Thermal Conductivity of aHe3-He4Mixture Near the Superfluid Transition

Abstract

Measurements are presented which show that the thermal conductivity $\kappa$ in a ${\mathrm{He}}^3$-${\mathrm{He}}^4$ mixture is finite but singular at the superfluid transition temperature $T_{\lambda }$. From this it can be concluded that dynamic scaling predicts a divergent mass-diffusion coefficient for the normal phase. Through a semiempirical approach, $\kappa$ for the mixture is shown to be consistent with the divergent $\kappa$ for pure ${\mathrm{He}}^4$.