JPH0589555A - Information recording and reproducing method - Google Patents
Information recording and reproducing methodInfo
- Publication number
- JPH0589555A JPH0589555A JP1302892A JP1302892A JPH0589555A JP H0589555 A JPH0589555 A JP H0589555A JP 1302892 A JP1302892 A JP 1302892A JP 1302892 A JP1302892 A JP 1302892A JP H0589555 A JPH0589555 A JP H0589555A
- Authority
- JP
- Japan
- Prior art keywords
- magneto
- information
- recording medium
- written
- optical
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
- G11C13/04—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam
- G11C13/06—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam using magneto-optical elements
Landscapes
- Thin Magnetic Films (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光磁気メモリー，磁気記
録，表示素子などにおける情報記録再生方法に関し、特
に光熱エネルギーを用いて情報を書き込み、書き込まれ
た情報を磁気光学効果を用いて読み出す方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing method for a magneto-optical memory, a magnetic recording device, a display device, etc., and more particularly to a method for writing information by using photothermal energy and reading the written information by utilizing a magneto-optical effect. Regarding
【０００２】[0002]
【従来の技術】従来、磁気光学記録媒体としてはＭｎＢ
ｉ，ＭｎＣｕＢｉなどの多結晶体薄膜、ＧｄＣｏ，Ｇｄ
Ｆｅ，ＴｂＦｅ，ＤｙＦｅ，ＧｄＴｂＦｅ，ＴｂＤｙＦ
ｅなどの非晶質薄膜、ＧＩＧなどの単結晶薄膜などが知
られている。これらの薄膜のうち、大面積の薄膜を室温
近傍の温度で製作する成膜姓，信号を小さな光熱エネル
ギーで書込むための書込み効率，書込まれた信号をＳ／
Ｎ比よく読出すための読出し効率などを勘案し、最近で
は前記非晶質薄膜が磁気光学記録媒体として優れている
と考えられている。2. Description of the Related Art Conventionally, MnB is used as a magneto-optical recording medium.
i, MnCuBi or other polycrystalline thin film, GdCo, Gd
Fe, TbFe, DyFe, GdTbFe, TbDyF
Amorphous thin films such as e and single crystal thin films such as GIG are known. Of these thin films, a large-area thin film is manufactured at a temperature near room temperature, writing efficiency for writing a signal with a small photothermal energy, and the written signal is S /
Considering the reading efficiency for reading with a good N ratio, the amorphous thin film has recently been considered to be excellent as a magneto-optical recording medium.
【０００３】[0003]
【発明が解決しようとする課題】然しながら、これ等の
非晶質薄膜においても種々の欠点が指摘されている。例
えば、ＧｂＦｅは保磁力が小さく、記録された情報が不
安定である。またＧｄＦｅ，ＧｄＣｏは磁気的補償点を
利用した書込みを行っており、書込み効率を均一にする
為に製膜の際、膜組成を厳しく管理しなければならない
と言う難点がある。ＴｂＦｅ，ＤｙＦｅ，ＴｂＤｙＦｅ
はキューリー点書込みの為膜組成をそれほど厳しく管理
することはないが、キューリー点が１００℃以下と低い
為に、信号を読出す時にパワーの強い光を用いることが
できないという難点がある。However, various drawbacks have been pointed out in these amorphous thin films. For example, GbFe has a small coercive force, and recorded information is unstable. Further, GdFe and GdCo perform writing using magnetic compensation points, and there is a drawback that the film composition must be strictly controlled during film formation in order to make the writing efficiency uniform. TbFe, DyFe, TbDyFe
However, since the Curie point is not written, the film composition is not so strictly controlled, but the Curie point is as low as 100 ° C. or lower, so that it is difficult to use light with high power when reading a signal.
【０００４】Ｓ／Ｎ比を良く読出す為に、非晶質薄膜の
磁気光学定数を大きくする為の提案としては、特開昭５
６−１２６９０７号公報にＧｄ−Ｔｂ−Ｆｅより成る非
晶質３元合金薄膜が示されている。表１には、従来の磁
気光学薄膜の磁気カー定数とキューリー温度が示されて
いる。As a proposal for increasing the magneto-optical constant of an amorphous thin film in order to read out the S / N ratio well, Japanese Patent Application Laid-Open No. Sho 5 has been proposed.
No. 6-126907 discloses an amorphous ternary alloy thin film made of Gd-Tb-Fe. Table 1 shows the magnetic Kerr constant and Curie temperature of the conventional magneto-optical thin film.
【０００５】[0005]
【表１】 [Table 1]
【０００６】表１より分る様に、磁気カー定数が最も大
きいのはＧｄＴｂＦｅで０．２７度であり、Ｓ／Ｎ比が
安定して読出せるには、磁気カー定数の値として少なく
とも０．２度以上の値が望ましい。そしてＳ／Ｎ比が良
く読出せる為には、磁気カー定数の如き磁気光学定数が
大きければ大きい程良いことは言うまでもない。As can be seen from Table 1, GdTbFe has the largest magnetic Kerr constant of 0.27 degrees, and in order to stably read the S / N ratio, the value of the magnetic Kerr constant should be at least 0. A value of 2 or more is desirable. It is needless to say that the larger the magneto-optical constant such as the magnetic Kerr constant, the better in order to obtain a good S / N ratio.
【０００７】又、キューリー温度は低ければ書込む為の
効率は向上するが、書き込まれた信号が周囲の温度と
か、読出し光により乱されてしまう。従って、磁気変態
温度は使用上の状態を考慮すると１００℃以上〜２００
℃以下位が望ましい。Further, if the Curie temperature is low, the efficiency for writing is improved, but the written signal is disturbed by the ambient temperature or the reading light. Therefore, the magnetic transformation temperature is 100 ° C or higher to 200 or less in consideration of the state of use.
It is desirable that the temperature is below ℃.
【０００８】本発明の目的は、上記従来技術の問題点を
解決し、効率良く、安定に情報を書き込み、且つ、書き
込まれた情報を高いＳ／Ｎ比で読み出すことのできる情
報記録再生方法を提供することにある。An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an information recording / reproducing method capable of efficiently and stably writing information and reading the written information with a high S / N ratio. To provide.
【０００９】[0009]
【課題を解決するための手段】本発明は、膜面に垂直方
向に磁化容易軸を有するＴｂ−Ｆｅ−Ｃｏ三元系非晶質
磁性合金より成る磁気光学記録媒体に、光熱エネルギー
を用いて情報を書き込み、書き込まれた情報を磁気光学
効果を用いて読み出すことによって上記目的を達成する
ものである。The present invention uses photothermal energy for a magneto-optical recording medium made of a Tb-Fe-Co ternary amorphous magnetic alloy having an easy axis of magnetization perpendicular to the film surface. The above object is achieved by writing information and reading the written information using the magneto-optical effect.
【００１０】本発明に用いる磁気光学記録媒体は、膜面
に垂直な方向に磁化容易軸を向けるのに十分な磁気異方
性を持たせる組成として、ＦｅとＣｏとを合わせた原子
比が６０ａｔｏｍ％〜９０ａｔｏｍ％の範囲に存在する
ことが望ましい。The magneto-optical recording medium used in the present invention has a composition in which magnetic anisotropy is sufficient to direct the easy axis of magnetization in a direction perpendicular to the film surface, and the atomic ratio of Fe and Co combined is 60 atom. % To 90 atom% is desirable.
【００１１】また、本発明に用いる磁気光学記録媒体
は、記録された磁気信号が熱に対して安定な状態を保つ
為には、ＦｅとＣｏとを合わせた原子比を１００％とし
た場合、ＣｏがＦｅに対して１％以上の原子比で存在す
ることが望ましい。In the magneto-optical recording medium used in the present invention, in order to keep the recorded magnetic signal stable against heat, if the atomic ratio of Fe and Co is 100%, It is desirable that Co exists in an atomic ratio of 1% or more with respect to Fe.
【００１２】本発明においては、従来になかったＴｂ−
Ｆｅ−Ｃｏの組み合わせの非晶質磁気光学媒体を用いる
ことにより、大きな磁気光学定数が得られたものであ
る。この結果は後述する実施例より明らかな様に、組成
によっては従来知られている最も大きなカー回転角であ
るＧｄＴｂＦｅの０．２７度を大幅に凌ぐ値を有するも
のである。In the present invention, Tb-
A large magneto-optical constant was obtained by using an amorphous magneto-optical medium of a combination of Fe and Co. As is clear from the examples described below, this result has a value that greatly exceeds 0.27 degrees of GdTbFe, which is the largest Kerr rotation angle conventionally known, depending on the composition.
【００１３】又、本発明に用いられるＴｂ−Ｆｅ−Ｃｏ
系非晶質３元合金の磁気光学記録媒体は、磁化容易軸が
膜面に垂直な方向に向けられるだけに十分な磁気異方性
を持たなければならない。この為には、まず薄膜を非晶
質で構成する必要がある。これは、一般には室温近傍以
下の温度に保持された基体上にスパッターリング法、あ
るいは真空蒸着法などによって薄膜を製膜することによ
って達成される。又、十分な磁気異方性を持たせる為の
組成としては、ＴｂとＦｅとＣｏとの組成をＴｂ
1-X（Ｆｅ1-YＣｏY）Xとすると、 ０．６≦Ｘ≦０．９ であることが望ましい。The Tb-Fe-Co used in the present invention
A magneto-optical recording medium of a system amorphous ternary alloy must have sufficient magnetic anisotropy so that the easy axis of magnetization is oriented in the direction perpendicular to the film surface. For this purpose, the thin film must first be made amorphous. This is generally achieved by forming a thin film on a substrate kept at a temperature of around room temperature or lower by a sputtering method, a vacuum vapor deposition method, or the like. As a composition for providing sufficient magnetic anisotropy, a composition of Tb, Fe and Co is Tb.
If 1-X (Fe 1-Y Co Y ) X , 0.6 ≦ X ≦ 0.9 is desirable.
【００１４】更に、熱安定性を持たせる為の組成として
は、 ０．０１≦Ｙ＜１．０ であることが望ましい。即ちＦｅとＣｏの原子を合わせ
て１．０としたとき、その中でＣｏが少なくとも０．０
１以上存在すれば、キューリー温度が約１００℃以上に
なり、熱安定性が良くなる。Further, the composition for imparting thermal stability is preferably 0.01 ≦ Y <1.0. That is, when the total number of Fe and Co atoms is 1.0, Co is at least 0.0
If 1 or more is present, the Curie temperature is about 100 ° C. or higher, and the thermal stability is improved.
【００１５】更に磁化を安定して膜面に垂直な方向に向
かせるには、膜厚は１００Å以上にする必要がある。Further, in order to stabilize the magnetization and direct it in the direction perpendicular to the film surface, the film thickness must be 100 Å or more.
【００１６】[0016]
【実施例】以下に本発明に係る実施例１〜３を示すが、
この実施例の結果をまとめて示したものが図１，図２で
ある。図１はＴｂ0.21（Ｆｅ1-YＣｏY）0.79の組成にお
いて、Ｃｏの量に対する磁気カー定数の関係を示すもの
で、縦軸に磁気カー定数，横軸にＣｏの量が取られてい
る。図２は、Ｔｂ0.21（Ｆｅ1-YＣｏY）0.79の組成にお
いて、Ｃｏの量に対するキューリー温度の関係を示すも
ので、縦軸にキューリー温度，横軸にＣｏの量が取られ
ている。EXAMPLES Examples 1 to 3 according to the present invention will be shown below.
The results of this example are shown together in FIGS. 1 and 2. FIG. 1 shows the relationship between the magnetic Kerr constant and the amount of Co in the composition of Tb 0.21 (Fe 1-Y Co Y ) 0.79 , where the vertical axis represents the magnetic Kerr constant and the horizontal axis represents the amount of Co. . FIG. 2 shows the relationship between the Curie temperature and the amount of Co in the composition of Tb 0.21 (Fe 1 -Y Co Y ) 0.79. The Curie temperature is plotted on the vertical axis and the amount of Co is plotted on the horizontal axis.
【００１７】（実施例１）高周波スパッター装置におい
て、２５ｍｍ角の白板ガラスを基板にし、ターゲットと
してＴｂ0.21（Ｆｅ0.95Ｃｏ0.05）0.79となるようにア
ークメルトしたものを使用し、基板とターゲットとの間
隔が５０ｍｍとなるようにセットした後、３×１０-7Ｔ
ｏｒｒ以下になるまで真空排気した。この後、真空槽に
９９．９９９％のアルゴン（Ａｒ）ガスを５×１０-4Ｔ
ｏｒｒまで導入し、真空排気系のメインバルブを操作す
ることによりＡｒ圧を５×１０-2Ｔｏｒｒにする。高周
波電源よりターゲットへ２Ｗ／ｃｍ2の割合で電力を投
入して製膜を行った。この様にしてできた膜厚１５００
Åの膜は、膜面に垂直な方向に磁気容易軸を有し、また
Ｘ線的に非晶質であり、磁気カー定数は０．２度であっ
た。これはＴｂ0.21Ｆｅ0.79の磁気カー定数０．１８度
より大きかった。またキューリー温度はＴｂ0.21（Ｆｅ
0.95Ｃｏ0.05）0.79で１２０℃であり、Ｔｂ0.21Ｆｅ
0.79のキューリー温度９１℃より２９℃高かった。この
ようにＦｅをＣｏで５％置換することにより磁気カー定
数，キューリー温度とも改善することができた。(Embodiment 1) In a high frequency sputtering apparatus, a white plate glass of 25 mm square was used as a substrate, and an arc- melted Tb 0.21 (Fe 0.95 Co 0.05 ) 0.79 was used as a target. After setting so that the space is 50 mm, 3 × 10 -7 T
The chamber was evacuated to or or less. Thereafter, 99.999% argon (Ar) gas was added to the vacuum chamber at 5 × 10 −4 T.
The pressure of Ar is adjusted to 5 × 10 -2 Torr by introducing the gas up to orr and operating the main valve of the vacuum exhaust system. A film was formed by applying power from the high frequency power source to the target at a rate of 2 W / cm 2 . Film thickness 1500 made in this way
The film of Å had a magnetic easy axis in the direction perpendicular to the film surface, was X-ray amorphous, and had a magnetic Kerr constant of 0.2 degree. This was larger than the magnetic Kerr constant of 0.18 degree of Tb 0.21 Fe 0.79 . The Curie temperature is Tb 0.21 (Fe
0.95 Co 0.05 ) 0.79 at 120 ° C, Tb 0.21 Fe
The Curie temperature of 0.79 was 29 ° C higher than 91 ° C. Thus, by substituting Fe by 5% for Co, both the magnetic Kerr constant and the Curie temperature could be improved.
【００１８】（実施例２）スパッター用ターゲットの組
成をＴｂ0.21（Ｆｅ0.90Ｃｏ0.10）0.79として実施例１
と全く同様にして製膜した。この膜は膜面の垂直方向に
磁化容易軸を有し、かつＸ線的に非晶質であり磁気カー
定数，キューリー温度を測定したところ、それぞれ０．
２８度，１３５℃であった。この様にＦｅをＣｏで１０
％置換した結果、Ｔｂ0.21Ｆｅ0.79の特性よりも磁気カ
ー定数で０．１度，キューリー温度で４４℃改善され
た。(Embodiment 2) The composition of the target for sputtering is Tb 0.21 (Fe 0.90 Co 0.10 ) 0.79 and the embodiment 1 is used.
A film was formed in exactly the same manner as. This film has an axis of easy magnetization in the direction perpendicular to the film surface and is amorphous in X-ray. The magnetic Kerr constant and Curie temperature were measured to be 0.
It was 28 degrees and 135 ° C. In this way, Fe is 10 with Co
%, The magnetic Kerr constant was improved by 0.1 degree and the Curie temperature was improved by 44 ° C. as compared with the characteristics of Tb 0.21 Fe 0.79 .
【００１９】（実施例３）スパッター用ターゲットの組
成をＴｂ0.21（Ｆｅ0.85Ｃｏ0.15）0.79として実施例１
と全く同様にして製膜した。この膜は非晶質であり、ま
た膜面の垂直方向に磁化容易軸を有し、磁気カー定数は
０．３５度，キューリー温度は１５０℃であった。この
様にＦｅをＣｏで１５％置換することにより、Ｔｂ0.21
Ｆｅ0.79よりも磁気カー定数で０．７度，キューリー温
度で５９℃改善された。(Embodiment 3) The composition of the sputtering target is Tb 0.21 (Fe 0.85 Co 0.15 ) 0.79 and the composition of Embodiment 1
A film was formed in exactly the same manner as. This film was amorphous, had an easy axis of magnetization in the direction perpendicular to the film surface, had a magnetic Kerr constant of 0.35 degrees and a Curie temperature of 150 ° C. By substituting 15% of Fe with Co, Tb 0.21
The magnetic Kerr constant was improved by 0.7 degrees and the Curie temperature was improved by 59 ° C. compared with Fe 0.79 .
【００２０】[0020]
【発明の効果】以上説明したように、本発明の情報記録
再生方法は、膜面に垂直方向に磁化容易軸を有するＴｂ
−Ｆｅ−Ｃｏ三元系非晶質磁性合金より成る磁気光学記
録媒体に、光熱エネルギーを用いて情報を書き込み、書
き込まれた情報を磁気光学効果を用いて読み出すように
したので、従来得られなかった大きい磁気光学効果が得
られ、高いＳ／Ｎ比で読み出しが可能であり、また、媒
体が適度のキュリー温度を有するので、情報を効率良
く、安定に書き込むことができるようになった。As described above, according to the information recording / reproducing method of the present invention, Tb having the easy axis of magnetization in the direction perpendicular to the film surface is used.
Since information is written in the magneto-optical recording medium made of a -Fe-Co ternary amorphous magnetic alloy by using photothermal energy and the written information is read out by using the magneto-optical effect, it has not been obtained conventionally. In addition, a large magneto-optical effect can be obtained, reading can be performed with a high S / N ratio, and since the medium has an appropriate Curie temperature, information can be efficiently and stably written.
【図１】本発明に用いる磁気光学記録媒体の一組成にお
けるＣｏの量と磁気カー定数との関係を示す図である。FIG. 1 is a diagram showing the relationship between the amount of Co and the magnetic Kerr constant in one composition of a magneto-optical recording medium used in the present invention.
【図２】本発明に用いる磁気光学記録媒体の一組成にお
けるＣｏの量とキュリー温度との関係を示す図である。FIG. 2 is a diagram showing the relationship between the amount of Co and the Curie temperature in one composition of the magneto-optical recording medium used in the present invention.
Claims (1)
ｂ−Ｆｅ−Ｃｏ三元系非晶質磁性合金より成る磁気光学
記録媒体に、光熱エネルギーを用いて情報を書き込み、
書き込まれた情報を磁気光学効果を用いて読み出す情報
記録再生方法。1. A T having an easy axis of magnetization perpendicular to the film surface.
Information is written to a magneto-optical recording medium made of a b-Fe-Co ternary amorphous magnetic alloy by using photothermal energy,
An information recording / reproducing method for reading written information by using a magneto-optical effect.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1302892A JPH0589555A (en) | 1992-01-28 | 1992-01-28 | Information recording and reproducing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1302892A JPH0589555A (en) | 1992-01-28 | 1992-01-28 | Information recording and reproducing method |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4241182A Division JPS58159252A (en) | 1982-03-17 | 1982-03-17 | Magnetooptic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0589555A true JPH0589555A (en) | 1993-04-09 |
Family
ID=11821688
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1302892A Pending JPH0589555A (en) | 1992-01-28 | 1992-01-28 | Information recording and reproducing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0589555A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5873746A (en) * | 1981-10-27 | 1983-05-04 | Kokusai Denshin Denwa Co Ltd <Kdd> | Photomagnetic recording medium |
-
1992
- 1992-01-28 JP JP1302892A patent/JPH0589555A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5873746A (en) * | 1981-10-27 | 1983-05-04 | Kokusai Denshin Denwa Co Ltd <Kdd> | Photomagnetic recording medium |
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