High‐pressure Brillouin study of the elastic properties of rare‐gas solid xenon at pressures up to 45 GPa

Abstract

The pressure dependences of three adiabatic elastic constants, adiabatic bulk modulus, refractive index, and elastic anisotropy, as well as Cauchy deviation of fcc solid Xe have been determined up to 10 GPa at 296 K by high-pressure Brillouin scattering spectroscopy. The characteristics of elastic properties at high pressure of rare-gas solid Xe are investigated by comparison with the previous studies on Ne, Ar, and Kr. Above 10 GPa, the occurrence of splitting in the Brillouin signals and the direction dependence of acoustic velocities for solid Xe clearly show partial phase transformation to the hcp structure reported by the previous X-ray diffraction and Raman scattering studies. The shear elastic modulus in the hcp phase of solid Xe has also been estimated at pressures up to 45 GPa by using the pressure dependence of the Raman wavenumber shift for the E 2g mode.

Elastic properties of compressed cryocrystals in a deformed atom model

“…With an increase in the pressure, as was shown by the experiment performed in [10], there is an individual dependence of on the pressure. The experiment shows, that the values of Ne Kr Xe…”

“…It is not obvious in advance, which of the interactions dominates and in which range of pressure. The presented calculations give an opportunity to describe the individual pressure dependence of δ(p) which is being observed during the experiment [10]. It should also be noted that the ab initio calculations performed in the framework of the density functional theory do not reproduce exp in the case of Kr [10,11].…”

“…The use of Brillouin spectroscopy in combination with the DAC method has opened up new possibilities for intensive investigations of the elastic properties of RGC over a wide range of pressures [7][8][9][10]. In the last article from this series concerned with the particularly accurate measurements of the elastic properties of RGC, Sasaki et al [10] have summarized and discussed, in particular, how well the currently existing theory describes the experiment on the deviation from the Cauchy relation.…”

“…In the last article from this series concerned with the particularly accurate measurements of the elastic properties of RGC, Sasaki et al [10] have summarized and discussed, in particular, how well the currently existing theory describes the experiment on the deviation from the Cauchy relation. In the experiment for the deviation from the Cauchy relation δ, the sequence Ne Ar Kr…”

“…Furthermore, Sasaki et al [10] note that the ab initio calculations carried out in terms of the density functional theory (DFT) [11] even qualitatively do not reproduce the deviation from the Cauchy relation . Their calculations of have demonstrated a negative pressure dependence for all RGC (Ne, Ar, Kr, Xe) with the pressure coefficients clearly depending on the atomic weight.…”