| 摘要 |
PROBLEM TO BE SOLVED: To provide a silica-coating magnetic material particle including a magnetic material particle and silica particles directly coupled to the surface of the magnetic material particle.SOLUTION: A silica-coating magnetic material particle comprises: a magnetic material particle; and silica particles having a volume average particle diameter of 5-200 nm which is smaller than that of the magnetic material particle, and covering the surface of the magnetic material particle almost so that no gap is left therebetween after having been baked. The magnetic material particle and each silica particle are coupled with each other by baking, where eliminates the need for using a binder (lubricant) as used in the prior art. It is found that a strong binding can be realized with the silica particles deposited to the surface by performing the baking operation under the condition that neither the silica particles nor the magnetic material particle are molten after covering the magnetic material particle with the silica particles. |
