Thermal Diffusion in Mixtures Containing Carbon Dioxide

Measurements are reported of the thermal diffusion factor for mixtures of carbon dioxide with argon, with krypton, and with xenon. For the first, the thermal diffusion factor passes through a positive minimum value, and Waldmann's conclusion, from his study of the diffusion thermo-effect, that the thermal diffusion factor increases with decreasing temperature in the range 400–200°K is confirmed. For the other mixtures, the thermal diffusion factor becomes negative as the temperature decreases, and there is no indication of a minimum value in the accessible temperature range.