Acoustic emission during a phase transition of the first kind in a liquid crystal

Abstract

Crystallization with a volume contraction effect is accompanied by the radiation of sound - acoustic emission (AE). It is proposed in the theory in [2] that the sources of the ultrasonic waves are the fluctuationally occurring nuclei of the daughter phase. The integral characteristics of the AE flux generated in the phase transition are determined by the structure of the nuclei, and the thermokinetics and dynamics of their evolution. However, as a result of methodological errors in the measurement of the AE parameters and the weak dominance over noise of the latter, the available experimental data are obviously insufficient for a unique identification of the mechanisms responsible for the acoustic radiation. The present paper describes the AE which is directly correlated with the elementary processes of the formation and growth of a new phase in the crystallization of a smectic liquid crystal (LC) of cholesterylpelargeonate.