Facile synthesis and enhanced microwave absorption properties of multiferroic Ni0.4Co0.2Zn0.4Fe2O4/BaTiO3 composite fibers

Multiferroic composite fibers composed of Ni0.4Co0.2Zn0.4Fe2O4 (NCZFO) spinel ferrite and BaTiO3 (BTO) have been successfully synthesized by a simple electrospinning and subsequent heat treatment. The effects of the BTO content on the structure, static magnetic performance, electromagnetic and microwave absorption properties of the as-prepared samples are thoroughly investigated. The electromagnetic parameters and microwave absorption performances can be readily and effectively tuned through controlling the molar ratio of the two phases. The sample of NCZFO/(40 mol%)BTO fibers shows the enhanced complex permittivity making it better in microwave absorption capability than the composite fibers with other compositions and the mixture of NCZFO fibers and BTO fibers. The microwave absorption values less than −10 dB can cover the entire 2-18 GHz frequency range over the absorber thickness of 2-7.5 mm, and the minimum reflection loss value reaches −65.6 dB at 15.7 GHz with a broad effective absorption bandwidth below −10 dB of 7.8 GHz ranging from 2.6 to 6.8 GHz and 13.7 to 17.3 GHz for a layer thickness of 5 mm. The enhanced absorbing ability for the optimal NCZFO/(40 mol%)BTO fibers arises from the good synergistic effect between magnetic and dielectric components within the quasi-one-dimensional space, the improved interfacial effect as well as the proper electromagnetic impedance matching.