THESIS
2004
xvi, 151 leaves : ill. ; 30 cm
Abstract
Improved quality 0.4 nm single-walled carbon nanotubes (SWNTs) can be grown in the channels of the Silicon doped aluminophosphate (SAPO-5) framework. Raman spectra of SWNTs@SAPO-5 were measured at different temperatures ranging from 7K to 297K (room temperature). Temperature-induced shifts of peaks in Raman spectra of carbon nanotubes were reported in this thesis.
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Improved quality 0.4 nm single-walled carbon nanotubes (SWNTs) can be grown in the channels of the Silicon doped aluminophosphate (SAPO-5) framework. Raman spectra of SWNTs@SAPO-5 were measured at different temperatures ranging from 7K to 297K (room temperature). Temperature-induced shifts of peaks in Raman spectra of carbon nanotubes were reported in this thesis.
The frequency decreases with increasing temperature for most of the major Raman peaks. Linear temperature dependence is consistently found in the radial breathing mode frequency at ~563 cm
-1 and the graphite-like mode frequency at ~1618 cm
-1. The temperature coefficient of these two frequencies were determined to be in the range of -0.026 to -0.028 cm
-1/K and -0.011 to -0.014 cm
-1/K, respectively. Temperature dependences of the rest of the peaks were also investigated.
Samples prepared by a newly-developed method, named optical annealing pyrolysis approach, were expected to be better in quality. The obtained Raman spectra for this kind of sample were higher in intensity and sharper in lineshape. The temperature coefficients for RBM and G-band peaks were found to be different from that of obtained from samples prepared by conventional thermal heating method. Comparison between these two kinds of samples was made.
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