Synthesis and structural characterization of carbon-rich SiCxOy derived from a Ni-containing hybrid polymer

Thermal evolution of ladder-like silsesquioxanes during formation of black glasses

“…550 cm -1 [7,8]. The Si-C 3 vibration from the Si-CH 3 molecules can be observed at 700 cm -1 [21,27,30]. Based on the XRD analysis (Fig.…”

“…Literature data state that a band at 1900 cm -1 can be a combinational band or a residual bonding of -C:C-specimen [41,42]. Bands at 2050 and 2230 cm -1 can be attributed to the Si-H stretching vibrations (SiCSi-H and O 3 Si-H groups) [30,31,34]. A, B, C5 samples (fired at 1000°C) are much alike.…”

“…1000-1200 cm -1 two bands are visible. The first one can be attributed to va vibrations of Si-O-Si (bridging) vibrations of ladder-like structure, while the other at around 1100 cm -1 is responsible for cage-like vibrations in ringlike structures of Si-O-Si ladder [7,28,30,32,34,36,37]. The vs vibration of Si-O-Si bridges is visible in the range of approx.…”

“…Bands responsible for CH vibrations are very well visible on the xerogel spectra-Si-(CH 3 )x bending vibrations are visible at 750-860 cm -1 range, and the Si-CH 3 and Si-C 2 H 5 stretching vibrations are visible at 1273 cm -1 (vs) and 1413 cm -1 (va) along with stretching vibrations of C-H groups at 2971 (va) and 2913 cm -1 (va) [7-9, 18, 20, 28, 29, 33, 34, 43, 45]. For A0 sample also 2800 cm -1 (vs) C-H band is visible [7,28,30]. The Si-OH stretching bands at 3600-3800 cm -1 along with approx.…”

Solid state magnetic resonance investigation of the thermally-induced structural evolution of silicon oxide-doped hydrogenated amorphous carbon

“…For comparison, SiC is known to give shifts within the range of -14 to -25 ppm depending on the crystal environment about silicon atoms, and the cubic form gives a resonance near -18 ppm [70]. The data are not conclusive concerning the presence of Si-O bonds, as the resonance of the SiC3O unit is expected to be near -6 ppm, and other oxycarbides (SiC2O2, SiCO3, SiO4) typically reside beyond -30 ppm [71]. Since the width of the MAS spectrum is about 90 ppm, the existence of some of these units cannot be categorically discounted.…”