Improvement of the microwave absorption properties in FeNi/PANI nanocomposites fabricated with different structures

FeNi/PANI nanocomposites were successfully synthesized via different routes, including in-situ polymerization, multilayer structure, and physical blending route. Various electromagnetic (EM) wave absorption behaviors were observed by varying the fabrication processes. Compared to pure FeNi nanoparticles, FeNi/PANI nanocomposites demonstrated a reduced saturation magnetization (Ms). The maximum reflection loss value of ‒ 43 dB at about 8.3 GHz was observed in FeNi/PANI nanocomposite (FeNi:PANI = 1:1) synthesized by physical blend route. The excellent EM wave absorption in this sample can be resulted from a higher dielectric loss as well as the efficient complementarity between relative permittivity and permeability. Strong fluctuations were found in the permittivity and permeability of the nanocomposites with ratios of FeNi:PANI to 1:2 and 2:1. Meanwhile, the minimum Ms and reflection loss values were observed in the nanocomposite synthesized by in-situ polymerization, probably due to the corrosion of the magnetic alloy in the used acid.