JPS63293710A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain a high magnetic permeability even if a film thickness is small by positioning the easy magnetization direction of a magnetic Fe-Al-Si film to the direction nearly perpendicular to the direction of a main magnetic path. CONSTITUTION:The easy magnetization direction of the magnetic Fe-Al-Si film of a magnetic head 1 having a magnetic core formed by vapor deposition of the magnetic Fe-Al-Si film on the surface of a substrate 10 is positioned at the direction nearly perpendicular to the direction of the main magnetic path. The magnetic Fe-Al-Si film is preferably composed, by weight %, of 2-10% Al, 3-16% Si, and the balance substantially Fe and is more preferably composed of 4-85% Al, 6-11% Si, and the balance substantially Fe. The magnetic Fe-Al-Si film is formed on the surface of the substrate 10 by a vapor deposition method such as sputtering in such a manner that uniaxial anisotropy is imparted thereto. The magnetic head having the thin Fe-Al-Si alloy film which possesses the high magnetic permeability even if the film thickness is small is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, and particularly to a magnetic head having a Fe-Al2Si magnetic film.

[Prior Art] In the field of magnetic recording, studies toward higher density are being actively pursued in terms of both media and heads. For the medium, metal materials such as Co-Ni alloy and Co-Cr alloy, as well as oxide materials such as Ba ferrite, in addition to the conventional γ-Fe 203, have been considered, and manufacturing methods include coating, plating, and Efforts are being made to improve performance by diversifying the use of thin film forming methods such as sputtering.

In general, in order to achieve higher density, the major requirements are to shorten the recording wavelength, increase the recording frequency, and narrow the recording track width.

Therefore, the media will be addressed by increasing the coercive force, increasing the saturation magnetic flux density, reducing the thickness of the medium, changing the magnetization direction, etc. In contrast, magnetic heads have narrower gaps and
Although attempts have been made to narrow the track, conventional ferrite heads have a saturation magnetic flux density of approximately 5000 G, and are no longer able to generate a head magnetic field sufficient to saturate the medium.

Therefore, instead of conventional heads using ferrite and sendust bulk materials, thin film magnetic heads were used for high-density recording magnetic heads such as computer recording/reproducing magnetic heads, VTR tape positioning magnetic sensors, PCM recording tape heads, electronic camera heads, etc. Magnetic heads that utilize this are attracting attention.

The inventors discovered Fe-AIL used in this magnetic head.
We are currently investigating Si-based alloy films. This alloy system is called sendust in bulk material and is known as a high-performance soft magnetic material, but when it is in the form of a thin film, it has not been able to achieve the characteristics of conventional bulk materials. On the other hand, Japanese Patent Application Laid-Open No. 60-218820 discloses that a Fe-AlSi alloy thin film obtained by sputtering in an inert gas containing N2 gas has high magnetic permeability and lowers the saturation magnetic flux density. It is described that it has high hardness.

[Problems to be Solved by the Invention] In the above-mentioned Japanese Patent Application Laid-Open No. 60-218820, for a Fe-AILSi film with a thickness of about 5 to 6 μm, the magnetic permeability is μm5.
I got about 000. However, as a result of various studies conducted by the present inventors, it has been found that the magnetic permeability .mu. decreases considerably in a thin film of about 3 .mu.m.

[Means and effects for solving the problems] The present invention provides a magnetic head having a magnetic core made by depositing an Fe-AIL-Si magnetic film on a substrate surface.
- This is a magnetic head characterized in that the easy magnetization direction of the St-based magnetic film is approximately perpendicular to the direction of the main magnetic path.

According to the present invention, there is provided a magnetic head having a magnetic film having high magnetic permeability even if the film thickness is small.

The present invention will be explained in more detail below.

FIG. 1 is a schematic diagram of an embodiment of the magnetic head of the present invention. The magnetic helad 1 consists of a non-magnetic slider 2 and a tip 3, and the tip 3 is molded and fixed with glass or the like in a slit 6 formed in one side 4 of the slider 2 and two air bearing surfaces 4.5. has been done.

A detailed structure of an example of the chip 3 is shown in FIG. 2.3. Second
．． In FIG. 3, a sputtered film is formed on a core 10 made of a non-magnetic substrate, and this sputtered film includes magnetic alloy layers 11-13, 14-16 and insulating layers 17-18, 19-
20 are alternately stacked. The pair of chip members has a magnetic alloy layer 1 so as to have a gap 21.
3 and 16 are glass-bonded. 22 indicates a glass joint. Further, a predetermined winding is applied to the winding window 23.

In the present invention, it is preferable that the Fe-Alt, -Si-based magnetic film is composed of Aρ2 to 10%, Si: 3 to 16%, and the remainder substantially Fe, particularly Al: 4% by weight.
-8%, Si: 6-11%, and the balance is preferably Fe. Note that even if Ti%Ru is contained in an amount of 2% or less, corrosion resistance and wear resistance can be improved, which is preferable. Further, the same effect can be obtained even if Cr is contained in an amount of 4% or less.

This Fe-AILSi magnetic film is formed on the substrate surface by a vapor phase deposition method such as sputtering so as to impart −axis anisotropy. Examples of how to impart -axis anisotropy in this way include: (1) Setting the substrate surface roughness to 0. 1 μm (100OA)
Hereinafter, the thickness is particularly set to 0.06 μm or less.

■ Sputtering while applying a magnetic field to the substrate surface.

■ A magnetic field is created on the substrate surface using the leakage magnetic field of magnetron sputtering.

Any one of these methods may be used. Further, a combination of ■ and ■ or a combination of ■ and ■ may also be used.

That is, the present inventor preferably formed a film on a base substrate with a surface roughness of 0.1 μm or less by a sputtering film formation method using a mixed gas of an inert gas such as Ar and N2 gas. It has been found that uniaxial anisotropy can be imparted to the sendust film by heat-treating it at a temperature range of 400 to 750°C.

When a Fe-Ajl-St' alloy film is formed by sputtering in an atmosphere in which N2 gas is added to Ar gas,
The amount of N2 added to Ar is 0.1 to 5.0 voJZ%, preferably 0. 2-1. By controlling it to 0 vofL%, the He content of the film after heat treatment is reduced and the magnetic permeability is greatly improved. However, the surface roughness of the base substrate to which the film is attached is 0.1μ.
If it exceeds m, -axis anisotropy is not induced and its B
-H curves are isodirectional. Therefore, the magnetic permeability is 20
It is about 00. However, when the surface roughness becomes 0.1 μm or less, -axis anisotropy is induced, so the magnetic permeability in the difficult axis direction increases to about 4000.

Although the cause of this is not clear, it is thought that N2 gas has the effect of slightly improving crystal orientation, and that the effect of N2 appears by reducing the surface roughness of the underlying substrate.

In the present invention, since the magnetic permeability in the direction of the hard magnetization axis is high as described above, the magnetic film having this -axis anisotropy has an easy axis direction almost perpendicular to the direction of the main magnetic path (for example, 70 to 1100
range).

In the present invention, in order to improve the frequency characteristics of magnetic permeability, it is desirable that the sputtered thin film be multilayered. in this case,
A magnetic material such as silicon oxide is interposed between each magnetic alloy layer. If the insulating layer is 1/20 or less of the magnetic alloy layer, the magnetic resistance is sufficiently small, and if it is 0.02 μm or more, sufficient insulation can be obtained. Generally, the thickness of the insulating layer is 0.01~1.0μ
m1 is preferably 0.05 to 0.2 μm.

Although FIG. 2 shows a sputtered thin film having three magnetic alloy layers, two, four, or more layers can be used if desired.

In order to improve magnetic permeability, it is preferable to heat-treat a magnetic head on which a magnetic alloy thin film is formed by sputtering. The heat treatment is preferably carried out in vacuum or in an inert gas at 400 to 750°C, particularly preferably at 500 to 700°C.
The treatment is carried out at a temperature of 0.3 to 2 hours, preferably 0.5 to 1 hour. Heat treatment may be performed simultaneously with glass bonding. Through such heat treatment, the structure changes from the disordered α phase to the ordered DO3
A phase transformation occurs, and the magnetic properties are improved accordingly.

In the present invention, the substrate may be either a magnetic substrate or a nonmagnetic substrate.

An example of the magnetic substrate is a magnetic ferrite such as Mn-Zn ferrite. In addition, non-magnetic substrates include barium titanate, calcium titanate, alumina,
Baka Special Publication for Zinc Ferrite, Glass, etc. 1973-2173
2. Examples include those known in Japanese Patent Application Laid-Open No. 59-908, Mn0-Ni0 ceramics, and the like.

The surfaces of these substrates are mirror-finished to achieve the above-mentioned surface roughness.

[Example] Examples and comparative examples will be described below.

Using an alloy target containing Fe, AJ2, and St with a diameter of 76 mm and a thickness of 2 mm, sputtering was performed by the magnetron sputtering method according to the sputtering conditions below, and a Fe-AX-St based magnetic film was sputtered onto a Mn0-Ni0 certain ceramic substrate or crystal. It was formed on a chemically modified glass substrate. The surface roughness is as shown in Table 1.

Note that a magnetic field was applied in the plane direction of the substrate using the leakage magnetic field of the magnetron target.

RF power 400w Distance between target substrates 76cm Basic temperature ~70℃ (water cooling) Ultimate vacuum 4X10-'Pa gas pressure
7X10-'Pa Magnetic 1Illi thickness Approximately 1 μm The sputtering atmosphere was Ar+N2, and the amount of N2 gas mixed was controlled by partial pressure. The obtained Fe-AIL-Ni alloy film was heat-treated at a predetermined temperature in an atmosphere of 400 to 800° C. for 1 hour, and its coercive force and magnetic permeability were measured. The results are shown in Table 1.

Note that the magnetic permeability and coercive force were measured using a ferrite yoke and a B-H loop tracer, respectively.

According to Table 1, the Fe-AfSi alloy thin film obtained by sputtering in Ar gas containing 0.5 voA% N2 exhibits uniaxial anisotropy only when a substrate with a surface roughness of 100 OA or less is used, and the magnetic permeability shows excellent properties such as 400, whereas when a substrate with surface roughness greater than 1 tooA is used, it is recognized that -axis anisotropy is not shown and the magnetic permeability is 1800 or less. .

Table 1 also shows that Fe-Al1-Ni alloy thin films obtained by sputtering in Ar gas containing 1.0vojZ% or more of N2 or in Ar gas containing no N2 gas do not exhibit uniaxial anisotropy. Is recognized.

Note that the frequency characteristics of the effective magnetic permeability μaff were measured for the samples of Example 1.6 and Comparative Example 2.3. In addition, the BH characteristics of the samples of Example 1 and Comparative Example 2 were measured. These results are shown in Figures 4-6.

From Figures 4 to 6, the examples of the present invention have high magnetic permeability and BH
It is recognized that the properties are also excellent.

Further, characteristics of heads made using the films of Comparative Example 1 and Example 1 are shown in FIG. From this, the output voltage of the head is 1
It can be seen that the improvement is 0%.

[Effects] According to the present invention, there is provided a magnetic head having an Fe-Al-St alloy thin film that has high magnetic permeability even if the film thickness is small. This alloy thin film can be made extremely thin, for example, 4 μm or less, so it can be easily multilayered and is extremely suitable for high-density magnetic recording. Further, even when used as a single layer, the film can be made thinner, which is preferable from the viewpoint of head production.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the magnetic head according to the example, FIGS. 2 and 3 are partially enlarged views of FIG. 1, and each of FIGS. 4 to 7 is a graph showing the measurement results in the example. be. Agent Patent Attorney Tsuyoshi Shigeno Figure 1 1 Magnetic head 2 Slider 3 Magnetic tip 4.
5 Air bearing surface 6 Slit Fig. 2 10 Substrate 22 Glass joint Fig. 5 (a) v45 Fig. (b) Fig. 6 Fig. 7 Resolution (・mu)

Claims (6)

[Claims] (1) In a magnetic head having a magnetic core with a Fe-Al-Si magnetic film deposited on the substrate surface, the Fe-Al-Si
- A magnetic head characterized in that the easy magnetization direction of the Si-based magnetic film is approximately perpendicular to the direction of the main magnetic path. (2) The composition of the Fe-Al-Si magnetic film is Al: 2 to 1
2. The magnetic head according to claim 1, wherein the magnetic head comprises: 0% by weight, Si: 3-16% by weight, and the remainder substantially Fe. (3) The magnetic head according to claim 1 or 2, wherein the surface roughness of the substrate surface to which the Fe-Al-Si magnetic film is attached is 0.1 μm or less. (4) The magnetic head according to any one of claims 1 to 3, wherein the substrate is made of magnetic ferrite. (5) The magnetic head according to claim 4, wherein the substrate is Mn-Zn ferrite. (6) The magnetic head according to any one of claims 1 to 3, wherein the substrate is made of a nonmagnetic material.