JPH0467250B2 - - Google Patents
Info
- Publication number
- JPH0467250B2 JPH0467250B2 JP28256085A JP28256085A JPH0467250B2 JP H0467250 B2 JPH0467250 B2 JP H0467250B2 JP 28256085 A JP28256085 A JP 28256085A JP 28256085 A JP28256085 A JP 28256085A JP H0467250 B2 JPH0467250 B2 JP H0467250B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic layer
- recording medium
- magnetic recording
- alloy
- 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.)
- Expired
Links
- 238000004544 sputter deposition Methods 0.000 claims description 17
- 229910045601 alloy Inorganic materials 0.000 claims description 15
- 239000000956 alloy Substances 0.000 claims description 15
- 239000000758 substrate Substances 0.000 claims description 12
- 230000001681 protective effect Effects 0.000 claims description 10
- 229910020630 Co Ni Inorganic materials 0.000 claims description 7
- 229910002440 Co–Ni Inorganic materials 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 239000000314 lubricant Substances 0.000 claims description 6
- 239000010408 film Substances 0.000 description 23
- 239000010409 thin film Substances 0.000 description 20
- 239000011651 chromium Substances 0.000 description 15
- 230000007797 corrosion Effects 0.000 description 12
- 238000005260 corrosion Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 229910052688 Gadolinium Inorganic materials 0.000 description 5
- 229910000990 Ni alloy Inorganic materials 0.000 description 5
- 235000013980 iron oxide Nutrition 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000004907 flux Effects 0.000 description 4
- 229910000748 Gd alloy Inorganic materials 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 229910018104 Ni-P Inorganic materials 0.000 description 2
- 229910018536 Ni—P Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000007772 electroless plating Methods 0.000 description 2
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 2
- 229910001004 magnetic alloy Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- ZGDWHDKHJKZZIQ-UHFFFAOYSA-N cobalt nickel Chemical compound [Co].[Ni].[Ni].[Ni] ZGDWHDKHJKZZIQ-UHFFFAOYSA-N 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
Description
【発明の詳細な説明】
（発明の属する技術分野）
本発明は磁気記録装置に用いられる磁気デイス
クなどの磁気記録媒体に関する。DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a magnetic recording medium such as a magnetic disk used in a magnetic recording device.
（従来技術とその問題点）
近年磁気記録装置に用いられる磁気デイスクな
どの磁気記録媒体はますます高記録密度となる傾
向にあり、これに伴い磁気記録媒体の磁性層の膜
厚を従来の約1μｍ程度から0.1μｍ以下まで薄く
し、保磁力Hcもより高くする必要がある。その
ため磁気記録媒体の製造方法もサブミクロンオー
ダでは磁性層の膜厚が不均一になるスピンコート
法に代つて、均一な薄膜を容易に形成することが
可能なスパツタ法やメツキ法が注目されるととも
に、従来の鉄酸化物例えばγ−Fe2O3の磁性層
は、その磁気特性、特に残留磁束密度が小さく出
力が低いということから、磁性層として、スパツ
タ法によつて形成されるコバルトCo系合金例え
ばコバルト−ニツケルNi合金磁性薄膜が使用さ
れるようになつた。Ni含有量の範囲は20〜30at
％がよいことが知られている。(Prior art and its problems) In recent years, magnetic recording media such as magnetic disks used in magnetic recording devices have tended to have higher and higher recording densities. It is necessary to reduce the thickness from about 1 μm to 0.1 μm or less, and to increase the coercive force Hc. For this reason, as a manufacturing method for magnetic recording media, sputtering and plating methods, which can easily form a uniform thin film, are attracting attention instead of the spin coating method, which causes the thickness of the magnetic layer to be uneven in the submicron order. At the same time, conventional magnetic layers made of iron oxides such as γ-Fe 2 O 3 have low magnetic properties, especially residual magnetic flux density, and low output. Co-based alloys such as cobalt-nickel Ni alloy magnetic thin films have come into use. Ni content ranges from 20 to 30at
% is known to be good.
第６図に例えばCo−Ni合金磁性薄膜の磁性層
を備えたデイスク状磁気記録媒体の要部構成断面
図を示す。 FIG. 6 shows a sectional view of the main part of a disk-shaped magnetic recording medium having a magnetic layer made of, for example, a Co--Ni alloy magnetic thin film.
第６図の磁気記録媒体は合金基板１上に非磁性
基体層２を被覆し、この非磁性基体層２の上にさ
らに非磁性金属下地層３を介してCo−Ni合金薄
膜の磁性層４ａを被覆し、磁性層４ａ上に保護潤
滑膜５を被覆したものである。 The magnetic recording medium shown in FIG. 6 has a non-magnetic base layer 2 coated on an alloy substrate 1, and a magnetic layer 4a of a Co--Ni alloy thin film on the non-magnetic base layer 2 with a non-magnetic metal underlayer 3 interposed therebetween. The magnetic layer 4a is coated with a protective lubricant film 5.
このように構成された磁気記録媒体の合金基板
１にはアルミニウム合金が多用されているが、場
合によつてはプラスチツクを用いてもよく、所定
の面粗さ、平行度および平面度に仕上げられる。
非磁性基体層２はニツケル−りんNi−Ｐ合金を
無電解メツキしたもの、もしくは基板１自体をア
ルマイト処理して得たものが好ましく、いずれも
所定の硬さを必要とし、表面は機械的研磨により
鏡面仕上げを行なう。非磁性金属下地層３は一般
にクロムCrを用いてスパツタ法などにより形成
する。この下地層３はCo−Ni合金薄膜磁性層４
ａの保磁力Hcを高める作用をもつものであり、
下地層３の厚さによつても磁性層４ａの保磁力が
変化する。下地層３は膜厚の増加とともに磁性層
４ａの保磁力を飽和させる傾向があり、その保磁
力を飽和させる下地層３の膜厚は材料によつて大
きく異なる。したがつて実用的な磁気記録媒体を
作製するときは下地層３の膜厚はあまり厚くする
ことなく薄膜の形成時間を短かくし適当な保磁力
を磁性層４ａに付与するようにしている。下地層
３に磁性層４ａをスパツタにより形成した後、引
続き最後にカーボンもしくは二酸化珪素SiO2な
どの保護潤滑膜５を連続して被覆する。 Aluminum alloy is often used for the alloy substrate 1 of the magnetic recording medium constructed in this way, but plastic may also be used in some cases, and it can be finished to a predetermined surface roughness, parallelism, and flatness. .
The nonmagnetic base layer 2 is preferably obtained by electroless plating of a nickel-phosphorous Ni-P alloy or by alumite treatment of the substrate 1 itself. Both require a certain hardness, and the surface is mechanically polished. A mirror finish is achieved. The nonmagnetic metal underlayer 3 is generally formed using chromium Cr by a sputtering method or the like. This underlayer 3 is a Co-Ni alloy thin film magnetic layer 4.
It has the effect of increasing the coercive force Hc of a,
The coercive force of the magnetic layer 4a also changes depending on the thickness of the underlayer 3. The underlayer 3 tends to saturate the coercive force of the magnetic layer 4a as its thickness increases, and the thickness of the underlayer 3 that saturates the coercive force varies greatly depending on the material. Therefore, when producing a practical magnetic recording medium, the film thickness of the underlayer 3 is not made too thick, the time for forming the thin film is shortened, and an appropriate coercive force is imparted to the magnetic layer 4a. After forming the magnetic layer 4a on the underlayer 3 by sputtering, a protective lubricant film 5 of carbon, silicon dioxide, SiO 2 or the like is successively coated.
以上のようにして得られるCo−Ni合金薄膜を
スパツタ法により形成した磁性層をもつ磁気記録
媒体は良好な磁気特性を示すという点で有効なも
のである。しかしながら、このCo−Ni合金薄膜
についてその後の研究が進むにつれて、初期の磁
気特性はすぐれているが、薄膜磁性層自体の耐食
性が十分でないために、使用される環境によつて
は遂には磁気特性の劣化を起こすことがわかつ
た。 A magnetic recording medium having a magnetic layer formed by sputtering a Co--Ni alloy thin film obtained as described above is effective in that it exhibits good magnetic properties. However, as further research progressed on this Co-Ni alloy thin film, it was found that although the initial magnetic properties were excellent, the corrosion resistance of the thin film magnetic layer itself was insufficient, and the magnetic properties could eventually deteriorate depending on the environment in which it was used. It was found that it causes deterioration of
これに対して種々な対策も試みられている。そ
の一つは耐食性という点からみれば鉄酸化物は周
囲環境に対して安定しているから、例えばγ−
Fe2O3をスパツタによつて薄膜化するのがよい
が、その反面前述のように鉄酸化膜は磁気特性の
とくに残留磁束密度が低く、しかも鉄酸化物をス
パツタ法により薄膜として形成するにはスパツタ
条件や熱処理など複雑な手順を要するので問題点
が多く好ましくない。第２の対策は例えば金属材
料の分野で屡々行なわれているようにクロムCr
を添加することによつて耐食性を向上させるとい
う手法を利用することであるが、Co系合金にCr
を単独添加しても耐食性は向上するものの、逆に
磁気特性が低下するのを避けることができない。
第３の対策として、Co−Ni合金薄膜の表面に周
囲環境の影響を完全に遮断することのできる保護
膜を形成することも効果的とみられるが、磁気ヘ
ツドとの潤滑性や薄膜状の保護膜に必要な硬さや
緻密性を保持することなどを同時に満足する保護
膜は未だ見られない。 Various countermeasures against this problem have been attempted. One is that iron oxides are stable in the surrounding environment in terms of corrosion resistance, so for example, γ-
It is better to form Fe 2 O 3 into a thin film by sputtering, but on the other hand, as mentioned above, iron oxide film has low magnetic properties, especially residual magnetic flux density, and it is difficult to form iron oxide as a thin film by sputtering. Since this method requires complicated procedures such as sputtering conditions and heat treatment, it has many problems and is not preferred. The second countermeasure is, for example, chromium Cr, which is often taken in the field of metal materials.
The method is to improve corrosion resistance by adding Cr to Co-based alloy.
Although the corrosion resistance is improved even if the addition of .
As a third measure, forming a protective film on the surface of the Co-Ni alloy thin film that can completely block out the influence of the surrounding environment seems to be effective. A protective film that simultaneously maintains the hardness and denseness required for the film has not yet been found.
これらのことから、磁気記録媒体にスパツタ法
により形成される磁性層は、保護膜には補助的な
効果を期待し、従来相反関係にあるとみなされて
いた磁気特性と耐食性を両立させたすぐれたもの
を開発する必要がある。 For these reasons, the magnetic layer formed on magnetic recording media by the sputtering method is expected to have an auxiliary effect as a protective film, and is an excellent material that combines magnetic properties and corrosion resistance, which were previously considered to be in a contradictory relationship. It is necessary to develop something new.
（発明の目的）
本発明は上述の点に鑑みてなされたものであ
り、その目的はCo系合金の磁気特性を損うこと
なく、耐食性も向上した薄膜磁性層を形成した磁
気記録媒体を提供することにある。(Object of the Invention) The present invention has been made in view of the above points, and its purpose is to provide a magnetic recording medium in which a thin film magnetic layer is formed that has improved corrosion resistance without impairing the magnetic properties of the Co-based alloy. It's about doing.
（発明の要点）
本発明は不活性ガス雰囲気中でアルミニウム基
板上のNi−Ｐ層の上に連続的にスパツタして形
成した下地層、磁性層および保護潤滑膜からなる
積層薄膜の磁性層として、ガドリニウムGdを適
量含有したCo−Ni合金磁性薄膜を形成すること
により達せられる。(Summary of the Invention) The present invention provides a magnetic layer of a laminated thin film consisting of an underlayer, a magnetic layer and a protective lubricant film formed by continuous sputtering on a Ni-P layer on an aluminum substrate in an inert gas atmosphere. This can be achieved by forming a Co--Ni alloy magnetic thin film containing an appropriate amount of gadolinium (Gd).
（発明の実施例） 以下本発明を実施例に基づき説明する。(Example of the invention) The present invention will be explained below based on examples.
第１図に本発明により得られた磁気記録媒体の
要部構成断面図を示し第６図と共通部分を同一符
号で表わしてある。第１図は第６図と基本的な構
成は同じであるが、第１図が第６図と異なる点は
磁性層４にCo−Ni−Gd合金薄膜を用いた所にあ
る。 FIG. 1 shows a cross-sectional view of the main part of a magnetic recording medium obtained according to the present invention, and parts common to those in FIG. 6 are designated by the same reference numerals. The basic structure of FIG. 1 is the same as that of FIG. 6, but the difference between FIG. 1 and FIG. 6 is that a Co--Ni--Gd alloy thin film is used for the magnetic layer 4.
まず非磁性合金基板１として旋盤加工および加
圧焼鈍により、十分に小さなうねりすなわち円
周・半径方向とも20μｍ以下の面に仕上げたデイ
スク状アルミニウム板を用い、この上にNi−Ｐ
合金の無電解メツキを約30μｍの厚さに被膜し、
メツキ被膜を平均表面粗さ0.02μｍ、厚さ15μｍま
で鏡面仕上げを行なうことにより非磁性基体２を
形成する。次いで非磁性基体２の上に非磁性金属
下地層３としてCrをスパツタして形成するがCr
膜の厚さは前述のように磁性層４の磁気特性に影
響を与えるので0.1μｍ間隔で0.8μｍまで変化させ
た。下地層３を形成した後、直ちに引続き同じス
パツタ槽内で磁性層４として本発明によるCo−
30at％Ni−Gd合金をスパツタにより下地層３の
上に500Åの厚さに設けた。この磁性合金薄膜に
ついてはGdを添加する効果を明らかにするため、
Gd含有量を15at％まで変えたものを作製した。
この際、下地層３に続いて磁性層４をスパツタす
るまでにあまりに長い時間スパツタ槽内に放置し
たり、大気に曝したりすると、下地層３の効果を
発揮することができず、磁性層４の必要とする大
きな保磁力が得られなくなる。例えば下地層３を
形成した後、大気に曝して磁性層４をその上に形
成した場合、磁性層４の保磁力は僅か200Oeにし
かならない。これはスパツタ槽内に長時間放置し
たときも同様の効果となるから、下地層３の形成
後は直ちに磁性層４のスパツタを実施しなければ
ならない。最後に表面保護潤滑膜５としてカーボ
ンをスパツタして膜厚500Åに形成することによ
り、この磁気記録媒体を作製した。 First, as the non-magnetic alloy substrate 1, a disc-shaped aluminum plate finished with sufficiently small waviness, that is, 20 μm or less in both the circumferential and radial directions, was used by lathe processing and pressure annealing.
Electroless plating of alloy is coated to a thickness of approximately 30μm,
The nonmagnetic substrate 2 is formed by mirror-finishing the plating film to an average surface roughness of 0.02 μm and a thickness of 15 μm. Next, a nonmagnetic metal underlayer 3 is formed on the nonmagnetic substrate 2 by sputtering Cr.
Since the thickness of the film affects the magnetic properties of the magnetic layer 4 as described above, it was varied up to 0.8 μm at intervals of 0.1 μm. Immediately after forming the underlayer 3, a Co-layer according to the present invention is applied as a magnetic layer 4 in the same sputtering bath.
A 30at% Ni-Gd alloy was provided on the base layer 3 to a thickness of 500 Å by sputtering. In order to clarify the effect of adding Gd to this magnetic alloy thin film,
We created samples with varying Gd contents up to 15at%.
At this time, if the magnetic layer 4 is left in the sputtering bath for too long or exposed to the atmosphere before sputtering the magnetic layer 4 following the underlayer 3, the effect of the underlayer 3 will not be exhibited, and the magnetic layer 4 will The large coercive force required by the magnetic field cannot be obtained. For example, if the underlayer 3 is formed and then the magnetic layer 4 is formed thereon by exposing it to the atmosphere, the coercive force of the magnetic layer 4 will be only 200 Oe. This effect is similar even when the magnetic layer 4 is left in a sputtering tank for a long time, so the magnetic layer 4 must be sputtered immediately after the underlayer 3 is formed. Finally, this magnetic recording medium was manufactured by sputtering carbon to form a surface protective lubricant film 5 to a thickness of 500 Å.
次に以上のごとくして得られた磁気記録媒体の
諸特性について述べる。 Next, various characteristics of the magnetic recording medium obtained as described above will be described.
第２図ａ〜ｄは磁性層４として設けたCo−
30at％Ni−Gd合金のGd含有量を変えたときの磁
気特性との関係を示した線図であり、いずれも横
軸をGd含有量とし、縦軸を磁気特性としてプロ
ツトしたものである。すなわちGd含有量に対し
て第２図ａは保磁力、第２図ｂは角形比Ｓおよび
保磁力角形比S*、第２図ｃは残留磁束密度Brと
膜厚δとの積、第２図ｄは飽和磁束密度Bsと膜
厚δとの積の関係線図である。ただしこのときそ
の他の条件は全て同じに設定してあり、いずれも
RFスパツタ装置を用いて出力500W、全ガス圧
4.0×10-2Torr、基板温度は室温である。なお下
地層３のCrの膜厚はすべて3000Åとした。 Figures 2 a to d show Co-
It is a diagram showing the relationship between the magnetic properties and the Gd content of a 30at% Ni-Gd alloy when the Gd content is changed. In both cases, the horizontal axis is the Gd content and the vertical axis is the magnetic properties. In other words, for the Gd content, Figure 2a shows the coercive force, Figure 2b shows the squareness ratio S and coercive force squareness ratio S * , Figure 2c shows the product of the residual magnetic flux density Br and the film thickness δ, and the second FIG. d is a relationship diagram of the product of the saturation magnetic flux density Bs and the film thickness δ. However, at this time, all other conditions are set the same, and both
Output 500W, total gas pressure using RF sputter device
4.0×10 -2 Torr, substrate temperature is room temperature. Note that the Cr film thickness of the base layer 3 was all 3000 Å.
第２図ａ〜ｄからわかるようにGd含有量に対
して最も大きく変る磁気特性はａ図のHcであつ
て磁気記録媒体として有効な900Oe以上の得られ
るGd含有量の範囲は0.5〜6at％であり1000Oeを
超える最も好ましい範囲は１〜5at％である。こ
の範囲のGd含有量についてみるとｃ図のBr・
δ、ｄ図のBs・δはいずれも低下の傾向にある。
しかしこの程度の低下は磁気特性の上でとくに問
題となることはない。 As can be seen from Figure 2 a to d, the magnetic property that changes the most with respect to the Gd content is Hc in Figure a, and the range of Gd content that can be obtained over 900 Oe, which is effective as a magnetic recording medium, is 0.5 to 6 at%. The most preferable range exceeding 1000 Oe is 1 to 5 at%. Regarding the Gd content in this range, Br・
δ and Bs and δ in the d diagram both tend to decrease.
However, this degree of decrease does not pose any particular problem in terms of magnetic properties.
次に下地層３として設けたCr被膜の厚さに対
する磁性層４のHcの変化を第３図の線図に示す。
この場合は磁性層４は前述の第２図ａの結果に基
づきCo−30at％Ni−2.5at％Gdを選び、その他の
条件も一定とした。第３図において横軸は0.1μｍ
間隔に目盛つたCr被膜の厚さ、縦軸は磁性層４
のHcとして示してあるが、第３図ではほかに二
つの比較例を併記し本発明と従来例とを対比させ
本発明の有効性を明らかにしている。 Next, the change in Hc of the magnetic layer 4 with respect to the thickness of the Cr film provided as the underlayer 3 is shown in the diagram of FIG.
In this case, Co-30at%Ni-2.5at%Gd was selected for the magnetic layer 4 based on the results shown in FIG. 2a, and other conditions were kept constant. In Figure 3, the horizontal axis is 0.1μm
The thickness of the Cr coating is graduated at intervals, the vertical axis is the magnetic layer 4
However, in FIG. 3, two other comparative examples are also shown to compare the present invention and the conventional example to clarify the effectiveness of the present invention.
比較例１の磁気記録媒体の製造方法は上述の実
施例の場合と全く同様であるが、磁性層がCo単
独の薄膜である点のみが異なり、比較例２では同
様に磁性層をCo−30at％Niの薄膜としGdを添加
してないものである。 The manufacturing method of the magnetic recording medium of Comparative Example 1 is exactly the same as that of the above-mentioned Example, except that the magnetic layer is a thin film made of Co alone, and in Comparative Example 2, the magnetic layer is made of Co-30at. This is a thin film of %Ni and no Gd is added.
第３図から本発明に係るCo−30at％Ni−2.5at
％Gdの磁性層は下地のCr被膜によりHcを高くす
る効果が顕著であり、Cr膜厚0.3μｍ以上でHcが
大きな値で飽和に達することがわかる。これに対
して比較例１および比較例２はCr膜厚を増して
も磁性層のHcはあまり大きくならず、本発明実
施例におけるGd添加効果が明瞭である。また下
地層３はCrの代りにBiを用いることができるが、
Biの膜厚を500Å程度とすることにより、Crの場
合と同様の効果が得られる。 From Fig. 3, Co-30at%Ni-2.5at according to the present invention
%Gd has a remarkable effect of increasing Hc due to the underlying Cr film, and it can be seen that Hc reaches saturation at a large value when the Cr film thickness is 0.3 μm or more. On the other hand, in Comparative Examples 1 and 2, the Hc of the magnetic layer did not increase much even when the Cr film thickness was increased, and the effect of Gd addition in the examples of the present invention is clear. Also, Bi can be used instead of Cr for the base layer 3, but
By setting the Bi film thickness to about 500 Å, the same effect as in the case of Cr can be obtained.
さらに本発明の磁気記録媒体の磁性層の耐食性
について言及する。 Furthermore, the corrosion resistance of the magnetic layer of the magnetic recording medium of the present invention will be mentioned.
第４図は温度40℃、相対湿度80％の雰囲気中に
曝したCo−30at％Ni−2.5at％Gdの磁気記録媒体
の磁気特性の変化を示した線図であり、第５図は
同じくこの条件に曝した磁気記録媒体を記録装置
に用いたときのエラー個数の変化を示した線図で
あるが第４図、第５図の場合も比較のために第３
図のときと同じ比較例１と比較例２を併記した。 Figure 4 is a diagram showing the change in magnetic properties of a Co-30at%Ni-2.5at%Gd magnetic recording medium exposed to an atmosphere at a temperature of 40°C and a relative humidity of 80%, and Figure This is a diagram showing the change in the number of errors when a magnetic recording medium exposed to these conditions is used in a recording device.
Comparative Example 1 and Comparative Example 2, which are the same as in the figure, are shown together.
第４図は磁気記録媒体の放置期間に対する磁性
層のBr・δおよびHcの変化を示したものであ
り、磁気特性の初期値はそれぞれ異なるが、放置
時間経過に対する変化の割合はあまり変らない。
しかしながら第５図にみられるようにエラー個数
は本発明の記録媒体は12weeks放置してはじめて
僅かにエラーがカウントされるのに対して、比較
例１、比較例２のものは短い日数のうちにエラー
個数が急激に増加し使用に耐えなくなる。このこ
とは磁性層全体の磁気特性は環境条件によつて比
較的長時間大きな変化を示すことはないが、湿気
などの雰囲気に曝されたとき、従来の磁性層は表
面の微小な局部から順次腐食されて変質すること
に起因している。これに対しGdを適量添加した
磁性層を有する本発明の磁気記録媒体は第５図か
ら耐食性もすぐれたものであることがわかる。な
お第５図には図示してないが0.5〜6at％の範囲で
Gdを添加したものについて同様の結果を得るこ
とができる。 FIG. 4 shows changes in Br, δ, and Hc of the magnetic layer with respect to the storage period of the magnetic recording medium.Although the initial values of the magnetic properties are different, the rate of change over the storage period does not change much.
However, as can be seen in Figure 5, the number of errors in the recording medium of the present invention is only slightly counted after being left unused for 12 weeks, whereas the number of errors in Comparative Examples 1 and 2 is counted within a short number of days. The number of errors increases rapidly, making it unusable. This means that the magnetic properties of the entire magnetic layer do not show large changes over a relatively long period of time depending on environmental conditions, but when exposed to an atmosphere such as humidity, conventional magnetic layers gradually change from tiny localized areas on the surface. This is caused by corrosion and deterioration. On the other hand, it can be seen from FIG. 5 that the magnetic recording medium of the present invention having a magnetic layer doped with an appropriate amount of Gd also has excellent corrosion resistance. Although not shown in Figure 5, in the range of 0.5 to 6 at%
Similar results can be obtained with the addition of Gd.
また本発明の磁気記録媒体を磁気記録装置に組
み込んでcss試験を行なつた結果、２万回のコン
タクト・スタート・ストツプに対しても記録媒体
表面になんら傷を発生せず、再生出力もほとんど
低下することなく、十分な耐久性をもつているこ
とがわかつた。 Furthermore, as a result of conducting a CSS test by incorporating the magnetic recording medium of the present invention into a magnetic recording device, no scratches were generated on the surface of the recording medium even after 20,000 contact starts and stops, and the playback output was almost constant. It was found that it had sufficient durability without any deterioration.
以上説明してきたように、本発明の磁気記録媒
体はすぐれた磁気特性と耐食性を兼備したものと
いうことができる。 As explained above, the magnetic recording medium of the present invention can be said to have both excellent magnetic properties and corrosion resistance.
（発明の効果）
磁気デイスクなどの磁気記録媒体は記録密度を
あげるために磁性層の膜厚を薄くし、磁気特性を
向上させるためにスパツタによるCo−Ni系合金
薄膜が用いられるようになつたが、一方でこの磁
性層はCo−Ni系合金では使用環境における耐食
性が例えば鉄酸化物膜などより劣るという欠点を
もつていたのに対し、本発明はCo−Ni系合金に
0.5〜6at％のGdを含んだ磁性層を用いて、基板
上に非磁性基体層、下地層、磁性層および保護潤
滑膜をこの順に堆積してなる磁気記録媒体として
従来と同様に構成したものであつて、磁性層の
Co−Ni系合金にGdを添加したことにより、Cr下
地層が磁性層のHcを高めるのに極めて効果的に
働くと同時に磁性層自体の耐食性を著しく向上さ
せ、磁気特性と耐食性という従来相反関係にあつ
た問題を一挙に解決し、この両者を一つの記録媒
体で兼ね備えることができ、しかも本発明の記録
媒体は製造効率もよく記録装置の出力も十分であ
り、長寿命を保持することができるという多くの
点で大きな利点を有するものである。(Effect of the invention) In magnetic recording media such as magnetic disks, the thickness of the magnetic layer has been reduced to increase the recording density, and sputtered Co-Ni alloy thin films have come to be used to improve magnetic properties. However, on the other hand, this magnetic layer has a disadvantage in that the corrosion resistance in the usage environment is inferior to that of, for example, iron oxide films in Co-Ni alloys.
A magnetic recording medium constructed in the same way as before, using a magnetic layer containing 0.5 to 6 at% Gd, and depositing a nonmagnetic base layer, an underlayer, a magnetic layer, and a protective lubricant film in this order on a substrate. and of the magnetic layer.
By adding Gd to the Co-Ni alloy, the Cr underlayer works extremely effectively to increase the Hc of the magnetic layer, while at the same time significantly improving the corrosion resistance of the magnetic layer itself. The above problems can be solved all at once, and both of these can be achieved in one recording medium. Furthermore, the recording medium of the present invention has good manufacturing efficiency, sufficient output from the recording device, and has a long lifespan. It has great advantages in many ways.
第１図は本発明の磁気記録媒体の要部構成断面
図、第２図は磁性層のGd含有量と磁気特性との
関係を示す線図、第３図は下地層の厚さに対する
磁性層のHcの変化を示す線図、第４図は温度40
℃、相対湿度80％の雰囲気中に曝した磁気記録媒
体の磁気特性の変化を示す線図、第５図は同じく
エラー個数の変化を示す線図、第６図は従来の磁
気記録媒体の要部構成断面図である。
１……合金基板、２……非磁性基体層、３……
非磁性金属下地層、４，４ａ……磁性層、５……
保護潤滑膜。
Fig. 1 is a sectional view of the main part of the magnetic recording medium of the present invention, Fig. 2 is a diagram showing the relationship between the Gd content of the magnetic layer and magnetic properties, and Fig. 3 is a diagram showing the relationship between the thickness of the magnetic layer and the thickness of the magnetic layer. Figure 4 shows the change in Hc at temperature 40
℃ and 80% relative humidity. Figure 5 is a diagram showing changes in the number of errors. Figure 6 is a diagram showing the main points of conventional magnetic recording media. FIG. 3 is a partial cross-sectional view. 1...Alloy substrate, 2...Nonmagnetic base layer, 3...
Non-magnetic metal underlayer, 4, 4a...Magnetic layer, 5...
Protective lubricating film.
Claims (1)
非磁性金属下地層、磁性層および保護潤滑膜をこ
の順に連続スパツタして積層形成した磁気記録媒
体において、前記磁性層がGdを0.5〜6at％含む
Co−Ni合金からなることを特徴とする磁気記録
媒体。 ２ 特許請求の範囲第１項記載の媒体において磁
性層のGd含有量を１〜5at％とすることを特徴と
する磁気記録媒体。 ３ 特許請求の範囲第１項または第２項記載の媒
体において、非磁性金属下地層としてCrを用い
ることを特徴とする磁気記録媒体。 ４ 特許請求の範囲第１項または第２項記載の媒
体において、非磁性金属下地層としてBiを用い
ることを特徴とする磁気記録媒体。[Claims] 1. On a non-magnetic substrate covering the main surface of a substrate,
A magnetic recording medium in which a nonmagnetic metal underlayer, a magnetic layer, and a protective lubricant film are laminated by continuous sputtering in this order, wherein the magnetic layer contains 0.5 to 6 at% of Gd.
A magnetic recording medium characterized by being made of a Co-Ni alloy. 2. A magnetic recording medium according to claim 1, wherein the magnetic layer has a Gd content of 1 to 5 at%. 3. A magnetic recording medium according to claim 1 or 2, characterized in that Cr is used as the non-magnetic metal underlayer. 4. A magnetic recording medium according to claim 1 or 2, characterized in that Bi is used as the non-magnetic metal underlayer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28256085A JPS62141629A (en) | 1985-12-16 | 1985-12-16 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28256085A JPS62141629A (en) | 1985-12-16 | 1985-12-16 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62141629A JPS62141629A (en) | 1987-06-25 |
| JPH0467250B2 true JPH0467250B2 (en) | 1992-10-27 |
Family
ID=17654063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28256085A Granted JPS62141629A (en) | 1985-12-16 | 1985-12-16 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62141629A (en) |
-
1985
- 1985-12-16 JP JP28256085A patent/JPS62141629A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62141629A (en) | 1987-06-25 |
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