Carbon and diamond
Raman spectroscopy is an essential tool in the carbon industry, whether for quality control of diamond-like carbon (DLC) coatings, characterising the structure and chirality of carbon nanotubes, or quantitatively measuring the thickness and oxidation state of graphene and related materials.
The Raman and photoluminescence capabilities of Renishaw's inVia Raman systems are widely used to identify whether diamonds have been artificially treated at high temperature and pressure (known as HPHT treated or GE-POL diamonds) to change their colour and hence value.
The images on the right illustrate the use of Raman imaging for revealing the stress distributions produced when type Ib and type IIb diamonds are impressed at high temperatures by a cubic boron nitride (CBN) indenter.
For quality control functions, Renishaw provide a custom analysis program (CAP), allowing automated data collection with integrated complex spectra analysis followed by a 'pass or fail' output.
Documents for download
Temperature-mediated growth of single-walled carbon-nanotube intramolecular junctions (2007), Yagang Yao et al, Nature materials, 6, 283-286
Elimination of D-band in Raman spectra of double wall carbon nanotubes by oxidation (2005), S Osswald et al, Chemical Physics letters, 402, 422-427
Identification of GE POL diamonds: a second step (2000), J L Chalain et al, Journal of Gemmology, 27, 2, 73-78
Detection of GE POL diamonds: a first stage (1999), J P Chalain et al, Revue de Gemmologie A. F. G., 138/139, 30-33