JPS5938780A - Magnetooptic storage element - Google Patents

Abstract

PURPOSE:To consume intruded oxygen with easily oxidizable metallic materials such as Ti, Mg or the like and to decrease the oxidation of a thin amorphous magnetic material film as far as possible by incorporating said easily oxidizable metallic materials into the thin amorphous magnetic material film. CONSTITUTION:A magnetooptic storage element is constituted of a transparent substrate 1 of glass, acrylic resin, etc., a thin transparent film 2 of SiO, SiO2, Si3N4, etc., a thin amorphous magnetic material film 3' consisting of rare earth- transition metal alloys such as GdTbFe, TbDyFe, GdCo, TbFe, GdTbDyFe or the like and a reflection film 5 of SiO, SiO2, Si3N4, etc. The easily oxidizable metallic materials which are more easily oxidizable than rare earth metals such as Ti, Mg or the like are incorporated into the film 3'. The Ti, Mg, etc. can suppress the oxidation of the thin amorphous magnetic material film as far as possible by the presence of the easily oxidizable metallic materials which are more easily oxidizable than rare earth metals, the magnetic characteristics of the thin amorphous magnetic material are stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Scope) The present invention relates to a magneto-optical storage element that can record, reproduce, and erase information using laser light.

(Prior Art) In recent years, the development of optical storage elements capable of recording, reproducing, and erasing information has been actively promoted, centering on magneto-optical storage elements.

In addition, among the structures of this magneto-optical memory element, there is an element having a reflective film structure, which is highly evaluated. FIG. 1 shows a side view of an example of an element having a reflective film structure. In the figure, / is a transparent substrate made of glass, acrylic resin, etc., 2 is SiO, 5i
02゜Transparent thin film such as Si3N4, 3 is G d T b
F e , T b I) y F c, GdCo, T
Amorphous magnetic thin film made of rare earth or transition metal alloys such as bFe, GdTbDyFe, etc., 5IO1S +02,
Transparent thin film such as S i3 N4, j is Cu, AA.

It is a reflective film such as AusAg. In the above reflective film structure element, the thickness of the amorphous magnetic thin film 3 is extremely thin, approximately 100A', so that the incident laser light incident from the transparent substrate/side is not transmitted through the amorphous magnetic thin film 3. The transmitted light is reflected by the reflective film j. 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 amorphous magnetic thin film 3 described above are reflected by the reflective film layer j and are again non-conductive. The Faraday effect of the light transmitted through the crystalline magnetic thin film 3 acts synergistically to increase the Kerr rotation angle. Furthermore, the effect of increasing the Kerr rotation angle is also obtained by the interference of one beam of light inside the transparent thin film.

(Problems to be Solved by the Invention) The element with the above-mentioned reflective film structure has an extremely excellent structure from the point of view of the magneto-optic effect, but on the other hand, the characteristics may deteriorate due to oxidation of the amorphous magnetic thin film 3. It turns out to be a big problem or a problem. That is, the outside air enters through the reflective film 5 and the transparent thin film 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 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 disappears completely, making both recording and reproducing impossible. A very inconvenient problem arises.

(Means for Solving the Problems) In order to solve the above problems, the present invention has a structure of a magneto-optical memory element in which an easily oxidizable metal substance such as Ti or Mg is contained in an amorphous magnetic thin film. By adopting such a structure, the invading oxygen is consumed by the easily oxidizable metal substance contained therein, thereby reducing oxidation of the amorphous magnetic thin film as much as possible.

(Example) What is shown in FIG. 1 is a side view of an example of the magneto-optical storage element according to the present invention. In the same figure, / is a transparent substrate made of crow, acrylic resin, etc. is S i O,5i0
2, transparent thin film such as Si3N4, 3' is G d T
l) Fc, TbDyFe, GdCo, TbFe
, GdTbI)yFc and other amorphous magnetic thin films made of rare earth/transition metal alloys, G is SiO, 5i02, Si3
A transparent thin film such as N4, 5 is a reflective film such as Cu, Affl, Au, Ag, etc. -]- In the amorphous magnetic thin film 3', there is a transparent thin film such as fi, Mg, etc. Contains easily oxidized metal substances. In the configuration shown in the figure, the transparent thin film 2 may be omitted.

In the above description of the embodiments, the present invention is applied to an element having a reflective film structure. However, in the present invention, the thickness of the amorphous magnetic thin film is sufficiently thick (10°).

It can also be applied to devices with a thick film structure (about A°), that is, devices that utilize the Kerr effect.

(Effect) According to Misfire-1, in the amorphous magnetic thin film ((containing T
The presence of easily oxidizable metal substances such as i, Mg, etc., which are more easily oxidized than rare earth metals, can suppress oxidation of the amorphous magnetic thin film as much as possible, so the magnetic properties of this amorphous magnetic thin film can be It can be stabilized and the reliability of the device can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional magneto-optical memory element, and FIG. 2 is a side view of an embodiment of the magneto-optic memory element according to the present invention. In the figure, /: transparent substrate, -2 transparent thin film, 3: amorphous magnetic thin film, ri: transparent thin film, j: reflective film, 3': amorphous magnetic thin film containing an easily oxidizable substance. Agent: Patent attorney Yoshihiko Fukushi (and others!) Figure 1 Figure 2

Claims (1)

[Claims] 1. In a magneto-optical memory element formed by forming an amorphous magnetic thin film made of a rare earth or transition metal alloy having an axis of easy magnetization in a direction perpendicular to the film surface on a transparent substrate, the amorphous magnetic thin film contains A magneto-optical memory element characterized by containing an easily oxidizable metal substance such as T i and M g that is more easily oxidized than rare earth metals.