Fizika Nizkikh Temperatur: Volume 25, Number 8-9 (August 1999), p. 796-814 ( to contents , go back )
Kinetics of growth and dissolution of 3He inclusions in stratified 4He solid solutions
A. N. Ganshin, V. N. Grigor\'ev, V. A. Maidanov, N. F. Omelaenko, A. A. Penzev, E. Ya. Rudavskii, A. S. Rybalko, and Yu. A. Tokar
B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 47, Lenin Ave., 310164, Kharkov, Ukraine
(Received March 1, 1999 )
The comprehensive experimental results on growth, dissolution, and melting kinetics of solid 3He precipitates formed due to phase separation of solid mixtures of 3He in 4He are given. A new method for obtaining high-quality crystals by cycling the temperature of solid mixture within the separation region was developed, permitting us to obtain reproducible values of the time constants growth and dissolution of the precipitates. The data on effective mass diffusion of the 3He atoms in the crystal was obtained by precision pressure measurements at a constant volume. The quantum diffusion was shown to be suppressed strongly at low temperatures due to elastic fields occurred near the inclusions boundary. During dissolution of the inclusions an abnormally rapid transport of substance was observed. The transport was found to be of a threshold character. The effects observed can be explained qualitatively with the multistage 3He dissolving model. The data on pressure change through melting and crystallization of the 3He inclusions were obtained. It is proposed that upon crystallizing the 3He inclusions a part of 3He remains in the liquid phase.