Microwave-assisted preparation of magnetic ternary core-shell nanofiller (CoFe_2O_4/rGO/SiO_2) and their epoxy nanocomposite for microwave absorption properties

摘要

A novel type microwave absorbing ternary core-shell nanofiller (CoFe_2O_4/rGO/SiO_2) was prepared in-situ via microwave synthesizer. The prepared ternary core-shell nanofiller was incorporated in the epoxy matrix with the weight percentages of 45, 55 and 60 wt% to form coaxial toroidal shaped nanocomposites. The morphology, crystallite structure, thermal and magnetic properties were analyzed by FESEM, TEM, XRD, TGA, DSC and VSM respectively. Agilent E8364B vector network analyzer was used to compute the complex permittivity and complex permeability of the nanocomposites at 2-8 GHz. The computed ε_r and μ_r of nanocomposites were employed for the calculation of reflection loss (RL) of nanocomposites with varying thickness. The minimum RL was observed as -24.8 dB at 5.8 GHz frequency for the absorber with a thickness of 2.0 mm and 60 wt% loading. Based on the above results these nanocomposites may have potential application as excellent microwave absorbers in 2-8 GHz frequency region.