Enhanced microwave absorption properties of facile synthesized FeNi3 and FeNi3-C60 nanoparticles

FeNi3 nanoparticles were synthesized using chemical reduction, with FeCl2.4H2O and NiCl2.6H2O as starting materials, and N2H4.H2O as the reduction agent. FeNi3-C60 core shells were subsequently prepared through hydrothermal process on a mixture of C60 and FeNi3 nanoparticles. The mean crystallite sizes of both FeNi3 and FeNi3-C60, calculated from Scherrer’s formula, were 17 and 29 nm, respectively with most of the relatively spherical formed FeNi3-C60 grains ranging in size from 200 to 350 nm. The vibrating sample magnetometry confirmed ferromagnetism in both produced nanoparticles, with saturation magnetizations (MS) and coercive force (HC), 110.1 emu g−1, 79.3 Oe and 95.2 emu g−1, 70.0 Oe for FeNi3 and FeNi3-C60, respectively. The lowest reflection losses (RL) were achieved − 47.9 dB at peak frequency (({mathrm{f}}_{mathrm{m}})) 4.1 GHz with a matching thickness (({mathrm{d}}_{mathrm{m}})) of 3.7 mm for FeNi3 and − 39.7 dB at peak frequency (({mathrm{f}}_{mathrm{m}})) 2.2 GHz with a matching thickness (({mathrm{d}}_{mathrm{m}})) of 6 mm for FeNi3-C60. Due to their small specimen thicknesses and wide effective absorption bandwidth (below − 10 dB) in the Ku (12.4–18.0 GHz) band, both samples are excellent for designing lightweight EM wave absorbers with broadband capabilities. Additionally, these nanoparticles, especially FeNi3-C60, can filter specific localized frequencies in the L (1.0–2.0 GHz) and S (2.0–4.0 GHz) bands.