Effect of Particle Size and Its Distribution on the Fabrication and Magnetic Properties of Barium Ferrite Powders Prepared from Coprecipitated Precursors

Six kinds of powder samples with a different particle size and its distribution have been prepared from coprecipitated precursors by light grinding followed by sieving, and calcined in air to form the barium ferrite (BaFe 1 2 O 1 9 ) phase. Correlation between the particle morphology and Fe/Ba molar ratio or magnetic properties has been examined. The results indicated that the powders consisting of coarse particles (100-200 μm) exhibit a single phase of BaFe 1 2 O 1 9 , and a higher saturation magnetization and coercivity than the powders having fine particles or a wide size distribution. The optimized powders showed a high coercivity of 5.85 kOe and a saturation magnetization of 71 emu/g that are closed to the theoretical values.