Influence on Microstructure and Magnetic Performance of Co-doped Mg Ferrites by Low Temperature Sintering

This work investigated the effect of Co²⁺ ions substitution on microstructure and magnetic properties of Mg_1−xCo_xFe₂O₄ (x = 0.0, 0.2, 0.4, 0.6, and 0.8) bulk ferrites, which was successfully synthesized by low temperature (960 °C) with 5 wt.% Bi₂O₃. XRD analysis confirmed that the samples have spinel cubic \({\text{Fd}}\overline{3}{\text{m}}\) $\text{Fd}\overline{3}\text{m}$ space group and lattice parameter increase linearly with Co²⁺ content. The SEM results indicate that the grains of samples are highly agglomerated relatively uniform from 2 to 2.3 μm. Meanwhile, the experimental density (ρ_E) of samples increases from 4.35 to 4.65 g/cm³ with the increase of Co²⁺ content and relative density (ρ_R) of all samples reach 90%. VSM test results demonstrate that the saturation magnetization (Ms) increases from 25 to 68 emu/g, and the value of coercivity (Hc) increases from 3 to 373 Oe. This work provides a reference for ferrite sintered by low temperature solid-state method, making the preparation process more low-carbon and environmentally friendly.