JPH0227546A - Magneto-optical recording medium - Google Patents
Magneto-optical recording mediumInfo
- Publication number
- JPH0227546A JPH0227546A JP17503588A JP17503588A JPH0227546A JP H0227546 A JPH0227546 A JP H0227546A JP 17503588 A JP17503588 A JP 17503588A JP 17503588 A JP17503588 A JP 17503588A JP H0227546 A JPH0227546 A JP H0227546A
- Authority
- JP
- Japan
- Prior art keywords
- magneto
- optical recording
- recording
- recording medium
- coercive force
- 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
- 230000005291 magnetic effect Effects 0.000 claims abstract description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 229910052763 palladium Inorganic materials 0.000 claims description 3
- 229910052703 rhodium Inorganic materials 0.000 claims description 3
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims description 2
- 230000005415 magnetization Effects 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 16
- 238000000034 method Methods 0.000 abstract description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 abstract description 7
- 230000003247 decreasing effect Effects 0.000 abstract description 3
- 230000005292 diamagnetic effect Effects 0.000 abstract description 2
- 230000007423 decrease Effects 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 11
- 239000000463 material Substances 0.000 description 8
- 230000006866 deterioration Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000001681 protective effect Effects 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
- G11B11/10589—Details
- G11B11/10591—Details for improving write-in properties, e.g. Curie-point temperature
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、レーザー光を用いて記録・再生・消去を行う
光磁気記録に係り、特に情報記録の感度の制御に好適な
光磁気記録材料に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to magneto-optical recording in which recording, reproduction and erasing are performed using laser light, and in particular to a magneto-optical recording material suitable for controlling the sensitivity of information recording. Regarding.
近年の高度情報化社会の進展に伴ない、高密度。 With the recent development of an advanced information society, high density.
大容量なファイルメモリーへのニーズが高まっている。The need for large-capacity file memory is increasing.
その中で、このニーズにこたえるメモリーとして光磁気
記録が注目されている。この光磁気記録は、情報の記録
及び消去にはレーザー光を照射し、記録膜をキュリー温
度以上に加熱し、レーザー光照射を止め、冷却と同時に
外部から磁界を印加して行なう、この場合、情報を記録
する感度は、光磁気記録膜のキュリー温度に依存するこ
とが知られており、それを制御する手段として記録材料
の組成を制御してキュリー温度を最適化する手法或いは
下地膜や保護膜の材料を選択して、レーザー光源から供
給された熱エネルギーを制御する手法があげられており
、その例として、特開昭５７−２７４９５等をあげるこ
とができる。Among these, magneto-optical recording is attracting attention as a memory that meets this need. In this magneto-optical recording, information is recorded and erased by irradiating the recording film with laser light, heating the recording film above the Curie temperature, stopping the laser light irradiation, and applying a magnetic field from the outside at the same time as cooling. It is known that the sensitivity of recording information depends on the Curie temperature of the magneto-optical recording film, and methods to control this include optimizing the Curie temperature by controlling the composition of the recording material, or using an underlayer or protection film. A technique has been proposed in which the thermal energy supplied from the laser light source is controlled by selecting the material of the film, and an example of this technique is disclosed in Japanese Patent Application Laid-Open No. 57-27495.
上記従来技術では、キュリー温度を変えて記録感度の制
御を行う場合、補償温度との関係で、その制御が困難で
ある。さらに記録膜を構成する成分系が複雑になる程、
その制御が蔑しくなってくる。また、従来の手法で補償
温度を一定にし、キュリー温度を制御する手法では、特
にキュリー温度と補償温度が近づく程、その制御が困難
になる。In the above-mentioned conventional technology, when controlling the recording sensitivity by changing the Curie temperature, it is difficult to control the recording sensitivity due to the relationship with the compensation temperature. Furthermore, the more complex the component system that makes up the recording film, the more
That control becomes despising. Further, in the conventional method of keeping the compensation temperature constant and controlling the Curie temperature, the closer the Curie temperature and the compensation temperature become, the more difficult the control becomes.
そこで、本発明の目的は、情報の記録感度を制御する手
法を提供することにある。Therefore, an object of the present invention is to provide a method for controlling information recording sensitivity.
上記目的は、光磁気記録膜の保磁力の温度変化を、白金
属元素を記録媒体に添加することで制御することにより
達成される。The above object is achieved by controlling the temperature change in the coercive force of the magneto-optical recording film by adding a platinum metal element to the recording medium.
光磁気記録媒体に白金属元素を添加し、その添加量を制
御すると、温度の上昇にともなう保磁力の減少過程にお
いて、記録或いは消去時の磁界（外部印加磁界十反磁界
の和）以下になる温度を変えることができるので、記録
膜の温度がキュリー温度に達しなくても記録や消去が行
なえる。When a platinum metal element is added to a magneto-optical recording medium and the amount of addition is controlled, the magnetic field during recording or erasing (the sum of the externally applied magnetic field and 10 diamagnetic fields) becomes lower in the process of decreasing coercive force as the temperature rises. Since the temperature can be changed, recording and erasing can be performed even if the temperature of the recording film does not reach the Curie temperature.
以下、本発明の詳細を実施例１〜２を用いて詳細に説明
する。Hereinafter, the details of the present invention will be explained in detail using Examples 1 and 2.
［実施例１］
作製した光磁気ディスクの断面構造は第１図に示すとお
りである。本ディスクは以下に述べる手順にて作製した
。まず、案内溝を有するディスク基板１上に、窒化シリ
コン下地膜２をスパッタリング法により６５０人の膜厚
（屈折率ｎ＝２．３５）に形成した。ひき続き、光磁気
記録膜３を真空を破ることなくスパッタ法により作製し
た。〜記録膜３の材料としては、（ＴｂｚｙＦｅａｓＣ
ｏｚｘＮｂａ）ｚ−ｘＰｔ−を用い、ｐｔの濃度としｘ
＝４．７．１０の３種類のディスクを作製した。そして
最後に窒化シリコン保護膜４をスパッタリング法により
１０００人の膜厚に形成し、光磁気ディスクとした。[Example 1] The cross-sectional structure of the produced magneto-optical disk is as shown in FIG. This disc was manufactured using the procedure described below. First, on a disk substrate 1 having guide grooves, a silicon nitride base film 2 was formed by sputtering to a thickness of 650 mm (refractive index n=2.35). Subsequently, a magneto-optical recording film 3 was produced by sputtering without breaking the vacuum. ~As the material of the recording film 3, (TbzyFeasC
ozxNba)z-xPt-, and the concentration of pt is x
Three types of disks were prepared: =4.7.10. Finally, a silicon nitride protective film 4 was formed to a thickness of 1000 mm by sputtering to form a magneto-optical disk.
こうして添加するｐｔ濃度を変えて作製したディスクの
保磁力の温度変化をまず測定した。その結果を第２図に
示す、記録膜の補償温度は７０〜９０℃の範囲で、キュ
リー温度も２１０℃〜２４０℃の闇で、大きな開きはな
い、また、比較例として、ｐｔを含まないＴｂｚ＋Ｆｅ
６ｓＣｏ工ｏＮｂｓなる組成の記録膜を用いた第１図に
示す構造の光磁気ディスクにおける保磁力の温度変化を
点線にて示した。First, temperature changes in coercive force of disks manufactured by changing the added PT concentration were measured. The results are shown in Figure 2. The compensation temperature of the recording film is in the range of 70 to 90°C, and the Curie temperature is in the range of 210 to 240°C, with no large difference. Also, as a comparative example, PT is not included. Tbz+Fe
The dotted line indicates the change in coercive force with temperature in a magneto-optical disk having the structure shown in FIG. 1 using a recording film having a composition of 6sCo-CoNbs.
この図より、Ｐｔの濃度が高くなるほど補償温度付近の
保磁力の温度変化が急峻になり、補償温度を超えた後の
保磁力の温度変化が大きく異なっていることがわかる。From this figure, it can be seen that as the concentration of Pt increases, the temperature change in coercive force near the compensation temperature becomes steeper, and the temperature change in coercive force after exceeding the compensation temperature differs greatly.
この変化は、垂直磁気異方性エネルギを、白金の添加量
ｘ＝４のときとＸ＝１０のときとを比較すると、ｘ ＝
１０のディスクの方が５ｘ＝４のディスクに比較して
１／２になっていることに原因があると考えられる。This change shows that when comparing the perpendicular magnetic anisotropy energy when the amount of platinum added is x = 4 and when X = 10, x =
This is thought to be due to the fact that the size of the 10 disk is 1/2 that of the 5x=4 disk.
次にこのディスクを用いて、再生出力の記録レーザーパ
ワー依存性について調べ、その結果を第３図に示す、こ
の図より、いずれの系を用いても搬送波対雑音比（Ｃ／
Ｎ）（記録レーザー出力８ｍＷにおける）は５５ｄＢ（
ｆ＝ＩＭＨｚ、ｄｕｔｙ５０）と変らないが、最小記録
パワーは、Ｐｔｉ度がｘ＝４〜１０ａｔ％と増大するに
つれて、５．７ｍＷ〜４．０ｍＷと変化しており、いず
れの系においても記録感度が従来材料より向上している
ことがわかる。この時の作用している磁界は、印加磁界
４０００ ｅ 、反磁界１０００θであった。Next, using this disk, we investigated the dependence of the reproduction output on the recording laser power, and the results are shown in Figure 3.From this figure, it can be seen that no matter which system is used, the carrier-to-noise ratio (C/
N) (at a recording laser output of 8 mW) is 55 dB (
f = IMHz, duty 50), but the minimum recording power changes from 5.7 mW to 4.0 mW as the Pti degree increases from x = 4 to 10 at%, and in both systems, the recording sensitivity It can be seen that this is improved compared to conventional materials. The magnetic field acting at this time was an applied magnetic field of 4000 e and a demagnetizing field of 1000 θ.
また、比較例では、最小記録レーザーパワーが、６．５
ｍＷと本発明の系と比較して高く、その分再生出力が飽
和していないのでＣ／Ｎも３ｄＢ低い５２ｄＢであった
。このように保磁力の温度変化で５０００ｅ以下になる
温度が記録感度に作用していることがわかった。上述の
如く、本発明を用いることにより、キュリー温度を変え
ず、保磁力の温度変化を制御することで最小レーザー出
力すなわち記録感度を自由に制御できることがわかる。In addition, in the comparative example, the minimum recording laser power was 6.5
mW, which was higher than that of the system of the present invention, and because the reproduction output was not saturated, the C/N was also 3 dB lower, at 52 dB. In this way, it was found that the temperature of 5000 e or less due to temperature change in coercive force affects the recording sensitivity. As described above, it can be seen that by using the present invention, the minimum laser output, that is, the recording sensitivity can be freely controlled by controlling the temperature change in coercive force without changing the Curie temperature.
さらに、ｐｔを添加することにより、ｐｔを含まない系
より耐食性、特に孔食に対する耐性が向上することが寿
命試験の結果より明らかとなった。Furthermore, the life test results revealed that the addition of PT improves corrosion resistance, particularly resistance to pitting corrosion, compared to a system that does not contain PT.
すなわち、ディスクを６０℃−９５％ＲＨ中に３０００
時間放置したところ、Ｃ／Ｎの劣化（湿食の程度に対応
）が、比較例では２ｄＢ減少したのに対し、本発明では
ｘ＝４〜１０のい′ずれのディスクでも劣化がみられな
かった。また、欠陥レートは、ディスク作製初期では３
Ｘ１０−６（件／ｂｉｔ）であったものが、上記環境中
に放置後の比較例では５倍に増加したのに対し１本発明
を用いた場合には１．５〜２倍程度と著しく変化が小さ
いことがわかる。このように、本発明は、記録感度の制
御を自由に行なえるだけでなく、ディスクの長寿命化に
も効果があることがわかった。That is, the disc was heated to 3000°C in 60°C-95%RH
When left for a period of time, the C/N deterioration (corresponding to the degree of moisture corrosion) decreased by 2 dB in the comparative example, whereas in the present invention, no deterioration was observed even with discs with x = 4 to 10. Ta. In addition, the defect rate is 3 at the initial stage of disk production.
X10-6 (bits/bit) increased by 5 times in the comparative example after being left in the above environment, but when the present invention was used, it increased significantly by about 1.5 to 2 times. It can be seen that the change is small. As described above, it has been found that the present invention not only allows the recording sensitivity to be freely controlled, but is also effective in extending the life of the disk.
さらに、この効果は、ｐｔ以外にＰｄやＲｈを用いた場
合も同様で、何ら差は見当らない。Furthermore, this effect is the same when Pd or Rh is used in addition to pt, and no difference is observed.
［実施例２コ
作製した光磁気ディスクの断面構造は、実施例１と同様
で、第１図に示すとおりである。ディスクの構成は、光
磁気記録膜として
（ＴｂｅｏＮｄ４ｏ）ｏ、ｚ７Ｆ ｅｏ＊ａａｃｏｏ、
ｚｏ Ｔａｏ、ｏａ Ｐｔｏ、ｏｅなる組成を有する材
料を用いた以外、実施例１と同様である。[Example 2 The cross-sectional structure of the produced magneto-optical disk was the same as that of Example 1, as shown in FIG. 1. The configuration of the disk is (TbeoNd4o)o, z7F eo*aacoo, as a magneto-optical recording film.
This example is the same as Example 1 except that materials having the compositions zo Tao, oa Pto, and oe were used.
このディスクにおける記録膜の保磁力の温度変化を第４
図に示す、比較例として、ｐｔを含まず、補償温度及び
キュリー温度が同じになるように調整したＴｂＮｄＦａ
ＣｏＴａ系の結果について合わせて示した。この図より
、本実施例と比較例とを比べると実施例１の場合と同様
に、補償温度近傍での保磁力の温度変化は急峻であるが
、保磁力がＩＫＯｅを下まわってからの変化が極端にな
だらかになる点が比較例と大きく異なっている。The temperature change in the coercive force of the recording film in this disk is measured as follows.
As a comparative example shown in the figure, TbNdFa which does not contain pt and whose compensation temperature and Curie temperature are adjusted to be the same.
The results for the CoTa system are also shown. From this figure, when comparing the present example and the comparative example, it can be seen that, as in the case of Example 1, the temperature change in coercive force is steep near the compensation temperature, but the change after the coercive force falls below IKOe. It differs greatly from the comparative example in that the curve becomes extremely smooth.
この材料を用いたディスクの再生出力の記録レーザー出
力依存性を第５図に示す。これより、補償温度及びキュ
リー温度が等しいにもかがわらず、最小記録パワーでは
４．２ｍＷと、比較例の５．９ｍＷに比べて１．７ｍＷ
も低くい、また、Ｃ／Ｎもレーザーパワー８ｍＷで比較
してみると、６２ｄＢ （ＩＭＨｚ、ｄｕｔｙ ５０
）と約２ｄＢ高いことがわかる。これは、比較例では感
度が低いために再生出力がレーザーパワーに対して飽和
していないためである。このように、保磁力の温度変化
を制御することにより、補償温度およびキュリー温度を
変えなくとも、記録感度が変化させることができる。FIG. 5 shows the dependence of the reproduction output of a disc using this material on the recording laser output. From this, even though the compensation temperature and Curie temperature are equal, the minimum recording power is 4.2 mW, which is 1.7 mW compared to 5.9 mW in the comparative example.
Also, when comparing the C/N with a laser power of 8 mW, it is 62 dB (IMHz, duty 50
), which is approximately 2 dB higher. This is because in the comparative example, the reproduction output is not saturated with respect to the laser power due to low sensitivity. In this way, by controlling the change in coercive force with temperature, the recording sensitivity can be changed without changing the compensation temperature and the Curie temperature.
また、このディスクの寿命を実施例１と同様の手法で３
０００時間、６０℃−９５％ＲＨ中にディスクを放置し
、諧特性の変化を測定した。まず、湿食に対応したＣ／
Ｎの劣化は、本発明の場合は劣化がみられないのに対し
、比較例では３ｄＢの低下となった。また、孔食に対応
している欠陥レートの変化は、作製初期でいずれも４Ｘ
１０−６（件／ｂｉｔ）であったのに対し、上記環境中
に放置後では、本実施例の場合が２倍であったのに対し
、比較例では７倍であった。In addition, the lifespan of this disk was measured using the same method as in Example 1.
The disk was left at 60° C. and 95% RH for 1,000 hours, and changes in gradation characteristics were measured. First, C/
Regarding the deterioration of N, while no deterioration was observed in the case of the present invention, the deterioration of N was 3 dB in the comparative example. In addition, the change in defect rate corresponding to pitting corrosion was 4X at the initial stage of fabrication.
10-6 (cases/bit), but after being left in the above environment, the number was twice as high in the case of the present example, while it was seven times as high in the comparative example.
さらにこの効果は、ｐｔ以外のＰｄやＲｈを用いた場合
についても同様にみられた。また、いずれの種類の希土
類元素や鉄族元素（Ｆｅ、Ｃ：ｏのいずれか一方でも）
に対しても、垂直磁化膜である限り本発明の実施による
記録感度の向上あるいは耐湿性の向上の効果が認められ
た。Furthermore, this effect was similarly observed when Pd and Rh other than pt were used. Also, any kind of rare earth element or iron group element (either Fe or C:o)
Also, as long as the perpendicularly magnetized film was used, the effect of improving recording sensitivity or moisture resistance by practicing the present invention was recognized.
本発明によれば、保磁力の温度変化を制御することによ
りキュリー温度や補償温度を変えなくとも、記録感度を
容易に制御できる効果がある。そしてその感度が従来材
料よりも高感度を有する光磁気ディスクが得られる。According to the present invention, by controlling temperature changes in coercive force, recording sensitivity can be easily controlled without changing the Curie temperature or compensation temperature. A magneto-optical disk having a sensitivity higher than that of conventional materials can be obtained.
この他に、光磁気ディスクの信頼性向上、長寿命化にも
効果がある。In addition, it is also effective in improving the reliability and extending the life of magneto-optical disks.
第１図は本発明の実施例の光磁気ディスクの断面模式図
、第２図、第４図は本発明と従来例のディスクにおける
光磁気記録膜の保磁力の温度特性図、第３図、第５回は
本発明と従来例における光磁気ディスクの再生出力のレ
ーザーパワー依存性を示す特性図である。
１・・・ディスク基板。
２・・・下地膜、
３・・・光磁気記録
￥
図
玄で球し一す゛−出力（菖Ｗつ
冴
図
茅
図
逼
廣
（′Ｃ）
ギ
斗
図
逼 攬
（′乙）FIG. 1 is a schematic cross-sectional view of a magneto-optical disk according to an embodiment of the present invention, FIGS. 2 and 4 are temperature characteristic diagrams of coercive force of the magneto-optical recording film in disks of the present invention and a conventional example, and FIG. The fifth is a characteristic diagram showing the laser power dependence of the reproduction output of the magneto-optical disk in the present invention and the conventional example. 1... Disk board. 2... Underlayer film, 3... Magneto-optical recording ￥ Zugen and ball one-output (Iris W Tsusae-zu-mozu-zu-hiro ('C) Gito-zu-zu-yu ('Otsu)
Claims (1)
化膜にレーザー光と外部印加磁界或いはいずれか一方に
より記録、再生、消去を行う光磁気記録媒体において情
報を記録する光磁気記録膜の保磁力の温度変化を制御し
たことを特徴とする光磁気記録媒体。 ２、特許請求の範囲第１項記載の光磁気記録媒体中にＰ
ｔ、Ｒｈ、Ｐｄの中から選ばれる少なくとも１種類の元
素を含むことを特徴とする光磁気記録媒体。 ３、特許請求の範囲第１項記載の光磁気記録媒体として
希土類元素と鉄族元素を主体とし、さらに優位には形成
した膜が非晶質であることを特徴とする光磁気記録媒体
。 ４、特許請求の範囲第１項記載の光磁気記録膜の保磁力
の温度変化の変化として、温度の上昇に伴ない保磁力が
、外部印加磁界と反磁界の和以下になる温度を制御した
ことを特徴とする光磁気記録媒体。 ５、特許請求の範囲第２項記載の元素の含有量を変える
ことで、特許請求の範囲第１項及び第２項の保磁力の温
度変化を制御したことを特徴とする光磁気記録媒体。[Claims] 1. Information is recorded in a magneto-optical recording medium in which recording, reproduction, and erasure are performed using a laser beam and/or an externally applied magnetic field on a perpendicularly magnetized film having an axis of easy magnetization perpendicular to the substrate. 1. A magneto-optical recording medium characterized in that temperature changes in the coercive force of a magneto-optical recording film are controlled. 2. P in the magneto-optical recording medium according to claim 1
A magneto-optical recording medium characterized by containing at least one element selected from t, Rh, and Pd. 3. A magneto-optical recording medium according to claim 1, characterized in that the film is mainly composed of a rare earth element and an iron group element, and more preferably, the formed film is amorphous. 4. As the temperature change of the coercive force of the magneto-optical recording film described in claim 1, the temperature is controlled such that the coercive force becomes equal to or less than the sum of the externally applied magnetic field and the demagnetizing field as the temperature rises. A magneto-optical recording medium characterized by: 5. A magneto-optical recording medium characterized in that temperature changes in the coercive force as set forth in claims 1 and 2 are controlled by changing the content of the element set forth in claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17503588A JPH0227546A (en) | 1988-07-15 | 1988-07-15 | Magneto-optical recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17503588A JPH0227546A (en) | 1988-07-15 | 1988-07-15 | Magneto-optical recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0227546A true JPH0227546A (en) | 1990-01-30 |
Family
ID=15989080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17503588A Pending JPH0227546A (en) | 1988-07-15 | 1988-07-15 | Magneto-optical recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0227546A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5598399A (en) * | 1994-08-24 | 1997-01-28 | Hitachi Maxell, Ltd. | Magneto-optical recording medium having multiple magnetic layers for magneto-optical recording medium |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60253040A (en) * | 1984-05-30 | 1985-12-13 | Toshiba Corp | Photomagnetic recording medium |
| JPS61253655A (en) * | 1985-05-02 | 1986-11-11 | Pioneer Electronic Corp | Photomagnetic recording medium |
-
1988
- 1988-07-15 JP JP17503588A patent/JPH0227546A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60253040A (en) * | 1984-05-30 | 1985-12-13 | Toshiba Corp | Photomagnetic recording medium |
| JPS61253655A (en) * | 1985-05-02 | 1986-11-11 | Pioneer Electronic Corp | Photomagnetic recording medium |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5598399A (en) * | 1994-08-24 | 1997-01-28 | Hitachi Maxell, Ltd. | Magneto-optical recording medium having multiple magnetic layers for magneto-optical recording medium |
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