| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain magnetic powder for preventing the surface property or the durability of a magnetic tape from degrading as the magnetic particle powder becomes finer that is suitable for high-density magnetic recording. <P>SOLUTION: The magnetic powder made of Fe-based particles, having at least one of oxides of Al, Si, and Ra (Ra represents at least one of rare earth elements including Y) on its surface layer, is arranged so as to have an average grain diameter less than 70 nm, basic site's number of 0.85/nm<SP>2</SP>or less, and acid site's number of 0.75/nm<SP>2</SP>or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
