JPH0198203A - Magnetic substance film and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve soft magnetic characteristics, and to enhance corrosion resistance by laminating an Fe-Al film, which mainly comprises Fe and contains Al in a trace quantity within a specific range, and an Ni-Fe alloy (permalloy) film. CONSTITUTION:A magnetic substance film has thin-film structure in which FeAl films 10, which mainly comprise Fe and contain a trace quantity of Al, and NiFe alloy (permalloy) films 11 are laminated alternately in plural layers. The FeAl films 10 are laminated alternately to a shape that they hold the NiFe films 11. A film, which uses Al as a principal ingredient and to which Al is added in a trace quantity within a range of 3.0-16.0atomic% is sufficient as the composition of the FeAl film 10. A composition in which Al is added to a base material Fe within a range of 12.0-16.0atomic% is particularly preferable at the point of corrosion resistance. The soft magnetic characteristics of the film are not reduced and deteriorated even when a temperature is elevated to 500 deg.C or higher by glass fusion working, etc., at the stage of the manufacture of a head. The film can resist corrosion and deterioration and the lowering of saturation magnetic flux density with the corrosion and the deterioration sufficiently even under the conditions of a high temperature and high humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic film suitable for use as a magnetic pole material of a magnetic head for high-density recording, which requires a high saturation magnetic flux density (Bs = 4FπMs), and its manufacture. Regarding the method.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, ferrite, permalloy, sendust, amorphous alloys, and the like have been used as magnetic materials constituting the magnetic poles of magnetic heads for magnetic recording and reproduction.

Incidentally, in order to achieve higher density magnetic recording, it is necessary to increase the coercive force Hc of the recording medium. When attempting to perform high-density recording on a recording medium having such a high coercive force, a magnetic material with a sufficiently high saturation magnetic flux density is required as the magnetic pole material of the magnetic head.

However, conventionally used magnetic materials such as ferrite and sendust have a saturation magnetic flux density that is considerably lower than the coercive force of the recording medium, and thus have the disadvantage that sufficiently high-density recording cannot be achieved. Incidentally, the conventional magnetic materials mentioned above have a ferrite material of 5 to 6 KG (+logauss), a permalloy of 8 KG, and a sendust material of about 10 KG, making it impossible to obtain the high saturation magnetic flux density required for high-density recording.

On the other hand, Co-based amorphous alloys can provide a relatively high saturation magnetic flux density necessary for recording on the order of 15 to 16 KG, but have a problem of poor thermal stability. In other words, the processing of magnetic heads often involves a glass fusing process at a high temperature of about 500°C, but even Co-based amorphous alloys, which are currently considered to have excellent properties, cannot be heated at a temperature of about 500°C. There is a problem that the soft magnetic properties deteriorate due to heating, and there is a drawback that it lacks reliability as a magnetic material. In addition, corrosion resistance of materials using Fe as a base material is also a problem.

In addition, in the case of any of the above-mentioned magnetic materials or Fe, etc., there is a problem that the soft magnetic properties, particularly the saturation magnetic flux density, decrease due to changes over time, making it difficult to use from a practical level.

Therefore, there is a strong demand for a magnetic film with sufficiently high saturation magnetic flux density, sufficiently low coercive force, excellent soft magnetic properties, excellent corrosion resistance, and low eddy current loss due to high frequency current. .

The present invention was proposed in order to solve the above-mentioned problems, and its purpose is to provide a sufficiently high saturation magnetic flux density, a sufficiently low coercive force, excellent soft magnetic properties, and corrosion resistance due to aging. An object of the present invention is to provide an excellent magnetic film and a method for producing the same.

Means for Solving the Problems In order to achieve the above object, the present invention provides Fe-AlFX having Fe as a main component and containing a small amount of Al in the range of 3.0 to 18.0 at%, The gist is a magnetic film in which a Ni-Fe alloy (permalloy) film is laminated.

In addition, the above purpose is to use Fe as the main component and Al as 3.0
Fe-Al containing a trace amount in the range of ~18.0at,%
The film and the permalloy film are placed on a non-magnetic substrate such as glass or ceramic to a thickness of 0°03 to 0.5 μm11 to 9.
This can be achieved by selecting and laminating layers alternately so that the thickness is in the nanometer range, and then heat-treating in vacuum under predetermined temperature conditions and time.

Function: When Fe-Al films containing Fe as the main component and a small amount of Al in the range of 3.0 to 18.0 at% and permalloy films are alternately laminated, high saturation magnetic flux density and low retention can be achieved. A magnetic film having magnetic force and excellent soft magnetic properties is formed.

Then, by heat-treating this under predetermined temperature conditions, time, etc., a magnetic film with excellent thermal stability of soft magnetic properties during the manufacturing stage and good corrosion resistance can be obtained. That is,
During the manufacturing stage, when performing the glass fusing process, etc., a temperature of approximately 500°C is required, but even if the temperature rises above this temperature to approximately 600'C, no change will be observed in the soft magnetic properties. There is no possibility of deterioration of the characteristics. Further, even if the product is left under high temperature and high humidity conditions, no deterioration in corrosion resistance due to changes over time, such as a decrease in saturation magnetic flux density, is observed.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the basic structure of a magnetic film according to the present invention. This magnetic film has Fe as a main component and Al as a main component.
A trace amount of F was selected within the range of 18.0at%.
It is formed into a thin film structure in which a plurality of eAl films 10 and NiFe alloy (permalloy) films 11 are alternately laminated.

The FeAl films 10 are alternately stacked with NiFe films 11 sandwiched therebetween. In the example, these two films 10 and 11 are shown in the case where the FeAl film 10 has three layers and the NiFe film 11 has two layers. There is no problem even if there are even more layers.

The composition of the FeAl film 10 is mainly composed of Fe and 3% Al.
．． Sufficiently satisfactory results can be obtained if a small amount of At is added in the range of 0 to 16.0 at.
．． Particularly preferred is one selected within the range of 0 at.% and added to the base material Fe. Also, in terms of corrosion resistance, Al is 12.
Particularly preferred is a composition in which Fe is added to the base material in a range of 0 to 16.0 at.%.

According to the experimental results, the composition of the FeAl film is 18% Al.
When it exceeds 0at,%, the saturation magnetic flux density is high, 4πMs (K
G: kilogauss) cannot be obtained.

On the other hand, if the Al content is less than 3.0 at.%, even if a high saturation magnetic flux density is obtained, the coercive force cannot be made low enough to be suitable for applications such as high-density recording magnetic heads. Therefore, as mentioned above, the FeA1 film 10 needs to have a composition containing a very small amount of Al in the range of 3.0 to 18.0 at%.

The magnetic film of the present invention is primarily composed of F as described above.
It is a laminated film of an eAl film 10 and a NiFe film 11, and more specifically, it has the following film structure.

The thickness of the FeAl film 10 is selected in the range of 0.03 to 0.5 μm, and the thickness of the NiFe film 11 is selected in the range of 1 to 9 nm (nanometer). This film thickness is a value obtained from experimental results, and by selecting a film thickness within this range, two WX
By stacking LO and 11, satisfactory soft magnetic properties can be obtained for the overlay, as will be described later. The thus obtained laminated film 10.11 is further heat-treated in a vacuum under set conditions such as a predetermined temperature and time. This heat treatment reduces the coercive force, resulting in a good soft magnetic film. In addition, this film has heat resistance that will not cause the soft magnetic properties to deteriorate even if the temperature rises to over 500 degrees Celsius during the glass fusing process during the head manufacturing stage, and it will not corrode or deteriorate even under high temperature and high humidity conditions. , and excellent corrosion resistance that can sufficiently withstand the accompanying decrease in saturation magnetic flux density can be obtained.

Next, the manufacturing method and processing procedure of the magnetic film according to the present invention will be explained by showing specific numerical values.

Please note that the numerical values shown below are examples, and are not included in the "Claims".
Within the range of numerical values shown in , the desired film properties of the present invention can be fully satisfied. Any value within that range can be selected.

■First, use argon gas pressure 1X10'T.

FeA is deposited on a non-magnetic substrate such as glass or ceramic by ion beam sputtering in a vacuum chamber of RR.
1 film and NiFe alloy (permalloy) film alternately.
Laminate. The target material in this case is an FeA1 alloy and a NiFe alloy having the compositions described below.

The composition of FeAl is mainly composed of Fe, and this base material F
3.0-18. A value is selected within the range of Oat.%, and a small amount of Al (aluminum) is contained. Further, the NiFe alloy has a permalloy composition.

By alternately sputtering using these target materials, Fe having the same composition as the target material described above is deposited on a non-magnetic substrate such as glass or ceramic.
Al films and NiFe films are alternately stacked and formed to a predetermined thickness. The film thickness of FeA1 alloy is 0.03~0°58
The m1NiFe alloy film is set to have a thickness in the range of 1 to 9 nm. Within this range of film thickness, sufficiently high soft magnetic properties (high saturation magnetic flux density Bs and low coercive force He) necessary for high-density recording and high high frequency properties can be obtained. In other words, in terms of soft magnetic properties, as is clear from the comparative example of experimental results shown later, not only Fe alone but also Fe
Good results that are sufficiently higher than those of a single Al film or a single film of magnetic materials such as ferrite, sendust, and permalloy that have been conventionally used for aggregation can be obtained. In addition, in terms of the high-frequency characteristics required when forming a magnetic node for high-density recording, by using a laminated film of two thin films as described above, Fe alone, which has excellent soft magnetic characteristics, can be used. Better results can be obtained than with a single FeAl film or the like.

That is, as is generally well known, the single Fe film has a high saturation magnetic flux density Bs=4πMs and a low coercive force He.
Although it is considered to be a magnetic material suitable for high-density recording, if it is used alone as a core material of a head, the eddy current loss due to high frequency current is large and it cannot be put to practical use.

On the other hand, as mentioned above, a thin film of F e A I alloy and Ni
By alternately stacking ultra-thin films of Fe alloy, high frequency characteristics are greatly improved and almost no eddy current loss occurs. Therefore, it is possible to generate a high external magnetic field according to the high frequency current that is applied.

As described above, FeA1 alloy thin film and Ni
A laminated film is formed in which ultra-thin Fe alloy films are alternately laminated and formed. In this case, the FeAl film is formed in the form of a sandwich sandwiching the NiFe film.

Note that the order in which the two films are formed may be formed first, and can be arbitrarily selected. Further, the film forming method according to the present invention is not limited to the above-mentioned ion beam sputtering method, but can be realized by other thin film forming techniques such as RF magnetron sputtering method and vapor deposition method.

(2) The laminated film obtained by the ion beam sputtering process as described above is then subjected to heat treatment. The processing conditions selected for the heat treatment were 0de (Oersted) during vacuum heating.
A rotating magnetic field is given. That is, heat treatment is performed in a vacuum φ rotating magnetic field. The time required for the processing was 1 hour [
:Hr].

Under the conditions set as above, the laminated film is left for 1 hour during vacuum heating, and the necessary heat treatment is performed. Even when the film thus obtained is heated to 500°C or higher in a glass fusing process, for example, it can reliably prevent deterioration of the soft magnetic properties caused by the heating, and
Even when heated to 0° C. or higher, it can sufficiently withstand deterioration in magnetic properties. Furthermore, as will be shown later, even when left in a high temperature and high humidity atmosphere for a long time, there is almost no decrease in the residual rate of saturation magnetic flux density. That is, it exhibits good corrosion resistance.

Through the above-described thin film lamination process and heat treatment process of the obtained laminated film, a magnetic film having the following characteristics was obtained.

(a) Coercive force He → 2[Φe] (b) Saturation magnetic flux density Bs = 4πMs≧20[KCl (c) Heat resistance of magnetic properties (coercive force) = 600℃ or more (
(D) Excellent corrosion resistance: There is no corrosion or deterioration of the film due to changes over time.

[Experimental Example Figures 2 to 5 show the results of experiments conducted in terms of soft magnetic properties and corrosion resistance by actually selecting numerical values for the magnetic film of the present invention obtained through the above-mentioned steps and procedures. It is a characteristic diagram. In this case, the film thickness of F e A I M, NiFeM and the amount of Al added in FeAl, that is, the content, should be selected from the numerical ranges listed above to obtain the best results. A magnetic film that has been coated and heat-treated is used.

The magnetic films are formed by setting the FeAl film to a thickness of 0.1 μm, the NiFe film to a film thickness of 6 nm (nanometer), and the Al content in the FeAl to 10.7 at%.

Note that these film thicknesses and contents are just examples used in the experiment, and it is the present invention that excellent characteristics similar to those shown in this experimental example can be obtained within the above-mentioned numerical ranges. This has been confirmed by the results of experiments conducted by researchers. This experimental example presents a typical example thereof, and it is clear that the present invention is not limited to only the numerical values shown in this experimental example.

Next, the experimental results of this experimental example will be explained using the above-mentioned figures.

First, Figures 2 and 3 are characteristic diagrams showing the results of examining the relationship between the coercive force He and the NiFe film thickness and FeAl film thickness by changing the temperature conditions during heat treatment. is fixed at 0.1 μm, and the NiAlM thickness is varied within the numerical range of the dirt floor to see the dependence of the coercive force Hc on the NiFe1i thickness.
The film thickness is fixed at 6 nm, and the FeAl film thickness is varied within the numerical value range of Doma to see the dependence of the coercive force Hc on the FeA1 film thickness.

In FIGS. 2 and 3, three representative temperature conditions are selected from the above-mentioned range of 500° C. to 800° C. for the heat treatment of the laminated film. The graph shown by the broken line shows the temperature condition at 500°C.
The graph shown by the solid line is 6.
The graph shown by the - dotted chain line shows the result of looking at the dependence of the coercive force Hc on the film thickness for the case where the temperature was set at 00°C, and the graph shown by the -dotted chain line was set at 800°C.

As is clear from FIGS. 2 and 3, no matter which temperature condition the magnetic film is heat-treated, the thickness of the FeA11E film is 0.03 to 0.5 μm, the thickness of the NiFe film is 1 to 9 μm.
If the film is laminated and formed in the nanometer range, the coercive force He is less than 10[de] and approximately 5[de].
It is clearly seen that a sufficiently low value necessary for high-density magnetic recording below del is obtained.

Next, FIG. 4 shows the results obtained to examine the corrosion resistance of the magnetic film obtained by setting the film thickness and Al content as described above. In this experiment, the temperature was 60″C.
1. The degree of decrease in saturation magnetic flux density is measured when a magnetic film is left in an atmosphere with a relative humidity of 90%. In the figure, the horizontal axis is the standing time [Hr], and the vertical axis is the residual rate of saturation magnetic flux density,
That is, the saturation magnetic flux density Bst at the time of standing time t=4
πMst and the saturation magnetic flux density Bso at time zero = 4π・
It represents the ratio with Mso. In this figure, graph A is a magnetic film according to the present invention, graph B is a magnetic film made of FeAl alone,
Graph C represents the respective characteristics of pure iron Fe. As is clear from this comparative example, the magnetic film according to the present invention maintains its initial value of 1.0 even after being left at high temperature and high humidity for over 500 hours. The FeAl single film deteriorates gradually from the initial stage of storage, and after 500 hours, the residual rate of saturation magnetic flux density decreases to 0.8 or less and tends to deteriorate. In addition, in the case of pure iron (Fe), the survival rate decreases rapidly from the initial stage of storage, and after 500 hours, the survival rate decreases to 0.
It is clearly seen that the corrosion resistance has decreased to a value of 2 or less, which is completely unacceptable for practical use in terms of corrosion resistance. As a result, it was clearly understood that in the case of pure iron, Fe, not only the magnetic film of the present invention, but also the single FeAl film, cannot be compared in terms of corrosion resistance and is extremely poor. Therefore, it is impossible to create a magnetic film of a practical level using Fe alone.

As described above, the magnetic film according to the present invention is extremely excellent in corrosion resistance.

Next, FIG. 5 shows the results of measuring the magnetic hysteresis of the magnetic film according to the present invention obtained by setting as described above, and the horizontal axis represents the coercive force (magnetizing force) Hc (be) , the vertical axis indicates the magnetic flux density Bs (KG: kilogauss).

As is clear from this figure, the coercive force Hc is HcLq2
(Ue), and it can be clearly understood that a sufficiently low value required for high-density magnetic recording has been obtained. This is Fe
By laminating Al and NiFe films.

As described in detail, according to the present invention, Fe is the main component, and A is added to the base material Fe in a range of 3.0 to 16.0 at 1%.
Since the FeAl film containing a small amount of l and the NiFe (permalloy) film were alternately laminated, the coercive force
The saturation magnetic flux density Bs is sufficiently low as Bs≧20[KG], and the soft magnetic properties required for high-density magnetic recording are significantly improved compared to magnetic films made of conventional magnetic materials. can be improved. Furthermore, a magnetic film with excellent corrosion resistance can be realized. Furthermore, 60
It can sufficiently withstand heating above 0°C. Therefore, characteristic deterioration due to high-temperature heating of 500° C. or higher, which conventionally occurs during film production, is eliminated, and a magnetic film with high thermal stability of soft magnetic properties can be produced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the film structure of the magnetic film according to the present invention, and FIGS. 2 and 3 show the N of the magnetic film obtained by the present invention.
A characteristic diagram showing the film thickness dependence of the coercive force Hc on the film thickness of the iFe film and the FeAl film. Figure 4 is a characteristic diagram showing the corrosion resistance of the magnetic film from the perspective of saturation magnetic flux density. Figure 5 is the same. This shows the magnetic hysteresis of the obtained magnetic film, and particularly indicates that a sufficiently low coercive force He has been obtained. 10***FeAl film, 11...NiFe (permalloy) film, Hs...coercive force, Bs...saturation magnetic flux density, 0.03 to 0.5 μm**FeAl film thickness, 1 to 9 nm
...NiFe film thickness. Fig. 1 Ni Fe thickness (nml) 3rd anguish FeAz (nm)

Claims (5)

[Claims] (1) Fe is the main component, Al is 3.0 to 16.0 at
．． 1. A magnetic film characterized in that a Fe-Al film containing a minute amount in the range of atomic percent (atomic percent) and a Ni-Fe alloy (permalloy) film are laminated. (2) The thickness of the Fe-Al film is 0.03 to 0.5 μm.
) The magnetic film according to claim 1, wherein the permalloy film is laminated with a film thickness selected in the range of 1 to 9 nm (nanometers). (3) The magnetic material according to claim (1) or (2), wherein the stacked Fe-Al film and permalloy film are heat-treated at a predetermined temperature and time. film. (4) Fe is the main component, Al is 3.0 to 16.0 at
．． A Fe-Al film and a permalloy film containing a very small amount in the range of 1.5% are selected on a non-magnetic substrate such as glass or shellac so that the film thickness is in the range of 0.03 to 0.5 μm and 1 to 9 nm, respectively. A method for manufacturing a magnetic film, which comprises alternately laminating layers in a vacuum and then heat-treating the film in a vacuum. (5) Set temperature conditions in the range of 500°C to 800°C,
The method for producing a magnetic film according to claim 4, further comprising performing heat treatment in a vacuum chamber for about one hour.