Dual Ca-Zn substituted strontium hexaferrite; investigation of structural, magnetic and optical properties

In this work, the Sr1-xCaxFe12-yZnyO19 (x = 0, 0.05, 0.1, 0.15; y = 0, 0.25, 0.5, 0.75) hexaferrite were prepared employing the sol-gel combustion method and their structural, magnetic and optical properties were investigated. The formation of the hexaferrite phase was confirmed in all the samples using the X-ray diffraction and Fourier transform-infrared spectroscopy measurements. The field emission scanning electron microscopy images revealed agglomerated particles with rod-like shapes. A vibrating sample magnetometer was used to record the hysteresis loop at room temperature. The results obtained showed a drop in the saturation magnetization from 47.14 to 21.02 emu/g upon an increase in the substitution concentration and an increase in the coercivity from 5520 Oe to 5645 Oe. The bandgap energy values were obtained using the reflectance spectra; they increased from 1.59 eV to 1.72 eV with an increase in the substitution contents.