JPS6043221A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To upgrade coercive force and to make magnetic characteristic isotropic without execution of a diagonal vapor deposition method by forming an underlying layer consisting of Ge or an alloy contg. Ge on one main plane of a non-magnetic base and forming a thin magnetic metallic film thereon. CONSTITUTION:A thin magnetic metallic film 2 consisting of any one matel among Co, Fe and Ni or an alloy thereof is formed on a non-magnetic base 1 and an underlying layer 3 which expands volumetrically when solidifies, more particularly an underlying layer consisting of Ge or an alloy contg. Ge, for example, an alloy of Ge (5.0% volumetric expansion rate when Ge solidifies) and Au or In is deposited by evaporation under said film to 30-300Angstrom thickness. The layer 3 consists of 80-100atom% Ge and the balance Au or In, etc. The film 2 is formed to 50-1,000Angstrom thickness by vapor deposition from the direction roughly perpendicular to for example, the base 1 without execution of diagonal vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic recording media, and particularly to so-called metal thin film type magnetic recording media in which a metal magnetic thin pattern is deposited on a non-magnetic support.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventional magnetic recording media have been made magnetic by coating a non-magnetic support with a magnetic paint mainly consisting of acicular magnetic powder and a polymeric binder. It is a coated magnetic recording medium with layers formed on it.

In contrast, magnetic metals such as Co, Fe, and Ni, or alloys thereof, are formed on a nonmagnetic support by so-called physical paper deposition techniques such as vacuum evaporation, spankling, or ion blating. Thin-film magnetic recording media can have extremely high residual magnetic flux density because no non-magnetic binder is mixed into the magnetic layer, and the magnetic layer can be formed extremely thin. Therefore, it has the advantage of high output and short wavelength response.

However, in this type of thin-film magnetic recording medium, it is impossible to obtain a magnetic layer having a coercive force 11c sufficiently high by depositing a magnetic metal such as CO on a non-magnetic support. Problem 1: In such a thin-film magnetic recording medium, a method for obtaining a magnetic layer having a coercive force of 11c is to apply evaporated particles of the above-mentioned magnetic metal to the support. An oblique evaporation method has been proposed in which the incident light is incident on P[°(°). However, when using such an oblique evaporation method, the disadvantage is that the J rate is low and the productivity is inferior.

Purpose of the Invention The present invention provides a magnetic metal thin film type magnetic material having a high coercive force on a non-magnetic support and whose magnetic properties are isotropic in the plane, even when the oblique vapor deposition method is not used. It proposes a recording medium.

Summary of the Invention In the present invention, as shown in FIG.
Support (1) - metal magnetic Wt made of any of Co, Fe, Ni, or an alloy of these metals
This is what forms the film (2), and this magnetic $ 11f
fi (Part 21 is a base layer (3) whose volume expands during solidification, especially Ge or an alloy containing Ge, such as Ge (
The volume expansion coefficient of Ge during solidification is 5.0%) and the sieve or I
A base layer made of an alloy with n is deposited to a thickness of 30 to 300 mm.

This layer (3) contains 80 to 100 atomic % of Ge, and the remainder is Au, In, or the like.

In addition, the number of VN K+ +21 is 50 to 1000 people,
It is preferably formed to a thickness of 100 to 309 nm, for example, not by oblique deposition, but by deposition, for example, in a direction substantially perpendicular to the nonmagnetic support (1).

Examples of the nonmagnetic support include polyethylene terephthalate, polyamide, and polyamideimide.

A molecular film such as polyimide, glass ceramic, sapphire, or a metal treated with an oxidized surface can be used.

Examples Example 1 A1 is treated as a non-magnetic support +11, on which Ge and an alloy of Co-30 atomic % Ni are sequentially deposited, as explained in FIG. 1. Non-magnetic support (1)
Through a 100-thick Ge land layer (3) on top
An o-Ni metal magnetic thin film (2) was formed. For these vapor depositions, a vapor deposition apparatus shown in FIG. 2 was used. This evaporation apparatus is capable of depositing a base layer (3) in a herger (4) at t5+.
<In this example, a Ge deposition source) and a metal magnetic thin film 11
2) vapor deposition source (6) (in this example, a Co-Ni alloy vapor deposition source) is placed, and a holder (7) holding a non-magnetic support +1) is placed opposite to these, and both A configuration may be adopted in which a shank (8) is disposed between them. (9) indicates a heating source such as a halogen lamp. In this case, I
The deposition was carried out under a pressure of lO=torr.

In this way, the magnetic properties of each magnetic recording medium when the heating temperature for the non-magnetic support (1) was set to 250"C and 300"C, that is, the coercive force Hc Figure 3 shows the results of measuring the relationship between the squareness ratio Rs and the film thickness of the Co-Ni gold metal magnetic film 2). 2
Ilc and Rs are shown when the temperature is 50°C, (12) and (13) are llc and Rs when the temperature is 300°C,
G.

-N People with a thickness of 4 legs (2) of 100 to 300 uniformly show high llc and Rs.

Example 2 The base layer (3) was bound by the same method as in Example 1.
A Ge-10 atomic% 1n alloy layer with a thickness of 120 mm is used as a metal magnetic thin film (2) and a Co-N1 layer with a similar thickness of 200 mm is used as the metal magnetic thin film (2).
W was vapor-deposited. The magnetic recording medium thus obtained had a coercive force tic of 5400e and a squareness ratio Rs of 73.4%.

Example 3 By the same method as in Example 1, ζ
Deposit a Ge-5 atomic%^U alloy layer with a thickness of 100 people,
A Co--Ni layer having a thickness of 220 mm was deposited as a metal magnetic thin film (2). 1 of the magnetic recording medium obtained in this way
1c was 6100e, Rs was 72.4%.

Example 4 As a non-magnetic support (1), an Il'lJ molecular film was placed on the surface, and a 5tO2 amorphous film was placed on top of it in a 50-person beam, and Example 1 was placed on top of this. 200mm thick through Ge underlayer (3) 100mm thick like Ni&J
A Co-Ni magnetic thin film (2) of a person was formed. θ) obtained in this way, Ilc of the recording medium is 4700e, R
s is 75.8% and 21. Ta. surface, in this case the support (
1) The formation of the 5i02 image inscribed in 1) can be achieved, for example, by providing a Sji-ring V (14) in the herjar (4) as shown in Fig. 2, and feeding oxygen gas into the herjar (4). In this manner, 5i02 is adhered to the support 1''i body 1-, and then the air is evacuated and CGe and Co--Ni are sequentially deposited.

Example 5 A metal magnetic thin film of 1'M (2
) as 200 thick Cog! It was used as an adhesive layer on the body.

The characteristics of the medium obtained in this way are that Ilc is 6500+
:, the squareness ratio was 70.1%.

surface, support fll,,l-3 as in Examples 4 and 5
When forming an amorphous film of i 02, the formation of the base layer (3) is +19! Instead of 411 quantum or 5i021%, it is also possible to form amorphous III of Si or other compounds.

Further, the metal magnetic film is not limited to a single layer as described above, but may have a multilayer structure, for example, with the above-mentioned land layer interposed therebetween.

Effects of the Invention As described above, according to the present invention, a magnetic recording medium having crystal coercive force, high squareness ratio, and excellent magnetic properties was produced.

This is achieved by placing a layer (1), which undergoes volumetric expansion during solidification, as 1. Geological layer (3), and due to the expansion during solidification, a thin metal magnetic thin film is deposited on top of this layer without diagonal deposition. It is thought that a crystalline coercive force can be obtained. And this layer (3) has 30 to 300 people and the above-mentioned l
Effects such as improvement in lc were obtained.

[Brief explanation of the drawing]

FIG. 1 is a linear sectional view of an example of a magnetic recording medium according to the present invention, FIG. 2 is a configuration diagram of an example of a vapor deposition system), and FIG. 3 is a diagram of magnetic characteristic curves. (41 is a non-magnetic support, (2) is a metal magnetic thin film, (3)
is the underlying layer.

Claims (1)

[Claims] A magnetic recording medium comprising a non-magnetic support, a land layer made of Ge or an alloy containing Ge formed on the entire surface of the non-magnetic support, and a metal magnetic thin film formed thereon.