抄録
An experiment was carried out to investigate the effect of Ni-Stearate as a reducing agent on the magnetic and physical properties of anisotropic BaFe2-W type ferrite magnets. It was found that the magnetic properties of BaFe2-W type hexagonal ferrite were improved by adding 0.5 wt% of Ni-Stearate, 0.5 wt% of SiO2, and 0.5 wt% of CaO together. The optimum conditions for making magnets were as follows; Chemical composition: BaO · 8.5Fe2O3, semisintering condition: 1350°C×4.0 h in nitrogen gas atmosphere, drying condition: 190°C×2.0 h in air, sintering condition: 1180°C×1.5 h in nitrogen gas atmosphere. Magnetic and physical properties of a typical sample were Jm=0.47 T, Jr=0.42 T, HcJ=203.5 kA/m, HcB=192.3 kA/m, (BH)max=31.5 kJ/m3, Tc=484°C. The lattice constants of this compound were a=5.905×10-10 m, c=32.62×10-10 m, and c/a=5.523.
