SmFeO3@(x)polyaniline composites with porous structure for efficient microwave-absorbing application

[Display omitted] •Porous SmFeO3@(x)PA composites were obtained by two liquid-phase synthesis methods.•Heterogeneous interfaces of SmFeO3@(x)PA composites enlarged the propagation paths and enhanced microwave absorption.•The effective combination of multiple magnetic loss mechanisms achieved good impedance and attenuation matching.•The minimum RL reached −31.3 dB at 6.61 GHz. SmFeO3@(x)Polyaniline(PA) composites were successfully synthesized by sol–gel self-propagating combustion and in-situ oxidation polymerization. Different contents of PA had distinct effects on the electromagnetic parameters of SmFeO3@(x)PA composites. The addition of PA not only increased the values of real and imaginary parts of dielectric constant, but also adjusted the impedance matching of SmFeO3@(x)PA composites. The effects of 50 wt%, 70 wt%, 90 wt% PA contents on the microwave-absorption properties of SmFeO3@(x)PA composites were also investigated and discussed. Due to the porous structure of dielectric-magnetic-type SmFeO3@(x)PA composites and the formation of heterogeneous interfaces, the multiple reflection and scattering of electromagnetic-wave in the composites were conducive to enhance the microwave attenuation. In all samples, SmFeO3@(70 wt%)PA composites had the strongest absorption capacity, RLmin was −31.3 dB at 6.61 GHz. The work show that the porous structure of SmFeO3@(x)PA was the key to realize the high microwave-absorption performances.