Dynamics of the phase separation in solid solutions of 3He-4He

Measurements of NMR longitudinal and transverse relaxation times together with diffusion coefficients and pressure variations have been performed on solid solutions of helium-3 and -4 isotopes with 4He concentrations 0<x4<0.4. All the measurements analyzed in the framework of a simple model follow the variation of the motion of 3He atoms as a function of the x4 concentration above the phase-separation temperature but also as the phase separation proceeds. In the mixed phase, the atomic motion appears to be sensitive to the quality and history of the crystal. Similar measurements have also been performed in a liquid mixture at x4=0.24 as it phase separates