Synergistic influence of barium hexaferrite nanoparticles for enhancing the EMI shielding performance of GNP/epoxy nanocomposites

Abstract

In this work, the electromagnetic interference (EMI) shielding performance of epoxy composites containing barium hexaferrite (BaM) nanoparticles and graphene nanoplatelets (GNP) over the X-band frequency range of 8–12.4 GHz is presented. The BaM nanoparticles having a platelike morphology were synthesized using a co-precipitation technique and characterized using XRD and SEM. A set of epoxy nanocomposites with varying content of GNP and/or BaM nanoparticles were prepared and characterized for their electrical, magnetic, dielectric, and EMI shielding properties. An electrical percolation threshold value of 4.21 wt% GNP was determined for composites containing 8 wt% BaM, suggesting efficient network formation of GNP in the presence of BaM nanoparticles. The permeability and permittivity results suggest higher dielectric and magnetic loss capability in the composites containing both nanoparticles. Furthermore, the composites containing both BaM and GNP exhibited significantly greater EMI shielding effectiveness (SE) values as compared to those containing equivalent loading of either GNP or BaM, which suggests synergy between these nanoparticles. The one-millimeter thick composite sample containing 8 wt% BaM and 10 wt% GNP exhibited an EMI SE value of 17.2 dB in the X-band frequency range, which equates to attenuation of 98.17% of incident wave power.