Brillouin scattering and ultrasonic studies at high temperature and high pressure

Brillouin scattering provides a possibility to determine accurately acoustic velocities. However, usual Brillouin scattering measurement cannot be performed on a molten sample. The S/G/S Brillouin scattering method was thus proposed. In the present work, we report acoustic velocity measurements on two glasses (water-white glass and window glass) at high pressures and temperatures, where a sharp turning point in the velocity-temperature plots indicates the passing of the glass transition temperature θg. rasonic method was used for measurement of the velocity of the compressional wave at high temperature and pressure up to 1500°C and 6.5 GPa. The high-temperature experiments at different pressures have shown the same phenomenon as found in S/G/S Brillouin scattering measurements.