Barium Ferrite Powders Obtained by Co-Precipitation

Abstract

Barium ferrites are usually produced by the ceramic method. On the other hand, very fine particles with high chemical homogeneity can be obtained by wet methods, such as co-precipitation. In this work, barium ferrite powders were obtained by co-precipitation. The effects of Fe/Ba molar ratio, reagent addition order, pH, temperature calcination and the presence of NaCl during calcination were investigated. The products were characterized by differential thermal analysis, X-ray diffractometry and scanning electron microscopy. The magnetic properties were evaluated by a vibrating sample magnetometer. The presence of a large amount of NaCl during calcination had a detrimental effect on the magnetic properties. Very fine particles with intrinsic coercivities up to 440 kA/m (5.50 kOe) and saturation magnetization σs up to 71 Am2/kg (71 emu/g) were achieved.