JPH02116018A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the magnetic recording medium for a perpendicular magnetic recording which is improved in both durability and C/N by forming a perpendicularly magnetized Co alloy film having projections formed of fine planar particles as a magnetic recording layer. CONSTITUTION:The perpendicularly magnetized Co alloy film 3 having the projections formed of the pulverized fine planar particles by an evaporation method of Cr, Mo, Ta, W, Cs, Rb, Ba, etc., in a vacuum is formed as the magnetic recording layer. Co-Cr, Co-Tf, Co-W, Co-Mo, Co-Cr-Nb, etc., are used as the magnetized film 3. The disturbance in crystal orientability by the fine particles 2 is, therefore, lowered to a negligible level and the difference in C/N from the smooth surface can be decreased even if the higher density is promoted. On the other hand, the true contact area can be drastically decreased and, therefore, the eventual improvement in the durability is resulted. The perpendicular magnetic recording medium which is improved in the C/N and the durability with good balance is obtd. in this way.

Description

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

BACKGROUND ART Perpendicular magnetic recording is expected to become a recording technology that can realize information exchange in a bit area of 1 μm×1 μm in the future because the higher the density, the smaller the loss. However, from a practical point of view, there are still problems to be solved, such as the problem of partial destruction and damage to the magnetic recording medium when the head slides. Currently, research on perpendicularly magnetized films such as Co-Cr is being carried out mainly using sputtering methods, and attempts are being made to improve them by changing film-forming conditions [Proceedings of the 29th Spring Conference of the Japan Society of Lubricants, p. 377 (1985)]
:] Various protective films [Japan Society of Applied Magnetics.

46th Research Meeting, p. 46-7.57 (1986)), confirmation of the effectiveness of reducing protrusions by examining surface properties [Magnetic Recording Research Group Materials MR87-46, p. 9 (19B?)], and C.
In the o-Cr vapor deposited film, improvement by post-oxidation has been reported [Magnetic Recording Research Group material MR5s-11 (1988) E, etc.].

Problems to be Solved by the Invention However, the above configuration is not sufficient to achieve the required durability, and it has been reported that it is effective to arrange fine particles on the film surface to reduce the actual contact area. , frictional resistance and still durability have been improved [JP-A-59-121631, JP-A-6
No. 1-16020], when trying to advance perpendicular magnetic recording to a higher density area, /N was poor, and durability and c/N
It was hoped that improvements would be made in the face of problems such as not being able to satisfy both of the following.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a magnetic recording medium for perpendicular magnetic recording that has improved both durability and c/N.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention comprises:
C having protrusions formed by plate-like fine particles.

The magnetic recording layer is a perpendicularly magnetized alloy film.

Effect The magnetic recording medium of the present invention has the above-described configuration, so that disturbances in crystal orientation due to fine particles can be ignored, and c/
Although the difference between N and a smooth surface can be reduced even if the density is increased, the actual contact area can be significantly reduced in terms of durability.
This means that you will be able to improve your skills.

EXAMPLE Hereinafter, an example of the present invention will be described 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 smooth polyethylene terephthalate, polyphenylene sulfide, polyethylene naphthalate, polyether ether ketone, polysal 7
Preferably, the film is a polymer film made of polyester, polyether sulfon, polyamide, polyimide, etc., and has an average roughness of 6 to 50 grains and a maximum roughness of 30 to 10 grains. 2 is a tabular fine particle, which is Cr, Mo, Ta, W,
Among the fine particles made of Cs, Rb, Ba, etc. by evaporation method, the thickness is 80 to 160 mm, and the effective size (defined as equivalent to the diameter when considered as a circle) is 300 to 300 mm.
Choose from about 800 (people), 0.6 to 2
It is desirable that the voltage be within the range of 0V (μm)2. 3 is Co-0r.

Go-Ti, Co-W, Co-Mo,
Non-direct magnetized materials such as Co-Cr-Nb are formed by sputtering, electron beam evaporation, ion blating, ion beam deposition, etc.
It is preferable that the number of people is 1000 to 3000, and it goes without saying that a stacked structure may be used. 4 is a protective lubricant layer, which is a layer of a so-called protective film such as a 5lo2 film, a BN film, a carbon film, or a plasma polymerized film, and a so-called lubricant such as a perfluoroalkyl polyether, a fatty acid, a fatty acid amide, or an organic compound containing phosphoric acid. The design must be designed to provide the required lubricity and durability without increasing the thickness in terms of pacing loss. The present invention can be implemented not only with disk tapes.

Examples of the present invention will be described in more detail below in comparison with comparative examples.

[Example-1] On a polyethylene naphthalate film with a thickness of 10 μm and an average roughness of 30 people and a maximum roughness of 60 people, Nb obtained by an evaporation method was applied.
Fine particles [flat plate-like, 100 mm thick.

Co-Cr-Nb(
Co:Cr:Nb=79:15:6 wt%) 1,900 perpendicularly magnetized films were arranged, and perfluoropolyether 6-Fonpurine 2-26” manufactured by Montefluos was applied as a trifluoro-emolene solution on top of the perpendicularly magnetized film and dried. Approximately 80 people formed a lubricant layer and processed it into an 8 mm wide magnetic tape.

[Example 2] Or fine particles obtained by evaporation of Nb fine particles [thickness 8 on a flat plate]
6 pieces/Cpm)
A Co--Cr (Cr: 20 wt%) perpendicularly magnetized film was formed thereon by high-frequency sputtering, and the same lubricant was applied to obtain an 8 mm tape.

[Example-3] V fine particles obtained by the evaporation method of Nb fine particles in Example-1 [flat plate shape, thickness 130 mm2 equivalent circular diameter 330 mm (hexagonal and quadrilateral mixed at approximately 1:1 ratio)] were heated to 1oV. (μm) and Co-Cr-W-V (Co:
Cr:W:V=77:15:3:swt
%) A perpendicularly magnetized film of 200 mm was placed, and the other 8 mm tapes were the same.

[Comparative Examples-1 to 3] Corresponding to the examples, fine particles were made into spherical S with a diameter of 160 people.
16 i02 particles/(μm)2. Polyethylene terephthalate film with a thickness of 10 μm (average roughness of 26 people,
Co-Cr-Nb, respectively
Co-Cr, Co-0r-W-V perpendicular magnetization film.

7 Ombrine Z-26 was arranged and processed into a tape with a width of 8 mm.

Nine 8mm videos modified from the above-mentioned tapes were compared and evaluated. A metal-in-gap amorphous head with a gap length of 0.12 μm records a rectangular wave signal with a track pitch of 10 μm and a bit length of 0.2 μm.
) c/N (dB) and repeated playback of each environment, 1
The c/N of the 00th pass and the results of examining the presence or absence of jitter are summarized in a table.

Effects of the Invention As described above, the present invention has the excellent effect of providing a perpendicular magnetic recording medium with improved c/N and durability in a well-balanced manner.

[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...Tabular fine particles, 3...Perpendicular magnetization film.

Claims (1)

[Claims] A magnetic recording medium comprising a Co-based alloy perpendicularly magnetized film having protrusions formed by plate-like fine particles.