Ordering of helium mixtures in porous gold

Torsional oscillator measurements show that the phase diagram of He-3-He-4 mixtures in porous gold is fundamentally different from that of bulk mixtur es but similar to that found for mixtures in 98% porous silica aerogel. The similarities found in the mixture phase diagram and in the vapor pressure isotherms in these two media clarify our understanding of the nature of the ordering and the phase transitions in these systems. [S0031-9007(98)08041- 7].