JPH0773427A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH0773427A JPH0773427A JP21542293A JP21542293A JPH0773427A JP H0773427 A JPH0773427 A JP H0773427A JP 21542293 A JP21542293 A JP 21542293A JP 21542293 A JP21542293 A JP 21542293A JP H0773427 A JPH0773427 A JP H0773427A
- Authority
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- Japan
- Prior art keywords
- layer
- magnetic
- underlayer
- recording medium
- film thickness
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は磁気記録媒体に関し、特
に、磁気ディスク、フレキシブルディスク、スチルカメ
ラ、又はビデオ等の磁気記録用金属薄膜媒体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium, and more particularly to a magnetic thin film medium for magnetic recording such as a magnetic disk, a flexible disk, a still camera or a video.
【０００２】[0002]
【従来の技術】一般に、磁気記録媒体用合金として保磁
力（Ｈｃ）及び残留磁化膜厚積（Ｍｒ・δ）の高いＣｏ
Ｐｔ系合金が用いられている。このＣｏＰｔ系合金を用
いて磁気記録媒体を構成する際、その磁気特性を向上さ
せるため、一般に基板と磁性層との間に下地層を形成す
ることが行なわれている。2. Description of the Related Art Generally, Co having a high coercive force (Hc) and a remanent magnetization film thickness product (Mr.delta.) Is used as an alloy for magnetic recording media.
A Pt-based alloy is used. When a magnetic recording medium is formed using this CoPt-based alloy, an underlayer is generally formed between the substrate and the magnetic layer in order to improve its magnetic characteristics.
【０００３】このような磁気記録媒体として下地層にＣ
ｒ及びＭｏを含み、磁性層にＣｏ及びＰｔを含むととと
もにＭｏを含む磁気記録媒体が本発明者らによって提案
されている（特願平４−３１１２２４号明細書）。そし
て、この磁気記録媒体では従来のＣｏＰｔ系磁気記録媒
体の磁気特性（保磁力及び残留磁化膜厚積）に比べてそ
の磁気特性をさらに向上させることができた。As such a magnetic recording medium, C is used as an underlayer.
A magnetic recording medium containing r and Mo, Co and Pt in the magnetic layer and Mo was proposed by the present inventors (Japanese Patent Application No. 4-31224). Further, in this magnetic recording medium, the magnetic characteristics could be further improved as compared with the magnetic characteristics (coercive force and residual magnetization film thickness product) of the conventional CoPt-based magnetic recording medium.
【０００４】[0004]
【発明が解決しようとする課題】ところで、特願平４−
３１１２２４号明細書に記載された磁気記録媒体におい
ては、その磁気特性、つまり、保磁力及び残留磁化膜厚
積を向上させることができるが、信号対雑音比（Ｓ／Ｎ
比）に関しては十分には満足できる値が得られない。つ
まり、媒体ノイズを低減させることが難しいという問題
点がある。By the way, Japanese Patent Application No. 4-
In the magnetic recording medium described in Japanese Patent No. 3112424, its magnetic characteristics, that is, the coercive force and the remanent magnetization film thickness product can be improved, but the signal-to-noise ratio (S / N
As for (ratio), a sufficiently satisfactory value cannot be obtained. That is, it is difficult to reduce the medium noise.
【０００５】本発明の目的は磁気特性が良好なばかりで
なくＳ／Ｎ比も良好な磁気記録媒体を提供することにあ
る。An object of the present invention is to provide a magnetic recording medium having not only good magnetic characteristics but also good S / N ratio.
【０００６】[0006]
【課題を解決するための手段】本発明による磁気記録媒
体は、非磁性基板と、この非磁性基板上に形成された下
地層と、この下地層上に形成された磁性膜とを有してお
り、上記の下地層は非磁性基板側に形成された第１の層
と磁性層側に形成された第２の層とを備え、第１の層に
はクロムが含まれ、第２の層にはクロム及びモリブデン
が含まれ、磁性層にはコバルト及び白金が含まれている
ことを特徴としている。A magnetic recording medium according to the present invention has a nonmagnetic substrate, an underlayer formed on the nonmagnetic substrate, and a magnetic film formed on the underlayer. The underlayer includes a first layer formed on the non-magnetic substrate side and a second layer formed on the magnetic layer side, the first layer containing chromium, and the second layer Contains chromium and molybdenum, and the magnetic layer contains cobalt and platinum.
【０００７】そして、第１の層の膜厚は第２の層の膜厚
よりも厚いことが望ましく、非磁性基板から磁性膜に向
かう方向に第２の層中のモリブデン濃度を高くすること
が望ましい。加えて、磁性層にはさらにモリブデンを加
えるようにしてもよい。The thickness of the first layer is preferably thicker than that of the second layer, and the molybdenum concentration in the second layer is increased in the direction from the nonmagnetic substrate to the magnetic film. desirable. In addition, molybdenum may be further added to the magnetic layer.
【０００８】なお、本発明では非磁性基板と第１の層と
の間に他の層を形成してもよく、また、第２の層と磁性
膜との間に他の層を介在させるようにしてもよい。In the present invention, another layer may be formed between the non-magnetic substrate and the first layer, and another layer may be interposed between the second layer and the magnetic film. You may
【０００９】[0009]
【作用】本発明では下地層が第１及び第２の層を備え
て、第１の層にクロムを含有し、第２の層にクロム及び
モリブデンを含有させて、しかも下地層上にコバルト及
び白金を含む磁性層を形成するようにしたから、第２の
層において結晶粒子を均一化させることができるばかり
でなく磁性層における結晶粒子を均一化できる。この結
果、媒体ノイズを低減できるばかりでなく磁気特性を良
好に維持できる。According to the present invention, the underlayer comprises the first and second layers, the first layer contains chromium, the second layer contains chromium and molybdenum, and the underlayer contains cobalt and molybdenum. Since the magnetic layer containing platinum is formed, not only the crystal grains in the second layer can be made uniform, but also the crystal grains in the magnetic layer can be made uniform. As a result, not only the medium noise can be reduced, but also the magnetic characteristics can be favorably maintained.
【００１０】[0010]
【実施例】以下本発明について実施例によって説明す
る。EXAMPLES The present invention will be described below with reference to examples.
【００１１】（実施例１）図１を参照して、直径６５ｍ
ｍ厚さ０．９ｍｍのガラス基板１を準備して、このガラ
ス基板１をＲＦマグネトロンスパッタ装置（図示せず）
のチャンバー内に装着する。そして、チャンバー内を５
×１０-7Ｔｏｒｒ以下の圧力まで減圧する。その後、ア
ルゴンガスをスパッタガスとしてガス圧１０ｍＴｏｒｒ
でスパッタ装置に供給し、基板温度を室温として投入電
力密度を２．５Ｗ／ｃｍ2 、Ｃｒをターゲットとしてガ
ラス基板１上に膜厚１５００オングストロームの第１の
層（第１の下地層）２を形成した。続いて、同様にして
アルゴンガスをスパッタガスとして用いてＣｒ90Ｍｏ10
（ａｔ％）をターゲットとして、Ｃｒ90Ｍｏ10の組成を
有する膜厚５００オングストロームの第２の層（第２の
下地層）３を第１の下地層２上に形成した。(Embodiment 1) Referring to FIG. 1, a diameter of 65 m
A glass substrate 1 having a thickness of 0.9 mm is prepared, and the glass substrate 1 is provided with an RF magnetron sputtering device (not shown).
Install in the chamber. And 5 in the chamber
Depressurize to a pressure of × 10 -7 Torr or less. Then, using argon gas as the sputtering gas, the gas pressure is 10 mTorr.
To a sputtering apparatus, the substrate temperature is room temperature, the input power density is 2.5 W / cm 2 , and the target is Cr, and the first layer (first underlayer) 2 having a film thickness of 1500 Å is formed on the glass substrate 1. Formed. Subsequently, in a similar manner, using argon gas as a sputtering gas, Cr 90 Mo 10
A second layer (second underlayer) 3 having a composition of Cr 90 Mo 10 and a film thickness of 500 Å was formed on the first underlayer 2 with (at%) as a target.
【００１２】次に、アルゴンガスをスパッタガスとして
用いてＣｏ76Ｐｔ16Ｍｏ8 （ａｔ％）をターゲットとし
てＣｏ76Ｐｔ16Ｍｏ8 の組成を有する膜厚４００オング
ストロームの磁性層４を第２の下地層３上に形成した。
同様に、アルゴンガスをスパッタガスとして用いて磁性
層４上に膜厚５０オングストロームのＣｒ層５ａ及び膜
厚３００オングストロームのカーボン層５ｂを形成し、
これらＣｒ層５ａ及びカーボン層５ｂを保護層５とし
た。そして、保護層５上にパーフルオロポリエーテルか
らなる潤滑層６を２０オングストロームの厚さ塗布して
磁気ディスク（磁気記録媒体）７を得、この磁気ディス
ク７を実施例１とした。Next, a magnetic layer 4 having a composition of Co 76 Pt 16 Mo 8 and a film thickness of 400 Å and a thickness of 400 Å is formed on the second lower layer by using Ar gas as a sputtering gas and Co 76 Pt 16 Mo 8 (at%) as a target. It was formed on the formation 3.
Similarly, a Cr layer 5a having a film thickness of 50 Å and a carbon layer 5b having a film thickness of 300 Å are formed on the magnetic layer 4 by using argon gas as a sputtering gas.
These Cr layer 5a and carbon layer 5b were used as the protective layer 5. Then, a lubricating layer 6 made of perfluoropolyether was applied on the protective layer 5 to a thickness of 20 Å to obtain a magnetic disk (magnetic recording medium) 7. This magnetic disk 7 was referred to as Example 1.
【００１３】さらに、比較のため、下地層としてＣｒ層
（つまり、上述の第１の下地層２）のみを有する磁気デ
ィスクを作成し、この磁気ディスクを比較例１とした。
なお、比較例１において他の構成要素は実施例１と同様
である。また、下地層としてＣｒ90Ｍｏ10層（つまり、
上述の第２の下地層３）のみを有する磁気ディスクを作
成し、この磁気ディスクを比較例２とした。なお、比較
例２において他の構成要素は実施例１と同様である。Further, for comparison, a magnetic disk having only a Cr layer (that is, the above-mentioned first underlayer 2) as an underlayer was prepared, and this magnetic disk was designated as Comparative Example 1.
The other constituent elements in Comparative Example 1 are the same as those in Example 1. In addition, a Cr 90 Mo 10 layer (that is,
A magnetic disk having only the above-mentioned second underlayer 3) was prepared, and this magnetic disk was designated as Comparative Example 2. The other constituent elements of Comparative Example 2 are the same as those of Example 1.
【００１４】これら実施例１及び比較例１及び２からそ
れぞれ直径８ｍｍの試料を切り出して、振動試料型磁力
計を用いて、各試料について保磁力（Ｈｃ）を測定し
た。この際膜面方向に最大外部印加磁場を１２ｋＯｅと
して磁場を印加した。Samples each having a diameter of 8 mm were cut out from these Example 1 and Comparative Examples 1 and 2, and the coercive force (Hc) of each sample was measured using a vibrating sample magnetometer. At this time, the maximum external applied magnetic field was set to 12 kOe and the magnetic field was applied in the film surface direction.
【００１５】さらに、実施例１及び比較例１及び２の磁
気ディスクを用いて記録再生出力を測定した。ここで
は、磁気ヘッド浮上量が０．０５５μｍの薄膜ヘッドを
用いて、この薄膜ヘッドと磁気ディスクの相対速度を６
ｍ／ｓとし、線記録密度８０ｋｆｃｉ（１インチ当たり
８０，０００ビットの線記録密度）における記録再生出
力を測定した。さらに、キャリア周波数９．４ＭＨｚ
で、測定帯域を１５ＭＨｚとしてスペクトルアナライザ
ーによって各磁気ディスクについて信号記録再生時にお
けるノイズスペクトラムを測定し（媒体ノイズＮｍで表
す）、Ｓ／Ｎｍを求めた。この結果を表１に示す。な
お、上述の測定で用いた薄膜ヘッドはコイルターン数５
０、トラック幅６μｍ、磁気ヘッドギャップ長０．２５
μｍである。Further, the recording / reproducing output was measured using the magnetic disks of Example 1 and Comparative Examples 1 and 2. Here, a thin film head having a flying height of the magnetic head of 0.055 μm is used, and the relative speed between the thin film head and the magnetic disk is 6
The recording / reproducing output at a linear recording density of 80 kfci (linear recording density of 80,000 bits per inch) was measured at m / s. Furthermore, carrier frequency 9.4MHz
Then, the noise spectrum at the time of signal recording / reproduction was measured (represented by medium noise Nm) for each magnetic disk with the measurement band set to 15 MHz and the S / Nm was obtained. The results are shown in Table 1. The thin film head used in the above measurement had 5 coil turns.
0, track width 6 μm, magnetic head gap length 0.25
μm.
【００１６】[0016]
【表１】 [Table 1]
【００１７】表１から明らかなように比較例１では、実
施例１に比べて保磁力及び記録再生出力ともに小さく、
さらに、Ｓ／Ｎｍ比も小さいことが分かる。また、比較
例２では、保磁力及び記録再生出力については実施例１
と同等であるが、媒体ノイズＮｍが実施例１に比べて大
きく、このため、比較例２ではＳ／Ｎｍが小さくなって
いる。As is clear from Table 1, in Comparative Example 1, both the coercive force and the recording / reproducing output are smaller than those in Example 1,
Further, it can be seen that the S / Nm ratio is also small. In Comparative Example 2, the coercive force and the recording / reproducing output are those in Example 1.
Although the medium noise Nm is larger than that of the first embodiment, the S / Nm of the second comparative example is smaller than that of the first embodiment.
【００１８】このように、実施例１では下地層としてＣ
ｒ層とＣｒＭｏ層を積層した層を用いているから比較例
１及び２のように単一の下地層を用いる場合に比べて良
好な磁気特性が得られるばかりでなくＳ／Ｎ比も改善で
きる。As described above, in Example 1, C was used as the underlayer.
Since the layer in which the r layer and the CrMo layer are laminated is used, not only good magnetic characteristics can be obtained as compared with the case where a single underlayer is used as in Comparative Examples 1 and 2, but also the S / N ratio can be improved. .
【００１９】（実施例２）次に、実施例１において第１
の下地層２と第２の下地層３の合計膜厚を２０００オン
グストロームのままとして、第１の下地層２と第２の下
地層３との割合（つまり、膜厚比）を種々変化させて磁
気ディスクを作成した（実施例２）。(Embodiment 2) Next, the first embodiment
While keeping the total film thickness of the underlayer 2 and the second underlayer 3 of 2000 angstroms, the ratio (that is, the film thickness ratio) between the first underlayer 2 and the second underlayer 3 can be variously changed. A magnetic disk was prepared (Example 2).
【００２０】これら磁気ディスクについて上述の実施例
１の場合と同様にして保磁力（Ｈｃ）、記録再生出力、
媒体ノイズ（Ｎｍ）、及びＳ／Ｎｍ比を測定した。そし
て、膜厚比の変化に対する各測定値の変化を図２に示
す。For these magnetic disks, the coercive force (Hc), recording / reproducing output,
The medium noise (Nm) and the S / Nm ratio were measured. The change in each measured value with respect to the change in film thickness ratio is shown in FIG.
【００２１】図２から明らかなように保磁力（Ｈｃ、図
中、○で示す）及び記録再生出力（図中、□で示す）に
ついては膜厚比の変化による影響はないが、媒体ノイズ
（図中、◆で示す）については第２の下地層３の割合が
大きくなるにつれて大きくなる。また、第２の下地層３
の膜厚が第１の下地層２の膜厚より薄い場合は、Ｓ／Ｎ
ｍはほぼ同等であるが、逆に第２の下地層３の方が厚く
なると、下地層として第２の下地層３のみを用いた磁気
ディスクのＳ／Ｎｍは小さくなってしまう。従って、第
２の下地層３の膜厚は第２の下地層の膜厚よりも薄くす
る必要がある。As is apparent from FIG. 2, coercive force (Hc, indicated by ◯ in the figure) and recording / reproduction output (indicated by □ in the figure) are not affected by the change in the film thickness ratio, but medium noise ( (Indicated by ♦ in the figure) increases as the proportion of the second underlayer 3 increases. In addition, the second underlayer 3
Is less than the thickness of the first underlayer 2, S / N
Although m is almost the same, conversely, if the second underlayer 3 is thicker, the S / Nm of the magnetic disk using only the second underlayer 3 as the underlayer will be smaller. Therefore, the film thickness of the second underlayer 3 needs to be smaller than the film thickness of the second underlayer.
【００２２】（実施例３乃至１６）次に、直径４８ｍｍ
で厚さ０．６４ｍｍのガラス基板上に実施例１と同様に
してガラス基板上に膜厚１２００オングストロームの第
１の下地層（Ｃｒ層）を形成し、この第１の下地層上に
膜厚３００オングストロームの第２の下地層（Ｃｒ95Ｍ
ｏ5 （ａｔ％）層）を形成する。さらに、第２の下地層
上に膜厚４５０オングストロームの磁性層（Ｃｏ79Ｐｔ
13Ｍｏ8 （ａｔ％）層）を形成し、この磁性層上にＳｉ
Ｏ2 を厚さ１４０オングストローム形成して保護膜と
し、磁気ディスクを作成した（実施例３）。そして、こ
の磁気ディスクについて実施例１と同様にしてＳ／Ｎｍ
比を測定した。この結果を表２に示す。(Examples 3 to 16) Next, the diameter is 48 mm.
Then, a first underlayer (Cr layer) having a film thickness of 1200 Å was formed on the glass substrate having a thickness of 0.64 mm in the same manner as in Example 1 and the film thickness was formed on the first underlayer. Second underlayer of 300 Å (Cr 95 M
o 5 (at%) layer) is formed. Further, on the second underlayer, a magnetic layer (Co 79 Pt) having a film thickness of 450 angstrom is formed.
13 Mo 8 (at%) layer) and Si is formed on this magnetic layer.
A magnetic disk was prepared by forming O 2 with a thickness of 140 Å as a protective film (Example 3). Then, with respect to this magnetic disk, S / Nm was performed in the same manner as in Example 1.
The ratio was measured. The results are shown in Table 2.
【００２３】[0023]
【表２】 [Table 2]
【００２４】さらに、第２の下地層、磁性層、及び保護
層の組成を表２に示す組成として、磁気ディスクを作成
した（実施例４乃至実施例１６）。そして、これら磁気
ディスクについて実施例１と同様にしてＳ／Ｎｍ比を測
定した。Further, magnetic disks were prepared with the compositions of the second underlayer, the magnetic layer and the protective layer shown in Table 2 (Examples 4 to 16). Then, the S / Nm ratio of these magnetic disks was measured in the same manner as in Example 1.
【００２５】表２から明らかなようにＣｒ、Ｍｏ、ある
いはさらに他の追加成分を添加した第２の下地層を用い
ても同様にＳ／Ｎｍ比を高くすることができる。As is clear from Table 2, the S / Nm ratio can be similarly increased by using the second underlayer to which Cr, Mo, or another additional component is added.
【００２６】（実施例１７乃至２６）さらに、直径６５
ｍｍで厚さ０．６４ｍｍのガラス基板上に実施例１と同
様にしてガラス基板上に膜厚２０００オングストローム
の第１の下地層（Ｃｒ層）を形成し、この第１の下地層
上に膜厚６００オングストロームの第２の下地層（Ｃｒ
85Ｍｏ15（ａｔ％）層）を形成する。さらに、第２の下
地層上に膜厚５００オングストロームの磁性層（Ｃｏ73
Ｐｔ12Ｍｏ13Ｔａ2 （ａｔ％）層）を形成し、この磁性
層上にＴａ2 Ｏ5 を厚さ１６０オングストローム形成し
て保護膜とし、磁気ディスクを作成した（実施例１
７）。そして、この磁気ディスクについて実施例１と同
様にしてＳ／Ｎｍ比を測定した。この結果を表３に示
す。(Examples 17 to 26) Further, a diameter of 65
A first underlayer (Cr layer) having a film thickness of 2000 angstrom is formed on the glass substrate in the same manner as in Example 1 on a glass substrate having a thickness of 0.64 mm and a thickness of 0.64 mm, and a film is formed on the first underlayer. 600 Å thick second underlayer (Cr
85 Mo 15 (at%) layer) is formed. Further, a magnetic layer (Co 73 ) having a film thickness of 500 Å is formed on the second underlayer.
A Pt 12 Mo 13 Ta 2 (at%) layer) was formed, and Ta 2 O 5 was formed to a thickness of 160 Å on the magnetic layer to form a protective film, thereby forming a magnetic disk (Example 1).
7). Then, the S / Nm ratio of this magnetic disk was measured in the same manner as in Example 1. The results are shown in Table 3.
【００２７】[0027]
【表３】 [Table 3]
【００２８】さらに、第２の下地層、磁性層、及び保護
層の組成を表３に示す組成として、磁気ディスクを作成
した（実施例１８乃至実施例２６）。そして、これら磁
気ディスクについて実施例１と同様にしてＳ／Ｎｍ比を
測定した。Further, magnetic disks were prepared with the compositions of the second underlayer, the magnetic layer and the protective layer shown in Table 3 (Examples 18 to 26). Then, the S / Nm ratio of these magnetic disks was measured in the same manner as in Example 1.
【００２９】表３から明らかなようにＣｏ，Ｐｔ，Ｍｏ
に他の追加成分を添加した磁性層を用いても同様にＳ／
Ｎｍ比を高くすることができる。As is clear from Table 3, Co, Pt, Mo
Even if a magnetic layer in which other additional components are added is used,
The Nm ratio can be increased.
【００３０】（実施例２７）直径６５ｍｍで厚さ０．９
ｍｍのガラス基板をＲＦマグネトロンスパッタ装置（図
示せず）のチャンバー内に装着し、チャンバー内を４×
１０-8Ｔｏｒｒ以下の圧力まで減圧する。その後、アル
ゴンガスをスパッタガスとしてガス圧１０ｍＴｏｒｒで
スパッタ装置に供給し、基板温度を室温として投入電力
密度を２．５Ｗ／ｃｍ2 、Ｃｒをターゲットとしてガラ
ス基板上に膜厚１３００オングストロームの第１の下地
層を形成した。続いて、スパッタ装置の他のカソードを
用いてＭｏをターゲットとするとともに上記のＣｒもタ
ーゲットとしてＭｏ，Ｃｒを同時スパッタした。この
際、Ｍｏターゲットに対する投入電力密度を０．１Ｗ／
ｃｍ2 から１．２Ｗ／ｃｍ2 まで連続的に変化させた。
これによって、膜厚４００オングストロームの第２の下
地層を第１の下地層上に形成した。上述のように投入電
力密度を０．１Ｗ／ｃｍ2 から１．２Ｗ／ｃｍ2 まで連
続的に変化させた結果、第２の下地層は上方に向かって
順次Ｍｏ濃度が増加している。(Example 27) Diameter 65 mm and thickness 0.9
A glass substrate of mm is mounted in the chamber of an RF magnetron sputtering device (not shown), and the inside of the chamber is 4 ×.
Depressurize to a pressure below 10 -8 Torr. After that, argon gas is supplied as a sputtering gas to the sputtering apparatus at a gas pressure of 10 mTorr, the substrate temperature is room temperature, the input power density is 2.5 W / cm 2 , and the target is Cr, and the first target having a film thickness of 1300 Å is formed on the glass substrate. An underlayer was formed. Subsequently, Mo and Cr were simultaneously sputtered by using another cathode of the sputtering apparatus as a target of Mo and also the above-mentioned Cr as a target. At this time, the applied power density to the Mo target is 0.1 W /
It was continuously changed from cm 2 to 1.2 W / cm 2 .
As a result, a second underlayer having a film thickness of 400 angstrom was formed on the first underlayer. Result of the continuously changed from 0.1 W / cm 2 to 1.2 W / cm 2 the input power density as described above, the second base layer is increased sequentially Mo concentration upward.
【００３１】さらに、アルゴンガスをスパッタガスとし
てＣｏ74Ｐｔ13Ｍｏ13（ａｔ％）をターゲットとしてＣ
ｏ74Ｐｔ13Ｍｏ13の組成を有する膜厚４５０オングスト
ロームの磁性層を第２の下地層上に形成した後、同様
に、アルゴンガスをスパッタガスとして膜厚５０オング
ストロームのＣｒ層及び膜厚３００オングストロームの
ＳｉＯ2 層を磁性層上に順次成形して、これらＣｒ層及
びＳｉＯ2 層を保護層とした。Further, argon gas is used as a sputtering gas, Co 74 Pt 13 Mo 13 (at%) is used as a target, and C is used.
After a magnetic layer having a composition of 74 Pt 13 Mo 13 and a film thickness of 450 angstrom is formed on the second underlayer, similarly, a Cr layer having a film thickness of 50 angstrom and a film thickness of 300 angstrom are formed by using argon gas as a sputtering gas. Of the SiO 2 layer were sequentially formed on the magnetic layer, and these Cr layer and SiO 2 layer were used as protective layers.
【００３２】その後、パーフルオロポリエーテルからな
る潤滑層を２０オングストロームの厚さ保護層上に塗布
して磁気ディスク（磁気記録媒体）を得、この磁気ディ
スクを実施例２７とした。Then, a lubricating layer made of perfluoropolyether was coated on the protective layer having a thickness of 20 Å to obtain a magnetic disk (magnetic recording medium), and this magnetic disk was used as Example 27.
【００３３】この実施例２７の磁気ディスクについて振
動試料型磁力計を用いて、保磁力（Ｈｃ）を測定した。
この際膜面方向に最大外部印加磁場を１２ｋＯｅとして
磁場を印加した。この結果、実施例２７の保磁力は２１
００（Ｏｅ）であった。The coercive force (Hc) of the magnetic disk of Example 27 was measured using a vibrating sample magnetometer.
At this time, the maximum external applied magnetic field was set to 12 kOe and the magnetic field was applied in the film surface direction. As a result, the coercive force of Example 27 was 21.
It was 00 (Oe).
【００３４】さらに、実施例２７の磁気ディスクを用い
て記録再生出力を測定した。ここでは、磁気ヘッド浮上
量が０．０５５μｍの薄膜ヘッドを用いて、この薄膜ヘ
ッドと磁気ディスクの相対速度を６ｍ／ｓとし、線記録
密度８０ｋｆｃｉにおける記録再生出力を測定した。こ
の結果、記録再生出力は１６３μＶであった。Further, the recording / reproducing output was measured using the magnetic disk of Example 27. Here, a recording / reproducing output at a linear recording density of 80 kfci was measured using a thin film head having a flying height of the magnetic head of 0.055 μm and a relative speed between the thin film head and the magnetic disk of 6 m / s. As a result, the recording / reproducing output was 163 μV.
【００３５】加えて、キャリア周波数９．４ＭＨｚで、
測定帯域を１５ＭＨｚとしてスペクトルアナライザーに
よって実施例２７の磁気ディスクについて信号記録再生
時におけるノイズスペクトラムを測定し（媒体ノイズＮ
ｍで表す）、Ｓ／Ｎｍ比を求めた。なお、上述の測定で
用いた薄膜ヘッドはコイルターン数５０、トラック幅６
μｍ、磁気ヘッドギャップ長０．２５μｍである。この
結果、媒体ノイズＮｍは２．３２μＶｒｍｓ、Ｓ／Ｎｍ
比は３６．９ｄＢであった。In addition, at a carrier frequency of 9.4 MHz,
The noise spectrum at the time of signal recording / reproduction was measured for the magnetic disk of Example 27 using a spectrum analyzer with the measurement band set to 15 MHz (medium noise N
m), and the S / Nm ratio was determined. The thin film head used in the above measurement had 50 coil turns and a track width of 6
μm, and the magnetic head gap length is 0.25 μm. As a result, the medium noise Nm is 2.32 μVrms, S / Nm
The ratio was 36.9 dB.
【００３６】このように、第２の下地層におけるＭｏ濃
度を上方に向かって増加するように変化させた場合であ
っても、つまり、第２の下地層におけるＭｏ濃度を第１
の下地層から磁性層に向う方向に順次増加するように変
化させた場合でも良好な磁気特性が得られるばかりでな
くＳ／Ｎ比も改善できる。Thus, even when the Mo concentration in the second underlayer is changed so as to increase upward, that is, the Mo concentration in the second underlayer is changed to the first Mo concentration.
Not only good magnetic properties can be obtained but also the S / N ratio can be improved even when the magnetic field is changed from the underlayer to the magnetic layer.
【００３７】上述の実施例では、第２の下地層としてＣ
ｒ，Ｍｏからなる層及び追加成分としてＺｒ，Ｂ，Ｐ，
Ｚｎ，Ｔｉ，Ｖ，Ｎｂ，Ｔａ，Ｆｅ，Ｎｉ，Ｒｅ，Ｃ
ｕ，Ｓｉ，Ｇａ，Ｇｅ，Ｈｆ，及びＡｌのうち一種以上
を含む層について説明したが、第２の下地層には追加成
分としてさらにＷ等を用いてもよく、これら追加成分を
添加した場合にも同様にして良好な磁気特性が得られる
ばかりでなくＳ／Ｎ比も改善できる。In the above embodiment, C was used as the second underlayer.
a layer composed of r and Mo and Zr, B, P, and
Zn, Ti, V, Nb, Ta, Fe, Ni, Re, C
Although the layer containing at least one of u, Si, Ga, Ge, Hf, and Al has been described, W or the like may be further used as an additional component in the second underlayer. Similarly, not only good magnetic characteristics can be obtained, but also the S / N ratio can be improved.
【００３８】また、磁性層としてＣｏ，Ｐｔ，Ｍｏから
なる層及び追加成分としてＴａ，Ｏ，Ｎ，Ｃｒ，Ｎｂ，
Ｍｎ，Ｗ，Ｐｂ，Ｒｅ，Ｖ，Ｚｎ，及びＺｒのうち一種
以上を含む層について説明したが、磁性層には追加成分
としてさらにＢ等を用いてもよく、これら追加成分を添
加した場合にも同様にして良好な磁気特性が得られるば
かりでなくＳ／Ｎ比も改善できる。Further, a layer made of Co, Pt, Mo as a magnetic layer and Ta, O, N, Cr, Nb as an additional component,
The layer containing at least one of Mn, W, Pb, Re, V, Zn, and Zr has been described, but B or the like may be further used as an additional component in the magnetic layer. Similarly, not only good magnetic characteristics can be obtained, but also the S / N ratio can be improved.
【００３９】実施例では非磁性基板としてガラス基板を
用いたが、非磁性であれば特に限定する必要はなく、例
えば、結晶化ガラス基板及びアルミニウム基板も用いる
ことができる。Although a glass substrate was used as the non-magnetic substrate in the examples, it is not particularly limited as long as it is non-magnetic, and for example, a crystallized glass substrate and an aluminum substrate can also be used.
【００４０】保護層を形成する場合には保護層の種類は
特に限定されず、単層又は複層からなる保護層を設けて
もよい。この保護層としては実施例に示したように、例
えば、酸化ケイ素（ＳｉＯ2 ）、カーボン（Ｃ）、酸化
ジルコニウム（ＺｒＯ2 ）、窒化ケイ素（Ｓｉ3 Ｎ4
）、窒化ホウ素（ＢＮ）、クロム（Ｃｒ）、及びクロ
ムモリブデン合金（ＣｒＭｏ）が用いられる。When forming the protective layer, the type of the protective layer is not particularly limited, and a protective layer composed of a single layer or multiple layers may be provided. As the protective layer, as shown in the embodiment, for example, silicon oxide (SiO2), carbon (C), zirconium oxide (ZrO2), silicon nitride (Si3 N4).
), Boron nitride (BN), chromium (Cr), and chromium molybdenum alloy (CrMo) are used.
【００４１】潤滑層を形成する際にも潤滑層の種類は特
に限定されず、実施例で示したパーフルオロポリエーテ
ルの他に、例えば、脂肪酸、脂肪酸アミド、脂肪酸エス
テル、フルオロカーボンを用いることができ、これらは
単品で用いてもよく、混合物として用いてもよい。Also when forming the lubricating layer, the kind of the lubricating layer is not particularly limited, and for example, fatty acids, fatty acid amides, fatty acid esters and fluorocarbons can be used in addition to the perfluoropolyethers shown in the examples. These may be used alone or as a mixture.
【００４２】[0042]
【発明の効果】以上説明したように本発明によれば、非
磁性基板と磁性層との間に第１及び第２の層を有する下
地層を介在させ、第１の下地層にクロムを含み、第２の
下地層にクロム及びモリブデンを含み、磁性層にコバル
ト及び白金を含むようにしたから、保磁力等の磁気特性
が良好となるばかりでなく、媒体ノイズを低減でき、そ
の結果、高線記録密度における記録再生時のＳ／Ｎ比を
向上させることができるという効果がある。As described above, according to the present invention, the underlayer having the first and second layers is interposed between the non-magnetic substrate and the magnetic layer, and the first underlayer contains chromium. Since the second underlayer contains chromium and molybdenum, and the magnetic layer contains cobalt and platinum, not only the magnetic characteristics such as coercive force are improved, but also the medium noise can be reduced. There is an effect that the S / N ratio at the time of recording / reproducing at the linear recording density can be improved.
【図１】本発明による磁気記録媒体の一実施例を示す断
面図である。FIG. 1 is a sectional view showing an embodiment of a magnetic recording medium according to the present invention.
【図２】本発明による磁気記録媒体において第１及び第
２の下地層の膜厚割合を変化させた際の保磁力、記録再
生出力、媒体ノイズ、及びＳ／Ｎ比の変化を示す図であ
る。FIG. 2 is a diagram showing changes in coercive force, recording / reproducing output, medium noise, and S / N ratio when the film thickness ratio of the first and second underlayers is changed in the magnetic recording medium according to the present invention. is there.
１ ガラス基板 ２ 第１の下地層 ３ 第２の下地層 ４ 磁性層 ５ 保護層 ６ 潤滑層 ７ 磁気記録媒体 1 Glass Substrate 2 First Underlayer 3 Second Underlayer 4 Magnetic Layer 5 Protective Layer 6 Lubricating Layer 7 Magnetic Recording Medium
───────────────────────────────────────────────────── フロントページの続き (72)発明者 野沢 順 東京都新宿区中落合２丁目７番５号 ホー ヤ株式会社内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Jun Nozawa 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Hoya Co., Ltd.
Claims (4)
れた下地層と、該下地層上に形成された磁性層とを有す
る磁気記録媒体であって、前記下地層は前記非磁性基板
側に形成された第１の層と前記磁性層側に形成された第
２の層とを備えており、前記第１の層にはクロムが含ま
れ、前記第２の層にはクロム及びモリブデンが含まれ、
前記磁性層にはコバルト及び白金が含まれていることを
特徴とする磁気記録媒体。1. A magnetic recording medium having a non-magnetic substrate, a base layer formed on the non-magnetic substrate, and a magnetic layer formed on the base layer, wherein the base layer is the non-magnetic substrate. A first layer formed on the side of the magnetic layer and a second layer formed on the side of the magnetic layer, the first layer containing chromium, and the second layer containing chromium and molybdenum. Included,
A magnetic recording medium, wherein the magnetic layer contains cobalt and platinum.
いて、前記第１の層の膜厚は前記第２の層の膜厚よりも
厚いことを特徴とする磁気記録媒体。2. The magnetic recording medium according to claim 1, wherein the film thickness of the first layer is thicker than the film thickness of the second layer.
体において、前記非磁性基板から前記磁性膜に向かう方
向に前記第２の層中のモリブデンはその濃度が高くなる
ようにしたことを特徴とする磁気記録媒体。3. The magnetic recording medium according to claim 1, wherein the concentration of molybdenum in the second layer increases in a direction from the non-magnetic substrate toward the magnetic film. Characteristic magnetic recording medium.
磁気記録媒体において、前記磁性層にはさらにモリブデ
ンが含まれていることを特徴とする磁気記録媒体。4. The magnetic recording medium according to any one of claims 1 to 3, wherein the magnetic layer further contains molybdenum.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21542293A JP2920723B2 (en) | 1993-08-31 | 1993-08-31 | Magnetic recording media |
| US09/312,162 US6287429B1 (en) | 1992-10-26 | 1999-05-14 | Magnetic recording medium having an improved magnetic characteristic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21542293A JP2920723B2 (en) | 1993-08-31 | 1993-08-31 | Magnetic recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0773427A true JPH0773427A (en) | 1995-03-17 |
| JP2920723B2 JP2920723B2 (en) | 1999-07-19 |
Family
ID=16672078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21542293A Expired - Lifetime JP2920723B2 (en) | 1992-10-26 | 1993-08-31 | Magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2920723B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6544667B1 (en) | 1999-03-11 | 2003-04-08 | Hitachi, Ltd. | Magnetic recording medium, producing method of the same and magnetic recording system |
| US6596420B2 (en) | 1996-05-20 | 2003-07-22 | Hitachi, Ltd. | Magnetic recording media and magnetic recording system using the same |
| US6682834B2 (en) | 2000-09-25 | 2004-01-27 | Fujitsu Limited | Magnetic storage medium having a high recording density |
-
1993
- 1993-08-31 JP JP21542293A patent/JP2920723B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6596420B2 (en) | 1996-05-20 | 2003-07-22 | Hitachi, Ltd. | Magnetic recording media and magnetic recording system using the same |
| US7056604B2 (en) | 1996-05-20 | 2006-06-06 | Hitachi Global Storage Technologies Japan, Ltd. | Magnetic recording media and magnetic recording system using the same |
| US6544667B1 (en) | 1999-03-11 | 2003-04-08 | Hitachi, Ltd. | Magnetic recording medium, producing method of the same and magnetic recording system |
| US6682834B2 (en) | 2000-09-25 | 2004-01-27 | Fujitsu Limited | Magnetic storage medium having a high recording density |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2920723B2 (en) | 1999-07-19 |
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