Effect of Sn4+–Co2+ co-substitution on structural and magnetic properties of SrFe12-2xSnxCoxO19 M–type strontium ferrite

With the continuous improvement of the performance of M–type ferrite, it has been paid more attention to and become more and more popular, and it has been applied to social production and development. For improving the magnetic properties of ferrite, the most common method used by researchers is ion replacement. This method of improving magnetic properties is the mainstream of research. In this study, SrFe12-2xSnxCoxO19 (x = 0, 0.05, 0.1, 0.15, 0.2) strontium ferrite with Sn4+ and Co2+ co-substitution was prepared using ceramic technology. The influence of Sn4+ and Co2+ co-substitution on the structure and magnetism of strontium ferrite were analyzed. X-ray diffraction analysis shows that as the substitution amount of Sn4+ and Co2+ ions increased, the main structure of strontium ferrite remained hexagonal. The morphology of the samples was analyzed by scanning electron microscope, and the results showed that the morphology of ferrite was mainly hexagonal strontium ferrite. Magnetic property show that the remanence (Br), coercivity (Hcj) and saturation magnetization (Ms) of the sample first increased and then decreased with the Sn4+- Co2+ ions increase of doping amount. When the substitution amount x = 0.15, the Ms reaches its maximum value of 83.8 emu/g, the Br reaches its maximum value of 405.4 mT. And when the substitution amount x = 0.05, Hcj reaches its maximum value of 312.5 kA·m−1.