HE-3-HE-4 MIXTURES IN 95-PERCENT POROUS AEROGEL

Torsional oscillator measurements of He-3-He-4 mixtures in 95% porous aerogel found a phase diagram similar to that in 98% porous aerogel. T he coexistence boundary on the He-3 rich side resides very close to, b ut nevertherless is detached from the superfluid transition line. Toge ther with the findings in 98%, 87%, and 99.5% porous aerogel, this res ult supports the interpretation that the phase separation of He-3-He-4 mixture in aerogel is induced by the capillary condensation of He-4 f ilms from neighboring silica strands into He-4 rich domains.