JP2858036B2 - Soft magnetic thin film and magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a soft magnetic thin film and a magnetic head, in particular, a metal-in-gap (MIG) type magnetic head, and an enhanced dual gap length (EDG) type. The present invention relates to a magnetic head and a thin-film magnetic head.

<Prior Art> A MIG type magnetic head having a soft magnetic thin film such as sendust having a higher saturation magnetic flux density Bs than the core on at least one of the first and second cores made of ferrite and opposed to the gap is known.

In this magnetic head, since a strong magnetic flux can be applied to the magnetic recording medium from the soft magnetic thin film, effective recording can be performed on a medium having a high coercive force.

In addition, a flying-type thin-film magnetic head having excellent characteristics such as high-density recording and high-speed data transfer has been put to practical use.

Then, in order to generate a high-density magnetic flux in the thin film magnetic head, the upper and lower magnetic pole layers, permalloy high saturation magnetic flux density B _s, the soft magnetic thin film such as sendust is used.

Incidentally, the saturation magnetic flux density Bs of such a soft magnetic thin film used for a magnetic head is at most about 12000G.

For this reason, conventional magnetic heads have insufficient electromagnetic conversion characteristics such as overwrite characteristics. Particularly, in the case of a magnetic recording medium having a high coercive force, a higher saturation magnetic flux density Bs is required.

Incidentally, the Fe and the target, and sputtering in a mixed gas of Ar and N _2, can be obtained Fe-N soft magnetic thin film further has a high saturation magnetic flux density B _s than sendust.

This is because, by mixing N, the Fe crystal grains are refined and the magnetic anisotropy dispersion is reduced.

For example, JP-A-64-15907 discloses a soft magnetic thin film mainly composed of Fe and containing iron nitride composed of Fe ₄ N and / or Fe ₃ N.

The soft magnetic thin film has a saturation magnetic flux density of 15000 G or more, has a low coercive force Hc, and has magnetic properties suitable for the magnetic head.

However, Fe-N soft magnetic thin film has low heat resistance, about 350 ° C.
At about the temperature, the crystal grain size becomes large, and the coercive force Hc sharply increases.

For this reason, MIG-type magnetic heads and EDG-type magnetic heads that are kept at a temperature of about 450 to 600 ° C. by heat treatment such as glass welding, and about 35 mm in a film forming process by sputtering or the like.
It is difficult to use the thin-film magnetic head at a temperature of 0 ° C. or higher.

In addition, it is known that soft magnetic thin films such as Co-N, Fe-Co, and Fe-Co-N also have a high saturation magnetic flux density Bs and show soft magnetism. In particular, with a composition near Fe ₅₀ Co ₅₀ , the highest saturation magnetic flux density of about 24000 G is obtained as a magnetic material.

However, the Co—N soft magnetic thin film has low heat resistance, like the Fe—N soft magnetic thin film.

In addition, Fe—Co and Fe—Co—N soft magnetic thin films have insufficient soft magnetic properties.

<Problems to be Solved by the Invention> An object of the present invention is to use a soft magnetic thin film having a high saturation magnetic flux density Bs, high heat resistance and high corrosion resistance, and excellent soft magnetic properties, and such a soft magnetic thin film. By having a soft magnetic thin film with low coercive force Hc and high saturation magnetic flux density Bs
An object of the present invention is to provide a MIG type magnetic head, an EDG type magnetic head, and a thin film magnetic head.

<Means for Solving the Problems> Such an object is achieved by the present invention of the following (1) to (4).

(1) A soft magnetic thin film having an atomic ratio composition represented by the following formula:

Formula (Fe _1-xyz Co _x Ni _y M _z ) _1-w (N _1-v O _v ) _w (where M is Mg, Ca, Ti, Zr, Hf, V, Nb, T
a, one or more selected from Cr, Mo, Mn and B;
0.2 ≦ x ≦ 0.7, 0 ≦ y ≦ 0.2, 0.001 ≦ z ≦ 0.15, 0 ≦ v
≦ 0.1, 0.001 ≦ w ≦ 0.15. (2) The saturation magnetic flux density Bs is 20,000 G or more, and the coercive force Hc is
The soft magnetic thin film according to (1), wherein the soft magnetic thin film has a thickness of 2 Oe or less.

(3) A magnetic head comprising the soft magnetic thin film according to (1) or (2) between a pair of cores.

(4) A thin-film magnetic head having an upper magnetic pole layer, a lower magnetic pole layer, and a protective layer, wherein the upper magnetic pole layer and the lower magnetic pole layer are formed of the soft magnetic thin film according to the above (1) or (2). A magnetic head characterized in that:

<Function> The soft magnetic thin film of the present invention particularly suitable for a magnetic head is Fe-
Because of the Co-N system, the saturation magnetic flux density Bs is very high.

By adding an appropriate amount of an element that forms a nitride that is more stable than Fe and Co to Fe, Co, and N, the soft magnetic characteristics are improved while the saturation magnetic flux density Bs is maintained at about 20,000 G or more. And corrosion resistance is improved.

Here, assuming that the temperature at which the coercive force rapidly changes due to the heat treatment, for example, the heat treatment temperature at which the coercive force Hc becomes 2 Oe is the heat-resistant temperature, the heat-resistant temperature of the soft magnetic thin film used in the present invention is about
500 ° C or higher.

Therefore, the soft magnetic thin film of the present invention has high saturation magnetic flux density Bs, low coercive force Hc, high magnetic permeability μ, and excellent soft magnetic characteristics.

For this reason, the magnetic head of the present invention having such a soft magnetic thin film has excellent overwrite characteristics, recording / reproduction sensitivity, etc., and excellent electromagnetic conversion characteristics, particularly for a magnetic recording medium having a high coercive force.

In addition, since the soft magnetic thin film of the present invention is excellent in corrosion resistance and wear resistance, a highly reliable magnetic head is realized.

JP-A-60-218820 and JP-A-60-220913 disclose Fe, 2 to 10% by weight of Al, and 3 to 16% by weight of Si.
And a magnetic thin film containing 0.005 to 4% by weight of nitrogen.

It is described that the saturation magnetic flux density Bs can be improved by replacing part of Fe with Co, and the magnetic permeability μ can be kept high without reducing Bs by replacing Ni with Ni. .

However, the specific example shown in the embodiment has a high heat resistance temperature, but the saturation magnetic flux density Bs is at most about 12000G.

Thus, the saturation magnetic flux density Bs is high, the coercive force Hc is low,
There is no known soft magnetic thin film having a high magnetic permeability μ and excellent heat resistance.

<Specific Configuration of the Invention> Hereinafter, a specific configuration of the present invention will be described in detail.

The soft magnetic thin film of the present invention particularly suitable for a magnetic head has an atomic ratio composition represented by the following formula.

Formula (Fe _1-xyz Co _x Ni _y M _z ) _1-w (N _1-v O _v ) _{w In the} above formula, M is Mg, Ca, Ti, Zr, Hf, V, Nb, T
a, Cr, Mo, Mn and at least one selected from B.

Among them, Ti and / or Zr are particularly preferable from the viewpoint of heat resistance.

Elements other than the above do not provide the effects of the present invention, particularly the heat resistance.

 X is 0.2 to 0.7, preferably 0.3 to 0.6.

Outside the above range, the saturation magnetic flux density Bs decreases. Therefore, when applied to a magnetic head, the overwrite characteristics tend to deteriorate.

 y is 0 to 0.2, preferably 0 to 0.1.

By adding Ni, the magnetic permeability μ can be improved.

However, if it exceeds the above range, the saturation magnetic flux density Bs tends to decrease.

When Ni is contained as an essential component, the content y is preferably 0.01 to 0.2, more preferably 0.01 to 0.1.

 z is 0.001 to 0.15, preferably 0.01 to 0.1.

 If it is less than the above range, heat resistance is insufficient.

As a result, the soft magnetic properties deteriorate due to heat treatment, etc., and the coercive force
Hc tends to increase significantly.

If it exceeds the above range, the saturation magnetic flux density Bs decreases. Therefore, when applied to a magnetic head, the overwrite characteristics tend to deteriorate.

 v is 0 to 0.1, preferably 0 to 0.05.

By adding 0, the coercive force Hc tends to decrease and the magnetic permeability μ tends to increase.

However, if it exceeds the above range, Bs tends to decrease, and the soft magnetic properties tend to deteriorate.

When 0 is included as an essential component, the content v is preferably 0.001 to 0.1, more preferably 0.01 to 0.05.

 w is 0.001 to 0.15, preferably 0.03 to 0.07.

If the ratio is less than the above range, the crystal grains are not sufficiently refined by N, and soft magnetic characteristics tend to be not obtained.

If it exceeds the above range, soft magnetic properties tend not to be obtained because nitrides of Fe, Co, Ni and M are generated more than necessary.

In addition, even if Si contains 5 at% or less and / or 2 at% or less Al, substantially the same effect can be obtained within the above composition range.

The composition of the soft magnetic thin film of the present invention is, for example, El
What is necessary is just to measure by the ectron Probe Micro Analysis (EPMA) method.

The thickness of the soft magnetic thin film may be appropriately selected depending on the application and the like, and is usually about 0.1 to 10 μm.

To form the soft magnetic thin film of the present invention, various vapor phase methods such as vapor deposition sputtering, ion plating, and CVD may be used.

Of these, it is particularly preferable to form a film by a sputtering method. For example, the film may be formed as follows.

As the target, an alloy cast, a sintered body, or a multi-target is used. Then, sputtering is performed in an atmosphere of an inert gas such as Ar.

In the case of performing reactive sputtering, the composition of the target may be substantially the same as that of the above-mentioned formula that does not contain N or O.

Then, sputtering, a N ₂ or N ₂ and O ₂ 0.1 to 15 vol% in Ar, is preferably carried out in an atmosphere containing 2-10 vol%.

If the ratio is outside the above range, soft magnetic properties tend not to be obtained.

There is no particular limitation on the sputtering method, and there is no limitation on the sputtering apparatus to be used, and a normal sputtering method may be used.

 Note that the operating pressure may be generally about 0.1 to 1.0 Pa.

In this case, various conditions such as a sputter input voltage and a current are appropriately determined according to the sputtering method and the like.

After film formation, it is preferable to perform heat treatment on the soft magnetic thin film.

 The following conditions are particularly preferable as the heat treatment conditions.

 Heating rate: about 2 to 8 ° C / min Holding temperature: about 200 to 700 ° C Holding time: about 10 to 60 minutes Cooling rate: about 2 to 8 ° C / min The atmosphere may be an inert gas such as Ar.

By performing the heat treatment under the above conditions, a soft magnetic thin film having more excellent soft magnetic properties can be obtained.

The soft magnetic thin film of the present invention has the following characteristics when the thickness is, for example, about 1 to 5 μm.

Coercive force Hc (50 Hz): about 0.1 to 2 Oe, especially about 0.1 to 1 Oe Initial permeability μ _i (5 MHz): about 1000 to 3000 Saturated magnetic flux density Bs (DC): about 20,000 G to 23000 G Average grain size D of crystal grains : About 100 ~ 300Å, especially 150 ~ 250
Å heat-resistant temperature: about 450-700 ° C, especially about 500-700 ° C Here, the heat-resistant temperature is a temperature at which the coercive force Hc rapidly increases when heat treatment is performed, and in the above case, the coercive force Hc is 2O
It is the temperature that becomes e.

The measurement of the magnetic properties of the soft magnetic thin film is performed, for example, when applied to a magnetic head, after forming a film on a non-magnetic substrate under the same conditions as when forming the magnetic head and performing a heat treatment under the same conditions, It should be done as follows.

Initial permeability (μ _i ): Measured with an applied magnetic field of 5 mOe using a figure 8 coil permeability meter Coercive force (Hc): Measured with a BH tracer Saturated magnetic flux density (Bs): 10,000 G using VSM the measurement in a magnetic field, the average crystal grain diameter D of the crystal grains, the bcc (110) peak half width W ₅₀ of the X-ray diffraction line according to powder method measures may be obtained from the equation Scherrer below.

Formula D = 0.9λ / W ₅₀ cos θ In the above formula, λ is the wavelength of the X-ray used, and θ is the diffraction angle.

When CuKα is used, 2θ of the bcc (110) peak
Is about 45 degrees.

Such a soft magnetic thin film of the present invention can be applied to various magnetic heads such as a metal-in-gap (MIG) magnetic head and a thin-film magnetic head.

In addition to the magnetic head, the present invention can be applied to various soft magnetic components such as a thin film inductor.

 Next, the magnetic head of the present invention will be described.

1 and 2 show a preferred embodiment of the MIG type magnetic head of the present invention.

The magnetic head shown in FIG. 1 has a first core 1 and a second core 2 having a soft magnetic thin film 4 formed on a surface facing a gap portion. ,
It is welded and integrated by the welding glass 3.

The magnetic head shown in FIG.
Are formed on both surfaces of the first core 1 and the second core 2 facing the gap.

In the present invention, the cores 1 and 2 are preferably made of ferrite.

In this case, the ferrite used is not particularly limited, but Mn
It is preferable to use -Zn ferrite or Ni-Zn ferrite according to the purpose.

The Mn-Zn ferrite, Fe ₂ O ₃ 50 to 60 mol%, ZnO 8 to 25 mol% of the balance is preferably of substantially MnO.

Further, Ni-Zn ferrite exhibits excellent characteristics particularly in a high-frequency region.
₂ O ₂ 30-60 mol%, NiO 15-50 mol%, ZnO 5-40
It is about mol%.

The saturation magnetic flux density Bs of the cores 1 and 2 at DC is preferably
3,000-6,000G.

When the saturation magnetic flux density is less than the above range, the overwrite characteristics are reduced, and in such a composition having the saturated magnetic flux density, the Curie temperature is lowered, so that the thermal stability is lowered. If the ratio is outside the above range, the magnetostriction increases and the characteristics as a magnetic head deteriorate, or the magnetic head is easily magnetized.

Initial permeability mu _i at DC cores 1 1,000 or more, and a coercive force Hc is less 0.3Oe.

It is preferable that the surfaces of the cores 1 and 2 facing the gaps are smoothed by mirror polishing or the like so that a soft magnetic thin film 4 and a base film described later are easily formed.

The soft magnetic thin film 4 is provided in order to generate a magnetic flux having a high density during recording and perform effective recording on a magnetic recording medium having a high coercive force.

As the soft magnetic thin film 4, the above-described soft magnetic thin film of the present invention is used.

Saturation magnetic flux density Bs of soft magnetic thin film 4 when magnetic head is completed
Is preferably 20000 G or more.

If it is less than the above range, the overwrite characteristics deteriorate,
In particular, it is difficult to record on a magnetic recording medium having a high coercive force.

In addition, since the soft magnetic thin film 4 has higher soft magnetic characteristics, the average crystal grain size of the crystal grains of the soft magnetic thin film 4 is preferably about 100 to 300 °.

When the magnetic head is completed, the soft magnetic thin film 4
Is preferably 2 Oe or less, more preferably 1 Oe or less.

The initial magnetic permeability μ _i at 5 MHz of the soft magnetic thin film 4 is 10
It is preferably at least 00.

If the coercive force Hc exceeds the above range, or the initial permeability μ
_{If i} is less than the above range, the recording / reproducing sensitivity tends to decrease.

The thickness of the soft magnetic thin film 4 is preferably 0.2 to 5 μm, and more preferably 0.5 to 3 μm.

When the film thickness is less than the above range, the volume of the entire soft magnetic thin film 4 is insufficient, and the soft magnetic thin film 4 is likely to be saturated.

In addition, when the above range is exceeded, the abrasion of the soft magnetic thin film 4 increases, and the eddy current loss increases.

By having the soft magnetic thin film 4 having such a high saturation magnetic flux density, the magnetic head of the present invention can perform effective recording on a magnetic recording medium having a coercive force of 1000 Oe or more, particularly 1500 to 2000 Oe.

If the core 1, the core 2, and the soft magnetic thin film 4 have the above-described magnetic characteristics, a high output and a high resolution can be obtained as a magnetic head. Also, the overwrite characteristics are-
Good value of 35dB or less can be obtained.

The resolution means, for example, that the output of the 1f signal is V _1f , 2f
When the signal output is _V2f , ( _V2f / _V1f ) x 100 [%]
It is represented by

Also, the overwrite characteristic is, for example,
This is a 1f signal output with respect to a 2f signal output when a 2f signal is overwritten.

 The gap 5 is formed from a non-magnetic material.

In particular, it is preferable to use an adhesive glass for the gap 5 in order to increase the adhesive strength.
Glass shown in No. 6, etc. is preferred.

Further, the gap 5 may be formed only of the adhesive glass, but is preferably formed of two layers of the gap 51 and the gap 53 as shown in the figure in order to increase the gap formation speed and the gap strength.

In this case, it is preferable to use SiO ₂ for the gap 51 and use an adhesive glass for the gap 53.

In the case of a magnetic head of a type in which the glass 3 to be described later flows into both sides of the gap, the gap 5 may be formed only of silicon oxide.

The method of forming the gap 5 is not particularly limited, but it is preferable to use a sputtering method.

 The gap length is usually about 0.2 to 2.0 μm.

In the MIG type magnetic head of the present invention, as shown in FIGS. 1 and 2, the gap between the first core 1 and the second core 2 is 5 mm.
Are joined and integrated via a.

The bonding of the cores is usually performed by simultaneously applying thermo-compression bonding with the adhesive glass in the gap 53 and simultaneously pouring in the welding glass 3.

The working temperature Tw of the welding glass 3 to be used is 450 to 700 ° C., especially
The temperature is preferably about 460 to 650 ° C.

Here, the working temperature Tw is a temperature at which the viscosity of the glass becomes 10 ⁴ poise, as is well known.

In the present invention, since the soft magnetic thin film 4 having high heat resistance is used, the coercive force Hc maintains a value of 2 Oe or less, particularly 1 Oe or less even when welding is performed using such a glass of Tw.

Although there is no particular limitation on the welding glass 3, it is preferable to use lead silicate glass.

Among them, for example, the following glass is suitable.

PbO: 67.5-87.5 wt% of B ₂ O _3: 4.0~8.1 wt% of SiO _2: 7.5-13.6 wt% of Al ₂ O _3: 0.3~0.8 wt% of ZnO: from 2.2 to 3.3 wt% of Bi ₂ O ₃ : about 0 to 0.1% by weight Na ₂ O, K ₂ O, CaO, etc .: about 0 to 4% by weight Sb ₂ O ₃ : about 0 to 1% by weight In welding, the welding temperature is set to around the working temperature Tw. This is performed by a usual method.

In this case, the welding process may also serve as a heat treatment for the soft magnetic thin film 4.

In the present invention, as shown in FIG.
A so-called EDG type MIG type magnetic head in which a low saturation magnetic flux density alloy thin film 6 having a lower saturation magnetic flux density Bs than the core is formed by the first core 1 and the above-described soft magnetic thin film 4 is formed on the second core 2. it can.

Then, the same effect as that of the above-described MIG type magnetic head can be obtained.

In this case, the low saturation magnetic flux density alloy thin film 6 includes, for example,
A low saturation magnetic flux density amorphous thin film disclosed in Japanese Patent Application No. 63-311591 can be used, and excellent overwrite characteristics and high sensitivity can be obtained.

The magnetic head of the present invention is integrated with a slider as required and assembled to form a head assembly.

Floppy heads that perform overwrite recording, such as so-called laminating and bulk type tunnel erasing types or read / write types that do not have an erasing head, monolithic type and composite type flying computer heads, and rotary VTRs Used as various magnetic heads such as a head and an R-DAT head.

In this manner, various known overwrite recording methods can be performed using the magnetic head of the present invention.

 Next, the thin-film magnetic head of the present invention will be described.

FIG. 4 shows a flying type thin film magnetic head according to a preferred embodiment of the present invention.

The thin-film magnetic head shown in FIG. 4 has an insulating layer 81, a lower pole layer 91, a gap layer 10, an insulating layer 8 on a slider 7.
3, coil layer 11, insulating layer 85, upper pole layer 95 and protective layer 1
It has 2 sequentially.

In the present invention, the slider 7 may be made of various known materials, and is made of, for example, ceramics or ferrite.

In this case, ceramics, particularly ceramic mainly composed of Al ₂ O ₃ -TiC, ceramics composed mainly of ZrO _2,
Ceramics mainly composed of SiC or ceramics mainly composed of AlN are preferred. Note that these may contain Mg, Y, ZrO ₂ , TiO _2, or the like as an additive.

Various conditions such as the shape and size of the slider 7 may be any known conditions, and are appropriately selected according to the application.

 An insulating layer 81 is formed on the slider 7.

As the material of the insulating layer 81, any of conventionally known materials can be used. For example, when a thin film is formed by a sputtering method, SiO ₂ , glass, Al ₂ O ₃ or the like can be used.

The thickness and pattern of the insulating layer 81 may be any known ones, for example, the thickness is about 5 to 40 μm.

The magnetic poles are usually provided as a lower magnetic pole layer 91 and an upper magnetic pole layer 95 as shown.

In the present invention, the lower magnetic pole layer 91 and the upper magnetic pole layer 95 include:
As in the case of the above-described MIG type magnetic head and EDG type MIG type magnetic head, respectively, the soft magnetic thin film of the present invention having the atomic ratio composition represented by the above formula is used.

Therefore, a magnetic head having excellent overwrite characteristics and high recording / reproducing sensitivity can be obtained.

 Note that film formation, heat treatment, and the like may be performed in the same manner as described above.

The pattern and thickness of the lower and upper magnetic pole layers 91 and 95 may be any known ones. For example, the lower magnetic pole layer 91
Is about 1 to 5 μm, and the thickness of the upper magnetic pole layer 95 is 1 to 5 μm.
It may be about μm.

Gap layer between lower pole layer 91 and upper pole layer 95
10 is formed.

For the gap layer 10, various known materials such as Al ₂ O ₃ and SiO ₂ may be used.

Further, the pattern, thickness, and the like of the gap layer 10 may be any known one. For example, the thickness of the gap 10 is 0.
The thickness may be about 2 to 1.0 μm.

The material of the coil layer 11 is not particularly limited, and a commonly used metal such as Al and Cu may be used.

There is no limitation on the winding pattern or the winding density of the coil, and a known coil may be appropriately selected and used. For example, the winding pattern may be any of a spiral type, a lamination type, a zigzag type, and the like.

For forming the coil layer 11, various vapor deposition methods such as a sputtering method, a plating method, or the like may be used.

In the illustrated example, the coil layer 11 is spirally disposed between the upper and lower pole layers 91 and 95 as a so-called spiral type, and the coil layer 11 and the upper and lower pole layers 91 and 95 are spirally arranged.
Insulating layers 83 and 85 are provided between them.

As the material of the insulating layers 83 and 85, any of conventionally known materials can be used. For example, when a thin film is formed by a sputtering method, SiO ₂ , glass, Al ₂ O ₃ or the like can be used.

On the upper pole layer 95, a protective layer 12 is provided. As the material of the protective layer 12, any conventionally known material can be used, and for example, Al ₂ O ₃ or the like can be used.

In this case, any of conventionally known patterns and film thicknesses of the protective layer 12 can be used, for example, the film thickness is 10 to 50 μm.
m.

By the way, when the protective layer 12 is formed by, for example, sputtering, the protective layer 12 is exposed to plasma, so that the temperature is about 200 to 400 ° C.

Therefore, in the present invention, the upper and lower pole layers 91 and 95
The above-mentioned soft magnetic thin film having high heat resistance is used for each.

In the present invention, various resin coat layers may be further laminated.

The manufacturing process of such a thin film magnetic head is usually performed by forming a thin film and forming a pattern.

As described above, the thin film of each layer is formed by a vapor phase deposition method, which is a conventionally known technique, for example, a vacuum deposition method, a sputtering method,
Alternatively, a plating method or the like may be used.

The pattern formation of each layer of the thin-film magnetic head can be performed by a conventionally known technique such as selective etching or selective deposition. The etching can be performed by wet etching or dry etching.

The thin-film magnetic head of the present invention is used in combination with a conventionally known assembly such as an arm.

Further, various types of overwrite recording can be performed using the thin-film magnetic head of the present invention. In this case, recording / reproduction can be effectively performed on a magnetic recording medium having a coercive force Hc of 1000 Oe or more, particularly 1500 to 2000 Oe.

<Example> Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

Embodiment 1 As shown in FIG. 1, a first core 1 and a second core 2 having a soft magnetic thin film 4 formed on a surface facing a gap portion are joined and integrated via a gap 5 to form an MIG type magnetic core. The head was manufactured.

The material of the core 1, 2 and Mn-Zn ferrite, saturation magnetic flux density B _s of the DC is 5000 G, initial permeability mu _i is 3000, the coercive force H
_c was 0.1 Oe.

The soft magnetic thin film 4 was formed by RF magnetron sputtering, and the thickness was 1 μm.

In this case, the sputtering is Fe _0.65 Co _0.30 Zr
_A target of _0.05 (atomic ratio) alloy with 5 N ₂ in Ar
The test was performed under an atmosphere containing volume%. Operating pressure is 0.4Pa
And

The composition of the soft magnetic thin film 4, saturation magnetic flux density Bs of the DC, initial permeability mu _i and the heat resistance temperature of coercive force Hc, the frequency 5MHz in the frequency 50Hz is as shown in Table 1.

Incidentally, Bs, Hc and mu _i is the value after the welding heat treatment.
In this case, the heat treatment temperature was 500 ° C., and the holding time was 60 minutes.

Further, the heat resistance temperature is a heat treatment temperature when Hc is measured after performing heat treatment for 60 minutes and Hc becomes 2 Oe or more.

The measurement of the magnetic properties and the like was carried out by forming the soft magnetic thin film 4 on a non-magnetic substrate under the same conditions as those for manufacturing the head.

Then, the composition analysis EPMA, the Bs measurements were made using VSM, Hc B-H tracer in the measurement, mu _i 8 of shaped coils Toruji rate measuring unit to measure the (applied magnetic field 5mOe).

The gap 51 is formed by sputtering using SiO ₂ ,
The thickness was 0.3 μm.

For the gap 53, an adhesive glass having a working temperature Tw of 550 ° C. was used.

The gap 53 was formed by sputtering, and the thickness was set to 0.1 μm.

The welding glass 3 has a working temperature Tw of 77.50 PbO at 500 ° C.
−6.05B ₂ O ₃ −10.57SiO ₂ −0.55Al ₂ O ₃ −2.75ZnO−0.05Bi ₂
Welding was performed at 500 ° C. using O ₃ -2.50Na ₂ O-0.30Sb ₂ O ₃ (wt%).

 The number of coil turns was 20 × 2 turns.

Then, it was fixed and sealed to a calcium titanate slider to obtain a composite type floating magnetic head.

The magnetic head manufactured in this manner is referred to as Sample No. 1.
And

Also, magnetic head samples No. 2 to No. 9 and comparative samples No. 10 to No. 16 having different compositions of the soft magnetic thin film 4 were manufactured.

Using each of these samples and a hard disk having a coercive force of 1800 Oe, the following characteristics were measured at a track width of 14 μm.

At the time of measurement, the first core 1 was on the hard disk leading side.

(Overwrite characteristics) Record 1f signal of 1.25MHz, then 2.5MHz from above
2f signal was overwritten.

The output of the 1f signal with respect to the output of the 2f signal was calculated, and the overwrite characteristics were evaluated.

(Recording / reproduction sensitivity measurement) A 5MHz signal was recorded, and then the recorded signal was reproduced.
The reproduced output voltage value V ′ _PP (peak-to-peak) at that time is measured.

In the table, a value V _{PP obtained} by standardizing the measured value V ′ _PP is shown.

 The results are as shown in Table 1.

Table 1 clearly shows the effect of the present invention.

After immersing the sample in a 5% (weight percentage) aqueous solution of sodium chloride for 168 hours, the surface of the soft magnetic thin film 4 was observed with an electron microscope.
~ No.15, generation of rust was confirmed.

On the other hand, in samples No. 1 to No. 9 of the present invention, generation of rust was hardly confirmed.

In addition, various samples having different compositions of the soft magnetic thin film 4 were manufactured, and the same evaluation was performed. The same result was obtained.

Example 2 As shown in FIG. 3, a first core 1 in which a low saturation magnetic flux density alloy thin film 6 having a lower saturation magnetic flux density Bs than a core is formed on a surface facing a gap portion, and a soft magnetic thin film 4 are formed. The second core 2 is joined and integrated via the gap 5,
An EDG type MIG type magnetic head was manufactured.

Then, when the same measurement as in Example 1 was performed, an equivalent result was obtained.

Third Embodiment As shown in FIG. 4, an insulating layer 81, a lower magnetic pole layer 91, a gap layer 10, an insulating layer 83, a coil layer 11, an insulating layer 85, an upper magnetic pole layer 95, and a protective layer are sequentially formed on the slider 7. A thin film magnetic head having 12 was manufactured. In this case, a sputtering method was used to form each layer, and dry etching was used to form a pattern.

The slider 7 with Al ₂ O ₃ -TiC.

The insulating layer 81 was made of Al ₂ O _{3 and} had a thickness of 30 μm.

For the lower and upper magnetic pole layers 91 and 95, soft magnetic thin films having the compositions shown in Table 2 were used.

In this case, the lower and upper magnetic pole layers 91 and 95 are
The lower and upper magnetic pole layers 91 and 95 were each formed to have a thickness of 3 μm in the same manner as the soft magnetic thin film 4 described above.

Saturation magnetic flux density Bs at DC of the magnetic pole layers 91 and 95, frequency 50 Hz
Initial permeability mu _i and the heat resistance temperature of coercive force Hc, the frequency 5MHz in are as shown in Table 2.

The heat treatment conditions were as follows: heat treatment temperature 350 ° C, holding time 60
Minutes.

The gap layer 10 was made of SiO _{2 and} had a thickness of 0.25 μm.

The coil layer 11 was made of Cu and formed in a spiral shape as shown in the figure.

Al ₂ O ₃ was used for the insulating layers 83 and 85.

The protective layer 12 was made of Al ₂ O _{3 and} had a thickness of 40 μm. The magnetic head being manufactured was kept at a temperature of about 350 ° C. when the protective layer 12 was sputtered.

Thus, the magnetic head samples No. 1 to No. 9 of the present invention
And comparative samples No. 10 to No. 15 were manufactured.

The same measurement as in Example 1 was performed using each of these samples and a hard disk having a coercive force of 1800 Oe.

 The results are as shown in Table 2.

Table 2 clearly shows the effect of the present invention.

 Further, the sample of the present invention also had good corrosion resistance.

<Effect of the Invention> The soft magnetic thin film of the present invention has a high saturation magnetic flux density Bs. In addition, because of its high heat resistance, it has low coercive force Hc and high magnetic permeability μ, and has excellent soft magnetic properties.

Therefore, the magnetic head of the present invention has high overwrite characteristics, recording / reproducing sensitivity, etc., and excellent electromagnetic conversion characteristics, particularly for a magnetic recording medium having a high coercive force.

Since the soft magnetic thin film of the present invention is excellent in corrosion resistance and wear resistance, a highly reliable magnetic head is realized.

[Brief description of the drawings]

1 and 2 show a MIG type magnetic head 1 according to the present invention.
It is a partial sectional view showing an example. FIG. 3 is a partial sectional view showing an example of the EDG type MIG type magnetic head of the present invention. FIG. 4 is a partial sectional view showing an example of the thin-film magnetic head of the present invention. DESCRIPTION OF SYMBOLS 1... First core 2... Second core 3... Deposition glass 4... Soft magnetic thin film 5, 51, 53... Gap 6. , 85 ... insulating layer 91 ... lower magnetic pole layer 95 ... upper magnetic pole layer 10 ... gap layer 11 ... coil layer 12 ... protective layer

Claims (4)

(57) [Claims] 1. A soft magnetic thin film having an atomic ratio composition represented by the following formula: Formula (Fe _1-xyz Co _x Ni _y M _z ) _1-w (N _1-v O _v ) _w (where M is Mg, Ca, Ti, Zr, Hf, V, Nb, T
a, one or more selected from Cr, Mo, Mn and B;
0.2 ≦ x ≦ 0.7, 0 ≦ y ≦ 0.2, 0.001 ≦ z ≦ 0.15, 0 ≦ v
≦ 0.1, 0.001 ≦ w ≦ 0.15. ) 2. The soft magnetic thin film according to claim 1, wherein the saturation magnetic flux density Bs is 20,000 G or more, and the coercive force Hc is 20 Oe or less. 3. A magnetic head comprising the soft magnetic thin film according to claim 1 between a pair of cores. 4. A thin-film magnetic head having an upper magnetic pole layer, a lower magnetic pole layer, and a protective layer, wherein the upper magnetic pole layer and the lower magnetic pole layer are formed of the soft magnetic thin film according to claim 1 or 2. A magnetic head comprising: