JP2022109474A - Soft magnetic alloy and magnetic part - Google Patents

Abstract

To provide a soft magnetic alloy that contains Co, and has higher saturation magnetic flux density Bs and does not significantly increase coercive force Hc as compared with the case that does not contain Co.SOLUTION: There is provided a soft magnetic alloy that is made up of a compositional formula (Fe(1-(α+β+γ))CoαNiβXγ)(1-(a+b+c))MaCbX3c (atomic ratio). X is one or more selected from a group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, Ca, Mg, Ti, Na, N, V, Mo, O, S and rare earth elements, M is one or more selected from a group consisting of Ta, Zr, Hf, Nb and W, and X3 is one or more selected from a group formed of P, B, Si and Ge, in which, a-c and α-γ are in a prescribed range.SELECTED DRAWING: Figure 1

Description

The present invention relates to soft magnetic alloys and magnetic parts.

Patent Document 1 describes an invention relating to a FeCo-based alloy containing Cu and B in particular, and describes an FeCo-based alloy that provides a particularly high saturation magnetic flux density and is excellent in mass productivity.

Patent Document 2 describes an alloy composition obtained by substituting part of Fe with one or more of Co and Ni and containing B, Si, P and Cu. A high saturation magnetic flux density can be obtained by substituting part of Fe with one or more of Co and Ni.

Japanese Patent Application Laid-Open No. 2008-231462 JP 2012-012699 A

However, the inventions described in Patent Documents 1 and 2 have a drawback that the coercive force increases significantly as the content of Co increases.

An object of the present invention is to provide a soft magnetic alloy containing Co, which has a higher saturation magnetic flux density Bs and does not greatly increase the coercive force Hc as compared with a soft magnetic alloy containing no Co.

In order to achieve the above objects, the soft magnetic alloy of the present invention is
A soft magnetic alloy having a composition formula (Fe _{(1-(α+β+γ))} Co _α Ni _β X _γ ) _(1-(a+b+c)) M _a C _b X3 _c (atomic ratio),
X is 1 selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, Ca, Mg, Ti, Na, N, V, Mo, O, S and rare earth elements; one or more
M is one or more selected from the group consisting of Ta, Zr, Hf, Nb and W;
X3 is one or more selected from the group consisting of P, B, Si and Ge;
0.050≤a≤0.120
0.040<b≦0.140
0.020≤c≤0.080
0.060<b+c≦0.160
0.400<α(1−(a+b+c))≦0.800
0≦β(1−(a+b+c))≦0.200
γ≧0
0≤β+γ≤0.500
is.

It may contain nano-sized crystals.

0.500≦α(1−(a+b+c))≦0.800.

It may be in the form of a thin film.

It may be in the shape of a ribbon.

It may be in powder form.

The magnetic component of the present invention contains the above soft magnetic alloy.

The electronic device of the present invention contains the above soft magnetic alloy.

FIG. 1 is an example of a chart obtained by X-ray crystal structure analysis of a ribbon. FIG. 2 is an example of a pattern obtained by profile fitting the chart of FIG. FIG. 3 is an example of a chart obtained by X-ray crystal structure analysis of a thin film. FIG. 4 is an example of a chart obtained by X-ray crystal structure analysis of a thin film.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on embodiments.

The soft magnetic alloy of this embodiment is
A soft magnetic alloy having a composition formula (Fe _{(1-(α+β+γ))} Co _α Ni _β X _γ ) _(1-(a+b+c)) M _a C _b X3 _c (atomic ratio),
X is 1 selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, Ca, Mg, Ti, Na, N, V, Mo, O, S and rare earth elements; one or more
M is one or more selected from the group consisting of Ta, Zr, Hf, Nb and W;
X3 is one or more selected from the group consisting of P, B, Si and Ge;
0.050≤a≤0.120
0.040<b≦0.140
0.020≤c≤0.080
0.060<b+c≦0.160
0.400<α(1−(a+b+c))≦0.800
0≦β(1−(a+b+c))≦0.200
γ≧0
0≤β+γ≤0.500
is.

Since the soft magnetic alloy of the present embodiment has a composition within the above range, it becomes a soft magnetic alloy that has a high saturation magnetic flux density Bs and does not greatly increase the coercive force Hc compared to the case where Co is not included.

Hc is generally determined by magnetostriction and anisotropy. In a soft magnetic alloy mainly containing Fe and Co, when the content of Co with respect to the total of Fe and Co is about 0 to 60 at %, the magnetostriction increases as the content of Co increases. As a result, when the content of Co in the soft magnetic alloy mainly containing Fe and Co is about 0 to 60 at% with respect to the total of Fe and Co, Hc tends to monotonously increase as the Co content increases. It is in. If the Co content is further increased, the Bs is lowered. Therefore, in order to obtain a soft magnetic alloy containing Co and having excellent soft magnetic properties, particularly low Hc, it is common to reduce the Co content as much as possible.

However, the present inventors have found that a composition containing a specific type of metal element (M), carbon (C) and a specific type of metalloid element (X3) within a specific range contains a large amount of Co. The inventors have found that the increase in Hc can be suppressed to some extent compared to the case where Co is not contained when the content of Co in the soft magnetic alloy is more than 40 at % and not more than 80 at %. Furthermore, it has been found that Hc may rather decrease in comparison with the case where the Co content is approximately 20 to 40 atomic %. On the other hand, even if the Co content is more than 40 atomic % and 80 atomic % or less, the effect of improving Bs by containing Co is exhibited, as in the case where the Co content is 40 atomic % or less. Therefore, it is possible to provide a soft magnetic alloy which has a higher Bs and does not have a large increase in Hc compared to the case where Co is not included. It should be noted that the content of Co being more than 40 at % and not more than 80 at % is substantially equivalent to satisfying 0.400<α(1−(a+b+c))≦0.800.

The relationship between composition and magnetic properties will be described in more detail below.

M is one or more selected from the group consisting of Ta, Zr, Hf, Nb and W; The M content (a) is 0.050≦a≦0.120. 0.080≦a≦0.120 may be satisfied.

When a is within the above range, it is possible to obtain a soft magnetic alloy that has a higher Bs than the case where Co is not included and does not greatly increase Hc. In particular, when 0.080≦a≦0.120, the increase rate of Hc becomes smaller than when Co is not contained.

The content (b) of C is 0.040<b≦0.140. 0.041≦b≦0.140 or 0.060≦b≦0.080.

X3 is one or more selected from the group consisting of P, B, Si and Ge. The content (c) of X3 is 0.020≦c≦0.080. 0.020≦c≦0.060 may be satisfied.

b and c further satisfy 0.060<b+c≦0.160.

When b, c, and b+c are all within the above ranges, when the Co content is more than 40 at % and 80 at % or less, Bs is higher and Hc is higher than when Co is not included. A soft magnetic alloy that does not rise can be obtained. On the other hand, if at least one of b, c and b+c is out of the above range, Hc increases significantly as the Co content increases, as in conventional soft magnetic alloys.

Generally, it is said that the magnitude of Hc is generally determined by the magnitude of magnetostriction and the magnitude of magnetic anisotropy. In Fe-based alloys such as Fe-based nanocrystalline alloys, the magnitude of magnetostriction varies more with the Co content than with one or more selected from the C content and the X3 content. Specifically, as the Co content increases, the magnitude of magnetostriction greatly increases in the positive direction, and Hc greatly increases. However, only when it has the above-mentioned specific composition, the rate of increase in Hc becomes smaller than when Co is not included. Furthermore, Hc is rather lowered only when it has the above-mentioned specific composition, as compared with the case where Co is contained in an amount of approximately 20 to 40 at %. This phenomenon occurs only when M, C, and X3 exist in a specific ratio under the condition that Fe and Co are present, compared to the case where M, C, and X3 do not exist in a specific ratio. It is presumed that this is caused by the action of some factor that greatly changes the orientation.

1-(a+b+c) representing the total content of Fe, Co, Ni and X is not particularly limited. For example, 0.760≦1−(a+b+c)≦0.850.

The Co content satisfies 0.400<α(1−(a+b+c))≦0.800. 0.500≦α(1−(a+b+c))≦0.800. When 0.500≦α(1−(a+b+c))≦0.800 is satisfied, the increase rate of Hc is further reduced compared to the case where Co is not contained.

Regarding the Ni content, 0≦β(1−(a+b+c))≦0.200. When Ni is contained, both the rate of increase of Bs and the rate of increase of Hc are lowered compared to the case where Ni is not included.

X is 1 selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, Ca, Mg, Ti, Na, N, V, Mo, O, S and rare earth elements; more than one. X is an element that can be contained in the soft magnetic alloy in addition to Fe, Co, M, C and X3. Although the content of X is not particularly limited, it satisfies γ≧0 and 0≦β+γ≦0.500. 0≦γ<0.030 may be satisfied. Also, 0≦γ(1−(a+b+c))≦0.010 may be satisfied.

Elements other than the above, that is, elements other than Fe, Co, Ni, X, M, C and X3 may be included as unavoidable impurities. For example, 0.1% by weight or less of each may be contained with respect to 100% by weight of the soft magnetic alloy.

The microstructure of the soft magnetic alloy of this embodiment is not particularly limited. It may have an amorphous structure or may have a nanocrystalline structure. In other words, an amorphization rate X, which will be described later, may be 85% or more, or may be less than 85%. In addition, among the structures composed of nanocrystals, it may have a structure composed particularly of Fe-based nanocrystals.

An Fe-based nanocrystal is a crystal whose grain size is nano-order and whose Fe crystal structure is bcc (body-centered cubic lattice structure). In this embodiment, Fe-based nanocrystals having an average particle size of 5 to 30 nm may be precipitated. In the present embodiment, when the soft magnetic alloy has a structure containing Fe-based nanocrystals, the later-described amorphization rate X is less than 85%, and the soft magnetic alloy has a structure composed of Fe-based nanocrystals. may have

Further, when the amorphous soft magnetic alloy having the above composition is heat-treated at a heat treatment temperature of 400° C. or higher and 700° C. or lower, Fe-based nanocrystals are likely to precipitate in the soft magnetic alloy. In other words, the amorphous soft magnetic alloy having the above composition can easily be used as a starting material for the soft magnetic alloy of the present embodiment having a structure of Fe-based nanocrystals.

In addition, the soft magnetic alloy having the above composition before heat treatment may have a structure consisting only of amorphous material, or may have a nano-heterostructure in which microcrystals are present in amorphous material. Also, a soft magnetic alloy having a structure composed of Fe-based nanocrystals can be obtained by heat-treating a soft magnetic alloy having a nanoheterostructure. The above microcrystals may have an average grain size of 0.3 to 10 nm.

The soft magnetic alloy according to this embodiment may contain nano-sized crystals. A nano-sized crystal is a crystal with a particle size of 30 nm or less. All of the above microcrystals, nanocrystals and Fe-based nanocrystals are nano-sized crystals.

A method for confirming whether a soft magnetic alloy has an amorphous structure (an amorphous structure or a nano-heterostructure) or a crystalline structure will be described below.

When the soft magnetic alloy according to the present embodiment is a bulk, which will be described later, the soft magnetic alloy having an amorphous rate X of 85% or more shown in the following formula (1) has an amorphous structure. , a soft magnetic alloy having an amorphization rate X of less than 85% has a crystalline structure.
X=100−(Ic/(Ic+Ia)×100) (1)
Ic: integrated intensity of crystalline scattering Ia: integrated intensity of amorphous scattering

The amorphization rate X is obtained by performing X-ray crystal structure analysis on the soft magnetic alloy by XRD, identifying the phase, and peaking the crystallized Fe or compound (Ic: crystalline scattering integrated intensity, Ia: Amorphous scattering integrated intensity) is read, the crystallization rate is determined from the peak intensity, and calculated by the above formula (1). The calculation method will be described in more detail below.

The soft magnetic alloy according to this embodiment is subjected to X-ray crystal structure analysis by XRD, and a chart as shown in FIG. 1 is obtained. This is subjected to profile fitting using the Lorentz function of the following formula (2), and the crystalline component pattern α _c indicating the integrated crystalline scattering intensity and the amorphous We obtain the component pattern α _a and the combined pattern α _c+a . From the integrated crystalline scattering intensity and the integrated amorphous scattering intensity of the obtained pattern, the amorphization rate X is obtained by the above formula (1). The measurement range is a diffraction angle 2θ of 30° to 60° where a halo originating from the amorphous material 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 should be within 1%.

When the soft magnetic alloy according to the present embodiment is in the form of a thin film, which will be described later, charts as shown in FIGS. 3 and 4 are obtained by X-ray crystal structure analysis of the thin film. By analyzing the charts shown in FIGS. 3 and 4 with software, it is possible to confirm whether the thin film has an amorphous structure or a crystalline structure. FIG. 3 is a chart when the thin film has a structure containing crystals, and FIG. 4 is a chart when the thin film has an amorphous structure. Furthermore, the crystal grain size of crystals contained in the thin film can also be confirmed at the same time. Peak a in FIG. 3 is a crystal-derived peak. Peaks b to d in FIGS. 3 and 4 are derived from the substrate.

The reason why the above formula (1) is not used is that it is difficult to accurately calculate the amorphization rate X for a thin film. The reason why it is difficult to accurately calculate the amorphization rate X for thin films is that when the thin film is subjected to X-ray crystal structure analysis, it is difficult to analyze only the thin film by X-ray crystal structure analysis, and the thin film and the substrate are subjected to X-ray crystal structure analysis. This is because structural analysis is required. X-ray crystal structure analysis of thin films and substrates is greatly affected by the substrate. This is because the S/N ratio of the resulting chart is reduced as a result.

The shape of the soft magnetic alloy of this embodiment is not particularly limited. For example, a thin film shape, ribbon shape, and powder shape are mentioned.

A thin film method is used to produce soft magnetic alloys in the form of thin films. The type of thin film method is not particularly limited. For example, a thin film can be formed by a sputtering method or a vapor deposition method. A case of forming a thin film by a sputtering method will be described below.

The films may be formed simultaneously by multi-target sputtering using a plurality of types of targets, or may be formed by single-target sputtering while appropriately changing the targets.

There is no particular limitation on the temperature of the substrate during film formation. For example, it may be 100°C to 350°C.

The type of substrate is not particularly limited. For example, thermally oxidized silicon substrates, silicon substrates, glass substrates, and ceramic substrates can be used. Examples of ceramic substrates include barium titanate substrates and ALTIC substrates. In addition, cleaning may be performed as appropriate before performing sputtering.

The film thickness of the thin film is not particularly limited. For example, it may be 50 nm to 200 nm.

There is no particular limitation on the method for producing the ribbon-shaped soft magnetic alloy. For example, there is a manufacturing method by a single roll method. Also, the ribbon may be a continuous ribbon.

In the single roll method, first, pure metals of each metal element contained in the finally obtained soft magnetic alloy ribbon are prepared and weighed so as to have the same composition as the finally obtained soft magnetic alloy ribbon. Then, pure metals of each metal element are melted and mixed to prepare a master alloy. The method of melting the pure metal is arbitrary, but for example, there is a method of melting by high-frequency heating after evacuating the chamber. The master alloy and the finally obtained soft magnetic alloy ribbon usually have the same composition.

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 1200 to 1500°C.

In this embodiment, the temperature of the rolls is not particularly limited. For example, room temperature to 90°C may be used. Moreover, there is no particular limitation on the differential pressure (injection pressure) between the inside of the chamber and the inside of the injection nozzle. For example, it may be 20 to 80 kPa.

In the single roll method, the thickness of the ribbon obtained can be adjusted mainly by adjusting the rotational speed of the rolls. The thickness of the ribbon obtained can be adjusted. There is no particular limitation on the thickness of the ribbon. For example, it is 10 to 80 μm.

The soft magnetic alloy ribbon before the heat treatment does not contain crystals with a grain size larger than 30 nm. The soft magnetic alloy ribbon before the heat treatment may have a structure consisting only of an amorphous material, or may have a nano-heterostructure in which microcrystals are present in the amorphous material.

A method of manufacturing a soft magnetic alloy ribbon having a structure composed of Fe-based nanocrystals by heat-treating the soft magnetic alloy ribbon will be described below. In this embodiment, the structure composed of Fe-based nanocrystals is a structure composed of crystals having an amorphization rate X of less than 85%. As described above, the amorphization rate X can be measured by carrying out X-ray crystal structure analysis by XRD.

There are no particular restrictions on the heat treatment conditions for producing the soft magnetic alloy ribbon having a structure composed of Fe-based nanocrystals. For example, the heat treatment temperature is 400 to 700° C., and the heat treatment time is 0.5 to 10 hours. Moreover, the atmosphere during the heat treatment is not particularly limited. It may be carried out in an active atmosphere such as air, an inert atmosphere such as Ar gas, or in vacuum.

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

There is no particular limitation on the method for producing the powdery soft magnetic alloy. For example, a method of pulverizing a ribbon-shaped soft magnetic alloy can be used. Moreover, the method by a gas atomization method is mentioned.

In the gas atomization method, first, pure metals of each metal element contained in the finally obtained soft magnetic alloy are prepared and weighed so as to have the same composition as the finally obtained soft magnetic alloy. Then, pure metals of each metal element are melted and mixed to prepare a master alloy. The method for melting the pure metal is not particularly limited, but there is, for example, a method in which the chamber is evacuated and then melted by high-frequency heating. The master alloy and the finally obtained soft magnetic alloy usually have the same composition.

Next, the produced master alloy is heated and melted to obtain a molten metal (molten metal). Although the temperature of the molten metal is not particularly limited, it can be, for example, 1200-1500.degree. After that, the molten alloy is jetted by a gas atomizer to produce powder.

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

The particle size of the soft magnetic alloy powder is not particularly limited. For example, D50 is 1 to 150 μm. When the soft magnetic alloy powder has a structure composed of Fe-based nanocrystals, one particle of the soft magnetic alloy powder usually contains a large number of Fe-based nanocrystals. Therefore, the grain size of the soft magnetic alloy powder and the crystal grain size of the Fe-based nanocrystals are different.

Suitable injection conditions vary depending on the composition of the molten metal and the target particle size, but are, for example, 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.

Soft magnetic alloy powder before heat treatment is obtained by the above method. In order to suitably control the particle size, it is preferable that the soft magnetic alloy powder has an amorphous structure at this point.

In order to suitably obtain a soft magnetic alloy powder having a structure composed of Fe-based nanocrystals, it is preferable to heat-treat the soft magnetic alloy powder having an amorphous structure obtained by the gas atomization method. . For example, heat treatment at 400 to 700° C. for 0.5 to 10 hours makes it easier to obtain a soft magnetic alloy powder having a structure preferably composed of Fe-based nanocrystals.

A soft magnetic alloy having an amorphous structure can be obtained by lowering the heat treatment temperature. Although the heat treatment may not be performed, it is preferable to perform the heat treatment at a low temperature such as 200 to 400.degree. This is because the heat treatment relaxes the strain and stress and reduces the coercive force.

There is no particular limitation on the use of the soft magnetic alloy according to this embodiment. For example, in the case of soft magnetic alloy ribbons, cores, inductors, transformers, motors, and the like are included. Soft magnetic alloy powders include dust cores. In particular, it can be suitably used as a dust core for inductors, particularly power inductors. It can also be suitably used for magnetic parts using soft magnetic alloy thin films, such as thin film inductors and magnetic heads.

In addition, the soft magnetic alloy according to the present embodiment can be suitably used for electronic devices containing the above soft magnetic alloy, such as geomagnetic sensors of smartphones, and actuators of camera shake correction mechanisms of image sensors of digital cameras and smartphones.

EXAMPLES The present invention will be described below based on more detailed examples, but the present invention is not limited to these examples.

(Experimental example 1)
Thin-film-shaped soft magnetic alloys having the compositions shown in Tables 1 to 13 were produced. Compositions are described in terms of atomic number ratios. The Co content ratio is the atomic number ratio of Co when the soft magnetic alloy is set to 1. Specifically, it is equal to α(1−(a+b+c)). The Ni content ratio is the atomic number ratio of Ni when the soft magnetic alloy is set to 1. Specifically, it is equal to β(1−(a+b+c)). The X content ratio is the content ratio of Ni in the atomic number ratio when the soft magnetic alloy is set to 1. Specifically, it is equal to γ(1−(a+b+c)).

The thin film was formed using magnetron sputtering (ES340 manufactured by Eiko Co., Ltd.). In addition, simultaneous film formation was performed by multi-source sputtering using a plurality of types of targets. The temperature of the substrate was 250°C.

Next, the thin film was heat-treated, but before that, it was confirmed whether the thin film before the heat treatment was amorphous or crystalline. Charts such as those shown in FIGS. 3 and 4 were prepared for each thin film using XRD. Then, the obtained chart was analyzed using software (Panalytical; Highscore) to confirm whether the thin film before the heat treatment was amorphous or crystalline. 3 shows an example in which the thin film is made of crystal, and FIG. 4 shows an example in which the thin film is made of amorphous. All the thin films shown in Tables 1 to 13 were amorphous before the heat treatment.

Next, heat treatment was performed at temperatures shown in Tables 1 to 13 for each of the thin films produced. The atmosphere during heat treatment was a vacuum.

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 with a maximum applied magnetic field of 1000 Oe using a vibrating sample magnetometer (VSM). A case in which the rate of increase in Bs was 5.0% or more compared to the case of the same composition except that it did not contain Co was evaluated as good. Also, a case where the rate of increase in Hc was less than 50.0% was evaluated as good. In some cases, the heat treatment temperature is set lower for the case where Co is not included, because the Curie temperature may be lower when Co is not included than when Co is included. Although Hc and Bs are not particularly limited, Hc is preferably 15.0 Oe or less. Bs is preferably 1.50 T or more.

Of the thin films after heat treatment shown in Tables 1 to 13, all the thin films after heat treatment shown in tables other than Tables 2 and 6 have an average grain size of 5 to 30 nm and a crystal structure of Fe. It was confirmed by X-ray diffraction measurement and observation using a transmission electron microscope that the base nanocrystals were present. Also, it was confirmed by ICP analysis that there was no change in the alloy composition before and after the heat treatment. In addition, the thin films after the heat treatment shown in Tables 2 and 6 were amorphous like the thin films before the heat treatment.

The thin films shown in Table 1 do not contain C. The thin films shown in Table 2 do not contain M and C. The thin films shown in Table 3 do not contain X3. As a result, even if the Co content ratio is changed, the Bs increase rate and/or the Hc increase rate are not as good as those of the comparative examples having the same composition except that Co is not included.

The thin films shown in Tables 4 to 6 are experimental examples in which the Co content ratio was changed in the case where the composition was within a predetermined range except for the Co content ratio. Each example in which the Co content ratio was within a predetermined range had a higher Bs increase rate and a lower Hc increase rate than the comparative example having the same composition except that it did not contain Co. In other words, the addition of Co could significantly increase Bs without significantly increasing Hc. On the other hand, in each of the comparative examples containing Co but with an excessively low Co content ratio, Hc was remarkably increased compared to the comparative examples having the same composition except that Co was not contained. In addition, sample number 60, in which the Co content ratio is too high, had a lower Bs and a significantly higher Hc than the comparative example having the same composition except that it did not contain Co.

The films shown in Table 7 have compositions with too little X3(P) content. As a result, even if the Co content ratio is changed, the Bs increase rate and/or the Hc increase rate are not as good as those of the comparative examples having the same composition except that Co is not included.

The thin films shown in Table 8 are thin films of sample numbers 51 and 56 in which b and c are changed. When b, c, and b+c are within the predetermined ranges, the example having a Co content ratio of 0.500 is compared with the comparative example having the same composition except that the Co content ratio is 0.000. As a result, Hc did not increase significantly, but Bs increased significantly. On the other hand, when any one or more of b, c and b+c is outside the predetermined range, the comparative example with the Co content ratio of 0.500 is compared with the Co content ratio of 0.000. Hc increased greatly compared to the example.

The thin films shown in Table 9 are thin films of sample numbers 51 and 56 in which a is changed. When a is within a predetermined range, the Hc of the example having a Co content ratio of 0.500 is higher than that of the comparative example having the same composition except that the Co content ratio is 0.000. Bs increased significantly without a large increase. On the other hand, when a is outside the predetermined range, the comparative example with a Co content ratio of 0.500 showed a large increase in Hc compared to the comparative example with a Co content ratio of 0.000. .

The thin films shown in Table 10 are thin films obtained by changing the type of X3 for sample numbers 51 and 56. Even when the type of X3 was changed, the example with a Co content ratio of 0.500 did not show a large increase in Hc and a large increase in Bs compared to the comparative example with a Co content ratio of 0.000.

The thin films shown in Table 11 are thin films obtained by changing the type of M for sample numbers 51 and 56. Even when the type of M was changed, the example with a Co content of 0.500 did not show a large increase in Hc and a large increase in Bs compared to the comparative example with a Co content of 0.000. For sample numbers 107 and 108, the heat treatment temperature is lowered. This is because when Hf is used as M, the crystallization temperature is lower than when other M is used.

The thin films shown in Table 12 are thin films of sample numbers 51 and 56 with different Ni content ratios. Even if the Ni content ratio is changed, Hc is greatly increased in the example having a Co content ratio of 0.500 compared to the comparative example having the same composition except that the Co content ratio is 0.000. Bs increased significantly without Note that when Ni was contained, both the Bs increase rate and the Hc increase rate were lower than when Ni was not contained.

The thin films shown in Table 13 are thin films containing 1 at % of X for sample numbers 51 and 56. Even if the type of X is changed, the Hc of the example having a Co content ratio of 0.500 is significantly increased compared to the comparative example having the same composition except that the Co content ratio is 0.000. Bs increased significantly.

(Experimental example 2)
Ribbon-shaped soft magnetic alloys having the compositions shown in Tables 14 to 16 were produced. Compositions are described in terms of atomic number ratios.

A method for producing a ribbon-shaped soft magnetic alloy will be described below. First, pure metal materials were weighed so as to obtain master alloys having the compositions shown in Tables 14 to 16. Then, after the chamber was evacuated, it was melted by high-frequency heating to produce a master alloy.

After that, the prepared mother alloy was heated and melted to form a metal in a molten state at 1200° C., and then the rolls were rotated at a rotation speed of 15 m/sec. The metal was jetted onto a roll by a single roll method in which the roll was rotated at a pressure of 100 rpm to prepare a ribbon. The material of the roll was Cu. The roll temperature was 25° C., and the differential pressure (injection pressure) between the chamber and the injection 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. The length was set to several tens of meters.

Next, the ribbon was heat-treated, but before that, it was confirmed whether the ribbon before the heat treatment was amorphous or crystalline. The amorphization rate X of each ribbon was measured using XRD, and when X was 85% or more, it was determined to be amorphous. It was said to be crystalline if X was less than 85%. All ribbons shown in Tables 14 to 16 were amorphous before the heat treatment.

Next, heat treatment was performed for 60 minutes at the temperatures shown in Tables 14 to 16 for each of the produced ribbons. The atmosphere during the heat treatment was an inert atmosphere (Ar atmosphere).

The coercive force Hc and saturation magnetic flux density Bs of each ribbon after the heat treatment were measured. The coercive force Hc was measured using an Hc meter. The saturation magnetic flux density Bs was measured with a maximum applied magnetic field of 1000 Oe using a vibrating sample magnetometer (VSM). A case in which the rate of increase in Bs was 5.0% or more compared to the case of the same composition except that it did not contain Co was evaluated as good. Also, a case where the rate of increase in Hc was less than 50.0% was evaluated as good. In some cases, the heat treatment temperature is set lower for the case where Co is not included, because the Curie temperature may be lower when Co is not included than when Co is included. Although Hc and Bs are not particularly limited, Hc is preferably 5.0 A/m or less. Bs is preferably 1.50 T or more.

Of the ribbons after heat treatment shown in Tables 14 to 16, all the ribbons after heat treatment shown in Tables 14 and 15 have an average grain size of 5 to 30 nm and a crystal structure of bcc. The presence of nanocrystals was confirmed by X-ray diffraction measurement and observation using a transmission electron microscope. Also, it was confirmed by ICP analysis that there was no change in the alloy composition before and after the heat treatment. Further, the ribbons after the heat treatment shown in Table 16 were amorphous like the ribbons before the heat treatment.

The ribbons shown in Table 14 are experimental examples in which the Co content ratio was changed in the case where the composition was within a predetermined range except for the Co content ratio. Each example in which the Co content ratio was within a predetermined range had a higher Bs increase rate and a lower Hc increase rate than the comparative example having the same composition except that it did not contain Co. In other words, the addition of Co could significantly increase Bs without significantly increasing Hc. On the other hand, in each of the comparative examples containing Co but with an excessively low Co content ratio, Hc was remarkably increased compared to the comparative examples having the same composition except that Co was not contained. In addition, sample No. 148, which has an excessively high Co content, has a lower Bs and a significantly higher Hc than the comparative example having the same composition except that it does not contain Co. Note that when Hf is used as M, the heat treatment temperature is lowered compared to when other M is used. This is because when Hf is used as M, the crystallization temperature is lower than when other M is used.

The ribbons shown in Table 15 are thin films containing 1 at % of X for sample numbers 141 and 145. Even if the type of X is changed, the Hc of the example having a Co content ratio of 0.500 is significantly increased compared to the comparative example having the same composition except that the Co content ratio is 0.000. Bs increased significantly.

The ribbons shown in Table 16 are experimental examples in which the composition and heat treatment temperature were changed compared to the ribbons shown in Tables 14 and 15. Unlike the ribbons shown in Tables 14 and 15, the ribbons shown in Table 16 are amorphous. In this case as well, the inclusion of Co enabled a large increase in Bs without a large increase in Hc.

Claims (8)

A soft magnetic alloy having a composition formula (Fe _{(1-(α+β+γ))} Co _α Ni _β X _γ ) _(1-(a+b+c)) M _a C _b X3 _c (atomic ratio),
X is 1 selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, Ca, Mg, Ti, Na, N, V, Mo, O, S and rare earth elements; one or more
M is one or more selected from the group consisting of Ta, Zr, Hf, Nb and W;
X3 is one or more selected from the group consisting of P, B, Si and Ge;
0.050≤a≤0.120
0.040<b≦0.140
0.020≤c≤0.080
0.060<b+c≦0.160
0.400<α(1−(a+b+c))≦0.800
0≦β(1−(a+b+c))≦0.200
γ≧0
0≤β+γ≤0.500
A soft magnetic alloy. A soft magnetic alloy according to claim 1, comprising nano-sized crystals. 3. The soft magnetic alloy according to claim 1, wherein 0.500≦α(1−(a+b+c))≦0.800. The soft magnetic alloy according to any one of claims 1 to 3, which is in the form of a thin film. The soft magnetic alloy according to any one of claims 1 to 3, which has a ribbon shape. The soft magnetic alloy according to any one of claims 1 to 3, which is in powder form. A magnetic component comprising the soft magnetic alloy according to any one of claims 1 to 6. An electronic device comprising the soft magnetic alloy according to any one of claims 1 to 6.

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