Engineering flaky carbonyl iron/MoS2 composites with tuned and broadband absorption towards low-frequency electromagnetic waves

Abstract

The contemporary frequency spectrum utilized by wireless devices predominantly resides in the L–C bands, thus addressing electromagnetic wave (EMW) pollution within these ranges has emerged as a critical research challenge. In this study, flaky carbonyl iron powder/molybdenum disulfide (FCIP/MoS₂) composites were synthesized through a combination of hydrothermal and ball milling techniques. The introduction of MoS₂ not only optimizes the impedance matching of the samples to a great extent, but also allows the composite to adjust its EMW absorption from the X-band to the L-band with only a slight adjustment of the MoS₂ content. Particularly, the optimized FCIP/MoS₂ composites demonstrated an impressive minimum reflection loss (RL_min) of −54.86 dB at a thickness of 3.09 mm with the absorption bandwidth spanning 55.5% of the S-band. Furthermore, the underlying mechanism of the enhanced and modulated wave absorption performance was elucidated. Theoretical simulations revealed that the maximum radar scattering cross-section (RCS) value of the composite can be reduced by approximately 29 dB m², revealing exceptional wave absorption performance. This investigation presents a novel approach to the preparation of highly efficient tunable EMW absorbers which may find great potential in 5G technology, new energy vehicles as well as military applications.