| 摘要 |
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 mu 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 sigma s/Dx ratio of 0.7 or higher, wherein, sigma s represents the saturation magnetization and Dx represents the crystallite size determined by X-ray diffraction. <IMAGE> |
