Investigating the Effect of Changing the Nanostructure of the Core in the Core–Shell Assembly for High-Efficiency Electromagnetic Wave Absorbers

The magnetic-dielectric core–shell structure is considered to achieve high-performance electromagnetic absorption due to the ability to use a wide range of materials and different geometrics. In this work, the effects of various nanostructures of cores on the electromagnetic absorption behavior of magnetic-dielectric core–shell structures are investigated. Herein, a BaFe 12 O 19 @MoS 2 core–shell was synthesized by a hydrothermal method, and for preparing BaFe 12 O 19 as a core with two different geometrics, the hydrothermal and sol–gel methods are used. The minimum value of reflection loss (RL min ) for BaFe 12 O 19 @MoS 2, where the hexaferrite core is prepared as a nanostructure, is −53.36 at 13.1 GHz (Ku band), and the absorption bandwidth is 4.6 GHz (11.0–15.6 GHz) at a 2.0 mm thickness. Meanwhile, for BaFe 12 O 19 @MoS 2, in which the structure of its core is a nanostructure (a hexagonal plate-like structure), RL min is −41.71 at 5.1 GHz (C band), and the absorption bandwidth is 2.0 GHz (4.3–6.3 GHz) at 5.0 mm. However, in our research, by changing the size and geometry of the core nanostructures, a suitable reflection loss with an appropriate absorption bandwidth is obtained in C or Ku band frequencies.