Activating Basal Plane Inert Sites of Iron Telluride for Motivational Electromagnetic Microwave Absorption

Abstract The basal plane inert sites and inadequate intrinsic dielectric relaxation are the major bottlenecks limiting the electromagnetic microwave (EMW) absorption performance of transition metal tellurides (TMTs). Here, an effective dual defect model based on electron polarization relaxation is established on iron telluride (FeTe) flakes via one‐step O ₂ plasma treatment. Therefore, the basal plane inert sites of FeTe are activated by Te vacancies and O incorporation, which form abundant polarization centers, resulting in charge redistribution and increased dipole site density, thereby effectively optimizing dielectric relaxation loss. Consequently, the optimal EMW attenuation performance achieves a minimum reflection loss exceeding −69.6 dB at a thickness of 2.2 mm, with an absorption bandwidth of up to 4.9 GHz at a thickness of 1.3 mm. Besides, FeTe with dual defect exhibits a prominent radar cross‐section reduction of 42 dBsm, indicating excellent radar wave attenuation capability. This study illustrates an innovative model system for elucidating dielectric relaxation loss mechanisms and provides a feasible approach to developing high‐loss TMTs‐based absorbers.