JPS62239351A - Magneto-optical recording medium - Google Patents
Magneto-optical recording mediumInfo
- Publication number
- JPS62239351A JPS62239351A JP8194586A JP8194586A JPS62239351A JP S62239351 A JPS62239351 A JP S62239351A JP 8194586 A JP8194586 A JP 8194586A JP 8194586 A JP8194586 A JP 8194586A JP S62239351 A JPS62239351 A JP S62239351A
- Authority
- JP
- Japan
- Prior art keywords
- magneto
- recording medium
- optical recording
- film
- diamond
- 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.)
- Granted
Links
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
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Abstract
Description
【発明の詳細な説明】
１１ユ少Ｂ」±！
本発明は光磁気記録体に関する。更に詳しくいえば、量
産性、耐久性を改善するためにダイヤモンド状炭素膜を
設けた高性能の光磁気記録媒体に関するものである。[Detailed description of the invention] 11 yu small B''±! The present invention relates to a magneto-optical recording medium. More specifically, the present invention relates to a high-performance magneto-optical recording medium provided with a diamond-like carbon film to improve mass productivity and durability.
従来の技術
高度情報社会への移行を背景として、小型化、大容量化
を目的とした高密度記録媒体の開発が必要となってきて
おり、そのための有力な手段として磁気記録がある。磁
気記録としては、磁気テープ、磁気ディスク、磁気バブ
ルメモリーなどが知られ、これらはいずれも記録、再生
、消去に磁束を利用したものである。また、記録や再生
に光を利用する方法も光磁気メモリーとして知られ、こ
れは従来の磁気記録に比してより高密度記録が可能であ
り、またランダムアクセスが可能であり、非接触で記録
再生が可能であるなどの各種利点を有している。Background of the Invention With the transition to an advanced information society, it has become necessary to develop high-density recording media with the aim of downsizing and increasing capacity, and magnetic recording is an effective means for achieving this. Known examples of magnetic recording include magnetic tapes, magnetic disks, and magnetic bubble memories, all of which utilize magnetic flux for recording, reproduction, and erasing. Additionally, a method that uses light for recording and playback is known as magneto-optical memory, which enables higher density recording than conventional magnetic recording, and also enables random access and non-contact recording. It has various advantages such as being reproducible.
後者の光磁気メモリーでは、レーザによる加熱と外部印
加磁界を併用して記録し、磁化の向きによる光の振動面
の回転方向の違いを利用して再生を行う。ここで、光磁
気メモリーの記録密度を高めるために、一般に記録媒体
に対して磁化は垂直とされる。記録方法としては、（ｉ
）記録部分の温度をキューリ一点以上に上げ、一時的に
磁化を消失させることからなるキューリ一点記録と（ｉ
ｉ ）室温近傍に補償温度をもつ記録媒体を部分加熱し
、低下した保磁力を上まわる外部磁界を印加して磁化を
反転させることからなる補償温度記録法とが知られてい
る。The latter type of magneto-optical memory uses a combination of laser heating and an externally applied magnetic field to record information, and performs reproduction by utilizing the difference in the rotational direction of the light vibration plane depending on the direction of magnetization. Here, in order to increase the recording density of a magneto-optical memory, magnetization is generally perpendicular to the recording medium. The recording method is (i
) Curie single point recording, which consists of raising the temperature of the recording area above the Curie point and temporarily eliminating magnetization; and (i
i) A compensation temperature recording method is known in which a recording medium having a compensation temperature near room temperature is partially heated and the magnetization is reversed by applying an external magnetic field that exceeds the reduced coercive force.
また、再生法は、ファラデー効果、カー効果即ち磁気光
学効果を利用するものであり、前者では記録媒体を透過
する光を利用しており、一方後者では反射光を利用する
ものであり、これらはいずれも磁化の向きによる偏光面
の回転方向の違いを読取ることからなっている。即ち、
例えば直線偏光を記録ビット部分に照射し、記録ビット
の磁イヒの正負の向きに応じて、透過光または反射光の
偏光面を右または左に回転させ、このいずれかの回転方
向に直交するように検光子の透過軸を設定することによ
り、意図した一方の向きの磁化に対応した記録ビット部
分のみを選択的に検出する。Furthermore, reproduction methods utilize the Faraday effect, the Kerr effect, or the magneto-optical effect; the former uses light that passes through the recording medium, while the latter uses reflected light. Both methods involve reading the difference in the direction of rotation of the plane of polarization depending on the direction of magnetization. That is,
For example, linearly polarized light is irradiated onto the recording bit area, and the polarization plane of the transmitted light or reflected light is rotated to the right or left depending on the positive or negative direction of the magnetic field of the recording bit, so that the plane of polarization is perpendicular to either direction of rotation. By setting the transmission axis of the analyzer to , only the recorded bit portion corresponding to the intended magnetization in one direction is selectively detected.
以上の如く光磁気記録媒体に記録された情報を再生する
場合には、偏光された光が磁性体表面で反射もしくは透
過する際に偏光面が回転する、いわゆる磁気カー効果を
利用しており、従って再生の際には信号と雑音との比Ｓ
／Ｎが極めて重要なファクターとなり、これをできるだ
け大きくする必要がある。この雑音の発生原因としては
キャリアのふらつきによるショット雑音、熱雑音、媒体
の不均一性からくる雑音などがある。このＳ／Ｎは雑音
の大部分がショット雑音である場合には、ＪＰＱに （
ここでＰは検出器、例えばアバランシェフォトダイオー
ド（ＡＰＤ）などに到達する光虫であり、Ｑｇはカー回
転角である）に比例する。As described above, when reproducing information recorded on a magneto-optical recording medium, the so-called magnetic Kerr effect is used, in which the plane of polarization rotates when polarized light is reflected or transmitted through the surface of a magnetic material. Therefore, during playback, the signal to noise ratio S
/N becomes an extremely important factor, and it is necessary to make it as large as possible. The causes of this noise include shot noise due to carrier fluctuation, thermal noise, and noise due to non-uniformity of the medium. When most of the noise is shot noise, this S/N is determined by JPQ (
where P is the light beam reaching the detector, such as an avalanche photodiode (APD), and Qg is the Kerr rotation angle).
従って、このＳ／Ｎを大きくするためには上記カー回転
角（ＱＸ）を大きくすることが必要となる。Therefore, in order to increase this S/N, it is necessary to increase the Kerr rotation angle (QX).
一般に、このような光磁気記録媒体を作製するめだの磁
性材料としては、例えばＧｄＰｅ５ＧｄＣｏ、ＧｄＦｅ
Ｃｏ、 ＴｂＰｅ５ＴｅＣｏＳＴｂＦｅＣｏ、 ＧｄＴ
ｂＰｅ５ＧｄＴｂＣｏ等の希土類−遷移金属多元合金の
非晶質膜が用いられ、また基板としてはガラス、プラス
チックなどを使用できるが、射出成形によりガイド・ト
ラック入りの製品が大量に複製できることからプラスチ
ック材料を使用することが、量産性、コスト等の点から
好ましいとされている。In general, examples of magnetic materials for producing such magneto-optical recording media include GdPe5GdCo and GdFe.
Co, TbPe5TeCoSTbFeCo, GdT
An amorphous film of a rare earth-transition metal multi-component alloy such as bPe5GdTbCo is used, and glass, plastic, etc. can be used as the substrate, but plastic materials are used because products with guide tracks can be reproduced in large quantities by injection molding. It is said that it is preferable to do so in terms of mass productivity, cost, etc.
発明が解決しようとする問題点
以上述べたように、垂直記録体や光磁気記録媒体などを
用いた高密度、大容量記録が盛んに研究されており、従
来から磁気ドラムに代る電算機用記録媒体等として期待
され、一部では既に実用化されている。Problems to be Solved by the Invention As mentioned above, high-density, large-capacity recording using perpendicular recording media, magneto-optical recording media, etc. has been actively researched, and conventional magnetic drums have been used for computers as an alternative to magnetic drums. It is expected to be used as a recording medium, etc., and has already been put into practical use in some places.
ところで、この記録媒体用の基板材料としては、射出成
形によりガイド・トラックを有するものが大工生産でき
、またその他の基板材料としてのガラスなどと比較して
コスト的に有利であることから、プラスチック材料が支
配的に使用されている。By the way, as a substrate material for this recording medium, plastic material is preferred because it can be manufactured by carpenters with guide tracks by injection molding, and it is cost-effective compared to other substrate materials such as glass. is predominantly used.
しかしながら、基板としてプラスチック材料を用いた場
合、磁性材料としての希土類−遷移金属合金が極めて酸
化され易い性質を有しているために、基板としてのプラ
スチックから侵入してくる水分等により磁性材料膜が腐
食され、記録媒体の性質、信頼性が著しく損なわれると
いう大きな問題があった。However, when a plastic material is used as a substrate, the rare earth-transition metal alloy used as the magnetic material has a property of being extremely easily oxidized, so the magnetic material film may be damaged by moisture entering from the plastic substrate. There was a major problem in that the recording medium was corroded and the properties and reliability of the recording medium were significantly impaired.
また、このような光磁気記録媒体において、特にカー効
果を利用するものに右いては、Ｓ／Ｎをできるだけ太き
（して、再生感度を高める必要があり、そのためにはカ
ー回転角（Ｑイ）をできるだけ大きくする必要がある。In addition, in such magneto-optical recording media, especially those that utilize the Kerr effect, it is necessary to increase the S/N ratio as much as possible (and thereby increase the reproduction sensitivity, and for this purpose, the Kerr rotation angle (Q b) must be made as large as possible.
しかし、非晶質垂直磁化膜の場合にはＱＫが小さいとい
う問題があった。そこで、これに対する解決策として、
従来は第２図に示すように非晶質磁性膜１を基板２とＡ
ｕ。However, in the case of an amorphous perpendicular magnetization film, there is a problem that QK is small. Therefore, as a solution to this,
Conventionally, as shown in FIG.
u.
Ｃｕ等の反射膜３としてサンドイッチ状に挟んだ構成と
し、多重反射を利用することによってＱにを大きくさせ
る方法が採用されていた。A method has been adopted in which a reflective film 3 made of Cu or the like is sandwiched, and Q is increased by utilizing multiple reflections.
しかしながら、上記解決策によれば、反射率が極端に小
さくなるために、Ｓ／Ｎ比が減少し、信号検出に不都合
が生じるという新たな間ツを提示したにすぎなかった。However, the above solution merely presents a new problem in that the reflectance becomes extremely small, resulting in a decrease in the S/N ratio and inconvenience in signal detection.
そこで、経済的に有利な、また量産性に富むプラスチッ
ク基板を用いた光磁気記録媒体をより有利に実用化し得
るものとするために、ＱＩｌを大きくシ得、しかも耐久
性を改善し得る新しい技術を開発することは、この光磁
気記録媒体において極めて重要であり、これに対する大
きな要求がある。Therefore, in order to more advantageously put into practical use magneto-optical recording media using plastic substrates, which are economically advantageous and can be easily mass-produced, we have developed a new technology that can significantly increase QIl and improve durability. It is extremely important to develop this magneto-optical recording medium, and there is a great demand for it.
本発明の目的は量産性に富み、しかも耐久性の優れた光
磁気記録媒体を提供せんとするものである。An object of the present invention is to provide a magneto-optical recording medium that is easy to mass produce and has excellent durability.
問題点を解決するための手段
本発明者等は大容量、高密度記録可能な光磁気記録媒体
、特にプラスチック基板を用いた記録媒体における上記
の如き現状に鑑みて、その諸欠点を解消し、Ｑにを大き
くし、Ｓ／Ｎ比を大巾に改善し、記録された情報の再生
・読出し感度を向上させ、しかも耐久性等の高い信頼性
を確保すべく種々検討・研究した結果、プラスチック基
板と磁性膜との間に特定の介在層を設けることが極めて
有効であることを見出し本発明を完成した。Means for Solving the Problems In view of the above-mentioned current state of magneto-optical recording media capable of large-capacity, high-density recording, particularly recording media using plastic substrates, the present inventors have solved the various drawbacks thereof, As a result of various studies and research to increase the Q, greatly improve the S/N ratio, improve the sensitivity for reproducing and reading recorded information, and ensure high reliability such as durability, we have found that plastic The present invention was completed based on the discovery that it is extremely effective to provide a specific intervening layer between the substrate and the magnetic film.
即ち、本発明の光磁気記録媒体はプラスチック基板と、
その上に形成された希土類−遷移金属多元合金からなる
非晶質垂直磁化膜と、上記プラスチック基板と非晶質垂
直磁化膜との間に設けられたダイヤモンド状炭素膜とを
含むことを特徴とするものである。That is, the magneto-optical recording medium of the present invention includes a plastic substrate,
The plastic substrate is characterized by comprising an amorphous perpendicularly magnetized film made of a rare earth-transition metal multi-component alloy formed thereon, and a diamond-like carbon film provided between the plastic substrate and the amorphous perpendicularly magnetized film. It is something to do.
本発明の光磁気記録媒体はプラスチック基板と、非晶質
垂直磁化膜との間に不透湿性のダイヤモンド状炭素膜を
形成したことにあり、従って基板、磁化膜用材料として
は特に制限はなく、従来公知の各種材料がいずれも利用
でき、その典型例を挙げると、例えばプラスチック基板
材料としてはアクリル樹脂〔ポリメチルメタクリレート
（ＰＭＭＡ））ポリカーボネート、ポリアミド、シリコ
ーン樹脂などが、また磁化膜材料としては上記の如き希
土類−遷移金属多元合金、例えばＧｄＦｅ、 ＧｄＣｏ
５ＧｄＦｅＣｏ。The magneto-optical recording medium of the present invention has a moisture-impermeable diamond-like carbon film formed between a plastic substrate and an amorphous perpendicularly magnetized film, so there are no particular restrictions on the materials for the substrate and magnetized film. Various conventionally known materials can be used; typical examples include acrylic resin (polymethyl methacrylate (PMMA)), polycarbonate, polyamide, silicone resin, etc. as plastic substrate materials, and as magnetic film materials. Rare earth-transition metal multi-component alloys such as those mentioned above, such as GdFe, GdCo
5GdFeCo.
ＴｂＦｅ、 ＴｂＣｏ５ＴｂＦｅ（’ｏＳＧｄＴｂＦｅ
ＳＧｄＴｂＣｏなどの非晶質膜などを挙げることができ
る。TbFe, TbCo5TbFe ('oSGdTbFe
Examples include amorphous films such as SGdTbCo.
本発明の光磁気記録媒体は選ばれたプラスチック基板上
に、まずダイヤモンド状炭素膜を形成する。グラファイ
トをターゲットとする高周波スパッタ蒸着などの物理的
成膜法の他、メタン、エタン、エチレンなどの低級飽和
もしくは不飽和炭化水素ガスの熱分解などの従来から知
られた方法のいずれかを使用して実施することができる
。また、最近注目されているイオンビーム蒸着、イオン
ビームスパッタ蒸着などの物理的成膜法、メタンと水素
との混合ガスなどの熱分解、プラズマ中での分解などの
手法も当然利用でき、本発明の範囲内にはいる。尚、基
板がプラスチックであることから、低温で成膜できるプ
ラズマ分解法が最も好ましい方法である。In the magneto-optical recording medium of the present invention, a diamond-like carbon film is first formed on a selected plastic substrate. In addition to physical deposition methods such as radio-frequency sputter deposition targeting graphite, conventional methods such as pyrolysis of lower saturated or unsaturated hydrocarbon gases such as methane, ethane, or ethylene are used. It can be implemented by Naturally, physical film-forming methods such as ion beam evaporation and ion beam sputter deposition, which have been attracting attention recently, as well as thermal decomposition of a mixed gas of methane and hydrogen, and decomposition in plasma, can also be used. is within the range. Note that since the substrate is made of plastic, the most preferred method is the plasma decomposition method, which allows film formation at low temperatures.
かくして、ダイヤモンド状炭素膜を基板上に形成した後
、非晶質磁性膜を形成する。これはスパッタリング法、
真空蒸着法、イオンブレーティング法などの物理的蒸着
法などが利用できるが、この場合にも同様に基板として
プラスチックを使用する必要上、低温条件下で成模し得
る方法を採用することが有利であり、これは熱変形等の
欠陥の発生を未然に防止する上で重要である。After the diamond-like carbon film is thus formed on the substrate, an amorphous magnetic film is formed. This is a sputtering method,
Physical vapor deposition methods such as vacuum evaporation method and ion blating method can be used, but in this case as well, it is necessary to use plastic as the substrate, so it is advantageous to adopt a method that can be imitated under low temperature conditions. This is important in order to prevent defects such as thermal deformation from occurring.
本発明の光磁気記録媒体においては、上記３層構造のも
のの他、上記非晶質磁性膜上に更にダイヤモンド状炭Ｓ
膜を設けた四層構造のものとすることができ、非晶質磁
性層の経時安定性を更に一層良好なものとすることがで
きる。In the magneto-optical recording medium of the present invention, in addition to the three-layer structure described above, diamond-like carbon S is further provided on the amorphous magnetic film.
The amorphous magnetic layer can have a four-layer structure provided with a film, and the stability over time of the amorphous magnetic layer can be further improved.
本発明の光磁気記録媒体において、ダイヤモンド状炭素
膜の厚さは、一般に５００〜２０００人の範囲内とする
ことが有利であり、これによって以下に述べる種々の効
果を確保することができる。更に、非晶質磁性膜上に設
けられるダイヤモンド状炭素膜の厚さも上記同様である
。In the magneto-optical recording medium of the present invention, it is advantageous that the thickness of the diamond-like carbon film is generally within the range of 500 to 2000, thereby ensuring the various effects described below. Furthermore, the thickness of the diamond-like carbon film provided on the amorphous magnetic film is also the same as above.
罫」
以上述べたように、従来の特に基板としてプラスチック
材料を用いた光磁気記録媒体において問題となっていた
点は、その上に設けられて実際の情報の記録、再生を行
う非晶質磁性膜、即ち希土類−遷移金属合金が極めて酸
化され易いことに基き、基板のプラスチックから侵入し
てくる水分により、膜が腐食され、性能の劣化を招くこ
とにあった。更に非晶質垂直磁化膜においてはＱにが小
さいという問題もあり、その対策として例えば多重反射
を利用する試みがなされたが、満足できるものではなか
った。As mentioned above, the problem with conventional magneto-optical recording media, especially those that use plastic materials as substrates, is that the amorphous magnetic material that is placed on top of the media and which actually records and reproduces information. Since the film, that is, the rare earth-transition metal alloy, is extremely susceptible to oxidation, moisture entering from the plastic substrate corrodes the film, leading to deterioration of performance. Furthermore, amorphous perpendicularly magnetized films have the problem of a small Q. As a countermeasure to this problem, attempts have been made to utilize, for example, multiple reflections, but these have not been satisfactory.
しかしながら、これら従来の諸問題点は、本発明によっ
てほぼ満足に解決し得ることとなった。However, these conventional problems can be almost satisfactorily solved by the present invention.
即ち、まず本発明の光磁気記録媒体では基板と非晶質磁
性膜との間、あるいは更に非晶質磁性膜上にダイヤモン
ド状の炭素膜を設けており、プラスチック基板からの水
分などの侵入を未然に防止し、これに基（非晶質磁性膜
の酸化等による劣化の問題を解決し、ひいてはその記録
媒体としての性能・信頼性を大１１１に数置することが
可能となった。That is, first, in the magneto-optical recording medium of the present invention, a diamond-shaped carbon film is provided between the substrate and the amorphous magnetic film, or further on the amorphous magnetic film, to prevent moisture from entering from the plastic substrate. Based on this, it has become possible to solve the problem of deterioration of amorphous magnetic films due to oxidation, etc., and to improve the performance and reliability of the recording medium.
また、非晶質磁性膜上にもダイヤモンド状炭素膜を設け
た場合には不慮の摩擦等によるキズの形成が防止でき、
耐久性に優れた、長寿命の製品を得ることが可能となる
。Furthermore, if a diamond-like carbon film is also provided on the amorphous magnetic film, it is possible to prevent the formation of scratches due to accidental friction, etc.
It becomes possible to obtain a product with excellent durability and long life.
更に、本発明の光磁気記録媒体においては、上記ダイヤ
モンド状炭素膜の厚さを適当に調節することにより、以
下の実施例で証明するようにかなり大きな値まで高める
ことができる。従って、このカー回転角の観点並びに保
護層としての機能の観点からダイヤモンド状炭素膜の厚
さは、上記の如＜５００〜２０００人の範囲内とするこ
とが好ましく、この範囲内に保つことにより上記の如き
、従来法にみられた各種問題点を有利に解決し得ること
になる。Furthermore, in the magneto-optical recording medium of the present invention, by appropriately adjusting the thickness of the diamond-like carbon film, it is possible to increase the thickness to a considerably large value, as will be demonstrated in the following examples. Therefore, from the viewpoint of the Kerr rotation angle and the function as a protective layer, the thickness of the diamond-like carbon film is preferably within the range of <500 to 2,000 as described above, and by keeping it within this range. As mentioned above, various problems seen in the conventional methods can be advantageously solved.
このような本発明の光磁気記録媒体は従来のものと同様
に、情報の記録はレーザ光による加熱と外部印加磁界と
を併用することにより実施され、また再生は磁気光学効
果（カー効果）を利用して、磁化の向きによる光の振動
面の回転方向の違いを利用して行う。また、この光磁気
記録媒体の適用分野としては、従来のものと同様にラン
ダムアクセスが可能な電子計算機用メモリーをはじめと
する各稲磁気ディスク等として広く利用することができ
る。In the magneto-optical recording medium of the present invention, information is recorded by using a combination of heating by laser light and an externally applied magnetic field, and reproduction is performed by using the magneto-optic effect (Kerr effect). This is done by taking advantage of the difference in the direction of rotation of the vibration plane of light depending on the direction of magnetization. Furthermore, this magneto-optical recording medium can be widely used as various magnetic disks, including memory for electronic computers that can be randomly accessed, similar to conventional ones.
実施例
以下、実施例および製造例によって本発明の光磁気記録
媒体につき更に詳しく説明すると共にその奏する効果を
明らかにする。しかしながら本発明は以下の例により何
隻制限されるものではない。EXAMPLES Hereinafter, the magneto-optical recording medium of the present invention will be explained in more detail and its effects will be clarified through examples and manufacturing examples. However, the present invention is not limited to the following examples.
実施例１
添付第１図に本発明の光磁気記録媒体を模式的に断面図
で示した。本例は基板と磁性膜との間にダイヤモンド状
炭素膜を介在させた３層構造のものである。図から明ら
かな如く円板状のポリメチルメタクリレート樹脂基板１
０と、介在層としての１１７さ８０〇へのダイヤモンド
状炭素膜１１と、５００へのｊゾさの非晶質磁性膜１２
とで構成される。Example 1 The attached FIG. 1 schematically shows a sectional view of a magneto-optical recording medium of the present invention. This example has a three-layer structure in which a diamond-like carbon film is interposed between the substrate and the magnetic film. As is clear from the figure, a disc-shaped polymethyl methacrylate resin substrate 1
0, a diamond-like carbon film 11 of 117 and 800 as an intervening layer, and an amorphous magnetic film 12 of 500 and
It consists of
製造例１
厚さ２ ｍｍ、直径２０ｍｍの円板状のアクリル樹脂（
ＰＭＭＡ）を基板として高周波分解法によりダイヤモン
ド状炭素膜を厚みｉ、 ｏｏｏ八で蒸着し、次いで磁性
膜としてＴｂＦｅをスパッタリングにより厚み５００人
蒸着し、更にその上にダイヤモンド状炭素膜を厚さｌ、
０００人で同様に高周波分解により形成し４層構造の
光磁気記録材料を作製した。また、比較サンプルとして
、同様なＰＭＭＡ樹脂基板上に直接ＴｂＰｅを蒸着し、
その上にダイヤモンド状炭素膜を形成したものも作製し
た。Production example 1 A disc-shaped acrylic resin with a thickness of 2 mm and a diameter of 20 mm (
PMMA) was used as a substrate, and a diamond-like carbon film was deposited to a thickness of i, ooo by high-frequency decomposition, then TbFe was deposited as a magnetic film by sputtering to a thickness of 500, and then a diamond-like carbon film was deposited on top of it to a thickness of l,
A magneto-optical recording material having a four-layer structure was also produced by high-frequency decomposition using 1,000 people. In addition, as a comparison sample, TbPe was directly deposited on a similar PMMA resin substrate.
A diamond-like carbon film was also formed on top of the diamond-like carbon film.
実施例２
製造例１で作製した本発明のサンプルと比較サンプルに
つき、保磁力Ｈｃの経時変化を測定した。Example 2 Changes in coercive force Hc over time were measured for the sample of the present invention prepared in Production Example 1 and a comparative sample.
結果を添付第３図に示した。この第３図の結果から明ら
かな如く、本発明に従ってＰＭＭＡ樹脂基板とｒｂＦｅ
層との間にダイヤモンド状炭素膜を設けた構造のもので
は測定期間（４５日以上）を通じて殆ど一定であり、磁
性膜の劣化は殆どみられなかった。一方、比較サンプル
では測定開始直後から低下し始め、２５日前後で殆ど零
となってしまうことがわかった。尚、第３図において、
縦軸は時間零における保磁力Ｈ６（０）に対する所定の
時間経過後の測定値Ｈｃ（ｔ）の割合を表し、横軸は経
過時間を表す。The results are shown in attached Figure 3. As is clear from the results shown in FIG. 3, according to the present invention, PMMA resin substrate and rbFe
In the structure in which a diamond-like carbon film was provided between the magnetic layers, the magnetic film remained almost constant throughout the measurement period (45 days or more), and almost no deterioration of the magnetic film was observed. On the other hand, it was found that in the comparative sample, the value began to decrease immediately after the start of the measurement, and reached almost zero around 25 days. In addition, in Figure 3,
The vertical axis represents the ratio of the measured value Hc(t) after a predetermined time has elapsed to the coercive force H6(0) at time zero, and the horizontal axis represents the elapsed time.
実施例３
製造例１に従って、ただしダイヤモンド状炭素膜の厚さ
を種々変化させて本発明の構成の光磁気記録媒体を作製
した。かくして得た各サンプルにつきカー回転角（Ｑｌ
ｌ ）を測定し、ＱＫのダイヤモンド状炭素膜の膜厚依
存性を調べた結果を第４図に示した。また、製造例１で
作製した比較サンプルについてもＱ８の測定を行った。Example 3 Magneto-optical recording media having the structure of the present invention were manufactured according to Production Example 1, but with various thicknesses of the diamond-like carbon film. For each sample thus obtained, the Kerr rotation angle (Ql
Figure 4 shows the results of measuring the dependence of QK on the thickness of the diamond-like carbon film. Further, Q8 measurements were also performed on the comparative sample prepared in Production Example 1.
第４図の結果から明らかな如く、Ｑｌｌは、ダイヤモン
ド状炭素膜の膜厚８００人近傍に最大値を示し、これを
境にして徐々に低下する。また、この膜厚でのレーザ光
（８３０ｎｍ ） ’対する透過率は８０％以上であっ
た。図示のように、比較サンプルではカー回転角は約１
３ｍ１ｎであるが、本発明の製品では最大２５ｍ１ｎと
大［［］にカー回転角を高めることがモきることがわか
る。As is clear from the results shown in FIG. 4, Qll shows a maximum value near the thickness of the diamond-like carbon film of 800 mm, and gradually decreases after this point. Furthermore, the transmittance for laser light (830 nm) at this film thickness was 80% or more. As shown, in the comparative sample, the Kerr rotation angle is approximately 1
3 m1n, but with the product of the present invention, it is possible to increase the Kerr rotation angle to a maximum of 25 m1n.
発明の効果
以上詳細にのべたように、本発明に従って樹脂基板と非
晶質磁性膜との間に、基板からの水分等の磁性膜への侵
入を有効に防止できるダイヤモンド状炭素膜を介在層と
して設けたことにより、磁性膜の酸化による変質・劣化
が防止でき、耐用寿命を大巾に改善することができる。Effects of the Invention As described in detail above, according to the present invention, a diamond-like carbon film is interposed between the resin substrate and the amorphous magnetic film to effectively prevent moisture from entering the magnetic film from the substrate. By providing this as a magnetic film, alteration and deterioration of the magnetic film due to oxidation can be prevented, and the service life can be greatly improved.
再に、光磁気記録媒体にとって最も重要と思われるカー
回転角の点でもダイヤモンド状炭素膜を設けたことによ
り大巾な改善を図ることが可能であり、従来の製品に比
して最大２倍ものカー回転角が実現できた。再に、記録
・再生時に使用される、例えばλ＝８３０ｎｍのレーザ
光に対しても太きな透過率を保っており、情報の記録・
再生に有利である。Also, by providing a diamond-like carbon film, it is possible to make a significant improvement in the Kerr rotation angle, which is considered to be the most important factor for magneto-optical recording media, and it is up to twice that of conventional products. A monocar rotation angle was achieved. Furthermore, it maintains a high transmittance even for laser beams of λ = 830 nm, which are used during recording and reproduction, making it ideal for recording and reproducing information.
It is advantageous for reproduction.
かくして、本発明によれば、電算機用の磁気ディスクを
はじめとする各種高密度記録用材料として有利な光磁気
記録媒体を提供することができる。Thus, according to the present invention, it is possible to provide a magneto-optical recording medium that is advantageous as a material for various high-density recordings including magnetic disks for computers.
添付第１図は本発明の光磁気記録媒体の好ましい１実施
例の基本的な構成を模式的な断面図で示した図であり、
第２図は従来の光磁気記録媒体の典型例を説明するため
の第１図と同様な図であり、
第３図は本発明の、および従来の構成の各光磁気記録媒
体につき、保磁力Ｈ０の経時変化を調べた結果を比較し
てプロットしたグラフであり、第４図は光磁気記録媒体
におけるダイヤモンド状炭素膜の厚さの、カー回転角に
対する影響を調べた結果をプロットしたものである。
（主な参照番号）
１・・非晶質磁性膜、 ２・・基板、Attached FIG. 1 is a schematic sectional view showing the basic configuration of a preferred embodiment of the magneto-optical recording medium of the present invention, and FIG. 2 illustrates a typical example of a conventional magneto-optical recording medium. Figure 3 is a graph comparing and plotting the results of examining changes in coercive force H0 over time for each magneto-optical recording medium of the present invention and a conventional configuration. FIG. 4 is a plot of the results of investigating the effect of the thickness of the diamond-like carbon film on the Kerr rotation angle in the magneto-optical recording medium. (Main reference numbers) 1. Amorphous magnetic film, 2. Substrate,
Claims (5)
状炭素膜と、該炭素膜上に設けられた非晶質磁性体膜と
を含むことを特徴とする光磁気記録媒体。(1) A magneto-optical recording medium comprising a resin substrate, a diamond-like carbon film disposed on the substrate, and an amorphous magnetic film disposed on the carbon film.
有することを特徴とする特許請求の範囲第１項記載の光
磁気記録媒体。(2) The magneto-optical recording medium according to claim 1, further comprising a diamond-like carbon film on the amorphous magnetic film.
Åの範囲内の厚さを有することを特徴とする特許請求の
範囲第１項または第２項記載の光磁気記録媒体。(3) The diamond-like carbon film has a thickness of 500 Å to 2000 Å.
3. The magneto-optical recording medium according to claim 1, wherein the magneto-optical recording medium has a thickness within the range of .ANG.
られたものであることを特徴とする特許請求の範囲第１
〜３項のいずれか１項に記載の光磁気記録媒体。(4) Claim 1, wherein the diamond-like carbon film is obtained by a plasma decomposition method.
The magneto-optical recording medium according to any one of items 1 to 3.
ｄＦｅＣｏ、ＴｂＦｅ、ＴｂＣｏ、ＴｂＦｅＣｏ、Ｇｄ
ＴｂＦｅおよびＧｄＴｂＣｏからなる群から選ばれた少
なくとも１種の材料で形成されたものであることを特徴
とする特許請求の範囲第１〜４項のいずれか１項に記載
の光磁気記録媒体。(5) The amorphous magnetic film is made of GdFe, GdCo, G
dFeCo, TbFe, TbCo, TbFeCo, Gd
5. The magneto-optical recording medium according to claim 1, wherein the magneto-optical recording medium is made of at least one material selected from the group consisting of TbFe and GdTbCo.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61081945A JPH0766580B2 (en) | 1986-04-09 | 1986-04-09 | Magneto-optical recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61081945A JPH0766580B2 (en) | 1986-04-09 | 1986-04-09 | Magneto-optical recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62239351A true JPS62239351A (en) | 1987-10-20 |
| JPH0766580B2 JPH0766580B2 (en) | 1995-07-19 |
Family
ID=13760639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61081945A Expired - Lifetime JPH0766580B2 (en) | 1986-04-09 | 1986-04-09 | Magneto-optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0766580B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0237549A (en) * | 1988-07-28 | 1990-02-07 | Semiconductor Energy Lab Co Ltd | Magneto-optical memory medium |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6134747A (en) * | 1984-07-27 | 1986-02-19 | Hitachi Ltd | Photoelectromagnetic multilayered film medium |
-
1986
- 1986-04-09 JP JP61081945A patent/JPH0766580B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6134747A (en) * | 1984-07-27 | 1986-02-19 | Hitachi Ltd | Photoelectromagnetic multilayered film medium |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0237549A (en) * | 1988-07-28 | 1990-02-07 | Semiconductor Energy Lab Co Ltd | Magneto-optical memory medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0766580B2 (en) | 1995-07-19 |
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