Thermal Diffusion in Some Mixtures of Inert Gases

Thermal diffusion has been investigated experimentally in several binary mixtures of inert gases, especially at low ``reduced'' temperatures, and the results compared with theoretical values based on the Lennard-Jones and exponential-six molecular models. The thermal diffusion factor for krypton-argon mixtures is found to pass through a positive minimum value; this behavior, theoretically possible, has not previously been observed. Other mixtures examined are xenon-krypton and krypton-nitrogen; the mixtures of radon with neon, argon, and krypton; and the isotopic mixture 22Ne−20Ne.