| 摘要 |
PURPOSE:To produce ferromagnetic fine powder suitable for a high-density magnetic recording medium by heating alkaline suspension contg. Fe, the other metallic element and Ba to produce the precipitate of Ba ferrite and adding the compd. of Si or at least one kind of compd. of Na, K, Li, B and Sr thereto and calcining the mixture. CONSTITUTION:Alkali such as NaOh is added to an aq. soln. contg. Ba at the proportion of 1/6-1/10 molar ratio for (Fe+Me) (Me is at least one kind of Co, Ti, Ni, Mn, Zr, Nn, Ge, Nb and V, and <=0.2mol for 1mol Fe) to make alkaline suspension having >=1.5mol/l alkali concn. shown in free OH standard. This mixture is heated at 120-250 deg.C in an autoclave or the like to produce lamellate granular Ba ferrite precipitate. If necessary, Si compd. or at least one kind of compd. of Na, K, Li, B and Sr is added to this precipitate and the mixture is calcined at 650-950 deg.C to produce Ba ferrite-base ferromagnetic fine powder for magnetic recording.
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