Kinetic Growth Properties Of The Interface In Phase-Separated He-3-He-4 Liquid Mixtures

The interfacial dynamics in a phase-separated He-3-He-4 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 delta(omega) 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 similar to 70 mK for 9 MHz, similar to 100 mK for 14 MHz, and similar to 160 mK for 32 MHz. Correspondingly, the growth coefficient xi(omega) starts to increase drastically with the further decrease of the temperature. The whole data for the anomalous behavior of xi(omega) can be fitted very well as xi(omega) proportional to omega(5/2)/T-3. (C) 2002 Elsevier Science B.V. All rights reserved.