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 (M s). 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 M s and reflection loss