US4920013A
Expired / Lapsed
US
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Magnetic Multilayer structure
Assignee: Hitachi Ltd
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Filing: 1987-09-23
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Granted: 1990-04-24
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Expires: 2007-09-23
Abstract
Abstract A magnetic multilayer structure having an increased permeability and an increased saturation magnetic flux density comprises a plurality of magnetic layers and a plurality of intermediate layers alternately laminated one upon another. Each of the magnetic layers is made of Fe, Co, Ni or an alloy containing one of Fe, Co and Ni, while each of the intermediate layers is made of a material capable of interstitially forming a solid solution with the material of the magnetic layers.
Inventors
- 👤 Toshio Kobayashi
- 👤 Shigekazu Otomo
- 👤 Ryoichi Nakatani
- 👤 Noriyuki Kumasaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:50
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; B; B82; B82Y; B82Y25/00; G11B5/127; G11B5/1278; G11B5/147; G11B5/31; G11B5/65; G11B5/653; G11B5/84; G11B5/851; H; H01; H01F; H01F10/00; H01F10/26; H01F10/30; H01F10/32; H01F10/324; H01F10/3254; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
109 words
A magnetic multilayer structure having an increased permeability and an increased saturation magnetic flux density, the structure comprising a plurality of magnetic layers and a plurality of intermediate layers, each of said intermediate layers being formed between adjacent two of said magnetic layers, wherein each of said magnetic layers is crystalline and is made of a magnetic material selected from the group consisting of Fe, Co, Ni and an alloy containing as its main component at least one of said elements, Fe, Co and Ni, and each of said intermediate layers is made of a material which forms an interstitial solid solution with said material of said magnetic layers.
Claim 2
Dependent Claim
109 words
A magnetic multilayer structure having an increased permeability and an increased saturation magnetic flux density, the structure comprising a plurality of magnetic layers and a plurality of intermediate layers, each of said intermediate layers being formed between adjacent two of said magnetic layers, wherein each of said magnetic layers is crystalline and is made of a magnetic material selected from the group consisting of Fe, Co, Ni and an alloy containing as its main component at least one of said elements, Fe, Co and Ni, and each of said intermediate layers is made of a material which forms an interstitial solid solution with said material of said magnetic layers.
Claim 3
Dependent Claim
28 words
A magnetic multilayer structure according to claim 1, in which said alloy further contains an additive selected from the group consisting of C, Si, B, N and Ti.
Claim 4
Dependent Claim
40 words
A magnetic multilayer structure according to claim 1, in which said material of said intermediate layer is selected from the group consisting of B, C, S and a compound containing at least one of B, C, N, P and S.
Claim 5
Dependent Claim
84 words
A magnetic multilayer structure according to claim 1, in which the sum of the thicknesses of any one of said magnetic layers and of an intermediate layer thereon is substantially in a range from 0.2 nm to 250 nm, each of said intermediate layers has a thickness substantially in a range from 0.05 nm to 5 nm, and the ratio of the thickness of said each intermediate layer to that of said each magnetic layer is substantially in a range from 0.01 to 0.25.
Claim 6
Dependent Claim
85 words
A magnetic multilayer structure according to claim 1, in which the sum of the thicknesses of any one of said magnetic layers and of an intermediate layer thereon is substantially in a range from 0.2 nm to 50 nm while each of said intermediate layers has a thickness substantially in a range from 0.05 nm to 5 nm, and the ratio of the thickness of said each intermediate layer to that of said each magnetic layer is substantially in a range from 0.01 to 0.25.
Claim 7
Dependent Claim
29 words
A magnetic multilayer structure according to claim 1, in which said alloy further contains an additive selected from the group consisting of a group IV element, N and B.
Claim 8
Dependent Claim
30 words
A magnetic multilayer structure according to claim 1, in which said alloy further contains an additive selected from the group consisting of a group VIII element, Cu, Ag or Au.
Claim 9
Dependent Claim
31 words
A magnetic multilayer structure according to claim 1, in which said alloy further contains an additive selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo and W.
Claim 10
Dependent Claim
28 words
A magnetic head having a magnetic pole portion, at least a part of said magnetic pole portion being made of a magnetic multilayer structure defined in claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |