Comparative study of the magnetic properties of Barium hexaferrites obtained by co-precipitation and microemulsions

Abstract

Using the chemical coprecipitation method a precursor formed by iron and barium hidroxides and carbonates was obtained. For calcination temperatures higher than 730°C this precursor transforms into barium ferrite. Calcining the precursor during 2 hours a maximum magnetization of 59.1 emu/g for 925°C was obtained. Using the microemulsion method a fine precursor formed by iron and barium hidroxides and carbonates was obtained. For calcination temperatures higher than 760°C this precursor transforms into barium ferrite. Calcining the precursor during 12 hours a maximum magnetization of 60.5 emu/g for 925°C was obtained. For the barium ferrite obtained by microemulsion the intrinsic coercitivity was 20% lower than the intrinsic coercitivity of the barium ferrite obtained by chemical coprecipitation. This lower intrinsic coercivity should favor the microemulsion method for producing barium ferrite particles used as perpendicular magnetic recording medium.