The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 2003
Filed:
Aug. 10, 2000
Seiichi Hisano, Chiba, JP;
Kazuhisa Saito, Okayama, JP;
Kazushi Sano, Okayama, JP;
Akio Sawabe, Okayama, JP;
Akito Inoue, Funabashi, JP;
Kenichi Inoue, Okayama, JP;
Dowa Mining Co., Ltd., Tokyo, JP;
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 1 of the Periodic Table, and 0.1% by weight or less (inclusive of 0% by weight) of an element belonging to Group 2 of the Periodic Table, the powder comprising flat acicular particles having a mean major axis length of 0.01 to 0.40 &mgr;m 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 &sgr; /Dx ratio of 0.7 or higher, wherein, &sgr; represents the saturation magnetization and Dx represents the crystallite size determined by X-ray diffraction.