Lattice Dynamics of Mercury under High Pressure

Mercury is a metal with special physical and chemical properties. High pressure can significantly alter its crystal structures and interatomic interactions. However, vibration-related experimental data of mercury under high pressure have been scarce for a long time, which limits the in-depth understanding of its high-pressure phase transition mechanisms. To fill this research gap, this study based on a low-wavenumber high-pressure Raman experimental platform, conducted in-situ high pressure Raman measurements using diamond anvil cell (DAC) technology, and combined with theoretical calculation methods to systematically investigate the laws of structural transformation and vibrational mode evolution of mercury under high pressure. The study successfully detected the vibrational signals of two solid phases of mercury under high pressure for the first time, obtained the Raman spectroscopy experimental results of mercury under high-pressure conditions, revealed the characteristics of pressure-dependent vibrational frequencies, and calculated the relevant thermodynamic parameters of two phases. The experimental data is highly consistent with the reported structural phase transitions of mercury, filling the long-standing experimental gap in this field and providing key experimental support for an in-depth understanding of the Phase transition behaviors and related mechanisms of mercury under high pressure.