| 摘要 |
PURPOSE:To enable to make high density of magnetic recording medium by a method wherein acicular ferromagnetic cementite particulates are made as a main constituent. CONSTITUTION:Acicular ferro-hydroxide particulates are prepared and are designated as acicular ferromagnetic reduced iron powder class by adhesion and denaturalization, sintering and reduction process and secondly, acicular ferromagnetic iron carbide particulates of Fe3C is designated as molecular species by carbonization process. According to the working of this ferromagnetic particulates, particle's size, which is indicated by the same Hc value as the particulates mentioned later, can be designed in fully small in comparison with alpha-Fe particulates. Moreover, even if said particulates are contained carbon more than stoichometry, as Fe3C is formed as a molecular species, saturated magnetization is not lowered largely. This face is extremely favarorable. As a result of this fact, the system which magnetic property is hardly changed, can be realized using particulates system being microminiaturized as raw material powder at the time of medium processing work. |
