JPH0782672B2 - Magnetic thin film recording medium - Google Patents
Magnetic thin film recording mediumInfo
- Publication number
- JPH0782672B2 JPH0782672B2 JP1036887A JP1036887A JPH0782672B2 JP H0782672 B2 JPH0782672 B2 JP H0782672B2 JP 1036887 A JP1036887 A JP 1036887A JP 1036887 A JP1036887 A JP 1036887A JP H0782672 B2 JPH0782672 B2 JP H0782672B2
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- JP
- Japan
- Prior art keywords
- thin film
- layer
- recording medium
- magnetic
- magnetic field
- 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.)
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、光(熱)磁気記録,熱磁気転写,磁気的表示
素子などに用いられる磁性薄膜記録媒体に関するもので
ある。The present invention relates to a magnetic thin film recording medium used for optical (thermo) magnetic recording, thermomagnetic transfer, magnetic display elements and the like.
膜面と垂直な方向に磁化容易軸を有する磁性薄膜記録媒
体では、例えばレーザー等の光ビームを照射すると共に
照射領域にバイアス磁界をかけることにより、該照射領
域に、一様に磁化された他領域の磁化方向とは逆向きの
反転磁区を作り、この反転磁区の有無を“1"“0"に対応
付けて情報を記録することができる。そして、このよう
に記録された情報は磁気光学効果を利用して読み出すこ
とが可能である。そのため、この種の磁性薄膜記録媒体
は、高密度,大容量,高速アクセス等種々の要求を満足
し得る光磁気ディスクとして開発が進められている。In a magnetic thin film recording medium having an easy axis of magnetization in the direction perpendicular to the film surface, for example, by irradiating a light beam such as a laser and applying a bias magnetic field to the irradiation area, the irradiation area is uniformly magnetized. Information can be recorded by creating an inverted magnetic domain in the direction opposite to the magnetization direction of the region and associating the presence or absence of this inverted magnetic domain with “1” or “0”. Then, the information thus recorded can be read by utilizing the magneto-optical effect. Therefore, this kind of magnetic thin film recording medium is under development as a magneto-optical disk which can satisfy various requirements such as high density, large capacity and high speed access.
このように膜面と垂直な方向に磁化容易軸を有してい
て、高密度の磁気記録が可能でビームアドレサブルファ
イルとして使用可能な強磁性薄膜記録媒体としては、従
来は例えば第4図に示した如きものがあった。As a ferromagnetic thin film recording medium having an easy axis of magnetization in a direction perpendicular to the film surface and capable of high-density magnetic recording and usable as a beam addressable file, there is conventionally known one as shown in FIG. There was something like the one shown.
第4図において、1は透明基板であって、ディスクを回
転させた時トラッキングを容易に行えるよう溝を形成す
るか或は溝を形成していない平坦なガラス基板や樹脂基
板から成っている。2は基板1の上に設けた光磁気記録
層であって、MnBiに代表される多結晶金属薄膜又は磁性
ガーネット等の化合物単結晶薄膜又はGd-Co,Gd-Fe,Tb-F
e.Dy-Fe,Gd-Tb-Fe,Tb-Co-Fe等の希土類−遷移金属非晶
質薄膜から成っている。In FIG. 4, reference numeral 1 denotes a transparent substrate, which is formed of a flat glass substrate or a resin substrate in which a groove is formed so that tracking can be easily performed when the disc is rotated or in which a groove is not formed. Reference numeral 2 denotes a magneto-optical recording layer provided on the substrate 1, which is a polycrystalline metal thin film typified by MnBi or a compound single crystal thin film such as magnetic garnet or Gd-Co, Gd-Fe, Tb-F.
e. Dy-Fe, Gd-Tb-Fe, Tb-Co-Fe and other rare earth-transition metal amorphous thin films.
又、このような強磁性薄膜記録媒体に書き込みを行うに
は、実際には第5図に示した如き記録・再生・消去装置
が用いられる。LDはレーザーダイオード、Lはコリメー
ターレンズ、Pは偏光子、OLは対物(集光レンズ)であ
って、これらが記録媒体RMに対する偏光レーザー照射光
学系を構成している。BMCはバイアス磁界印加コイルで
あって、これが上記偏光レーザー照射光学系と共に記録
・消去系を構成している。M1,M2はハーフミラー、A1,
A2は検光子、PD1,PD2は光ダイオード、DAMPは差動増巾
器であって、これらが磁気光学効果(記録媒体RMの磁化
方向によって反射光,透過光の偏光面の回転方向が異な
る効果)を利用した再生系を構成している。Further, in order to write on such a ferromagnetic thin film recording medium, the recording / reproducing / erasing apparatus as shown in FIG. 5 is actually used. LD is a laser diode, L is a collimator lens, P is a polarizer, and OL is an objective (condensing lens), which constitute a polarized laser irradiation optical system for the recording medium RM. BMC is a bias magnetic field applying coil, which constitutes a recording / erasing system together with the polarized laser irradiation optical system. M 1 , M 2 are half mirrors, A 1 ,
A 2 is an analyzer, PD 1 and PD 2 are photo diodes, and DAMP is a differential amplifier. These are magneto-optical effects (rotation directions of polarization planes of reflected light and transmitted light depending on the magnetization direction of the recording medium RM). However, different effects are used) to construct a playback system.
そして、書き込みの際は、第6図(a)の如く一方向磁
化した記録媒体に第6図(b)に示した如くレーザー光
4を照射すると同時にバイアス磁界印加コイル5により
バイアス磁界Hexを印加した状態にし、その状態で第6
図(c)に示した如くレーザー光4を切ると、照射され
ていた領域に反転磁区(1〜2μm径のビット)が形成
されるようになっている。At the time of writing, the recording medium magnetized in one direction as shown in FIG. 6A is irradiated with the laser beam 4 as shown in FIG. 6B, and at the same time, the bias magnetic field Hex is applied by the bias magnetic field applying coil 5. And then in the state
When the laser beam 4 is turned off as shown in FIG. 6C, a reversed magnetic domain (bit having a diameter of 1 to 2 μm) is formed in the irradiated region.
ところが、上述の如く基板1上に光磁気記録層2のみを
設けて成る記録媒体には次のような欠点があった。However, the recording medium having only the magneto-optical recording layer 2 provided on the substrate 1 as described above has the following drawbacks.
即ち、光磁気記録層2として多結晶薄膜を用いたもの
は、室温で数KOeという大きな保磁力を有するものの、
相変態があるために熱的に不安定であること、キュリー
温度が高い(例えばMnBiではキュリー温度Tcは360℃で
ある。)ために書き込みに必要なレーザーパワーが数十
mWと大きくなること、粒界による光の散乱ノイズが無視
できないことなどの欠点があった。That is, although the one using the polycrystalline thin film as the magneto-optical recording layer 2 has a large coercive force of several KOe at room temperature,
It is thermally unstable due to the phase transformation, and the Curie temperature is high (for example, the Curie temperature Tc is 360 ° C for MnBi), the laser power required for writing is several tens.
There were drawbacks such as increase in mW and noise of light scattering due to grain boundaries that cannot be ignored.
又、化合物単結晶薄膜を用いたものも、これもキュリー
温度を利用して記録するものであるが、キュリー温度が
高い(例えば磁性ガーネットではキュリー温度はおよそ
280〜300℃である。)ために、書き込みに大きなエネル
ギーを必要とすると共に、単結晶薄膜であるために大面
積化が難しいという欠点があった。Also, in the case of using a compound single crystal thin film, this is also recorded using the Curie temperature, but the Curie temperature is high (for example, in the case of magnetic garnet, the Curie temperature is approximately
280-300 ° C. Therefore, there is a drawback that a large energy is required for writing and it is difficult to increase the area because it is a single crystal thin film.
又、希土類金属−遷移金属非晶質薄膜を用いたものの中
で、Gd-Co,Gd-Feなどの磁気補償温度を利用して記録す
るものは、磁気補償温度が薄膜の組成に大きく依存する
ため均一特性の膜を作ることが困難であり、保磁力が小
さいため記録された情報が不安定であるという問題があ
った。In addition, among those using rare earth metal-transition metal amorphous thin films, when recording is performed by using magnetic compensation temperature of Gd-Co, Gd-Fe, etc., the magnetic compensation temperature greatly depends on the composition of the thin film. Therefore, it is difficult to form a film having uniform characteristics, and there is a problem that recorded information is unstable because the coercive force is small.
又、希土類金属−遷移金属非晶質薄膜を用いたものの中
で、Tb-Fe,Dy-Fe,Gd-Tb-Fe,Tb-Co-Feなどのキュリー温
度を利用して記録するものは、一般にキュリー温度が10
0〜250℃と比較的低く、保磁力が2〜3KOe以上と比較的
大きいという特徴を有しているが、必要なバイアス磁界
が約500Oeと大きいため、記録・再生・消去が安定して
行え且つバイアス磁界印加コイルの発熱を抑えるために
はバイアス磁界印加装置の寸法や重量が大となり、記録
・再生・消去装置の小型化,軽量化への大きな障害とな
っていた。Further, among those using a rare earth metal-transition metal amorphous thin film, those recorded using the Curie temperature of Tb-Fe, Dy-Fe, Gd-Tb-Fe, Tb-Co-Fe, etc. Curie temperature is typically 10
It has a relatively low value of 0 to 250 ° C and a relatively large coercive force of 2 to 3 KOe or more, but the required bias magnetic field is about 500 Oe, so recording, reproduction and erasing can be performed stably. In addition, in order to suppress heat generation of the bias magnetic field applying coil, the size and weight of the bias magnetic field applying device become large, which has been a major obstacle to downsizing and weight saving of the recording / reproducing / erasing device.
本発明は、上記問題点に鑑み、書き込みに必要なエネル
ギーが小さくて済むと共に、書き込み及び消去時に用い
るバイアス磁界を低下させることができ、その結果記録
・再生・消去装置を小型化,軽量化できる磁性薄膜記録
媒体を提供することを目的としている。In view of the above problems, the present invention requires less energy required for writing, and can lower the bias magnetic field used during writing and erasing, and as a result, the recording / reproducing / erasing apparatus can be made smaller and lighter. It is an object to provide a magnetic thin film recording medium.
本発明による磁性薄膜記録媒体は、基板上に膜面と垂直
な方向に磁化容易軸を有する結晶質又は非晶質の合金薄
膜から成る第一層を設けると共に、該第一層に重ねて該
第一層のキュリー温度よりも低い反強磁性−強磁性相転
移温度を有する第二層を設けて、第二層の磁気相転移を
利用して第一層に反転磁区を形成するようにしたことに
より、反転磁区形成の際にバイアス磁界に加えて第二層
の自発磁化による漏洩磁界及び磁気相互作用が作用する
ようにしたものである。A magnetic thin film recording medium according to the present invention is provided with a first layer made of a crystalline or amorphous alloy thin film having an easy axis of magnetization in a direction perpendicular to the film surface on a substrate, and is laminated on the first layer. A second layer having an antiferromagnetic-ferromagnetic phase transition temperature lower than the Curie temperature of the first layer is provided, and an inversion domain is formed in the first layer by utilizing the magnetic phase transition of the second layer. Thus, the leakage magnetic field and the magnetic interaction due to the spontaneous magnetization of the second layer act in addition to the bias magnetic field when forming the inverted magnetic domain.
以下、図示した一実施例に基づき本発明を詳細に説明す
る。Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment.
第1図は本発明による磁性薄膜記録媒体の断面図であっ
て、11は透明基板であり、ディスクを回転させた時にト
ラッキングを容易に行えるように溝を形成するか或は溝
を形成していない平坦なガラス基板又は樹脂基板から成
っている。12は基板1上に設けられた膜面と垂直な方向
に磁化容易軸を有する結晶質又は非晶質の合金薄膜から
成る光磁気記録層(第一層)であって、例えばR-Co-Fe
等の希土類金属−遷移金属非晶質膜から成っている。但
し、RはGd,Tb,Dy及びHoのうちの一種又は二種以上の金
属である。又、13は光磁気記録層12上に重ねて設けられ
た光磁気記録層12のキュリー温度より低い反強磁性−強
磁性相転移温度(50〜150℃)を有する補助層(第二
層)であって、例えばFe-Rh-Co等の合金膜から成ってい
る。そして、これらの光磁気記録層12及び補助層13は、
スパッタリング法や真空蒸着法などにより形成され、そ
れらの膜厚は200〜5000Å好ましくは約1000Åに設定さ
れている。FIG. 1 is a cross-sectional view of a magnetic thin film recording medium according to the present invention, in which a transparent substrate 11 is provided with a groove or grooves so that tracking can be easily performed when the disk is rotated. Not made of flat glass substrate or resin substrate. Reference numeral 12 denotes a magneto-optical recording layer (first layer) made of a crystalline or amorphous alloy thin film having an easy axis of magnetization in a direction perpendicular to the film surface provided on the substrate 1, and is, for example, R-Co- Fe
And other rare earth metal-transition metal amorphous films. However, R is one or more metals of Gd, Tb, Dy and Ho. Reference numeral 13 denotes an auxiliary layer (second layer) having an antiferromagnetic-ferromagnetic phase transition temperature (50 to 150 ° C.) lower than the Curie temperature of the magneto-optical recording layer 12 provided on the magneto-optical recording layer 12. And is made of an alloy film such as Fe—Rh—Co. Then, the magneto-optical recording layer 12 and the auxiliary layer 13 are
It is formed by a sputtering method or a vacuum deposition method, and the film thickness thereof is set to 200 to 5000Å, preferably about 1000Å.
尚、光磁気記録層12の組成は、RxCoy Fe1-x-yとして、
それぞれの原子比x,yについては、0.15≦x≦0.35,0.01
≦y≦0.30なる条件を満足させることが必要である。即
ち、0.15≦x≦0.35なる条件を外れると、記録媒体とし
て適切な保磁力がなくなる。又、0.01≦y≦0.30なる条
件を外れてy<0.01であると、Co添加効果は現われず、
カー回転角θkが小さくなってしまう。又、y>0.30で
あると保磁力が大きくなり過ぎると共に、キュリー温度
も高くなり過ぎて、書き込みに必要なエネルギーが大き
くなり記録に適さなくなる。The composition of the magneto-optical recording layer 12 is R x Co y Fe 1-xy ,
For each atomic ratio x, y, 0.15 ≦ x ≦ 0.35,0.01
It is necessary to satisfy the condition ≦ y ≦ 0.30. That is, if the condition of 0.15 ≦ x ≦ 0.35 is not satisfied, the coercive force appropriate for the recording medium is lost. If y <0.01 is not satisfied with the condition of 0.01 ≦ y ≦ 0.30, the effect of adding Co does not appear.
The car rotation angle θ k becomes small. If y> 0.30, the coercive force becomes too large, and the Curie temperature becomes too high, so that the energy required for writing becomes large and it becomes unsuitable for recording.
又、補助層13の組成には、FeaRhbCo1-a-bとして、夫々
の原子比a,bについては0.45≦a≦0.55、0.45≦b≦0.5
0なる条件を満足させることが必要である。即ち、0.45
≦a≦0.55,0.45≦b≦0.50なる条件を満足しないと、
反強磁性強磁性の相転移を起こすCsCl構造の合金膜と
ならず、本発明が成り立たなくなってしまう。一方、こ
の条件を満足する例えばFe0.49Rh0.49Co0.02なる組成を
有する膜は、第2図に示した如く、温度上昇の際約65℃
で反強磁性から強磁性に相転移を起こす。そして、この
現象は可逆的であり、温度が約65℃以下に低下すると相
転移して強磁性から反強磁性に戻る。The composition of the auxiliary layer 13 is Fe a Rh b Co 1-ab , and the atomic ratios a and b are 0.45 ≦ a ≦ 0.55 and 0.45 ≦ b ≦ 0.5.
It is necessary to satisfy the condition of 0. That is, 0.45
If the conditions ≦ a ≦ 0.55, 0.45 ≦ b ≦ 0.50 are not satisfied,
The present invention does not hold because the alloy film does not have a CsCl structure that causes antiferromagnetic / ferromagnetic phase transition. On the other hand, a film having a composition such as Fe 0.49 Rh 0.49 Co 0.02 that satisfies this condition, as shown in FIG.
Then, a phase transition from antiferromagnetism to ferromagnetism occurs. This phenomenon is reversible, and when the temperature drops below about 65 ° C., the phase transition occurs and the ferromagnetism returns to antiferromagnetism.
次に本発明磁性薄膜記録媒体に書き込みを行った時の反
転磁区の形成過程について第3図により説明する。Next, a process of forming a reversed magnetic domain when writing is performed on the magnetic thin film recording medium of the present invention will be described with reference to FIG.
まず、室温即ちT<Tp(補助層の相転移温度)<Tc(記
録層のキュリー温度)では、第3図(a)に示した如
く、記録層12は膜面と垂直な方向に一方向磁化してお
り、補助層13は反強磁性を示し、自発磁化を形成してい
ない。次に、第3図(b)に示した如く、レーザー光14
を照射し、これと同時にバイアス磁界印加コイル15によ
りバイアス磁界Hexを加えると、記録層12のレーザー光1
4のあたった部分の磁化は減少して行きキュリー温度以
上になる即ちT<Tcとなると消滅する。又、補助層13の
レーザー光のあたった部分は、相転移温度以上になる即
ちT>Tpなると、反強磁性から強磁性に相転移し、自発
磁化はバイアス磁界Hexの方向にそろう。次に、レーザ
ー光14を切ると温度が低下して行くが、相転移温度以上
即ちT>Tpでは補助層13は強磁性を示しているので、第
3図(c)に示した如く、記録層12は冷却されてキュリ
ー温度以下になる即ちTc>T>Tpとなると、バイアス磁
界Hexと補助層13の自発磁化による漏洩磁界及び磁気相
互作用によって反転磁区が形成される。最後に、第3図
(d)に示した如く、室温まで下がる即ちTc>Tp>Tと
なると、補助層13の磁化は強磁性から反強磁性に戻ると
共に、記録層12には反転磁区が形成されたままとなる。First, at room temperature, that is, T <Tp (phase transition temperature of the auxiliary layer) <Tc (Curie temperature of the recording layer), the recording layer 12 is unidirectional in the direction perpendicular to the film surface as shown in FIG. 3 (a). It is magnetized, the auxiliary layer 13 exhibits antiferromagnetism, and does not form spontaneous magnetization. Next, as shown in FIG.
When the bias magnetic field Hex is applied by the bias magnetic field applying coil 15 at the same time, the laser light 1 of the recording layer 12 is irradiated.
The magnetization of the portion indicated by 4 decreases, and disappears when the temperature exceeds the Curie temperature, that is, T <Tc. When the temperature of the auxiliary layer 13 exposed to the laser light is equal to or higher than the phase transition temperature, that is, T> Tp, the phase transitions from antiferromagnetism to ferromagnetism, and the spontaneous magnetization aligns with the bias magnetic field Hex. Next, when the laser beam 14 is turned off, the temperature decreases, but at the phase transition temperature or higher, that is, T> Tp, the auxiliary layer 13 exhibits ferromagnetism, so as shown in FIG. When the layer 12 is cooled to a Curie temperature or lower, that is, Tc>T> Tp, a reversal magnetic domain is formed by a bias magnetic field Hex and a leakage magnetic field and magnetic interaction due to spontaneous magnetization of the auxiliary layer 13. Finally, as shown in FIG. 3D, when the temperature drops to room temperature, that is, Tc>Tp> T, the magnetization of the auxiliary layer 13 returns from ferromagnetic to antiferromagnetic, and the recording layer 12 has an inversion domain. It remains formed.
かくして、書き込みが終了するが、本発明磁性薄膜記録
媒体は、記録層12への反転磁区形成の際にバイアス磁界
に加えて補助層13の自発磁化による漏洩磁界及び磁気相
互作用が作用するので、外部より加えるバイアス磁界が
小さくて済む。又、同様な理由により、反転磁区の形成
即ち書き込みが容易となる。又、上述の如く、記録層12
のキュリー温度及び補助層13の磁気相転温度が低いの
で、書き込みに必要なエネルギーが小さくて済む。従っ
て、以上の結果から、記録・再生・消去装置を小型化,
軽量化できるという実用上重要な利点を有することとな
る。Thus, although the writing is completed, in the magnetic thin film recording medium of the present invention, the leakage magnetic field and the magnetic interaction due to the spontaneous magnetization of the auxiliary layer 13 act in addition to the bias magnetic field at the time of forming the reversed magnetic domain in the recording layer 12, The bias magnetic field applied from the outside can be small. Further, for the same reason, formation of the reversed magnetic domain, that is, writing is facilitated. In addition, as described above, the recording layer 12
Since the Curie temperature and the magnetic phase inversion temperature of the auxiliary layer 13 are low, the energy required for writing can be small. Therefore, from the above results, downsizing the recording / playback / erasing device,
This has an important practical advantage that the weight can be reduced.
次に下記表に実験例と比較例との比較結果を示す。Next, the following table shows the comparison results between the experimental example and the comparative example.
尚、バイアス磁界Hexが上記表の範囲内であれば、光磁
気ディスクの信号品質の目安となるC/N比にはほとんど
変化はなかった。 If the bias magnetic field Hex is within the range shown in the above table, there is almost no change in the C / N ratio, which is a measure of the signal quality of the magneto-optical disk.
上記表によれば、本発明磁性薄膜記録媒体は従来例に較
べて必要バイアス磁界を低減できることが明らかであ
る。From the above table, it is clear that the magnetic thin film recording medium of the present invention can reduce the required bias magnetic field as compared with the conventional example.
上述の如く、本発明の磁性薄膜記録媒体は、記録・再生
・消去装置を小型化,軽量化できるという実用上重要な
利点を有している。As described above, the magnetic thin film recording medium of the present invention has an important practical advantage that the recording / reproducing / erasing apparatus can be made compact and lightweight.
【図面の簡単な説明】 第1図は本発明による磁性薄膜記録媒体の一実施例の断
面図、第2図は上記実施例の補助層の温度に応じた磁化
変化特性を示す図、第3図は上記実施例へ書き込みを行
った時の反転磁区形成過程を示す図、第4図は従来例の
断面図、第5図は光磁気記録に用いられる記録・再生・
消去装置の構成図、第6図は上記従来例の書き込みを行
った時の反転磁区形成過程を示す図である。 11……透明基板、12……光磁気記録層(第一層)、13…
…補助層(第二層)、14……レーザー光、15……バイア
ス磁界印加コイル。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of an embodiment of a magnetic thin film recording medium according to the present invention, FIG. 2 is a view showing magnetization change characteristics according to temperature of an auxiliary layer of the above embodiment, and FIG. FIG. 4 is a diagram showing a reversed magnetic domain formation process when writing is performed in the above embodiment, FIG. 4 is a sectional view of a conventional example, and FIG.
FIG. 6 is a configuration diagram of the erasing device, and FIG. 6 is a diagram showing a process of forming an inverted magnetic domain when writing is performed in the conventional example. 11 ... Transparent substrate, 12 ... Magneto-optical recording layer (first layer), 13 ...
… Auxiliary layer (second layer), 14 …… Laser light, 15 …… Bias magnetic field application coil.
Claims (1)
有する結晶質又は非晶質の合金薄膜から成る第一層を設
けると共に、該第一層に重ねて該第一層のキュリー温度
より低い反強磁性−強磁性相転移温度を有する第二層を
設けたことを特徴とする磁性薄膜記録媒体。1. A first layer comprising a crystalline or amorphous alloy thin film having an easy axis of magnetization in a direction perpendicular to a film surface is provided on a substrate, and the first layer is laminated on the first layer. A magnetic thin film recording medium comprising a second layer having an antiferromagnetic-ferromagnetic phase transition temperature lower than the Curie temperature.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1036887A JPH0782672B2 (en) | 1987-01-20 | 1987-01-20 | Magnetic thin film recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1036887A JPH0782672B2 (en) | 1987-01-20 | 1987-01-20 | Magnetic thin film recording medium |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS63179435A JPS63179435A (en) | 1988-07-23 |
JPH0782672B2 true JPH0782672B2 (en) | 1995-09-06 |
Family
ID=11748216
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1036887A Expired - Lifetime JPH0782672B2 (en) | 1987-01-20 | 1987-01-20 | Magnetic thin film recording medium |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0782672B2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5175714A (en) * | 1988-09-30 | 1992-12-29 | Kabushiki Kaisha Toshiba | Method of magneto-optically recording/erasing information and magneto-optical information storage medium including recording and bias layers satisfying certain conditions |
JPH02304750A (en) * | 1989-05-19 | 1990-12-18 | Nec Corp | Magneto-optical disk medium |
JPH0467338A (en) * | 1990-06-30 | 1992-03-03 | Daicel Chem Ind Ltd | Magneto-optical recording medium |
KR100455273B1 (en) * | 1998-02-24 | 2004-12-17 | 삼성전자주식회사 | Method of recording optical recordable medium |
EP1158507A4 (en) * | 1999-02-09 | 2006-07-26 | Japan Science & Tech Agency | Magneto-optical recording medium and magneto-optical recording device |
JP4267323B2 (en) | 2001-02-14 | 2009-05-27 | 富士通株式会社 | Magneto-optical recording medium |
-
1987
- 1987-01-20 JP JP1036887A patent/JPH0782672B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS63179435A (en) | 1988-07-23 |
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