JPS618719A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the titled recording medium suitable for high-density recording and to improve the S/N by composing the soft magnetic layer and the vertical magnetic film of the same element. CONSTITUTION:A high molecular substrate, a soft magnetic layer, a vertical magnetic film, and a protective film are shown in order by the figures 1, 2, 3, and 4. The soft magnetic layer 2 and the vertical magnetic film 3 are composed of the same element. The diameter of a cleaning can 5 is regulated to 50cm, and Co is arranged directly under the can. Cr is arranged at the center g3 which is situated at 10cm distance from g1 in the moving direction of the substrate. The opening part I 13 of a mask 12 has 7.5cm opening width in the moving direction o the substrate with g1 as the center. The opening part II14 has a center axis g2 at 8.5cm distance from g1 in the direction revers to the moving direction, and the opening width is regulated to 4.5cm. The vaporization source is situated 30cm below the can. A binary vaporization source, a vapor-deposition material A, and a vapor deposition material B are shown in order by the figures 9, 10, and 11. Since the soft magnetic layer 2 and the vertical magnetic film 3 are composed of the same element, the medium has the satisfactory S/N and is suitable for high-density recording.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium whose magnetic recording layer is a ferromagnetic thin film suitable for short wavelength recording.

BACKGROUND ART In recent years, magnetic recording media in which a so-called perpendicular magnetization film, which can be magnetized in the perpendicular direction of a substrate, is used as a magnetic recording layer have attracted attention as a medium with excellent short wavelength recording characteristics.

The most promising technology in terms of recording density is a so-called 2-layer structure consisting of an auxiliary pole excitation type perpendicular head, a soft magnetic layer typified by Ni-Fe, and a perpendicular magnetization film typified by a Co-Cr sputtered film. Although it is thought to be a combination of layered media, in practice, including the use of ring-shaped heads, the so-called signal-to-noise (hereinafter referred to as S/N) ratio is important, and narrower tracks and shorter wavelengths are important. The reality is that the limits of magnetic recording are rather limited by noise, and improvements in magnetic recording media in this respect are desired.

OBJECTS OF THE INVENTION The present invention was made in view of the above circumstances, and it is an object of the present invention to provide a perpendicular recording medium with an improved S/N ratio.

Structure of the Invention The magnetic recording medium of the present invention is characterized in that the soft magnetic layer and the perpendicular magnetization film are composed of the same element, and has a good S/N ratio and is suitable for high-density recording.

Description of examples The present invention will be described below with reference to the drawings.

FIG. 1 is an enlarged cross-sectional view of the magnetic recording medium of the present invention, and FIG. 2 is a configuration diagram of the main parts of a winding vapor deposition machine used for manufacturing the magnetic recording medium of the present invention.

In FIG. 1, 1 is a polymer substrate, 2 is a soft magnetic layer, 3 is a perpendicular magnetization film, and 2 and 3 are characterized in that the constituent elements are the same. 4 is a protective film.

In Figure 2, 6 is a cooling can, 6 is a substrate 7 is a feeding shaft, 8 is a winding shaft, 9 is a binary evaporation source, 1o is a vapor deposition material A111 is a vapor deposition material B, and 12 is a mask. , 13
The opening 1114 is the opening ■.

Polymer substrates that can be used in the present invention include polyesters such as polyethylene terephthalate.

Polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and nitrocellulose,
polyamide, polyamideimide, polyparapanic acid,
Examples include polyimide.

The elements constituting the soft magnetic layer and perpendicular magnetization film used in the present invention are Co-Cr, Co-Ni-Cr,
Co-W,C.

-Mo, Co-Ti, Co-Ru, Co-V
, Co-P, Co-0°Co-Ni-0, etc.

The method for forming the soft magnetic layer and the perpendicular magnetization film may be based on electron beam evaporation, sputtering, electroless plating, etc., and may be modified as appropriate.

The reason why a magnetic recording medium with low noise can be obtained by the configuration of the present invention is that although the ratio of elements is slightly different, there is no distortion of the crystal due to the self-epitaxy effect, so it is not possible to simply analyze the crystal orientation using X-ray diffraction. , cannot be clearly distinguished, but this is thought to be due to its excellent microscopic uniformity.

Hereinafter, one embodiment will be described in more detail.

EXAMPLE The present invention was carried out in a CO-Cr system using the apparatus shown in FIG.

In Figure 2, the diameter of the cooling can 6 is 6ocm, the Cof is placed directly below, and the center q3 position is 1o on the moving side of the board.
Cr f was placed where crt1mf was placed. The aperture 113 of the mask 12 has an aperture width of 6 cm with respect to the direction of movement of the substrate centered at ql, and the aperture 14 has a center axis 92 at 8.5 crn in the opposite direction to the movement direction from ql; The opening width was 4.5 cm.

The evaporation source was 30 crrL below the can.

The characteristics of the soft magnetic layer were measured by forming only the soft magnetic layer (deposited with the opening 1 closed).

The substrate used was polyimide with a thickness of 14 μm, which was deposited by varying the surface temperature of the can. Furthermore, the ratio of CO and Cr was controlled by changing the electron beam irradiation conditions.

Comparative examples include Ni-Fe (Ni 80wt%), Co-
The material used was one in which Cr (Cr20 wt%) was laminated by a high frequency sputtering method.

The main pole of the present invention and comparative example is a CO-based amorphous alloy (width 0.2
Recording and reproduction were performed using an auxiliary magnetic pole excitation type perpendicular head using an auxiliary magnetic pole (μm), and the reproduction S/N (5) was evaluated.

A comparison of manufacturing conditions, analysis results, and S/H is shown in Table 1.

Note that the S/N is track width 5 μm and recording wavelength 0.3 μm.
A relative comparison was made using the value of the medium as ○I:dB).

As is clear from the results shown in the margin below, it can be seen that the S/N ratio is improved even though the characteristics of the perpendicularly magnetized film are almost the same as those of the conventional product.

As an embodiment of the pond of the present invention, the other combinations of materials described above similarly reduce noise and result in S/N.
I am sure that I can improve.

Furthermore, since the magnetic recording medium of the present invention has the same elemental composition, it is resistant to corrosion due to electrochemical reasons like a normal structure, even though it has a laminated structure, and from this point of view, it is also practical. It is characteristic.

Effects of the Invention In the magnetic recording medium of the present invention, since the soft magnetic layer and the perpendicular magnetization film have the same element composition, the crystallinity is improved and the microscopically uniformity is improved, and noise is suppressed. It has excellent S/Ni in density recording and reproduction, and its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the magnetic recording medium of the present invention, and FIG. 2 is a diagram showing the main part of a vapor deposition apparatus used for manufacturing the magnetic recording medium of the present invention. DESCRIPTION OF SYMBOLS 1...Polymer substrate, 2...Soft magnetic layer, 3-Perpendicular magnetization film, 6... Cooling can, 9... Binary evaporation source.

Claims (1)

[Claims] A magnetic recording medium characterized in that a soft magnetic layer and a perpendicular magnetization film are composed of the same element.