Synergistic Optimization of Microwave Absorption and Thermal Properties via Morphology Control in Tin Disulfide Coated FeCoCrNiAl Powders

ABSTRACT This study employed a FeCoCrNiAl high entropy alloy matrix to regulate the nucleation and growth of SnS 2 through solvent polarity, viscosity, and sulfur source release rates. Three distinct nanostructures including nanoribbons, nanoflowers, and nanosheets were synthesized and integrated onto a silicone rubber substrate. Comprehensive characterization using X‐ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM) confirmed the chemical states and soft magnetic properties of the core–shell structures. Density functional theory (DFT) analysis elucidates the interfacial electronic structure and loss pathways. Periodic frequency‐selective surface (FSS) patches were introduced to optimize impedance matching and specular reflection. The different morphologies were analyzed through electromagnetic parameters to investigate their distinct regulatory mechanisms on loss and impedance matching. Among these, the SnS 2 @HEA‐flake morphology exhibits optimal comprehensive performance, demonstrating an absorption peak with (RL) min < −30 dB at approximately 12.3 GHz. In thermal‐conduction tests, silicone rubber containing the SnS 2 @HEA‐flake powder exhibits a rise of 62.7°C within 8 s, exceeding two other morphologies. Following the introduction of FSS, the SnS 2 @HEA‐flake sample further extends the effective reflection loss coverage to nearly the entire X‐band, with the reflection coefficient being further reduced. This study achieves synergistic enhancement of thermal conductivity and broadband X‐band absorption through SnS 2 morphology regulation, providing novel design insights for integrating microwave absorption with thermal management.