JP2702997B2 - Thin film magnetic head and magnetic disk device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head, and more particularly to a thin film magnetic head and a magnetic disk device for high recording density, and develops a material having a high saturation magnetic flux density suitable for these. The present invention provides a thin-film magnetic head for high recording density and a magnetic disk device having excellent performance by using the material as a core of the thin-film magnetic head.

[Conventional technology]

As a conventional magnetic core material for a thin film magnetic head, a permalloy (8) having a saturation magnetic flux density of about 1.0 Tesla (T) deposited by a plating method, a vapor deposition method, a sputtering method, or the like is mainly used.
0Ni-20Fe) film, but the saturation magnetic flux density is about
With permalloy of about 1.0T, there is a limit in achieving high recording density, and conventional magnetic core materials cannot sufficiently cope with the large capacity and high recording density of large-scale computers. The emergence of a material having a high saturation magnetic flux density is desired.

In addition, it has excellent uniaxial anisotropy as a magnetic property required for a core material for a thin film magnetic head, and has a low anisotropic magnetic field of 3 to 5 oersteds (Oe) for high magnetic permeability, making it difficult to magnetize. It is required that the coercive force in the axial direction be 1 Oe or less. More importantly, the magnetostriction constant should be as close to zero as possible to make it less susceptible to external stress. Desirably, the magnetostriction constant needs to be in the range of +0.5 to −2.0 × 10 ⁻⁶ from the relationship with the shape of the magnetic core or the stress of the Al ₂ O ₃ film sputtered on the magnetic core. Have been.

In response to these requirements, various types of amorphous alloy thin films using an amorphous alloy thin film have been developed because the crystalline magnetic anisotropy can be ignored. Among them, the saturation magnetic flux density
Co-Zr or Co- can be as high as 1.3T or more
An Hf-based metal-metal-based amorphous alloy thin film has been found. However, each of them has a magnetostriction constant of 2 × 10
^{-6, which} is a positive and large value, contains Nb, Ta, W, etc., which are known as elements that reduce the magnetostriction constant.
Two-dimensional amorphous films have been proposed. A typical example of this is
One using a Co-Zr-Ta amorphous film;
As described in Japanese Patent No. 21504 and Japanese Patent Application Laid-Open No. 60-22727, those using a Co-Hf-Ta amorphous film are known.

[Problems to be solved by the invention]

However, these conventional Co-Zr-Ta ternary or Co-Hf-Ta ternary amorphous alloys are susceptible to oxidation of Zr and Ta.
Since Zr, Ta, etc. are oxidized by moisture in the atmosphere to impair magnetism, there is a problem in corrosion resistance in that
There is a problem that high reliability as a thin film magnetic head is poor.

In addition, since the Co-Hf-Ta ternary system has a high saturation magnetic flux density and a very narrow composition region where the magnetostriction constant decreases to near zero, it is difficult to stably form a magnetic film of a thin-film magnetic head. There was a problem.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a thin film magnetic head and an amorphous magnetic alloy thin film for a magnetic head which can be formed stably with a wide composition range in which the magnetic film has excellent corrosion resistance, high saturation magnetic flux density, and low magnetostriction constant. is there.

Further, an object of the present invention is to use the thin-film magnetic head,
An object of the present invention is to provide a magnetic disk device capable of achieving high recording density.

That is, as a result of various studies on an amorphous magnetic thin film obtained by a sputtering method, cobalt is used as a main component, and tantalum and haunium, which are amorphous elements, are added thereto. At that time, the amount of tantalum having difficulty in corrosion resistance is reduced as much as possible. Haunium, which is excellent in corrosion resistance, is added to that much, and palladium, which is excellent in corrosion resistance and reduces the magnetostriction constant, is added in an appropriate amount. This 4
The amorphous magnetic thin film having the original composition has a high saturation magnetic flux density, shows a low magnetostriction near zero, and is a material suitable as a core material for a thin film magnetic head having excellent corrosion resistance.

[Means for solving the problem]

A thin-film magnetic head according to the present invention has a pair of magnetic films disposed above and below a non-magnetic substrate, wherein the magnetic film contains cobalt as a main component and has a hafnium 3.5 atomic ratio.
-7%, Tantalum 1-4% and Palladium 0.2-6%
From an quaternary amorphous alloy thin film containing The magnetic film is a material having a high saturation magnetic flux density, a magnetostriction constant near zero, and excellent corrosion resistance.

The present invention comprises cobalt as a main component, and has an atomic ratio of hafnium of 3.5 to 7%, tantalum of 1 to 4%, and palladium.
An amorphous magnetic alloy thin film for a magnetic head, comprising 0.2 to 6%.

The present invention provides a magnetic disk for recording information, a thin-film magnetic head for writing and reading information to and from the magnetic disk, a unit for rotating the magnetic disk,
In the magnetic disk device including the thin-film magnetic head, means for rotating the magnetic disk, and means for positioning the thin-film magnetic head, the thin-film magnetic head includes:
A lower magnetic core, an upper magnetic core formed on the lower magnetic core, one end of which contacts one end of the lower magnetic core and the other end of which faces the other end of the lower magnetic core via a magnetic gap; A conductive coil wound so as to intersect with the magnetic circuit, and an insulating layer interposed between the upper magnetic core and the lower magnetic core, wherein at least one of the upper magnetic core and the lower magnetic core includes: It is characterized by being composed of an amorphous magnetic alloy thin film containing cobalt as a main component and containing 3.5 to 7% of hafnium, 1 to 4% of tantalum and 0.2 to 6% of palladium in atomic ratio.

As a comparative example of the present invention, Co-Hf-Ta3
FIG. 2 shows the relationship between the composition of the binary amorphous alloy thin film and the saturation magnetic flux density Bs and the magnetostriction constant λ. High saturation magnetic flux density of 1.3 Tesla or more and magnetostriction constant of + 1.0 × 10 ^{-6 to} 2.0 × 10
^-6, preferably + 0.5 × 10 ⁻⁶ to −2.0 × 10 ^−6, and the composition region suitable for the magnetic film of the thin-film magnetic head from near zero to the negative side is a, b, b in FIG. This is a range surrounded by a thick line connecting c and is extremely narrow, so that it is difficult to produce a stable magnetic film.

Therefore, reducing the magnetostriction constant, lowering the saturation magnetic flux density, and reducing the amount of Ta that has the property of being easily oxidized by atmospheric moisture, the reduced amount is used to reduce the saturation magnetic flux density relatively small, The constant is a large positive value, but a stable amorphous is formed, hafnium having characteristics such as good corrosion resistance is increased, amorphousization is stabilized, and the magnetostriction constant is maintained while maintaining a relatively high saturation magnetic flux density. +1.0 to +2.0
× 10 _-6 as a composition with a large positive value, and then add Pd, which has the property of reducing the magnetostriction constant and making it difficult to oxidize, to keep the saturation magnetic flux density at a low value , And the magnetostriction constant is a negative value. For example, the composition of A in FIG. 2, that is, a film having a composition of 93 at% Co, 2 at% Ta, and 5 at% Hf (saturation magnetic flux density: 1.4 Tesla, magnetostriction constant is 2 × 10 ⁻⁶ )
3A and 3B show changes in the saturation magnetic flux density and the magnetostriction constant when Pd is added to the steel. By adding 2.2 to 4 at% of Pd, the magnetostriction constant is +0.5 at a saturation magnetic flux density of 1.3 Tesla or more.
It can be set to a value close to zero, such as × 10 ⁻⁶ to −0.5 × 10 ⁻⁶ . The composition of B in FIG. 2, that is, 95 at% Co, 1
Fig. 3A shows the changes in the saturation magnetic flux density and magnetostriction constant when Pd was added to a film with a composition of at% Ta and 4at% Hf (saturation magnetic flux density: 1.45 Tesla, magnetostriction constant + 0.8 x ^10-6 ). Also shown in Fig. 3B. The magnetostriction constant is + within the range of 0.2 at% to 4.5 at% of Pd addition.
In addition to showing appropriate values in a wide range of 0.5 × 10 ^-6 to-2 × 10 ^-6 ,
It can be seen that the saturation magnetic flux density shows a high value of 1.3 Tesla or more.

Also, Hf and Ta should be set within a range where the saturation magnetic flux density is not significantly reduced.
The content of was increased, and a composition stable as amorphous was studied. That is, the composition in FIG.
% Co, 3.5at% Ta, 6.0at% Hf film (saturation magnetic flux density 1.
FIGS. 3A and 3B show changes in saturation magnetic flux density and magnetostriction constant when Pd is added to 3 Tesla and magnetostriction constant + 2 × 10 ⁻⁶ ). The magnetostriction constant is +1.0 when the Pd content is in the range of 2 at% to 5 at%.
It can be seen that, in addition to showing an appropriate value over a wide range of × 10 ^-6 to -1.0 × 10 ^-6 , the saturation magnetic flux density shows a high value of 1.2 Tesla or more.

However, the change of the magnetostriction constant with respect to the amount of added Pd shows exactly the same tendency as in the case of the composition shown in FIG. 2, but the starting point, that is, the Ta and Hf are both smaller than those of the composition having zero Pd content (shown in FIG. 2). Because of the large number, the saturation magnetic flux density tends to be lower than that in the case.

Therefore, to keep the saturation magnetic flux density high, Ta, Hf,
The content of Pd or the like is preferably as small as possible. That is,
Preferably, Ta: 1 to 3 at%, Hf: 3.5 to 5.5 at%, Pd: 0.2 to 3.0 a
t is good.

The thin-film magnetic head preferably has a multilayer structure in which at least one of the first layer and the second layer includes a layer made of a nonmagnetic material. For example, the non-magnetic material may be an insulating material such as Cr, Ta, or Al ₂ O ₃ .

As shown in FIG. 5, the magnetic disk device includes a magnetic disk for recording information, a thin-film magnetic head for writing and reading information to and from the magnetic disk, a means for rotating the magnetic disk, and a thin-film magnetic head. Means for determining the position of

The thin-film magnetic head includes a lower magnetic core, an upper magnetic core formed on the lower magnetic core, one end of which is in contact with one end of the lower magnetic core, and the other end of which faces the other end of the lower magnetic core via a magnetic gap. A conductive coil wound between the two magnetic cores so as to cross the magnetic circuit, and an insulating layer interposed between the upper magnetic core and the lower magnetic core.

The present invention is attained when at least one of the upper magnetic core and the lower magnetic core is composed of a quaternary amorphous magnetic alloy containing cobalt as a main component and the above-mentioned hafnium, tantalum and palladium.

[Action]

Co-Hf-Ta-Pd4 amorphous alloy containing cobalt as a main component
In the base alloy, cobalt (Co) is a ferromagnetic material and has a high saturation magnetic flux density. Hafnium (Hf) easily forms an amorphous phase, but increases the magnetostriction constant and lowers the saturation magnetic flux density. Tantalum (Ta) has a characteristic that it reduces the magnetostriction constant but lowers the saturation magnetic flux density and is easily oxidized. Palladium (Pd) has a characteristic that it has a small magnetostriction constant and is hardly oxidized.

The material of both magnetic films of the thin film magnetic head is Co-Hf-Ta-Pd4
The use of the original amorphous alloy can increase the saturation magnetic flux density of the magnetic film and reduce the magnetostriction constant, so that the composition range can be widened and the oxidation resistance can be further improved.

Therefore, the composition ratio of each of these elements is important, and particularly in an amorphous magnetic thin film, the amounts of Hf and Ta are important, and by optimizing the amounts of these two elements, Pd
Can be effective.

That is, in the Co-Hf-Ta ternary system, the effect of Pd is to reduce the saturation magnetic flux density by 0.025 T per 1 at% and to reduce the magnetostriction constant by 0.6 × 10
^-6 was found to be reduced by the experimental results. Therefore,
It is important to determine the amounts of Hf and Ta based on these experimental results.

With respect to Hf, if it is 3.5 at% or less, it crystallizes and does not show excellent soft magnetism, and if it is 7 at% or more, the amorphization becomes stable, but the saturation magnetic flux density is greatly reduced, which is not preferable. As for Ta, if this amount is large, the corrosion resistance is degraded. Therefore, it is desirable that Ta be as small as possible.
If it is 1 at% or less, there is a possibility of crystallization, the initial value of the magnetostriction constant is too large, and if it is 4 at% or more, the corrosion resistance is deteriorated and the saturation magnetic flux density is undesirably increased. . Therefore, Hf is 3.5 to 7 at.
%, Ta is 1 to 4 at%, the balance is Co, and the saturation magnetic flux density is 1.35.
Keep high value up to 1.45T, magnetostriction constant up to + 3 ~ 10 ^-6
To keep. By adding Pd to this in consideration of the amounts of Hf and Ta, the saturation magnetic flux density is increased to 1.2 T or more, preferably 1.3 T or more.
As described above, the addition amount is adjusted in the range of 0.2 to 6 at% so that the magnetostriction constant is close to zero or negative.

〔Example〕

 Hereinafter, details of the present embodiment will be described.

First Embodiment In FIGS. 1A and 1B, a lower magnetic film 2a is placed on a ceramic substrate 1 having a thickness of 4 to 5 mm whose surface has been sufficiently polished and cleaned.
For example, a Co-Hf-Ta-Pd quaternary amorphous alloy film having a film thickness of 1 to 2 μm is laminated by an RF sputtering method. At this time, the composition of the magnetic film 2 is the composition of A shown in FIG.
% Co, 2 at% Ta, 5 at% Hf), and 20 Pd chips of 1 mm and 4 mm square were mounted on the target and sputtered. The high-frequency output was 300 W, the sputtering gas was argon gas, and the substrate 1 was water-cooled. The composition of the film sputtered separately on the dummy substrate is 91.2 at% Co, 1.7
at% Ta, 5.1at% Hf, 2.0at% Pd and saturation magnetic flux density 1.
It was 3 Tesla and the magnetostriction constant was -0.5 × 10 ^-6 .

The anisotropic magnetic field of the thin film immediately after sputtering is large, and therefore the magnetic permeability is small.

It is known that heat treatment in a rotating magnetic field is effective in reducing the anisotropic magnetic field.

Therefore, the substrate after the lower magnetic film 2a was sputtered was subjected to a heat treatment at 350 ° C. for 1 hour in a rotating magnetic field, and then patterned into a predetermined shape of the magnetic core 6 by an ion milling method.

Then, use a thin film technique to make the thickness of alumina
A gap non-magnetic film 3, an insulating layer 4 having a thickness of 10 μm, and a conductor coil 5 are deposited and finished in a predetermined shape by an ion milling method or a wet etching method.
After the upper magnetic film 2b is sputtered thereon in the same manner as the lower magnetic film 2a, heat treatment is performed in a rotating magnetic field at 300 ° C. for 1 hour, and then patterned into a predetermined shape of the magnetic core 6 by ion milling. . After that, an insulating film such as alumina is deposited on the entire surface of the substrate by sputtering,
The protective film 7 is used. Next, the magnetic head g is cut out from the substrate 1 and the front end side of the magnetic head is polished to a predetermined size to form a magnetic gap g.

FIG. 1A is a perspective view of the thin-film magnetic head cut out in FIG. 1A.
The figure shows a sectional view of the magnetic core portion of the thin-film magnetic head.
The electrical characteristics of the thin-film magnetic head thus manufactured are
The electrical characteristics of a thin-film magnetic head using conventional permalloy were compared. As a result, the overwrite characteristic, that is, the characteristic indicating how much the recording on the recording medium can be erased by a high-frequency magnetic field of 20 KHz, is improved by about 4 to 5 dB, and the recording magnetic field intensity is increased by about 30% as compared with the thin film magnetic head using permalloy. It is improved and is sufficiently applicable to a medium having a high coercive force for a high recording density.

Second Embodiment In the same manner as in the first embodiment, as shown in FIGS. 1A and 1B, a 1 μm-thick Co-Hf-Ta-Pd4
Original amorphous alloy films were deposited by RF sputtering. At this time, the target of the composition of B (95 at% Co, 1.0 at% Ta, 4.0 at% Hf) shown in FIG. 3 was used as the composition of the magnetic film 2, and 1 mm thick and 4 mm square palladium was formed on the target. Eight chips were placed and sputtered. Sputtering conditions are the same as in the first embodiment. The composition of the film sputtered separately on the dummy substrate is 94 at% Co, 1.0 at% Ta, 4.0 at
% Hf, 1.0at% Pd, saturation magnetic flux density is 1.40 Tesla,
The magnetostriction constant was −0.1 × 10 ⁻⁶ . After spaghetti,
A thin-film magnetic head was manufactured in the same process as in the first embodiment, and its electrical characteristics were measured. As a result, it was confirmed that the overwrite characteristics were slightly superior to those of the first example.

Third Embodiment In the same manner as in the first embodiment, as shown in FIGS. 1A and 1B, a 1 μm thick Co—Hf—Ta—Pd4 layer is formed on a ceramics substrate 1.
Original amorphous alloy films were deposited by RF sputtering. At this time, the composition of the magnetic film 2 was a target having the composition shown in FIG. 2 (90.5 at% Co, 3.5 at% Ta, 6.0 at% Hf), and a 1 mm thick, 4 mm square palladium was formed on the target. We sputtered 35 chips. Sputtering conditions are the same as in the first embodiment. The composition of the film sputtered separately on the dummy substrate is 87.3 at% Co, 3.4 at% Ta, 5.8 a
t% Hf and 3.5at% Pd, and the composition of the film showed larger values for both Ta, Hf and Pd than those of the first and second examples. Therefore, the saturation magnetic flux density was slightly lower than those, and was 1.24 Tesla. The magnetostriction constant is small as in the first and second embodiments,
It was −0.1 × 10 ⁻⁶ .

After sputtering, a thin-film magnetic head was manufactured in the same process as in the first embodiment, and its electrical characteristics were measured. As a result, the overwrite characteristics were slightly lower or almost equal to those of the first embodiment.

However, when the amount of Ta, Hf, and Pd is increased, the amorphization becomes stable, but the saturation magnetic flux density tends to decrease, so that the overwrite characteristics as a thin film magnetic head tends to decrease. Therefore, in order to effectively utilize the effect of high saturation magnetic flux density, it is preferable that the contents of Ta, Hf, and Pd are as low as possible. There is a risk of becoming. Therefore, the contents of Ta, Hf, and Pd are preferably Ta: 1 to 3 at%, and Hf: 3.
Those regulated to 5 to 5.5 at% and Pd: 0.2 to 3.0 at% show excellent soft magnetic properties and high saturation magnetic flux density.

From the above, the Co-Hf-Ta-Pd quaternary system, which can be achieved only in a narrow composition region, can obtain desired magnetic characteristics in a wide composition range by using the Co-Hf-Ta-Pd quaternary system. I'm sorry.

In addition, by adding Ta, which is less oxidizable, and Pd, which is less oxidizable by increasing Hf, the corrosion resistance is higher than that of the Co-Hf-Ta ternary system (curve II) as shown by the curve I in FIG. It improved remarkably and reached the same level as Permalloy.

From the above results, Co-Hf-Ta-Pd4 containing Co as a main component
In the original amorphous alloy, Hf is 3.5 to 7 at%, preferably 3.
5 to 5.5 at%, Ta is 1 to 4 at%, preferably 1 to 3 at%, Pd
By containing 0.2 to 6 at%, preferably 0.2 to 3 at%, it was confirmed that a magnetic film having excellent corrosion resistance, high saturation magnetic flux density, and a wide composition range in which the magnetostriction constant is near zero can be obtained.

FIG. 5 is a schematic diagram of a magnetic disk device using the thin-film magnetic head of the present invention.

The magnetic disk device has components indicated by reference numerals 1 to 8 shown in FIG. 1 and a voice coil motor control circuit.

 Reference numeral 1 denotes a base, and reference numeral 2 denotes a spindle.

One is that a plurality of disk-shaped magnetic disks 4 are attached to the spindle as shown in the figure.

FIG. 1 shows an example in which five magnetic disks are provided on one spindle, but the number is not limited to five.

Further, a plurality of magnetic disks provided with a plurality of magnetic disks on one spindle may be provided.

Reference numeral 3 denotes a motor for driving the spindle 2 and rotating the magnetic disk.

Reference numeral 5 denotes a magnetic head for data, and reference numeral 5a denotes a magnetic head for positioning.

Reference numeral 6 denotes a carriage, reference numeral 7 denotes a voice coil, reference numeral 8
Is a magnet.

The voice coil motor is constituted by the voice coil 7 and the magnet 8.

The head is positioned by the elements denoted by reference numerals 6, 7, and 8.

The voice coil 7 and the magnetic heads 5 and 5a are connected via a voice coil motor control circuit.

In FIG. 1, the host device indicates, for example, a computer system.

〔The invention's effect〕

According to the configuration of the present invention, Co-Hf-Ta containing Co as a main component
-By applying Pd quaternary amorphous alloy to the magnetic film of the thin film magnetic head, the corrosion resistance of the magnetic film is excellent,
Since the saturation magnetic flux density is about 1.3 times higher than that of the conventional permalloy thin film, it has excellent write characteristics as a magnetic head, and also has a high saturation magnetic flux density, thus exhibiting a high value of magnetic permeability and excellent read characteristics. As a result, it has been found that the thin film magnetic head can sufficiently cope with high recording density.

In addition, a high-density magnetic disk device was clarified.

In addition, when the magnetic film has a multilayer structure, the reproducing quality in the magnetic domain structure is improved, and by using the present invention, a thinner magnetic film can be realized, so that the frequency characteristics can be improved.

[Brief description of the drawings]

FIG. 1A is a perspective view of a thin-film magnetic head manufactured by forming a Co-Hf-Ta-Pd quaternary amorphous alloy according to the present invention.
FIG. 1B is a cross-sectional view of the thin-film magnetic head of FIG. 1A, taken along the line 1B-1B, and FIG. 2 is a diagram of Co-Hf-Ta which is the basis of the present invention.
FIG. 3A is a diagram showing the test results of the magnetic properties of the ternary amorphous alloy, and FIG. 3A is a diagram showing the effect of the amount of Pd added on the magnetostriction constant in the compositions A, B, and C in FIG. Fig. 3B
FIG. 4 is a diagram showing the effect of the addition amount of Pd on the saturation magnetic flux density in A, B, and C compositions, and FIG. 4 shows Co-Hf-Ta- according to the present invention.
It is a figure which shows the corrosion test result of a Pd quaternary amorphous alloy, and FIG. 5 is the schematic of a magnetic disk device. 1 ... substrate, 2 ... magnetic film, 2a ... lower magnetic film, 2b ...
Upper magnetic film, 3 ... Gap non-magnetic film, 4 ... Insulating film,
5 ... conductor coil, 6 ... magnetic core, 7 ... protective film, 10
...... Thin-film magnetic head.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Narishige 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Masanobu Kaen 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Inside the laboratory (72) Inventor Takashi Onishi 2880 Kozu, Odawara City, Kanagawa Prefecture Inside Odawara Plant, Hitachi, Ltd. JP-A-61-95503 (JP, A) JP-A-60-22722 (JP, A) JP-A-63-20429 (JP, A)

Claims (11)

(57) [Claims] 1. A method according to claim 1, wherein said first and second thin layers of magnetic material are arranged to form a closed magnetic circuit, and said first and second thin films are formed to form a magnetic gap in a portion of said magnetic circuit. An intermediate layer of a nonmagnetic material disposed between the first layer and the second layer, wherein at least one of the first and second layers contains cobalt as a main component and has an atomic ratio of hafnium 3.
5-7%, Tantalum 1-4% and Palladium 0.2-6%
A thin-film magnetic head comprising an amorphous magnetic alloy containing: 2. A thin film magnetic head according to claim 1, wherein said amorphous magnetic alloy contains 3.5 to 5.5% of hafnium, 1 to 3% of tantalum and 0.2 to 3% of palladium in atomic ratio. 3. The method according to claim 1, wherein the amorphous magnetic alloy is
A thin-film magnetic head having a saturation magnetic flux density of 1.2 T or more and a magnetostriction constant of 1.0 × 10 ⁻⁶ to −2.0 × 10 ⁻⁶ . 4. The thin-film magnetic head according to claim 1, wherein at least one of the first layer and the second layer has a multilayer structure with a layer made of a non-magnetic material interposed therebetween. 5. A substrate made of a non-magnetic material, a layer of a thin film of first and second magnetic materials formed on the substrate and forming a closed magnetic circuit partially having a magnetic gap, An intermediate layer of a non-magnetic material forming a magnetic gap; and a conductor coil winding the magnetic circuit, wherein at least one of the first and second layers contains cobalt as a main component, and has an atomic ratio of hafnium 3.5. A thin film magnetic head comprising an amorphous magnetic alloy containing about 7%, about 1% to about 4% of tantalum, and about 0.2% to about 6% of palladium. 6. An amorphous magnetic alloy according to claim 5, wherein the atomic ratio of hafnium is 3.5 to 5.5% and tantalum is 1 to 3%.
And 0.2 to 3% of palladium. 7. The method according to claim 5, wherein the amorphous magnetic alloy is
A thin-film magnetic head having a saturation magnetic flux density of 1.2 T or more and a magnetostriction constant of 1.0 × 10 ⁻⁶ to −2.0 × 10 ⁻⁶ . 8. Hafnium 3.5 to 7%, tantalum 1 to 4% and palladium 0.2 at the atomic ratio containing cobalt as a main component.
An amorphous magnetic alloy thin film for a magnetic head, wherein the thin film comprises about 6%. 9. The amorphous magnetic alloy thin film according to claim 8, wherein the atomic ratio of hafnium is 3.% to 5.5% and tantalum is 1%.
An amorphous magnetic alloy thin film for a magnetic head, characterized in that the amorphous magnetic alloy thin film contains 0.1 to 3% and 0.2 to 3% of palladium. 10. The amorphous magnetic alloy thin film according to claim 8, wherein said amorphous magnetic alloy thin film has a saturation magnetic flux density of 1.2 T or more and 1.0 × 10 ⁻⁶ to −2.0 ×.
An amorphous magnetic alloy thin film for a magnetic head, having a magnetostriction constant of 10 ^-6 . 11. A magnetic disk for recording information, a thin-film magnetic head for writing and reading information to and from the magnetic disk, means for rotating the magnetic disk, and means for positioning the thin-film magnetic head. In the magnetic disk device, the thin-film magnetic head is formed on the lower magnetic core and the lower magnetic core, one end of which is in contact with one end of the lower magnetic core, and the other end of which is in contact with the other end of the lower magnetic core via a magnetic gap. An opposing upper magnetic core, a conductor coil wound between the two magnetic cores so as to cross a magnetic circuit, and an insulating layer interposed between the upper magnetic core and the lower magnetic core. At least one of the magnetic core and the lower magnetic core contains cobalt as a main component and contains, by atomic ratio, 3.5 to 7% of hafnium, 1 to 4% of tantalum, and 0.2 to 6% of palladium. Magnetic disk apparatus, comprising the amorphous magnetic alloy.