Adjustable microwave absorption properties of flake shaped (Ni0.5Zn0.5)Fe2O4/Co nanocomposites with stress induced orientation

Flake shaped (Ni0.5Zn0.5)Fe2O4/Co nanocomposites were successfully fabricated by co-precipitating of Ni-Zn ferrite on the surface of cobalt nanoflakes. The electromagnetic characteristics of the samples were studied at the frequency of 0.1–14 GHz. The results showed that the cobalt nanoflakes in compacted nanocomposites were well orientated, and the nanocomposites were characterized with low optimal reflection loss (RL) of −33.8 dB at 11.5 GHz and broad RL bandwidth for <−20 dB in the frequency range of 7.6–12.1 GHz. At the same time, the position of the absorptive band can be adjusted by changing the mass ratio of ferrite to cobalt in the nanocomposites. It is proposed that the excellent microwave absorption properties are related to the combination of strong shape anisotropy of cobalt nanoflakes and adjustable dielectric loss.

► In this paper, we combined the flake shaped cobalt nanopaticles and Ni-Zn ferrte and studied the microwave absorption properties.
► The strong shape anisotropy was observed in the nanocomposites which contributes to the magnetic loss.
► The Ni-Zn ferrite coatings play a role of adjusting the center of absorption band.