JPH0555941B2 - - Google Patents
Info
- Publication number
- JPH0555941B2 JPH0555941B2 JP59152164A JP15216484A JPH0555941B2 JP H0555941 B2 JPH0555941 B2 JP H0555941B2 JP 59152164 A JP59152164 A JP 59152164A JP 15216484 A JP15216484 A JP 15216484A JP H0555941 B2 JPH0555941 B2 JP H0555941B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- magnetic
- substrate
- recording medium
- photothermal
- 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
- 239000000758 substrate Substances 0.000 claims description 19
- 229910045601 alloy Inorganic materials 0.000 claims description 12
- 239000000956 alloy Substances 0.000 claims description 12
- 229910052723 transition metal Inorganic materials 0.000 claims description 12
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 5
- 150000002910 rare earth metals Chemical class 0.000 claims description 5
- 150000003624 transition metals Chemical class 0.000 claims description 5
- 239000010408 film Substances 0.000 description 68
- 239000010409 thin film Substances 0.000 description 20
- 230000000694 effects Effects 0.000 description 9
- 238000004544 sputter deposition Methods 0.000 description 7
- 230000005415 magnetization Effects 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000010355 oscillation Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 230000005374 Kerr effect Effects 0.000 description 2
- 229910016629 MnBi Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052774 Proactinium Inorganic materials 0.000 description 1
- 229910001117 Tb alloy Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 229910000808 amorphous metal alloy Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
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
Description
〔技術分野〕
本発明は光磁気メモリー、磁気記録、表示素子
等に用いられる光熱磁気記録媒体に関する。より
詳しくは、カー効果、フアラデー効果等の磁気光
学効果を用いて読出すことのできる光熱磁気記録
媒体に関する。
〔従来技術〕
従来、光熱磁気記録媒体としてはMnBi、
MnCuBi等の多結晶薄膜、GdCo、GdFe、TbFe、
DyFe、GdTbFe、GdTbFeCo等の非晶質薄膜、
GdCo、GdFe、TbFe、DyFe、GdTbFe、
GdTbFeCo等の非晶質薄膜、TbFeO3等の単結晶
薄膜等が知られている。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性、
信号を小さなエネルギーで書込むための書込効
率、記録信号をＳ／Ｎ比よく読出すための再生効
率等を勘案すると、最近では、非晶質薄膜が光磁
気記録媒体として優れていると考えられている。
しかしながら、これらの非晶質薄膜においても未
だ、再生信号のＳ／Ｎ比が十分でなく満足な再生
信号レベルが得られないという欠点があつた。特
にカー効果を用いる再生方式ではカー回転角が小
さいためＳ／Ｎ比を高めることが困難であつた。
そのため本発明者らはカー回転角をさらに増大さ
せるためにGdFeやTbFeにCoを添加した
GdFeCo、TbFeCoまたGdTbFeにCoを添加した
GdTbFeCoの研究をすすめ、特にGdTbFeCoの
４元非晶質合金膜が十分カー回転角が大きく、熱
安定性にすぐれ、かつＳ／Ｎ比の良く再生できる
光熱磁気記録媒体であることを見出した。
このように記録媒体である磁性材料の特性の改
良検討を進める一方、記録媒体上に誘電体膜や金
属反射膜を形成してみかけのカー回転角を高める
試みについても検討が続けられている。しかしな
がらＳ／Ｎ比を高めるものとして最適な層構成は
未だ見出されておらず、多くの改良の余地が残さ
れている。
〔発明の目的〕
本発明は以上の点に鑑みなされたものであり、
従来の種々の光熱磁気記録媒体よりも、みかけの
カー回転角が大きくでき、高いＳ／Ｎ比を得るこ
とが可能な新規な積層構造を有する光熱磁気記録
媒体を提供することにある。
〔発明の構成〕
以上の目的は下記の本発明の光熱磁気記録媒体
によつて達成される。すなわち本発明の光熱磁気
記録媒体は、透明膜と、該透明膜上に形成された
希土類−遷移金属合金からなる磁性膜とからなる
一単位の積層構造体が基板上に前記透明膜を基板
側にして少なくとも二単位以上積層されていると
共に最も基板側の磁性膜以外の磁性膜は最も基板
側の磁性膜よりキユリー温度が低い希土類−遷移
金属合金からなり、更に、基板から最も離れた前
記積層構造体の基板側とは逆側には透明膜と反射
膜が形成されていることを特徴とする。
本発明で用いる希土類−遷移金属合金からなる
磁性膜は、記録光（例えばレーザー光）を照射す
ると、その照射された部分に於いて光エネルギー
が熱エネルギーに変換されることにより温度が上
昇し、キユリー点に達して、磁化が反転するよう
な磁性薄膜である。このような磁化の反転により
記録ビツトを形成することができ、この記録ビツ
トに再生光を照射し、その反射光を検知すること
により再生が可能である。このような磁気光学効
果を有する希土類−遷移金属合金からなる磁性膜
（以下、磁気光学効果を有する薄膜という）とし
ては、次に挙げるものが好ましい。すなわち、
Fe、Co、Ni等の遷移金属から選ばれた一種以上
の金属元素とGd、Tb、Dy等の希土類金属から
選ばれた一種以上の金属元素（以下、遷移金属−
希土類金属と略す。）とを含有し、膜面に垂直方
向に磁化容易軸を有する非晶質磁性薄膜が好まし
い。例えば、GdFe、TbFe、DyFe、
GdTbFeCo、GdDyFeCo、TbDyFeCo等の非晶
質薄膜である。このように、薄膜が非晶質物質か
ら構成されれば、磁化容易軸が膜面の垂直方向に
向けられるのに十分な垂直磁気異方性を有する。
このような非晶質磁性薄膜は、この薄膜を構成
する成分である各金属元素を蒸着源として、スパ
ツタリング法、真空蒸着法等の方法によつて成膜
することができる。
以上述べたような遷移金属−希土類金属からな
る非晶質磁性薄膜に於いて、十分な垂直磁気異方
性かつ大きなカー回転角を得るためには下記表１
に示すような組成範囲が好ましい。
[Technical Field] The present invention relates to a magneto-optical recording medium used for magneto-optical memory, magnetic recording, display elements and the like. More specifically, the present invention relates to a photothermal magnetic recording medium that can be read using magneto-optical effects such as the Kerr effect and the Faraday effect. [Prior art] Conventionally, MnBi, MnBi,
Polycrystalline thin films such as MnCuBi, GdCo, GdFe, TbFe,
Amorphous thin films such as DyFe, GdTbFe, and GdTbFeCo,
GdCo, GdFe, TbFe, DyFe, GdTbFe,
Amorphous thin films such as GdTbFeCo and single crystal thin films such as TbFeO 3 are known. Among these thin films, the film-forming ability of producing a large-area thin film at a temperature near room temperature,
In recent years, amorphous thin films have been considered to be superior as magneto-optical recording media, considering the writing efficiency for writing signals with small energy and the reproduction efficiency for reading recorded signals with a good S/N ratio. It is being
However, these amorphous thin films still have the drawback that the S/N ratio of the reproduced signal is insufficient and a satisfactory reproduced signal level cannot be obtained. In particular, in the reproduction method using the Kerr effect, it is difficult to increase the S/N ratio because the Kerr rotation angle is small.
Therefore, the present inventors added Co to GdFe and TbFe in order to further increase the Kerr rotation angle.
Co added to GdFeCo, TbFeCo and GdTbFe
We conducted research on GdTbFeCo and found that a quaternary amorphous alloy film of GdTbFeCo has a sufficiently large Kerr rotation angle, excellent thermal stability, and is a photothermal magnetic recording medium that can be reproduced with a good S/N ratio. While efforts are being made to improve the properties of the magnetic materials used as recording media, studies are also being conducted on attempts to increase the apparent Kerr rotation angle by forming dielectric films or metal reflective films on recording media. However, the optimal layer structure for increasing the S/N ratio has not yet been found, and there remains much room for improvement. [Object of the invention] The present invention has been made in view of the above points,
It is an object of the present invention to provide a photothermal magnetic recording medium having a novel laminated structure that can have a larger apparent Kerr rotation angle and obtain a higher S/N ratio than various conventional photothermal magnetic recording media. [Structure of the Invention] The above objects are achieved by the following photothermal magnetic recording medium of the present invention. That is, in the photothermal magnetic recording medium of the present invention, a unit laminated structure consisting of a transparent film and a magnetic film made of a rare earth-transition metal alloy formed on the transparent film is placed on a substrate, with the transparent film on the substrate side. The magnetic films other than the magnetic film closest to the substrate are made of a rare earth-transition metal alloy having a lower Curie temperature than the magnetic film closest to the substrate, and the laminated layers farthest from the substrate A transparent film and a reflective film are formed on the opposite side of the structure from the substrate side. When the magnetic film made of the rare earth-transition metal alloy used in the present invention is irradiated with recording light (e.g. laser light), the temperature of the irradiated area increases as the light energy is converted into thermal energy. It is a magnetic thin film whose magnetization reverses when it reaches the Kyrie point. Recording bits can be formed by such reversal of magnetization, and reproduction is possible by irradiating the recording bits with reproduction light and detecting the reflected light. As a magnetic film made of a rare earth-transition metal alloy having such a magneto-optic effect (hereinafter referred to as a thin film having a magneto-optic effect), the following are preferable. That is,
One or more metal elements selected from transition metals such as Fe, Co, and Ni and one or more metal elements selected from rare earth metals such as Gd, Tb, and Dy (hereinafter referred to as transition metals).
Abbreviated as rare earth metal. ) and has an axis of easy magnetization perpendicular to the film surface. For example, GdFe, TbFe, DyFe,
These are amorphous thin films such as GdTbFeCo, GdDyFeCo, and TbDyFeCo. Thus, if the thin film is made of an amorphous material, it has sufficient perpendicular magnetic anisotropy so that the axis of easy magnetization is oriented in the direction perpendicular to the film surface. Such an amorphous magnetic thin film can be formed by a method such as a sputtering method or a vacuum evaporation method using each metal element that constitutes the thin film as a deposition source. In order to obtain sufficient perpendicular magnetic anisotropy and a large Kerr rotation angle in the amorphous magnetic thin film made of transition metals and rare earth metals as described above, Table 1 below is required.
A composition range as shown in is preferable.
本発明の光熱磁気記録媒体により従来の種々の
層構造を有する光熱磁気記録媒体よりもみかけの
カー回転角を大きくすることができるようにな
り、再生に於て高いＳ／Ｎ比を得ることが可能と
なつた。
〔実施例〕
以下、本発明を実施例をあげて詳細に説明す
る。
参考例 １
３インチ角の白板ガラスを基板とし、高周波ス
パータ法において前記基板１上にMgF2からなる
透明膜２を成膜した。この際にターゲツトとして
５インチφのMgF2化合物を用い、真空槽内を１
×10-5Pa程度まで排気の後Arガスを、0.6Paまで
導入し、高周波電源より200Wのスパツタ電力を
供給して成膜を行なつた。
次いで、高周波スパツタ法において前記透明膜
２上に磁性膜３を成膜した。この際ターゲツトと
して５インチφのFe70Co30（原子％）合金上に１
cm角で組成比が１：１のGdTb合金片を均一に並
べたものを使用し、透明膜２を成膜するのと同一
のガス圧、スパツタ電力の条件を用いて成膜を行
なつた。膜厚はこの膜の透光率が10％以上を有す
るように20〜300Åとした、このようにしてでき
た磁性膜３はＸ線回析により非晶質であることを
確認した。また組成分析の結果この膜は（Gd0.5
Tb0.5）0.25（Fe0.7 Co0.3）0.75であり、膜面に垂
直方向に磁化容易軸を有することを確認した。カ
ー回転角は発振波長633nｍのHeNeレーザを用い
た測定の結果、0.37度、キユリー温度は280度で
あつた。
次に、透明膜４及び磁性膜５を成膜する際、前
記透明膜２及び磁性膜３を成膜するのと、同一の
方法、条件で、真空を破らずに連続的に成膜し
た。さらに、干渉膜６を高周波スパツタ法で成膜
した。この際ターゲツトとしてAlNを用いる以
外は透明膜２及び４を成膜するのと同様に膜厚
1000Åを有する膜を成膜した。その上に蒸着法に
よつて500ÅのCuを成膜し、反射膜７とした。こ
の反射膜の材料をAu、Ag、Alに変えても回転角
に変化はなかつた。
更にその上に蒸着法によつて2000ÅのSiO薄膜
を成膜し、保護膜８とした。
以上のようにして作製した本発明の光熱磁気記
録媒体に対して発振波長830nｍのHeNeレーザ光
を基板１側から入射させた場合に得られたカー回
転角は1.5度であり、希土類−遷移金属合金非晶
質膜を一層のみ有する光熱磁気記録媒体のカー回
転角0.25〜0.35度に比較して大幅に増大させるこ
とができた。
参考例 ２
参考例１における反射膜７、保護膜８を成膜し
ない以外は、参考例１と同様にして光熱磁気記録
媒体を作製した。これを参考例１と同様にしてカ
ー回転角を測定した結果、値は0.80度であつた。
参考例１及び参考例２との比較から本発明の光
熱磁気記録媒体における反射膜７は明らかにみか
けの磁気光学効果を増大させる効果を有してい
る。
参考例 ３
参考例１における、透明膜と磁性膜の組合せを
１組にした以外は参考例１と同様にして光熱磁気
記録媒体を作製した。これを参考例１と同様にし
てカー回転角を測定したところ、1.20度であつ
た。
参考例１と参考例３と比較すると、本発明の光
熱磁気記録媒体において透明膜と磁性膜の組合せ
数を増したことによる優位性は明らかである。
参考例 ４、５
参考例１において透明膜と合せ数を３組にした
以外は参考例１と同様にして光熱磁気記録媒体を
作製した。これを参考例１と同様にしてカー回転
角を測定した結果を表２に示す。このように、透
明膜と磁性膜の組の数を増していくとカー回転角
は少し増加した。
The photothermal magnetic recording medium of the present invention makes it possible to increase the apparent Kerr rotation angle compared to conventional photothermal magnetic recording media having various layer structures, making it possible to obtain a high S/N ratio during reproduction. It became possible. [Example] Hereinafter, the present invention will be explained in detail by giving examples. Reference Example 1 A 3-inch square white glass plate was used as a substrate, and a transparent film 2 made of MgF 2 was formed on the substrate 1 using a high frequency sputtering method. At this time, a 5-inch φ MgF 2 compound was used as a target, and the inside of the vacuum chamber was
After evacuation to about ×10 -5 Pa, Ar gas was introduced to 0.6 Pa, and film formation was performed by supplying sputtering power of 200 W from a high frequency power source. Next, a magnetic film 3 was formed on the transparent film 2 using a high frequency sputtering method. At this time, as a target, 1 was placed on a 5 inch φ Fe 70 Co 30 (atomic%) alloy.
The film was formed using uniformly arranged cm square GdTb alloy pieces with a composition ratio of 1:1, and using the same gas pressure and sputtering power conditions as those used to form transparent film 2. . The film thickness was set to 20 to 300 Å so that the film had a light transmittance of 10% or more. The magnetic film 3 thus formed was confirmed to be amorphous by X-ray diffraction. Also, as a result of compositional analysis, this film has (Gd 0.5
Tb 0.5 ) 0.25 (Fe 0.7 Co 0.3 ) 0.75 , and it was confirmed that the film had an axis of easy magnetization perpendicular to the film surface. As a result of measurement using a HeNe laser with an oscillation wavelength of 633 nm, the Kerr rotation angle was 0.37 degrees and the Curie temperature was 280 degrees. Next, when forming the transparent film 4 and the magnetic film 5, the films were formed continuously without breaking the vacuum using the same method and conditions as those used to form the transparent film 2 and the magnetic film 3. Furthermore, an interference film 6 was formed by a high frequency sputtering method. At this time, the film thickness was the same as that for forming transparent films 2 and 4 except that AlN was used as the target.
A film having a thickness of 1000 Å was formed. A 500 Å thick Cu film was formed thereon by vapor deposition to form a reflective film 7. Even when the material of this reflective film was changed to Au, Ag, or Al, there was no change in the rotation angle. Further, a 2000 Å thin SiO film was formed thereon by vapor deposition to form a protective film 8. The Kerr rotation angle obtained when a HeNe laser beam with an oscillation wavelength of 830 nm was incident on the photothermal magnetic recording medium of the present invention produced as described above from the substrate 1 side was 1.5 degrees, and the rare earth-transition metal The Kerr rotation angle could be significantly increased compared to the 0.25 to 0.35 degree of a photothermal magnetic recording medium having only one layer of alloy amorphous film. Reference Example 2 A photothermal magnetic recording medium was produced in the same manner as in Reference Example 1, except that the reflective film 7 and protective film 8 in Reference Example 1 were not formed. The Kerr rotation angle was measured in the same manner as in Reference Example 1, and the value was 0.80 degrees. From a comparison with Reference Examples 1 and 2, the reflective film 7 in the photothermal magnetic recording medium of the present invention clearly has the effect of increasing the apparent magneto-optic effect. Reference Example 3 A photothermal magnetic recording medium was produced in the same manner as in Reference Example 1 except that the transparent film and magnetic film were combined into one set. The Kerr rotation angle was measured in the same manner as in Reference Example 1 and found to be 1.20 degrees. Comparing Reference Example 1 and Reference Example 3, it is clear that the advantage of increasing the number of combinations of transparent films and magnetic films in the photothermal magnetic recording medium of the present invention is obvious. Reference Examples 4 and 5 A photothermal magnetic recording medium was produced in the same manner as in Reference Example 1, except that three sets of transparent films were used in Reference Example 1. The Kerr rotation angle was measured in the same manner as in Reference Example 1, and the results are shown in Table 2. In this way, as the number of pairs of transparent films and magnetic films was increased, the Kerr rotation angle slightly increased.
【表】
参考例 ４
参考例１において磁性膜５を成膜する際にター
ゲツトとして６インチφのFeを用い、その上に
１cm角のTb合金を並べたものを用いて高周波ス
パツタ法によつて成膜する以外は参考例１と同様
にして光熱磁気記録媒体を作製した。TbFe膜の
カー回転角は0.21度である。これを参考例１と同
様にしてカー回転角を測定したところ1.45度であ
つた。TbFeはキユリー温度が125℃であり、
GdTbFeCoの280℃に比較して低いため、記録効
率の点で有利である。実際、発振波長8300Åパワ
ー10ｍＷの半導体レーザを用いてこの光熱磁気記
録媒体に書込みを試みたところ、1.2μｍのスポツ
トが形成されることを確認した。
このように、TbFe膜を基板１側から第１番目
の磁性膜以外の磁性膜として用いると、再生効率
をあまり劣化させることなく、より記録効率を高
めることができた。
参考例 ６、７
参考例１において非晶質磁性膜３および５を形
成する際に５インチφの（Fe70 Co30）（原子％）
円板上に１cm角のGdDy合金（１：１）、或いは
TbDy合金（１：１）を並べたものをターゲツト
として用いる以外は参考例１と同様にして光熱磁
気記録媒体を作製した。これを参考例１と同様に
してカー回転角を測定した結果を表３に示す。[Table] Reference Example 4 When forming the magnetic film 5 in Reference Example 1, a 6-inch φ Fe was used as the target, and 1 cm square Tb alloy was arranged on top of it by high-frequency sputtering. A photothermal magnetic recording medium was produced in the same manner as in Reference Example 1 except for the film formation. The Kerr rotation angle of the TbFe film is 0.21 degrees. The Kerr rotation angle was measured in the same manner as in Reference Example 1 and found to be 1.45 degrees. TbFe has a Kyrie temperature of 125℃,
It is lower than the 280°C of GdTbFeCo, which is advantageous in terms of recording efficiency. In fact, when writing was attempted on this photothermal magnetic recording medium using a semiconductor laser with an oscillation wavelength of 8300 Å and a power of 10 mW, it was confirmed that a 1.2 μm spot was formed. In this way, when the TbFe film was used as a magnetic film other than the first magnetic film from the substrate 1 side, the recording efficiency could be further improved without significantly deteriorating the reproduction efficiency. Reference Examples 6 and 7 When forming amorphous magnetic films 3 and 5 in Reference Example 1, (Fe 70 Co 30 ) (atomic %) of 5 inches φ was used.
1 cm square GdDy alloy (1:1) on a disk, or
A photothermal magnetic recording medium was produced in the same manner as in Reference Example 1 except that an array of TbDy alloys (1:1) was used as the target. The Kerr rotation angle was measured in the same manner as in Reference Example 1, and the results are shown in Table 3.
【表】
以上述べた実施例から明らかなように、本発明
の光熱磁気記録媒体により再生時に大きなカー回
転角を得ることが可能となり、再生信号レベルが
向上した。また、非晶質磁性薄膜と透明膜との積
層構造体を３単位或いは４単位有するような光熱
磁気記録媒体のカー回転角はそれを２単位有する
記録媒体と同等又はそれ以上の値を示した。この
ため、磁気光学効果を有する薄膜として希土類−
遷移金属からなる非晶質磁性薄膜を用いる場合は
前記の積層構造体の数は２ないし３単位が適当で
ある。しかし、磁気光学効果を有する薄膜として
透光性のよいものを用いれば磁性層を透過する時
の光量損失が減少するのでこの限りではない。
また、最も基板側の磁性膜以外の磁性膜を、最
も基板側の磁性膜よりキユリー温度が低い希土類
−遷移金属合金から形成することで、再生効率を
劣化させることなく記録効率を高めることが可能
となつた。[Table] As is clear from the examples described above, the photothermal magnetic recording medium of the present invention made it possible to obtain a large Kerr rotation angle during reproduction, and the reproduction signal level was improved. In addition, the Kerr rotation angle of a photothermal magnetic recording medium having 3 or 4 units of a laminated structure of an amorphous magnetic thin film and a transparent film was equal to or greater than that of a recording medium having 2 units. . For this reason, rare earth metals can be used as thin films with magneto-optic effects.
When an amorphous magnetic thin film made of a transition metal is used, the number of laminated structures is suitably 2 to 3 units. However, this is not the case because if a thin film having a magneto-optic effect is used that has good light transmittance, the amount of light lost when passing through the magnetic layer will be reduced. In addition, by forming the magnetic films other than the magnetic film closest to the substrate from a rare earth-transition metal alloy whose Curie temperature is lower than that of the magnetic film closest to the substrate, it is possible to increase recording efficiency without deteriorating playback efficiency. It became.
第１図は本発明に係る光熱磁気記録媒体の一実
施例を示す模式断面図である。
１……基板、２，４……透明膜、３，５……非
晶質磁性薄膜、６……干渉膜、７……反射膜、８
……保護膜。
FIG. 1 is a schematic cross-sectional view showing an embodiment of a photothermal magnetic recording medium according to the present invention. 1... Substrate, 2, 4... Transparent film, 3, 5... Amorphous magnetic thin film, 6... Interference film, 7... Reflective film, 8
……Protective film.
Claims (1)
遷移金属合金からなる磁性膜とからなる一単位の
積層構造体が基板上に前記透明膜を基板側にして
少なくとも二単位以上積層されていると共に最も
基板側の磁性膜以外の磁性膜は最も基板側の磁性
膜よりキユリー温度が低い希土類−遷移金属合金
からなり、更に、基板から最も離れた前記積層構
造体の基板側とは逆側には透明膜と反射膜が形成
されていることを特徴とする光熱磁気記録媒体。1 Transparent film and rare earth formed on the transparent film
At least two units of a laminated structure consisting of a magnetic film made of a transition metal alloy are laminated on a substrate with the transparent film facing the substrate, and the magnetic films other than the magnetic film closest to the substrate are stacked on the substrate. It is made of a rare earth-transition metal alloy whose Curie temperature is lower than that of the magnetic film on the side, and furthermore, a transparent film and a reflective film are formed on the opposite side of the laminated structure from the substrate side that is farthest from the substrate. A photothermal magnetic recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15216484A JPS6132242A (en) | 1984-07-24 | 1984-07-24 | Optothermomagnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15216484A JPS6132242A (en) | 1984-07-24 | 1984-07-24 | Optothermomagnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6132242A JPS6132242A (en) | 1986-02-14 |
| JPH0555941B2 true JPH0555941B2 (en) | 1993-08-18 |
Family
ID=15534421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15216484A Granted JPS6132242A (en) | 1984-07-24 | 1984-07-24 | Optothermomagnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6132242A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH071559B2 (en) * | 1986-05-30 | 1995-01-11 | 住友金属鉱山株式会社 | Magneto-optical disk |
| JP2578418B2 (en) * | 1986-12-29 | 1997-02-05 | 三菱化学株式会社 | Method for manufacturing magneto-optical recording medium |
| JPH0823939B2 (en) * | 1989-05-17 | 1996-03-06 | 三洋電機株式会社 | Optical recording medium and manufacturing method thereof |
| JPH04114667A (en) * | 1990-09-03 | 1992-04-15 | Suishiyou:Kk | Organic halogenide decomposition treating device |
| JP3808917B2 (en) * | 1995-07-20 | 2006-08-16 | オリンパス株式会社 | Thin film manufacturing method and thin film |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5552535A (en) * | 1978-10-12 | 1980-04-17 | Nippon Hoso Kyokai <Nhk> | Magnetic recording medium |
| JPS58153244A (en) * | 1982-03-05 | 1983-09-12 | Matsushita Electric Ind Co Ltd | Photomagnetic recording medium |
| JPS59148161A (en) * | 1983-02-14 | 1984-08-24 | Seiko Instr & Electronics Ltd | Photomagnetic disk |
-
1984
- 1984-07-24 JP JP15216484A patent/JPS6132242A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5552535A (en) * | 1978-10-12 | 1980-04-17 | Nippon Hoso Kyokai <Nhk> | Magnetic recording medium |
| JPS58153244A (en) * | 1982-03-05 | 1983-09-12 | Matsushita Electric Ind Co Ltd | Photomagnetic recording medium |
| JPS59148161A (en) * | 1983-02-14 | 1984-08-24 | Seiko Instr & Electronics Ltd | Photomagnetic disk |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6132242A (en) | 1986-02-14 |
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