Microstructure and Magnetic Properties of Anisotropic Strontium Hexaferrite Powders

Anisotropic strontium hexaferrite powders were prepared by solid-state method with subsequent magnetic field alignment and annealing. The microstructure of the powders was investigated using X-ray diffraction and scanning electron microscopy to understand the effect of the process on magnetic properties, magnetic texture, particle size, and morphology of the powders. The magnetic properties were measured using a vibrating sample magnetometer. A high coercivity ( H_{\mathrm {c}} ) of 502 kA/m, hysteresis squareness ( M_{\mathrm {r}}/M_{\mathrm {s}}) of 96%, and maximum energy product [( BH ) max ] of 32.2 kJ/m 3 were obtained in the powders prepared via magnetic field (800 kA/m) alignment and annealing. The high M_{\mathrm {r}}/M_{\mathrm {s}} and H_{\mathrm {c}} obtained in the powders were correlated with the magnetic texture, and defect free fine particles present in the powder.