JPH04192139A - Magneto-optical recording medium and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a recording medium of a higher C/N by laminating a plurality of magnetic layers on the medium enabling to over write by irradiating with erase beam consisting of continuous optical pulse being narrower at a time internal than at the time of formation of the recording bit. CONSTITUTION:On a transparent glass substrate 11 having a groove, a protective film 12-1 consisting of SiO2-Tb is provided with a spattering method and on it a first magnetic layer 13 of a Gd-Fd alloy is formed by a spattering method. Subsequently on it a second magnetic layer 14 consisting of a Dy-Fe-Co alloy is formed with a spattering method and further on it a protective film 12-2 consisting of SiO2-Tb is provided by a spattering method. Hence the magneto- optical recording medium of high signal quality enabling to over write is obtained.

Description

[Detailed description of the invention] [Table of contents] Overview
・・・・・・・・・・・・・・・・・・・・・・・・3 pages Industrial application fields・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・Page 3 Conventional technology・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
・・Problem that the 3-page invention aims to solve・・・・・・・・・・
...Means for solving the 5 page assignments...
・・・・・・・・・Page 6 Action・・・・・・・・・・・・
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・・・・・・7 pages Examples・・・・・・・・・・・・・
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・・・・Page 9 Effects of the invention・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・24 pages [Summary] Concerning overwritable magneto-optical recording media and their manufacturing method. C/N in magnetic recording media
With the aim of obtaining a magneto-optical recording medium with improved performance, we developed a magneto-optical recording medium that enables overwriting by irradiating an erase beam consisting of a series of optical pulses with narrower time intervals than those used to form recording bits. The recording medium is constructed using a magnetic multilayer film in which a large number of magnetic layers are laminated.

[Industrial application field]

The present invention relates to an overwritable magneto-optical recording medium and a method for manufacturing the same.

[Conventional technology]

In recent years, with the demand for higher speed magneto-optical disks, there has been a demand for magneto-optical recording media that can be overwritten. For this reason, various overwriting methods have been proposed9, for example, in the literature (Appl, Phy, Letter, Vol.
49. No.8. Page 473, 1986) proposes a method of recording and erasing information using a demagnetizing field. According to this method, when erasing information,
While checking whether the bit being written turns on or not,
If a bit has been written, an erase beam is applied to the center of the written bit to erase it.
If it is not written, the above operation will not be performed.

On the other hand, when recording information, check whether there is a bit that has been written in the same way, and if there is no write bit, write a new bit, and if there is already a write bit, do nothing. Overwriting is in progress.

However, this overwriting method has the problem that the position of the information that has already been written must be detected before rewriting the information, and the applicant has previously proposed a method that solved this problem. Unexamined Japanese Patent Publication No. 1-119941
No. 1-119942. As shown in FIG. 10, in this method, in an area other than the area of the magneto-optical recording medium where a new recording bit 1 is to be formed, the recording pulse 2 used for forming the recording bit 1 is
This method involves irradiating continuous light pulses so that erase pulses 3 with narrow pulse widths are formed.

The structure of such an overwritable magneto-optical recording medium is as shown in FIG.
Protective film 12-1 consisting of b, gadolinium-terbium-
A magnetic layer 41 made of a rare earth transition metal such as iron (Gd-Tb-Fe) and a protective film 12-2 made of SiO and -Tb are laminated, and the magnetic layer for performing magneto-optical recording has a single-layer structure.

[Problem to be solved by the invention]

However, although this overwriting method is simple in terms of method and equipment, it is sensitive to subtle changes in the composition of the magneto-optical recording medium, so even if the composition of the magneto-optical recording medium changes slightly, information cannot be erased. The remaining bits are generated, making it impossible to write accurate bits, making it difficult to obtain a magneto-optical recording medium with high quality signals with a high C/N ratio.

The present invention solves the above problems and provides an overwritable magneto-optical recording medium that can obtain high signal quality.
and its manufacturing method.

[Means for Solving the Problem 3] The magneto-optical recording medium of the present invention achieves the above object by irradiating an erasing beam consisting of a series of optical pulses with narrower time intervals than those used for forming recording bits. A magneto-optical recording medium that allows overwriting is characterized in that the medium uses a magnetic multilayer film in which a large number of magnetic layers are laminated. In addition, the first magnetic layer on the side where the laser beam is incident and the second magnetic layer above it are exchange-coupled.
A rare earth material in which the first magnetic layer contains gadolinium is characterized in that a domain wall is not formed between the two upper and lower magnetic layers.
It is characterized by a magnetic layer made of a transition metal. Further, the eleventh magnetic layer is a magnetic layer made of a rare earth-transition metal system having a compensation temperature between room temperature and the Curie temperature.

Furthermore, when manufacturing the above-mentioned magneto-optical recording medium, when forming the first magnetic layer and the second magnetic layer of the magneto-optical recording medium, A second magnetic layer is formed without any time interval while maintaining the vacuum state and gas pressure in the container of the film apparatus.

[For production]

The present inventors have discovered that in a magneto-optical recording medium with a single magnetic layer,
A medium that can be overwritten was confirmed as having a compensation temperature equal to or higher than room temperature.

Gd-Tb-Fe is used as such a magneto-optical recording medium.

Gd-Tb-Fe-Co, Gd-Tb-Co, G
It was confirmed that materials containing Gd such as d-Fe are good.

The reason for this is that Gd has the property of making it easier to move domain walls and making erasing easier. Therefore, increasing the amount of Gd results in a magneto-optical recording medium that is very easy to erase. However, if erasing becomes easier, the bits may become unstable and the signal quality before overwriting may not be good.

In other words, when Gd is increased, the magneto-optical recording medium becomes easier to erase, but the signal quality before overwriting deteriorates. On the other hand, if Gd is decreased, the signal quality before overwriting improves, but it becomes difficult to erase, and the signal quality after overwriting deteriorates.

This is shown in FIG. The figure shows the composition dependence of overwriting, and the horizontal axis is Gd in Gd-Tb-Fe.
The vertical axis indicates the signal quality C/N.

A song 1t51 in the figure shows a signal quality curve before overwriting, and a curve 52 shows a signal quality curve after overwriting.

According to curves 51 and 52, erasing becomes possible when the Gd amount is around 20 atomic %, but when the Gd amount exceeds 30 atomic %, erasing becomes easier, but the signal quality before overwriting deteriorates. Even when the amount of Gd that is most easily erased is 30 atomic %, the problem with using a single magnetic film is that the signal quality is poor.

Therefore, the magnetic layer has a two-layer structure, and the first layer uses a magneto-optical recording medium containing a large amount of Gd, which can be overwritten and easily erased, and the second layer is not overwritable, but has a high signal quality. By using a good magneto-optical recording medium and performing exchange coupling between the two, a magneto-optical recording medium that is easy to erase and has good signal quality can be obtained.

In addition, after forming the first magnetic layer, the second magnetic layer is formed without breaking the vacuum of the vacuum chamber of the sputtering device, allowing oxidation of the magnetic layer and moisture in the atmosphere to be absorbed by the magnetic layer. Therefore, a high-quality magneto-optical recording medium with no deterioration in signal quality can be obtained.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

A sectional view of a first embodiment of the magneto-optical recording medium of the present invention is shown in FIG. On a transparent glass substrate 11 having grooves, a protective film 12-1 made of silicon dioxide-terbium (Sin2Tb) is provided to a thickness of 9Or+m by sputtering, and on top of this a protective film 12-1 made of silicon dioxide-terbium (Sin2Tb) is formed by sputtering. ) An 11M magnetic layer 13 of the alloy is formed by sputtering to a thickness of 30 nm, on which is deposited a dysprosium-iron-copal (dysprosium-iron-copal) (
A second magnetic layer 14 made of a Dy-Fe-Co alloy is formed to a thickness of 60 nm by sputtering, and a protective film 12-2 made of silicon dioxide-terbium (Stow Tb) is further formed on it to a thickness of 90 nm. It is provided by sputtering method to a thickness of .

The first and second magnetic layers are both rare earth metal-rich (RE-rich) magnetic layers.

A method for manufacturing such a magnetic recording medium is as shown in FIG. 2 and FIG.
A substrate 11 made of a transparent glass plate with grooves inside 1 and 5i0
z Target 22 for forming a protective film such as Tb, Gd
- Target 23 for forming the first magnetic layer of Fe alloy, D
Targets 24 for forming a second magnetic layer made of a y-Fe-Co alloy are placed facing each other, and a shutter 25 is placed between these targets and the substrate.

It is assumed that the two targets are arranged on a circumference of a predetermined diameter, and that the shutter is disk-shaped and rotates over the shutter so that the opening provided on the corresponding target is located.

Once the inside of the container 21 is modified under a vacuum of 5 Xl0-'Pa or less,
After exhausting from the exhaust pipe 26, the gas introduction pipe 2 of the container 21
Ar gas is introduced from 7, and while maintaining the gas pressure at 0.2 Pa, the shutter 25 is moved from below the protective film forming target 22, and the target is sputtered to form Si.
A protective film 12-1 made of ng Tb is formed by sputtering to a thickness of 90 nm.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuation to a vacuum level of Xl0-'Pa, Ar gas is again introduced into the container 21, and the sputtering gas pressure is set to 0.2 Pa, and the shutter 25 is opened from below the target 23 for forming the first magnetic layer of Gd-Fe alloy. is moved, and the target is sputtered to form the first magnetic layer 13 of the Gd-Fe alloy.
It is formed to a thickness of 0 nm.

Next, after maintaining the vacuum state in the container 21 and the sputtering gas pressure of Ar gas, the Dy-Fe-Co
The shutter 25 is moved from below the target 24 for forming a second magnetic layer made of an alloy, and the target is sputtered to form a second magnetic layer 14 made of a Dy-Fe-Co alloy to a thickness of 60 nIl. .

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuating the vacuum to a pressure of less than A protective film 12-2 made of Tb is formed to a thickness of 90 nm.

Overwriting is performed using the magneto-optical recording medium made of the RE glitch magnetic double layer film thus formed.

The magneto-optical recording medium is rotated at a constant speed of 7.4 m/sec, and the laser power is set to 71. The writing frequency of old information is 1.5 MHz (mark length is 2.5 urn)
, the overwrite writing frequency is 1.9MHz (
Mark length: 2 μm) The erase pulse was recorded at 9 MHz. In this case, the signal quality C/N was 48 dB. FIG. 3 shows a state diagram showing the direction of the recording magnetic field in this magneto-optical recording medium, and FIG. 4 shows the state of the pulse waveform used in this magneto-optical recording medium.

As shown in FIG. 3, the magnetic field is reversed in the laser beam irradiation region 28, and the domain wall 29 at the boundary where the magnetic field is reversed moves together with the first magnetic layer 13 and the second magnetic layer 14. They are exchange-coupled, and no domain wall is formed between the two magnetic layers. Therefore, even if the first and second magnetic layers have some compositional variation, the characteristics of each magnetic layer are the same. A high-quality magneto-optical recording medium with no deterioration in signal quality can be obtained because the signals compensate for each other.

A second practical example of the magneto-optical recording medium of the present invention is shown in FIG.
A protective film 1 made of silicon dioxide-terbium (Sing Tb) is placed on a transparent glass substrate 11 having grooves.
2-1 is provided with a thickness of 9On+w by sputtering, and gadolinium-terbium-iron (Gd-Tb-F
e) A first magnetic layer 13 made of an alloy is formed by sputtering to a thickness of 40 nni, and a second magnetic layer 14 made of a terbium-iron-copal (Tb-Fe-Co) alloy is formed thereon. is formed by sputtering to a thickness of 60 ns, and silicon dioxide-terbium (SiOl-T
A protective film 12-2 as shown in b) is provided to a thickness of 90 nm by sputtering.

The first magnetic layer 13 is a rare earth metal rich (RE glitch) magnetic layer, and the second magnetic layer 14 is a transition metal rich (7M rich) magnetic layer.

The method for manufacturing such a magneto-optical recording medium is the second method described above.
As shown in FIG. 5 and FIG.
1 and a target 2 for forming a protective film such as SiO□-Tb.
2. A first magnetic layer forming target 23 made of a Gd-Tb-Pe alloy and a second N magnetic layer forming target 24 made of a Tb-Fe-Co alloy are arranged facing each other, and between these targets and the substrate. A shutter 25 is placed at.

After the inside of the container 21 is once evacuated from the vacuum modified exhaust pipe 26 at a pressure of 5 Xl0-'Pa or less, Ar gas is introduced from the gas introduction pipe 27 of the container 21, and while maintaining the gas pressure at 0.2 Pa. , the shutter 25 is moved from below the target 22 for forming a protective film, and the target is exposed to form a protective film 12-1 such as Sing Tb with a thickness of 90 nm.
Form to a thickness of .

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuation to a vacuum level of The shutter 25 is moved further, and the target is sputtered to form the first magnetic layer 13 of Gcl-Tb-Fe alloy to a thickness of 30 na+.

Next, after maintaining the vacuum state in the container and the sputtering gas pressure of Ar gas, Tb-Fe-C was formed.

The shutter 25 is moved from below the second N magnetic layer forming target 24 made of an alloy, and the target is sputtered to form a second magnetic layer 14 made of a Tb--Fe--Co alloy to a thickness of 60 nm.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuation to a vacuum of less than
The shutter 25 is moved from below 2, and the target is sputtered to form a protective film 12-2 such as 5ift Tb.
It is formed to a thickness of 0 nm.

Overwriting is performed using the magneto-optical recording medium made of the RE-rich, 7M-rich magnetic double-layer film thus formed. The magneto-optical recording medium thus formed is rotated at a constant speed of 7.4 m/sec, and the laser power is set to 9 mW. The writing frequency of old information is 1.5M)
The overwriting frequency was 1.9 MHz (mark length 2 μm), and the erase pulse was 9 MHz. In this case signal quality C
/N = 47 dB. The state of the pulse waveform used in this magneto-optical recording medium is shown in FIG. 4, and the state of the magnetic field in this magnetic layer is shown in FIG. 6.

As shown in FIG. 6, in the laser beam irradiation area 28, the magnetic field is reversed with respect to the area not irradiated with the laser beam.
In this laser beam irradiation region, the magnetic fields of the first magnetic layer 13 and the second magnetic layer 14 are reversed.

In addition, the domain wall 29 at the boundary where the magnetic field is reversed is the first magnetic layer 1.
3 and the second magnetic layer 14 and are exchange-coupled together, and no domain wall is formed between the two magnetic layers.
Therefore, even if there is some variation in composition between the first and second magnetic layers, a high-quality magneto-optical recording medium with no deterioration in signal quality can be obtained because the magnetic layers compensate for each other's characteristics. .

A third embodiment of the magneto-optical recording medium of the present invention is shown in FIG.

As shown in the figure, on a transparent glass substrate 11 having grooves,
A protective film 12-1 such as silicon dioxide-terbium (SiO□-Tb) is provided to a thickness of 90 nm by sputtering, and a first magnetic layer 13 of gadolinium-iron (Gd-Fe) alloy is formed thereon. is formed to a thickness of 30 nm by sputtering, and dysprosium-iron-cobalt (D
The second magnetic layer 14 made of y-Fe-Go) alloy is 6
It is formed to a thickness of 0 nm by sputtering, and on top of that is gadolinium-terbium-cobalt (Gd-Tb-C).
o) The third magnetic layer 31 made of an alloy is formed by sputtering.
A protective film 1 such as silicon dioxide-terbium (Sift Tb) is formed on the film to have a thickness of 0 nm.
2-2 is provided with a thickness of 9Or+n+ by sputtering.

The method for manufacturing such a magneto-optical recording medium is the second method described above.
As shown in FIG. 7 and FIG.
1 and a target 2 for forming a protective film such as SiO□-Tb.
2. A first magnetic layer forming target 23 made of a Gd-Fe alloy, a second magnetic layer forming target 24 made of a Dy-Fe-Co alloy, and a third magnetic layer made of a Gd-Tb-Co alloy. Forming targets 32 are arranged facing each other, and a shutter 25 is installed between these targets and the substrate.
Place.

After the inside of the container 21 is once evacuated from the vacuum modified exhaust pipe 26 at a pressure of 5 Xl0-'Pa or less, Ar gas is introduced from the gas introduction pipe 27 of the container 21, and while maintaining the gas pressure at 0.2 Pa. , the shutter 25 is moved from below the target 22 for forming a protective film, and the target is sputtered to form a protective film 12-1 such as Sin, -'fb to a thickness of 90 nm.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuating to a vacuum level of X 10-'Pa, Ar
Gas is introduced into the container, the sputtering gas pressure is set to 0.2 Pa, the shutter 25 is moved from below the target 23 for forming the first layer of Gd-Fe alloy, and the target is sputtered to form the first layer of Gd. -Magnetic layer 13 of Fe alloy is 30
Formed to a thickness of nm.

Next, after maintaining the vacuum state in the container 21 and the sputtering gas pressure of Ar gas, the Dy-Fe-Co
The shutter 25 is moved from below the target 24 for forming the second layer magnetic layer made of alloy, and the target is sputtered to form the second layer magnetic layer 14 made of the Roy-Fe-Go alloy with a thickness of 60 nm. Form into a thick layer.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuating the vacuum to less than X 10-'Pa, ^r
Gas is introduced into the container 21, and the sputtering gas pressure is set to 0.2P.
As a, the shutter 25 is moved from below the target 32 for forming the third magnetic layer of the Gd-Tb-Co alloy, and the target is sputtered to form the third magnetic layer 31 of the Gd-Tb-Co alloy with a thickness of 80 nm. Form into a thick layer.

Then, the supply of Ar gas was further stopped, and the inside of the container 21 was
After evacuation to a vacuum of less than
Move the shutter 25 from below 2 and sputter the target to form a protective film 12-2 such as Sin, -Tb at 90%
Formed to a thickness of nm.

RE glitch RE glitch RE formed in this way
Overwriting is performed using a magneto-optical recording medium having a magnetic layer with a glitch three-layer structure.

The magneto-optical recording medium thus formed was 7.4 so/s
It is rotated at a constant speed of ec, and the laser power is set to 9IIW. The writing frequency for old information was 1.5 MHz (mark length 2.5 μl11), the writing frequency for % overwriting was 1.9 MHz (mark length 2 μl11), and the erase pulse was recorded at 9 MHz. In this case, signal quality C/N
=51 dB. FIG. 8 shows the state of the magnetic field in this magnetic layer. As shown in FIG. 8, in the laser beam irradiation area 28, the magnetic field is reversed with respect to the area not irradiated with the laser beam, and the first magnetic layer 13 in the area irradiated with the laser beam The magnetic fields are reversed between the magnetic layer 14 and the second magnetic layer 14. Also, the domain wall 29 at the boundary where the magnetic field is reversed
moves together with the first magnetic layer and the second magnetic layer and is exchange-coupled with each other. Therefore, even if there is a slight change in the composition of the first and second magnetic layers, the magnetic properties of each other remain the same. Since the layers complement each other in their characteristics, a high-quality magneto-optical recording medium with no deterioration in signal quality can be obtained.

In order to compare with the magneto-optical recording media of the first, second and third embodiments of the present invention, the present inventors used the apparatus shown in FIG. A magneto-optical recording medium was formed.

As shown in FIGS. 2 and 11, a substrate 11 made of a glass plate with grooves is placed in a container 21, and the inside of the container is evacuated to a degree of vacuum of I Xl0-'Pa.

Next, Ar gas is introduced into the container 21, and while maintaining the sputtering gas pressure at 0.2 Pa, the shutter 25 is moved from below the protective film forming target 22, and the target is sputtered to form a Tb-Si0g film. Protective film 12-1
is formed to a thickness of 90 nm.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuating until the degree of vacuum is less than Xl0-'Pa,
Introduce the gauge gas into the container 21 again, and set the gas pressure to 0.2 Pa.
While maintaining the target, the shutter is moved from the magnetic layer forming target, and a Gd-Tb-Fe alloy is sputtered to a thickness of 40 nm to form the magnetic layer 41.

Then, the supply of Ar gas is stopped, and the inside of the container 21 is
After evacuation to below Xl0-'Pa, Ar gas is introduced into the container again, and while maintaining the gas pressure at 0.2 Pa, a protective film 12-2 of Tb-5iOz film is sputtered to a thickness of 90 nm. Form.

Overwriting is performed using the magnetic recording medium in which the RE glitch magnetic layer thus formed is formed in one layer.

The magneto-optical recording medium is rotated at a constant speed of 7.4 so/sec, the laser power is 9 m-, the old information writing frequency is 1.5 M) Iz (mark length = 2.5 utm)
), overwrite write frequency is 1,9M)
Iz (mark length 2μff1), erase pulse is 9MHz
And so. The signal quality after overwriting in this manner was 40 dB, which was found to be lower than that of the magneto-optical recording media of the first, second and third embodiments.

The above matters are summarized in Table 1 on the next page.

In Table 1, 1.2.3 is the 1st. Second. A third example is shown.

Table 1 Note that the exchange coupling force σ of the magneto-optical recording medium formed by the method of the first example is 7.3 erg/cm2, and the exchange coupling force of the optical axis recording medium formed by the method of the second example force σ. is 7
．． 7erg/cm", and after forming the first layer of a magneto-optical recording medium having the same structure as the first example, the gas supply was stopped and the inside of the container was evacuated, and then the second layer was deposited. As a result of experiments, it was found that the exchange coupling force σ when a layer was formed was as small as 3.3 erg/cm.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the recording video
In a magneto-optical recording medium that is overwritten by irradiation with an erasing beam consisting of a series of optical pulses with a narrower time interval than that used for forming a signal, it is possible to obtain a magneto-optical recording medium with high signal quality. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first embodiment of the magneto-optical recording medium of the present invention, FIG. 2 is a schematic diagram of an apparatus used for manufacturing the magneto-optical recording medium of the present invention, and FIG. 3 is a recording of the first embodiment. FIG. 4 is a waveform diagram of recording pulses in the first and second embodiments, FIG. 5 is a sectional view of the second embodiment of the present invention, and FIG. 6 is a diagram showing the second embodiment. FIG. 7 is a cross-sectional view of the third embodiment of the present invention, FIG. 8 is a state diagram showing the direction of the recording magnetic field of the third embodiment, and FIG. 9 is a state diagram showing the direction of the recording magnetic field of the third embodiment. Diagram showing composition dependence of light, No. 10
The figure is an explanatory diagram of recording pulses of a magneto-optical recording medium, and FIG. 11 is a cross-sectional view of a conventional magneto-optical recording medium. In the figure, 11 is a substrate, 12-1, 12-2 are protective films, and 13 is a first
14 is a second magnetic layer, 21 is a container, 22 is a target for forming a protective film, 23 is a target for forming a first magnetic layer, 24 is a target for forming a second magnetic layer, 25
is a shutter, 26 is an exhaust pipe, 27 is a gas introduction pipe, 28
29 is the laser beam irradiation area, 29 is the domain wall, 31 is the third magnetic layer, 32 is the target for forming the third magnetic layer, 41 is the magnetic layer, 51 is the signal quality curve before overwriting, and 52 is the first Fig. 2 Fig. 311 4th WJ mb Fig. 6B Fig. 7 % (dB) tilt Kiyama Shisuke - Inferior Zeme Dome Dodo Ascending Pulse ^qtip
rrnFig.

Claims (5)

[Claims] (1) A magnetic layer is provided on the substrate (11), and a recording bit (1
) in a magneto-optical recording medium that enables overwriting by irradiating an erase pulse (3) consisting of a series of light pulses with a narrower time interval than the recording pulse (2) used to form the medium. A magneto-optical recording medium characterized by using a magnetic multilayer film in which a large number of magnetic layers (13, 14, 31) are laminated. (2) In claim (1), the first magnetic layer (13) on the side into which the laser beam is incident and the second magnetic layer (13) above the first magnetic layer (13)
14) is exchange-coupled, and a magnetic domain wall (29) is not formed between two upper and lower magnetic layers (13, 14). (3) In claim (1), the first magnetic layer (13)
1. A magneto-optical recording medium, wherein the magnetic layer is made of a rare earth-transition metal containing gadolinium. (4) In claim (1), the first magnetic layer (13)
1. A magneto-optical recording medium, characterized in that the magnetic layer is made of a rare earth-transition metal system and has a compensation temperature between room temperature and the Curie temperature. (5) The first magnetic layer (13) and the second magnetic layer of the magneto-optical recording medium.
When forming the magnetic layer (14) of the first layer, the first magnetic layer (13)
The second magnetic layer (14) is formed without any time interval while maintaining the vacuum state and gas pressure in the container (21) of the film forming apparatus during film formation. A method for manufacturing a magneto-optical recording medium.