โ Scribed by V. Mennella; G. Monaco; L. Colangeli; E. Bussoletti
No coin nor oath required. For personal study only.
This paper reports the Raman spectra, obtained by using an excitation laser at 1064 nm, of carbon-based materials characterised by different microstructural properties and structural perfection. The use of a NIR excitation evidences new aspects of Raman activity in carbons. The Ezg mode at 1582 cm-' in HOPG does not show dispersion to 1064 nm. On the other hand, in polycrystalline
graphites the dependence on the exciting wavelength seems to be extended to all the bands, with the only exception of those arising from the k = 0 selection rule in the graphitic lattice. A new description of two characteristic bands of disordered carbons, the D band and its overtone, is presented.
๐ SIMILAR VOLUMES
We report Raman spectra of microcrystalline graphite and amorphous hydrogenated carbon films excited by a Nd:YAG laser. A comparison with spectra excited by visible laser lines shows large differences in both peak positions and relative intensities, which can be used for a non-ambiguous discriminat