Patent US4772976A successfully refreshed from Google Patents.
US4772976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing magnetic layer and magnetic head prepared using the same
Assignee: Hitachi Ltd
•
Filing: 1985-08-23
•
Granted: 1988-09-20
•
Expires: 2005-08-23
Abstract
Abstract Ion implantation is conducted in a desired area(s) of the surface of a magnetic layer, and annealing of the layer is carried out to control the composition in that desired area(s). The control of the composition may be facilitated by applying a one-directional or rotating magnetic field during ion implantation. In preparing a magnetic head, a portion of a magnetic pole at least on one side thereof in close proximity to a magnetic recording medium is formed into an iron or iron-based magnetic alloy film, at least part of which is subjected to ion implantation and annealing.
Inventors
- 👤 Shigekazu Otomo
- 👤 Noriyuki Kumasaka
- 👤 Ryo Imura
- 👤 Ryo Suzuki
- 👤 Yutaka Sugita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:38
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; H; H01; H01F; H01F41/00; H01F41/14; H01F41/18; G11B5/1278; G11B5/147; G11B5/187; G11B5/1875; G11B5/1877; G11B5/1878; G11B5/21; G11B5/31; G11B5/3163; Y; Y10; Y10S; Y10S148/00; Y10S148/90; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
A magnetic head comprising a magnetic pole having a portion at least on one side of said magnetic pole in close proximity to a magnetic recording medium formed of an iron or iron-based alloy film, at least a portion of said iron or iron-based alloy film constituting a region in which at least one element is ion-implanted, said at least one element being selected from the group consisting of nitrogen, carbon and boron, said region in which at least one element is ion-implanted having an average density of said at least one element of 0 to 20 at. % exclusive and a higher saturation magnetization than the iron or iron-based alloy film without said at least one element.
Claim 2
Dependent Claim
118 words
A magnetic head comprising a magnetic pole having a portion at least on one side of said magnetic pole in close proximity to a magnetic recording medium formed of an iron or iron-based alloy film, at least a portion of said iron or iron-based alloy film constituting a region in which at least one element is ion-implanted, said at least one element being selected from the group consisting of nitrogen, carbon and boron, said region in which at least one element is ion-implanted having an average density of said at least one element of 0 to 20 at. % exclusive and a higher saturation magnetization than the iron or iron-based alloy film without said at least one element.
Claim 3
Dependent Claim
35 words
A magnetic head as claimed in claim 1, wherein said region in which at least one element is ion-implanted has an average density of said at least one element of 5 to 18 at. %.
Claim 4
Dependent Claim
32 words
A magnetic head as claimed in claim 1 or 2, wherein said iron or iron-based alloy film is one annealed at a temperture of 500° C. or lower after the ion implantation.
Claim 5
Dependent Claim
44 words
A magnetic head as claimed in claim 1 or 2, wherein said iron or iron-based alloy film is one subjected to ion implantation while applying a one-directional magnetic field inside said film or a magnetic field rotating relative to said film inside said film.
Claim 6
Dependent Claim
49 words
A magnetic head as claimed in claim 1 or 2, wherein said iron or iron-based alloy film is one annealed at a temperature of 500° C. or lower while applying a one-directional magnetic field inside said film or a magnetic field rotating relative to said film inside said film.
Claim 7
Dependent Claim
21 words
A magnetic head as claimed in claim 1, wherein said iron or iron-based alloy film is provided on a non-magnetic substrate.
Claim 8
Dependent Claim
73 words
A magnetic head as claimed in claim 1, wherein said magnetic pole comprises a plurality of iron or iron-based alloy film layers provided on a substrate, each of said film layers having a region in which at least one element selected from the group consisting of nitrogen, carbon and boron is ion-implanted and which has a higher saturation magnetization than the iron or iron-based alloy film layer without said at least one element.
Claim 9
Dependent Claim
48 words
A magnetic head as claimed in claim 7, further comprising at least one intermediate layer provided between selected iron or iron-based alloy film layers, said at least one intermediate layer being made of a material selected from the group consisting of a ferro-magnetic material and a non-magnetic material.
References Cited (Backward Citations)
SU107443A1
Cited
DE2553754A1
Cited
DE2655572A1
Cited
EP0012912A1
Cited
JPS5766611A
Cited
US4372985A
Cited
SU997098A1
Cited
US4451500A
Cited
US4578728A
Cited
EP0082526A2
Cited
JPS58189816A
Cited
EP0115842A1
Cited
JPS607605A
Cited
US4641213A
Cited
JPS60131609A
Cited
US4631613A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |