| 摘要 |
PURPOSE:To obtain magnetic powder of hexagonal ferrite which is suitable for a high-density magnetic recording material having almost the same performance even if producing method and the producing conditions are different by comprising a fine grain shown in a specified composition formula, containing furthermore a specified metal besides Co and Ti. CONSTITUTION:Magnetic powder of hexagonal ferrite for a magnetic recording which is shown in the formula and has 0.01-0.3mu mean grain size is obtained wherein MI is Ba, Sr, Ca and Pb and MII is Al, Cr, Ga, In, Tl and Y and (a), (b), (c), (d), (e) and (f) are atomic number of Fe, Co, Ti, MI, MII and O. (a)=8-11.8 (b)=0.05-2.0 (c)=0.05-2.0 (d)=0.5-3.0 (e)=0.01-2.0 (f) is atomic number of 0 satisfying the valency of the other atoms. In the magnetic powder of hexagonal ferrite, the control of coercive force is insufficient in such case that only one part of Fe is substituted with Co and Ti but the magnetic powder having almost same performance is obtained, for example, even when a producing method and the producing conditions are different by adding furthermore the other specified metal and it is preferable for a high-density magnetic recording material. |
