JPH0885821A - Production of nano-crystal alloy with high magnetic permeability - Google Patents

Abstract

PURPOSE: To produce a nano-crystal alloy having remarkably high relative initial permeability by rapidly solidifying a molten Fe-base alloy of specific composition, applying heat treatment to the resulting amorphous body under specific temp. conditions, and forming a microcrystalline structure. CONSTITUTION: A molten Fe-base alloy, having a composition represented by general formula (Fe1-a Ma )100- X- Y- Z-b-c-d AXM'YM"ZXb Sic Bd (where M means Co and/or Ni, A means Cu and/or Au, M' means one or more elements among Ti, V, Zr, Nb, Mo, Hf, Ta, and W, M" means one or more kinds among Cr, Mn, Sn, Zn, Ag, In, platinum group metals, Mg, Ca, Sr, Y, rare earth elements, N, O, and S, and 0<=a<=0.1, 0.1<=X<=3, 1<=Y<=10, 0<=Z<=10, 0<=b<=10, 11<=c<=17, and 3<=d<=10, by atomic %, are satisfied, respectively) is used. This molten alloy is rapidly solidified, and the resulting amorphous alloy is heated to a temp. not lower than the crystallization temp., held at the temp. for <5min, and cooled down to room temp. while regulating the cooling rate to >=20 deg.C/min until at least 400οC is reached. By this method, the nano-crystal alloy containing microcrystalline grains of <=30nm average crystalline grain size can be stably produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a nanocrystalline alloy having a particularly high magnetic permeability used in various magnetic parts such as transformers and choke coils.

[0002]

2. Description of the Related Art As a magnetic core material used for a noise filter, a pulse transformer, etc., a high magnetic permeability material such as ferrite or amorphous alloy having excellent high frequency characteristics is used. Not only does the magnetic core material for common mode chokes used for noise filters (line filters) exhibit high permeability characteristics, but it also prevents malfunction of equipment due to high voltage pulse noise generated from lightning or large inverter devices. In order to prevent this, one having excellent pulse attenuation characteristics is required. In order to meet such demands, the conventional ferrite material has a low saturation magnetic flux density and is easily magnetically saturated, so that there is a problem that sufficient performance cannot be obtained with a small magnetic core. Therefore, it has been necessary to use a conventional ferrite material to increase the size of the magnetic core in order to obtain sufficient performance.

Further, the Fe-based amorphous alloy has a high saturation magnetic flux density and exhibits superior attenuation characteristics to high-voltage pulse noise than ferrite, but has a lower magnetic permeability than the Co-based amorphous alloy and has a low voltage level. There is a drawback that the amount of attenuation with respect to noise is not sufficient. Further, since the magnetostriction is extremely large, there is a problem that resonance occurs due to the magnetostrictive vibration depending on the frequency and the characteristics change, and a problem that the magnetic core beats when a current having an audible frequency component flows through the coil.

On the other hand, the Co-based amorphous alloy has a high magnetic permeability and thus is greatly excellent in the amount of attenuation with respect to noise at a low voltage level, but has a saturation magnetic flux density of 1 T or less and a high voltage pulse as compared with the Fe-based amorphous alloy. Is inferior in the attenuation characteristic. In addition, a Co-based amorphous alloy having a high magnetic permeability has a large change over time, and in a high ambient temperature environment, the characteristics are greatly deteriorated and there is a problem in reliability.

Further, a magnetic core material used for a pulse transformer for an ISDN (Integrated Services Digital Network) interface is required to have high magnetic permeability and excellent temperature characteristics. IS
Especially for DN applications, it is important to have high magnetic permeability around 20kHz. Further, depending on the purpose of use, a BH loop having a low squareness ratio and a flat BH loop is required. The initial magnetic permeability was less than 100,000, and the relative magnetic permeability was 10 or less.
Those over 0000 were difficult to realize.

However, in recent years, pulse transformers used in ISDN interfaces have been considered for use in card-type interfaces and are required to be smaller and thinner. In order to satisfy such a small and thin shape, a material having a higher magnetic permeability is required. Further, in order to faithfully transmit a waveform, a material having a low squareness ratio and a flat BH loop and excellent magnetic permeability is also desired.

However, ferrite and Fe-based amorphous alloys have low magnetic permeability, and it is difficult to meet such requirements. Further, ferrite has inferior temperature characteristics, and there is also a problem that the magnetic permeability sharply decreases especially at room temperature or lower.
It is easy to obtain a Co-based amorphous alloy having a high magnetic permeability, but when the ambient temperature is high, there is a problem that the change over time is large and the cost is high, and there is a limit to its general use.

Further, in current sensors such as leakage alarms, magnetic sensors, etc., materials having higher magnetic permeability are required from the viewpoint of small size and high sensitivity. Further, from the viewpoint of realizing linear output, a material having a low squareness ratio, a flat BH loop shape, excellent magnetic permeability and high magnetic permeability is also required.

Since the nanocrystalline alloy exhibits excellent soft magnetic characteristics, it is used in magnetic cores of common mode choke coils, high frequency transformers, earth leakage alarms, pulse transformers and the like.
As a typical composition system, the alloy system described in Japanese Patent Publication No. 4393/1992 and JP-A-1-242755 is known. These nanocrystalline alloys are usually produced by rapidly cooling from a liquid phase or a vapor phase to form an amorphous alloy, and then microcrystallizing the amorphous alloy by heat treatment. As a method of quenching from the liquid phase, a single roll method, a twin roll method,
Centrifugal quenching method, rotating submerged spinning method, atomizing method, cavitation method and the like are known. Further, as a method of quenching from the gas phase, a sputtering method, a vapor deposition method, an ion plating method and the like are known. A nanocrystalline alloy is a microcrystal of an amorphous alloy produced by these methods, and has almost no thermal instability as seen in amorphous alloys.
It is known to exhibit excellent soft magnetic characteristics with high saturation magnetic flux density and low magnetostriction. Furthermore, it is known that the nanocrystalline alloy has a small change over time and is excellent in temperature characteristics.

Further, it is disclosed that a Fe-based microcrystalline alloy (nanocrystalline alloy) as described in JP-B-4-4393 exhibits high permeability and low core loss characteristics and is suitable for these applications. ing.

[0011]

A high relative permeability is required for a common mode choke magnetic core used for a noise filter, an ISDN pulse transformer, and the like. Japanese Patent Examination 4-4393
Describes that the heat treatment of the nanocrystalline alloy is maintained for 5 minutes or more and 24 hours or less. However, it was difficult to realize a remarkably high magnetic permeability exceeding 100,000 with the nanocrystalline alloy produced by heat treatment by the conventional method. An object of the present invention is to provide a method for producing a nanocrystalline alloy having a remarkably high relative magnetic permeability.

[0012]

Means for Solving the Problems The present inventors to solve the above problems, the general _{formula: (Fe 1-a M a} ) 100-xyzbcd A x M 'y M''z X b Si c B _d
(Atomic%) In the formula, M is at least one element selected from Co and Ni, and A is
At least one element selected from Cu, Au, M'is Ti, V, Zr,
Nb, Mo, Hf, at least one element selected from Ta and W, M '' is Cr, Mn, Sn, Zn, Ag, In, white metal element, Mg, Ca, Sr, Y,
Rare earth element, at least one element selected from N, O and S, X represents at least one element selected from C, Ge, Ga, Al and P, a, x, y, z, b , c and d are 0 ≦ a ≦ 0.
1, 0.1 ≦ x ≦ 3, 1 ≦ y ≦ 10, 0 ≦ z ≦ 10, 0 ≦ b ≦ 10, 11 ≦ c
≦ 17, a composition represented by a number satisfying 3 ≦ d ≦ 10, the average crystal grain size is 30 nm or less than the crystallization temperature to obtain a nanocrystalline alloy occupying at least a part of the structure From a low temperature to a temperature above the crystallization temperature, or after the temperature has been raised, hold the temperature at a constant temperature for less than 5 minutes, and set a cooling rate up to 400 ° C.
The inventors have found that by setting the temperature to 20 ° C./min or more, it is possible to obtain the characteristic that the relative initial magnetic permeability is 100000 or more without performing magnetic field treatment, etc.

The above-mentioned crystal is a bccFe phase mainly containing Si and may include a regular lattice. In addition, elements other than Si, such as B, Al, Ge, and Zr, may be solid-dissolved. The balance other than the crystalline phase is mainly an amorphous phase, but an alloy consisting essentially of the crystalline phase is also included in the present invention.

The relative initial permeability is obtained from the initial magnetization curve of the DC BH loop, but the relative initial permeability (effective relative permeability) becomes constant or decreases as the frequency increases. Therefore, for example, if the relative initial magnetic permeability μ _ir (effective relative magnetic permeability μ _e ) at a frequency of about 50 Hz to 1 kHz exceeds 100000, it is naturally included in the present invention. The measured excitation level at this time is usually 0.05 A · m ⁻¹ or less.

The alloy of the present invention has an average grain size of 30 nm or less after the amorphous alloy having the above composition is produced by the ultra-quenching method such as the single roll method, processed into the shape of the magnetic core, and heat-treated within a certain condition range. It is produced by forming fine crystals of.

More specifically, the temperature is raised from the temperature lower than the crystallization temperature to the temperature higher than the crystallization temperature or kept at a constant temperature for less than 5 minutes, and the cooling rate is 20 ° C / min or more up to at least 400 ° C. The high permeability nanocrystalline alloy can be manufactured by the heat treatment of cooling to room temperature. Conventionally, the holding time was considered to be 5 minutes or more in consideration of variations in characteristics, but it has been found that a heat treatment time of less than 5 minutes is desirable in order to realize a high magnetic permeability exceeding 100000. Furthermore, it was found that, as a result of intensive study, the variation can be made equal to that obtained when the temperature rising rate is controlled for 5 minutes or more. A preferable temperature rising rate is 0.2 to 30 ° C./min,
A more preferable temperature rising rate is 1 to 10 ° C./min.

It has been found that extending the holding time is not so important in terms of promoting crystallization and improving the characteristics, since crystallization progresses considerably during temperature rise. Rather, it has been found that holding for a long time after crystallization causes an originally unnecessary induced magnetic anisotropy during holding and acts in the direction of decreasing the initial magnetic permeability.

In this heat treatment, it is important to cool to room temperature while maintaining a cooling rate of 20 ° C / min or more up to at least 400 ° C. At a cooling rate of less than 20 ° C / min, unnecessary induced magnetic anisotropy occurs and high specific permeability cannot be obtained. More preferable cooling rate range is 30 to 400.
C / min.

In the heat treatment for crystallization, after the first heat treatment step in which the temperature is raised or kept at a constant temperature for less than 5 minutes, the magnetic field is cooled to a temperature lower than 500 ° C. lower than the above temperature. After the second heat treatment step of holding for a certain period of time while applying, the temperature is cooled to room temperature, or the temperature is raised to the crystallization temperature or higher and then held for 0 to 5 minutes and cooled to near room temperature
The high permeability nanocrystalline alloy can also be obtained by applying a magnetic field for at least part of a temperature lower than the first heat treatment at 500 ° C. or lower after the heat treatment for crystallization of 1, and performing the second heat treatment. It becomes possible to manufacture. The second heat treatment is preferably performed at 250 ° C. or higher.

In this case, a nanocrystalline alloy having a low squareness ratio and a high magnetic permeability can be realized. The reason for this is that the holding time after elevating the temperature above the crystallization temperature is shorter than in the conventional heat treatment, and induced magnetic anisotropy in which various directions are easy axes depending on the location related to the magnetic domain structure is less likely to occur, so it is low. It is considered that when annealed in a magnetic field at a temperature, anisotropy dispersion is reduced, and high permeability is realized with a low squareness ratio.

Further, in this case, the frequency characteristic of magnetic permeability is also improved, and the magnetic permeability is improved at a high frequency as compared with the case where no heat treatment is performed in a magnetic field. The time for applying the magnetic field is determined in relation to the magnetic permeability, but from the viewpoint of obtaining high magnetic permeability, it is within 2 hours, more preferably within 1 hour, and particularly preferably 30
Within minutes is preferable.

It is difficult to produce a nanocrystalline alloy having a relative initial magnetic permeability of 100,000 or more even if these heat treatment methods are applied to alloys having a deviated composition. The direction of applying the magnetic field may be slightly deviated from the width direction or the thickness direction of the alloy ribbon, but particularly in the width direction or the thickness direction of the alloy ribbon, it is easy to obtain a high magnetic permeability with a low squareness ratio. In the case of a magnetic core, it corresponds to the height direction or the radial direction of the magnetic core. The strength of the applied magnetic field is usually 80 kA · m ⁻¹ or more in a practical shape. The magnetic field should be applied to the extent that the alloy is saturated. The larger the applied magnetic field, the more reliable the alloy becomes, which is preferable.
If the magnetic field is such that the alloy is completely saturated, it is not necessary to apply a stronger magnetic field.

The plate thickness of the alloy is usually about 2 μm to 50 μm, but when it is a thin band of 15 μm or less, excellent characteristics can be realized particularly in frequency characteristics such as magnetic permeability and magnetic core loss. in this case,
In particular, it is suitable for a core for a noise filter such as a common mode choke and a core for a high frequency transformer.

It is desirable that the heat treatment is carried out in an atmosphere of at least one gas selected from nitrogen, argon and helium, since the soft magnetic characteristics are not particularly deteriorated. Oxygen is generally contained in the atmosphere gas, but it is desirable that the amount of oxygen is small because it adversely affects the magnetic permeability, and the amount of oxygen is 1% or less,
It is more preferably 0.1% or less, and particularly preferably 0.01% or less. It is effective to move the atmosphere gas in the furnace when processing a large magnetic core or a large number of magnetic cores.

The alloys and magnetic cores of the present invention may contain Si if necessary.
At least one surface of the alloy ribbon surface is coated with a powder or film mainly containing O ₂ , MgO, Al ₂ O _3, etc., and the surface is treated by chemical conversion treatment or anodic polarization treatment to form an insulating layer on the surface. Interlayer insulation may be performed. This is particularly effective in reducing the effect of eddy currents at high frequencies and improving magnetic permeability and core loss. The interlayer insulation is particularly effective in the case of a magnetic core having a good surface condition and composed of a wide ribbon.

[0026]

In the present invention, by shortening the holding time after the temperature is raised above the crystallization temperature, the induced magnetic anisotropy whose size and direction are different depending on the location generated during the heat treatment without magnetic field, which is not originally necessary for the purpose of improving the magnetic permeability. This has the effect of reducing the directionality and achieving high magnetic permeability. Furthermore, by applying heat treatment in a magnetic field at a low temperature and imparting induced magnetic anisotropy in one direction, it is possible to reduce the anisotropy dispersion caused by the induced magnetic anisotropy that occurs during heat treatment without a magnetic field. In addition, it is possible to realize a flat BH loop with a low squareness ratio and a high magnetic permeability.

[0027]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto. (Example 1) Cu 1%, Nb 3.2%, Si 15.4%, B 6.6 in atomic%
The remaining molten alloy consisting essentially of Fe was quenched by a single roll method to obtain an amorphous alloy with a width of 6.5 mm and a thickness of 18 μm.
This amorphous alloy is wound around an outer diameter of 20 mm and an inner diameter of 10 mm,
A toroidal magnetic core was produced. The crystallization temperature T _x of this alloy was measured and found to be 506 ° C. The produced magnetic core was inserted into a heat treatment furnace kept at 450 ° C in an argon atmosphere, and heat-treated in the heat treatment pattern shown in Fig. 1 to produce alloys A, B and C. Alloy A is t _a = 0 min, the alloy B is t _a = 2 min, alloy C was t _a = 4 min.

For comparison, at 550 ° C for 5 minutes, 15 minutes, 30 minutes, 60
The magnetic properties of alloys D, E, F, and G that were held for minutes and heat treated were also examined. Table 1 shows the obtained magnetic characteristics. Where 800A
・ When a magnetic field of m ^-1 is applied, the magnetic flux density is B ₈₀₀ and the residual magnetic flux density is B _r .

[0029]

[Table 1]

As can be seen from the table, the alloys A, B and C which have been subjected to the heat treatment according to the present invention have characteristics that the specific initial magnetic permeability μ _ir is 100000 or more. On the other hand, alloys D to G which had been subjected to the conventional heat treatment at 550 ° C for 5 minutes or more showed specific initial magnetic permeability µ _ir of less than 100000. Fig. 2 shows DC of alloy D of the conventional example.
An example of a BH loop is shown. Inventive alloy A is conventional alloy D
Coercive force is smaller than It is considered that since the alloy of the present invention originally has an unnecessary induced magnetic anisotropy and the degree of magnetic domain fixation is small, the alloy of the present invention to which the heat treatment of the present invention is applied has a higher magnetic permeability. . On the other hand, the magnetic properties of the alloy (Fe _bal. Cu ₁ Nb ₃ Si ₁₀ B ₉ ) having a composition other than the composition according to the present invention as a comparative example and subjected to the same heat treatment as in the present invention are also shown in Table 1.
Shown in In this case, even if the same heat treatment was performed, a high specific initial magnetic permeability exceeding 100,000 like the invention alloy could not be obtained.

(Example 2) Cu 1%, Nb 3%, Si 1 in atomic%
3.8%, B 8.5% balance The alloy melt consisting essentially of Fe was rapidly cooled in a helium gas atmosphere under reduced pressure by the single roll method, and the width was 5 m.
An amorphous alloy with a thickness of 6 μm was prepared. Next, the surface of this amorphous alloy ribbon was covered with SiO ₂ . This amorphous alloy ribbon is wound around an outer diameter of 19 mm and an inner diameter of 15 mm,
A toroidal magnetic core was produced. The crystallization temperature T _x of this alloy was measured and found to be 523 ° C. Next, this alloy was heat-treated by the heat treatment pattern shown in FIG. Temperature rising rate is 1.5 ° C / mi
n, the temperature was raised to 550 ° C, the holding time was zero, and the average cooling rate S ₂ up to 400 ° C was changed. The obtained results are shown in Table 2.

[0032]

[Table 2]

When S ₂ was 20 ° C./min or more, a high specific initial magnetic permeability exceeding 100000 was obtained. On the other hand, 1000 at less than 20 ° C / min
Only values less than 00 were obtained.

Example 3 A molten alloy having the composition shown in Table 3 was rapidly cooled by a single roll method to obtain an amorphous alloy ribbon having a width of 12.5 mm and a thickness of 18 μm. Next, this alloy ribbon was wound around an outer diameter of 20 mm and an inner diameter of 14 mm to prepare a toroidal wound magnetic core. Next, heat treatment was performed using the heat treatment pattern shown in FIG. The squareness ratio B _r · B ₈₀₀ ⁻¹ and the relative initial permeability μ _ir of the heat-treated alloy were measured. Table 3 shows the measured results.

[0035]

[Table 3]

In the alloy having the composition range according to the present invention,
A relative magnetic permeability of 100,000 or more can be obtained. Also, the squareness ratio is 30%
It was as follows. However, alloys outside the composition range related to the present invention could not obtain high magnetic properties. It is considered that the reason for this is that, outside the scope of the present invention, large anisotropy and large magnetostriction are caused by heat treatment in a magnetic field.

(Example 4) Cu 1%, Nb 2.5%, Cr in atomic%
0.2%, Si 14.8%, B 7.5%, Sn 0.05% The balance is made by quenching the alloy melt consisting essentially of Fe by the single roll method, and width 10 mm and thickness 18
An amorphous alloy ribbon of μm was obtained. The crystallization temperature of this alloy was 490 ° C. This amorphous alloy has an outer diameter of 30 m
The toroidal magnetic core was produced by winding the m-shaped steel sheet with an inner diameter of 20 mm. Next, heat treatment was performed using the heat treatment patterns shown in FIGS. 5 (a) (b) (c). This alloy when performed with each heat treatment pattern
Table 4 shows the squareness ratio and relative magnetic permeability of C. For comparison, alloys having compositions outside the range of the alloy of the present invention (Cu 1% at atomic%, Nb 2.5%,
The magnetic properties of Si 10%, B 11%) (alloy D) are also shown.

The present heat treatment is effective for the composition of the alloy of the present invention, and a high specific initial magnetic permeability exceeding 100000 is realized, but a specific initial magnetic permeability exceeding 100000 cannot be obtained outside the composition range of the alloy of the present invention.

[0039]

[Table 4]

Example 5 A molten alloy having the composition shown in Table 5 was rapidly cooled by a single roll method to obtain an amorphous alloy ribbon having a width of 12.5 mm and a thickness of 18 μm. Next, use this alloy ribbon with an outer diameter of 20 mm
The toroidal wound magnetic core was wound around 14 mm. Next in FIG.
The heat treatment was performed by the heat treatment pattern shown in. Squareness ratio of heat-treated alloy B _r · B ₈₀₀ ^-1 , specific initial permeability μ _ir and 100 kHz,
The core loss P _c at 0.2 T was measured. Table 5 shows the measured results.

[0041]

[Table 5]

In the composition range of the alloy of the present invention, a specific initial magnetic permeability of 100,000 or more is obtained. It is considered that the reason for this is that, outside the scope of the present invention, large anisotropy and large magnetostriction are caused by heat treatment in a magnetic field. When a heat treatment in a magnetic field at _a holding temperature T _a exceeding 500 ° C, which deviates from the heat treatment of the present invention, _a specific initial magnetic permeability exceeding 100000 cannot be obtained, and it is only when such a low squareness ratio is obtained by combining with the heat treatment of the present invention. A high relative magnetic permeability has been realized. Moreover, the magnetic core loss P _c is as low as 300 kW · m ⁻³ or less, and it is suitable for various transformers, choke coils, and the like where low magnetic core loss is important.

[0043]

EFFECTS OF THE INVENTION According to the present invention, a method for producing a nanocrystalline alloy exhibiting a remarkably high relative initial magnetic permeability can be provided, so that the effect is remarkable.

[Brief description of drawings]

FIG. 1 is a diagram showing a heat treatment pattern according to the present invention.

FIG. 2 is a diagram showing an example of a DC BH loop of an alloy according to the present invention.

FIG. 3 is a view showing a heat treatment pattern according to the present invention.

FIG. 4 is a view showing a heat treatment pattern according to the present invention.

FIG. 5 is a view showing a heat treatment pattern according to the present invention.

FIG. 6 is a view showing a heat treatment pattern according to the present invention.

Front page continuation (72) Inventor Shunsuke Arakawa 5200 Mikageri, Kumagaya, Saitama Hitachi Metals Co., Ltd.

Claims (6)

[Claims] 1. A general formula: (Fe _1-a M _a ) _100-xyzbcd A _x
M'y M '' _z X _b Si _c B _d (atomic%) In the formula, M is at least one element selected from Co and Ni, and A is at least 1 selected from Cu and Au.
Element, M'is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta and W, M '' is Cr, Mn, Sn, Zn, Ag, In, white metal Element, Mg, Ca, Sr, Y, at least one element selected from rare earth elements, N, O and S, X represents at least one element selected from C, Ge, Ga, Al and P , A, x, y, z, b, c and
d is 0 ≦ a ≦ 0.1, 0.1 ≦ x ≦ 3, 1 ≦ y ≦ 10, 0 ≦ z ≦ 1
0, 0 ≤ b ≤ 10, 11 ≤ c ≤ 17, 3 ≤ d ≤ 10 In the method for producing a nanocrystalline alloy that crystallizes an amorphous alloy by heat treatment, the crystallization temperature After raising the temperature from a lower temperature to above the crystallization temperature, at least 40
A method for producing a high-permeability nanocrystalline alloy, which comprises cooling to room temperature at a cooling rate of 20 ° C / min or more up to 0 ° C. 2. The method for producing a nanocrystalline alloy according to claim 1, wherein after the temperature is raised from a temperature lower than the crystallization temperature to the crystallization temperature or more and then kept at a constant temperature for less than 5 minutes, at least 4
A method for producing a high-permeability nanocrystalline alloy, which comprises cooling to room temperature at a cooling rate of 20 ° C / min or more up to 00 ° C. 3. A holding temperature of the first heat treatment of 500 ° C. or lower after the heat treatment for the first crystallization, which is performed after the temperature is raised to the crystallization temperature or higher or after being kept at a constant temperature for a certain period and then cooled to around room temperature. The method for producing a high-permeability nanocrystalline alloy according to claim 1 or 2, wherein the second heat treatment is carried out by applying a magnetic field at a low temperature for a certain period of time and holding the same. 4. The general formula: (Fe _1-a M _a ) _100-xyzbcd A _x
M'y M '' _z X _b Si _c B _d (atomic%) In the formula, M is at least one element selected from Co and Ni, and A is at least 1 selected from Cu and Au.
Element, M'is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta and W, M '' is Cr, Mn, Sn, Zn, Ag, In, white metal Element, Mg, Ca, Sr, Y, at least one element selected from rare earth elements, N, O and S, X represents at least one element selected from C, Ge, Ga, Al and P , A, x, y, z, b, c and
d is 0 ≦ a ≦ 0.1, 0.1 ≦ x ≦ 3, 1 ≦ y ≦ 10, 0 ≦ z
In the method for producing a nanocrystalline alloy, in which an amorphous alloy having a composition represented by a number satisfying ≦ 10, 0 ≦ b ≦ 10, 11 ≦ c ≦ 17, 3 ≦ d ≦ 10 is microcrystallized by heat treatment, crystallization is performed. After the first heat treatment step of raising the temperature above the temperature, after cooling to a temperature of 500 ° C or less, after the second heat treatment step of holding for a certain time while applying a magnetic field, it is cooled to room temperature. Method for producing magnetic permeability nanocrystalline alloy. 5. The method for producing a nanocrystalline alloy according to claim 4, wherein in the first heat treatment step, the temperature is raised to crystallization temperature or higher, held at a constant temperature for less than 5 minutes, and then cooled to a temperature of 500 ° C. or lower. After applying the magnetic field, hold for a certain period of time while applying a magnetic field.
A method for producing a high-permeability nanocrystalline alloy, which comprises cooling to room temperature after the heat treatment step of 2. 6. The method for producing a nanocrystalline alloy according to claim 3, wherein the direction in which the magnetic field is applied is the width direction or the thickness direction of the alloy ribbon.