Synthesis and Microwave Absorption Properties of Fe3O4/CuS Composites

A two‐step hydrothermal method is used to produce Fe3O4/CuS composites with a distinct layered structure of CuS. The composition, magnetism, and absorbing properties of the different proportions of Fe3O4/CuS composites are characterized. The results show that Fe3O4 absorbs electromagnetic waves through orientation polarization and magnetically related natural resonance and that high conductivity enhances CuS microwave absorption. Compared with single‐phase Fe3O4 and CuS, Fe3O4/CuS composites exhibit superior microwave absorption performance with a considerably reduced matching thickness and increased effective absorption bandwidth in the 1–18 GHz range, which can be attributed to the interfacial coupling‐induced polarization between heterostructure Fe3O4 and CuS. Based on these results, Fe3O4/CuS composites can be absorbers with a far wider microwave‐effective absorption bandwidth. Compared with single‐phase Fe3O4 and CuS, Fe3O4/CuS composites exhibit superior microwave absorption performance, which can be attributed to the interfacial coupling‐induced polarization between Fe3O4 and CuS. At a ratio of Fe3O4 and CuS of 7:3, its reflection loss (RL) at 1.75 mm thickness is −34.75 dB and the effective absorption bandwidth increases to 3.57 GHz (9.92–13.49 GHz).