JPS6326819A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium having good durability by forming a diamond-like hard carbon film on a thin ferromagnetic metallic film which consists of a Co-base ferromagnetic alloy and is surface-segregated with Ti or B. CONSTITUTION:A thin 'Permally(R)' film 2 is formed to 0.42mum thickness by a high-frequency sputtering method on a high-polymer film 1 consisting of PE terephthalate having 25mum thickness. A perpendicularly magnetized film 3 consisting of Co-Cr-B (Cr=19wt%, B=3.5wt%) is formed on the thin film by the high-frequency sputtering method in such a manner that the Cr and B segregate on the surface. The diamond-like hard carbon film 4 is further formed to 60Angstrom thickness on the film 3 by a sputtering method using graphite as a target and gaseous H2 as a sputtering gas. A lubricating agent layer 5 consisting of a perfluorobehenic is formed to 40Angstrom thickness on the film 4 by a vacuum deposition method.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium suitable for high-density magnetic recording.

Conventional technology Regarding magnetic recording media, the use of ferromagnetic metal thin films has been actively studied in various fields to promote high-density recording in all forms of magnetic disks, such as hard disks, floppy disks, and magnetic tapes. ing. Recently, in order to put such magnetic recording media into practical use, understanding of tribology has progressed, and the structure of the magnetic recording layer with excellent wear resistance has been developed.
It is becoming important to realize the system with a small spacing loss. [For example, foreign journals: IKKE TRANSACTIONS ON MAGNETICS
GNETIC3) volume MAG-21, No.
, 5 P, P, 1533-1535 As ferromagnetic metal thin films, Go-Or sputtered films, Go-Ni-P plated films, Go-Ni-0 obliquely deposited films, etc. are well known. In order to protect these films, a method of reducing the actual contact area with the magnetic head or a method of covering the film with a retention film in combination with a lubricant has been studied, and many proposals have been made. [9th Japanese Society of Applied Magnetics Academic Lecture Abstracts 2saA-11 (
1985, 11), Japanese Patent Application Laid-Open No. 59-92428.

JP-A-58-102330, JP-A-58-6042
However, the above-mentioned structure cannot be used under limited conditions as a magnetic tape, such as using a ferrite head and lowering the tension. However, in order to obtain C8S characteristics for hard disks and durability for floppy disks, the thickness of the reinforcing film must be 300 mm.
Å or more is required, and spacing loss becomes a problem, and improvement is desired.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a magnetic recording medium with improved practical reliability in high-density packing using an alloy head.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention is a CO-based ferromagnetic alloy in which diamond-like hard carbon is coated on a ferromagnetic metal thin film in which titanium or boron is polarized on the surface. A removal membrane (hereinafter referred to as L and C membranes) is provided.

Function The magnetic recording medium of the present invention has the above-described structure, so that the surface of the CO-based ferromagnetic alloy thin film is hardened by Tic or BC, and at the same time, the n, r, . However, since the protective effect is stronger, the durability is improved and the spacing loss can be reduced.

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

FIG. 1 is an enlarged cross-sectional view of the first magnetic recording medium of the present invention.
2 is a polymer film made of polyethylene terephthalate film with a thickness of 26 μm, and 2 is a permalloy thin film formed by high frequency sputtering method, and the film thickness is 0.42 μm. 3 is 0.2μ formed by high frequency sputtering method.
m Go-Or-B (Cr: 19wt%, B: 3
．． 5wt%) perpendicularly magnetized film, the can temperature was set to 160°C, and B was surface polarized at the same time as cr. 4
A 60 mm thick film was formed using a sputtering method using H2 gas as a sputtering gas using graphite as a target.

In the L and C films, 6 is a lubricant layer of perfluorobehenic acid formed by vacuum deposition.

When short wavelength recording and reproduction with a bit length of 0.2 μm was performed on a 3.5-inch floppy disk with such a configuration using a layered amorphous alloy, the output after 42 million passes was 0.6 (compared to the initial value). dB), but the error rate was 1.9 times the initial value, showing stable performance.

For comparison, Co-Cr (Cr: 20.5wt
%) How many people compared the same configuration except for the sputtered film.

Comparative Example B, in which 300 D, L, G films were applied on the Go-Or film, was compared with that of this example.

In comparison, the initial values of output and error rate were the same as those of this example, but the durability was poor, and the output decreased by 4.6 (dB) after 3.4 million passes, at which point the error rate decreased. has increased 34 times. Comparative example B has an initial output of 7.0 compared to this example. The sdB is low, the error rate is 73 times high, and the electromagnetic conversion characteristics are not practical, but the output stability is still worse than this example, with an output drop of 1.3 (dB) and an error in 34 million passes. The rate increase was 4.2 times.

FIG. 2 is an enlarged cross-sectional view of a magnetic recording medium according to a second embodiment of the present invention, in which 6 is a polymer film made of a polyimide film with a thickness of 10 μm, and 7 is a titania fine particle with an average particle size of 120 particles/cyA. This is a fine particle coating layer fixed with polyimide resin at a ratio of . 8 is 0, which was obliquely deposited along a cylindrical cap with a diameter of 50α at a minimum incident angle of 62 degrees.
A 16μm Co-Ni-Ti film lowers the can temperature to 140℃.
°C to cause surface polarization of B. In addition, Co in wt%:
Ni:Ti=76.5:19:4.5.

9 is formed by high frequency sputtering method or is made of L and C films with a thickness of 50 mm.

1o is a perfluorope/tadecylic acid lubricant layer formed by vacuum deposition. This was made into an 8-panel-wide magnetic tape and recorded and played back repeatedly on 8mm video. In a comparative example, a deposited film of Co:N1=80:20 was used as a co-Ni-Ti
It has been replaced with .

As a result of measuring the playback output in a still state at -5°C and 40°C 990% R1, there was no change in the output in the example of the present invention even after 60 minutes in each environment. An example is 1.0 at -6°C for 6 minutes at 40°C and 99o% RH.
The output dropped by 4dB in 6 minutes.

The head is a composite ring head with Sendust alloy sputtered in the gap.

In addition to those used as the polymer film in the above embodiments, polyethylene naphthalate, polyphelene sulfide, polyamideimide, etc. may also be used.

Other particle forming materials used for the fine particle coating layer include carbon, silica, CaCo, and Ba5o. Polyester, polymer latex, etc. are used.

Other ferromagnetic metal thin films include Go-B and Go-Ti.

Go-Ce-B, Go-Pr-Ti, Go-R
Ti and B must be surface polarized in h-B and the like.

The D, L, and C films may be formed by other methods such as ion beam deposition, ion blating, and electric field deposition.

The lubricant may be appropriately selected from fatty acids, fatty acid esters, fatty acid amides, fluorine compounds, etc., and may be used in combination with the plasma polymerized film.

Effects of the Invention As described above, according to the present invention, an excellent effect can be obtained in that a magnetic recording medium with good practical durability can be obtained while reducing spacing loss, which is a large loss in short wavelength recording and reproduction. .

[Brief explanation of drawings]

FIGS. 1 and 2 are enlarged cross-sectional views of magnetic recording media according to embodiments of the present invention, respectively. 1.6...Polymer film, 3...Go
-Or-B perpendicular magnetization film, 4, 9...D, L, C
Film, 8... Co-Ni-Ti film, 5, 10.
・-=lubricant layer.

Claims (1)

[Claims] A magnetic recording medium comprising a Co-based ferromagnetic alloy and a diamond-shaped hard carbon coating disposed on a ferromagnetic metal thin film in which titanium or boron is polarized on the surface.