Thermal Conductivity of Isotopic Mixtures of Solid Helium

Comments are given concerning the work carried out by Walker and Fairbank on the thermal conductivity of He/sup 4/ containing small amounts of He/ sup 3/ and its comparison to the Klemens theory and results calculated from the variational treatment of Berman et al. It is pointed out that the Klemens formula is in error by a factor of 55. An increase of 55 in the Walker and Fairbank's theoretical curve causes this curve to rest almost in the middle of the observed data. It is concluded that there seems to be no need to invoke lines of He/sup 3/ atoms to explain the observations made during the investigations. (B.O.G.)