Polarized micro-Raman studies at 180 and 90 degrees geometries

During the last decades, micro-Raman spectroscopy became a very popular, non destructive, tool for the structural and compositional characterization, at the micrometric scale, of a large variety of both organic and inorganic compounds. In the meantime, it has also emerged as a very reliable technique for vibrational dynamics studies of crystalline solids, since it can suitably exploits both different scattering geometries and different polarization configurations of the incident and scattered light. Through this thesis, we will show the usefulness and completeness of the polarized Raman micro-spectroscopy in the study of a set of anisotropic, single crystals. To obtain these results, some improvements in the measurement approach have been adopted by us, with the respect to the traditional backscattering configuration. In fact, this experimental implementation consists of the combination of a home-assembled micro-manipulator with a confocal micro-Raman spectrometer within the 90 degrees scattering geometry. The experimental results, achieved by means of this innovative micro-Raman setup allowed to remove some ambiguities and gaps in the international scientific literature, establishing themselves as highly reliable, reproducible, and, in brief, definitive. In particular, using this approach we were able to selected in turn and properly assign in symmetry Raman active modes of a set of crystalline compounds with zircon structure never reported before.