Study on Large-Scale Spatial Dynamic Absorption of Fe₃O₄@SiO₂ Shell–Core and Nano-Fe₃O₄ Magnetic Particles

Research on the dynamic wave absorption of particles dispersed in a large-scale space has an important practical value in the military field. In this study, Fe3O4@SiO2 magnetic core–shell composite particles and nano-ferroferric oxide particles obtained by improving the carbonyl iron in two ways are dispersed in a large-scale space of 3 m and their dynamic absorbing characteristics are studied. First, simulation showed the relationship between the concentration of Fe3O4@SiO2 magnetic core–shell composite particles and nano-Fe3O4 particles dispersed in large-scale space with time. Then, we combine the strong disturbance equivalent theory to derive its dynamic equivalent electromagnetic parameters εeff′ and μeff′. Second, simulation calculated the electromagnetic loss of Fe3O4@SiO2 magnetic core–shell composite particles at a frequency of 2–18 GHz to be 1.00–39.92 W and the electromagnetic loss of nano-Fe3O4 particles to be 0.40–11.59 W. Finally, we further analyze the absorption loss mechanism of Fe3O4@SiO2 core–shell and Fe3O4 nanoparticles.