JPS62298044A - Magneto-optical disk - Google Patents
Magneto-optical diskInfo
- Publication number
- JPS62298044A JPS62298044A JP13922786A JP13922786A JPS62298044A JP S62298044 A JPS62298044 A JP S62298044A JP 13922786 A JP13922786 A JP 13922786A JP 13922786 A JP13922786 A JP 13922786A JP S62298044 A JPS62298044 A JP S62298044A
- Authority
- JP
- Japan
- Prior art keywords
- film
- magneto
- substrate
- optical disk
- recording film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000758 substrate Substances 0.000 claims abstract description 22
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 20
- 230000001681 protective effect Effects 0.000 claims abstract description 8
- 229910052723 transition metal Inorganic materials 0.000 claims description 13
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- FOPBMNGISYSNED-UHFFFAOYSA-N [Fe].[Co].[Tb] Chemical group [Fe].[Co].[Tb] FOPBMNGISYSNED-UHFFFAOYSA-N 0.000 claims 1
- 229910002546 FeCo Inorganic materials 0.000 abstract description 11
- 230000008021 deposition Effects 0.000 abstract description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 4
- 238000001704 evaporation Methods 0.000 abstract description 3
- 230000008020 evaporation Effects 0.000 abstract description 3
- 229920003229 poly(methyl methacrylate) Polymers 0.000 abstract description 3
- 239000004926 polymethyl methacrylate Substances 0.000 abstract description 3
- 235000012239 silicon dioxide Nutrition 0.000 abstract description 2
- 239000000377 silicon dioxide Substances 0.000 abstract description 2
- 238000007740 vapor deposition Methods 0.000 abstract 2
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 150000003624 transition metals Chemical class 0.000 description 8
- 238000000151 deposition Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 230000005415 magnetization Effects 0.000 description 4
- 238000007738 vacuum evaporation Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 230000002393 scratching effect Effects 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【発明の詳細な説明】
３、発明の詳細な説明
〔概 要〕
希土類−遷移金属合金の記録膜を有する光磁気ディスク
において、特性向上のために記録膜中の希土類元素含有
量を膜厚さ方向で基板に近い部分で多くしている。[Detailed Description of the Invention] 3. Detailed Description of the Invention [Summary] In a magneto-optical disk having a recording film of a rare earth-transition metal alloy, the rare earth element content in the recording film is determined by changing the film thickness in order to improve the characteristics. It is more concentrated in the area closer to the board in terms of direction.
本発明は、高密度大容量メモリに用いられる光ディスク
、より詳しくは、書き換え可能な光磁気ディスクに関す
るものである。The present invention relates to an optical disk used in a high-density, large-capacity memory, and more particularly to a rewritable magneto-optical disk.
光磁気ディスクへの書き込み、読み出し、すなわち、記
録・再生はスポット径１μｍ以下のレーザー光線を利用
して透明な基板側から照射することにより行なわれる。Writing and reading, that is, recording and reproducing, on a magneto-optical disk is performed by irradiating it from the transparent substrate side using a laser beam with a spot diameter of 1 μm or less.
特に、再生は基板と記録膜との界面でのレーザー光線反
射の際の偏光面の回転（カー回転）を利用しているので
、記録膜の基板側界面の性質は重要な要素である。In particular, since reproduction utilizes the rotation of the plane of polarization (Kerr rotation) upon reflection of a laser beam at the interface between the substrate and the recording film, the properties of the interface of the recording film on the substrate side are an important factor.
光磁気ディスクは透明な基板と、光磁気記録媒体膜（記
録膜）と、保３Ｉ膜とからなり、この記録１１りとして
希土類（ＲＥ）−遷移金属（ＴＭ）合金が用いられてい
る。記録膜は真空蒸着法あるいはスパック法によって基
板上に作製される。例えば、今村修武：「光磁気ディス
ク材料を探る」、日経ニューマテリアル、創刊前１号、
昭和６０年５月２０日発行、日経マグロウヒル社、ｐ、
４７−５４、参照。A magneto-optical disk consists of a transparent substrate, a magneto-optical recording medium film (recording film), and a recording film, and a rare earth (RE)-transition metal (TM) alloy is used as the recording material. The recording film is fabricated on the substrate by vacuum evaporation or spacing. For example, Shutake Imamura: “Exploring magneto-optical disk materials,” Nikkei New Materials, pre-launch issue 1,
Published May 20, 1985, Nikkei McGraw-Hill Publishing, p.
47-54, see.
このような記録膜の特性は、希土類元素と遷移金属との
組成比に敏感に依存しており、例えば、希土類元素とし
てテルビウム（Ｔｂ）および遷移金属として鉄・コバル
ト（ＦｅＣｏ）を用いたＴｂＦｅＣ。The characteristics of such a recording film depend sensitively on the composition ratio of the rare earth element and the transition metal. For example, TbFeC uses terbium (Tb) as the rare earth element and iron/cobalt (FeCo) as the transition metal.
の記録膜の場合には、その特性として重要なカー回転角
（θＫ）および保磁力（Ｈｃ）はＴｂ含有量との関係で
第八図および第８図に示したように変化する。そして、
磁気モーメントに関して、補償組成を境に希土類元素（
Ｔｂ）リッチ側ではＴｂの磁気モーメントμ８．が遷移
金属（ＦｅＣｏ）の磁気モーメントμＴ４よりも優勢で
あってトータルの磁化（合成磁気モーメント）はその差
で求まり、磁化の方向はＴｂの磁気モーメントの方向と
なる。In the case of the recording film, the Kerr rotation angle (θK) and coercive force (Hc), which are important characteristics thereof, change as shown in FIGS. 8 and 8 in relation to the Tb content. and,
Regarding the magnetic moment, rare earth elements (
Tb) On the rich side, the magnetic moment of Tb μ8. is more dominant than the magnetic moment μT4 of the transition metal (FeCo), the total magnetization (synthetic magnetic moment) is determined by the difference, and the direction of magnetization is the direction of the magnetic moment of Tb.
他方、遷移金属（ＦｅＣｏ） リッチ側ではＦｅＣｏ
の磁気モーメントが優勢であってトータルの磁化はＴｂ
磁気モーメントとの差で求まり、磁化の方向はＦｅＣｏ
の石荘気モーメントの方向となる。第 図および第４図
かられかるように記録膜の組成制御は重要であり、従来
は膜厚方向に均一な組成となるように記録膜形成が行な
われていた。On the other hand, on the transition metal (FeCo) rich side, FeCo
The magnetic moment of Tb is dominant, and the total magnetization is Tb
It is determined by the difference between the magnetic moment and the direction of magnetization is FeCo.
The direction of Shizhuang Qi moment will be. As can be seen from FIGS. 4 and 4, controlling the composition of the recording film is important, and conventionally the recording film was formed so that the composition was uniform in the film thickness direction.
光磁気ディスクの特性向上を図るために、光磁気ディス
クで重要な記録膜と基板との界面近傍での掻く薄い記録
膜層の状態がどのようになっているかを調べた。記録膜
（ＴｂＦｅＣｏ膜）の厚さと保磁力との関係は第５図に
示すようになることがわかった（ムお、ＴｂＦｅＣｏｖ
のＴｂ含有量は３０ａｔ％であった）。In order to improve the characteristics of magneto-optical disks, we investigated the state of the thin recording film layer near the interface between the recording film and the substrate, which is important in magneto-optical disks. It was found that the relationship between the thickness of the recording film (TbFeCo film) and the coercive force is as shown in Figure 5.
The Tb content was 30 at%).
通常採用されている膜厚１１００ｎでは、Ｔｂ２７ａｔ
％含有ＴｂＦｅＣｏ膜のように希土類元素（Ｔｂ）磁気
モーメント（μＲＥ）が遷移金属（ＦｅＣｏ） ４Ｎ気
モーメント（８７Ｍ）より大きな組成であっても、膜厚
がｌＱｎｍ程度の部分では遷移金属磁気モーメント（μ
ｔｘ）の方が優勢になっている。このことは厚さ１１０
０ｎの記録膜において、界面近傍の薄い部分が遷移金属
磁気モーメント（８７Ｍ）の優勢な部分であり、そして
その他の部分が希土類元素磁気モーメント（μＲ１）の
優勢な部分であると考えられる。このようにひとつの膜
を形成する２つの部分でそれぞれの磁気モーメントの極
性が逆となっているので相互干渉によって光磁気ディス
ク特性を低下させていると考えられる。At the normally adopted film thickness of 1100n, Tb27at
% TbFeCo film, even if the rare earth element (Tb) magnetic moment (μRE) is larger than the transition metal (FeCo) 4N moment (87M), the transition metal magnetic moment ( μ
tx) is more dominant. This means that the thickness is 110
In the 0n recording film, it is considered that the transition metal magnetic moment (87M) is dominant in the thin part near the interface, and the rare earth element magnetic moment (μR1) is dominant in the other parts. As described above, since the polarities of the respective magnetic moments are opposite in the two parts forming one film, it is thought that mutual interference deteriorates the magneto-optical disk characteristics.
本発明の目的は、上述した相互干渉による特性の低下を
回避した光磁気ディスクを提供することである。An object of the present invention is to provide a magneto-optical disk that avoids the deterioration of characteristics due to the above-mentioned mutual interference.
本発明の別の目的は、光磁気ディスクの特性向上、特に
、カー回転角（θＫ）を従来の均一組成膜のものよりも
大きくすることである。Another object of the present invention is to improve the characteristics of a magneto-optical disk, particularly to make the Kerr rotation angle (θK) larger than that of a conventional uniform composition film.
上述の目的が、透明な基板と、希土類−遷移金属合金の
記録膜と、保護膜とからなる光磁気ディスクにおいて、
記録膜中の希土類元素の含有量を該記録膜の厚さ方向で
基板に近い部分に遠い部分よりも多（しであることを特
徴とする光磁気ディスクによって達成される。The above purpose is to provide a magneto-optical disk comprising a transparent substrate, a recording film of a rare earth-transition metal alloy, and a protective film.
This is achieved by a magneto-optical disk characterized in that the content of rare earth elements in the recording film is greater in the thickness direction of the recording film in a portion closer to the substrate than in a portion farther away.
記録膜の希土類元素含有量の多い部分の厚さが５〜３０
ｎｍであることは望ましく、第５図かられかるようにこ
の部分では従来遷移金属磁気モーメント（８７Ｍ）の優
勢となるところである。The thickness of the portion of the recording film with high rare earth element content is 5 to 30
It is desirable that the magnetic moment be 1 nm, and as can be seen from FIG. 5, the conventional transition metal magnetic moment (87M) is dominant in this part.
基板と記録膜との界面に近い記録膜部分を希土類元素含
有量の制御によって希土類元素磁気モーメントの優勢な
ものとすることができ、記録膜全体として希土類元素磁
気モーメントが優勢と極性が揃っており、光４ｉ１気デ
ィスクの特性が向上する。By controlling the rare earth element content in the recording film portion near the interface between the substrate and the recording film, it is possible to make the rare earth element magnetic moment dominant, and the entire recording film has a dominant rare earth element magnetic moment with uniform polarity. , the characteristics of the optical 4i1 disc are improved.
以下、添付図面を参照して本発明の実施態様例によって
本発明の詳細な説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of embodiments with reference to the accompanying drawings.
第１図に示す本発明に係る光磁気ディスクは透明基板１
と、記録膜２と、保護膜３とからなり、その記録膜２が
希土類元素含有量を多く含有させた部分２Ａと、所定の
希土類元素含有量の部分２Ｂとからなる。例えば、透明
なＰＭＭＡ基板ｌの上にＴｂＦｅＣｏの記録膜２がさら
に二酸化珪素（ＳｉＯ□）の保護膜３が形成されている
。The magneto-optical disk according to the present invention shown in FIG.
, a recording film 2, and a protective film 3, and the recording film 2 consists of a portion 2A containing a large amount of rare earth elements and a portion 2B having a predetermined rare earth element content. For example, a recording film 2 of TbFeCo and a protective film 3 of silicon dioxide (SiO□) are formed on a transparent PMMA substrate 1.
本発明に係る磁気ディスクが、例えば、次のようにして
製造される。The magnetic disk according to the present invention is manufactured, for example, as follows.
まず、真空蒸着装置の真空槽４内にＰ聞Ａ基板１が配置
され、Ｔｂ試料６およびＦｅＣｏ試料７を加熱容器８お
よび９のそれぞれに入れる。真空槽４内を排気して５
Ｘ １０−’Ｐａ以下に減圧する０次に、加熱容器８お
よび９を加熱して収容されているＴｂ試料６を０．３ｎ
ｍ／秒の蒸着速度で同時にＦｅＣｏ試料７を０．２ｎｍ
／秒の蒸着速度で蒸発させ、ＰＭＭＡ基＋Ｆｊ、ｌ上に
ＴｂＦｅＣｏ膜２Ａを堆積させる。この場合にＴｂＦｅ
Ｃｏ膜のＴｂとＦｅＣｏ０比は３８ ： ６２（原子比
で）となっている。ＴｂＦｅＣｏ膜２Ａの厚さがｌＱｎ
ｍになったところで、Ｔｂの蒸着速度を０．２５ｎｍ／
秒に下げ、一方、ＦｅＣｏの蒸着速度を０．２ｎｍ／秒
とそのままにて蒸着を合計厚さ１１００ｎとなるまで継
続してＴｂＦｅＣｏ膜２Ｂを堆積させる。この場合に、
ＴｂＦｅＣｏ膜２ＢのＴ ｂ Ｃ！：ＦｅＣｏの比は３
０ニア０ （原子比）となっている。First, a P-type A substrate 1 is placed in a vacuum chamber 4 of a vacuum evaporation apparatus, and a Tb sample 6 and a FeCo sample 7 are placed in heating containers 8 and 9, respectively. Evacuate the vacuum chamber 4 and 5
X The pressure is reduced to below 10-'Pa. Next, heating containers 8 and 9 are heated and the Tb sample 6 contained therein is heated to 0.3n
0.2 nm of FeCo sample 7 was simultaneously deposited at a deposition rate of m/s.
The TbFeCo film 2A is deposited on the PMMA group +Fj,l by evaporation at a deposition rate of /sec. In this case, TbFe
The Tb and FeCo0 ratio of the Co film is 38:62 (in atomic ratio). The thickness of TbFeCo film 2A is lQn
m, the Tb deposition rate was increased to 0.25 nm/
On the other hand, the TbFeCo film 2B is deposited by decreasing the FeCo deposition rate to 0.2 nm/sec and continuing the deposition until the total thickness is 1100 nm. In this case,
TbC! of TbFeCo film 2B! :The ratio of FeCo is 3
0 near 0 (atomic ratio).
次に、ＴｂＦｅＣｏ１１９２ Ｂ上に薄着法によってＳ
ｉＯを堆積させて１１００ｎ厚さの保護膜３を形成する
。Next, S was deposited on TbFeCo1192B by thin coating method.
A protective film 3 having a thickness of 1100 nm is formed by depositing iO.
このようにして製造した光磁気ディスクのカー回転角を
Ｐ Ｍ Ｍ Ａ 基板側からのレーザー光線によって測
定したところ、０．２９度であった。The Kerr rotation angle of the magneto-optical disk thus manufactured was measured with a laser beam from the PMMA substrate side, and was found to be 0.29 degrees.
上述した真空蒸着装置にてＴｂ蒸着速度を変化させるこ
となく ０．２５ ｎ ｍ ７秒として形成した均一組
成のＴｂＦｅＣｏ膜の場合には、カー回転角は０．２５
度であった。したがって、本発明の磁気ディスクのほう
がカー回転角が大きくなり、再生信号の対雑音比が向上
する。In the case of a TbFeCo film with a uniform composition formed at 0.25 nm for 7 seconds without changing the Tb evaporation rate in the vacuum evaporation apparatus described above, the Kerr rotation angle is 0.25.
It was degree. Therefore, in the magnetic disk of the present invention, the Kerr rotation angle is larger, and the noise ratio of the reproduced signal is improved.
上述した実施例での記録膜はＴｂＦｅＣｏであったが、
ＴｂＣｏあるいはＧｄＴｂＦｅなどについても通用でき
る。The recording film in the above example was TbFeCo, but
It can also be applied to TbCo or GdTbFe.
透明基板および保護膜についてもＰ聞Ａあるいは５ｉＯ
ｚの代わりに、ガラス、エポキシ、ポリカーボネートな
ど、そしてＳｉ３Ｎ４． ＳｉＯなどが使用できる。Transparent substrate and protective film are also P-A or 5iO.
Instead of z, glass, epoxy, polycarbonate, etc., and Si3N4. SiO etc. can be used.
本発明によれば、基板と記録膜との界面近傍にくる記録
膜部分における磁気モーメントを他の部分と同じ掻性の
磁気モーメントに揃えることができ、カー回転角を従来
よりも太き（することができる。According to the present invention, the magnetic moment in the recording film portion near the interface between the substrate and the recording film can be made equal to the magnetic moment of the same scratching property as other parts, and the Kerr rotation angle can be made thicker than in the past. be able to.
【図面の簡単な説明】
第１図は本発明に係る磁気ディスクの部分断面図であり
、
第２図は真空蒸着装置の概略図であり、第３図はＴｂＦ
ｅＣｏ膜のＴｂ含有量とカー回転角との関係を示すグラ
フである。
第４図はＴｂＦｅＣｏ１１ｌの’ｒ ｂ含有量と保磁力
との関係を示すグラフであり、および
第５図はＴｂＦｅＣｏ膜の厚さと保磁力との関係を示す
グラフである。
１・・・透明基板、
２・・・記録膜、
２Ａ・・・希土類元素含有量の多い部分、２Ｂ・・・所
定希土類元素含有量の部分、３・・・保護膜。[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a partial sectional view of a magnetic disk according to the present invention, FIG. 2 is a schematic diagram of a vacuum evaporation apparatus, and FIG. 3 is a TbF
It is a graph showing the relationship between the Tb content of an eCo film and the Kerr rotation angle. FIG. 4 is a graph showing the relationship between the 'r b content and coercive force of TbFeCo111, and FIG. 5 is a graph showing the relationship between the thickness of the TbFeCo film and coercive force. DESCRIPTION OF SYMBOLS 1... Transparent substrate, 2... Recording film, 2A... Portion with high rare earth element content, 2B... Portion with predetermined rare earth element content, 3... Protective film.
Claims (1)
保護膜とからなる光磁気ディスクにおいて、前記記録膜
中の希土類元素の含有量を該記録膜の厚さ方向で前記基
板に近い部分に遠い部分よりも多くしてあることを特徴
とする光磁気ディスク。 ２、前記記録膜の希土類元素含有量が多い部分の厚さが
５〜３０ｎｍであることを特徴とする特許請求の範囲第
１項の光磁気ディスク。 ３、前記希土類−遷移金属合金がテルビウム・鉄・コバ
ルトであることを特徴とする特許請求の範囲第１項記載
の光磁気ディスク。[Claims] 1. A transparent substrate, a recording film made of a rare earth-transition metal alloy,
A magneto-optical disk comprising a protective film, wherein the content of a rare earth element in the recording film is greater in a portion closer to the substrate than in a portion farther from the substrate in the thickness direction of the recording film. disk. 2. The magneto-optical disk according to claim 1, wherein the thickness of the portion of the recording film with a high content of rare earth elements is 5 to 30 nm. 3. The magneto-optical disk according to claim 1, wherein the rare earth-transition metal alloy is terbium-iron-cobalt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13922786A JPS62298044A (en) | 1986-06-17 | 1986-06-17 | Magneto-optical disk |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13922786A JPS62298044A (en) | 1986-06-17 | 1986-06-17 | Magneto-optical disk |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62298044A true JPS62298044A (en) | 1987-12-25 |
Family
ID=15240450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13922786A Pending JPS62298044A (en) | 1986-06-17 | 1986-06-17 | Magneto-optical disk |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62298044A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01184631A (en) * | 1988-01-13 | 1989-07-24 | Hitachi Ltd | Information recording and reproducing method |
-
1986
- 1986-06-17 JP JP13922786A patent/JPS62298044A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01184631A (en) * | 1988-01-13 | 1989-07-24 | Hitachi Ltd | Information recording and reproducing method |
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