Patent EP0144150A1 successfully refreshed from Google Patents.
EP0144150A1
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Ferromagnetic material, ferromagnetic laminate and magnetic head
Assignee: Hitachi Ltd
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Filing: 1984-10-29
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Granted: —
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Expires: 2004-10-29
Abstract
Abstract A ferromagnetic material comprising an iron alloy which contains 2 to 12% by weight of silicon and 5 to 25% by weight of at least one of ruthenium, rhodium, palladium, iridium, platinum, gold and silver, exhibits a high saturation flux density and good corrosion resistance. Excellent magnetic characteristics are obtained in a multilayered film which is obtained by alternatingly laminating the above ferromagnetic material and a spacer layer composed of other material. Further, a markedly increased recording density is exhibited by a magnetic head for perpendicular magnetic recording, when the end of the main pole is composed of the ferromagnetic material.
Inventors
- 👤 Kazuo Shiiki
- 👤 Noriyuki Kumasaka
- 👤 Yoshihiro Shiroishi
- 👤 Hitoshi Nakamura
- 👤 Yoshihiro Hamakawa
- 👤 Noritoshi Saito
- 👤 Shigeo Aoki
- 👤 Kiminari Shinagawa
- 👤 Mitsuhiro Kuro
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:03
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14766; C; C22; C22C; C22C38/00; C22C38/02; G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278; G11B5/187; G11B5/21; G11B5/31; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/14; H01F10/142; H01F10/145; H01F10/26; H01F10/265; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/11; Y10T428/115; Y10T428/12; Y10T428/12493; Y10T428/12632; Y10T428/12771; Y10T428/12861; Y10T428/12937; Y10T428/12951
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
37 words
A ferromagnetic material comprising an iron alloy which contains 2 to 12% by weight of silicon, and 5 to 25% by weight of at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 2
Dependent Claim
37 words
A ferromagnetic material comprising an iron alloy which contains 2 to 12% by weight of silicon, and 5 to 25% by weight of at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 3
Dependent Claim
32 words
A ferromagnetic material according to claim 1, wherein said iron alloy contains 10 to 20% by weight of at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 4
Dependent Claim
32 words
A ferromagnetic material according to claim 2, wherein said iron alloy contains 15 to 20% by weight of at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 5
Dependent Claim
22 words
A ferromagnetic material according to any one of the preceding claims, wherein the content of silicon is 4.5 to 8% by weight.
Claim 6
Dependent Claim
24 words
A ferromagnetic material according to any one of the preceding claims, wherein said iron alloy contains silicon and ruthenium, the balance being substantially iron.
Claim 7
Dependent Claim
27 words
A ferromagnetic material according to any one of the preceding claims, wherein said iron alloy further contains aluminum in an amount of less than 3% by weight.
Claim 8
Dependent Claim
36 words
A ferromagnetic material according to any one of the preceding claims, wherein said iron alloy further contains less than 5% by weight of at least one element selected from titanium, chromium, vanadium, molybdenum, zirconium, and niobium.
Claim 9
Dependent Claim
44 words
A ferromagnetic material obtained by alternately laminating a main ferromagnetic film and a spacer material layer, said main ferromagnetic film being comprised of an iron alloy according to any one of the preceding claims, and said spacer material layer being comprised of other material.
Claim 10
Dependent Claim
38 words
A ferromagnetic material according to claim 8, wherein said layer of said main ferromagnetic film has a thickness of 0.02 to 0.5 pm, and each of said spacer material layers has a thickness of 20 to 500 angstroms.
Claim 11
Dependent Claim
37 words
A ferromagnetic material according to claim 9, wherein each layer of said main ferromagnetic film has a thickness of 0.05 to 0.1 pm, and each of said spacer layers has a thickness of 50 to 200 angstroms.
Claim 12
Dependent Claim
39 words
A ferromagnetic material according to any one of claims 8 to 10, wherein said spacer material layer comprises a material selected from Si0 2 , A1 2 0 3 , cobalt, a ferromagnetic cobalt alloy and a nickel-iron alloy.
Claim 13
Dependent Claim
38 words
A magnetic head wherein at least a portion of at least one magnetic pole is composed of an iron alloy which contains silicon and at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 14
Dependent Claim
38 words
A magnetic head wherein at least a portion of at least one magnetic pole is composed of an iron alloy which contains silicon and at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 15
Dependent Claim
22 words
A magnetic head according to claim 12, wherein said iron alloy is one according to any one of claims 1 to 7.
Claim 16
Dependent Claim
76 words
A magnetic head according to claim 12, wherein at least a portion of at least one magnetic pole is composed of a ferromagnetic multilayered film constituted by alternatingly laminating a main ferromagnetic film and a spacer material layer, said main ferromagnetic film being composed of an iron alloy which contains silicon and at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver, and said spacer material layer being composed of other material.
Claim 17
Dependent Claim
40 words
A magnetic head according to claim 14, wherein said iron alloy contains 2 to 12% by weight of silicon, and less than 25% by weight of at least one element selected from ruthenium, rhodium, palladium, iridium, platinum, gold and silver.
Claim 18
Dependent Claim
23 words
A magnetic head according to claim 15, wherein the ferromagnetic multilayered film is one according to any one of claims 8 to 11.
Claim 19
Dependent Claim
43 words
A magnetic head according to any one of claims 12 to 16, wherein at least a portion, on the side of a magnetic recording medium, of a magnetic pole which generates and detects a signal magnetic field, is composed of said iron alloy.
Claim 20
Dependent Claim
40 words
A magnetic head according to any one of claims 14 to 16 for perpendicular magnetic recording, wherein at least a portion of the main pole on the side of the magnetic recording medium is composed of said ferromagnetic multilayered film.
Claim 21
Dependent Claim
21 words
A magnetic head according to claim 18, whrein the number of layers of said ferromagnetic multilayered film is 2 to 10.
Claim 22
Dependent Claim
21 words
A magnetic head according to claim 18, wherein the number of layers of said ferromagnetic multilayered film is 4 to 8.
Claim 23
Dependent Claim
21 words
A magnetic head according to claim 18, wherein the number of layers of said ferromagnetic multilayered film is 4 to 6.
Claim 24
Dependent Claim
32 words
A magnetic head according to any one of claims 18 to 21, wherein said ferromagnetic multilayered film at the end of said main pole has a thickness of 0.1 to 0.5 pm.
Claim 25
Dependent Claim
27 words
A magnetic head according to claim 22, wherein said ferromagnetic multilayered film at the end of said main pole has a thickness of 0.1 to 0.3 pm.
References Cited (Backward Citations)
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