JPH04330654A - Magneto-optical storage element - Google Patents

Abstract

PURPOSE:To provide the magneto-optical storage element having a structure capable of preventing the oxidation of the thin film of an amorphous magnetic material. CONSTITUTION:At least one of Ti, Mg and rare earth metals which are easily oxidizable metals are incorporated into a transparent thin film 2 or 4 provided in proximity to the thin film 3 of the amorphous magnetic material consisting of a rare earth/transition metal alloy having an axis of easy magnetization in the direction perpendicular to the film plane on a transparent substrate 1. The infiltering oxygen is consumed by the easily oxidizable metals in a reflection film 6 in this way.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical memory element capable of recording, reproducing and erasing information using laser light.

0002

2. Description of the Related Art In recent years, the development of optical storage devices capable of recording, reproducing, and erasing information has been actively promoted, centering on magneto-optical storage devices. Furthermore, one of the magneto-optical storage element structures that has received high praise is an element with a reflective film structure.

FIG. 2 shows a side view of an example of an element having a reflective film structure. In the figure, 1 is a transparent substrate made of glass, acrylic resin, etc., 2 is a transparent thin film of SiO, SiO2, Si3N4, etc., and 3 is GdTbFe, TbDyFe, GdCo, T
amorphous magnetic thin film made of rare earth/transition metal alloy such as bFe, GdTbDyFe, etc. 4 is SiO, SiO2, Si
A transparent thin film such as 3N4 is used, and 5 is a reflective film made of Cu, Al, Au, Ag, etc.

[0004] In the above reflective film structure element, the thickness of the amorphous magnetic thin film 3 is very thin, about 100 Å, so that the incident laser light incident from the transparent substrate 1 side does not penetrate the amorphous magnetic thin film 3. The transmitted light is reflected by the reflective film 5. Therefore, the Kerr effect of the incident laser beam reflected on the surface of the amorphous magnetic thin film 3 and the Kerr effect of the light transmitted through the above-mentioned amorphous magnetic thin film 3 and reflected by the reflective film 5 are reflected again on the amorphous magnetic thin film 3. The Faraday effect of the light transmitted through 3 causes a synergistic effect to increase the Kerr rotation angle. Furthermore, light interferes inside the transparent thin film 2, which also increases the Kerr rotation angle.

[0005]

[Problems to be Solved by the Invention] Although the above-mentioned reflective film structure element has an extremely excellent structure from the point of view of magneto-optic effect, on the other hand, the characteristic deterioration due to oxidation of the amorphous magnetic thin film 3 occurs. The large size has proven to be a drawback. In other words, the outside air enters through the reflective film 5 and the transparent thin film 4 and oxidizes the amorphous magnetic thin film 3, or the reflective film 5
A phenomenon occurs in which oxygen contained within the transparent thin film 4 oxidizes the amorphous magnetic thin film 3. If the amorphous magnetic thin film 3 oxidizes, the coercive force decreases, making reproduction by the magneto-optic effect difficult, and in extreme cases, the perpendicular magnetic anisotropy of the amorphous magnetic thin film 3 is completely lost, resulting in failure in both recording and reproduction. The extremely inconvenient problem arises that this is possible.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a magneto-optical memory element having a structure capable of preventing oxidation of an amorphous magnetic thin film.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an amorphous magnetic thin film made of a rare earth/transition metal alloy having an axis of easy magnetization perpendicular to the film surface on a transparent substrate. The magneto-optical memory element thus formed includes a transparent thin film adjacent to the amorphous magnetic thin film, and the transparent thin film contains at least one of easily oxidizable metals Ti, Mg, and rare earth metals. This is a magneto-optical memory element characterized by:

[0008]

[Operation] Ti, an easily oxidizable metal, is formed in a transparent thin film provided on a transparent substrate adjacent to an amorphous magnetic thin film made of a rare earth/transition metal alloy with an axis of easy magnetization perpendicular to the film surface. By containing at least one of , Mg, and a rare earth metal, the invading oxygen is consumed by the easily oxidizable metal in the reflective film.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view of an embodiment of a magneto-optic memory element according to the present invention. In the figure, numeral 1 is a transparent substrate made of glass, acrylic resin, etc., and 2 is SiO, Si.
Transparent thin film such as O2, Si3N4, 3 is GdTbFe, T
Amorphous magnetic thin film made of rare earth/transition metal alloy such as bDyFe, GdCo, TbFe, GdTbDyFe, etc., 4
is a transparent thin film such as SiO, SiO2, Si3N4, etc., and 6 is C
Ti, M in metal films such as u, Al, Au, Ag, SUS, etc.
This is a reflective film containing easily oxidizable metal substances such as g, rare earth metals (Gd, Tb, Dy, Ho, Y).

Here, the inclusion of the easily oxidizable metal substance may be carried out in the transparent thin film 2 or in the transparent thin film 4.
The treatment may be applied to any two or more of the transparent thin film 2, the transparent thin film 4, and the reflective film 6. Furthermore, the transparent thin film 2 may not be provided in the configuration shown in the figure.

In the above description of the embodiment, the present invention has been applied to an element having a reflective film structure, but the present invention is applicable to a thick film type device in which the amorphous magnetic thin film is sufficiently thick (approximately 1000 Å). The present invention can also be applied to an element having the following structure, that is, an element that utilizes only the Kerr effect.

0012

According to the present invention, easily oxidizable metals such as Ti, Mg, and rare earth metals (Gd, Tb, Dy, Ho, and Y) contained in the transparent thin film adjacent to the amorphous magnetic thin film. The presence of the substance can significantly suppress the oxidation of the amorphous magnetic thin film, making it possible to stabilize the magnetic properties of the amorphous magnetic thin film and significantly improving the reliability of the device. Can be done.

[Brief explanation of drawings]

FIG. 1 is a side view of a magneto-optical storage element according to the present invention.

FIG. 2 is a side view of a conventional magneto-optic storage element.

[Explanation of symbols]

1 Transparent substrate 2 Transparent thin film 3 Amorphous magnetic thin film 4 Transparent thin film 5 Reflective film

Claims (1)

[Claims] 1. A magneto-optical memory element comprising an amorphous magnetic thin film made of a rare earth/transition metal alloy having an axis of easy magnetization perpendicular to the film surface and formed on a transparent substrate, wherein the amorphous magnetic 1. A magneto-optical memory element comprising a transparent thin film adjacent to a body thin film, and containing at least one of easily oxidizable metals Ti, Mg, and rare earth metals.