Enhanced microwave absorption and improved broadband with synergistic effect of nest like self-assembly of CoFe2O4/Co3O4 heterostructured composites

The effectiveness of augmenting electromagnetic wave absorption (EWA) can be achieved by the optimization of components and regulation of micromorphology. One approach to make this improvement is by harnessing the polarization that results from heterogeneous interfaces. Here, CoFe2O4/Co3O4 composites were synthesized via a simple sol-gel self-combustion propagation method. By carefully altering the amount of citric acid (CA) used in the synthesis process, composites with CoFe2O4 nanoparticles and Co3O4 nanorods were synthesized. The electromagnetic (EM) characteristics were investigated using a vector network analyzer (VNA), which demonstrated a trend of EWA, initially increasing and then falling when the CA content was increased. The composite's EWA properties exhibit a pattern of initially rising and then falling as the CA content increases. Remarkably, when mass ratio of CA is 1.0, the reflection loss (RLmin) reaches a low value of -54.47 dB, and the effective absorption bandwidth (EAB) extends to 6.00 GHz with a thin thickness of 1.3 mm. The exceptional results are due to synergistic effects, encompassing increased polarization loss, conductive loss, and better impedance matching. This study introduces a novel approach to synthesize ferrites-based composites, showing their potential as exceptional materials for applications in EWA.