Optimized electromagnetic wave absorption of Ag/Fe3O4/SiO2 via magnetic field-induced synthesis

This study reports on the synthesis and electromagnetic wave-absorbing properties of Ag/Fe 3 O 4 /SiO 2 under various magnetic field intensities. The nanocomposites were prepared via a solvothermal method followed by a Stober proces, during which uniform magnetic fields were applied to induce the formation of one-dimensional nanochain structures. Results indicate that the Ag/Fe 3 O 4 /SiO 2 exhibit enhanced wave-absorbing capabilities under strong magnetic fields. Specifically, at a magnetic field of 600 mT, the composite achieves a minimum reflection loss value of −48.61 dB, accompanied by a broad effective absorption bandwidth. Furthermore, the microwave absorption performance of samples oriented horizontally along the circumference surface during preparation shows a significant improvement compared to non-oriented samples. It is attributed to the optimized electromagnetic wave transmission pathways and improved electrical conductivity and magnetic loss capabilities facilitated by the nanochain structures. Specifically, the nanochains effectively lengthen the wave propagation distance, promote charge migration, and intensify natural and exchange resonance effects. This research not only broadens the design paradigm for electromagnetic wave-absorbing materials but also offers novel strategies for their development.