Flexible CoFe ₂ O ₄ /MXene-Derived CoFe/Fe ₃ O ₄ /TiO ₂ Electromagnetic Wave Absorbers Embedded in PDMS with Robust Performance Stability

Advances in wearable and foldable electronics urge the development of ultrathin electromagnetic wave absorbers with simultaneous strong absorption and performance stability. Herein, CoFe/Fe 3 O 4 /TiO 2 composites have been derived from CoFe 2 O 4 /MXene, for which not only chemically stable TiO 2 maintains the layered structure for enhanced wave-absorber interactions, the introduced CoFe/Fe 3 O 4 also results in magnetic and dielectric synergy for improved impedance matching and attenuation. Such an absorber dispersed in the PDMS matrix allows both flexibility and exceptional performance (strong minimum reflection loss of −62.28 dB with an effective bandwidth of 4.65 GHz at a small thickness of 1.2 mm) and stability after multiple compressions. Simulations confirm the absorption efficiency with maintained RCS values of around 30 dB·m 2 achieved after cyclic deformations. As such, this work provides insights on synergistic magnetic and dielectric effects and the design of advanced electromagnetic wave absorbers for flexible electronics.