Barium ferrite powders obtained by co-precipitation

Barium ferrites are usually produced by the ceramic method. On the other ha nd, very fine particles with high chemical homogeneity can be obtained by w et methods, such as co-precipitation, In this work, barium ferrite powders were obtained by co-precipitation. The effects of Fe/Ba molar ratio, reagen t addition order, pH, temperature calcination and the presence of NaCl duri ng calcination were investigated. The products were characterized by differ ential thermal analysis, X-ray diffractometry and scanning electron microsc opy. The magnetic properties were evaluated by a vibrating sample magnetome ter. The presence of a large amount of NaCl during calcination had a detrim ental effect on the magnetic properties. Very fine particles with intrinsic coercivities up to 440 kA/m (5.50 kOe) and saturation magnetization sigma (s) up to 71 Am-2/kg (71 emu/g) were achieved.