| 摘要 |
PURPOSE:To prevent lowring of coersive force while in storage in the state of fine powderly particle as well as to contrive improvement in output characteristics in high frequency number by a method wherein cobalt denatured ferrite magnetic powder is treated by a silane coupling agent. CONSTITUTION:The cobalt denatured ferrite magnetic powder to be processed contains 0.1-10atom% of cobalt atoms, and it is desirable that the powder contains bivalent iron atoms together with trivalent iron atoms. However, it is necessary that the ratio of said bivalent/trivalent atoms of iron is to be 0.15 or below. When the treatment of cobalt denatured ferrite magnetic powder is going to be performed, the cablat denatured ferrite magnetic powder is dispersed in the solution of dispersed liquid wherein a silane coupling agent, for example, is dissolved or dispersed in suitable solvent medium, and said treatment can be performed using a method wherein said powder and the silane coupling agent are contacted with each other for a fixed period of time. |
