EP0054269A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Perpendicular magnetic recording medium, method for producing the same, and sputtering device
Assignee: Teijin Ltd
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Filing: 1981-12-11
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Granted: —
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Expires: 2001-12-11
Abstract
Abstract Magnetic recording medium conventionally utilizes the in-plane magnetization mode, but, recently, the perpendicular magnetization mode utilizing the perpendicular anisotropy of an hcp cobalt alloy layer, in which C axis is oriented normal to the layer surface, is proposed. The known perpendicular magnetic recording medium has been produced by an RF sputtering, but such medium is of too low flexibility to use it in the form of a magnetic tape. In addition, the production rate of the perpendicular magnetic recording medium by RF sputtering is very low. The perpendicular magnetic recording medium is very flexible due to particle pattern (Figures 10, 12 and 13) completely distinct from the conventional columnar pattern (Figures 8 and 11). In addition, the production rate is high, because the base (20) is located beside a space between the targets (T,, T 2 ) of a sputtering device and further the magnetic field is generated perpendicularly to the sputtering surfaces (T 1s , T 25 ) by a field coil (31) or magnets (32,33). The present invention makes it possible to commercially produce the perpendicular magnetic recording medium, especially in the tape form.
Inventors
- 👤 Sadao Kadokura
- 👤 Takashi Tomie
- 👤 Masahiko Naoe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 14:24
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/84; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
A perpendicular magnetic recording medium formed on a base and comprising an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base, characterized in that the cobalt alloy layer has a particle pattern as seen in a cross section of the layer observed with an electronmicroscope.
Claim 2
Dependent Claim
62 words
A perpendicular magnetic recording medium formed on a base and comprising an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base, characterized in that the cobalt alloy layer has a particle pattern as seen in a cross section of the layer observed with an electronmicroscope.
Claim 3
Dependent Claim
16 words
A perpendicular magnetic recording medium according to claim 1, wherein said base is a polyester film.
Claim 4
Dependent Claim
17 words
A perpendicular magnetic recording medium according to claim 1, further comprising a layer of soft magnetic metal.
Claim 5
Dependent Claim
66 words
A perpendicular magnetic recording medium according to claim 2 or 3, wherein the degree of curl (Kp), which is expressed by: is not more than 15%, the symbol "ℓ 0 " indicating the length of a specimen of said medium without curl and the symbols "h and "h 2 " indicating the deviation of a specimen with curl from both ends of the specimen without curl.
Claim 6
Dependent Claim
172 words
A perpendicular magnetic recording medium formed on a base and comprising an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base, characterized in that: said medium has a degree of curl (Kp) of not more than 15%, which degree of curl being defined by: the symbol "ℓ 0 " indicating the length of said medium without curl and the symbols "h and "h 2 " indicating the deviation of a specimen with curl from both ends of the specimen without curl, and said magnetic film is formed by a sputtering method, wherein a magnetic field is generated in a direction perpendicular to the surfaces of a pair of cathode targets (T 1 , T2) arranged opposite to one another within a sputtering device, and said cobalt alloy layer is deposited on the base (20), which is located beside a space between said pair of cathode targets (T 1 , T2) and which faces said space.
Claim 7
Dependent Claim
172 words
A perpendicular magnetic recording medium formed on a base and comprising an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base, characterized in that: said medium has a degree of curl (Kp) of not more than 15%, which degree of curl being defined by: the symbol "ℓ 0 " indicating the length of said medium without curl and the symbols "h and "h 2 " indicating the deviation of a specimen with curl from both ends of the specimen without curl, and said magnetic film is formed by a sputtering method, wherein a magnetic field is generated in a direction perpendicular to the surfaces of a pair of cathode targets (T 1 , T2) arranged opposite to one another within a sputtering device, and said cobalt alloy layer is deposited on the base (20), which is located beside a space between said pair of cathode targets (T 1 , T2) and which faces said space.
Claim 8
Independent Claim
113 words
A method for producing a perpendicular magnetic recording medium, wherein an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base is deposited on the base by means of a sputtering method, characterized in that a magnetic field is generated in a direction perpendicular to the surfaces of a pair of cathode targets (T 1 , T 2 ) arranged opposite to one another within a sputtering device, and said hcp cobalt alloy layer is deposited on the base (20), which is located beside a space between said pair of cathode targets and which faces said space.
Claim 9
Independent Claim
113 words
A method for producing a perpendicular magnetic recording medium, wherein an hcp cobalt alloy layer which comprises mainly cobalt and additionally chromium and which has a direction of easy magnetization in a direction normal to the base is deposited on the base by means of a sputtering method, characterized in that a magnetic field is generated in a direction perpendicular to the surfaces of a pair of cathode targets (T 1 , T 2 ) arranged opposite to one another within a sputtering device, and said hcp cobalt alloy layer is deposited on the base (20), which is located beside a space between said pair of cathode targets and which faces said space.
Claim 10
Dependent Claim
26 words
A method according to claim 6, wherein said perpendicular magnetic field is formed only between said pair of cathode targets (T 1 , T 2 ).
Claim 11
Dependent Claim
30 words
A method according to claim 6 or 7, wherein said perpendicular magnetic field is generated by permanent magnets (32 , 33) located behind said cathode targets (T T2 ) .
Claim 12
Dependent Claim
14 words
A method according to claim 8, wherein said permanent magnets (32, 33) are hollow.
Claim 13
Dependent Claim
37 words
A method according to claim 9, wherein the cross section of said permanent magnets (32, 33) is such that said permanent magnets are positioned solely along the periphery of said targets (T 1 , T 2 ).
Claim 14
Dependent Claim
30 words
A method according to claim 6, wherein an electric field is generated from said base (20) and virtually perpendicularly to said base during at least the initial period of sputtering.
Claim 15
Dependent Claim
20 words
A method according to claim 6, wherein said base is subjected to the bombardment in a glow discharge before sputtering.
Claim 16
Dependent Claim
95 words
A sputtering device, comprising: a vacuum vessel (10); a pair of oppositely arranged cathode targets (T 1 , T2 ) in said vacuum vessel (10); a holder (21) for a base (20), on which a layer is deposited by the sputtering, said holder being located beside a space between the pair of. said cathode targets (T 1 , T 2 ) and facing said space; a means (31, 32, 33) for generating a magnetic field perpendicularly to said cathode targets; and, a power source (41) for applying a negative bias voltage to said holder (21).
Claim 17
Dependent Claim
95 words
A sputtering device, comprising: a vacuum vessel (10); a pair of oppositely arranged cathode targets (T 1 , T2 ) in said vacuum vessel (10); a holder (21) for a base (20), on which a layer is deposited by the sputtering, said holder being located beside a space between the pair of. said cathode targets (T 1 , T 2 ) and facing said space; a means (31, 32, 33) for generating a magnetic field perpendicularly to said cathode targets; and, a power source (41) for applying a negative bias voltage to said holder (21).
Claim 18
Dependent Claim
22 words
A sputtering device according to claim 13, wherein said magnetic field generating means are magnets (32, 33) situated behind said cathode targets.
References Cited (Backward Citations)
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