Optimization of the magnetic properties and microstructure of Co2+-La3+ substituted strontium hexaferrite by varying the production parameters

The aim of this paper was to improve the magnetic properties of magnetoplumbite-type (M-type) strontium hexaferrite substituted with Co2+-La3+ produced by conventional ceramic forming techniques. The effect on the magnetic properties of varying the composition of the target compound Sr1−xLaxFe12−yCoyO19 and the primary and secondary firing temperatures was investigated. Microstructure studies and XRD phase analysis indicated that optimum values of the remanent magnetization Br and coercive field Hcj were obtained with a primary firing temperature of 1240 °C and a final firing temperature of 1180 °C, where (x=y)th1=0.15, (y/x)exp2=0.75 and the molar ratio of ferric oxide to strontium oxide=5.8. The optimized magnetic properties obtained under these conditions were Br=4070 Gs, Hcj=4710 Oe, (Hk/Hcj)=82.