JPS60231911A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium having strong coercive force Hc and improved magnetic characteristics by using a Co-Re alloy as the material of a magnetic layer so as to form a crystal structure made of only an hcp phase having high anisotropy. CONSTITUTION:A nonmagnetic layer 2 of a low m.p. metal and the magnetic layer 3 of a Co1-xRex alloy (0.1<=x<=0.35) are successively formed on a nonmagnetic substrate 1 by vapor deposition, sputtering or other method to obtain the magnetic recording medium. The film of a polymer such as polyethylene terephthalate, polyamide, polyamidoimide or polyimide or a plate of glass, ceramics, sapphire or a surface oxidized metal may be used as the substrate 1. The nonmagnetic and low m.p. metal 2 is a metal having <=650 deg.C m.p. such as Bi, Ga, Sb, In, Sn, Tl, B, Al or an alloy thereof such as Ga-Al or Bi-In.

Description

[Detailed description of the invention] Industrial applications The present invention relates to magnetic recording media.

BACKGROUND TECHNOLOGY AND PROBLEMS In recent years, for the purpose of increasing the density of magnetic recording, magnetic thin film type magnetic recording media, that is, Co with a thickness of several hundred to approximately 1 μm, have been deposited on a non-magnetic substrate by vacuum evaporation, sputtering, etc. There is active research into magnetic recording media made of ferromagnetic metals such as ferromagnetic metals. As such a magnetic thin film type magnetic recording medium, a magnetically isotropic magnetic recording medium has been proposed that exhibits high coercive force and has a high squareness ratio not only by oblique evaporation but also by almost perpendicular evaporation. There is. In this magnetic recording medium, a nonmagnetic metal such as Bi is deposited as an underlayer on a nonmagnetic substrate, and then a metal magnetic layer such as Co is formed thereon.

However, in such a ferromagnetic metal thin film mainly composed of Co, X-ray diffraction results show that CO is divided into a hap phase (hexagonal close-packed structure) and an fcc phase (face-centered cubic structure). This causes deterioration of magnetic properties. Incidentally, regarding magnetocrystalline anisotropy, the hcp phase has uniaxial anisotropy, and the fcc phase has triaxial anisotropy, and the anisotropy constant is large for the hcp phase and small for the fcc phase. and,
The coercive force Hc, which is important as a property of magnetic recording media, is proportional to the magnitude of the anisotropy constant, so the presence of the fcc phase increases the coercive force H
This leads to a decrease in c.

OBJECTS OF THE INVENTION In view of the above points, the present invention provides a magnetic recording medium having high magnetic properties.

Summary of the Invention The present invention provides a non-magnetic low melting point metal and a CoR on a non-magnetic substrate.
This is a magnetic recording medium in which an e-alloy magnetic layer is continuously deposited.

In the magnetic recording medium of this invention, all CO phases are hcp
phase, and the magnetic properties, especially the coercive force IC, are improved.

Example In the present invention, as shown in FIG.
Non-magnetic low melting point metal (2) and Cox-xRex (0,1≦X≦0
．． 35) A magnetic recording medium is constructed by successively depositing the alloy magnetic layer (3).

As the nonmagnetic substrate (1), for example, a polymer film such as polyethylene terephthalate, polyamide, polyamideimide, polyimide, glass, ceramic, sapphire, or a metal plate with an oxidized surface can be used.

The non-magnetic low melting point metal (2) is a metal with a temperature of 650°C or less, such as Bit Ga, sb, In, Sn+
Tj! + Bt^β or an alloy containing it, such as Ga
-An! , Bi-In, etc. can be used.

FIG. 2 is a schematic diagram of a vapor deposition apparatus for forming a nonmagnetic low melting point metal (2) and a CoRe alloy magnetic layer (3).

In this apparatus α, a non-magnetic substrate (1) is run in a vacuum deposition tank between a supply reel (11) and a take-up reel (12). A low melting point metal evaporation source (13), for example, a Bl evaporation source (13), is arranged opposite to this non-magnetic substrate (1), and a CoRe alloy layer evaporation source (14), a Co evaporation source (14), and a Re
A vapor deposition source (15) is provided. (16) is a shielding plate.

In such a configuration, a non-magnetic substrate (11) is heated by an infrared lamp while running from a supply reel (11) toward a take-up reel (12), and while it is running, the non-magnetic substrate (11) is first heated by a Bi vapor deposition source (13). Bi is deposited on the substrate (11), and then a Co deposition source (14) is deposited on this.
) and evaporation of Co and Re from the Re evaporation source (15) to deposit a CoRe alloy magnetic layer.

The composition ratio of Go and Re is determined by the respective vapor deposition sources (14) and (15).
) can be controlled by the evaporation rate from

Example 1 Using the above vapor deposition apparatus side, a non-magnetic substrate (1) made of a polymer film was run under vacuum, and the substrate temperature at this time was 200°C, and Bi (2) was deposited from the vapor deposition source (13). 2
Deposited to a thickness of 0.00 mm, followed by a deposition source (14) on top of this.
and (15) for CO[12Rets alloy 1i(C
.

(82 atomic % of Re, 18 atomic % of Re) (3) was deposited to produce a magnetic recording medium.

Comparative Example 1 A magnetic recording medium was produced in the same manner as in Example 1, except that a 250-layer CO magnetic layer was deposited on a 200-layer thick Bi layer.

The coercive force Hc of the magnetic recording medium on each side is shown in the table below.

Table As is clear from this table, it is recognized that the coercive force He of the magnetic recording medium in which the CoRe alloy magnetic layer is deposited on the Bi underlayer is improved. The reason for this is considered to be that the CO phase becomes only the hcp phase with large crystal magnetic anisotropy due to alloying with Re.

Furthermore, in this embodiment, since the 'EoRe alloy magnetic layer is formed by substantially perpendicular deposition, a magnetic recording medium having an in-plane magnetic recording medium can be obtained.

Effects of the Invention According to the present invention, by using a CoRe alloy as the magnetic layer, the crystal structure becomes only the hcp phase with large anisotropy, a high coercive force Hc is obtained, and a magnetic recording medium with improved magnetic properties is obtained. can get. In addition, non-magnetic low melting point metals and CoR can be produced using methods such as vertical evaporation and sputtering.
Since the e-alloy magnetic layer is formed, a magnetic recording medium that is magnetically isotropic in plane can be obtained. Therefore, it is suitable for application to high-density recording magnetic tapes, magnetic disks, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the magnetic recording medium of the present invention, and FIG. 2 is a configuration diagram of a vapor deposition apparatus applied to manufacturing the present invention. (11 is a non-magnetic substrate, (2) is a non-magnetic low melting point metal, (
3) is a CoRe alloy magnetic layer.

Claims (1)

[Claims] A magnetic recording medium comprising a nonmagnetic low melting point metal and a CoRe alloy magnetic layer successively deposited on a nonmagnetic substrate.