Raman scattering investigations of nano-crystalline rare earth sesquioxides: pressure and temperature driven phenomena

High pressure investigations play an important role for addressing the issues of stability and structural transformations, metal-insulator transitions, enhancement or collapse of magnetic ordering and amorphization, etc. Under such conditions, the bonding patterns established for the systems near ambient conditions change dramatically, causing profound effects on numerous physical and chemical properties and leading to the formation of new classes of materials. Further, the Raman spectra of phonons have a very high sensitivity, which permits finger-printing analysis of composition and state of a material. Hence Raman scattering is one of the most powerful techniques to investigate the phonon spectrum, electron phonon coupling, structural phase transitions, and anharmonic behavior of the optical modes