JPH07220920A - Laminated soft magnet thin film for magnet head - Google Patents

Abstract

PURPOSE:To greatly change a temperature at which magnetic permeability becomes the maximal value by laminating a plurality of FeAlSi alloy thin films and varying Si content of each FeAlSi alloy thin film from other's. CONSTITUTION:Three layers of FeAlSi alloy thin films 2a, 2b and 2c each having a composition of 4 to 7wt.% of Al, 8.5 to 10.5wt.% of Si and the remainder of Fe are formed on a member to be formed with films 1, and nonmagnetic thin films 3, 3 are alternately sandwiched between said layers thereby forming a laminated soft magnetic thin film 4. Also, respective FeAlSi alloy thin films 2a, 2b and 2c have Si contents which are mutually different, the difference in the Si content is within the range of 0.5 to 2.0wt.%, and the mean of respective Si contents is 9.5+ or -0.5wt.%. By doing this, excellent characteristics can be provided compared to the conventional one, that is, the change in magnetic permeability due to temperature change is much smaller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft magnetic laminated thin film for a magnetic head used for high density magnetic recording and reproduction.

[0002]

2. Description of the Related Art In recent years, with the increasing density of magnetic recording,
Frequencies up to about MHz are required as magnetic characteristics of the magnetic head. As a magnetic head satisfying such requirements, for example, as shown in FIG. 7, FeA having a high saturation magnetic velocity density is formed on a film forming member 11 made of a non-magnetic material.
There is known a laminated thin film magnetic head having a structure in which the 1Si alloy thin film 12 and the nonmagnetic thin film 13 such as SiO ₂ are alternately laminated. In this specification, Fe represents iron, Al represents aluminum, Si represents silicon, and O represents oxygen.

The laminated thin film used for such a magnetic head has been manufactured by the following method. That is, first, as shown in FIG.
Forming an FeAlSi alloy thin film 12 having a composition in which Al is 5 to 6% by weight, Si is 9 to 10% by weight, and the balance is Fe.
A non-magnetic thin film 13 such as SiO 2 is formed on it.

After that, the Fe is deposited on the non-magnetic thin film 13.
FeAlSi having the same composition as the AlSi alloy thin film 12
The alloy thin film 12 is formed, and the non-magnetic thin film 13 is further formed thereon.
To form. The laminated thin film 14 is obtained by repeating such steps as many times as necessary.

The plurality of FeAlSi alloy thin films 12 forming the laminated thin film 14 had a difference in Si content of 0.5 wt% or less.

[0006]

However, in the above-mentioned conventional structure, as is clear from FIG. 9 showing the relationship between the magnetic permeability of the laminated thin film 14 at 1 MHz and the temperature, the magnetic permeability greatly changes depending on the temperature. . Such a laminated thin film 1
When 4 is used as a magnetic head, a temperature range of −50 ° C. to 100 ° C. can be assumed as its operating environment temperature,
In this temperature range, there is a problem that the magnetic permeability greatly changes and the magnetic characteristics greatly change due to the temperature change.

[0007]

The present inventor has found that FeAlS
When the i alloy thin films having various composition ratios were examined in detail, it was found that the FeAlSi alloy thin films having the above respective compositions had a large change in the temperature at which the magnetic permeability showed the maximum due to the change in the Si content, and the present invention completed.

That is, in the soft magnetic laminated thin film for a magnetic head according to claim 1 of the present invention, in order to solve the above-mentioned problems, Al is 4 to 7% by weight and Si is 8.5 to 10.5% by weight. , A plurality of FeAlSi having a composition with the balance being Fe
The alloy thin films are laminated, and the Fe contents of the FeAlSi alloy thin films are different from each other.

The soft magnetic laminated thin film for a magnetic head according to claim 2 of the present invention is the soft magnetic laminated thin film for a magnetic head according to claim 1 in order to solve the above problems. Difference in Si content of 0.5-
It is characterized in that it is within the range of 2.0% by weight and the average of the above Si contents is 9.5 ± 0.5% by weight.

[0010]

According to the structure of claim 1, each FeAlSi
The alloy thin film contains 4 to 7 wt% of Al and 8.5 to 1 of Si.
Since it has a composition of 0.5 wt% and the balance being Fe, it has a high magnetic permeability of more than 2000 at the temperature at which the magnetic permeability reaches its maximum, and thus has good soft magnetic properties.

Further, in the above structure, since the respective Si contents of the FeAlSi alloy thin films are different from each other, the temperatures at which the magnetic permeability of the FeAlSi alloy thin films has a maximum can be set to be different from each other.

From the above, in the above structure, even if the temperature environment changes, the magnetic permeability of each of the laminated FeAlSi alloy thin films changes complementarily to each other, so that the temperature change as seen in the conventional laminated thin film. It is possible to suppress the change in magnetic permeability due to.

According to the second aspect of the invention, the temperature at which the magnetic permeability has a maximum value greatly depends on the Si content.
When the content is around 9.5% by weight, the temperature at which the magnetic permeability has a maximum can be set near room temperature (see FIG. 6). Moreover, by setting the difference between the respective Si contents within the range of 0.5 to 2.0% by weight, the deviation of the temperature at which the magnetic permeability of each FeAlSi alloy thin film exhibits a maximum can be within the predetermined range. .

From the above, in the above configuration, each Si
A plurality of FeAlSi alloy thin films having a difference in content in the range of 0.5 to 2.0% by weight and an average Si content of 9.5 ± 0.5% by weight are stacked. As a result, it becomes possible to remarkably suppress the change in magnetic permeability due to the change in temperature under normal operating temperature conditions, that is, at room temperature and before and after it.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In soft magnetic laminated thin film for magnetic head,
As shown in FIG. 1, a three-layer FeAlSi alloy thin film 2a having a composition in which Al is 5.4% by weight, Si is 8.5 to 10.5% by weight, and the balance is Fe on the film formation target member 1 is formed.・ 2b
.2c and non-magnetic thin films 3.3 sandwiched between them
And are alternately laminated to form the soft magnetic laminated thin film 4.

Then, the above FeAlSi alloy thin films 2a
-2b and 2c are manufactured so that they have mutually different Si contents. The film forming member 1 may be made of a non-magnetic material such as glass or ceramic, or may be made of a magnetic material such as ferrite.
As the non-magnetic thin film 3, a non-magnetic material such as SiO ₂ is used.

As will be described later, such a soft magnetic laminated thin film 4 is formed by laminating FeAlSi alloy thin films 2a, 2b and 2c having different Si contents while having a good soft magnetic property such as high magnetic permeability. This has the characteristic that the change in magnetic permeability due to temperature changes is small, and when used in the magnetic material of the magnetic head, it has good soft magnetic properties such as high magnetic permeability and permeability due to temperature changes in the actual temperature environment. The magnetic head can have good characteristics that the change in magnetic susceptibility is small.

Next, a method for manufacturing the soft magnetic laminated thin film 4 will be described. First, Al5.
A FeAlSi alloy thin film 2a having a composition in which 4 wt%, Si 8.5 wt% and the balance Fe are formed.

Next, a non-magnetic thin film 3 is formed on the FeAlSi alloy thin film 2a. On this non-magnetic thin film 3, Al is 5.4% by weight, Si is 9.5% by weight, and the balance is Fe. The FeAlSi alloy thin film 2b having the composition is formed.

After that, a non-magnetic thin film 3 is formed on the FeAlSi alloy thin film 2b, and a FeAlSi alloy thin film having a composition in which 5.4% by weight of Al, 10.5% by weight of Si, and the balance of Fe are further formed thereon. 2c is formed. FeA above
The 1Si alloy thin films 2a to 2c and the non-magnetic thin films 3 can be formed by a usual sputtering method or vapor deposition method.

The above FeAlSi alloy thin films 2a.2
The order of laminating b.2c is not limited to the above, and the FeAlSi alloy thin film 2b, the FeAlSi alloy thin film 2a, the FeAlSi alloy thin film 2c, the FeAlSi alloy thin film 2c may be stacked from the film forming member 1 side. , Fe
It may be the AlSi alloy thin film 2b or the FeAlSi alloy thin film 2a.

The soft magnetic laminated thin film 4 is obtained by heat-treating the thus obtained laminated body at 500 to 700 ° C. in a nitrogen gas atmosphere. By the above heat treatment, the magnetic permeability can be improved, and by forming the nonmagnetic thin film 3 between the FeAlSi alloy thin films 2a to 2c as described above, the thickness of each FeAlSi alloy thin film 2a to 2c can be increased. Therefore, the high frequency characteristics of the soft magnetic laminated thin film 4 can be improved.

Next, the soft magnetic laminated thin film 4 of the above embodiment is
It will be described that excellent characteristics that the change in magnetic permeability due to temperature change is small can be exhibited. First, the soft magnetic laminated thin film 4 is formed, and each FeAl having different Si content is
2 to 4 show temperature characteristics of magnetic permeability of the Si alloy thin films 2a to 2c at 1 MHz.

As is clear from FIGS. 2 to 4, Si
Of FeAlSi alloy thin film 2a containing 8.5 wt% of Si has a maximum magnetic permeability at about 100 ° C. and 9.5 wt% of Si.
The magnetic permeability of the contained FeAlSi alloy thin film 2b is about 30.
The FeAlSi alloy thin film 2c containing 10.5% by weight of Si showed the maximum magnetic permeability at about -70 ° C.

These FeAlSi alloy thin films 2a to 2c
The temperature characteristic of magnetic permeability of the above-mentioned soft magnetic laminated thin film 4 obtained by laminating is obtained by synthesizing the temperature characteristic of magnetic permeability of the FeAlSi alloy thin films 2a to 2c, which is shown in FIG.

As is apparent from FIG. 5, the soft magnetic laminated thin film 4 thus obtained in the above-mentioned embodiment has the respective FeAlSi
By changing the Si contents of the alloy thin films 2a to 2c to each other, the magnetic permeability is 1800 μm or more in the temperature range of −100 ° C. and 120 ° C., which has a good soft magnetic property of high magnetic permeability, and It can be seen that the change of the magnetic permeability due to the temperature change is much smaller than that of the conventional one, and the temperature characteristic is good.

In particular, the soft magnetic laminated thin film 4 has a thickness of about -70.
Permeability is 2000μ in the temperature range of ℃ and 110 ℃
As described above, it has a good soft magnetic property such as a higher magnetic permeability, and the change in magnetic permeability due to a temperature change is further reduced to be almost flat, and thus it may have a better temperature characteristic. I understand.

As a result, the soft magnetic laminated thin film 4 of the above-described embodiment has excellent soft magnetic characteristics such as high magnetic permeability, and is excellent in that characteristic changes such as magnetic permeability due to temperature changes are small as compared with the conventional ones. It has excellent characteristics.

From the above, the soft magnetic laminated thin film 4 is
When used in a magnetic head such as a VTR which is used up to a high frequency band up to about 10 MHz and has a large change in temperature environment used, it has good soft magnetic characteristics such as high magnetic permeability and practical use. In all temperature environments including room temperature and temperatures around the room temperature, it is possible to impart good magnetic characteristics that the characteristic changes such as magnetic permeability due to temperature changes are small.

Next, each composition of the FeAlSi alloy thin film,
The relationship with the temperature at which the magnetic permeability of the composition shows a maximum was investigated. The results are shown in the graph shown in FIG.

From this result, FeA having the constitution of the above-mentioned embodiment is obtained.
In the 1Si alloy thin films 2a to 2c, an example in which Al is fixed to 5.4% by weight has been described, but the present invention is not limited to the above Al content, and for example, FeAlSi alloy thin films 2a to 2c.
On the other hand, Al is 4 to 7% by weight and Si is 8.5 to 10.5.
A FeAlSi alloy thin film having a weight% and the balance being Fe can be used.

In the above embodiment, a plurality of Fe
The difference in Si content between the AlSi alloy thin films 2a to 2c is 0.
It can be appropriately selected within the range of 5 to 2.0% by weight. The difference in the Si content of the above FeAlSi alloy thin films 2a to 2c is
If it is less than 0.5% by weight, the respective maximum temperatures are close to each other, and the temperature range in which the change in magnetic permeability due to the temperature change becomes substantially flat is small, which is not preferable.

On the other hand, each of the FeAlSi alloy thin films 2a to
If the difference in Si content of 2c exceeds 2.0% by weight, the variation in each temperature at the maximum becomes large, and the decrease in the magnetic permeability between the maximum temperatures becomes large. The change in magnetic susceptibility becomes large, which is not preferable.

Further, each of the above FeAlSi alloy thin films 2a-
The average Si content of 2c may be within the range of 9.5 ± 0.5% by weight. If the average deviates from the above range, the temperature range in which the change in magnetic permeability due to temperature change is flat does not include the vicinity of room temperature, which is disadvantageous because the magnetic permeability at actual use temperature decreases.

The FeAlSi alloy thin film 2a to be laminated is also used.
The number of 2 to 2c is not particularly limited to three layers as described above, and can be appropriately selected from two layers, four layers or more depending on the required characteristics of the soft magnetic laminated thin film 4.

[0036]

As described above, the soft magnetic laminated thin film for a magnetic head according to claim 1 of the present invention contains 4 to 7% by weight of Al,
A plurality of FeAlSi alloy thin films having a composition in which Si is 8.5 to 10.5% by weight and the balance is Fe are laminated, and the Si content of each FeAlSi alloy thin film is different from each other.

Therefore, the above-described structure has a good soft magnetic property such as high magnetic permeability, and by stacking a plurality of FeAlSi alloy thin films having different Si contents, the magnetic permeability due to temperature change is higher than that of the conventional one. It is possible to have an excellent characteristic that the change of the is small.

As a result, when the above-mentioned structure is used, for example, in a magnetic head, the magnetic head has excellent soft magnetic characteristics such as high magnetic permeability and excellent characteristics that the change in magnetic permeability due to temperature change is small. Has the effect of being able to add

In the soft magnetic laminated thin film for a magnetic head according to claim 2 of the present invention, the difference in Si content among the plurality of FeAlSi alloy thin films is within a range of 0.5 to 2.0% by weight, and The average of the above Si contents is 9.5 ± 0.5% by weight.

Therefore, in the above structure, the difference in the Si content is set within the range of 0.5 to 2.0% by weight, so that the change in the magnetic permeability due to the change in the temperature can be improved as compared with the conventional one. It can be made smaller.

As a result, when the above-mentioned structure is used for a magnetic head, for example, it is possible to provide excellent soft magnetic characteristics such as high magnetic permeability and excellent characteristics that the change in magnetic permeability due to temperature change is even smaller. Play.

[Brief description of drawings]

FIG. 1 is a perspective view of a soft magnetic laminated thin film showing an embodiment of a soft magnetic laminated thin film for a magnetic head of the present invention.

FIG. 2 is used for the soft magnetic laminated thin film, and Al is 4 to 7;
3 is a graph showing the relationship between the magnetic permeability and the temperature at 1 MHz of a FeAlSi alloy thin film having a composition in which wt%, Si is 8.5 wt%, and the balance is Fe.

FIG. 3 is used for the soft magnetic laminated thin film, and Al is 4-7.
6 is a graph showing the relationship between magnetic permeability and temperature at 1 MHz of a FeAlSi alloy thin film having a composition in which the weight%, Si is 9.5% by weight, and the balance is Fe.

FIG. 4 is used for the soft magnetic laminated thin film and has Al of 4 to 7;
3 is a graph showing the relationship between the magnetic permeability and the temperature at 1 MHz of a FeAlSi alloy thin film having a composition in which wt%, Si is 10.5 wt%, and the balance is Fe.

5 is a graph showing the relationship between magnetic permeability and temperature at 1 MHz of the soft magnetic laminated thin film of FIG.

FIG. 6 is Fe that can be used for the soft magnetic laminated thin film.
3 is a graph showing the relationship between the composition of an AlSi alloy thin film and the temperature at which the magnetic permeability exhibits a maximum.

FIG. 7 is a perspective view of a magnetic head using a conventional laminated thin film.

FIG. 8 is a perspective view showing a conventional laminated thin film.

9 is a graph showing the relationship between magnetic permeability and temperature at 1 MHz of the laminated thin film shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deposition member 2a FeAlSi alloy thin film 2b FeAlSi alloy thin film 2c FeAlSi alloy thin film 3 Nonmagnetic thin film 4 Soft magnetic laminated thin film

Claims (2)

[Claims] 1. Al is 4 to 7% by weight and Si is 8.5 to 1.
A plurality of Fs having a composition of 0.5 wt% and the balance being Fe
eAlSi alloy thin films are laminated, and each of the above FeAl
A soft magnetic laminated thin film for a magnetic head, wherein Si contents of the Si alloy thin film are different from each other. 2. The difference in Si content of a plurality of FeAlSi alloy thin films is in the range of 0.5 to 2.0 wt%, and the average of each Si content is 9.5 ± 0.5 wt. %, The soft magnetic laminated thin film for a magnetic head according to claim 1.