JPS61914A - Vertical magnetic recording medium - Google Patents

Abstract

PURPOSE:To decrease the thickness of a titled medium by forming an iron nitride film as a soft magnetic film on a base body and forming a CoCr alloy film on the iron nitride film. CONSTITUTION:Pure iron as a target is reactively sputtered to form the iron nitride film on the supporting base body. A Cr-Co alloy film is then formed on the iron nitride film by a sputtering method using a Cr-Co alloy as a target by which a vertical magnetic recording medium having a comosite structure is obtd. The medium is thus constituted into the small thickness and therefore film curling is decreased in the case of, for example, a tape and good runnability is obtd. The medium is made more inexpensive as well.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to perpendicular magnetic recording media.

[Conventional ML technique]

Current magnetic recording methods mainly use magnetization in the direction of movement of the recording medium, so as the recording density of the signal increases, the demagnetizing field within the medium increases, causing attenuation and rotation of the residual magnetization, which causes the recording signal to change. It has the disadvantage of being difficult to use.

On the other hand, when using residual magnetization perpendicular to the magnetic film surface of the recording medium, the anti-energetic field decreases and the residual magnetization increases as the recording density increases, so excellent recording characteristics are achieved in the density range. As a recording medium that satisfies these demands, a 0oCr thin film whose axis of easy magnetization is perpendicular to the magnetic field is #! It has been east.

What are the drawbacks of the above 000r film, namely poor recording efficiency, long wave submission cuff) low F, and more? '1 use t
i! As a means of solving the problem of restrictions on the types and shapes of recording heads, we developed a composite 'Bi! m
The recording medium is being trimmed. However, the perpendicular #1 recording medium with the above-mentioned composite structure has improved recording efficiency, increased long wavelength output, and wider selection of recording heads to be used9.
In addition, it will be easier to put into practical use floppy-type and other types of perpendicular magnetic disks that have a perpendicular magnetic recording medium layer and perpendicular magnetic disks that have a thick non-magnetic support substrate. The conventional example (Japanese Unexamined Patent Publication No. 54-51804) states that it is desirable that the soft magnetic film has a thickness of 0.5 μm or more, since the effectiveness in increasing the reproduction output is lost if the soft magnetic film is too thin. Ta.

That is, conventionally, as the underlying soft magnetic film, for example, Ou
- Taking Mo permalloy thin g as an example, 1!7. As shown in FIG. 1, the reproduction output increases as the thickness increases, reaches a maximum value of t at 0.5 μm, and remains constant even if the thickness increases by 7.

[Summary of the invention]

This invention is intended to improve the conventional vertical anaerobic recording medium rod.
JX, basically formed a soft magnetic film using iron oxide, and by forming this iron oxide film lζCoCr, a thin direct magnetic film, i! , recording medium? l-T
The purpose is to do 4 things.

[Embodiments of the invention]

When iron nitride is used as the soft magnetic film, the relationship between the thickness and the reproduction output shows the lowest value of reproduction output at a thickness of 0.2 μm.

The method will be explained below using an example.

Example A polyimide film with a thickness of 25 μm and a width g()gi was prepared as a support base, and a pure iron target was set as Ar +-
The iron nitride film τ is deposited on the support substrate by reactive sputtering in N and gas to a thickness t of 0.05, 0.1°o, i 5 , respectively.
0゜2, 0.8, 0.5/Jm was deposited. ◎Next, a 0.2μm-shaped multi-unit structure was formed on the iron nitride film by sputtering using a Cr18%-Co yarn target. A perpendicular magnetic recording medium was obtained. The resulting spiral, i! , the thickness of the iron oxide film δ for the recording medium
Figure 2 shows the maximum reproduction output at a thickness of 0.2μm, and the reproduction output remains unchanged even if the thickness is increased beyond that. is constant and friendly.

In the above embodiment, the underlying soft magnetic iron nitride film, CoCr
Although the sputtering method was used to form the base metal thin film, ablation methods, ion blasting, and other methods may also be used.

Further, in the above embodiment, a 5F magnetic material was used as the base, but the same applies to the case of a magnetic base.

〔Effect of the invention〕

As described above, according to the present invention, an iron nitride film is formed on the base as a soft magnetic film, and a CoCr base metal film is formed on the iron nitride film, so that the thickness of the perpendicular magnetic recording medium can be reduced. There is an effect that it can be done. Also, since perpendicular magnetic recording media can be constructed with a thin thickness, for example, in the case of tape,
It has less film curl, exhibits good runnability as a tape, and is economically cheaper than conventional tapes.

[Brief explanation of drawings]

The first factor is a characteristic diagram showing the relationship between the thickness of the soft magnetic film of a conventional perpendicular magnetic recording medium and the playback output. FIG. 3 is a characteristic diagram showing how the regenerated metal is produced and the opened gold.

Claims (1)

[Claims] A perpendicular magnetic recording medium in which an iron nitride film is formed as a soft magnetic film on a base, and a CoCr alloy film is formed on the iron nitride film.