JPS6021509A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve magnetic characteristics of a magnetic recording medium for a vertical magnetic recording system by a method wherein the 1st magnetic material thin film formed on a surface of a supporting material is composed of a Co-Hf-W 3-component amorhpous alloy. CONSTITUTION:The 1st magnetic material thin film 2 is formed on a surface of a supporting material 1 made of a synthetic resin such as polyester or a polyimide or an anode-oxidized aluminum plate or the like by sputtering of a Co- Hf-W 3-pomponent amorphous alloy which contains 1-5 atomic % of Hf and 5-12 atomic % of W. Then the 2nd magnetic material thin film 3 is formed on the surface of the 1st magnetic material thin film 2 by sputting of a Co-Cr 2- component alloy which contains cobalt as a main component and a small amount of crome. The amorphous alloy of the 1st magnetic material thin film thus formed has a low coercive force and a permeability and high saturate flux density and an excellent magnetic anisotropy. Therefore, a magnetic recording medium with excellent recording and regenerating characteristics can be obtained and the 2nd magnetic material thin film can be made as thin as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fiber-based recording medium, and more particularly to a magnetic recording medium capable of perpendicular magnetic recording.

In recent years, magnetic il+! To increase the recording density of recording media.

The perpendicular magnetic recording system is being tested. The magnetic field used in this recording method is tl! +! The recording body includes a base material, a first magnetic material film formed on the surface of the base material, and a second magnetic material thin film formed on the surface of the first magnetic material thin film. This second magnetic +A thin 11
Desired data is recorded by being magnetized in the film thickness direction of g, that is, in the perpendicular direction.

The first magnetic material g1+* has a role of forming part of a magnetic path when magnetizing the second magnetic material thin film, and has a low coercive force and high magnetic permeability and saturation magnetic flux severity. This is required. On the other hand, the second magnetic material thin film,
In this case, it is required to have anisotropy especially in the vertical direction.
In order to meet this demand, thin films of cobalt-chromium based alloys such as 1--chrome t1 binary alloy for cobalt, or 3j-branch type imakane which is added with rosium l-x l' and any third metal are available. There is.

In conventional magnetic recording media of this type, permalloy made of an iron-nickel alloy is used as the first magnetic 4A thin film. On the contrary, this material does not have sufficiently high magnetic permeability and saturation magnetic flux density, and is not compatible with the second magnetic material thin film made of the cobalt-chromium alloy in terms of magnetic properties. In other words, on top of the first magnetic material thin film made of Barmaro, A, which has a crystal structure or face-centered cubic system,
- When a second magnetic material thin film of a chromium-based alloy is formed, it is affected by the permalloy thin film that is the underlying layer (particularly due to the thinness of the second magnetic +4 thin film), and the "Partau chromium-based alloy" The crystalline structure of the thin film becomes a regular hexagonal system. Therefore, the excellent perpendicular anisotropy, which is a feature of the chromium-copper 1-based alloy, is not sufficiently developed. In this way, permalloy is not compatible with cobalt-chromium alloys in terms of magnetic properties, and as mentioned above, its magnetic permeability and saturation magnetic flux density are not high enough. 1. J-PAL 1~-- Even if a second magnetic film made of a l-based alloy was used, it had the drawback that its characteristics could not be fully exhibited.

The object of the present invention is to overcome the drawbacks of the prior art and to improve the magnetic properties of a magnetic recording medium.

According to the present invention H61, as a result of various studies on thin films obtained by sputtering etc., it was found that cobalt (C,o) was used as the main component, and a small amount of hafnium (moonf) and tantasten CW) was used as a power source). 1 (
: o -)1 f -W c71 : A ternary amorphous alloy is used as the first magnetic material thin film of this type of magnetic R+4ttJr medium and has excellent characteristics. ．． Being &
One color.

Used for crystallized glass as a substrate, disk for ``Bazuki'' (diameter 1111.fimm, JW a !-+nuII)
l-IC Huff 1- Ram (L/T to h)
II. The alloy composition can be changed by adjusting the number of pellets (width: 10 mm, thickness: 1 mm) radially radially from the center. .Then, the vacuum before changing to argon was reduced to a high vacuum of less than 6 Torr, and sputtering was performed on the substrate in an atmosphere of argon with a high frequency power of 2 W/cIn2. G o -1 (f - W ternary amorphous Q-, with cobalt as the main component)
f, 1 (vI film is created. Alloy samples of various compositions created in this way are used for each characteristic test described below.

FIG. 1 is a magnetic characteristic diagram when the t(f content X is variously changed while the W content Y in the alloy is always 7.0 atomic % in the alloy composition table described later.

In the figure, the curve Rs is the saturation magnetic flux density 9 curve μe.
is the magnetic permeability 9 curve H in the hard axis direction at the frequency IMHz
c is the coercive force in the hard axis direction. As is clear from this figure, the Co-W2+rQ6) alloy with an Hf content of 0 atomic %4- has high T3s but too high HC and low μ(I. When a small amount is added, Hc decreases extremely and /Z 6 increases.

Incidentally, when the content of Ll and f reaches a certain point or more.

μθ becomes lower. On the other hand, F3 g is not extreme but Hf
tends to decrease as the content increases.

Amidst these characteristic trends, Bs is kept high and ](c
In order to lower the I-(f content X
It is necessary to control the content to a range of 1 atomic % or more, preferably less than 5 atomic %, and 5□-3 atomic %. This holds true even if the W# percentage Y is slightly changed. .

FIG. 2 is a magnetic characteristic diagram when the W content y is varied while the Hf content X in the alloy is always 2.2 H% in the alloy composition table.

As is clear from this figure, Co with a W content of 0 at%
-Hf binary alloy also has high BS, but He is too high and μe is low. By adding a small amount of W to this, the value -1c is extremely reduced, and the value 11~/le becomes extremely high. Note that when the W content exceeds a certain level, μe decreases. On the other hand, Bs tends to decrease as the W content increases, although this is not extreme.

Given these characteristic trends, in order to maintain high Bs, lower He, and achieve high μe, the W content Y should be increased from 5 to 12
It is necessary to limit the content to atomic %, preferably within the range of 6 to 8 atomic %. This holds true even if the 1-1f content X is slightly changed.

FIG. 3 shows a magnetic recording medium according to an embodiment of the present invention.
FIG. On the surface of a base material 1 made of synthetic resin such as polyester, polyimide, or anodized aluminum plate, the Co content is 90.8 at%, the Hf content is 2.2 at%, and the W content is 7. A ternary amorphous alloy thin film of Co-Hf-W having a concentration of .0 atomic % is formed by sputtering to form the first magnetic material thin film 2. Next, on the surface of this first magnetic material thin film 2, a binary alloy thin film of Go-Cr containing cobalt as the main component (with a small amount of chromium added thereto) is formed by sputtering. Then, a second magnetic material thin film 3 is obtained.

This magnetic 11.1 IFJ ;shi 3 (/11ff/
The i thickness of both is about 0°3μ river r47N+ , , -
Jl, j', 1 group 4 (1st magnetic material thin film 2nd 2nd
A tape-shaped or disk-shaped magnetic recording medium is constructed from the magnetic thin film 3. The magnetic t (1 side 2,
31: There is also a dυJ filter match on both sides of tM, 1-t1.

, Second magnetic%T, K11! When the recording medium is attached, the main magnetic pole 5 and the auxiliary magnetic pole 1 are arranged.
Well, there's -c. The main pole 5 has a thickness of about 1 horn 711"
1+ C, glass, polyimide resin tc, etc.
A non-magnetic #1 substrate 4” is formed by sputtering 9! ! , take. The auxiliary magnetic pole 6 is wound with coils and coils 7 having a predetermined number of turns. This:1-(When the main magnetic pole 5 is excited from the auxiliary magnetic pole 6 side by flowing the signal I41 flow to be recorded in Lua, a strong ili
;i! A magnetic field is generated. By this, the tip r of the magnet 5
Magnet 11 and thin material film 2 near IF. j3 is thickness t7 direction 1.
Data is recorded on the magnetic 44 thin 1 model 3 of the second magnetic material 44. The first magnetic material thin film 2 is used when magnetically recording data on the second magnetic material thin film 3 , which serves to form part of the magnetic path.

As described above, the present invention includes a base material, a first magnetic thin film formed on the surface of the base material, and a second magnetic material thin film formed on the surface of the first magnetic material thin film and having perpendicular anisotropy. a magnetic recording medium in which the second magnetic material thin film is magnetized in the film thickness direction, wherein the first magnetic material thin film contains cobal as a main component and a small amount of zirconium. Consisting of a three-component amorphous alloy with niobium added, the hafnium content in the alloy is 1 atomic % or more and less than 5 atomic %, and the tungsten content is 5 atomic % or more]: 12 atoms % or less.

The above-mentioned amorphous alloy has a low coercive force, high magnetic permeability and saturation magnetic flux density, and its magnetic properties are very similar to those of the cobalt-chromium alloy, which has the excellent magnetic difference of the cobalt-chromium alloy. Directionality can be demonstrated as is. Therefore, it has excellent recording and reproducing characteristics, and the second magnetic material thin film can be made as thin as possible.

9- 18・

[Brief explanation of the drawing]

Figure 1 shows the relationship between the Hf Nff ratio and various magnetic properties in the CQ-Hf-W amorphous alloy according to the present invention. FIG. 3 is an explanatory diagram for explaining the magnetic recording medium according to the embodiment of the present invention). DESCRIPTION OF SYMBOLS 1... Base material, 2... 1st magnetic material thin film, 3... 2nd magnetic material thin film. 10- Figure 1 Figure 2

Claims (1)

[Claims] rl)! l111. J, that J+! The first 1tlN-th(iil) film formed on the surface of i 4() and the first magnetic material thin film formed on the surface of
In a magnetic recording medium in which the second magnetic material thin film is magnetized in the film thickness direction, the first magnetic material thin film is magnetized in the film thickness direction. It is a 3-component system consisting of 21 baltic acid 2) and a small amount of half chive 11 and 9) stainless steel.
The afT ratio of 1 is 11 atomic % or more and less than 5 atomic %, and the tannos content is 5 atomic % or more.
!ノIrl I'-') f1 or more;
Especially when it comes to magnetic recording media. (2.C1 in claim 5(1))
4. A magnetic recording medium characterized in that said second magnetic) (thin one layer) is composed of a thin film of an alloy based on the metal and black metals.