Low-Frequency Sound Velocity in CO2Near the Critical Point

Abstract

We have used a standing wave technique to measure the velocity of ≈1-kHz sound waves in C${\mathrm{O}}_2$ near its critical point along critical and near-critical isochores. The measurements indicate the existence of a logarithmic divergence over several decades in $T-T_c$ for the adiabatic compressibility and the specific heat at constant volume along the critical isochore.