JPH0440626A - Magnetic recording medium - Google Patents

Magnetic recording medium

Info

Publication number
JPH0440626A
JPH0440626A JP14725190A JP14725190A JPH0440626A JP H0440626 A JPH0440626 A JP H0440626A JP 14725190 A JP14725190 A JP 14725190A JP 14725190 A JP14725190 A JP 14725190A JP H0440626 A JPH0440626 A JP H0440626A
Authority
JP
Japan
Prior art keywords
magnetic recording
protective layer
layer
recording medium
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
Application number
JP14725190A
Other languages
Japanese (ja)
Other versions
JP2952967B2 (en
Inventor
Shinichi Fukawa
府川 信一
Toshio Inao
俊雄 稲生
Akio Kondo
近藤 昭夫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tosoh Corp
Original Assignee
Tosoh Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tosoh Corp filed Critical Tosoh Corp
Priority to JP14725190A priority Critical patent/JP2952967B2/en
Publication of JPH0440626A publication Critical patent/JPH0440626A/en
Application granted granted Critical
Publication of JP2952967B2 publication Critical patent/JP2952967B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

PURPOSE:To improve CSS durability and to attain high-density recording by increasing the concn. of a carbon element in the thickness direction from the magnetic recording layer side of a protective layer toward the front surface. CONSTITUTION:A substrate 1 is coated with a nonmagnetic underlying layer 2 consisting of a nonmagnetic metallic film of chromium, etc., for the purpose of improving the magnetic characteristics of the magnetic recording medium. The magnetic recording layer 3 is formed on the nonmagnetic underlying layer 2. Further, the protective layer 4 is formed on the magnetic recording layer 3 and the protective layer 4 is formed by incorporating a silicon element and the carbon element therein. In addition, the concn. of the carbon element in the protective layer 4 is increased in the thickness direction from the magnetic recording layer 3 side of the protective layer to the front surface. The sufficient CSS durability is exhibited even if the thickness of the protective layer is reduced in this way and, therefore, the high-density recording is attained.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は磁気記録媒体に関するものであり、例えばコン
ピュータ等の外部記憶装置(磁気ディスク装置)におけ
る磁気記憶体などに用いることの(従来の技術) コンピュータなどの記憶媒体として磁気記録媒体が用い
られており、従来磁性粉を塗布したテープなどが広く用
いられていたが、この記憶テープは記憶密度が小さ(、
アクセス時間が長いなどの欠点があるため、テープにか
わりランダムアクセスが可能な円板状の磁気ディスクが
用いられてきている。なかでもアルミニウムなどの堅い
基板上に、厚さ1μm程度の磁気記録層を形成して構成
された磁気ディスクが磁気記録媒体として使用されはじ
めている。このような磁気記録媒体の磁気記録層は、酸
化鉄などの磁性粉末をバインダと混合し、これを基板上
にスピンコードなどの手法で塗布することにより得られ
ていたが、この磁気記録層には飽和磁化の大きさに限界
があるため、記録密度に限界があった。そこで最近では
、高記録密度の磁気記録媒体を得るために、より大きい
飽和磁化を有する金属薄膜を磁気記録層として用いた磁
気記録媒体が開発されており、このような磁気記録層は
コバルトあるいはコバルト系合金からなる薄膜を真空蒸
着法、スパッタリング法などの真空成膜技術により形成
したり、コバルト−リン、コバルト−ニッケルーリンな
どの合金薄膜を無電解メツキなどの湿式法により形成す
ることにより得られている。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic recording medium, and relates to a magnetic recording medium for use in, for example, a magnetic storage medium in an external storage device (magnetic disk device) of a computer or the like (conventional technology). ) Magnetic recording media are used as storage media in computers, etc., and conventionally tape coated with magnetic powder was widely used, but this storage tape has a low storage density (,
Due to drawbacks such as long access times, disk-shaped magnetic disks that allow random access have been used instead of tapes. Among these, magnetic disks constructed by forming a magnetic recording layer with a thickness of about 1 μm on a hard substrate such as aluminum are beginning to be used as magnetic recording media. The magnetic recording layer of such magnetic recording media was obtained by mixing magnetic powder such as iron oxide with a binder and applying it onto a substrate using a technique such as a spin cord. Since there is a limit to the magnitude of saturation magnetization, there is a limit to the recording density. Recently, in order to obtain magnetic recording media with high recording density, magnetic recording media using metal thin films with higher saturation magnetization as the magnetic recording layer have been developed, and such magnetic recording layers are made of cobalt or cobalt. It can be obtained by forming a thin film made of an alloy based on a vacuum film forming technique such as vacuum evaporation or sputtering, or by forming a thin film of an alloy such as cobalt-phosphorus or cobalt-nickel-phosphorus using a wet method such as electroless plating. ing.

ところで、現在一般に使用されている磁気記録媒体のド
ライブ装置には、ドライブ装置の停止、駆動に伴ないド
ライブ装置のヘッドが磁気記録媒体に接触、擦れ合う、
コンタクト・スタート・ストップ(C8S)方式が採用
されているため、磁気記録媒体には上記のドライブ装置
におけるC8Sに対する耐久性(C5S耐久性)が要求
される。
By the way, in drive devices for magnetic recording media that are currently in general use, the head of the drive device contacts and rubs against the magnetic recording medium as the drive device stops and drives.
Since the contact start/stop (C8S) method is adopted, the magnetic recording medium is required to have durability against C8S (C5S durability) in the above drive device.

そこで、磁気記録媒体にはその磁気記録層上に保護層が
設けられており、この保護層によって磁気記録媒体にC
8S耐久性を付与している。通常この保護層としては厚
み300Å以上の炭素膜が用いられているが、その一方
でより高い記録密度を達成するためにこの保護層の厚み
を薄くし、磁気記録媒体の使用の際にドライブ装置のヘ
ッドと磁気記録層のスペーシングロスを小さくすること
により磁気記録媒体の記録密度を向上させることが提案
されている。しかしながら、保護層として厚みの薄い炭
素膜を有する磁気記録媒体は、C8S耐久性が十分では
ないという問題がある。従って、薄い炭素膜を保護層と
して有する磁気記録媒体は、記録密度が向上するものの
、その保護層は使用に伴ないヘッドとの接触、擦れ合い
により磨耗し、更にこのような保護層の磨耗はヘッドと
磁気記録層とが衝突するヘッド・クラッシュを引き起こ
し、磁気記録媒体あるいはドライブ装置のヘッドの損傷
を招いてしまうこととなる。
Therefore, magnetic recording media are provided with a protective layer on the magnetic recording layer, and this protective layer protects the magnetic recording medium from carbon dioxide.
Provides 8S durability. Normally, a carbon film with a thickness of 300 Å or more is used as this protective layer, but on the other hand, in order to achieve higher recording density, the thickness of this protective layer is reduced, and when using magnetic recording media, the drive device It has been proposed to improve the recording density of a magnetic recording medium by reducing the spacing loss between the head and the magnetic recording layer. However, magnetic recording media having a thin carbon film as a protective layer have a problem in that C8S durability is not sufficient. Therefore, although a magnetic recording medium having a thin carbon film as a protective layer has an improved recording density, the protective layer wears out due to contact with the head and rubbing against each other during use, and furthermore, such wear of the protective layer increases. This causes a head crash in which the head collides with the magnetic recording layer, resulting in damage to the magnetic recording medium or the head of the drive device.

(発明が解決しようとする課題) 本発明の目的は、C8S耐久性に優れ、かつ高記録密度
を達成し得る磁気記録媒体を提供することにある。
(Problems to be Solved by the Invention) An object of the present invention is to provide a magnetic recording medium that has excellent C8S durability and can achieve high recording density.

(課題を解決するための手段) 本発明者らは上記課題を解決するために鋭意検討を行っ
た結果、珪素元素及び炭素元素を含んでなる保護層を有
する磁気記録媒体はC8S耐久性に優れたものとなるこ
とを見出だし本発明を完成するに至った。すなわち本発
明は、非磁性下地層を被覆した基板、その上に設けた磁
性金属薄膜からなる磁気記録層及び該磁気記録層を保護
するための保護層を含んでなる磁気記録媒体において、
保護層が珪素元素及び炭素元素を含んでなり、かつ炭素
元素の濃度が保護層の前記磁気記録層側から表面への厚
み方向に向かって増加することを特徴とする磁気記録媒
体である。本発明の磁気記録媒体は、特に保護層が珪素
元素及び炭素元素を含んでなり、かつ炭素元素の濃度が
保護層の厚み方向に伴なって変化するところに特徴を有
するものであるが、このことにより磁気記録媒体のC8
S耐久性は向上し、また保護層の厚みを薄くしても十分
なC8S耐久性を有するものとなる。その理由は明らか
ではないが、珪素元素の濃度が高い磁気記録層側の保護
層は硬いという特性を示し、炭素元素の濃度が増加する
保護層の表面は潤滑性を示すことに起因するものと考え
られる。
(Means for Solving the Problems) The present inventors have conducted extensive studies to solve the above problems, and have found that a magnetic recording medium having a protective layer containing silicon and carbon elements has excellent C8S durability. The present inventors have discovered that the present invention can be achieved by completing the present invention. That is, the present invention provides a magnetic recording medium comprising a substrate coated with a non-magnetic underlayer, a magnetic recording layer made of a magnetic metal thin film provided thereon, and a protective layer for protecting the magnetic recording layer.
The magnetic recording medium is characterized in that the protective layer contains a silicon element and a carbon element, and the concentration of the carbon element increases in the thickness direction from the magnetic recording layer side to the surface of the protective layer. The magnetic recording medium of the present invention is particularly characterized in that the protective layer contains a silicon element and a carbon element, and the concentration of the carbon element changes in the thickness direction of the protective layer. C8 of the magnetic recording medium
The S durability is improved, and even if the thickness of the protective layer is reduced, sufficient C8S durability can be achieved. The reason for this is not clear, but it is thought to be due to the fact that the protective layer on the magnetic recording layer side, where the concentration of silicon element is high, exhibits hardness, and the surface of the protective layer, where the concentration of carbon element increases, exhibits lubricity. Conceivable.

以下、図面を参照して本発明の詳細な説明する。Hereinafter, the present invention will be described in detail with reference to the drawings.

第1図は本発明の磁気記録媒体の一例の部分断面図であ
る。本発明の磁気記録媒体は第1図に示すように非磁性
下地層2を被覆した基板1上に磁気記録層3及び保護層
4を形成して構成される。この基板1としてはニッケル
ーリンメツキ膜、陽極酸化アルマイト膜などを被覆した
アルミニウム合金、窒化珪素焼結体、酸化アルミニウム
焼結体などのセラミックスやステンレス、チタン合金な
どの金属、ガラスあるいは樹脂などが用いられる。
FIG. 1 is a partial cross-sectional view of an example of the magnetic recording medium of the present invention. The magnetic recording medium of the present invention is constructed by forming a magnetic recording layer 3 and a protective layer 4 on a substrate 1 coated with a non-magnetic underlayer 2, as shown in FIG. The substrate 1 may be made of an aluminum alloy coated with a nickel-phosphorus plating film, an anodized alumite film, etc., ceramics such as silicon nitride sintered body, aluminum oxide sintered body, metal such as stainless steel or titanium alloy, glass, or resin. It will be done.

また、基板1は磁気記録媒体の磁気特性を向上させる目
的で、厚み500〜5000人程度のクロムなどの非磁
性金属膜からなる非磁性下地層2により被覆される。次
に非磁性下地層2の上には磁気記録層3が形成される。
Further, the substrate 1 is coated with a nonmagnetic underlayer 2 made of a nonmagnetic metal film such as chromium and having a thickness of approximately 500 to 5,000 layers for the purpose of improving the magnetic properties of the magnetic recording medium. Next, a magnetic recording layer 3 is formed on the nonmagnetic underlayer 2.

この磁気記録層3を構成する材料としては、例えばコバ
ルト、コバルトニッケル合金からなる磁性金属あるいは
これら磁性金属にプラチナ、ロジウム、クロム、サマリ
ウム、タンタル、レニウム及びタングステンから選ばれ
る少なくとも一種以上の金属を添加したものなどが用い
られ、その厚みは300〜1000人程度に形成される
。更に、この磁気記録層3上には保護層4が形成され、
保護層4は珪素元素及び炭素元素を含んでなり、かつ保
護層4中の炭素元素の濃度は保護層の磁気記録層3側か
ら表面への厚み方向に向かって増加している。炭素の濃
度増加は特に限定されないが、例えば第2図あるいは第
3図に示すように増加させることなどが考えられる。な
お保護層4の厚みは、厚い場合スペーシングロスが大き
くなり、磁気記録媒体の高記録密度領域での特性が悪く
なるおそれがあり、一方薄い場合は得られる磁気記録媒
体のC8S耐久性が向上しないことあるので、20〜5
00人とすることが好ましい。また本発明の磁気記録媒
体の使用にあたっては、必要に応じて液体潤滑剤、固体
潤滑剤あるいはこれらの複合潤滑剤を塗布し、潤滑層5
を形成して使用することができる。
The material constituting the magnetic recording layer 3 is, for example, a magnetic metal such as cobalt or cobalt-nickel alloy, or these magnetic metals doped with at least one metal selected from platinum, rhodium, chromium, samarium, tantalum, rhenium, and tungsten. The thickness of the board is approximately 300 to 1,000 people. Furthermore, a protective layer 4 is formed on this magnetic recording layer 3,
The protective layer 4 contains silicon element and carbon element, and the concentration of carbon element in the protective layer 4 increases in the thickness direction from the magnetic recording layer 3 side to the surface of the protective layer. Although the increase in carbon concentration is not particularly limited, it is conceivable to increase it as shown in FIG. 2 or FIG. 3, for example. Note that if the thickness of the protective layer 4 is thick, the spacing loss will increase and the characteristics of the magnetic recording medium in a high recording density region may deteriorate, whereas if it is thin, the C8S durability of the obtained magnetic recording medium will improve. There are things I don't do, so 20-5
It is preferable to set the number to 00 people. In addition, when using the magnetic recording medium of the present invention, a liquid lubricant, a solid lubricant, or a combination of these lubricants may be applied as necessary to form a lubricant layer 5.
can be formed and used.

以上、非磁性下地層2から保護層4までの金属または無
機物質の薄膜の形成にあたってはDC。
As described above, the thin film of metal or inorganic material from the non-magnetic underlayer 2 to the protective layer 4 is formed using DC.

RFスパッタリング法あるいは真空蒸着法などの真空成
膜技術が有効に用いられる。また、保護層4は珪素ター
ゲットと炭素ターゲットあるいは炭化珪素ターゲットと
炭素ターゲットによる同時スパッタリングなどの方法に
よって厚み方向で炭素元素の濃度を変化させることによ
って形成することができる。
Vacuum film forming techniques such as RF sputtering or vacuum evaporation are effectively used. Further, the protective layer 4 can be formed by changing the concentration of the carbon element in the thickness direction by a method such as simultaneous sputtering using a silicon target and a carbon target or a silicon carbide target and a carbon target.

(実施例) 以下、本発明を実施例に基づき説明するが、本発明はこ
れら実施例に限定されるものではない。
(Examples) Hereinafter, the present invention will be explained based on Examples, but the present invention is not limited to these Examples.

実施例1 第1図に示す構造の磁気記録媒体を作製した。Example 1 A magnetic recording medium having the structure shown in FIG. 1 was manufactured.

基板1としてニッケルーリンメツキ膜を被覆した円板状
アルミニウム合金を用い、この基板1の上にDCスパッ
タリング法により3000人のクロム膜からなる非磁性
下地層2を形成した。次にこの上に磁気記録層3として
ニッケル20原子%、クロム10原子%を含むコバルト
合金膜をDCスパッタリング法により600人の厚みに
形成した。
A disc-shaped aluminum alloy coated with a nickel-phosphorus plating film was used as the substrate 1, and a non-magnetic underlayer 2 made of a 3000 chrome film was formed on the substrate 1 by DC sputtering. Next, a cobalt alloy film containing 20 atom % of nickel and 10 atom % of chromium was formed thereon as a magnetic recording layer 3 to a thickness of 600 mm by DC sputtering.

更に、この上に珪素元素及び炭素元素を含んでなる保護
層4を珪素ターゲットと炭素ターゲットを用いた同時ス
パッタリング法により、それぞれの印加電力を調整し、
厚み方向で炭素元素の濃度を第2図のように増加させる
ようにして厚み200人形成し、その上に潤滑層5とし
て液体潤滑剤をディッピング法により形成し、磁気記録
媒体を作製した。
Furthermore, a protective layer 4 containing a silicon element and a carbon element is formed on this by a simultaneous sputtering method using a silicon target and a carbon target, adjusting the applied power of each,
A magnetic recording medium was produced by increasing the concentration of carbon element in the thickness direction as shown in FIG. 2 to a thickness of 200 mm, and forming a liquid lubricant as a lubricant layer 5 thereon by dipping.

その後、得られた磁気記録媒体のC8S耐久性を測定し
た。この耐久性の測定はCS S II定装置を用いて
行ない、磁気記録媒体上でヘッドをスタート・ストップ
させ、これを1回とし、所定の回数後の磁気記録媒体上
の摩擦係数を求めることにより行った。その結果を表1
に示す。表1から得られた磁気記録媒体の摩擦係数の増
加は少な(、C8S耐久性に優れていることがわかる。
Thereafter, the C8S durability of the obtained magnetic recording medium was measured. This durability is measured using a CS S II measuring device, by starting and stopping the head on the magnetic recording medium, counting this as one time, and determining the coefficient of friction on the magnetic recording medium after a predetermined number of times. went. Table 1 shows the results.
Shown below. From Table 1, it can be seen that the increase in the coefficient of friction of the magnetic recording medium obtained is small (it is clear that C8S has excellent durability.

実施例2 保護層4中の炭素元素濃度を第3図に示すように変化さ
せた以外は実施例1と同様の方法で磁気記録媒体を作製
し、C8S耐久性を測定した。その結果を表1に示す。
Example 2 A magnetic recording medium was produced in the same manner as in Example 1 except that the carbon element concentration in the protective layer 4 was changed as shown in FIG. 3, and the C8S durability was measured. The results are shown in Table 1.

比較例1 保護層4を厚み200人の炭素膜のみで構成した以外は
実施例1と同様の方法で磁気記録媒体を作製し、C8S
耐久性を測定した。その結果を表1に示す。
Comparative Example 1 A magnetic recording medium was produced in the same manner as in Example 1 except that the protective layer 4 was composed of only a carbon film with a thickness of 200 mm.
Durability was measured. The results are shown in Table 1.

比較例2 保護層4を厚み200人の炭化珪素膜(S i C)の
みで構成した以外は実施例1と同様の方法で磁気記録媒
体を作製し、C8S耐久性を測定した。
Comparative Example 2 A magnetic recording medium was produced in the same manner as in Example 1 except that the protective layer 4 was composed only of a silicon carbide film (S i C) having a thickness of 200 μm, and the C8S durability was measured.

その結果を表1に示す。The results are shown in Table 1.

表1 の磁気記録媒体は保護層の厚みを薄くしても十分なC8
S耐久性を示すので、高記録密度を達成し得るものとな
る。
The magnetic recording media in Table 1 have sufficient C8 even if the thickness of the protective layer is reduced.
Since it exhibits S durability, high recording density can be achieved.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の磁気記録媒体の構造の一例を示す断面
図である。 第2図および第3図は本発明の磁気記録媒体の有する保
護層中の厚み方向における炭素元素の濃度変化の例を示
す図である。 1・・・基板      2・・・非磁性下地層3・・
・磁気記録層   4・・・保護層5・・・潤滑層 を各々示す。 (発明の効果)
FIG. 1 is a sectional view showing an example of the structure of the magnetic recording medium of the present invention. FIGS. 2 and 3 are diagrams showing examples of changes in the concentration of carbon element in the thickness direction of the protective layer of the magnetic recording medium of the present invention. 1...Substrate 2...Nonmagnetic underlayer 3...
-Magnetic recording layer 4...Protective layer 5...Lubricating layer is shown respectively. (Effect of the invention)

Claims (1)

【特許請求の範囲】[Claims] (1)非磁性下地層を被覆した基板、その上に設けた磁
性金属薄膜からなる磁気記録層及び該磁気記録層を保護
するための保護層を含んでなる磁気記録媒体において、
保護層が珪素元素及び炭素元素を含んでなり、かつ炭素
元素の濃度が保護層の前記磁気記録層側から表面への厚
み方向に向かって増加することを特徴とする磁気記録媒
体。
(1) A magnetic recording medium comprising a substrate coated with a non-magnetic underlayer, a magnetic recording layer made of a magnetic metal thin film provided thereon, and a protective layer for protecting the magnetic recording layer,
A magnetic recording medium characterized in that the protective layer contains a silicon element and a carbon element, and the concentration of the carbon element increases in the thickness direction from the magnetic recording layer side to the surface of the protective layer.
JP14725190A 1990-06-07 1990-06-07 Magnetic recording media Expired - Lifetime JP2952967B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14725190A JP2952967B2 (en) 1990-06-07 1990-06-07 Magnetic recording media

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14725190A JP2952967B2 (en) 1990-06-07 1990-06-07 Magnetic recording media

Publications (2)

Publication Number Publication Date
JPH0440626A true JPH0440626A (en) 1992-02-12
JP2952967B2 JP2952967B2 (en) 1999-09-27

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JP14725190A Expired - Lifetime JP2952967B2 (en) 1990-06-07 1990-06-07 Magnetic recording media

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6623836B1 (en) 1992-11-19 2003-09-23 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium
US6805941B1 (en) 1992-11-19 2004-10-19 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium
JP2006161075A (en) * 2004-12-03 2006-06-22 Shinko Seiki Co Ltd Hard carbon film, and its depositing method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6623836B1 (en) 1992-11-19 2003-09-23 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium
US6805941B1 (en) 1992-11-19 2004-10-19 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium
US7083873B2 (en) 1992-11-19 2006-08-01 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium including a diamond-like carbon protective film with hydrogen and at least two additional elements
US7391592B2 (en) 1992-11-19 2008-06-24 Semiconductor Energy Laboratory Co., Ltd. Magnetic recording medium including a diamond-like carbon protective film and at least two additional elements
JP2006161075A (en) * 2004-12-03 2006-06-22 Shinko Seiki Co Ltd Hard carbon film, and its depositing method

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