Improved broadband electromagnetic interference shielding and strain sensing properties of multifunctional reduced graphene oxide/iron–cobalt ferrite composites

Herein we report, an enhanced dielectric and electromagnetic shielding interference (EMI) shielding properties of reduced graphene oxide (rGO) doped with iron–cobalt (Fe–Co–O4) ferrite composites in broadband microwave frequencies (GHz) as well as strain sensors. The surface morphology, particle size, structures, and optical absorption properties were characterized different analytical techniques, such as scanning electron microscopy (SEM), X-ray diffraction, and UV–Visible spectroscopy methods. The synthesized ferrite nanoparticles (NPs) were used to study the dielectric, magnetic, EMI shielding in broadband frequencies, and strain sensing applications. The doping of rGO into Fe–Co–O4 lead to the formation of superior conducting grains and enhances the dielectric, magnetic, and EMI shielding properties of the ferrite composites. Amongst different samples prepared, rGO-doped Fe–Co–O4 ferrites with thickness 0.5 mm exhibit superior absorption-dominated EM shielding features with shielding efficiency of − 24.16 dB (which is equal to 99.50% of absorption) in the broadband microwave frequency regime. Furthermore, the prepared rGO-doped Fe–Co–O4 ferrite composite shows the excellent long-term stability in terms of EMI shielding efficiency under the variable mechanical strains. In addition to the good level of the shielding efficiency, this rGO-doped Fe–Co–O4 composite relays superior mechanical strain sensing response. Due to excellent properties, such as light weight, mechanically robust, enhanced EMI-SE, and excellent level of strain sensing behaviour, these ferrites-based composites could be employed as a covering layer in next-generation folding and wearable electronic gadgets for potential broadband shielding and mechanical strain sensors.