| Popis: |
Carbon-sulfur nonstoichiometric compound, C x S, and its related carbons have been studied by Raman spectroscopy along with X-ray diffractometry. A partially carbonized polymer heat-treated at 600°C shows a weak Raman band at 1600 cm −1 and a broad strong band centering at 1300 cm −1 . A heat treatment temperature of 1000°C transforms the Raman spectrum into two strong bands at 1600 and 1350 cm −1 characteristic of disordered carbons. However, the E 2 g 2 Raman band of C x S samples prepared from the same polymer at 600°C is red-shifted to 1550 cm −1 . In addition to the 1550 cm −1 band and a strong 1360 cm −1 band, a weak band at about 490 cm −1 is also observed. Based on the present results and those obtained earlier, a simple model of the C itx S material is proposed as a turbostratic carbon which consists of random layer hexagonal carbon ring networks with C=S and thiophenic C-S-C groups existing in the peripheral rings at the layer edges. For the C x S materials with higher sulfur contents, cross-linkings with -S n - groups exist between layers and/or crystallites. |
