In-situ fabrication of Fe@ZrO2 nanochains for the heat-resistant electromagnetic wave absorber

Abstract

Novel microwave absorber of Fe@ZrO2 nanocapsules chains has been fabricated by the one-step process of arc discharge plasma. The Fe@ZrO2 nanochains exhibit a saturation magnetization (Ms) of 188 emu/g and a coercivity of 253 Oe. It is found that the high dielectric ZrO2 shell (εr ≈ 14 in bulk) has less interference on intrinsic magnetism of the Fe core, which favors to build up a strong magnetic/dielectric coupling within the core@shell type Fe@ZrO2 nanocapsules. The Fe@ZrO2 nanochains are stable up to ∼437 °C in the air, implying its higher anti-oxidization ability in a severe environment. The minimum reflection loss (RL) value of Fe@ZrO2 nanochains reaches to −45.36 dB in a thickness of 3 mm, and the frequency band covers 10.0–18.0 GHz with RLs less than −10 dB in a thickness of 1.5 mm. The excellent microwave absorption ability is attributed to the high magnetic/dielectric losses from multi-resonances and interfacial polarization, as well a proper matching between electromagnetic phases. This work may provide inspiration and insight into the combination of highly stable ceramics and metallic components within an encapsulated nanostructure. Also, it would be an effective route for designing and exploiting novel high-temperature microwave absorbers.