Synthesis, oxidation resistance and microwave absorbing properties of FeCo-based heterostructures

摘要: Abstract The fabrication of a shell on the surfaces ferromagnetic particles has been proved to be an efficient approach tailoring and improving electromicrowave (EM) absorption. In this study, core–shell composites (FeCo@SiO2/TiO2, FeCo@SiO2@TiO2) were designed fabricated by facile hydrolysis reactions. these novel composites, combined effects characteristics each component result in excellent properties. FeCo core exhibits strong magnetic loss, SiO2/TiO2 not only acts as impedance matching medium, but also dielectric loss. Moreover, SiO2 TiO2 can efficiently limit direct contact between protect from oxidation at high temperature. FeCo@SiO2, FeCo@TiO2, FeCo@SiO2@TiO2 absorbers exhibit enhanced EM absorption, with maximum reflection losses (RLmax) −38.49, −36.53, −33.72 dB at thicknesses d 2, 5, 3 mm, respectively, compared −19.23 dB for single (d = 5 mm). improvement is due mainly improved multiple interfacial polarization. particular, after annealing 500 °C, RLmax values are −25.41, −24, −32.38 dB at 3, 5 mm, which much higher than that uncoated (−1.39 dB, d = 5 mm). These findings demonstrate FeCo-based structures good candidates use room- high-temperature absorbers.