Investigation of the optical, magnetic, and radar absorption characteristics of Co_xFe_3-xO₄/ZnO/graphite nanocomposites

In this study, we have successfully prepared Co_xFe_3-xO₄/ZnO/graphite nanocomposites [x = 0, 0.1, 0.2, 0.3, 0.4, 0.5] as radar-absorbing materials. The X-ray diffraction characterization results signified that the crystallite size of Co_xFe_3-xO₄ in the nanocomposites increased from 8.5 nm to 11 nm as x increased. However, the crystallite sizes of ZnO and graphite were constant at around 55.1 and 25.8 nm, respectively. The presence of such phases was also detected at the wavenumbers of 400–560, 678, and 1637 cm⁻¹, originating from M − O [M = Fe, Co], Zn–O, and C[dbnd]C bonds, respectively. The energy-dispersive X-ray spectra also showed the presence of Fe, Co, Zn, and C as constituents of the nanocomposites. The optical absorption of the nanocomposites was observed at a wavelength of 390 nm, showing bandgap values of 2.991–3.029 eV. The nanocomposites had superparamagnetic features, with magnetic saturation values between 12.78 and 25.27 emu/g, which decreased following the increase in x composition. Interestingly, the Co_xFe_3-xO₄/ZnO/graphite nanocomposites attained a maximum reflection loss of −32.26 dB at the frequency of 11.82 GHz. In general, the reflection loss increased following the increase in x composition. Therefore, the prepared Co_xFe_3-xO₄/ZnO/graphite nanocomposites can be a potential candidate as radar-absorbing materials with excellent performance.