## 3 Results and Discussion
As seen in Figure 5, in the range of wave vectors \(s<s_{0}\) (\(s_{0}\approx 0.55\,\mathrm{nm}^{-1}\)), the small-angle patterns of samples NC1_10 and NC1_5 almost coincide and are characterized by a higher scattering intensity compared with the NC2 sample. At the same time, the NC2 sample is characterized by a significantly higher scattering intensity in the range of values \(s>s_{0}\). This result can be explained by an increase \begin{table}
\begin{tabular}{c c c c c c} \hline
**Sample** & **20**, \({}^{\circ}\) & \(d\)**, nm** & **FWHM**, \({}^{\circ}\) & **\(l\)**/\(l_{0}\)** & **\(L_{c}\), nm** \\ \hline NC1\_10 & 9.70 & 0.910 & 7.4 & 19.2 & 1.3 \\  & 22.80 & 0.390 & 13.2 & 100.0 & 1.3 \\ NC1\_5 & 10.45 & 0.850 & 4.9 & 7.3 & \\  & 22.45 & 0.400 & 13.1 & 100 & 2.0 \\ NC2 & 14.00 & 0.630 & 4.6 & 9.6 & 2.2 \\  & 23.50 & 0.380 & 11.4 & 100 & 2.2 \\ \hline \end{tabular}
\end{table} 
Table 1: Parameters of carbon phase peaks in synthesized nanocomposites. Figure 6: Analysis of the diffuse peak profile of the carbon phase in NC1_10 (a); NC1_5 (b); NC2 (c) samples. in the relative fraction of electron density inhomogeneities (pores), a typical size of which is less than \(L=2\pi/s_{0}\approx 11.5\) nm. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & \(\mathbf{d}\), Å & **20, \({}^{\circ}\)** & \(\mathbf{III_{0}}\) & **FWHM\({}_{\star}\)** & \(\mathbf{hkl}\) \\ \hline \multirow{6}{*}{NC1\_10} & 2.0268 & 44.709 & 100.0 & 0.721 & 1 1 1 \\  & 1.7557 & 52.089 & 47.4 & 0.744 & 2 0 0 \\  & 1.2437 & 76.603 & 26.1 & 0.751 & 2 2 0 \\  & 1.0613 & 93.155 & 24.8 & 0.732 & 3 1 1 \\  & 1.0158 & 98.725 & 8.5 & 0.799 & 2 2 2 2 \\  & 2.0319 & 44.591 & 100.0 & 0.503 & 1 1 1 \\  & 1.7595 & 51.968 & 42.3 & 0.600 & 2 0 0 \\  & 1.2455 & 76.477 & 20.3 & 0.635 & 2 2 0 \\  & 1.0627 & 92.999 & 15.9 & 0.701 & 3 1 1 \\  & 1.0176 & 98.499 & 5.0 & 0.759 & 2 2 2 \\  & 2.0244 & 44.764 & 100.0 & 0.595 & 1 1 1 \\  & 1.7559 & 52.082 & 48.8 & 0.597 & 2 0 0 \\ \multirow{2}{*}{NC2} & 1.2446 & 76.537 & 30.7 & 0.612 & 2 2 0 \\  & 1.0621 & 93.069 & 35.3 & 0.650 & 3 1 1 \\  & 1.0172 & 98.540 & 10.9 & 0.704 & 2 2 2 \\ \hline \hline \end{tabular} \(d\)-interplanar distance (Å), 20-diffraction angle, \(l/\)fo-relative intensity of peaks, FWHM-full width at half maximum.  
\end{table} 
Table 2: Analysis of diffraction patterns of polycrystalline Ni in synthesized nanocomposites. Figure 7: Curves of intensity of X-ray scattering by samples NC1_10 (1), NC1_5 (2), NC2 (3) after collimation correction for the height of the detector receiving slit. The distribution functions of effective pore radii were calculated by an integral equation using an indirect Fourier transform, which integrates the scattering intensity with the pore distribution function in a polydisperse system of spherical particles:  
\[I(s)=\int_{0}^{R_{max}}i_{0}(sR)\cdot m(r)\cdot D_{v}(R)dR \tag{1}\]  
where \(I(s)\) is the scattering intensity, \(i_{0}(sR)\) is the form factor of scattering by a polydisperse spheres system, \(D_{v}(R)=\pi R^{3}\cdot N(R)\) is the volume function of pore distribution, and \(N(R)\) is the number of pores with effective radius \(R\). The functions \(D_{v}(R)\) were calculated using the GNOM software package. The average pore radius was determined by the formula:  
\[Rg_{\rm s}=[\frac{\sum_{k=1}^{N}D_{k}}{\sum_{k=1}^{N}(D_{k}/R_{k} ^{3})}]^{\frac{1}{3}}, \tag{2}\]  
where \(N\) is the number of experimental points of the curve \(D_{v}(R)\). Our qualitative analysis of SAXS patterns is confirmed by the calculation of volume functions of the effective pore radii distribution (Figure 8). As can be seen, samples NC1_10 and NC1_5 are characterized by a wide distribution of pore radii in the range up to 50 nm. The largest volume contribution to the formation of the porous structure is observed from pores the radii of which are in the range from 5 to 30 nm. At the same time, a significantly different volume distribution of pores is observed for the NC2 sample.