MAGNETIC POWDER FOR MAGNETIC RECORDING AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain magnetic powder having stable coercive force in a wide range and high magnetization, by suspending orientating lamellar hexagonal ferrite fine powder in an aqueous solution having dissolved Fe<2+> and reacting the suspension with an alkali aqueous solution. CONSTITUTION:Orientating lamellar hexagonal ferrite fine particles are suspended in an aqueous solution having dissolved ferrous ion and further an alkali aqueous solution is added to the suspension. The prepared blended suspension is reacted while stirring the suspension in a nonoxidizing atmosphere and further in an oxidizing atmosphere at 50-100 deg.C solution temperature to give magnetic powder. The magnetic powder is powder wherein spinel type ferrite is combined with orientating lamellar hexagonal ferrite fine particles of c-axis crystal. When the powder is used as magnetic powder for magnetic recording media of coating type, excellent regenerative output can be obtained in a wide frequency range. Change of coercive force with temperature can be reduced and an excellent magnetic recording media medium is obtained.