Magnetic and microwave absorption properties of FeNi3/NiFe2O4 composites synthesized by solution combustion method

Abstract

FeNi3/NiFe2O4 composites were prepared by solution combustion synthesis method. The solution combustion process was conducted in a closed system by use of conventional and microwave heating. Phase evolution, microstructure, magnetic and microwave absorption properties were studied by X-ray diffraction, electron microscopy, vibrating sample magnetometry and vector network analyzer techniques. The amount of FeNi3 phase was tuned by heating mode and amount of nickel precursor. The composites with higher amounts of FeNi3 phase and larger sintered particles (0.4–0.8 μm) were synthesized by microwave heating. The highest value of saturation magnetization (81 emu/g) was attained in the NiFe2O4-45 wt % FeNi3 composite. The FeNi3/NiFe2O4 composites had the high permeability due to the high saturation magnetization. The composites synthesized by conventional heating showed the maximum reflection loss of −15 dB in Ku band (12–18 GHz) with the band width of 3.8 GHz.