JPS62281142A - Magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To improve recording and reproducing characteristics and to prevent the deterioration of a thin magnetic film layer by incorporating nitrogen into an intermediate layer formed of aluminum nitride in such a manner that the nitrogen content on the substrate side is larger than the nitrogen content on the thin magnetic film layer side. CONSTITUTION:The intermediate layer 3 is formed of the aluminum nitride and the N/Al atomic ratio in the aluminum nitride intermediate layer 3 is 0.4-0.9, more preferably 0.5-0.8 in average over the entire part. The prescribed nitrogen concn. distribution in which the nitrogen content on the substrate side in the intermediate layer 3 is larger than the nitrogen content on the thin magnetic film layer 4 side exists in the thickness direction of the intermediate layer 3. The recording and reproducing characteristics are thereby improved and the deterioration of the thin magnetic film layer with age is lessened.

Description

Detailed Description of the Invention ■Background of the Invention)jE Technical Field The present invention relates to a magneto-optical recording medium for recording and reproducing information using heat and light such as laser light.

Prior art and its problems As a recording medium for magneto-optical memory, MnB1. MnAffiGe, MnSb, MnCuB1
．． GdFe, TbFe, GdCo, PtCo, TbCo.

TbFeCo, GdFeCo, TbFe0. , Gd1G, GdTbFe,
GdTbFeCoBi, CoFe2
Materials such as o4 are known. These are formed as a thin film on a transparent substrate such as plastic or glass by a method such as a vacuum evaporation method or a sputtering method. The common characteristics of these magneto-optical recording media are that the axis of easy magnetization is vaguely perpendicular, and that the Kerr effect and Faraday effect are large.

What is required of such a medium is that firstly, the Curie point is around 100 to 200°C and the compensation point is around room temperature, and secondly, defects such as grain boundaries that cause noise are relatively free. Thirdly, a magnetically and mechanically uniform film can be obtained over a relatively large area.

In response to such demands, among the above-mentioned materials, amorphous biorthomagnetic thin films of rare upper-transition metals have attracted much attention in recent years.

However, in such an optoelectric recording medium made of a rarefied transition metal (amorphous thin layer), if the magnetic groove layer is stored in contact with the atmosphere, it will be diluted by oxygen and water in the fire. The upper class is selectively corroded or oxidized, making it impossible to record or reproduce information.

Therefore, in general, many studies have been conducted on magneto-optical recording media having a structure in which a protective layer is provided on the surface of the first layer of magnetic grooves.

Conventionally, such moisture-proof protective layers include silicon oxide, silicon dioxide, aluminum nitride, silicon nitride,
Attempts have been made to provide inorganic vacuum evaporation materials such as zinc sulfide, resin materials, etc. (Japanese Patent Laid-Open No. 58-80142, etc.).

In magneto-optical recording media, it is advantageous to perform recording and reproduction from the substrate side, and a transparent substrate is used as the substrate.

As the substrate for optical disks, resin-based substrates are preferable from the viewpoint of ease of manufacture and handling.Among these, acrylic resins, especially acrylic resins, are preferred from the viewpoints of transparency, productivity, economy, etc. Polycarbonate resin etc. are suitable.

On such a resinous substrate, an intermediate layer of an inorganic material is usually formed, and a magnetic thin film layer is provided through this intermediate layer.

This intermediate layer has a function as a magnetic layer, improves the C/N ratio, and prevents deterioration of the magnetic groove layer.1-Corrosion-resistant cropping! It has the following functions.

The material for such an intermediate layer is, for example, 5iO5Si.
Oxidation '7-(element, ARN, Si3N4, ZnS
, Si, Ge, etc. have been proposed.
No. 142, etc.).

Among these, aluminum nitride is preferable in terms of C/N ratio, durability, etc., but the film structure used conventionally is still insufficient in terms of C/N ratio, corrosion resistance, durability, etc. Yes, further improvement is necessary.

■ Purpose of the invention 1 MOTSUK LI11-1/7"1IENyl→壬、1仝＾、7ffノ←片〕；NeJ←1.-71111÷11 Also prevents deterioration of the magnetic thin film layer and improves corrosion resistance and durability. The object of the present invention is to provide a magneto-optical recording medium which has excellent properties and also has excellent stability in dimensional accuracy against warping and the like.

■Disclosure of the Invention These objects are achieved by the present invention as described below.

That is, the present invention provides a magneto-optical recording medium having an intermediate layer formed of aluminum nitride on a resin substrate, and having a magnetic thin film layer of a rare transition metal in the intermediate layer. This is a magneto-optical recording medium characterized in that the nitrogen content on the substrate side in the intermediate layer is larger than that on the magnetic eight layer side.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

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

In FIG. 1, a magneto-optical recording medium 1 of the present invention includes a substrate 2
It has an intermediate layer 3 on top.

The intermediate layer 3 of the present invention is formed from aluminum nitride.

The N/Aj2 atomic ratio in the aluminum nitride intermediate layer 3 is 0.4 to 0.9, more preferably 0.5 as an average of the entire layer.
~0.8.

At this time, if the N/Ax ratio is less than 0.4, the reflected light fft
decreases and gives a bad fis 9 to the characteristics.

On the other hand, if it exceeds 0.9, the apparent Kerr rotation angle decreases, which also adversely affects the characteristics.

In the thickness direction of the intermediate layer 3, there is a predetermined nitrogen concentration distribution such that the nitrogen content on the substrate side in the intermediate layer 3 is larger than that on the magnetic thin film layer 4 side, which will be described later.

Such a nitrogen concentration distribution in the aluminum nitride intermediate layer 3 is such that, for example, the N/A2 original r-ratio at a position up to 1/4 from the substrate 2 side of the aluminum nitride intermediate layer 3 is equal to the electric power source II!
The N/A ffi atomic ratio at a position up to 1/4 from the second layer 4 side is 1.4 times or more, particularly 2.0 to 4.5 times, more preferably 2.5 to 3.5 times. Make it.

When this value is less than 1.4 times, the C/N ratio, corrosion resistance, and fire resistance deteriorate. - On the other hand, when this value becomes 2.5 to 3.5 times the above preferred range, the C/N ratio and durability are significantly improved.

By providing the above-mentioned nitrogen concentration outside 11 in the aluminum nitride intermediate layer 3, the above-mentioned effect is produced.

That is, firstly, by appropriately setting the nitrogen concentration on the substrate side of the aluminum nitride intermediate layer 3, the refractive index at 830 nm for JLk<polycarbonate resin is approximately 1.57.
) and the aluminum nitride intermediate layer 3 can be effectively prevented, and good recording/reproducing characteristics can be obtained.

By keeping the nitrogen concentration in the aluminum nitride intermediate layer 3 on the side of the magnetic thin film layer 4 low to 7trJ2, deterioration of the magnetic thin film layer 4 containing Fe and Co as essential components, which will be described later, can be effectively prevented.

Note that the nitrogen concentration outside I5 may be continuous or discontinuous.

The atomic ratio distribution of N/AR existing in the thickness direction of the aluminum nitride intermediate layer 3 is measured, for example, by the method described below.

That is, first, while performing ion etching on the aluminum nitride intermediate layer 3 from the magnetic thin film layer 4 side at a constant etching rate, SIMS (secondary ion mass spectrometry) is performed.
Perform elemental analysis using , AES (Auger spectroscopy), ESCA, etc. Then, a substrate 2 made of polycarbonate resin, etc.
The time it takes for carbon C to be detected is set as d(11).

The time from the beginning to 1/4 and 3/
The average atomic ratio of N/An at a predetermined location in the layer is calculated from the elemental analysis results in the layer during the time from 4 to the time it reaches the substrate.

Needless to say, it is possible.

In order to form the aluminum nitride intermediate layer 3 in which the nitrogen concentration distribution exists in the thickness direction, AffiN and AQ are used as targets, and the sputtering rate of both is controlled and the sputtering rate is varied while the growth rate is increased. ! A binary sputtering method is used, or reactive sputtering is used in which AM is used as a target in an atmosphere containing nitrogen, the nitrogen concentration is controlled, and the nitrogen concentration is varied to simulate the formation.

These sputtering conditions may be normal conditions.

Furthermore, it is also possible to use other vapor phase film forming methods, such as vapor deposition, as appropriate.

The thickness of the aluminum nitride intermediate layer 3 formed in this way is 300 to 1500, more preferably 600 to 90.
There are 0 people.

Note that the aluminum nitride intermediate layer is usually in a polycrystalline or amorphous T state.

It's okay.

In addition, in some cases, small amounts of 2n, Si, Cr, Ba
You may add elements such as.

The substrate 2 on which the aluminum nitride intermediate layer 3 described above is formed is formed of resin.

Preferred resins include acrylic resin, polycarbonate resin, epoxy resin, and polymethylpentene resin.

Among these resins, polycarbonate resins are preferred in terms of durability, particularly resistance to warping and the like.

The polycarbonate resin in this case may be any of aliphatic polycarbonate, hexaaromatic-aliphatic polycarbonate, and aromatic polycarbonate, but aromatic polycarbonate resin is particularly preferred. Among these, polycarbonate resins made from bisphenol are preferred in terms of melting point, crystallinity, handling, etc. Among them, bisphenol A type polycarbonate resin is most preferably used.

In addition, the number average molecular weight of the polycarbonate tree is 10
,000 to about 15,000, preferably Ruco.

The refractive index of such a substrate 2 at 830 nm is usually 1.5.
It is about 5 to 1.59.

Note that since recording is performed through the substrate 2, the transmittance for writing light or reading light is set to 86% or more.

Further, the substrate 2 is usually disk-shaped and has a diameter of 51.2 to 1.5
The thickness is approximately n.

Tracking grooves may be formed on the magnetic thin film layer forming surface of such a disk-shaped substrate.

The depth of the groove is about λ/8n, especially λ/6n~λ
/ 12 n (where n is the refractive index of the substrate). Further, the width of the groove is approximately the width of a track.

In general, it is preferable to use the magnetic thin film layer located at the four parts of the groove as a recording track part, and to irradiate the writing light and the reading light from the back side of the substrate.

With this configuration, the writing sensitivity and the reading C/N ratio are improved, and the tracking control signal is also increased.

In addition, other shapes of the substrate may be used, such as a tape or a drum.

A magnetic thin film layer 4 is provided on the aluminum nitride intermediate layer 3 described above.

In the magnetic thin film layer 4 of the present invention, information is magnetically recorded by a modulated heat beam or a modulated magnetic field, and the recorded information is converted into ilF by magneto-optical conversion.

The material of the magnetic thin film layer 4 is an amorphous film made of an alloy of rare metals such as Gd and Tb and transition metals such as Fe and Co by sputtering, vapor deposition, etc. Moreover, it contains Fe and CO as essential components.

In this case, the total content of Fe and CO is 65-85aL%
It is preferable that

Part 1. Te Ji! Yen (6 sun 1te?pt■1ζ-, M;
1-Sugar 4 Rumor: “Gd and/or Tb.

Suitable examples include TbFeCo, GdFe
Co, GdTbFeCo, etc.

In addition, these magnetic thin film layers contain Cr, Affi, Ti, Pt, Si, Mo, Mn, V,
Ni, Cu, Zn, Ge.

Au etc. may be contained.

In addition, as a rare element, Sc in a range of 10 at% or less,
Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Dy
, Ho, Er, Tm, Yb.

It may also contain Lu or the like.

The diameter of such a magnetic thin film layer is 0.01 to 1 μm.
is preferred.

Furthermore, it is preferable to provide one or more various protective layers on the opposite side of the magnetic thin film layer 4 from the substrate 2.

In FIG. 1, a protective layer 5 and a protective film 6 are provided.

6 sun 4q as the material of the upper 2 go, hold', @enter η5
There is no particular restriction as long as it has the function of 3 Hagi ■, but thin II of oxides and nitrides are preferred. It is 2.

Suitable oxides include silicon oxides such as -silicon oxide and silicon dioxide, aluminum oxide, titanium oxide, and zinc oxide.

In addition, silicon nitride, aluminum nitride, titanium nitride, boron nitride, etc. are suitable as the vacuole.

Among these, aluminum nitride is particularly suitable.

The thickness of such a thin strip is about 0.1 to 10 μm.

Note that the protective layer 5 may be formed by vacuum deposition, sputtering, or the like.

On the other hand, as the material for the protective film 6, various known organic substances may be used.

More preferably, a radiation-curable compound cured with radiation such as an electron beam or ultraviolet rays is used.

The radiation-curable compounds to be used include acrylic double bonds such as acrylic acid, methacrylic acid, or their ester compounds, which are sensitive to ionization energy and have unsaturated double bonds that exhibit radical polymerization, and acrylic double bonds such as diallyl phthalate. Crosslinking or polymerization by radiation irradiation of allylic double bonds, unsaturated double bonds such as maleic acid, maleic acid derivatives, etc., monomers, oligomers and oligomers containing a drying group in the molecule. Examples include polymers and the like.

As a radiation-curable monomer, a compound with a molecular weight of less than 2000 is used, and as an oligomer, a compound with a molecular weight of H2ooo~100 is used.
00 is used.

These include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexane glycol diacrylate, 1,6-hexane glycol diacrylate, etc., but are particularly preferred. These include pentaerythritol tetraacrylate (methacrylate), pentaerythritol acrylate (
methacrylate), trimethylolpropane triacrylate (methacrylate), trimethylolpropane diacrylate (methacrylate), polyfunctional oligoester acrylate (Aronix M-7100, M-5400, M-5500, M-5700
, M-6250, M-6500, M-8030, M-8
060, M-8100, etc. (Toagosei), urethane elastomers with acrylic modified products of Tuborane 4040), or products with functional groups such as C0OH introduced into these, acrylates of phenol ethylene oxide adducts (
methacrylate), an acrylic group (methacrylic group) or ε in the pentaerythritol condensed ring represented by the general formula below.
-Caprolactone-A compound with an acrylic group, 1) (CH2=CHCOOCH2)3-CCH20
H (special acrylate A) 2) (CH2=CHCOOCH2)3-CCH2
CH3 (special acrylate B) 3) (CH2=CHC0(OC3Hs)n −
0CH2) 3-CCH2CH3 (Special Acrylate C) (), 'Kin Acrylate D) (Ri, 'Kin Acrylate E) Cloudy CH2CH2C00CH=CH2 (Special Acrylate F) In the formula, m = 1, a = 2, b = 4 Compound (hereinafter referred to as special pentaerythritol condensate A), compound where m=l, a=3, b=3 (hereinafter referred to as special pentaerythritol condensate B), m=1, a=6, b=
o compound (hereinafter referred to as special pentaerythritol condensate C
), m=2, a=6, b=o (hereinafter referred to as special pentaerythritol condensate), and special acrylates represented by the general formula below.

8) CH2=CHCOO-(CH2CH20)4-
COCH=CH2 red acrylate H) CH2CH2C00CH=CH2 (special acrylate I) (special acrylate J) A: acrylate, M-A A: Acryno 4, M: Dihydric alcohol N, 2 salt droplets (special acrylate) In addition, as radiation-curable oligomers, polyfunctional oligomer acrylates represented by the following general formula and urethane elastomer acrylic Examples include modified products, or products in which a functional group such as C0OH is introduced into these products.

(In the formula, R,, R2: alkyl, n, an integer) Furthermore, a radiation-curable compound obtained by radiation-sensitizing modification of a thermoplastic resin may be used.

Specific examples of such radiation-curable resins include acrylic acid, methacrylic acid, or acrylic double bonds such as ester compounds thereof, and diallylphthalate, which exhibits an unsaturated double bond that has radical polymerizability. It is a thermoplastic resin in which groups that can be crosslinked or polymerized by radiation irradiation, such as allylic double bonds and unsaturated bonds such as maleic acid and maleic acid derivatives, are contained or introduced into the molecule of the thermoplastic resin.

Examples of thermoplastic resins that can be modified into radiation-curable resins include vinyl chloride copolymers, saturated polyvinyl sulfate resins,
Examples include polyvinyl alcohol resin, epoxy; f-resin, phenoxy; f-resin, cellulose conductor, and the like.

Other resins that can be used for radiation and 1!11 sensitive modification include polyfunctional polyester resins, polyether Nisder resins, polyvinyl pyrrolidone resins and derivatives (pvp olefin copolymers), polyamide resins, polyimide resins, Phenolic resin, spiroacetal resin,
Acrylic containing at least one kind of acrylic ester and methacrylic ester containing a hydroxyl group as a polymerization component; f
- Resin etc. are also effective.

11Q J of the protective film 6 of such a radiation-curable compound
The size of the tube is 0.1 to 30 μl, more preferably 1 to 10 μm.

If the film thickness is less than 0.1 μm, it will not be possible to form a uniform film, and the moisture-proofing effect will not be sufficient in a humid atmosphere.
Magnetic thin IIl;! , the durability of layer 4 does not improve. If the thickness exceeds 30 μm, the recording medium may warp or cracks may occur in the protective film due to shrinkage during curing of the resin film, making it unsuitable for practical use.

Such ffi IIQ can usually be deposited using a combination of known methods such as spinner coating, gravure coating, spray coating, and dipping. The conditions for forming the coating film at this time may be appropriately determined in consideration of the viscosity of the mixture of coating film composition, the intended coating thickness, etc.

In order to cure such a coating film and make it into a protective layer, '1'
``The paint film can be irradiated with radiation such as ultraviolet radiation or ultraviolet radiation.

When using an electron beam, the radiation characteristics include acceleration voltage 1
It is advantageous to use a radiation acceleration of 0.00 to 750 kV, preferably 150 to 300 kV, and to deliver an absorbed dose of 0.5 to 20 megarads.

On the other hand, when ultraviolet rays are used, a photopolymerizable sensitizer is usually added to the radiation-curable compound as described above.

The photopolymerization sensitizer may be a conventionally known one, such as benzoin-based sensitizers such as benzoin methyl ether, benzoin ethyl ether, α-methylbenzoin, α-chlordeoxybenzoin, benzophenone, acetophenone, bisdialkylaminohensiphenone, etc. , quinones such as acedraquinone and phenanthraquinone, and sulfites such as hensyl disulfide and tetramethylthiuram monosulfide.
The photopolymerization sensitizer is desirably in a range of 01 to 10% by weight based on the solid content of the resin.

In order to cure a coating film containing such a photopolymerizable sensitizer and a radiation-curable compound using ultraviolet rays, various known methods may be used.

For example, an ultraviolet light bulb such as a xenon discharge tube or a hydrogen discharge tube may be used.

A protective plate 8 is usually provided on the protective film 6 with an adhesive layer 7 interposed therebetween.

1- That is, the back surface of the directly mounted substrate 2 (magnetic thin II!2 layer 4
Recording/playback is performed only from the side without
This protection plate 8 is used only in the case of so-called single-sided recording.

The resin material of the protective plate 8 is not particularly required to have transparency, and may be made of various resins, such as polystyrene, polypropylene, polyvinyl alcohol, methacrylic resin, polyamide, polyester, etc. Various irradiated J-type resins such as vinylidene chloride, polycarbonate, polyacetal, and fluororesin, various thermal IiT plastic resins such as phenol resin, urea resin, unsaturated polyester resin, polyurethane, alkyd resin, melamine resin, epoxy resin, silicone resin, etc. is available.

In addition, various types of glass, ceramic, etc. ! l: All materials may be used as the plate 8.

The shape, dimensions, etc. of this material are substantially the same as those of the substrate 2 described above.

Such a protection plate 8 is adhered via the adhesive layer 7 as described above. The adhesive layer is usually an adhesive such as hot melt resin, and has a thickness of about 1 to 100 μm.

On the other hand, instead of using the above-mentioned protective plate 8, the above-mentioned magnetic thin film 1 is used.
112 layer 4, protective layer 5. By using one more set of substrates for applying the protective film 6, etc., the image quality is thinner! A so-called double-sided recording type may be used, in which the A layer is placed on the inside and the substrates are bonded together using the adhesive layer 7, and -F is recorded from the back side of the inner substrate.

Furthermore, it is preferable to provide a hard coat layer as various types of protection 11Q on the back surfaces of these substrates 2 and protection plates 8 (the surfaces on which the Wl thin film layer 4 is not provided).

The material of the hard coat layer may be the same as that of the continuous protective film 6.

(2) Effects of the Invention The magneto-optical recording medium of the present invention has an aluminum nitride intermediate layer having a predetermined nitrogen concentration distribution between the resinous substrate and the magnetic thin film layer. Therefore, it has excellent recording and playback characteristics,
Furthermore, there is little deterioration of the magnetic thin film layer over time.

Especially when the substrate is made of polycarbonate resin,
Deterioration of the magnetic PN layer over time is less. death
Resistance to corrosion, etc. is also further improved.

(2) Specific Examples of the Invention The present invention will be described in more detail below with reference to Examples.

[Example 1] An intermediate layer of aluminum nitride was formed on a substrate made of bisphenol Ai polycarbonate resin (molecular weight 15,000) with a diameter of 13 cm and a thickness of 1.2 mm by reactive sputtering! A total of 700 people were appointed.

Note that during sputtering, in order to provide a predetermined nitrogen concentration distribution in the aluminum nitride intermediate layer, nitrogen-containing A
A2 was used as a target at an operating pressure of IPa in an r atmosphere, and the nitrogen concentration was temporally controlled.

After layer formation, elemental analysis in the film was performed using Auger spectroscopy without ion etching, and the N/A ILJQ:F ratio (×1
) was 0.9, and the N/An atomic ratio (X4) from the magnetic thin layer side to the 1/4th position was 0.3.

Moreover, the average N/Afi atomic ratio (X) of the whole area was 0.6.

On top of this aluminum nitride intermediate layer, 21% Tb
, 68aL% Fe, 7at% CO
, 4aL%Cr alloy thin film was deposited to a thickness of 800 mm by sputtering to form a magnetic thin film layer.

In addition, the target is Fe target with Tb, Co, and C.
The one with the r chip on it was used.

On this i-type thin film layer, a protective layer of AfiN was sputtered to a thickness of 1000 mm, and a coating composition containing the following radiation-curable compound was applied as a protective film on top of this protective layer by spinner coating. did.

(Coating Composition) 100 parts by weight of polyfunctional oligoester acrylate 5 parts by weight of photosensitizer After the coating composition was formed, it was crosslinked and cured by irradiation with ultraviolet rays for 15 seconds to obtain a cured film.

II at this time! 2JrA was 5 μm.

Note that a similar process was also performed on the back surface of the above substrate. Furthermore, a polycarbonate resin protective plate having a diameter of 13 cm was adhered onto the protective film using an adhesive to prepare a sample of the present invention (sample No. 1). According to this, the aluminum nitride intermediate layer of sample No. 1 was prepared in Table 1 below.
Various samples were prepared in the same manner as in case No. 1, except that the aluminum nitride intermediate layer had the nitrogen concentration distribution shown in FIG.

The following characteristic values were measured for the above samples.

(1) C/N ratio (deterioration on storage) The initial C/N ratio and the amount of change in the C/N ratio after storage for 1000 hours at 60° C. and 90% RH were determined under the following conditions.

Rotation speed 4 m/s e
cCarrier frequency 500KHz resolution
30KHz recording power (830
nm) 3~4mW reproduction power (830nm)
1 mW (2) Pit error rate The pit error rate of the EFM signal was measured at the initial stage and after storage for 1000 hours at 60° C. and 90% RH.

The results are shown in Table 1.

Table 1 From the results shown in Table 1, the effects of the present invention are clear.

That is, in the case of the present invention indicated by No. 1 x No. 4, X is thicker than x4 x + /
Since 4 is 164 or more and X is 0.4 to 0.9,
The C/N ratio, pit error rate, and these values after storage all show good results. Especially No, 1~No,
No. 3 shows extremely excellent results because X is 0.5 to 0.8 and the value of X 1 /

Furthermore, No. 1 and No. 2 are X I/X
4 is in the optimum range of 2.5 to 3.5, which indicates that the effect of preventing storage deterioration is extremely large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a magneto-optical recording medium showing one example of the present invention. Explanation of symbols (...magneto-optical recording medium, 2...substrate, 3...-aluminum nitride intermediate layer, 4...magnetic source l15! layer, 5...protective layer, 6...protective film , 7... Adhesive layer, 8... Protective plate applicant TDC Co., Ltd., -゛go,

Claims (4)

[Claims] (1) In a magneto-optical recording medium that has an intermediate layer formed of aluminum nitride on a resin substrate, and a magnetic thin film layer of a rare class transition metal on the intermediate layer, the substrate side of the intermediate layer A magneto-optical recording medium characterized in that the nitrogen content is greater than that on the magnetic thin film layer side. (2) The N/Al atomic ratio in the aluminum nitride intermediate layer at a position up to 1/4 from the substrate side of the aluminum nitride intermediate layer is lower than the N/Al atomic ratio in the aluminum nitride intermediate layer at a position up to 1/4 from the magnetic thin film layer side. 2. The magneto-optical recording medium according to claim 1, wherein the atomic ratio of Al/Al is 1.4 times or more. (3) Average N/A of the entire aluminum nitride intermediate layer
The magneto-optical recording medium according to claim 1 or 2, wherein the l atomic ratio is from 0.4 to 0.9. (4) The magneto-optical recording medium according to any one of claims 1 to 3, wherein the resin substrate is made of polycarbonate resin.