| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide magnetic powder that maintains a needle-line shape, shows high coercive field strength as a fine particle state, and is suitable for a magnetic record medium for high-density recording such as a digital video tape and a backup tape for computers. <P>SOLUTION: An oxide of iron or a hydroxide is used as a starting raw material for directly depositing at least one element selected from a rare earth element, boron, silicon, aluminum, and phosphorus to perform heating reduction treatment. After that, nitriding treatment is applied at a temperature not higher than reduction treatment temperature, thus obtaining iron nitride-based magnetic powder. In the iron nitride-based magnetic powder, iron and nitrogen are used as constitutional elements; at least Fe<SB>16</SB>N<SB>2</SB>phase is included; the content of nitrogen to iron is 1.0-20.0 atom.%; and the shape of the iron nitride-based magnetic powder is a spindle or needle shape where the average size of a particle long axis is within 20-100 nm. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
