JP2000082245A - Magneto-optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magneto-optical recording medium suitable for near-field magneto-optical recording, having high SNR and high recording magnetic field sensitivity, and having excellent durability and glide characteristics. SOLUTION: A reflective layer is formed on a substrate, and a recording layer composed of a main recording layer having perpendicular magnetization and a large coercive force thereon and an auxiliary layer having a coercive force at room temperature smaller than that of the main recording layer. To form The main recording layer is made of TbFeCo, and the auxiliary layer is made of TbFeCo or GdFeCo, using a noble metal or a metal film mainly composed of Cu, especially Au as the reflective layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable optical recording medium, and more particularly to a magneto-optical recording medium for recording, reproducing and erasing information by changing the direction of magnetization of a main recording layer by a laser beam and a magnetic field. .

[0002]

2. Description of the Related Art Magneto-optical recording media are portable recording media capable of large-capacity, high-density recording, and have been demanded as rewritable media for recording large-capacity files and moving images of computers accompanying the recent increase in multimedia. Is rapidly increasing.

A magneto-optical recording medium generally forms a multilayer film including a recording layer on a transparent disc-shaped substrate such as plastic, and performs recording and erasing by irradiating a laser while applying a magnetic field.
Reproduce with laser reflected light. Conventionally, the recording method has mainly been a so-called optical modulation recording in which a fixed magnetic field is applied and erased, and then a fixed magnetic field in the opposite direction is applied for recording.
A magnetic field modulation method that modulates a magnetic field according to a recording pattern while irradiating a laser is attracting attention as a method that can perform recording (direct overwrite) in one rotation and can accurately record even at a high recording density.

Conventionally, a laser for recording / reproducing has been applied to a recording film through a substrate. Recently, so-called near-field optical recording, in which an optical head is brought close to a recording film to perform recording / reproducing, has attracted attention as a means for increasing the density (Appl.
hys. Lett. 68, p. 141 (1996)).
In this recording method, Solid ImmersionLe
By using an ns (hereinafter abbreviated as SIL) head to reduce the laser beam spot size, the conventional recording limit (限界 λ / 2) determined by the laser wavelength (λ) of the light source is obtained.
NA: NA can be reproduced with a mark shorter than NA (numerical aperture of the objective lens), and recording and reproduction with an ultra-high recording density can be realized. In this near-field optical recording, it is necessary to bring the optical head close to the recording medium (up to 100 nm). A method of directly irradiating the recording film with a laser beam. In other words, the structure of the recording film is generally substrate / first protective layer / recording layer / second protective layer / reflective layer in a conventional optical recording medium, whereas in the near-field optical recording, the substrate / first protective layer / recording layer / second protective layer / reflective layer is used. A recording / reproducing operation is performed by irradiating a laser beam from the film surface side as a film structure having a reverse structure of a reflective layer / first protective layer / recording layer / second protective layer (surface reading type recording). At this time, a flying slider head is often used to bring the recording film and the SIL head closer to each other. As for recording, near-field magneto-optical recording is a magnetic field modulation recording in which recording is performed by irradiating a laser beam to raise the recording layer above the Curie temperature and modulating the magnetic field with a thin-film coil formed on the slider head. It is said to be suitable.

Although high-density recording is possible by magnetic field modulation recording on a magneto-optical recording medium as described above, it is necessary to sufficiently increase the recording magnetic field sensitivity for high-speed magnetic field modulation recording. For a conventional magneto-optical recording medium, in order to increase the recording magnetic field sensitivity, rare earth-preferred TbFeCo and transition metal-preferred TbFeCo are used.
bFeCo is laminated to reduce the demagnetizing field (Japanese Patent Application Laid-Open No. Sho 62-128040), a part of the TbFeCo film is oxidized (Japanese Patent Application Laid-Open No. 61-188762), and the TbFeCo film having a large coercive force is added to GdFeCo having a small coercive force. Laminating films (IEEJ Technical Meeting Material MAG-91-167)
Have been proposed in the past.

In order to reproduce high-density recording magnetic domains, it is necessary to increase the Kerr rotation angle to increase the reproduction output. For a conventional magneto-optical recording medium, as a method for increasing the reproduction output, a two-layered recording layer of TbFe having a low Curie temperature and GdFe having a high Curie temperature (Japanese Patent Laid-Open No. 57-78652) is used. A method of using a single-layer recording layer of TbFeCo having a somewhat higher Curie temperature of 10 to 10 atomic% has been proposed, and the latter method is used in current magneto-optical disks.

Further, since the near-field optical recording has a reversed film structure, the distance between the head and the recording medium is very short (up to 0.1 μm). Interface problem (head crash etc.).

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to increase the reproduction output to increase the signal-to-noise ratio (SNR), to increase the recording magnetic field sensitivity for high-speed magnetic field modulation recording, and to further improve the head. An object of the present invention is to provide a magneto-optical recording medium for near-field magneto-optical recording having a film structure opposite to that of the related art, which has a small impact between the recording medium and the recording medium.

[0009]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned current situation, and as a result, completed the present invention.

That is, the present invention relates to a magneto-optical recording medium in which at least a reflective layer, a recording layer and a dielectric layer are laminated on a substrate in this order, wherein the recording layer has a main recording layer and an auxiliary layer, The main recording layer has perpendicular magnetization, has a sufficiently large coercive force to stably hold recorded information, and the coercive force at room temperature of the auxiliary layer is smaller than that of the main recording layer. It is a characteristic magneto-optical recording medium. The surface roughness Ra of the reflective layer of the magneto-optical recording medium of the present invention is preferably 1.3 nm or less.
It is preferable that the metal film be made of a metal film made of u or a metal film mainly composed of a noble metal or Cu. The noble metal or the metal film mainly composed of Cu in the present invention has a noble metal of 9%.
Metal film containing 0 atomic% or more, or 90 atomic% of Cu
The metal film contained above.

The reflective layer is made of a noble metal or Cu, such as Cr, Ti,
More preferably, it is composed of an alloy to which 0.01 to 5 atomic% of Zr, Nb or Ta is added.
More preferably, it is composed of an alloy film to which 0.01 to 2 atomic% of i, Zr or Cr is added.

Further, as the reflection layer of the present invention, an alloy film obtained by adding 0.1 to 5 atomic% of Pd and 0.1 to 5 atomic% of Cu to Ag, and 0.1 to 5 atomic% of Pd to Ag And an alloy film to which 0.1 to 5 atomic% of Ti is added.

These reflective layers are preferably formed on an underlayer made of a metal film. As the underlayer, a metal film of Cr, Ti, Zr, Nb or Ta having a thickness of 0.5 nm or more and 100 nm or less, It is preferable to use an alloy film of two or more metals selected from the group consisting of Ti, Zr, Nb and Ta. In particular, a Ti film or a Cr film having a thickness of 0.5 nm or more and 100 nm or less as an underlayer of the reflection layer.
It is preferable to form a film and then form an Au film thereon to form a reflective layer. Further, as the reflection layer of the present invention, an aluminum film or an aluminum alloy film having a thickness of 5 nm or more and 50 nm or less is laminated on a metal film composed of a noble metal or Cu or a metal film mainly composed of a noble metal or Cu.
A layer film can also be used.

[0014] The magneto-optical recording medium of the present invention is made of TbFeCo.
Or, a main recording layer of perpendicular magnetization mainly composed of TbFeCo and TbFeCo.
An auxiliary layer of perpendicular magnetization mainly composed of bFeCo or TbFeCo is laminated, and the saturation magnetization at room temperature of the main recording layer is 50 emu / cc or less when a transition metal is preferred, and 200 emu / cc or less when a rare earth is preferred. The auxiliary layer has transition metal priority, and its saturation magnetization at room temperature is 200 emu / cc.
Above 600 emu / cc or less, the average saturation magnetization at room temperature of the laminated film of the main recording layer and the auxiliary layer is 100 emu / cc or less, and the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer. Curie temperature difference is 100
A magneto-optical recording medium in which the thickness of the auxiliary layer is 2 nm or more and 10 nm or less and the thickness of the main recording layer is half or less in the range of not more than ° C.

Further, the magneto-optical recording medium of the present invention has a Tb
A main layer of perpendicular magnetization mainly composed of FeCo or TbFeCo and an auxiliary layer of perpendicular magnetization mainly composed of GdFeCo or GdFeCo are laminated, and both the main recording layer and the auxiliary layer have a saturation magnetization at room temperature of 100 emu / cc or less. Thus, a magneto-optical recording medium in which the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer, the thickness of the auxiliary layer is 2 nm or more, and the thickness of the main recording layer is 2/3 or less.

The recording layer of the present invention is that the main recording layer is formed after the formation of the auxiliary layer, that is, the auxiliary layer is formed closer to the substrate than the main recording layer. preferable.

The main recording layer or auxiliary layer mainly composed of TbFeCo or the auxiliary layer mainly composed of GdFeCo of the present invention is preferably one to which Ta is added in order to enhance corrosion resistance.

In the main recording layer or auxiliary layer mainly composed of TbFeCo of the present invention, 90 atomic% or more of TbFeCo is used.
A main recording layer or an auxiliary layer of Co;
In the auxiliary layer mainly composed of dFeCo, 90 atomic% or more of G is
The auxiliary layer is dFeCo.

Hereinafter, the present invention will be described in more detail.

FIG. 1 is a partial sectional view of an embodiment of the magneto-optical recording medium of the present invention. On a substrate 11, a reflective layer 12, a main recording layer 13, an auxiliary layer 14, and a dielectric layer 15 are laminated.

The substrate 11 is not particularly limited as long as it satisfies the characteristics of a medium substrate such as mechanical characteristics, and glass, polycarbonate, amorphous polyolefin, engineering plastic, or the like can be used. It is preferably sufficiently smooth, and particularly preferably, Ra (center line average roughness) is 1.3 nm or less.

The reflection layer 12 is made of Al, Al alloy, Ag, A
It is made of a highly reflective metal such as u or Cu. The present inventors have reported that, in a magneto-optical recording medium for near-field magneto-optical recording having a film structure reverse to that of a conventional one, the surface roughness and properties of the reflective layer depend on the recording magnetic field sensitivity and noise level. Is a major factor in determining
The following has been found regarding the reflective layer.

That is, the surface roughness Ra of the reflection layer is set to 1.3.
By setting it to nm or less, the recording magnetic field sensitivity can be increased, and the SNR can be increased by setting the noise level to an appropriate level. When the reflective layer is formed by the sputtering method, when the material constituting the reflective layer is Al, the thickness is reduced to about 30 nm, or a corrosion resistant element such as Cr, Ti, Zr, Nb, or Ta is added. By doing so, the surface roughness can be reduced.

If the reflective layer is made of a metal film made of a noble metal such as Ag or Au or Cu, or a metal film mainly made of a noble metal such as Ag or Au or Cu, the surface roughness of the reflective layer is not less than 100 nm. Ra is easily 1.3 nm
It is possible to:

The recording / reproducing laser wavelength is 550 n.
In the case of m or less, the reflectivity of the Ag film hardly decreases, so that the reflective layer is preferably made of the Ag film. The noble metal or Cu may not be able to make the reflective layer too thick from the viewpoint of recording sensitivity because heat conduction is too good. However, the reflective layer is made of an alloy film in which Cr, Ti, Zr, Nb or Ta is added to a noble metal, or Cr is added to Cu. , Ti, Zr, Nb or Ta
, The corrosion resistance is increased, and a thickness of the reflective layer of 50 nm or more can be easily secured. Cr,
Ti, Zr, Nb, or Ta may be added in combination of two or more elements, but the total amount is preferably 0.01 to 5 atomic%, and the required recording sensitivity It is good to select appropriately according to. Except when Au is used as a noble metal, the addition amount of Cr, Ti, Zr, Nb or Ta is more preferably 0.1 to 5 atomic%.
The added amount of r, Ti, Zr, Nb or Ta is 0.01
More preferably, it is set to 2 atomic%. In particular, Au has C
0.01 to 2 atomic% of r, Ti or Zr,
More preferably, when the alloy layer to which 0.02 to 0.5 atomic% is added is used as the reflective layer, a recording medium having good corrosion resistance and good glide characteristics can be obtained. Sufficient corrosion resistance can be obtained even when a metal film made of Au alone is used as the reflective layer. However, by adding Cr, Ti or Zr, the glide characteristics are further improved, and a recording medium that is unlikely to cause head crash can be obtained. Obtainable. It is considered that the addition of Cr, Ti, or Zr to Au increases the hardness of the reflection film, thereby improving the glide characteristics. In this case, Cr, Ti or Zr
If the addition amount is too large, the laser power for recording may be too small and the recording may become unstable, so the addition amount is preferably 2 atomic% or less.

As a base layer of the reflective layer, a thickness of 0.5 nm or more and 10
A metal film of Cr, Ti, Zr, Nb or Ta having a thickness of 0 nm or less, more preferably 3 nm or more and 100 nm or less;
Alternatively, by forming an alloy film of two or more metals selected from the group consisting of Cr, Ti, Zr, Nb and Ta on the substrate, the corrosion resistance can be increased. In particular, C
When a base layer having a thickness of 0.5 nm or more and 100 nm or less is formed with r or Ti, and an Au film is formed thereon to form a reflective layer, a recording medium having good corrosion resistance and good glide characteristics can be obtained. Sufficient corrosion resistance can be obtained even when only the Au film is used as the reflective layer without forming the underlayer, but the glide characteristics are further improved by forming the Cr film or the Ti film as the underlayer, and the head crashes. It is possible to obtain a recording medium in which the occurrence of hardly occurs.
This is achieved by forming a Cr or Ti underlayer.
It is considered that the adhesion to the substrate is suppressed to some extent as compared with the case of only the u film, and the glide characteristics are improved.

Further, when the coercive force is insufficient because the surface roughness of the reflective layer is too small, the surface roughness of the reflective layer can be controlled by forming the underlayer. That is, the surface roughness of the reflective layer is increased by forming the underlayer, but the surface roughness of the reflective layer is increased as the thickness of the underlayer is increased.

A guide groove and a pit of a format are formed on the substrate 11. When the reflection layer is a noble metal or Cu,
There is a case where the signal of the guide groove or the pit is several tens% lower than that of the medium having the reflective layer of Al or Al alloy. The reflective layer is formed as a two-layer film in which an aluminum film or an aluminum alloy film having a thickness of 5 nm or more and 50 nm or less is laminated on a metal film made of a noble metal or Cu or a metal film mainly containing a noble metal or Cu. Signals in guide grooves and pits can be increased. By laminating an aluminum film or an aluminum alloy film on a noble metal film or a Cu film, the recording magnetic field sensitivity is increased. This is because the crystal grain size of the aluminum film or aluminum alloy film is larger than the thickness of the domain wall of the recording film (about 10 nm), and the flat noble metal film or Cu
It is considered that the film above the film has a particularly uniform crystal grain size, so that the domain wall becomes slippery, and the magnetization is easily reversed by the movement of the domain wall during recording.

The surface roughness Ra of the reflection layer is, for example,
It can be measured by scanning with an atomic force microscope (AFM) while keeping the atomic force constant by bringing the probe close to the surface of the reflective layer until the tip having a tip of 0.1 μm or less almost contacts the surface.

The main recording layer 13 may be made of a material having a perpendicular magnetization and a large coercive force, but TbFeCo or a material mainly composed of TbFeCo is particularly preferred because it has a large coercive force. The coercive force of the main recording layer is preferably as large as possible in order to stably hold recorded information, but is preferably 5 kOe or more as a magneto-optical recording medium for near-field magneto-optical recording.

To this TbFeCo, corrosion-resistant elements such as Cr, Ti, Zr, Nb, and Ta are added to increase the corrosion resistance, and several atomic% of Nd and the like are added to increase the Kerr rotation angle at a short wavelength. It may be something. In general,
The Kerr rotation angle decreases when an element that enhances corrosion resistance is added, but in the case of adding Ta, a Kerr rotation angle almost equal to that of TbFeCo can be obtained if the Curie temperature is made the same by correcting the Co concentration.

The auxiliary layer 14 preferably has a coercive force of 1/3 or less of the coercive force of the main recording layer. Materials satisfying this condition include GdFeCo near the compensation composition, and D
yFeCo, NdDyFeCo, TbFeCo, NdT
Thin films such as bFeCo and Pt / Co artificial lattice can be used. The thickness of the auxiliary layer 14 is preferably smaller than the thickness of the main recording layer 13.

As described above, at least the reflection layer on the substrate,
A magneto-optical recording medium comprising a main recording layer, an auxiliary layer, and a dielectric layer laminated in this order, wherein the main recording layer has perpendicular magnetization and has a sufficiently large coercive force to stably hold recorded information. And the coercive force at room temperature of the auxiliary layer is smaller than the coercive force of the main recording layer, so that the Kerr rotation is smaller than when a single recording layer without such an auxiliary layer is used. The angle can be increased, and the recording magnetic field sensitivity can be increased.

The order of lamination of the main recording layer and the auxiliary layer may be the above order or the reverse order. However, the main recording layer is formed after the auxiliary layer is formed. Preferably, the auxiliary layer is formed closer to the substrate than the main recording layer. In this case, the effect of increasing the Kerr rotation angle by the auxiliary layer is small, but noise is reduced, so that good signal quality can be obtained by the effect of increasing the recording magnetic field sensitivity.

As a preferable combination of the main recording layer and the auxiliary layer, a main layer of perpendicular magnetization mainly composed of TbFeCo or TbFeCo and an auxiliary layer of perpendicular magnetization mainly composed of TbFeCo or TbFeCo are laminated. 50 emu when the saturation magnetization at room temperature of the
/ Cc or less, 200 emu / cc or less in the case of rare earth priority, and the auxiliary layer has transition metal priority, and its saturation magnetization at room temperature is 200 emu / cc or more and 600 emu / cc or less.
The average saturation magnetization of the laminated film of the main recording layer and the auxiliary layer at room temperature is 1
When the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer and the difference between the Curie temperatures is 100 ° C. or less, the film thickness of the auxiliary layer is 2 emu / cc or less.
Those having a thickness of not less than 10 nm and not more than half the thickness of the main recording layer are fried. The coercive force of the main recording layer is more preferably 5 kOe or more at room temperature, and the coercive force of the auxiliary layer is more preferably 1/3 or less of the coercive force of the main recording layer at room temperature.

Here, the laminated film of the main recording layer and the auxiliary layer exhibits the property of giving priority to the transition metal, and the average saturation magnetization at room temperature of 100 emu / cc or less enhances the magnetic field sensitivity and the recording stability. Preferred above. Here, the average saturation magnetization is a value obtained by summing (film thickness × saturation magnetization of each layer) and dividing by the total film thickness. Both the main recording layer and the auxiliary layer are perpendicularly magnetized at room temperature, so they are coupled by exchange coupling so that the spin direction is the same. When the main recording layer has priority on rare earth, the magnetization direction is opposite to that of the auxiliary layer. Therefore, the average saturation magnetization decreases.
Accordingly, the average saturation magnetization is calculated assuming that the transition metal priority magnetization is positive and the rare earth priority magnetization is negative.

The saturation magnetization of the main recording layer and the auxiliary layer at room temperature and the average saturation magnetization of the laminated film of the main recording layer and the auxiliary layer at room temperature are not necessarily required to be as described above. Although the effect can be obtained, the Kerr rotation angle can be further increased and the recording magnetic field sensitivity can be improved.

The relationship between the Curie temperature and the film thickness of the main recording layer and the auxiliary layer is the same as described above. As for the Curie temperature, by setting the Curie temperature of the auxiliary layer higher than the Curie temperature of the main recording layer, the magnetization of the auxiliary layer is preliminarily aligned with the recording magnetic field at the time of recording, thereby assisting the recording. However, if the difference between the Curie temperatures of the auxiliary layer and the main recording layer exceeds 100 ° C., the magnetization of the auxiliary layer at the Curie temperature of the main recording layer becomes too large, which causes a recording obstacle due to the demagnetizing field. In addition, by setting the film thickness to 2 nm or more and 10 nm or less, the effect of increasing the magnetic field sensitivity and the demagnetizing field are balanced, and high magnetic field sensitivity is obtained.

As another preferable combination of the main recording layer and the auxiliary layer, a main recording layer mainly composed of TbFeCo or TbFeCo and having perpendicular magnetization and GdFeCo or GdFeCo is used.
And an auxiliary layer mainly composed of perpendicular magnetization is laminated. Both the main recording layer and the auxiliary layer have a saturation magnetization of 100 emu at room temperature.
/ Cc or less, the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer, and the thickness of the auxiliary layer is 2 nm or more and 2/3 or less of the main recording layer. The coercive force of the main recording layer is more preferably 5 kOe or more, and the coercive force of the auxiliary layer is more preferably 1 kOe or less at room temperature. The perpendicular magnetization auxiliary layer mainly composed of GdFeCo or GdFeCo has a coercive force of 0.1 kOe at a temperature higher than the Curie temperature of the main recording layer.
Since the magnetization is small and the demagnetizing field is small because the composition is close to the compensation composition, the difference between the Curie temperatures of the auxiliary layer and the main recording layer may be 200 ° C. or less.

The auxiliary layer 13 and the main recording layer 14 are formed by vacuum deposition, sputtering, or the like. In the sputtering method, the coercive force can be easily adjusted by changing the film forming pressure.
By adjusting the film formation pressure of the main recording layer 14 higher,
Since the coercive force of the main recording layer can be made to be larger than the coercive force of the auxiliary layer up to near the Curie temperature of the main recording layer, stable recording is possible.

The dielectric layer 15 is made of SiN, AlN, SiAl
ON, made of a transparent dielectric such as Ta ₂ O ₅ . In order to improve the flying characteristics of the slider head, the dielectric layer 15 may be a laminate of a transparent dielectric layer and a diamond-like carbon (DLC) solid lubricant layer obtained by adding hydrogen or nitrogen to carbon. . Also, on top of this,
By forming a lubricating layer of a liquid such as ultra-thin perfluoropolyether by a dip pulling method or the like, the floating characteristics of the slider head are further improved.

The thickness of the dielectric layer 15 is set so as to increase the Kerr rotation angle from the main recording layer and the auxiliary layer. This film thickness is also affected by the recording / reproducing laser wavelength, the material of the reflective layer, the refractive index of the dielectric layer, the material and the film thickness of the main recording layer and the auxiliary layer.

Here, according to the present invention, as shown in FIG.
The present invention is not necessarily limited to the case where the main recording layer 13 or the auxiliary layer 14 is in direct contact with the main recording layer 13 or the auxiliary layer 14. A dielectric layer may be provided between the reflective layer 12 and the main recording layer 13 or the auxiliary layer 14. However, the main recording layer 13 or the auxiliary layer 14 is
If the reflective layer 12 is directly laminated, even if the reflective layer 12 has some surface roughness and mixes between the main recording layer or the auxiliary layer and the reflective layer, the material of the reflective layer is metal, so that the magnetic non-uniformity is extremely high. Does not occur, and the recording magnetic field sensitivity is improved.

In the case where there is a dielectric layer between the reflective layer and the main recording layer or the auxiliary layer, if the reflective layer is made of a noble metal such as Ag or Au or Cu, the surface will not be roughened and the recording magnetic field sensitivity will be reduced. It is possible to increase considerably.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples.

Example 1 A medium for near-field magneto-optical recording having a structure as shown in FIG. 2 was manufactured. Track pitch 0.
Polycarbonate substrate 2 with 43 μm guide groove
A reflective layer 22 made of Al _0.99 Cr _0.01 was formed on the first _substrate 1 by DC sputtering to a thickness of 60 nm (surface roughness Ra = 1.2 nm).
Formed. On top of this, coercive force of 12 kOe with rare earth priority,
The main recording layer 23 made of Tb _0.25 (Fe _0.77 Co _0.20 Ta _0.03 ) _{0.75 having a} Curie temperature of 260 ° C. and a saturation magnetization of 120 emu / cc is 15 nm, and the coercive force is 2 kO with transition metal priority.
e, Curie temperature 340 ° C, saturation magnetization 400 emu / c
An auxiliary layer 24 made of Tb _0.15 (Fe _0.77 Co _0.20 Ta _0.03 ) _0.85 was formed to a thickness of 5 nm by DC sputtering. Further thereon, a dielectric layer 2 made of SiN is formed.
5 was formed by a reactive DC sputtering method using a Si target in a mixed atmosphere of Ar and N ₂ to form a solid lubricating layer 26 made of diamond-like carbon (DLC) of 50 nm.
And it was 15nm formed by a reactive RF sputtering method using a C target in a mixed atmosphere of CH _4. After forming the DLC layer, a perfluoropolyether-based lubricating layer 27 was applied by 1 nm by a pull-up method to produce a magneto-optical recording medium.
The average saturation magnetization at room temperature of the laminated film of the main recording layer and the auxiliary layer was 10 emu / cc.

(Embodiment 2) In the same manner as in Embodiment 1,
l _0.99 Only the thickness of the reflective layer 22 made of Cr _0.01 is 100 n
m (surface roughness Ra = 1.6 nm) to produce a magneto-optical recording medium.

(Example 3) A magneto-optical recording medium was manufactured in exactly the same manner as in Example 1 except that a dielectric layer made of SiN having a thickness of 5 nm was formed between the reflective layer 22 and the main recording layer 23. did.

(Example 4) In the same manner as in Example 1, a 40 nm-thick Au film (surface roughness Ra = 0.
6 nm) to produce a magneto-optical recording medium.

(Example 5) In the same manner as in Example 1, a 35 nm-thick Cu film (surface roughness Ra = 0.
6 nm) to produce a magneto-optical recording medium.

(Example 6) In the same manner as in Example 1, the reflective layer 22 was formed of a two-layer film of a 5-nm thick Ti film and a 35-nm thick Cu film (surface roughness Ra = 0.7 nm, 5nm T
A magneto-optical recording medium was manufactured in place of the i-film corresponding to the underlayer.

(Embodiment 7) In the same manner as in Embodiment 1, a 30 nm thick Ti film and a 30 nm thick Cu
Two-layer film (surface roughness Ra = 1.2 nm, film thickness 30 nm)
And the magneto-optical recording medium was manufactured in place of the Ti film (corresponding to the underlayer).

(Example 8) In the same manner as in Example 1, a 30 nm-thick Ag film (surface roughness Ra = 0.
6 nm) to produce a magneto-optical recording medium.

Example 9 A magneto-optical recording medium was manufactured in the same manner as in Example 1, except that the reflective layer 22 was replaced with a 60-nm-thick Ag _0.99 Zr _0.01 film (surface roughness Ra = 0.6 nm). .

(Comparative Example 1) Instead of forming the auxiliary layer 24, the main recording layer 23 has a coercive force of 12 kO.
e, Curie temperature 290 ° C, saturation magnetization 100 emu / c
c, Tb _0.20 (Fe _0.77 Co _0.20 Ta
_0.03 ) A magneto-optical recording medium was produced in exactly the same manner as in Example 1, except that the medium was made _0.80 . Here, the main recording layer 23
Was adjusted so that the magnetic field sensitivity would be the best in a single layer.

(Comparative Example 2) As the auxiliary layer 24, a coercive force of 1
3kOe, Curie temperature 270 ° C, saturation magnetization 50emu
A magneto-optical recording medium was produced in exactly the same manner as in Example 1, except that a layer of Tb _0.21 (Fe _0.77 Co _0.20 Ta _0.03 ) _0.79 / cc was formed to a thickness of 5 nm.

For the magneto-optical recording media of Examples 1 to 9 and Comparative Examples 1 and 2, the media were rotated at a linear velocity of 10 m / s, and a slider SIL having a laser wavelength of 680 nm and an effective numerical aperture of 1.2 was formed on the thin film surface. The recording was performed while the coil magnetic field on the SIL head was modulated at 10 MHz while the main recording layer was heated above the Curie temperature by irradiating a laser in a pulsed manner with the head flying at a height of 100 nm. here,
By changing the modulation width of the magnetic field from ± 50 Oe to ± 150 Oe, the magnitude of the magnetic field at which the reproduction signal was saturated was examined and defined as the recording magnetic field sensitivity. SNR when recording at 10 MHz
Was examined. The value of the SNR was obtained by adjusting the reproduction power of each medium and measuring the SNR under the condition that the SNR was maximized. Table 1 summarizes the evaluation results.

[0058]

[Table 1]

As for the recording magnetic field sensitivity, the target is set to 120 Oe.
As described below, the medium of each of Examples 1 to 9 was 100 Oe,
110Oe, 120Oe, 80Oe, 80Oe, 80O
e, 100 Oe, 80 Oe, 80 Oe all reached the target. Here, the recording magnetic field sensitivity is such that the surface roughness Ra is 1.6n.
5 nm between the reflective layer 22 and the main recording layer 23 according to the second embodiment.
Example 3 in which a dielectric layer made of SiN having a thickness of 10 mm was inserted.
Other than that, it is 100 Oe or less, and it is possible to take a high margin with respect to 120 Oe even in consideration of variations in manufacturing the disk. In contrast, in Comparative Example 1 in which the auxiliary layer was not formed and in Comparative Example 2 in which the coercive force was larger than that of the main recording layer, the signal was not completely saturated even at 150 Oe.

As shown in Table 1, the recording power at which the SNR was saturated when recording was performed with magnetic fields having respective recording magnetic field sensitivities was 6 mW and 8 m for the media of Examples 1 to 9, respectively.
W, 6mW, 11mW, 12mW, 12mW, 11m
W, 12 mW and 11 mW.

As shown in Table 1, the SNRs obtained when the media of Examples 1 to 9 were reproduced at the reproduction power at which the SNR was maximized were respectively 20 dB, 18 dB, 18 dB, 24 dB, 2 dB and 2 dB.
They were 3 dB, 24 dB, 23 dB, 23 dB, and 25 dB. The reproducing power at this time was 0.9 mW and 1.1 mW, respectively.
mW, 1.0mW, 1.2mW, 1.2mW, 1.2m
W, 1.4 mW, 1.1 mW and 1.2 mW. SNR of Examples 4 to 9 of noble metal or Cu reflection layer is 23 dB
This is probably because the main recording layer and the auxiliary layer are cooled and the Kerr rotation angle is increased due to the high recording power as a whole. In the seventh embodiment, the reflective layer 22 has a thickness of 30.
as a two-layer film of a Ti film having a thickness of 30 nm and a Cu film having a thickness of 30 nm.
By appropriately increasing the surface roughness Ra to 1.2 nm,
The coercive force of the main recording layer increased, and the maximum reproducing power increased to be stable. In Example 9, it was considered that the addition of Zr to Ag slightly reduced the thermal conductivity and increased the thickness of the reflective layer up to 60 nm, so that light loss was eliminated and SNR was improved. On the other hand, in Comparative Example 1 in which the auxiliary layer was not formed and in Comparative Example 2 in which the coercive force was larger than that of the main recording layer, the signal was not saturated as described above, so that recording was performed at the maximum magnetic field of 150 Oe. S when you
The NR was 15 dB and 10 dB, respectively.

Example 10 A medium for near-field magneto-optical recording having a structure as shown in FIG. 2 was manufactured. A 10 nm thick Ta film and a 45 nm thick Cu film are formed on a polycarbonate substrate 21 having a guide groove with a track pitch of 0.43 μm.
A reflective layer 22 consisting of a two-layer film (surface roughness Ra = 0.8 nm) was formed by DC sputtering (T nm having a thickness of 10 nm).
a film corresponds to the underlayer). A coercive force of 13 kOe, a Curie temperature of 210 ° C., and a saturation magnetization of 100 emu / cc T
The main recording layer 23 made of b _0.25 (Fe _0.87 Co _0.11 Ta _0.02 ) _0.75 was coated with 15 nm, the coercive force was 2 kOe, and the Curie temperature was 2
Tb _0.14 (Fe) having a saturation magnetization of 430 emu / cc at 50 ° C.
_0.87 Co _0.11 Ta _0.02 ) The auxiliary layer 24 of _0.86
m, each formed by a DC sputtering method. A dielectric layer 25 made of SiN is further formed thereon by a reactive DC sputtering method using a Si target in a mixed atmosphere of Ar and N ₂ to a thickness of 50 nm using diamond-like carbon (DL).
A solid lubricating layer 26 made of C) was formed to a thickness of 15 nm by a reactive RF sputtering method using a C target in a mixed atmosphere of Ar and CH ₄ . After forming the DLC layer, a perfluoropolyether-based lubricating layer 27 was applied to a thickness of 1 nm to produce a magneto-optical recording medium. The average saturation magnetization at room temperature of the laminated film of the main recording layer and the auxiliary layer was 20 emu / cc.

(Embodiment 11) In the same manner as in Embodiment 10, only the auxiliary layer 24 was formed to a thickness of 5 nm, a coercive force of 3 kOe,
A magneto-optical recording medium was prepared as a Tb _0.16 (Fe _0.87 Co _0.11 Ta _0.02 ) _0.84 film having a Curie temperature of 240 ° C. and a saturation magnetization of 320 emu / cc.

(Example 12) In the same manner as in Example 10, only the auxiliary layer 24 was formed to a thickness of 5 nm, a coercive force of 5 kOe,
A magneto-optical recording medium was manufactured as a Tb _0.19 (Fe _0.87 Co _0.11 Ta _0.02 ) _0.81 film having a Curie temperature of 270 ° C. and a saturation magnetization of 160 emu / cc.

(Example 13) In the same manner as in Example 10, only the auxiliary layer 24 was formed to a thickness of 5 nm and a coercive force of 0.8 kO.
e, Curie temperature 270 ° C, saturation magnetization 650 emu / c
A magneto-optical recording medium was prepared as a Tb _0.09 (Fe _0.87 Co _0.11 Ta _0.02 ) _0.91 film of c.

In the same manner as in Examples 1 to 9, Example 10,
11, 12, and 13 were evaluated. Table 2 summarizes the evaluation results.

In Examples 10 and 11, the recording magnetic field sensitivity was 10
Although it is as good as 0 Oe or less, in Examples 12 and 13, 13
If it is 0 Oe or more, the recording magnetic field sensitivity is inferior. As shown in Table 2, the SNR is relatively good at 22 dB or more at the optimum recording magnetic field. However, when recording was performed at 120 Oe, in Examples 12 and 13, unerased data was left, and a good SNR was not obtained. Was.

[0068]

[Table 2]

(Embodiment 14) A substrate 21 having a width of 0.25 μm
A magneto-optical recording medium was fabricated in exactly the same manner as in Example 10 except that prepits having 10 m periods, a depth of 0.08 μm, a mark length of 0.5 μm, and a space length of 0.5 μm were formed beforehand. did.

(Example 15) In the same manner as in Example 14, only the reflection layer 22 was coated with a 50-nm-thick Ag _0.99 Zr film.
A two-layer film (surface roughness Ra = 0.8 nm) of a _0.01 film and an Al _0.97 Ti _0.03 film having a thickness of 15 nm or an Ag _0.99 Zr _0.01 film having a thickness of 50 nm and Al _0.97 Ti _0.03 film having a thickness of 30 nm
A magneto-optical recording medium was manufactured in place of a two-layer film (surface roughness Ra = 1.0 nm).

The media of Examples 14 and 15 have linear velocities of 1
While rotating the medium at 0 m / s, a slider SIL having a laser wavelength of 680 nm and an effective numerical aperture of 1.2 was formed on the thin film surface.
While flying the head to a height of 100 nm, a pre-pit signal was reproduced with a reproduction power of 1 mW. Table 3 shows the signal strength of the pre-pits, the recording magnetic field sensitivity, and the results of the SNR measurement. Although the SNR is almost the same in Examples 14 and 15, the signal intensity of the pre-pit is about 30% larger in Example 15, and it is found that the signal of the pre-pit is improved by using an Al alloy for the reflective layer. did. The recording magnetic field sensitivity was improved by about 20% by laminating the Al alloy on the Ag alloy film. Further, the SNR was almost the same in Examples 14 and 15.

[0072]

[Table 3]

(Example 16) Coercive force of 14 kOe, Curie temperature of 220 ° C., saturation magnetization of 60 emu /
The main recording layer 23 made of cc Tb _0.21 (Fe _0.87 Co _0.11 Ta _0.02 ) _{0.79 has a} thickness of 15 nm, a coercive force of 0.2 kOe, a Curie temperature of 380 ° C., and a saturation magnetization of 50 emu with priority given to rare earth elements.
A magneto-optical recording medium was produced in exactly the same manner as in Example 10 except that an auxiliary layer 24 made of Gd _0.25 (Fe _0.78 Co _0.20 Cr _0.02 ) _0.75 / cc was formed by DC sputtering using an alloy target with a thickness of 5 nm. .

Next, the recording magnetic field sensitivity and SNR were evaluated in the same manner as in Examples 1 to 9. The recording magnetic field sensitivity was 70 Oe, the recording power was 11 mW, the optimum reproducing power was 1.3 mW, and the SNR at that time was a very good value of 26 dB.
This is presumably because TbFeCoTa has a large Kerr rotation angle due to transition metal priority and the reproduction output does not drop to high reproduction power because the Curie temperature of GdFeCoCr is extremely high.

(Example 17) Magneto-optical recording was performed in the same manner as in Example 16 except that the order of the main recording layer (thickness: 15 nm) and the auxiliary layer (thickness: 5 nm) was reversed. A medium was prepared. Next, the recording magnetic field sensitivity and SNR were evaluated in the same manner as in Examples 1 to 9. Recording magnetic field sensitivity is 75
Oe, recording power 12 mW, optimal reproduction power 1.4
At that time, the SNR was 25 dB at mW, which was almost the same value as that of Example 16. This is because the car rotation angle was reduced but the noise was also reduced as compared with the sixteenth embodiment.

(Embodiment 18) In the same manner as in Embodiment 1,
A magneto-optical recording medium was manufactured by replacing the reflective layer 22 with an AuTi alloy film having a thickness of 50 nm. When sputtering the reflective layer, Au
AuTi films of various compositions were obtained by sticking Ti chips on the target.

The magneto-optical recording medium of Example 18 was set at a linear velocity of 10
Rotating at m / s, laser wavelength 680n on the thin film surface
m, slider SIL head with an effective numerical aperture of 1.2
The laser was floated to a height of 0 nm, irradiated with a laser pulse, and recorded while modulating the coil magnetic field on the SIL head at 10 MHz. Here, the modulation width of the magnetic field is ± 100 O
e. The CNR was measured while changing the laser power. The laser power at which the CNR was maximized was defined as the recording power (Pw), and Pw was measured for each AuTi composition magneto-optical recording medium. The result is shown in FIG. A
The recording power decreases as the Ti concentration in the uTi reflective layer increases, but the recording power is preferably 6 mW or more.
Preferably, the i concentration is 2 atomic% or less.

Further, the following glide test was performed.

The magneto-optical recording medium is set on the spindle and rotated. First, a glide head with a piezo element (made by Glide Height, flying height: 50 n)
In step m), the disk is sought, and the voltage value induced in the piezo element is monitored. When the voltage value is 300 mV or more, the hit is ranked A, and when the voltage value is 500 mV or more, the hit is ranked B. The number of hits of ranks A and B when a seek is performed once at a linear velocity of 7 m / s between a radius of 20 to 60 mm is counted. Next, a seek is performed once at a linear velocity of 8 m / s between a radius of 20 to 60 mm using a waffle burnish head (manufactured by Glide Height, flying height: 25 nm). Thereafter, the number of hits of ranks A and B when the seek is performed once at a linear velocity of 3 m / s between a radius of 20 to 60 mm with a glide head having a piezo element is counted again.

Table 4 shows the glide test and 80 ° C., 85%
The result of a 250-hour accelerated durability test in an RH environment is shown. The numerical value in the glide test result indicates the number of hits, and in the durability test result, ○ indicates good and ◎ indicates very good. The durability test results are all good, and a good magneto-optical recording medium having no B rank hit after burnishing can be obtained by using an AuTi film as the reflective layer.

[0081]

[Table 4]

(Embodiment 19) In the same manner as in Embodiment 1,
A magneto-optical recording medium was manufactured by changing the reflective layer 22 to an Au film having a thickness of 50 nm.

(Example 20) In the same manner as in Example 1,
A magneto-optical recording medium was manufactured by changing the reflective layer 22 to an Au _0.996 Ti _0.004 alloy film having a thickness of 50 nm.

(Example 21) In the same manner as in Example 1,
A magneto-optical recording medium was manufactured by replacing the reflective layer 22 with an Au _0.996 Cr _0.004 alloy film having a thickness of 50 nm.

(Example 22) In the same manner as in Example 1,
A magneto-optical recording medium was manufactured by replacing the reflective layer 22 with an Au _0.999 Zr _0.001 alloy film having a thickness of 50 nm.

(Example 23) In the same manner as in Example 1,
The reflective layer 22 is made of a 5 nm-thick Ti film and a 50 nm-thick Au film.
A magneto-optical recording medium was manufactured in place of a two-layer film (a Ti film having a thickness of 5 nm corresponds to an underlayer).

(Example 24) In the same manner as in Example 1,
The reflective layer 22 is made of a 5 nm-thick Cr film and a 50 nm-thick Au film.
A magneto-optical recording medium was manufactured in place of a two-layer film (a 5 nm-thick Cr film corresponds to an underlayer).

The magneto-optical recording media of Examples 19 to 24 were subjected to the following glide test.

The magneto-optical recording medium is set on the spindle and rotated. First, a glide head with a piezo element (flying height: 50 n, manufactured by Glide Height Co., Ltd.)
In step m), the disk is sought, and the voltage value induced in the piezo element is monitored. When the voltage value is 300 mV or more, the hit is ranked A, and when the voltage value is 500 mV or more, the hit is ranked B. The number of hits of ranks A and B when a seek is performed once at a linear velocity of 7 m / s between a radius of 20 to 60 mm is counted. Next, a seek is performed once at a linear velocity of 8 m / s between a radius of 20 to 60 mm using a waffle burnish head (flying height: 25 nm, manufactured by Glide Height). Thereafter, the number of hits of ranks A and B when the seek is performed once at a linear velocity of 3 m / s between a radius of 20 to 60 mm with a glide head having a piezo element is counted again.

Table 5 shows the results of the above glide test. Even if the waffle burnish head is used for the reflective layer of the Au single layer film, the hit is reduced, but the AuTi alloy reflective film, the AuCr alloy reflective film, or the Ti / Au two-layer film,
It can be seen that hits can be reduced more efficiently when a Cr / Au two-layer film is used. Further, the disk after the glide test was subjected to 25 ° C in an environment of 80 ° C and 85% RH.
A 0 hour accelerated durability test confirmed that no pitting occurred on any of the disks and that the disks had good durability.

[0091]

[Table 5]

(Example 25) In the same manner as in Example 1,
A magneto-optical recording medium was manufactured by changing the reflective layer 22 to an AgPdCu alloy film having a thickness of 50 nm. When sputtering the reflective layer,
An Ag _0.98 Pd _0.01 Cu _0.01 film and an Ag _0.95 P are formed by attaching Pd and Cu chips on an Ag target.
d _0.01 Cu _0.04 film, Ag _0.95 Pd _0.04 Cu _0.01 film, Ag
_{A 0.94} Pd _0.03 Cu _0.03 film was obtained.

(Example 26) In the same manner as in Example 1,
A magneto-optical recording medium was manufactured by replacing the reflective layer 22 with an AgPdTi alloy film having a thickness of 50 nm. When sputtering the reflective layer,
An Ag _0.98 Pd _0.01 Ti _0.01 film and an Ag _0.95 P are formed by attaching a Pd and Ti chip on an Ag target.
d _0.01 Ti _0.04 film, Ag _0.95 Pd _0.04 Ti _0.01 film, Ag
_{A 0.94} Pd _0.03 Ti _0.03 film was obtained.

The disks obtained in Examples 25 and 26 were subjected to an accelerated durability test in an environment of 80 ° C. and 85% RH for 250 hours. As a result, it was confirmed that no pitting occurred on any of the disks and that the disks had good corrosion resistance.

Example 27 A magneto-optical recording medium was manufactured in the same manner as in Example 1. However, in the case of the present example, a recording layer was formed by forming a film by sputtering while changing the order of the main recording layer 23 and the auxiliary layer 24.

For the magneto-optical recording media of Examples 1, 27 and Comparative Example 1, the media were rotated at a linear velocity of 10 m / s, and a slider SIL having a laser wavelength of 680 nm and an effective numerical aperture of 1.2 was formed on the thin film surface. The head was floated to a height of 100 nm, and recording was performed while modulating the coil magnetic field on the SIL head at 20 MHz while irradiating a laser in a pulsed manner to warm the main recording layer above the Curie temperature. here,
The modulation width of the magnetic field is ± 120 Oe. Table 6 shows the recording / reproducing characteristics at this time. Note that the value of this SNR (20 MHz) is determined by adjusting the reproduction power in each medium and adjusting the SNR at 20 MHz.
It is obtained by measuring under the condition that the NR is maximized.
Write Noise is an average value of 1 MHz to 10 MHz of a difference between a baseline at the time of DC erasure and a time of signal recording when a reproduced waveform is observed by a spectrum analyzer. From Table 6, the write noise of the disk on which the recording layer was formed in the order of the auxiliary layer and the main recording layer was low and the SN was high.
It can be seen that it has R.

[0097]

[Table 6]

[0098]

According to the present invention, a reflective layer is formed on a substrate, and a main recording layer having a large coercive force due to perpendicular magnetization and an auxiliary layer having a smaller coercive force at room temperature are formed on the reflective layer. By forming such a recording layer, a near-field magneto-optical recording medium having good recording magnetic field sensitivity can be obtained. In the present invention, a two-layer film of TbFeCo or Tb with proper characteristics is used by using a reflection film mainly composed of noble metal or Cu having a small surface roughness and good heat conduction.
By laminating FeCo and GdFeCo, particularly good recording magnetic field sensitivity and high SNR can be obtained. In addition, as a result of improving the recording magnetic field sensitivity, it is expected that high-speed recording will be possible and that the power consumption of the drive will be reduced.

Further, by forming the reflective layer from an AuTi, AuZr or AuCr alloy, or forming an Au reflective layer on a Ti or Cr underlayer, a recording medium having not only corrosion resistance but also good glide characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing the structure of an example of a magneto-optical recording medium according to the present invention.

FIG. 2 is a partial sectional view showing the structure of another example of the magneto-optical recording medium of the present invention.

FIG. 3 shows T in the AuTi reflection layer according to the embodiment of the present invention.
FIG. 6 is a diagram illustrating a relationship between i density and recording power.

[Explanation of symbols]

 11, 21: Substrate 12, 22: Reflective layer 13, 23: Main recording layer 14, 22: Auxiliary layer 15, 25: Dielectric layer 26: Solid lubricating layer 27: Lubricating layer

Claims (17)

[Claims] 1. A magneto-optical recording medium in which at least a reflective layer, a recording layer, and a dielectric layer are laminated on a substrate in this order, wherein the recording layer has a main recording layer and an auxiliary layer, The layer is perpendicularly magnetized, has a sufficiently large coercive force to stably hold recorded information, and the coercive force at room temperature of the auxiliary layer is smaller than that of the main recording layer. Magneto-optical recording medium. 2. The magneto-optical recording medium according to claim 1, wherein the reflective layer has a surface roughness Ra of 1.3 nm or less. 3. The magneto-optical recording medium according to claim 1, wherein the reflection layer is made of a metal film made of a noble metal or Cu or a metal film mainly made of a noble metal or Cu. 4. The reflection layer is made of a noble metal or Cu containing Cr, Ti,
4. The magneto-optical recording medium according to claim 3, wherein the magneto-optical recording medium is made of an alloy containing 0.01 to 5 atomic% of Zr, Nb or Ta. 5. The magneto-optical recording medium according to claim 1, wherein the reflection layer is made of an alloy obtained by adding 0.01 to 2 atomic% of Cr, Ti or Zr to Au. 6. The magneto-optical device according to claim 1, wherein the reflection layer is made of an alloy obtained by adding 0.1 to 5 atomic% of Pd and 0.1 to 5 atomic% of Cu to Ag. recoding media. 7. The magneto-optical device according to claim 1, wherein the reflection layer is made of an alloy obtained by adding 0.1 to 5 atomic% of Pd and 0.1 to 5 atomic% of Ti to Ag. recoding media. 8. The magneto-optical recording medium according to claim 1, wherein the reflection layer is formed on a base layer made of a metal film. 9. An underlayer of a reflective layer having a thickness of 0.5 nm or more and 1
Cr, Ti, Zr, Nb or T
The magneto-optical recording medium according to claim 8, wherein the metal film (a) is formed on a substrate. 10. Cr, Ti, Zr, Nb and T having a thickness of 0.5 nm or more and 100 nm or less as an underlayer of the reflection layer.
9. The magneto-optical recording medium according to claim 8, wherein an alloy film of two or more metals selected from the group consisting of a is formed on the substrate. 11. A Cr film or a Ti film as an underlayer.
3. The reflective layer according to claim 1, wherein said reflective layer is formed by forming an Au film on said reflective layer.
A magneto-optical recording medium according to claim 1. 12. The reflection layer is a two-layer film in which an aluminum film or an aluminum alloy film having a thickness of 5 nm or more and 50 nm or less is laminated on a metal film made of noble metal or Cu or a metal film mainly made of noble metal or Cu. 3. The magneto-optical recording medium according to claim 1, wherein: 13. A perpendicular recording main recording layer mainly composed of TbFeCo or TbFeCo, and TbFeCo or Tb.
A perpendicular magnetization auxiliary layer mainly composed of FeCo is laminated. 2) The saturation magnetization at room temperature of the main recording layer is 50 emu / cc or less when a transition metal is preferred, and 200 emu when a rare earth is preferred.
3) The auxiliary layer has transition metal priority, and its saturation magnetization at room temperature is 200 emu / cc or more and 600 emu / cc or less. 4) At room temperature of the laminated film of the main recording layer and the auxiliary layer. 5) the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer, and the difference between the Curie temperatures is 100 ° C. or less; 6) the auxiliary layer 13. The magneto-optical recording medium according to claim 1, wherein the thickness is 2 nm or more and 10 nm or less and half or less of the thickness of the main recording layer. 14. A perpendicular recording main recording layer mainly composed of TbFeCo or TbFeCo, and GdFeCo or Gd.
A perpendicular magnetization auxiliary layer mainly composed of FeCo is laminated. 2) Both the main recording layer and the auxiliary layer have a saturation magnetization of 10 at room temperature.
0 emu / cc or less, the Curie temperature of the auxiliary layer is higher than the Curie temperature of the main recording layer. 3) The film thickness of the auxiliary layer is 2 nm or more and ２ or less of the film thickness of the main recording layer. The magneto-optical recording medium according to claim 1. 15. The magneto-optical device according to claim 1, wherein the recording layer composed of the main recording layer and the auxiliary layer is formed in the order of the auxiliary layer and the main recording layer. recoding media. 16. The magneto-optical recording medium according to claim 13, wherein the auxiliary layer contains Ta. 17. The magneto-optical recording medium according to claim 13, wherein the main recording layer contains Ta.