Magnetic particles

Abstract

The present invention can provide magnetic particles capable of eliminating variation in magnetic permeability at a higher frequency than before.　The magnetic particles have an average particle diameter D50 of 100-300 nm, and a standard deviation σ of the particle size distribution of 30 nm or more.

Description

Magnetic particles

[0001] The present invention relates to magnetic particles.

[0002] Conventionally, inductor components using magnetic particles have been studied. For example, Japanese Patent Application Laid-Open No. 2016-184641 (Patent Document 1) describes soft magnetic metal powder used for inductors. Also, Japanese Patent Application Laid-Open No. 2023-138191 (Patent Document 2) describes magnetic metal particles used for motors, generators, etc.

[0003] Japanese Patent Application Laid-Open No. 2016-184641, Japanese Patent Application Laid-Open No. 2023-138191

[0004] Conventionally, since powder particles have been used at frequencies of 10 MHz or less, the frequency variation of magnetic permeability has not been studied. In contrast, the inventor of the present case has found a new problem that the magnetic permeability of conventional magnetic particles varies when used at a higher frequency than before.

[0005] In order to solve the above problems, the magnetic particles which are one aspect of the present disclosure have an average particle size D50 of 100 nm or more and 300 nm or less, and a standard deviation σ of the particle size distribution of 30 nm or more.

[0006] In the above aspect, as the standard deviation σ of the particle size distribution increases, the particle size distribution included in the molded body becomes wider. Since the variation of magnetic permeability differs depending on the particle diameter, the variation of magnetic permeability is averaged as the particle size distribution becomes wider. As a result, the variation range of magnetic permeability becomes smaller, and the frequency characteristics are improved. If the particle size distribution becomes too narrow, the variation of magnetic permeability may decrease.

[0007] According to the present disclosure, it is possible to provide magnetic particles with suppressed variation of magnetic permeability at high frequencies.

[0008] This is a perspective view showing a first embodiment of the inductor component of the present invention. This is an exploded view of the inductor component. This is a cross-sectional view of the inductor component taken along line X-X. This is a graph showing the relationship between particle size and probability density in Examples 1 and 2 and Comparative Examples 1 and 2. This is a graph showing the relationship between particle size and probability density in Example 3. This is a graph showing the relationship between particle size and probability density in Examples 4 to 7 and Comparative Example 3. This is a graph showing the relationship between the standard deviation σ [nm] and the variation in magnetic permeability [%] in Examples 1 to 7 and Comparative Examples 1 to 2.

[0009] Hereinafter, a magnetic particle, which is one aspect of this disclosure, will be described in detail with reference to the illustrated embodiment. Note that some of the drawings are schematic and may not reflect actual dimensions or proportions.

[0010] (First Embodiment) Figure 1 is a perspective view showing a first embodiment of the inductor component 1. Figure 2 is an exploded view of the inductor component 1. The inductor component 1 is formed by stacking layers sequentially from the upper left layer to the lower right layer in Figure 2. Figure 3 is a cross-sectional view of the inductor component 1 taken along the line X-X.

[0011] As shown in Figures 1 to 3, the inductor component 1 includes a base body 10, a coil 20 provided on the base body 10, and a first external electrode 30 and a second external electrode 40 provided on the base body 10 and electrically connected to the coil.

[0012] The inductor component 1 is electrically connected to the wiring of a circuit board (not shown) via first and second external electrodes 30 and 40. The inductor component 1 is used, for example, as an impedance matching coil in high-frequency circuits and is used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, car electronics, and medical and industrial machinery. However, the applications of the inductor component 1 are not limited to these, and it can also be used in tuning circuits, filter circuits, rectifier and smoothing circuits, for example.

[0013] The base body 10 further includes an insulator 11, a first external magnetic member 61, a second external magnetic member 62, and an internal magnetic member 63.

[0014] The insulator 11 includes glass. More specifically, the insulator 11 consists of a sintered glass body. Examples of glass include borosilicate glass. The insulator 11 may further include nonmagnetic ferrite, alumina, resin, etc. The insulator 11 is composed of a plurality of layers stacked in the W direction. Each layer is layered and extends in the LT plane perpendicular to the stacking direction in the W direction. Note that in some cases, the interface between two adjacent layers may not be clearly defined due to firing or other processes.

[0015] The base body 10 is formed in a substantially rectangular parallelepiped shape. The base body 10 includes a first end face 13 and a second end face 14 facing each other, a third end face 15 and a fourth end face 16 facing each other, a bottom surface 17 connected between the first end face 13 and the second end face 14 and between the third end face 15 and the fourth end face 16, and a top surface 18 facing the bottom surface 17. That is, the outer surface of the base body 10 is composed of a first end face 13, a second end face 14 facing the first end face 13, a third end face 15 connected between the first end face 13 and the second end face 14, a fourth end face 16 facing the third end face 15, a bottom surface 17 connected between the third end face 15 and the fourth end face 16, and a top surface 18 facing the bottom surface 17. As shown in the figure, the L direction is perpendicular to the first end face 13 and the second end face 14, the W direction is perpendicular to the third end face 15 and the fourth end face 16, and the T direction is perpendicular to the bottom face 17 and the top face 18. The L, W, and T directions are mutually orthogonal.

[0016] The coil 20 has a helical structure in which the coil axis is parallel to the bottom surface 17 of the base body 10 and is wound along the coil axis so as to intersect the third end face 15 and the fourth end face 16 of the base body 10.

[0017] The coil 20 is formed in a substantially rectangular shape when viewed from the axial direction, but is not limited to this shape. The shape of the coil 20 may be, for example, circular, elliptical, rectangular, or other polygonal. The axial direction of the coil 20 refers to the direction parallel to the central axis of the helix around which the coil 20 is wound. The axial direction of the coil 20 and the lamination direction of the insulating layer 11 are in the same direction. In this application, "parallel" is not limited to a strictly parallel relationship, but also includes a substantially parallel relationship, taking into account the range of realistic variations.

[0018] The coil 20 includes coil wiring 21 wound along a plane. Multiple coil wirings 21 are stacked along the axial direction. The coil wiring 21 is formed by winding it on the main surface (LT plane) of the insulating layer 11 perpendicular to the axial direction. Adjacent coil wirings 21 in the stacking direction are electrically connected in series via via wirings 26 that penetrate the insulating layer 11 in the thickness direction (W direction). That is, the coil 20 includes coil wirings 21 and via wirings 26. In this way, multiple coil wirings 21 form a helix while being electrically connected in series with each other. Specifically, the coil 20 has a configuration in which multiple coil wirings 21, each with fewer than one turn, are stacked and electrically connected in series with each other. The coil wiring 21 is composed of one coil conductor layer. Note that the coil wiring 21 may be composed of multiple coil conductor layers stacked in surface contact with each other, in which case a coil wiring 21 with a high aspect ratio and high rectangularity can be formed. Also, the coil wiring 21 may have a spiral shape of one or more turns.

[0019] The coil 20 contains Ag. The coil 20 may also contain conductive materials other than Ag (e.g., Cu, Au, etc.) and glass.

[0020] The first external electrode 30 is L-shaped and extends from the first end face 13 to the bottom face 17. The second external electrode 40 is L-shaped and extends from the second end face 14 to the bottom face 17. That is, both the first and second external electrodes 30 and 40 are exposed to the bottom face 17. The first external electrode 30 is connected to the first end of the coil 20, and the second external electrode 40 is connected to the second end of the coil 20.

[0021] The first external electrode 30 consists of two layers: a base electrode layer 31 and a plating film layer 32. The second external electrode 40 also consists of two layers: a base electrode layer 41 and a plating film layer 42.

[0022] The base electrode layer 31 is composed of multiple layers of external electrode conductor layers 33 that are stacked in surface contact with each other. The base electrode layer 41 is composed of multiple layers of external electrode conductor layers 43 that are stacked in surface contact with each other. The base electrode layers 31 and 41 may be composed of conductive materials such as Ag, Cu, Au, and glass particles, or they may be formed from the same material as the coil 20. The external electrode conductor layers 33 and 43 may be embedded in the base body 10 or formed on the outer surface of the base body 10.

[0023] The plating layers 32 and 42 are formed by, for example, Ni, Sn, Au, or Cu plating, and more specifically, by Ni and Sn plating.

[0024] The first external magnetic member 61 and the second external magnetic member 62 are located outside the coil 20 in the axial direction of the coil 20. The first external magnetic member 61 constitutes the third end face 15 of the base body 10, and the second external magnetic member 62 constitutes the fourth end face 16 of the base body 10. The first external magnetic member 61 and the second external magnetic member 62 contain a magnetic material and may be composed of a composite body of resin and magnetic material. In this specification, a magnetic member means a member containing a magnetic material, and does not necessarily contain resin. In addition, other members such as insulating layers made of resin material or inorganic material may be laminated (coated) on the outer surfaces of the first and second external magnetic members 61 and 62 for the purpose of insulation and protection. In other words, by providing other members, peeling and cracking of the first and second external magnetic members 61 and 62, and short circuits and current leakage between the first and second external electrodes 30 and 40 can be suppressed.

[0025] The internal magnetic member 63 is connected to the first external magnetic member 61 and the second external magnetic member 62. The internal magnetic member 63 is located inside the coil 20 in the axial direction of the coil 20.

[0026] The internal magnetic member 63 is composed of a composite body of resin and magnetic particles contained within the resin. This configuration improves the DC superposition characteristics compared to a magnetic layer made of ferrite. Furthermore, this configuration reduces high-frequency losses (eddy current losses and hysteresis losses) because the resin insulates the magnetic particles. The internal magnetic member 63 may be made of the same material as the first external magnetic member 61 and the second external magnetic member 62.

[0027] The resin is, for example, epoxy resin.

[0028] Magnetic particles may be single particles. Furthermore, magnetic particles may be aggregates of multiple particles (i.e., aggregates of particles that are not linked together), or they may be granular aggregates formed by the sintering or linking of multiple particles.

[0029] The magnetic particles may consist of an alloy containing iron (Fe), nickel (Ni), and cobalt (Co). The alloy may be an amorphous alloy.

[0030] The average particle size D50 of the magnetic particles is between 100 nm and 300 nm, and the standard deviation σ of the particle size distribution is 30 nm or more. By making the average particle size larger than 100 nm, the fluctuation in magnetic permeability is reduced. By making the average particle size smaller than 300 nm, losses due to eddy currents can be suppressed. By increasing the standard deviation σ of the particle size distribution, the particle size distribution contained in the molded body becomes wider. Since the fluctuation in magnetic permeability differs depending on the particle size, the fluctuation in magnetic permeability is averaged out by widening the particle size distribution. As a result, the fluctuation in magnetic permeability is reduced and the frequency characteristics are improved.

[0031] The average particle size D50 is preferably 200 nm or more and 300 nm or less.

[0032] The average particle size D50 of magnetic particles refers to the volume-based median diameter. The median diameter can be measured using images obtained with a scanning electron microscope (SEM).

[0033] The particle size distribution of magnetic particles can be obtained based on the image analysis method described in International Publication No. 2020 / 261939. Specifically, the particle size distribution is measured by counting particles in a cross-sectional image analysis.

[0034] The average particle size D50 (i.e., μ) and the standard deviation σ of the particle size distribution of magnetic particles can be obtained specifically as follows.

[0035] First, the cross-section of the base body 10, including the winding axis of the wound portion and extending in the longitudinal direction (i.e., the L direction), is image-analyzed to measure the particle size. The magnification of the SEM observation image is set to 30,000x, and 10 images are analyzed. The equivalent circle diameter of the particles contained in the image is determined, the obtained equivalent circle diameters are counted, and a histogram is obtained. In order to make the frequency of the histogram a volume-based distribution, a calculation is performed based on quantitative morphology by multiplying the frequency by the volume calculated from the particle size classification and dividing by the particle size ("Quantitative Morphology," Uchida Rokakuho Shinsha, 1972, pp. 167-203). Here, the frequency of each section is normalized by dividing by the sum of the frequencies so that the total value of the frequencies is 1.

[0036] Subsequently, the particle size range to be measured (maximum particle size: x １ Minimum particle size: x ｎ＋１ ) is divided into n sections, and each particle size interval is [x ｊ , x ｊ＋１ Let j = 1, 2, ..., n. The representative particle size for each particle size interval is calculated using the following formula. Furthermore, q ｊ (j = 1, 2, ..., n) is defined as particle size interval [x ｊ , x ｊ＋１ The relative particle amount (difference %) corresponding to ] is used, and the total for all sections is taken as 100%. The average value μ on the logarithmic scale is obtained by the following formula. The average value μ is equal to the average particle size D ５０ It means...

[0037] Based on the above μ, the standard deviation σ defined on the logarithmic scale is calculated using the following formula.

[0038] The standard deviation σ of the particle size distribution is preferably 50 nm or more, more preferably 80 nm or more, and still more preferably 110 nm or more. Thereby, the variation in magnetic permeability is further reduced, and the frequency characteristics are further improved.

[0039] The upper limit value of the standard deviation σ of the particle size distribution is not particularly limited, but for example, it is 150 nm or less.

[0040] The coefficient of variation (CV value) is a value defined by the ratio of the standard deviation σ to the average particle size D50. When the value of the coefficient of variation increases, the variation in the particle size distribution increases. When the value of the coefficient of variation decreases, the variation in the particle size distribution decreases, and the distribution width becomes narrower. Specifically, the coefficient of variation is obtained by the following formula. σ and μ are the values described above, respectively.

[0041] The coefficient of variation is preferably in the range of 0.35 to 0.45. When the coefficient of variation is in the above range, the variation in the specific magnetic permeability and the decrease in the Q value can be suppressed.

[0042] The variation in the specific magnetic permeability in magnetic resonance may be, for example, 15% or less, 10% or less, or 8% or less. The lower limit value of the variation in the specific magnetic permeability is not particularly limited, but for example, it is 1% or more.

[0043] The variation in the specific magnetic permeability can be obtained as follows. In a composite body of a resin and magnetic particles, the frequency characteristics of the specific magnetic permeability are measured in the range from 200 MHz to 2 GHz. The frequency characteristics of the specific magnetic permeability are measured using, for example, E5071C (manufactured by Keysight Technologies). The average value of the specific magnetic permeability, and the maximum value and the minimum value derived from magnetic resonance are obtained, and the difference between the maximum value and the minimum value when the average value of the specific magnetic permeability is set to 100% is obtained. The variation in the specific magnetic permeability due to magnetic resonance means the difference between the maximum value and the minimum value. The maximum value means the point with the largest amplitude in the positive direction, and the minimum value means the point with the largest amplitude in the negative direction.

[0044] The average Q value is, for example, 20 or higher, specifically 25 or higher, and especially 30 or higher. Here, the average Q value is calculated by determining the Q value in the range from 200 MHz to 2 GHz and then finding the average value of these Q values. The Q value represents μ' / μ'', which is the ratio of the real part μ' of the permeability to the imaginary part μ'' of the permeability. Here, the real part μ' of the effective permeability is the permeability of the part that actually functions as an inductor, and the imaginary part μ'' of the permeability represents the value related to loss. When the real part μ' of the permeability decreases, the imaginary part μ'' of the permeability increases. By having the Q value within the above range, the Q value of the inductor component 1 can be increased when magnetic particles are used in the inductor component 1.

[0045] The present invention is not limited to the first embodiment described above, and design modifications are possible without departing from the spirit of the invention. The magnetic member may have at least one particle that satisfies the above conditions. Preferably, in the magnetic member, all particles satisfy the above conditions.

[0046] For example, the above magnetic particles can be used in other applications. The above magnetic particles may also be used as an electromagnetic wave adsorbent. The above magnetic particles may also be used in electronic components such as capacitor components.

[0047] For example, the magnetic particles can be used as a sheet-like magnetic material containing the magnetic particles. In this embodiment, radio wave loss can be introduced at a specific frequency, and the system can be controlled to prevent such radio waves from entering.

[0048] The materials used are not limited to those exemplified above, and any known materials may be used.

[0049] This disclosure includes the following embodiments: <1> Magnetic particles having an average particle size D50 of 100 nm or more and 300 nm or less, and a standard deviation σ of the particle size distribution of 30 nm or more. <2> Magnetic particles according to <1>, wherein the standard deviation σ of the particle size distribution of 80 nm or more. <3> Magnetic particles according to <1> or <2>, wherein the standard deviation σ of the particle size distribution of 110 nm or more. <4> Magnetic particles according to any one of <1> to <3>, wherein the coefficient of variation is in the range of 0.35 to 0.45. <5> Magnetic particles according to any one of <1> to <4>, wherein the average particle size D50 is 200 nm or more and 300 nm or less. <6> High-frequency inductor components containing magnetic particles according to any one of <1> to <5>.

[0050] This disclosure will be explained in more detail through the following examples, but is not limited to these examples.

[0051] (Example 1) Procedure 1: 13.00 g of FeCoNi particles, 19.33 g of ethylcellulose, and 8.48 g of terpineol were weighed and mixed. Table 1 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring the mixture at room temperature for 120 seconds, then 90 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedure 2: A sheet was prepared from the paste prepared in Procedure 1 using a doctor blade. Procedure 3: The sheet prepared in Procedure 2 was placed in an explosion-proof oven (SPHH-201) and left to stand at 85°C for 45 minutes to dry the solvent. Procedure 4: The two sheets dried in Procedure 3 were pressed together using a press machine at 10 MPa for 60 seconds. Furthermore, the process of adding and pressing one sheet at a time, dried under the above conditions, was repeated multiple times to obtain a sheet with a thickness of approximately 1.0 mm. Operation 5: A 5 mm x 18 mm sheet was cut from the sheet pressed in Operation 4.

[0052] (Example 2) Procedure 1: 13.00 g of FeCoNi particles, 28.99 g of ethylcellulose, and 6.25 g of terpineol were weighed and mixed. Table 1 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 120 seconds, followed by 90 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0053] (Comparative Example 1) Procedure 1 13.00 g of FeCoNi particles, 45.910 g of ethylcellulose, and 2.54 g of terpineol were weighed and mixed. Table 1 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 120 seconds, followed by 90 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0054] (Comparative Example 2) 13.00 g of FeCoNi particles, 45.910 g of ethylcellulose, and 2.54 g of terpineol were weighed and mixed. Table 1 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 240 seconds, followed by 120 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Operations 2 to 5 were performed in the same manner as operations 2 to 5 in Example 1.

[0055] [Measurement of average particle size D50] The average particle size D50 was measured using images obtained with a scanning electron microscope (SEM, Hitachi High-Technologies Corporation, field emission scanning electron microscope: S-4800).

[0056] [Measurement of Relative Permeability Fluctuation] The frequency characteristics of the relative permeability of the above sheet were measured using an E5071C (Keysight) analyzer. The average value of the relative permeability and the maximum and minimum values ​​originating from magnetic resonance were determined in the range from 200 MHz to 2 GHz. The absolute value of the difference between the maximum and minimum values ​​was defined as the fluctuation of relative permeability due to magnetic resonance.

[0057] The results are shown in Table 1. Figure 4 shows graphs illustrating the relationship between particle size and probability density in Examples 1 and 2 and Comparative Examples 1 and 2.

[0058]

[0059] As shown in Table 1, in Examples 1 and 2, the average particle size D50 was between 100 nm and 300 nm, and the standard deviation σ of the particle size distribution was 30 nm or more. In Examples 1 and 2, the average Q value was 30 or more. In Comparative Example 1, the average particle size D50 was less than 100 nm, and the standard deviation σ of the particle size distribution was 20 nm or more. In Comparative Example 1, the average Q value was smaller, and the range of variation in magnetic permeability was also larger. In Comparative Example 2, the average particle size D50 was 100 nm or more, but the standard deviation σ of the particle size distribution was 20 nm or more. In Comparative Example 2, the range of variation in magnetic permeability was smaller than in Comparative Example 1, but the average Q value was also smaller.

[0060] (Example 3) Procedure 1: 13.00 g of FeCoNi particles, 28.99 g of ethylcellulose, and 6.25 g of terpineol were weighed and mixed. Table 2 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 60 seconds, followed by 30 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0061] The results are shown in Table 2. Figure 5 shows a graph illustrating the relationship between particle size and probability density in Example 3.

[0062]

[0063] As shown in Table 2, in Example 3, the average particle size D50 was between 100 nm and 300 nm, and the standard deviation σ of the particle size distribution was 30 nm or more. In Example 3, the variation in magnetic permeability was reduced to 9.0% or less.

[0064] (Example 4) Procedure 1: 13.00 g of FeCoNi particles, 45.10 g of ethylcellulose, and 2.54 g of terpineol were weighed and mixed. Table 3 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 60 seconds, followed by 30 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0065] (Example 5) Procedure 1: 13.00 g of FeCoNi particles, 28.99 g of ethylcellulose, and 6.25 g of terpineol were weighed and mixed. Table 3 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 30 seconds, followed by 10 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0066] (Example 6) Procedure 1: 13.00 g of FeCoNi particles, 28.99 g of ethylcellulose, and 6.25 g of terpineol were weighed and mixed. Table 3 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 120 seconds, followed by 30 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0067] (Example 7) Procedure 1: 13.00 g of FeCoNi particles, 45.10 g of ethylcellulose, and 2.54 g of terpineol were weighed and mixed. Table 3 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 30 seconds, followed by 10 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0068] (Comparative Example 3) Procedure 1: 13.00 g of FeCoNi particles, 19.33 g of ethylcellulose, and 8.48 g of terpineol were weighed and mixed. Table 3 shows the average particle size D50, standard deviation σ, and coefficient of variation (CV value) of the FeCoNi particles. Then, a paste was prepared by stirring at room temperature for 30 seconds, followed by 10 seconds, using a stirring and defoaming device (SK-2000T, Shashinkagaku). Procedures 2 to 5 were performed in the same manner as procedures 2 to 5 in Example 1.

[0069] The results are shown in Table 3. Figure 6 shows a graph illustrating the relationship between particle size and probability density in Examples 4-7 and Comparative Example 3.

[0070]

[0071] As shown in Table 3, in Examples 4 to 7, the average particle size D50 was between 100 nm and 300 nm, and the standard deviation σ of the particle size distribution was 30 nm or more. In Examples 4 to 7, the variation in magnetic permeability was reduced to 7.3% or less. In Comparative Example 3, the standard deviation σ of the particle size distribution was 30 nm or more, but the average particle size D50 was greater than 300 nm. In Comparative Example 3, although the variation in magnetic permeability was reduced, the average Q value became small, and it could not be used as a high-frequency inductor, such as inductor component 1.

[0072] Figure 7 shows the relationship between the standard deviation σ [nm] and the variation in magnetic permeability [%] when the average particle size D50 is 300 nm or less, i.e., in Examples 1 to 7 and Comparative Examples 1 to 2. From Figure 7, it can be seen that when the standard deviation σ is 30 nm or more, the slope of the graph becomes smaller and the amplitude variation becomes smaller.

[0073] 1 Inductor component 10 Base body 13 First end face 14 Second end face 15 Third end face 16 Fourth end face 17 Bottom face 18 Top face 20 Coil 21 Coil wiring 26 Via wiring 30 First external electrode 40 Second external electrode 31, 41 Underlay electrode layer 32, 42 Plating film layer 61 First external magnetic member 62 Second external magnetic member 63 Internal magnetic member

Claims

1. Magnetic particles with an average particle size D50 of 100 nm or more and 300 nm or less, and a standard deviation σ of particle size distribution of 30 nm or more.

2. The magnetic particle according to claim 1, wherein the standard deviation σ of the particle size distribution is 80 nm or more.

3. The magnetic particle according to claim 1 or 2, wherein the standard deviation σ of the particle size distribution is 110 nm or more.

4. A magnetic particle according to any one of claims 1 to 3, wherein the coefficient of variation is in the range of 0.35 to 0.

45.

5. Magnetic particles according to any one of claims 1 to 4, wherein the average particle size D50 is 200 nm or more and 300 nm or less.

6. A high-frequency inductor component comprising magnetic particles according to any one of claims 1 to 5.

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