The influence of the coprecipitation conditions on the low-temperature formation of barium hexaferrite

We have investigated the formation of barium hexaferrite via the coprecipitation method. Various reagent salts and solvents were tested, and the coprecipitates were calcined at 300–800 C for 1–50 h. The samples were characterized with X-ray powder diffraction, electron microscopy and magnetometry. The coprecipitation conditions had a significant influence on the formation time of the barium hexaferrite, which started to form at as low as 500 C. The optimum coprecipitation conditions were: ethanol as a solvent and chlorides as reagent salts. Powders with optimum magnetic properties, saturation magnetization 60–63 emu/g and coercivity 4–5 kOe, were obtained by calcining at 600–700 C.