| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnet excellent in the magnetic characteristic by fining the average particle diameter of pulverized powder, kneading a slurry, and controlling the quantities of additives of sintering assistants. SOLUTION: Sintering assistants such as CaCO3 , SrCO3 , SiO2 , etc., and water are added to coarse ferrite powder having a composition of MO.nFe2 O3 (M: one kind or more out of Ba, Sr, Pb, n=5 or 6), and a pulverized. A slurry containing the pulverized ferrite powder obtained is kneaded. By wet-molding the kneaded substance in a magnetic field and sintering it after that, a ferrite magnet containing MO, Fe2 O3 , SiO2 and CaO and having a constitution comprizing an SiO2 /(MO+Fe2 O3 ) ratio by weight of 3×10<-3> -6×10<-3> and a CaO /(MO+Fe2 O3 ) ratio by weight of 5×10<-3> -7×10<-3> and an Fe2 O3 /MO mole ratio of 5.7-5.9, an average crystal particle diameter of 0.9-0.6μm, and a degree of orientation of Br /(Br +Br⊥) pr 0.9 or more is obtained. |
