JPH0916940A - Perpendicular magnetic recording medium - Google Patents
Perpendicular magnetic recording mediumInfo
- Publication number
- JPH0916940A JPH0916940A JP18804095A JP18804095A JPH0916940A JP H0916940 A JPH0916940 A JP H0916940A JP 18804095 A JP18804095 A JP 18804095A JP 18804095 A JP18804095 A JP 18804095A JP H0916940 A JPH0916940 A JP H0916940A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- layer
- recording
- film
- recording medium
- 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
- 239000000203 mixture Substances 0.000 claims description 7
- 239000000956 alloy Substances 0.000 claims description 5
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 230000035945 sensitivity Effects 0.000 abstract description 9
- 239000000758 substrate Substances 0.000 abstract description 4
- 239000011521 glass Substances 0.000 abstract description 3
- 230000001681 protective effect Effects 0.000 abstract description 3
- 238000010030 laminating Methods 0.000 abstract description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract 2
- ZZUFCTLCJUWOSV-UHFFFAOYSA-N furosemide Chemical compound C1=C(Cl)C(S(=O)(=O)N)=CC(C(O)=O)=C1NCC1=CC=CO1 ZZUFCTLCJUWOSV-UHFFFAOYSA-N 0.000 abstract 2
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 239000000377 silicon dioxide Substances 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 239000010408 film Substances 0.000 description 29
- 230000005415 magnetization Effects 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
- Thin Magnetic Films (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、垂直磁気記録媒体に関
するものであり、特に、その入出力特性の改良に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perpendicular magnetic recording medium, and more particularly to improvement of its input / output characteristics.
【０００２】[0002]
【従来の技術】垂直磁気記録は、面内記録よりも高密度
化が可能な方式として研究開発が進められている。一般
に、垂直磁気記録の高密度化を図るためには、高い記録
感度と高い再生出力が要求される。このような垂直磁気
記録媒体として、例えば、特開昭５７−１１３４１５号
公報（文献１）又は特開昭６１−１３１２２８号公報
（文献２）で示すものが提案されている。文献１に開示
された垂直磁気記録媒体は、飽和磁化Ｍｓが小さく保磁
力Ｈｃの大きい垂直異方性磁性薄膜からなる書き込み層
と飽和磁化Ｍｓが大きく保磁力Ｈｃの小さい垂直異方性
磁性薄膜からなる読み出し層を重ねて２重構造としたも
のである。そして、このような構成により、情報の保存
性及び読み出し時のＳ／Ｎをよくすることができる旨が
示されている。2. Description of the Related Art Perpendicular magnetic recording is being researched and developed as a method capable of higher density than in-plane recording. Generally, high recording sensitivity and high reproduction output are required in order to increase the density of perpendicular magnetic recording. As such a perpendicular magnetic recording medium, for example, ones disclosed in JP-A-57-113415 (reference 1) or JP-A-61-131228 (reference 2) have been proposed. The perpendicular magnetic recording medium disclosed in Document 1 is composed of a writing layer composed of a perpendicular anisotropic magnetic thin film having a small saturation magnetization Ms and a large coercive force Hc and a perpendicular anisotropic magnetic thin film having a large saturation magnetization Ms and a small coercive force Hc. The read layer is formed into a double structure. Further, it is shown that such a configuration can improve the storability of information and the S / N at the time of reading.
【０００３】また、文献２に開示された垂直磁気記録媒
体は、基板上に高透磁率磁性体層を形成し、この高透磁
率磁性体層上に非磁性体層を介して膜面に垂直方向に磁
気異方性を有する磁性体層を設けてなる磁気記録媒体に
おいて、この膜面に対し垂直方向に磁気異方性を有する
磁性体層上に、面内方向に対して高透磁率である磁性体
層（Ｎｉ−Ｆｅ）を積層形成したものである。そして、
このような構成により、スペ−シングに対する記録密度
の変動を抑えるのに有効である旨が示されている。Further, in the perpendicular magnetic recording medium disclosed in Document 2, a high magnetic permeability magnetic layer is formed on a substrate, and the high magnetic permeability magnetic layer is perpendicular to the film surface via a nonmagnetic layer. In a magnetic recording medium provided with a magnetic layer having magnetic anisotropy in the direction, on the magnetic layer having magnetic anisotropy in the direction perpendicular to the film surface, with high magnetic permeability in the in-plane direction. It is formed by laminating a certain magnetic layer (Ni-Fe). And
It has been shown that such a structure is effective in suppressing the fluctuation of the recording density with respect to the spacing.
【０００４】[0004]
【発明が解決しようとする課題】しかし、文献１の垂直
磁気記録媒体ように、上の層である読み出し層が下の層
である書き込み層より飽和磁化Ｍｓが大きく、保磁力Ｈ
ｃが小さいというだけでは、下の高Ｈｃ層に信号を書き
込むことが困難であるという事情は変わらず、記録感度
は向上しない。また、記録時には、書き込み層と同時に
上の層である読み出し層（低Ｈｃ）にも記録されてしま
うため、必ずしも読み出し時のＳ／Ｎ比の向上は期待で
きない。また、文献２の垂直磁気記録媒体は、垂直記録
層の上に面内方向に対して高透磁率である磁性層を設け
たもので、スペ−シングに対する記録密度の変動を抑え
るのには有効であるが、ヘッドと高透磁率磁性層との間
で閉ル−プが形成されてしまうため、記録感度、再生出
力の点ではマイナスである。そこで、本発明は上記の点
に着目してなされたものであり、記録感度、再生出力の
両方を向上させることを目的とするものである。However, as in the perpendicular magnetic recording medium of Document 1, the upper layer of the read layer has a larger saturation magnetization Ms than the lower layer of the write layer, and has a coercive force H.
Just because c is small does not change the situation that it is difficult to write a signal in the high Hc layer below, and the recording sensitivity is not improved. Further, at the time of recording, since the data is recorded on the upper layer, ie, the reading layer (low Hc), simultaneously with the writing layer, it is not necessarily expected that the S / N ratio at the time of reading is improved. Further, the perpendicular magnetic recording medium of Document 2 is one in which a magnetic layer having a high magnetic permeability in the in-plane direction is provided on the perpendicular recording layer, and it is effective for suppressing the fluctuation of the recording density due to the spacing. However, since a closed loop is formed between the head and the high-permeability magnetic layer, the recording sensitivity and the reproduction output are negative. Therefore, the present invention has been made in view of the above points, and an object thereof is to improve both recording sensitivity and reproduction output.
【０００５】[0005]
【課題を解決するための手段】本願発明は、斯かる問題
に鑑みなされたものであり、請求項１に係る発明は、
「垂直記録層の上に、垂直方向の磁界に対して軟磁性で
ある垂直軟磁性層を有することを特徴とする垂直磁気記
録媒体。」を提供するものであり、請求項２に係る発明
は、「該垂直軟磁性層は、ＣｏＰｒを主成分とする合金
であることを特徴とする請求項１記載の垂直磁気記録媒
体。」を提供するものであり、請求項３に係る発明は、
「該垂直軟磁性層のＣｏＰｒを主成分とする合金は、Ｐ
ｒの組成比が４atm％乃至３０atm％であることを特徴と
する請求項２記載の垂直磁気記録媒体。」を提供するも
のである。The present invention has been made in view of such problems, and the invention according to claim 1 is
The invention according to claim 2 provides "a perpendicular magnetic recording medium having a perpendicular soft magnetic layer which is soft magnetic with respect to a perpendicular magnetic field on the perpendicular recording layer." , "The perpendicular soft magnetic layer is an alloy containing CoPr as a main component, and the perpendicular magnetic recording medium according to claim 1."
“The alloy containing CoPr as the main component of the perpendicular soft magnetic layer is P
3. The perpendicular magnetic recording medium according to claim 2, wherein the composition ratio of r is 4 atm% to 30 atm%. ”.
【０００６】[0006]
【作用】記録時には、ヘッドから発生する磁束が効率良
く集束し、垂直記録層において小さな起磁力で大きなヘ
ッド磁界が得られる。この結果、記録感度が向上する。
また、再生時には、垂直記録層から発生した磁界が、垂
直軟磁性層によって増幅され、再生出力が向上する。In recording, the magnetic flux generated from the head is efficiently focused, and a large head magnetic field can be obtained with a small magnetomotive force in the perpendicular recording layer. As a result, the recording sensitivity is improved.
Further, during reproduction, the magnetic field generated from the perpendicular recording layer is amplified by the perpendicular soft magnetic layer, and the reproduction output is improved.
【０００７】[0007]
【実施例】以下、図面を参照して本発明の実施例につい
て説明する。図１は、本発明の垂直磁気記録媒体をディ
スク状の媒体として実施した場合の積層膜構造を示す断
面図である。同図において、１はガラス基板、２はＣｏ
Ｓｍからなる面内ハード膜（膜厚１５０ｎｍ）、３はＣ
ｏＺｒＮｂからなる軟磁性膜（膜厚６００ｎｍ）、４は
ＣｏＣｒＴａからなる垂直記録膜（膜厚５０ｎｍ）、５
はＣｏＰｒからなる垂直軟磁性層（膜厚５０〜２００ｎ
ｍ）、６はＳｉＯ2からなる保護膜（膜厚１５ｎｍ）を
それぞれ示す。なお、ＣｏＰｒ垂直軟磁性層５をＣｏＣ
ｒＴａ垂直記録層４の上に成膜するのにはＤＣマグネト
ロンスパッタ法を用いた。この際、ＣｏＰｒの組成は、
Ｃｏの円板状のタ−ゲットの上にＰｒのチップを配置
し、このＰｒのチップ数を変えることにより制御した。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a laminated film structure when the perpendicular magnetic recording medium of the present invention is implemented as a disk-shaped medium. In the figure, 1 is a glass substrate, 2 is Co
In-plane hard film made of Sm (film thickness 150 nm), 3 is C
Soft magnetic film made of oZrNb (film thickness 600 nm), 4 is a perpendicular recording film made of CoCrTa (film thickness 50 nm), 5
Is a perpendicular soft magnetic layer made of CoPr (film thickness 50 to 200 n
m) and 6 are protective films made of SiO 2 (film thickness 15 nm), respectively. The CoPr perpendicular soft magnetic layer 5 is formed of CoC.
A DC magnetron sputtering method was used to form a film on the rTa perpendicular recording layer 4. At this time, the composition of CoPr is
A Pr chip was placed on a Co disk-shaped target, and control was performed by changing the number of Pr chips.
【０００８】次に、ここで用いたＣｏＰｒ垂直軟磁性層
の磁気特性について説明する。図２に、ＣｏＰｒ膜の膜
面垂直方向と面内方向の典型的なＭ−Ｈカ−ブを示す。
同図において、カーブＡは膜面に垂直な方向のＭ−Ｈカ
ーブを示し、カーブＢは面内方向のＭ−Ｈカーブを示
す。垂直方向の保磁力Ｈｃは、２００ Ｏｅ以下と小さ
い。また、異方性磁界Ｈｋを同図のように面内方向のカ
−ブＢの接線から求めると、約４ＫＯｅと大きい。更に
垂直方向のカ−ブをＨｄ＝４πＭで反磁界補正して得ら
れる角型比Ｒｓはほぼ１である。以上のことから、この
ＣｏＰｒ膜は垂直磁気異方性が極めて強く、かつ垂直方
向の磁界に対して軟磁性を示しているといえる。Next, the magnetic characteristics of the CoPr perpendicular soft magnetic layer used here will be described. FIG. 2 shows typical MH curves of the CoPr film in the direction perpendicular to the film surface and the in-plane direction.
In the figure, a curve A shows an MH curve in a direction perpendicular to the film surface, and a curve B shows an MH curve in an in-plane direction. The coercive force Hc in the perpendicular direction is as small as 200 Oe or less. Further, when the anisotropic magnetic field Hk is calculated from the tangent line of the curve B in the in-plane direction as shown in FIG. Further, the squareness ratio Rs obtained by demagnetizing the vertical curve with Hd = 4πM is approximately 1. From the above, it can be said that this CoPr film has extremely strong perpendicular magnetic anisotropy and exhibits soft magnetism with respect to a magnetic field in the perpendicular direction.
【０００９】図３は、ＣｏＰｒの組成比と磁気特性との
関係を示したものである。同図（Ａ）、（Ｂ）、（Ｃ）
の横軸は何れも、ＣｏＰｒ合金中のＰｒの組成比（ａｔ
ｍ％）を表し、縦軸は、それぞれ飽和磁化Ｍｓ、異方性
磁界Ｈｋ、保磁力Ｈｃを表す。なお、ＣｏＰｒの膜厚は
何れも０．１μｍである。垂直記録層４の上に設ける垂
直軟磁性層５としては、Ｍｓ≧５００ ｅｍｕ／ｃｃ、
Ｈｋ≧１ ｋＯｅ、Ｈｃ≦２００ Ｏｅ、Ｒｓ≧０．９で
あることが望ましい。即ちＰｒの組成比は、４〜３０ a
tm％が望ましい。FIG. 3 shows the relationship between the composition ratio of CoPr and the magnetic characteristics. The same figure (A), (B), (C)
The abscissa of each of the graphs is the composition ratio of Pr in the CoPr alloy (at
m%), and the vertical axis represents the saturation magnetization Ms, the anisotropic magnetic field Hk, and the coercive force Hc, respectively. The film thickness of CoPr is 0.1 μm. As the perpendicular soft magnetic layer 5 provided on the perpendicular recording layer 4, Ms ≧ 500 emu / cc,
It is desirable that Hk ≧ 1 kOe, Hc ≦ 200 Oe, and Rs ≧ 0.9. That is, the composition ratio of Pr is 4 to 30 a.
tm% is desirable.
【００１０】次に、図１に示した本発明の垂直磁気記録
媒体の電磁変換特性について図４を参照して説明する。
図４は、横軸に記録電流（ｍＡ）、縦軸に孤立波再生出
力（ｍＶ）をとったものであり、同図中、カーブＣは垂
直軟磁性層５としてＣｏＰｒを５０ｎｍ形成したサンプ
ルの特性を示し、カーブＤは同様に垂直軟磁性層５とし
てＣｏＰｒを１００ｎｍ形成したサンプルの特性を示
し、カーブＥは同様に垂直軟磁性層５としてＣｏＰｒを
２００ｎｍ形成したサンプルの特性を示す。なお、図５
は、比較例として、垂直軟磁性層５を形成していないサ
ンプルの特性であり、カーブＦは垂直記録膜４としてＣ
ｏＣｒＴａを５０ｎｍ形成したサンプルの特性を示し、
カーブＧは垂直記録膜４としてＣｏＣｒＴａを１００ｎ
ｍ形成したサンプルの特性を示す。なお、これらの特性
評価は、トラック幅７μｍ、主磁極厚０．３μｍ、コイ
ル４０タ−ンの単磁極ヘッドを用いて行なった。また、
測定条件は、相対速度２１．４ｍ／ｓ、スペ−シング
０．１７μｍとした。Next, the electromagnetic conversion characteristics of the perpendicular magnetic recording medium of the present invention shown in FIG. 1 will be described with reference to FIG.
FIG. 4 shows the recording current (mA) on the horizontal axis and the solitary-wave reproduction output (mV) on the vertical axis. In FIG. 4, a curve C represents a sample in which CoPr of 50 nm is formed as the perpendicular soft magnetic layer 5. Curve D shows the characteristics of the sample in which CoPr was formed to 100 nm as the vertical soft magnetic layer 5, and curve E similarly shows the characteristics of the sample in which CoPr was formed to 200 nm as the vertical soft magnetic layer 5. FIG.
Is a characteristic of a sample in which the perpendicular soft magnetic layer 5 is not formed as a comparative example, and the curve F is C as the perpendicular recording film 4.
Shows the characteristics of a sample in which oCrTa is formed to 50 nm,
The curve G is 100 n of CoCrTa for the perpendicular recording film 4.
m shows the characteristics of the formed sample. The evaluation of these characteristics was performed using a single magnetic pole head having a track width of 7 μm, a main magnetic pole thickness of 0.3 μm, and a coil 40 turn. Also,
The measurement conditions were a relative speed of 21.4 m / s and a spacing of 0.17 μm.
【００１１】これらの測定結果から明かなように、Ｃｏ
Ｐｒ垂直軟磁性層がない場合、飽和記録ができておらず
再生出力も小さい。これに対し、本発明の実施例に係る
垂直磁気記録媒体では、垂直記録膜４の上に垂直軟磁性
膜５としてＣｏＰｒを設けることにより、小さな起磁力
Ｍ．Ｍ．Ｆでも充分飽和した高い記録感度が得られると
ともに、大きな再生出力が得られる。As is clear from these measurement results, Co
When the Pr perpendicular soft magnetic layer is not provided, saturated recording is not achieved and the reproduction output is small. On the other hand, in the perpendicular magnetic recording medium according to the embodiment of the present invention, by providing CoPr as the perpendicular soft magnetic film 5 on the perpendicular recording film 4, a small magnetomotive force M.M. M. Even at F, a sufficiently saturated high recording sensitivity can be obtained and a large reproduction output can be obtained.
【００１２】[0012]
【発明の効果】以上説明したように本発明の、垂直記録
層の上に、垂直方向の磁界に対して軟磁性である層を有
する垂直磁気記録媒体によれば、記録感度および再生出
力が高くなるという効果がある。As described above, according to the perpendicular magnetic recording medium of the present invention, which has the soft magnetic layer against the perpendicular magnetic field on the perpendicular recording layer, the recording sensitivity and the reproduction output are high. There is an effect that.
【図１】本発明の実施例に係る垂直磁気記録媒体の積層
膜構造を示す断面図である。FIG. 1 is a cross-sectional view showing a laminated film structure of a perpendicular magnetic recording medium according to an example of the present invention.
【図２】ＣｏＰｒ膜の膜面垂直方向と面内方向のＭ−Ｈ
カ−ブを示す図である。FIG. 2 is an MH in a direction perpendicular to the film surface of the CoPr film and in the in-plane direction.
It is a figure which shows a curve.
【図３】ＣｏＰｒの組成比と磁気特性との関係を示す図
である。FIG. 3 is a diagram showing a relationship between a composition ratio of CoPr and magnetic characteristics.
【図４】本発明の実施例に係る垂直磁気記録媒体の入出
力特性を示す図である。FIG. 4 is a diagram showing input / output characteristics of a perpendicular magnetic recording medium according to an example of the present invention.
【図５】比較例に係る垂直磁気記録媒体の入出力特性を
示す図である。FIG. 5 is a diagram showing input / output characteristics of a perpendicular magnetic recording medium according to a comparative example.
１ ガラス基板 ２ ＣｏＳｍからなる面内ハード膜 ３ ＣｏＺｒＮｂからなる軟磁性膜 ４ ＣｏＣｒＴａからなる垂直記録膜 ５ ＣｏＰｒからなる垂直軟磁性層 ６ ＳｉＯ2からなる保護膜DESCRIPTION OF SYMBOLS 1 Glass substrate 2 In-plane hard film made of CoSm 3 Soft magnetic film made of CoZrNb 4 Perpendicular recording film made of CoCrTa 5 Vertical soft magnetic layer made of CoPr 6 Protective film made of SiO 2
Claims (3)
て軟磁性である垂直軟磁性層を有することを特徴とする
垂直磁気記録媒体。1. A perpendicular magnetic recording medium comprising a perpendicular soft magnetic layer which is soft magnetic with respect to a perpendicular magnetic field on the perpendicular recording layer.
る合金であることを特徴とする請求項１記載の垂直磁気
記録媒体。2. The perpendicular magnetic recording medium according to claim 1, wherein the perpendicular soft magnetic layer is an alloy containing CoPr as a main component.
合金は、Ｐｒの組成比が４atm％乃至３０atm％であるこ
とを特徴とする請求項２記載の垂直磁気記録媒体。3. The perpendicular magnetic recording medium according to claim 2, wherein the alloy containing CoPr as a main component in the perpendicular soft magnetic layer has a Pr composition ratio of 4 atm% to 30 atm%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7188040A JP3019140B2 (en) | 1995-06-29 | 1995-06-29 | Perpendicular magnetic recording media |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7188040A JP3019140B2 (en) | 1995-06-29 | 1995-06-29 | Perpendicular magnetic recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0916940A true JPH0916940A (en) | 1997-01-17 |
| JP3019140B2 JP3019140B2 (en) | 2000-03-13 |
Family
ID=16216629
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7188040A Expired - Lifetime JP3019140B2 (en) | 1995-06-29 | 1995-06-29 | Perpendicular magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3019140B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8498081B2 (en) | 2011-03-24 | 2013-07-30 | Kabushiki Kaisha Toshiba | Perpendicular magnetic recording medium including soft-magnetic-particles-mixed protective layer on top of recording layer and magnetic disk device having the same |
-
1995
- 1995-06-29 JP JP7188040A patent/JP3019140B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8498081B2 (en) | 2011-03-24 | 2013-07-30 | Kabushiki Kaisha Toshiba | Perpendicular magnetic recording medium including soft-magnetic-particles-mixed protective layer on top of recording layer and magnetic disk device having the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3019140B2 (en) | 2000-03-13 |
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