Novel magnetic silicate composite for lightweight and efficient electromagnetic wave absorption

A series of silicates with double shell hollow sphere morphology were prepared by hydrothermal method with ultra-high temperature calcined, and used in the field of electromagnetic (EM) wave absorption. By characterizing the chemical composition, crystal structure, micro morphology and EM parameters of the several materials, the evaluation results of EM wave absorption capacity of the materials were obtained. In the discussion section, we will discuss the reasons for the differences in EM wave absorption capabilities of the several silicates from multiple aspects such as EM wave absorption mechanism in detail. Especially for iron-based silicate (HGMs@Fe₂SiO₄) materials, after reasonable composition and morphology design, the minimum reflection loss (RL_min) reached up to −41.14 dB with a matching thickness (d) of 3.4 mm, and the corresponding effective absorption bandwidth (f_E, RL < −10 dB) was 6.80 GHz. Because of the wide EM wave absorption bandwidth, light weight and low water absorption, this kind of double shell silicate material has gained huge application potential in the EM wave absorption field.