Solid krypton: Equation of state and elastic properties

Abstract

The properties of solid krypton have been measured as a function of pressure in a diamond-anvil cell using energy-dispersive x-ray diffraction and Brillouin scattering. A room-temperature equation of state and a complete set of elastic constants are deduced. The analysis of these results indicates a possible phase transition above 30 GPa.

Solidification and fcc to metastable hcp phase transition in krypton under variable compression rates

“…Consequently, the formation of the metastable hcp at low pressure under dynamic loading confirms the predicted small volume difference between fcc and hcp phases. The isothermal compressibility, ~ 0.123 (±0.006) GPa -1 measured in this study agrees reasonably well with that, 0.167 GPa -1 previously obtained from the energy-dispersive x-ray diffraction and Brillouin scattering [25]. The measured linear strain rate of the fcc phase supports the suggestion that the fcc-to-hcp transition arises from stacking disorder in the fcc phase -not by the plastic deformation or twinning.…”

“…In fact, the measured linear compressibility, ~ 0.041(±0.002) GPa -1 is calculated by dividing a 0 = 5.8213 Å from V 0 of B-M EOS [13]. Based on the reasonable assumption that fcc is isotropic, the isothermal compressibility, ~ 0.123 (±0.006) GPa -1 in this study is quite similar to the isothermal compressibility of fcc-Kr, 0.167 GPa -1 , derived from the adiabatic bulk modulus (Ks=6 GPa at 1 GPa) of Kr from energydispersive x-ray diffraction and Brillouin scattering [25]. Hence, based on this observation we conclude that the formation of the hcp phase is indeed induced by a simple stacking disorder of the fcc phase -not by the plastic deformation or twinning.…”

Effective potential for many-body interactions in some properties of the HFD-like solids

“…According to Fig. 4, the effective potential has decreased the two-body values to get better agreement with the experimental values [45,46,29,47,48]. This can be due to the effect of adding U MB to U 2B .…”

“…(3)) from the two-body interaction without incurring the computational cost of the three-body calculations. Many studies about the solids (especially rare gas solids) have been concentrated at room temperature [45,46,29,[47][48][49]. Therefore, we have performed the NVT MD simulation to obtain pressures (up to 200 GPa) of the solid systems at room temperature (T = 298 K) and different densities using the two-body HFD-like (Eq.…”

Validating density-functional theory simulations at high energy-density conditions with liquid krypton shock experiments to 850 GPa on Sandia's Z machine

“…Extensive literature on static compression of krypton at low temperatures that provides a valuable reference on how pressure affects the soild phase and its melting behavior. [9][10][11][12][13] Upon shock compression, krypton turns metallic, resulting in a reflective shock front, allowing for very high precision measurements of the shock velocity. Few experimental data on krypton at high pressures exist, with prior Hugoniot data limited to just below 100 GPa.…”