## 2 Results and Discussion
the shape and shift of this band resembled turbostratic stacking of several graphene sheets along the c-axis, as the width of the band (w = 77 cm\({}^{-1}\)) was significantly larger than that of monolayer graphene (w = 24 cm\({}^{-1}\)) [47]. Thus, the progressive changes in the Raman spectra of C-11 might be correlated to the evolution of the segregated carbon from amorphous to nanocrystalline and eventually to turbostratic microcrystalline carbon. Figure 2 shows the lateral crystal size L\({}_{\text{a}}\) and its progress with increasing the annealing temperature for the C-11 based samples. As shown by [PERSON] and [PERSON], the relative intensity ratio I\({}_{\text{D}}\)/I\({}_{\text{G}}\) of the D and G bands depends inversely on L\({}_{\text{a}}\) for graphitic samples; whereas, L\({}_{\text{a}}\) has been best described for highly disordered carbons upon using the ratio of the integrated areas A\({}_{\text{D}}\)/A\({}_{\text{G}}\) of the D and G band instead of their intensities [48; 49]. Consequently, the disordered carbon phase in SiC/C was assessed by using the following equation [49; 50]. \[\text{L}_{\text{a}}=\left(2.4\cdot 10^{-10}\right)\lambda_{\text{l}}^{4}\left( \frac{\text{A}_{\text{D}}}{\text{A}_{\text{G}}}\right)^{-1} \tag{2}\]  
with \(\lambda_{\text{l}}\) being the laser wavelength. As clearly indicated in Figure 2, the lateral crystal size L\({}_{\text{a}}\) was not affected by the treatment temperature in the temperature range from 1000 to 1500 \({}^{\circ}\)C and only slightly varied around a value of ca. 7.5 nm. This is in agreement with the work of [PERSON] et al. who obtained similar values (L\({}_{\text{a}}\) = 5-7 nm) for amorphous carbon films heat treated at temperatures up to 1500 \({}^{\circ}\)C. At higher temperatures, the crystalline lattice started to grow, as intrinsic lattice defects were removed. The onset of graphitization was emphasized by the increase in intensity of the G band and the clear development of D' at temperatures beyond 1600 \({}^{\circ}\)C, as shown in Figure 1. Thus, the L\({}_{\text{a}}\) value found in the C-11 sample annealed at 1800 \({}^{\circ}\)C was ca. 20 nm. This is in excellent agreement with a study of [PERSON] et al. who investigated the graphitization behavior of diamond-like carbon thin films at temperatures ranging from 1800 to 2700 \({}^{\circ}\)C, which revealed a L\({}_{\text{a}}\) value of 20 nm for the films annealed at 1800 \({}^{\circ}\)C [50] (see empty symbols in the inset of Figure 2). Figure 2: Evolution of the lateral crystal size L\({}_{\text{a}}\) in C-11 as a function of the treatment temperature. The open data points in the inset represent the work of Ref. [50], indicating the evolution of L\({}_{\text{a}}\) with the annealing temperature for diamond-like thin films. As the series of SiOC/C samples in the present study showed, the content of the segregated carbon phase in the prepared materials can be adjusted in a broad range. Within this context, Raman spectroscopic investigations were done in order to rationalize whether the amount of segregated carbon in SiOC/C ceramic might have an effect on the lateral crystal size L\({}_{\text{a}}\). Figure 3 plots the L\({}_{\text{a}}\) as a function of the volume fraction of the segregated carbon phase in the studied SiOC/C ceramics and revealed a constant L\({}_{\text{a}}\) value of 9 \(\pm\) 1 nm for samples showing carbon contents above \(\phi_{\text{C}}\)\(>\) 10 vol.%; whereas the samples possessing of lower carbon contents, (\(\phi_{\text{C}}\)\(<\) 10 vol.%) exhibited smaller L\({}_{\text{a}}\) values of 6 \(\pm\) 2 nm. Thus, it may be concluded that the large(r) amount of segregated carbon in silicon oxycarbides correlates to its relative higher graphitization degree [39]. The evolution of the segregated carbon phase in silicon oxycarbides as a function of the annealing temperatures was also assessed by considering the interdefect distance L\({}_{\text{D}}\). L\({}_{\text{D}}\) was calculated according to Ref.