JPH01125719A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve a C/N characteristic at a short wavelength by disposing a thin hard-carbon film on a thin ferromagnetic metallic film and fluorinating a part of the thin hard-carbon film. CONSTITUTION:The thin hard-carbon film 4 is disposed on the thin ferromagnetic metallic film 3 and a part of this thin hard-carbon film 4 is subjected to a fluorination treatment. The treatment area ratio is preferably confined to 10% to 30% of the entire part to obtain the balance between the hardness and slipperiness of the thin hard-carbon film in the case of the fluorination treatment. The thin hard-carbon film is thereby provided with the slipperiness and is reduced in the overall thickness; therefore, the spacing loss relating largely with the short-wavelength output is decreased and the C/N is improved.

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 metal thin film suitable for high-density magnetic recording and reproduction.

Conventional technology The so-called coated magnetic layer, which has been widely used as a magnetic recording layer, has achieved a significant increase in output by switching the fine particles responsible for magnetism from iron oxide to pure iron.
．． A recording wavelength close to 7 μm has been put into practical use. However, in the future, in magnetic recording where the wavelength of the layer becomes shorter, it will become difficult to obtain the necessary C/N.
O-Ni.

The practical application of magnetic recording media using ferromagnetic metal thin films such as Qo-Ni-0 is expected.
EEK TRANSACTIONS ONMAGN
KTIC8) Vol, MAG-21, No-5.

p, p, 1217-1220 (1 eats)].

In order to put magnetic recording media with such a configuration into practical use, it is essential to ensure durability, especially during high-speed sliding with alloy-based magnetic heads, and many improvements have been proposed from this point of view [for example, Publication No. 53-88704, No. 59-1216
Publication No. 31, Publication No. 69-171026, Publication No. 62-1
See Publication No. 97917, etc.]. Among them, the method of forming fine irregularities on the magnetic recording layer is attracting a lot of attention for its durability improvement effect [IEE Transactions on Magnetics (IICICICTRMN5ACTI)]
ONSON MAGNRTIC8) Vol, MAG-
21°No-5, p, p, 1524-1526 (198
See 5)].

Problems to be Solved by the Invention However, there is a problem of unevenness on polymer films! 205+
Electron beam evaporation is applied on top of a fine particle coating layer in which fine particles such as CaCO3 and polyester spheres are coated and fixed.

In magnetic recording media in which a ferromagnetic metal thin film is deposited by a method such as sputtering or ion blasting, and a conventionally known protective lubricant layer is deposited, the C/H decreases significantly when the recording wavelength is about 0.5 μm or less. Improvement was desired.

The present invention was made in view of the above circumstances, and provides a magnetic recording medium with a good C/N ratio even at short wavelengths.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention has a hard carbon thin film arranged on a ferromagnetic metal thin film, and a part of the hard carbon thin film is fluorinated. be.

Function: Due to the above-described structure of the magnetic recording medium of the present invention, the hard carbon thin film obtains slipperiness9, and the total thickness can be reduced, so the spacing loss, which is largely related to short wavelength output, can be reduced and the O/N can be reduced. It can be improved.

EXAMPLE Hereinafter, a magnetic recording medium according to an example of the present invention will be described in detail with reference to the drawings. The figure is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In the figure, 1 is polyethylene terephthalate.

2 is a polymer film such as polyethylene naphthalate, polyphenylene sulfide, polyimide, etc.
．． BaH3O4, CaO, Ca005. Xu205°T
3 is a fine particle coating layer in which fine particles such as iO2+, 05, etc. are coated and fixed, and 3 is Co-H'h, C3o-0, Co-
0r, Co-B.

Co-B1. Go-V, Go-W, Co-Mo, Co-
Mi-0゜Oo-Or-Rh, Co-Or
- Electron beam evaporation method, ion blating with ferromagnetic metal thin film such as Nb.

It is formed by a manufacturing method such as sputtering, and 4 is a hard carbon thin film, which is obtained by sputtering using graphite as a target or by using discharge decomposition of a hydrocarbon gas. 6 is a fluoridation treatment part for improving slipperiness by fluoridation treatment by implanting y ions or by masking and glow discharge treatment with a gas containing y; the area ratio is 10 30 from chi
It is preferable to take into consideration the hardness and slipperiness of the hard carbon thin film. 6 is a lubricant layer made of fatty acid, fatty acid amide, perfluorocarboxylic acid, perfluorosulfonic acid, etc. .

With the above configuration, the required 4
The size effectively related to the spacing of the thickness of and 6 can be reduced from 60 people to 16.0 people in total, which is effective for improving O/H at short wavelengths.

Hereinafter, one embodiment of the present invention will be described in more detail in comparison with a comparative example.

16 pieces/(μm1) of 1205 particles with a diameter of 100 mm on a 12 μm thick polyethylene terephthalate film.
I) Co-N1 (Co: 5 ovt%) was irradiated with an electron beam along a cylindrical can with a diameter of 1 m at a minimum incident angle of 50 degrees in oxygen at s x 1o-5 (Torr). evaporate to form a 0.13 μm Go-14-0 film,
Furthermore, target Graffito, Mr + H2 = o,
os(Torr), mr:H2==1:3.

By glow discharge of 13.5 s (MHz) and 1.1 (Kw), 70 diamond-shaped hard carbon thin films were formed, and one ion of 130 (Key) was generated at 30 μm/
Ca was injected, and a circular portion of approximately 400 μm was fluorinated using a beam with a spot diameter of 120 μm, and the treatment area ratio was 15% of the whole. Perfluorostearic acid was deposited thereon by 40 people using a vacuum deposition method to form a magnetic tape with a width of 8 mm. On the other hand, Comparative Example B has 70 hard carbon thin films and 40 perfluorostearic acid, and Comparative Example B has 150 hard carbon thin films and 80 perfluorostearic acid, each prepared as an 8 mm wide magnetic tape. did.

Each tape was modified into an 8mm video and the C/N and durability were compared. An amorphous alloy sputter stacking head with a gap length of 0.2 μm increases the carrier frequency to 7.6 (
MHz), and the O/N of band 1o (MHz) was evaluated. Example and Comparative Example B is 2.7 (
dB) showed good 07M.

The initial dynamic friction coefficient was 0.22 for the example and 0 for the comparative example.
．． 24, Comparative Example B is 0.23 and 1 at 40°C and 10% RH.
The values after 60 runs were 0.26 and 0.49, respectively.

o, it was 28. The still characteristics are 2(d) from the initial output.
B) In terms of time until the output decreases, the example is 66
The comparison personal test time was 19 minutes, and the comparative example B was 69 minutes, which is considered to indicate the excellent head compatibility of the example. From the above results, it can be seen that the example can be made thinner than the conventional protective film and can improve cA.

In addition, even if it is a Co-0r perpendicular magnetization film, the hard carbon thin film 1
It has been confirmed that the protective effect is sufficient in oO people.

Effects of the Invention As described above, according to the present invention, there is an excellent effect that a magnetic recording medium with a good C/N ratio in a short wavelength region can be obtained.

[Brief explanation of the drawing]

The figure is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. 1...Polymer film, 2...Fine particle coating layer, 3...Ferromagnetic metal thin film, 4...
・Hard carbon thin film, 6...Fluoride treatment part.

Claims (1)

[Claims] A magnetic recording medium characterized in that a hard carbon thin film is disposed on a ferromagnetic metal thin film, and a portion of the hard carbon thin film is fluorinated.