JPH0522284B2 - - Google Patents

Description

[Detailed Description of the Invention] Field of Application This invention relates to the improvement of a composite magnetic head that is mainly composed of a ferromagnetic oxide such as ferrite and uses a magnetic metal material near the operating gap, and the invention relates to the improvement of a composite magnetic head that uses a magnetic metal material near the operating gap. Eliminate the magnetic pseudo gap that occurs in the
It has flat output characteristics by preventing magnetic characteristics such as undulations in the frequency characteristics of the reproduced output, and has a structure that is easy to manufacture, and is suitable for various magnetic recording and reproducing devices using recording media with high coercive force. Concerning a suitable composite magnetic head.

BACKGROUND ART In recent years, in the field of magnetic recording, so-called metal-based recording media having high coercive force have been used to meet the demand for higher density recording signals. for example,
It is being used in magnetic recording and reproducing devices for a wide variety of recording formats, such as FDDs, HDDs, VTRs, magnetic tape storage devices for computers, S-DATs, and still video floppies.

A magnetic head that magnetically records and reproduces information on a magnetic recording medium having a high residual magnetic flux density, such as a metal tape, has had to generate a magnetic field strength higher than before in its magnetic gap.

On the other hand, in the case of a magnetic head that consists of a magnetic core made of a ferromagnetic oxide such as single-crystal ferrite, which is split into halves, and a pair of halves are abutted against each other, with the abutting portion forming a magnetic gap, the ferrite forming the gap is Since Bs was as low as 6000G at most, there was a problem that sufficient recording magnetic field strength could not be obtained.

Therefore, in a magnetic head mainly made of ferromagnetic oxide, the area near the magnetic gap of the magnetic head is
Various so-called composite magnetic heads have been proposed that are constructed from metal magnetic thin films having a higher saturation magnetic flux density Bs than ferrite.

For example, referring to the schematic diagram of the medium facing surface of a conventional composite magnetic head shown in FIGS. Half piece 1, 2
A metal magnetic thin film 3, is formed on each abutting surface 1a, 2a using a vacuum thin film forming technique such as a sputtering method.
After the magnetic core halves 1 and 2 are formed, a magnetic gap 5 is formed by butting the magnetic core halves 1 and 2 together.

In addition, the metal magnetic thin film of the composite magnetic head with such a configuration is required to have the following characteristics:
An Fe-Al-Si metal magnetic thin film is a material that satisfies the following requirements.

Has a Bs higher than that of ferrite materials Has excellent wear resistance Has excellent thermal stability Has excellent magnetic permeability at high frequencies (e.g. 10MHz) Problems with conventional technology The above-mentioned A composite magnetic head using an Fe--Al--Si alloy film as a metal magnetic thin film is widely used as an excellent magnetic head that satisfies various conditions for the use of metal tapes. However, the following problems arose.

To explain using the schematic diagram of the magnetic head in Fig. 6,
When forming the metal magnetic thin films 3 and 4 on the abutting surfaces of the magnetic cores 1 and 2 to form a head, depending on the thin film formation conditions and the difference in coefficient of thermal expansion between the cores 1 and 2 and the thin films 3 and 4, etc. , the magnetic properties of the initial adhesion layer of the metal magnetic thin film deteriorate, and the joints 1b, 2 with the magnetic cores 1, 2 deteriorate.
When a magnetic discontinuity occurs in b, and such a composite magnetic head is used for reproduction, the junctions 1b and 2b act as a pseudo gap, and a pseudo peak as shown in Fig. 7 appears, causing the frequency characteristics of the reproduction output to change. There was a problem that caused undulations.

Furthermore, if there is a processed strain layer on the abutting surface of the magnetic cores 1 and 2 on which the metal magnetic thin film is to be deposited, the joining portion 1b
It was found that a magnetic discontinuity occurs in the magnetic field, which acts as a pseudo gap in the same way as described above.

For this kind of pseudo-gap generation problem,
In general, azimuth loss is used to make the joints 1b and 2b, which form a pseudo gap, and the magnetic gap 5 non-parallel, for example, as shown in FIG.
This problem has been dealt with by providing a predetermined azimuth angle.

However, in the structure shown in FIG. 5, it is necessary to deposit the metal magnetic thin film to a thickness of about 20 μm, which reduces the yield due to film peeling or takes a long time to form the deposit, reducing productivity. There were problems such as poor quality.

Purpose of the Invention The object of the present invention is to provide a composite magnetic head suitable for high-density recording and reproducing on a magnetic recording medium having a high coercive force Hc, which prevents the formation of so-called pseudo gaps, is suitable for mass production, and is highly reliable. The objective is to create a composite magnetic head with high wear resistance and good wear resistance.

Structure of the Invention The present invention provides a composite magnetic head in which a magnetic core mainly composed of a ferromagnetic oxide is made of a metal magnetic material at least in the vicinity of the operating gap, wherein the metal magnetic material contains 70 wt% to 90 wt% of Ni and Mn. 5wt%~25wt
% of ferromagnetic Ni-Mn alloy thin film and Fe-
The ferromagnetic Ni-Mn alloy thin film is formed between the ferromagnetic oxide surface, which has a strain-free high flatness surface, and the Fe-Al-Si alloy thin film. This is a composite magnetic head characterized by the following features:

That is, in the composite magnetic head of the present invention, for example, the abutting surfaces of the magnetic core halves made of ferromagnetic oxide such as Ni-Zn ferrite or Mn-Zn ferrite are subjected to mechanochemical polishing or float polishing. After processing a high-precision flat surface into a strain-free surface using stress-free processing such as
After depositing a ferromagnetic Ni-Mn alloy film containing % to 25wt%, and further depositing a Fe-Al-Si alloy thin film, a so-called sendust film, and processing it into a predetermined shape,
It is characterized by a structure in which the magnetic core halves are butted together to form a magnetic gap.

The composite magnetic head according to the present invention is characterized by metal magnetic bodies having a laminated structure laminated in a predetermined order on the abutting surfaces of the magnetic core halves, and wherein the ferromagnetic
Not only does it have a two-layer structure consisting of a Ni-Mn alloy thin film and a Fe-Al-Si alloy thin film, but also a ferromagnetic oxide, which is the magnetic core half, the ferromagnetic Ni-Mn alloy film, and a Ni-Mn alloy film. This also includes the case of a laminated structure having a diffusion layer formed on one or both of the bonding surfaces of the alloy film and the Fe-Si-Al alloy film.

Effects of the Invention By providing a metal magnetic material with a two-layer structure of a Fe-Al-Si alloy thin film and a ferromagnetic Ni-Mn alloy thin film on the surface of a ferromagnetic oxide magnetic core, it is possible to A composite magnetic head suitable for high-density recording and reproducing on a magnetic recording medium having a coercive force Hc is obtained, the so-called pseudo gap is virtually eliminated, the waviness of the frequency characteristic is significantly reduced, and the metal magnetic material is A relatively thin film is required, and a composite magnetic head with excellent productivity, high reliability, and good wear resistance can be obtained since it does not require much time to form the film.

The reason why such an effect can be obtained will be explained in detail.

The initial deterioration layer of the Fe-Al-Si alloy thin film, which is thought to be one of the causes of the pseudo-gap mentioned above, cannot be easily removed even if the film-forming conditions of the usual sputtering method or vacuum evaporation method are changed. .

The reason for this is not clear, but as shown in Figure 8, which shows the relationship between the influence of film thickness on the magnetic properties of the sendust film produced by the sputtering method, as the film thickness becomes thinner, the magnetic permeability decreases significantly. It can be seen that this decreases.

Therefore, the number of sides close to the interface with the magnetic core half
The magnetic permeability of the 100 Å to several 1000 Å region is significantly lower than that of the upper region, and it is presumed that this acts as a pseudo gap.

As a result of various studies, the present inventors have found that the reason for the significant deterioration of the magnetic properties of the initial layer of the Fe-Al-Si alloy thin film is that the ferromagnetic oxide forming the magnetic core halves is directly affected.
When a Fe-Al-Si film is formed, the crystal orientation tends to be disordered in the initial stage of film formation, and recrystallization and grain growth are difficult to occur near the interface with the ferromagnetic oxide even after heat treatment. It is believed that there is.

Therefore, we investigated various metal magnetic materials for the purpose of preventing pseudo gaps, and found that Ni was 70wt% to 90wt%.
Ferromagnetic Ni-Mn containing 5wt% to 25wt% Mn
By making the alloy into a thin film using sputtering or vapor deposition and subjecting it to appropriate heat treatment, unlike Fe-Al-Si alloy films, an initial deterioration layer does not substantially appear, and the thickness is from several hundred Å to several thousand Å. It was discovered that even a thin film of this type exhibits excellent soft magnetic properties.

That is, the ferromagnetic Ni-Mn alloy film is
First, a film is formed on a substrate made of ferromagnetic oxide, etc.
Next, when a Fe-Al-Si alloy film is formed, the initial deterioration layer of the Fe-Al-Si alloy film is removed due to the magnetic interaction between the underground Ni-Mn alloy film and the Fe-Al-Si alloy film. It was found that the magnetic properties were improved and the pseudo gap virtually disappeared.

In addition, this invention provides an Fe-Al-Si alloy film and a Ni
The two-layer structure of the -Mn alloy film has the effect of relieving stress in the film, and can prevent peeling of the film after heat treatment.

Preferred Embodiment of the Invention In the present invention, the composite magnetic head has a structure in which the metal magnetic material contains 70 wt% to 90 wt% of Ni, which is deposited on the ferromagnetic oxide surface which forms a strain-free and high flatness surface.
Ferromagnetic Ni-Mn containing 5wt% to 25wt% Mn
Fe- based alloy thin film and Fe-
Any known structure can be used as long as it has a laminated structure with an Al--Si alloy thin film.

In addition, in this invention, the ferromagnetic oxide that is the main component of the magnetic core includes Ni-Zn ferrite and Mn-
Single-crystal ferrite such as Zn ferrite and HIP-treated sintered ferrite can be used.

As mentioned above, the Ni-Mn alloy film, which is a feature of this invention, contains 70wt% Ni for the purpose of improving the magnetic properties of the initial layer of the Fe-Al-Si alloy film.
~90wt%, containing 5wt% to 25wt% Mn,
The Ni--Mn alloy film itself needs to be ferromagnetic so as not to form a pseudo gap.

Further, the saturation magnetic flux density Bs needs to be approximately 70% or more of the Bs of the ferromagnetic oxide serving as the base, and is preferably equal to or higher than the Bs of the ferromagnetic oxide serving as the base.

A coercive force of several 100e or less can be used, but preferably 10Oe or less, more preferably a few
Oe or lower is better.

The composition of this Ni-Mn alloy film is at least Ni
It is sufficient to contain 70wt% to 90wt% of Mn and 5wt% to 25wt% of Mn, that is, a Ni-Mn binary alloy may be used.Furthermore, as subcomponents, Sb15wt% or less, Ge15wt% or less, Sn20wt% or less, Si5% wt or less, Al5wt% or less, Co15wt% or less, Fe9wt% or less, Cu10wt% or less, Cr10wt% or less, Mo10wt% or less, W10wt%
Below, V10wt% or less, Nb10wt% or less, Ta10wt
It may be a Ni-Mn alloy containing at least 20 wt % or less of at least one of the following.

However, the soft magnetic properties of this Ni-Mn alloy film depend on the heat treatment conditions, especially the cooling rate, and the optimal heat treatment conditions differ depending on the alloy composition. It is advisable to use it in combination with heat treatment before and after processing after film formation or during bonding processing.

The Fe-Al-Si alloy thin film provided in the outermost layer is a so-called sendust alloy, which has been widely used in composite magnetic heads, and a known composition can be selected as appropriate depending on the purpose of the magnetic head. I get it, but 3
An alloy in the range of ~10wt%Al, 6~15wt%Si, 80~90wt%Fe is often used, and if necessary, Cr, Ti, Ni, Co, Mo, Zr, rare earth elements, etc. It is also good to add.

On the surface of the ferromagnetic oxide constituting the magnetic core half, the ferromagnetic Ni-Mn alloy thin film and the Fe-Al-Si alloy thin film are formed on top of the ferromagnetic Ni-Mn alloy thin film, but the deposition method is as follows. , various sputtering methods, vacuum evaporation, ion plating, and other known vapor phase film forming methods can be used.

As for preferred deposition methods and conditions, in any method, the higher the degree of vacuum achieved, the better, and it is necessary to maintain a high vacuum of at least 10 ^-6 Torr or less, preferably 2 × 10 ^-6 Torr or less, and more preferably Preferably it is 1×10 ^-6 Torr or less.

When using the sputtering method, an inert gas such as argon gas is used as the sputtering gas, and the pressure may be appropriately selected depending on the structure of the sputtering device. For example, in the case of a magnetron type sputtering device, the gas pressure is 1 × 10 ^-3 Torr ~
20×10 ^-3 Torr is preferred, more preferably 2
×10 ^-3 Torr to 8×10 ^-3 Torr is good.

Further, the substrate temperature is preferably 300°C or less, preferably 200°C or less, and more preferably 100°C or less.

Furthermore, the substrate roughness of the ferromagnetic oxide surface to which this ferromagnetic Ni-Mn alloy thin film is deposited is preferably
The thickness should be 40Å or less. The reason for this is that the thickness of the ferromagnetic Ni-Mn alloy thin film to be deposited is as thin as several Å to several thousand Å, so the surface condition of the ferromagnetic oxide, such as residual strain stress and roughness, etc. This is because there is a possibility that the magnetic properties will be deteriorated.

According to the inventor's experiments, the characteristic deterioration of the ferromagnetic Ni-Mn alloy thin film, which is a feature of this invention, becomes noticeable when the surface roughness of the ferromagnetic oxide reaches 1/10 of the thickness of the magnetic film. Therefore, the surface roughness of the ferromagnetic oxide is preferably 100 Å or less, more preferably 40 Å or less.

Methods for obtaining a strain-free, high flatness state of the ferromagnetic oxide surface include mechanochemical polishing, float polishing, mechanochemical polishing after diamond polishing, or mechanochemical polishing after diamond polishing, and Float polishing is a good method.

In addition, in this invention, as a mechanochemical polishing method, MgO, ZrO ₂ , Al ₂ with a particle size of 0.1 μm or less
Using a suspension of 0.5wt% to 20wt% of O ₃ , SiO ₂ , etc. alone or mixed fine powder in pure water, for example, hard cloth, solder, Sn, etc. It is preferable that a disc-shaped polisher consisting of a polisher is rotatably disposed, the workpiece is brought into contact with the polisher surface in this suspension under a predetermined load, and the two are rotated relative to each other to perform polishing.

In the polishing method, the polisher material, rotation speed, and load pressure may be appropriately selected depending on conditions such as the particle size of the fine powder, the amount of suspension in pure water, and the workpiece material ^. Conditions of ~1 Kg/cm ² and rotational speed of 10 m/min to 100 m/min are preferable. In addition, the particle size of the single or mixed fine powder is
If the particle size exceeds 0.1 μm, scratches will occur, so the particle size is preferably 0.1 μm or less.

In this invention, the thickness of the metal magnetic material consisting of a ferromagnetic Ni-Mn alloy film and a Fe-Al-Si alloy film is 0.3 μm to 30 μm based on the magnetic properties of the alloy magnetic film, head productivity, and reliability. , preferably 0.5 μm ~
It is 20μm.

Furthermore, the deposited thickness of the Ni-Mn alloy film, which is a feature of this invention, is required to be 0.01 μm or more for the purpose of improving the soft magnetic properties of the Fe-Al-Si alloy film.
Preferably 0.05μm or more, more preferably 0.1μm
The above is preferable. However, if the thickness exceeds 1/2 of the thickness of the Fe-Al-Si alloy film, the saturation magnetization of the entire metal magnetic film will deteriorate. 1/3 or less is good.

In addition, the thickness of the Fe-Al-Si alloy film needs to be 0.1 μm or more in order to perform saturation recording on high coercive force media, and has high magnetic properties (magnetic permeability, coercive force).
In order to stably ensure this and obtain excellent workability, the thickness is 30 μm or less, preferably 20 μm or less, and more preferably 10 μm or less.

Further, the metal magnetic material may be formed only on one of the magnetic core halves in the vicinity of the gap of the pair of magnetic core halves made of ferromagnetic oxide, or may be formed on both.

Further, when formed on both of the pair of magnetic core halves, the film thickness structure of each metal magnetic material may be within the above-mentioned film thickness range, and does not need to be unified.

In order to improve the magnetic properties of the metal magnetic film thus deposited in two layers, heat treatment may be performed as necessary.

Heat treatment may be performed after film formation and before processing, or may be performed after processing into the shape of the magnetic head, or may be performed during glass welding when bonding the magnetic head halves. Heating for this purpose may be used in combination with heat treatment.

The temperature and time of the heat treatment should be selected appropriately to improve the magnetic properties of the metal magnetic film, and at the same time, the difference in thermal expansion coefficient between the magnetic core half and the ferromagnetic oxide, and the magnetic core half. The selection should be made by simultaneously considering the heat resistance of the ferromagnetic oxide that makes up the body, the mutual diffusion between the ferromagnetic oxide, the Ni-Mn alloy film, and the Fe-Al-Si alloy film. It is necessary to select it appropriately depending on the ferromagnetic oxide used and the composition of the metal magnetic film.

Normal temperature is preferably 300℃ or higher and 900℃ or lower.
More preferably, the temperature is 400°C or higher and 600°C or lower. The time is preferably 1 minute or more and 1000 hours or less, and more preferably 10 minutes or more and 100 hours or less.

As with the heat treatment temperature and time, the cooling rate also needs to be selected appropriately depending on the ferromagnetic oxide used and the composition of the metal magnetic film, but it is usually preferably 1°C/hr or more and 10,000°C/hr or less. , a range of 5°C/hr to 2000°C/hr is more preferable.

Any atmosphere may be used as long as it does not significantly deteriorate the magnetic properties of the metal magnetic film and the ferromagnetic oxide, but vacuum, inert gas, or nitrogen gas is preferable.

When heat treatment is performed in this manner, depending on the heat treatment temperature and time, an interdiffusion layer may be formed to a degree that can be detected by an analytical instrument.

In such a case, the magnetic head according to the present invention has a structure including a diffusion layer on at least one of the interfaces between the ferromagnetic oxide and the ferromagnetic Ni-Mn alloy film and the Fe-Si-Al alloy film. Become.

DISCLOSURE OF THE INVENTION BASED ON THE DRAWINGS FIG. 1 is an explanatory perspective view of a composite magnetic head according to the present invention. FIGS. 2, 3, and 4 are perspective explanatory views showing the manufacturing process of the composite magnetic head according to the present invention.

As shown in FIG. 1, the composite magnetic head according to the present invention has magnetic core halves 10 and 11 made of a ferromagnetic oxide such as Mn-Zn ferrite, which are processed without strain, and a portion near a magnetic gap 12. on the surface,
Ferromagnetic thin films 13, 14 and ferromagnetic thin films 13', 1
4' are deposited using a vacuum thin film forming technique such as sputtering to form a multilayer structure, and the gap 12 is made of a non-magnetic material 15 such as SiO ₂ deposited on a ferromagnetic thin film. It also forms a window 16 for coil winding, and the pair of core halves 10 and 11 are joined by a glass 17.

The manufacturing process of such a composite head is shown in FIGS. 2 and 3.
This will be explained based on FIG.

First, mechanochemical polishing is applied to the surface of the magnetic substrate 20 made of a ferromagnetic oxide such as Mn-Zn ferrite, which will be bonded to the metal magnetic thin film in the subsequent process, and if necessary, a polishing surface plate is applied. Float polishing is performed with a gap of several μm between the two to polish the substrate surface with high precision and without distortion.
At this time, ensure that the surface roughness does not exceed 100 Å,
Preferably it is 40 Å or less.

Next, a first magnetic film 13 of a ferromagnetic Ni-Mn alloy is deposited on the polished surface of the magnetic substrate 20 using a vacuum thin film forming technique such as sputtering, and the vacuum level of the vacuum thin film forming apparatus is Continuously without changing the second magnetic film 14 of Fe-Al-Si alloy
Form the adhesion.

Furthermore, 15 films of non-magnetic material for forming a magnetic gap with a predetermined thickness are formed.

On the surface of the thus obtained composite magnetic substrate 20 to which the magnetic film is attached, a plurality of grooves 22 having a concave cross-section extending across the upper surface are formed using, for example, a rotary grindstone, as shown in FIG. .

Furthermore, a plurality of grooves 21 having a concave boat shape are formed in a direction on the same plane that is perpendicular to the groove 22 having a concave cross section by 90 degrees.

Next, as shown in FIG.
The composite magnetic substrate 20 on which a groove 31 is formed and the composite magnetic substrate 30 on which only a groove 31 with a concave cross section is formed and two layers of magnetic films are adhered are brought together, and a glass rod is inserted into the groove 22 of the magnetic substrate 20. For example, the glass is melted at 600° C., the groove 22 is filled with glass, and the substrates 20 and 30 are bonded together to obtain the block 40.

During this glass bonding, by cooling to room temperature at a required cooling rate, the magnetic properties of the metal magnetic film are improved at the same time.

Next, a plurality of head chips can be obtained by slicing this block 40 along the a-a line and the bb-line.

Thereafter, the recording medium sliding surface of the head chip is cylindrically polished to obtain the composite magnetic head shown in FIG. 1.

Example Similar to FIG. 2, one main surface of a magnetic substrate made of Mn-Zn single-crystal ferrite was coated with mechanochemical polyamide using a suspension of _MgO powder with a particle size of 0.1 μm or less manufactured by Amplex. After polishing, float polishing was applied using the same suspension while maintaining a gap of 5 μm between the polishing surface plate and one main surface, and the main surface was finished into a highly accurate distortion-free surface. .

At this time, the roughness was measured to be 40 Å or less using a Talystep (manufactured by Taylor Hobson) surface step measuring device. Further, the state of removal of the surface strain layer was confirmed by ellipsometry.

On the main surface of the above strain-free processed magnetic substrate,
A 20wt%Mn-1.2wt%Al-Ni alloy film with a thickness of 0.2μm was formed using an RF two-pole magnetron sputtering device.
A Fe-Al-Si film was continuously deposited to a thickness of 5 μm without exposing the thin film layer to the atmosphere.

Additionally, Al ₂ O ₃ to form a magnetic gap
A film was deposited to a thickness of 0.1 μm using an RF two-pole magnetron sputtering device to obtain a three-layer composite magnetic substrate as shown in FIG.

Next, as shown in FIG. 3, a large number of track grooves for forming tracks and winding grooves for winding wires for recording and reproduction were formed.

Furthermore, a 0.05 μm thick Cr film was formed on one main surface of this composite magnetic substrate in order to improve glass flowability during glass bonding later.

Next, the composite magnetic substrate is cut into a plurality of halves having predetermined dimensions, and as shown in FIG.
At the same time, the magnetic properties of the metal magnetic film were improved by glass bonding by vacuum heat treatment for 1 hour and cooling to room temperature at a cooling rate of 100°C/hr.

At this time, when the magnetic properties of a sheet-like film subjected to the same heat treatment as a dummy were measured, Bs was about 11 KG or more, Hc was less than 0.2 Oe, and μ at 10 MHz was more than 2000.

Furthermore, in the same manner as in FIG. 4, the product was sliced along lines a-a and line bb-b, externally processed to have predetermined dimensions and shape, and made into chips.

Next, as shown in FIG. 9, a composite head was formed and the electromagnetic conversion characteristics were measured.

For comparison, a composite head using only a conventional Fe--Al--Si film was also fabricated and its electromagnetic conversion characteristics were measured.

FIG. 10 is a schematic diagram of reproduction waveforms of the composite head according to the conventional method and the present invention, where a is the output from the magnetic gap, and b is the pseudo waveform due to the magnetic discontinuity between the metal magnetic film and the magnetic core half. This is the output due to the gap.

As a result of measuring the output ratio b/a, the b/a of the present invention is
0.02, b/a of the conventional method was 0.2, and it was confirmed that in the case of the head according to the present invention, the effect of the pseudo gap was significantly reduced to the extent that it was practically no problem, and it had good recording and reproducing characteristics. did it.

Furthermore, as a natural result, the waviness of the reproduction frequency characteristics of the composite head according to the present invention was significantly improved and was less than 1 dB.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a composite magnetic head according to the present invention. FIGS. 2, 3, and 4 are perspective explanatory views showing the manufacturing process of the composite magnetic head according to the present invention. FIGS. 5a and 5b and 6 are explanatory diagrams of a conventional composite magnetic head. FIGS. 7 and 10 are schematic diagrams of reproduction output waveforms of the magnetic head. FIG. 8 is a graph of the relationship between film thickness and magnetic permeability, illustrating the influence of film thickness on the magnetic properties of the Sendust film. FIG. 9 is a perspective explanatory view of the composite head. DESCRIPTION OF SYMBOLS 10, 11...Magnetic core half, 12...Magnetic gap, 13...First magnetic film, 14...Second magnetic film, 15...Nonmagnetic material, 16...Window for coil winding, 17... ...Glass, 20,30...Magnetic substrate,
21, 22, 31...Groove, 40...Block.

Claims (1)

[Scope of Claims] 1. In a composite magnetic head in which at least a portion near the operating gap of a magnetic core mainly composed of a ferromagnetic oxide is made of a metal magnetic material, the ferromagnetic oxide surface has a strain-free high flatness surface. ,
Ferromagnetic Ni-Mn alloy thin film containing 70wt% to 90wt% Ni and 5wt% to 25wt% Mn, Fe-Al-
A composite magnetic head characterized by having a metal magnetic material laminated in the order of Si-based alloy thin films.