JPS6038718A - Vertical magnetic recording medium - Google Patents
Vertical magnetic recording mediumInfo
- Publication number
- JPS6038718A JPS6038718A JP58145073A JP14507383A JPS6038718A JP S6038718 A JPS6038718 A JP S6038718A JP 58145073 A JP58145073 A JP 58145073A JP 14507383 A JP14507383 A JP 14507383A JP S6038718 A JPS6038718 A JP S6038718A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- recording medium
- magnetic
- magnetic layer
- soft magnetic
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 121
- 230000005415 magnetization Effects 0.000 claims abstract description 26
- 239000010409 thin film Substances 0.000 claims abstract description 20
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 18
- 239000000956 alloy Substances 0.000 claims abstract description 18
- 239000000758 substrate Substances 0.000 claims abstract description 17
- 230000005389 magnetism Effects 0.000 claims 1
- 229910003271 Ni-Fe Inorganic materials 0.000 abstract description 3
- 229910000599 Cr alloy Inorganic materials 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 84
- 239000010408 film Substances 0.000 description 20
- 238000004544 sputter deposition Methods 0.000 description 13
- 238000000691 measurement method Methods 0.000 description 6
- 238000004804 winding Methods 0.000 description 6
- 229920002799 BoPET Polymers 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 229910000684 Cobalt-chrome Inorganic materials 0.000 description 4
- 239000010952 cobalt-chrome Substances 0.000 description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 description 4
- 239000005020 polyethylene terephthalate Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- -1 polyethylene terephthalate Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910000979 O alloy Inorganic materials 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 241000238425 Polyplacophora Species 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 235000012489 doughnuts Nutrition 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000005477 sputtering target Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
Landscapes
- Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明はポリエチレンテレフタレート（ＰＥＴ）フィル
ム等の非磁性の支持基板にＮｉ Ｆｅ合合金薄情９の軟
磁性層とＣｏＣ’ｒ合金薄膜等の垂直磁気異方性層を順
次積にりした二円構造を右１°る垂直１１気記録媒体に
関し、特にポリエチレンテレフタレート（ＰＥＴ）フィ
ルム等の可撓性基板を用（１だフロッピーディスク等の
ディスク型記録媒体にａｈ適なものである。Detailed Description of the Invention [Industrial Application Field] The present invention is based on a non-magnetic support substrate such as a polyethylene terephthalate (PET) film, and a soft magnetic layer of Ni-Fe alloy thin film 9 and a CoC'r alloy thin film or the like perpendicular to each other. Concerning a perpendicular 11-degree recording medium in which a two-circle structure in which magnetically anisotropic layers are sequentially stacked is oriented 1 degree to the right, a flexible substrate such as a polyethylene terephthalate (PET) film is particularly used (1 degree is a disk-type recording medium such as a floppy disk). It is suitable for recording media.
［従来技術］
従来の強磁性微粉末をバインダー樹脂中にｆＮＢｔせし
めた記録層を有する＠ イ１ｉ型磁気中己録媒体にＩＪ
ｓねり、近年、高密度記録への要望【こともな（１、垂
直磁気記録方式の媒体がさかん【こ研究さ才しており、
’ＩＨこフロッピーディスクｌ＼の馴ｕがＷＪ侍され、
４１でも上述の２層構造の垂直磁気記録媒４本力＜注目
されている。（特公昭５８−９１号１日経エレク１−〇
二クス １９８２年１０月２５日号９．１４１等参照）
上述の垂直磁気記録媒体の基本構成【よ、＋１寺公昭５
８−’Ｉｔ号公報等で公知の通り、支持基板上にスノ＼
ツク等の手段で作製される磁束集中層として作用１」る
０、２〜１．０μｍ１１程度の厚さのＮｉ Ｆｅ合金λ
９膜ｑからなる軟磁性層と記録層どして作用する０、１
〜０．７μｍｎ程度の厚さのＣｏ Ｃｒ合金薄膜等から
なる垂直磁気異方性層を順次積層したもので、高５Ｊ、
度、高密度記録が可能Ｃある。[Prior art] IJ is applied to a type 1i magnetic recording medium having a recording layer made of conventional ferromagnetic fine powder and fNBt in a binder resin.
In recent years, the demand for high-density recording has increased.
'The IH floppy disk l\ was used by WJ Samurai,
In 41, the above-mentioned two-layer perpendicular magnetic recording medium is attracting attention. (Refer to Special Publication No. 58-91, Nikkei Elec 1-〇Nix, October 25, 1982, No. 9.141, etc.)
Basic configuration of the above-mentioned perpendicular magnetic recording medium
8-' As is known from the It publication, etc., snow ＼ is placed on the support substrate.
Ni-Fe alloy λ with a thickness of about 0.2 to 1.0 μm11 which acts as a magnetic flux concentration layer and is made by a method such as
0 and 1 act as a soft magnetic layer consisting of 9 films q and a recording layer.
It consists of sequentially laminated perpendicular magnetic anisotropic layers made of CoCr alloy thin films, etc. with a thickness of ~0.7 μm.
High-density recording is possible.
Ｆ問題点］
ところで前述の２層ＷＪ造の垂直磁気記録媒体は、支持
基板を回転させながら作製したフロッピーディスクぐは
問題とならなかったが、長尺のフィルムを連続的に送行
させながら作製しドーナツ状に１］抜いたフロッピーデ
ィスクぐは再生出力が同一１−ラック内の一周期で変化
することがわかり、それが軟磁性層の面内磁気異方性に
基づくものぐあることがわかった。[Problem F] By the way, with the above-mentioned two-layer WJ structure perpendicular magnetic recording medium, there was no problem with the floppy disk produced while rotating the support substrate, but when the floppy disk was produced while continuously feeding a long film. It was found that the playback output of the floppy disk pulled out in a donut shape changed in one cycle within the same rack, and that this was due to the in-plane magnetic anisotropy of the soft magnetic layer. .
ずなわら、第１図に示した様な面内磁気異方性（ＭＤ１
３板移送板曲送方向Ｉ）：是板移送方向と直交する方向
）を右り−る軟磁性層と−する垂直磁気記録媒体のフロ
ッピーディスクにおいては、ヘッドがＴＤ力方向通過Ｊ
る時は出力電圧が高く、ＭＤ力方向通過りる時は出ノｊ
電圧が低くなり、ヘッドが１−ラックを一周する間に再
生比ツノのエンベロープに山が２つ、谷が２つ存在り−
ることか観察された。これは、ＪＩＳ Ｃ６２９０のモ
ジュレーションが１０％以下という規定からも大きな問
題Ｃある。However, in-plane magnetic anisotropy (MD1) as shown in Figure 1
3. In a floppy disk with a perpendicular magnetic recording medium having a soft magnetic layer with a soft magnetic layer extending to the right in the direction perpendicular to the direction of plate movement I), the head passes in the TD force direction J.
The output voltage is high when the MD force is flowing, and the output voltage is high when the MD force is passing in the direction of the MD force.
As the voltage decreases, there are two peaks and two valleys in the envelope of the playback ratio horn while the head goes around the 1st rack.
It was observed that. This is a big problem because of the JIS C6290 regulation that modulation is 10% or less.
本発明は、２層構造の垂直磁気記録媒体においてフロッ
ピーディスクに適した上記のにうな問題のない垂直磁気
記録媒体を目的としたもので、再生出力の変化が実用に
供し得る変化幅にある垂直磁気記録媒体を目的としたも
のである。The present invention aims at a perpendicular magnetic recording medium having a two-layer structure, which is suitable for floppy disks and which does not have the above-mentioned problems. It is intended for magnetic recording media.
［光用の）７Ｍ成及び作用効果］ 上）ホの目的は、以下の本発明により達成される。[7M formation and effects for light] The object (a) above is achieved by the present invention as described below.
りなわら、本発明は、前述の非磁性の基板上に軟磁性層
と垂直磁気異方性層を形成した垂直磁気記録媒体にδ３
いて、前記軟磁性層がその面内方向の保磁力が１５１ル
スデツド（ＯＯ）以下であり、且つその面内方向の各方
向で測定した磁化曲線の増磁曲線の磁界軸どの交点にお
【ノる接線の勾配の最大値がその最小値の２．５倍以下
であることを特徴とする垂直磁気記録媒体である。However, the present invention provides a perpendicular magnetic recording medium in which a soft magnetic layer and a perpendicular magnetic anisotropic layer are formed on the above-mentioned non-magnetic substrate.
The soft magnetic layer has a coercive force in the in-plane direction of 151 lusdead (OO) or less, and has a magnetic field axis of the magnetization curve measured in each direction in the in-plane direction. The perpendicular magnetic recording medium is characterized in that the maximum value of the slope of the tangent line is 2.5 times or less the minimum value.
上述の本発明は軟磁性層が面内磁気異方性を有しつつも
、上述の特性具体的にはその磁化曲線、づなわらＭ−１
１ループが第２図に示り一様な特定の形状を有りる時に
は、再生出力の方向による変化がきわめて小さくモジュ
レーションが良好になり、実用上支障のなくなることを
見出しなされたものである。In the present invention described above, although the soft magnetic layer has in-plane magnetic anisotropy, the above-mentioned characteristics, specifically its magnetization curve, M-1
It has been discovered that when one loop has a specific uniform shape as shown in FIG. 2, the change due to the direction of the reproduction output is extremely small, the modulation is good, and there is no problem in practical use.
以下、本発明に至った経緯と、本発明の詳細な説明りる
。Hereinafter, the circumstances leading to the present invention and a detailed explanation of the present invention will be given.
本発明者らは、後述の第８図に概略図を示した巻取式ス
パッタ装置を用い、基板の長尺のＰ Ｅ １−フィルム
を支持ロールに添って連続的に移送さμながらスパッタ
法によりＮｉＦｏＭｏ合金よりなる軟磁性層とＣｏ Ｃ
ｒ合金よりなる垂直磁気異方性層の記録層を順次積層し
、２層構造の垂直磁気記録媒体を作製しできたが、得ら
れる軟磁性層のＭ −１４ループの形状が、スパッタに
よる膜作製中Ｐ Ｅ Ｔフィルムの温度（支持キトン温
度）、張ツバ及びその他のスパッタ条件により大きく変
化づること、ぞして使用１゛るＰＥＴフィルムの物性（
厚さ、ヤング率、熱収縮率１等）によっても変化づるこ
とが判明した。またＰＥＴフィルム上にすでに形成され
た軟磁性層も、後で加熱すれば、その温度と張力と時間
等のある条件下でＭ−Ｈループが変化り−ることも判明
した。すなわち、軟磁性層上に記録層をスパッタする時
の温度どフィルム張力により軟磁性層の磁気特性が変化
Ｊ゛ることが十分に推察される。The present inventors used a winding type sputtering device as shown schematically in FIG. Soft magnetic layer made of NiFoMo alloy and CoC
A two-layer perpendicular magnetic recording medium was fabricated by sequentially laminating recording layers of perpendicular magnetic anisotropy layers made of r alloy, but the M-14 loop shape of the resulting soft magnetic layer was different from that of the sputtered film. During production, the temperature of the PET film (support chiton temperature), tension, and other sputtering conditions can greatly change the physical properties of the PET film used.
It was found that it also varies depending on the thickness, Young's modulus, thermal shrinkage rate, etc.). It has also been found that if a soft magnetic layer already formed on a PET film is heated later, the M-H loop changes under certain conditions such as temperature, tension, and time. That is, it is fully inferred that the magnetic properties of the soft magnetic layer change depending on the temperature and film tension when sputtering the recording layer onto the soft magnetic layer.
実際に、ベースフィルムの表裏に各々軟磁性層と記録層
の２病を積層した両面フロッピーディスクにおいては、
表裏の計４層の積層順序によっても軟磁性層の面内磁気
異方性が変化することか観察された。In fact, in a double-sided floppy disk that has two layers, a soft magnetic layer and a recording layer, on the front and back sides of a base film,
It was observed that the in-plane magnetic anisotropy of the soft magnetic layer changed depending on the stacking order of the four layers on the front and back sides.
・りなわち、２層構造の垂直磁気記録媒体では下層の軟
磁性層の磁気特性は、上層の垂直磁気異方性層を製膜す
ることによって変化し、たとえ製膜条件が同じであって
も上層の有無で異なった値を示すことを見出した。従っ
て垂直磁気記録媒体としての電磁変換特性は垂直磁気異
方性層を形成したあとでの軟磁性層の磁気特性によって
規定される。・In other words, in a two-layer perpendicular magnetic recording medium, the magnetic properties of the lower soft magnetic layer change by forming the upper perpendicular magnetic anisotropic layer, even if the forming conditions are the same. It was also found that the values showed different values depending on the presence or absence of the upper layer. Therefore, the electromagnetic conversion characteristics of a perpendicular magnetic recording medium are defined by the magnetic characteristics of the soft magnetic layer after forming the perpendicular magnetic anisotropic layer.
ところが、従来は、上）ホの軟磁性層の磁気特性は、垂
直磁気媒体の作’Ｎ詩と同条件で基板上に軟磁性層のみ
を形成した４ノンプル′ＣＭ −１−１ループを測定し
、その測定値を用いていた。上）ホの点から、かかる従
来の測定方法では軟磁性層の２層１７４造での磁気特性
の正確な把１屋は困１１［である。However, conventionally, the magnetic properties of the soft magnetic layer (above) were measured using a 4 non-pull CM-1-1 loop in which only the soft magnetic layer was formed on the substrate under the same conditions as those for perpendicular magnetic media. and used the measured values. From the above point, it is difficult to accurately estimate the magnetic properties of a two-layer soft magnetic layer using such conventional measurement methods.
以上の理由ににす、２層媒イホにおりる軟磁性層の磁気
性↑４．特に面内磁気異方性の程度を正確に把握できる
測定方法を検関し、本発明者らは以下の測定方法を見出
した。その手順を１）〜３）に示り−０
１）表裏の両面に軟１．１目１層と記録層を形成した両
面媒体にＪ３いては、まずハ面に耐酸レジスＩ〜を塗布
し、片面を酸く塩化第２鉄と塩酸の混合水溶液。For the above reasons, the magnetic properties of the soft magnetic layer in the two-layer medium ↑4. In particular, the present inventors investigated a measurement method that can accurately determine the degree of in-plane magnetic anisotropy, and found the following measurement method. The procedure is shown in 1) to 3).-0 1) For J3 double-sided media with a soft 1.1 layer and a recording layer formed on both the front and back sides, first apply acid-resistant resist I~ on the front and back sides. , a mixed aqueous solution of ferric chloride and hydrochloric acid acidified on one side.
等）で溶解し、基板の片面にのみ２層が形成された１層
成とりる。etc.) to form a single layer with two layers formed only on one side of the substrate.
２）以上の構成（ハ面２層媒体）の面内各り向のＭ −
１−１ループを測定する。第３図にその代表的なＭ−１
４ループを示した。第３図は飽和さりに十分な磁界を加
えて測定したＭ−日ループの低磁界の所を拡大して示し
たものであり、実線はＭＤｈ向に測定したもので保磁力
が最大であり、点線はＴＤＤ方向測定したもので保磁力
が最小である。その他のｊｊ向はこの間にある。2) M − in each in-plane direction of the above configuration (C-plane two-layer medium)
1-1 Measure the loop. Figure 3 shows a typical M-1
4 loops were shown. Figure 3 shows an enlarged view of the low magnetic field area of the M-day loop measured by applying a magnetic field sufficient to reach saturation, and the solid line is measured in the MDh direction, where the coercive force is maximum. The dotted line indicates the minimum coercive force measured in the TDD direction. Other jj directions are between this.
ここでＭＤｈ向とは第４図（ａ）に示すごとく、連続的
に作製した試わ１の長手Ｉ）向（膜作製時の基板フィル
ムの送行方向）を云い、Ｔ Ｄ方向とはＭ［） 方向に
直交する面内方向を云う。また周知の通り図の縦軸は磁
化Ｍ、横軸は磁界Ｈである。Here, the MDh direction refers to the longitudinal I) direction (the direction in which the substrate film is fed during film fabrication) of the continuously fabricated samples 1, as shown in FIG. 4(a), and the TD direction refers to the M[ ) refers to the in-plane direction perpendicular to the direction. Further, as is well known, the vertical axis of the figure is the magnetization M, and the horizontal axis is the magnetic field H.
３）第３図のＭ−１−１ループにおいて、チＡ・−ト上
で増磁曲線をＲ３／２だけ上方に平行移動し、減磁曲線
をＲ８／２だけ下方に平行移動し、第１図に示した軟磁
性層のみＭ−Ｈループを臂る。そしＣ１これを２層構造
での軟磁性層の磁化曲線とづる。なお、ＭＤｈ向と−１
−Ｄ方向ともにＲ８／２７どけ平行移動する為に、第１
図のＭＤｈ向がＰ、Ｑ点イ］近でも口が問いた形状とな
る。3) In the M-1-1 loop of Fig. 3, the magnetization curve is translated upward by R3/2 on chart A, the demagnetization curve is translated downward by R8/2, and the Only the soft magnetic layer shown in Figure 1 has an M-H loop. C1 This is called the magnetization curve of the soft magnetic layer in the two-layer structure. In addition, for MDh and -1
- In order to move in parallel by R8/27 in both the D direction, the first
Even if the direction of MDh in the figure is P and point Q is close to A], the mouth will have the desired shape.
上述の測定り法により２筋構造での軟磁性層の正確な磁
化曲線が得られたのは、次の理由による。The reason why an accurate magnetization curve of a soft magnetic layer with a two-wire structure was obtained by the above-mentioned measurement method is as follows.
すなわら、手順２）で１！１られる２層構造の軟磁性層
のＭ−１１ループは一般にそのループが第３図のＰＱ、
Ｒ３の様に閉じないで口が開いた形状どなるが、これは
主に記録層の残留磁化にＪ、るものでぞの磁化分だり口
が開くことになる。これは、基板フィルムのハ面に記録
層のみを設【ノＩこものの面内のＭ−１−１ループを測
定すると、第５図に示すように、低磁界領域Ｃは図示の
ごとく磁化Ｍは磁界軸に平行に１ｖＦ、移づるのみで、
残留磁化の値で一定であり、その大きさＥＦは第３図の
Ｒ３と概略一致することから明らかである。従って、手
順３）により記録層の残留磁化分が補正され、２層４，
１１造の軟磁性層のＭ −１−１ループが寄られる。In other words, the M-11 loop of the soft magnetic layer of the two-layer structure, which is 1!1 in step 2), is generally PQ in Fig. 3,
Although it has an open shape like R3, this is mainly due to the residual magnetization of the recording layer, and the gap opens due to the residual magnetization of the recording layer. This is because only the recording layer is provided on the C side of the substrate film.If the M-1-1 loop in the plane of the object is measured, as shown in Figure 5, the low magnetic field region C is the magnetized M is only shifted by 1vF parallel to the magnetic field axis,
It is clear that the value of residual magnetization is constant, and the magnitude EF approximately coincides with R3 in FIG. 3. Therefore, the residual magnetization of the recording layer is corrected by step 3), and the two layers 4,
The M-1-1 loop of the soft magnetic layer of No. 11 is gathered.
以上説明した本測定手法にＪこり、前）ホした従来方法
では不可能ぐあった２層構造の垂直磁気記録媒体の軟磁
性層の磁気特性、特に面内磁気界方性の程度を正確にめ
ることが可能どなった。The present measurement method described above allows accurate measurement of the magnetic properties of the soft magnetic layer of a two-layer perpendicular magnetic recording medium, especially the degree of in-plane magnetic field orientation, which was impossible with the conventional method described above. What is it possible to do?
本発明の軟磁性層の磁気特性は全て上述の測定方法によ
り測定したデータに基づくものぐある。The magnetic properties of the soft magnetic layer of the present invention are all based on data measured by the above-mentioned measuring method.
次に前述の本発明の４１４成について説明する。Next, the above-mentioned 414 configuration of the present invention will be explained.
ところで、２層構造の垂直磁気媒体で前述した再生出力
のエンベロー１が変動するものの軟磁性層は、第１図に
示Ｊような磁気特性を承り。第１図の例においては、１
５〜２５０ｅ！！ｉ！度の外部磁界に対してＭ−１４ル
ープが閉じないＩｊ向はＭＤｈ向であり、図の如く明白
に磁化容易軸となっていることがわかる。そしＵ、Ｍ−
Ｈループが閉じるｌノ向はｒ Ｄ方向であり、磁化困難
軸となつＣいる。それぞれの保磁力をｌ−１ｃｅ、トｌ
ｃｈとする。本例においてはＭＤｈ向、ＴＤ方向以外の
任が、の面内の他の方向で測定した保磁力はい一す゛れ
もｌ−１ｅｅとｌ−１ｃｔ＋の中間の値を示し、Ｈｃｅ
が最大値であり、１〜ＩＣ１１か最小値であった。By the way, although the above-mentioned envelope 1 of the reproduction output fluctuates in the perpendicular magnetic medium having a two-layer structure, the soft magnetic layer has magnetic characteristics as shown in FIG. In the example of Figure 1, 1
5~250e! ! i! It can be seen that the Ij direction in which the M-14 loop does not close against an external magnetic field of 20°C is the MDh direction, which is clearly the axis of easy magnetization as shown in the figure. So U, M-
The direction in which the H loop closes is the rD direction, which is the axis of difficult magnetization. The respective coercive forces are l-1ce and tol
Ch. In this example, all coercive forces measured in other directions within the plane of the MDh direction and the TD direction show intermediate values between l-1ee and l-1ct+, and Hce
was the maximum value, and 1 to IC11 was the minimum value.
これに対して、実用上再生出力の変動が問題とならない
本発明の垂直磁気記録媒体は、その軟磁性層が第２図の
如さＭ−Ｈループをイｊりるしのである。以下、そのＭ
−１−１ループを第２図の例についＣ説明Ｊる。第２
図は第１図Ｊ、り類推するなら実線のＭＤｈ向を磁化容
易軸とし、点線のＴＤＤ方向磁化困難軸とする若干の異
方性を有しつつも、第１図より、はるかに改善された等
方向な磁気特性をイ１している。そして、このＪ：うな
軟磁性層におい（は、第６図に示り−ごと＜ Ｍ−１−
１ループの増（６曲線Ａの磁界軸どの交点、具体的には
保磁力１−ＩＣを示り点にａハノる接Ｆｉｌ Ｌの勾配
を面内の（■意の各方向でめた場合、これがいずれも似
た値を承り場合、再生出力が安定Ｊることがわかった。On the other hand, in the perpendicular magnetic recording medium of the present invention, in which variations in reproduction output do not pose a problem in practice, the soft magnetic layer eliminates the M-H loop as shown in FIG. Below, that M
-1-1 loop will be explained using the example of FIG. Second
The figure is much improved from Figure 1, although it has some anisotropy, with the solid line MDh direction being the easy axis of magnetization and the dotted line being the TDD direction hard magnetization axis. It also has isotropic magnetic properties. And this J: soft magnetic layer (is shown in FIG. 6).
1 loop increase (6 Which intersection point of the magnetic field axis of curve A, specifically, if you set the slope of Fil L tangent to the point indicating coercive force 1-IC in each direction in the plane (■) , it has been found that when these values are all similar, the playback output is stable.
そして、面内の任意の各方向で測定した接線ｌ−の勾配
の最大値１−ａと最小値Ｌｂとの比が２．５以下であれ
ば、再生出力の変動を実用上８′（容箱υ１１内とり゛
ることができる。具体的には前述のＪＩＳ規格をクリア
できる。If the ratio between the maximum value 1-a and the minimum value Lb of the slope of the tangent line l- measured in each arbitrary direction within the plane is 2.5 or less, the variation in the reproduction output can be reduced to 8' (approximately 8') in practical terms. It can be carried out within the box υ11.Specifically, it can clear the above-mentioned JIS standard.
一方、大きな再生出力を得るためには、上述の軟磁性層
の保磁力１−１ｃは後述の通り１５０ｏ以１；であるこ
とが好ましい。な（１３、その膜ＪＦ；ｉは通常０．２
〜１．０μｎＬ程度である。第７図は本発明に特有な形
状のＭ−１−４ループを石りる電磁１１層の保磁力１−
ＩＣと再生出力（ＩＥＩＩ ）との関係を２ Ｋ Ｆ
ＲＰ Ｉど４５Ｋ［ＲＰＩにおいて示したものであり、
保磁力１−ＩＣが小さい程再生出力が大きく良好どなる
。保磁力Ｈｃ１５０ｅ以下であれば」−分であるが、よ
り好ましくは１０００以下の方が良い。なお、第７図の
軟磁性層は厚さ約０．４４μｍｎのＮｉ ＦｅＭｏ合金
薄膜であり、記録層のＣｏ Ｃｒ合金薄膜（Ｃｒ ：２
０νｉｔ％）の特性と、電磁変換特性の測定条件をそれ
ぞれ表−１と表−２に示覆。なお表−１の八〇（７）は
Ｘ線回折の六方最密構造（ｈｃｐ）の（００２）面のロ
ッキング曲線の半ｆｉＱ中である。On the other hand, in order to obtain a large reproduction output, it is preferable that the coercive force 1-1c of the above-mentioned soft magnetic layer is 150° or more as described later. (13, the film JF; i is usually 0.2
~1.0 μnL. Figure 7 shows the coercive force 1- of the 11 electromagnetic layers forming the M-1-4 loop with the unique shape of the present invention.
The relationship between IC and playback output (IEII) is 2K F
RP Ido 45K [shown in RPI,
The smaller the coercive force 1-IC, the greater the reproduction output and the better. If the coercive force Hc is 150e or less, it is "-min", but it is more preferably 1000 or less. The soft magnetic layer in FIG. 7 is a NiFeMo alloy thin film with a thickness of about 0.44 μm, and the recording layer is a CoCr alloy thin film (Cr:2
Table 1 and Table 2 show the measurement conditions for the characteristics of 0 νit%) and the electromagnetic conversion characteristics, respectively. Note that 80(7) in Table 1 is the half-fiQ of the rocking curve of the (002) plane of the hexagonal close-packed structure (hcp) in X-ray diffraction.
（以下余白）
表−ｉ ：Ｃｏ Ｑｒ合金薄膜の特性
表−２：電磁変換特性の測定条件
以上の通り本発明によれば前述の勾配を規定するのみＣ
再生出力に異方性がなく、且つ再生出力レベルも高い垂
直磁気記録媒体が実現される。(Leaving space below) Table-i: Characteristics of Co Qr alloy thin film Table-2: Measurement conditions for electromagnetic conversion characteristics As described above, according to the present invention, only C
A perpendicular magnetic recording medium with no anisotropy in reproduction output and a high reproduction output level can be realized.
さらに、第２図のもので特徴的なことは１５〜２５Ｑｅ
程度の外部磁界においてＭ −１−１ループの閉じる一
ＦＤ方向、換言り−れば磁化困ｆｆ１ｌＬ軸方向の保磁
力ｌ−１ｃｌ＋はＭ−Ｈループの閉じないＭＤ力方向Ｊ
９！言り一れば磁化容易軸方向の保磁ツノｌ−１ｃｃよ
り大きく、第１図の保磁力の関係りなわちＨｃｅ ＞
ｌ−１ｃｈどは逆の関係をイボしていることである。す
なわら、異方性材料の一般的傾向であるｌ−Ｉ ｃｅ＞
１−１ ｃｔ＋なる明瞭な関係をこの軟磁性層はイｊ
していない。そして、トＩｃｅ＜ １，２Ｈｃｈにおい
て、再生出力の異方性による変動は低下しており、再生
出力の均一化により一層の好ましい結果を生じる。さら
に第２図の様にトＩＣｏ≦ト１ｃｈＦある方がより好ま
しい。Furthermore, the characteristic feature of the one in Figure 2 is 15 to 25 Qe.
In an external magnetic field of about
9! In other words, it is larger than the coercive force l-1cc in the direction of the easy axis of magnetization, and the coercive force relationship in Figure 1 is Hce >
The 1-1 channel has the opposite relationship. That is, l-I ce>, which is a general tendency of anisotropic materials.
This soft magnetic layer has a clear relationship of 1-1 ct+.
I haven't. When Ice < 1,2Hch, the variation due to the anisotropy of the reproduced output is reduced, and a more favorable result is produced by making the reproduced output uniform. Furthermore, as shown in FIG. 2, it is more preferable that tICo≦t1chF.
更に、面内の各方向で測定した保磁力１−ＩＣの最大値
と最小（＋ｆｊどの比を検ｉｊＬ、たところ、その比が
１．６以下のものでは前述のものにおい−Ｃより好まし
い結果が得られることがわかった。Furthermore, we examined the ratio between the maximum and minimum coercive force 1-IC measured in each direction in the plane (+fj, ijL), and found that when the ratio was 1.6 or less, the result was more preferable than the above-mentioned odor-C. was found to be obtained.
ところＣ′、本発明の垂直磁気記録媒体は１￥公昭、５
８−９１号で開示されＣいる２層媒体であり、記録層は
通常ＣＩ・を１ｏ〜２５■量％含右りるＣｏ Ｃｒ合金
薄膜が使用されるが、他にバ１戸ンムフｌライト薄膜や
Ｇｏ−１ｙｌｒメツキ膜やバ１戸シムフェライ［・微粉
末の塗布膜ＣあっＣもがよりない。又、軟磁性層は通常
ＮｉＦｅ系合金（一般にパーマロイといわれる）薄膜が
一般に用いられ、本発明におい（ム、ＩＪｌｉ １ｌｌ
ｌｉな々Ａ １１ぐあること、及びスパッタ用ターゲッ
１〜どして加工性にツぐれ経済的であることによりＮｉ
Ｆｅ系台金薄膜が好ましいが、他にＣＯ，ＦＱをｔ＼−
７，とし、７ｒ、Ｎｂ、１−ａ、Ｗ、 Ｂ、 ｓｉ等を
添加したア七ルノアス合金膜等も使用され得る。要は保
磁ツノの小さい材料（がっ、適当な飽和磁化Ｍｓ（！−
右りる）であればにり、更に）ｆｉ磁率の大ぎいものが
好ましく用いられる。However, C', the perpendicular magnetic recording medium of the present invention is 1 yen Kimiaki, 5
It is a two-layer medium disclosed in No. 8-91, and the recording layer is usually a CoCr alloy thin film containing 10 to 25% of CI. Thin films, Go-1ylr plating films, and simferai coatings of fine powder do not move easily. In addition, a thin film of a NiFe-based alloy (commonly called permalloy) is generally used as the soft magnetic layer, and in the present invention (mu, IJli 1lll
Due to the fact that there are 11 types of li, and because the sputtering target has poor processability and is economical, Ni
Fe-based base metal thin film is preferable, but CO and FQ may also be used.
7, and an aryl nois alloy film to which 7r, Nb, 1-a, W, B, si, etc. are added may also be used. The key is to find a material with a small coercive horn (gah, appropriate saturation magnetization Ms(!-
It is preferable to use a material with a large fi magnetic coefficient.
［実施例］
特開昭５８−１５８３８０＠公報等で、公知の対向ター
グツ１へ式スパッタ法を用いた後述Ｊる第８図の巻取式
の対向ターグツ１〜スパツタ装置を用い、約０、ＡＡμ
ｍｎのＮｉ Ｆｃ Ｍ’ｏ （Ｎｉ ニア９． Ｆｅ
：１６゜ＭＯ；５重量％）合金薄膜の軟磁性層と、約０
．４５ａｍのＣＯＣｒ （Ｃｒ ： ２Ｏｉ量％）合金
薄膜の記録層をＰＥＴフィルムの両面に形成した。用い
た２軸延伸ＰＥＴフイルムは５０μ７＋１厚さＣ中心線
平均粗ざＲａが０．０１μ？＋１の表面粗度のもの（Ａ
）と、７５ｔ１７ｎ厚さ′ｃＲａ ＝ ０．００６μｍ
のもの（Ｂ）の２種類である。[Example] In Japanese Unexamined Patent Publication No. 58-158380@, etc., a known sputtering method was used to sputter a sputtering sputtering method to a sputtering sputtering device as shown in FIG. AAμ
mn Ni Fc M'o (Ni near 9. Fe
:16°MO; 5% by weight) alloy thin film soft magnetic layer and about 0
．． A recording layer of a 45 am COCr (Cr: 2 Oi amount %) alloy thin film was formed on both sides of the PET film. The biaxially stretched PET film used had a thickness of 50μ7+1 and a center line average roughness Ra of 0.01μ? +1 surface roughness (A
), 75t17n thickness 'cRa = 0.006μm
There are two types (B).
ところで、巻取式の対向ターグツ１〜式スパッタ装置は
、良民の基板フィルムの両面に２層構造の垂直磁気記録
媒イホを）Ｗ続的に製造Ｃきるように第８図に示づ４１
１１成どなっている。す゛なわら、図の１１゜１２は温
度コンｌ−Ｌ：Ｉ−ル可能なキＩＩン、１３は巻出しロ
ール、１４は巻取ロール、１５はガイトロール、２０は
真空槽、２１はアルゴンガスシ９人系、２２は排気口ひ
ある。Ｆは基板フィルムであり、Ｐ１〜Ｐ４は３３０ｎ
ｍ＋ Ｗ Ｘ １．５Ｏｎ＋ｍＬのターゲット２枚を対
向させた対向ターゲット陰極ひ、遮蔽板Ｓにより不要部
への粒子飛散を防止しである。ＰＩ、Ｐ３はＮｉＦｅＭ
Ｏ合金ターゲッｌ−＋ Ｐ２ 、ＰＪはＣ０Ｃｒ合金タ
ーグツｌ−を設置しである。なＪ５ Ｎ対向ターグツ１
一式スパッタ法は前述の通り公知であり、イ］帯設備の
真空ポンプ、ターグツ１〜冷ＩＩ水系統、ターゲットへ
の電力供給電源及び配線系統は図示省略しＩこ。又、そ
のスパッタ作用の説明も省略する。By the way, the winding-type opposed tag type sputtering apparatus is shown in FIG.
11 is yelling. In other words, 11 and 12 in the figure are temperature control keys II, 13 is an unwinding roll, 14 is a winding roll, 15 is a guide roll, 20 is a vacuum tank, and 21 is an argon gas cylinder. 9 people, 22 has an exhaust port. F is the substrate film, P1 to P4 are 330n
A facing target cathode in which two targets of m+ W PI and P3 are NiFeM
O alloy target l-+ P2, PJ is set with C0Cr alloy target l-. J5 N opposing tags 1
The one-set sputtering method is well known as described above, and the vacuum pump, target 1 to cold water systems, power supply to the target, and wiring system of the equipment in zone A are omitted from illustration. Further, explanation of the sputtering effect will also be omitted.
イしく、この対向ターゲット式スパッタ法圃により、目
的の垂直磁気記録媒体を以下のように作成した。すなわ
ら、基板フィルムＦを巻出しロール１３にしットしたフ
ィルムロールより送り出し、巻取りｌ」−ル１４に巻取
る。この間にターゲットＰ１１−）３によりＮｉ Ｆｃ
１ｙｊｏ薄膜を基板フィルムＦの両１ｎ１に形成した。Using this facing target sputtering method, the intended perpendicular magnetic recording medium was fabricated as follows. That is, the substrate film F is fed out from a film roll set on an unwinding roll 13 and wound onto a winding roll 14. During this time, Ni Fc was produced by target P11-)3
A 1yjo thin film was formed on both 1n1 of the substrate film F.
又は、まず片面にのみｌ’＋′Ｃ″Ｎｉ ＦｃＭｏ薄膜
を形成し巻取りロール１４に巻取っ１、：後に、リベＣ
のキレン、ロールを逆転さｕ１１’３ Ｃ：Ｎ ｉ Ｆ
ＯＭＯ薄膜を他の面に形成しロール１３に巻取っＩｃ０
いずれにしでも、二１：Ｐン１１．１２の謁Ｉ哀を９０
℃どし、アルゴンガス圧０．５ｐａ 、平均１１１積速
痕０．３μｍ ／ ｍｉｎでＮｉＦｅＭｏ合金ターグツ
１〜のスパッタを行い、まず基板フィルムＦの両面にＮ
ｉＦｃＭｏ薄膜を形成し、しかる後に、同様の方法で、
キ１７ン１ｉ、 １２の温度を１５０℃とし、Ｃｏ Ｑ
ｒ 薄膜を両面に形成した。このようにしく軟磁性層の
特性の異なる８種類の垂直磁気記録媒体を形成した。Alternatively, first, a l'+'C'' Ni FcMo thin film is formed only on one side, and then the film is wound on the winding roll 14.
Killen reverses the roll u11'3 C:N i F
An OMO thin film is formed on the other surface and wound on a roll 13 Ic0
In any case, the audience of 21:Pn11.12 is 90
℃, an argon gas pressure of 0.5 pa, and an average stacking velocity of 0.3 μm/min, NiFeMo alloy tags 1 to 1 were sputtered, and first N was applied to both sides of the substrate film F.
Form an iFcMo thin film, and then, in the same manner,
The temperature of keys 17 and 1i and 12 was set to 150℃, and CoQ
r Thin films were formed on both sides. In this way, eight types of perpendicular magnetic recording media with different characteristics of the soft magnetic layer were formed.
そして、前述した測定方法通り、片面を酸で溶解し、片
面にのみ２層が積層されたザンブルを作製し、各方向の
軟磁性層の磁気特性を評価した。Then, according to the measurement method described above, one side was dissolved in acid to produce a zumble in which two layers were laminated on only one side, and the magnetic properties of the soft magnetic layer in each direction were evaluated.
また、第４図（ｂ）のにうにＭＤ力方向Ｔ Ｄ方向Ｊ：
す０．５インヂＩ１１に切り出し、表−２の条（！＋で
再生出力を測定した。なお、Ｃｏ Ｃｒ膜の垂直方向保
４１１力はいずれし３９５〜４９０ＱＯＴ”あった。In addition, as shown in Fig. 4(b), MD force direction T D direction J:
A 0.5-inch I11 piece was cut out, and the reproduction output was measured using the strips shown in Table 2 (!+).The vertical retention force of the CoCr film was 395 to 490QOT'' in each case.
Ｍ Ｄ方向と丁り方面の中間の方向の軟磁性層の１ｊｊ
性（１（１はりへ−（’ ｔｖｌ Ｄ方向１ＪＩ竹１１
ｃｆと−「Ｄ方向ｆｊ性値の中間の値を示した為に、軟
磁性１１）ｊのＭＤプノ向とＩ−［） 方向の特性値の
み表−３に示した。そして再生出力値Ｅｐ （ｌｌＶｏ
−ｐ ）どその変化率を表−４に示した。M 1jj of the soft magnetic layer in the middle direction between the D direction and the center direction
Sex (1 (1 beam - (' tvl D direction 1 JI bamboo 11
cf and −D direction fj characteristic values, only the characteristic values of soft magnetic 11)j in the MD direction and I−[) direction are shown in Table 3.The reproduction output value Ep (llVo
-p) Table 4 shows the rate of change.
変化率は（Ｆ ｐｍａｘ−（三ｐｍｉｎ） −ｒ （ｌ
Ｅｐｍａｘ＋、 Ｅ ｐｍｉｎ） ｘ ｉｏｏ％でめＩ
ｃ。The rate of change is (F pmax-(3 pmin)-r (l
Epmax+, E pmin) x ioo%
c.
表〜３：軟１１計１層の■）１気特性
表−４：再生出力（’Ｅｐ ）とＭＤ／ＴＤ変化率表変
化率衣−４の実施例１〜４の結果から磁化曲線の増磁曲
線の磁界軸との交点に（１３ｆｊる接線の勾配の最大値
Ｉ−ａと最小値Ｌｂとの比Ｌａ ／Ｌｂが１．９以下で
あれば、再生出力の変化率は２ Ｋ ＦｌくＰｌ及びｎ
５ＫＦＩＩＰｌにおいで６．３％以下となり、実用上全
く問題のない再生出力が胃られることがわかる。Table 3: Soft 11 total 1 layer ■) 1 characteristic Table 4: Reproduction output ('Ep) and MD/TD change rate table From the results of Examples 1 to 4 of Change rate clothes 4, the increase in magnetization curve If the ratio La/Lb between the maximum value I-a and the minimum value Lb of the slope of the tangent to the intersection of the magnetic curve with the magnetic field axis (13fj) is 1.9 or less, the rate of change of the reproduction output is 2K Fl Pl and n
It can be seen that the reproduction output is 6.3% or less at 5KFIIPl, which is no problem for practical use.
なｄ３、再生出力の変化率はＪＩＳｐ格等から約１０％
程度よ？’ ｉ’ｒ容されるので、比較例６の結果等か
らもわかるように、前述の通り、比Ｌａ ／ｌ ｂは２
．５以下Ｃ−あれば実用上問題ない。d3, the rate of change in playback output is approximately 10% from JISp rating, etc.
What's the extent? 'i'r, so as can be seen from the results of Comparative Example 6, the ratio La /l b is 2.
．． If C- is 5 or less, there is no practical problem.
更に実施例１．２Ｊ：り上述の条件下で、磁化容易軸方
向の保磁）Ｊｌ−１ｃｅど磁化困難軸方向の保磁力１（
ｃｌ＋どの比１−１ ｃｃ／ Ｉ−１ａｈが０．９以下
であれば、再生出力の変化率は両記録密痘で３．２％以
下となり、非゛７：（に均一な１［■生出力ｂ（得られ
る。Furthermore, Example 1.2J: Under the above conditions, coercive force in the direction of the easy axis of magnetization) Jl-1ce and coercive force in the direction of the hard axis of magnetization 1 (
If the ratio 1-1 cc/I-1ah is less than 0.9, the rate of change in reproduction output will be less than 3.2% for both records, and if the non- Output b (obtained.
なお、前述の比Ｌａ／Ｌｂど（１１１！、実用上の前記
基準からは、１１０述の通り比１−１ ｃｃ／ ｌ−ｌ
ｃｔ＋は１．２以下であれば十分である。In addition, the above-mentioned ratio La/Lb (111!), from the above-mentioned practical standard, the ratio is 1-1 cc/l-l as described in 110.
It is sufficient that ct+ is 1.2 or less.
また、比較例８の結果から保磁力Ｈｃが１５Ｑ Ｑを越
えると再生用］Ｊレベルの低下が大ぎく、前述の通り保
磁力ＨＣは１５０ｅ以下にする必要があることがわかる
。Furthermore, from the results of Comparative Example 8, it can be seen that when the coercive force Hc exceeds 15Q, the reduction in the reproduction]J level is significant, and as mentioned above, the coercive force HC needs to be 150e or less.
第１図は比較例の代表的な面内のＭ −１−１ループの
グラフ、第２図は実施例の代表的な面内のＭ−（」ルー
プのグラフ、第３図は２層構造の垂直磁気記録媒体の面
内のＭ−Ｈループのグラフ、第４図は長尺フィルムのＭ
Ｄｈ向と−［Ｄ方向の説明図。
第５図は記録層のみの面内のＭ−Ｈループの±１５０ｅ
の部分を示したグラフ、第６図はＭ−１４ループの保磁
力を示り点にお（〕る接線りの説明図、第７図は転磁↑
１層の保磁力（１−１ｃ）と再生出力（Ｅｌ））との関
係を示リーグラフ、第８図は巻取式スパッタ装置の概略
図である。
１１、１２：ギ１７ン、１３：巻出しロール。
１４：巻取りロール、１〕１〜Ｐ４ ：対抗ターゲット
陰極、２０：真空槽
オｌ酬
−〉
」
（０，）
オ斗図Figure 1 is a graph of a typical in-plane M-1-1 loop of a comparative example, Figure 2 is a graph of a typical in-plane M-('' loop of an example, and Figure 3 is a two-layer structure Figure 4 is a graph of the in-plane M-H loop of a perpendicular magnetic recording medium.
Explanatory diagram of Dh direction and -[D direction. Figure 5 shows the in-plane M-H loop of the recording layer only, ±150e.
Graph showing the part of , Figure 6 shows the coercive force of the M-14 loop and is an explanatory diagram of the tangent line at the point, Figure 7 shows the magnetic change ↑
A graph showing the relationship between coercive force (1-1c) and reproduction output (El) of one layer, and FIG. 8 is a schematic diagram of a winding type sputtering apparatus. 11, 12: Gin 17, 13: Unwinding roll. 14: Winding roll, 1] 1 to P4: Opposing target cathode, 20: Vacuum tank orifice -> (0,)
Claims (1)
成しＩ、：垂直磁気記録媒体において、前記軟磁性層が
その面内方向の保磁力が１５エルステツド以下であり、
且つその面内方向の磁化曲線の増磁曲線の磁界軸との交
点における接線の勾配の最大値がその最小値の２．５倍
以下であることを特徴とりる垂直磁気記録媒体。 ２）前記軟磁性層の磁化容易軸方向の保磁ツノが該方向
に直交−りる磁化困難軸方向の保磁力の１．２倍以下で
ある特許請求の範ｔｉ１１第１項記載の垂直磁気記録媒
体。 ３）前記軟磁性層がＮｉとＦｅを主成分とした合金薄膜
である特許請求の範囲第１項若しくは第２項記載の垂直
磁気記録媒体。[Claims] 1) A soft magnetic layer and a perpendicular magnetic anisotropic layer are formed on a non-magnetic substrate. less than ersted,
A perpendicular magnetic recording medium characterized in that the maximum value of the gradient of the tangent at the intersection of the magnetization curve in the in-plane direction with the magnetic field axis is 2.5 times or less of the minimum value. 2) The perpendicular magnetism according to claim 11, wherein the coercive force in the direction of the easy axis of magnetization of the soft magnetic layer is 1.2 times or less the coercive force in the direction of the hard axis of magnetization perpendicular to the soft magnetic layer. recoding media. 3) The perpendicular magnetic recording medium according to claim 1 or 2, wherein the soft magnetic layer is an alloy thin film containing Ni and Fe as main components.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58145073A JPS6038718A (en) | 1983-08-10 | 1983-08-10 | Vertical magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58145073A JPS6038718A (en) | 1983-08-10 | 1983-08-10 | Vertical magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6038718A true JPS6038718A (en) | 1985-02-28 |
| JPH0262890B2 JPH0262890B2 (en) | 1990-12-26 |
Family
ID=15376749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58145073A Granted JPS6038718A (en) | 1983-08-10 | 1983-08-10 | Vertical magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6038718A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63197028A (en) * | 1987-02-12 | 1988-08-15 | Tdk Corp | Perpendicular magnetic recording medium |
| JPH02104374U (en) * | 1989-02-07 | 1990-08-20 | ||
| JPH03226786A (en) * | 1990-01-31 | 1991-10-07 | Matsushita Electric Ind Co Ltd | Pitch display device |
| JPH0489983U (en) * | 1990-11-27 | 1992-08-05 | ||
| JPH04270390A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Stress comparing display device |
| JPH04270392A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Stress indicating device |
| JPH04270391A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Musical interval comparing display device |
| JPH04270393A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Musical interval instructing device |
| JPH04270389A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Vocal data display device |
| JPH0535181A (en) * | 1991-07-30 | 1993-02-12 | Victor Co Of Japan Ltd | Orchestral accompaniment reproduction device with image display function |
| SG95701A1 (en) * | 2001-09-27 | 2003-04-23 | Toshiba Kk | Perpendicular magnetic recording/reading apparatus |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2023543156A (en) | 2020-09-14 | 2023-10-13 | マス・イノベイション・（プライベイト）・リミテッド | Knitting machine and method for knitting fabric by yarn plating with multiple threads |
| JPWO2022158251A1 (en) | 2021-01-22 | 2022-07-28 |
-
1983
- 1983-08-10 JP JP58145073A patent/JPS6038718A/en active Granted
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63197028A (en) * | 1987-02-12 | 1988-08-15 | Tdk Corp | Perpendicular magnetic recording medium |
| JPH02104374U (en) * | 1989-02-07 | 1990-08-20 | ||
| JPH03226786A (en) * | 1990-01-31 | 1991-10-07 | Matsushita Electric Ind Co Ltd | Pitch display device |
| JPH0489983U (en) * | 1990-11-27 | 1992-08-05 | ||
| JPH04270390A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Stress comparing display device |
| JPH04270392A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Stress indicating device |
| JPH04270391A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Musical interval comparing display device |
| JPH04270393A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Musical interval instructing device |
| JPH04270389A (en) * | 1991-01-16 | 1992-09-25 | Ricos:Kk | Vocal data display device |
| JPH0535181A (en) * | 1991-07-30 | 1993-02-12 | Victor Co Of Japan Ltd | Orchestral accompaniment reproduction device with image display function |
| SG95701A1 (en) * | 2001-09-27 | 2003-04-23 | Toshiba Kk | Perpendicular magnetic recording/reading apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0262890B2 (en) | 1990-12-26 |
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