JPH01287821A - magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a magnetic recording medium suitable for high-density recording.

Conventional technology In recent years, due to the demand for high-density recording, both conventional longitudinal recording and perpendicular magnetic recording, which is showing new development,
There is a strong desire to put into practical use magnetic recording media in which a Go-based ferromagnetic metal thin film is used as a magnetic recording layer, and research is being actively carried out.

In particular, perpendicular magnetic recording, in which recording demagnetization can be ignored during short wavelength recording, uses a single magnetic pole head, permalloy thin film, and Go-O.
It is known to exhibit extremely excellent high-density recording characteristics when used in combination with a two-layer medium with a perpendicularly magnetized film.
-91 Publication], improvements continued in various fields, and the possibility of high-density recording was demonstrated even with the helical scan method using a ring head, which is currently the most advanced interface technology for high-density recording [JP-A No. 61] Although there have been remarkable advances in short-term performance, such as [Reference No. 77128], it is difficult to say that durability is sufficient, and most methods of disposing a protective film on the magnetic recording layer are Various attempts have been made to improve this idea
-151835, JP 61-151830, JP 61-126627].

Problems to be Solved by the Invention However, the thickness of the protective film required to ensure durability is usually around 200 mm, and the spacing loss at short wavelengths due to this film thickness cannot be ignored, so it is necessary to improve the magnetic layer itself. was the issue.

In view of the above-mentioned circumstances, the present invention provides a magnetic recording medium that improves the C/N of the magnetic layer itself, thereby making it possible to secure a sufficiently practical C/N even with the subbasing loss caused by the protective film. It provides:

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention is provided by disposing a thin film of Be, Hf, or Zr on a polymer film, and then disposing a perpendicular magnetization film on the polymer film. This is how it was done.

Operation The magnetic recording medium of the present invention has the above-described structure, which improves the C/N due to noise improvement, which is thought to be due to the improvement of the crystal orientation of the perpendicularly magnetized film, and also improves the C/N by reducing Be, Hf.
, combined with an improvement in effective output due to improved head touch, which is thought to be due to the elasticity of the Zr thin film, the C/N ratio has been significantly improved, making it possible to obtain a practical level C/N ratio even with a protective film. It will become.

EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings. FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In Figure 1, 1 is polyamide, polyimide, polysulfone.

A polymer film such as polyether ether ketone, polyether sulfate, polyphenylene sulfide, polyethylene naphthalate, etc. If necessary, a worm-like undercoat layer made of a water-soluble polymer, 5i02, Ca
It is also possible to use a layer coated with fine particles such as CO3, TiO2, ZrO2, or the like. 2 is B
A thin film of any one of e, Hf, and Zr, formed by a sputtering method, an ion beam deposition method, an electron beam evaporation method, an ion blating method, etc., and the film thickness is from 300 to 3000, preferably , 500 to 1600 people is appropriate. This film thickness is
This is determined as a preferable range because the preferred thickness of the perpendicularly magnetized film is 1,600 to 3,000 Å compared to the required level of magnetic flux, and below 500 Å, the crystallinity improvement effect is less than the C/N improvement effect. The criticality is determined by the fact that it becomes non-uniform depending on the location, and the criticality is determined by the fact that if the thickness exceeds 1500 Å, the head touch becomes unstable, and conversely, the C/N becomes unstable.

3 is Co-0r, Go-Ti, Co-Zr
, Go-Ru.

Go'-Ta, Go-Mo, Go-W,
Go-Or-Wb.

A perpendicular magnetization film such as Go-Ni-Or, with a film thickness preferably in the range of 1,500 to 3,000, is formed by sputtering,
It is formed by an electron beam evaporation method, an ion blating method, or the like. 4 is a protective film, BO film, TiC film, B
Thin films such as N film, diamond-like hard carbon thin film, plasma polymerized film, fatty acid amide, perfluorophoriether, etc.
A combination of lubricants such as higher alcohols is often used, and the preferred film thickness is 100 to 200 mm.
It's a person.

The magnetic recording medium of the present invention may be either a magnetic disk or a magnetic tape, and specific examples of magnetic tape will be shown below in comparison with comparative examples.

On a polyethylene terephthalate film with a thickness of 11.5 μm, two pieces of ZrO2 with a diameter of 60 pieces (20 pieces/ωm) were placed,
On top of that, 680 pieces of Be were placed by high-frequency sputtering method, 100 pieces of Hf were placed on top of that, and 1 piece was placed with Zr.
1,900 layers of Go-Cr perpendicular magnetization film (Co: awtL%) were placed on each layer, and on top of that, 90 layers of diamond-like hard carbon were deposited using a high-frequency sputtering method using graphite as a target. A thin film was deposited, and 60 perfluorostearic acids were deposited on the thin film using a vacuum evaporation method to obtain a magnetic tape with a width of 8 mm. The product with Be thin film was designated as Tape No., the Hf product was designated as Tape B, and the Zr product was designated as Tape C. As a comparative example (tape D), Be
, Hf, and Zr without intervening thin films.
A device manufactured under the same conditions as in the example except that a perpendicular magnetization film was provided was prepared. Transferred D from the tape to a modified 8mm video, pit length 0.2μm, track pitch 5μm.
Digital recording of 100 MHz was performed using an amorphous head with a gap length of 0.15 μm, and the broadband C/N of band 12 (MHz) was compared.

As a result of relative comparison of Tape D as Q (dB), Tape person is +3.3 (dB) and Tape B is +2.6 (dB).
, Tape C was excellent at +2.0 (dB).

FIG. 2 is a characteristic diagram showing the relationship between C/N and film thickness when a Be thin film is formed with a film thickness other than the conditions described above.

Effects of the Invention As described above, the present invention has the excellent effect of providing a magnetic recording medium for perpendicular magnetic recording with improved C/N in high-density recording.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of a magnetic recording medium according to an embodiment of the present invention;
FIG. 2 is a characteristic diagram in an embodiment of the present invention. 1...Polymer film, 2...Be(
Hf, Zr) film, 3... Perpendicular magnetization film. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
Polymer film 2-・-day e (Hf, 1r) a Figure 1 Figure 2 Be robust (wa

Claims (1)

[Claims] A magnetic recording medium characterized in that a thin film of Be, Hf, or Zr is disposed on a polymer film, and a perpendicular magnetization film is disposed on the thin film.