercive force. From the above, a very preferable condition for achieving high characteristics is "to have a coercive force difference depending on the direction in the flat plane". This reduces the hysteresis loss and increases the magnetic permeability, which is preferable.

The average ratio a/b of the maximum length a to the minimum length b in the flat plane is preferably 2 or more, more preferably 3 or more, still more preferably 5 or more, still more preferably 10 or more. Preferably, the ratio a/b of the maximum length a to the minimum length b in the flat plane is 2 or more, more preferably 3 or more, more preferably 5 or more, and still more preferably 10 or more. preferably included. This makes it easier to impart magnetic anisotropy, which is desirable. When magnetic anisotropy is imparted, a coercive force difference is generated within the flat surface, and the minimum coercive force value becomes smaller than that of a magnetically isotropic material. This reduces the hysteresis loss and improves the magnetic permeability, which is preferable. More preferably, in the flat magnetic metal particles, the first direction of one or both of a plurality of concave portions and a plurality of convex portions, which will be described later, is arranged in the maximum length direction. In addition, when the flat magnetic metal particles are compacted, the a/b of the flat magnetic metal particles is large, so the area (or area ratio) where the flat surfaces of the individual flat magnetic metal particles overlap becomes large, and the powder compact The strength of is increased, which is preferable. Moreover, a larger ratio of the maximum length to the minimum length is preferable because the magnetic moment is confined in the direction parallel to the flat plane, and the magnetization tends to progress by rotational magnetization. When the magnetization proceeds by rotational magnetization, the magnetization tends to proceed reversibly, so the coercive force is reduced, which is preferable because the hysteresis loss can be reduced. On the other hand, from the viewpoint of increasing strength, the ratio a/b of the maximum length a to the minimum length b in the flat plane is preferably 1 or more and less than 2 on average, more preferably 1 or more and 1 More preferably less than 0.5. This is desirable because it improves the fluidity and filling properties of the particles. In addition, compared to the case where a/b is large, the strength in the direction perpendicular to the flat plane is increased, which is preferable from the viewpoint of increasing the strength of the flat magnetic metal particles. Furthermore, when the particles are compacted, the particles are less likely to be bent and compacted, and the stress on the particles is likely to be reduced. In other words, strain is reduced, coercive force and hysteresis loss are reduced, and stress is reduced, so mechanical properties such as thermal stability, strength, and toughness are likely to be improved.

In addition, it is preferable to use a flat surface having at least a part of the contour shape with a corner. For example, contour shapes such as squares and rectangles, in other words, corner angles of approximately 90 degrees are desirable. These degrade the symmetry of the atomic arrangement at the corners and constrain the electron trajectories.

On the other hand, from the viewpoint of low loss and high strength, it is desirable that the contour shape of the flat surface is formed by a rounded curve. As an extreme example, it is desirable to have a rounded contour such as a circle or an ellipse. These desirably improve the abrasion resistance of the particles. Moreover, it is desirable that stress is less likely to be concentrated around the contour shape, magnetic distortion of the flat magnetic metal particles is reduced, coercive force is lowered, and hysteresis loss is reduced. Since stress concentration is reduced, mechanical properties such as thermal stability and strength and toughness are easily improved, which is desirable.

The flat magnetic metal particles desirably have a magnetic metal phase containing Fe, Co and Si. This case will be described in detail below. In the magnetic metal phase, the amount of Co is preferably 0.001 at% or more and 80 at% or less, more preferably 1 at% or more and 60 at% or less, still more preferably, with respect to the total amount of Fe and Co. is preferably 5 at % or more and 40 at % or less, more preferably 10 at % or more and 20 at % or less. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. Also, the Fe—Co system is preferable because it is easy to realize high saturation magnetization. Furthermore, it is preferable that the composition range of Fe and Co is within the above range because higher saturation magnetization can be realized. In addition, the amount of Si is preferably 0.001 at % or more and 30 at % or less, more preferably 1 at % or more and 25 at % or less, and still more preferably 5 at % or more and 20 at %, with respect to the entire magnetic metal phase. % or less. As a result, the magnetocrystalline anisotropy can be appropriately increased, the coercive force can be easily reduced, and low hysteresis loss and high magnetic permeability can be easily realized, which is preferable.

When the magnetic metal phase is a system containing Fe, Co, and Si, and the amount of Co and the amount of Si are within the above ranges, the anisotropy-imparting effect is particularly large. Express. Compared to the monoatomic system of Fe or Co, the diatomic system of Fe and Si, or the diatomic system of Fe and Co, in the triatomic system of Fe, Co and Si, the magnetic anisotropy is particularly moderate. It is easy to impart a large amount, and the coercive force becomes small, thereby reducing the hysteresis loss and improving the magnetic permeability, which is preferable. This great effect is especially brought about only within the above composition range. Further, when the composition of Fe, Co, and Si is within the above composition range, the thermal stability and oxidation resistance are remarkably improved, which is preferable. Moreover, since the thermal stability and oxidation resistance are improved, the mechanical properties at high temperatures are also improved, which is preferable. Furthermore, mechanical properties at room temperature such as strength, hardness and wear resistance are improved, which is preferable. Further, when synthesizing the flat magnetic metal particles, a ribbon is synthesized by a roll quenching method or the like, and when the ribbon is pulverized to obtain the flat magnetic metal particles, the magnetic metal phase includes Fe, Co and Si. and the amount of Co and the amount of Si are within the above ranges, it is particularly easy to pulverize, thereby realizing a state in which the flat magnetic metal particles are relatively unlikely to be strained. It is possible and preferable. If the flat magnetic metal particles are less likely to be distorted, the coercive force is likely to be reduced, and low hysteresis loss and high magnetic permeability are likely to be achieved, which is preferable. Further, when the strain is small, the stability over time is improved, the thermal stability is improved, and the mechanical properties such as strength, hardness and wear resistance are excellent, which is preferable.

The average crystal grain size of the magnetic metal phase is preferably 1 μm or more, more preferably 10 μm or more, still more preferably 50 μm or more, still more preferably 100 μm or more. preferable. When the average crystal grain size of the magnetic metal phase is increased, the ratio of the surface of the magnetic metal phase is decreased, so that the number of pinning sites is decreased, which is preferable because the coercive force is decreased and the hysteresis loss is decreased. Further, when the average crystal grain size of the magnetic metal phase is large within the above range, the magnetic anisotropy is likely to be moderately large, and the above magnetic properties are improved, which is preferable.

In particular, when the magnetic metal phase is a system containing Fe, Co, and Si, the amount of Co and the amount of Si are within the ranges described above, and the average crystal grain size of the magnetic metal phase is If it falls within the above range, the magnetic anisotropy tends to be moderately large, and the above magnetic properties are remarkably improved, which is more preferable. In particular, the magnetic metal phase is a system containing Fe, Co, and Si, and the amount of Co is 5 at% or more and 40 at% or less, more preferably 10 at% or more and 20 at% or less, relative to the total amount of Fe and Co. and the amount of Si is 1 at % or more and 25 at % or less, more preferably 5 at % or more and 20 at % or less with respect to the entire magnetic metal phase, and the average crystal grain size of the magnetic metal phase is 10 μm or more, When the thickness is more preferably 50 μm or more, more preferably 100 μm or more, a moderately large magnetic anisotropy tends to be imparted, and the above magnetic properties are particularly significantly improved, which is more preferred.

The magnetic metal phase preferably has a portion having a body-centered cubic (bcc) crystal structure. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. In addition, even with a “bcc and fcc mixed phase crystal structure” partially having a crystal structure of a face-centered cubic structure (fcc), a moderately large magnetic anisotropy is likely to be imparted, and the above magnetic properties are improved. preferred because

Further, it is preferable that the flat surfaces of the flat magnetic metal particles are substantially crystalline. As the orientation direction, (110) plane orientation is preferable. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. A more preferable orientation direction is the (110) [111] direction. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. The crystal planes of the flat planes of the flat magnetic metal particles are such that crystal planes other than (110) and (220) (for example, (200), (211), (310), (222), etc.) are (110). On the other hand, the peak intensity ratio measured by XRD (X-ray diffraction method) is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved.

In order to (110)-orientate the flat planes of the flat magnetic metal particles, it is effective to select appropriate heat treatment conditions. The heat treatment temperature is preferably set to 800° C. or higher and 1200° C. or lower, more preferably 850° C. or higher and 1100° C. or lower, still more preferably 900° C. or higher and 1000° C. or lower, still more preferably 920° C. or higher and 980° C. or lower (around 940° C. is preferred). If the heat treatment temperature is too low or too high, the (110) orientation hardly progresses, and the heat treatment temperature within the above range is most preferable. The heat treatment time is preferably 10 minutes or longer, more preferably 1 hour or longer, and still more preferably about 4 hours. If the heat treatment time is too short or too long, the (110) orientation is unlikely to proceed, and a heat treatment time of about 4 hours is most preferable. The heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, more preferably a reducing atmosphere such as H ₂ (hydrogen), CO (carbon monoxide), CH ₄ (methane), or the like. is preferred. This is preferable because the oxidation of the flat magnetic metal particles can be suppressed and the oxidized portions can be reduced. By selecting the above heat treatment conditions, the (110) orientation is likely to progress, and crystal planes other than (110) and (220) (for example, (200), (211), (310), (222) etc.) can be 10% or less, further 5% or less, further 3% or less relative to (110) in peak intensity ratio measured by XRD (X-ray diffraction method). Moreover, strain can be removed appropriately, and a state in which oxidation is suppressed (reduced state) can be realized, which is preferable.

Further, the flat magnetic metal particles preferably have a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and an additional element. This case will be described in detail below. More preferably, the additive element contains B and Hf. Further, the total amount of the additive elements is preferably 0.002 at % or more and 80 at % or less, more preferably 5 at % or more and 80 at % or less, still more preferably 5 at %, based on the entire magnetic metal phase. % or more and 40 at % or less, more preferably 10 at % or more and 40 at % or less. This is preferable because it promotes amorphization, makes it easier to impart magnetic anisotropy, and improves the above magnetic properties. In addition, the amount of Hf is preferably 0.001 at % or more and 40 at % or less, more preferably 1 at % or more and 30 at % or less, and still more preferably 1 at % or more and 20 at %, based on the entire magnetic metal phase. %, more preferably 1 at % or more and 15 at % or less, even more preferably 1 at % or more and 10 at % or less. This is preferable because it promotes amorphization, makes it easier to impart magnetic anisotropy, and improves the above magnetic properties.

In addition, when the magnetic metal phase is a system containing the first element and B and Hf as the additive elements, and the total amount of the additive elements and the amount of Hf are within the above ranges, In particular, a large effect is exhibited with respect to the above-mentioned anisotropy-imparting effect. This great effect is especially brought about only within the above composition range. In addition, compared to systems containing other additive elements, in systems containing Hf in particular, even a small amount of Hf facilitates amorphization, easily imparts magnetic anisotropy, and achieves both high saturation magnetization and high saturation magnetization. easy and preferable. Further, Hf has a high melting point, and when it is contained in the magnetic metal phase in the above amount range, thermal stability and oxidation resistance are remarkably improved, which is preferable. Moreover, since the thermal stability and oxidation resistance are improved, the mechanical properties at high temperatures are also improved, which is preferable. Furthermore, mechanical properties at room temperature such as strength, hardness and wear resistance are improved, which is preferable. Further, when synthesizing the flat magnetic metal particles, a ribbon is synthesized by a roll quenching method or the like, and when the flat magnetic metal particles are obtained by pulverizing the ribbon, the magnetic metal phase contains the first element and B and Hf as the additive elements, and when the total amount of the additive elements and the amount of Hf are within the above ranges, it is particularly easy to be pulverized relatively easily. This is preferable because a state in which the flat magnetic metal particles are relatively resistant to distortion can be achieved. If the flat magnetic metal particles are less likely to be distorted, the coercive force is likely to be reduced, and low hysteresis loss and high magnetic permeability are likely to be achieved, which is preferable. In addition, when the distortion is small, the stability over time is improved, the thermal stability is improved, and the mechanical properties such as strength, hardness and wear resistance are excellent, which is preferable.

Further, when the magnetic metal phase is a system containing the first element and B and Hf as the additive elements, and the total amount of the additive elements and the amount of Hf are within the above ranges, Since the thermal stability is excellent, it is possible to set the optimum heat treatment conditions for the flat magnetic metal particles to high values. That is, in the method for producing flat magnetic metal particles, it is preferable to synthesize a ribbon, subject the obtained ribbon to heat treatment (or not), pulverize the ribbon, and then perform heat treatment to remove distortion. (More preferably, heat treatment in a magnetic field is preferable.) At this time, the heat treatment temperature can be set relatively high. This makes it easier to release the strain, making it easier to realize a low-strain, low-loss material. For example, heat treatment at 500 ° C. or higher makes it easier to achieve low-loss materials (low-loss can be achieved at higher heat treatment temperatures than other systems and compositions. For other systems and compositions, for example, about 400 ° C. is optimal. heat treatment temperature).

The additive element preferably contains one or more "another different element" in addition to B and Hf. "Another different element" includes C, Ta, W, P, N, Mg, Al, Si, Ca, Zr, Ti, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V , Nb, Pb, Cu, In, Sn, and rare earth elements are preferred, and among these, rare earth elements are more preferred, and Y is even more preferred. By containing "another different element", the diffusion of the element contained in the magnetic metal phase is effectively suppressed, the amorphization progresses, the magnetic anisotropy is easily imparted, and the It is preferable (because low coercive force, low hysteresis loss, and high magnetic permeability can be easily realized). In particular, when the "different element" has an atomic radius different from that of B and Hf, the diffusion of the element contained in the magnetic metal phase is effectively suppressed. For example, since Y has a larger atomic radius than B and Hf, it can very effectively suppress the diffusion of elements contained in the magnetic metal phase. An appropriate composition range will be described below, taking as an example the case where "another different element" is Y. The amount of Y is preferably 1 at% or more and 80 at% or less, more preferably 2 at% or more and 60 at% or less, still more preferably 4 at% or more and 60 at% or less, with respect to the total amount of Hf and Y. Further, the total amount of Hf and Y is preferably 0.002 at % or more and 40 at % or less, more preferably 1 at % or more and 30 at % or less, still more preferably 1 at %, based on the entire magnetic metal phase. % or more and 20 at % or less, more preferably 1 at % or more and 15 at % or less, still more preferably 1 at % or more and 10 at % or less. This is preferable because it promotes amorphization, makes it easier to impart magnetic anisotropy, and improves the above magnetic properties. By falling within the above compositional range, the above-mentioned anisotropy-imparting effect, in particular, is significantly greater than when only B and Hf are added. This remarkably large effect is produced especially only within the above composition range. In addition, even in a small amount, amorphization is likely to proceed, magnetic anisotropy is likely to be imparted, and coexistence with high saturation magnetization is likely to be achieved, which is preferable. In FIG. 5, this effect will be described using a specific example. FIG. 5 is a graph showing the saturation magnetization and coercive force of flat magnetic metal particles of (FeCo) ₉₀ (BHf) ₁₀ composition and (FeCo) ₉₀ (BHfY) ₁₀ composition. From this figure, it can be seen that by adding Y to the FeCo--BHf system to form an FeCo--BHfY system, the coercive force is remarkably lowered at the same saturation magnetization. That is, it becomes easier to achieve both low coercive force (which enables low hysteresis loss and high magnetic permeability) and high saturation magnetization. FIG. 5 is only an example, but by appropriately selecting the composition of the system to which Y is added, it is possible to achieve characteristics that cannot be achieved with the BHf system. Moreover, thermal stability and oxidation resistance are remarkably improved, which is preferable. Moreover, since the thermal stability and oxidation resistance are improved, the mechanical properties at high temperatures are also improved, which is preferable. Furthermore, mechanical properties at room temperature such as strength, hardness and wear resistance are improved, which is preferable.

Also, the average crystal grain size of the magnetic metal phase is preferably 100 nm or less, more preferably 50 nm or less, still more preferably 20 nm or less, still more preferably 10 nm or less. The smaller, the better, more preferably 5 nm or less, and still more preferably 2 nm or less. This is preferable because it facilitates imparting anisotropy and improves the above magnetic properties. In addition, since the crystal grain size is small means that it is close to amorphous, the electrical resistance is higher than that of the highly crystalline one, which is preferable because the eddy current loss is easily reduced. In addition, it is preferable because it is superior in terms of corrosion resistance and oxidation resistance as compared with those with high crystallinity.

In addition, the additive element contains one or more "another different element (for example, Y)" in addition to B and Hf, the amount of "another different element (for example, Y)", and the amount of "another different element (for example, Y)" is within the above range, the average crystal grain size of 30 nm or less can be achieved relatively easily, which is preferable. That is, since it is closer to amorphous, the electrical resistance is higher than that of a highly crystalline one, which is preferable because eddy current loss is easily reduced. In addition, it is preferable because it is superior in terms of corrosion resistance and oxidation resistance as compared with those with high crystallinity. It is also preferable because it facilitates imparting anisotropy and improves the above magnetic properties.

In particular, when the magnetic metal phase is a system containing the first element and B and Hf as the additive elements, and the total amount of the additive elements and the amount of Hf are within the above ranges. And when the average crystal grain size of the magnetic metal phase falls within the above range, the magnetic properties are improved by the effect of imparting magnetic anisotropy, the electrical resistance is increased by making it amorphous (reduced eddy current loss), the corrosion resistance is high, The effect of high oxidation resistance is remarkably improved, which is more preferable. Among them, in particular, the magnetic metal phase is a system containing the first element and B and Hf as the additive elements, and the total amount of the additive elements is 5 at % or more with respect to the entire magnetic metal phase. It is 40 at% or less, more preferably 10 at% or more and 40 at% or less, and the Hf amount is 1 at% or more and 20 at% or less, still more preferably 1 at% or more and 15 at% or less, still more preferably 1 at% or more with respect to the entire magnetic metal phase. When the content is 10 at % or less and the average crystal grain size of the magnetic metal phase is 50 nm or less, preferably 20 nm or less, and further preferably 10 nm or less, magnetic properties are improved by the effect of imparting magnetic anisotropy. Amorphization is more preferable because the effects of high electric resistance (reduction of eddy current loss), high corrosion resistance, and high oxidation resistance are significantly improved.

The crystal grain size of 100 nm or less can be easily calculated by Scherrer's formula by XRD measurement. It can also be determined by averaging the particle sizes. When the crystal grain size is small, it is preferable to determine by XRD measurement, and when the crystal grain size is large, it is preferable to determine by TEM observation. It is preferable to make a comprehensive judgment based on

The flat magnetic metal particles preferably have a high saturation magnetization, preferably 1 T or more, more preferably 1.5 T or more, still more preferably 1.8 T or more, and still more preferably 2.0 T or more. is preferably Magnetic saturation is suppressed by this, and it is possible to sufficiently exhibit the magnetic properties on the system, which is preferable. However, depending on the application (for example, magnetic wedges in motors), even a relatively small saturation magnetization can be used satisfactorily, and it is rather preferable to specialize in low loss. The magnetic wedge of the motor is like a lid for the slot into which the coil is inserted. Normally, a non-magnetic wedge is used, but by using a magnetic wedge, the density of the magnetic flux can be reduced. , harmonic losses are reduced and motor efficiency is improved. At this time, it is preferable that the saturation magnetization of the magnetic wedge is large, but a sufficient effect can be obtained even with a relatively small saturation magnetization. Therefore, it is important to select the composition according to the application.

The lattice strain of the flat magnetic metal particles is preferably 0.01% or more and 10% or less, more preferably 0.01% or more and 5% or less, still more preferably 0.01% or more and 1% or less, and still more preferably 0.01%. % or more and 0.5% or less. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved.

The lattice strain can be calculated by detailed analysis of line widths obtained by X-ray diffraction (XRD). That is, by performing Halder-Wagner plots and Hall-Williamson plots, the contribution of line width broadening can be separated into grain size and lattice strain. Lattice strain can be calculated from this. Halder-Wagner plots are preferred from the standpoint of reliability. Regarding Halder-Wagner plots, see, for example, N. C. Halder, C. N. J. Wagner, Acta Cryst. 20 (1966) 312-313. Please refer to Etc. Here, the Halder-Wagner plot is represented by the following formula.

That is, plotting β ² /tan ² θ on the vertical axis and β/tan θ sin θ on the horizontal axis, the grain size D is calculated from the slope of the approximate straight line, and the lattice strain ε is calculated from the intercept on the vertical axis. Lattice strain (lattice strain (root mean square)) by Halder-Wagner plot of the above formula is 0.01% or more and 10% or less, more preferably 0.01% or more and 5% or less, still more preferably 0.01% or more 1 %, more preferably 0.01% or more and 0.5% or less, the magnetic anisotropy is likely to be moderately large, and the above magnetic properties are improved, which is preferable.

The above lattice strain analysis is an effective method when multiple peaks can be detected by XRD. is difficult. In such a case, it is preferable to calculate the lattice strain in the following procedure. First, the composition is determined by high-frequency inductively coupled plasma (ICP) emission analysis, energy dispersive X-ray spectroscopy (EDX), etc., and magnetic metal elements Fe, Co, Ni, three Calculate the composition ratio (if there are only two magnetic metal elements, there are two composition ratios; if there is only one magnetic metal element, there is one composition ratio (=100%)). Next, the ideal lattice spacing d ₀ is calculated from the Fe—Co—Ni composition (see literature values, etc. In some cases, an alloy with that composition is produced and the lattice spacing is calculated by measurement). . After that, the strain amount can be obtained by obtaining the difference between the lattice spacing d of the peak of the measured sample and the ideal lattice spacing _d0 . That is, in this case, the distortion amount is calculated as (d−d ₀ )/d ₀ ×100(%). As described above, it is preferable to use the above two methods for the analysis of the lattice strain depending on the state of the peak intensity, and to evaluate using both methods in some cases.

The lattice spacing in the flat plane has a difference depending on the direction, and the ratio of the difference between the maximum lattice spacing d _max and the minimum lattice spacing d _min (=(d _max −d _min )/d _min ×100 (%) ) is preferably 0.01% or more and 10% or less, more preferably 0.01% or more and 5% or less, still more preferably 0.01% or more and 1% or less, still more preferably 0.01% or more and 0.5% It is preferable to: This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. The lattice spacing can be easily obtained by XRD measurement. By performing this XRD measurement while changing the direction in the plane, the difference in lattice constant depending on the direction can be obtained.

It is preferable that the crystallites of the flat magnetic metal particles are either strung together in one direction within the flat plane, or the crystallites are rod-shaped and oriented in one direction within the flat plane. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved.

The flat surfaces of the flat magnetic metal particles preferably have one or both of a plurality of concave portions and a plurality of convex portions arranged in the first direction and having a width of 0.1 μm or more, a length of 1 μm or more, and an aspect ratio of 2 or more. . As a result, magnetic anisotropy is easily induced in the first direction, and the difference in coercive force depending on the direction in the flat plane is increased, which is preferable. From this point of view, it is more preferable that the width is 1 μm or more and the length is 10 μm or more. The aspect ratio is preferably 5 or more, more preferably 10 or more. In addition, by providing such recesses or protrusions, the adhesion between the flat magnetic metal particles is improved when the flat magnetic metal particles are compacted to synthesize the dust material (the recesses or protrusions are formed between the particles). bring about an anchoring effect that sticks together), which is preferable because it improves mechanical properties such as strength and hardness and thermal stability.

FIG. 6 is a schematic perspective view of flat magnetic metal particles according to the first embodiment. In the upper diagram of FIG. 6, only the concave portion is provided, and in the central diagram of FIG. 6, only the convex portion is provided. You may have both. FIG. 7 is a schematic diagram of the flat magnetic metal particles of the first embodiment as viewed from above. The width and length of the recesses or protrusions and the distance between the recesses or protrusions are indicated. One flat magnetic metal particle may have both recesses and protrusions. The aspect ratio of the concave portion or convex portion is the length of the major axis/the length of the minor axis. That is, if the length is greater (longer) than the width of the recess or protrusion, the aspect ratio is defined as length/width, and if the width is greater (longer) than the length, the aspect ratio is width/length. defined by The larger the aspect ratio, the easier it is to have uniaxial anisotropy (anisotropy) magnetically, which is more preferable. In FIG. 7, concave portions 2a, convex portions 2b, flat surfaces 6, and flat magnetic metal particles 10 are shown.

Moreover, "arranged in the first direction" means that the longer of the length and width of the concave portion or the convex portion is arranged in parallel with the first direction. In addition, if the longer of the length and width of the concave portion or the convex portion is arranged within ±30 degrees from the direction parallel to the first direction, it is considered to be "arranged in the first direction". These are preferable because the flat magnetic metal particles tend to have magnetically uniaxial anisotropy in the first direction due to the shape magnetic anisotropy effect. The flat magnetic metal particles preferably have magnetic anisotropy in one direction within the flat plane, which will be described in detail. First, when the magnetic domain structure of the flat magnetic metal particles is a multi-domain structure, the magnetization process proceeds by domain wall motion. Loss (hysteresis loss) is reduced. Also, the magnetic permeability in the easy axis direction is higher than that in the hard axis direction. In addition, compared with isotropic flat magnetic metal particles, flat magnetic metal particles having magnetic anisotropy have a smaller coercive force particularly in the easy axis direction, which is preferable because the loss is smaller. . Moreover, the magnetic permeability is also increased, which is preferable. That is, by having magnetic anisotropy in the flat plane direction, magnetic properties are improved compared to isotropic materials. In particular, the easy-axis direction in the flat plane is preferable to the hard-axis direction because the magnetic properties are superior. Next, when the magnetic domain structure of the flat magnetic metal particles is a single magnetic domain structure, the magnetization process proceeds by rotating magnetization. smaller and less loss. When the magnetization progresses completely by rotational magnetization, the coercive force becomes zero and the hysteresis loss becomes zero, which is preferable. Whether the magnetization proceeds by domain wall motion (domain wall motion type) or by rotating magnetization (rotary magnetization type) is determined by whether the magnetic domain structure is a multi-domain structure or a single domain structure. . At this time, whether a multi-domain structure or a single-domain structure is determined by the size (thickness and aspect ratio) and composition of the flattened magnetic metal particles, the state of interaction between the particles, and the like. For example, the smaller the thickness t of the flattened magnetic metal particles, the easier it is to have a single domain structure. As for the composition, the single domain structure can be easily maintained even if the thickness is large in the composition with large crystal magnetic anisotropy, and the single domain structure can be maintained in the composition with small crystal magnetic anisotropy unless the thickness is small. tends to be difficult. In other words, the boundary thickness between the single-domain structure and the multi-domain structure varies depending on the composition. In addition, when flat magnetic metal particles are magnetically coupled to each other to stabilize the magnetic domain structure, a single magnetic domain structure is likely to occur. Whether the magnetization behavior is domain wall displacement type or rotational magnetization type can be easily determined as follows. First, in the material plane (the plane parallel to the flat surface of the flat magnetic metal particle), magnetization is measured by changing the direction in which the magnetic field is applied. 90 degrees to each other). Next, by comparing the curves in the two directions, it is possible to distinguish between the domain wall displacement type and the rotational magnetization type.

As described above, the flat magnetic metal particles preferably have magnetic anisotropy in one direction within the flat plane. By having one or both of a plurality of concave portions and a plurality of convex portions each having a length of 1 μm or more and an aspect ratio of 2 or more, magnetic anisotropy is easily induced in the first direction, which is more preferable. From this point of view, it is preferable that the width is 1 μm or more and the length is 10 μm or more. The aspect ratio is preferably 5 or more, more preferably 10 or more. In addition, by providing such recesses or protrusions, the adhesion between the flat magnetic metal particles is improved when the flat magnetic metal particles are compacted to synthesize the dust material (the recesses or protrusions are formed between the particles). bring about an anchoring effect that sticks together), which is preferable because it improves mechanical properties such as strength and hardness and thermal stability.

Moreover, in the flat magnetic metal particles, it is preferable that the first direction of one or both of the plurality of concave portions and the plurality of convex portions having the largest number is arranged in the magnetization easy axis direction. That is, in the flat surface of the flat magnetic metal particles, when there are many arrangement directions (= first direction), the arrangement direction (= first direction) with the largest number among the many arrangement directions (= first direction) direction) coincides with the easy axis direction of the flattened magnetic metal particles. The length direction in which the recesses or protrusions are arranged, that is, the first direction, is likely to be the axis of easy magnetization due to the effect of shape magnetic anisotropy. is easily imparted, which is preferable.

One or both of the plurality of concave portions and the plurality of convex portions is desirably included in one flat magnetic metal particle at least five on average. Here, five or more concave portions may be included, five or more convex portions may be included, or the sum of the number of concave portions and the number of convex portions may be five or more. In addition, more preferably, it is desirable to include 10 or more. Moreover, it is desirable that the average distance in the width direction between the recesses or protrusions is 0.1 μm or more and 100 μm or less. Furthermore, a plurality of deposited metals containing at least one of the first elements selected from the group consisting of Fe, Co and Ni and having an average size of 1 nm or more and 1 μm or less are arranged along the recesses or protrusions. It is desirable that The method for determining the average size of the deposited metal is calculated by averaging the sizes of a plurality of deposited metals arranged along the concave or convex portions based on observation with a TEM, SEM, optical microscope, or the like. . Satisfying these conditions is preferable because magnetic anisotropy is easily induced in one direction. In addition, the adhesion between the flat magnetic metal particles is improved when the flat magnetic metal particles are compacted to synthesize the compacted powder material (the recesses or protrusions bring about an anchoring effect that sticks the particles together). , strength, hardness and other mechanical properties and thermal stability are improved.

It is desirable that the flat magnetic metal particles further include a plurality of magnetic metal small particles, 5 or more on average, on the flat surface. The magnetic metal small particles contain at least one first element selected from the group consisting of Fe, Co and Ni, and have an average particle diameter of 10 nm or more and 1 μm or less. More preferably, the small magnetic metal particles have the same composition as the flat magnetic metal particles. By providing the small magnetic metal particles on the surface of the flat surface, or by integrating the small magnetic metal particles with the flat magnetic metal particles, the surface of the flat magnetic metal particles is slightly roughened in a pseudo manner. As a result, the adhesion when compacting the flat magnetic metal particles together with the intervening phase, which will be described later, is greatly improved. This makes it easier to improve mechanical properties such as thermal stability, strength and toughness. In order to maximize such an effect, the average particle size of the small magnetic metal particles should be 10 nm or more and 1 μm or less, and five or more magnetic metal small particles on average should be formed on the surface of the flat magnetic metal particles, i.e., It is desirable to integrate it into a flat surface. It is more preferable to arrange the small magnetic metal particles in one direction within the flat plane, because magnetic anisotropy is likely to be imparted within the flat plane, and high magnetic permeability and low loss can be easily realized. The average particle diameter of the magnetic metal small particles is determined by observation with a TEM, SEM, optical microscope, or the like.

The variation in particle size distribution of flat magnetic metal particles can be defined by a coefficient of variation (CV value). That is, CV value (%)=[standard deviation of particle size distribution (μm)/average particle size (μm)]×100. It can be said that the smaller the CV value, the smaller the variation in particle size distribution and the sharper the particle size distribution. When the CV value defined above is 0.1% or more and 60% or less, it is preferable because low coercive force, low hysteresis loss, high magnetic permeability, and high thermal stability can be achieved. In addition, since there is little variation, it is easy to achieve a high yield. A more preferable CV value range is 0.1% or more and 40% or less.

One effective method for imparting a coercive force difference depending on the direction within the flat surface of the flat magnetic metal particles is to apply heat treatment in a magnetic field. It is desirable to perform the heat treatment while applying a magnetic field in one direction within the flat surface. It is desirable to search for the direction of the easy axis in the flat plane (search for the direction in which the coercive force is the smallest) before performing the heat treatment in the magnetic field, and perform the heat treatment while applying the magnetic field in that direction. It is preferable that the magnetic field to be applied is as large as possible, but it is preferable to apply 1 kOe or more, more preferably 10 kOe or more. This is preferable because magnetic anisotropy can be expressed in the flat planes of the flat magnetic metal particles, a coercive force difference depending on the direction can be imparted, and excellent magnetic properties can be realized. The heat treatment is preferably performed at a temperature of 50°C or higher and 800°C or lower. The heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, more preferably H ₂ (hydrogen), CO (carbon monoxide), CH ₄ (methane), or the like. is preferably under a reducing atmosphere. The reason for this is that even if the flat magnetic metal particles are oxidized, heat treatment in a reducing atmosphere can reduce the oxidized metal and return it to metal. As a result, the flat magnetic metal particles whose saturation magnetization has been reduced due to oxidation can be reduced to restore their saturation magnetization. If the crystallization of the flat magnetic metal particles progresses significantly due to the heat treatment, the characteristics deteriorate (increase in coercive force and decrease in magnetic permeability), so the conditions are selected to suppress excessive crystallization. preferably.

Further, when synthesizing the flat magnetic metal particles, when synthesizing a ribbon by a roll quenching method or the like and pulverizing the ribbon to obtain the flat magnetic metal particles, a plurality of concave portions and a plurality of convex portions are formed when synthesizing the ribbon. are likely to be arranged in the first direction (concave portions and convex portions are likely to be formed in the rotation direction of the roll), and this facilitates having a coercive force difference depending on the direction within the flat surface, which is preferable. That is, the direction in which one or both of the plurality of concave portions and the plurality of convex portions in the flat plane are arranged in the first direction tends to be the direction of the axis of easy magnetization, and in the flat plane, the coercive force difference depending on the direction becomes effective. Given and preferred.

According to this embodiment, it is possible to provide flat magnetic metal particles having excellent magnetic properties such as low magnetic loss.

(Second embodiment)
In the plurality of flat magnetic metal particles of the present embodiment, at least part of the surface of the flat magnetic metal particles has a thickness of 0.1 nm or more and 1 μm or less, and contains oxygen (O), carbon (C), nitrogen (N) and fluorine. It differs from the first embodiment in that it is covered with a coating layer containing at least one second element selected from the group consisting of (F).

In addition, the description of the content which overlaps with 1st Embodiment is abbreviate|omitted.

FIG. 8 is a schematic diagram of flat magnetic metal particles according to the second embodiment. A covering layer 9 is shown.

The coating layer is Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, At least one second metal selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F), containing at least one non-magnetic metal selected from the group consisting of rare earth elements It is more preferable to contain elements. As the non-magnetic metal, Al and Si are particularly preferable from the viewpoint of thermal stability. Flat magnetic metal particles are Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn , when containing at least one non-magnetic metal selected from the group consisting of rare earth elements, the coating layer contains at least one non-magnetic metal that is the same as the non-magnetic metal that is one of the components of the flattened magnetic metal particles. is more preferred. Among oxygen (O), carbon (C), nitrogen (N) and fluorine (F), it preferably contains oxygen (O), and is preferably an oxide or composite oxide. The above is from the viewpoint of ease of coating layer formation, oxidation resistance, and thermal stability. As described above, the adhesion between the flat magnetic metal particles and the coating layer can be improved, and the thermal stability and oxidation resistance of the compacted powder material, which will be described later, can be improved. The coating layer can improve not only the thermal stability and oxidation resistance of the flat magnetic metal particles, but also the electrical resistance of the flat magnetic metal particles. By increasing the electrical resistance, it is possible to suppress eddy current loss and improve the frequency characteristic of magnetic permeability. Therefore, the coating layer 14 preferably has a high electrical resistance, for example, a resistance value of 1 mΩ·cm or more.

The presence of the coating layer is also preferable from the magnetic point of view. A flat magnetic metal particle can be regarded as a pseudo-thin film because its thickness is smaller than the size of its flat surface. At this time, the flat magnetic metal particles formed with a coating layer on their surfaces and integrated can be regarded as a pseudo laminated thin film structure, and the magnetic domain structure is energetically stabilized. This makes it possible to reduce the coercive force (thereby reducing the hysteresis loss), which is preferable. At this time, the magnetic permeability is also increased, which is preferable. From such a point of view, it is more preferable that the coating layer is non-magnetic (the magnetic domain structure is easily stabilized).

From the viewpoint of thermal stability, oxidation resistance, and electrical resistance, the thicker the coating layer, the better. However, if the thickness of the coating layer is too thick, the saturation magnetization will decrease and the magnetic permeability will also decrease, which is not preferable. Also, from a magnetic point of view, if the thickness is too thick, the "effect of stabilizing the magnetic domain structure to reduce the coercive force, reduce the loss, and increase the magnetic permeability" is reduced. Considering the above, the thickness of the coating layer is preferably 0.1 nm or more and 1 μm or less, more preferably 0.1 nm or more and 100 m or less.

As described above, according to the present embodiment, it is possible to provide flat magnetic metal particles having excellent properties such as high magnetic permeability, low loss, excellent mechanical properties, and high thermal stability.

(Third Embodiment)

The dust material of the present embodiment has a flat surface and a magnetic metal phase containing Fe, Co, and Si, and the amount of Co is 0.001 at% or more and 80 at% or less with respect to the total amount of Fe and Co. The amount of Si is 0.001 at% or more and 30 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the ratio of the average length in the flat surface to the thickness is present between a plurality of flat magnetic metal particles whose average value is 5 or more and 10000 or less, and the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F) and an intervening phase containing at least one second element selected from, wherein the flattened planes of the compacted material are oriented parallel to the planes of the compacted material, It is a dust material having a coercive force difference depending on the direction in the plane.

Further, the dust material of the present embodiment has a flat surface and a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and an additive element, and the additive element is B and Hf are included, the total amount of the additive element is 0.002 at% or more and 80 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the flat surface with respect to the thickness exists between a plurality of flat magnetic metal particles having an average length ratio of 5 or more and 10000 or less, and oxygen (O), carbon (C), nitrogen (N) and fluorine (F) an intervening phase containing at least one second element selected from the group consisting of: It is a powder material that is oriented parallel to the plane and has a coercive force difference depending on the direction in the plane.

The composition, average crystal grain size, and crystal orientation (approximately (110) orientation) of the magnetic metal phase should preferably satisfy the requirements described in the first embodiment. Description is omitted.

In addition, the saturation magnetization of the dust material is preferably high, preferably 0.2 T or more, more preferably 0.5 T or more, 1.0 T or more, further preferably 1.8 T or more, More preferably, it is 2.0 T or more. Magnetic saturation is suppressed by this, and it is possible to sufficiently exhibit the magnetic properties on the system, which is preferable. However, depending on the application (for example, magnetic wedges in motors), even a relatively small saturation magnetization can be used satisfactorily, and it is rather preferable to specialize in low loss. Therefore, it is important to select the composition according to the application.

FIG. 9 is a schematic diagram of the compacted powder material of the third embodiment. The intervening phase 20, the compacted material 100, and the flat surface 102 of the compacted material are shown. The figure shown on the right side of FIG. 9 is a schematic diagram in which hatching is removed from the figure shown on the left side of FIG. 9 in order to make the intervening phase easier to see.

Orientation is defined as the angle between the plane parallel to the flat surface of the flat magnetic metal particles and the flat surface of the dust material is closer to 0 degree. FIG. 10 is a schematic diagram showing an angle between a plane parallel to the flat surface of the flat magnetic metal particles and a plane of the compacted powder material in the third embodiment. The above angles are obtained for a number of 10 or more flat magnetic metal particles, and the average value thereof is preferably 0 degrees or more and 45 degrees or less, more preferably 0 degrees or more and 30 degrees or less, and still more preferably 0 degrees or more and 10 degrees or less. It is desirable to have That is, in the dust material, it is preferable that the flat surfaces of the plurality of flat magnetic metal particles are oriented parallel to each other or in layers so as to be nearly parallel to each other. This is preferable because the eddy current loss of the dust material can be reduced. Moreover, since the demagnetizing field can be reduced, the magnetic permeability of the dust material can be increased, which is preferable. Moreover, since the ferromagnetic resonance frequency can be increased, the ferromagnetic resonance loss can be reduced, which is preferable. Furthermore, such a laminated structure is preferable because the magnetic domain structure is stabilized and a low magnetic loss can be realized.

In the case of measuring the coercive force depending on the direction within the plane of the dust material (the plane parallel to the flat plane of the flat magnetic metal particles), for example, 22. for an angle of 360 degrees within the plane. The coercive force is measured by changing the direction every 5 degrees.

By having a coercive force difference in the plane of the powder material, the minimum coercive force value is preferably smaller than in the isotropic case where there is almost no coercive force difference. A material having in-plane magnetic anisotropy has a difference in coercive force depending on the in-plane direction, and the minimum coercive force value is smaller than that of a magnetically isotropic material. As a result, the hysteresis loss is reduced and the magnetic permeability is improved, which is preferable.

Within the plane of the dust material (inside the plane parallel to the flat plane of the flat magnetic metal particles), the ratio of the coercive force difference depending on the direction is preferably as large as possible, and is preferably 1% or more. More preferably, the coercive force difference ratio is 10% or more, still more preferably 50% or more, and even more preferably 100% or more. The ratio of the coercive force difference here means (Hc (max) - Hc (min)) using the maximum coercive force Hc (max) and the minimum coercive force Hc (min) in the flat plane. /Hc (min) x 100 (%).

The coercive force can be easily evaluated using a vibrating sample magnetometer (VSM) or the like. If the coercivity is low, coercivities below 0.1 Oe can also be measured by using a low field unit. Measurement is performed by changing the direction of the measurement magnetic field within the plane of the dust material (the plane parallel to the flat plane of the flat magnetic metal particles).

When calculating the coercive force, a value obtained by dividing the difference between the magnetic fields of two points (magnetic fields H1 and H2 where the magnetization becomes zero) that intersects the horizontal axis by 2 can be used (that is, the coercive force = |H2- H1|/2).

From the viewpoint of imparting magnetic anisotropy, it is preferable that the magnetic metal particles are arranged with the maximum length direction aligned. Whether or not the maximum length direction is aligned is determined by observing the magnetic metal particles contained in the dust material with a TEM, SEM, or an optical microscope, and obtaining the angle formed by the maximum length direction and an arbitrarily determined reference line. Judgment is made based on the degree of variation. Preferably, it is preferable to determine the average degree of variation for 20 or more flat magnetic metal particles, but if 20 or more flat magnetic metal particles cannot be observed, as many flat magnetic metal particles as possible It is preferable to observe the magnetic metal particles and judge the average degree of dispersion for them. In this specification, when the degree of variation is within the range of ±30°, it is said that the maximum length directions are aligned. The degree of variation is more preferably within the range of ±20°, more preferably within the range of ±10°. This is desirable because it facilitates imparting magnetic anisotropy to the compacted powder material. More preferably, the first direction of one or both of the plurality of concave portions and the plurality of convex portions on the flat surface is arranged in the maximum length direction. This is desirable because a large magnetic anisotropy can be imparted.

In the compacted powder material, it is preferable that the "arrangement ratio" in which the approximate first direction is arranged in the second direction is 30% or more. More desirably, it is 50% or more, and still more desirably 75% or more. As a result, the magnetic anisotropy is moderately increased, and the magnetic properties are improved as described above, which is preferable. First, for all the flat magnetic metal particles to be evaluated in advance, the direction in which the arrangement direction of the recesses or protrusions of each flat magnetic metal particle occupies the largest number is defined as the first direction, and the first direction of each flat magnetic metal particle However, the second direction is defined as the direction in which the largest number of particles are arranged in the compacted powder material as a whole. Next, directions are determined by dividing the angle of 360 degrees with respect to the second direction at intervals of 45 degrees. Next, the direction of which angle the first direction of each flat magnetic metal particle is arranged closest to is classified, and that direction is defined as an "approximate first direction." That is, it is classified into one of four directions of 0 degrees, 45 degrees, 90 degrees, and 135 degrees. The proportion of the approximate first direction being arranged in the same direction as the second direction is defined as the “arrangement ratio”. When evaluating this "arrangement ratio", four adjacent flat magnetic metal particles are selected in order, and the four are evaluated. By repeating this at least three times or more (more is better, preferably 5 times or more, more preferably 10 times or more), the average value is adopted as the arrangement ratio. A flat magnetic metal particle in which the direction of the concave portion or the convex portion cannot be determined is excluded from the evaluation, and the adjacent flat magnetic metal particle is evaluated. For example, in flat magnetic metal particles obtained by pulverizing a ribbon synthesized by a single-roll quenching apparatus, only one flat surface has recesses or protrusions, and the other flat surface often does not have recesses or protrusions. When such flat magnetic metal particles are observed with an SEM, even if a flat surface with no recesses or protrusions is visible on the observation screen, it is possible that the probability is about half (in this case as well, in fact, the A flat surface should have concave or convex portions, but it is excluded in the above evaluation).

In addition, it is preferable that the most approximate first directions are arranged in the magnetization easy axis direction of the dust material. That is, it is preferable that the axis of easy magnetization of the dust material is parallel to the second direction. The longitudinal direction in which the recesses or protrusions are arranged tends to be the axis of easy magnetization due to the effect of shape magnetic anisotropy. and is preferable.

A portion of the intervening phase is preferably attached along the first direction. In other words, it is preferable that part of the intervening phase adheres along the direction of the recesses or protrusions on the flat surfaces of the flat magnetic metal particles. This makes it easier to induce magnetic anisotropy in one direction, which is preferable. In addition, the adhesion of such an intervening phase is preferable because it improves the adhesion between the flat magnetic metal particles, thereby improving mechanical properties such as strength and hardness and thermal stability. Moreover, it is preferable that the intervening phase contains a particulate one. As a result, the adhesion between the flat magnetic metal particles is maintained in an appropriate state, and the distortion is reduced (there is a particulate intervening phase between the flat magnetic metal particles, so that the voltage applied to the flat magnetic metal particles stress is relieved), coercive force can be easily reduced (hysteresis loss is reduced, magnetic permeability is increased), which is preferable.

The intervening phase preferably contains 0.01 wt% or more and 80 wt% or less, more preferably 0.1 wt% or more and 60 wt% or less, and still more preferably 0.1 wt% or more and 40 wt% or less with respect to the entire green compact material. If the proportion of the intervening phase is too large, the proportion of the flat magnetic metal particles responsible for magnetism becomes small, which is not preferable because the saturation magnetization and magnetic permeability of the compacted powder material become small. Conversely, if the ratio of the intervening phase is too small, the bonding between the flat magnetic metal particles and the intervening phase becomes weak, which is undesirable from the viewpoint of mechanical properties such as thermal stability and strength/toughness. From the viewpoint of magnetic properties such as saturation magnetization and magnetic permeability, thermal stability, and mechanical properties, the optimum ratio of the intervening phase is 0.01 wt% or more and 80 wt% or less, more preferably 0 wt% or less, relative to the entire powder material. .1 wt % or more and 60 wt % or less, more preferably 0.1 wt % or more and 40 wt % or less.

Moreover, the lattice mismatch ratio between the intervening phase and the flat magnetic metal particles is preferably 0.1% or more and 50% or less. This is preferable because a moderately large magnetic anisotropy tends to be imparted and the above magnetic properties are improved. Setting the lattice mismatch within the above range can be achieved by selecting a combination of the composition of the intervening phase and the composition of the flat magnetic metal particles 10 . For example, fcc structure Ni has a lattice constant of 3.52 Å, and NaCl structure MgO has a lattice constant of 4.21 Å, and the lattice mismatch between the two is (4.21−3.52)/3.52×100 = 20%. That is, the lattice mismatch can be set to 20% by making the main composition of the flat magnetic metal particles fcc-structured Ni and the intervening phase 20 of MgO. Thus, by selecting a combination of the main composition of the flattened magnetic metal particles and the main composition of the intervening phase, it is possible to set the lattice mismatch within the above range.

The intervening phase contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F). This is because the resistance can be increased thereby. The electrical resistivity of the intervening phase is preferably higher than that of the flat magnetic metal particles. This is because the eddy current loss of the flat magnetic metal particles can be reduced. Since the intervening phase surrounds the flat magnetic metal particles, it is possible to improve the oxidation resistance and thermal stability of the flat magnetic metal particles, which is preferable. Among these, those containing oxygen are more preferable from the viewpoint of high oxidation resistance and high thermal stability. The intervening phase also plays a role of mechanically bonding the flat magnetic metal particles to each other, so it is also preferable from the viewpoint of high strength.

In addition, the intervening phase is "an oxide having a eutectic system", "containing a resin", "containing at least one magnetic metal selected from Fe, Co and Ni", or at least one of these three You may have one. These points will be explained below.

First, the first case "when the intervening phase is an oxide having a eutectic system" will be described. In this case, the intervening phases are B (boron), Si (silicon), Cr (chromium), Mo (molybdenum), Nb (niobium), Li (lithium), Ba (barium), Zn (zinc), La (lanthanum ), P (phosphorus), Al (aluminum), Ge (germanium), W (tungsten), Na (sodium), Ti (titanium), As (arsenic), V (vanadium), Ca (calcium), Bi (bismuth) ), Pb (lead), Te (tellurium), and Sn (tin). In particular, it preferably contains a eutectic system containing at least two elements of B, Bi, Si, Zn and Pb. This strengthens the adhesion between the flat magnetic metal particles and the intervening phase (increases the bonding strength), making it easier to improve mechanical properties such as thermal stability, strength, and toughness.

The softening point of the eutectic oxide is preferably 200° C. or higher and 600° C. or lower, more preferably 400° C. or higher and 500° C. or lower. More preferably, it is an oxide having a eutectic system containing at least two elements selected from B, Bi, Si, Zn, and Pb, and has a softening point of 400° C. or higher and 500° C. or lower. As a result, the bonding between the flat magnetic metal particles and the oxide having the eutectic system is strengthened, and mechanical properties such as thermal stability, strength and toughness are easily improved. When the flat magnetic metal particles are integrated together with the oxide having the eutectic system, they are integrated while being heat treated at a temperature near the softening point of the oxide having the eutectic system, preferably at a temperature slightly higher than the softening point. By converting the flat magnetic metal particles to the oxide having the eutectic system, the adhesion between the flat magnetic metal particles and the oxide having the eutectic system can be improved, and the mechanical properties can be improved. In general, the higher the temperature of the heat treatment, the better the adhesion between the flat magnetic metal particles and the oxide having the eutectic system, and the better the mechanical properties. However, if the temperature of the heat treatment is too high, the coefficient of thermal expansion increases, and the adhesion between the flat magnetic metal particles and the oxide having the eutectic system may decrease (flat magnetic metal particles and the thermal expansion coefficient of the oxide having the eutectic system, the adhesion may be further reduced). In addition, when the crystallinity of the flat magnetic metal particles is amorphous or non-crystalline, if the heat treatment temperature is high, crystallization proceeds and the coercive force increases, which is not preferable. Therefore, in order to achieve both mechanical properties and coercive force properties, the softening point of the oxide having the eutectic system is set to 200° C. or higher and 600° C. or lower, more preferably 400° C. or higher and 500° C. or lower. It is preferable to unify while heat-treating at a temperature near the softening point of the oxide having a eutectic system, preferably at a temperature slightly higher than the softening point. Moreover, when the integrated material is actually used in a device or system, it is preferable to use a temperature lower than the softening point.

Moreover, the oxide having the eutectic system desirably has a glass transition point. Furthermore, it is desirable that the oxide having the eutectic system has a thermal expansion coefficient of 0.5×10 ⁻⁶ /° C. or more and 40×10 ⁻⁶ /° C. or less. As a result, the bonding between the flat magnetic metal particles 10 and the oxide having the eutectic system is strengthened, and mechanical properties such as thermal stability, strength, and toughness are easily improved.

It is more preferable to include at least one particulate (preferably spherical) eutectic particle having a particle size of 10 nm or more and 10 μm or less. The eutectic particles comprise the same materials as the above eutectic oxides except in particulate form. Voids may also partially exist in the compacted material, and it is easy to observe that some of the oxides having the eutectic system are present in the form of particles, preferably in the form of spheres. can do. Particulate or spherical interfaces can be easily discerned even in the absence of voids. The particle diameter of the eutectic particles is more preferably 10 nm or more and 1 μm, and still more preferably 10 nm or more and 100 nm or less. As a result, the strain applied to the flat magnetic metal particles can be reduced and the coercive force can be reduced by moderately relaxing the stress while maintaining the adhesion between the flat magnetic metal particles during the heat treatment. . This also reduces hysteresis loss and improves magnetic permeability. The particle size of the eutectic particles can be measured by TEM or SEM observation. In the scanning electron micrograph of FIG. 28 described above, it can be seen that a plurality of spherical eutectic particles composed of the intervening phase are present.

In addition, the intervening phase has a softening point higher than that of the oxide having the eutectic system, more preferably higher than 600° C., O (oxygen), C (carbon), N ( It is preferable to further include intermediate intervening particles containing at least one element selected from the group consisting of nitrogen) and F (fluorine). The existence of the intermediate intervening particles between the flat magnetic metal particles can prevent the flat magnetic metal particles from thermally fusing together and degrading the properties when the powder material is exposed to high temperatures. That is, the presence of intermediate intervening particles is desirable primarily for thermal stability. The softening point of the intermediate intervening particles is higher than the softening point of the oxide having the eutectic system, and more preferably the softening point is 600° C. or higher, so that the thermal stability can be further enhanced. .

Intermediate particles include Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn , containing at least one non-magnetic metal selected from the group consisting of rare earth elements, and at least one element selected from the group consisting of O (oxygen), C (carbon), N (nitrogen) and F (fluorine) preferably included. Oxygen-containing oxides or composite oxides are more preferred from the viewpoint of high oxidation resistance and high thermal stability. In particular, oxides such as aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₃ ), and complex oxides such as Al—Si—O are high. It is preferable from the viewpoint of oxidation resistance and high thermal stability.

As a method for producing a powder material containing intermediate intervening particles, for example, flat magnetic metal particles and intermediate intervening particles (aluminum oxide (Al ₂ O ₃ ) particles, silicon dioxide (SiO ₂ ) particles, titanium oxide (TiO ₂ ) particles, zirconium oxide (ZrO ₃ ) particles, etc.) are mixed by a ball mill or the like to create a dispersed state, and then integrated by press molding or the like. The method of dispersing is not particularly limited as long as it is a method capable of dispersing appropriately.

Next, the second case where the intervening phase contains a resin will be described. In this case, the resin is not particularly limited, but polyester resin, polyethylene resin, polystyrene resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl alcohol resin, polybutadiene resin, Teflon (registered trademark, polytetrafluoroethylene). ) resin, polyurethane resin, cellulose resin, ABS resin, nitrile-butadiene rubber, styrene-butadiene rubber, silicone resin, other synthetic rubber, natural rubber, epoxy resin, phenol resin, allyl resin, polybenzimidazole resin , amide resins, polyimide resins, polyamide-imide resins, or copolymers thereof are used. In particular, in order to achieve high thermal stability, it is preferable to contain silicone resin or polyimide resin having high heat resistance. As a result, the bonding between the flat magnetic metal particles and the intervening phase is strengthened, and mechanical properties such as thermal stability, strength and toughness are likely to be improved.

The resin preferably has a weight loss rate of 5% or less, more preferably 3% or less, still more preferably 1% or less, and still more preferably 0.1% or less after being heated at 180° C. for 3000 hours in an air atmosphere. is preferably In addition, the weight loss rate after heating at 220° C. for 200 hours in an air atmosphere is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less, and still more preferably 0.1% or less. is preferably In addition, the weight loss rate after heating at 250° C. for 200 hours in an air atmosphere is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less, and still more preferably 0.1% or less. In addition, evaluation of these weight reduction rates is performed using materials in an unused state. An unused state is a state in which it has been molded and ready for use, and has not been exposed to heat (for example, heat at a temperature of 40 degrees or more), chemicals, sunlight (ultraviolet rays), etc. be. The weight reduction rate shall be calculated from the mass before and after heating by the following formula: Weight reduction rate (%) = [mass before heating (g) - mass after heating (g)] / mass before heating (g )×100. Moreover, it is preferable that the strength after heating at 180° C. for 20000 hours in an air atmosphere is half or more of the strength before heating. More preferably, the strength after heating at 220° C. for 20,000 hours in an air atmosphere is at least half the strength before heating. Moreover, it is preferable to satisfy the H type specified by Japanese Industrial Standards (JIS). In particular, it is preferable to satisfy heat resistance to withstand a maximum temperature of 180°C. More preferably, it satisfies the H class specified by the Japanese National Railways Standards (JRE). In particular, it is preferable to satisfy heat resistance that can withstand a temperature rise of 180° C. relative to the ambient temperature (standard: 25° C., maximum: 40° C.). Preferred resins for this include polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, aromatic polyimide, aromatic polyamide, aromatic polyamideimide, polybenzoxazole, fluororesin, silicone resin, and liquid crystal polymer. These resins are preferable because they have high intermolecular cohesive force and high heat resistance. Among them, aromatic polyimides and polybenzoxazoles are preferable because they have a high proportion of rigid units in the molecule and therefore have higher heat resistance. Moreover, it is preferable that it is a thermoplastic resin. The above definition of weight loss rate upon heating, definition of strength, and definition of resin type are effective for enhancing the heat resistance of the resin. In addition, when a compacted powder material composed of a plurality of flat magnetic metal particles and an intervening phase (here, resin) is formed by these, the heat resistance as a compacted powder material is increased (thermal stability is increased), and high temperature ( For example, after exposure to the above 200° C. or 250° C.) or at high temperatures (for example, the above 200° C. or 250° C.), mechanical properties such as strength and toughness are easily improved, which is preferable. In addition, since many intervening phases surround the flat magnetic metal particles even after heating, they are excellent in oxidation resistance, and deterioration of magnetic properties due to oxidation of the flat magnetic metal particles is less likely to occur, which is preferable.

In addition, the powder material preferably has a weight loss rate of 5% or less after heating at 180° C. for 3000 hours, more preferably 3% or less, more preferably 1% or less, and still more preferably 0.1% or less. is preferably In addition, the powder material preferably has a weight loss rate of 5% or less after heating at 220° C. for 3000 hours, more preferably 3% or less, still more preferably 1% or less, and still more preferably 0.1% or less. is preferably In addition, the weight reduction rate of the compacted material after heating at 250 ° C. for 200 hours in an air atmosphere is preferably 5% or less, more preferably 3% or less, further preferably 1% or less, and still more preferably 0%. .1% or less is preferable. The evaluation of the weight reduction rate is the same as in the case of the above resins. Further, it is preferable that the strength of the powder material after heating at 180° C. for 20000 hours in an air atmosphere is half or more of the strength before heating. More preferably, the strength of the powder material after heating at 220° C. for 20,000 hours in an air atmosphere is half or more of the strength before heating. Moreover, it is preferable to satisfy the H type specified by the Japanese Industrial Standards (JIS). In particular, it is preferable to satisfy heat resistance to withstand a maximum temperature of 180°C. More preferably, it satisfies the H class specified by the Japanese National Railways Standards (JRE). In particular, it is preferable to satisfy heat resistance that can withstand a temperature rise of 180° C. relative to the ambient temperature (standard: 25° C., maximum: 40° C.). The above definition of the heating weight reduction rate, the definition of the strength, and the above definition of the resin type are effective for increasing the heat resistance of the compacted powder material, and a highly reliable material can be realized. In addition, the heat resistance as a powder material is increased (thermal stability is increased), and after exposure to high temperatures (for example, 200 ° C. or 250 ° C. above), or at high temperatures (for example, 200 ° C. or 250 ° C. above) mechanical properties such as strength and toughness are likely to be improved, which is preferable. In addition, since many intervening phases surround the flat magnetic metal particles even after heating, they are excellent in oxidation resistance, and deterioration of magnetic properties due to oxidation of the flat magnetic metal particles is less likely to occur, which is preferable.

Furthermore, it preferably contains a crystalline resin that does not have a glass transition point up to the thermal decomposition temperature. Also, it preferably contains a resin having a glass transition temperature of 180° C. or higher, and more preferably contains a resin having a glass transition temperature of 220° C. or higher. More preferably, it contains a resin having a glass transition temperature of 250° C. or higher. In general, flat magnetic metal particles have a larger crystal grain size as the heat treatment temperature increases. Therefore, when it is necessary to reduce the crystal grain size of the flat magnetic metal particles, it is preferable that the glass transition temperature of the resin to be used is not too high, specifically 600° C. or less. In addition, the crystalline resin that does not have a glass transition point up to the thermal decomposition temperature preferably contains a resin with a glass transition temperature of 180°C or higher, more preferably a resin with a glass transition temperature of 220°C or higher. Specifically, it preferably contains a polyimide having a glass transition temperature of 180° C. or higher, more preferably contains a polyimide having a glass transition temperature of 220° C. or higher, and more preferably contains a thermoplastic polyimide. . As a result, fusion to the magnetic metal particles is facilitated, and it is particularly suitable for powder compaction. Examples of thermoplastic polyimides include thermoplastic aromatic polyimides, thermoplastic aromatic polyamideimides, thermoplastic aromatic polyetherimides, thermoplastic aromatic polyesterimides, thermoplastic aromatic polyimidesiloxanes, etc., which have imide bonds in their polymer chains. It is preferable to have Among them, when the glass transition temperature is 250° C. or higher, the heat resistance becomes higher, which is preferable.

（１）
化学式（１）中、Ｒはビフェニル、トリフェニル、テトラフェニルのいずれかの構造、Ｒ’は構造内に少なくとも１つ以上の芳香環を有する構造を示す。 Aromatic polyimides and polybenzoxazoles have a planar structure in which aromatic rings and heterocyclic rings are directly bonded, and are immobilized by π-π stacking, resulting in high heat resistance. This can increase the glass transition temperature and improve the thermal stability. In addition, it is preferable that a desired glass transition point can be easily adjusted by appropriately introducing a bending unit such as an ether bond into the molecular structure. Among them, it is preferable from the viewpoint of strength that the benzene ring structure of the acid anhydride-derived unit constituting the imide polymer is any one of biphenyl, triphenyl, and tetraphenyl structures. The symmetrical structure between imide groups, which affects heat resistance, is not impaired, and orientation extends over long distances, improving material strength. A preferred aromatic polyimide structure for this purpose is represented by the following chemical formula (1). In other words, the polyimide resin of this embodiment contains a repeating unit represented by the following chemical formula (1).

(1)
In chemical formula (1), R is a biphenyl, triphenyl or tetraphenyl structure, and R' is a structure having at least one or more aromatic rings in the structure.

When obtaining the properties (weight reduction rate, type of resin, glass transition temperature, molecular structure, etc.) of the intervening phase (here, resin) that is a component of the powder material, only the resin part is removed from the powder material. Cut out and perform various property evaluations. If it is not possible to visually determine whether the particles are resin or not, the magnetic metal particles are distinguished from the resin using elemental analysis using EDX or the like.

The larger the content of the resin in the whole dust material, the more the polymer that wets (covers) the flat magnetic metal particles and the polymer that wets (covers) the adjacent flat magnetic metal particles. The polymer can connect the gaps without difficulty, and mechanical properties such as strength are improved. Moreover, the electric resistivity is also increased, and the eddy current loss of the powder material can be reduced, which is preferable. On the other hand, the higher the resin content, the lower the ratio of the flat magnetic metal particles, which lowers the saturation magnetization and magnetic permeability of the dust material, which is not preferable. In order to achieve a well-balanced material that comprehensively considers mechanical properties such as strength, electrical resistivity/eddy current loss, saturation magnetization, and magnetic permeability, the content of resin in the entire dust material is 93 wt % or less, more preferably 86 wt % or less, more preferably 2 wt % or more and 67 wt % or less, still more preferably 2 wt % or more and 43 wt % or less. The content of the flat magnetic metal particles is preferably 7 wt % or more, more preferably 14 wt % or more, still more preferably 33 wt % or more and 98 wt % or less, and still more preferably 57 wt %. It is preferable that it is more than 98 wt% or less. In addition, when the particle diameter of the flat magnetic metal particles becomes small, the surface area increases and the amount of resin required increases dramatically. As a result, the dust material can be made to have a high saturation magnetization, and the magnetic permeability can be increased, which is advantageous for miniaturization and high output of the system.

Next, the third case where the intervening phase contains at least one magnetic metal selected from Fe, Co and Ni and has magnetism will be described. In this case, when the intervening phase has magnetism, the flat magnetic metal particles are easily magnetically coupled to each other, which is preferable because the magnetic permeability is improved. Moreover, since the magnetic domain structure is stabilized, the frequency characteristic of magnetic permeability is also improved, which is preferable. The term "magnetism" as used herein means ferromagnetism, ferrimagnetism, weak magnetism, antiferromagnetism, and the like. In particular, ferromagnetism and ferrimagnetism are preferred because the magnetic coupling strength increases. The magnetism of the intervening phase can be evaluated using a VSM (Vibrating Sample Magnetometer) or the like. The fact that the intervening phase contains at least one magnetic metal selected from Fe, Co, and Ni and has magnetism can be easily examined using EDX or the like.

Three modes of the intervening phase have been described above, but it is preferable that at least one of the three modes is satisfied, but two or more, or even all three, may be satisfied. "When the intervening phase is an oxide having a eutectic system" (first case) is slightly inferior to the case where the intervening phase is a resin (second case), although mechanical properties such as strength are slightly inferior. On the other hand, it is very excellent and preferable from the viewpoint that the strain is easily released, and in particular, the reduction in coercive force is easily progressed (this makes it easy to realize low hysteresis loss and high magnetic permeability, which is preferable). . In addition, it is preferable because it often has higher heat resistance than resin and is excellent in thermal stability. Conversely, in the case where the intervening phase contains a resin (the second case), the adhesion between the flat magnetic metal particles and the resin is high, so stress is likely to be applied (strain is likely to occur), and this leads to retention. Although there is a drawback that the magnetic force tends to increase, it is preferable because it is extremely excellent in terms of mechanical properties such as strength. In the case where "the intervening phase contains at least one magnetic metal selected from Fe, Co, and Ni and has magnetism" (third case), flat magnetic metal particles are more likely to be magnetically coupled to each other. In particular, it is preferable because it is extremely excellent in terms of high magnetic permeability and low coercive force (hence low hysteresis loss). Based on the above advantages and disadvantages, it is possible to use them properly or combine several to create a well-balanced product.

It is desirable that the flat magnetic metal particles contained in the dust material satisfy the requirements described in the first and second embodiments. Since the content is duplicated here, the description is omitted.

In the dust material, it is preferable that the flat surfaces of the plurality of flat magnetic metal particles are oriented in layers so as to be parallel to each other. This is preferable because the eddy current loss of the dust material can be reduced. Moreover, since the demagnetizing field can be reduced, the magnetic permeability of the dust material can be increased, which is preferable. Moreover, since the ferromagnetic resonance frequency can be increased, the ferromagnetic resonance loss can be reduced, which is preferable. Furthermore, such a laminated structure is preferable because the magnetic domain structure is stabilized and a low magnetic loss can be realized. Here, it is defined that the closer the angle between the flat surface of the flat magnetic metal particles and the flat surface of the compacted material is to 0 degree, the more the particles are oriented. Specifically, the average value of the above-described angles obtained for a large number of 10 or more flat magnetic metal particles 10 is preferably 0 degrees or more and 45 degrees or less, more preferably 0 degrees or more and 30 degrees or less, and still more preferably 0 degrees. It is desirable that the angle is between 10 degrees and 10 degrees.

The dust material may have a laminated structure comprising a magnetic layer containing the flat magnetic metal particles and an intermediate layer containing any one of O, C and N. In the magnetic layer, the flat magnetic metal particles are preferably oriented (orientated so that their flat surfaces are parallel to each other). Further, it is preferable that the magnetic permeability of the intermediate layer is lower than the magnetic permeability of the magnetic layer. These measures are preferable because a pseudo thin film laminated structure can be realized and the magnetic permeability in the layer direction can be increased. Moreover, in such a structure, since the ferromagnetic resonance frequency can be increased, the ferromagnetic resonance loss can be reduced, which is preferable. Furthermore, such a laminated structure is preferable because the magnetic domain structure is stabilized and a low magnetic loss can be realized. In order to further enhance these effects, it is more preferable to make the magnetic permeability of the intermediate layer smaller than the magnetic permeability of the intervening phase (the intervening phase in the magnetic layer). This is preferable because the magnetic permeability in the layer direction can be further increased in the pseudo thin film laminated structure. Moreover, since the ferromagnetic resonance frequency can be further increased, the ferromagnetic resonance loss can be reduced, which is preferable.

As described above, according to the present embodiment, it is possible to provide a dust material having excellent magnetic properties such as low magnetic loss.

(Fourth embodiment)
The system and device apparatus of this embodiment have the compacted material of the third embodiment. Therefore, the description of the contents overlapping with those of the first to third embodiments is omitted. The parts made of dust material included in this system and device include, for example, rotating electric machines such as various motors and generators (for example, motors, generators, etc.), cores such as transformers, inductors, transformers, choke coils, filters, etc. and magnetic wedges for rotating electric machines. FIG. 11 is a conceptual diagram of the motor system of the fourth embodiment. A motor system is an example of a rotating electric machine system. A motor system is a system including a control system that controls the number of revolutions and power (output power) of a motor. Methods for controlling the number of revolutions of the motor include control methods using a bridge servo circuit, proportional current control, voltage comparison control, frequency synchronization control, PLL (Phase Locked Loop) control, and the like. As an example, FIG. 11 shows a control method using a PLL. A motor system for controlling the number of revolutions of a motor by means of a PLL includes a motor, a rotary encoder that converts mechanical displacement of the rotation of the motor into an electrical signal to detect the number of revolutions of the motor, and a motor given by a command. It comprises a phase comparator that compares the number of revolutions and the number of revolutions of the motor detected by the rotary encoder and outputs the difference between the number of revolutions, and a controller that controls the motor so as to reduce the difference in the number of revolutions. On the other hand, methods for controlling the power of the motor include PWM (Pulse Width Modulation) control, PAM (Pulse Amplitude Modulation) control, vector control, pulse control, bipolar drive, pedestal control, resistance There is a control method by control, etc. Other control methods include microstep drive control, polyphase drive control, inverter control, switching control, and the like. As an example, FIG. 11 shows a control method using an inverter. A motor system that controls the power of a motor by an inverter is controlled by an AC power supply, a rectifier that converts the output of the AC power supply into a DC current, an inverter circuit that converts the DC current into an AC of any frequency, and the AC. and a motor.

FIG. 12 shows a conceptual diagram of the motor of the fourth embodiment. Motor 200 is an example of a rotating electric machine. Motor 200 includes a first stator and a second rotor. Although the figure shows an inner rotor type in which the rotor is arranged inside the stator, it may be an outer rotor type in which the rotor is arranged outside the stator.

FIG. 13 is a conceptual diagram of the motor core (stator) of the fourth embodiment. FIG. 14 is a conceptual diagram of the motor core (rotor) of the fourth embodiment. The motor core 300 (motor core) corresponds to the stator and rotor cores. This point will be explained below. FIG. 13 is an example of a conceptual cross-sectional view of the first stator. The first stator has a core and windings. The winding wire is wound around a part of the core's protrusion provided inside the core. Within this core can be placed the compacted material of the third embodiment. FIG. 14 is an example of a cross-sectional conceptual diagram of the first rotor. The first rotor has a core and windings. The winding wire is wound around a part of the protrusions of the core, which are provided outside the core. Within this core can be placed the compacted material of the third embodiment.

13 and 14 merely show an example of the motor, and the application of the compacted powder material is not limited to this. It can be applied to all kinds of motors as a core for facilitating the guidance of magnetic flux.

FIG. 15 is a conceptual diagram of a transformer according to the fourth embodiment. FIG. 16 is a conceptual diagram of an inductor (ring-shaped inductor, bar-shaped inductor) according to the fourth embodiment. FIG. 17 is a conceptual diagram of an inductor (chip inductor, planar inductor) according to the fourth embodiment. These are also shown only as examples. Apply dust material to all kinds of transformers and inductors in order to facilitate the guidance of magnetic flux or to utilize high magnetic permeability in the same way as the motor core in transformers 400 and inductors 500. can be done.

FIG. 18 is a conceptual diagram of the generator 500 of the fourth embodiment. Generator 500 is an example of a rotating electric machine. The generator 500 includes a second stator (stator) 530 using the powder material of the first to third embodiments as a core, and a powder material of the first to third embodiments as a core. Either or both of the second rotors 540 are provided. In the drawing, the second rotor (rotor) 540 is arranged inside the second stator 530, but it may be arranged outside. Second rotor 540 is connected via shaft 520 to turbine 510 provided at one end of generator 500 . Turbine 510 is rotated by, for example, fluid supplied from the outside (not shown). It should be noted that it is also possible to rotate the shaft by transmitting dynamic rotation, such as regenerative energy of an automobile, instead of a turbine that is rotated by a fluid. Various known configurations can be adopted for the second stator 530 and the second rotor 540 .

The shaft contacts a commutator (not shown) located on the opposite side of the second rotor from the turbine. The electromotive force generated by the rotation of the second rotor is stepped up to the system voltage and transmitted as power for the generator via a phase separation bus (not shown) and a main transformer (not shown). The second rotor is charged by static electricity from the turbine and shaft current accompanying power generation. For this reason, the generator is equipped with brushes for discharging the charge of the second rotor.

In addition, the rotary electric machine of the present embodiment can be preferably used for railway vehicles. For example, it can be preferably used for a motor 200 that drives a railroad vehicle, or a generator 500 that generates electricity for driving a railroad vehicle.

FIG. 19 is a conceptual diagram showing the relationship between the direction of the magnetic flux and the arrangement direction of the powder material. First, in both the domain wall displacement type and the rotational magnetization type, the flat surfaces of the flat magnetic metal particles contained in the dust material are arranged in a direction that is parallel to each other and aligned in layers as much as possible with respect to the direction of the magnetic flux. is preferred. This is because the eddy current loss can be reduced by minimizing the cross-sectional area of the flat magnetic metal particles penetrating the magnetic flux. In addition, in the domain wall displacement type, it is preferable to arrange the axis of easy magnetization (in the direction of the arrow) in the flat plane of the flat magnetic metal particles parallel to the direction of the magnetic flux. As a result, it can be used in a direction in which the coercive force is further reduced, which is preferable because the hysteresis loss can be reduced. Moreover, the magnetic permeability can also be made high, which is preferable. Conversely, in the rotary magnetization type, it is preferable to arrange the axis of easy magnetization (in the direction of the arrow) in the flat plane of the flat magnetic metal particles perpendicular to the direction of the magnetic flux. As a result, it can be used in a direction in which the coercive force is further reduced, which is preferable because the hysteresis loss can be reduced. In other words, it is preferable to determine the magnetization characteristics of the compacted powder material, determine whether it is the magnetic domain wall motion type or the rotational magnetization type (the determination method is as described above), and then arrange the magnets as shown in FIG. 13 . If the direction of the magnetic flux is complicated, it may be difficult to completely arrange them as shown in FIG. 13, but it is preferable to arrange them as shown in FIG. 13 as much as possible. The above arrangement method can be applied to all systems and devices of the present embodiment (for example, rotating electric machines such as various motors and generators (for example, motors, generators, etc.), transformers, inductors, transformers, choke coils, filters and magnetic wedges for rotating electric machines).

In order to apply this system and device apparatus, the compacted material allows various processing. For example, sintered bodies are subjected to machining such as grinding and cutting, and powders are mixed with a resin such as epoxy resin or polybutadiene. Further surface treatment is applied as necessary. Moreover, winding processing is performed as needed.

According to the system and device of the present embodiment, it is possible to realize a motor system, motor, transformer, transformer, inductor, and generator having excellent characteristics (high efficiency, low loss).

(Example)
Examples 1 to 20 will be described in more detail below in comparison with Comparative Examples 1 to 13. For the flat magnetic metal particles obtained in the following examples and comparative examples, the average thickness t of the flat magnetic metal particles, the average ratio A of the average length in the flat plane to the thickness, and the flatness of the flat magnetic metal particles Table 1 shows a summary of the in-plane coercive force difference ratio (%) and the in-plane coercive force difference ratio (%) of the dust material.

(Example 1)
First, a ribbon of Fe--Co--Si (Co/(Fe+Co)=10 at %, Si/(Fe+Co+Si)=12 at %) is produced using a single roll quenching apparatus. The resulting ribbon is then heat treated at 300° C. in H ₂ atmosphere. Next, this ribbon is pulverized using a mixer device and subjected to heat treatment in a magnetic field at 1000° C. in an H ₂ atmosphere to obtain flat magnetic metal particles. The obtained flat magnetic metal particles had an average thickness t of 10 µm, an average value A of the ratio of the average length in the flat surface to the thickness of 20, and the ratio of the maximum length to the minimum length of the flat surface a/ The average value of b is 1.6 and has a sharp contour shape. Also, the crystal grain size of the magnetic metal phase is about 50 μm. The resulting flattened magnetic metal particles are mixed with an inorganic oxide intervening phase (B ₂ O ₃ —Bi ₂ O ₃ —ZnO), molded in a magnetic field (to orient the flattened particles), and subjected to heat treatment in a magnetic field. to obtain a compacted material. In the magnetic field heat treatment, the heat treatment is performed by applying a magnetic field in the direction of the easy axis of magnetization.

(Example 2)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=80 at %, Si/(Fe+Co+Si)=12 at %).

(Example 3)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=0.001 at %, Si/(Fe+Co+Si)=12 at %).

(Example 4)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=10 at %, Si/(Fe+Co+Si)=30 at %).

(Example 5)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=10 at %, Si/(Fe+Co+Si)=0.001 at %).

(Example 6)
In Example 1, the ribbon pieces are recovered, pulverized and rolled at about 1000 rpm in an Ar atmosphere by a bead mill using ZrO ₂ balls and a ZrO ₂ container to form flat powder. By repeating the work of pulverization, rolling, and heat treatment, the material is processed to have a predetermined size and structure. Other than that, it is substantially the same as the first embodiment. The obtained flat magnetic metal particles had an average thickness of 10 nm, and an average ratio of 200 to the thickness of the average length in the flat plane.

(Example 7)
It is almost the same as Example 6 except that the average thickness of the flat magnetic metal particles is 1 μm and the average value of the ratio of the average length in the flat surface to the thickness is 100.

(Example 8)
It is almost the same as Example 6 except that the average thickness of the flat magnetic metal particles is 100 μm and the average value of the ratio of the average length in the flat surface to the thickness is 5.

(Example 9)
Example 6 was substantially the same as Example 6 except that the average thickness of the flat magnetic metal particles was 10 nm, and the average value of the ratio of the average length in the flat plane to the thickness was 1,000.

(Example 10)
Example 6 was substantially the same as Example 6 except that the average thickness of the flat magnetic metal particles was 10 nm and the average value of the ratio of the average length in the flat plane to the thickness was 10,000.

(Example 11)
The quenching conditions are controlled during ribbon synthesis, and the obtained ribbon is heat-treated at 300°C in an _H2 atmosphere, then pulverized using a mixer device, and heat-treated in a magnetic field at 940°C for 4 hours in an _H2 atmosphere. This is substantially the same as Example 1, except that the obtained flat magnetic metal particles are generally (110) oriented. All crystal planes other than (110) have a peak intensity ratio of 3% or less with respect to (110).

(Example 12)
The composition is Fe-Co-B-Hf (Co/(Fe+Co)=30at%, (B+Hf)/(Fe+Co+B+Hf)=10at%, Hf/(Fe+Co+B+Hf)=6at%), and the magnetic field heat treatment temperature is 500.degree. It is almost the same as Example 1 except that The grain size of the magnetic metal phase is about 15 nm.

(Example 13)
Almost the same as Example 12 except that the composition is Fe-Co-B-Hf (Co/(Fe+Co) = 30at%, (B+Hf)/(Fe+Co+B+Hf) = 80at%, Hf/(Fe+Co+B+Hf) = 6at%) are the same. The grain size of the magnetic metal phase is about 15 nm.

(Example 14)
The composition is Fe-Co-B-Hf (Co/(Fe+Co)=30at%, (B+Hf)/(Fe+Co+B+Hf)=0.002at%, Hf/(Fe+Co+B+Hf)=0.001at%) Almost the same as Example 12. The grain size of the magnetic metal phase is about 1 μm.

(Example 15)
Almost the same as Example 12 except that the composition is Fe-Co-B-Hf (Co/(Fe+Co) = 30at%, (B+Hf)/(Fe+Co+B+Hf) = 80at%, Hf/(Fe+Co+B+Hf) = 40at%) are the same. The grain size of the magnetic metal phase is about 15 nm.

(Example 16)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 10 at%, Y / (Hf + Y) = 1 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 6 at %), which is substantially the same as Example 12. The crystal grain size of the magnetic metal phase is about 12 nm.

(Example 17)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 10 at%, Y / (Hf + Y) = 20 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 6 at %), which is substantially the same as Example 12. The crystal grain size of the magnetic metal phase is about 12 nm.

(Example 18)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30at%, (B+Hf+Y)/(Fe+Co+B+Hf+Y) = 10at%, Y/(Hf+Y) = 80at%, (Hf+Y)/(Fe+Co+B+Hf+Y) = 6 at %), which is substantially the same as Example 12. The crystal grain size of the magnetic metal phase is about 12 nm.

(Example 19)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 60 at%, Y / (Hf + Y) = 50 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 0.002 at %), which is almost the same as Example 12. The grain size of the magnetic metal phase is about 11 nm.

(Example 20)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 60 at%, Y / (Hf + Y) = 50 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 40 at %), which is almost the same as Example 12. The grain size of the magnetic metal phase is about 11 nm.

(Comparative example 1)
Commercially available Fe--Si--Cr--Ni flat particles are used. The flat magnetic metal particles have a thickness of about 400 nm and an aspect ratio of about 100. Flattened magnetic metal particles are mixed with an intervening phase and compacted to obtain a powder material (no compaction in a magnetic field or heat treatment in a magnetic field).

(Comparative example 2)
The composition is substantially the same as Example 1 except that the composition is Fe—Si (Co amount=0 at %, Si/(Fe+Si)=12 at %).

(Comparative Example 3)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=90 at %, Si/(Fe+Co+Si)=12 at %).

(Comparative Example 4)
It is almost the same as Example 1 except that the composition is Fe--Co (Co/(Fe+Co)=10 at %, Si content=0 at %).

(Comparative Example 5)
It is almost the same as Example 1 except that the composition is Fe--Co--Si (Co/(Fe+Co)=10 at %, Si/(Fe+Co+Si)=40 at %).

(Comparative Example 6)
Almost the same as Example 12 except that the composition is Fe-Co-B-Hf (Co/(Fe+Co)=30at%, (B+Hf)/(Fe+Co+B+Hf)=90at%, Hf/(Fe+Co+B+Hf)=6at%) are the same. The crystal grain size of the magnetic metal phase is about 20 nm.

(Comparative Example 7)
It is almost the same as Example 12 except that the composition is Fe--Co (Co/(Fe+Co)=30 at %, B content=0 at %, Hf content=0 at %). The grain size of the magnetic metal phase is about 2 μm.

(Comparative Example 8)
It is almost the same as Example 12 except that the composition is Fe--Co--B (Co/(Fe+Co)=30 at %, B/(Fe+Co+B)=10 at %, Hf content=0 at %). The crystal grain size of the magnetic metal phase is about 20 nm.

(Comparative Example 9)
Almost the same as Example 12 except that the composition is Fe-Co-B-Hf (Co/(Fe+Co)=30at%, (B+Hf)/(Fe+Co+B+Hf)=80at%, Hf/(Fe+Co+B+Hf)=50at%) are the same. The crystal grain size of the magnetic metal phase is about 20 nm.

(Comparative Example 10)
The composition is Fe-Co-B-Zr (Co/(Fe+Co) = 30at%, (B+Zr)/(Fe+Co+B+Zr) = 10at%, Zr/(Fe+Co+B+Zr) = 6at%), and the resulting ribbon is placed in an _H2 atmosphere. After heat treatment at 300°C in a medium, the ribbon was pulverized using a mixer device and subjected to a magnetic field heat treatment at 400°C in an _H2 atmosphere (heat treatment at a temperature 100°C lower than the heat treatment temperature in Example 12). is carried out), and the procedure is substantially the same as in Example 12 except that flat magnetic metal particles are obtained. The crystal grain size of the magnetic metal phase is about 20 nm.

(Comparative Example 11)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 10 at%, Y / (Hf + Y) = 90 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 6 at %), which is substantially the same as Example 12. The crystal grain size of the magnetic metal phase is about 20 nm.

(Comparative Example 12)
The composition is Fe-Co-B (-Hf-Y) (no Hf and Y, Co/(Fe+Co) = 30at%, (B+Hf+Y)/(Fe+Co+B+Hf+Y) = 60at%, (Hf+Y)/(Fe+Co+B+Hf+Y) = 0at% ) is substantially the same as Example 12. The crystal grain size of the magnetic metal phase is about 40 nm.

(Comparative Example 13)
The composition is Fe-Co-B-Hf-Y (Co/(Fe+Co) = 30 at%, (B + Hf + Y) / (Fe + Co + B + Hf + Y) = 60 at%, Y / (Hf + Y) = 50 at%, (Hf + Y) / (Fe + Co + B + Hf + Y) = 50 at %), which is substantially the same as Example 12. The grain size of the magnetic metal phase is about 50 nm.

Next, regarding the evaluation materials of Examples 1 to 20 and Comparative Examples 1 to 13, the iron loss, the rate of change over time of the real part of magnetic permeability (μ'), the rate of oxidation over time, the strength ratio, and the hardness ratio were measured by the following methods. , the high temperature strength ratio. Table 2 shows the evaluation results.

(1) Core loss: Measure core loss at 100 Hz, 1 T operating conditions using a BH analyzer. If it is not possible to directly measure the iron loss at 100 Hz and 1 T, measure the frequency dependence and magnetic flux density dependence of the iron loss, and estimate the iron loss at 100 Hz and 1 T from the data (and adopt this estimated value ).

(2) Temporal change rate of magnetic permeability real part μ′: Using an impedance analyzer, the magnetic permeability real part μ′ of a ring-shaped sample is measured at 100 Hz. After that, the evaluation sample was heated at a temperature of 100° C. in the air for 100 hours, and then the magnetic permeability real part μ′ was measured again. Obtain the real part μ' of the magnetic flux.

(3) Percentage of oxidation over time: The percentage of oxidation after heating the sample for evaluation at 100° C. in the atmosphere for 100 hours is determined.

(4) Strength ratio: The bending strength of the evaluation sample at room temperature is measured, and the ratio to the bending strength of the sample of Comparative Example 1 at room temperature (= bending strength of the evaluation sample at room temperature/comparative example bending strength of the sample No. 1 at room temperature).

(5) Hardness ratio: The hardness of the evaluation sample at room temperature is measured, and the ratio to the hardness of the sample of Comparative Example 1 at room temperature (= hardness of the evaluation sample at room temperature / room temperature of the sample of Comparative Example 1 hardness).

(6) High temperature strength ratio: The bending strength of the evaluation sample at 100 ° C. in the air is measured, and the ratio of the bending strength of the sample of Comparative Example 1 at 100 ° C. in the air (= 100 ° C. of the evaluation sample at 100° C.).

As is clear from Table 1, the flat magnetic metal particles according to Examples 1 to 20 have an average thickness of 10 nm or more and 100 μm or less, and an average ratio of the average length in the flat plane to the thickness of 5 or more and 10000 or less. is. In addition, there is a difference in coercive force depending on the direction in the flat plane of the flat magnetic metal particles, and there is also a difference in coercive force depending on the direction in the plane of the dust material. Examples 1-11 are Fe--Co--Si systems, and Examples 12-15 are Fe--Co--B--Hf systems. Examples 16 to 20 are Fe--Co--B--Hf--Y systems. In Example 11, the magnetic metal phase is generally (110) oriented. Examples 1 to 11 have an average grain size of 1 μm or more. Examples 12, 13, and 15-20 have an average crystal grain size of 100 nm or less (also 30 nm or less), which is smaller than Comparative Examples 6-13. In particular, the average grain size of Examples 16 to 20 (Fe—Co—B—Hf—Y system) is smaller than the average grain size of Examples 12 to 15 (Fe—Co—B—Hf system), 30 nm or less.

As is clear from Table 2, the dust materials using the flat magnetic metal particles of Examples 1 to 20 are compared to the dust material of Comparative Example 1, the iron loss, the rate of change in μ' over time, and the rate of oxidation over time. , strength ratio, hardness ratio, and high-temperature strength ratio. In other words, it is found to be superior in magnetic properties, thermal stability, oxidation resistance, mechanical properties (strength, hardness), and high-temperature mechanical properties (high-temperature strength). In addition, the powder materials using the flat magnetic metal particles of Examples 1 to 11 are compared with the powder materials of Comparative Examples 2 to 5, and the iron loss, the rate of change with time of μ', the rate of oxidation with time, and the strength ratio , hardness ratio, and high-temperature strength ratio. In addition, the powder materials using the flat magnetic metal particles of Examples 12 to 15 were compared with the powder materials of Comparative Examples 6 to 10, and the iron loss, the rate of change with time of μ', the rate of oxidation with time, and the strength ratio , hardness ratio, and high-temperature strength ratio. In other words, only when the magnetic metal phase is a system containing Fe, Co, and Si, and the amount of Co and the amount of Si are each within the scope of the claims, a remarkable anisotropy-imparting effect can be obtained, It can be seen that excellent properties (iron loss, rate of change in μ' over time, rate of oxidation over time, strength ratio, hardness ratio, and high-temperature strength ratio) are thereby obtained. Similarly, the magnetic metal phase is a system containing the first element and B and Hf as the additive elements, and the total amount of the additive elements and the amount of Hf are within the ranges described in the claims. A remarkable anisotropic effect can be obtained only in the case of 1000 deg. I understand. Furthermore, compared with the dust material of Comparative Example 10, the dust material using the flat magnetic metal particles of Example 12 has an iron loss, a rate of change with time of μ', a rate of oxidation with time, strength ratio, hardness ratio, high temperature In terms of these characteristics, the Fe-Co-B-Hf system seems to be more preferable than the Fe-Co-B-Zr system (Fe-Co-B-Zr system is undoubtedly preferable). Further, Examples 16-20 (Fe--Co--B--Hf--Y system) are Examples 12-15 (Fe--Co--B--Hf system without Y), Comparative Example 12 (Hf, Fe without Y -Co-B system), and Comparative Examples 11 and 13 (Fe-Co-B-Hf-Y system, but the composition range is outside the claimed range), the rate of change over time of iron loss, μ', It can be seen that the rate of oxidation over time, strength ratio, hardness ratio, and high-temperature strength ratio are excellent. In other words, it is found to be superior in magnetic properties, thermal stability, oxidation resistance, mechanical properties (strength, hardness), and high-temperature mechanical properties (high-temperature strength). That is, the magnetic metal phase is a system containing the first element and B, Hf, and Y as the additive elements, and the amount of Y and the total amount of Y and Hf are within the scope of the claims. A remarkable anisotropic effect can be obtained only when it is contained, and as a result, excellent properties (iron loss, rate of change in μ' over time, rate of oxidation over time, strength ratio, hardness ratio, high-temperature strength ratio) can be obtained. It is understood that
In addition, since the materials of the examples are compacted powder materials, they can be applied to complicated shapes.

While several embodiments and examples of the invention have been described, these embodiments and examples are provided by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

2a concave portion 2b convex portion 4 small magnetic metal particles 6 flat surface 8 adhesion metal 9 coating layer 10 flat magnetic metal particles 20 intervening phase 100 compacted powder material 102 flat surface 200 motor 300 motor core 400 transformer/transformer 500 inductor

Claims (28)

It has a flat surface and a magnetic metal phase containing Fe, Co, and Si and having an average crystal grain size of 1 µm or more , and the amount of Co is 0.001 at% or more and 80 at% or less with respect to the total amount of Fe and Co. The amount of Si is 0.001 at% or more and 30 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the ratio of the average length in the flat surface to the thickness is 5 or more and 10000 or less, and a plurality of flat magnetic metal particles having a coercive force difference depending on the direction in the flat plane. 2. A plurality of flat magnetic metal particles according to claim 1, wherein the ratio of said coercive force difference due to said direction in said flat plane is 1% or more. 3. A plurality of flat magnetic metal particles according to claim 1, wherein the magnetic metal phase has an average crystal grain size of 10 [ mu]m or more. 4. The magnetic metal phase according to any one of claims 1 to 3, wherein all crystal planes other than (110) of the magnetic metal phase have a peak intensity ratio of 10% or less to (110) measured by an X-ray diffraction method. a plurality of flattened magnetic metal particles. It has a flat surface and a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and an additive element, the additive element including B and Hf, and the total amount of the additive element. contains 0.002 at% or more and 80 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the average value of the ratio of the average length in the flat surface to the thickness is 5 or more. A plurality of flat magnetic metal particles having a coercive force difference of 10,000 or less depending on the direction in the flat plane. 6. A plurality of flat magnetic metal particles according to claim 5, wherein the ratio of the coercive force difference due to the direction in the flat plane is 1% or more. 7. A plurality of flat magnetic metal particles according to claim 5, wherein the amount of Hf is 0.001 at % or more and 40 at % or less with respect to the entire magnetic metal phase. 8. A plurality of flat magnetic metal particles according to any one of claims 5 to 7, wherein said additive element further contains Y. 9. A plurality of flat magnetic metal particles according to claim 8, wherein the amount of Y is 1 at % or more and 80 at % or less with respect to the total amount of Hf and Y. 10. A plurality of flat magnetic metal particles according to claim 8, wherein the total amount of Hf and Y is 0.002 at % or more and 40 at % or less with respect to the entire magnetic metal phase. 11. A plurality of flat magnetic metal particles according to any one of claims 5 to 10, wherein the magnetic metal phase has an average crystal grain size of 100 nm or less. 12. A plurality of flat magnetic metal particles according to claim 11, wherein the magnetic metal phase has an average crystal grain size of 30 nm or less. 2. The flat surface has one or both of a plurality of concave portions and a plurality of convex portions arranged in the first direction and having a width of 0.1 μm or more, a length of 1 μm or more, and an aspect ratio of 2 or more. 13. A plurality of flattened magnetic metal particles according to any one of claims 12. 14. The plurality of flat magnetic metal particles according to any one of claims 1 to 13, wherein lattice strain of the plurality of flat magnetic metal particles is 0.01% or more and 10% or less. At least part of the surface of the plurality of flat magnetic metal particles has a thickness of 0.1 nm or more and 1 μm or less, and is selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F). 15. A plurality of flat magnetic metal particles according to any one of claims 1 to 14, which are covered with a coating layer containing at least one second element. It has a flat surface and a magnetic metal phase containing Fe, Co, and Si and having an average crystal grain size of 1 µm or more , and the amount of Co is 0.001 at% or more and 80 at% or less with respect to the total amount of Fe and Co. The amount of Si is 0.001 at% or more and 30 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the ratio of the average length in the flat surface to the thickness a plurality of flat magnetic metal particles having an average value of 5 or more and 10000 or less;
an intervening phase present between the flat magnetic metal particles and containing at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F);
A compacted material comprising
In the compacted powder material, the flat surfaces are oriented parallel to a plane of the compacted powder material, and the compacted powder material has a coercive force difference depending on the direction within the plane. 17. The dust material according to claim 16, wherein the ratio of the coercive force difference due to the direction in the plane is 1% or more. 18. The powder material according to claim 16, wherein the magnetic metal phase has an average crystal grain size of 10 [ mu]m or more. 19. The magnetic metal phase according to any one of claims 16 to 18, wherein all crystal planes other than (110) of the magnetic metal phase have a peak intensity ratio of 10% or less to (110) measured by an X-ray diffraction method. of the compacted material. It has a flat surface and a magnetic metal phase composed of at least one first element selected from the group consisting of Fe, Co and Ni and an additive element, the additive element including B and Hf, and the total amount of the additive element. contains 0.002 at% or more and 80 at% or less with respect to the entire magnetic metal phase, the average thickness is 10 nm or more and 100 μm or less, and the average value of the ratio of the average length in the flat surface to the thickness is 5 or more. a plurality of flat magnetic metal particles of 10,000 or less;
an intervening phase present between the flat magnetic metal particles and containing at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F);
A compacted material comprising
In the compacted powder material, the flat surfaces are oriented parallel to a plane of the compacted powder material, and the compacted powder material has a coercive force difference depending on the direction within the plane. 21. The dust material according to claim 20, wherein the ratio of the coercive force difference due to the direction in the plane is 1% or more. 22. The dust material according to claim 20, wherein the amount of Hf is 0.001 at % or more and 40 at % or less with respect to the entire magnetic metal phase. 23. The powder material according to any one of claims 20 to 22, wherein said additive element further contains Y. 24. The powder material according to claim 23, wherein the amount of Y is 1 at% or more and 80 at% or less with respect to the total amount of Hf and Y. 25. The dust material according to claim 23, wherein the total amount of Hf and Y is 0.002 at % or more and 40 at % or less with respect to the entire magnetic metal phase. 26. The powder material according to any one of claims 20 to 25, wherein the magnetic metal phase has an average crystal grain size of 100 nm or less. 27. The dust material according to claim 26, wherein the magnetic metal phase has an average crystal grain size of 30 nm or less. A rotary electric machine comprising a plurality of flat magnetic metal particles or powder material according to any one of claims 1 to 27.

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