| 摘要 |
PURPOSE:To obtain magnetic ferrite powder having higher saturation magnetic susceptibility than magnetic ferrite powder obtd. by a conventional vitrifying method when the powder has the same grain size by substituting silicon dioxide (SiO2) for part of boron oxide (B2O3) used as a glass forming component. CONSTITUTION:A B2O3 component and an SiO2 component are used in 0.05- 0.8, preferably 0.1-0.5 molar ratio of SiO2/(B2O3+SiO2) as glass forming components contained in starting materials for manufacturing magnetic hexagonal ferrite powder for magnetic recording by a conventional vitrifying method. A mixture contg., by mole, 20-40% B2O3+SiO2, 25-50% RO, 20-50% Fe2O3, 2-10% MO and 2-10% M'O2 is preferably used as a mixture of starting materials for ferrite, that is, a mixture contg. the basic components of hexagonal ferrite, a component for reducing coercive force and glass forming components. |
