## 3 Results and Discussion  
Figure 3 presents the coated samples' Raman spectra that were produced by fitting the baseline corrected normalized Lorentz curves (FWHM), allowing the intensities of the D and G peaks--which represent diamond-like sp\({}^{3}\) bonds, and graphite-like sp\({}^{2}\) bonds, respectively. A 2D peak, centered at around 2640 cm\({}^{-1}\), was also observed, which is also a characteristic peak of GO [33; 34; 35]. The I\({}_{\text{D}}\)/I\({}_{\text{G}}\) ratio likewise tended to diminish in parallel with a decrease in the nitrogen flow rate. It was observed that, for the coated surfaces (SCN and SC), a typical spectrum of GO and its other forms, such as CNT and nanodiamond, were grown. The presence of nanocrystalline diamond is confirmed by the peaks at around 1620 cm\({}^{-1}\) and 1330 cm\({}^{-1}\), which indicate that the structure contains \begin{table}
\begin{tabular}{c c} \hline
**Variable** & **Error (\%)** \\ \hline COF & \(\pm\)1.6 \\ \(\phi\) & \(\pm\)2.2 \\ R\({}_{\text{a}}\) & \(\pm\)2.5 \\ Hardness & \(\pm\)3.7 \\ \hline \end{tabular}
\end{table} 
Table 3: Error data. graphitized materials [36; 37; 38; 39]. The \(\rm I_{D}/I_{G}\) ratios of 0.95 and 1.02 (FWHM) show the D peaks centered at around 1320 cm\({}^{-1}\) and 1314 cm\({}^{-1}\), and the G peaks centered at around 1595 cm\({}^{-1}\) and 1598 cm\({}^{-1}\), for each \(\rm N_{2}\)-incorporated plasma-coated surface [40; 41; 42]. The formation of less-defective graphite microcrystallines (smooth film surface) can also be attributed to these \(\rm I_{D}/I_{G}\) values. The disorder (D) peaks (1320 cm\({}^{-1}\)), which also match the typical nanodiamond properties, are the strongest peaks [43; 44; 45]. Figure 3: _Cont._  
The GO peaks in the XRD analysis (Gaussian fit) of SCN (Figure 4a) indicate that the dominant crystalline structure was formed, and GO was composed on the surface in multiple forms [46]. Nanodiamond (111) was observed on the surface, and the average nanocrystalline size (\(L\)) was computed (Tables 4 and 5) using the Scherrer formula, as shown in Equation (4). The shape factor, \(\kappa\), was taken as 0.94, the XRD radiation wavelength, \(\lambda\), as 0.15406 nm and the FWHM as \(\beta\). \[L=\frac{\kappa\lambda}{\beta\cos 2\theta} \tag{4}\]  
For SC, there was a decrease in the rGO (002) peak, while the C (002) seemed to become the dominant peak, showing that the structure would tend to shift to an amorphous rather than a crystalline form. GO revealed a multi-orientation for both samples. The peaks around 45\({}^{\circ}\) are indications of carbon nanocomposite structures like nanocrystalline diamond (111) [47], which is also supported by the Raman analysis. Figure 3: Raman spectra of the coated substrates: (**a**,**b**) SCN, and (**c**,**d**) SC. Figure 4: _Cont_. Figure 5 depicts the SEM images of the surface of SCN. The visual analyses demonstrate that the CNT and rGO are the dominant structures with wrinkles and crumbles [48,49]. Moreover, when the examination area is expanded (20,000\(\times\)), carbon heaps can be clearly observed on the coated substrate. CNT structures embedded in the GO sheets were spotted, and the mean size of the GO sheets on SCN and SC was determined to be 223 nm, with a standard deviation of 106 nm, and 336 nm, with a standard deviation of 189 nm, respectively. Thanks to the high-energy plasma, the effective penetration of carbon atoms was achieved, leading to the filling of the grooves in the very rough steel substrate (polishing effect) and the formation of nanocomposite rGO/CNT. \begin{table}
\begin{tabular}{c c c} \hline \hline
**26** & **FWMH (\({}^{\circ}\))** & **Grain Size (nm)** \\ \hline
10.44 & 4.47 & 1.86 \\
14.48 & 0.30 & 27.87 \\
17.33 & 0.55 & 15.25 \\
26.26 & 0.76 & 11.21 \\
43.98 & 0.02 & 447.27 \\
75.5 & 0.02 & 524.59 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: XRD parameters and calculated grain size information for SCN. Figure 4: XRD data of the coated substrates: (**a**,**b**) SCN, and (**c**,**d**) SC.