JPS6126926A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium which has a good S/N and substantial signal output and is suitable for high-density recording by laminating >=2 kinds of vertically magnetizable films consisting of a magnetic alloy in such a manner that the films are vertically magnetizable and that the magnetical sepn. of the magnetic alloy component themselves are made several times in the vertical direction. CONSTITUTION:An Ni-Fe alloy film 5 is first formed on a high-polymer substrate 4 consisting of polyester, etc. and thereafter a Co-Cr film 6 and a Co-Ti film 7 are successively formed thereon as the vertically magnetizable films. The magnetical sepn. is made plural times in the thickness direction by the equiv. non-magnetic layers coating substantially the surface of fine crystal particles as a result of the segregation of the alloy components in the respective films without forming the non-magnetic films between the substrate 4 and the film 5, between the film 5 and the film 6 and between the film 6 and the film 7 in the above-mentioned manner, by which the vertical magnetic recording medium having the improved S/N and good corrosion resistance is obtd.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は高密度磁気記録に適する磁気記録媒体に関する
。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium suitable for high-density magnetic recording.

従来例の構成とその問題点 近年、短波長記録特性の優れた媒体として、基板の垂直
方向に磁化可能ないわゆる垂直磁化膜を磁気記録層とし
た磁気記録媒体が注目されている。BACKGROUND ART In recent years, magnetic recording media in which a so-called perpendicular magnetization film, which can be magnetized in the perpendicular direction of a substrate, is used as a magnetic recording layer have attracted attention as a medium with excellent short wavelength recording characteristics.

記録密度的に最も期待されているのは補助磁極励磁型垂
直ヘッドとＮｉ−Ｆｅに代表される軟磁性層とＣ０−Ｃ
ｒスパッタ膜に代表される垂直磁化膜の積層されたいわ
ゆる２層媒体を組み合わせたものと考えられているが、
現状では、周波数特性は、良好であるが、信号出力が小
さすぎるため、信号対雑音比（Ｓ／Ｎ比）として十分な
値が確保できず、かかる記録方式の実用化の為に、低雑
音の媒体の開発が望まれている。The most promising technologies in terms of recording density are the auxiliary pole excitation type vertical head, the soft magnetic layer represented by Ni-Fe, and the C0-C
It is thought to be a combination of so-called two-layer media in which perpendicularly magnetized films such as r-sputtered films are laminated.
Currently, the frequency characteristics are good, but because the signal output is too small, it is not possible to secure a sufficient value for the signal-to-noise ratio (S/N ratio). It is desired to develop a medium for this purpose.

発明の目的 本発明は上記事情に鑑みなされたもので、Ｓ／Ｎの改良
された垂直磁気記録用の媒体を提供するものである。OBJECTS OF THE INVENTION The present invention was made in view of the above circumstances, and it is an object of the present invention to provide a medium for perpendicular magnetic recording with an improved S/N ratio.

発明の構成 本発明の磁気記録媒体は、垂直方向に磁化可能で、合金
成分自身での磁気的分離が垂直方向に複数回なされてい
ることを特徴とするもので、雑音を改良し、Ｓ／Ｎｉ改
良できるものである。Structure of the Invention The magnetic recording medium of the present invention is characterized in that it can be magnetized in the perpendicular direction and that the alloy component itself is magnetically separated multiple times in the perpendicular direction. Ni can be improved.

実施例の説明 以下図面を参照しながら本発明を説明する。Description of examples The present invention will be described below with reference to the drawings.

第１図は、従来の多層構造の磁気記録媒体の拡大断面図
で、第２図は本発明の磁気記録媒体の拡大断面図である
。FIG. 1 is an enlarged sectional view of a conventional multilayer magnetic recording medium, and FIG. 2 is an enlarged sectional view of a magnetic recording medium of the present invention.

第１図で１は高分子基板、２は非磁性層、３は垂直磁化
膜でへ一軟磁性層は略しである。In FIG. 1, 1 is a polymer substrate, 2 is a nonmagnetic layer, 3 is a perpendicular magnetization film, and the soft magnetic layer is omitted.

第２図で、４は高分子基板で５，６．了は夫々垂直磁化
膜１．ｎ、ＩＩＩである。In FIG. 2, 4 is a polymer substrate, 5, 6. At the end, the perpendicular magnetization film 1. n, III.

第１図の構成は、従来、垂直抗磁力を大きくするため提
唱されたものであるが、研究開発の進展により、必ずし
も垂直抗磁力を大きく設けすることが、周波数特性を改
善するのに不可欠ではないことが明らかにされ、逆に、
信号出力の面からみると、スペーシング損失の点からは
、非磁性層により、磁気ヘッド面から媒体が遠ざかるこ
との方がマイナスに大きく作用し、信号出力そのものが
余り大きくない点の認識と共に、好ましい構成ではない
ことが気付かれるようになった。The configuration shown in Figure 1 was proposed in the past to increase the vertical coercive force, but with the progress of research and development, it has become clear that increasing the vertical coercive force is not necessarily essential to improving frequency characteristics. It was revealed that there was no such thing, and on the contrary,
From the point of view of signal output, from the point of view of spacing loss, moving the medium away from the magnetic head surface due to the nonmagnetic layer has a large negative effect, and while recognizing that the signal output itself is not very large, It has come to be noticed that this is not a desirable configuration.

本発明は、第１図の構成に実験的検討を加え、雑音面で
は、優れている特徴を見出し、改良を重ね完成させたも
ので、第２図に示すように、非磁性層として独立した層
をもたずに、合金成分自身の偏析により実質的に微細結
晶粒子表面を被覆する等測的非磁性層により磁気的分離
を厚み方向に複数回行うことで、目的を達成したもので
ある。The present invention was developed by conducting experimental studies on the configuration shown in Figure 1, finding superior characteristics in terms of noise, and completing repeated improvements. This objective was achieved by performing magnetic separation multiple times in the thickness direction using an isometric nonmagnetic layer that substantially covers the surface of fine crystal grains due to the segregation of the alloy components themselves, without having any layers. .

磁気的分離の回数は、１回九ら１０Ｉｉ］１、好ましく
は２回から４回が、Ｓ／Ｎの最適範囲と、生産し易さの
面の兼ね合いから選は詐る〇 本発明によりＳ／Ｎが改良されるのは、信号出力は、独
立した非磁性層がないから、スペーシング損失を最小限
にとどめることができるのに、雑音は、磁気ヘッドから
みて、磁気的に磁石単位が小さくなりその分だけ均゛−
にみえるようになることから大幅に改良されるためと推
察されるものである。The number of times of magnetic separation is 1 time to 10 times, preferably 2 to 4 times, depending on the optimum range of S/N and ease of production. According to the present invention, S /N is improved because there is no independent non-magnetic layer for signal output, so spacing loss can be kept to a minimum, but from the perspective of the magnetic head, noise is reduced magnetically by a unit of magnet. It gets smaller and becomes more even.
This is presumed to be due to a significant improvement as it now looks like this.

本発明に用いることの出来る高分子基板はポリエステル
類、ポリオレフィン類、ポリアミド、ポリイミド等で、
垂直磁化膜としては、Ｃｏ−Ｃｒ。Polymer substrates that can be used in the present invention include polyesters, polyolefins, polyamides, polyimides, etc.
The perpendicular magnetization film is Co-Cr.

Ｃｏ−Ｖ　、Ｇｏ−０，Ｇｏ　−Ｐ　、Ｃｏ−Ｗ、Ｃｏ
　−Ｍｏ　、Ｃｏ−Ｔｉ　。Co-V, Go-0, Go-P, Co-W, Co
-Mo, Co-Ti.

Ｃｏ−Ｎｉ−Ｃｒ　、Ｃｏ−１（ｉ−○、Ｃｏ−Ｎ１−
Ｐ、等で、電層膜化きれたものである。Co-Ni-Cr, Co-1(i-○, Co-N1-
P, etc., which can be used as an electric layer.

以下、さらに具体的に〜実施例を説明する。Examples will be described in more detail below.

〔実施例〕〔Example〕

巻取″り式スパッタリング装置により製造した。 It was manufactured using a take-up type sputtering device.

この装置は双方向巻取り可能なもので、ターゲットはＮ
ｉ−Ｆｅと、垂直用の２つが装着できるものであり、回
転支持体は、１６０°Ｃまで加熱可能な円筒状キャンで
直径８０ｃｒｎである。高周波は１３．５６用を用いた
。This device is capable of bidirectional winding, and the target is N
An i-Fe and a vertical type can be installed, and the rotating support is a cylindrical can that can be heated up to 160°C and has a diameter of 80 crn. The high frequency used was 13.56.

厚み１３μｍのポリエチレンテレフタレートフィルムに
先ず、Ｎｉ−Ｆｅ　（Ｎｉ８０ｗｔ％）膜全０．６μｍ
形成した後、Ｃｏ−Ｃｒ　、Ｃｏ　−Ｔ　ｉの２種類を
垂直磁化膜としてくり返し積層し形成した。これを磁気
ティスフとし、Ｃｏ−Ｂ系非晶質合金を主磁極として用
いた補助磁極励磁型垂直ヘッドにより配合再生した時の
Ｓ／Ｎを比較した。磁気的分離に寄与していると考えら
れる。偏析層厚みはオージェ電子分光法で調べた。比較
例は、Ｔｉ　を非磁性層として用いたものである。得ら
れた媒体の条件と特性を表に壕とめて示した。First, a Ni-Fe (Ni 80wt%) film with a total thickness of 0.6 μm was applied to a 13 μm thick polyethylene terephthalate film.
After the formation, two types of perpendicular magnetization films, Co--Cr and Co--Ti, were repeatedly laminated and formed. This was used as a magnetic tape, and the S/N was compared when compound reproduction was performed using an auxiliary magnetic pole excitation type vertical head using a Co--B amorphous alloy as the main magnetic pole. It is thought that this contributes to magnetic separation. The thickness of the segregation layer was investigated using Auger electron spectroscopy. In the comparative example, Ti was used as the nonmagnetic layer. The conditions and characteristics of the obtained medium are shown in the table.

（以下余白） 本発明品は表より明らかなようにＳ／Ｎで優れているも
のであるが、実用特性上重要な耐食性についても大幅に
改良されている点は注目すべきである。例えば、比較例
が５５°Ｃ９０％ＲＨに１ケ月放置前後で全磁束量が１
０％から１６％減少したのに対して、表に示した本発明
品は全て、３％以下であった。(The following is a blank space) As is clear from the table, the products of the present invention are excellent in S/N, but it should be noted that the corrosion resistance, which is important for practical properties, is also significantly improved. For example, in a comparative example, the total magnetic flux amount was 1 after being left at 55°C and 90%RH for one month.
While the reduction was from 0% to 16%, all the products of the present invention shown in the table had a reduction of 3% or less.

尚、本発明品は磁気ディスクの他にテープ状媒体として
用いても良く、前述した他の材料の組み合わせでも同様
に効果をもつのは勿論、異なる材質の積層でもよいし、
保護層等が必要に応じ配設されるのは勿論である。It should be noted that the product of the present invention may be used as a tape-shaped medium in addition to a magnetic disk, and of course a combination of the other materials mentioned above will have the same effect, or a stack of different materials may be used.
Of course, a protective layer or the like may be provided as necessary.

発明の効果 本発明の磁気記録媒体は、垂直磁化膜を構成する合金成
分自身での磁気的分離が垂直方向に複数回なされている
ことを特徴とし、Ｃ／Ｎが高密度記録再生で大幅に改良
されているものでその実用的価値は大きい。Effects of the Invention The magnetic recording medium of the present invention is characterized in that the alloy components constituting the perpendicularly magnetized film are magnetically separated multiple times in the perpendicular direction, and the C/N can be significantly improved during high-density recording and reproduction. It has been improved and has great practical value.

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

第１図は従来の磁気記録媒体の拡大断面図、第２図は本
発明の磁気記録媒体の拡大断面図である。 ４・・・・・・基板、５，６，７・・・・・垂直磁化膜
。FIG. 1 is an enlarged sectional view of a conventional magnetic recording medium, and FIG. 2 is an enlarged sectional view of a magnetic recording medium of the present invention. 4...Substrate, 5, 6, 7... Perpendicular magnetization film.

Claims (1)

【特許請求の範囲】[Claims] 垂直方向に磁化可能で、合金成分自身での磁気的分離が
垂直方向に複数回なされていることを特徴とする磁気記
録媒体。A magnetic recording medium that can be magnetized in the perpendicular direction and is characterized in that the alloy components themselves are magnetically separated multiple times in the perpendicular direction.