Gigantic asymmetry of phase separation and homogenization kinetics in solid 3He– 4He mixtures

Abstract

The kinetics of the separation and homogenization processes in solid 3He– 4He mixtures has been measured using a precise barometry for three types of samples: dilute mixture of 3He in 4He, dilute mixture of 4He in 3He and concentrated 3He– 4He mixture. The initial rate of homogenization is found to exceed the separation rate by more than 500 times. Such a behavior is observed for all samples under consideration and does not depend on the initial mixture concentration. According to the present-day view of kinetic processes in quantum crystals, the impurity atoms in the concentrated mixtures should be localized. The appreciable separation rate in the concentrated mixtures indicates that a new unknown mechanism of mass transport works under such conditions. The fast homogenization is considered as an evidence of nondiffusional nature of the process.