JPH01133243A - Magneto-optical recording medium - Google Patents
Magneto-optical recording mediumInfo
- Publication number
- JPH01133243A JPH01133243A JP20957588A JP20957588A JPH01133243A JP H01133243 A JPH01133243 A JP H01133243A JP 20957588 A JP20957588 A JP 20957588A JP 20957588 A JP20957588 A JP 20957588A JP H01133243 A JPH01133243 A JP H01133243A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic layer
- coercive force
- magnetization
- layer
- dominant
- 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
- 230000005415 magnetization Effects 0.000 claims abstract description 66
- 229910017061 Fe Co Inorganic materials 0.000 claims abstract description 32
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 32
- 229910052692 Dysprosium Inorganic materials 0.000 claims abstract description 3
- 229910052771 Terbium Inorganic materials 0.000 claims abstract description 3
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 20
- 150000002910 rare earth metals Chemical class 0.000 claims description 16
- 229910000808 amorphous metal alloy Inorganic materials 0.000 claims description 11
- 230000000694 effects Effects 0.000 abstract description 11
- 230000003647 oxidation Effects 0.000 abstract description 7
- 238000007254 oxidation reaction Methods 0.000 abstract description 7
- 239000000758 substrate Substances 0.000 abstract description 7
- 239000004417 polycarbonate Substances 0.000 abstract description 4
- 229920000515 polycarbonate Polymers 0.000 abstract description 4
- 230000001681 protective effect Effects 0.000 abstract description 2
- 229910000640 Fe alloy Inorganic materials 0.000 abstract 2
- 229910045601 alloy Inorganic materials 0.000 abstract 1
- 239000000956 alloy Substances 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 110
- 239000000203 mixture Substances 0.000 description 18
- 239000010408 film Substances 0.000 description 17
- 238000000034 method Methods 0.000 description 15
- 230000035945 sensitivity Effects 0.000 description 7
- 239000010409 thin film Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 238000000151 deposition Methods 0.000 description 6
- 230000008021 deposition Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000003993 interaction Effects 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000004453 electron probe microanalysis Methods 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000001755 magnetron sputter deposition Methods 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 239000011241 protective layer Substances 0.000 description 3
- 229910017112 Fe—C Inorganic materials 0.000 description 2
- 239000003989 dielectric material Substances 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000005381 magnetic domain Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 229910003172 MnCu Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000001637 plasma atomic emission spectroscopy Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000009751 slip forming Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］−
本発明は、光ビームの照射によって熱磁気的に情報が記
録され、記録された情報を磁気光学効果を用いて読み出
すことが可能な光磁気記録媒体に関する。[Detailed Description of the Invention] [Industrial Application Field] - The present invention is an optical technology in which information is recorded thermomagnetically by irradiation with a light beam, and the recorded information can be read using the magneto-optic effect. Related to magnetic recording media.
ｒ従来の技術］
従来、光磁気記録媒体としては、ＭｎＢ ｉ％ＭｎＣｕ
Ｂ１などの多結晶体薄膜、ＧｄＣｏ、ＧｄＦｅ、 Ｔｂ
Ｆｅ、 ＤｙＦｅ。rPrior art] Conventionally, as a magneto-optical recording medium, MnB i%MnCu
Polycrystalline thin films such as B1, GdCo, GdFe, Tb
Fe, DyFe.
ＧｄＴｂＦｅ、 ＴｂＤＶＦｅなどの非晶質薄膜、ＧＩ
Ｇなどの単結晶薄膜などを用いたものが知られている。Amorphous thin films such as GdTbFe and TbDVFe, GI
One using a single crystal thin film such as G is known.
これらの薄膜のうち、大面積の薄膜を室温近傍の温度で
作製する製膜性などを勘案し、最近では、希土類−遷移
金属非晶質合金薄膜が光磁気記録媒体に用いるのに適し
ていると考えられている。Among these thin films, rare earth-transition metal amorphous alloy thin films have recently been found to be suitable for use in magneto-optical recording media, taking into account the ease of manufacturing large-area thin films at temperatures near room temperature. It is believed that.
ところで、一般に光磁気記録媒体には、記録感度の高い
こと、磁気光学効果の大きいこと、更には高い保磁力を
有することが要求される。しかし、上記のごとき薄膜を
用いた場合、単体ではこのような要求を全て満たすこと
は困難であった。Incidentally, magneto-optical recording media are generally required to have high recording sensitivity, a large magneto-optic effect, and furthermore a high coercive force. However, when using the above-mentioned thin film, it is difficult to satisfy all of these requirements by itself.
すなわち、補償点書き込みが可能なＧｄＣｏ、 ＧｄＦ
ｅなどは、比較的キュリー温度が高いため、読み出し時
において、磁気光学°効果が大きく、高いＳ／Ｎ比が得
られるが、保磁力が低く、記録された磁区が不安定であ
った。一方、キュリー点書き込みが可能なＴｂＦｅ、
ＤＹＦｅは、比較的保磁力が高いため、上記問題は生じ
ないが、キュリー点が低いため、読み出し時のＳ／Ｎ比
が悪くなる。そこで、これらの欠点を解消するため、二
層構成の光磁気記録媒体が特開昭５７−７８６５２号で
提案されている。この記録媒体は、垂直磁化可能な低キ
ユリー温度を有する高保磁力層と垂直磁化可能な高キュ
リー温度を有する低保磁力層との二層から成り、高保磁
力層と低保磁力層とは、互いに交換結合しているもので
ある。そして、低キユリー温度を有する高保磁力層で情
報の記録と保存が行なわれ、記録された情報は低保磁力
層に転写され、高キュリー温度を有しかつ磁気光学カー
回転角の大きな低保磁力層で情報の読み出しがなされる
。In other words, GdCo and GdF that can write compensation points.
Since the Curie temperature of magnets such as e is relatively high, the magneto-optical effect is large during reading, and a high S/N ratio can be obtained, but the coercive force is low and the recorded magnetic domains are unstable. On the other hand, TbFe, which can be written with a Curie point,
Since DYFe has a relatively high coercive force, the above problem does not occur, but since the Curie point is low, the S/N ratio during reading becomes poor. In order to overcome these drawbacks, a magneto-optical recording medium having a two-layer structure has been proposed in Japanese Patent Application Laid-open No. 78652/1983. This recording medium consists of two layers: a high coercive force layer that is perpendicularly magnetizable and has a low Curie temperature, and a low coercive force layer that is perpendicularly magnetizable and has a high Curie temperature. It is exchange coupled. Information is recorded and stored in a high coercive force layer with a low Curie temperature, and the recorded information is transferred to a low coercive force layer with a high Curie temperature and a large magneto-optic Kerr rotation angle. Information is read out in the layer.
さらに、この高保磁力層として鉄族副格子磁化優勢な希
土類−鉄族非晶質合金、低保磁力層としてもやはり鉄族
副格子磁化優勢な希土類−鉄族非晶質合金を用い、両者
の飽和磁化の向きを平行にした光磁気記録媒体が、特開
昭６１−１１７７４７号により提案されている。Furthermore, we used a rare earth-iron group amorphous alloy with dominant iron group sublattice magnetization as the high coercive force layer, and a rare earth-iron group amorphous alloy with dominant iron group sublattice magnetization as the low coercive force layer. A magneto-optical recording medium in which the direction of saturation magnetization is parallel has been proposed in JP-A-61-117747.
［発明が解決しようとする問題点］
しかしながら、この媒体にも以下に示すような問題点が
あった。即ち、交換結合二層膜においては、二層間の交
換相互作用により、各層の磁化過程（保磁力）が単層の
ときと比べてかなり変化する。二層化によって変化した
磁化反転磁界のことをみかけの保磁力と呼ぶことにする
と、上記特開昭６１−１１７７４７号の媒体は、低保磁
力層の見かけの保磁力は増加し、低保磁力における情報
の安定性は改善される。[Problems to be Solved by the Invention] However, this medium also has the following problems. That is, in an exchange-coupled two-layer film, the magnetization process (coercive force) of each layer changes considerably compared to the case of a single layer due to the exchange interaction between the two layers. If we call the magnetization reversal magnetic field changed by double layering the apparent coercive force, then in the medium of JP-A-61-117747, the apparent coercive force of the low coercive force layer increases, and the low coercive force The stability of information in is improved.
ところが、高保磁力層も低保磁力層からの交換相互作用
により磁化過程が変化し、単層膜のときと比べて見かけ
の保磁力が減少する。この様子を第３図に示す０図中で
実線は交換結合二層膜の高保磁力層の見かけの保磁力の
温度変化、破線は高保磁力層の単独の保磁力の温度変化
である０図かられかるように、二層化によって高保磁力
層の見かけの保磁力は単独の保磁力よりも小さくなり、
さらにその温度変化もキュリー温度に向かって単調に減
少している。However, the magnetization process of the high coercive force layer also changes due to exchange interaction from the low coercive force layer, and the apparent coercive force decreases compared to the case of a single layer film. This situation is shown in Figure 3. In Figure 3, the solid line is the temperature change in the apparent coercive force of the high coercive force layer of the exchange-coupled bilayer film, and the broken line is the temperature change in the individual coercive force of the high coercive force layer. As can be seen, the apparent coercive force of the high coercive force layer becomes smaller than the single coercive force due to the double layering,
Furthermore, the temperature change also decreases monotonically toward the Curie temperature.
一方、一般に光磁気記録媒体の磁性層の理想的な特性は
、第４図に示すようにキュリー温度Ｔｃまでは高い保磁
力を有するものである。その理由は記録ビーム以外の外
乱によって、温度が上昇しても、磁区が安定に保たれる
からである。On the other hand, the ideal characteristic of the magnetic layer of a magneto-optical recording medium is generally to have a high coercive force up to the Curie temperature Tc, as shown in FIG. The reason for this is that the magnetic domain remains stable even if the temperature rises due to disturbances other than the recording beam.
このことから考えると、上記特開昭６１−１１７７４７
号の媒体は、高保磁力層の見かけの保磁力が減少してし
まうので、記録情報の安定性に問題があることになる。Considering this, the above-mentioned Japanese Patent Application Laid-Open No. 61-117747
In the medium of No. 2, the apparent coercive force of the high coercive force layer decreases, so there is a problem with the stability of recorded information.
本発明の目的は、上記従来技術の問題点を解決し、記録
が容易で読み出し性が良く、更に記録情報の安定性にも
優れた光磁気記録媒体を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to provide a magneto-optical recording medium that is easy to record, has good readability, and has excellent stability of recorded information.
［問題点を解決するための手段］
本発明の上記目的は、第１の磁性層及び該第１の磁性層
と交換結合した、第１の磁性層よりも高い保磁力と低い
キュリー温度とを有する第２の磁性層を有する光磁気記
録媒体において、前記第１の磁性層を、鉄族副格子磁化
優勢で、その飽和磁化が２５〜１２５ ｅｍｕ／ｃｍ’
の範囲にあるＧｄ−Ｆｅ−Ｃｏ非晶質合金により形成し
、且つ前記第２の磁性層を、希土類副格子磁化優勢で、
その飽和磁化が２５〜１７５ ｅｍｕ／ｃｍ”の範囲に
あるＲ−Ｆｅ−Ｃｏ非晶質合金（ＲはＴｂ及びｏｙの少
なくとも一種の元素）により形成することにより達成さ
れる。[Means for Solving the Problems] The above-mentioned object of the present invention is to provide a first magnetic layer, which is exchange-coupled with the first magnetic layer, and has a higher coercive force and a lower Curie temperature than the first magnetic layer. In the magneto-optical recording medium having a second magnetic layer, the first magnetic layer has an iron group sublattice magnetization predominance and a saturation magnetization of 25 to 125 emu/cm'.
The second magnetic layer is formed of a Gd-Fe-Co amorphous alloy having a rare earth sublattice magnetization dominantly,
This is achieved by forming an R-Fe-Co amorphous alloy (R is at least one element of Tb and oy) whose saturation magnetization is in the range of 25 to 175 emu/cm''.
以下、本発明を、図面を用いて詳細に説明する。Hereinafter, the present invention will be explained in detail using the drawings.
第１図は、本発明の光磁気記録媒体の一実施態様の構成
を示す略断面図である。図中、１はガラスあるいはプラ
スチックから成る透明基板を示す、この基板ｌ上には干
渉効果と腐食防止効果を得るための、５ｉｓＮ４等の誘
電体から成る下引き層が設けられている。更に、この下
引き層２の上に、第１の磁性層３と、この第１の磁性層
３よりも高い保磁力と低いキュリー温度とを有する第２
の磁性層４が形成されている。これらの磁性層は、媒体
の作製時に真空を破ることなく、連続して成膜され、互
いに交換結合している。また、第２の磁性層上にはこれ
らの磁性層の腐食を防止するため、５ｉｓＮａ等の誘電
体から成る保護層が形成されている。FIG. 1 is a schematic cross-sectional view showing the structure of one embodiment of the magneto-optical recording medium of the present invention. In the figure, reference numeral 1 indicates a transparent substrate made of glass or plastic. On this substrate l, an undercoat layer made of a dielectric material such as 5isN4 is provided to obtain an interference effect and a corrosion prevention effect. Furthermore, a first magnetic layer 3 and a second magnetic layer having a higher coercive force and a lower Curie temperature than the first magnetic layer 3 are formed on the undercoat layer 2.
A magnetic layer 4 is formed. These magnetic layers are continuously formed without breaking the vacuum during the production of the medium, and are exchange-coupled with each other. Further, a protective layer made of a dielectric material such as 5isNa is formed on the second magnetic layer in order to prevent corrosion of these magnetic layers.
上記媒体において、第１の磁性Ｎ３は、鉄族副格子磁化
優勢で、その飽和磁化が２５〜１２５ｅｍｕ／ｃｍ”の
範囲にあるＧｄ −Ｆｅ −Ｃｏ非晶質合金から形成さ
れる。一方、第２の磁性層４はＴｂ−Ｆｅ−Ｃ０１Ｏｙ
−Ｆｅ−ＧｏまたはＴｂ −１）ｙ −Ｆｅ −Ｃｏ非
晶質合金から形成される。また、この第２の磁性Ｍ４は
室温とキュリー温度Ｔｃとの間に、補償温度Ｔ ｃｏａ
ｐが存在するように、希土類副格子優勢で、その飽和磁
化が２５〜１７５ ｅｍｕ／ｃｍ３の範囲にあるように
形成される。In the above medium, the first magnetic N3 is formed from a Gd-Fe-Co amorphous alloy in which the iron group sublattice magnetization is dominant and the saturation magnetization is in the range of 25 to 125 emu/cm. The magnetic layer 4 of No. 2 is Tb-Fe-C01Oy
-Fe-Go or Tb -1)y -Fe-Co is formed from an amorphous alloy. Moreover, this second magnetic M4 has a compensation temperature T coa between the room temperature and the Curie temperature Tc.
p exists, the rare earth sublattice is dominant and the saturation magnetization is in the range of 25 to 175 emu/cm3.
第１の磁性層の膜厚は、１００Ａ〜１０００人、第２磁
性層の膜厚は１ｏ○〜２００ＯＡ、第１と第２の磁性層
の膜厚の合計は５００Ａ〜２０００人の範囲が良い。The thickness of the first magnetic layer is preferably in the range of 100A to 1000mm, the thickness of the second magnetic layer is 1o○ to 200OA, and the total thickness of the first and second magnetic layers is preferably in the range of 500A to 2000mm. .
また、好ましくは第１の磁性層の膜厚よりも第２の磁性
層の膜厚が厚い方が良い。Further, it is preferable that the second magnetic layer is thicker than the first magnetic layer.
本発明のように交換結合した複数の磁性層を有する媒体
においては、第２の磁性層の保磁力の大きさが記録情報
の安定性を大きく左右する。記録情報の安定性を考える
場合、室温における保磁力と共にその温度変化について
も考える必要がある。それは次のような理由による。す
なわち、■光磁気ドライブ装置内は様々な熱の発生源が
存在するので、その中は５０〜６０℃程度に温度が上昇
することがある。■さらに、情報の読み出しにおいては
、情報を記録しない程度の弱いレーザー光を媒体に照射
して読み出しを行なうが、それでもある程度の媒体の温
度上昇は避けられない。■ドライブ装置の都合上、記録
消去用のバイアス磁界が印加された状態で読み出しをし
なければならない場合がある。したがって、５０〜６０
℃程度のドライブ装置の中でバイアス磁界の印加のもと
で、読み出し光によってさらに媒体の温度が上昇しても
、記録情報が安定である必要がある。In a medium having a plurality of exchange-coupled magnetic layers as in the present invention, the magnitude of the coercive force of the second magnetic layer greatly influences the stability of recorded information. When considering the stability of recorded information, it is necessary to consider not only the coercive force at room temperature but also its temperature change. This is due to the following reasons. That is, (1) there are various sources of heat inside the magneto-optical drive, so the temperature inside may rise to about 50 to 60°C. (2) Furthermore, when reading information, the medium is irradiated with a weak laser beam that does not record information, but a certain degree of temperature rise in the medium is still unavoidable. (2) Due to the convenience of the drive device, it may be necessary to read data while a bias magnetic field for recording and erasing is applied. Therefore, 50-60
Recorded information needs to be stable even if the temperature of the medium further increases due to read light under the application of a bias magnetic field in a drive device at a temperature of about .degree.
この要請に答える記録媒体の理想的な保磁力の温度変化
の様子が、前述の第４図に示すよ・うなものとなる、す
なわち、室温から記録が行なわれるキュリー温度Ｔｃ付
近まで保磁力が大きいことが必要となる。The ideal coercive force of a recording medium that meets this requirement changes with temperature as shown in Figure 4. In other words, the coercive force is large from room temperature to around the Curie temperature Tc at which recording is performed. This is necessary.
第２図は、本発明の第２の磁性層４の保磁力の温度特性
を示す図である０図中で、実線は第１の磁性層３からの
交換相互作用による見かけの保磁力、破線はこのような
第２の磁性層４を単独で形成した場合の保磁力を示す０
図かられかるように室温と補償温度Ｔｃ、、□との間で
は、二層化によって第２の磁性層の見かけの保磁力は単
独の場合より大きくなり、補償温度Ｔ ｃｏｍｅとキュ
リー温度Ｔｃの間では、二層化によって第２の磁性層の
見かけの保磁力は単独の場合より小さくなっている。こ
れは、補償温度Ｔ Ｃ＠ｌａｅとキュリー温度Ｔｃの間
では第２の磁性層が鉄族副格子磁化優勢に変化している
ためである。FIG. 2 is a diagram showing the temperature characteristics of the coercive force of the second magnetic layer 4 of the present invention. In FIG. 0 indicates the coercive force when such a second magnetic layer 4 is formed alone.
As can be seen from the figure, between the room temperature and the compensation temperature Tc, , □, the apparent coercive force of the second magnetic layer becomes larger than that of the second magnetic layer alone, and the difference between the compensation temperature T come and the Curie temperature Tc Between the layers, the apparent coercive force of the second magnetic layer is smaller than that of the second magnetic layer alone. This is because the second magnetic layer changes to be dominated by iron group sublattice magnetization between the compensation temperature T C@lae and the Curie temperature Tc.
このように本発明の媒体では、室温から補償温度まで見
かけの保磁力がかなり大きくなって、補償温度からキュ
リー温度の間で見かけの保磁力が急激に低下していで、
第４図に示すような理想的な媒体に近い特性を有してい
る。As described above, in the medium of the present invention, the apparent coercive force increases considerably from room temperature to the compensation temperature, and the apparent coercive force decreases rapidly between the compensation temperature and the Curie temperature.
It has characteristics close to ideal media as shown in FIG.
なお、第２図のような物性を示すために第１と第２の磁
性層に要求される飽和磁化の大きさの前記範囲は実験（
後述の実施例参照）によって得られたものである。The range of saturation magnetization required for the first and second magnetic layers in order to exhibit the physical properties shown in Figure 2 was determined experimentally (
(See Examples below).
第１及び第２の磁性層を、各々の要件を満たすようにす
るためには、希土類と鉄族元素の組成比を変えて調節す
ればよい、補償組成よりも希土類の組成比をふやせば、
希土類副格子磁化優勢となり、補償温度が室温以上に存
在する。希土類の組成比をふやすにつれて、補償温度が
上昇し、キュリー温度に近づくが、ふやしすぎると、補
償温度が仮想的にキュリー温度以上になってしまうので
好ましくない。In order to make the first and second magnetic layers satisfy each requirement, the composition ratio of rare earth and iron group elements can be adjusted by changing the composition ratio.
The rare earth sublattice magnetization becomes dominant, and the compensation temperature exists above room temperature. As the composition ratio of the rare earth element increases, the compensation temperature increases and approaches the Curie temperature, but if it increases too much, the compensation temperature will virtually become equal to or higher than the Curie temperature, which is not preferable.
なお、第１の磁性層が希土類副格子磁化優勢である媒体
は、記録がなされる第２の磁性層のキュリー温度付近に
おいて、第１の磁性層の保磁力が増加するため記録が非
常に困難となり、記録媒体として適当でない。Note that recording on a medium in which the first magnetic layer is dominated by rare earth sublattice magnetization is extremely difficult because the coercive force of the first magnetic layer increases near the Curie temperature of the second magnetic layer where recording is performed. Therefore, it is not suitable as a recording medium.
第５図は、第２の暇性屡をＴｂ −Ｆｅ −Ｇｏで形成
した場合のＴｂの組成ｘ （ａｔｏｍｉｃ％）と飽和磁
化との関係を示す、斜線部は、本発明で要する飽和磁化
の範囲である。Ａ１．Ｂ＋ 、Ｃ＋およびり、はそれぞ
れＴｂ組成をエレクトロンプローブマイクロアナライズ
（ＥＰＭＡ）法、プラズマ発光分析（工ＣＰ）法、膜付
着速度より算出する方法及び蛍光Ｘ線分析（ＸＲＦ）法
を用いて検出した場合を示す０分析法によって組成範囲
にばらつきがあるが、例えば膜付着速度により算出する
方法では、Ｔｂの組成Ｘとして２３ 、８〜２７ 、６
ａｔｏｍｉｃ％の範囲を示すものであれば、本発明の媒
体が実現できることになる。また、ＸＲＦ法では、Ｔｂ
の組成Ｘとして２０．２〜２３ 、８ ａｔｏｍｉｃ％
の範囲を示すものである。FIG. 5 shows the relationship between the Tb composition x (atomic%) and the saturation magnetization when the second free layer is formed of Tb-Fe-Go. range. A1. B+, C+, and Tb composition were detected using electron probe microanalysis (EPMA) method, plasma emission spectrometry (CP) method, method calculated from film deposition rate, and X-ray fluorescence analysis (XRF) method, respectively. Although there are variations in the composition range depending on the analysis method, for example, in the method of calculating based on the film deposition rate, the Tb composition X is 23, 8 to 27, 6
The medium of the present invention can be realized as long as it shows a range of atomic%. In addition, in the XRF method, Tb
As composition X of 20.2 to 23, 8 atomic%
This indicates the range of
第６図は、同様に第２の磁性層をＤｙ−Ｆｅ−Ｇｏで形
成した場合のＤｙの組成Ｘ （ａｔｏｍｉｃ％）と飽和
磁化との関係を示す、Ａｚは、ＥＰＭＡ法を用いた分析
結果である０本発明のように、室温とキュリー温度との
間に補償温度が存在するようにするためには、Ｘが２３
．４〜２７ 、 Ｏａｔｏｍｉｃ％の範囲を示すように
すればよい。Figure 6 similarly shows the relationship between Dy composition X (atomic%) and saturation magnetization when the second magnetic layer is formed of Dy-Fe-Go.Az is the analysis result using the EPMA method. 0 In order to have a compensation temperature between room temperature and the Curie temperature as in the present invention, X is 23
．． 4 to 27, Oatomic% may be indicated.
第７図は、第２の磁性層をＴｂ −Ｄｙ −Ｆｅ −Ｃ
ｏで形成した場合のＴｂ−Ｄｙの組成Ｘ （ａｔｏｍｉ
ｃ％）と飽和磁化との関係を示す、Ａ、はＥＰＭＡ法を
用いた分析結果である０本発明のように室温とキュリー
温度とあの間委に補償温度が存在するようにするために
はキュリー温度との間に補償温度が存在するようにする
ためには、Ｘが２３．０〜２６．６ａｔｏｍｉｃ％の範
囲を示すようにすればよい。FIG. 7 shows that the second magnetic layer is Tb-Dy-Fe-C
The composition of Tb-Dy when formed with
A, which shows the relationship between c%) and saturation magnetization, is the analysis result using the EPMA method. In order to have a compensation temperature between room temperature, Curie temperature, and that temperature as in the present invention, In order to ensure that a compensation temperature exists between the Curie temperature and the Curie temperature, X may be in the range of 23.0 to 26.6 atomic%.
第８図は、Ｇｄ −Ｆｅ −Ｃｏから成る第１の層にお
けるＧｄの組成Ｚ （ａｔｏｍｉｃ％）と飽和磁化との
関係を示す図である。斜線部が本発明の要件を満足する
飽和磁化の範囲である。Ｂ４、Ｃ４及びＤ４は、それぞ
れＧｄ組成をＩＣＰ法、膜付着速度より算出する方法及
びＸＲＦ法を用いて検出した場合を示す。例えば、膜付
着速度により算出する方法では、Ｇｄの組成Ｚが２０．
Ｃ１〜２２．２ａｔｏｍｉｃ％の範囲を示すようにす
ればよい、また、ＸＲＦ法ではＺが２３．５〜２５．７
ａｔｏｍｉｃ％の範囲を示すようにすればよい。FIG. 8 is a diagram showing the relationship between the Gd composition Z (atomic %) and the saturation magnetization in the first layer made of Gd-Fe-Co. The shaded area is the range of saturation magnetization that satisfies the requirements of the present invention. B4, C4, and D4 show cases where the Gd composition was detected using the ICP method, the method of calculating from the film deposition rate, and the XRF method, respectively. For example, in the method of calculating based on the film deposition rate, the composition Z of Gd is 20.
It is sufficient to show a range of C1 to 22.2 atomic%, and in the XRF method, Z is 23.5 to 25.7.
What is necessary is to indicate the range of atomic%.
また、記録情報の安定性に関しては、第２の磁性層のキ
ュリー温度も大きく関係する。キュリー温度が高いほど
記録情報の安定性は増すが、記録感度が悪くなる。高保
磁力層の望ましいキュリー温度は１００℃以上、より望
ましくは１３０℃以上さらに望ましくは１５０”Ｃ以上
である。ただし、１９０℃以上となるのは好ましくない
。Furthermore, the Curie temperature of the second magnetic layer also has a large effect on the stability of recorded information. The higher the Curie temperature, the more stable the recorded information becomes, but the recording sensitivity deteriorates. The Curie temperature of the high coercive force layer is preferably 100° C. or higher, more preferably 130° C. or higher, and even more preferably 150”C or higher. However, it is not preferable that the Curie temperature is 190° C. or higher.
第２の磁性層の希土類元素としてＴｂ、 ａｙを用いる
のは、保磁力を大きくするために非Ｓ状態（角運動量に
はスピン角運動量と軌道角運動量の両方があるが、その
両方をもつ場合）の元素を要するからである。 Ｔｂ−
Ｆｅ、 Ｄｙ−Ｆｅのキュリー温度はそれぞれ約１３０
℃、約７０’Ｃであるが、さらにＣＯを添加したものも
使用できる。 Ｃｏの添加することによってキュリー温
度を自由に制御することが可能である。The reason for using Tb and ay as the rare earth elements in the second magnetic layer is to increase the coercive force in a non-S state (angular momentum includes both spin angular momentum and orbital angular momentum; ) elements are required. Tb-
The Curie temperatures of Fe and Dy-Fe are approximately 130, respectively.
℃, about 70'C, but it is also possible to use one to which CO is added. By adding Co, it is possible to freely control the Curie temperature.
Ｔｂ−（Ｆｅ＋ｏｏ−ｙｃＯｙ） 、Ｄｙ−（Ｆ６＋ｏ
ｏ−ｙ・ｃＯｙＪのキュリー温度はそれぞれ近似的に、
１３０＋６Ｙ （”Ｃ）
７０＋６Ｙ’ （’Ｃ）
と表されるので、この式を用いて所望の温度になるよう
にＣｏを添加すればよい、上記望ましい範囲内にキュリ
ー温度を設定するには
０＜Ｙ≦１０ （ａｔｏｍｉｃ％）
５≦Ｙ°≦２０ （ａｔｏｍｉｃ％）となる。Tb-(Fe+oo-ycOy), Dy-(F6+o
The Curie temperatures of o-y and cOyJ are approximately expressed as 130+6Y ('C) 70+6Y'('C), so using this formula, Co can be added to the desired temperature. To set the Curie temperature within the above desirable range, 0<Y≦10 (atomic%) and 5≦Y°≦20 (atomic%).
同様に、Ｔｂ−Ｄｙ−（Ｆｅ＋ｏｏ−ｙ−Ｃｏｙ−）の
場合には、０＜Ｙ”≦１５ （ａｔｏｍｉｃ％）とすれ
ば良い。Similarly, in the case of Tb-Dy-(Fe+oo-y-Coy-), 0<Y''≦15 (atomic%) may be satisfied.
低保磁力層の希土類元素としてＧｄを用いるのは保磁力
を小さくするためにＳ状態（スピン角運動量のみもつ場
合）の元素を要するからである。The reason why Gd is used as the rare earth element in the low coercive force layer is that an element in the S state (having only spin angular momentum) is required to reduce the coercive force.
Ｇｄ−Ｆｅのキュリー温度は約２２０℃であり、さらに
Ｃｏを添加することによって、キュリー温度が上昇し磁
気光学カー回転角が増加し、読み出し特性が良くなる。The Curie temperature of Gd-Fe is about 220° C., and by further adding Co, the Curie temperature increases, the magneto-optic Kerr rotation angle increases, and the readout characteristics improve.
ただし、Ｇｄ−（Ｆｅ＋ｏｏ−ｗｃＯｗ）において、Ｗ
が大きくなるにつれて、鉄族磁気モーメントが減少し、
また、垂直磁気異方性が低下するので、Ｏ＜Ｗ≦５０が
望ましい。However, in Gd-(Fe+oo-wcOw), W
As becomes larger, the iron group magnetic moment decreases,
Further, since the perpendicular magnetic anisotropy decreases, it is desirable that O<W≦50.
〔実施例］
実施例１
１３０闘φのプリグループの付いているボリカーボネー
ト基板上に、酸化防止と干渉効果を得るために５ｉＪ４
を７００人、第１の磁性層としてＧｄ−Ｆｅ−Ｃｏを４
０ＯＡ、第２の磁性層としてＴｂ−Ｆｅ−Ｇｏを４０Ｏ
Ａ、そして酸化防止のために５ｉｓＬを７０ＯＡ順次真
空を破ることなく連続してマグネトロンスパッタリング
装置を用いて、交換結合二層膜の光磁気記録ディスクを
作製した。 Ａｒガス圧は０． ＋５Ｐａとした。磁性
層のターゲットにはＧｄｓ。[Example] Example 1 On a polycarbonate substrate with a pre-group of 130mm diameter, 5iJ4 was applied to obtain oxidation prevention and interference effects.
700 people, and 4 Gd-Fe-Co as the first magnetic layer.
0OA, Tb-Fe-Go as the second magnetic layer at 40O
A. Then, a magneto-optical recording disk with an exchange-coupled two-layer film was fabricated using a magnetron sputtering apparatus in which 5 isL was sequentially applied to 70 OA to prevent oxidation without breaking the vacuum. Ar gas pressure is 0. It was set to +5Pa. Gds is used as the target for the magnetic layer.
Ｃ０５ｏ、ＴｂとＦｅ＠４ＣＯ６を用い、ＧｄａｏＣＯ
ｓｏとｐｅａ＜Ｃｏａを使ってＧｄ−Ｆｅ−Ｇｏを作製
し、 ＴｂとＦｅｅ４Ｃｏ＠を使ってＴｂ−Ｆｅ−Ｃｏ
を作製した。希土類と鉄族の組成比はＧｄ５ｏＣｏ＠ｏ
とＦｅｅ＜Ｃｏｓ ％あるいはＴｂとＦｅｅ４Ｃｏａの
ターゲットに加える電力を変えることによって制御し、
第２の磁性層、第１の磁性層を各々本発明の要件を満た
すように形成した。Using C05o, Tb and Fe@4CO6, GdaoCO
Gd-Fe-Go is made using so and pea<Coa, and Tb-Fe-Co is made using Tb and Fee4Co@.
was created. The composition ratio of rare earth and iron group is Gd5oCo@o
and Fee<Cos % or by changing the power applied to the target of Tb and Fee4Coa,
The second magnetic layer and the first magnetic layer were each formed to satisfy the requirements of the present invention.
電力の範囲は、Ｇｄ−Ｆｅ−ＣｏではＧｄ５ｏＣＯｓｏ
のターゲットに加久る電力を２４０Ｗ（ＤＣ） （７７
へ／ｍｉｎ、 ）一定としたとき、Ｆｅｅ４Ｃｏａのタ
ーゲットに加える電力を２８０ Ｗ （ＤＣ） （５０
Ａ／ｍｉｎ、 ）以上にすると、鉄族副格子磁化優勢に
なった。Ｔｂ−Ｆｅ−ＣｏではＴｂのターゲットに加え
る電力を１５０Ｗ（ＲＦ）（３６人／ｍｉｎ、）一定と
したとき、Ｆｅｅ４Ｃｏ６のターゲットに加える電力を
２５０ Ｗ （ＤＣ）（４６人／ｍｉｎ、）以下にする
と、希土類副格子磁化優勢となった。The power range is Gd5oCOso for Gd-Fe-Co
240W (DC) that increases the power to the target (77
/min, ) constant, the power applied to the Fee4Coa target is 280 W (DC) (50
A/min, ) or more, iron group sublattice magnetization became dominant. For Tb-Fe-Co, when the power applied to the Tb target is constant at 150 W (RF) (36 people/min,), the power applied to the Fee4Co6 target is 250 W (DC) (46 people/min,) or less. Then, the rare earth sublattice magnetization became dominant.
なお、５ｉＪ４の成膜速度は約４ＯＡ／ｍｉｎ、であっ
た。Note that the film formation rate of 5iJ4 was about 4OA/min.
作製されたＧｄ−（Ｆｅ＋ｏｏ−ｗｃＯｗ）膜のＷは約
３０ａｔｏｍｉｃ％であり、また交換結合二層膜の界面
磁壁エネルギー密度は約２ ｅｒｇ／ｃｍ２であり、両
者間に良好な交換結合相互作用が働いていることを確認
した。The produced Gd-(Fe+oo-wcOw) film has a W content of about 30 atomic%, and the interfacial domain wall energy density of the exchange-coupled bilayer film is about 2 erg/cm2, indicating that there is good exchange-coupling interaction between the two. I confirmed that it was working.
ディスクの記録再生特性は回転数１５００ｒｐｍ 、半
径６０ｍｍの位置において測定した。The recording and reproducing characteristics of the disc were measured at a rotation speed of 1500 rpm and a radius of 60 mm.
Ｇｄ−Ｆｅ−Ｃａｍが鉄族副格子磁化優勢でその飽和磁
化が２５ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ／ｃｍ’
、 ＴｂＦｅＣｏ層が希土類副格子磁化優勢でその飽
和磁化が２５ｅｍｕ／ｃｍ３〜１７５ ｅｍｕ／ａｍ３
の範囲では、記録感度が約７ｍＷ、再生ＣＮ比が約５７
ｄＢであり、徳好な記録再生特性が得られた。Gd-Fe-Cam has dominant iron group sublattice magnetization and its saturation magnetization is 25 emu/cm' to 125 emu/cm'
, TbFeCo layer has rare earth sublattice magnetization dominant and its saturation magnetization is 25 emu/cm3 to 175 emu/am3
In the range of , the recording sensitivity is approximately 7 mW and the reproduction CN ratio is approximately 57.
dB, and good recording and reproducing characteristics were obtained.
また、第２の磁性層のＴｂ−Ｆｅ−Ｃｏのキュリー温度
は約１６０℃であり、約１００℃においても見かけの保
磁力が３ ｋｏｅ以上と高かった。Further, the Curie temperature of Tb-Fe-Co of the second magnetic layer was about 160°C, and the apparent coercive force was as high as 3 koe or more even at about 100°C.
Ｔ ｃｏｓｔは飽和磁化の大きさによって異なるが、は
ぼ５０〜１００”Ｃ程度であった。T cost varied depending on the magnitude of saturation magnetization, but was approximately 50 to 100''C.
飽和磁化が上記範囲を逸脱すると、第２の磁性層が室温
とキュリー温度との間に補償温度を持つようにはならず
、磁化安定性が低下した。When the saturation magnetization deviated from the above range, the second magnetic layer did not have a compensation temperature between room temperature and the Curie temperature, and the magnetization stability decreased.
実施例２
１３０ｍｍφのプリグループの付いているポリカーボネ
ート基板上に、酸化防止と干渉効果を得るために５ｉｓ
Ｌを７０ＯＡ、第１の磁性層としてＧｄ−Ｆｅ−Ｃｏを
４０ＯＡ、第２の磁性層としてＤｙ−Ｆｅ−Ｃ０を４０
ＯＡ、そして酸化防止のために５ｉｓＮａを７０ＯＡ順
次真空を破ることなく連続してマグネトロンスパッタリ
ング装置を用いて、交換結合二層膜の光磁気記録ディス
クを作製した。 Ａｒガス圧は０．１５Ｐａとした。Ｍ
ｉ性暦のターゲットにはＧｄｓ。Example 2 On a polycarbonate substrate with a 130mmφ pre-group, 5is was applied to obtain oxidation prevention and interference effects.
L is 70OA, Gd-Fe-Co is 40OA as the first magnetic layer, Dy-Fe-C0 is 40OA as the second magnetic layer.
A magneto-optical recording disk with an exchange-coupled double-layer film was fabricated using a magnetron sputtering apparatus in which OA and 70 OA of 5isNa were sequentially applied to prevent oxidation without breaking the vacuum. Ar gas pressure was 0.15 Pa. M
Gds is the target of i-sexual calendar.
Ｃｏｗ ｏ、ＤｙとＦｅａｓＣｏ＋ｓを用い、Ｇｄ５ｏ
ＣＯｓｏとＦｅａｓＣＯ＋ｓを使ってＧｄ−Ｆｅ−Ｃｏ
を作製し、ＤｙとＦｅａｓＣｏ＋ｓを使ってＤｙ−Ｆｅ
−Ｃｏを作製した。希土類と鉄族の組成比はＧｄｓｏＣ
ｏｇａとＦｅａ＠Ｇｏｒ８、あるいはＤｙとＦｅａＢｃ
Ｏ＋ｓのターゲットに加える電力を変えることによって
制御し、第２の磁性層、第１の磁性層を各々本発明の要
件を満たすように形成した。Using Cow o, Dy and FeasCo+s, Gd5o
Gd-Fe-Co using COso and FeasCO+s
was prepared and Dy-Fe was prepared using Dy and FeasCo+s.
-Co was produced. The composition ratio of rare earth and iron group is GdsoC
oga and Fea@Gor8 or Dy and FeaBc
This was controlled by changing the power applied to the O+s target, and the second magnetic layer and the first magnetic layer were each formed to satisfy the requirements of the present invention.
電力の範囲は、Ｇｄ−Ｆｅ−ＣｏではＧｄｓｏＣｏｇａ
のターゲットに加＾る電力を２４０Ｗ（ＤＣ） （７７
Ａ／ｍｉｎ、 ）一定としたとき、ＦｅａａＣｏ＋ｓの
ターゲットに加える電力を２８０ Ｗ （ＤＣ） （５
０Ａ／ｍｉｎ、 ）以上にすると、鉄族副格子磁化優勢
になった。 ｏｙ−Ｆｅ−Ｃｏではｏｙのターゲットに
加える電力を１６０Ｗ（ＲＦ）（４０人／ｍｉｎ、）一
定としたとき、ＦｅａｓＣｏ＋ｓのターゲットに加える
電力を２７０ Ｗ （ＤＣ）（５ＱＪ／ｍｉｎ、）以下
にすると、希土類副格子磁化優勢となった。The power range is GdsoCoga for Gd-Fe-Co.
The power applied to the target is 240W (DC) (77
When A/min, ) is constant, the power applied to the FeaaCo+s target is 280 W (DC) (5
0 A/min, ) or more, iron group sublattice magnetization became dominant. For oy-Fe-Co, when the power applied to the oy target is constant at 160 W (RF) (40 people/min,), if the power applied to the FeasCo+s target is 270 W (DC) (5QJ/min,) or less. , the rare earth sublattice magnetization became dominant.
なお、５ｊＪ４の成膜速度は約４ＯＡ／ｍｉｎ、磁性層
の成膜速度は約１００ Ａ ／ｍｉｎであった。Note that the film-forming speed of 5jJ4 was about 4 OA/min, and the film-forming speed of the magnetic layer was about 100 A/min.
作製されたＧｄ−（Ｆｅ＋ｏａ−ｚｃＯｔ）膜のＺは約
４０であり、また交換結合二層膜の界面磁壁エネルギー
密度は約２ ｅｒｇ／ｃｍｚであり、両者間に良好な交
換結合相互作用が働いていることを確認した。The Z of the prepared Gd-(Fe+oa-zcOt) film is approximately 40, and the interfacial domain wall energy density of the exchange-coupled bilayer film is approximately 2 erg/cmz, indicating that a good exchange-coupling interaction exists between the two. I confirmed that
ディスクの記録再生特性は回転数１５０゜ｒｐｍ 、半
径６０ｍｍの位置において測定した。The recording and reproducing characteristics of the disc were measured at a rotation speed of 150° rpm and a radius of 60 mm.
Ｇｄ−Ｆｅ−Ｃｏ層が鉄族副格子磁化優勢でその飽和磁
化が２５ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ／ｃｍ’
％ Ｄｙ −Ｆｅ −Ｃｏ層が希土類副格子磁化優勢
でその飽和磁化が２５ ｅｍｕ／ａｍ３〜１７５ ｅｍ
ｕ／ａｍ’の範囲では、記録感度が約６．５ｍＷ、再生
ＣＮ比が約５８ｄＢであり、良好な記録再生特性が得ら
れた。The Gd-Fe-Co layer has dominant iron group sublattice magnetization and its saturation magnetization is 25 emu/cm' to 125 emu/cm'
%Dy-Fe-Co layer is dominated by rare earth sublattice magnetization and its saturation magnetization is 25 emu/am3 to 175 em
In the u/am' range, the recording sensitivity was about 6.5 mW, the reproduction CN ratio was about 58 dB, and good recording and reproduction characteristics were obtained.
また、第２の磁性層のＤｙ−Ｆｅ−Ｃｏのキュリー温度
は約１５０’Ｃであり、約１００℃においても見かけの
保磁力が２．５ｋＯｅ以上と高かった。Further, the Curie temperature of Dy-Fe-Co of the second magnetic layer was about 150'C, and the apparent coercive force was as high as 2.5 kOe or more even at about 100°C.
Ｔ ｅａｌｌｔは飽和磁化の大きさによって異なるが、
はぼ５０〜１００℃程度であった。T realt varies depending on the magnitude of saturation magnetization, but
The temperature was approximately 50-100°C.
飽和磁化が上記範囲を逸脱すると、第２の磁性層が室温
とキュリー温度との間に補償温度を持つようにはならず
、磁化安定性が低下した。When the saturation magnetization deviated from the above range, the second magnetic layer did not have a compensation temperature between room temperature and the Curie temperature, and the magnetization stability decreased.
実施例３
１３０ｍｍφのプリグループの付いているポリカーボネ
ート基板上に、酸化防止と干渉効果を得るだめに５ｉｓ
Ｎａを７０ＯＡ、第１の磁性層としてＧｄ−Ｆｅ−Ｃｏ
を４００人、第２の磁性層としてＴｂ−Ｄｙ−Ｆｅ−Ｃ
ｏを４００Ａ、そして酸化防止のために５ｊＪ４を７０
ＯＡ順次真空を破ることなく連続してマグネトロンスパ
ッタリング装置を用いて、交換結合二層膜の光磁気記録
ディスクを作製した。Example 3 On a polycarbonate substrate with a 130mmφ pre-group, 5is was applied to obtain oxidation prevention and interference effects.
70OA of Na and Gd-Fe-Co as the first magnetic layer.
400 people, Tb-Dy-Fe-C as the second magnetic layer
o to 400A, and 5jJ4 to 70A to prevent oxidation.
A magneto-optical recording disk with an exchange-coupled two-layer film was fabricated using a magnetron sputtering apparatus in OA sequential order without breaking the vacuum.
Ａｒガス圧は０．１５Ｐａとした。磁性層のターゲット
にはＧｄ５ｏＣＯｓｏ、Ｔｂ５ｏＤｙｓｏとＦｅａｓＣ
ｏ＋ｓを用い、Ｇｄｓ。Ar gas pressure was 0.15 Pa. The magnetic layer targets include Gd5oCOso, Tb5oDyso and FeasC.
Gds using o+s.
Ｃ０５ｏとＦｅａｓＣｏ＋ｓを使ってＧｄ−Ｆｅ−Ｃｏ
を作製し、Ｔｂｓ。Gd-Fe-Co using C05o and FeasCo+s
and Tbs.
Ｄｙ、。とＦｅａｓＣｏ＋ｓを使って７１） −［１ｙ
−Ｆｅ−Ｇｏを作製した。希土類と鉄族の組成比はＧｄ
ｓ。Ｃｏｓ。とＦｅａｓＣＯ＋ｓ、あるいはＴｂ５ｏＤ
ｙｓｏとＦｅａｓＣＯ＋ｓのターゲットに加える電力を
変えることによって制御し、第２の磁性層、第１の磁性
層を各々本発明の要件を満たすように形成した。Dy. and FeasCo+s 71) −[1y
-Fe-Go was produced. The composition ratio of rare earths and iron group is Gd
s. Cos. and FeasCO+s, or Tb5oD
The second magnetic layer and the first magnetic layer were each formed to satisfy the requirements of the present invention by controlling by changing the power applied to the yso and FeasCO+s targets.
電力の範囲は、Ｇｄ−Ｆｅ−ＣｏではＧｄ５ｏＣＯ１ｌ
ｏツタ−ゲットに加える電力を２４０Ｗ（ＤＣ） （７
７へ／ｍｉｎ、 ）一定としたとき、ＦｅａｊＣｏ＋ｓ
のターゲットに加える電力を２８０Ｗ（ＤＣ）（５０，
／ｊ／ｍｉｎ、）以上にすると、鉄族副格子磁化優勢に
なった。 Ｔｂ−Ｄｙ−Ｆｅ−ＣｏではＴｂ５ｏＤｙｓ
ｏのターゲットに加える電力を１５０Ｗ（ＲＦ） （４
０Ａ／ｍｉｎ、）一定としたとき、Ｆ６ａｉＣＯ＋ｓの
ターゲットに加える電力を２７０Ｗ （ＤＣ） （５０
Ａ／ｍｉｎ、）以下にすると、希土類副格子磁化優勢と
なった。The power range is Gd5oCO1l for Gd-Fe-Co
The power applied to the target is 240W (DC) (7
7/min, ) when constant, FeajCo+s
The power applied to the target is 280W (DC) (50,
/j/min, ), iron group sublattice magnetization became dominant. Tb5oDys for Tb-Dy-Fe-Co
The power applied to the target of o is 150W (RF) (4
0A/min, ) constant, the power applied to the target of F6aiCO+s is 270W (DC) (50
A/min, ) or less, the rare earth sublattice magnetization became dominant.
なお、５ｉｓＮ４の成膜速度は約４ＯＡ／ｍｉｎ、磁性
層の成膜速度は約１００ＡＺＩＩＩｉ口であった。Note that the deposition rate of 5isN4 was approximately 4OA/min, and the deposition rate of the magnetic layer was approximately 100AZIIIi.
作製されたＧｄ−（Ｆｅｌｏ。−ｍｃＯｊ ＩＩ！のＺ
は約４０であり、また交換結合二層膜の界面磁壁エネル
ギー密度は約２ ｅｒｇ／ａｍ”であり、両者間に良好
な交換結合相互作用が働いていることを確認した。Z of the prepared Gd-(Felo.-mcOj II!
was approximately 40, and the interfacial domain wall energy density of the exchange-coupled bilayer film was approximately 2 erg/am'', confirming that a good exchange-coupling interaction was working between the two.
ディスクの記録再生特性は回転数１５００ｒｐｍ 、半
径６０ｍｍの位置において測定した。The recording and reproducing characteristics of the disc were measured at a rotation speed of 1500 rpm and a radius of 60 mm.
Ｇｄ−Ｆｅ−Ｃｏ層が鉄族副格子磁化優勢でその飽和磁
化が２５ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ／ａｍ！
、 Ｔｂ−ｏｙ−Ｆｅ−Ｃｏ層が希土類副格子磁化優勢
でその飽和磁化が２５ ｅｍｕ／ｃｍ’ 〜１７５ ｅ
ｍｕ／ｃｍ’の範囲では、記録感度が約７．４ｍＷ、再
生ＣＮ比が約５８ｄＢであり、良好な記録再生特性が得
られた。The Gd-Fe-Co layer is dominated by iron group sublattice magnetization, and its saturation magnetization is 25 emu/cm' to 125 emu/am!
, the Tb-oy-Fe-Co layer is dominated by rare earth sublattice magnetization and its saturation magnetization is 25 emu/cm' to 175 e
In the range of mu/cm', the recording sensitivity was about 7.4 mW, the reproduction CN ratio was about 58 dB, and good recording and reproduction characteristics were obtained.
また、第２の磁性層のＴｂ−Ｄｙ−Ｆｅ−Ｇｏのキュリ
ー温度は約１７０℃であり、約１００℃においても見か
けの保磁力が３．７ｋＯｅ以上と高かった。Further, the Curie temperature of Tb-Dy-Fe-Go of the second magnetic layer was about 170°C, and the apparent coercive force was as high as 3.7 kOe or more even at about 100°C.
Ｔ ｃａｍｐは飽和磁化の大きさによって異なるが、は
ぼ５０〜１００”Ｃ程度であった。T camp varied depending on the magnitude of saturation magnetization, but was approximately 50 to 100''C.
飽和磁化が上記範囲を逸脱すると、第２の磁性層が室温
とキュリー温度との間に補償温度を持つようにはならず
、磁化安定性が低下した。When the saturation magnetization deviated from the above range, the second magnetic layer did not have a compensation temperature between room temperature and the Curie temperature, and the magnetization stability decreased.
比較例１
実施例１の比較例として同じターゲットを用いて、Ｔｂ
−Ｆｅ −Ｃｏ層を形成する際に、Ｆｅｅ４Ｃｏｓの
ターゲットに加える電力を２５０Ｗ（ＤＣ）（４６Ａ／
ｍｉｎ、）以上にする他は同様にしてディスクを作製し
、Ｇｄ−Ｆｅ−Ｃｏ Ｎは鉄族副格子磁化優勢でその飽
和磁化が２５ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ／ｃ
ｍ’ 、Ｔｂ−Ｆｅ−Ｃｏ層も鉄族副格子磁化優勢でそ
の飽和磁化が２５ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ
／ｃｍ’であった。このディスクに記録再生を行ったと
ころ、記録感度が約６．５ｍＷ、再生ＣＮ比が約５９ｄ
Ｂであり、良好な記録再生特性が得られたが、第２の磁
性層のＴｂ−Ｆｅ−Ｃｏの約１００”Ｃにおける見かけ
の保磁力が１ｋｏｅ以下と低かった。Comparative Example 1 Using the same target as the comparative example of Example 1, Tb
When forming the -Fe-Co layer, the power applied to the Fee4Cos target was 250W (DC) (46A/
A disk was prepared in the same manner except that the Gd-Fe-Co N had iron group sublattice magnetization dominant and its saturation magnetization was 25 emu/cm' to 125 emu/c.
m', the Tb-Fe-Co layer is also dominated by iron group sublattice magnetization, and its saturation magnetization is 25 emu/cm' to 125 emu
/cm'. When recording and playing back on this disc, the recording sensitivity was approximately 6.5mW, and the reproduction CN ratio was approximately 59d.
Although good recording and reproducing characteristics were obtained, the apparent coercive force of Tb--Fe--Co of the second magnetic layer at about 100''C was as low as 1 koe or less.
比較例２
実施例１の比較例として、同じターゲットを用いて、Ｇ
ｄ −Ｆｅ −Ｃｏ層を形成する際に、Ｆｅｏ４Ｃｏ６
のターゲットに加える電力を２８０Ｗ（ＤＣ）（５０Ａ
／ｍｉｎ、）以上とした他は同様にしてディスクを作製
した。Ｇｄ−Ｆｅ−Ｃｏ層は希土類副格子磁化優勢でそ
の飽和磁化が１０ ｅｍｕ／ｃｍ’ 〜１２５ ｅｍｕ
／ｃｍ’であった。このディスクに記録再生を行ったと
ころ、Ｔｂ−Ｆｅ−Ｃｏ層の組成に関係なく記録感度が
約９ｍＷ、再生ＣＮ比が４０〜５０ｄＢであり、良好な
記録・再生特性が得られなかった。Comparative Example 2 As a comparative example of Example 1, using the same target, G
When forming the d-Fe-Co layer, Feo4Co6
The power applied to the target is 280W (DC) (50A
A disk was produced in the same manner except that the heating speed was set at 200 m/min, or higher. The Gd-Fe-Co layer is dominated by rare earth sublattice magnetization, and its saturation magnetization is 10 emu/cm' to 125 emu
/cm'. When this disk was subjected to recording and reproduction, the recording sensitivity was approximately 9 mW and the reproduction CN ratio was 40 to 50 dB, regardless of the composition of the Tb-Fe-Co layer, and good recording and reproduction characteristics were not obtained.
本発明は、以上説明した実施例の他にも種々の応用が可
能である１例えば、第３図示の構成の保護層の上に、更
にＡｉ等から成る金属反射層を設けたり、接着剤を介し
て保護プレートを貼り合わせたりしても良い、また、媒
体の形状もディスクに限らず、カード状あるいはテープ
状にしても良い。本発明は特許請求の範囲を逸脱しない
限りにおいて、このような応用例を全て包含する。The present invention can be applied in various ways in addition to the embodiments described above.1 For example, a metal reflective layer made of Al or the like may be further provided on the protective layer having the structure shown in the third figure, or an adhesive may be applied. A protective plate may be bonded to the medium via the media.The shape of the medium is not limited to a disk, but may be in the form of a card or tape. The present invention includes all such applications without departing from the scope of the claims.
［発明の効果１
以上詳細に説明したように、光磁気記録用交換結合二層
膜において、高保磁力を示す第２の磁性Ｍとして室温と
キュリー温度との間に補償温度を有する希土類副格子磁
化優勢な希土類−鉄族非晶質合金を、低保磁力を示す第
１の磁性層として鉄族副格子磁化優勢な希土類−鉄族非
晶質合金を用い、更に所定の要件を満たすようにするこ
とにより、記録・再生特性に優れ、かつ記録情報の安定
性に優れた光磁気記録媒体を得ることができるようにな
った。[Effect of the invention 1] As explained in detail above, in the exchange-coupled double-layer film for magneto-optical recording, rare earth sublattice magnetization having a compensation temperature between room temperature and the Curie temperature is used as the second magnetism M exhibiting a high coercive force. Using a dominant rare earth-iron group amorphous alloy as the first magnetic layer exhibiting a low coercive force, a rare earth-iron group amorphous alloy with dominant iron group sublattice magnetization is further made to satisfy predetermined requirements. As a result, it has become possible to obtain a magneto-optical recording medium with excellent recording/reproducing characteristics and excellent stability of recorded information.
第１図は本発明の光磁気記録媒体の一実施態様の構成を
示す略断面図、第２図は本発明の媒体における第２の磁
性層の温度変化を示す図、第３図は従来の光磁気記録媒
体における高保磁力層の保磁力の温度変化を示す図、第
４図は光磁気記録媒体の磁性層の保磁力の、理想的な特
性を示す図、第５図乃至第７図はそれぞれ本発明の媒体
における第２の磁性層の希土類元素の組成と飽和磁界と
の関係を示す図、第８図は本発明の媒体における第１の
磁性層の希土類元素の組成と飽和磁化との合本を示す図
である。
１・・・基板、２・・・下引き層、３・・・第１の磁性
層、４・・・第２の磁性層、５・・・保護層。
特許出願人 キャノン株式会社FIG. 1 is a schematic cross-sectional view showing the structure of an embodiment of the magneto-optical recording medium of the present invention, FIG. 2 is a diagram showing temperature changes in the second magnetic layer in the medium of the present invention, and FIG. A diagram showing temperature changes in the coercive force of a high coercive force layer in a magneto-optical recording medium, FIG. 4 is a diagram showing ideal characteristics of the coercive force of a magnetic layer of a magneto-optical recording medium, and FIGS. FIG. 8 shows the relationship between the rare earth element composition of the second magnetic layer and the saturation magnetic field in the medium of the present invention, and FIG. It is a diagram showing a combined copy. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Undercoat layer, 3... First magnetic layer, 4... Second magnetic layer, 5... Protective layer. Patent applicant Canon Co., Ltd.
Claims (1)
、第１の磁性層よりも高い保磁力と低いキュリー温度と
を有する第２の磁性層を有する光磁気記録媒体において
、 前記第１の磁性層が、鉄族副格子磁化優勢で、その飽和
磁化が２５〜１２５ｅｍｕ／ｃｍ＾３の範囲にあるＧｄ
−Ｆｅ−Ｃｏ非晶質合金から成り、且つ前記第２の磁性
層が、希土類副格子磁化優勢で、その飽和磁化が２５〜
１７５ｅｍｕ／ｃｍ＾３の範囲にあるＲ−Ｆｅ−Ｃｏ非
晶質合金（ＲはＴｂ及びＤｙの少なくとも一種の元素）
から成ることを特徴とする光磁気記録媒体。(1) A magneto-optical recording medium having a first magnetic layer and a second magnetic layer exchange-coupled with the first magnetic layer and having a higher coercive force and a lower Curie temperature than the first magnetic layer, The first magnetic layer is made of Gd in which the iron group sublattice magnetization is dominant and the saturation magnetization is in the range of 25 to 125 emu/cm^3.
-The second magnetic layer is made of a Fe-Co amorphous alloy, and the second magnetic layer has a rare earth sublattice magnetization predominance, and its saturation magnetization is 25 to 25.
R-Fe-Co amorphous alloy in the range of 175 emu/cm^3 (R is at least one element of Tb and Dy)
A magneto-optical recording medium characterized by comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20957588A JP2648623B2 (en) | 1987-08-25 | 1988-08-25 | Magneto-optical recording medium |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20929987 | 1987-08-25 | ||
| JP62-209299 | 1987-08-25 | ||
| JP20957588A JP2648623B2 (en) | 1987-08-25 | 1988-08-25 | Magneto-optical recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01133243A true JPH01133243A (en) | 1989-05-25 |
| JP2648623B2 JP2648623B2 (en) | 1997-09-03 |
Family
ID=26517357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20957588A Expired - Fee Related JP2648623B2 (en) | 1987-08-25 | 1988-08-25 | Magneto-optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2648623B2 (en) |
-
1988
- 1988-08-25 JP JP20957588A patent/JP2648623B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2648623B2 (en) | 1997-09-03 |
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