JPH08315435A - Magneto-optical recording medium - Google Patents

Abstract

PURPOSE: To obtain a magneto-optical recording medium having especially high recording sensitivity while maintaining a high resolution by using a magnetic layer which acts as an intra-plane magnetization film at room temp. for a reproducing layer. CONSTITUTION: The medium has a reproducing layer 13 and a recording layer 214 having the compsn. of Gdx Mey (Fe1-z Coz )1-x-y (wherein x, y, z satisfy 0.25<=x<=0.31, 0.01<=y<=0.03, 0.3<=z<=0.5, and Me is Nb, Mo, etc.,) on a base body 11. Reproducing is performed by transferring the recorded information from the recording layer 14 to the reproducing layer 13 by irradiation with reproducing light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording medium for recording, reproducing and erasing information by using light. In particular, it relates to a magneto-optical recording medium that performs super-resolution reproduction.

[0002]

2. Description of the Related Art A magnetic super-resolution reproducing system has been proposed as a method for reproducing information recorded in a size smaller than the optical diffraction limit of reproduction light for the purpose of further increasing the density of magneto-optical recording. (See, for example, Japanese Patent Laid-Open Nos. 1-143041 and 1-143042). In this reproducing method, at least the reproducing layer and the recording layer are used, and a certain region of the beam spot irradiated with the reproducing light is used as a mask so that the beam spot has substantially the same effect. It utilizes the intensity distribution of light in the beam spot and the large temperature rise behind the beam traveling direction.

This reproducing method is roughly classified into two methods. One is an extinction method in which the reproducing layer is in a specific state in a region where the temperature is equal to or higher than a certain level, and is used as a mask
On the other hand, in the embossing type method, the reproducing layer is in a specific state before reproduction, and the information recorded in the recording layer is transferred to the reproducing layer in an area where the temperature becomes a certain temperature or higher. In the latter method, the reproduction layer is in a specific state even in the adjacent track, so that the crosstalk with the adjacent track is very small.

In this reproducing method, when a perpendicularly magnetized film is used for the reproducing layer, an initializing magnet is required to bring the reproducing layer into a specific state before reproducing, and in order to stabilize this state. The control layer and so on are required. In order to solve this problem, a method has been proposed in which a magnetic layer that is an in-plane magnetized film at room temperature and serves as a perpendicular magnetized film in a region where the temperature is above a certain level is used as a reproducing layer (for example, Japanese Patent Laid-Open No. Hei 10 (1999) -242242). 5-817
17).

This method uses a film in which a reproducing layer, which is an in-plane magnetized film, and a recording layer, which is a perpendicularly magnetized film, are exchange-coupled at room temperature, but the magnetization of the reproducing layer before reproduction is in-plane. Since it faces in the direction, it does not require an initializing magnet, and in principle, it can be composed of only two layers of a reproducing layer and a recording layer, which is advantageous in terms of manufacturing.

A method for improving resolution by providing an intermediate layer between the reproducing layer and the recording layer has also been proposed (see, for example, Japanese Patent Laid-Open No. 5-205336).

However, in a magneto-optical super-resolution medium using such an in-plane magnetized film as a reproducing layer, the reproducing layer and the recording layer must be thick in order to obtain high resolution, and the laser for recording is high. Since it requires power, it is difficult to rotate the disc at high speed. Especially when TbFeCo, which has excellent record retention, is used for the recording layer,
It has been reported that a thickness of dFeCo of 80 nm or more is preferable for improving resolution (Magneto-Optica
29-Q-05 in l Recording International Symposium '94
).

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magneto-optical recording medium in which a reproducing layer is formed of a magnetic layer which serves as an in-plane magnetized film at room temperature while maintaining a high resolution, and in particular, the recording sensitivity is enhanced. To provide.

[0009]

As a result of intensive studies, the present inventor magnetically coupled a reproducing layer mainly composed of GdFeCo, which is an in-plane magnetized film at room temperature, and a recording layer of a perpendicular magnetized film. By using a film that has a specific element added to the reproducing layer within a specific composition range, the reproducing layer is thinner than the conventional one, and has a resolution equal to or higher than the conventional one. It was found that a medium was obtained, and a magneto-optical recording medium of the present invention was obtained.

That is, according to the present invention, at least a reproducing layer which is an in-plane magnetized film at room temperature and a recording layer which is a perpendicularly magnetized film are provided on a substrate, and information is transferred from the recording layer to the reproducing layer by irradiation of reproducing light. A magneto-optical recording medium for transfer and reproduction, wherein the composition of the reproducing layer is Gd _x Me _y (Fe _1-z Co _z ) _1-xy (0.25 ≦ x ≦ 0.31, 0.01 ≦ y ≤0.03,
0.3 ≦ z ≦ 0.5, Me is rare earth, Ia group, IIa
The present invention relates to a magneto-optical recording medium represented by one or more elements selected from elements other than those belonging to Group Vb, Group VIb, Group VIIb).

The present invention will be described in detail below.

In the present invention using the in-plane magnetized film as the reproducing layer,
In the embossed type magnetic super-resolution reproducing method, the reproducing layer becomes a perpendicularly magnetized film only in the area of the reproducing beam spot where the temperature exceeds a predetermined temperature, and the information recorded in the recording layer is transferred to the reproducing layer by the exchange coupling force. And is detected as a reproduced signal. With this method, a recording pit smaller than the size of the beam spot can be reproduced.

That is, it is important that the reproducing layer has almost no component perpendicular to the film surface of its magnetization at a predetermined temperature or lower. In order to realize this, the composition of the reproducing layer is made to have a rare earth-dominant structure. That is. Further, it is necessary that the intensity of the reproducing light at the time of reproducing is not so great as to record on the recording layer.

As a result of the research conducted by the present inventor, in order to satisfy these conditions, the reproducing layer of the magneto-optical recording medium was made of GdFeCo.
In that case, it is necessary to adjust the Gd concentration and the Co concentration, but the perpendicular magnetic anisotropy of GdFeCo is mainly determined by the Co concentration, and the Gd concentration affects the temperature adjustment from the in-plane to the perpendicular magnetic field. I understood. The perpendicular magnetic anisotropy of GdFeCo monotonically decreases in proportion to the Co concentration, and the Curie temperature monotonically increases. According to the examination result of the present inventor, Co and F
A GdFeCo reproducing layer having the best reproducing characteristics was obtained with an eCo ratio of about 40 to 50 at%. At this time, when TbFeCo having excellent record retention is used for the recording layer, the reproducing layer preferably has a thickness of 800 A or more. It required a large laser power for recording.

To increase the recording sensitivity, it is necessary to make the thickness of the reproducing layer as thin as possible.
Rare earth, Ia group, IIa group, Vb group, VIb group, VII
The Curie temperature and the perpendicular magnetic anisotropy were appropriately reduced by using a material to which one or more elements (Me) selected from elements other than the group b were added, and this was realized. Here, the reason why the rare earth element and others are excluded is that the addition of the rare earth element raises the perpendicular magnetic anisotropy.
This is because the addition of the Group IIIa, Group IIa, Group Vb, Group VIb, and Group VIIb elements causes deterioration in corrosion resistance.

When the Me concentration (y) of the present invention is less than 0.01, the effect of sufficiently lowering the Curie temperature and perpendicular magnetic anisotropy cannot be obtained, and the film thickness of the reproducing layer necessary for obtaining high resolution is obtained. Becomes thicker, and if it exceeds 0.03, the Kerr rotation angle becomes small and the reproduction output decreases. Co concentration (z) of the reproducing layer is 0.3
If it is less than 0.5, the perpendicular magnetic anisotropy is large, and the magnetization of the reproducing layer does not change smoothly when standing perpendicularly from the in-plane. Therefore, noise tends to occur. However, there are problems that the magnetization does not stand vertically because of too much, and that the reproducing layer film thickness necessary for obtaining high resolution becomes thick due to the high Curie temperature. Also,
By adjusting the Gd concentration (x) within the range of 0.25 ≦ x ≦ 0.31, it is possible to set the temperature at which the in-plane changes vertically to 100 to 200 ° C. which is a preferable range.

In the present invention, although the effect of lowering the Curie temperature and the perpendicular magnetic anisotropy can be seen in all the elements satisfying the above-mentioned conditions, the Curie temperature and the perpendicular magnetic anisotropy are lowered, and In order to suppress the decrease of the rotation angle, higher resolution can be obtained by selecting an additive which brings about a decrease in the Curie temperature and the perpendicular magnetic anisotropy with addition in the smallest possible amount. In the present invention, in the composition of the reproducing layer, Me is Nb, Mo,
It is particularly preferable to use one added with one or more kinds of elements selected from Hf, Ta, W, Pt and Au in order to obtain the above effects.

In the present invention, when the recording layer is a perpendicular magnetic film mainly composed of TbFeCo, the thickness of the reproducing layer is 50 to 70.
When the thickness is nm and the thickness of the recording layer is 40 to 70 nm, higher sensitivity and particularly good recording and reproduction can be obtained.

Further, in the present invention, the composition of the recording layer is Tb _x M.
e _y (Fe _1-z Co _z ) _1-xy (0.14 ≦ x ≦ 0.2
2, 0.04 ≦ y ≦ 0.12, 0.1 ≦ z ≦ 0.25)
And Me is Ia group, IIa group, Vb group,
When it is one or more elements selected from elements other than those belonging to the VIb group and the VIIb group, the thickness of the reproducing layer is 40 to 60.
When the recording layer has a thickness of nm and the recording layer has a thickness of 40 to 70 nm, excellent recording and reproduction with higher sensitivity can be obtained.

Here, regarding the Tb concentration (x) of the recording layer, the Tb concentration is 0.1 in order to obtain an appropriate recording magnetic field characteristic.
It is necessary to satisfy 4 ≦ x ≦ 0.22. Me has the effect of reducing the perpendicular magnetic anisotropy of the recording layer, reducing the exchange coupling between the recording layer and the reproducing layer, and facilitating the in-plane even when the reproducing layer is thin, so that the concentration (y) is The larger the value, the greater the effect. The Me concentration is 0.
04 ≦ y ≦ 0.12 is preferable. The Curie temperature of the recording layer is preferably 200 to 300 ° C. in order to keep the recording sensitivity appropriate, but the Co concentration is 0.1 ≦ z ≦ 0.25 depending on the Me concentration.
It can be easily achieved by adjusting within the range.

When the recording layer of the present invention is a perpendicular magnetic film mainly composed of DyFeCo, the perpendicular magnetic anisotropy of the recording layer is T.
The thickness of the reproducing layer is 30 to 50 nm, and the thickness of the recording layer is 40 to 70 nm, because it is smaller than when bFeCo is used.
Therefore, high sensitivity and excellent recording / reproducing can be obtained.

Here, TbFeCo and DyFeC of the recording layer
The thickness of o is set to 40 nm or more because if the thickness is more than 40 nm, it is written in the recording layer without being affected by exchange coupling from the reproducing layer during recording. Also, the thinner the recording layer is, the more preferable it is in terms of recording sensitivity, and when it exceeds 70 nm, recording becomes difficult at the outer peripheral portion of the disk.

In addition, the recording layer has a TbF excellent in storage stability.
In the case of a perpendicular magnetic film mainly composed of eCo, the thickness of the reproducing layer is 30 to 30 by providing an intermediate layer of the perpendicular magnetic film mainly composed of DyFeCo having a Curie temperature lower than that of the recording layer between the reproducing layer and the recording layer. The thickness can be 50 nm, and the recording layer can be made as thin as 10 to 50 nm to achieve high sensitivity. Here, the thickness of the intermediate layer is 10 to 3
0 nm is preferred.

In the present invention, the Curie temperature of the recording layer is 2
The Curie temperature of the intermediate layer when the intermediate layer is provided is preferably 20 ° C. or more lower than the Curie temperature of the recording layer and 150 ° C. or more for stable reproduction. Further, by setting the difference between the Curie temperatures of the recording layer and the intermediate layer to be 60 ° C. or higher, the method disclosed in Japanese Patent Laid-Open No.
Super-resolution using the second mask disclosed in Japanese Patent No. 205336 is possible.

The substrate used in the present invention is preferably a resin such as polycarbonate or a transparent substrate such as glass,
SiN, SiO ₂ , ZnS, Al for the purpose of increasing the polar Kerr effect on the laser light incident side of the reproducing layer.
It is also effective to provide a dielectric layer made of N or the like and having a thickness of about 80 nm. The thickness of this layer can be changed appropriately in order to adjust the reflectance of the medium and the reproduction signal strength. Further, for adjusting the recording laser power and the like, a thermal diffusion layer such as an Al alloy film having a thickness of about 20 nm is provided on the side opposite to the laser light incident side, and an acrylic resin or the like is used to protect the thin film. It is also possible to provide a protective film.

It is also conceivable to add elements such as Cr and Ti to the recording layer in order to improve the corrosion resistance of the present invention, but it is not particularly limited.

The thin film of the magneto-optical recording medium of the present invention is preferably manufactured by a sputtering method using a target corresponding to each layer from the viewpoint of productivity, but in addition, a vacuum evaporation method, an ion beam sputtering method. It can also be produced by a method or the like.

[0028]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 As shown in FIG. 1, a polycarbonate (PC) substrate having a track pitch of 1.2 μm formed by a magnetron sputtering method.
A dielectric layer (12) made of SiN is formed on (11) to a thickness of 80 nm,
After that, a reproducing layer (13) having a composition of Gd _0.29 Me _0.02 (Fe _0.6 Co _0.4 ) _0.69 was formed at 60 nm with Tb _0.19 Fe _0.7 Co _0.11.
The recording layer (14) having the composition of 50 nm, a dielectric layer made of SiN
A disk was prepared by depositing (15) in the order of 80 nm and a thermal diffusion layer (16) consisting of Al in the order of 20 nm. Here, Me is Cr, T
a and Pt were used, respectively. Furthermore, as Comparative Example 1, a reproduction layer (1
3) Gd _0.29 (Fe _0.6 Co _0.4 ) _0.71 as 60 nm,
A disk having the same structure as in Example 1 except that the thickness was 80 nm was produced. In addition, as Comparative Example 2, the reproduction layer (13) was formed with Gd.
_0.29 Nd _0.02 (Fe _0.6 Co _0.4 ) _0.69 at 60 nm, 80
A disk having the same structure as in Example 1 except that the thickness was set to nm was manufactured.

A recording frequency of 9.4 was set at a rotation speed of 2400 rpm so that the mark length becomes 0.5 μm (which is regarded as half of the mark pitch) at a position where the radius of the manufactured disk is 30 mm.
Recording was carried out using a laser beam of 780 nm (NA of objective lens = 0.55) at MHz and duty of 33%. A magnetic field of 300 Oe was applied during recording. The carrier-to-noise ratio (C / N) was measured using the same light. The reproducing laser power at the time of C / N measurement was set to a value that maximizes C / N in each sample in the range of 2 to 4 mW.

Table 1 shows the C / N of Example 1 and Comparative Example 1 and the laser power required for recording.

[0032]

[Table 1]

The recording power was about 8 mW when the thickness of the reproducing layer was 60 nm, and it was possible to reduce the recording power by about 1.5 mW as compared with the case where the thickness of the reproducing layer of Comparative Example 1 was 80 nm. Regarding C / N, although only 40 dB was obtained when the thickness of the reproducing layer in Comparative Example 1 was 60 nm, Example 1
2 to 4 dB higher than the above value, and especially when Me is Ta or Pt, the C / N equivalent to that when the thickness of the reproducing layer of Comparative Example 1 is 80 nm is obtained. Furthermore, M of Comparative Example 2
When e = Nd and the thickness of the reproducing layer was 60 nm, only C / N equal to or lower than that of Comparative Example 1 was obtained.

Table 2 shows the Kerr rotation angle at room temperature and the Curie temperature of the reproduction layer of the samples of Example 1 and Comparative Example 1.

[0035]

[Table 2]

The addition of Me lowers the Kerr rotation angle by about 10%, but also lowers the Curie temperature. Especially T
A and Pt have a large decrease in the Curie temperature, which is the reverse of C / N. When the Curie temperature is lowered, the exchange stiffness constant and the perpendicular magnetic anisotropy are lowered, so that the thickness of the domain wall in the reproducing layer is reduced, and it is considered that the information of the recording layer can be masked even at a thin reproducing layer at room temperature. It is considered that although the Kerr rotation angle was decreased in Me and Cr and Ta and Pt showed almost no difference, Ta and Pt were able to particularly lower the Curie temperature, so that particularly good resolution was obtained. Further, when Me = Nd in Comparative Example 2, the Curie temperature and the curl rotation angle are almost the same as when Cr,
It has been confirmed that the perpendicular magnetic anisotropy is increased, and it is considered that for that reason, the thickness of the domain wall is not reduced and the resolution is low.

On the other hand, the Me concentration (y) is 0.
It was found that the C / N was maximum around 02 and the Curie temperature did not decrease remarkably when the ratio was less than 0.01, and the C / N decreased because the Kerr rotation angle decreased when it exceeded 0.03.

The inventors of the present invention further investigated the additive Me in the reproducing layer, and found that Me was a rare earth element, a group Ia group, or a IIa group.
Even if the reproducing layer has a thickness of about 60 nm, the resolution can be increased by super-resolution when it is one or more elements selected from elements other than those belonging to Group Vb, Group VIb, Group VIIb. I knew it was. In addition, it is particularly preferable that Me is one or more kinds of elements selected from Nb, Mo, Hf, Ta, W, Pt, and Au as a substance that particularly lowers the Curie temperature compared to the Kerr rotation angle, such as Ta and Pt. understood.

Example 2 As in Example 1, a dielectric layer made of SiN was formed to a thickness of 80 nm on a polycarbonate (PC) substrate having a track pitch of 1.2 μm by the magnetron sputtering method, and then G
The reproducing layer having the composition of d _0.29 Ta _0.02 (Fe _0.6 Co _0.4 ) _0.69 is 60 nm, the recording layer having the composition of Tb _0.19 Fe _0.7 Co _0.11 is 50 nm, the dielectric layer made of SiN is 80 nm, and the thermal diffusion layer made of Al is 20 nm. The film was formed in this order to prepare a disk. Using these conditions as standard conditions, the thickness of the reproducing layer was changed from 50 to 70 nm, and the thickness of the recording layer was changed from 40 to 70 nm. Next, as Comparative Example 3, a disc having a reproducing layer having a thickness of 40 to 80 nm and a recording layer having a thickness of 30 to 80 nm was manufactured. Recording and reproducing were performed on these discs under the same conditions as in Example 1, and the C / N was measured.
Table 3 shows C / N of Example 2 and Comparative Example 3 and the laser power required for recording.

[0040]

[Table 3]

From this table, it was found that good C / N was obtained when the thickness of the reproducing layer was 50 nm or more and the thickness of the recording layer was 40 nm or more. When the recording layer is thin, the recording magnetic field is 10
Since it was improved to C / N = 42 dB by setting it to 00 Oe,
It is presumed that the magnetic field due to exchange coupling from the reproducing layer to the recording layer during recording hinders recording. It was also found that the recording sensitivity was considerably deteriorated when the thickness of the reproducing layer and the recording layer exceeded 70 nm.

Example 3 As in Example 1, a dielectric layer made of SiN was formed to a thickness of 80 nm on a polycarbonate (PC) substrate having a track pitch of 1.2 μm by the magnetron sputtering method, and then G
The reproducing layer having a composition of d _0.28 W _0.02 (Fe _0.6 Co _0.4 ) _0.70 is 50 nm, the recording layer having a composition of Tb _0.18 Ta _0.05 Fe _0.64 Co _0.13 is 50 nm, the dielectric layer made of SiN is 80 nm, A
A thermal diffusion layer consisting of 1 was formed in the order of 20 nm to prepare a disk. With this condition as the standard condition, the thickness of the reproducing layer is set to 40.
To 60 nm were manufactured. Next, as Comparative Example 4, a disc having a reproducing layer having a thickness of 30 nm was manufactured.

Recording / reproduction was performed on these discs under the same conditions as in Example 1, and C / N was measured. Table 4 shows the C / N of Example 3 and Comparative Example 4 and the laser power required for recording.

[0044]

[Table 4]

From this table, it was found that good C / N was obtained when the thickness of the reproducing layer was 40 nm or more. By adding Ta to the composition of the recording layer, the reproducing layer was made thinner than in Example 1 and the recording sensitivity could be improved. It is considered that this is because the perpendicular magnetic anisotropy was halved by adding Ta to the recording layer.

Example 4 As in Example 1, a dielectric layer made of SiN was formed to a thickness of 80 nm on a polycarbonate (PC) substrate having a track pitch of 1.2 μm by the magnetron sputtering method, and then G
d _0.29 Nb _0.02 (Fe _0.6 Co _0.4 ) _0.69 composition reproducing layer 40 nm, Dy _0.23 Fe _0.63 Co _0.14 composition recording layer 50 nm, SiN dielectric layer 80 nm, Al thermal diffusion layer 20 nm The film was formed in this order to prepare a disk. Using these conditions as standard conditions, discs were produced in which the thickness of the reproducing layer was changed from 30 to 50 nm. Next, as Comparative Example 5, a disc having a reproducing layer having a thickness of 20 nm was manufactured.

Recording / reproducing was performed on these discs under the same conditions as in Example 1, and C / N was measured. Table 5 shows the C / N ratios of Example 4 and Comparative Example 5 and the laser power required for recording.

[0048]

[Table 5]

From this table, it was found that good C / N was obtained when the thickness of the reproducing layer was 30 nm or more. Recording layer is Tb
From FeCo to DyFe with perpendicular magnetic anisotropy of about 1/3 or less
When Co was used, the reproducing layer was made thinner than in Example 1 and the recording sensitivity could be increased.

Example 5 As shown in FIG. 2, a polycarbonate (PC) substrate having a track pitch of 1.2 μm by the magnetron sputtering method.
A dielectric layer (22) made of SiN is formed on (21) to a thickness of 80 nm,
After that, a reproducing layer (23) having a composition of Gd _0.28 Mo _0.02 (Fe _0.6 Co _0.4 ) _0.70 was deposited at 40 nm and Dy _0.23 Fe _0.65 Co _0.12
The intermediate layer (24) having the composition of 15 nm, Tb _0.19 Fe _0.7 Co
The recording layer (25) having a composition of _0.11 is 20 nm, the dielectric layer (26) made of SiN is 80 nm, and the thermal diffusion layer (27) made of Al is 20 nm.
The film was formed in this order to prepare a disk.

This disc was recorded and reproduced under the same conditions as in Example 1 to obtain C / N of 45 dB and recording power of 5.2 mW.
Both C / N and recording sensitivity were quite good. The composition of the intermediate layer is Dy _0.23 Fe _0.69 Co _0.08 ,
Set about 80 degrees lower than the Curie temperature of the recording layer,
When the film thickness was set to 10 mn, super-resolution by the second mask occurred and C / N of 50 dB was obtained. Also in this case, a high sensitivity with a recording power of 5.0 mW was obtained.

[0052]

As is clear from the above description, in the magneto-optical super-resolution medium using the reproducing layer which becomes the in-plane magnetized film at room temperature, the recording sensitivity is particularly enhanced while maintaining high resolution according to the present invention. be able to. Therefore, recording can be performed under high-speed rotation of the disk, and a medium having both high recording density and high transfer speed can be obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of an embodiment of a magneto-optical recording medium using an in-plane magnetized film as a reproducing layer.

FIG. 2 is a conceptual diagram showing another example of an embodiment of a magneto-optical recording medium using an in-plane magnetized film as a reproducing layer.

[Explanation of symbols]

 11: Polycarbonate (PC) substrate 12: Dielectric layer 13: Reproducing layer 14: Recording layer 15: Dielectric layer 16: Thermal diffusion layer 21: Polycarbonate (PC) substrate 22: Dielectric layer 23: Reproducing layer 24: Intermediate layer 25: recording layer 26: dielectric layer 27: thermal diffusion layer

Claims (6)

[Claims] 1. A reproducing layer which is an in-plane magnetized film and a recording layer which is a perpendicular magnetized film are provided on a substrate at least at room temperature, and information is transferred from the recording layer to the reproducing layer by irradiation of reproducing light. A magneto-optical recording medium for reproducing, the composition of a reproducing layer of which is shown below. Gd _x Me _y (Fe _1-z Co _z ) _1-xy (0.25 ≦ x ≦ 0.31, 0.01 ≦ y ≦ 0.03,
0.3 ≦ z ≦ 0.5, Me is rare earth, Ia group, IIa
(One or more elements selected from elements other than those belonging to Group Vb, Group VIb, Group VIb, and Group VIIb) 2. Me is Nb, Mo, Hf, Ta, W, P
The magneto-optical medium according to claim 1, which is an element selected from t and Au. 3. The magneto-optical medium according to claim 1, wherein the reproducing layer has a thickness of 50 to 70 nm, the recording layer is a perpendicularly magnetized film mainly composed of TbFeCo, and the thickness thereof is 40 to 70 nm. 4. The magneto-optical medium according to claim 1, wherein the reproducing layer has a thickness of 40 to 60 nm and the recording layer has a composition shown below and a thickness of 40 to 70 nm. Tb _x Me _y (Fe _1-z Co _z ) _1-xy (0.14 ≦ x ≦ 0.22, 0.04 ≦ y ≦ 0.12,
0.1 ≦ z ≦ 0.25, Me is Ia group, IIa group, Vb
(One or more elements selected from elements other than those belonging to Group VIb, VIIb) 5. The magneto-optical medium according to claim 1, wherein the reproducing layer has a thickness of 30 to 50 nm, the recording layer is a perpendicularly magnetized film mainly containing DyFeCo, and the thickness thereof is 40 to 70 nm. 6. A reproducing layer having a thickness of 30 to 50 nm, a recording layer being a perpendicular magnetic film mainly composed of TbFeCo, having a thickness of 10 to 50 nm, and a Curie temperature between the reproducing layer and the recording layer being a recording layer. The magneto-optical medium according to claim 1, further comprising an intermediate layer of a perpendicular magnetization film mainly composed of lower DyFeCo.