JPH07116563B2 - Fe-based soft magnetic alloy - Google Patents

Description

The present invention relates to a Fe-based soft magnetic alloy having a high saturation magnetic flux density and excellent high frequency magnetic properties.

[Conventional technology]

In magnetic recording / reproducing devices such as audio tape recorders, VTRs (video tape recorders), and storage devices of computers, in recent years, high density and high quality of recording signals have been advanced. A metal tape, a vapor deposition tape, a magnetic disk, etc. using a metal alloy powder such as Fe as magnetic powder used as a magnetic recording medium have been developed.

In order to fully exhibit the characteristics of the magnetic recording medium having the high coercive force described above, the magnetic characteristics of the core material used for the magnetic head preferably have a high saturation magnetic flux density from the viewpoint of recording, and further reproduction If the same magnetic head is used, it is necessary to have high magnetic permeability characteristics.

However, the conventionally used ferrite has a low saturation magnetic flux density, and permalloy has problems such as insufficient wear resistance.

In recent years, in response to the above requirements, Fe-Al-Si alloys and Co-
The thinning of Nb-Zr type amorphous alloys is being studied.

Such an attempt is made by, for example, Shibaya et al.
(2), 51-106 (1977), Functional Materials August 1986 P68.

[Problems to be solved by the invention]

However, in the Fe—Al—Si alloy film, both the magnetostriction λ _S and the crystal magnetic anisotropy K must be near zero in order to obtain high magnetic permeability, and with such a composition, the saturation magnetic flux density is 12
The limit is about kG.

On the other hand, the saturation magnetic flux density of the Co—Nb—Zr type amorphous alloy film of λ _S 0 is limited to about 12 kG.

At present, there is a demand for an alloy film having a higher saturation magnetic flux density for higher recording density, but the present situation is not sufficient, and Fe-Si alloy film having a high saturation magnetic flux density and a small magnetostriction has been studied. There is.

The saturation magnetic flux density of this alloy film is about 17.6 when the composition of λ _S is zero.
Although it is about kG, which is higher than that of the alloy film described above, the saturation magnetic flux density is further reduced in consideration of corrosion resistance and the like.

By the way, the current recording medium is required to have a higher coercive force, and further, for high density recording of an alloy film having a high saturation magnetic flux density and excellent high frequency magnetic characteristics.

As other alloys having a small magnetostriction and a high saturation magnetic flux density, for example, Fe-B solid solution alloys described in JP-B-58-28341 and JP-A-59-100254 are known.

This alloy is a continuous filament made by ejecting a melt of Fe and B onto a rapidly rotating quenching surface and quenching it at a cooling rate of about 10 ⁴ to 10 ⁶ ° C / sec. . The saturation magnetization is about 2T. This alloy is said to be suitable for transformers.

However, Fe-B produced by the liquid quenching method as described above
Particularly, it is difficult to form an alloy ribbon having a thickness of 10 μm or less, a sufficient magnetic permeability cannot be obtained at a high frequency, and corrosion resistance and wear resistance are not sufficient, and it is not suitable for a magnetic head or the like.

[Means for solving problems]

As a result of earnest research in view of the above object, the inventors have found that the present invention is a polycrystalline alloy having a body-centered cubic structure containing Fe-B as a basic component, and the crystal grain size measured by the maximum dimension of each crystal grain is 500 Å or less. The inventors have found that an alloy having an average particle size of 1 has an excellent magnetic permeability and is optimal for a magnetic head, and has conceived the present invention.

That, Fe-based soft magnetic alloy of the present invention the composition formula: represented by _{Fe 100-X-Y M Y} B X ( atomic%), wherein M is Ti, Zr, Hf, V, Nb, Ta, Cr , W, Mn, Ru, Rh, Pd, Os, Ir,
A polycrystalline alloy film having a body-centered cubic structure having a composition of 2 ≦ x ≦ 10,0 <y ≦ 10, which is at least one element selected from Pt, and has a maximum size of each crystal grain. The average of the measured particle size is
It is characterized by being less than 500Å.

In the present invention, B is an essential element, adjusts magnetostriction,
It has the effect of reducing the deterioration of magnetic characteristics due to the influence of strain.

The additional element M has effects of improving wear resistance and corrosion resistance, and refining crystal grains to improve soft magnetic characteristics. Due to the presence of these elements, the alloy film for the magnetic head has more balanced characteristics.

The reason why the B amount x is limited to 2 ≦ x ≦ 10 is that the soft magnetic characteristics are deteriorated if the B amount is out of this range, and the M amount y is 0 <y ≦.
The reason for limiting the value to 10 is that if y exceeds 10, the saturation magnetic flux density is significantly reduced, which is not preferable. Further, the crystal grain size needs to be 500 Å or less, and if it exceeds 500 Å, the magnetic permeability decreases, which is not preferable. A particularly preferable range of crystal grain size is
50-200Å.

Further, the composition formula: represented by _{Fe 100-X-Y-Z} M Y B X A Z ( atomic%), wherein M is Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mn, Ru, Rh, Pd, Os, Ir,
At least one element selected from Pt, A is C, Si, Ge, G
It is at least one element selected from a, Al, In and Sn, and is a polycrystalline alloy having a body-centered cubic structure having a relationship of 2 ≦ x ≦ 10,0 <y ≦ 10,0 <z ≦ 10. An alloy having a crystal grain size measured with the maximum size of each crystal grain and an average grain size of 500Å or less has a high saturation magnetic flux density, a small magnetostriction, and an excellent magnetic permeability, and is suitable for a magnetostrictive head alloy film. Here, the additional element A has an effect of adjusting magnetostriction and crystal magnetic anisotropy.

The alloy of the present invention can be used as a film usually by sputtering, ion plating, vacuum deposition method, cluster ion beam method and the like.

When the alloy of the present invention is used as a film, the film thickness is adjusted according to the operating frequency region, but generally the film thickness is 20 μm or less. In particular, when a non-magnetic film or a ferromagnetic soft magnetic film is alternately laminated to form a laminated film, the crystal grains are easily miniaturized, and excellent characteristics can be obtained even at high frequencies.

Further, in the alloy of the present invention, 10% or less of the amount of Fe can be replaced with Co and / or Ni. If it exceeds 10%, the magnetic permeability decreases, which is not preferable.

In the present invention, a well-balanced alloy composition having high saturation magnetic flux density, excellent wear resistance and corrosion resistance is 0.5 ≦ y ≦ 5, z ≦
The range is 5.

When an alloy film is produced, the substrate may be heated during production to produce it, or heat treatment may be performed after the film is produced on the substrate. A magnetic field may be applied during the production of the film, or a magnetic field may be applied during the heat treatment.

Since the magnetic head made of the alloy film described above has a high saturation magnetic flux density and a high magnetic permeability even in a high frequency region, high density magnetic recording is possible and excellent characteristics are obtained.

〔Example〕

 The present invention will be described below with reference to examples.

Example 1 Fe _99.5-X Ru _0.5 B _X 1 An alloy film having a composition represented by 1 ≦ x ≦ 12 and a thickness of 2 μm was formed by a sputtering method. As a result of X-ray diffraction, the obtained alloy film was composed of a Fe solid solution having a bcc structure, and as a result of observation with an electron microscope, it was confirmed that the grain size was 500 Å or less. Table 1 shows the saturation magnetic flux density, B _S, and saturation magnetostriction λ _S.

It can be seen from Table 1 that the alloy film of the present invention has a high saturation magnetic flux density and a small magnetostriction. When x exceeds 10%, the saturation magnetic flux density is lowered, amorphous is easily formed, and magnetostriction is increased, which is not preferable.

Example 2 An alloy film having a composition shown in Table 2 and having a thickness of 2 μm was formed by an ion beam sputtering method, heat-treated at 300 ° C. for 1 hour, and then the magnetic permeability μ _{1 M} at 1 MHz was measured. The film obtained is bc
It was an Fe solid solution of c structure and had a crystal grain size of 500Å or less. The results obtained are shown in Table 2. It also shows the corrosion resistance after soaking in tap water for 3 days.

As can be seen from Table 2, the alloy of the present invention is 900 at 1 MHz.
It is suitable for VTR and computer heads because it has a high magnetic permeability of more than 10% and relatively good corrosion resistance.

Example 3 A multilayer film having a composition of one shown in Table 3 and having a thickness of 1 μm and an SiO ₂ intermediate layer film was formed by a sputtering method and was 1 MHz.
The magnetic permeability μ _1M at 10 MHz and the magnetic permeability μ _10M at 10 MHz were measured. The results obtained are shown in Table 3. The crystal grain size of the obtained film was 200 Å or less, which was extremely small, and it was confirmed by X-ray diffraction that it was a bcc Fe solid solution.

As can be seen from Table 3, the multilayer alloy film of the present invention is 1 MHz, 1
It has a magnetic permeability of more than 1000 at 0 MHz, high magnetic permeability at high frequencies, and relatively good corrosion resistance, making it ideal for magnetic heads for high-density magnetic recording.

Example 4 Fe _94-y Ru _y B ₆ composition represented by Table 4 thickness of 10 μm
An alloy film of m was prepared on the simulated head by the sputtering method,
A wear test was performed at a temperature of 20 ° C and a humidity of 90%. The wear resistance after 50 hours is shown in Table 4. It also shows the corrosion resistance after soaking in tap water for 3 days.

It can be seen that the addition of Ru reduces the amount of wear, improves the corrosion resistance, and increases the life of the magnetic head, which is preferable.

Example 5 An alloy film having a composition of Fe ₉₃ Cr _0.5 Ru ₁ B _5.5 and having a thickness of 3 μm was formed on a photoceram substrate by a sputtering method, kept at 350 ° C. for 1 hour in a rotating magnetic field, and then kept at room temperature at 5 ° C./min. After cooling at a speed, the frequency dependence of the effective magnetic permeability μe was investigated.

FIG. 1 shows an example of frequency dependence of effective magnetic permeability.

It can be seen that the alloy film of the present invention has a high effective magnetic permeability up to high frequencies and is suitable for magnetic heads and the like.

Example 6 A magnetic head having a structure shown in FIG. 2 and composed of a multilayer film of an alloy represented by the composition of Fe _91.9 Ru ₂ B _6.1 was prepared, and the recording / reproducing characteristics for a metal tape were measured. The results are shown in FIG.

The magnetic head made of the alloy film of the present invention has better recording / reproducing characteristics than the magnetic head made of ferrite.

〔The invention's effect〕

According to the present invention, it is possible to obtain an alloy film for a magnetic head having a high saturation magnetic flux density and excellent in high-frequency magnetic characteristics and a magnetic head suitable for high-density magnetic recording, so that the effect is remarkable.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of the frequency dependence of the effective magnetic permeability of the alloy film of the present invention, FIG. 2 is a diagram showing an example of the structure of a magnetic head made of the alloy film of the present invention, and FIG. FIG. 6 is a diagram showing an example of recording / reproducing characteristics of the magnetic head of the invention.

Claims (8)

[Claims] 1. A composition formula is represented by _{Fe 100-X-Y M Y} B X ( atomic%), wherein M is T
At least one element selected from i, Zr, Hf, V, Nb, Ta, Cr, W, Mn, Ru, Rh, Pd, Os, Ir, Pt, and 2 ≦ x ≦ 10,0 <y ≦
A polycrystalline alloy having a body-centered cubic structure having a composition of 10 relations, and the average grain size measured by the maximum dimension of each grain is
Fe-based soft magnetic alloy characterized by being less than 500Å. 2. The Fe soft magnetic alloy according to claim 1, wherein the average grain size measured by the maximum dimension of each crystal grain is 50 to 200Å. 3. A composition formula: (Fe100-αM'α) represented by _{100-X-Y M Y B} X ( atomic%), wherein M is Ti, Zr, Hf, V, Nb, Ta, Cr , W, Mn, Ru, Rh, Pd,
At least one element selected from Os, Ir, and Pt, M'is Co
And one or more of Ni, and 2 ≦ x ≦ 10,0 <y ≦ 10,0 <
Fe-based soft magnetic alloy having a body-centered cubic structure having a composition of α ≦ 10, characterized in that the average grain size measured at the maximum size of each grain is 500Å or less . 4. The Fe soft magnetic alloy according to claim 3, wherein the average grain size measured by the maximum dimension of each crystal grain is 50 to 200Å. 5. The composition formula represented by _{Fe 100-X-Y-Z} M Y B X A Z ( atomic%), wherein M is Ti, Zr, Hf, V, Nb, Ta, Cr, W , Mn, Ru, Rh, Pd, Os, Ir, Pt, at least one element, A is C, Si, Ge, Ga, Al,
At least one element selected from In and Sn, and 2 ≦
A polycrystalline alloy having a body-centered cubic structure having a composition of X ≦ 10,0 <y ≦ 10,0 <z ≦ 10, and the average grain size measured at the maximum size of each grain is 500Å or less. Fe-based soft magnetic alloy characterized by: 6. The Fe soft magnetic alloy according to claim 5, wherein the average grain size measured by the maximum dimension of each crystal grain is 50 to 200Å. 7. A composition _{formula: (Fe100-αM'α) 100-} X-Y-Z M Y B X A Z ( atomic%)
, Where M is Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mn, Ru,
At least one element selected from Rh, Pd, Os, Ir and Pt, A
Is at least one element selected from C, Si, Ge, Ga, Al, In and Sn, M ′ is at least one element of Co and Ni, and 2 ≦ X ≦ 1
A polycrystalline alloy having a body-centered cubic structure having a composition of 0,0 <y ≦ 10,0 <z ≦ 10,0 <α ≦ 10, and having a grain size Fe-based soft magnetic alloy characterized by an average of 500Å or less. 8. The Fe soft magnetic alloy according to claim 7, wherein the average grain size measured by the maximum dimension of each crystal grain is 50 to 200Å.