Characterization of carbon coatings on SiC monofilaments using Raman spectroscopy

Microstructure and thermal residual stress analysis of SiC fiber through Raman spectroscopy

“…D band appearing in the Raman spectrum of graphitic materials is usually assigned to structural defects (including those related to the crystallite edges). [25] In this work, according to the spectra in Fig. 1, near tungsten core, there exist two small peaks in the range of 1300-1600 cm À1 , which refers to excessive carbon.…”

“…According to the concept of 'large zone and zone folding', these peaks are divided into four groups: longitudinal optical phonon (LO), transverse optical phonon (TO), longitudinal acoustic and transverse acoustic phonon branches. [16] In the range of 100-600 cm À1 , there exists a double hump throughout fiber radius, which attributes to acoustic phonon scattering of silicon carbide and silicon due to defects (such as stacking faults and disorders) in crystals, [17] and optical phonon scattering of amorphous silicon. The 3C-SiC (β-SiC) exhibits two sharp bands, corresponding to the zone-centre TO mode at 796 cm À1 and the zone-centre LO mode at 972 cm À1 .…”

“…[7] The Raman technique also has the advantages of being very quick and efficient, as well as requiring little sample preparation. Raman spectroscopy has been applied successfully to characterize SiC crystal polytypes, [8] polymer fibers, [9] polymeric precursor SiC fiber, [10,11] CVD SiC fiber, [11,12] as well as residual stress in ceramic matrix composites and TMCs. [11][12][13][14] Previous studies [13,15] on thermal residual stresses of CVD SiC fiber in a matrix used the deformation of carbon coating as calibration, which can only obtain average stress in axial direction of the fibers.…”

Electrochemical reduction of trinitrotoluene on core–shell tin–carbon electrodes

“…The Raman spectra of the Sn(C) core-shell and of the carbon-TMB particles contain two pairs of major bands. Peaks D and G around 1327 cm −1 and at 1590 cm −1 in these spectra can be attributed to the in-plane vibrations of sp 3 and sp 2 C C bonds in disordered carbon and in crystalline graphitic carbon, respectively ( [29] and references therein). The ratio of the Raman-band intensities (I D /I G ) was found to be 3.0 and 2.6 for the Sn(C)-a core-shell particles and for the TMB-based carbon, respectively.…”

Opto-Electronic Study of SiC Polytypes: Simulation with Semi-Empirical Tight-Binding Approach

“…In this aspect, there has been renewed interest in SiC as one of the wide band gap compounds with great potential for the next generation of electronic devices operating at high temperature (61)- (68). This compound has been also used primarily in light-emitting diodes.…”