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

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.