FLAT BA-FERRITE FINE PARTICLE FOR MAGNETIC RECORDING AND MANUFACTURE THEREOF

摘要

PURPOSE:To form flat BaCoxTixFe12-2xO19 particle for magnetic recording and improve its characteristics by a method wherein the ratio of Ba ion to Fe(III), Co(II) and Ti(IV), the density of an alkaline solvent, the reaction temperature and time, the stirring condition of a suspension and the like are varied to obtain the prescribed production condition. CONSTITUTION:The ratio of the total number of atoms of Co(II) and Ti(IV) is 0.17-0.09 to one atom of Fe(III). A high alkaline suspension, in which the number of atoms of contained Ba ion is one to 7-9 atoms of Fe, Co and Ti metal ions, is subjected to hydro-heat treatment at the temperature range of 250- 320 deg.C. BaCoxTixFe12-2xO19 (where 0.1=x=0.5) fine particle, whose BEF rational surface area is 20-70m2g-1, average diameter is 0.05-0.3mum, magnetization value under the magnetic field of 10kOe is more than 30enug-1 and coercive force is 300-1,000Oe, is produced from the solution. This fine particle is used as flat Ba-ferrite fine particle for magnetic recording.