2001 Volume 48 Issue 8 Pages 724-729
An experiment was carried out to investigate the effects of a Zn-organic-compound as a new reducing agent, and SiO2 and CaO additives, on the magnetic and physical properties of SrFe2-hexagonal ferrite (W type). It was found that the magnetic properties of SrO⋅9.0Fe2O3 were considerably improved by adding 0.1 wt% of Zn-organic-compound, 0.3 wt% of SiO2, and 0.7 wt% of CaO together. The optimum conditions for making magnets and the prime properties of typical specimens are as follows: Based on chemical analysis: Composition: Sr2+0.930Si4+0.097 Ca2+0.169Zn2+0.007Fe2+1.307, Fe3+16.265O27; semisintering conditions (S.S.C.): 1350°C×4.0h in nitrogen gas atmosphere; drying condition (D.C.): 200°C×4.0 h in air; sintering condition (S.C.): 1170°C×1.5 h in nitrogen gas atmosphere. Magnetic and physical properties are as follows: Jm=0.468(T). Jr=0.433(T), HcJ=175(kA/m), HcB=161(kA/m), (BH)max=32.70(kJ/m3), Tc=500.9(°C), HA=1401 (kA/m), KA=3.28, and nB=30.0μB, a=5.757×10-10(m), c=33.41×10-10(m), and c/a=5.804.
