JPH0123927B2 - - Google Patents
Info
- Publication number
- JPH0123927B2 JPH0123927B2 JP17083781A JP17083781A JPH0123927B2 JP H0123927 B2 JPH0123927 B2 JP H0123927B2 JP 17083781 A JP17083781 A JP 17083781A JP 17083781 A JP17083781 A JP 17083781A JP H0123927 B2 JPH0123927 B2 JP H0123927B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- magnetic
- magneto
- recording medium
- curie point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000010409 thin film Substances 0.000 claims description 30
- 239000010408 film Substances 0.000 claims description 14
- 230000005415 magnetization Effects 0.000 claims description 12
- 229910017061 Fe Co Inorganic materials 0.000 claims 2
- 229910002058 ternary alloy Inorganic materials 0.000 claims 1
- 230000005291 magnetic effect Effects 0.000 description 15
- 239000000203 mixture Substances 0.000 description 8
- 229910000808 amorphous metal alloy Inorganic materials 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 7
- 230000005381 magnetic domain Effects 0.000 description 6
- 230000005294 ferromagnetic effect Effects 0.000 description 4
- 230000015654 memory Effects 0.000 description 4
- 230000005374 Kerr effect Effects 0.000 description 3
- 229910016629 MnBi Inorganic materials 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000005300 metallic glass Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910002546 FeCo Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- -1 Gd-Co Inorganic materials 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Description
本発明は光磁気メモリー、磁気記録表示素子な
どに用いられる光磁気記録媒体に関するもので、
具体的には膜面と垂直な方向に磁化容易方向を有
し、円形あるいは任意の形状の反転磁区を作るこ
とにより情報を記録することが出来、磁気カー効
果などの磁気光学効果を利用して読み出すことの
できる磁性薄膜記録媒体に関するものである。
磁化容易軸が膜面と垂直な方向にある強磁性薄
膜では、Ｓ極あるいはＮ極に一様に磁化された膜
面内の一様磁化極性と逆向きの磁極をもつ小さな
反転磁区を作ることができる。この反転磁区の有
無を「１」、「０」に対応させれば、このような強
磁性薄膜を高密度の磁気記録媒体として用いるこ
とができる。このような強磁性薄膜のうち、室温
にて大きな保磁力を有し、かつキユーリー点又は
磁気的補償温度が比較的室温に近い薄膜は、キユ
ーリー点又は磁気的補償温度を利用して光ビーム
により、任意の位置に反転磁区を作ることによつ
て情報を記録させることができるため、一般にビ
ーム・アドレサブルフアイルとして用いられてい
る。
従来、公知である膜面と垂直な方向に磁化容易
軸を有し、かつビーム・アドレサブルフアイルと
して使用可能な強磁性薄膜としては、MnBiに代
表される多結晶金属薄膜、Gd―Co、Gd―Fe、
Tb―Fe、Dy―Fe等の非晶質金属薄膜、GIGに代
表される化合物単結晶薄膜があるが、それぞれ以
下に述べるような利点及び欠点を有している。
MnBiに代表されるキユーリー点を利用して書き
込みを行なう多結晶性金属薄膜は室温で数KOe
の大きな保磁力を有している点では磁気記録媒体
として優れているが、キユーリー点が高い
（MnBiではTc＝360℃）ために書き込みに大きな
エネルギーを必要とする欠点がある。また、多結
晶体であるため化学量論的な組成の薄膜を作製す
る必要があり、薄膜の作製が技術的に難しいとい
う欠点もある。また、Gd―Co、Gd―Feの磁気
的補償点を利用して書き込みを行なう非晶質金属
薄膜は、非晶質であるため任意の基体上に作製可
能であり、多少の不純物を加えることによつてあ
る程度磁気的補償温度を任意に制御できる等の利
点を有するが、室温における保磁力が小さく
（300〜500Oe）、記録された情報が不安定である
という欠点を有する。しかも、この程度の保磁力
を有する薄膜を作製するためにも組成をほぼ
1atom％以内に制御する必要があり、薄膜作製面
でも容易でない。
さらに、GGに代表される化合物単結晶薄膜は
他のものにくらべ非常にコスト高になるという大
きな欠点を有する。
又、これ等の欠点を除去した新しい磁性薄膜記
録媒体として提案された15atom％〜30atom％の
Tb又はDyを含むTbFeやDyFeの非晶質合金薄膜
は、次のような利点を有している。
膜面と垂直な方向に磁化容易軸を有し、室温
において数KOeの大きな保磁力を有するため、
高密度の情報記録が可能で、記録された情報が
極めて安定である。
保磁力が大きく所望の形状の磁区を書き込む
ことが可能である。
幅広い組成範囲にわたつて大きな保磁力を有
しており、記録媒体として優れた特性を持つて
いる組成範囲もまた広いため、組成の厳しく限
定された薄膜を作る必要がなく非常に容易に作
製でき歩留まりも良い。
キユーリー点がTbFeでは120℃、DyFeでは
60℃と低いため、キユーリー点を利用して熱書
き込みを行なう場合には非常に小さなエネルギ
ーにより書き込みを行なうことができる。
しかしながら、このTbFe、DyFe等の非晶質
合金薄膜は次の様な欠点がある。すなわち、キユ
ーリー点が低いと確かに小さなエネルギーで書き
込みは出来るが、光で読み出す時のＳ／Ｎは逆に
悪くなる。図１には、非晶質合金薄膜の光再生時
の光再生出力（Ｓ）及び信号対雑音比（Ｓ／Ｎ）
を照射レーザパワー（I0）の関数として示してあ
るが、記録媒体として良い特性を有するTbFe、
DyFeは光再生の点では記録媒体として良くない
GdFeよりも悪いことがわかる。これはこの記録
媒体を光磁気メモリとして考える場合には非常に
大きな欠点となる。
本発明の目的は、上記のような膜面と垂直な方
向に磁化容易軸を有する従来の光磁気記録媒体の
欠点を除去して効率よく光再生出力をとり出し得
る光磁気記録媒体を提供することにある。
以下本発明を詳細に説明する。
本発明の光磁気記録媒体は、膜面に垂直な方向
が磁化容易軸であるとともに、120℃〜200℃の間
のキユーリー点を有するTb―Fe―CoとDy―Fe
―Coの非晶質合金薄膜である。膜面に垂直な方
向に磁化を向けるに十分な磁気異方性をもたせる
ためには、薄膜を非晶質にすることが必要である
が、この条件は室温以下の温度に保持された基体
上にスパツタリング法あるいは真空蒸着法等によ
つて薄膜作製を行なうことによつて達成される。
また、磁化を安定して膜面に垂直な方向に向かせ
るためには、膜の厚さを100Å以上とし、上記の
ようにTb又はDyとFeとCoの組成をTbx（Fe1-y
Coy）1-x及びDyx（Fe1-yCoy）1-xとして0.15ｘ
0.35、0.00＜ｙ0.50の範囲にすることが必要で
ある。0.50＜ｙでは、キユーリー点または磁気的
補償温度の組成依存性が大きく、実用性がない。
また、ｘの範囲をこの組成範囲外にした光磁気記
録媒体は、膜面に垂直方向に磁化容易軸を揃える
ことが困難であり、角形ヒステリシス特性を劣化
するので、実用性のある記録再生特性は得られな
いことになる。
本発明の磁気光学記録媒体は120〜200℃程度の
比較的低いキユーリー点を有するにもかかわら
ず、磁気カー効果を利用した光再生出力が同程度
のキユーリー点を有するTbFeやDyFeのものよ
り大きいことを特徴としている。例として
TbFeCoの場合を示すと、図２に示すごとく、
Tb（FeCo）のカー回転角θKは二元のTbFeにCo
を添加するにつれて向上していることが分る。図
２において、横軸はCoのTbFeCo全体に対する
率（％）を示す。一方、記録特性に係わる保磁力
Hcとキユーリー点Tcについてみると、表１のよ
うに保磁力はTbFe二元系と比べかなり大きくな
つていて、またキユーリー点Tcは若干上昇はす
るけれどもTbFeのすぐれた記録特性はそのまま
残されている。
The present invention relates to magneto-optical recording media used in magneto-optical memories, magnetic recording display elements, etc.
Specifically, the direction of easy magnetization is perpendicular to the film surface, and information can be recorded by creating a circular or arbitrary-shaped reversal magnetic domain, making use of magneto-optical effects such as the magnetic Kerr effect. The present invention relates to a readable magnetic thin film recording medium. In a ferromagnetic thin film where the axis of easy magnetization is perpendicular to the film surface, a small reversal magnetic domain with a magnetic polarity in the opposite direction to the uniform magnetization polarity in the film surface that is uniformly magnetized to the S or N pole is created. Can be done. If the presence or absence of this inverted magnetic domain corresponds to "1" or "0", such a ferromagnetic thin film can be used as a high-density magnetic recording medium. Among such ferromagnetic thin films, thin films that have a large coercive force at room temperature and whose Curie point or magnetic compensation temperature is relatively close to room temperature can be It is generally used as a beam addressable file because information can be recorded by creating reversed magnetic domains at arbitrary positions. Conventionally known ferromagnetic thin films that have an axis of easy magnetization in the direction perpendicular to the film surface and can be used as beam addressable files include polycrystalline metal thin films represented by MnBi, Gd-Co, and Gd. -Fe,
There are amorphous metal thin films such as Tb--Fe and Dy-Fe, and compound single-crystal thin films typified by GIG, each of which has advantages and disadvantages as described below.
A polycrystalline metal thin film that performs writing using the Curie point, such as MnBi, has several KOe at room temperature.
Although it is excellent as a magnetic recording medium in that it has a large coercive force, it has the disadvantage that it requires a large amount of energy for writing due to its high Curie point (T c = 360°C for MnBi). Furthermore, since it is a polycrystalline material, it is necessary to produce a thin film with a stoichiometric composition, which also has the disadvantage that it is technically difficult to produce a thin film. In addition, since the amorphous metal thin film that performs writing using the magnetic compensation points of Gd-Co and Gd-Fe is amorphous, it can be fabricated on any substrate, and it is possible to create it on any substrate without adding some impurities. Although it has the advantage that the magnetic compensation temperature can be arbitrarily controlled to some extent, it has the disadvantage that the coercive force at room temperature is small (300 to 500 Oe) and the recorded information is unstable. Moreover, in order to produce a thin film with this level of coercive force, the composition must be adjusted to approximately
It must be controlled within 1 atom%, which is not easy in terms of thin film production. Furthermore, compound single crystal thin films typified by GG have a major drawback in that they are extremely expensive compared to other films. In addition, 15atom% to 30atom% magnetic thin film recording media have been proposed as new magnetic thin film recording media that eliminate these drawbacks.
Amorphous alloy thin films of TbFe or DyFe containing Tb or Dy have the following advantages. It has an axis of easy magnetization perpendicular to the film surface and has a large coercive force of several KOe at room temperature.
High-density information recording is possible, and the recorded information is extremely stable. It has a large coercive force and can write magnetic domains in a desired shape. It has a large coercive force over a wide composition range, and has excellent properties as a recording medium.Because the composition range is also wide, there is no need to create a thin film with a strictly limited composition, and it can be produced very easily. Yield is also good. The Curie point is 120℃ for TbFe and 120℃ for DyFe.
Since the temperature is as low as 60°C, when performing thermal writing using the Curie point, writing can be performed with extremely small energy. However, amorphous alloy thin films such as TbFe and DyFe have the following drawbacks. That is, if the Curie point is low, it is true that writing can be done with small energy, but the S/N ratio when reading with light becomes worse. Figure 1 shows the optical reproduction output (S) and signal-to-noise ratio (S/N) during optical reproduction of an amorphous alloy thin film.
is shown as a function of the irradiated laser power (I 0 ), but TbFe, which has good characteristics as a recording medium,
DyFe is not good as a recording medium in terms of optical reproduction.
It turns out to be worse than GdFe. This is a very serious drawback when considering this recording medium as a magneto-optical memory. An object of the present invention is to provide a magneto-optical recording medium that can efficiently extract optical reproduction output by eliminating the drawbacks of the conventional magneto-optical recording medium having an axis of easy magnetization in a direction perpendicular to the film surface as described above. There is a particular thing. The present invention will be explained in detail below. The magneto-optical recording medium of the present invention has an axis of easy magnetization perpendicular to the film surface and a Curie point between 120°C and 200°C.
-It is an amorphous alloy thin film of Co. In order to have sufficient magnetic anisotropy to orient the magnetization in the direction perpendicular to the film surface, it is necessary to make the thin film amorphous, but this condition cannot be achieved on a substrate kept at a temperature below room temperature. This is achieved by fabricating a thin film using a sputtering method, a vacuum evaporation method, or the like.
In addition, in order to stably direct the magnetization in the direction perpendicular to the film surface, the film thickness should be 100 Å or more, and the composition of Tb or Dy, Fe, and Co should be changed to Tb x (Fe 1-y
Co y ) 1-x and Dy x (Fe 1-y Co y ) 1-x as 0.15x
It is necessary to set the range to 0.35, 0.00<y0.50. When 0.50<y, the Curie point or magnetic compensation temperature is highly dependent on the composition and is not practical.
In addition, magneto-optical recording media in which the x range is outside this composition range have difficulty aligning the axis of easy magnetization in the direction perpendicular to the film surface and deteriorate the rectangular hysteresis characteristics, so they have practical recording and reproducing characteristics. will not be obtained. Although the magneto-optical recording medium of the present invention has a relatively low Curie point of about 120 to 200°C, the optical reproduction output using the magnetic Kerr effect is higher than that of TbFe and DyFe, which have a similar Curie point. It is characterized by As an example
In the case of TbFeCo, as shown in Figure 2,
The Kerr rotation angle θ K of Tb(FeCo) is the binary TbFe and Co
It can be seen that as more is added, the improvement is improved. In FIG. 2, the horizontal axis indicates the ratio (%) of Co to the entire TbFeCo. On the other hand, coercive force related to recording characteristics
Looking at Hc and the Curie point Tc, as shown in Table 1, the coercive force is considerably larger than that of the TbFe binary system, and although the Curie point Tc rises slightly, the excellent recording properties of TbFe remain intact. There is.
【表】
以上説明したように、本発明の光磁気記録媒体
は良く知られた非晶質合金薄膜のTbFe、DyFe
等と同じく膜面に垂直な方向に磁化容易軸を有
し、かつ室温で大きな保磁力を有し、かつキユー
リー点が室温に近く、作製も容易であるという非
晶質合金薄膜の特長はそのまま有していて、しか
も光再生出力だけは従来のどれよりも大きい。従
つて、光ビームを用いて書き込み、カー効果を利
用して読み出しを行なう、いわゆるビーム・アド
レツサブルフアイルメモリ等の光磁気メモリの貯
蔵媒体として使用すれば、極めて高密度でＳ／Ｎ
の大きい優れたメモリ装置を実現することができ
る。書き込み方法としては光ビームに限らず、針
型磁気ヘツド、熱ペン、電子ビームなど反転磁区
を生じせしめるのに必要なエネルギーを供給する
いかなる方法で行なつても良いことは言うまでも
ない。[Table] As explained above, the magneto-optical recording medium of the present invention uses well-known amorphous alloy thin films such as TbFe and DyFe.
The advantages of amorphous alloy thin films are that they have an axis of easy magnetization in the direction perpendicular to the film surface, have a large coercive force at room temperature, have a Curie point close to room temperature, and are easy to fabricate. Moreover, the optical reproduction output is larger than any of the conventional ones. Therefore, if used as a storage medium for a magneto-optical memory such as a so-called beam-addressable file memory that writes using a light beam and reads using the Kerr effect, it can achieve extremely high density S/N.
It is possible to realize an excellent memory device with a large capacity. It goes without saying that the writing method is not limited to a light beam, but may be performed by any method that supplies the energy necessary to generate reversed magnetic domains, such as a needle-shaped magnetic head, a thermal pen, or an electron beam.
図１は従来の非晶質合金薄膜の光再生特性図、
図２は本発明のTbFeCo薄膜のCo（％）とカー回
転角θKの関係を示す特性図である。
Figure 1 shows the optical reproduction characteristics of a conventional amorphous alloy thin film.
FIG. 2 is a characteristic diagram showing the relationship between Co (%) and Kerr rotation angle θ K of the TbFeCo thin film of the present invention.
Claims (1)
質Tb―Fe―Co又はDy―Fe―Co三元系合金薄膜
を有し、Tbx（Fe1-yCoy）1-x、Dyx（Fe1-yCoy）1-x
としたとき、ｘが0.15ｘ0.35の範囲であり、
ｙが0.00＜ｙ0.50の範囲にあることを特徴とす
る光磁気記録媒体。1 has an amorphous Tb-Fe-Co or Dy-Fe-Co ternary alloy thin film with an axis of easy magnetization perpendicular to the film surface, Tb x (Fe 1-y Co y ) 1-x , Dy x (Fe 1-y Co y ) 1-x
Then, x is in the range of 0.15x0.35,
A magneto-optical recording medium characterized in that y is in the range of 0.00<y0.50.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17083781A JPS5873746A (en) | 1981-10-27 | 1981-10-27 | Photomagnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17083781A JPS5873746A (en) | 1981-10-27 | 1981-10-27 | Photomagnetic recording medium |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10160290A Division JPH0316049A (en) | 1990-04-19 | 1990-04-19 | Magneto-optical recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5873746A JPS5873746A (en) | 1983-05-04 |
| JPH0123927B2 true JPH0123927B2 (en) | 1989-05-09 |
Family
ID=15912243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17083781A Granted JPS5873746A (en) | 1981-10-27 | 1981-10-27 | Photomagnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5873746A (en) |
Families Citing this family (35)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58159252A (en) * | 1982-03-17 | 1983-09-21 | Canon Inc | Magnetooptic recording medium |
| JPH0616452B2 (en) * | 1983-03-01 | 1994-03-02 | キヤノン株式会社 | Magneto-optical recording medium |
| JPS59159510A (en) * | 1983-03-01 | 1984-09-10 | Canon Inc | Magnetooptical recording medium |
| JPS58196639A (en) * | 1982-05-10 | 1983-11-16 | Canon Inc | Photothermic and magnetic recording medium |
| JPS59201247A (en) * | 1983-04-28 | 1984-11-14 | Ricoh Co Ltd | Photomagnetic recording medium |
| JPS59217249A (en) * | 1983-05-25 | 1984-12-07 | Sony Corp | Photomagnetic recording medium |
| JPS6068607A (en) * | 1983-09-14 | 1985-04-19 | Sumitomo Metal Mining Co Ltd | Magnetic thin film recording medium |
| JPS6083305A (en) * | 1983-10-14 | 1985-05-11 | Hitachi Ltd | Magneto-optic medium |
| JPH0756691B2 (en) * | 1983-11-07 | 1995-06-14 | 大同特殊鋼株式会社 | Magnetic thin film recording medium |
| JPH061564B2 (en) * | 1984-02-22 | 1994-01-05 | 株式会社ニコン | Magneto-optical recording medium |
| JPH0638370B2 (en) * | 1984-05-22 | 1994-05-18 | 株式会社リコー | Amorphous magneto-optical layer |
| JPS616808A (en) * | 1984-06-20 | 1986-01-13 | Oki Electric Ind Co Ltd | Photomagnetic recording material |
| JPS6140012A (en) * | 1984-07-31 | 1986-02-26 | Oki Electric Ind Co Ltd | Material for photomagnetic recording |
| DE3536210A1 (en) * | 1984-10-11 | 1986-04-17 | Hitachi, Ltd., Tokio/Tokyo | Magneto-optical recording medium |
| JPH0673197B2 (en) * | 1985-02-25 | 1994-09-14 | 株式会社東芝 | Magneto-optical recording medium and manufacturing method thereof |
| JPS61214254A (en) * | 1985-03-20 | 1986-09-24 | Hitachi Ltd | Photomagnetic recording material |
| JPH0782670B2 (en) * | 1985-07-12 | 1995-09-06 | 株式会社日立製作所 | Magneto-optical recording medium |
| JPS62112251A (en) * | 1985-11-09 | 1987-05-23 | Nippon Gakki Seizo Kk | Photomagnetic recording material |
| EP0245833B1 (en) * | 1986-05-14 | 1991-10-09 | Teijin Limited | Magneto-optical recording medium |
| JP2673807B2 (en) * | 1987-10-30 | 1997-11-05 | パイオニア株式会社 | Method for manufacturing magneto-optical recording medium |
| JPH0296952A (en) * | 1988-06-28 | 1990-04-09 | Sharp Corp | Optical memory element |
| JPH0224853A (en) * | 1988-07-13 | 1990-01-26 | Matsushita Electric Ind Co Ltd | Magneto-optical recording medium |
| CA1333820C (en) * | 1988-09-13 | 1995-01-03 | Masahiko Sekiya | Magneto-optical recording medium |
| US5192626A (en) * | 1988-12-14 | 1993-03-09 | Teijin Limited | Optical recording medium |
| JP2660569B2 (en) * | 1989-02-10 | 1997-10-08 | 三菱電機株式会社 | Magneto-optical recording medium |
| US5667862A (en) * | 1989-03-15 | 1997-09-16 | Sony Corporation | Magneto-optical disk |
| CA2017284C (en) * | 1989-07-04 | 1995-10-03 | Kazutomi Suzuki | Optical recording medium |
| JPH0316049A (en) * | 1990-04-19 | 1991-01-24 | Kokusai Denshin Denwa Co Ltd <Kdd> | Magneto-optical recording medium |
| EP0482606B1 (en) * | 1990-10-26 | 1995-08-16 | Teijin Limited | Magneto-optical recording medium |
| JPH05174437A (en) * | 1991-04-30 | 1993-07-13 | Canon Inc | Magneto-optical recording medium |
| JP2763419B2 (en) * | 1991-07-08 | 1998-06-11 | シャープ株式会社 | Magneto-optical recording medium |
| JPH0589555A (en) * | 1992-01-28 | 1993-04-09 | Canon Inc | Information recording and reproducing method |
| JPH05189822A (en) * | 1992-06-19 | 1993-07-30 | Sharp Corp | Magneto-optical recording medium |
| JP2999895B2 (en) * | 1992-12-10 | 2000-01-17 | シャープ株式会社 | Magneto-optical recording medium |
| JPH0773516A (en) * | 1993-09-02 | 1995-03-17 | Nikon Corp | Magneto-optical recording medium and magneto-optical recording method |
-
1981
- 1981-10-27 JP JP17083781A patent/JPS5873746A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5873746A (en) | 1983-05-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0123927B2 (en) | ||
| JPS6032331B2 (en) | magneto-optical recording medium | |
| JPH0118506B2 (en) | ||
| JPH0249002B2 (en) | ||
| JPS6227459B2 (en) | ||
| US4814238A (en) | Magneto-optical recording medium | |
| US4612068A (en) | Magneto-optical recording medium | |
| JPH0330963B2 (en) | ||
| JPS5968854A (en) | Photomagnetic recording medium | |
| JPS60117436A (en) | Magnetooptic storage element | |
| JPS61255546A (en) | Photomagnetic recording medium | |
| JPS6131533B2 (en) | ||
| JPH0351082B2 (en) | ||
| JPH0465523B2 (en) | ||
| JPS61246946A (en) | Photomagnetic recording medium | |
| JPS60253040A (en) | Photomagnetic recording medium | |
| JPS5873030A (en) | Optical magnetic recording medium | |
| JPH0259603B2 (en) | ||
| JPS6196706A (en) | Photomagnetic recording medium | |
| KR930009647B1 (en) | Optical writing materials | |
| JPS6184004A (en) | Photo-magnetic recording medium | |
| JPS634443A (en) | Magneto-optical recording medium | |
| JPS6228947A (en) | Photomagnetic recording medium | |
| JPS63253553A (en) | Magneto-optical recording medium | |
| JPS6289254A (en) | Photomagnetic recording medium |