Vibrational Spectroscopy at High Pressures in CF4: Implications to the Phase Diagram

摘要: The molecular analogue of methane CF4 is the most fundamental saturated perfluorocarbon, exhibiting complex optical behavior that highly unusual for such a simple system. We present Raman measurements in solid over wide range pressure from 1.6 to 30 GPa at room temperature. spectra exhibit polarization-dependent intensity variations and history-dependent absence or presence high modes. Our results compellingly demonstrate previously identified phase transitions based on signatures need be reconsidered. Though our data suggest possible new high-pressure transitions, we do not identify phases because spectral complexity. Finally, used measured longitudinal transverse mode splitting estimate dipole moment derivative pressures find it close gaseous CF4.