Magnetic properties of La–Co substituted M-type strontium hexaferrites prepared by polymerizable complex method

Magnetic properties of La–Co substituted M-type strontium hexaferrites were studied. The samples were prepared by polymerizable complex method. Crystal structure of samples has been investigated by powder X-ray diffraction (XRD). Single-phase M-type strontium hexaferrites with chemical composition of Sr1.05−xLaxFe12−xCoxO19 (x=0–0.4) were formed by heating at 1173 K for 24 h in air. Magnetic properties were discussed by measurements of M–H curves with vibrating sample magnetometer (VSM). La–Co substituted M-type strontium hexaferrites prepared by polymerizable complex method showed typical magnetic hysteresis of hard ferrite. The coercive force increased significantly by La–Co substitution with polymerizable complex method. Maximum coercive force achieved in this study is 8.0 kOe (640 kA/m). Scanning electron microscopy revealed that the prepared ferrite particles have plate-like shape of diameter range between 20 and 500 nm.