*2.5. Micro-Raman*

Raman analysis was performed with a portable system assembled by Horiba Jobin-Yvon (Villeneuve d'Ascq, France). The system is composed of a microHR spectrometer with a spectral resolution of 5 cm−1; a CCD Synapse detector; a ModularHead analytical probe containing a video camera for visualisation of samples, a notch filter for elimination of Rayleigh radiation and a microscope objective (20×, 50× or 80×); a tripod to support the analytical probe, equipped with an XYZ stage with micrometric movements to allow accurate focusing; an Ar 532 nm and a He-Ne 632 nm lasers; optic fibres to carry laser radiation on the sample and Raman radiation to the spectrometer. The system is managed with LabSpec 5 dedicated software running under Windows XP.
