| 摘要 |
PURPOSE:To prepare fine powder of ferromagnetic iron oxide resistant to damage of the particle form, breakage, and sintering, and useful as a magnetic recording medium, by adding a specific weight ratio of Mn to fine acicular particle of iron oxyhydroxide, and reducing and oxidizing the particle. CONSTITUTION:Mn is added to the fine acicular particle of iron oxyhydroxide as a secondary component. The atomic weight ratio of Mn to Fe is 0.005-10 to 100. The Mn-doped acicular fine particle of iron oxyhydroxide is reduced and/or oxidized to obtain fine powder of a ferromagnetic iron compound such as Fe3O4, gamma-Fe2O3, alpha-Fe, etc. having excellent particle shape retainability and magnetic characteristics. |
