JPS63119210A - Amorphous magnetic film and magnetic head - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy film having high saturation magnetic flux density, excellent thermal stability and a magnetostriction constant of approximately zero and a magnetic head using said amorphous alloy film by forming a metallic foundation film between the Co group amorphous alloy film and a substrate. CONSTITUTION:A metallic foundation film 2 is shaped between a Co group amorphous alloy film 3 mainly comprising Co and a substrate 1. It is preferable that the metallic foundation film 2 consists of either one kind of a metal or two kinds or more of alloys of Zr, Ta, W, Nb and Mo. It is desirable that the metallic foundation film is constituted of at least one kind of the metal or two kinds or more or alloys of additional elements except Co of a Co group amorphous alloy from the point of chemical stability in the amorphous film having chemical formula CoaZrbTc (T=Zr, Ta, W, Nb, Mo...). Zr having the highest amorphous forming capacity of the Co group alloy is the most preferable among them. It is desirable that the film thickness of the metallic foundation film ranges from 30Angstrom to 500Angstrom .

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic film used in a magnetic head pole suitable for high-density magnetic recording, and particularly relates to a magnetic film having a high saturation magnetic flux density, a high crystallization temperature, and a high crystallization temperature.
The present invention relates to an amorphous residual film having a characteristic of a low magnetostriction constant and a magnetic head using the same.

[Conventional technology]

In recent years, there has been remarkable progress in increasing the density and performance of magnetic recording.
In the field of TR, high coercive force tapes are being used to improve recording density, and in order to sufficiently record and reproduce signals, there is a need for magnetic heads that use high-performance magnetic materials with high saturation magnetic flux density. is increasing. In addition, in thin-film heads used for computer disks, as recording density increases, magnetic poles must be made thinner to improve resolution, and thin magnetic pole tips tend to cause magnetic saturation. Therefore, a thin film magnetic head using a magnetic film with high saturation magnetic flux density is required. Furthermore, even in single-pole heads for perpendicular magnetic recording, which have been actively researched in recent years, it is necessary to make the main pole extremely thin in order to improve the recording density, so magnetic saturation occurs at the tip of the magnetic pole as described above. To solve this problem, a single-pole head for perpendicular magnetic recording using a high-performance magnetic film with high saturation magnetic flux density is required.

Conventionally, the magnetic film for these magnetic heads has mainly been Ni
-Fe-based alloy films (permalloy films) have been used, but in recent years, amorphous alloy sputtered films have been developed as high-performance magnetic films with high saturation magnetic flux density. Among these, especially Z
In the amorphous alloy consisting of r, the vitrification elements are B, Si, ○,
Compared to amorphous alloys made of metalloid elements such as P, it has excellent heat resistance and corrosion resistance, and has excellent properties as a magnetic film for magnetic heads. Specifically, the Zr-based amorphous alloy is represented by a composition formula of MaT+, ZrC.

Here, M is at least one of Co, Fe, and Ni having a magnetic moment, and T is a transition metal element other than M and Zr. Such vitrification elements are mainly transition metal elements other than Zr. Regarding such an amorphous alloy whose vitrifying element is mainly Zr, Japanese Patent Application Laid-Open No. 55-13
It is described in the specification of No. 8049 and the specification of Japanese Patent Application Laid-open No. 84439/1983.

[Problem that the invention seeks to solve]

Among these Zr-based amorphous alloys, C in which M is Co
The o-Zr amorphous alloy has a high saturation magnetic flux density,
It is an excellent magnetic material. However, since the magnetostriction constant of this amorphous alloy exhibits a relatively large value of 2 to 4×10 B, the additive elements T include V and Nb, which make a negative contribution to the magnetostriction constant of the amorphous alloy.

By using elements such as T a + Cr t M o + W, an amorphous alloy with a magnetostriction constant of approximately zero can be obtained.

However, these elements have a lower ability to form an amorphous state than Zr, so when they are substituted for Zr in a Co-Zr amorphous alloy, the crystallization temperature decreases and the thermal stability decreases. do. Furthermore, there is a problem that the crystallization-amorphization boundary moves to a low Co concentration, and the maximum saturation magnetic flux density obtained in the amorphous state decreases.

An object of the present invention is to solve such problems and to obtain an amorphous alloy film having a high saturation magnetic flux density, excellent thermal stability, and a magnetostriction constant of almost zero, and a magnetic head using the same. .

[Problem that the invention seeks to solve]

The above purpose is as shown in FIG.
This is achieved by providing a metal base film 2 between and the substrate 1. The metal base film 2 includes Zr, Ta, W, and Nb.
, Mo, or an alloy of two or more thereof. Also, the chemical formula is CoaZ r
bTc (T=Z r tTa, W, Nb, Mo・
), the metal base film is C from the viewpoint of chemical stability.

It is desirable that the amorphous alloy be composed of at least one single metal or an alloy of two or more of the additive elements other than Co. The most desirable among them is Zr, which has the highest ability to form an amorphous state in a Co-based alloy.

The thickness of the metal base film 2 may be 30 Å or more. However, since the metal base film 2 is non-magnetic, increasing the thickness of the metal base film reduces the total magnetic flux density of the magnetic film 3. Therefore, the thickness of the metal base film is preferably 30 Å or more and 500 Å or less.

[Effect]

Here, the metal base film promotes amorphization of the magnetic film formed thereon. That is, during formation of the amorphous film, metal atoms constituting the metal base film diffuse through the amorphous film and form an alloy, forming a layer with a high crystallization temperature near the interface with the substrate. It is thought that this newly formed layer suppresses crystallization of the amorphous film. Therefore, as the metal base film, it is desirable to use an element that can make the Co metal amorphous and form an alloy with a relatively high crystallization temperature. From the above, in the case of Co-based amorphous alloys, by providing a metal base film, the amorphous region expands to the high Co concentration side, increasing the maximum saturation magnetic flux density obtained in the amorphous state. . In addition, magnetic heads use this amorphous residual film with high saturation magnetic flux density in the magnetic core.

It has excellent recording characteristics because it can generate a large magnetic field at the tip of the magnetic core.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 In Fig. 2, a 1 μm thick Co −
A characteristic diagram when a Ta-Zr alloy film is formed is shown. A Co--Ta--Zr alloy film was produced on a 37059 (trade name, manufactured by Corning, USA) glass substrate using a high-frequency two-pole sputtering device. Whether or not the Co-Ta-Zr alloy film was in an amorphous state was confirmed by the X-ray diffraction pattern, resistivity, and coercive force.

In other words, there is a peak in the X-ray diffraction pattern, and when the resistivity is 0.3 μΩm or more and the coercive force is 10e or less, the C
It was assumed that the o T a Z r alloy film was in an amorphous state. The amorphous region has a Go-Ta system with a Co composition of 85
up to at%, Co-Zr system with Co composition of 94 a,t%
As the Zr composition increases, the Co concentration increases. Magnetostriction is determined approximately by the composition ratio of Ta and Zr, and is O when Ta:Zr==5:3. The saturation magnetic flux density Bs is determined by the Co composition, and the larger the Co composition, the higher the saturation magnetic flux density Bs obtained. When the magnetostriction desirable for the head material is O, the maximum saturation magnetic flux density Bs obtained in an amorphous state is 1.47.

FIG. 3 shows a characteristic diagram when a Zr metal base film was formed to a thickness of 30, and then a Go-Ta-Zr alloy film was formed to a thickness of 1 μm. The compositional dependence of magnetostriction and saturation magnetic flux density Bs is the same as when no metal underlayer is provided, but the amorphous region extends to the high Co concentration side, and the magnetostriction becomes O
The maximum saturation magnetic flux density Bs obtained in the amorphous state is 1
．． It became 6T.

This is 0.2T lower than when no metal base film is provided.
It's getting bigger. Furthermore, when comparing the crystallization temperature with the same composition, the crystallization temperature was 20° C. higher when the metal base film was provided, indicating excellent thermal stability.

Figure 4 shows the maximum saturation magnetic flux density (hereinafter referred to as maximum saturation magnetic flux density) obtained in an amorphous state in a Go-Ta-Zr alloy film with magnetostriction of 0 and the film thickness of the metal base film. It shows the relationship between The maximum saturation magnetic flux density when the metal base film is Zr increases as the thickness of the metal base film increases, but becomes saturated when the film thickness is 30 Å or more.

Example 2 Table 1 shows the maximum saturation magnetic flux density obtained in the amorphous state when the magnetostriction of the Co-based alloy film is zero, when the combinations of the metal base film and the Co-based alloy film are changed, and It shows the increase in crystallization temperature due to the provision of a metal base film. Both films were prepared using a high-frequency bipolar sputtering device using 37059 (
Made on a glass substrate (trade name of Corning, Inc., USA). The thickness of the metal base film is 30 people, and the thickness of the Co-based alloy film is 1 μm.
And so. In either combination, by providing a metal base film, the maximum saturation magnetic flux density obtained in an amorphous state increases, the crystallization temperature also increases, and thermal stability increases. Further, when the metal base film matches at least one of the additive elements other than Co of the Co-based alloy film, the increase in saturation magnetic flux density and crystallization temperature due to the provision of the metal base film is greater. Among these, the effect is greatest when using a Zr metal base film.

Table 1 Example 3 Next, Zr with a film thickness of 30 mm was used as the metal base film, and C
A thin-film magnetic head having a cross-sectional structure as shown in FIG. 5, which uses a Cox2Ta5Zrs alloy film with a saturation magnetic flux density Bs = 1.5T as the o-based alloy magnetic film and has an amorphous residual film as a magnetic pole, as shown in FIG. Created. This thin film head consists of a non-magnetic substrate 11 made of Af1205°T i C, A Q208 or ZrO2, a lower magnetic pole 12 of an amorphous residual film provided with a metal base film, and A Q xo8.
+ Gap layer 14 made of S i C2 etc., Cu,
A conductor coil 16 made of AΩ etc., polyimide resin,
It is composed of an insulating layer 15 made of 5iOz or the like, and an upper magnetic pole 13 made of an amorphous residual film provided with a metal base film.

A thin film magnetic head having the structure shown in FIG. 5 and a thin film magnetic head having a magnetic pole without a metal underlayer were fabricated, and the reproduction output was compared. Compared to the case where there is no metal base film,
It was about 10 times bigger.

This means that when the saturation magnetic flux density of a Co-Ta-Zr alloy film is 1°5T, in a film with a metal underlayer,
This is because the soft magnetic properties are excellent in the amorphous state, whereas the soft magnetic properties are extremely poor in the crystalline state in a film without a metal underlayer.

〔Effect of the invention〕

According to the present invention, an amorphous alloy film having a high saturation magnetic flux density, a high crystallization temperature, excellent thermal stability, and a magnetostriction constant of almost zero can be obtained. A magnetic head with a magnetic pole with excellent soft magnetic properties can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the amorphous residual film provided with the metal base film of the present invention, and FIG. 2 is a cross-sectional view of the amorphous residual film provided with the metal base film of the present invention.
-T a -Z r alloy film characteristic diagram, Fig. 3 is a characteristic diagram of Co - T a - Z r alloy film when a metal base film is provided, and Fig. 4 is a Co - T a - Z r alloy film. Figure 5 shows the relationship between the thickness of the metal base film and the maximum saturation magnetic flux density obtained in the amorphous state in the alloy film of the present invention. 1 is a cross-sectional view showing a thin film magnetic head using a film as a magnetic pole.

Claims (1)

[Claims] 1. In a Co-based amorphous alloy film containing Co as a main component,
An amorphous magnetic film characterized by providing a metal base film between it and a substrate. 2. The amorphous magnetic film according to claim 1, wherein the metal base film is made of a single metal of Zr, Ta, W, Nb, Mo, or an alloy of two or more kinds. 3. A patent claim characterized in that the metal base film is made of a metal or an alloy of two or more of the additive elements other than Co of the Co-based amorphous alloy film formed thereon. The amorphous magnetic film according to the range 1 to 2. 4. The amorphous magnetic film according to any one of claims 1 to 3, wherein the metal base film is Zr. 5. Claims 1 to 4, characterized in that the metal base film has a thickness of 30 Å to 500 Å.
The amorphous magnetic film described in . 6. In a Co-based amorphous alloy film containing Co as a main component,
1. A magnetic head comprising, as a magnetic pole, an amorphous residual film provided with a metal base film between it and a substrate. 7. The magnetic head according to claim 6, wherein the metal base film is made of a single metal such as Zr, Ta, W, Nb, or Mo, or an alloy of two or more of them.