JPS61131228A - Vertical magnetic recording medium - Google Patents

Abstract

PURPOSE:To confine residual magnetism in a vertical magnetic recording medium with a closed structure and to obtain the titled recording medium having high magnetic recording density by laminating a high-magnetic permeability magnetic body layer on a magnetic body layer having magnetic anisotropy vertical to the surface of a film. CONSTITUTION:A Ti film 12 is formed in specified thickness on a substrate 11 of alumite by sputtering, and an Ni-Fe film 13 is formed thereon by sputtering. A Ti film 14 is further formed in specified thickness on the film 13, and a Co-Cr film 15 of a vertical magnetic recording medium is formed on the film 14 in specified thickness by sputtering. An Ni-Fe film 16 is further formed in specified thickness thereon to constitute a recording medium, and the Cr-Cr film 15 is magnetized by a magnetic head provided on the film 16. The residual magnetization of the Co-Cr film 15 is magnetically combined by the high-magnetic permeability Ni-Fe films 13 and 16 provided above and below to keep stably the magnetizing force, and the magnetic recording density is increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording medium used in a magnetic recording device such as a magnetic disk device or a magnetic tape device, and particularly relates to a conventionally used horizontal magnetic recording medium. The present invention relates to improvements in perpendicular magnetic recording media that have higher recording densities than those of other media.

Instead of a horizontal magnetic recording medium, which is magnetized horizontally to the surface of a magnetic film formed on a substrate, this media is magnetized perpendicularly to the surface of the magnetic film, aiming for the direction of magnetic recording density. Perpendicular magnetic recording media have been developed.

[Conventional technology]

The second part about the conventional structure of such perpendicular magnetic recording media.
This will be explained using the cross-sectional view of the magnetic disk medium shown in the figure. In the figure, 1 is a substrate made of nonmagnetic alumite, etc., and 2 is a nonmagnetic material made of titanium (T+) to improve the adhesion between the high permeability magnetic layer and the substrate, which will be formed in a later process. A magnetic layer 3 is a high permeability magnetic layer made of N1-Fe (permalloy), 4 is a magnetic layer magnetized perpendicular to the film surface formed thereon, and the high permeability magnetic layer described above. 5 is a non-magnetic film made of titanium or the like to prevent deterioration of the magnetic properties of mutual magnetic films due to interaction between the magnetic layers, and 5 is made of Co-Cr having magnetic anisotropy in the direction perpendicular to the film surface. This is a magnetic layer.

The reason why a high permeability layer is formed on a substrate and a magnetic layer magnetized perpendicular to the film surface is formed on top of it is that if a perpendicularly magnetized recording medium is formed directly on the substrate, When magnetic heads are installed at a predetermined interval in
It is said that this is because it is not possible to record at high recording density.

[Problem that the invention seeks to solve]

By the way, when magnetic recording is performed by installing magnetic heads at predetermined intervals on a perpendicular magnetic recording medium as shown in FIG. FIG. 3 shows a diagram of the relationship between the magnetic recording density and the distance.

In the figure, the horizontal axis indicates the distance between the perpendicular magnetic recording medium and the head, and the vertical axis indicates the magnetic recording density recorded on the perpendicular magnetic recording medium. As shown by a curve 101, there is a problem in that the recording density changes significantly as the distance between the recording medium and the head changes.

When performing magnetic recording using a magnetic disk with such a perpendicular magnetic recording medium formed on its surface, the magnetic head comes into contact with the magnetic disk and generates magnetic waves when the magnetic disk starts rotating and when it stops rotating. In the so-called contact start-stop method of recording, installing the magnetic head a certain distance from the recording medium surface of the magnetic disk prevents the head crash phenomenon that causes scratches on the recording medium surface. is needed to do.

By the way, in a magnetic disk drive using a magnetic recording medium in which the recording density changes significantly in response to a change in the distance between the magnetic head and the recording medium, in order to avoid the Hendokrasosh phenomenon, it is necessary to If an attempt is made to maintain the distance at a certain value, there is a problem in that the recording density changes significantly.

However, in a horizontal magnetic recording medium, the number 10 in FIG.
As shown in curve 2, the magnetic recording density is not affected much by changes in the distance between the recording medium and the magnetic head, and the displacement is small.

[Means for solving problems]

The present invention has been made in view of the above-mentioned matters, and the magnetic recording medium of the present invention includes a high permeability magnetic layer formed on a substrate, and a non-magnetic layer interposed on the high permeability magnetic layer. In a magnetic recording medium in which a magnetic layer having magnetic anisotropy in a direction perpendicular to the film surface is provided, a high magnetic permeability layer is provided on the magnetic layer having magnetic anisotropy in a direction perpendicular to the film surface. It is formed by laminating magnetic layers.

[Effect]

That is, the perpendicular magnetic recording medium of the present invention has a high magnetic recording density, but the recording density is easily affected by the distance between the head and the recording medium, and the perpendicular magnetic recording medium has a small recording density, but the belly button 1- By forming a horizontal magnetic recording medium in which the recording density is hardly affected by the distance between the vertical magnetic recording medium and the recording medium, and by providing the horizontal recording medium, the residual magnetization formed in the vertical magnetic recording medium is reduced to a closed structure. By forming and confining the perpendicular magnetic recording medium, the objective is to obtain a perpendicular magnetic recording medium that has a high magnetic recording density and has little effect on the distance between the head and the recording medium.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of the perpendicular magnetic recording medium of the present invention. As shown in the figure, a Ti film 12 having a thickness of 200 mm is deposited on the second side of a substrate 11 made of alumite by sputtering. Furthermore, a Ni--Fe film 13 is formed on this by sputtering to a thickness of 0.5 μm. Further, on this, a TI film with a thickness of 4,200 mm is formed by sputtering, and on this, a Co-Cr film 15 of the perpendicular magnetic recording medium is formed.
is formed by sputtering to a thickness of 0.15 .mu.m, and a Ni--Fe film 16 is further formed thereon to a thickness of 100 to 500 .mu.m by sputtering.

When such a recording medium is used, the Co--Cr film 15 of the perpendicular magnetic recording medium is
is magnetized, and its residual magnetization is magnetically coupled by the high permeability Ni--Fe films 13 and 16 laminated above and below the Go--Cr film, and is kept stable. Therefore, the occurrence of a demagnetizing field between the magnetic head and the recording medium, which occurs in conventional perpendicular magnetic recording media, is also reduced. Therefore, the phenomenon in which the magnetic recording density of the magnetic recording medium changes significantly when the magnetic head approaches the magnetic recording medium, as in conventional magnetic recording media, is eliminated. The influence of the distance between magnetic heads is not as great as in conventional magnetic recording media.

Furthermore, when using the magnetic recording medium of the present invention, even if the distance between the recording medium and the magnetic head is kept larger than when recording using conventional magnetic recording media, the magnetic recording density will not be affected much. , magnetic recording can be performed with the magnetic head separated from the magnetic recording medium by a certain distance. Therefore, the head-crash phenomenon in which the magnetic head collides with the surface of the recording medium and damages the surface of the magnetic recording medium can be largely eliminated.
By using such a magnetic recording medium, a highly reliable magnetic disk device can be obtained.

Furthermore, as a result of various experiments, the present inventors found that the Co-Cr film 15
The Ni-Fe film 16 formed on top has a kind of magnetic flux shielding effect on the magnetic head installed next to it, so if the film is made too thick, the output of the magnetic head will decrease. It has been found that the thickness of the Ni--Fe film is optimally kept within the range of 100 to 500 layers.

〔Effect of the invention〕

As described above, according to the magnetic recording medium of the present invention, even if magnetic recording is performed with a certain distance between the magnetic head and the magnetic recording medium, the magnetic recording density is not significantly affected. Therefore, if a magnetic disk is formed using the magnetic recording medium of the present invention, the distance between the magnetic head and the magnetic disk can be kept large to a certain extent, and a highly reliable magnetic disk device in which the head crash phenomenon is unlikely to occur can be obtained. There are benefits to be gained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of the perpendicular magnetic recording medium of the present invention, Fig. 2 is a cross-sectional view showing the structure of a conventional perpendicular magnetic recording medium, and Fig. 3 is the magnetic recording density versus the distance between the recording medium and the head. It is a relationship diagram. In the figure, 11 is a substrate, 12.14 is a T+ film, 13.
16 is a Ni--Fe film, and 15 is a Co--Cr film.

Claims (1)

[Claims] Magnetic recording in which a high permeability magnetic layer is formed on a substrate, and a magnetic layer having magnetic anisotropy perpendicular to the film surface is provided on the high permeability magnetic layer via a nonmagnetic layer. In the media,
A perpendicular magnetic recording medium characterized in that a high magnetic permeability magnetic layer is laminated on the magnetic layer having magnetic anisotropy in a direction perpendicular to the film surface.