Elastic Constants of Argon and Neon by Brillouin Scattering from Single Crystals near Their Triple Points

Abstract

The adiabatic elastic constants of single crystals of neon at 24.3 K and of argon at 82.0 K have been determined by Brillouin scattering. For argon the values are $C_{11}=2.33\mathrm{}\pm 0.08$, $C_{12}=1.49\mathrm{}\pm 0.06$, $C_{44}=1.17\mathrm{}\pm 0.07$, in units ${10}^{10}$ dyne/${\mathrm{cm}}^2$ with the elastic anisotropy $A=2.80\mathrm{}\pm 0.60$; for neon, the values are $C_{11}=1.175\mathrm{}\pm 0.020$, $C_{12}=0.740\mathrm{}\pm 0.020$, $C_{44}=0.595\mathrm{}\pm 0.015$, and $A=2.74\mathrm{}\pm 0.25$.