Critical ultrasonic attenuation in the binary liquid cyclohexane + nitroethane

Abstract

The ultrasonic velocity and attenuation have been measured in the critical binary mixture cyclohexane + nitroethane over the frequency range 3–27 MHz and the temperature range 0.01≤T−Tc≤15 K. The sound velocity varies linearly with T and shows no critical dispersion in this frequency range. The critical attenuation is analyzed in terms of the dynamic scaling theory of Bhattacharjee and Ferrell. In general, the agreement between theory and experiment is good but the data conform to an empirical scaling function that differs in small but systematic ways from the theoretical scaling function. Universality in the critical acoustic behavior is demonstrated by a comparison of the scaled attenuation in three binary liquid systems with that in two pure fluids.