| 摘要 |
PURPOSE:To provide the title magnetic ion oxide particles and powder with high coersive force and the magnetic with-time stability by containing a moderate and specific compound in a suspension. CONSTITUTION:When a Si compound is contained in the suspension, Co (OH)2 or Fe(OH)2 reacts to Si ions to produce a complex compound. Later, the reaction can be restrained by the resultant adherent reaction. Even if a needlelike magnetic particles powder are used as a precursor or a lot of Fe<+2> salt is added to enhance high coersive force and black color reaction, the adherent layer shall be composed of a Co compound containing Si produced by denaturizing a Si compound or an Fe compound containing Si. Through these procedures, the magnetic with-time stability can be enhanced while when the uppermost adherent layer is composed of the Co compound containing Si, the oxygen in the air does not come into contact with Fe<+2> so as to further enhance the effect. |
