Ultrathin and high-performance electromagnetic wave absorbers enabled by phase-engineered FeSiAl@1T/2H MoS ₂ interfaces

With society progressing toward intelligent systems and the escalating challenges of electromagnetic radiation, the demand for advanced electromagnetic wave (EMW)-absorbing materials has intensified. The prevalent methodology combines magnetic components with dielectric matrices to harness interfacial synergy, enabling concurrent optimization of impedance matching and enhancement in functionality. With better understanding of absorption mechanisms, there has been an increase in microscopic studies. Herein, we demonstrate a hydrothermal route for synthesizing mixed-phase molybdenum disulfide (MoS₂-1T/2H) composites with magnetic FeSiAl particles, forming a core-shell FeSiAl@1T/2H MoS₂ architecture containing 61% metastable 1T phase. This design leverages the phase-dependent electronic contrast between metallic 1T and semiconducting 2H phases of MoS₂. Phase-engineering strategies enable the adjustment of conductive loss and the creation of heterogeneous interfaces, broadening the loss mechanisms and enhancing impedance matching (Z). Achieving an optimal balance between dielectric loss and Z is crucial for improving EMW absorption (EMWA) performance. The material exhibited a minimum reflection loss (RL_min) of -65.6 dB at 1.77 mm and a maximum effective absorption bandwidth (EAB_max) of 5.57 GHz at 1.91 mm, offering significant insights into the development of ultra-thin, high-efficiency EMW absorbers. Radar cross-section (RCS) simulations with CST Studio Suite confirmed a 34.0 dB m² reduction for flat model at 15.81 GHz, providing foundational guidelines for multifrequency adaptive EMWA material engineering.