JPS61237231A - Magnetic recording body and its production - Google Patents

Abstract

PURPOSE:To narrow a track and to stabilize the recording and reproduction by making the vertical anisotropy of a magnetic body in a data track in the title magnetic recording body larger than the vertical magnetic anisotropy of a guard band track between the data tracks. CONSTITUTION:A nonmagnetic thin film such as a thin film 1 of Cu, Cr, etc., is formed by sputtering, etc., as an undercoating effect on a substrate 4 to reduce the vertical magnetic anisotropy of a vertical magnetic recording medium 10 and then the vertical magnetic recording medium 10 is formed. A Co alloy typified by CoCr is used as the medium. Accordingly, the vertical magnetic anisotropy of the magnetic film 10 in a guard band track 2 between data trucks is reduced and the recording density characteristic is deteriorated. Consequently, even when data are recorded on the guard band in the high-density region in a data truck 3, the output from the region is small as compared with the output from the data track 3 by tracking deviation, unerased noises due to the crosstalk and tracking deviation can be controlled. Consequently, the track is narrowed and the recording and reproduction can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic recording medium, in particular a perpendicular borosilicate recording medium. This invention relates to a magnetic recording medium and its manufacturing method.

(Prior art and its problems) Improvement in the recording density of magnetic recording devices is a constant trend in the field. The magnetic recording medium used here generally extends in the longitudinal direction of the recording medium for recording and reproduction, but as the density increases, there is a limit to the recording density due to the influence of the demagnetizing field.

For this reason, a perpendicular magnetic recording method has been proposed in which the recording medium is magnetized in a direction perpendicular to the surface thereof, which enables high density recording. As the perpendicular magnetic recording medium used here, there is a C0 alloy thin film typified by CoCr formed by sputtering or vapor deposition.

In this way, in the perpendicular magnetic recording system, by giving the medium perpendicular magnetic anisotropy, it is possible to significantly improve the linear density in the longitudinal direction of the track. There is peace of mind that increases the However, as the track density increases, problems such as noises such as unerased data arise due to crosstalk between adjacent data tracks and tracking accuracy.

(Objective of the Invention) An object of the present invention is to provide a magnetic recording medium that can achieve narrower tracks in perpendicular magnetic recording, increase the tracking margin, and perform stable recording and reproduction.

(Structure of the Invention) According to the present invention, it is possible to obtain a magnetic recording body characterized in that the perpendicular magnetic anisotropy of the magnetic material of the guard band is smaller than the perpendicular magnetic anisotropy of the magnetic material of the data track. The manufacturing method is characterized in that a nonmagnetic thin film is formed on a substrate in a region corresponding to a guard band track between data tracks, and then a Co alloy-based perpendicular magnetic anisotropic medium is formed on the thin film and the substrate.

(Sho Invention, Kaname) An overview of the present invention will be explained using figures.

FIG. 1 shows an example of the present invention, which is applied to a magnetic disk as a magnetic recording medium, and shows a sectional view thereof. A non-magnetic thin film (which reduces the perpendicular magnetic anisotropy of the perpendicular magnetic recording medium 10) as a base effect on the substrate 4 by sputtering or the like is deposited.
After forming a thin WAi of (for example, Cu, Cr, etc.), the perpendicular magnetic recording medium 10 is formed. As this medium, a Co-based alloy typified by CoCr is used. As a result, the perpendicular magnetic anisotropy of the magnetic film 10 of the guard band track 2 between the data tracks becomes small, and the recording density characteristics deteriorate.

As a result, in the high recording density working area of data track 3, even if it is recorded on the guard band due to tracking deviation, the output from this area is sufficiently small compared to the output from data track 3 and data crosstalk. Unerased noise due to tracking deviation can be suppressed.

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

(Example 1) As shown in Fig. 1, a reinforced glass substrate was used as the substrate 4 of the magnetic disk, and 200% Cu was deposited on the substrate by sputtering.
A' I sputtered. The substrate on which Cu was formed was subjected to seven-shot etching to leave a region corresponding to guard band track 2 and remove a region corresponding to data track 3.

A CoCr alloy target (C
A CoCr thin film having a thickness of 0.3 μm was formed as the perpendicular magnetic recording medium 10 by sputtering using 22 at % (r22at%).

The perpendicular magnetic anisotropy field of the CoCr film with the Cu thin film as the base was 1,5 KOε·, and the perpendicular magnetic anisotropy field Hk of the CoCr thin film of the data track without the Cu thin film as the base was 4.5 KOe. . As a result of investigating the recording density characteristics of a data track and a guard band track using a ring-type arsenic head with a gap length of 0.3 μm, it was found that the recording density D1. is 1
It was 00KFRPI.

On the other hand, on the guard band track, Dl is 30 KFR.
It was PI and the output was less than half even when converted to the same track width. Therefore, at a high recording density of 30 KPRPI or more used in data track 3, the reproduction output from the guard band track was sufficiently small compared to the output from the data track, and good off-track characteristics could be obtained.

(Example 2) Polyethylene Tele7 (PET) was used as the substrate.
) 5011 rn thick, a high magnetic permeability thin film 5 of NiFe with a thickness of 0.5 μm was formed by sputtering as shown in FIG. 2, and the Cr thin film in the area corresponding to the data track 3 was removed by photoetching.

Co Cr (Cr22at
%) film p9. by sputtering using a target. Q
The perpendicular magnetic anisotropy field Hk of the CoCr film of the rack was Q, 9 KOe, and the Hk of the CoCr film of the data track was 3.6 KOe. . This is a magnetic head with a main pole equipped with a return path (
Main pole film: Co-based amorphous alloy, film thickness 0.25 μm
) were used to examine the recording and reproducing characteristics on the data track 3 and guard band track 2, respectively. As a result, on data track 3, Dl is 150KFRPI,
On guard band track 2 it was -FRPI at 50.

Therefore, 50KFR used in data trucks
It was confirmed that at a high recording density of PI or higher, the reproduction output from the guard band was sufficiently small and good off-track characteristics were obtained.

Although Cu and Cr thin films were used as the base film for the guard band region in Example 1.2, other non-magnetic thin base films that reduce the perpendicular magnetic anisotropy of the Co-based alloy may also be used.

Furthermore, the patterning of the data track and guard band track may be performed by forming a base film using a mask instead of photoetching.

(Effects of the Invention) The present invention improves the usable recording density of the data tracks by making the perpendicular magnetic anisotropy of the magnetic material of the data tracks in a magnetic recording medium larger than the perpendicular magnetic anisotropy of the guard band tracks between the data tracks. In this case, the playback output from the guard band can be made sufficiently small, and by defining the recording track on the medium side, the margin of recording and erasing due to tracking accuracy error can be increased, and the servo margin can be greatly improved.

(Simple explanation of - side) FIG. 1.2 is a diagram showing an implementation sequence of the present invention.

l...Nonmagnetic film 2...Guard band track 3
... Data track 4 ... Substrate 5 ... High magnetic permeability thin film 10 ... Perpendicular magnetic recording register fff helmet 1 Figure I Cu i felt Cr thin film 4: Substrate 2
Guard band track 1O: Emperor Zhiman a stable word ko ne '4-A smell 3 Ti11m/playback track 5: Takamichi, 5shomuusuen

Claims (2)

[Claims] (1) A magnetic recording body characterized in that the perpendicular magnetic anisotropy of the magnetic film of the guard band track between the data tracks is smaller than the perpendicular magnetic anisotropy of the magnetic film of the data track. (2) A nonmagnetic thin film is formed in a region corresponding to a guard band track between data tracks on a substrate, and a Co alloy-based perpendicular magnetic anisotropic medium is then formed on the thin film and the substrate. A method for manufacturing a magnetic recording medium.