What are the differences between raman spectroscopy of amorphous and crystalline carbon materials?
In Raman spectrum for Carbon materials we have mainly D,G and 2D peaks. In the case of Amorphous carbon (where defects are dominating) the intensity ratios of D/G peaks will be higher (i.e. the intensity of the D band will be higher than the intensity of G band). As the crystallization increases, the contribution of the G band will start dominating; reducing the intensity ratio of D/G peaks. That's the reason that in pure Graphite (highly crystallized structure) there is no D band observed. its only G and 2D (in graphite). As the amorphous nature increases, the D band starts growing.
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Syed Waqar Hasan Don't forget that Diamond, which is highly crystalline, has a single Raman peak at ~1325 cm-1. This is a feature of crystalline sp3 hybridised carbon. In a lattice of sp2 hybridised carbon (e.g. graphene) an sp2 defect will result in a diamond-like feature at ~1325 cm-1.
Raman makes it possible to distinguish graphite (bond sp2) from diamond (bond sp3), but he cannot distinguish the crystalline structure from the amorphous one.
However, there is a method of direct Visualization of Atoms, Molecules and Chemical Bonds, where both crystalline and amorphous structures are visible.
This is a picoscope, which is written in Russian:http://science-ua.com/gallery/maketn2.pdf
Or in English:https://DOI:10.1080/15421406.2019.1578510
Below I give a picture where graphite crystals are visible at the top and amorphous graphite below.
This is a new and very effective approach to solving your problem.
I propose to work together and write an article as a result.
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