Raman spectroscopy is a molecular vibrational spectroscopic technique which provides complementary information to FT-IR. Differently from FT-IR, Raman is based on a anelastic scattering process probing the vibrational properties of the materials. Being a molecular spectroscopic technique, it provides information concerning the functional groups constituting the molecules ultimately aiding a molecular identification of unlimited materials under exam. In the practice, mainly inorganic (but also organic) materials can be identified with particular attention to metal-oxides pigments that are not detectable by FT-IR. The use of long wavelegth lasers (i.e 785 and 1064 nm) enables to overcome the main limitation of the technique, namely the high fluorescence emissions which may compete with the scattering phenomena and cover any useful vibrational signals. Performing Surface Enhanced Raman Spectroscopy (SERS) by using nanoparticles substrate it is possible to investigate also organic dyes and lakes thank to the quenching of the fluorescence and the enhancement of the scattering signal.
archaeological object and site, architecture, art, decorative arts, demo anthropologic object, film, manuscript, mosaics, musical instrument, painting, papyrus, photo, sculpture, textile
animal product, botanic collection, fossil, gems, mineral, object in formalin, shell, skeleton, taxidermy collection
ceramic (clay/mud brick/terracotta/earthenware/stoneware/porcelain), glass, stone, metal and metallurgical By-Products, pigment
animal parts, binding media, glues, wood, paper, textiles, varnishes
The portable Raman spectrometer Rigaku Xantus-2, has lasers operating at 785 and 1064 nm. For the 785 nm laser set-up, the detector is a CCD cooled by a Peltier system and the power ranges from 30- 490 mW with a spectral resolution between 7 -10 cm-1. The 1064 nm laser set-up instead uses an InGaAs...