Ferromagnetic powder
First Claim
1. A ferromagnetic powder containing iron as the main component and containing more than 5 to 50 at. % Co, 0.1 to 30 at. % Al, 0.1 to 10 at. % of a rare earth element inclusive of Y, 0.05% by weight or less of an element belonging to Group 1a of the Periodic Table, and 0.1% by weight or less (inclusive of 0% by weight) of an element belonging to Group 2A of the Periodic Table,said powder comprising flat acicular particles having a mean major axis length of 0.01 to 0.40 μ
- m and a crystallite diameter as determined by X-ray diffraction (Dx) of 50 to 250 angstroms, provided that the cross section diameter in the minor axis direction cut perpendicular to the major axis has a larger width and a smaller width, and that a cross section ratio in the minor axis direction, which is a larger width to smaller width ratio, is uniformly in the major axis direction greater than 1, and said powder yielding a σ
s/Dx ratio of 0.7 or higher, wherein, σ
s represents the saturation magnetization and Dx represents the crystallite size determined by X-ray diffraction.
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Accused Products
Abstract
A ferromagnetic powder containing iron as the principal component and containing more than 5 to 50 at. % Co, 0.1 to 30 at. % Al, 0.1 to 10 at. % of a rare earth element inclusive of Y, 0.05% by weight or less of an element belonging to Group 1a of the Periodic Table, and 0.1% by weight or less (inclusive of 0% by weight) of an element belonging to Group 2a of the Periodic Table, the powder comprising flat acicular particles having a mean major axis length of 0.01 to 0.40 μm and a crystallite diameter as determined by X-ray diffraction (Dx) of 50 to 250 angstrom, provided that the cross section diameter in the minor axis direction cut perpendicular to the major axis has a larger width and a smaller width, and that this cross section ratio in the minor axis direction, which is a larger width to smaller width ratio, uniformly yields a value of greater than 1, preferably 1.5 or higher, and the powder yielding a σs/Dx ratio of 0.7 or higher, wherein, σs represents the saturation magnetization and Dx represents the crystallite size determined by X-ray diffraction.
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Citations
6 Claims
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1. A ferromagnetic powder containing iron as the main component and containing more than 5 to 50 at. % Co, 0.1 to 30 at. % Al, 0.1 to 10 at. % of a rare earth element inclusive of Y, 0.05% by weight or less of an element belonging to Group 1a of the Periodic Table, and 0.1% by weight or less (inclusive of 0% by weight) of an element belonging to Group 2A of the Periodic Table,
said powder comprising flat acicular particles having a mean major axis length of 0.01 to 0.40 μ - m and a crystallite diameter as determined by X-ray diffraction (Dx) of 50 to 250 angstroms, provided that the cross section diameter in the minor axis direction cut perpendicular to the major axis has a larger width and a smaller width, and that a cross section ratio in the minor axis direction, which is a larger width to smaller width ratio, is uniformly in the major axis direction greater than 1, and
said powder yielding a σ
s/Dx ratio of 0.7 or higher, wherein, σ
s represents the saturation magnetization and Dx represents the crystallite size determined by X-ray diffraction.- View Dependent Claims (2, 3, 4, 5, 6)
- m and a crystallite diameter as determined by X-ray diffraction (Dx) of 50 to 250 angstroms, provided that the cross section diameter in the minor axis direction cut perpendicular to the major axis has a larger width and a smaller width, and that a cross section ratio in the minor axis direction, which is a larger width to smaller width ratio, is uniformly in the major axis direction greater than 1, and
Specification
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- Resources
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Current AssigneeDowa Mining Company Limited (DOWA Holdings Company Limited)
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Original AssigneeDowa Mining Company Limited (DOWA Holdings Company Limited)
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InventorsSaito, Kazuhisa, Sawabe, Akio, Inoue, Akito, Hisano, Seiichi, Inoue, Kenichi, Sano, Kazushi
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Primary Examiner(s)SHEEHAN, JOHN P
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Application NumberUS09/601,942Time in Patent Office887 DaysField of Search148/301, 148/306, 148/311, 148/315, 420/83, 420/77, 420/80, 420/103, 428/694.RE, 428/694.BR, 428/694.BHUS Class Current148/301CPC Class CodesB22F 1/05 Metallic powder characteris...C22C 33/0285 with Cr, Co, or Ni having a...G11B 5/70621 containing Co metal or alloysG11B 5/714 characterised by the dimens...H01F 1/06 in the form of particles, e...
