JPH06325355A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH06325355A JPH06325355A JP5111470A JP11147093A JPH06325355A JP H06325355 A JPH06325355 A JP H06325355A JP 5111470 A JP5111470 A JP 5111470A JP 11147093 A JP11147093 A JP 11147093A JP H06325355 A JPH06325355 A JP H06325355A
- Authority
- JP
- Japan
- Prior art keywords
- film
- magnetic
- recording medium
- substrate
- ferrite
- 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.)
- Pending
Links
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- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、磁気ディスク装置等に
使用される磁気記録媒体に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium used in a magnetic disk device or the like.
【０００２】[0002]
【従来の技術】磁気ディスク装置に使われている磁気デ
ィスク媒体の記録薄膜には、金属磁性膜およびフェライ
ト媒体が使われている。これらの記録膜には、磁気ヘッ
ドとの接触による摩擦摩耗から記録膜を保護するため
に、図４のごとく基体１上に下地膜２を介して形成され
た金属磁性膜３上に保護膜５が形成されている。保護膜
には、カーボン系、ＳｉＯ2 などの酸化物系などが使わ
れている。2. Description of the Related Art Metal magnetic films and ferrite media are used as recording thin films of magnetic disk media used in magnetic disk devices. In order to protect these recording films from frictional wear due to contact with the magnetic head, a protective film 5 is formed on the metal magnetic film 3 formed on the substrate 1 via the underlayer film 2 as shown in FIG. Are formed. The protective film is made of carbon or oxide such as SiO 2 .
【０００３】また、特開昭６０−２３９９１７号公報に
は、耐摩耗性を改善するためＣｏ系垂直磁化膜上に、Ｎ
ｉフェライト、Ｎｉ−Ｚｎフェライト、Ｍｎ−Ｚｎフェ
ライトが形成された垂直磁化記録媒体が提案されてい
る。Further, in Japanese Laid-Open Patent Publication No. 60-239917, in order to improve wear resistance, a Co-based perpendicular magnetization film is coated with N.
Perpendicular magnetization recording media on which i-ferrite, Ni-Zn ferrite, and Mn-Zn ferrite are formed have been proposed.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、保護膜
は記録膜を保護する反面、ヘッドと媒体とのスペーシン
グとなり、高密度記録特性を劣化させる問題点があっ
た。特に高密度特性を達成するためには、カーボン等の
保護膜を薄くしなければならないが、磁気ヘッド等の摺
動に対する耐久性が劣化する問題があった。However, while the protective film protects the recording film, it causes a spacing between the head and the medium, which causes a problem that the high density recording characteristic is deteriorated. In particular, in order to achieve high density characteristics, it is necessary to thin the protective film of carbon or the like, but there is a problem that durability against sliding of a magnetic head or the like deteriorates.
【０００５】また、特開昭６０−２３９９１７号公報で
は、Ｃｏ系合金の垂直磁化膜上にＮｉフェライト、Ｎｉ
−Ｚｎフェライト、Ｍｎ−Ｚｎフェライトを形成し、垂
直磁化記録体の耐摩耗性を改善している。しかしなが
ら、Ｎｉフェライト、Ｎｉ−Ｚｎフェライト、Ｍｎ−Ｚ
ｎフェライトは磁気ヘッド材料として使用されているほ
ど保磁力が小さく、このまま記録すると軟磁性のフェラ
イト膜がヘッド磁場の分解能を劣化させ、また記録磁化
として軟磁性フェライト膜では大きなジグザグ磁区が発
生しノイズも増大するという大きな問題があった。Further, in Japanese Patent Laid-Open No. 60-239917, Ni ferrite and Ni are formed on a perpendicularly magnetized film of Co-based alloy.
-Zn ferrite and Mn-Zn ferrite are formed to improve the wear resistance of the perpendicular magnetization recording material. However, Ni ferrite, Ni-Zn ferrite, Mn-Z
The n-ferrite has a smaller coercive force as it is used as a magnetic head material, and if it is recorded as it is, the soft magnetic ferrite film deteriorates the resolution of the head magnetic field, and a large zigzag magnetic domain is generated in the soft magnetic ferrite film as the recording magnetization to cause noise. There was a big problem that it also increased.
【０００６】本発明の目的は、このような問題を解決し
た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 that solves such problems.
【０００７】[0007]
【課題を解決するための手段】本発明の磁気記録媒体
は、基体上に金属磁性薄膜が形成され、前記金属薄膜上
にＣｏ元素およびその他の元素を含有したγ−Ｆｅ2 Ｏ
3 膜もしくはＢａフェライト磁性膜が形成された構造を
有する。In the magnetic recording medium of the present invention, a metal magnetic thin film is formed on a substrate, and γ-Fe 2 O containing Co element and other elements is contained on the metal thin film.
It has a structure in which three films or a Ba ferrite magnetic film are formed.
【０００８】また、さらに基体上に金属磁性薄膜が形成
され、前記金属磁性薄膜上に非磁性中間層が形成され、
さらに前記非磁性中間層上にＣｏ元素およびその他の元
素を含有したγ−Ｆｅ2 Ｏ3 膜もしくはＢａフェライト
磁性膜が形成された構造を有する。Further, a metal magnetic thin film is further formed on the substrate, and a non-magnetic intermediate layer is formed on the metal magnetic thin film,
Furthermore, it has a structure in which a γ-Fe 2 O 3 film containing a Co element and other elements or a Ba ferrite magnetic film is formed on the non-magnetic intermediate layer.
【０００９】[0009]
【実施例】以下に図面を参照して本発明の実施例を説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００１０】図１は、本発明の一例の磁気記録媒体の断
面図を示す。基体１上に下地膜２が形成され、さらに金
属磁性膜３上にＣｏ元素を含有したγ−Ｆｅ2 Ｏ3 膜も
しくはＢａフェライト磁性膜４が形成されている。FIG. 1 is a sectional view of a magnetic recording medium according to an example of the present invention. A base film 2 is formed on a substrate 1, and a γ-Fe 2 O 3 film containing a Co element or a Ba ferrite magnetic film 4 is further formed on a metal magnetic film 3.
【００１１】本発明に係わる基体１には、Ｎｉ−Ｐ被覆
アルミ合金、ガラス、カーボン、セラミック等を用いる
ことができる。下地膜２としてＣｒを主成分とした合金
膜、非磁性酸化物、窒化物を用いることができる。下地
膜２はなくともよい。金属磁性膜３には、Ｃｏ−Ｃｒ−
Ｔａ系、Ｃｏ−Ｃｒ−Ｐｔ系、Ｃｏ−Ｎｉ−Ｃｒ系強磁
性合金、もしくはこれらに添加物を加えたものを用いる
ことができる。フェライト磁性膜４には、Ｃｏ含有γ−
Ｆｅ2 Ｏ3 膜、さらにＯｓなどのその他金属元素を含有
したγ−Ｆｅ2 Ｏ3 膜およびＢａフェライト磁性薄膜を
用いることができる。For the substrate 1 according to the present invention, Ni-P coated aluminum alloy, glass, carbon, ceramics or the like can be used. As the base film 2, an alloy film containing Cr as a main component, a nonmagnetic oxide, or a nitride can be used. The base film 2 may be omitted. The metal magnetic film 3 has Co-Cr-
It is possible to use Ta-based, Co-Cr-Pt-based, Co-Ni-Cr-based ferromagnetic alloys, or those to which additives are added. The ferrite magnetic film 4 contains Co-containing γ-
An Fe 2 O 3 film, a γ-Fe 2 O 3 film containing another metal element such as Os, and a Ba ferrite magnetic thin film can be used.
【００１２】図２は、本発明の他の例の磁気記録媒体の
断面図を示す。基体上に下地膜２が形成され、さらに下
地膜２上の金属磁性膜３が形成され、金属磁性膜３上に
非磁性中間層１０が形成され、さらに非磁性中間層１０
上にγ−Ｆｅ2 Ｏ3 膜もしくはＢａフェライト磁性膜４
が形成されている。非磁性中間層１０には、金属酸化膜
もしくはシリコン酸化膜、もしくはシリコン窒化膜を用
いることができる。FIG. 2 is a sectional view of a magnetic recording medium according to another example of the present invention. The base film 2 is formed on the substrate, the metal magnetic film 3 is further formed on the base film 2, the nonmagnetic intermediate layer 10 is formed on the metal magnetic film 3, and the nonmagnetic intermediate layer 10 is further formed.
Γ-Fe 2 O 3 film or Ba ferrite magnetic film 4 on top
Are formed. A metal oxide film, a silicon oxide film, or a silicon nitride film can be used for the nonmagnetic intermediate layer 10.
【００１３】また、γ−Ｆｅ2 Ｏ3 膜もしくはＢａフェ
ライト磁性膜上には、潤滑性を付与するため液体潤滑剤
もしくは固体潤滑剤を形成することができる。A liquid lubricant or a solid lubricant can be formed on the γ-Fe 2 O 3 film or the Ba ferrite magnetic film to impart lubricity.
【００１４】以下、具体的な実施例と比較例を示す。Specific examples and comparative examples will be described below.
【００１５】（実施例１）実施例１として、基体の鏡面
仕上げＮｉ−Ｐ被覆アルミ合金の基板を用い、基板上に
アルゴンガス中でのスパッタによりＣｒ下地膜を０．１
μｍ形成した。Ｃｏ８０−Ｃｒ１５−Ｐｔ１０の合金タ
ーゲットを用い、Ｃｒ下地膜上にＣｏ−Ｃｒ−Ｐｔ膜を
０．０４μｍ形成した。さらにＣｏ−Ｃｒ−Ｐｔ膜上に
Ｃｏ（２．５ｗｔ％）およびＣｕ（２ｗｔ％）含有のマ
グネタイト（Ｆｅ3 Ｏ4 ）を主成分とするターゲットを
用い、アルゴンガスを用いＣｏ，Ｃｕ含有のマグネタイ
ト（Ｆｅ3 Ｏ4 ）を主成分とする磁性膜を０．０２μｍ
形成した。この時のＣｏＣｒＰｔ膜およびマグネタイト
膜の保磁力は、それぞれ１７００Ｏｅおよび３００Ｏｅ
であった。この媒体を大気中、２９０℃で１時間アニー
ルを行った。これを試料Ａとする。試料ＡのＣｏ−Ｃｒ
−Ｐｔ膜およびフェライト膜の保磁力は、それぞれ２０
００Ｏｅおよび１８００Ｏｅであり、アニールすること
によりそれぞれ保磁力が増大した。γ−Ｆｅ2 Ｏ3 膜の
角形比は０．７０であった。(Example 1) As Example 1, a mirror-finished Ni-P-coated aluminum alloy substrate was used as a substrate, and a Cr underlayer of 0.1 was formed on the substrate by sputtering in argon gas.
μm formed. A Co80-Cr15-Pt10 alloy target was used to form a Co-Cr-Pt film on the Cr underlayer in a thickness of 0.04 [mu] m. Further, a target containing Co (2.5 wt%) and Cu (2 wt%)-containing magnetite (Fe 3 O 4 ) as a main component was used on the Co-Cr-Pt film, and argon and Co-containing Cu and magnetite were used. The magnetic film containing (Fe 3 O 4 ) as the main component is 0.02 μm.
Formed. At this time, the coercive forces of the CoCrPt film and the magnetite film are 1700 Oe and 300 Oe, respectively.
Met. This medium was annealed in air at 290 ° C. for 1 hour. This is designated as Sample A. Co-Cr of sample A
The coercive force of each of the -Pt film and the ferrite film is 20
It was 00 Oe and 1800 Oe, and the coercive force increased by annealing. The squareness ratio of the γ-Fe 2 O 3 film was 0.70.
【００１６】（実施例２）実施例２として、実施例１と
同様に、基体に鏡面仕上げＮｉ−Ｐ被覆アルミ合金の基
板を用い、基板上にアルゴンガス中でのスパッタにより
Ｃｒ下地膜を０．１μｍ形成した。Ｃｏ８０−Ｃｒ１５
−Ｐｔ１０の合金ターゲットを用い、Ｃｒ下地膜上にＣ
ｏ−Ｃｒ−Ｐｔ膜を０．０４μｍ形成した。さらにＣｏ
−Ｃｒ−Ｐｔ膜上に非磁性層としてＳｉＯ2 膜を０．０
１μｍ形成した。非磁性層上に、実施例１と同様にＣｏ
（２．５ｗｔ％）およびＣｕ（２ｗｔ％）含有のマグネ
タイト（Ｆｅ3 Ｏ4 ）を主成分とするターゲットを用
い、アルゴンガスを用いＣｏ，Ｃｕ含有のマグネタイト
（Ｆｅ3 Ｏ4 ）を主成分とする磁性膜を０．０２μｍ形
成した。この時のＣｏ−Ｃｒ−Ｐｔ膜およびマグネタイ
ト膜の保磁力は、それぞれ１７００Ｏｅおよび３１０Ｏ
ｅであった。この媒体を大気中、２９０℃で１時間アニ
ールを行った。これを試料Ｂとする。試料ＢのＣｏ−Ｃ
ｒ−Ｐｔ膜およびγ−Ｆｅ2 Ｏ3 膜の保磁力は、それぞ
れ１９００Ｏｅおよび２１００Ｏｅであり、アニールす
ることによりそれぞれ保磁力が増大した。γ−Ｆｅ2 Ｏ
3 膜の角形比は０．８５であり、非磁性中間層を形成す
ることによりさらにγ−Ｆｅ2 Ｏ3膜の角形比を向上で
きた。(Embodiment 2) As Embodiment 2, as in Embodiment 1, a substrate of a mirror-finished Ni-P-coated aluminum alloy is used as a substrate, and a Cr underlayer of 0 is formed on the substrate by sputtering in argon gas. .1 μm was formed. Co80-Cr15
Using a Pt10 alloy target, C on the Cr underlayer
An o-Cr-Pt film was formed with a thickness of 0.04 μm. Further Co
A SiO 2 film as a non-magnetic layer is formed on the —Cr—Pt film by 0.0
1 μm was formed. Co on the non-magnetic layer as in Example 1.
(2.5 wt%) and Cu (2 wt%)-containing magnetite (Fe 3 O 4 ) as a main component, and argon gas is used as a main component of Co and Cu-containing magnetite (Fe 3 O 4 ). To form a magnetic film of 0.02 μm. At this time, the coercive forces of the Co—Cr—Pt film and the magnetite film are 1700 Oe and 310 O, respectively.
It was e. This medium was annealed in air at 290 ° C. for 1 hour. This is designated as Sample B. Sample B Co-C
The coercive forces of the r-Pt film and the γ-Fe 2 O 3 film were 1900 Oe and 2100 Oe, respectively, and the coercive force increased by annealing. γ-Fe 2 O
The squareness ratio of the three films was 0.85, and the squareness ratio of the γ-Fe 2 O 3 film could be further improved by forming the non-magnetic intermediate layer.
【００１７】（比較例１）比較例１として、実施例と同
様に基体に鏡面仕上げＮｉ−Ｐ被覆アルミ合金の基板を
用い、基板上にアルゴンガス中でのスパッタによりＣｒ
下地膜を０．１μｍ形成した。Ｃｏ８０−Ｃｒ１５−Ｐ
ｔ１０の合金ターゲットを用い、Ｃｒ下地膜上にＣｏ−
Ｃｒ−Ｐｔ膜を０．０４μｍ形成した。さらにＣｏ−Ｃ
ｒ−Ｐｔ膜上に従来法と同じように、カーボン保護膜を
なるべくスペーシング損失をなくすために、スパッタに
より０．０２μｍ形成した。これを試料Ｃとする。(Comparative Example 1) As Comparative Example 1, a mirror-finished Ni-P-coated aluminum alloy substrate was used as a substrate in the same manner as in Example 1, and Cr was sputtered on the substrate in argon gas.
A base film having a thickness of 0.1 μm was formed. Co80-Cr15-P
Using an alloy target of t10, Co-
A Cr-Pt film was formed with a thickness of 0.04 μm. Further Co-C
As in the conventional method, a carbon protective film was formed on the r-Pt film to a thickness of 0.02 μm by sputtering in order to eliminate spacing loss as much as possible. This is designated as Sample C.
【００１８】（比較例２）比較例２として、実施例と同
様に基体に鏡面仕上げＮｉ−Ｐ被覆アルミ合金の基板を
用い、基板上にアルゴンガス中でのスパッタによりＣｒ
下地膜を０．１μｍ形成した。Ｃｏ８０−Ｃｒ１５−Ｐ
ｔ１０の合金ターゲットを用い、Ｃｒ下地膜上にＣｏ−
Ｃｒ−Ｐｔ膜を０．０４μｍ形成した。さらにＣｏ−Ｃ
ｒ−Ｐｔ膜上にＭｎ−Ｚｎフェライトを、スパッタによ
り０．０２μｍ形成した。これを試料Ｄとする。(Comparative Example 2) As Comparative Example 2, a mirror-finished Ni-P-coated aluminum alloy substrate was used as the substrate as in the example, and Cr was sputtered on the substrate in argon gas.
A base film having a thickness of 0.1 μm was formed. Co80-Cr15-P
Using an alloy target of t10, Co-
A Cr-Pt film was formed with a thickness of 0.04 μm. Further Co-C
Mn-Zn ferrite was formed on the r-Pt film to a thickness of 0.02 μm by sputtering. This is designated as Sample D.
【００１９】上記の試料Ａ，Ｂ，Ｃ，Ｄにそれぞれフッ
素系潤滑剤を塗布し、２レール型薄膜ヘッドナノスライ
ダーでＣＳＳ（コンタクト・スタート・ストップ）試験
および記録再生試験を行った。記録再生試験条件は、ヘ
ッド浮上量が０．１μｍ、ヘッドのギャップ長０．２μ
ｍのものを用いた。A fluorine-based lubricant was applied to each of the above samples A, B, C and D, and a CSS (contact start / stop) test and a recording / reproducing test were conducted using a 2-rail type thin film head nanoslider. The recording / reproducing test conditions were that the head flying height was 0.1 μm and the head gap length was 0.2 μm.
m was used.
【００２０】図３は、試料Ａ，Ｂ，Ｃ，Ｄの記録再生特
性を比較する図である。横軸は記録密度（ＫＦＲＰＩ）
を、縦軸は相対出力を示す。また、表１は、試料Ａ，
Ｂ，Ｃ，ＤをＣＳＳし、傷が観測されるまでの回数を示
した結果を示す。FIG. 3 is a diagram comparing the recording / reproducing characteristics of the samples A, B, C, and D. Recording density (KFRPI) on the horizontal axis
And the vertical axis represents relative output. In addition, Table 1 shows sample A,
The results showing the number of times until scratches are observed by CSS of B, C and D are shown.
【００２１】[0021]
【表１】 [Table 1]
【００２２】図３より、分かるように本発明の記録媒体
は、従来媒体より出力および記録密度とも優れている。
また、表１からも明らかなように耐久性も従来媒体とほ
ぼ同じ耐久性を有する。As can be seen from FIG. 3, the recording medium of the present invention is superior in output and recording density to the conventional medium.
Further, as is clear from Table 1, the durability is almost the same as that of the conventional medium.
【００２３】[0023]
【発明の効果】本発明によれば、基体上に金属磁性薄膜
が形成し、さらに金属磁性薄膜上に金属磁性薄膜と同程
度の保磁力を有するＣｏを含有したγ−Ｆｅ2 Ｏ3 膜も
しくはＢａフェライト磁性膜を形成することにより、低
ノイズで記録特性を劣化させず、耐摩耗性も従来の保護
膜と同等の特性が得られる。According to the present invention, a metal magnetic thin film is formed on a substrate, and a γ-Fe 2 O 3 film containing Co having a coercive force similar to that of the metal magnetic thin film is formed on the metal magnetic thin film. By forming the Ba ferrite magnetic film, it is possible to obtain the same characteristics as the conventional protective film with low noise and without degrading the recording characteristics.
【００２４】また本発明によれば、基体上に金属磁性膜
を形成し、この金属磁性膜上に非磁性中間層を形成する
ことにより、Ｃｏを含有したγ−Ｆｅ2 Ｏ3 膜もしくは
Ｂａフェライト磁性膜の熱処理過程において磁気特性を
向上させることができる。Further, according to the present invention, a γ-Fe 2 O 3 film containing Co or Ba ferrite is formed by forming a metal magnetic film on a substrate and forming a non-magnetic intermediate layer on the metal magnetic film. The magnetic characteristics can be improved in the heat treatment process of the magnetic film.
【図１】本発明の実施例の磁気記録媒体の断面図であ
る。FIG. 1 is a sectional view of a magnetic recording medium according to an embodiment of the present invention.
【図２】本発明の他の実施例の磁気記録媒体の断面図で
ある。FIG. 2 is a sectional view of a magnetic recording medium of another embodiment of the present invention.
【図３】実施例の試料Ａ，Ｂ，Ｃの記録再生特性を比較
する図である。FIG. 3 is a diagram comparing recording / reproducing characteristics of samples A, B, and C of an example.
【図４】従来の磁気記録媒体の断面図である。FIG. 4 is a sectional view of a conventional magnetic recording medium.
１ 基体 ２ 下地膜 ３ 金属磁性膜 ４ フェライト磁性膜 ５ 保護膜 １０ 非磁性中間層 1 Base 2 Underlayer 3 Metal Magnetic Film 4 Ferrite Magnetic Film 5 Protective Film 10 Non-Magnetic Intermediate Layer
Claims (4)
属薄膜上にＣｏ元素およびその他の元素を含有したγ−
Ｆｅ2 Ｏ3 膜もしくはＢａフェライト磁性膜が形成され
ていることを特徴とする磁気記録媒体。1. A γ-containing metal magnetic thin film formed on a substrate and containing Co element and other elements on the metal thin film.
A magnetic recording medium having an Fe 2 O 3 film or a Ba ferrite magnetic film formed thereon.
属磁性薄膜上に非磁性中間層が形成され、さらに前記非
磁性中間層上にＣｏ元素およびその他の元素を含有した
γ−Ｆｅ2 Ｏ3 膜もしくはＢａフェライト磁性膜が形成
されていることを特徴とする磁気記録媒体。2. A metal magnetic thin film is formed on a substrate, a nonmagnetic intermediate layer is formed on the metal magnetic thin film, and γ-Fe 2 containing Co element and other elements is further formed on the nonmagnetic intermediate layer. A magnetic recording medium having an O 3 film or a Ba ferrite magnetic film formed thereon.
シリコン酸化膜、もしくはシリコン窒化膜であることを
特徴とする請求項２記載の磁気記録媒体。3. The magnetic recording medium according to claim 2, wherein the non-magnetic intermediate layer is a metal oxide film, a silicon oxide film, or a silicon nitride film.
分とした合金膜を用いていることを特徴とする請求項
１，２または３記載の磁気記録媒体。4. The magnetic recording medium according to claim 1, wherein an alloy film containing Cr as a main component is used as a base film of the metal magnetic film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5111470A JPH06325355A (en) | 1993-05-13 | 1993-05-13 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5111470A JPH06325355A (en) | 1993-05-13 | 1993-05-13 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06325355A true JPH06325355A (en) | 1994-11-25 |
Family
ID=14562067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5111470A Pending JPH06325355A (en) | 1993-05-13 | 1993-05-13 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06325355A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5759617A (en) * | 1996-05-20 | 1998-06-02 | Fujitsu Limited | Production process for a hard disk magnetic recording medium |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60160028A (en) * | 1984-01-31 | 1985-08-21 | Mitsubishi Metal Corp | Vertically magnetized recording body |
-
1993
- 1993-05-13 JP JP5111470A patent/JPH06325355A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60160028A (en) * | 1984-01-31 | 1985-08-21 | Mitsubishi Metal Corp | Vertically magnetized recording body |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5759617A (en) * | 1996-05-20 | 1998-06-02 | Fujitsu Limited | Production process for a hard disk magnetic recording medium |
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