JPS6043226A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain high coercive force and isotropy of a magnetic characteristic without execution of diagonal vapor deposition by depositing an underlying layer of a metal which expands volumetrically when solidifies by ion planting on a nonmagnetic base and forming a thin magnetic metallic film thereon. CONSTITUTION:An underlying layer consisting of a metal which expands volumetrically when solidifies is formed on a nonmagnetic base 1 and a thin magnetic metallic film is formed thereon. The formation is accomplished by ion vapor deposition by discharge in gas, i.e., ion plating. If such method is used, both of coercive force and squareness ratio can be upgraded by performing low vacuum deposition. The underlying layer is formed of a metal which expands volumetrically when solidifies on the base 1 in the stage of deposition, for example, Bi, Ga, Sb, Ce and Si respectively or an alloy of metals contg. any among these metals and the thickness thereof is selected to 30-300Angstrom . The thin magnetic metallic film 3 is formed by depositing any among Co, Fe and Ni or an alloy thereof to 100-1,000Angstrom thickness on the base by ion plating or usual vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic recording media, particularly to so-called metal thin film type magnetic recording media in which a gold dielectric layer (')'+V 112 is deposited on a non-magnetic substrate. LiJ law is involved.

BACKGROUND TECHNOLOGY AND PROBLEMS The magnetic recording media that have been widely used in the past have a magnetic backbone formed by coating a non-magnetic substrate with a magnetic paint mainly consisting of acicular powder and a polymeric binder. It is a coating type magnetic recording medium.

In contrast, magnetic metals such as Co, Fe, and Ni, or alloys thereof, are formed on non-magnetic substrates by so-called physical vapor deposition techniques such as vacuum deposition, sputtering, or ion blasting. The metal thin film type magnetic recording medium has the ability to obtain a significantly higher residual magnetic flux density because no non-magnetic binder is mixed into the magnetic layer, and the magnetic layer can be formed extremely thin. It has the advantage of high output and short wavelength response.

However, in this type of thin-film type recording medium, if a magnetic metal such as Co is dropped onto a non-magnetic substrate on a car, for example, one drop of magnetic metal will have a sufficient resistance (d) to 100 ml. It is difficult to maintain the magnetic layer at t4. In such a thin single-film magnetic recording medium, it is difficult to maintain the magnetic layer at t4.

The method for obtaining magnetic 1t4t having a non-θ magnetic property is
, (An oblique evaporation method has been proposed in which the above-mentioned magnetic metal stem particles are incident on the body at the ♀ 1st point. Togo 7) When such an oblique evaporation method is used, the evaporation efficiency is low. The disadvantage is that productivity is low.

OBJECTS OF THE INVENTION The first object of the present invention is to provide a non-magnetic support with an anti-magnetic force of 11]1 to 9 degrees even when the oblique vapor deposition method is not used, so that the magnetic properties are uniformly oriented within that plane. metal magnetic fil
The purpose is to obtain a 'r+V, IQ type magnetic recording medium.

Another object of the present invention is to obtain a metal magnetic thin film type magnetic recording medium which has a high coercive force and a high squareness ratio as described above.

Summary of the Invention In the present invention, as shown in Fig. 1, a non-magnetic substrate (
1) A metal layer (2) whose volume expands during solidification (assimilation) is formed on top, and a metal magnetic thin film (3) is formed on top of this.
form.

In particular, in the present invention, at least the above-mentioned stratum (2),
If a further layer is to be formed, a metal magnetic thin film (3) is subsequently formed thereon by ion vapor deposition using discharge in gas, so-called ion blating.

Incidentally, in the case where a metal base material whose volume expands during solidification is formed on the substrate +11 by a normal vacuum evaporation method, and a metal magnetic thin film is formed on this, the presence of the base layer is Therefore, even if a metal magnetic thin film is formed on this film not by oblique evaporation but by evaporation from a substantially perpendicular direction, the coercive force H can be obtained. The squareness ratio Rs of the upper layer is
! These Hc and Rs and the thickness of the overlying layer are shown in curves (21) and (22) in Figure 2 as shown in Figure 2. As the 111 of the layer increases, Hc
However, on the other hand, there is a tendency for Rs to decrease and ζ to increase.

However, in the case of the method of the present invention described above, namely,
When the F formation is ion-blated by discharge in gas, that is, by so-called low-vacuum evaporation, it is possible to reduce both Hc and Rs.

Embodiment In the present invention, "ζ" is a base layer M (2) on a non-magnetic substrate +11 and a metal magnetic thin film i'F as explained in FIG.
II history (3) and form the "ζ magnetic recording medium f.

Here, the nonmagnetic substrate +11 may be, for example, a polymeric soil substrate such as polyethylene phthalate, polyamide, polyamideimide, polyimide, or an inorganic substrate such as glass ceramic, zaphire, or a metal treated with an R'IF surface. .

The above ttl l = 12) is deposited on the substrate (1) by an ion beam, but during the deposition, it is solidified from a liquid phase to a surface phase, that is, on the substrate (1). Metals whose volume expands when solidified, such as Bi, Ga, Sb, Ge, and St, or metals containing any of these, such as Si-Cu, 5
It is made of an alloy such as i-Au, Ge-Au, Ge-In, etc., and its thickness is selected from 30 to 300.

Table 1 shows the volumetric expansion rate 1Δ of each of the -J double feeds upon solidification.
V/Vl (herein, ■ is the volume in liquid state, and Δ■ is the change in body f'IV due to solidification), and the melting points rn and p are shown.

Table 1 Metal magnetism +! ¥ 11% +31 can be formed by depositing Co, I'e, Ni, or an alloy thereof to a thickness of 100 to 1000 mm by ion blasting or ordinary vapor deposition.

Figure 3 shows the underlayer (2), and if it further comprises a metal magnetic m
Ion brating device that forms Shin+31! 'J
In the diagram, (4) is a Herja, Zunawara vacuum container, and inside this container (4), non-magnetic 11. Substrate (
1) is arranged, and this support f
A DC power supply (6) is connected between 51 and the container (4). Also, inside the container (4), a vapor deposition layer 7 is arranged facing the substrate ([). l: It's been done.

On the other hand, there is an il' between the vapor deposition source (7) and the substrate (1).
li inhago 1 ile (8) is placed, and to this, t:i1
frequency? 1111 le! (9) Commercial waves are supplied.

001 is Δr fed into the container (4).

In the gas supply sea such as N2.02, (11) is connected to a vacuum pump such as a diffusion type pump, and the exhaust port that produces air (υ) inside the container (4) is connected to the corner. For example, although not shown, the deposited phase is evaporated by f!ii!!S'! of an electron beam from an electron gun or by resistance heating.
) to be done.

The inside of the container (4) is evacuated to a vacuum of - and juI, and a gas, e.g.
The gas is fed at a pressure of about 1 O-3 torr, and ions of the deposit are generated by the discharge in the gas, and the ions are deposited on the substrate (11) by injection.

Example 1 A base layer (2) was formed on a polyimide substrate (1) having a thickness of 50 μm by ion-blating Bi to a thickness of 50 μm using the ion-blating apparatus described in FIG. In this case, 8r is 3.8X in the container (4).
The power of the image frequency power supply (9) was set to 200-1, and the power of the DC power supply (6) was set to -' i kV. After that, the inside of the container (4) was bled out, and
Co-N is applied on the substrate (1) from a direction almost perpendicular to the blood.
A metal magnetic thin film (3) is made by vacuum evaporating i to a thickness of 350 mm.
A -C magnetic recording medium was obtained. The medium thus obtained is designated as sample 1.

Next, Comparative Examples 1 to 3 will be listed as examples to be compared with the present invention.

Comparative Example 1 Similarly to Example 1, a layer of Bi with a thickness of 50 μm was placed on a polyimide substrate with a thickness of 50 μm, and a metal magnetic layer of Co-Ni with a thickness of 350 μm was placed on top of this. form, but
In this example, the Bi base layer is replaced with Ar gas (3,8X 1
After that, Co--Ni was vacuum-deposited to form a metal magnetic thin film (a magnetic recording medium was prepared. Sample 2 was a medium with 14 Il in this way.

Comparative Example 2 Even with the same configuration as Comparative Example 1, a Bi land layer and a Co--Ni metal magnetic layer thereon were formed. Both crotches were vacuum-deposited. The magnetic recording medium prepared in this manner is referred to as sample 3.

Comparative Example 3 Continuing with Comparative Example 2, the number of people (B i ''I・thickness of the stratum) was set at 30 people.The magnetic recording medium obtained in this manner is referred to as Sample 4.

The magnetic properties of these samples 1 to 4 are listed in Table 2.

Table 2 As is clear from this, the magnetic recording medium obtained by the manufacturing method of the present invention exhibits excellent characteristics in terms of both the coercive force He and the squareness ratio Rs.

In the embodiment of the production method of the present invention described above, the underlayer was formed by ion blating using discharge in gas, but the metal magnetic thin film on one geological layer was ion-blasted. Even when ζ was formed by rating, a magnetic recording medium with excellent l(c and Rs) could be obtained.

In addition, the metal magnetic thin film 1 can be formed not only by vertical vapor deposition but also by oblique vapor deposition, and this metal magnetic thin film is not limited to a single layer, but can have a multilayer structure with the above-mentioned underlayer interposed. It is also possible to do this.

Moreover, the above-mentioned formation layer (2) is not limited to the case where it is directly deposited on the substrate (1).

It is also possible to form an amorphous R layer of 5302 with an intervening amorphous R layer.

Effects of the Invention As described above, according to the manufacturing method of the present invention, a metal magnetic thin film pattern is formed through the underlayer that expands in volume during solidification. Due to the surface properties of the surface to which the magnetic thin film is adhered, the magnetic t! 1. The coercive force Hc can be obtained by making the AV, IK+ finer and the coercive force Hc not only by oblique evaporation but also by almost vertical evaporation.In addition, in the present invention, this 1. Brating was carried out, and at this time, it was possible to measure not only the direction of the coercive force Hc, but also the direction of the squareness ratio Rs.

Furthermore, according to the present invention, the direction of coercive force and squareness ratio
In addition to this, the adhesion strength of the metal magnetic HvI pattern was also improved.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an example of a zero-temperature recording medium obtained by the manufacturing method of the present invention, and Figure 2 shows the relationship between the thickness of the stratum and magnetic properties of a magnetic recording medium that is not produced by the manufacturing method of the present invention. The Shimezu characteristic curve diagram and Figure 3 are configuration diagrams of an example of an ion brating device used in the manufacturing method of the present invention. (1) is a non-magnetic substrate, (2) is a land layer, and (3) is a metal magnetic thin film. be.

Claims (1)

[Claims] A method for manufacturing a magnetic recording medium in which a metal underlayer that expands in volume upon solidification is deposited on a nonmagnetic substrate by ion blating, and then a metal magnetic thin film is formed on this.