Absorption properties of CNF mixed cobalt nickel ferrite nanocomposite for radar and stealth applications

For the first time, the cobalt doped nickel ferrite/carbon nano-fiber based nanocomposites are synthesized for radar and stealth applications. Initially, the Co_xNi_1−xFe₂O₄ with x = 0.0–0.4, nanoparticles are synthesized and then dispersed in the epoxy matrix to investigate their microwave absorption properties. Among all the synthesized nanocomposites, the Co_xNi_1−xFe₂O₄, x = 0.4 (55 wt% epoxy) nanocomposite exhibits maximum −10 dB absorption bandwidth of 1.4 GHz only for 10.3 mm thick sample. The synthesized nanocomposite is not suitable to be used for aforementioned application due to high thickness and low absorption bandwidth. To overcome this problem, carbon nanofiber (CNF ~ 1, 2 and 3 wt% epoxy) is added to the earlier synthesized ferrite epoxy system. The nanocomposite sample consisting of Co_xNi_1−xFe₂O₄, x = 0.4 (55 wt% epoxy) and CNF (2 wt% epoxy) shows enhanced absorption bandwidth of 3.23 GHz at a very low thickness of 1.6 mm. The addition of CNF into the ferrite system thus substantially enhanced the microwave absorption properties of the resultant nanocomposite, suitable for the radar and stealth applications.