Phase Separation and the Superfluid Transition in LiquidHe3-He4Mixtures

The phase-separation and superfluid-transition temperatures of ${\mathrm{He}}^3$-${\mathrm{He}}^4$ liquid mixtures have been investigated as functions of ${\mathrm{He}}^3$ concentration under conditions of saturated vapor pressure by means of dielectric-constant and thermal-equilibrium time-constant measurements. The $\lambda$ line, which divides the normal and superfluid phases in the temperature-concentration plane, is found to intersect the phase-separation curve at its peak.