کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10610903 | 986027 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Origin of the 2450Â cmâ1 Raman bands in HOPG, single-wall and double-wall carbon nanotubes
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی انرژی
انرژی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Origin of the 2450Â cmâ1 Raman bands in HOPG, single-wall and double-wall carbon nanotubes Origin of the 2450Â cmâ1 Raman bands in HOPG, single-wall and double-wall carbon nanotubes](/preview/png/10610903.png)
چکیده انگلیسی
The second order Raman signals around the Gâ²-band region of graphite and carbon nanotubes have been investigated at more than 15 excitation laser lines. Two distinct Raman bands have been observed around 2700 cmâ1; a prominent one is due to the so-called Gâ²-band and the other is a weak band around 2450 cmâ1. Both two bands can be from the double resonance process involving two phonons around the K-point in the phonon dispersion of a two-dimensional graphite. The 2450 cmâ1-band has exhibited little power dependence, whereas the intensity of Gâ²-band has shown large photon energy dependence as already reported. The 2450 cmâ1-band and the Gâ²-band correspond to non-dispersive q = 0 and fully-dispersive q = 2k, respectively. From the phonon dispersion and the corresponding phonon frequency, the 2450 cmâ1-band can be assigned as an overtone mode of LO phonon (i.e. 2LO). This is revealed by calculated Raman spectra of graphite with proper electron-phonon matrix elements. The present study is the first report on the origin and assignment of the 2450 cmâ1-band, which is based on the double resonance Raman scattering.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbon - Volume 43, Issue 5, 2005, Pages 1049-1054
Journal: Carbon - Volume 43, Issue 5, 2005, Pages 1049-1054
نویسندگان
T. Shimada, T. Sugai, C. Fantini, M. Souza, L.G. Cançado, A. Jorio, M.A. Pimenta, R. Saito, A. Grüneis, G. Dresselhaus, M.S. Dresselhaus, Y. Ohno, T. Mizutani, H. Shinohara,