## 3 Results
### Studying the Properties of Nanocomposites Using Physico-Chemical Research Methods
\begin{table}
\begin{tabular}{l l l l l l} \hline
**No** & **Name** & **Is, mm/c** & **Qs, mm/s** & **H, keV** & **S\({}_{\text{relatives}}\) \%** & **G, mm/s** \\ \hline
1-C & Fe\({}^{3+}\)\({}_{\text{octahedron}}\) & 0.4299 & \(-\)0.0044 & 408.93 & 11.98 & 0.7759 \\ \hline
2-C & Fe\({}^{3+}\)\({}_{\text{octahedron}}\) & 0.3909 & 0.0293 & 446.46 & 23.32 & 0.5719 \\ \hline
3-C & Fe\({}^{3+}\)\({}_{\text{tetrahedron}}\) & 0.2870 & 0.0280 & 486.82 & 21.45 & 0.5049 \\ \hline
4-D & Fe\({}^{3+}\)\({}_{\text{octahedron}}\) & 0.3555 & \(-\)0.0396 & 475.15 & 38.75 & 0.6014 \\ \hline
5-D & Doublet\({}_{\text{1}}\) & 0.0905 & 0.5371 & - & 4.50 & 0.7759 \\ \hline \end{tabular} Note: Is is the isomer shift, mm/s; Qs is the quadrupole splitting, mm/c; H is the magnetic field on the Fe nuclei, mm/c; S is the area of the component; and G is the width of the line, mm/s.  
\end{table} 
Table 3: Parameters of sextets and doublets of CoFe\({}_{2}\)O\({}_{4}\)/PVP. The Mossbauer spectra of the obtained magnetic composite CoFe\({}_{2}\)O\({}_{4}\)/PVP (Figure 2b, Table 3) showed the contents of trivalent iron ions in tetrahedral and octahedral environments, and also have a doublet spectrum. The parameters of this doublet included isomeric Is shift and quadrupole splitting. The decrease in effective fields can be explained by a decrease in the particle size of cobalt ferrite stabilized by PVP (particle diameter is less than 1000). The difference in the calculated magnetic composition is due to the fact that the magnetic composition is not constant. The decrease in the particle size is due to the fact that the magnetic composition is constant. than 16 nm). Surface stabilization leads to a decrease in the size of ferrite nanocrystallites in nanocomposites. IR spectra were obtained in the range from 500 to 4000 cm\({}^{-1}\). Figure 3 shows the IR spectra of the magnetic CoFe\({}_{2}\)O\({}_{4}\), CoFe\({}_{2}\)O\({}_{4}\)/PVP composite, and pure PVP for comparison. The detection of hydrocarbons by the method of the elemental analysis of composites [58] based on iron and cobalt nanoparticles stabilized by PVP shows that there is an interaction between nanoparticles and polymer, and suggests the effective formation of nanocomposites. Based on the results of the SEM analysis [65], it was shown that PVP forms composites together with metal nanocrystals. PVP can be adsorbed on iron nanoparticles due to a weak coordination bond that stabilizes it [75; 88; 89; 90; 91]. For nanocomposites, the bands in the region of 600-800 cm\({}^{-1}\) are caused by stretching vibrations of the Fe-O bond in oxides. The absorption bands at 735, 663, 649, and 626 cm\({}^{-1}\) are natural vibrations of composite nanoparticles embedded in the PVP matrix. PVP-specific bands were found in the polymer matrix at 1657 cm\({}^{-1}\) (Raman amide band), 1498 cm\({}^{-1}\), 1461 cm\({}^{-1}\), 1423 cm\({}^{-1}\) and 1372 cm\({}^{-1}\) (deformation vibrations of CH\({}_{2}\) groups in the pyrrolidone cycle), and 1287 cm\({}^{-1}\) (bending vibrations of III-C-H amide), with small shifts compared to pure PVP. This may indicate that PVP forms a composite together with a ferrite nanocrystal. The inclusion of CoFe\({}_{2}\)O\({}_{4}\) nanoparticles in the polymer matrix leads to a slight displacement of some bands in nanocomposites. The characteristic peaks for PVP are consistent with the literature data [88; 89; 90; 91]. The analytical wavenumbers for determining PVP are 1638 cm\({}^{-1}\) (amide combination band); 1443 cm\({}^{-1}\), 1425 cm\({}^{-1}\), and 1374 cm\({}^{-1}\) (deformation vibrations of CH\({}_{2}\) groups in the pyrrolidone cycle); and 1294 cm\({}^{-1}\) (amide III -C-H deformation vibrations) [90; 91]. The N\({}_{2}\) adsorption isotherms for CoFe\({}_{2}\)O\({}_{4}\) and CoFe\({}_{2}\)O\({}_{4}\)/PVP are shown in Figure 4, and the obtained textural properties are shown in Table 4. As can be seen from Table 4, the most developed surface has CoFe\({}_{2}\)O\({}_{4}\)/PVP.