## 3 Results and Discussion
Effect of Distribution of Ferrites/CNT Nanocomposites in an Epoxy Matrix on the Electromagnetic Wave Absorption Performance of (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/CNT-ER Systems  
Figure 4 illustrates the experimental results of measurements of the complex permittivity at 9 GHz for the systems (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/0.07 CNT (x = 0, 0.5, and 1) with the epoxy matrix. The incorporation of (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/0.07 CN nanocomposites into the epoxy resin results in an elevation of both \(\varepsilon^{\prime}\) and \(\varepsilon^{\prime\prime}\) for all examined amounts of filler. This effect can be explained by the existence of a polarisation mechanism--interfacial polarisation in multicomponent heterogeneous media. Namely, this effect occurs in heterojunction structures due to the accumulation of charges at the conductor/insulator interfaces. In our case, when forming polymer-filled composites based on epoxy resin, a boundary layer of polymer macromolecules with reduced mobility is formed on the surface of the filler [37], which hinders the relaxation processes and contributes to the formation of a dipole layer, which causes the occurrence of interfacial polarization With increasing filler concentration in polymer composites, an increase in the interfacial specific surface area on which the interaction of components occurs. As the interfacial surface increases, the contribution of interfacial polarization increases, thereby increasing the values of \(\varepsilon^{\prime}\). As the content of carbon nanotubes modified by substituted ferrite rises in the epoxy matrix a greater number conductive paths are formed, which leads to an increase in conduction losses and an increase in \(\varepsilon^{\prime\prime}\) values (Figure 4b). A nonlinear increase of \(\varepsilon^{\prime}\) and \(\varepsilon^{\prime\prime}\) values in these polymer nanocomposites with subsequent increase volume content of carbon nanotubes was found which is associated with the presence of a percolation transition (approximately 0.005-0.015 vol. fractions) and corresponds to its threshold. It was found that the system (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/0.07 CNT-ER (x = 0.5) is characterized by the highest values of \(\varepsilon^{\prime}\) and \(\varepsilon^{\prime\prime}\). The maximum values of the complex dielectric constant were confirmed for the (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/CNT-ER system, which is probably due to a change in the structure of ferrite clusters on the surface of carbon nanotubes in (NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/CNT nanocomposites. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample** & **x** & \(\mu^{\prime}\) & \(\mu^{\prime\prime}\) & \(\varepsilon^{\prime}\) & \(\varepsilon^{\prime\prime}\) & \(\sigma_{\sigma}\)**(Om**\(\cdot\)**cm)\({}^{-1}\) (100 Hz)** \\ \hline \multirow{4}{*}{(NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)} & 0 & 1.08 & 0.04 & 3.1 & 1.7 & 2 \(\times\) 10\({}^{-5}\) \\ \cline{2-7}  & 0.5 & 1.02 & 0.02 & 2.5 & 1.4 & 3 \(\times\) 10\({}^{-5}\) \\ \cline{2-7}  & 1 & 1.07 & 0.01 & 2.6 & 0.7 & 5 \(\times\) 10\({}^{-5}\) \\ \hline \multirow{4}{*}{(NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/0.05 CNT} & 0 & 1.06 & 0.02 & 2.8 & 2.2 & 4 \(\times\) 10\({}^{-3}\) \\ \cline{2-7}  & 0.5 & 1.04 & 0.04 & 3.1 & 2.1 & 6 \(\times\) 10\({}^{-3}\) \\ \cline{2-7}  & 1 & 1.02 & 0.02 & 5.0 & 5.3 & 2 \(\times\) 10\({}^{-2}\) \\ \hline \multirow{4}{*}{(NiZn)\({}_{1-\mathrm{x}}\)Mn\({}_{\mathrm{x}}\)Fe\({}_{2}\)O\({}_{4}\)/0.07 CNT} & 0 & 1.08 & 0.02 & 3.6 & 2.4 & 1 \(\times\) 10\({}^{-2}\) \\ \cline{2-7}  & 0.5 & 1.06 & 0.06 & 3.9 & 3.3 & 2 \(\times\) 10\({}^{-2}\) \\ \cline{1-1} \cline{2-7}  & 1 & 1.08 & 0.04 & 5.7 & 5.8 & 7 \(\times\) 10\({}^{-2}\) \\ \hline \hline \end{tabular}
\end{table}