Kinetic growth properties of the interface in phase-separated 3He–4He liquid mixtures

The interfacial dynamics in a phase-separated 3 He- 4 He liquid mixture plays an important role in the nucleation process of the c-phase from the supersaturated d-phase. We have determined the kinetic growth coefficient of interface ξ by measuring the transmission of a sound wave through the interface within 12-200 mK at frequencies 9, 14 and 32 MHz. It is observed that the sound transmission coefficient demonstrates a remarkable reduction compared with the standard acoustic-mismatch theory below ∼70 mK for 9 MHz, ∼100 mK for 14 MHz, and ∼160 mK for 32 MHz. Correspondingly, the growth coefficient ξ starts to increase drastically with the further decrease of the temperature. The whole data for the anomalous behavior of ξ can be fitted very well as ξ ω 5/2 /T 3 .