Experimental results and analysis of Yb-Co doped strontium ferrites prepared by the coprecipitation

M-type strontium ferrites Sr1-xYbxFe12-xCoxO19 (x = 0, 0.05, 0.1, 0.15, 0.2) were co-doped with equivalent Yb-Co ions by the co-precipitation method. When the doping amount was 0 <= x <= 0.1, the synthesized products shown a single phase M-type strontium ferrite. When x > 0.1, the phase of alpha-Fe2O3 and CoFe2O4 appeared in the sample, and the most of grains were the six angle flake structure. When x = 0.1, the saturation magnetization (Ms), the remanent magnetization (Mr) and the coercive force (Hc) of strontium ferrites Sr0.9Yb0.1Fe11.9Co0.1O19 reached to the maximum values of 60.89 emu/g, 31.96 emu/g and 6846 Oe, respectively.