Effect of Mg2+ on Enhancing Stabilization and Microwave Absorption Performance of MgxFe3−xO4

Magnetite (Fe3O4) is an essential material for enhancing microwave absorption performance and is widespread and abundant as a solid solution in natural minerals and metallurgical slags. In this work, the effect of Mg2+ on the structure, stabilization, and microwave absorption performance of magnesium-containing magnetite (MgxFe3−xO4) was investigated. On the basis of experiments on the reactions of Fe2O3 and MgO under different levels of pCO/(pCO + pCO2), MgxFe3−xO4 (x=0.0,0.2,0.4,0.6,1.0) was synthesized, and Mg2+ was found to inhibit the re-oxidation of magnetite. On this basis, the microwave absorption performance of various synthesized MgxFe3−xO4 samples was measured and analyzed, where Mg2+ was found to enhance the microwave absorption performance of Fe3O4, and the RLmin value of Mg0.2Fe2.8O4 increased to −50.43 dB compared to that of −19.20 dB for Fe3O4. Furthermore, the enhancement mechanism of Mg2+ was revealed through impedance matching, dielectric and magnetic loss tangents, and magnetization curves, where the Mg2+ ions were found to accelerate the hopping of electrons and change the impedance matching of MgxFe3−xO4 to a more ideal state.