| 摘要 |
PURPOSE:To improve the plate-shape ratio of the particle powder, and to obtain superior dispersibility and stable quality, by using tungstate or molybdate as flux for the source material coprecipitate of the hexagonal ferrite particles. CONSTITUTION:A solution containing elements which constitute hexagonal ferrite is prepared. Then, this solution is mixed with an aqueous alkali solution to produce coprecipitate. The source material coprecipitate thus obtained is mixed with a flux and is sintered to obtain sintered material in which individual hexagonal ferrite particles in hexagonal plate-shaped are present separately one from the other. A tungstate or molybdate is used as the flux for them. The sintered material thus obtained is washed and dried to obtain hexagonal ferrite particles. The ferrite particles thus obtained improve the plate-shape ratio, with superior dispersibility and stable quality, thereby providing a magnetic recording medium with higher vertical angular-shape ratio. |
