PENZYEV A. Phase Diagram and Mass Transfer at Phase Separation in Solid Solutions of Helium Isotopes

Objects: isotopic phase separation in solid 3He - 4He solutions. Goals: measurement of kinetic properties and phase diagram of dilute solid solutions of 3He in 4He. Methods: precise pressure measurement. New results: a new quantum kinetic effect was observed, namely anomalously fast mass transfer at large heating of the separated solution and its threshold character was found. A model suggested for the dissolution of solid 3He inclusions in 4He matrix, that explaines these effects. At first the mass transfer was studied at growth and dissolution of liquid 3He droplets in solid 4He. A new method was developed for investigations of the separation diagram through precise pressure measurements. At first the equilibrium separation line in dilute solid mixtures of 3He in 4He was measured and found a good agreement with the model, which takes the difference in structures between the phases into account