摘要 |
PROBLEM TO BE SOLVED: To provide means for improving separation and recovery properties from a forming mother liquid in spite of obtaining a fine particle having a primary particle diameter of 30 nm or less, and further, to provide a hexagonal ferrite particle which is suitable for high-density magnetic recording by adopting this means.SOLUTION: Aggregated particles are formed by aggregating a plurality of particles while a primary particle of a hexagonal ferrite particle keeps its form. The shape is an approximately spherical shape when observed at a magnification of about 1,000 times of SEM, and the aggregated particles comprise the hexagonal ferrite particles of which the average particle diameter is 20 μm or more and 100 μm or less. |