A study on barium ferrite particles prepared by chemical coprecipitation

Chemical coprecipitation was employed to prepare fine particles of barium f errite with high coercivity (450 kA/m). Magnetic properties of the bonded b arium ferrite magnet were measured at different temperatures. The results w ere found to be fairly close to the theoretical values based on the Stoner- Wohlfarth model. Mechanical milling was utilized to prepare ultrafine dispe rsed barium ferrite particles. NaF was introduced as a dispersing agent dur ing milling and subsequent heat treatment. The dispersed particles were com pacted and then subjected to die upsetting at room temperature. A weak anis otropy in the coercivity and remanence was found in the directions parallel and perpendicular to the compaction direction.