In this study, Zn-doped Fe3O4 nanoparticles were successfully synthesized by a facile solvothermal method in the presence of sodium dodecyl sulfate (SDS). The morphology, magnetic properties and electromagnetic wave absorbing properties of these materials were characterized. Results showed that Zn[Formula: see text] played a significant role in the formation of Zn-doped Fe3O4. With the protection of SDS, highly dispersed Fe3O4 nanoparticles were obtained. The nanoparticle size decreased after Zn[Formula: see text] doping, and the dispersity deteriorated with increasing Zn[Formula: see text] doping concentration. Zn-doped Fe3O4 exhibited excellent electromagnetic wave absorbing property, which resulted in magnetic loss and dielectric loss at an appropriate doping concentration. The minimum reflection loss (RL) was approximately [Formula: see text][Formula: see text]dB at 16.9[Formula: see text]GHz. As the coating layer thickness increased to 4.0[Formula: see text]mm, the bandwidth was approximately 5.0[Formula: see text]GHz corresponding to RL below [Formula: see text][Formula: see text]dB, which nearly covered the entire S band (2–4[Formula: see text]GHz) and C band (4–8[Formula: see text]GHz). The peak frequency of RL and the number of peaks matched the quarter-wave thickness criteria. It was believed that the Zn-doped Fe3O4 could be a potential electromagnetic wave absorbing material in S and C bands.
