JPH01287818A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the magnetic recording medium for perpendicular magnetic recording which is improved in wide band C/N by laminating a thin diamond- like hard carbon film imparted with a semiconducting property and a perpendicularly magnetized film on a substrate. CONSTITUTION:The thin diamond-like hard carbon film 2 which is imparted with the semiconducting property, consists essentially of carbon and is incorporated with elements such as B, P and N to control the conductivity is provided on the substrate 1 consisting of a high-polymer film of Al alloy, etc., and further, the perpendicularly magnetized film 3 consisting of Co-Cr, Co-Ti, Co-Ta, Co-Ru, Co-W, Co-Mo, Co-Cr-Nb, Co-Cr-Rh, etc., is laminated thereon. The nonuniformity of crystal growth by the electrified atoms contained therein at the time of forming the perpendicularly magnetized film 3 is thereby eliminated and the noises are lowered, by which the C/N of the wide band is improved.

Description

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

2. Description of the Related Art Conventionally, a perpendicular recording method has been known as a magnetic recording method with excellent short wavelength recording characteristics. In this method.

A perpendicular magnetic recording medium having perpendicular magnetic anisotropy is required.

When a signal is recorded on such a medium, the residual magnetization is oriented approximately perpendicular to the film surface of the medium. Therefore, as the wavelength of the signal becomes shorter, the demagnetizing field within the medium decreases, and superior reproduction output can be obtained. What is considered to be the best perpendicular magnetic recording medium is a perpendicular magnetic recording medium that is formed on a polymeric material or non-magnetic substrate, either directly or through a soft magnetic layer such as a permalloy thin film.
A magnetic layer containing Go and Or as main components and having perpendicular magnetic anisotropy (hereinafter this magnetic layer will be referred to as a Go-Or perpendicular magnetization film) is formed by sputtering or vacuum evaporation.

Problems to be Solved by the Invention So-called two-layer media, in which a soft magnetic layer such as permalloy is placed on a substrate and a perpendicular magnetization film is placed on top of it, can achieve high-density recording when combined with an auxiliary pole excitation type monomagnetic head. (Japanese Patent Publication No. Sho 58-91), it is possible to provide high-density recording characteristics using the helical scanning method using a ring-type magnetic head, which currently ensures the highest-density recording at a practical level. Perpendicular magnetic recording media are long-awaited, and 2
Progress has been made to improve performance to bring it closer to that of a layered medium
However, it cannot be said that this is sufficient to obtain the broadband C/N required for digital recording, and an improvement has been desired.

The present invention has been made in view of the above-mentioned circumstances and provides a magnetic recording medium for perpendicular magnetic recording with improved broadband C/N.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention has a semiconducting diamond-like hard carbon thin film and a perpendicularly magnetized film laminated on a substrate.

Operation The magnetic recording medium of the present invention has the above-described structure, which eliminates non-uniformity in crystal growth due to the charged atoms contained in the perpendicularly magnetized film, reduces noise, and achieves broadband C/N.
will be improved.

In addition, unlike the case of a metal base, it is amorphous and repels water, which has the effect of making the crystal orientation uniform, and this effect also reduces noise.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to one drawing. The figure is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In the figure, ■ indicates a substrate made of a polymer film such as polyamide, polyimide, polysulfone, polyether ether ketone, polyether sulfone, polyphenylene sulfide, polyethylene naphthalate, etc., or an Ae alloy. Alternatively, a substrate made of an Ae alloy or the like having fine structural anisotropy arranged in the circumferential direction of the disk may be used.

■ is semi-conducting diamond-like hard carbon thin film,
It is suitable that the material is mainly composed of carbon and contains elements such as B, P, and N to control the conductivity.

The formation of such a thin film involves the use of hydrocarbon gas, B, and P.

It may be formed by decomposing a gas mixture containing N by glow discharge. Film thickness is 500(A) to 5000(1),
The resistance is preferably between 100Ω/port and 100Ω/port. ■ Go-Or, Go-Ti, Go-Ta.

Go-Ru, Go-W, Go-Mo, Co
-0r-Nb.

Perpendicular magnetization film such as Co-0r-Rh, ■ is a protective lubricant layer, plasma polymer film, amorphous carbon film.

When combining a thin film such as a TiC film, a BN film, or a 5i02 film with a lubricant such as fatty acid amide or perfluorocarboxylic acid, the total thickness is preferably from 100 to 250 films in consideration of spacing loss.

Although the present invention can be carried out in the form of either a magnetic disk or a magnetic tape, a more specific example will be explained by comparing the characteristics of the magnetic tape in comparison with a comparative example.

CaCO3 particles with a diameter of 100 on a polyethylene terephthalate film with a thickness of 10 μm.

13 pieces/(μm)2 were arranged, and 1000 diamond-like hard carbon thin films containing B were formed thereon by sputtering using graphite as a target. The discharge gas is m r + B H5 = o, o8 (Torr).

Mr:BH, = 5:1 and the high frequency is 13.56 (MHz
).

The thin film obtained at 1.4 (KW) was 1.4 (KW). s (KCl port)
It is. On top of that, Go-Cr was added by high-frequency sputtering method.
(Go: 80 wt%) A perpendicular magnetization film of 0.18 μm was formed, and a plasma polymerized film was vacuum-deposited by 80 people using tetramethylcyclodisilazane as a 70% gas and a high frequency of 20 (KHz) and 800 (W). Using the method, 40 people placed perfluoromyristic acid and processed it into an 8 mm wide magnetic tape.

Comparative Example B, which had the same configuration as the Example, except that 1000 people formed a diamond-like hard carbon thin film, which is an insulator that does not contain B, was used as a comparative example.

A sample having the same configuration as the example was prepared except that 70,000 Or thin films, which are good conductors, were formed by high-frequency sputtering.

Using 8mm video modified from each tape.

Digital recording was performed with a bit length of 0.2 μm and a track pitch of 6 μm, and the broadband C/N in a band of 10 (MHz) was compared. The head used is an amorphous head with a gap length of 0.15 μm.

If the example is o(dB), the comparative example-person is -2,2(dB)
B), Comparative Example-B is -2.5 (dB) and C/N of Example
was in good condition. Further widening the band and C at 15 (MH2)
/N is 0 (dB) for the example, -3 for the comparison individual,
1 (dB), and -3.5 (dB) for Comparative Example B.

In addition, the resistance value of the diamond-shaped hard carbon thin film is 10QKΩ.
If the value exceeds 100 Ω/mouth, the C/N will vary by pl (dB) depending on the location, and if it becomes less than 100 Ω/mouth, the water-repellent property of the diamond-like hard carbon thin film will decrease, and the This is thought to be due to the influence of residual gas in C.
/H instability is noticeable, so 100Ω/mouth ~ 100
It can be said that Ω/mouth is a preferable range.

In this range, compared to Go-Or film, Go-T
Conventionally, confirmation of excellent high-density recording characteristics of materials such as I, Co-Mo, etc. was delayed, but according to the five examples, it was confirmed that the difference could be improved to a difference of about 1 (dB).

Effects of the Invention As described above, the present invention has the excellent effect of providing a magnetic recording medium that enables high-density broadband digital recording.

[Brief explanation of the drawing]

The figure is an enlarged cross-sectional view of a magnetic recording medium according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Polymer film, 2...Half-4 electrified diamond-like hard carbon thin model, 3...Perpendicular magnetization film. 1- Polymer film 2- + Conductive diamond film 2*Carbon thin film 3- Haruka Muronako

Claims (1)

[Claims] A magnetic recording medium characterized in that a semiconducting diamond-like hard carbon thin film and a perpendicular magnetization film are laminated on a substrate.