Comparative study of barium ferrite prepared by mechanical milling and co-precipitation

Abstract

Barium ferrite powder has been prepared using mechanical milling process and co-precipitation followed by subsequent heat treatments. The sintering, magnetic and structural properties of the powder obtained via these two processing routes have been studied and compared. For the mechanical milling process, barium carbonate (BaCO3) and hematite (Fe2O3) powders were used as starting materials. After the mixture has been mechanically milled, consolidation was carried out subsequently at high temperature. The magnetic and structural properties were studied for different milling conditions. Sintering property of the powder was examined. Nearly fully dense barium ferrite magnet was obtained after sintering at 1000-1100°C. In the co-precipitation process, precursors were synthesized by co-precipitation of mixture of hydroxides of barium and iron from barium nitrate and iron nitrate in ammonia solution. The properties of barium ferrite prepared by these two methods were discussed.