US4943883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quarternary amorphous magnetic alloy thin film and magnetic head including same
Assignee: HGST Japan Ltd
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Filing: 1988-11-02
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Granted: 1990-07-24
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Expires: 2008-11-02
Abstract
Abstract A thin film magnetic head provided with a first and a second thin film made of a magnetic material, disposed so as to form a closed magnetic circuit; and an intermediate film made of a non-magnetic material, disposed between the first and the second thin films so as to form a magnetic gap at a part of the magnetic circuit; wherein at least one of the first and the second thin films is made of a quaternary amorphous magnetic alloy, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Inventors
- 👤 Masaaki Sano
- 👤 Takao Imagawa
- 👤 Kouichi Nishioka
- 👤 Shinji Narishige
- 👤 Masanobu Hanazono
- 👤 Takashi Onishi
- 👤 Toshihiro Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:38
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
91 words
A thin film magnetic head comprising: a first and a second thin film made of a magnetic material, disposed so as to form a closed magnetic circuit; and an intermediate film made of a non-magnetic material, disposed between said first and said second thin films so as to form a magnetic gap at a part of said magnetic circuit; wherein at least one of said first and said second thin films is made of a quaternary amorphous magnetic alloy, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 2
Dependent Claim
91 words
A thin film magnetic head comprising: a first and a second thin film made of a magnetic material, disposed so as to form a closed magnetic circuit; and an intermediate film made of a non-magnetic material, disposed between said first and said second thin films so as to form a magnetic gap at a part of said magnetic circuit; wherein at least one of said first and said second thin films is made of a quaternary amorphous magnetic alloy, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 3
Dependent Claim
34 words
A thin film magnetic head according to claim 1, wherein said amorphous magnetic alloy has a saturated magnetic flux density above 1.2 T and a magnetostriction constant between 1.0×10 -6 and -2.0×10 -6 .
Claim 4
Dependent Claim
28 words
A thin film magnetic head according to claim 1, wherein said amorphous magnetic alloy contains hafnium 3.5-7 atomic %, tantalum 1-4 atomic % and palladium 0.2-6 atomic %.
Claim 5
Dependent Claim
28 words
A thin film magnetic head according to claim 3, wherein said amorphous magnetic alloy contains hafnium 3.5-5.5 atomic %, tantalum 1-3 atomic % and palladium 0.2-3 atomic %.
Claim 6
Dependent Claim
100 words
A thin film magnetic head comprising: a substrate made of a non-magnetic material; a first and a second thin film made of a magnetic material superposed on said substrate, disposed so as to form a closed magnetic circuit having a magnetic gap at a part thereof; an intermediate film made of a non-magnetic material, interposed in said magnetic gap; and a conductor coil wound around said magnetic circuit; wherein at least one of said first and said second thin films is made of a quaternary amorphous magnetic alloy, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 7
Dependent Claim
100 words
A thin film magnetic head comprising: a substrate made of a non-magnetic material; a first and a second thin film made of a magnetic material superposed on said substrate, disposed so as to form a closed magnetic circuit having a magnetic gap at a part thereof; an intermediate film made of a non-magnetic material, interposed in said magnetic gap; and a conductor coil wound around said magnetic circuit; wherein at least one of said first and said second thin films is made of a quaternary amorphous magnetic alloy, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 8
Dependent Claim
34 words
A thin film magnetic head according to claim 5, wherein said amorphous magnetic alloy has a saturated magnetic flux density above 1.2 T and a magnetostriction constant between 1.0×10 -6 and -2.0×10 -6 .
Claim 9
Dependent Claim
28 words
A thin film magnetic head according to claim 5, wherein said amorphous magnetic alloy contains hafnium 3.5-7 atomic %, tantalum 1-4 atomic % and palladium 0.2-6 atomic %.
Claim 10
Dependent Claim
28 words
A thin film magnetic head according to claim 7, wherein said amorphous magnetic alloy contains hafnium 3.5-5.5 atomic %, tantalum 1-3 atomic % and palladium 0.2-3 atomic %.
Claim 11
Dependent Claim
27 words
A thin film made of an amorphous magnetic alloy of quaternary system for magnetic heads, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 12
Dependent Claim
27 words
A thin film made of an amorphous magnetic alloy of quaternary system for magnetic heads, whose principal component is cobalt and which contains hafnium, tantalum and palladium.
Claim 13
Dependent Claim
27 words
A thin film made of an amorphous magnetic alloy according to claim 9, containing hafnium 3.5-7 atomic %, tantalum 1-4 atomic % and palladium 0.2-6 atomic %.
Claim 14
Dependent Claim
27 words
A thin film made of an amorphous magnetic alloy according to claim 10, containing hafnium 3.5-5.5 atomic %, tantalum 1-3 atomic % and palladium 0.2-3 atomic %.
Claim 15
Dependent Claim
33 words
A thin film made of an amorphous magnetic alloy according to claim 10, having a saturated magnetic flux density above 1.2 T and a magnetostriction constant between 1.0×10 -6 and -2.0×10 -6 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-23 | 1994-01-22 | 1994-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-23 | 1998-01-22 | 1998-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-23 | 2002-01-22 | 2002-07-24 | $7700.00 | Window Closed / Lapsed |