JPS62236122A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the reliability of the titled medium in high-density recording and reproducing by forming the first layer of a magnetic recording layer consisting of two layers of partially oxidized columnar crystals which are inclined to the same side, with a >=60 deg. oblique incidence film having a lower content of an oxygen atom than the second layer. CONSTITUTION:The magnetic recording medium has the magnetic recording layer consisting of two layers of partially oxidized crystals which are inclined to the same side, and the first layer 9 is a >=60 deg. oblique incidence film and has a lower content of an oxygen atom than the second layer 10. Since the magnetic recording layer to be abutted on an annular magnetic head rotating at a high speed has the first layer having softness and hence the second layer is substantially the only high-hardness film soft contact with the magnetic head can be maintained, the spacing is not changed, the error rate is not increased even when the density of digital recording is increased, and the reliability is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium suitable for high-density magnetic recording.

Conventional technology In recent years, magnetic recording media that can further increase the density of magnetic recording have attracted attention, in which a thin ferromagnetic metal film is formed on a substrate such as a polymer film by sputtering, electron beam evaporation, etc. .

[For example, foreign journals IEE Transactions
n Magnetics) vol, MAG-21, N
o-3, PP, 1217-1220 (1sees)) Figure 2 shows an example of a magnetic recording medium having a multilayered magnetic recording layer, and in Figure 2, 1 is a non-magnetic substrate such as a polymer film. 2, 4.6 is a nonmagnetic layer made of Or, 3,
5.7 is a sputtered magnetic layer made of Co, for example, and has a laminated structure in order to improve magnetic properties such as coercive force and squareness ratio.

Furthermore, as a laminated structure, many ferromagnetic metal thin films such as a laminated layer of an in-plane magnetization film and a perpendicular magnetization film have been proposed.

Problems to be Solved by the Invention However, in reality, in order to make full use of the short wavelength recording and reproducing features of a ferromagnetic metal thin film, it must be able to maintain good contact with the ring-shaped magnetic head and be durable. is important, but in the above configuration,
When the recording wavelength is around 0.5 μm, there is a problem that the spacing loss has a large effect and the error rate in digital recording becomes unstable.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a magnetic recording medium that maintains good head touch and provides reliable digital recording and reproducing performance.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention has a magnetic recording layer having two layers of partially oxidized columnar crystals tilted to the same side. This is the oblique incidence film described above, and is composed of a lower oxygen atomic ratio than that of the second layer.

Effect The magnetic recording medium of the present invention has the above-described configuration, and since the first layer of the magnetic recording layer that comes into contact with the ring-shaped magnetic head that rotates at high speed has flexibility, the highly hard film is substantially the first layer. Since it can be considered as only two layers, it maintains a soft contact state with the magnetic head, provides stable contact, does not change the spacing, and does not increase the error rate even when the density of digital recording is increased. It is possible to ensure reliability.

EXAMPLES Hereinafter, examples of the magnetic recording medium of the present invention will be described with reference to the drawings.

FIG. 1 is an enlarged sectional view of the magnetic recording medium of the present invention. In FIG. 1, reference numeral 8 denotes a polymer film made of polyethylene terephthalate trilam having a thickness of 10 μm. 9 is the polymer film 8 along the cylindrical can with a diameter of 1 m.
While winding up Go-N with a thickness of 0.055 pTIr, vapor deposition was started from the tangential direction under the condition of a minimum incident angle of 60 degrees.
An i-0 film was formed.

The GoNi alloy was evaporated by electron beam heating so that the atomic ratio of Co:Ni:O was 58:15:27, and 0.16 J/illin of external oxygen was introduced.

This film consists of columnar crystals formed by partially oxidized oblique vapor deposition, and the columnar crystals have axes that are inclined with respect to the normal to the substrate surface.

The deposition direction of the second magnetic layer 10 was also aligned so as to form columnar crystals tilted to the same side. Under these conditions, a Go-Ni-0 film was formed at a minimum incident angle of 38 degrees while immersed in a cylindrical can with a diameter of 1 m, and Go:Ni:0=49:
0.311 / when oxygen is evaporated to be 13:38
I installed Win. The formed Go-Ni-〇 film is 0.0
It was set to 76 μm.

On this film, perfluorooctanoic acid was formed as a human protective lubricant layer 11 with an average thickness of 4 degrees by vacuum evaporation to produce a magnetic tape with a width of smm.

As a comparative example, a base layer was formed on the same polyethylene terephthalate film with a thickness of 10 μm by Ctalo and Qspm sputtering methods, and on top of that, CoCo-0
An r(Cr2o%) perpendicular magnetization film of 0.13 μm was formed by the same sputtering method, and 40 people formed the same protective lubricant layer as in the example by vacuum evaporation on the film to produce a magnetic tape of 1 width.

Both have a gap length of 0.22 μIa and a track width of 16
A rectangular wave with a bit length of 0.22 μm was recorded and reproduced using a μm amorphous metal in-gap ring head, and the error rate was repeatedly measured.

As a result, the magnetic tape of the example had a 20"060% RH
The error rate when recording and reproducing 160 times is 4×1σ5.
-5 x 1 σ5, which was stable, whereas the error rate of the comparative example was unstable at 3 x 10-5 to 6 x 10-'. Also, at 40°C and 80% RH, recording and reproducing were repeated 226 times. However, the error rate of the example was 4 x 10 to 6 x 10, and the error rate of the comparative example was 6 x 10 to 1 x 10.

In the example, polyethylene terephthalate with a thickness of 10 μm was used as the polymer film, but the thickness ranged from 20 μm to 6 μm.
μm can be used, and polyethylene naphthalate film, polyesterimide film, cellulose acetate phthalate film, polycarbonate film, polyimide film, polyamideimide film, etc. may also be used.

If the first layer 9 has an incident angle of 60 degrees or more, the effects of the present invention can be stably obtained. The angle of incidence varies from 60″ to 60″ depending on the material.
There are some cases where the angle is within the range of 60', but if it is over 60 degrees, Co-Ni -00, C0-0, Go-Ti
-0, Go-Or-0, Go-Mg-0, Go-Mo-
0, Go-Fe-0, Go-W-0, etc.
The oxygen atomic ratio is lower than that of the second layer 1o, preferably,
It is preferable to have 30 atoms or less.

The first layer and the second layer of the magnetic recording layer may be made of the same material or may be made of different materials.

The obliquely deposited film may be formed along a cylindrical can or over a belt-shaped rotating support as long as the incident angle is 60 degrees or more.

Effects of the Invention As described above, according to the present invention, good head touch can be maintained, spacing loss is small and does not fluctuate, and reliability in high-density magnetic recording and reproduction is improved. There is.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a conventional magnetic recording medium. 8...Polymer film, 9...First magnetic layer, 10...Second magnetic layer, 11...
Protective lubricating layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 8-Basic 7 (+L4 9- 勺对) 1 Thoughts to 1-Ya 2 Rii 1--I 禾 1 連 t1 N1-3 West Diagram 2

Claims (1)

[Claims] The first layer of the magnetic recording layer having a two-layer structure of partially oxidized columnar crystals tilted to the same side is an oblique incidence film of 60 degrees or more, and
A magnetic recording medium characterized in that the second layer has a lower oxygen atomic ratio.