Phase Conversion And Interface Growth In Phase-Separated He-3-He-4 Liquid Mixtures

We have developed a method for measuring the transmission coefficient of a sound propagating through the interface in phase-separated He-3-He-4 liquid mixtures. The method and the results are described with discussions by examining the phase-conversion process of He-3 quasiparticles driven to flow across the interface. From the data, we have determined the kinetic growth coefficient of the interface, xi(T,P,omega), as a function of temperature, pressure, and frequency. The temperature range of the present investigation is about 2-100 mK at the pressure mainly around 1 bar with sound frequency 9.64, 14.4, and 32.4 MHz. The main specific features observed for the kinetic growth coefficient are, as follows: (i) there is a maximum at some temperature T-m(omega) depending on the frequency, (ii) above T-m(omega), xi decreases with the increase of temperature as proportional to omega T-5/2 (-3), and (iii) below T-m(omega), xi becomes frequency independent and diminishes as a cube of temperature, T-3.