JPH0519213B2 - - Google Patents
Info
- Publication number
- JPH0519213B2 JPH0519213B2 JP16971082A JP16971082A JPH0519213B2 JP H0519213 B2 JPH0519213 B2 JP H0519213B2 JP 16971082 A JP16971082 A JP 16971082A JP 16971082 A JP16971082 A JP 16971082A JP H0519213 B2 JPH0519213 B2 JP H0519213B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- thin film
- composition
- rare earth
- transition metal
- 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 - Lifetime
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
- G03G5/16—Layers for recording by changing the magnetic properties, e.g. for Curie-point-writing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
- G11B11/10504—Recording
- G11B11/10506—Recording by modulating only the light beam of the transducer
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10586—Record carriers characterised by the selection of the material or by the structure or form characterised by the selection of the material
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
Description
【発明の詳細な説明】
本発明は光磁気効果を有する非晶質希土類−遷
移金属合金薄膜を用いた光磁気記録媒体に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magneto-optical recording medium using an amorphous rare earth-transition metal alloy thin film having a magneto-optical effect.
書き替え可能な光デイスクの記録媒体としては
光磁気記録材料がある。この材料は、情報の書き
込みには熱磁気効果を用い、読み出しには磁気カ
ー効果、フアラデー効果などの磁気光学効果を利
用する。すなわち、磁気情報は、直線偏光の光ビ
ームが記録媒体に貯えられている磁気情報との相
互作用を受けた後の反射光の偏光方向の回転を検
出することによつて得られる。しかし、現在の光
磁気記録媒体は情報の読み出しＳ／Ｎ比が低いと
いう欠点を有し、特に光磁気記録媒体からの反射
光を利用して、情報の再生を行なうカー効果方式
においては、カー回転角が小さいため単層構造で
はＳ／Ｎ比を上げることが困難である。そこで、
Ｓ／Ｎ比を上げる方策としては各種の多層構造が
考えられている（例えば特開昭56−156943号、特
開昭57−12428号など）。即ち、光磁気記録媒体薄
膜上にSiO，CeO2などの高屈折率透明薄膜層を
設けることにより、カー回転角を増大させる方
法、また記録媒体薄膜の裏側にAu，Ag，Cu，
Alなどの反射膜を設けて、媒体表面からの反射
光だけでなく、記録媒体を通過してしまう透過光
も反射させて利用しカー効果とフアラデー効果の
相乗作用によつてＳ／Ｎ比を上げる方法などが知
られている。しかしながら、従来の高屈折率透明
薄膜層を設ける方法ではカー効果を増加する透明
薄膜の膜厚は反射率を減少させ、Ｓ／Ｎ比の大き
な増加は望み得なかつた。また、Cuなどの反射
層を用いる記録媒体では磁性層のフエラデー効果
を主に利用するものであるが、フアラデー効果に
よる回転角の増加は磁性層の膜厚によつて制限を
受けるため充分大きなみかけのカー回転角を得る
ことができなかつた。 Magneto-optical recording materials are available as recording media for rewritable optical discs. This material uses thermomagnetic effects to write information, and uses magneto-optical effects such as the magnetic Kerr effect and Faraday effect to read information. That is, magnetic information is obtained by detecting the rotation of the polarization direction of reflected light after a linearly polarized light beam interacts with magnetic information stored in a recording medium. However, current magneto-optical recording media have the disadvantage of a low S/N ratio for information readout, and in particular, the Kerr effect method, which uses reflected light from the magneto-optical recording medium to reproduce information, Since the rotation angle is small, it is difficult to increase the S/N ratio with a single layer structure. Therefore,
Various multilayer structures have been considered as a measure to increase the S/N ratio (for example, Japanese Patent Application Laid-open Nos. 156943-1982 and 12428-1980). That is, there is a method of increasing the Kerr rotation angle by providing a high refractive index transparent thin film layer such as SiO, CeO 2 on the magneto-optical recording medium thin film, and a method of increasing the Kerr rotation angle by providing a high refractive index transparent thin film layer such as SiO or CeO 2 on the magneto-optical recording medium thin film.
A reflective film such as Al is provided to reflect and utilize not only the reflected light from the medium surface but also the transmitted light that passes through the recording medium, and the S/N ratio is improved by the synergistic effect of the Kerr effect and Faraday effect. There are known ways to raise it. However, in the conventional method of providing a transparent thin film layer with a high refractive index, the thickness of the transparent thin film, which increases the Kerr effect, reduces the reflectance, and a large increase in the S/N ratio cannot be expected. In addition, recording media that use reflective layers such as Cu mainly utilize the Faraday effect of the magnetic layer, but the increase in rotation angle due to the Faraday effect is limited by the thickness of the magnetic layer, so the apparent increase in the rotation angle is limited by the thickness of the magnetic layer. It was not possible to obtain the Kerr rotation angle.
本発明は上記問題に鑑みてなされたものであつ
て、磁気光学効果を増大させるための誘電体膜層
と、フアラデー効果を利用するための反射膜を設
けて、Ｓ／Ｎ比を増大させると共に、この反射膜
を非晶質希土類−遷移金属合金薄膜の補償組成に
対して希土類に富んだ側の薄膜とし、記録層を非
晶質希土類−遷移金属の補償組成に対して遷移金
属に富んだ側の薄膜とすることにより、基本的に
記録時のバイアス磁界を不要とし、且つ反射膜作
成のための装置が複雑化するのを抑制することを
目的とするものである。 The present invention has been made in view of the above problems, and includes a dielectric film layer for increasing the magneto-optical effect and a reflective film for utilizing the Faraday effect, thereby increasing the S/N ratio and , the reflective film is a rare earth-rich thin film with respect to the compensation composition of the amorphous rare earth-transition metal alloy thin film, and the recording layer is a transition metal-rich thin film with respect to the compensation composition of the amorphous rare earth-transition metal alloy thin film. By forming a thin film on the side, the purpose is to basically eliminate the need for a bias magnetic field during recording and to suppress the complexity of the apparatus for forming the reflective film.
本発明の光磁気記録媒体は基板上に、透明な誘
電体膜層をはさんで情報再生用の光に対して充分
な透過率を有する膜厚の非晶質希土類−遷移金属
合金薄膜と、上記の光に対して充分な反射率を有
する膜厚の非晶質希土類−遷移金属合金薄膜とを
設け、そして上記の充分な透過率を有する膜厚の
非晶質希土類−遷移金属合金薄膜の組成を補償組
成より遷移金属側の組成にし、一方上記の光に対
して充分な反射率を有する膜厚の非晶質希土類−
遷移金属合金薄膜の組成を補償組成より希土類金
属側の組成としたことを特徴とするものである。 The magneto-optical recording medium of the present invention includes, on a substrate, an amorphous rare earth-transition metal alloy thin film having a thickness sufficient to transmit light for information reproduction, sandwiching a transparent dielectric film layer therebetween; An amorphous rare earth-transition metal alloy thin film having a thickness sufficient to reflect the above light is provided, and an amorphous rare earth-transition metal alloy thin film having a thickness sufficient to transmit the above light is provided. The composition is closer to the transition metal than the compensation composition, while the amorphous rare earth has a film thickness that has sufficient reflectance for the above light.
The present invention is characterized in that the composition of the transition metal alloy thin film is closer to the rare earth metal than the compensation composition.
ここで「補償組成」について説明すると、一般
にフエリ磁性体において、副格子Ａ，Ｂによる磁
気モーメントを各々IA，IBとすると、全磁気モー
メントＩは、IA＋IBで表わされる。ところがIAと
IBは方向が逆であるので、副格子Ａ，Ｂの原子の
組成比により、ちようどIA＝−IBになる、すなわ
ちＩ＝０の場合が存在する。この時フエリ磁性体
の磁化は零となる。この場合の組成比を「補償組
成」という（室温において）。本発明では、希土
類と遷移金属のある組成比において、磁化が零と
なる場合、その組成比が補償組成である（室温
で）。 To explain the "compensation composition" here, in general, in a ferrimagnetic material, if the magnetic moments due to sublattices A and B are I A and I B , respectively, the total magnetic moment I is expressed as I A + I B. However, with I A
Since I B is in the opposite direction, depending on the composition ratio of atoms in sublattices A and B, there is a case where I A = -I B , that is, I = 0. At this time, the magnetization of the ferrimagnetic material becomes zero. The composition ratio in this case is called a "compensation composition" (at room temperature). In the present invention, if magnetization becomes zero at a certain composition ratio of rare earth and transition metal, that composition ratio is a compensation composition (at room temperature).
以下、図面を参照して本発明をさらに詳細に説
明する。 Hereinafter, the present invention will be explained in more detail with reference to the drawings.
第１図は本発明の光磁気記録媒体の一実施例を
示す断面図であつて、１は保護膜、２は非晶質希
土類−遷移金属合金薄膜であり、且つ補償組成よ
り遷移金属側の組成を持つ薄膜（Ａ層）である。
この膜厚は情報再生用の光に対して、充分な透過
率を持つ厚さに設定される。３は透明誘電体層で
あり、高屈折率の材料を用い、その膜厚を情報再
生用の光の波長に対して適当に設定して磁気光学
効果を増大させるようにする。４は２と同じく非
晶質希土類−遷移金属合金薄膜であるがその組成
は補償組成より希土類側の薄膜（Ｂ膜）である。
この膜厚は、情報再生用の光に対して充分な反射
率を有するように２の膜厚より厚く設定される。
５は基板である。 FIG. 1 is a sectional view showing an embodiment of the magneto-optical recording medium of the present invention, in which 1 is a protective film, 2 is an amorphous rare earth-transition metal alloy thin film, and the transition metal side is smaller than the compensation composition. It is a thin film (layer A) having a certain composition.
This film thickness is set to a thickness that has sufficient transmittance for light for information reproduction. Reference numeral 3 denotes a transparent dielectric layer, which is made of a material with a high refractive index, and whose film thickness is set appropriately for the wavelength of light for information reproduction to increase the magneto-optic effect. 4 is an amorphous rare earth-transition metal alloy thin film like 2, but its composition is closer to the rare earth than the compensation composition (film B).
This film thickness is set to be thicker than the film thickness 2 so as to have a sufficient reflectance for light for information reproduction.
5 is a substrate.
保護膜の材料としては、SiO2，SiO2などが用
いられる。非晶質希土類−遷移金属合金薄膜は、
Fe，Co，Niなどの遷移金属とSm，Eu，Gd，
Tb，Dy，Ho，Erなどの重希土類とを種々の組
成比で混合して形成された非晶質薄膜であり、膜
厚はＡ層が200〜500Å程度、Ｂ層が1500〜2000Å
程度を用いる。透明誘電体は屈折率２以上のもの
が良く、SiO，CeO2，TiO2などを用いることが
できる。基板としては、ガラスあるいはアクリ
ル、ポリカーボネートなどのプラスチツクが用い
られる。この基板の上に、スパツタリングあるい
は蒸着法などによつて各層を形成させる。 SiO 2 , SiO 2 , etc. are used as the material for the protective film. Amorphous rare earth-transition metal alloy thin film is
Transition metals such as Fe, Co, Ni and Sm, Eu, Gd,
It is an amorphous thin film formed by mixing heavy rare earth elements such as Tb, Dy, Ho, Er, etc. in various composition ratios, and the film thickness is about 200 to 500 Å for layer A and 1500 to 2000 Å for layer B.
Use degrees. The transparent dielectric preferably has a refractive index of 2 or more, and SiO, CeO 2 , TiO 2 and the like can be used. As the substrate, glass or plastic such as acrylic or polycarbonate is used. Each layer is formed on this substrate by sputtering or vapor deposition.
次に、本発明の光磁気記録媒体の作用について
説明する。 Next, the operation of the magneto-optical recording medium of the present invention will be explained.
第２図に示すように矢印６の方向に磁界を印加
し、記録媒体の各磁気薄膜層の磁気モーメントの
方向を図のように配向させて初期状態とする。次
に、第３図に示すように矢印７の方向からレーザ
ービームを照射すると照射部分のＡ層の温度がキ
ユリー温度近くに上昇し、保磁力が低下して、そ
の部分のトータルの磁化は図中上向きで小さいも
のとなるが、この時、Ａ層の隣接の全磁気モーメ
ントによる磁界（いわゆる反磁界で当該レーザー
ビーム照射部分には図中下向きに作用する）とＢ
層からのバイアス効果的な力とによつて、基本的
な無バイアスで、レーザービームの照射部分の磁
化が反転し、冷却する過程で反転状態のまま大き
さが次第に増し、Ａ層のレーザービーム照射部分
に反転磁区が形成される。なお、第３図にはＡ層
の磁化が反転した直後の状態が示してある。ここ
で、上記のバイアス効果的な力について説明す
る。レーザービーム照射時に、Ａ層のレーザービ
ーム照射部分の他、Ｂ層の照射部分も温度上昇す
るが、Ｂ層は補償組成より希土類側の組成である
ため、補償温度を越えてキユリー温度付近まで上
昇した部分の磁気モーメントは希土類金属より遷
移金属が大となり、この部分の磁化の向きはＢ層
の他の部分の磁化の向きと逆、即ち、Ｂ層の隣接
の全磁気モーメントによる磁界と同じ方向になる
ため、この部分の磁化の向きは反転することはな
く、またこの部分の磁化の向きは図中下向きであ
るため、Ａ層のレーザービーム照射部分に対して
は磁化反転を促進するバイアス効果的な力とな
る。そしてレーザービーム照射時において、上記
Ａ層の隣接の全磁気モーメントによる磁界とＢ層
からのバイアス効果的な力との和の絶対値が、Ａ
層のレーザービーム照射部分の磁化の大きさより
大きくなることで、基本的に無バイアスで磁化反
転が行われる。この場合、書込をより容易にする
ためバイアス磁界を加えてもよいが、その値は従
来のものに比べて極めて小さいものでよい。な
お、Ｂ層のレーザービーム照射部分は第３図の状
態から補償温度を過ぎ室温にまで降温することに
より第２図のような状態に戻る。読出し時は、矢
印７の方向からレーザービームを照射し、ビーム
はＡ層が充分透過できるような膜厚に設定してあ
るため、Ａ層を通過し透明誘電体膜を通過する。
さらに、Ｂ層はビームに対して充分な反射率を有
するような膜厚に設定してあるためＢ層表面でビ
ームは反射し、ビームは再び透明誘電体膜を通過
しさらにＡ層を通過する。レーザービームは、Ａ
層を通過する時フアラデー効果を受けて偏光面が
回転する。また、透明誘電体膜により、この偏光
面の回転が増加する。第４図は本発明の光磁気記
録媒体の他の実施例でＡ層を基板側に作製したも
ので、記録、再生のレーザービームは矢印８の方
向から行なう。 As shown in FIG. 2, a magnetic field is applied in the direction of arrow 6, and the direction of the magnetic moment of each magnetic thin film layer of the recording medium is oriented as shown in the figure to obtain an initial state. Next, as shown in Figure 3, when a laser beam is irradiated from the direction of arrow 7, the temperature of the A layer in the irradiated area rises to near the Curie temperature, the coercive force decreases, and the total magnetization of that area decreases as shown in Figure 3. At this time, the magnetic field due to the total magnetic moment of the adjacent layer A (a so-called demagnetizing field, which acts downward in the figure on the part irradiated with the laser beam) and B
Due to the bias effective force from the layer, the magnetization of the laser beam irradiated area is reversed without any basic bias, and during the cooling process, the magnetization of the inverted state gradually increases, and the laser beam of the A layer is A reversed magnetic domain is formed in the irradiated area. Note that FIG. 3 shows the state immediately after the magnetization of the A layer is reversed. Here, the above-mentioned bias effective force will be explained. During laser beam irradiation, the temperature rises not only in the laser beam irradiated part of layer A but also in the irradiated part of layer B, but since layer B has a composition closer to the rare earth than the compensation composition, it exceeds the compensation temperature and rises to around the Curie temperature. The magnetic moment in this part is larger for transition metals than for rare earth metals, and the direction of magnetization in this part is opposite to the direction of magnetization in other parts of the B layer, that is, in the same direction as the magnetic field due to the total magnetic moment of the adjacent B layer. Therefore, the direction of magnetization in this part is not reversed, and since the direction of magnetization in this part is downward in the figure, there is a bias effect that promotes magnetization reversal on the laser beam irradiated part of layer A. It becomes a powerful force. Then, during laser beam irradiation, the absolute value of the sum of the magnetic field due to the total magnetic moment adjacent to layer A and the bias effective force from layer B is
Since the magnitude of magnetization is larger than that of the laser beam irradiated portion of the layer, magnetization reversal is basically performed without bias. In this case, a bias magnetic field may be applied to make writing easier, but its value may be extremely small compared to the conventional one. The portion of the B layer irradiated with the laser beam returns from the state shown in FIG. 3 to the state shown in FIG. 2 by cooling down past the compensation temperature to room temperature. At the time of reading, a laser beam is irradiated from the direction of arrow 7, and since the film thickness is set so that the beam can sufficiently pass through layer A, the beam passes through layer A and then passes through the transparent dielectric film.
Furthermore, since the B layer is set to have a film thickness that has sufficient reflectivity for the beam, the beam is reflected on the surface of the B layer, passes through the transparent dielectric film again, and then passes through the A layer. . The laser beam is A
When passing through the layer, the plane of polarization rotates due to the Faraday effect. Furthermore, the rotation of this plane of polarization is increased by the transparent dielectric film. FIG. 4 shows another embodiment of the magneto-optical recording medium of the present invention in which the A layer is formed on the substrate side, and the laser beam for recording and reproduction is performed from the direction of arrow 8.
以下、実施例にもとづいて説明する。 The following is a description based on examples.
第４図は本発明の光磁気記録媒体の一実施例を
示す断面図であつて、まず基板５の上に非晶質希
土類−遷移金属合金薄膜であるTbFe膜２を約
200Å形成する。作成にはTbFe合金ターゲツト
を用い、スパツタ法を用いた。形成された薄膜２
の組成はTb18％Fe82％であり、補償組成（Tb21
％Fe79％）より遷移金属側の組成を持つ。その
上にSiO膜３をスパツタ法にて200Å形成した。 FIG. 4 is a sectional view showing an embodiment of the magneto-optical recording medium of the present invention. First, a TbFe film 2, which is an amorphous rare earth-transition metal alloy thin film, is deposited on a substrate 5.
Forms 200Å. A TbFe alloy target was used for fabrication, and the sputtering method was used. Formed thin film 2
The composition is Tb18%Fe82%, and the compensation composition (Tb21
%Fe79%) has a composition closer to transition metals. A SiO film 3 of 200 Å was formed thereon by sputtering.
さらに、この上にTbFe膜４を約1500Å形成す
る。この組成はTb24％Fe76％であり、補償組成
より希土類側の組成を持つ。その上に保護膜
SiO2(1)を約2000Å形成した。 Furthermore, a TbFe film 4 of about 1500 Å is formed on this. This composition is 24% Tb and 76% Fe, which is closer to the rare earth element than the compensation composition. a protective film on top of it
About 2000 Å of SiO 2 (1) was formed.
このようにして作製された光磁気記録媒体を約
10KOeの外部磁場で、初期化を行なつた後、無
バイアス（Oe）の条件でレーザー照射条件を変
えて記録を行なつた。その結果レーザパワー
6mW以上で書き込みを行なうことができた。 The magneto-optical recording medium produced in this way is approximately
After initialization with an external magnetic field of 10 KOe, recording was performed under no bias (Oe) conditions while changing the laser irradiation conditions. The resulting laser power
I was able to write with more than 6mW.
以上のように構成された本発明によれば、記録
時、Ｂ層の磁化による磁界がバイアス磁界の働き
をし、基本的に無バイアスで、Ａ層に記録でき
る、磁性層を反射膜とするため反射膜用材料を新
たに、蒸着、あるいはスパツタリングする必要な
く装置が簡単化される、および透明誘電体膜層に
より、磁気光学効果が増大するなどの利点が得ら
れる。 According to the present invention configured as described above, during recording, the magnetic field due to the magnetization of the B layer acts as a bias magnetic field, and recording can be performed on the A layer basically without bias.The magnetic layer is a reflective film. Therefore, there are advantages such as the apparatus is simplified without the need to newly evaporate or sputter a reflective film material, and the magneto-optic effect is increased by the transparent dielectric film layer.
第１図および第４図は本発明の光磁気記録媒体
の構成例を示す断面図でありそして第２図および
第３図は本発明の光磁気記録媒体の作用を説明す
る模式図である。
１……保護層、２，４……非晶質希土類−遷移
金属合金薄膜、３……透明誘電体膜層、５……基
板、遷移金属の磁気モーメント、希土類の磁気モ
ーメント。
1 and 4 are cross-sectional views showing an example of the structure of the magneto-optical recording medium of the present invention, and FIGS. 2 and 3 are schematic diagrams illustrating the operation of the magneto-optical recording medium of the present invention. 1... Protective layer, 2, 4... Amorphous rare earth-transition metal alloy thin film, 3... Transparent dielectric film layer, 5... Substrate, magnetic moment of transition metal, magnetic moment of rare earth.
Claims (1)
再生用の光に対して充分な透過率を有する膜厚の
非晶質希土類−遷移金属合金薄膜と、上記の光に
対して充分な反射率を有する膜厚の非晶質希土類
−遷移金属合金薄膜とを設け、そして上記の充分
な透過率を有する膜厚の非晶質希土類−遷移金属
合金薄膜の組成を補償組成より遷移金属側の組成
にし、一方上記の光に対して充分な反射率を有す
る膜厚の非晶質希土類−遷移金属合金薄膜の組成
を補償組成より希土類金属側の組成としたことを
特徴とする、光磁気記録媒体。1. A thin amorphous rare earth-transition metal alloy thin film having a thickness sufficient to transmit light for information reproduction by sandwiching a transparent dielectric film layer on a substrate, and a thin film having a thickness sufficient to transmit the light for information reproduction. The composition of the amorphous rare earth-transition metal alloy thin film having a thickness of sufficient transmittance is changed from the compensation composition to the transition metal. A light source characterized in that the composition of the amorphous rare earth-transition metal alloy thin film having a film thickness sufficient to reflect the above-mentioned light is set to be a composition closer to the rare earth metal side than the compensating composition. magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16971082A JPS5960746A (en) | 1982-09-30 | 1982-09-30 | Photomagnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16971082A JPS5960746A (en) | 1982-09-30 | 1982-09-30 | Photomagnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5960746A JPS5960746A (en) | 1984-04-06 |
| JPH0519213B2 true JPH0519213B2 (en) | 1993-03-16 |
Family
ID=15891429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16971082A Granted JPS5960746A (en) | 1982-09-30 | 1982-09-30 | Photomagnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5960746A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0619859B2 (en) * | 1984-02-16 | 1994-03-16 | 株式会社ニコン | Magneto-optical recording medium |
| US5239524A (en) * | 1985-06-11 | 1993-08-24 | Nikon Corporation | Over write capable magnetooptical recording method, and magnetooptical recording apparatus and medium used therefor |
| JPH07105082B2 (en) * | 1985-11-28 | 1995-11-13 | ソニー株式会社 | Magneto-optical recording medium |
| JP2607476B2 (en) * | 1986-05-16 | 1997-05-07 | 株式会社日立製作所 | Magneto-optical recording method |
| EP0838814B1 (en) * | 1986-07-08 | 2002-02-27 | Canon Kabushiki Kaisha | Magnetooptical recording medium allowing overwriting with two or more magnetic layers and recording method utilizing the same |
| US5599619A (en) * | 1991-10-18 | 1997-02-04 | International Business Machines Corporation | Write once magneto-optic media and system |
-
1982
- 1982-09-30 JP JP16971082A patent/JPS5960746A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5960746A (en) | 1984-04-06 |
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