Investigation of K_u band microwave absorption of three-layer BaFe₁₂O₁₉, carbon-fiber@Fe₃O₄, and graphene@BaFe₁₂O₁₉@Fe₃O₄ composite

This paper reported the microwave absorption properties of BaFe₁₂O₁₉, carbon-fiber@Fe₃O₄ composite, and graphene@BaFe₁₂O₁₉@Fe₃O₄ composite. The prepared samples showed no impurity or any secondary phase during the XRD analysis. The morphology of the samples has indicated the successful arrangement of the Fe₃O₄ nanoparticles on the carbon fiber, which created pores thereby enhancing the absorption of microwaves. Similarly, the BaFe₁₂O₁₉ and Fe₃O₄ were also efficiently decorated on the surface of the graphene sheets. The presence of non-magnetic carbon fiber and graphene causes a significant reduction in coercivity while maintaining reasonable saturation and remnant magnetization, thereby improving the microwave absorption capability of the prepared composites. The B/C/A combination with 5 wt% filler loading offers better microwave absorption capabilities in all thickness variations with RL_max having value greater than −10 dB. Additionally, an increase in filler loading to 15 wt% for the B/C/A combination resulted in an increase in RL_max to −40 dB. The studies have demonstrated the synergic effect of the various components of the composites for efficient tuning of microwave absorption capabilities and the possibility of using the B/C/A combination for technological application.