JPS5891530A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a vertical magnetic recording medium with enhanced sliding strength by forming a porous aluminum oxide film impregnated with a liq. lubricant on a thin magnetic Co-Cr alloy film. CONSTITUTION:A layer such as an amorphous Co-Ti alloy film as a soft magnetic substance layer 2 is laid on each side of a nonmagnetic substrate 1 of Al or the like, and on the layer 2 a Co-Cr alloy film is formed as a magnetic medium layer 3 for vertical magnetization by a high-frequency sputtering or other method. On the layer 3 an Al film is formed by the high-frequency sputtering or other method, it is anodically oxidized, and the surface of the resulting porous aluminum oxide film 4 is coated with a liq. lubricant to impregnate the lubricant into the pores.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, in particular a CO-
The present invention relates to a recording medium for perpendicular magnetic recording using a Cr alloy thin film.

The perpendicular magnetic recording method records signals by magnetizing them in the direction perpendicular to the surface of the recording medium. Since the demagnetizing field inside the bit is small, this method is suitable for high-density recording.

A C0-Cr alloy thin film is a magnetic thin film in which the axis of easy magnetization is perpendicular to the surface, and is very promising as a material for perpendicular magnetic recording. However, the C0-Cr alloy thin film is a metal thin film and has a drawback in terms of sliding strength against a magnetic head.

An object of the present invention is to provide a magnetic recording medium in which the sliding strength of a metal thin film such as a Co--Cr alloy thin film is improved.

In order to achieve such an object, the present invention provides a porous aluminum oxide film on a metal magnetic material layer such as a CO-Cr alloy thin film, and impregnates this porous aluminum oxide film with a liquid lubricant. The magnetic layer has a lubricating effect to improve sliding strength. The magnetic recording medium according to the present invention is produced by depositing an At film on a metal magnetic layer such as a C0-Cr alloy thin film by high-frequency sputtering, and converting this At film into a porous aluminum oxide film by anodizing. After that, the porous aluminum oxide film is impregnated with a liquid lubricant.

Hereinafter, the present invention will be explained in detail by way of examples.

FIG. 1 shows an example of a magnetic recording medium according to the present invention.

A disk-shaped high-purity (99.9% or more) At plate whose surface has been smoothed by polishing is used as the non-magnetic substrate l, and a soft magnetic layer 2 is formed on both sides of the Co-coated plate by high-frequency sputtering.
Ti amorphous film (Tt: 19-21% by weight, film thickness 0.4
~0.6 μm) was formed.

The material of the non-magnetic substrate 1 is not limited to non-magnetic alloys such as At and brass, but may also be organic polymers, glass, etc., and may be a long tape rather than a disk. The soft magnetic layer 2 is provided to improve the efficiency of perpendicular magnetic recording and reproduction, and may be any magnetic material that has sufficiently low magnetic resistance, that is, high magnetic permeability. In addition to the above-mentioned Co-4'i alloy, examples of such high permeability magnetic materials include pc-Ni alloy, and an alloy generally known as permalloy in which MO, Cf, V, etc. are added. 8i-Be Co-Mo-Zr,C
Amorphous alloys such as O, -T wheel-○r, etc. can be used. In particular, 80-82% permalloy, CO-Zr-M
O(Zr: 8-10% by weight.

MO: 10-12% by weight) Amorphous alloys are preferred.

A CO-Cr alloy film (Cr: 17-25% by weight,
A film thickness of 0.4 to 1.5 μm) was formed.

The material for the magnetic medium layer is CO-Cr and Qd.

'['b, D)', an alloy to which Erl or HO is added can be used. Further, by providing a suitable nonmagnetic intermediate layer between the soft magnetic layer 2 and the magnetic medium layer 30, the magnetic properties of the magnetic medium layer 3 can be improved. Such non-magnetic intermediate layers include sto, tio, .
Insulators such as Az, O, or Ti, Cr, At,
Metal thin films such as MO, W, CO, and AV can be used.

Next, an At film with a thickness of α3 to 0.4 μm is formed on the magnetic medium layer 3 by high-frequency sputtering, and the disk thus constructed is immersed in a 5% oxalic acid solution, and a current density of 30C1 is 0.
．． Anodic oxidation was performed at 8 to 0.9 mA/cm'' for 60 minutes to form the above At film into a porous aluminum oxide film 4.

After that, this disk was washed with water and dried, and the surface □ of the porous aluminum oxide film 4 was smoothed by polishing.
The thickness of this porous aluminum oxide film 4 is 0.1 to 0.15μ.
I made it m. Then, on the surface of this porous aluminum oxide film 4, as a liquid lubricant, 5
% diluted solution was applied using a spinner. Finally, as a finishing step, burnishing is performed using a Nitsushi head to smooth the surface of the porous aluminum oxide film 40, and at the same time, the thickness of the porous aluminum oxide film 4 is made 0.05 to 0.1 μm. According to the magnetic recording medium of this example, the porous aluminum oxide film is impregnated with a liquid lubricant, and since the porous aluminum oxide film has high hardness, Co It acted effectively as a protective layer for the -Cr alloy thin film, and the sliding strength against the magnetic head was improved about 500 times compared to the case without the aluminum oxide film.

In the above-described embodiments, a recording medium having a two-layer structure of a soft magnetic layer and a magnetic medium layer was shown as an example, but the present invention can also be applied to a recording medium having a tz single layer structure of a soft magnetic layer. In this case, when a metal substrate such as an LT substrate or a brass substrate is used as the nonmagnetic substrate, in order to improve the perpendicular magnetic properties of the co-cr thin film, an 8i0 film is added between the nonmagnetic substrate and the magnetic medium layer. , It is effective to provide an amorphous film such as an A40m' film.

Further, in the above embodiment, the magnetic medium layer is made of cocoon.
- Although only a perpendicular magnetic recording medium using a Cr alloy thin film has been described, the present invention is not limited to such a perpendicular magnetic recording medium, but can also be applied to a magnetic medium layer formed by sputtering, vacuum evaporation, plating, etc. It is also applicable to magnetic recording media using metal magnetic thin films, for example, horizontal magnetic recording media using Co--N1-p alloy thin films.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

Claims (1)

[Claims] 1. In a magnetic recording medium having a magnetic layer for magnetic arrangement made of a co-Cr alloy on a non-magnetic substrate, a porous aluminum oxide film is provided on the magnetic layer, and 1. liquid lubrication is applied to the porous aluminum oxide H. A magnetic recording medium characterized by being impregnated with an agent.