JPH0756691B2 - Magnetic thin film recording medium - Google Patents
Magnetic thin film recording mediumInfo
- Publication number
- JPH0756691B2 JPH0756691B2 JP58209290A JP20929083A JPH0756691B2 JP H0756691 B2 JPH0756691 B2 JP H0756691B2 JP 58209290 A JP58209290 A JP 58209290A JP 20929083 A JP20929083 A JP 20929083A JP H0756691 B2 JPH0756691 B2 JP H0756691B2
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- coercive force
- thin film
- amorphous alloy
- magnetic thin
- 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
- 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
-
- 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
Description
【発明の詳細な説明】 本発明は主として垂直熱磁気記録方式に用いられる磁性
薄膜記録媒体に関するものである。The present invention mainly relates to a magnetic thin film recording medium used in a perpendicular thermomagnetic recording system.
垂直熱磁気記録方式とはガラス，セラミックス，プラス
チック等の非磁性体からなる基材上に磁性薄膜からなる
垂直磁化可能な記録媒体を形成せしめ、該記録媒体表面
にレーザ光線を照射して照射部分をキュリー点近傍、も
しくは補償点近傍に加熱し、この部分を含む該記録媒体
領域にバイアス磁界をかけることによってこの部分の磁
化を他の部分とは逆の方向に配向せしめることにより熱
磁気的に情報の書き込みを行い、該情報の読み出しには
別の直線偏光したレーザ光線を該記録媒体表面にあて、
該表面からの反射光を検光子を介して光学的に検出する
ことによる。即ち該レーザ光線は情報が書き込まれてい
る該記録媒体位置において、力−効果によって偏光面が
回転するので、読み出しの際は上記偏光面の回転を検出
することになる。上記偏光面の回転角度を力−回転角Θ
ｋという。The perpendicular thermomagnetic recording method is a method in which a perpendicularly magnetizable recording medium made of a magnetic thin film is formed on a substrate made of a non-magnetic material such as glass, ceramics, plastics, etc. Is heated near the Curie point or near the compensation point, and a bias magnetic field is applied to the recording medium area including this portion to orient the magnetization of this portion in the direction opposite to that of the other portion, thereby thermomagnetically. For writing information, for reading the information, another linearly polarized laser beam is applied to the surface of the recording medium,
By optically detecting the reflected light from the surface via an analyzer. That is, since the plane of polarization of the laser beam rotates due to the force-effect at the position of the recording medium where the information is written, the rotation of the plane of polarization is detected when reading. The rotation angle of the above-mentioned polarization plane is the force-rotation angle Θ
called k.
従来から上記記録媒体を構成する磁性薄膜の材料として
はTb−Fe非晶質合金、Dy−Fe非晶質合金、Gd−Fe非晶質
合金、Gd−Co非晶質合金等がある。そして該磁性薄膜表
面は通常SiO2,SnO2等の透明な金属酸化物等からなる酸
化物保護膜によって被覆保護されている。しかし上記非
晶質合金は長期間にわたる上記酸化物保護膜との接触に
よって酸化され保磁力が変動し、記録媒体の磁気記録特
性が変化するという問題がある。Conventionally, as a material of the magnetic thin film forming the recording medium, there are Tb-Fe amorphous alloy, Dy-Fe amorphous alloy, Gd-Fe amorphous alloy, Gd-Co amorphous alloy and the like. The surface of the magnetic thin film is usually covered and protected by an oxide protective film made of a transparent metal oxide such as SiO 2 or SnO 2 . However, there is a problem that the amorphous alloy is oxidized by contact with the oxide protective film for a long period of time, the coercive force is changed, and the magnetic recording characteristics of the recording medium are changed.
本発明は上記従来の問題点を解決することを目的とし、
保護膜としては実質的に非酸化性の材料が用いられる。
このような材料としてはAlN,TiN,VN,NbN,TaN等の金属窒
化物、TiC,TaC,ZrC,WC,MOC等の金属炭化物等が主として
用いられるが、Al2O3,Cr2O3,WO3等の非酸化性の金属酸
化物も用いられ得る。本発明は、上記非酸化性の材料の
内、金属炭化物を用いたことを特徴とする。The present invention aims to solve the above conventional problems,
A substantially non-oxidizing material is used as the protective film.
As such materials, metal nitrides such as AlN, TiN, VN, NbN and TaN, metal carbides such as TiC, TaC, ZrC, WC and MOC are mainly used.Al 2 O 3 , Cr 2 O 3 Also, non-oxidizing metal oxides such as WO 3 can be used. The present invention is characterized by using a metal carbide among the above non-oxidizing materials.
本発明の非晶質合金層としては通常Tb−Fe非晶質合金,D
y−Fe非晶質合金,Gd−Fe非晶質合金,Gd−Co非晶質合金,
Gd−Fe−Co非晶質合金,Gd−Fe−Bi非晶質合金等が用い
られる。The amorphous alloy layer of the present invention is usually Tb-Fe amorphous alloy, D
y-Fe amorphous alloy, Gd-Fe amorphous alloy, Gd-Co amorphous alloy,
Gd-Fe-Co amorphous alloy, Gd-Fe-Bi amorphous alloy, etc. are used.
非晶質合金層は書込みパワーを小さくするため書込み速
度を大とするため、良好なSN比を得るために相互に交換
結合している低キュリー点を有する高保磁力層と高キュ
リー点を有する低保磁力層とからなる二層構造にするこ
とが望ましい。Since the amorphous alloy layer increases the writing speed to reduce the writing power, the high coercive force layer having a low Curie point and the low Curie point having a high Curie point are exchange-coupled to each other in order to obtain a good SN ratio. It is desirable to have a two-layer structure including a coercive force layer.
上記二層構造の非晶質合金層を有する記録媒体の一実施
例を第１図に示す。図に示す記録媒体（10）において
（１）は前記したようなガラス，セラミックス、あるい
はポリメチルメタクリレート等のプラスチック等の主と
して透明な非磁性体からなる基材であり本実施例では厚
さ1.2mmのガラスを用いた。（２）は垂直磁化可能な高
キュリー点を有する低保磁力層であり、（３）は低キュ
リー点を有する高保磁力層であり、（４）は厚さ1000A
のTiNからなる保護膜である。そして高保磁力層（３）
としては厚さ500AのTb0.23Fe0.77非晶質合金を用い、低
保磁力層（２）としては厚さ300AのGd0.20Fe0.80非晶質
合金が材料として用いた。なお低保磁力層（２）と高保
磁力層（３）とは交換結合されている。また一般的には
膜厚としては基材（１）は1.0〜1.5mm程度、高保磁力層
（３）は200〜400A程度、低保磁力層（２）は400〜600A
程度、保護膜（４）は800〜1200A程度のものが用いられ
る。An embodiment of a recording medium having the above-mentioned two-layer structure amorphous alloy layer is shown in FIG. In the recording medium (10) shown in the figure, (1) is a base material mainly made of a transparent non-magnetic material such as glass, ceramics, or plastic such as polymethylmethacrylate as described above, and a thickness of 1.2 mm in this embodiment. Of glass was used. (2) is a low coercive force layer having a high Curie point capable of perpendicular magnetization, (3) is a high coercive force layer having a low Curie point, and (4) is a thickness of 1000A.
Is a protective film made of TiN. And a high coercive force layer (3)
A Tb 0.23 Fe 0.77 amorphous alloy with a thickness of 500 A was used as the material, and a Gd 0.20 Fe 0.80 amorphous alloy with a thickness of 300 A was used as a material for the low coercive force layer (2). The low coercive force layer (2) and the high coercive force layer (3) are exchange-coupled. Generally, the base material (1) has a thickness of about 1.0 to 1.5 mm, the high coercive force layer (3) has a thickness of about 200 to 400 A, and the low coercive force layer (2) has a thickness of 400 to 600 A.
The protective film (4) having a thickness of about 800 to 1200 A is used.
第２図において例えば気体レーザ，半導体レーザ等から
出力１〜100mWで近赤外ないしは可視領域の波長の光を
発振せしめ、該光は対物レンズ（５）を通して記録媒体
（10）表面にスポットを結像し、該記録媒体（10）を局
部的に低保磁力層（２）のキュリー点近傍に加熱する。
該加熱点を含む領域に磁界発生コイル（６）によって、
50〜500Oe程度のバイアス磁界をかければ加熱点の高保
磁力層（３）は該バイアス磁界および／または周辺の磁
化からの漏れ磁界によって他の部分とは反対方向に磁化
される。かくして上記スポットを除去すれば高保磁力層
（３）には情報が書き込まれ、同時に該高保磁力層
（３）に交換結合している低保磁力層（２）にも情報が
書き込まれる。In FIG. 2, for example, a gas laser, a semiconductor laser, or the like oscillates light having a wavelength in the near infrared or visible region with an output of 1 to 100 mW, and the light forms a spot on the surface of the recording medium (10) through the objective lens (5). Then, the recording medium (10) is locally heated near the Curie point of the low coercive force layer (2).
By the magnetic field generating coil (6) in the area including the heating point,
When a bias magnetic field of about 50 to 500 Oe is applied, the high coercive force layer (3) at the heating point is magnetized in the direction opposite to the other parts due to the bias magnetic field and / or the leakage magnetic field from the peripheral magnetization. Thus, by removing the spots, information is written in the high coercive force layer (3), and at the same time, information is also written in the low coercive force layer (2) exchange-coupled to the high coercive force layer (3).
第３図において例えば別のレーザから直線偏光した光を
ハーフミラー（７）を介し、対物レンズ（５）を通して
記録体（10）の基材（１）側からスポットとして結像せ
しめ、その反射光は対物レンズ（５）を通しハーフミラ
ー（７）を介して検光子（８）を通してフォトダイオー
ド（９）で検出する。読み出しは情報が書き込まれてい
る低保磁力層（２）の情報書き込み位置において前記し
たように力−効果によって該光の偏光面が回転するのを
検出することによって行われる。In FIG. 3, for example, linearly polarized light from another laser is imaged as a spot from the substrate (1) side of the recording medium (10) through the objective lens (5) through the half mirror (7), and the reflected light Is detected by a photodiode (9) through an objective lens (5), a half mirror (7) and an analyzer (8). The reading is performed by detecting the rotation of the polarization plane of the light due to the force-effect as described above at the information writing position of the low coercive force layer (2) where the information is written.
本発明の保護膜は上記したように非酸化性材料からなる
ので非晶質合金層を酸化せず、磁気記録特性は長期にわ
たって安定である。該安定性は第４図において示され
る。第４図に関する実験は、上記第１図に示す実施例の
磁性薄膜記録媒体（10）および比較例として該記録媒体
（10）の保護膜（４）を厚さ1000AのSiO2とし，他は第
１図に示す構成からなる記録媒体について行われ、保護
膜（４）と接触する高保磁力層（３）の保磁力Hcの経時
的変化を測定した。Since the protective film of the present invention is made of a non-oxidizing material as described above, it does not oxidize the amorphous alloy layer and the magnetic recording characteristics are stable for a long period of time. The stability is shown in FIG. In the experiment relating to FIG. 4, the protective film (4) of the magnetic thin film recording medium (10) of the embodiment shown in FIG. 1 and the recording medium (10) as a comparative example was SiO 2 having a thickness of 1000 A, and the others were The recording medium having the structure shown in FIG. 1 was used to measure the change with time of the coercive force Hc of the high coercive force layer (3) in contact with the protective film (4).
第４図にみるように点線で示す比較例、即ち従来の構成
では保護力Hcは経時とともに急激に低下するが実線で示
す本発明の実施例ではHc経時変化は殆んどない。As shown in FIG. 4, in the comparative example shown by the dotted line, that is, in the conventional configuration, the protective force Hc sharply decreases with time, but in the embodiment of the present invention shown by the solid line, there is almost no change in Hc with time.
第１図は本発明の磁性薄膜記録媒体の一実施例の断面
図、第２図は情報書き込み時の説明図、第３図は情報読
み出し時の説明図、第４図は保磁力Hc（KOe）の経時変
化（month）を示すグラフである。 図中、（１）……基板、（２）……低保磁力層、（３）
……高保磁力層、（４）……保護膜FIG. 1 is a cross-sectional view of an embodiment of a magnetic thin film recording medium of the present invention, FIG. 2 is an explanatory diagram for writing information, FIG. 3 is an explanatory diagram for reading information, and FIG. 4 is a coercive force Hc (KOe Is a graph showing a change over time (month) of FIG. In the figure, (1) ... Substrate, (2) ... Low coercive force layer, (3)
…… High coercive force layer, (4) …… Protective film
───────────────────────────────────────────────────── フロントページの続き 審判の合議体 審判長 藤田 孝司 審判官 犬飼 宏 審判官 上野 信 (56)参考文献 特開 昭59−168950（ＪＰ，Ａ) 特開 昭58−73746（ＪＰ，Ａ) ─────────────────────────────────────────────────── --Continued from the front page Judgment panel for referees Chief referee Takashi Fujita Referee Inquiry Hiroshi Inukai Referee Shin Ueno (56) References JP-A-59-168950 (JP, A) JP-A-58-73746 (JP, A)
Claims (1)
形成された保護膜とからなる磁性薄膜記録媒体におい
て、前記保護膜の材料として金属炭化物を用いたことを
特徴とする磁性薄膜記録媒体。1. A magnetic thin film recording medium comprising an amorphous alloy layer and a protective film formed on the surface of the amorphous alloy layer, wherein a metal carbide is used as a material of the protective film. Magnetic thin film recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58209290A JPH0756691B2 (en) | 1983-11-07 | 1983-11-07 | Magnetic thin film recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58209290A JPH0756691B2 (en) | 1983-11-07 | 1983-11-07 | Magnetic thin film recording medium |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22872292A Division JPH0644626A (en) | 1992-08-27 | 1992-08-27 | Magnetic thin film recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60101744A JPS60101744A (en) | 1985-06-05 |
| JPH0756691B2 true JPH0756691B2 (en) | 1995-06-14 |
Family
ID=16570492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58209290A Expired - Lifetime JPH0756691B2 (en) | 1983-11-07 | 1983-11-07 | Magnetic thin film recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756691B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60163248A (en) * | 1984-02-03 | 1985-08-26 | Kyocera Corp | Magnetic recording element |
| JPS62137754A (en) * | 1985-12-09 | 1987-06-20 | Canon Inc | Magneto-optical reproduction method |
| JPS6314342A (en) * | 1986-07-05 | 1988-01-21 | Canon Inc | Magneto-optical recording medium |
| US6261707B1 (en) | 1992-11-06 | 2001-07-17 | Sharp Kabushiki Kaisha | Magneto-optical recording medium and recording and reproducing method and optical head designed for the magneto-optical recording medium |
| US6665235B2 (en) | 1992-11-06 | 2003-12-16 | Sharp Kabushiki Kaisha | Magneto-optical recording medium and recording and reproducing method and optical head designed for the magneto-optical recording medium |
Family Cites Families (2)
| 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 |
| JPS59168950A (en) * | 1983-03-17 | 1984-09-22 | Ricoh Co Ltd | magneto-optical recording medium |
-
1983
- 1983-11-07 JP JP58209290A patent/JPH0756691B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60101744A (en) | 1985-06-05 |
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