Vacancy-induced heat transfer in solid Kr and Ar

We have measured constant-volume thermal conductivities of solid krypton at six molar volumes between 28.84 and 29.54 cm³ mole^?1 and of solid argon at a molar volume of 24.30 cm³ mole^?1 at temperatures of order and above the respective Debye temperatures. An excess thermal conductivity above that following from the T^? law is ascribed to an additional energy flux carried over by vacancies. The estimated activation energy Q_P for self-diffusion derived from the constant-volume values Q_V as determined from the temperature dependences of the “excess” thermal conductivities are in good agreement with the available data of direct diffusion measurements in solid Ar and Kr.