Kinetics of the phase transition in solid solutions of He4 in He3 at different degrees of supersaturation

Abstract

Precision measurements of the pressure during phase separation in samples of solid solutions of He4 in He3 have been used to obtain data on the characteristic times of the phase transition. A processing of the results gives additional evidence supporting the view that homogeneous nucleation is realized in He3–He4 solid solutions at significant supercoolings and heterogeneous nucleation at the smallest supercoolings. Two different ways are proposed for comparing the results with a theoretical calculation taking into account the processes at the boundary of a nucleus of the new phase. Both give roughly similar values of the coefficient of surface tension at the nucleus–matrix boundary, and those values agree with those obtained in other studies. It is conjectured that the bcc–hcp transition has a substantial influence on the kinetics of separation at the lowest supersaturations.