Characterization of free carbon in the as-thermolyzed Si-B-C-N ceramic from a polyorganoborosilazane precursor
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TLDR
In this article, the structure of polyorganoborosilazane (B[C2H4-Si(CH3)NH]3) was characterized using X-ray diffraction (XRD) and Raman spectroscopy.Abstract:
Polyorganoborosilazane ((B[C2H4-Si(CH3)NH]3)
n
) was synthesized via monomer route from a single-source precursor and thermolyzed at 1300 °C in argon atmosphere. The as-thermolyzed Si-B-C-N ceramic was characterized using X-ray diffraction (XRD) and Raman spectroscopy. The crystallization behavior of silicon carbide in the as-thermolyzed amorphous Si-B-C-N matrix was understood by XRD studies, and the crystallite size calculated using Scherrer equation was found to increase from 2 nm to 8 nm with increase in dwelling time. Concomitantly, Raman spectroscopy was used to characterize the free carbon present in the as-thermolyzed ceramic. The peak positions, intensities and full width at half maximum (FWHM) of D and G bands in the Raman spectra were used to study and understand the structural disorder of the free carbon. The G peak shift towards 1600 cm−1 indicated the decrease in cluster size of the free carbon. The cluster diameter of the free carbon calculated using TK (Tuinstra and Koenl) equation was found to decrease from 6.2 nm to 5.4 nm with increase in dwelling time, indicating increase in structural disorder.read more
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References
More filters
Journal ArticleDOI
Interpretation of Raman spectra of disordered and amorphous carbon
Andrea C. Ferrari,John Robertson +1 more
TL;DR: In this paper, a model and theoretical understanding of the Raman spectra in disordered and amorphous carbon is given, and the nature of the G and D vibration modes in graphite is analyzed in terms of the resonant excitation of \ensuremath{\pi} states and the long-range polarizability of the long range bonding.
Journal ArticleDOI
Raman Spectrum of Graphite
F. Tuinstra,J. L. Koenig +1 more
TL;DR: Raman spectra are reported from single crystals of graphite and other graphite materials as mentioned in this paper, and the Raman intensity of this band is inversely proportional to the crystallite size and is caused by a breakdown of the k-selection rule.
Journal ArticleDOI
Raman spectroscopy of graphene and graphite: Disorder, electron phonon coupling, doping and nonadiabatic effects
TL;DR: In this article, the authors focus on the origin of the D and G peaks and the second order of D peak and show that the G and 2 D Raman peaks change in shape, position and relative intensity with number of graphene layers.
Journal ArticleDOI
Studying Disorder in Graphite-Based Systems by Raman Spectroscopy
Marcos A. Pimenta,G. Dresselhaus,Mildred S. Dresselhaus,Luiz Gustavo Cançado,Ado Jorio,Riichiro Saito +5 more
TL;DR: In this review, experimental results for the D, D' and G' bands obtained with different laser lines, and in samples with different crystallite sizes and different types of defects are presented and discussed.
Journal ArticleDOI
Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamond
Andrea C. Ferrari,John Robertson +1 more
TL;DR: It is shown how to use resonant Raman spectroscopy to determine structure and composition of carbon films with and without nitrogen, and the assignment of the peaks at 1150 and 1480 cm−1 often observed in nanodiamond.