Abstract
Ba-Zn-system W-type hexagonal ferrite magnets were prepared by a new manufacturing method in which BaO was added after semisintering treatment, and without atmosphere control. This process was found to be very useful in stabilizing the W-type hexagonal structure. The optimum conditions for making magnets, and some properties of typical specimens are as follows: chemical analysis Ba1.092Zn1.725Fe2+0.410Fe3+15.848O27; semisintering condition 1275°C×1.0 h in air; sintering condition 1225°C ×0.5 h in air; magnetic and physical properties Jm=0.405T, Jr=0.364T, HcJ=86.0kA/m, HcB=82.0kA/m, (BH)max=18.5 kJ/m3, Tc=330°C, HA=987.0 kA/m, KA=1.87×105J/m3, and nB=33.7μB.
