Effect of Ba strate addition on magnetic properties of Ba-system W-type ferrite magnets

Experiment was carried out to investigate the effect of Ba 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 BaO - 8.5Fe(2)O(3) were improved by adding 0.3 wt% of Ba Stearate, 0.5 wt% of SiO2, and 0.5 wt% of CaO together. The optimum conditions for making magnets were as follows; chemical composition: Ba1.029Ca0.127Si0.097C0.053Fe2.4562+Fe15.3923+O27, semisintering condition: 1350 degrees Cx4.0 h in nitrogen gas atmosphere, drying condition: 180 degrees Cx2.0 h in air, sintering condition: 1160 degrees Cx1.5 h in nitrogen gas atmosphere. Magnetic and physical properties of a typical sample were J(m) = 0.46 T, J, = 0.43 T, H-cJ 182.3 kA/m, H-cB = 177.2 kA/m, (BH)(max) = 33.8 kJ/m(3), T-C = 495 degrees C and K-A = 2.65 x 10(5) J/m(3) and H-A 1332 kA/m. The lattice constants of this compound were a 5.883x10(-10) m, c 32.92x10(-10) m, and c/a = 5.596.