JPS6131532B2 - - Google Patents
Info
- Publication number
- JPS6131532B2 JPS6131532B2 JP54150953A JP15095379A JPS6131532B2 JP S6131532 B2 JPS6131532 B2 JP S6131532B2 JP 54150953 A JP54150953 A JP 54150953A JP 15095379 A JP15095379 A JP 15095379A JP S6131532 B2 JPS6131532 B2 JP S6131532B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic recording
- layer
- recording layer
- magnetic
- recording medium
- 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
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
Description
【発明の詳細な説明】
本発明は、磁気カー効果によつて記録の読み出
しが行なわれる垂直磁化記録用磁気記録媒体に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium for perpendicular magnetization recording in which recording is read out using the magnetic Kerr effect.
磁気カー効果を利用して情報の読み出しが行な
われる磁気記録媒体としては、情報の記録が密に
行なえること、磁気カー効果が大きくなること等
から支持体と垂直な方向に磁化容易軸を有する垂
直磁化膜を備えた磁気記録媒体が通常使用されて
いる。この磁気記録媒体への情報の書き込みは、
通常磁気記録層を予め同一向きに一様に垂直磁化
し、この磁気記録層に垂直磁化膜による反磁場ま
たは永久磁石等によつて上記垂直磁化の向きと反
対の向きの磁場をかけるとともに、磁気記録層を
情報を担持する光に露光し、露光領域の磁化の向
きを反転することによつて行なわれる。 A magnetic recording medium from which information is read using the magnetic Kerr effect has an axis of easy magnetization perpendicular to the support because information can be recorded densely and the magnetic Kerr effect is large. Magnetic recording media with perpendicularly magnetized films are commonly used. Writing information to this magnetic recording medium is
Normally, the magnetic recording layer is uniformly perpendicularly magnetized in the same direction in advance, and a magnetic field is applied to this magnetic recording layer in the opposite direction to the perpendicular magnetization using a demagnetizing field from a perpendicularly magnetized film or a permanent magnet. This is done by exposing the recording layer to information-carrying light and reversing the direction of magnetization in the exposed areas.
また、この磁気記録媒体からの記録の読み出し
は、磁気記録層に偏光を当て、この偏光が磁気記
録層によつて反射されるときに生ずる磁気カー効
果による旋光作用（カー回転）を測定することに
よつて行なわれている。 In addition, reading data from this magnetic recording medium involves applying polarized light to the magnetic recording layer and measuring the optical rotation (Kerr rotation) due to the magnetic Kerr effect that occurs when this polarized light is reflected by the magnetic recording layer. It is carried out by.
ところが、このように光を磁気記録層に当てて
記録の読み出しを行なうときは、この光の保持す
る熱が磁気記録層に蓄積され、この熱が記録層に
おける磁化の大きさを低下させる。カー回転角は
一般に磁化の大きさに比例し、Ｓ／Ｎ比はカー回
転角に比例するので上記の様に読み出し光が記録
層の温度を上昇させることは、Ｓ／Ｎ比を低下さ
せることになるので好ましくない。 However, when reading data by shining light onto the magnetic recording layer in this way, the heat held by this light is accumulated in the magnetic recording layer, and this heat reduces the magnitude of magnetization in the recording layer. The Kerr rotation angle is generally proportional to the magnitude of magnetization, and the S/N ratio is proportional to the Kerr rotation angle, so increasing the temperature of the recording layer by the readout light as described above will decrease the S/N ratio. This is not desirable because it becomes
そこで本発明は、上記した蓄積熱の影響が比較
的小さい磁気記録媒体を提供することを目的とす
るものである。 SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic recording medium in which the influence of the above-mentioned accumulated heat is relatively small.
本発明による磁気記録媒体は、磁気記録層とし
ててアモルフアス磁性薄膜を有し、磁気カー効果
によつて記録の読み出しが行なわれる垂直磁化記
録用磁気記録媒体であつて、上記記録層に隣接し
て熱の良導体からなる熱分散層を配置し、この熱
分散層に上記蓄積熱を拡散して上記記録層の温度
が上昇し難いように構成したことを特徴とするも
のである。 The magnetic recording medium according to the present invention is a magnetic recording medium for perpendicular magnetization recording, which has an amorphous magnetic thin film as a magnetic recording layer, and in which recording is read out by the magnetic Kerr effect, and the magnetic recording medium has an amorphous magnetic thin film as a magnetic recording layer. The present invention is characterized in that a heat dispersion layer made of a good thermal conductor is disposed, and the accumulated heat is diffused into the heat dispersion layer so that the temperature of the recording layer does not easily rise.
基体として銅等の金属の良熱伝導体を用いると
本発明の様に良熱伝導層を設ける必要はなくなる
が、金属は本発明で用いる樹脂等に比べ平滑な表
面を有する大面積を得にくく重く高価な欠点があ
る。 If a good thermal conductor such as copper is used as the substrate, there is no need to provide a good thermal conductive layer as in the present invention, but it is difficult to obtain a large area with a smooth surface with metal compared to the resin used in the present invention. It has the disadvantage of being heavy and expensive.
一方、樹脂は上記の欠点はないが熱伝導が非常
に悪く光を照射した場合磁気記録層が温度上昇し
易い欠点を有している。更に遷移金属−希土類ア
モルフアス磁性薄膜は基体上に形成される際の内
部応力によつて垂直磁化性を有するようになる場
合が多く、その為基体として軟かい樹脂を用いる
とこの内部応力が生ぜず良好な垂直磁化膜の形成
が非常に困難であるという欠点を有している。 On the other hand, although resin does not have the above-mentioned drawbacks, it has very poor thermal conductivity and has the drawback that the temperature of the magnetic recording layer tends to rise when irradiated with light. Furthermore, transition metal-rare earth amorphous magnetic thin films often have perpendicular magnetization due to internal stress when they are formed on a substrate, so if a soft resin is used as the substrate, this internal stress will not occur. It has the disadvantage that it is very difficult to form a good perpendicular magnetization film.
本発明により樹脂と良熱伝導体からなる層を組
み合せることで初めて大面積にわたる平滑な表面
を得られ、軽く、安価であり良好な垂直磁化膜を
有し、読み出し時にＳ／Ｎ比が高い記録媒体を得
ることができる。 According to the present invention, a smooth surface over a large area can be obtained for the first time by combining layers made of resin and a good thermal conductor, and it is lightweight, inexpensive, has a good perpendicular magnetization film, and has a high S/N ratio during readout. A recording medium can be obtained.
本発明において、磁気記録層を構成するアモル
フアス磁性薄膜は、アモルフアスRE（希土類）−
TM（遷移金属）合金系等によつて作成される。
これを磁気記録層の材料として用いる理由は、キ
ユリー温度（TC）、補償温度（Ｔ comp）が低
いため高感度であること、大面積化が可能である
こと、垂直磁化が可能であり、粒界がないため高
密度記録ができることおよび安価であること等が
あげられる。アモルフアスRE−TM合金は、例
えばREとしてGd，Tb，Eu，Dy，Ho，Erを、
TMとしてFe，Coを用いてそれらの任意の組合
せの合金およびこの合金にＹ，Bi，Mo，Au，
Ag，Cr，Ni，Nb等の不純物を混入させたもので
ある。これらの不純物は、カー回転角の増加や磁
気記録層の熱安定性をよくする目的等のために用
いられる。磁気記録層はスパツタリング、イオン
プレーテイング、熱蒸着等によつて形成される。 In the present invention, the amorphous magnetic thin film constituting the magnetic recording layer is amorphous RE (rare earth)-
Created from TM (transition metal) alloys, etc.
The reasons why this is used as a material for the magnetic recording layer are that it has high sensitivity due to its low Kyrie temperature (TC) and compensation temperature (T comp), that it can be made into a large area, that it can be perpendicularly magnetized, and that it has a low grain size. Because there is no field, high-density recording is possible and it is inexpensive. Amorphous RE-TM alloys include, for example, Gd, Tb, Eu, Dy, Ho, Er as RE,
Alloys with arbitrary combinations of Fe and Co using Fe and Co as TM, and Y, Bi, Mo, Au,
It contains impurities such as Ag, Cr, Ni, and Nb. These impurities are used for purposes such as increasing the Kerr rotation angle and improving the thermal stability of the magnetic recording layer. The magnetic recording layer is formed by sputtering, ion plating, thermal evaporation, or the like.
また熱分散層に使用される熱の良導体としては
Cu，Ag等で代表される単体金属、あるいはこれ
らの合金、金属間化合物、Si，Ge等の半導体が
ある。熱分散層もスパツタリング、イオンプレー
テイング、熱蒸着、メツキ等によつて形成するこ
とができる。また基体としてはポリエチレンテレ
フタレート等の樹脂が用いられる。 Also, as a good thermal conductor used in the heat dispersion layer,
There are single metals such as Cu and Ag, alloys of these metals, intermetallic compounds, and semiconductors such as Si and Ge. The heat dispersion layer can also be formed by sputtering, ion plating, thermal evaporation, plating, etc. Further, a resin such as polyethylene terephthalate is used as the base.
以下添付図面を参照して本発明の磁気記録媒体
について実施例により説明する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS The magnetic recording medium of the present invention will be described below by way of examples with reference to the accompanying drawings.
第１図は、第１の実施例による磁気記録媒体の
一部断面図である。 FIG. 1 is a partial cross-sectional view of a magnetic recording medium according to a first embodiment.
第１図において、符号１は基体を示し、この基
体は例えばプラスチツクで形成されている。この
基体１の上には、熱の良導体である熱分散層２が
配されており、この熱分散層２の上にはアモルフ
アスRE−TM系の合金で形成された磁気記録層
３が設けられている。この磁気記録媒体におい
て、記録書込光４、および記録読出用の光５は共
に磁気記録層３の上面から照射される。上記熱分
散層２の厚さは、記録媒体の厚さがあまり厚くな
らないような範囲で選択される。 In FIG. 1, reference numeral 1 designates a base body, which is made of plastic, for example. A heat dispersion layer 2, which is a good conductor of heat, is disposed on the base 1, and a magnetic recording layer 3 made of an amorphous RE-TM alloy is disposed on the heat dispersion layer 2. ing. In this magnetic recording medium, both the recording/writing light 4 and the recording/reading light 5 are irradiated from the upper surface of the magnetic recording layer 3 . The thickness of the heat dispersion layer 2 is selected within a range such that the thickness of the recording medium does not become too thick.
記録読出の際、上記したような本発明による磁
気記録媒体（予め垂直磁化記録がされている）に
記録読出用の偏光を当てると、この光による熱は
磁気記録層から熱分散層２に分散され、磁気記録
層３に熱が蓄積されることがない。 During recording and reading, when polarized light for recording and reading is applied to the magnetic recording medium according to the present invention (previously recorded with perpendicular magnetization) as described above, the heat generated by this light is dispersed from the magnetic recording layer to the heat dispersion layer 2. Therefore, heat is not accumulated in the magnetic recording layer 3.
第２図は、本発明の第２の実施例による磁気記
録媒体の一部断面図である。 FIG. 2 is a partial cross-sectional view of a magnetic recording medium according to a second embodiment of the present invention.
この実施例においては、基体１は透明な
PET、石英等で形成してある。この基体１上に
は、第１の実施例と同様熱分散層２および磁気記
録層３が設けられているが、この熱分散層２と磁
気記録層３の位置が入れ換えられている。すなわ
ち、磁気記録層３が基体１側に配されており、熱
分散層２はこの磁気記録層３上に配されている。
また、記録書込および記録読出は、基体１側であ
る。この第２の実施例の磁気記録媒体は、熱分散
層２を保護層の役割をもたすこともできる。この
実施例の場合には磁気記録層３の熱は基体１にも
一部伝導する。 In this example, the substrate 1 is a transparent
It is made of PET, quartz, etc. A heat dispersion layer 2 and a magnetic recording layer 3 are provided on this substrate 1 as in the first embodiment, but the positions of the heat dispersion layer 2 and magnetic recording layer 3 are switched. That is, the magnetic recording layer 3 is arranged on the base 1 side, and the heat dispersion layer 2 is arranged on this magnetic recording layer 3.
Further, record writing and record reading are performed on the base 1 side. In the magnetic recording medium of this second embodiment, the heat dispersion layer 2 can also serve as a protective layer. In this embodiment, part of the heat of the magnetic recording layer 3 is also conducted to the base 1.
上記した本発明による磁気記録媒体の実験例を
示す。 An experimental example of the magnetic recording medium according to the present invention described above will be shown.
まず高周波２極スパツタリングの装置によつて
Tb−Feからなる複合ターゲツトを約30分のスパ
ツタリングして基体となるガラス板上に磁気記録
層である約5000ÅのTb−Fe膜を形成した。この
後、この試料を蒸着装置にセツトし、磁気記録層
の上に熱分散層であるCu層を約１μ蒸着した。 First, by using a high-frequency two-pole sputtering device.
A composite target consisting of Tb-Fe was sputtered for about 30 minutes to form a Tb-Fe film with a thickness of about 5000 Å as a magnetic recording layer on a glass plate serving as a base. Thereafter, this sample was set in a vapor deposition apparatus, and a Cu layer of about 1 μm as a heat dispersion layer was vapor-deposited on the magnetic recording layer.
このようにして形成された磁気記録媒体に上記
した15KOeの磁場で一様に垂直磁化した後、そ
の逆向きに約100Oeの磁場を印加しながらArレー
ザビームで基板側から照射し磁気記録を行なつ
た。次に弱いArレーザビームで読み出しを行な
つたところＳ／Ｎは約20dBが得られた。従来の
熱分散層のない磁気記録媒体において同一条件で
情報の書込および読出を行なつた場合にはＳ／Ｎ
が約15dBであつたのでＳ／Ｎ比は明白に向上し
た。 After the magnetic recording medium thus formed is uniformly perpendicularly magnetized with the magnetic field of 15 KOe described above, magnetic recording is performed by irradiating it with an Ar laser beam from the substrate side while applying a magnetic field of approximately 100 Oe in the opposite direction. Summer. Next, when reading was performed using a weak Ar laser beam, an S/N ratio of about 20 dB was obtained. When writing and reading information under the same conditions on a conventional magnetic recording medium without a heat dispersion layer, the S/N
was about 15 dB, so the S/N ratio was clearly improved.
なお、第２の実施例におけるように、磁気記録
層の表面が熱分散層によつておおわれている場合
は必要ないが、第１の実施例の場合のように磁気
記録層の表面が露出しているときはこの表面に
Si3N4，Al，SiO，SiO2，AlN，Au、有機ポリマ
ー等の保護層（図示せず）を設けるのが望まし
い。 Although it is not necessary when the surface of the magnetic recording layer is covered with a heat dispersion layer as in the second embodiment, it is not necessary if the surface of the magnetic recording layer is exposed as in the first embodiment. on this surface when
It is desirable to provide a protective layer (not shown) of Si 3 N 4 , Al, SiO, SiO 2 , AlN, Au, organic polymer, or the like.
以上説明したように本発明の磁気記録媒体にお
いては、従来の磁気記録媒体にあつては磁気記録
層に蓄積されてしまつていた記録読出用光の熱を
この磁気記録層に隣接して配された熱分散層によ
つて分散し、該熱が磁気記録層にそのまま蓄積さ
れることがないので、この熱による磁化の大きさ
の低下を生ずることがなくなり、Ｓ／Ｎ比が向上
した。 As explained above, in the magnetic recording medium of the present invention, the heat of the recording/reading light, which is accumulated in the magnetic recording layer in conventional magnetic recording media, is disposed adjacent to the magnetic recording layer. Since the heat is dispersed by the heat dispersion layer and is not directly accumulated in the magnetic recording layer, the magnitude of magnetization does not decrease due to this heat, and the S/N ratio is improved.
第１図は、本発明の第１の実施例による磁気記
録媒体の一部断面図、第２図は、本発明の第２の
実施例による磁気記録媒体の一部断面図である。
１……基体、２……熱分散層、３……磁気記録
層、４……記録書込光、５……記録読出用光。
FIG. 1 is a partial sectional view of a magnetic recording medium according to a first embodiment of the invention, and FIG. 2 is a partial sectional view of a magnetic recording medium according to a second embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Heat dispersion layer, 3... Magnetic recording layer, 4... Recording/writing light, 5... Recording/reading light.
Claims (1)
なる磁気記録層と該層に積層された熱分散層とが
基板上に設けられた磁気記録媒体。1. A magnetic recording medium in which a magnetic recording layer made of a transition metal-rare earth amorphous magnetic thin film and a heat dispersion layer laminated on the layer are provided on a substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15095379A JPS5674844A (en) | 1979-11-21 | 1979-11-21 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15095379A JPS5674844A (en) | 1979-11-21 | 1979-11-21 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5674844A JPS5674844A (en) | 1981-06-20 |
| JPS6131532B2 true JPS6131532B2 (en) | 1986-07-21 |
Family
ID=15508028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15095379A Granted JPS5674844A (en) | 1979-11-21 | 1979-11-21 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5674844A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5873017A (en) * | 1981-10-26 | 1983-05-02 | Ricoh Co Ltd | Vertical magnetic recording medium |
| JPS59171054A (en) * | 1983-03-17 | 1984-09-27 | Sharp Corp | Magneto-optical storage element |
| EP0369226B1 (en) * | 1984-10-22 | 1995-01-11 | Hitachi, Ltd. | Magnetic recording medium |
| US4822675A (en) * | 1987-01-14 | 1989-04-18 | Minnesota Mining And Manufacturing Company | Stable magneto optic recording medium |
| JP2555891B2 (en) * | 1989-08-22 | 1996-11-20 | 日本電気株式会社 | Magneto-optical recording medium |
| JPH03156755A (en) * | 1990-10-19 | 1991-07-04 | Sharp Corp | Production of optical memory device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5231703A (en) * | 1975-09-05 | 1977-03-10 | Kokusai Denshin Denwa Co Ltd <Kdd> | Magnetic thin film recording medium |
| JPS5388530A (en) * | 1977-01-14 | 1978-08-04 | Mitsubishi Electric Corp | Information recording medium |
| US4189735A (en) * | 1978-02-24 | 1980-02-19 | Rca Corporation | Record playback apparatus and information record therefor |
-
1979
- 1979-11-21 JP JP15095379A patent/JPS5674844A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5674844A (en) | 1981-06-20 |
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