Structural, magnetic, and dielectric properties of Sr1-xCaxFe12-ySmyO19 (x=0.00-0.20, y=0.00-0.05) hexaferrite

Microstructural, magnetic, and dielectric properties of pure-phase Sr1 - xCaxFe12-ySmyO19 (x = 0.00-0.20, y = 0.00-0.05) hexaferrites prepared by auto-combustion of a sol-gel were investigated by several techniques, such as X-ray diffraction, field-emission electron microscopy, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometer. Structural analysis indicated that Sr1 - xCaxFe12 - ySmyO19 has been indexed in hexagonal structure with space group P6(3)/mmc. Magnetic investigations showed that the Ca-Sm co-substitution could increase saturation magnetization and coercive field from 5069.8 Oe and 79.25 emu/g for pure sample to 5495.5 Oe and 83.09 emu/g, respectively. The structural and magnetic results suggest that that the Sm3+ ions occupy the 4f(2) sites (spin down). The results of impedance analysis indicated that the decrease in the mobility of charge carriers in the samples with x,y = 0.08,0.02 that can be attributed to a larger number of defects commonly would block the movement of carriers. Overall, the Ca-Sm-co-substituted strontium hexaferrites could be a promising composition to enhance the coercive force with a slight increase in saturation magnetization of Sr hexaferrites which are likely to be useful in a series of practical applications, such as permanent magnets, microwave devices, and absorbers of electromagnetic radiation.