Fabrication of a highly efficient multilayer microwaves insulator based on CuFe2O4/(Pb1−xLax)/(Zr1−yTiy)O3 (composite: 7/60/40) (0 ≤ x, y ≤ 1) and Cu-doped g-C3N4 nanograins

Abstract

Nowadays, microwave pollution is a major concern around the world. Therefore, the construction of multilayer microwave absorbers with low thickness and wide bandwidth has been investigated. A novel multilayer broadband microwave insulator with high performance containing fillers comprised of copper ferrite spinel (CuFe2O4) nanograins (NGs), lead zirconium titanate ceramic (Pb1−xLax)(Zr1−yTiy)O3 (composite: 7/60/40) (0≤x,y ≤ 1) (PLZT) nanoparticles (NPs), and copper-doped carbon nitride graphitic (Cu-doped g-C3N4) nanosheets (NS) based on epoxy resin has been successfully prepared. The crystal structure and morphology of synthesized nanograins were specified using XRD, SEM, and EDX/mapping analysis. In addition, the microwave absorption properties of the resulting multilayer microwave insulator were evaluated using a vector network analyzer (VSM) in the frequency range of 8–12 GHz. Response surface methodology (RSM) was applied to the design of experiments to reduce the experimental time and cost, and obtain the optimal conditions. The weight percentage (wt.%) of CuFe2O4 magnetic nanograins, (Pb1−xLax)(Zr1−yTiy)O3 (0 ≤ x,y ≤ 1) dielectric NGs, Cu-doped g-C3N4 electric conductivity nanosheets, and thickness of the designed insulators were optimized using the RSM method to attain a multilayer microwave insulator with the optimal microwaves absorption efficiency. The minimum reflection loss (maximum absorption efficiency) was determined to be < –30 dB (absorption >99.9%) for the optimized multilayer microwaves insulator under the conditions of 3.0 wt% CuFe2O4 magnetic nanoparticles, 5 wt% (Pb1−xLax)(Zr1−yTiy)O3 (0≤x,y ≤ 1) dielectric NGs, 1.0 wt% Cu-doped g-C3N4 electric conductive nanosheets with 1 mm thickness in the microwave frequency range of 8–12 GHz (X-band). The highest attenuation coefficient (>500 dB/m) showed that the microwaves energy was weakened. In addition, the minimum reflection coefficient (maximum transmission coefficient) was calculated to be ∼0.01 (RL = −35 dB, AL = 99.99%). Finally, the obtained results show that these factors and their levels were correctly selected for the fabrication of high-performance multilayer microwave insulators.