JPS62281140A - Magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To improve recording and reproducing characteristics and to lessen the deterioration of a thin magnetic film layer with lapse of time by incorporating oxygen into an intermediate layer formed of zinc sulfide in such a manner that the oxygen content on the substrate side in the intermediate layer is larger than the oxygen content on the thin magnetic film layer side. CONSTITUTION:The intermediate layer 3 is formed of the zinc sulfide and the oxygen is incorporated into the zinc sulfide intermediate layer 3. The O/Zn atomic ratio in the layer is 0.01-0.7, more preferably 0.05-0.5 in average over the entire part of the layer. The prescribed oxygen concn. distribution in which the oxygen content on the substrate side in the intermediate layer 3 is larger than the oxygen content on the thin magnetic film layer 4 side exists in the thickness direction of the intermediate layer 3. The magneto-optical recording medium which has the excellent recording and reproducing characteristics, prevents the deterioration of the thin magnetic film layer 4 and has the excellent corrosion resistance and durability is thus obtd.

Description

3. Detailed Description of the Invention T Background of the Invention Technical Field The present invention relates to a magneto-optical recording medium that records and reproduces information using heat and light such as laser light.

Prior art and its problems As a recording medium for magneto-optical memory, MnB1. MnARGe, MnSb.

MnCuB1. GdFe, TbFe, GdCo, PtCo, TbCo, TbFeCo, GdFeCo, TbFe0. , Gd1G, GdTbFe, GdTbF
eCoB1. Materials such as CoFe2O4 are known.

These are Vacuum II! A thin film of 11% is applied to a transparent substrate F such as plastic or glass using a method such as a two-layer method or a sputtering method.
The common characteristics of these magneto-optical recording media are that they are easy to magnetize, are vaguely orthogonal to i, and have a large Kerr effect or Faraday effect. I can do it.

What is required of such a medium is, firstly, that a single Curie point be at a temperature of about 100 to 200°C, and that the compensation point be around room temperature, and secondly, that defects such as grain boundaries that cause noise be Thirdly, the film is electrically and mechanically uniform over a relatively large surface h1! ? I can give you something.

In response to such demands, among the materials listed in F, amorphous orthogonal thin films of rare class-transition metals have recently attracted a great deal of attention.

However, in such magneto-optical recording media consisting of rarefiber-transition metal amorphous thin films, if the magnetic thin film layer is stored in contact with the atmosphere, oxygen and water in the atmosphere will cause it to become rarefied or transitional metal. It becomes corroded or oxidized, making it impossible to record ++' or 11th grade.

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 thin magnetic layer.

Conventionally, as such a moisture-proof protective layer, attempts have been made to provide inorganic vacuum-deposited films or resin films of silicon oxide, silicon dioxide, aluminum nitride, silicon nitride, zinc sulfide, etc. (Japanese Patent Laid-Open No. 58-80142 etc.) are disclosed.

In a magneto-optical recording medium, it is advantageous to perform recording and reproduction from the di-c plate 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 membranes are preferred.

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 an interfering layer, improves the C/N ratio, and has a function of imparting corrosion resistance to prevent deterioration of the magnetic thin film layer by +1.

The material for such an intermediate layer is, for example, 5iO131.
Silicon oxide such as 02, /M2N, Si3N4. ZnS
, Si, Ge, etc. have been proposed in JP-A-58-8
No. 0142, etc.).

Among these, zinc sulfide is particularly suitable in terms of C/N ratio, durability, etc., but in the conventional film structure, zinc sulfide has poor C/N ratio, corrosion resistance, and In terms of performance, etc., there is still a lack of progress, and further improvement is essential.

■ Purpose of the Invention The purpose of the present invention is to provide a material that has excellent recording and rlF generation characteristics, prevents deterioration of the magnetic thin film layer, and has excellent corrosion resistance and durability.
Another object of the present invention is to provide a magneto-optical recording medium with excellent stability in dimensional accuracy against warpage and the like.

■ Disclosure of the Invention The first objective is achieved by the present invention as described below.

That is, the present invention has an intermediate layer formed from zinc sulfide on a resin substrate, and this intermediate layer has a
A magnetic recording medium on the conductive thin film layer side of a transition metal, wherein the intermediate layer contains oxygen, and an optomagnetic medium characterized in that the oxygen content π on the substrate side in the intermediate layer is larger than that on the conductive thin film layer side. It is a recording medium.

■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 zinc sulfide.

Although ZnS generally has a stoichiometric composition, it may be unbalanced.

In this case, the average S/Z n atomic ratio of the entire layer is 0.
It is about 3 to 0.99.

The zinc sulfide intermediate layer 3 contains oxygen, but the O/
Zn atomic ratio is 0.01 to 0.7 as an average of the entire layer
, more preferably 0.05 to 0.5.

At this time, if the O/Zn ratio is less than 0.01, the effect of improving durability is lost.

On the other hand, if it exceeds 0.7, the refractive index becomes small, the apparent Kerr rotation angle decreases, and the characteristics are adversely affected by I-1.

In the thickness direction of the intermediate layer 3, there is a predetermined oxygen concentration distribution such that the oxygen content on the substrate side in the intermediate layer 3 is larger than that on the i-type thin 11Q layer 4 side, which will be described later.

Such an oxygen concentration distribution in the zinc sulfide intermediate layer 3 is, for example, J! of the intermediate layer 3! O/ at position 1/4 from plate 2 side
The Zn atomic ratio or the O/Zn source at a position up to 1/4 from the magnetic thin film layer 4 side is at least twice the ratio, more preferably 5.
The number should be at least twice that.

When this value is less than twice, the C/N ratio, corrosion resistance, and durability deteriorate. On the other hand, when this value is 5 times or more, which is the preferable range of 1-:, the C/N ratio and durability are significantly improved.

By providing the zinc sulfide intermediate layer 3 with the oxygen concentration distribution as described above, the following effects occur.

That is, first, by appropriately setting the oxygen concentration on the substrate side of the zinc sulfide intermediate layer 3, a Reflection can be effectively prevented and good recording/reproducing characteristics can be obtained.

Second, by keeping the oxygen concentration in the zinc sulfide intermediate layer 3 on the side of the magnetic thin film layer 4 low, Fe and C
It is possible to effectively prevent the deterioration of the magnetic thin layer 4 containing o as an essential impregnating component.

Note that the oxygen concentration outside 4 may be continuous or discontinuous.

O present in the film thickness direction of such zinc sulfide intermediate layer 3
/Zn atomic ratio distribution is measured, for example, by the method described below.

That is, first, while ion etching the zinc sulfide intermediate layer 3 from the magnetic thin film layer 4 side at a constant etching rate, SrMS (secondary ion mass spectrometry), AES
Perform elemental analysis using (Auger spectroscopy), ESCA, etc. Then, the time required for carbon C to reach the substrate 2 made of polycarbonate resin or the like is measured.

The time from the beginning to 1/4 and 3/4 of this required time.
The 0/Z n average thickness r ratio 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.

It goes without saying that the average O/Zn atomic ratio of the entire layer can also be calculated.

Like this II! To form the sulfide 1++r lead intermediate layer 3 in which the oxygen concentration is outside 1) i in the 211 direction, ZnS
A binary sputtering method using ZnO and ZnO as a target and controlling the sputtering rate of both without changing them, or a binary sputtering method using ZnS as a target and controlling the oxygen concentration in an oxygen-containing atmosphere. Then, reactive sputtering or the like is used to form a film by changing this.

These sputtering conditions may be normal conditions.

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

The film thickness of the zinc sulfide intermediate layer 3 formed in this way is 50
0 to 1500 people, more preferably 700 to 1000 people.

Note that the zinc sulfide intermediate layer is usually in an amorphous state.

Furthermore, Ar or the like present in the film-forming atmosphere may be included.

In addition, in some cases, small amounts of Si, Affi, Cr,
Elements such as Ba may be added.

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

Preferred examples of the resin include acrylic resin, polycarbonate resin, epoxy resin, and polymethylpentene resin.

Among these resins, polycarbonate resin JIH is preferred in terms of durability, especially resistance to warping and the like.

In this case, the polycarbonate resin includes aliphatic polycarbonate, aromatic δ-aliphatic polycarbonate, )7
It may be any Group 6 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 company of polycarbonate resin is 10,
It is preferable that it is about 000 to 15,000.

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 J^ board 2, the transmittance for writing light or reading light is set to be 86% or more.

Further, the substrate 2 is usually disk-shaped, and has a diameter of 12 to 1.5[
+1[The thickness should be approximately +1.

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, [11] of the groove is approximately equal to the track rfr.

Normally, the magnetic thin film layer located in the recessed part of this groove is used as a recording track section, and old light and readout light are
(It is preferable to irradiate from the back side of the plate.

With this configuration, the core write sensitivity and the read C/N ratio are balanced, and the tracking control signal becomes large.

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

+iif A magnetic thin film layer 4 is provided on top of the zinc sulfide intermediate layer 3 described above.

Magnetic groove II of the present invention! In the second layer 4, ++7 information is recorded all at once using a modulated heat beam or a modulated magnetic field, and the recorded information is reproduced by converting warm air to light.

The material of the magnetic thin film layer 4 is an amorphous material 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

The remainder is actually a rare F-bearing metal, particularly Gd and/or Tb.

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

In addition, these magnetic thin film layers contain 10aL% or more.
In the river Cr, An, Ti, pt, Si, Mo, Mn,
It may also contain Ni, Cu, Zn, Ge, Au, etc.

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

The thickness of such a magnetic thin film layer is preferably 0.01 to 1-.

Generally, 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.

In this case, the material of the protective layer 5 is not particularly limited as long as it has a function as a protective layer, but is preferably a thin 11!2 of oxide or nitride.

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

Further, as the nitride, silicon nitride, aluminum nitride, titanium nitride, boron nitride, etc. are suitable.

Among these, silicon oxide is particularly suitable.

The thickness of such a thin film is approximately 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 acid, methacrylic acid, and acrylic double bonds such as ester compounds thereof, which have unsaturated double bonds that are sensitive to ionization energy and exhibit radical polymerizability, and diallylphthalate. Containing groups in the molecule that can be cross-linked by radiation irradiation, such as allylic di-I bonds, unsaturated double bonds such as maleic acid, maleic acid derivatives, etc., or
Examples include human monomers, oligomers and polymers.

As a radiation-curable compound, a compound with a molecular weight of less than 2,000 is used, and as an oligomer, a compound with a molecular weight of less than 2,000 to 10
000 is used.

Stiffeners include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexane gelicol cyacrylate, 1,6-hexane gelicol dimethacrylate, etc. Particularly preferred is pentaerythritol tetraacrylate (
methacrylate), pentaerythritol acrylate (methacrylate), trimethylolpropane triacrylate (methacrylate), trimethylolpropane diacrylate (methacrylate), polyfunctional oligonis 7100, M-5400, M-5500, M-5
700, M-6250, M-6500, M-8030
, M-8060, M-8100, etc., Toagosei), urethane elastomers with acrylic modified products of Tuborane 4040), or products with functional groups such as COOH introduced into these, acrylates (methacrylates) of phenol ethylene oxide adducts. , a compound with an acrylic J, c (methacrylic group) or ε-caprolactone-acrylic group attached to a pentaerythwatol condensed ring represented by the following general formula, 1) (CH2=CHC00C)+2):l-C
CH20H (special acrylate A) 2) (C)12 =CHCOOCH2)3
CCH2CH3 (special acrylate B) 3) (CH2=CHC0(OC3H6)n 0
CH2):l CCH2CH3 (special acrylate C
) (Special acrylate D) (Special acrylate E) CH2c) (2cooc) (=c) (2(), monospecial acrylate F) Compounds where m = 1, a = 2, b = 4 (hereinafter referred to as special pentaerythritol condensate A), m=1. A compound where 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 compounds (hereinafter referred to as special pentaerythritol condensates), and special acrylates represented by the general formula below.

8) CH2=CHC00C(CH2CH20)4-
COCH=CH2佳鴇東acrylate H) ■ CH2CH2C00CH=CH2 (4,8 unacrylate-) io> (脣, +4 acrylate J) 11) A A A-(X-Y+ X-A A.acrylic acid, X: ME Alcohol 12)
A+M-N+-M-A A, acrylic acid, M, dihydric alcohol N: 2 salts (), acrylate) In addition, as radiation-curable oligomers, polyfunctional oligomers represented by the following general formula are used. Examples include ester acrylates, acrylic modified urethane elastomers, and those into which functional groups such as COH are introduced.

(In the formula R,, R2・alkyl, n・integer) Also, heat 11
1:? by radiation-sensitizing the plastic resin. A radiation-curable compound may also be used.

Examples of such radiation-curable resins include acrylic acid, methacrylic acid, or acrylic double bonds such as ester compounds thereof, and diallyl phthalate, which exhibits an unsaturated double bond with 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 heat radiation-resistant resins that can be modified into radiation-curable resins include vinyl chloride copolymers, saturated polyvinyl sulfate resins, polyvinyl alcohol resins, epoxy resins, phenoxy resins, cellulose derivatives, etc. Can be done.

Other resins that can be used for radiation sensitivity modification include polyfunctional polyester resins, polyether ester resins, polyvinylpyrrolidone resins, and derivatives (pvp
Olefin co-i copolymerized polyamide resin, polyimide resin, phenol resin, spiroacetal resin, acrylic containing at least one type of acrylic ester ester containing a hydroxyl group as a polymerization component, f
- Resin etc. are also effective.

The average thickness of the calyx 6 of such a radiation-curable compound is 0.1 to 30 μm, more preferably 1 to 10 μm.

If the thickness of this film is less than 0.1 μm, a uniform film cannot be formed, the moisture-proofing effect in a humid atmosphere is not longer than 1 minute, and the durability of the magnetic thin 11q layer 4 is not improved. Also,
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, making it unsuitable for practical use.

Such coating 11 may normally be applied by combining various 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 desired coating thickness, etc.

In order to cure such a coating film to form a protective layer, the coating film may be irradiated with radiation such as electron beams or ultraviolet rays.

When using an electron beam, the radiation characteristics include acceleration voltage 1
It is convenient to use a radiation accelerator of 0.00 to 750 KV, preferably 150 to 300 KV, and irradiate the absorption line j7 at 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 hengein methyl ether, benzoin ethyl ether, α-methylbenzoin, α-chlordeoxyhenzoin, hensifhenone, acetophenone, bisdialkylaminogen, etc. Examples include ketones such as siphenon, quinones such as acedraquinone and phenanthraquinone, and sulfites such as benzyl disulfide and tetramethylthiuram monosulfide.

The photopolymerization sensitizer is 0.1 to
A range of 1011% in total is desirable.

In order to cure such a coating film containing a gold sensitizer and a radiation-curable compound with 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 protection plate 8 is usually provided on the L of such a protection pattern 6 with an adhesive layer 7 interposed therebetween.

That is, recording and performing [11 Raw] only from the back side of the substrate 2 (@the side on which the sexual film layer 4 is not provided) as described in 11.
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 required to be particularly transparent, and may be made of divine resins such as polyethylene, polyvinyl chloride, polystyrene, polypropylene, polyvinyl alcohol, methacrylic resin, polyamide, polychloride, etc. Various thermoplastic resins such as vinylidene, polycarbonate, polyacetal, fluororesin, phenolic resin,
Area resin, unsaturated polyester resin, polyurethane,
Various thermoplastic resins such as alkyd resins, melamine resins, epoxy resins, and silicone resins can be used.

In addition, various inorganic materials such as glass and ceramics can be protected by a protective plate 8.
It may also be used as

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 bonded via the adhesive layer 7 as described above. The adhesive layer is an adhesive such as a hot melt resin, and has a thickness of about 1 to 100 μm.

On the other hand, instead of using the above protection plate 8, the above magnetic thin film layer 4. Protective layer 5. Roughly roughen the substrate with the protective film 6, etc.! By using a set, facing each other with the image-related thin film layer on the inside, and pasting them together using adhesive layer 7, it is possible to create a 1-car set (! good.

Furthermore, it is preferable to provide a heart coat layer as a various protective film on the back surface of the J^ plate 2 and the protective plate 8 (the side where the &fi thin film layer 4 is not marked).

As for the material of the hard coat layer, the above-mentioned protection +1!2
It may be made of the same material as No. 6.

■ Effects of the Invention The magneto-optical recording medium of the present invention has a 1F lead sulfide intermediate layer containing oxygen and having a predetermined distribution of oxygen concentration between the resin substrate and the magnetic groove layer. . Therefore, records,
It has excellent reproduction characteristics, and the magnetic thin film layer shows little deterioration over time.

Especially when the substrate is made of polycarbonate resin,
Deterioration of the magnetic thin film layer over time is further reduced. Moreover, the resistance against warping and the like is further improved.

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

[Example 1] Bisphenol A with a diameter of 13 cm and a diameter of J' (1.2 mm)
A zinc sulfide intermediate layer was deposited to a thickness of 900 mm on a substrate made of polycarbonate resin (molecular weight: 15,000) by binary sputtering.

During sputtering, in order to provide a predetermined oxygen concentration distribution in the zinc sulfide intermediate layer, the sputtering rate was temporally controlled using ZnS and ZnO as targets in an Ar atmosphere at an operating pressure of IPa.

After layer formation, elemental analysis in the film was performed using Auger spectroscopy without ion etching.
O/Z n atomic ratio (x+
) was 0.8, and the O/Zn atomic ratio (x4) from the magnetic thin film layer side to the 1/4 position was 01.

Further, the average 0/Zn atomic ratio (x) and S/Zn atomic ratio (y) for the whole area were 0.3 and 0.7, respectively.

On top of this zinc sulfide intermediate layer, 21aL%Tb, 68aj
%Fe, 7aL%Co, 4aL%Cr alloy thin layer was deposited by sputtering to a thickness of 800mm to form a magnetic thin film layer.

In addition, the target is Fe target, Tb, C01C
The one with the r chip on it was used.

On this magnetic groove 11!2 layer 1-, a protective layer M of silicon oxide is formed by sputtering to a thickness of 1000 mm, and on top of this protective layer, a coating composition containing the above-mentioned radiation-curable compound is applied as a protective film. Layered with spinner coat.

(Coating Composition) Polyfunctional Oligoester Acrylate 1001 (Last Part Photosensitizer) 5 Layers After coating such a coating composition as a layer, it was irradiated with ultraviolet rays for 15 seconds to crosslink and cure to form a cured film.

The film thickness at this time was 5 μm.

Note that the same treatment was also performed on the back surface of the substrate. Furthermore, a polycarbonate resin protective plate having a diameter of 13 cm was adhered to the protective crotch using an adhesive to prepare a sample of the present invention (sample No. 1). According to this, samples No.
Various samples were prepared in the same manner as in case 1.

The following characteristic values were measured for the samples described below.

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

Rotation speed 4 m/s e
cCarrier frequency 500KHz resolution
30KHz 2jha'7- (
830nm) 3~4 mW regeneration ha'7-
(830 nm) 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 IIv 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 products of the present invention indicated by No. 1 to No. 4, X is larger than X4, and in particular, x+/x4 is 2.
As mentioned above, since X is 0.01 to 0.7 and y is 0.3 to 0.99, all of the C/N ratio, pit error rate, and these values after storage show good results. Especially no,
1, No. 3, and No. 3 show extremely good results because the values of x, x, /x, and y are within the optimal range, and
It can be seen that when is 0.05 to 0.5, X 1 /

[Brief explanation of drawings]

FIG. 1 is a sectional view of a magneto-optical recording medium showing one example of the present invention. Explanation of symbols 1... Magneto-optical recording medium, 2... Substrate 3... Sulfide i1 [ship intermediate layer, 4... Magnetic thin film layer, 5... Protective layer, 6... Protective film, 7...Adhesive layer, 8...Protection plate applicant TDC Co., Ltd.-5

Claims (5)

[Claims] (1) In a magneto-optical recording medium that has an intermediate layer formed of zinc sulfide on a resin substrate and a magnetic thin film layer of a rare transition metal on the intermediate layer, the intermediate layer does not contain oxygen. a magneto-optical recording medium, wherein the intermediate layer has a higher oxygen content on the substrate side than on the magnetic thin film layer side. (2) The O/Zn atomic ratio in the zinc sulfide intermediate layer at a position up to 1/4 from the substrate side of the zinc sulfide intermediate layer is lower than the O/Zn atomic ratio in the zinc sulfide 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 /Zn is twice or more. (3) The magneto-optical recording medium according to claim 1 or 2, wherein the zinc sulfide intermediate layer has an average O/Zn atomic ratio of 0.01 to 0.7. (4) The magneto-optical recording medium according to any one of claims 1 to 3, wherein the zinc sulfide intermediate layer has an average S/Zn atomic ratio of 0.3 to 0.99. (5) The magneto-optical recording medium according to any one of claims 1 to 4, wherein the resin substrate is made of polycarbonate resin.