Synthesis of BaFe12O19/MFe2O4 (M = Co, Mn) by sol-gel method

Composites of M-type hexaferrite BaFe12O19 and spinel ferrites MFe2O4 (M = Co, Mn) were directly synthesized by sol-gel method. The structure of composites was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation of BaFe12O19/CoFe2O4 composite was proved by XRD patterns with coexistence of diffraction peaks of the two kinds of ferrites, BaFe12O19 and CoFe2O4. Compared with BaFe12O19, the diffraction peaks of CoFe2O4 are fairly weak, revealing the dominant structure of hexaferrite in the composite. SEM micrographs provide further evidence and the particle size of composites is about several hundred nanometer, meaning that the co-synthesizing sol-gel method can be in favor of the formation of finer particles. However, the diffraction peaks of MnFe2O4 can be hardly found in BaFe12O19/MnFe2O4 composite, revealing the synthesis conditions are not favorable for the formation of MnFe2O4. Substitution reaction of Ba or Fe by Mn may be proposed.