3He-4He Mixtures in 95% Porous Aerogel

Torsional oscillator measurements of³He-⁴He mixtures in 95% porous aerogel found a phase diagram similar to that in 98% porous aerogel. The coexistence boundary on the³He rich side resides very close to, but nevertheless is detached from the superfluid transition line. Together with the findings in 98%, 87%, and 99.5% porous aerogel, this result supports the interpretation that the phase separation of³He-⁴He mixture in aerogel is induced by the capillary condensation of⁴He films from neighboring silica strands into⁴He rich domains.