Abstract
This experiment was carried out to investigate the magnetic properties of Sr-Zn-Ni system W-type hexagonal ferrite powders, and bonded magnets were prepared from these powders. It was found that Sr-Zn-Ni system W-type hexagonal ferrite can be easily produced in the air. The preparation conditions for a typical sample were as follows; chemical composition: SrO·0.5ZnO·1.0NiO·0.5FeO·8Fe2O3 with added 0.3 wt% SiO2, 0.7 wt% CaO, 1.0 wt% SrCO3; reaction sintering condition: 1300°C×4.0 h in air; annealing condition: 1025°C×5 min in air. The magnetic properties of Sr-Zn-Ni system W-type hexagonal ferrite powder are σs=88.63×10−6 Wb·m/kg, HcJ=217.8 kA/m. The magnetic properties of hybrid (mixed 80% M-type ferrite powder and 20% W-type ferrite powder) bonded magnets are Br=284 mT, (BH)max=15.3 kJ/m3, HcJ=183 kA/m.
