JPH0254448A - Magneto-optical disk medium - Google Patents

Abstract

PURPOSE:To drastically suppress the decrease in signal quantity in recording and reproducing characteristics by alternately laminating thin rare earth metallic films and thin transmission metallic films added with specific elements. CONSTITUTION:This disk medium is formed by alternately laminating the thin rare earth metallic films 2 consisting of Tb, etc., which are more easily oxidized than the thin transmission metallic films 3 and the thin transmission metallic films 3 which are added with metals forming a passive state and Fe, Co, etc., of inert metals at the concn. higher than in the thin films 31 by sputtering on the surface of a disk substrate 1 mounted with a dielectric layer. The optical recording medium is thus formed. The oxidation resistance of the recording film is then intensified and the decrease in the signal quantity in the recording and reproducing characteristics of the disk medium is drastically suppressed by the specific thin transmission metallic films.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magneto-optical disk medium, and particularly to a high-quality, high-performance magneto-optical disk medium.

[Conventional technology]

In a conventional magneto-optical disk medium, as shown in FIG. 2, a rare earth metal thin film 2' and a transition metal thin film 4 are alternately and repeatedly formed on a disk substrate 1. In order to improve the reliability of the metal thin film 4, especially its oxidation resistance, at least one of a metal forming a passive state such as Ti1Cr and an inert metal such as Pt is almost uniformly added to the recording film. ing.

[Problem to be solved by the invention]

However, in the above-mentioned conventional magneto-optical disk medium, Ti and C are added to the rare earth metal thin film and the transition metal thin film.
Although it is possible to improve the oxidation resistance of the recording film by adding a metal such as r or Pt almost uniformly to the entire recording film, the amount of signal (carrier) in the recording and reproducing characteristics of the medium is significantly reduced. It has the disadvantage of being stored away.

[Means to solve the problem]

The magneto-optical disk medium of the present invention is constructed by adding elements such as Ti, Cr, and Pt at a higher concentration than the transition metal thin film to a rare earth metal thin film that is more easily oxidized than the transition metal thin film.

〔Example〕

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

FIG. 1 is a sectional view showing an embodiment of the present invention.

The magneto-optical disk medium shown in FIG. 1 has a TbTi alloy and an F
The rare earth metal thin film 2 made of Tb and the transition metal thin film 3 made of FeCo are formed by a conventional co-sputtering method using an eCoTi alloy as a target, with addition of additional elements such as Ti.

In this magneto-optical disk medium, the recording and reproducing characteristics of the recording film were 1.0.8 to 1.5 dB larger in signal amount than the conventional recording film having the same oxidation resistance.

Here, Tb is used as a rare earth metal, and Tb is used as a transition metal.
Although an example using Fe and Co is shown, rare earth metals and transition metals are not limited to the exemplified elements, and targets for forming a recording film include rare earth metal additive elements, and The sputtering method is not limited to the transition metal additive element system, and a multi-source sputtering method using a rare earth metal target, a transition metal target, and an additive element target can also be used.

Further, the film can be formed by using these targets in a different combination than the above.

Further, the film forming method is not limited to the sputtering method, and the film can also be formed by a vapor deposition method using the various materials mentioned above as a source.

〔Effect of the invention〕

In the magneto-optical disk medium of the present invention, at least one of a metal forming a passive state and an inert metal element is added to the rare earth metal thin film, which is more easily oxidized than the transition metal thin film. This strengthens the oxidation resistance of the recording film, and by adding a lower concentration of additive elements in the transition metal thin film than in the rare earth thin film, it significantly suppresses the decrease in signal amount in the recording and playback characteristics of the disk medium. The effect is that it can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing an example of the conventional technology. 1...Disc substrate, 2,2'...Rare earth metal thin film, 3...Transition metal thin film, 4...
...Transition metal thin film.

Claims (1)

[Claims] a rare earth metal thin film, which is formed alternately and repeatedly with the transition metal thin film, to which at least one of a metal forming a passive state and an inert metal is added at a higher concentration than in the transition metal thin film; A magneto-optical disk medium comprising: