| 摘要 |
PURPOSE:To obtain barium ferrite crystalline particles which are large in saturated magnetization and have high dispersibility showing excellent vertical degree of orientation by treating alkaline suspension contg. an element such as Ba, Fe, Co and W in the prescribed proportion on the prescribed conditions. CONSTITUTION:Such alkaline suspension is prepared that contains 1/6-1/10 Ba/(Fe+Me) (wherein Me shows one or more kinds of elements selected from among Co, Ti, Ni and Zr, and is <=0.2mol for 1mol Fe) and has >=1.5mol/l concn. of free OH group. A precursory substance of barium ferrite is obtained by heat-treating this suspension at 60-120 deg.C temp. Then this substance is calcined at 650-950 deg.C temp. to obtain barium ferrite crystalline particles. |
