Soft magnetic alloys and magnetic components

Abstract

The present invention provides a soft magnetic alloy which has high saturation magnetic flux density Bs and low coercivity Hc.　A soft magnetic alloy which contains Fe and at least one metalloid element. With respect to this soft magnetic alloy, an amorphous and nanocrystals having a crystal size of from 5 nm to 30 nm are mingled with each other. The coefficient of determination for the atomic concentration of Fe and the atomic concentration of the at least one metalloid element is 0.700 or more.

Description

[Technical Field]

[0001] The present invention relates to soft magnetic alloys and magnetic components. [Background technology]

[0002] Patent Document 1 discloses an Fe-based soft magnetic alloy in which nano-sized crystals containing α-Fe as the main component and Si, B, etc. as a solid solution are precipitated by heat treating an amorphous alloy whose basic component is Fe-Si-B.

[0003] Patent Document 2 discloses a soft magnetic alloy in which Fe-based nanocrystals are precipitated by heat treating an alloy containing Si and mainly containing Fe. The soft magnetic alloy is composed of Fe-based nanocrystals and an amorphous material.

[0004] Non-Patent Document 1 discloses soft magnetic alloys having microstructures shown in Figures 4 and 5, which will be described later. Specifically, the soft magnetic alloy disclosed includes an α-Fe phase 11, an amorphous phase 13, and a TaC phase (an MZ compound phase 15, which will be described later) as shown in Figure 4, and a soft magnetic alloy includes an α-Fe compound phase 11 and a TaC phase (an MZ compound phase 15, which will be described later) as shown in Figure 5. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2713363 [Patent Document 2] Patent No. 6460276 [Non-patent literature]

[0006] [Non-Patent Document 1] Materials Transactions, JIM, Vol.36, No.7(1995), pp.952 to 961 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a soft magnetic alloy having a high saturation magnetic flux density Bs and a low coercive force Hc. [Means for solving the problem]

[0008] In order to achieve the above object, the soft magnetic alloy of the present invention is a soft magnetic alloy containing Fe and at least one metalloid element, It is a mixture of amorphous and nanocrystalline with a grain size of 5 to 30 nm. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is 0.700 or more.

[0009] The soft magnetic alloy of the present invention has the above-mentioned characteristics, and therefore can provide a soft magnetic alloy having a high saturation magnetic flux density Bs and a low coercive force Hc.

[0010] It may further contain at least one kind of M, where M is a transition element of Groups 4 to 6, The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one type of M may be 0.700 or more.

[0011] It may be a soft magnetic alloy having an Fe-MZ composition, M is one or more metals selected from transition metals of groups 4 to 6, and Z is two or more metals selected from C, P, Si, B, and Ge; The element Z having the highest content ratio in atomic number ratio relative to the entire soft magnetic alloy is designated as Z1, and the element having the highest content ratio excluding Z1 is designated as Z2, The coefficient of determination between the atomic concentration of M and the atomic concentration of Z1 may be 0.600 or more, or the coefficient of determination between the atomic concentration of M and the atomic concentration of Z2 may be 0.600 or more; The coefficient of determination between the atomic concentration of Z1 and the atomic concentration of Z2 may be less than 0.400.

[0012] It may be a soft magnetic alloy having an Fe-MZ composition, M is one or more metals selected from transition metals of groups 4 to 6, and Z is two or more metals selected from C, P, Si, B, and Ge; The element Z having the highest content ratio in atomic number ratio relative to the entire soft magnetic alloy is designated as Z1, and the element having the highest content ratio excluding Z1 is designated as Z2, The coefficient of determination between the atomic concentration of M and the atomic concentration of Z1 may be less than 0.500, or the coefficient of determination between the atomic concentration of M and the atomic concentration of Z2 may be less than 0.500; The coefficient of determination between the atomic concentration of Z1 and the atomic concentration of Z2 may be less than 0.400.

[0013] The composition of the Fe-MZ system is represented by the formula (Fe (1-(α+β)) X1 α X2 β ) (1-( a+b+c)) M1 a Z b Cr c may be expressed as X1 is at least one selected from Co and Ni; X2 is one or more selected from Al, Mn, Ag, Zn, Sn, Cu, Bi, N, O, S and rare earth elements; M1 is one or more selected from Ta, V, Zr, Hf, Ti, Nb, Mo, and W; 0.030≦a≦0.140 0.030≦b≦0.275 0.000≦c≦0.030 0≦α(1-(a+b+c))≦0.400 β≧0 0≦α+β≦0.50 may be.

[0014] The range of b may be 0.050≦b≦0.200.

[0015] It may be 0.730≦1−(a+b+c)≦0.930.

[0016] It may be a soft magnetic alloy having an Fe-MC system composition, The soft magnetic alloy may have no peak of an MC compound in a chart obtained by XRD, The soft magnetic alloy may have a first region in which the total concentration of Fe, Co, and Ni is 85 at% or more, and a second region in which the total concentration of Fe, Co, and Ni is 80 at% or less, and in the second region, the average M / C, which is the atomic concentration of M divided by the atomic concentration of C, may exceed 1.0.

[0017] The composition of the Fe-MC system is represented by the formula (Fe (1-(α+β)) X1 α X2 β ) (1-( a+b1+b2+c)) M1 a C b3 Z3 b4 Cr c may be expressed as X1 is one or more selected from the group consisting of Co and Ni; X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Bi, N, O, S and rare earth elements; M1 is one or more selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo and W; Z3 is one or more selected from the group consisting of P, B, Si, and Ge; 0.030≦a≦0.140 0.005≦b3≦0.200 0.000≦b4≦0.180 0.000≦c≦0.030 0≦α(1-(a+b3+b4+c))≦0.400 β≧0 0≦α+β≦0.50 may be.

[0018] The range may be 0.040≦b3≦0.120.

[0019] It may be 0.730≦1−(a+b3+b4+c)≦0.930.

[0020] 0.050≦a≦0.140 may be satisfied.

[0021] It may also contain Fe-based nanocrystals.

[0022] It may be in the form of a thin ribbon.

[0023] It may be in powder form.

[0024] It may be in the form of a thin film.

[0025] The magnetic component according to the present invention is made of the above soft magnetic alloy. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is an example of a scatter diagram created from the atomic concentration of Fe and the atomic concentration of Z. [Figure 2] 1 is an example of a scatter diagram created from the atomic concentration of Fe and the atomic concentration of Z. [Figure 3] 1 is a schematic diagram of the microstructure of the soft magnetic alloy 1 according to the present embodiment. [Figure 4] 1 is a schematic diagram of the microstructure of conventional soft magnetic alloy 101. [Figure 5] 1 is a schematic diagram of the microstructure of conventional soft magnetic alloy 201. [Figure 6] 1 is an example of a chart obtained by crystal structure analysis of a soft magnetic alloy by XRD. [Figure 7] 7 is an example of a pattern obtained by profile fitting the chart of FIG. 6. [Figure 8] This is a mapping image of Fe obtained by 3DAP measurement. [Figure 9] This is a mapping image of Ta obtained by 3DAP measurement. [Figure 10] This is a mapping image of C obtained by 3DAP measurement. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0028] The soft magnetic alloy of this embodiment is A soft magnetic alloy comprising Fe and at least one metalloid element, It is a mixture of amorphous and nanocrystalline with a grain size of 5 to 30 nm. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is 0.700 or more.

[0029] The soft magnetic properties of a soft magnetic alloy can be changed by changing the microscopic segregation and dispersion of each element contained in the soft magnetic alloy. Furthermore, the microscopic segregation and dispersion of each element contained in the soft magnetic alloy change depending on the composition of the soft magnetic alloy and the heat treatment conditions (thermal history of the soft magnetic alloy).

[0030] This paper explains how to confirm the microscopic segregation and dispersion state of two types of elements contained in soft magnetic alloys.

[0031] The atomic concentrations of two elements are measured at multiple measurement points within a soft magnetic alloy. Then, a scatter plot is obtained by plotting the atomic concentrations of the two elements at each measurement point, with the atomic concentrations of the two elements on the x-axis and y-axis, respectively. Then, a linear regression equation (y=ax+b) can be obtained by performing regression analysis.

[0032] When a is positive, the two elements tend to coexist and aggregate with each other. When a is negative, the two elements tend to be exclusive and separate from each other. The two elements tend to segregate.

[0033] In soft magnetic alloys containing Fe and metalloid elements, where amorphous and nanocrystalline phases coexist, a tends to be negative when a scatter plot is obtained from the atomic concentrations of Fe and metalloid elements. In other words, in such soft magnetic alloys, Fe and metalloid elements tend to be mutually exclusive and easily separated. Specifically, Fe is more likely to be contained in nanocrystalline phases and less likely to be contained in metalloid elements, and metalloid elements are more likely to be contained in amorphous phases and less likely to be contained in Fe.

[0034] Examples of scatter plots are shown in Figures 1 and 2. In the scatter plots, the x-axis (horizontal axis) represents the atomic concentration of Fe, and the y-axis (vertical axis) represents the atomic concentration of metalloid elements. The metalloid elements are designated as Z.

[0035] Here, the coefficient of determination R 2 The larger the coefficient of determination, the more easily the two elements aggregate or disperse with each other. In other words, the greater the influence of the two elements on each other. Conversely, the smaller the coefficient of determination, the less influence the two elements have on each other.

[0036] Figure 1 is a scatter plot with a coefficient of determination of approximately 0.9. Figure 2 is a scatter plot with a coefficient of determination of approximately 0.6. Figure 1 shows a tendency for Fe to be contained in the nanocrystals, and a tendency for Z to be contained less, compared to Figure 2. Furthermore, Figure 1 shows a tendency for Z to be contained in the amorphous phase, and a tendency for Fe to be contained less, compared to Figure 2. In other words, Figure 1 shows a greater separation of Fe and Z than Figure 2. The inventors have found that when a scatter plot is obtained from the atomic concentrations of Fe and Z in a soft magnetic alloy containing Fe and Z, where amorphous and nanocrystals are mixed, the larger the coefficient of determination, the more likely the magnetic properties are to be improved. In other words, the more Fe and Z are separated, the more likely the magnetic properties are to be improved. In other words, the more Fe aggregates into nanocrystals and the more Z aggregates into amorphous phases, the more likely the magnetic properties are to be improved.

[0037] The microscopic segregation and dispersion state of each element contained in a soft magnetic alloy can be observed and measured using a three-dimensional atom probe (3DAP).

[0038] The three-dimensional atom probe (3DAP) will be explained below.

[0039] 3DAP is a device used to obtain information on three-dimensional atomic arrangement. The procedure for measurements using 3DAP is explained below. First, a high voltage is applied to a needle-shaped sample, and then a laser pulse is applied. This causes electrolytic evaporation at the tip of the sample. A two-dimensional detector detects the ions generated by electrolytic evaporation, allowing the atomic arrangement of the sample to be identified. At the same time, the ion species can also be identified from the ion's time of flight.

[0040] By analyzing the measurement data obtained by 3DAP using software, the observation area can be virtually divided into multiple hexahedral grids of any size. Each hexahedral grid contains compositional information calculated from the measurement data. This allows for statistical analysis of microscopic compositional information. Therefore, 3DAP allows for the three-dimensional observation of microscopic compositional fluctuations in a sample. This also allows for the observation of atomic arrangements within the sample. In other words, it allows for the observation of the microscopic segregation and dispersion of each element contained in the sample.

[0041] The inventors used 3DAP to observe the microscopic segregation and dispersion of each element in samples prepared by varying the composition and heat treatment conditions. Furthermore, they measured the magnetic properties (saturation magnetic flux density Bs, coercive force Hc, etc.) using a vibrating sample magnetometer (VSM). As a result, they found that the concentration distribution of each element contained in the soft magnetic alloy changes when the composition and heat treatment conditions of the soft magnetic alloy are changed. Furthermore, they found that the dependence of the concentration distribution of each element on the concentration distribution of other elements changes when the composition and heat treatment conditions of the soft magnetic alloy are changed. Furthermore, they found that the variation in the concentration ratio of Fe element to metalloid elements in a microscopic region of the soft magnetic alloy has a significant correlation with the magnetic properties of the soft magnetic alloy. Examples of metalloid elements include B and C. 、S Examples include i, P, Ge, As, Se, Sb, Te, Po, and At.

[0042] An example of sample measurement conditions using 3DAP is shown below. Measurement is performed using a rectangular parallelepiped or cube with each side measuring at least 40 nm x 40 nm x 50 nm as the measurement range. By analyzing the measurement data obtained using software, the rectangular parallelepiped or cube (measurement range) is virtually divided into cubic grids with each side measuring 2 nm. In other words, there are 20 x 20 x 25 = 10,000 or more grids, each with composition information. There are no particular restrictions on the shape of the measurement range, as long as there are 10,000 or more grids in a row. Then, a large number of grids, each with composition information, can be statistically handled and analyzed. The inventors calculated the coefficient of determination R between the atomic concentration of Fe and the atomic concentration of at least one metalloid element. 2 Specifically, a scatter plot is created from the atomic concentration of Fe and the atomic concentration of at least one metalloid element in each grid. Next, a linear regression equation can be obtained by performing a regression analysis. The coefficient of determination R 2 Hereinafter, the metalloid element in question is designated as Z, and the coefficient of determination between the atomic concentration of Fe and the atomic concentration of Z is designated as R 2 (Fe-Z). Other coefficients of determination may also be written in a similar manner.

[0043] R 2 By setting (Fe-Z) to 0.700 or more, a soft magnetic alloy having a high saturation magnetic flux density Bs and a low coercive force Hc can be obtained. This is because the soft magnetic alloy of this embodiment is a mixture of amorphous and nanocrystalline phases with a grain size of 5 to 30 nm, and Fe aggregates in the nanocrystalline phase, and metalloid elements aggregate in the amorphous phase, resulting in R 2 On the other hand, the higher the concentration of metalloid elements in the nanocrystalline phase, the higher the R 2 (Fe-Z) decreases, and in particular the saturation magnetic flux density Bs decreases.

[0044] The soft magnetic alloy may further contain at least one element M in addition to Fe and at least one metalloid element. M is a transition metal of Groups 4 to 6. Then, the coefficient of determination R is calculated by the above method from the atomic concentration of Fe and the atomic concentration of at least one element M in each grid. 2 (Fe-M) can be calculated. 2 It is preferable that (Fe-M) is 0.700 or more. 2 When (Fe-M) is 0.700 or more, the magnetic properties, especially Bs, tend to be improved. This is because the soft magnetic alloy of this embodiment is a mixture of amorphous and nanocrystalline phases with a grain size of 5 to 30 nm, and Fe aggregates in the nanocrystalline phase, while the M element aggregates in the amorphous phase, resulting in R. 2 Conversely, the higher the concentration of M element in the nanocrystalline phase, the higher the R 2 (Fe-M) decreases, and in particular the saturation magnetic flux density Bs decreases.

[0045] Hereinafter, cases where the composition is specified more specifically will be described, specifically, the case of an Fe-MZ-based composition and the case of an Fe-MC-based composition will be described.

[0046] (1) Composition and coefficient of determination of the Fe-MZ system The soft magnetic alloy according to this embodiment may be a soft magnetic alloy having an Fe-MZ system composition, where M is one or more elements selected from Groups 4 to 6 of transition metals, and Z is two or more elements selected from C, P, Si, B, and Ge.

[0047] An Fe-MZ-based composition is a composition containing mainly Fe, M, and Z. A portion of the Fe may be substituted with Co and / or Ni. Specifically, 40 at% or less of the total Fe may be substituted with Co and / or Ni. The total content of Fe, Co, and Ni may be 73 at% or more of the entire soft magnetic alloy. When the soft magnetic alloy has an Fe-MZ-based composition, the total content of elements other than Fe, Co, Ni, M, and Z in the soft magnetic alloy is 25 at% or less of the entire soft magnetic alloy. Examples of elements other than Fe, Co, Ni, M, and Z include Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Bi, N, O, S, and rare earth elements.

[0048] M is one or more elements selected from transition metals of groups 4 to 6. For example, it may be one or more elements selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo, and W. Z is two or more elements selected from C, P, Si, B, and Ge. M and Z may be bonded to each other to form a crystal of an MZ compound. Hereinafter, one or more elements selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo, and W will be referred to as M1. Examples of M other than M1 include Cr.

[0049] In the soft magnetic alloy of this embodiment, the M1 content may be 3.0 at% or more and 14.0 at% or less, or 7.0 at% or more and 9.0 at% or less. The Z content may be 3.0 at% or more and 27.5 at% or less, or 5.0 at% or more and 16.0 at% or less. The Cr content may be 0 at% or more and 3.0 at% or less. That is, the soft magnetic alloy of this embodiment does not need to contain Cr. Furthermore, in the soft magnetic alloy of this embodiment, it is preferable that Ta is contained in an amount of 3 at% or more relative to the entire M1, since this makes it particularly easy to improve the saturation magnetic flux density Bs and reduce the coercive force Hc. Furthermore, Ta may be contained in an amount of 40 at% or more relative to the entire M1.

[0050] The microstructure of the soft magnetic alloy of this embodiment is not particularly limited. The soft magnetic alloy of this embodiment contains M and Z, but crystals of MZ compounds do not need to be precipitated; it is preferable that the soft magnetic alloy is substantially free of MZ compounds. Furthermore, M and Z may be contained in an amorphous state. That is, as shown in FIG. 3, the soft magnetic alloy 1 of this embodiment contains a crystalline α-Fe phase 11 and an amorphous phase 13, but preferably does not substantially contain an MZ compound phase 15 as shown in FIGS. 4 and 5.

[0051] "Substantially free of MZ compound phase 15" means that there are no peaks of MZ compounds in a chart obtained by XRD of the soft magnetic alloy. In other words, there are substantially no MZ compound crystals. "There are no peaks of MZ compounds in a chart obtained by XRD" means that the intensity of the MZ compound (200) peak relative to the intensity of the α-Fe (110) peak in a chart after background removal is 5% or less. It may be 1% or less. Since the accuracy of quantitative analysis by XRD is generally about 1 to 5% relative error or higher, this criterion for "substantially free of MZ compound crystals" is considered to be reasonable.

[0052] Here, the element Z with the highest content ratio in terms of atomic number relative to the entire soft magnetic alloy is designated Z1, and the element with the highest content ratio excluding Z1 is designated Z2. That is, Z1 and Z2 are metalloid elements with relatively high concentrations in the composition of the soft magnetic alloy. When the content ratios of two or more elements are the same, the highest content ratios are C, P, B, Si, and Ge in that order. There are no particular restrictions on the total content ratio of Z other than Z1 and Z2. For example, it may be 50 at% or less, with the entire Z being 100 at%.

[0053] In soft magnetic alloys with Fe-MZ compositions, the soft magnetic properties of the alloy change depending on the microscopic segregation and dispersion of each element contained in the alloy. The microscopic segregation and dispersion of each element contained in the alloy also change depending on the composition of the soft magnetic alloy and the heat treatment conditions (thermal history of the soft magnetic alloy).

[0054] As described above, the microscopic segregation and dispersion state of each element contained in a soft magnetic alloy can be observed and measured using a three-dimensional atom probe (3DAP).

[0055] The inventors used 3DAP to observe the microscopic segregation and dispersion of each element in samples prepared by varying the composition and heat treatment conditions. Furthermore, they measured the magnetic properties using VSM. As a result, they found that the variation in the concentration ratio of transition metals to metalloids in the microscopic regions of the soft magnetic alloy has a significant correlation with the magnetic properties of the soft magnetic alloy. The observation conditions for 3DAP can be the same as those described above.

[0056] The measurement range of the sample in the 3DAP and the grid settings are as described above. The inventors then performed analysis based on the atomic concentrations of transition metals in each grid, i.e., M, Z1, and Z2, using the atomic concentrations of M and Z1, M and Z2, and Z1 and Z2. Hereinafter, the coefficient of determination between the atomic concentrations of M and Z1 is referred to as R. 2 (M-Z1), the coefficient of determination between the atomic concentration of M and the atomic concentration of Z2 is R 2 (M-Z2), the coefficient of determination between the atomic concentration of Z1 and the atomic concentration of Z2 is R 2 It may be written as (Z1-Z2).

[0057] R 2 (M-Z1) is 0.600 or more, or R 2 (M-Z2) may be 0.600 or more, and R 2 (Z1-Z2) may be less than 0.400. 2 (M-Z1) and R 2 Of (M-Z2), the one that is not 0.600 or greater may be less than 0.500.

[0058] From another perspective, R 2 (M-Z1) is less than 0.500 or R 2 (M-Z2) may be less than 0.500, and R 2(Z1-Z2) may be less than 0.400. 2 (M-Z1) and R 2 Of (M-Z2), whichever is not less than 0.500 may be 0.600 or greater.

[0059] R 2 (M-Z1) or R 2 If (M-Z2) is less than 0.500, or R 2 (M-Z1) or R 2 When (M-Z2) is 0.600 or more, the coercive force Hc decreases and the saturation magnetic flux density Bs increases.

[0060] Also, R 2 When (Z1-Z2) is small, the coercive force Hc is low.

[0061] The inventors have found that by making the amorphous phase contained in the soft magnetic alloy non-uniform and controlling the local variations in the concentrations of M and Z, the saturation magnetic flux density Bs of the soft magnetic alloy can be increased and the coercive force Hc can be decreased. 2 (M-Z1) or R 2 (M-Z2) is 0.600 or more, and R 2 It was found that when (Z1-Z2) is less than 0.400, the saturation magnetic flux density Bs of the soft magnetic alloy becomes high and the coercive force Hc becomes low. 2 (M-Z1) or R 2 (M-Z2) is less than 0.500, and R 2 It was also found that when (Z1-Z2) is less than 0.400, the saturation magnetic flux density Bs of the soft magnetic alloy increases and the coercive force Hc decreases.

[0062] In addition, R 2 (M-Z1) and R 2 There are no particular upper and lower limits for (M-Z2). For example, it may be 0.750 or less. It may also be 0.308 or more. Furthermore, R 2 There is no particular lower limit for (Z1-Z2). 2 (Z1-Z2) may be 0.100 or more, or may be 0.203 or more.

[0063] In addition, the soft magnetic alloy of this embodiment has a composition of the Fe-MZ system represented by the formula (Fe (1-( α+β)) X1 α X2 β ) (1-(a+b+c)) M1 a Z b Cr c is expressed as X1 is at least one selected from Co and Ni; X2 is one or more selected from Al, Mn, Ag, Zn, Sn, Cu, Bi, N, O, S and rare earth elements; M1 may be one or more selected from Ta, V, Zr, Hf, Ti, Nb, Mo, and W; 0.030≦a≦0.140 0.030≦b≦0.275 0.000≦c≦0.030 0≦α(1-(a+b+c))≦0.400 β≧0 0≦α+β≦0.50 may be.

[0064] The content (a) of M1 may satisfy 0.050≦a≦0.140, or may be 0.070≦a≦0.090. Whether a is large or small, the coercive force Hc tends to be high and the saturation magnetic flux density Bs tends to be low.

[0065] It is preferable that M1 contains Ta, since this tends to increase the saturation magnetic flux density Bs and decrease the coercive force Hc. Furthermore, M1 may contain Ta at 3 at % or more, or may contain Ta at 40 at % or more.

[0066] The content (b) of Z may satisfy the relation 0.050≦b≦0.200, or 0.050≦b≦0.160. Whether b is large or small, the coercive force Hc tends to be high. When b is large, the saturation magnetic flux density Bs tends to be further reduced.

[0067] Z1 may be C and Z2 may be P, B, or Si, or Z1 may be C and Z2 may be P. The coercive force Hc tends to be low. Furthermore, the content of Z2 relative to the content of Z may be 0.0375 or more and 1.00 or less, or 0.125 or more and 1.00 or less, in terms of atomic ratio. When the content of Z2 relative to the content of Z is 0.125 or more and 1.00 or less, the coercive force Hc tends to be low.

[0068] The Cr content (c) may satisfy the condition 0.000≦c≦0.010. When the Cr content is high, the coercive force Hc tends to increase and the saturation magnetic flux density Bs tends to decrease.

[0069] The Fe content (1-(a+b+c)) may be 0.585≦1-(a+b+c)≦0.930, 0.730≦1-(a+b+c)≦0.930, or 0.730≦1-(a+b+c)≦0.890. By setting 1-(a+b+c) within the above range, the amorphous-forming ability of the soft magnetic alloy is improved, and crystals with a grain size greater than 30 nm are less likely to be produced during the production of the soft magnetic alloy.

[0070] In the soft magnetic alloy of this embodiment, a portion of Fe may be substituted with X1 and / or X2.

[0071] X1 is one or more selected from the group consisting of Co and Ni. When X1 is Ni, it has the effect of reducing the coercive force Hc, and when it is Co, it is easy to improve the saturation magnetic flux density Bs. The type of X1 can be selected appropriately. α=0 may be used. That is, X1 may not be contained. Furthermore, the number of X1 atoms may be 40 at% or less, with the number of atoms in the entire composition being 100 at%. That is, 0≦α{1-(a+b+c)}≦0.400 may be satisfied. 0≦α{1-(a+b+c)}≦0.100 may be satisfied. As the number of X1 atoms increases, magnetostriction increases and the coercive force Hc tends to increase.

[0072] X2 is one or more elements selected from Al, Mn, Ag, Zn, Sn, Cu, Bi, N, O, S, and rare earth elements. Furthermore, β=0 may be satisfied for the content of X2. In other words, X2 may not be contained. Furthermore, the number of X2 atoms is preferably 3.0 at% or less, where the number of atoms in the entire composition is 100 at%. In other words, it is preferable to satisfy the relationship 0≦β{1−(a+b+c)}≦0.030.

[0073] The range of the amount of Fe substituted with X1 and / or X2 may be half or less of that of Fe on an atomic number basis, that is, 0≦α+β≦0.50.

[0074] Furthermore, the soft magnetic alloy of this embodiment may contain elements other than those mentioned above as unavoidable impurities, for example, 0.1% by weight or less of each element relative to 100% by weight of the soft magnetic alloy.

[0075] The soft magnetic alloy of this embodiment may have a structure containing Fe-based nanocrystals.

[0076] Here, the Fe-based nanocrystals refer to crystals having a nano-order particle size and a bcc (body-centered cubic) Fe crystal structure. In this embodiment, it is preferable to precipitate Fe-based nanocrystals having an average particle size of 5 to 30 nm.

[0077] Furthermore, when an amorphous soft magnetic alloy is heat-treated, Fe-based nanocrystals are likely to precipitate in the soft magnetic alloy. In other words, the amorphous soft magnetic alloy having the above composition is likely to be used as a starting material for the soft magnetic alloy of this embodiment, which has a structure containing Fe-based nanocrystals.

[0078] Furthermore, the soft magnetic alloy before the heat treatment may have a structure consisting of only amorphous material, or may have a nano-heterostructure in which microcrystals exist in the amorphous material. The microcrystals may have an average particle size of 0.3 to 10 nm.

[0079] The amorphous ratio of the soft magnetic alloy will be explained below.

[0080] When the soft magnetic alloy according to this embodiment is a bulk material, as will be described later, a soft magnetic alloy having an amorphous ratio X of 85% or more as shown in the following formula (1) has an amorphous structure, and a soft magnetic alloy having an amorphous ratio X of less than 85% has a crystalline structure. X = 100 - (Ic / (Ic + Ia) × 100) ... (1) Ic: Crystalline scattering integrated intensity Ia: Amorphous scattering integrated intensity

[0081] The amorphous ratio X is calculated by performing a crystal structure analysis on the soft magnetic alloy by XRD, identifying the phase, reading the peaks of crystallized Fe or a compound (Ic: crystalline scattering integrated intensity, Ia: amorphous scattering integrated intensity), determining the crystallization ratio from the peak intensities, and then calculating the crystallization ratio X using the above formula (1). The calculation method will be explained in more detail below.

[0082] The soft magnetic alloy according to this embodiment is subjected to crystal structure analysis by XRD, and a chart as shown in Fig. 6 is obtained. This is subjected to profile fitting using the Lorentz function of the following formula (2), and a crystalline component pattern α , which indicates the crystalline scattering integrated intensity as shown in Fig. 7, is obtained. c , amorphous component pattern α showing amorphous scattering integral intensity a , and the combined pattern α c+a The amorphization rate X is calculated from the crystalline scattering integrated intensity and amorphous scattering integrated intensity of the obtained pattern using the above formula (1). The measurement range is set to a diffraction angle 2θ of 30° to 60°, where an amorphous halo can be confirmed. Within this range, the error between the integrated intensity actually measured by XRD and the integrated intensity calculated using the Lorentz function is set to within 1%.

[0083]

number

[0084] When the soft magnetic alloy according to this embodiment is a thin film, as described later, crystal structure analysis by XRD may be performed using an in-plane diffraction measurement method. In this case, a chart similar to that obtained when crystal structure analysis by XRD is performed on a bulk using a conventional method is obtained. The amorphous fraction X can be calculated by performing the same analysis on the thin film chart as that performed on the bulk chart.

[0085] (2) Composition and M / C of Fe-MC system The soft magnetic alloy of this embodiment may be a soft magnetic alloy having an Fe-MC system composition.

[0086] An Fe-MC composition is a composition containing mainly Fe, M, and C. A portion of the Fe may be substituted with Co and / or Ni. Specifically, 40 at% or less of the total Fe may be substituted with Co and / or Ni. The total content of Fe, Co, and Ni may be 70 at% or more of the entire soft magnetic alloy. When the soft magnetic alloy has an Fe-MC composition, the total content of elements other than Fe, Co, Ni, M, and C in the soft magnetic alloy is 25 at% or less of the entire soft magnetic alloy. Examples of elements other than Fe, Co, Ni, M, and C include P, B, Si, Ge, Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O, S, and rare earth elements.

[0087] M is a metal element capable of bonding with C to form a crystal of an MC compound. Examples of M include one or more elements selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo, and W. In the soft magnetic alloy of this embodiment, the M content may be 3 at% or more, or 3 at% to 14 at% or less, or 5 at% to 12 at% or less. Furthermore, in the soft magnetic alloy of this embodiment, it is preferable to include Ta at 3 at% or more relative to the total M content, since this particularly facilitates improving the saturation magnetic flux density Bs and reducing the coercive force Hc. Furthermore, Ta may be included at 40 at% or more relative to the total M content.

[0088] In the soft magnetic alloy of this embodiment, the C content may be 0.5 at % or more, or 4 at % or more.

[0089] The soft magnetic alloy of this embodiment has no peak of an MC compound in a chart obtained by XRD. In other words, it does not substantially contain crystals of an MC compound. "No peak of an MC compound in a chart obtained by XRD" means that in a chart after background removal, the intensity of the (200) peak of the MC compound is 5% or less of the intensity of the α-Fe (110) peak. It may be 1% or less. Since the accuracy of quantitative analysis by XRD is generally about 1 to 5% or more relative error, this criterion for being substantially free of crystals of an MC compound is considered to be reasonable.

[0090] The soft magnetic alloy of this embodiment contains M and C, but does not precipitate crystals of MC compounds and is substantially free of MC compounds. Instead, it contains M and C in an amorphous state. That is, as shown in FIG. 3, the soft magnetic alloy 1 of this embodiment contains a crystalline α-Fe phase 11 and an amorphous phase 13, but is substantially free of MC compounds.

[0091] In contrast, conventional soft magnetic alloys contain an MC compound phase 15 composed of an MC compound, as shown in Figures 4 and 5. The soft magnetic alloy 101 containing the amorphous phase 13 shown in Figure 4 and the soft magnetic alloy 201 not containing the amorphous phase 13 shown in Figure 5 can be produced primarily by controlling the M / C atomic ratio throughout the soft magnetic alloy. When the M / C atomic ratio throughout the soft magnetic alloy is greater than 1.0, the soft magnetic alloy 101 is likely to contain the amorphous phase 13. When the M / C atomic ratio is 1.0 or less, the soft magnetic alloy 201 is likely to contain essentially only the α-Fe phase 11 and the MC compound phase 15. Furthermore, the soft magnetic alloy 201 shown in Figure 5 tends to have a lower coercive force than the soft magnetic alloy 101 shown in Figure 4. Furthermore, by changing the heat treatment temperature, various microstructures other than those shown in Figures 4 and 5 can be produced.

[0092] The soft magnetic alloy of this embodiment further has a first region in which the total concentration of Fe, Co, and Ni is 85 at% or more, and a second region in which the total concentration of Fe, Co, and Ni is 80 at% or less. The first region, the second region, and other regions are distinguished using 3DAP. There are no particular restrictions on the location where the 3DAP measurement is performed. The measurement may be performed on the surface of the soft magnetic alloy or on a cut surface obtained by cutting the soft magnetic alloy.

[0093] An example of a method for measuring the M / C atomic ratio using 3DAP is described below. First, a measurement is performed using a rectangular parallelepiped or cube with each side measuring at least 40 nm × 40 nm × 50 nm. By analyzing the measurement data obtained using software, the rectangular parallelepiped or cube (measurement range) is virtually divided into cubic grids with each side measuring 1 nm. That is, there are 40 × 40 × 50 = 80,000 or more grids, each with composition information. Note that the shape of the measurement range in this embodiment is not particularly limited, as long as there are 80,000 or more grids in a continuous pattern. Then, a large number of grids, each with composition information, can be statistically treated and analyzed.

[0094] Among the grids, those with a total concentration of Fe, Co, and Ni of 85 at% or more constitute the first region (first region grid). Also, those with a total concentration of Fe, Co, and Ni of 80 at% or less constitute the second region (second region grid). The first region is generally crystalline, and the second region is generally amorphous.

[0095] The above-mentioned measurement using 3DAP is performed at least two times, preferably three times, with different measurement ranges set. The volume fraction of the first region obtained from each measurement is then averaged to calculate the volume fraction of the first region in the soft magnetic alloy. The same applies to the volume fraction of the second region.

[0096] There are no particular restrictions on the volume fraction of the first region and the volume fraction of the second region in the soft magnetic alloy. The volume fraction of the first region may be 5 vol% or more and 90 vol% or less. The volume fraction of the second region may be 10 vol% or more and 90 vol% or less. The volume fraction of the first region in the soft magnetic alloy may be the same as the number fraction of the first region grids included in the 80,000 or more grids. The volume fraction of the second region in the soft magnetic alloy may be the same as the number fraction of the second region grids included in the 80,000 or more grids.

[0097] 3DAP measurement was performed on the soft magnetic alloy of this embodiment, which does not contain Co or Ni and contains only Ta as M, and the results of mapping images of each element are shown in Figures 8 to 10. It can be seen that the Ta content and C content are lower in areas with a higher Fe content.

[0098] Then, in each second region grid, the M / C ratio, which is the value obtained by dividing the atomic concentration of M by the atomic concentration of C, is calculated and the average value exceeds 1.0.

[0099] As described above, a soft magnetic alloy having an Fe-MC system composition is substantially free of MC compound crystals, and has an average M / C ratio, which is the atomic concentration of M divided by the atomic concentration of C in the second region, of greater than 1.0. A soft magnetic alloy having the above characteristics is likely to have a higher saturation magnetic flux density Bs and a lower coercive force Hc than a soft magnetic alloy with the same composition but containing MC compound crystals or a soft magnetic alloy with the same composition but having an average M / C ratio of 1.0 or less in the second region. The average M / C ratio in the second region may be 1.2 or more and 2.8 or less, or 1.2 or more and 2.5 or less.

[0100] In addition, the soft magnetic alloy of this embodiment has a composition of the Fe-MC system represented by the formula (Fe (1-( α+β)) X1 α X2 β ) (1-(a+b3+b4+c)) M a C b3 X3 b4 Cr cmay be expressed as X1 is one or more selected from the group consisting of Co and Ni; X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Bi, N, O, S and rare earth elements; M is one or more selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo and W; X3 may be one or more selected from the group consisting of P, B, Si, and Ge; 0.030≦a≦0.140 0.005≦b3≦0.200 0.000≦b4≦0.180 0.000≦c≦0.030 0≦α(1-(a+b3+b4+c))≦0.400 β≧0 0≦α+β≦0.50 may be.

[0101] M is one or more selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo, and W. M is preferably one or more selected from Ta, V, and W, and more preferably Ta.

[0102] The M content (a) may satisfy 0.030≦a≦0.140. The M content (a) may also satisfy 0.050≦a≦0.140. Whether a is large or small, the coercive force Hc tends to be high. When a is large, the coercive force Hc tends to be particularly high, and the saturation magnetic flux density Bs tends to be low. When a is small, the coercive force Hc tends to be particularly high.

[0103] The C content (b3) may satisfy 0.005≦b3≦0.200. Alternatively, it may satisfy 0.040≦b3≦0.120, or 0.040≦b3≦0.100. When b3 is small, the coercive force Hc tends to be high. When b3 is large, the saturation magnetic flux density Bs tends to be low and the coercive force Hc tends to be high.

[0104] X3 is one or more selected from the group consisting of P, B, Si, and Ge. It may be one or more selected from the group consisting of P, B, and Si.

[0105] The content (b4) of X3 may satisfy 0.000≦b4≦0.180. It may also satisfy 0.003≦b4≦0.180, or 0.010≦b4≦0.080. When b4 is small, the amorphous phase-forming ability tends to decrease and the coercive force Hc tends to increase. When b4 is large, the saturation magnetic flux density Bs tends to decrease and the coercive force Hc tends to increase.

[0106] Furthermore, the sum of the C content and the X3 content (b3+b4) may be 0.080≦b3+b4≦0.130. When b3+b4 is within the above range, the coercive force Hc tends to be high.

[0107] The Cr content (c) may satisfy the condition 0.000≦c≦0.030, or 0.003≦c≦0.030. The larger c is, the more oxidation resistance tends to improve, but the larger c is, the more saturation magnetic flux density Bs tends to decrease.

[0108] The Fe content (1-(a+b3+b4+c)) may be 0.640≦1-(a+b3+b4+c)≦0.930, or 0.730≦1-(a+b3+b4+c)≦0.930. By setting 1-(a+b3+b4+c) within the above range, the amorphous-forming ability of the soft magnetic alloy is improved, and crystals with a grain size greater than 30 nm are less likely to be produced during the production of the soft magnetic alloy.

[0109] In the soft magnetic alloy of this embodiment, a portion of Fe may be substituted with X1 and / or X2.

[0110] X1 is one or more elements selected from the group consisting of Co and Ni. When X1 is Ni, it has the effect of reducing the coercive force Hc, and when it is Co, it is easy to improve the saturation magnetic flux density Bs after heat treatment. The type of X1 can be selected appropriately. α=0 may be used. That is, X1 may not be contained. Furthermore, the number of X1 atoms may be 40 at% or less, with the number of atoms in the entire composition being 100 at%. That is, 0≦α{1-(a+b3+b4+c)}≦0.400 may be satisfied. 0≦α{1-(a+b3+b4+c)}≦0.100 may be satisfied. As the number of X1 atoms increases, magnetostriction increases, and the coercive force Hc tends to increase.

[0111] X2 is one or more elements selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Bi, N, O, S, and rare earth elements. Furthermore, β=0 may be satisfied for the content of X2. In other words, X2 may not be contained. Furthermore, the number of X2 atoms is preferably 3.0 at% or less, where the number of atoms in the entire composition is 100 at%. In other words, it is preferable to satisfy the relationship 0≦β{1−(a+b3+b4+c)}≦0.030.

[0112] The range of the amount of Fe substituted with X1 and / or X2 may be half or less of that of Fe on an atomic number basis, that is, 0≦α+β≦0.50.

[0113] Furthermore, the soft magnetic alloy of this embodiment may contain elements other than those mentioned above as unavoidable impurities, for example, 0.1% by weight or less of each element relative to 100% by weight of the soft magnetic alloy.

[0114] The soft magnetic alloy of this embodiment may have a structure containing Fe-based nanocrystals.

[0115] Here, the Fe-based nanocrystals refer to crystals having a nano-order particle size and a bcc (body-centered cubic) Fe crystal structure. In this embodiment, it is preferable to precipitate Fe-based nanocrystals having an average particle size of 5 to 30 nm.

[0116] Furthermore, when an amorphous soft magnetic alloy is heat-treated, Fe-based nanocrystals are likely to precipitate in the soft magnetic alloy. In other words, the amorphous soft magnetic alloy having the above composition is likely to be used as a starting material for the soft magnetic alloy of this embodiment, which has a structure containing Fe-based nanocrystals.

[0117] Furthermore, the soft magnetic alloy before the heat treatment may have a structure consisting of only amorphous material, or may have a nano-heterostructure in which microcrystals exist in the amorphous material. The microcrystals may have an average particle size of 0.3 to 10 nm.

[0118] The amorphous ratio of the soft magnetic alloy will be explained below.

[0119] When the soft magnetic alloy according to this embodiment is a bulk material, as will be described later, a soft magnetic alloy having an amorphous ratio X of 85% or more as shown in the following formula (1) has an amorphous structure, and a soft magnetic alloy having an amorphous ratio X of less than 85% has a crystalline structure. X = 100 - (Ic / (Ic + Ia) × 100) ... (1) Ic: Crystalline scattering integrated intensity Ia: Amorphous scattering integrated intensity

[0120] The amorphous ratio X is calculated by performing a crystal structure analysis on the soft magnetic alloy by XRD, identifying the phase, reading the peaks of crystallized Fe or a compound (Ic: crystalline scattering integrated intensity, Ia: amorphous scattering integrated intensity), determining the crystallization ratio from the peak intensities, and then calculating the crystallization ratio X using the above formula (1). The calculation method will be explained in more detail below.

[0121] The soft magnetic alloy according to this embodiment is subjected to crystal structure analysis by XRD, and a chart as shown in Fig. 6 is obtained. This is subjected to profile fitting using the Lorentz function of the following formula (2), and a crystalline component pattern α , which indicates the crystalline scattering integrated intensity as shown in Fig. 7, is obtained. c , amorphous component pattern α showing amorphous scattering integral intensity a , and the combined pattern α c+aThe amorphization rate X is calculated from the crystalline scattering integrated intensity and amorphous scattering integrated intensity of the obtained pattern using the above formula (1). The measurement range is set to a diffraction angle 2θ of 30° to 60°, where an amorphous halo can be confirmed. Within this range, the error between the integrated intensity actually measured by XRD and the integrated intensity calculated using the Lorentz function is set to within 1%.

[0122]

number

[0123] When the soft magnetic alloy according to this embodiment is a thin film, as described later, crystal structure analysis may be performed using in-plane XRD. In this case, a chart similar to that obtained when crystal structure analysis by XRD is performed on a bulk material using a conventional method is obtained. The amorphous fraction X can be calculated by performing the same analysis on the thin film chart as on the bulk chart.

[0124] The shape of the soft magnetic alloy of this embodiment is not particularly limited, and examples thereof include ribbon, powder, and thin film shapes.

[0125] In the following description, ribbon-shaped soft magnetic alloys and powder-shaped soft magnetic alloys may be collectively referred to as "bulk." Furthermore, thin-film-shaped soft magnetic alloys may be abbreviated as "soft magnetic alloy thin film" or "thin film," ribbon-shaped soft magnetic alloys may be abbreviated as "soft magnetic alloy ribbon" or "thin ribbon," and powder-shaped soft magnetic alloys may be abbreviated as "soft magnetic alloy powder" or "powder."

[0126] Hereinafter, a method for producing the soft magnetic alloy according to this embodiment will be described, but the method for producing the soft magnetic alloy according to this embodiment is not limited to the method described below.

[0127] One example of the method for producing the soft magnetic alloy ribbon according to the present embodiment is a method for producing the soft magnetic alloy ribbon by a single roll method.

[0128] In the single-roll method, first, pure metals of each metal element to be contained in the soft magnetic alloy ribbon finally obtained are prepared and weighed so as to have the same composition as the soft magnetic alloy ribbon finally obtained. Then, the pure metals of each metal element are melted and mixed to prepare a master alloy. Note that any method for melting the pure metals may be used, but for example, a method in which the pure metals are melted by high-frequency heating after evacuating a chamber may be used. Note that the master alloy and the soft magnetic alloy ribbon finally obtained usually have the same composition.

[0129] Next, the produced master alloy is heated and melted to obtain a molten metal (molten metal). There are no particular restrictions on the temperature of the molten metal. For example, it may be set to 1200 to 1500°C.

[0130] In this embodiment, there is no particular limit to the temperature of the roll. For example, it may be room temperature to 90° C. Furthermore, there is no particular limit to the pressure difference (injection pressure) between the inside of the chamber and the inside of the injection nozzle. For example, it may be 20 to 80 kPa.

[0131] In the single-roll method, the thickness of the resulting ribbon can be adjusted mainly by adjusting the rotation speed of the roll, but the thickness of the resulting ribbon can also be adjusted by adjusting, for example, the gap between the nozzle and the roll, the temperature of the molten metal, etc. There are no particular limitations on the thickness of the ribbon; for example, it is 10 to 80 μm.

[0132] The soft magnetic alloy ribbon before the heat treatment described later does not contain crystals having a grain size larger than 30 nm. The soft magnetic alloy ribbon before the heat treatment may have a structure consisting of only amorphous material, or may have a nanoheterostructure in which microcrystals exist in the amorphous material. The amorphous ratio X may be 85% or more.

[0133] There are no particular limitations on the method for determining whether the ribbon contains crystals with a grain size greater than 30 nm. For example, the presence or absence of crystals with a grain size greater than 30 nm can be determined by ordinary X-ray diffraction measurement.

[0134] There are no particular limitations on the method for observing the presence or absence of the above-mentioned microcrystals and their average particle size. For example, they can be confirmed by obtaining a selected area diffraction image, a nanobeam diffraction image, a bright-field image, or a high-resolution image using a transmission electron microscope on a sample thinned by ion milling. When using a selected area diffraction image or a nanobeam diffraction image, ring-shaped diffraction is formed in the diffraction pattern in the case of an amorphous material, whereas diffraction spots due to the crystalline structure are formed in the case of a non-amorphous material. When using a bright-field image or a high-resolution image, a magnification of 1.00 × 10 5 ~3.00×10 5 The presence or absence of primary microcrystals and their average particle size can be observed by visual observation at a magnification of 100x.

[0135] Hereinafter, a method for producing a soft magnetic alloy ribbon according to this embodiment by heat treating the soft magnetic alloy ribbon will be described.

[0136] In order to produce a soft magnetic alloy ribbon in which each coefficient of determination is within a predetermined range, heat treatment conditions are particularly controlled. Preferably, the heating rate during heat treatment is set to a high rate of 100°C / min or more, the holding temperature after heating is set to 450°C or more and 650°C or less, and the holding time is set to a short time of 0.1 min or more and 5 min or less. In addition, the temperature drop rate after holding is set to 50°C / min or more and 1000°C / min or less. By controlling in this manner, the coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is easily set to 0.700 or more. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one M element is also easily set to 0.700 or more. Furthermore, it is possible to produce a soft magnetic alloy ribbon in which local variations in M and Z exist within specific ranges and each coefficient of determination is within a predetermined range.

[0137] The atmosphere during the heat treatment is not particularly limited, and the heat treatment may be performed in an active atmosphere such as air, in an inert atmosphere such as Ar gas, or in a vacuum.

[0138] Furthermore, when Fe-based nanocrystals are contained in the soft magnetic alloy ribbon obtained by heat treatment, there is no particular limitation on the method for calculating the average grain size. For example, it can be calculated by observation using a transmission electron microscope. Furthermore, there is no particular limitation on the method for confirming that the crystal structure is a bcc (body-centered cubic lattice structure). For example, it can be confirmed using X-ray diffraction measurement.

[0139] An example of a method for producing the soft magnetic alloy powder according to this embodiment is a method for producing the soft magnetic alloy powder by gas atomization.

[0140] In the gas atomization method, first, pure metals of each metal element contained in the soft magnetic alloy to be finally obtained are prepared and weighed so as to have the same composition as the soft magnetic alloy to be finally obtained. Then, the pure metals of each metal element are melted and mixed to prepare a master alloy. There are no particular restrictions on the method for melting the pure metals, but one method is to melt them by high-frequency heating after evacuating a chamber. The master alloy and the soft magnetic alloy to be finally obtained usually have the same composition.

[0141] Next, the prepared master alloy is heated and melted to obtain a molten metal (molten metal). There is no particular limitation on the temperature of the molten metal, but it can be set to, for example, 1200 to 1500°C. The molten alloy is then sprayed using a gas atomizer to produce powder.

[0142] By controlling the injection conditions at this time, the particle size of the soft magnetic alloy powder can be suitably controlled.

[0143] There are no particular restrictions on the particle size of the soft magnetic alloy powder. For example, D50 is 1 to 150 μm. When the soft magnetic alloy powder has a structure consisting of Fe-based nanocrystals, it is common for a single particle of the soft magnetic alloy powder to contain a large number of Fe-based nanocrystals. Therefore, the particle size of the soft magnetic alloy powder is different from the crystal grain size of the Fe-based nanocrystals.

[0144] Suitable injection conditions vary depending on the composition of the molten metal and the target particle diameter, but examples include a nozzle diameter of 0.5 to 3 mm, a molten metal discharge rate of 1.5 kg / min or less, and a gas pressure of 5 to 10 MPa.

[0145] The soft magnetic alloy powder before heat treatment is obtained by the above method. In order to suitably control the crystallite size, it is preferable that the soft magnetic alloy powder has an amorphous structure at this stage.

[0146] Hereinafter, a method for producing the soft magnetic alloy powder according to this embodiment by heat treating the soft magnetic alloy powder will be described.

[0147] To produce a soft magnetic alloy powder having the microstructure shown in FIG. 3 , i.e., a soft magnetic alloy powder containing a crystalline α-Fe phase 11 and an amorphous phase 13 but not containing an MZ compound, the heat treatment conditions are particularly controlled. Preferably, the heating rate during the heat treatment is set to a high rate of 100°C / min or more, the holding temperature after heating is set to 450°C to 650°C, and the holding time is set to a short time of 0.1 min to 3 min. Furthermore, the cooling rate after holding is set to 50°C / min to 1000°C / min. By controlling the conditions in this manner, the coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is easily set to 0.700 or more. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one M element is also easily set to 0.700 or more. Furthermore, a soft magnetic alloy ribbon can be produced in which the local variations in M and Z are within specific ranges and each coefficient of determination is within a predetermined range.

[0148] The atmosphere during the heat treatment is not particularly limited, and the heat treatment may be performed in an active atmosphere such as air, in an inert atmosphere such as N2 gas or Ar gas, or in a vacuum.

[0149] There are no particular limitations on the method for forming the thin film. For example, the thin film can be formed by sputtering or vapor deposition. Hereinafter, the case of forming the thin film by sputtering will be described.

[0150] The film may be formed by simultaneous multi-sputtering using multiple types of targets, or by single-target sputtering while appropriately changing the target. Simultaneous film formation by multi-target sputtering is preferred because it is easy to produce a thin film that reproduces the crystalline state of the bulk.

[0151] There is no particular limitation on the substrate temperature during film formation, and it is set to, for example, 25°C to 350°C.

[0152] There are no particular limitations on the type of substrate. For example, a thermally oxidized silicon substrate, a silicon substrate, a glass substrate, a ceramic substrate, or a resin substrate can be used. Examples of ceramic substrates include a barium titanate substrate and an ALTIC substrate. The substrate may also be cleaned appropriately before sputtering.

[0153] There are no particular limitations on the thickness of the thin film. For example, it may be 50 nm to 50 μm. Furthermore, it may be a multilayer film in which thin films are alternately laminated with films made of insulating materials and / or high-resistance materials. There are no particular limitations on the type of insulating material and / or high-resistance material, but examples include SiO2, Al2O3, and AlN. Furthermore, the insulating material and / or high-resistance material has a resistivity of 1000 μΩ·cm or more.

[0154] A method for producing the soft magnetic alloy thin film according to this embodiment by heat treating the soft magnetic alloy thin film will be described below.

[0155] To produce a soft magnetic alloy thin film having the microstructure shown in FIG. 3 , i.e., a soft magnetic alloy thin film containing a crystalline α-Fe phase 11 and an amorphous phase 13 but not containing an MZ compound, the heat treatment conditions are particularly controlled. Preferably, the heating rate during the heat treatment is set to a high rate of 100°C / min or more, the holding temperature after the heating is set to 450°C to 650°C, and the holding time is set to a short time of 0.1 min to 5 min. Furthermore, the temperature drop rate after the holding time is set to 50°C / min to 1000°C / min. By controlling the conditions in this manner, the coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is easily set to 0.700 or more. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one M element is also easily set to 0.700 or more. Furthermore, a soft magnetic alloy ribbon can be produced in which the local variations in M and Z are within specific ranges and each coefficient of determination is within a predetermined range.

[0156] The atmosphere during the heat treatment is not particularly limited, and the heat treatment may be performed in an active atmosphere such as air, in an inert atmosphere such as N2 gas or Ar gas, or in a vacuum.

[0157] There are no particular limitations on the applications of the soft magnetic alloy according to this embodiment. For example, in the case of a soft magnetic alloy ribbon, cores, inductors, transformers, and motors can be mentioned. In the case of a soft magnetic alloy powder, dust cores can be mentioned. In particular, the soft magnetic alloy can be suitably used as a dust core for inductors, especially power inductors. The soft magnetic alloy can also be suitably used in magnetic parts using a soft magnetic alloy thin film, such as thin film inductors and magnetic heads.

[0158] The soft magnetic alloy according to the present embodiment can be a soft magnetic alloy having a saturation magnetic flux density Bs higher than, for example, a known Fe-Si-B-Nb-Cu-based soft magnetic alloy. The soft magnetic alloy according to the present embodiment can also be a soft magnetic alloy having a coercive force Hc lower than an Fe-Nb-B-based soft magnetic alloy, which is known to have a higher saturation magnetic flux density Bs than the Fe-Si-B-Nb-Cu-based soft magnetic alloy. Furthermore, the soft magnetic alloy according to the present embodiment can easily have a saturation magnetic flux density Bs higher than an Fe-Nb-B-based soft magnetic alloy. That is, magnetic components using the soft magnetic alloy according to the present embodiment, for example, in the case of inductors, can easily achieve improved DC bias characteristics, reduced core loss, and increased inductance. That is, by using the soft magnetic alloy according to the present embodiment, it becomes easier to obtain magnetic components that are smaller, consume less power, and are more efficient than those using known Fe-Si-B-Nb-Cu-based soft magnetic alloys or Fe-Nb-B-based soft magnetic alloys. Furthermore, when a magnetic component such as a transformer using the soft magnetic alloy according to this embodiment is used in a power supply circuit, it becomes easier to achieve an improvement in power supply efficiency due to a reduction in energy loss. [Example]

[0159] The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

[0160] (Experimental Example 1) In Experimental Example 1, the soft magnetic alloy thin films shown in Tables 1A and 1B were produced. The method for producing the soft magnetic alloy thin films is described below. Note that there are some blank spaces in each of the tables below. This indicates that the values to be filled in the blank spaces have not been calculated.

[0161] First, thin films having the compositions shown in Tables 1A and 1B were formed by sputtering. The film formation was carried out using a magnetron sputtering machine (ES340 manufactured by Eiko Co., Ltd.). The film formation was carried out by simultaneous film formation using multiple types of targets by multi-target sputtering.

[0162] In this experimental example, the substrate temperature during film formation was set to 250°C, and multiple thin films were formed. The substrates were thermally oxidized silicon substrates cut into 6 mm x 6 mm pieces and ultrasonically cleaned using water, acetone, and IPA in that order. The film thickness was 100 nm. The gas flow rate in the chamber was set to 20 sccm, and the gas pressure in the chamber was set to 0.4 Pa.

[0163] The amorphous ratio X of each thin film before the heat treatment described below was measured using XRD. It was confirmed that the amorphous ratio X of the thin film before the heat treatment was 85% or more in all of the examples and comparative examples described below. Furthermore, the presence or absence of microcrystals was confirmed by observing selected area diffraction images and bright field images at 300,000 magnification using a transmission electron microscope. As a result, it was confirmed that the thin film before the heat treatment did not contain microcrystals in all of the examples and comparative examples described below.

[0164] The thin films were then heat-treated. The heat treatment was carried out by raising the temperature at a predetermined rate to a predetermined holding temperature and holding it at that temperature for a predetermined holding time. The heating rate, holding temperature, holding time, and temperature drop rate after heat treatment for each thin film are shown in Tables 1A and 1B. The heat treatment was carried out in a vacuum atmosphere.

[0165] The coercive force Hc and saturation magnetic flux density Bs of each thin film after heat treatment were measured. The coercive force Hc and saturation magnetic flux density Bs were measured using a vibrating sample magnetometer (VSM) with a maximum applied magnetic field of 1000 Oe. Note that the Bs and Hc of a thin film vary depending on the composition, but a Bs of 1.40 T or more was considered good, with 1.50 T or more being even better. A Hc of 10.0 Oe or less was considered good, with 5.0 Oe or less being even better.

[0166] The presence or absence of α-Fe and MZ compounds was confirmed for the thin film after heat treatment using XRD. Specifically, the presence or absence of α-Fe peaks and MZ compound peaks was examined in the chart obtained by XRD. In all of the examples listed in Tables 1A and 1B, the chart obtained by XRD showed α-Fe peaks but no MZ compound peaks.

[0167] The coefficients of determination for the thin film after heat treatment were measured using 3DAP. Specifically, measurements were carried out within a rectangular parallelepiped measuring 40 nm x 40 nm x 50 nm on each side. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 10,000 continuous cubic grids measuring 2 nm x 2 nm x 2 nm. The concentration of each element was calculated by statistically treating and analyzing the 10,000 grids, each containing composition information. The coefficient of determination R 2 (Fe-Z1), R 2 (Fe-Z2) and R 2 (Fe-M) was derived. In Table 1A, R 2 Only (Fe-C) is listed. In all comparative examples listed in Table 1A, R 2 It was confirmed that the coefficients of determination for not only (Fe-C) but also metalloid elements other than Fe and C were less than 0.700.

[0168] Furthermore, for all examples and comparative examples listed in Table 1A, the average M / C was measured in the region (second region) where the total concentration of Fe, Co, and Ni was 80 at% or less. Specifically, measurements were performed using a rectangular parallelepiped with side lengths of 40 nm × 40 nm × 50 nm as the measurement range. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 80,000 continuous cubic grids measuring 1 nm × 1 nm × 1 nm. The 80,000 grids, each with composition information, were statistically treated and analyzed to calculate the concentration of each element in each grid. Then, from the 80,000 grids, grids where the total concentration of Fe, Co, and Ni was 80 at% or less were extracted. The M / C of each extracted grid was calculated and then averaged to obtain the average M / C. The results are shown in Table 1A. Note that a portion of the measurement results was mapped onto a plane, resulting in the mapping images shown in Figures 8 to 10.

[0169] Furthermore, unless otherwise noted, the soft magnetic alloys (thin films, ribbons, and powders) of each of the following experimental examples were confirmed by 3DAP to contain a first region in which the total concentration of Fe, Co, and Ni was 85 at% or more. Specifically, it was confirmed that the 80,000 grids of 1 nm x 1 nm x 1 nm contained grids in which the total concentration of Fe, Co, and Ni was 85 at% or more. Measurements using 3DAP were performed three times for each sample. Furthermore, the soft magnetic alloys (thin films, ribbons, and powders) of each of the following experimental examples were confirmed to contain a first region with a total concentration of Fe, Co, and Ni of 85 at% or more, and a second region with a total volume fraction of 10 vol% or more and 90 vol% or less, unless otherwise noted.

[0170] In each experimental example shown below, unless otherwise specified, the soft magnetic alloys (thin films, ribbons, and powders) after heat treatment contained a mixture of α-Fe and amorphous materials. MC compounds were not included. Observations using XRD and a transmission electron microscope confirmed that the α-Fe was Fe-based nanocrystals with an average particle size of 5 to 30 nm and a bcc crystal structure.

[0171] In addition, in each of the experimental examples shown below, unless otherwise specified, it was confirmed by ICP analysis that there was no change in the composition of the soft magnetic alloy (thin film, ribbon, powder) before and after the heat treatment.

[0172] [Table 1A]

[0173] [Table 1B]

[0174] Table 1A shows that the coefficients of determination for each example, in which the heating rate was sufficiently fast, the holding temperature was sufficiently low, the holding time was sufficiently short, and the cooling rate was sufficiently fast, were within the specified range. Furthermore, the average M / C in the second region exceeded 1.0. In contrast, the coefficients of determination for Fe and each metalloid element were not 0.700 or greater for the comparative examples in which the heating rate was too slow, the holding temperature was too high, the holding time was too long, and the cooling rate was too slow. Furthermore, for sample numbers 14 to 16, which are comparative examples in Table 1A, a peak for the MC compound (TaC) was present in the chart obtained by XRD. Furthermore, while the examples exhibited good magnetic properties, the comparative examples exhibited high coercivity. Furthermore, some comparative examples also exhibited low saturation magnetic flux densities.

[0175] From Table 1B, when the heat treatment conditions were the same, the coefficient of determination changed depending on the composition. 2 (Fe-Z1), R 2 In the examples where at least one of (Fe-Z2) was 0.700 or more, good properties were obtained. Furthermore, the coefficient of determination R 2 In the examples and sample numbers 18 to 21 in which (Fe-M) is also 0.700 or more, R 2 Compared with sample numbers 25 and 26, which had (Fe-M) values less than 0.700, even better Bs was obtained. In contrast, the coefficient of determination R 2 (Fe-Z1), R 2 In the comparative examples in which both of (Fe-Z2) were less than 0.700, Bs and / or Hc were not good. Furthermore, in sample No. 24, a peak of an MC compound was present in the chart obtained by XRD.

[0176] (Experimental Example 2) In Experimental Example 2, thin films were deposited with varying compositions under fixed heat treatment conditions of a heating rate of 100°C / min, a holding temperature of 500°C, a holding time of 1 min, and a cooling rate of 50°C / min. The results are shown in Tables 2 to 6. For all samples listed in Tables 2 to 6, the XRD charts showed an α-Fe peak but no MZ compound peak. Note that in Tables 3 and 4, b1, b2, and b are all rounded to the fourth decimal place, so b1 + b2 may not equal b.

[0177] The coefficients of determination were measured for the thin film after heat treatment using 3DAP. Specifically, measurements were carried out within a rectangular parallelepiped measuring 40 nm x 40 nm x 50 nm on each side. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 10,000 continuous cubic grids measuring 2 nm x 2 nm x 2 nm. The concentration of each element in each grid was calculated by statistically treating and analyzing the 10,000 grids, each containing composition information. The coefficient of determination R 2 (Fe-Z1), R 2 (Fe-Z2), R 2 (Fe-M), R 2 (M-Z1), R 2 (M-Z2), and R 2 (Z1-Z2) was derived. In all of the following examples, the coefficient of determination R 2 (Fe-Z1), R 2 At least one of (Fe-Z2) is 0.700 or more, and the coefficient of determination R 2 (Fe-M) was also 0.700 or more. In contrast, the coefficient of determination R 2 (Fe-Z1), R 2 Both (Fe-Z2) were less than 0.700.

[0178] Furthermore, the average M / C was measured in the region (second region) where the total concentration of Fe, Co, and Ni was 80 at% or less. Specifically, measurements were performed using a rectangular parallelepiped with side lengths of 40 nm × 40 nm × 50 nm as the measurement range. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 80,000 continuous cubic grids measuring 1 nm × 1 nm × 1 nm. The 80,000 grids, each with composition information, were statistically treated and analyzed to calculate the concentration of each element in each grid. Then, from the 80,000 grids, grids where the total concentration of Fe, Co, and Ni was 80 at% or less were extracted. The M / C of each extracted grid was calculated and then averaged to obtain the average M / C. The results are shown in Tables 2 to 6. Note that a portion of the measurement results was mapped onto a plane, resulting in the mapping images shown in Figures 8 to 10.

[0179] [Table 2]

[0180] [Table 3]

[0181] [Table 4]

[0182] [Table 5A]

[0183] [Table 5B]

[0184] [Table 6]

[0185] Table 2 shows the results for each sample with different Ta content (a) for sample number 18 in Table 1B. As mentioned above, the coefficient of determination R 2 (Fe-Z1), R 2 In each example in which at least one of (Fe-Z2) was 0.700 or more, Bs and Hc were good. In particular, in the examples in which 0.070≦a≦0.090 was satisfied, Hc was lower, reaching 5.0 Oe or less, compared to the examples in which 0.070≦a≦0.090 was not satisfied.

[0186] Table 3 shows the results for each sample of sample No. 18 in Table 1B, where the sum of the C content (b1) and the P content (b2) (b1 + b2 = b) was fixed at 0.080 and b and c were varied. As mentioned above, the coefficient of determination R 2 (Fe-Z1), R 2 Each example in which at least one of (Fe-Z2) was 0.700 or more had good Bs and Hc. In Table 3, sample numbers 18, 34 to 36 have Z1 as C and Z2 as P, and sample numbers 37 and 38 have Z1 as P and Z2 as C. In particular, examples in which Z1 is C and Z2 is P and the content of Z2 relative to the content of Z is 0.125 or more and 1.00 or less in atomic ratio had lower Hc, reaching 5.0 Oe or less, compared with examples in which Z1 is P and Z2 is C and examples in which the content of Z2 relative to the content of Z is less than 0.125.

[0187] Table 4 shows the results for each sample with different C and P contents for sample number 18 in Table 1B. As mentioned above, the coefficient of determination R 2 (Fe-Z1), R 2 In each example in which at least one of (Fe-Z2) was 0.700 or more, Bs and Hc were good. In particular, in the examples in which 0.050≦b≦0.160 was satisfied, Hc was lower, reaching 5.0 Oe or less, compared to the examples in which 0.050≦b≦0.160 was not satisfied.

[0188] Tables 5A and 5B show the results of each sample in which the type and content of M1, Z1, and Z2 were changed for sample number 18 in Table 1B. As mentioned above, the coefficient of determination R 2(Fe-Z1), R 2 In each example in which at least one of (Fe-Z2) was 0.700 or more, Bs and Hc were good.

[0189] Table 6 shows the results for each sample in which part of the Fe in sample number 18 was replaced with X1 or X2, and the results for each sample containing Cr. As mentioned above, the coefficient of determination R 2 (Fe-Z1), R 2 In each example in which at least one of (Fe-Z2) was 0.700 or more, Bs and Hc were good.

[0190] (Experimental Example 3) In Experimental Example 3, a soft magnetic alloy ribbon was produced having an Fe-MZ-based composition shown in Table 7. A method for producing a soft magnetic alloy ribbon will be described below.

[0191] First, each pure metal material was weighed so as to obtain a master alloy having the composition shown in Table 7. Then, after evacuating the chamber, the material was melted by high-frequency heating to produce a master alloy.

[0192] The produced master alloy was then heated and melted to a molten metal at 1200°C, and the metal was then sprayed onto a roll using a single-roll method in which the roll was rotated at a rotational speed of 15 m / sec to produce a ribbon. The roll material was Cu. The roll temperature was 25°C, and the differential pressure (injection pressure) between the chamber and the spray nozzle was 40 kPa. The slit width of the slit nozzle was 180 mm, the distance from the slit opening to the roll was 0.2 mm, and the roll diameter was φ300 mm, resulting in a ribbon thickness of 20 μm, a ribbon width of 5 mm, and a ribbon length of several tens of meters.

[0193] The amorphous ratio X of each ribbon before the heat treatment described later was measured using XRD. It was confirmed that the amorphous ratio X of the ribbon before the heat treatment was 85% or more in all of the examples described later. Furthermore, the presence or absence of microcrystals was confirmed by observing selected area diffraction images and bright field images at 300,000 magnifications using a transmission electron microscope. As a result, it was confirmed that the ribbon before the heat treatment did not contain microcrystals in all of the examples and comparative examples described later.

[0194] Next, the ribbon was subjected to heat treatment. The heat treatment conditions were a temperature increase rate of 100°C / min, a holding temperature of 600°C, a holding time of 1 min, and a temperature decrease rate of 50°C / min after the heat treatment. The heat treatment was carried out in an inert atmosphere (Ar atmosphere).

[0195] The coercive force Hc and saturation magnetic flux density Bs of each ribbon after heat treatment were measured. The coercive force Hc was measured using an Hc meter. The saturation magnetic flux density Bs was measured using a vibrating sample magnetometer (VSM) with a maximum applied magnetic field of 1000 Oe. Note that the Bs and Hc of the ribbons vary depending on the composition, but a Bs of 1.40 T or more was considered good, and 1.50 T or more was considered even better. An Hc of 0.25 Oe or less (19.9 A / m or less) was considered good, and 0.06 Oe or less (4.8 A / m or less) was considered even better.

[0196] The heat-treated ribbons were examined for the presence or absence of α-Fe and MZ compounds using XRD. Specifically, the presence or absence of α-Fe peaks and MZ compound peaks was examined in the chart obtained by XRD. For all samples listed in Table 7, the chart obtained by XRD showed α-Fe peaks but no MZ compound peaks.

[0197] The coefficients of determination were measured for the heat-treated ribbon using 3DAP. Specifically, measurements were carried out within a rectangular parallelepiped measuring 40 nm x 40 nm x 50 nm on each side. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 10,000 continuous cubic grids measuring 2 nm x 2 nm x 2 nm. The concentration of each element in each grid was calculated by statistically treating and analyzing the 10,000 grids, each of which had composition information. The coefficient of determination R 2 (Fe-Z1), R 2 (Fe-Z2), R 2 (Fe-M), R 2 (M-Z1), R 2 (M-Z2), and R 2 (Z1-Z2) was derived. In all of the following examples, the coefficient of determination R 2 (Fe-Z1), R 2 At least one of (Fe-Z2) is 0.700 or more, and the coefficient of determination R 2 (Fe-M) was also over 0.700.

[0198] Furthermore, the average M / C was measured in the region (second region) where the total concentration of Fe, Co, and Ni was 80 at% or less. Specifically, measurements were performed using a rectangular parallelepiped with side lengths of 40 nm × 40 nm × 50 nm as the measurement range. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 80,000 continuous cubic grids measuring 1 nm × 1 nm × 1 nm. The 80,000 grids, each with compositional information, were statistically treated and analyzed to calculate the concentration of each element in each grid. Then, from the 80,000 grids, grids where the total concentration of Fe, Co, and Ni was 80 at% or less were extracted. The M / C of each extracted grid was calculated and then averaged to obtain the average M / C. The results are shown in Table 7.

[0199] [Table 7]

[0200] As mentioned above, all the examples listed in Table 7 have the coefficient of determination R 2 (Fe-Z1), R 2 At least one of (Fe-Z2) was 0.700 or more, and good magnetic properties were obtained.

[0201] (Experimental Example 4) In Experimental Example 4, thin film samples, ribbon samples, and powder samples were prepared using the compositions shown in Table 8 while changing the heat treatment conditions. The thin film samples were prepared in the same manner as in Experimental Example 1. The ribbon samples were prepared in the same manner as in Experimental Example 3, but the heat treatment conditions were as shown in Table 8. The method for preparing the powder samples will be described below.

[0202] First, each pure metal material was weighed so as to obtain a master alloy having the composition shown in Table 8. Then, after evacuating the chamber, the material was melted by high-frequency heating to prepare a master alloy.

[0203] The prepared master alloy was then heated to melt it to form a molten metal at 1500°C, and the metal was sprayed by gas atomization to produce powder, with the composition shown in Table 8. The powder was produced with a nozzle diameter of 1 mm, a molten metal discharge rate of 1 kg / min, and a gas pressure of 7.5 MPa.

[0204] The amorphous ratio X of each powder before the heat treatment described below was measured using XRD. It was confirmed that the amorphous ratio X of the powder before the heat treatment was 85% or more in all of the examples described below. Furthermore, the presence or absence of microcrystals was confirmed by observing selected area diffraction images and bright field images at 300,000 magnification using a transmission electron microscope. As a result, it was confirmed that the powder before the heat treatment did not contain microcrystals in all of the examples and comparative examples described below.

[0205] The powder was then subjected to heat treatment under the conditions shown in Table 8. The heat treatment was carried out in an inert atmosphere (Ar atmosphere).

[0206] The coercive force Hc and saturation magnetic flux density Bs of each powder after heat treatment were measured. Coercive force Hc was measured using an Hc meter. Saturation magnetic flux density Bs was measured using a vibrating sample magnetometer (VSM) with a maximum applied magnetic field of 1000 Oe. Note that the Bs and Hc of a powder vary depending on the composition, but a Bs of 1.40 T or more was considered good, and 1.50 T or more was considered even better. Hc of 15.0 Oe or less (1194 A / m or less) was considered good, and 5.0 Oe or less (398 A / m or less) was considered even better.

[0207] The heat-treated powder was examined using XRD to determine the presence or absence of α-Fe and MZ compounds. Specifically, the presence or absence of α-Fe peaks and MZ compound peaks was examined in the chart obtained by XRD. In all of the Examples listed in Table 8, the chart obtained by XRD had α-Fe peaks but no MZ compound peaks. In contrast, all of the Comparative Examples listed in Table 8 had α-Fe peaks and peaks for TaC, a type of MZ compound.

[0208] The coefficients of determination were measured for the heat-treated powder using 3DAP. Specifically, measurements were carried out within a rectangular parallelepiped measuring 40 nm x 40 nm x 50 nm on each side. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement range) was virtually divided into 10,000 continuous cubic grids measuring 2 nm x 2 nm x 2 nm. The concentration of each element in each grid was calculated by statistically treating and analyzing the 10,000 grids, each containing composition information. The coefficient of determination R 2 (Fe-Z1), R 2 (Fe-Z2), R 2 (Fe-M), R 2 (M-Z1), R 2 (M-Z2), and R 2 (Z1-Z2) was derived. In all of the following examples, the coefficient of determination R 2 (Fe-Z1), R 2 At least one of (Fe-Z2) is 0.700 or more, and the coefficient of determination R 2 (Fe-M) was also 0.700 or more. In contrast, the coefficient of determination R2 (Fe-Z1), R 2 Both (Fe-Z2) were less than 0.700.

[0209] Furthermore, the average M / C ratio was measured for the heat-treated powder using 3DAP in the region (second region) where the total concentration of Fe, Co, and Ni was 80 at% or less. Specifically, measurements were performed on a rectangular parallelepiped with side lengths of 40 nm × 40 nm × 50 nm. By analyzing the measurement data obtained using software, the rectangular parallelepiped (measurement region) was virtually divided into 80,000 continuous cubic grids measuring 1 nm × 1 nm × 1 nm. The concentration of each element in each grid was calculated by statistically treating and analyzing the 80,000 grids, each containing compositional information. Then, grids with a total concentration of Fe, Co, and Ni of 80 at% or less were extracted, and the M / C ratios of the extracted grids were calculated and averaged to obtain the average M / C ratio. The results are shown in Table 8.

[0210] [Table 8]

[0211] From Table 8, it can be seen that regardless of whether the soft magnetic alloy is in the form of a thin film, ribbon, or powder, the samples of the examples in which the heating rate is sufficiently fast and the holding time is sufficiently short have a coefficient of determination R 2 (Fe-Z1), R 2 In contrast, in the comparative example in which the heating rate was too slow and the holding time was too long, the coefficient of determination R 2 (Z1-Z2) was not within the specified range. Furthermore, as mentioned above, the coefficient of determination R 2 (Fe-Z1), R 2 Both (Fe-Z2) were less than 0.700. The examples provided good magnetic properties, but the comparative examples had high coercive forces. [Explanation of symbols]

[0212] 1. Soft magnetic alloy (of this embodiment) 101, 201... (conventional) soft magnetic alloys 11. α-Fe phase 13. Amorphous phase 15...MZ compound phase (MC compound phase)

Claims

1. A soft magnetic alloy comprising Fe and at least one metalloid element, It is a mixture of amorphous and nanocrystalline with a crystal grain size of 5 to 30 nm, The coefficient of determination of the atomic concentration of a first element and the atomic concentration of a second element is determined by performing measurements using a three-dimensional atom probe (3DAP) in a measurement range that is a rectangular parallelepiped or cube with each side having a length of at least 40 nm × 40 nm × 50 nm, virtually dividing the measurement range into cubic grids with a side length of 2 nm, and creating a scatter plot of each grid with the atomic concentration of the first element - the atomic concentration of the second element as the vertical and horizontal axes, which is created from the atomic concentration of the first element and the atomic concentration of the second element in each grid, and obtaining a linear regression equation for the scatter plot. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is 0.700 or more; The composition of the soft magnetic alloy is represented by the composition formula (Fe(1-(α + β))X1αX2β)(1-(a+b+c))M1aZbCrc, X1 is at least one selected from Co and Ni; X2 is at least one element selected from Al, Mn, Ag, Zn, Sn, Cu, Bi, N, O, S and rare earth elements; M1 is one or more selected from Ta, V, Zr, Hf, Ti, Nb, Mo, and W; Z is C and P; 0.030≦a≦0.140 0.030≦b≦0.160 0.000≦c≦0.030 0.730≦1-(a+b+c)≦0.890 0≦α(1-(a+b+c))≦0.400 0≦β(1-(a+b+c))≦0.010 ０≦α＋β≦０．５０ and The Ta content relative to M1 is 40 at% or more, the coefficient of determination between the atomic concentration of M1 and the atomic concentration of C is 0.600 or more, or the coefficient of determination between the atomic concentration of M1 and the atomic concentration of P is 0.600 or more; A soft magnetic alloy in which the coefficient of determination between the atomic concentration of C and the atomic concentration of P is less than 0.

400.

2. A soft magnetic alloy comprising Fe and at least one metalloid element, It is a mixture of amorphous and nanocrystalline with a crystal grain size of 5 to 30 nm, The coefficient of determination of the atomic concentration of a first element and the atomic concentration of a second element is determined by performing measurements using a three-dimensional atom probe (3DAP) in a measurement range that is a rectangular parallelepiped or cube with each side having a length of at least 40 nm × 40 nm × 50 nm, virtually dividing the measurement range into cubic grids with a side length of 2 nm, and creating a scatter plot of each grid with the atomic concentration of the first element - the atomic concentration of the second element as the vertical and horizontal axes, which is created from the atomic concentration of the first element and the atomic concentration of the second element in each grid, and obtaining a linear regression equation for the scatter plot. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is 0.700 or more; The composition of the soft magnetic alloy is represented by the composition formula (Fe(1-(α + β))X1αX2β)(1-(a+b+c))M1aZbCrc, X1 is at least one selected from Co and Ni; X2 is at least one element selected from Al, Mn, Ag, Zn, Sn, Cu, Bi, N, O, S and rare earth elements; M1 is one or more selected from Ta, V, Zr, Hf, Ti, Nb, Mo, and W; Z is C and P; 0.030≦a≦0.140 0.030≦b≦0.160 0.000≦c≦0.030 0.730≦1-(a+b+c)≦0.890 0≦α(1-(a+b+c))≦0.400 0≦β(1-(a+b+c))≦0.010 ０≦α＋β≦０．５０ and The Ta content relative to M1 is 40 at% or more, The coefficient of determination between the atomic concentration of M1 and the atomic concentration of C is less than 0.500, or the coefficient of determination between the atomic concentration of M1 and the atomic concentration of P is less than 0.500; A soft magnetic alloy in which the coefficient of determination between the atomic concentration of C and the atomic concentration of P is less than 0.

400.

3. A soft magnetic alloy according to claim 1 or 2, wherein the coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one type of M1 is 0.700 or more.

4. 4. The soft magnetic alloy according to claim 1, wherein 0.050≦b≦0.

160.

5. A soft magnetic alloy comprising Fe and at least one metalloid element, It is a mixture of amorphous and nanocrystalline with a crystal grain size of 5 to 30 nm, The coefficient of determination of the atomic concentration of a first element and the atomic concentration of a second element is determined by performing measurements using a three-dimensional atom probe (3DAP) in a measurement range that is a rectangular parallelepiped or cube with each side having a length of at least 40 nm × 40 nm × 50 nm, virtually dividing the measurement range into cubic grids with a side length of 2 nm, and creating a scatter plot of each grid with the atomic concentration of the first element - the atomic concentration of the second element as the vertical and horizontal axes, which is created from the atomic concentration of the first element and the atomic concentration of the second element in each grid, and obtaining a linear regression equation for the scatter plot. The coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one metalloid element is 0.700 or more; The composition of the soft magnetic alloy is expressed by the composition formula (Fe(1-(α + β))X1αX2β)(1-(a+b3+b4+c))M a C b3 Z3 b4 Cr c, X1 is one or more selected from the group consisting of Co and Ni; X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Bi, N, O, S and rare earth elements; M is one or more selected from the group consisting of Ta, V, Zr, Hf, Ti, Nb, Mo and W; Z3 is one or more selected from the group consisting of P, B, Si, and Ge; 0.030≦a≦0.140 0.040≦b3≦0.130 0.000≦b4≦0.080 0.040≦b3+b4≦0.160 0.000≦c≦0.030 0.730≦1-(a+b3+b4+c)≦0.890 0≦α(1-(a+b3+b4+c))≦0.400 0≦β(1-(a+b3+b4+c))≦0.010 ０≦α＋β≦０．５０ and The Ta content relative to M is 40 at% or more, In a chart obtained by performing crystal structure analysis on the soft magnetic alloy by XRD, there is no peak of an M-C compound, The soft magnetic alloy has a first region in which the total concentration of Fe, Co, and Ni is 85 at% or more, and a second region in which the total concentration of Fe, Co, and Ni is 80 at% or less, and in the second region, the average M / C, which is the atomic concentration of M divided by the atomic concentration of C, exceeds 1.

0.

6. A soft magnetic alloy according to claim 5, wherein the coefficient of determination between the atomic concentration of Fe and the atomic concentration of at least one type of M is 0.700 or more.

7. A soft magnetic alloy according to claim 5 or 6, wherein 0.040≦b3≦0.

120.

8. 8. The soft magnetic alloy according to claim 1, wherein 0.050≦a≦0.

140.

9. 9. The soft magnetic alloy according to claim 1, comprising Fe-based nanocrystals.

10. The soft magnetic alloy according to any one of claims 1 to 9, which is in the form of a thin ribbon.

11. The soft magnetic alloy according to any one of claims 1 to 9, which is in powder form.

12. The soft magnetic alloy according to any one of claims 1 to 9, which is in the form of a thin film.

13. A magnetic part made of the soft magnetic alloy according to any one of claims 1 to 12.

Images