Elastic Constants of a Cubic Crystal Grown in a High-Pressure Diamond Anvil Cell

Abstract

The acoustic velocities of a pressure-induced crystalline hydrogen sulfide (plastic phase, fcc) in a diamond anvil cell (DAC) were measured as a function of rotation angle φ by means of Brillouin spectroscopy. The best fitting of the angular dependence of the acoustic velocities between the experimental values and the calculations by the modified Every's expression for elastic waves of arbitrary direction, yields the evaluation for the orientation of the cubic crystal grown in the DAC, and the determinations of the refractive index, the density and the elastic constants under high-pressure.