US4232071A
Expired / Lapsed
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Method of producing magnetic thin film
Assignee: Fujitsu Ltd
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Filing: 1977-06-29
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Granted: 1980-11-04
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Expires: 1997-06-29
Abstract
Abstract A method of roducing γ-Fe 2 O 3 magnetic disk medium of continuous thin film is provided, in which a deposition source is deposited on an opposed Al-alloy substrate by means of a reactive vacuum deposition technique and the deposited film is thermally treated so as to be the magnetic disk medium. As the deposition source, a ferroalloy containing about 1 to 10 at.% Ti and about 0.5 to 5 at.% Co is employed.
Inventors
- 👤 Akira Terada
- 👤 Seizi Hattori
- 👤 Yoshikazu Ishii
- 👤 Akira Nohara
- 👤 Nobuo Inagaki
- 👤 Wakatake Matsuda
- 👤 Susumu Kawakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:02
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/58; C23C14/5806; C23C14/06; C23C14/08; C23C14/085; G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/658; G11B5/84; G11B5/851; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F41/00; H01F41/14; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
In a method of producing a γ-Fe 2 O 3 continuous thin film magnetic disk medium wherein a deposition source is deposited on an opposed aluminum alloy substrate by means of a reactive vacuum deposition and the film thus formed thermally treated to form the γ-Fe 2 O 3 magnetic disk medium, the improvement comprising employing as the deposition source a ferroalloy comprising from about 1 to about 10 at.% titanium, from about 0.5 to about 5 at.% cobalt, and from about 85 to about 98.5 at.% iron.
Claim 2
Dependent Claim
88 words
In a method of producing a γ-Fe 2 O 3 continuous thin film magnetic disk medium wherein a deposition source is deposited on an opposed aluminum alloy substrate by means of a reactive vacuum deposition and the film thus formed thermally treated to form the γ-Fe 2 O 3 magnetic disk medium, the improvement comprising employing as the deposition source a ferroalloy comprising from about 1 to about 10 at.% titanium, from about 0.5 to about 5 at.% cobalt, and from about 85 to about 98.5 at.% iron.
Claim 3
Dependent Claim
32 words
A method according to claim 10 wherein said depositing step comprises a step of performing a reactive sputtering employing said source as a negative electrode and said substrate as a positive electrode.
Claim 4
Dependent Claim
89 words
A method according to claim 2 wherein said reactive sputtering performing step comprises steps of primarily defining an Ar+O 2 gas atmosphere between and around said source and said substrate, forming a thin film of α-Fe 2 O 3 on the substrate with a sufficient reactive oxidation, and performing a hydrogen deoxidation with respect to said film to reduce the α-Fe 2 O 3 to Fe 3 O 4 , said Fe 3 O 4 being further oxidized to γ-Fe 2 O 3 in said thermal treatment performing step.
Claim 5
Dependent Claim
70 words
A method according to claim 2 wherein said reactive sputtering performing step comprises steps of primarily defining an Ar+O 2 gas atmosphere between and around said source and said substrate, forming a thin film of Fe 3 O 4 on the substrate with a weak reactive oxidation, and performing an atmospheric oxidation with respect to said film to oxidize said Fe 3 O 4 to γ-Fe 2 O 3 .
Claim 6
Dependent Claim
86 words
A method according to claim 2 wherein said Fe in said source is in the form of α-Fe 2 O 3 , and said reactive sputtering performing step comprises steps of primarily defining an Ar+H 2 gas atmosphere between and around said source and said substrate, forming a thin film of Fe 3 O 4 on the substrate with a reactive deoxidation, and performing an atmospheric thermal treatment with respect to said film to oxidize said Fe 3 O 4 to γ-Fe 2 O 3 .
Claim 7
Dependent Claim
24 words
A method according to claim 10 wherein said depositing step comprises a step of performing a reactive evaporation in which said source is heated.
Claim 8
Dependent Claim
91 words
A method according to claim 6 wherein said evaporation performing step comprises the steps of primarily defining an O 2 gas atmosphere between and around said source and said substrate, forming a thin film of α-Fe 2 O 3 on the substrate with a sufficient reactive oxidation, and performing hydrogen deoxidation with respect to said film to reduce the α-Fe 2 O 3 to Fe 3 O 4 , and said thermal treatment is performed in the atmosphere to oxidize said Fe 3 O 4 to γ-Fe 2 O 3 .
Claim 9
Dependent Claim
70 words
A method according to claim 6 wherein said evaporation performing step comprises the steps of primarily defining an O 2 gas atmosphere between and around said source and said substrate, and forming a thin film of Fe 3 O 4 on the substrate with a weak reactive oxidation, and said thermal treatment is performed in the atmosphere to oxidize said Fe 3 O 4 to γ-Fe 2 O 3 .
Claim 10
Dependent Claim
50 words
In a magnetic disk medium comprising a continuous Fe 2 O 3 thin film on an aluminum alloy substrate the improvement, wherein said film comprises from about 1 to about 10 at.% titanium, from about 0.5 to about 5 at.% Co and from about 85 to about 98.5 at.% iron.
Claim 11
Dependent Claim
50 words
In a magnetic disk medium comprising a continuous Fe 2 O 3 thin film on an aluminum alloy substrate the improvement, wherein said film comprises from about 1 to about 10 at.% titanium, from about 0.5 to about 5 at.% Co and from about 85 to about 98.5 at.% iron.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |