JPS63254709A - Laminated thin magnet film and magnetic head using the same - Google Patents

Abstract

PURPOSE:To obtain a laminated thin magnetic film having low coercive force, high permeability and high saturation magnetic flux density by laminating a thin Fe film and a thin alloy film which contains as a main ingredient Fe through a nonmagnetic metal in a laminated structure. CONSTITUTION:A thin Fe film and a thin alloy film which contains as a main ingredient Fe are laminated through a nonmagnetic metal in a laminated structure. Its saturation magnetic flux density is reduced by the influence of its lamination, but the saturation magnetic flux density is higher than that of the case that SiO2, or Al2O3, etc., is interposed therebetween. When the thickness per one layer of the nonmagnetic metal is less than 10A or 100Angstrom or larger, its coercive force is increased larger than that of a laminated thin magnetic film of 10-100Angstrom . Accordingly, the thickness per one layer of the nonmagnetic metal is preferably 10-100Angstrom . Thus, the laminated thin magnetic film having low corecive force and high permeability is obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a laminated magnetic thin film having high saturation magnetic flux density and high magnetic permeability, and particularly to magnetic heads used in magnetic disk drives, VTRs, etc., and core materials of magnetic heads. Concerning suitable laminated magnetic thin films.

[Conventional technology]

In order to prevent magnetic saturation during recording with a magnetic head, the magnetic head material needs to have a high saturation magnetic flux density. In addition, from the viewpoint of playback efficiency of the head, it is also necessary to have characteristics of low coercive force and high magnetic permeability.

In order to obtain magnetic materials with high saturation magnetic flux density, alloys containing Fe as a main component are being developed.

However, among these alloys, many of the materials with a saturation magnetic flux density of 1.8 layers or more have a large coercive force and are insufficient as magnetic head materials. As discussed in JP-A-52-112797.

In order to obtain the characteristics of low coercive force and high magnetic permeability, the magnetic thin film is
A laminated structure has been implemented via in2.

[Problem that the invention seeks to solve]

However, a 5in2. AQ
20. F
Depending on the composition of the e-based alloy, there was a problem in that the coercive force could not become sufficiently small. Also S 102 g A Q
Oxides such as 203 are porous, and therefore the Fe-based alloy deposited directly on these oxides also contains many defects such as pores, resulting in a problem that the saturation magnetic flux density is significantly reduced.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and provide a laminated magnetic thin film having low coercive force, high magnetic permeability, and high saturation magnetic flux density, and a magnetic head for high-density magnetic recording using the same. It is in.

[Means for solving problems]

The present inventors have conducted intensive research on magnetic thin films in which a Fe thin film and an alloy thin film mainly composed of Fe are laminated with thin films of other compositions. The changes in magnetic properties were clarified and the present invention was completed.

That is, by creating a laminated structure of an Fe thin film and an alloy thin film mainly composed of Fe with a nonmagnetic metal interposed therebetween, magnetic properties of low coercive force and high magnetic permeability can be obtained. Also, the saturation magnetic flux density decreases due to the effect of lamination, but 5i02. AQ
The saturation magnetic flux density is higher than that through 203 or the like.

Furthermore, if the thickness of each layer of the non-magnetic metal is less than 10 layers or greater than 100 layers, the coercive force will be increased compared to a laminated magnetic thin film with 10 to 100 layers. Therefore, the thickness of each layer of nonmagnetic metal is preferably 10 to 100 layers.

Furthermore, the magnetic properties of the laminated magnetic thin film vary depending on the thickness of one period of the laminated structure. If the thickness of one cycle is larger than 1,000 layers, the effect of lamination will be small, and if it is less than 100 layers, the internal stress of the laminated magnetic thin film will become large depending on the type of non-magnetic metal, causing the problem that the film will peel off from the substrate. arise.

Therefore, the thickness of one period of the laminated structure is preferably in the range of 100 to 1000λ.

Furthermore, by adding 1 to 20 at % of C to the Fe or Fe-based alloy thin film of the laminated magnetic thin film, a laminated magnetic thin film having even lower coercive force and higher magnetic permeability can be obtained.

Furthermore, by using the laminated magnetic thin film of the present invention in a magnetic circuit of a magnetic head, a magnetic head with excellent recording characteristics can be obtained.

[Effect]

As described above, a laminated magnetic thin film having low coercive force, high magnetic permeability, and high saturation magnetic flux density can be obtained by forming a laminated structure on an Fe thin film or an alloy thin film containing Fe as a main component with a nonmagnetic alloy interposed therebetween. Further, by setting the thickness of each layer of the non-magnetic metal to 10 to 100 layers, even better soft magnetic properties can be obtained. Further, when the thickness of one period of the laminated structure is 100 to 1000λ, a laminated magnetic thin film with good adhesion to the substrate and excellent soft magnetic properties can be obtained. Furthermore, even better soft magnetic properties can be obtained by adding 1 to 20 at % of C to the Fe or Fe-based alloy.

Further, by using the laminated magnetic thin film of the present invention in a magnetic circuit of a magnetic head, a magnetic head with excellent recording characteristics can be obtained.

〔Example〕

An example of the present invention will be described below in more detail with reference to figures and tables.

[Example 1] A dual ion beam sputtering device was used to fabricate a laminated magnetic thin film. Sputtering was performed under the following conditions.

Ion gas・・・・・・・・・・・・・・・・・・
......Ar gas pressure in Ar device...
・・・・・・・・・・・・・・・2.5X10-2P
a Ion gun acceleration voltage for evaporation・・・・・・・・・・・・
...1200V ion gun ion current for deposition...
......120mA target current...
・・・・・・・・・・・・・・・・・・70mA
Ion gun acceleration voltage for substrate irradiation...
200v ion gun ion current for substrate irradiation...
...40mA target-to-board distance...
127 mm The dual ion beam sputtering apparatus used in this experiment can produce a laminated film by rotating the target holder during sputtering.

A cross-sectional view of the laminated magnetic thin film produced in this manner is shown in FIG. In this embodiment, the main magnetic film 11 is made of Fe thin film, the intermediate layer 12 is made of various non-magnetic alloys, and the conventional S
As the io 2 y A Q 203 substrate 13, a 7059 glass substrate manufactured by Corning was used. In addition, the main magnetic film 11
The number of calendars is 10 layers, the film thickness per layer is 450 people, and the middle layer is 1.
2 film thickness for 50 people.

The total thickness of the laminated magnetic thin film was kept constant for about 5000 people.

Table 1 shows the relationship between the material of the intermediate layer 12 of the laminated magnetic thin film of the present invention, the coercive force in the direction of hard magnetization, and the saturation magnetic flux density. This is an indication.

Table 1 As shown in Table 1, Fe thin film is applied via non-magnetic metal.
If it is a 0-layer film, the coercive force decreases to 100e or less. These coercive forces are 5i02. Al220
This is smaller than when using 3.

In addition, 5i02. The saturation magnetic flux density of the laminated magnetic thin film using AQ20g is significantly lowered to 1.8T or less. This is considered to be because these oxides are porous, and therefore the Fe thin film deposited directly on them also contains many defects such as vacancies. On the other hand, when a non-magnetic metal is used as the intermediate layer, the saturation magnetic flux density is relatively high, about 1.9T. This is because the energy at the interface between Fe and non-magnetic metal is low, and the Fe thin film and non-magnetic metal are in close contact.
This is thought to be to prevent defects from occurring.

As described above, by creating a laminated structure of Fe thin films with nonmagnetic metal interposed therebetween, a characteristic of low coercive force can be obtained. Furthermore, even if a nonmagnetic metal other than those listed in Table 1 is used as an intermediate layer, the coercive force is reduced due to the effect of lamination.

Furthermore, if the laminated magnetic thin film of the present invention is subjected to heat treatment, the coercive force can be further reduced.

- To give an example: 1 For example, by heat-treating a laminated magnetic thin film using Cr as an intermediate layer at 300°C for 1 hour, the coercive force is 2.00e and the relative permeability at 5 MHz is 9.
00 characteristics were obtained.

[Example 2] Fe-12at%St in the same manner as in Example 1.

Fe-1,5at%Ni, Fe-2,Oat%v,
A 10-layer film was made of Fe1.7 at% Cr and Fe-1,3 at% Pt alloy with Cu interposed therebetween. Table 2 shows the relationship between the main magnetic film and the coercive force in the direction of difficult magnetization. The same table also shows the coercive force of a single layer film without an intermediate layer.

Table 2 As shown in Table 2, Fe-based alloys are
Coercive force is reduced by multilayering via u. Also, if the material of the main magnetic film is an Fe-based alloy other than those in Table 2,
The coercive force is reduced due to the effect of lamination using the Cu intermediate layer. Furthermore, even if a non-magnetic metal other than Cu is used as the intermediate layer material, the lamination effect remains the same.

Furthermore, the coercive force can be further reduced by heat-treating the laminated magnetic thin film of the present invention.

For example, when a laminated magnetic thin film using a Fe-12at%Si alloy and a Cu intermediate layer was heat-treated at 300° C. for 1 hour, a coercive force of 0.70e and a relative magnetic permeability of 1800 at 5MHz were obtained.

[Example 3] A magnetic film was produced by laminating Fe with an Nb intermediate layer interposed therebetween under the same sputtering conditions as in Example 1.

The number of layers was 10, and the thickness of each Nb intermediate layer was varied. FIG. 2 shows the relationship between the thickness of the Nb intermediate layer and the coercive force in the direction of difficult magnetization. In the figure, when the thickness of the Nb intermediate layer is 0, the results are shown for a Fe single layer film without an intermediate layer. As shown in FIG. 21, where the coercive force depends on the thickness of the intermediate layer, the coercive force is relatively small when the thickness of the Nb intermediate layer is in the range of 10 to 100 mm.

When the Nb intermediate layer has a thickness of 5λ, it exhibits almost the same coercive force as a single layer film.

This is considered to be because the Nb intermediate layer is not formed uniformly when the thickness is 5, and the Nb intermediate layer is formed in an island shape.

The coercive force is also large when the thickness of the Nb intermediate layer is 150 Å or more. This is thought to be because the magnetic interaction between the two Fe films sandwiching the intermediate layer is cut off.

In addition, various alloys containing Fe as a main component as the main magnetic film,
Even if various non-magnetic gold layers other than Nb are used as the intermediate layer,
The relationship between the intermediate layer thickness and coercive force showed the same tendency as shown in FIG. 2.

From the above results, it was found that the thickness of each nonmagnetic metal layer as an intermediate layer is preferably 10 to 100 layers.

[Example 4] Under the same sputtering conditions as in Example 1, a laminated magnetic film was produced using Fe-1, 5 at% Ni alloy as the main magnetic film and Cu as the intermediate layer.

The Cu intermediate layer was kept constant at 50 A per layer, and the total thickness of the laminated magnetic thin film was kept constant at about 5,000 layers. The experimental results are shown in FIG. 3. In the figure, when the number of layers is one, it indicates a single layer film without an intermediate layer.

As shown in the calendar number dependence 31 of the coercive force in the figure, the coercive force decreases as the number of layers increases. When the calendar number is 5 or more, the coercive force is 80e or less. Further, when the number of layers exceeded 50, the film peeled off from the substrate. This is because the internal stress of the film increases due to the fine layering.

From the above results, it is preferable that the main magnetic film has 5 to 50 layers, and when converted to the period of the laminated structure, it is 100 to 100.
The range is 0 people. In addition, the total film thickness of the laminated magnetic thin film was 10
It has been found that excellent soft magnetic properties can be obtained by setting the thickness of one period of the laminated structure in the range of 100 to 100 OA even when the thickness changes from 00 to 20,000 λ.

Furthermore, even if various Fe-based alloys other than Fe-Ni-based alloys are used as the main magnetic film and various non-magnetic alloys other than Cu are used as the intermediate layer, the dependence of the coercive force on the stacking period is almost the same as the above result. Met.

[Example 5] A laminated magnetic thin film using an Fe-VC alloy thin film as the main magnetic film and Nb as an intermediate layer was produced under the same sputtering conditions as in Example 1. The total thickness was 5000, the intermediate layer thickness was 50λ, and the number of layers was 10. Also, V in Fe-based alloys
The concentration was kept constant at 2 at%, and the C concentration was varied in the range of 0 to 30 at%. Figure 4 shows the relationship between the coercive force in the direction of difficult magnetization and the C concentration.As shown in the figure, the coercive force hardly changes when less than lat% of C is added.On the other hand, when C is added at lat% or more The coercive force then decreases significantly.

However, when more than 20e7% of C was added, the film peeled off from the substrate. This is because C is interstitial and forms a solid solution in Fe.
This is thought to be because the internal stress increases when the amount of .

From the above results, it was found that in a magnetic film in which a Fe-V alloy thin film is laminated via a Nb thin film, an even smaller coercive force can be obtained by adding 1 to 20 at% of C to the Fe-V alloy. . Furthermore, the relative magnetic permeability also increased due to the addition of C.

Further, even if the main magnetic film is made of Fe or an Fs-based alloy other than Fe-V based, the soft magnetic properties are improved by the above-mentioned addition of C. Further, the intermediate layer in this case may be made of a nonmagnetic metal other than Nb.

[Example 6] A magnetic thin film (thickness 0.5%) was prepared by laminating five Fe 1.5a%Ni-5,5at%C alloy thin films of the present invention with Cr interposed therebetween.
2 μm) or Permalloy (N
t -19,8at, %Fe) alloy thin film (thickness 0.2μ
A single-pole type magnetic head 71 for overlapping magnetic recording having the structure shown in FIG. 5 was manufactured using the same method.

The manufacturing process of this magnetic head 71 will be described below.

A substrate 63 made of Mn-Zn ferrite 61 and high melting point glass 62 shown in FIG. 5(,) was used.

On the surface thereof, as shown in FIG. 5(b), the magnetic thin film 6 is formed.
No. 4 was fabricated by an ion beam sputtering method. Furthermore, a PB-based glass film for adhesion is formed on this by ion beam sputtering method, and the substrate 63 shown in FIG. A main pole block 65 shown in FIG. 5(c) was manufactured. And Mn− shown in FIG. 5(d)
After preparing an auxiliary core block 68 made of Zn ferrite 66 and high melting point glass 67 and forming a PB-based glass film for adhesion similar to the above on the joint surface 70, the main pole block 65 is attached to the joint surface of the auxiliary core block 68. Pincer, 4
By heating at 50° C. for 30 minutes, the PB-based glass film was melted and fixed, thereby producing a bonded block 69. Next, cut the two-dot chain line shown in FIG. 5(d), and
) A single-pole head 71 for perpendicular magnetic recording was obtained.

The recording characteristics of the head using the laminated magnetic thin film of the present invention and the head using the permalloy thin film produced by the above steps were measured using a Go-Cr perpendicular magnetic recording medium.

A head having a permalloy thin film was used as the reproducing head. As a result, a head using the laminated magnetic thin film of the present invention has the following results:
It exhibited approximately 5 dB higher output than a head using a permalloy alloy thin film, which is a conventional practical material. As described above, it has been revealed that the magnetic head using the laminated magnetic thin film of the present invention has excellent recording characteristics.

〔Effect of the invention〕

As explained in detail above, the laminated magnetic thin film of the present invention, which is made of Fe thin film or Fe-based alloy thin film via non-magnetic metal, has the characteristics of low coercive force, high magnetic permeability, and high saturation magnetic flux density. have Further, if the thickness of each layer of the non-magnetic metal is 10 to 100, the soft magnetic properties will be improved. Moreover, if the thickness of one period of the laminated structure is 100 to 1000, the soft magnetic properties will be improved. Furthermore, by adding 1 to 20% of C to the Fe thin film or alloy thin film mainly composed of Fe, the soft magnetic properties are further improved.

Further, the magnetic head of the present invention in which the above laminated magnetic thin film is used in the magnetic circuit of the magnetic head has excellent recording characteristics.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the laminated magnetic thin film of the present invention, and Figure 2 is the relationship between coercive force and Nb film thickness of a magnetic film in which Fe thin films are laminated via Nb thin films in Example 3 of the present invention. FIG. 3 is a graph showing F e −N in Example 4 of the present invention.
A graph showing the relationship between the coercive force and the calendar number of a magnetic film in which an i-based alloy is laminated via Cu, and FIG. FIG. 5 is a graph showing the relationship between the coercive force and the C concentration of the magnetic film laminated through the film, and FIG. be. 5. Explanation of symbols 11... Main magnetic film, 12... Intermediate layer, 13... Substrate, 21... Intermediate layer thickness dependence of coercive force, 31...
Calendar number dependence of coercive force, 41... C concentration dependence of coercive force, 61.66-Mn-Zn ferrite, 62.67... High melting point glass, 63... Substrate, 64
...Magnetic thin film, 65...Main magnetic pole block, 68...
・Auxiliary core block, 69...Joint block, 70・
...Joint surface, 71...Single magnetic pole type magnetic head for perpendicular magnetic recording. ,lF/)fJ A〆b sai rlJA retardant emotion (X)/la CtL(at 〆)

Claims (5)

[Claims] 1. A laminated magnetic thin film characterized in that it has a laminated structure with a Fe thin film or an alloy thin film mainly composed of Fe with a nonmagnetic metal interposed therebetween. 2. The thickness of each layer of the non-magnetic metal is 10 to 100.
2. The laminated magnetic thin film according to claim 1, wherein the laminated magnetic thin film is Å. 3. 3. The laminated magnetic thin film according to claim 1 or 2, wherein the thickness of one period of the laminated structure is in the range of 100 to 1000 Å. 4. The alloy thin film mainly composed of Fe contains 1 to 20 atomic% of C.
Claims 1 to 3 are characterized in that they include
2. The laminated magnetic thin film according to any one of the above. 5. In a magnetic head that uses a magnetic thin film in at least a part of the magnetic circuit, the magnetic thin film is an Fe thin film or an F
1. A magnetic head using a laminated magnetic thin film, characterized in that the magnetic thin film has a laminated structure on an alloy thin film whose main component is e, with a non-magnetic metal interposed therebetween.