Giant asymmetry of the processes of separation and homogenization of 3 He – 4 He solid mixtures

A comparison of the kinetics of the separation processes and homogenization of 3 He – 4 He solid mixtures is made with the use of precision barometry for samples of three types—dilute mixtures of 3 He in 4 He and of 4 He in 3 He and concentrated 3 He – 4 He mixtures. It is found that in all types of mixtures studied the rate of the initial stage of homogenization can exceed the rate of separation by more than 500 times. An appreciable rate of phase separation in the concentrated mixtures, where, according to existing ideas, the impurity atoms in quantum crystals should be localized, attests to a new, unknown mechanism of mass transfer under those conditions, while the fast homogenization indicates that this process is nondiffusional in nature.