JPH03267353A - Soft-magnetic material and magnetic head - Google Patents

Abstract

PURPOSE:To produce a soft-magnetic material having low coercive force and high saturation magnetic flux density by preparing a soft-magnetic material having a specific atomic composition consisting of Fe and Be, etc. CONSTITUTION:A soft-magnetic material having an atomic composition represented by a formula Fe1-xZx (where Z means Be, a combination of Be and V, or a combination of Be and/or V and Si and/or Al and 0.05<=x<=0.4) is prepared. This soft-magnetic material has high adhesive strength to ceramics, such as ferrite, and also has high heat resistance, corrosion resistance, and wear resistance, and further, a thin film of this soft-magnetic material is suitable for magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a magnetic head and a soft magnetic material suitable for use in a magnetic head or the like.

<Prior art> Metal-in-gap (MIG) with a soft magnetic thin film such as sendust, which has a higher saturation magnetic flux density Bs than the core, on the opposing surface of the gap portion of the first and second cores made of ferrite. ) type magnetic heads are known.

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

However, in Sendust, the saturation magnetic flux density Bs is 12kG.
degree and not enough.

Furthermore, the adhesive strength with the ferrite core is low, so it is necessary to provide a base layer.

<Problems to be Solved by the Invention> The main object of the present invention is to develop a magnetic material using a soft magnetic material with a low coercive force (He), a high saturation magnetic flux density Bs, and a high adhesive strength with ceramics such as ferrite, and a thin film thereof. The head is to provide.

Means for Solving the Problems> These objects are achieved by the present invention described in (1) and (2) below.

(1) A soft magnetic material characterized by having an atomic composition represented by the following formula.

Formula Fe+-Zx (In the above formula, Z is Be, a combination of Be and ■, or Be and/or ■ and Si and/or A
It represents a combination with ff, and 0.05≦X≦0.4. ) (2) A magnetic head comprising a thin film of the soft magnetic material described in (1) above.

Effect> The soft magnetic thin film of the present invention has an improved saturation magnetic flux density Bs of about 15 kG and a low coercive force He.

Furthermore, it has high adhesive strength with ceramic bodies such as ferrite.

Furthermore, it has high heat resistance, corrosion resistance, and wear resistance.

<Specific structure of the invention> Hereinafter, the specific configuration of the present invention will be explained in detail.

The soft magnetic material of the present invention is usually a thin film and has an atomic composition represented by the following formula.

Formula Fe+-ZX In the above formula, Z is one or more of the following.

1) Be 2) Be+V 3) (One or two types of Be and ■) + (One or two types of Si and A°C) Among these, in the case of 2), ■ is the total 0. It is preferable that it is 7 or less (atomic ratio).

In addition, in the case of 3), the atomic ratio of V/B is arbitrary, but the total of Si and A℃ is 0.9 or less (atomic ratio)
, especially preferably 0.8 or less.

Note that among 1) to 3) above, 2) and 3) are preferable.

Also, X is 0.05 to 0.4, preferably 0.05 to 0
．． It is 3.

If it is less than the above range, the coercive force Hc will increase.

If it exceeds the above range, the saturation magnetic flux density Bs will decrease.

In such a composition, less than 20 at% of the total amount, especially 1
Nb, Zr, W, Ti, Cr, within the range of 0 at% or less
One or more of Ni, Co, Ta, Mn, Mo, C, P, Ge, B, etc. may be contained.

A soft magnetic thin film having such a composition may be formed generally to a thickness of about 0.05 to 10 - by a vapor phase method such as evaporation, sputtering, ion blating, or CVD.

During film formation, it is generally preferable to keep the substrate temperature at 200 to 500°C.

Coercive force H of the obtained soft magnetic thin film at DC ~ 50 Hz
It is preferable that c is 50e or less, more preferably 20e or less.

In addition, the initial magnetic permeability μ at 5 MHz is 1000 or more,
In particular, more than 1,500 items can be exchanged.

If the coercive force He exceeds the above range, or the initial permeability μ
is less than the above range, recording/reproducing sensitivity tends to decrease when applied to a magnetic head.

In addition, the saturation magnetic flux density Bs of the soft magnetic thin film is 15k
It is preferably 16 kG or more, particularly 16 kG or more.

If it is less than the above range, the override characteristics will deteriorate, making it particularly difficult to record on a high coercive force magnetic recording medium.

The soft magnetic thin film may be subjected to heat treatment after being formed.

In addition, the soft magnetic thin film is crystalline, and its crystal grain size is
Approximately 100 to 500 people.

An embodiment in which the soft magnetic material of the present invention is applied as a thin film to an MIG type magnetic head is shown in FIGS. 1 and 2.

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 the surface facing the gap, and both cores are connected to each other through a gap 5. joined,
They are integrated by welding with a welding glass 3.

The magnetic head shown in FIG. 2 is of a type in which a soft magnetic thin film 4 is formed on the surfaces of both the first core 1 and the second core 2 facing the gap portion.

In the present invention, the core 1.2 is preferably composed of ferrite.

In this case, there are no particular restrictions on the ferrite used, but M
It is preferable to use n-Zn ferrite or N1-Zn ferrite depending on the purpose.

As Mn-Zn ferrite, Fe 20 s50
It is preferable to use ZnO in an amount of about 60 mol %, about 8 to 25 mol % of znO, and the remainder being substantially MnO.

In addition, Ni-Zn ferrite exhibits excellent properties especially in the high frequency range, and its preferred composition is as follows:
Fe 20 g is 30-60 mol%, NiO is 15-60 mol%
ZnO is about 50 mol% and ZnO is about 5 to 40 mol%.

The soft magnetic thin film of the present invention exhibits high adhesive strength to these ferrites.

Note that the surface of the core 1.2 facing the gap portion is preferably smoothed by mirror polishing or the like so that a soft magnetic thin film 4, a base film, etc., which will be described later, can be easily formed thereon.

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

In such a case, the thickness of the soft magnetic thin film 4 is preferably 0.
．． 2 to 5-.

Gap 5 is formed from a non-magnetic material.

In particular, it is preferable to use adhesive glass for the gap 5 in order to increase adhesive strength.

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

In this case, SiO2 is used for the gap 51, and adhesive glass is used for the gap 53.

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

Although there are no restrictions on the formation of the gap 5, it is particularly preferable to use a sputtering method.

The gap length is approximately 0.2 to 2.0 layers.

In the MIG type magnetic head of the present invention, as shown in FIGS. 1 and 2, the first core 1 and the second core 2 have a gap 5
They are joined and integrated via the .

The cores are joined by thermocompression bonding using adhesive glass in the gap 53 and at the same time by pouring the welding glass 3.

In the present invention, since the above-mentioned soft magnetic thin film having high heat resistance is used, the coercive force Hc does not deteriorate even if glass having a Tw of 400 to 600''C is used for thermocompression bonding.

As the welded glass 3, it is preferable to use lead silicate glass.

The magnetic head of the present invention is integrated with a slider as necessary and assembled into a head assembly.

In addition, there are floppy heads that perform override recording such as tunnel erase types such as laminate types and bulk types, or read/write types that do not have an erase head, floating type computer heads such as monolithic types and composite types, and rotary type VTR heads. It is used in various magnetic heads such as heads for R-DAT and R-DAT.

In this way, using the above magnetic head of the present invention,
Override recording can be performed using various known methods.

Further, in the present invention, as shown in FIG. 3, a low saturation magnetic flux density alloy thin film 6 having a lower saturation magnetic flux density Bs than the core is formed on the first core 1, and the above-mentioned soft magnetic thin film is formed on the second core 2. 4 can be used as a so-called enhanced dual gap length (EDG) type magnetic head.

Further, the same effects as those of the above-mentioned MIG type magnetic head can be obtained.

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

The soft magnetic material of the present invention can also be applied to thin film magnetic heads.

FIG. 4 shows a floating type thin film magnetic head which is a preferred embodiment of the present invention.

The thin film magnetic head shown in FIG.
It has 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 12 in this order.

In the present invention, the slider 7 may be made of various conventionally known materials, such as ceramics, ferrite, etc.

In this case, ceramics, especially ceramics mainly composed of Aρ203TiC, ceramics mainly composed of ZrO2, ceramics mainly composed of SiC, or ceramics mainly composed of Aρ203TiC,
Ceramics containing 12N as a main component are suitable. In addition, these contain Mg, Y, ZrO□, T as additives.
ie, etc. may be contained.

Conditions such as the shape and size of the slider 7 may be any known ones and are appropriately selected depending on the application.

An insulator 1181 is formed on the slider 7.

As the material for the insulating layer 81, any conventionally known material can be used. For example, when a thin film is formed by sputtering, SiO□, glass, A.degree. C. 203, etc. 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 4 degrees).

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, a soft magnetic thin film having an atomic ratio represented by the above formula is used for the lower magnetic pole layer 91 and the upper magnetic pole layer 95, as in the case of the above-mentioned MIG type magnetic head and EDG type magnetic head.

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

Moreover, high adhesive strength can be obtained.

The patterns, film thicknesses, etc. of the lower and upper magnetic pole layers 91 and 95 may be any known ones. For example, the thickness of the lower magnetic pole layer 91 may be approximately 1 to 5p, and the thickness of the upper magnetic pole layer 95 may be approximately 1 to 5p.

A gap layer 10 is formed between the lower magnetic pole layer 91 and the upper magnetic pole layer 95.

The gap layer 10 includes Al220s, S L 02
Various known materials may be used.

Further, the pattern, film thickness, etc. of the gap layer 10 may be any known ones. For example, the film thickness of the gap 10 may be about 0.2 to 1.0 thick.

There is no particular restriction on the material of the coil layer 11 (usually used metals such as A.degree. C. and Cu may be used).

There are no restrictions on the winding pattern or winding density of the coil, and known patterns may be appropriately selected and used. For example, the winding pattern may be a spiral type as shown in the figure, a laminated type, a zigzag type, or the like.

Further, the coil layer 11 may be formed using various vapor deposition methods such as sputtering and plating.

In the illustrated example, the coil layer 11 is a so-called spiral type, and is spirally arranged between the upper and lower magnetic pole layers 91.95, and the insulating layer 83. 85 are installed.

Any conventionally known material can be used for the insulating layers 83, 85. For example, when a thin film is formed by sputtering, SiO2, glass, A(2tO-), etc. can be used.

Furthermore, a protective layer 12 is provided on the top pole layer 95 .

As the material for the protective layer 12, any conventionally known material can be used, such as Al2O2.

In this case, any conventionally known pattern and film thickness of the protective layer 12 can be used; for example, the film thickness is 10 to 5.
It may be about 0 presses.

In addition, in the present invention, various resin coat layers and the like may be further laminated.

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

As described above, the thin film of each layer may be formed using a conventionally known technique such as a vapor deposition method such as a vacuum evaporation method, a sputtering method, or a plating method.

Pattern formation of each layer of the thin film magnetic head can be performed by selective etching or selective deposition, which are conventionally known techniques. 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.

Furthermore, various types of override recording can be performed using the thin film magnetic head of the present invention.

The initial magnetic permeability μ at 5 MHz is as shown in Table 1.

In addition, EPMA was used for composition analysis, and VSM and H were used for Bs measurement.
The e measurement was performed using a B-H tracer, and the μ measurement was performed using a figure-8 coil permeability meter (applied magnetic field: 5 m0e).

<Example> Hereinafter, the present invention will be explained in further detail by giving specific examples of the present invention.

Example 1 By vapor deposition, the atomic ratio composition shown in Table 1 was obtained, and the film thickness was 1-
A soft magnetic thin film was formed on a glass substrate in a magnetic field.

During vapor deposition, substrate temperature: 300°C, degree of vacuum: 10-'T
orr, and a magnetic field of 2000e was applied in the in-plane direction.

The composition of the soft magnetic thin film, the saturation magnetic flux density Bs at direct current, the coercive force Hc at a frequency of 50 Hz, and the frequency. When the soft magnetic thin film was formed on a glass substrate by sputtering, results equivalent to ci + r were obtained.

Next, using the above-mentioned soft magnetic material, as shown in FIG. 5, and a MIG type magnetic head was manufactured.

The material of the core 1.2 is M n -Z n ferrite,
Saturation magnetic flux density Bs at DC is 5000G, initial permeability μm
was 3000, and the coercive force Hc was o, ioe.

The soft magnetic thin film 4 was formed from RF magnetron sand and had a film thickness of one layer.

In this case, the sputtering was performed in Ar at an operating pressure of 0.
．． The test was carried out by applying a static magnetic field of 4 Pa and 2000 e.

The gap 51 was formed using SiO2 by sputtering, and its film thickness was set to 0.4-.

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

Note that the gap 53 was formed by sputtering, and its film thickness was 0.2 μ.

The welding glass 3 has a working temperature Tw of 500°C, 77,
50PbO-6,05BaOx-10,57SiO□-
0,55Aj, 0a-2,75ZnO-0,05Bi2
0! Welding was performed at 500°C using -2,5ON8.0-0.30Sb2C1s (wt%).

Further, the number of coil turns was 20×2 turns.

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

Using each of these head samples and a hard disk with a coercive force of 15,000e, the following characteristics were measured at a track width of 14-.

Note that during the measurement, the first core 1 was placed on the hard disk reading side.

(Override characteristics) A 1.25 MHz 1f signal was recorded, and then a 2.5 MHz 2f signal was overwritten thereon.

The output of the 1f signal relative to the output of the 2f signal was calculated, and the override characteristics were evaluated.

(Measurement of Recording/Reproduction Sensitivity) A 5 MHz signal is recorded, then the recorded signal is reproduced, and the reproduction output voltage value V'p-p (peak-to-peak) at that time is measured.

As a result, the override characteristic of the sample of the present invention is -4
0 (dB) or less, and the reproduced output voltage value is 1.1 (μ■
/-/turn).

Further, when a bending test was performed on the head sample of the present invention, no peeling occurred at the interface of the soft magnetic thin film ferrite.

On the other hand, in the comparative sample, peeling was observed at the interface between the Sendust thin film and the ferrite.

These results clearly demonstrate the effects of the present invention.

<Effects of the Invention> When the soft magnetic material of the present invention is made into a thin film, it has soft magnetic properties such as a high saturation magnetic flux density Bs, a low coercive force Hc, and a high magnetic permeability μ. In addition, it has high adhesive strength.

Therefore, the magnetic head using the soft magnetic material of the present invention has
It has high override characteristics, recording/playback sensitivity, etc., and excellent electromagnetic conversion characteristics.

Furthermore, since the soft magnetic material used has high adhesive strength, a highly reliable magnetic head can be realized.

[Brief explanation of drawings]

FIGS. 1 and 2 are partial cross-sectional views showing one example of the MIG type magnetic head of the present invention. FIG. 3 is a partial sectional view showing an example of the EDG type magnetic head of the present invention. FIG. 4 is a partial sectional view showing one example of the thin film magnetic head of the present invention. Explanation of symbols 1...First core 2...Second core 3...Welded glass 4...Soft magnetic thin film 5.51.53...Gap 6...Low saturation magnetic flux density alloy thin film 7 ...Slider 81, 83, 85...Insulating layer 91...Bottom pole layer 95...Top pole layer 10...Gap layer 11...Coil layer 12...Protective layer Applicant T.D. −K Co., Ltd. Agent Patent Attorney Ishii Hikaru Patent Attorney
Increase 1) Tatsuya F I G. FIG, 3 FIG, 2 FIG, 4

Claims (2)

[Claims] (1) A soft magnetic material characterized by having an atomic composition represented by the following formula. Formula Fe_1_-_xZ_x (In the above formula, Z is Be, a combination of Be and V, or Be and/or V and Si and/or A
It represents a combination with l, and 0.05≦x≦0.4. ) (2) A magnetic head comprising a thin film of the soft magnetic material according to claim 1.