Sr1-xCexFe12O19 and Sr1-xCexFe12-yO19-δ (x = 0 ∼ 0.2, y = 0 ∼ 2) powders were synthesized by sol-gel auto-combustion method, and the effect on the structure and magnetic properties of changes in doping concentration and iron content has been investigated. XRD results confirmed the formation of M phase and impurities of CeO2 and Fe2O3. The SEM results show that cerium doping leads to a decrease in grain size. For Sr1-xCexFe12O19, the saturation magnetization increases to 77.73 emu/g first and then decreases with the increase of cerium doping. More importantly, our study also found that as the Ce doping concentration and iron content change, the interaction between the two changes differently. This interaction will have different effects on the occupancy of iron ions at spin-up and spin-down sites, ultimately leading to a significant characteristic change in magnetic properties. For Sr1-xCexFe12-yO19-δ, with the iron content decreases, the magnetic properties continue to decrease at x = 0.03, increase first and then decrease at x = 0.1, and keep improving at x = 0.2. It is of reference significance to change the magnetic properties of strontium ferrites by adjusting the relationship between rare earth doping concentration and iron content.
