JPS61113155A - Photomagnetic recording medium - Google Patents

Abstract

PURPOSE:To improve remarkably corrosion resistance by having an amorphous magnetic alloy film having the axis of easy magnetization in the direction perpendicular to the film plane. CONSTITUTION:The amorphous magnetic alloy film exhibits the compsn. expressed by the formula 1. The x is the formula is required to be at 0<=x<=0.9. The coercive force decreases and micro-recording bits hardly exist stably when Gd exceeds 90atom%. In addition, Curie temp. increases and therefore the writing of the compensation temp. under serve film forming conditions is compelled to be used. The y in the formula is also required to be at 0.2<=y<=1.0. The Curie temp. increases as well and the writing of the signal is difficult when Co exceeds 80atom%. A transition metal (Fe, Co) and rare earth metal (Gd, Tb) are required to exist at a suitable compsn. ratio in order to have the axis of easy magnetization perpendicular to the film plane and are therefore determined at 0.1<=p<=0.5. The corrosion resistance is improved by determining the above at 0.001<=1-q<=0.35, 0.6<=z<=0.8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a magneto-optical device which is used in magneto-optical memory, magnetic recording, display elements, etc. and which can be read out using magneto-optic effects such as the magnetic Kerr effect or the Faraday effect. The present invention relates to recording media, and particularly to magnetic thin film recording media with improved corrosion resistance.

(Prior Art) Conventionally, as a magneto-optical recording medium, MnB1. MnCuB
Other crystals of 1st class 91111. GdCo, GdFe,
TbFe.

Amorphous materials such as DyFe, GdTbFe, TbDyFe, etc.
Single crystal thin films such as sg and GdIG are known.

Among these thin films, there is the film-forming ability of producing a large-area thin film at a temperature close to room temperature, the writing efficiency of writing signals with small photothermal energy, and the S/N ratio of the written signal.
In consideration of readout efficiency and the like, the amorphous thin film has recently been considered to be excellent as a magneto-optical recording medium. In particular, GdTbFe has a large Kerr rotation angle and has a single Curie point of around 150''C, making it optimal as a magneto-optical recording medium.

Furthermore, we have found that GdTbFeCo, a bond that we have researched for the purpose of improving the Kerr rotation angle, has a sufficiently large Kerr rotation angle and S
It has been found that the present invention is a magneto-optical recording medium capable of r+f reading with a good /N ratio.

However, GdTbFe or GdTbFeC.

One of the characteristics of amorphous magnetic materials, including , is that they have poor corrosion resistance. In other words, when it comes into contact with the atmosphere or water vapor,
Not only will its magnetic properties deteriorate, but it will eventually oxidize completely and become transparent.

To this end, disk-shaped recording media have been proposed in which a protective layer is provided on the recording layer or the recording layer is further sealed with an inert gas.

(Summary of the Invention) An object of the present invention is to provide a magneto-optical recording medium that has optimal magnetic properties for recording and reproducing information and has excellent corrosion resistance.

The above object of the present invention is achieved by a magneto-optical recording medium having an amorphous magnetic alloy film having the following composition and having an axis of easy magnetization perpendicular to the film surface.

((GdxTJ-X) P (Fe, Co1-y) 1
-p) q(NizCrl,) 1-q However, 0≦X≦0.9 0.2≦y≦1.0 0.05≦2≦10 0.1≦P≦05 o,oot≦t-q ≦ 0.35 The magneto-optical recording medium of No. 1 has, as a recording layer, an amorphous magnetic alloy film having an axis of easy magnetization in the direction of normal force on the film surface.

When recording information on the recording medium of the present invention, which is capable of high-density recording of information, the alloy film, which is uniformly magnetized in a predetermined direction, is irradiated with a radiation beam modulated by an information signal. Then, by heating the irradiation section to a temperature higher than one Curie temperature and then cooling it, an information signal is recorded as a series of recording bits with reversed magnetization directions. Moreover, when reading out the information signal recorded in this way, +m
A high-speed linearly polarized light beam is made incident on the m-alloy gold film, and the light flux modulated in the polarization direction by the information is detected by the magneto-optic effect.

In the present invention, the amorphous magnetic alloy film has the following composition.

((G d'xTb 1-X) P (, Fe yc
Q l-y) l -pl q(N+2crl-2)
l-q Here, O≦X≦0.9, that is, Gd needs to be in the range of θ to 90 atomic% with respect to the total amount of Gd and Tb.

When Gd exceeds 9Q ltomic%, the coercive force becomes small, making it difficult for *small recording bits to exist stably.

Furthermore, since the Curie temperature increases, it is necessary to use compensation temperature writing with strict film forming conditions. Also, 0
．． 2≦y≦1.0, that is, Co needs to be in the range of O to 80 atomic% with respect to the total amount of Fe and Co. When Co exceeds 80 atomic%, the Curie temperature also increases, making it difficult to write signals. In particular, from the standpoint of recording sensitivity, 0.35
≦y≦1.0 That is, Co elm is 65 atoms
It is desirable that it is below ic%.

In addition, in order for the magneto-optical recording medium of the present invention to have an axis of easy magnetization perpendicular to the film surface, a-transfer metals (Fe, Co) and rare earth gold ffl (Gd, Tb) must be present in an appropriate composition ratio. Therefore, 0.15P≦0.5, that is.

F @ , CO* G d + T b (7)
The sum of Gd and Tb is required to be present in a range of 10 to 50 atomic% with respect to Q'BL. Outside this range, the axis of easy magnetization is parallel to the film surface, and the metal film cannot have (K direct magnetization 19. Furthermore, considering the stabilization of magnetic properties, Gd8 and T
The positive one of b is Fe.

total of Co, Gd, Tb) - 15 to 30 at
It is desirable to set it to omic% (0,15≦p≦0.3).

In order to improve corrosion resistance in the present invention, 0.0
01≦l-q≦0.35, that is, with respect to the total amount of magnetic alloy,
A combination of Ni and Cr is O1l ~ 35 atoms
ic% range.

This is because if Ni and Cr are less than 0.1 atomic%, corrosion resistance cannot be sufficiently improved, and 3
This is because if it exceeds 5 atocnic%, the magnetic properties will be affected and it will be difficult to obtain a perpendicularly magnetized film.

tta, Ni (7) ;IihaNi トCr ト'k
For the combination h seta & i1 rL, 5-100 atoms
Must be in the range of ic% (O, OS≦Z≦1
．． 0), However, if the amount of Ni becomes too large, Ni
Due to its ferromagnetism, the axis of easy magnetization of the alloy tends to be oriented parallel to the film surface.

Therefore, when considering a single Ni star, it is desirable that the amount of Ni is 30 atomic% or less based on the total amount of the alloy. Therefore, the preferable amount of Ni is 20 to 90% based on the total amount of Ni and Cr. atomic% range (0.2≦Z≦0.9).Furthermore, regarding corrosion resistance, the Ni bar is 6% compared to the combined amount of Ni and Cr.
Range of 0 to 80 atoonic% (0,6≦Z≦0.
8) gave good results.

From the above explanation, the chemical compositions of particularly preferable materials are: GdTbFeNiCr, TbFeCoNi
Cr.

It becomes GdTbFeCoNLCr. TbFeNiC
r is also considered, but cucumber temperature is 100-120℃
GdTbFeN is somewhat susceptible to thermal f# effects due to its low
(Cr is.

It has a strong cucumber temperature (150 to 200 degrees Celsius) and a relatively wide Kerr rotation angle (0.25 to 0.27 degrees).
Since it has a large coercive force, it is suitable for high-density recording that forms minute recording bits. Also, TbFeCoNiC
r has an appropriate Curie temperature and a large Kerr rotation angle of 0.3 degrees; GdTbFeCoNiCr is 0.35 to 0.4
It has a larger Kerr rotation angle of 5 degrees and is a material with excellent signal readout characteristics.

(Example 1) In a high-frequency sputtering device, a crystal oscillator plate of a film thickness meter using a quartz crystal oscillator was used as a substrate, and a 5 mm square Gd, Tb moon was uniformly spread on Fe 7 of 4 inches φ as the first tarquent. A 40% Cr-balance N1 alloy with a diameter of 4 ins was used as the second targent. After evacuating the chamber to below 1.5XlO-5Pa,
By introducing Ar gas up to 4×10-I Pa and operating the main valve of the A air exhaust system, the Ar pressure was reduced to 3P.
I made it a.

From the high frequency '+IL&I, the first target has a constant sputtering force of 250W, and the second target has a sputtering force of 250W.
Thickness Q, 2p, rn of various compositions as shown below were obtained by simultaneous two-source sputtering with different CLE forces.
1111 was produced.

Sample knee 1° ((G do, s T bo, s ) 0.21 Fe
o, 7a lo, ss (N io, a Cro, 4)
0.05 sample l-2° ((G do, s T bo, s ) 0.21 Fe
o, rs ) o, ao (N io, s Cro, <
) o, +.

Sample l-3゜((G do, s T bo, s )0.21 Fe
o, 7s ) 0.85 (N io, s Cro, <
) o, +s Sample 1-4; ((G do, s T bo, s )0.21 Fe
o,7s lo,ao (N io,s Cro,a
)0.20 Also similar equipment, Cr-free,
An alloy film having the following composition was produced.

Sample 1-5; ((Gdo, s Tbo, s ) 0
．． 21 Feo, 7s 10.97 Nio, oa These films were found to be amorphous films as a result of X-ray diffraction.

The alloy film having the above structure was placed in a constant temperature and humidity chamber at 80° C. and 85% RH, and a corrosion resistance test was conducted. The results are shown in FIG.

In FIG. 1, the vertical axis shows, on an arbitrary scale, the increase in iTffm of the medium measured using a film thickness meter using a crystal oscillator.

Number 0 on the horizontal axis, constant temperature constant 1! ! It took some time to leave it in the tank! It is shown that the corrosion progressed as ILm increased. Here, the code is the same as each sample number.

In addition, as a comparative example, a 1lIF# corrosion test was conducted on a magneto-optical recording medium with a conventional composition under the same conditions, and 17 was CdTb.
Example of Fe 18 shows an example of GdTbFeCr, Nl
The GdTbFe film that does not contain 8 or Cr loses its metallic luster after one day and is corroded, but as the amount of Ni and C'r increases, the weight increase, that is, the degree of oxidation, increases. It was found that the corrosion resistance was improved. It was also found that the film has better corrosion resistance than the GdTbFeCr film.

Furthermore, in GdTbFeNiCr plJ, even if Nl and Cri were increased, the rate of decrease in the Kerr rotation angle, which is related to readout efficiency, was small, and was about 1896 in Samples 1-4.

(Example 2) In Example 1, a 20% Cr-balance Ni alloy was used for the second target, and the other conditions were the same as in Example 1. The following species h f) Composition thickness 0.2 gm (1) GdTbFe
N1CrIIQ was produced.

Sample 2-1: ((G do, s T bo, 5) 0.21 F eo
, 7910.95 (N io, a Cro, 2) 0.
05 trial +2-2; ((G do, 5T bo, s) (1,21F eo
, t9+0.90 (N i o, a Cro, 2) o
, t.

Sample 2 = 3; ((Gdo, 5 Tb(1,5)0.21 FeO,?
910.85 (Nio,aCrO,2)6.15
Sample 2-4° ((G do, s T bo, s ) 0.21 Fe
o, v91o, go (N i O, 8Cro, 2) 0
．． 20 These films were found to be amorphous when subjected to X-ray diffraction.

Figure 2 shows the results of a corrosion resistance test in which the GdTbFeNiCr sample having the above configuration was placed in the same temperature and humidity chamber at 80°C and 85% RH as in Example 1. The results of the comparative example and samples 1-5 are also shown with the same reference numerals as in FIG. 1.

In this example, as in Example 1, GdTbFe or Gd
It was found that the corrosion resistance was further improved than that of TbFeCr. Furthermore, the rate of decrease in the Kerr rotation angle, which represents readout efficiency, was even smaller than in Example 1, and was approximately lθ% in Sample 2-4.

(Example 3) In Example 1, 30% co-
Same as Example 1, using 50%Gd-balance Tb pieces of 5mon square size evenly arranged on the balance Fe, and using 40%Cr-balance Ni alloy as the second target. GdTbFe with a thickness of 12°C with various compositions as shown below.
A CoNiCr film was fabricated.

Sample 3-1: ((GdO,5TbO,5)0.22 Fed,?
C00, 3) 0.7810.95 (N iQ, 9 Cr
Q, 4) Q, Q5 sample 3-2; ((G do, s T bo, 5) o22F eo7C
00,3) 0.7810.90(Nio,sCr
o, 4) o, t.

Trial #43-3゜((Gdo, 5 T bO, 5) 0.22 F eQ
,7 CO(1,3)Q,78)(1,85(N iO
, 6Crt), 4) t),) 5 test village 3-4; ((G do, s T bo, s) o, 22F eo,
7C00,3) 0.7810.80(Nio,s
Cro, 4)o, 2o' These n9s were found to be amorphous as a result of X-ray diffraction.

A corrosion resistance test was carried out by placing the membranes with the same number in a constant temperature and humidity chamber at 80°C and 85% RH in the same manner as in Example 1.
In FIG. 3 shown in FIG. 3, the same reference numerals as the sample numbers are given, and the results of the same comparative example and samples 1-5 as in FIG.

The results of a corrosion resistance test under the same conditions for a magneto-optical recording medium made of

The GdTbFeCoNiCr film has better corrosion resistance than GdTbFeCo IIQ, and
GdTbFe.

11LX of GdTbFeCr 7! More corrosion resistant than f
I found out that it was wrong. Also, the decrease in Kerr rotation angle −
V was about 12% in sample 3-4.

(Example 4) In Example 3, a 20% Cr-balance Ni alloy was used for the second target, and the other conditions were the same as in Example 1, to produce the following various GdTbFeCoNiCr pieces with a thickness of 0.2 #Lm. did.

Sample 4-1; f(G do, 5T bo, s) o, 22(F eo,
7Coo, a) o, 7a) o, 5s(N iO, B c
rO,2)0. (15 sample 4-2; i (G do, s T bo, s) o, 22 (F eo
,7C00,3)0.7810.90(N t O,8
Cr, ), 2) +), + (1 sample 4-3; ! (G do, 5T bo, s) o, 22 (F eo7
C80,3) 0.78+0.85(N t o, a C
ro, 2) o, +s sample 4-4; + (G do, 5 T bo, 5) 0.22 ('F
e O,7C00,3)Q,? 810.80 (N i
Q, 9 CrQ, 2) Q, 2Q These films were found to be amorphous as a result of X-ray diffraction.

The membrane with the above structure was placed in a constant temperature and humidity chamber at 80°C and 85% RH in the same manner as in Example 1, and a corrosion resistance test was conducted. The results are shown in Figure 4. The same reference numerals as the numbers are given, and the results of the comparative example and samples 1 to 5 are shown in FIG. 3. According to this example, GdTbF
eCoNiCr IK! T? The ratio of Ni to Cr is Ni
It was found that the product with /Cr = 8/2 had increased durability compared to Example 3. Furthermore, the rate of decrease in the Kerr rotation angle was even smaller than in Example 3, and was about 7% in Test Q L4-4.

(Example 5) In a high-frequency sputtering device, a crystal resonator plate of a film thickness meter using a crystal resonator was used as a substrate, and a 5 mm square plate was placed on a 4 inch φ 30% Co-balance Fa plate as a first target. Tb pieces arranged uniformly.

A 40% Cr to balance nN+ alloy was used as the second target. After evacuating the chamber to 1.5XlO-5Pa or less, Ar gas was evacuated to 4X I0-IP.
The Ar pressure was set to 3 Pa by operating the main valve of the true exhaust system with four people working up to a. At this time, input was made from the RF source to the substrate side, and the bias voltage was set to 80 volts. In this way, various compositions of GdFeCoNiCr (n=0.24 m tf)
I2 was produced.

Sample 5-1゜fT bo, +8 (F eo, 7C00,3) 0.11
21 o, as (N iO, [ic r,), 4
) 0.05 test #4s-z.

(T bOl(B (F e(1,7C00,3)0.
8210.90 (N iO, e CrO, 4) 0.
10 Sample 5-3: (T bo, +a (F eo, 7Coo, 3) 0.8
210.85 (N io, e Cro, < )0.
15 Sample 5-4; (T bO, 4a (F e (+, 7 Cog, 3)
0.821 Q, 80 (N io, 6 CrO, 4)
0.20 again. Using a similar apparatus, an alloy film containing no Cr and having the following composition was produced.

Trial $45-5゜IT ba, +a (F eo, 7COQ, 3) 0.8
21 o, s7N io, 93 These films were found to be amorphous as a result of X-ray diffraction.

The alloy film with the above structure was heated at 80°C and 85% R as in the first example.
The results of a corrosion resistance test placed in a constant temperature and humidity chamber of
The numbers shown in the figure are the same as the respective sample numbers. In addition, TbFeCo was used as a comparative example as in Example 1 and as 20.
An example is also shown.

According to this example, the TbFeCoNiCr film is made of Ni
and Cr-free T b Fe Corl
It was found that the corrosion resistance of silicon was significantly improved compared to Q. In addition, conventional I of GdTbFe, GdTbFeCr, etc.
It was found that it has better corrosion resistance than IA. Furthermore,
TbFeCoNiCr lip contains N1t-+ and Cr
Even if the number of stars increases, the rate of decrease in the Kerr rotation angle, which is related to readout efficiency, is small; in sample 5-4, the rate of decrease is 1. The burn rate was 10%.

(Example 6) Films were formed in the same manner as in Example 5, but here the self-bias voltage was set to zero, and various compositions (7
) TbFaCoNiCr nQ was prepared.

Sample 6-1゜fT bO, +8 (F eo, 7 C00,3)+)
,82)0.85 (N jO,8Cro,4')
0. +) 5 trials N6-2゜(T bo, +a (F eo7Coo, 3) 0.82
io, so (N io, e Cro, a) o, t
.

Sample 6-3° (Tbo, +8 (Feo, 7 CQo, 3)O
,8210,85(N i(1,6CrQ,4)cl,
+5 sample 6-4; 1Tbo, +a (Fao, 7C00,3)o, a2
1o, so (N io, s Cro, 4) 0.20 These films were found to be amorphous as a result of X-ray diffraction.

As in Example 1, the samples were placed in a constant temperature and humidity chamber at 80°C and 85% and subjected to one resistance and corrosion test.
In the figure, 11 is given the same code as the sample number.
Same as FIG. 5, the results of the comparative example and sample 5-5 are also shown.

In this example as well, the TbFeCoNiCr film is GdTbFe.
,.

It was found that this film has better corrosion resistance than films such as GdTbFeCr and TbFeCo.

In addition, the decreasing rate of Kerr rotation angle was 10 in sample 6-4.
It was about 13% after days. Also.

In this example, since the bias voltage was set to zero during film formation, a remarkable columnar structure appeared, the density was lower than in Example 5, and the J1if eclipse was faster. From this, it was found that the resistance and corrosion resistance were improved by applying a bias voltage.

(Example 7) A film was formed in exactly the same manner as in Example 6 except that a 20% Cr-balance Ni alloy was used as the second target.

In this way, Tb of various compositions with a thickness of 0.2 μm as shown below
A FeCoNiCr film was created.

Sample 7-1: fTbo, +7 (Feo, 7C00,3) 0.831
0-95 (N io, a CrO2) 0.05 sample 7
-2゜(Tbo, +7(Fao, 7C00,3)0.831
0.90 (N iO,8c r(1,2)0.10
Shimura 7-3: fTbo, +7 (Feo, 7CQo, 3) Q, +
1310.85 (N io, a Cro, 2) 0.
15 trials $47-4; tT bo, 17 (F eo, 7C00,3) 0.83
io, ao (N io, a Cr(1,2)0.
As a result of X-ray diffraction, all of Komaru et al.'s films were amorphous.

The above AI' film was heated at 85°C and 85% in the same manner as in Example 1.
A corrosion resistance test was conducted by placing it in a constant temperature and humidity chamber at RH. As a result, +1j is reduced to the 7th [7j, where again the sample number and -1
A - symbol is attached to Fig. 5 and comparative example and sample 5-5.
The results were combined and reduced.

(TbFeCoNiCr ty in the example) The film is GdT
bFe.

TbFaCo, GdTbFeCr”F (7)
It was found to be more corrosive than tlQ.

In addition, the decreasing rate of Kerr rotation angle was 10 in sample 7-4.
After 14 days, it was about 8% after liS.

(Example 8) 1°1. “In a single-frequency sputtering system, the substrate is a 3-inch square white glass plate, and the first target is a 4-inch diameter
5 mm square Gd, Tb, Co on inch inch Fe.

A uniform array of pieces and a 4 inch diameter Ni target were used as a second target.

After making the inside of the device a vacuum of 1.5Xlo-5Pa or less,
Ar gas was introduced to 4XIO-IPa, and the Ar pressure was set to 3 Pa by operating the main valve of the evacuation system. Using a high-frequency power source, the sputtering power of the first target was kept constant at 250 W, and the sputtering power of the second target was changed to form GdTbFeCaNI films with the following various compositions on the substrate by 2M simultaneous sputtering.

Sample 8-E; (Gdo, s (Tbo, s) 0.21 (Feo,
a Coo, t) 0.79) o, sa N 1G,
003 sample 8-2; (Gdo, s (Tbo, s) 0.21 CFea,
s Coo, r) 0.78) o, se N io,
o+Sample 8-3; (Gdo, s (T bo, s) 0.21 (Fso
, s COO, I) 0.79 ) o, ss N Io
, o5 sample 8-4; (Gdo, 5 (Tbo, s) 0.21 (Feo,
s Coo, +) o, 7s) o, so Nio, +
Sample 8-5: (Gdo,s (Tbo,s) 0.21 (Fe
o, a Coo, t) 0.7910.85 N io
, +5 sample 8-6; (Gdo, s (Tbo, s) 0.21 (Feo
, s Coo, +) 0.7E110.80 N io
, 2 above i7) GdTbFeCoNi pf2,
GdTbFaCo H'A (comparative example) and 55"
C, 75% constant I&! Corrosion resistance test was carried out in a constant humidity layer.

The results are shown in Figure W4a.

In Figure 8, the vertical axis shows the ratio of the holding force to the initial E on an arbitrary scale, and the horizontal axis shows the elapsed time.

A decrease in coercive force indicates progress of corrosion. Data for each sample is indicated by the same code as the sample number.

For comparison, reference numeral 21 shows a conventional example of a GdTbFeCo film to which no Ni is added.

As is clear from Fig. 8, GdTb containing no NL
For FeCo H, a significant decrease in holding power was observed after about 200 hours. As the Ni content of GdTbFeCo increases, the coercive force decreases less and IT1 corrosivity increases.
Amorphous again! Lai-based films tend to undergo 4Ii structural changes such as crystallization at relatively low temperatures, and their properties as magneto-optical materials may be impaired, but the addition of Ni raises the crystallization temperature by 1, improving thermal stability. has also improved.

(Example 9) Gd arranged on the first target in Example 1,
GdTbFeNiCr films with various compositions as shown below were prepared in the same manner as in Example 1 except that the number of Tb pieces was changed.
The bFe film was subjected to the same corrosion resistance test as in Example 1.

The weight increase after 4 days of this example according to this test was determined by Gd
Weight increase after 4 days in TbFe IIl is 100
The ratio bite value when

Composition Hair increase sample 9-
1; ((GdO, 05TbQ, 95) 0.21 Feo,
7slo, 5o (Nio, 5Cro, a) o, to
55 sample 9-2; ((GdO,1OTb0.90)0.21 Fao,
7s1o, 5o (Nio, eCro, 4)o, Io
50 sample 9-3: ((GdO,90Tbo,lo)Q,21Fe(1
,711(1,90(Niq,6CrO,4)0.1(
150 sample 9-4; 1 (Gdo, 5oTbo, 5o)o, Io FeO,
9010,90(Ni0.8CrQ,4)0.10
a.

Sample 9-5; ((GdO, 50TbQ, 50) 0.15 Feo, y
r) o, ao (Nio, 5Cro, 4) o, ro 4
5 sample 9-6; ((Gd0.50Tb0.50)0.25 FeG,
751o, 9o (NiO, B Cro, 4n (1,
+11 50 sample 9-7; ((Gdo, 5oTbo, 5o)o, 3o FaO,?
010.90 (?'1G, 8cr0.4) 0.10 5
0 sample 9-8: ((Gd0.50TbO,5G)0.35 Feo, a
slo, 5o (Nio, 5Cro, 4)o, to 5
5 (Example 10) In Example 1, 9 g% Cr was added to each of the second targets.
- Balance Ni alloy, 80% Cr - Balance O Ni alloy, 5% Cr - Balance Ni alloy were used, and the rest was the same as in Example 1 to prepare GdTbFeNi with the following various compositions.
Cr1li was produced. These films were subjected to the same corrosion resistance test as in Example 1, and the results were shown in the same manner as in Example 9.

Composition Weight increase sample 1
0-1; [(GdO, 50TbO, 5G) 0.21 Feo,
79io, ao (N io, osc ro, ss)
o, io 60 sample 10-2; + (GdO, 50TbO, 5G) 0.21 FeQ,
? 91o, eo (NiQ, 20Cro, 80) 0.
1055 sample 10-3; ((Gd0.50TbO,50) Q, 21 F eo
, 791o, so (N io, soc ro, to)
o, to 45 (Example 11) In Example 1, a 30% C〇-balance Fe alloy was used as the first target, and the number of Gd and Tb pieces arranged on it was changed, but the rest was the same as Example 1. The following various +7)
GdTbFeCoNiCr Ill with composition 0
Next, these films and a similarly prepared Gd film as a comparative example
TbFeCo IIS was subjected to the same corrosion resistance test as in Example 1. The increase in ball amount after 4 days of this example in this test is as follows: 4 days after GdTbFeCo IQ! 1! As a comparison value when the increase in amount is set as 100, the following compositions are summarized.

111 I increase sample 11-1° ((Gdo, os Tbo, ss) 0.22 (Fe
o, 7o CQo, 30 ) 0.781o, s.

(Nio, so Cro, io) o, to 35 samples 11-2° ((Gdo, io Tbo, so,) o, 22 (Feo
, 7o COo, 30 ) 0.78 ) 0.110 (N
io, ao Cro, 4o) o, io 30 sample 11-
3゜((Gdo, so Tbo, to)0.22 (Fe
o, 7o COo, 30) 0.78) o, s.

(Nio, 80Cry, 4g) (14 (130 samples 1
1-4゜((Gdo, so Tbo, so) o, to (Fe
o, 7o COo, 30) o, so ) o, s.

(NiO, 80CrO, 40) 0.1025 sample 11-
5; ((Gdo, so Tbo, so) Q, 15 (
Feg, 7g coo, 30) o, as lo, s.

(NiO, 80CrO, 40) 0.10 25 samples 11
-6; ((Gdo, so Tbo, so)0.25 (Fe
o, 7o COo, 30) 0.75) o-s.

(NiO, 80CrO, 40) 0.10 30 samples 11
-7゜((Gdo, so Tbo, so)0.30 (Fl
lo, 70 COo, 3G) 0.701o, s.

(Ni6,80Cr0.4g) 1), 1 (130 sample 1
1-8゜1 (Gdo, so Tbo, so)0.35 (Fe
o, 7o COo, 3G ) o, ss ) o, s.

(Nio, eo Cro, 4o)o, io 35(
Example 12) Fe of various compositions was used as the first target in Example 1.
The following various GdTbFeCoNiCr 11% samples were prepared in the same manner as in Example 1 except that a Co alloy was used. These films were subjected to the same corrosion resistance test as in Example 1, and the results were shown in the same manner as in Example 11.

Composition Meibori increase sample 12
-1゜((GdO,50Tb0.5G)0.22 (Feo
, 5sCoo, os) 0.78) o, 9° (NiO
,60CrO,40) 0.10 35 sample 12-2; ((G do, soT bo, so) 0.22 (F
eo, 11oc oo, to) o, 7a) o, s
o.

(Ni6,80Cr(1,40)0.10 35 sample 1
2-31 ((GdO,50TbO,50) 0.22 (F”0
．． 80CO0,2G) 0.78) 0.90(NiO
, 80Cr0.4G) 0.10 30 Sample 12-4.

+(G dO, 50T bo, 50) 0.22 (F
eo, soc 00.40) 0.78) 0.90
(Nio, 5oCro, to)o,io 30 sample 1
2-5.

i(G do, soT bo, so) 0.22 (F
1!0.50C00,50) 0.78i o, a.

(Nio, eoCro, 4o) o, io 25 sample 1
2-6.

((G do, soT bo, so) 0-22 (F
eo, 3sc 00.85) 0.7810.90(
N'0.80C40,40) 0.10 20 samples 12-
7; ((GdQ, 50Tb0.5G)0.22 (Feo
, 2oCoo, go) o, 7al o, s.

(N blind o, so Cro, ao) o, io l
5 (Example 13) In Example 1, a 30% Co-balance Fe alloy was used for the first target, and a 9% Cr-balanced alloy was used for the second targets.
Balance Ni alloy, 80% Cr- Balance Ni alloy, %Cr-
GdTbFeNiCrH with the following various compositions was prepared in the same manner as in Example 1 except that the remaining Ni alloy was 100% Ni.
and GdTbFeNi films were fabricated. These films were subjected to the same corrosion resistance test as in Example 1, and the results were summarized in Example 1.
Shown in the same manner as 1.

Group I & ball amount increase sample 1
3-1゜((G dQ, 50T bo, 50) 0.22 (F
eo, 70c 00.30) 0.781o, s.

(Nio, os Cro, ss) o, io 40 sample 13-2; + (G dO, 50T bo, so) 0.22 (F
eo, 70c 00.30 ) 0.78 ] [1,9
0 (Nio, 2oCro, ao) o, to 35 sample 13-3°f (G do, 5oTbo, so) 0.22 (F
eo,? Oc 00.30) Q, 781o, s.

(Nio, 5oCro, io) o, io 25 sample 1
3-4; ((G do; so T bo, so )0.22 (F
eo, 7oc 00.30) 0.7810.9ON
io, io 60 (Example 14) T b arranged on the first target in Example 5
TbFeCoNiCr films with various compositions as shown below were prepared in the same manner as in Example 5 except that the number of B sheets was changed.
o pfJ was subjected to the same corrosion resistance test as in Example 1. According to this test, the weight increase after unexamined example 40 was
TbFeCo! 1g @ lid increase after 4 days 1
The ratio bite value when set to 00 is summarized together with the composition below.

Sample 14-1; (T bo,io (F eO,?oc 00.30
) o, sol O, 90 (N io, eoc ro, 4
o ) o, to 30 samples 14-2° (T bo, +s (F eo, 7oc 00.30
) o, ssl o, so (N io, soCro, i
o ) o, to 30 samples! 4-3; (T bO, 25 (F eo, 70c 00.3G)
0.7510.90 (N io, eoc rO, 40
) 0.10 40 samples 14-4.

(T bo, 3o (F eo, 7oc 00.3Q
)o, 7o) o, so (N io, soc ro,
to ) o, to 40 samples 14-5° (T bo, 3s (F eo, 7oc oo, 3o
) o, ss) o, so (N io, soc ro,
4o) o, to 45 (Example 15) In Example 5, Fe of various compositions was used as the first target.
Using a Co alloy and a Tb piece, or using a Tb piece and a 5 mm square Co piece arranged on Fe, the rest is Example 5.
Similarly, the following various Al1 composition TbFeCoNi
A Cr film was produced. These films were subjected to the same corrosion resistance test as in Example 1, and the results were shown in the same manner as in Example 14.

Sample 15-1° (Tbo, +7 (Feo, ssCoo, o+)0
．． 831 o, so (N io, soc ro, io
) o, io 45 sample 15-2; fT bo, +7 (F eO, 90c QO, IO) 0
．． 831 o, so (N iQ, 80c rO, 40
) 0.10 40 samples 15-3.

(Tbo, +7 (Feo, soc 00.20)
0.831 o, so (N io, soCro, 4o
) o, io 35 sample 15-4; (T bo, +7 (F eo, soc 00.40)
0.83i o, so (N io, soCro, 4o
) o, io 35 sample 15-5.

(T bo, +7 (F eo, soCoo, so )o
, es1 o, so (N io, soCro, 4o
) o, io 30 samples 15-6° (T bo, l? (F eo, 3sCoo, es
) o, es1 o, so (N io, soc ro,
4o) o, io 25 samples 15-7° (TbO1+7 (Feo, 2oc 00.80)
0.831 o, so (N io, eoc ro, 4
o) o, to 25 (Example 16) In Example 5, 96% Cr was added to the second target, respectively.
- Remaining 1iffiNi alloy, 80% Cr-remaining O Ni alloy, and using %Cr-remaining Ni alloy, and in the same manner as in Example 5, TbFeCoNi with the following various compositions were used.
Cr IIQ was produced. These films were subjected to the same corrosion resistance test as in Example 1, and the results were shown in the same manner as in Example 14.

IT bo, +7 (F eo, 7oc 00.30
)0.83) 0.90 (N io, osc ro
, as) o, io 45 sample 16-2.

IT bo, +7(Feo, 7oc 00.30
) 0.8310.90 (N io, 2oc ro, g
o) o, io 40 trials Ml 6-3; (T bo, 17 (F eo, 7oc 00.30)
0.83+ 0.90 (N io, aoCro, io
) o, to 40 The magneto-optical recording medium according to the present invention,
glass, metal.

When laminating on a substrate such as plastic by the sputtering method or vacuum evaporation method of the embodiment, if a well-known protective layer, an antireflection layer that also serves as an anti-reflection layer, a heat insulating layer, etc. are provided on the recording medium, further Corrosion resistance is improved. Furthermore, it goes without saying that the corrosion resistance can be improved even if the conventionally known air sandwich type structure in which an inert gas is confined is used.

(Effects of the Invention) As explained above, the present invention has the effect of significantly improving corrosion resistance in conventional magneto-optical recording media.

[Brief explanation of drawings]

1st M and 2nd figure are husband // GdTbFeNiCr
FIG. 3 is a diagram showing the results of a corrosion resistance test of an example of the present invention made of pfJ. Figures 3 and 4 show husband hGdTbFeCoNiCr
FIG. 3 is a diagram showing the results of a corrosion resistance test of an example of the present invention made of nQ. :A5 figure, :11J6 figure and figure 7 are Hu*TbFeC
FIG. 3 is a diagram showing the results of a corrosion resistance test of an example of the present invention made of an oN1C:r film. FIG. 8 is a diagram showing the results of a corrosion resistance test of an example of the present invention made of GdTbFeCoNi 114J.

Claims (1)

[Claims] (1) In a magneto-optical recording medium having an amorphous magnetic alloy film having an axis of easy magnetization perpendicular to the film surface, the alloy film has the following structure: {(Gd_xTb_1_-_x)_p(Fe_yCo_
1_-_y)_1_-_p}_q(Ni_zCr_1_
-_z)_1_-_qHowever, 0≦x≦0.9 0.2≦y≦1.0 0.05<z<1.0 0.1≦p<0.5 0.001≦1-q≦ 0.35.