A useful test of temperature dependency of cluster populations under saturation conditions: the Ar 2 case

Abstract

The argon vapour in equilibrium with the condensed Ar phase is treated as mixture of the monomer and dimer. The gas-phase composition is evaluated using the calculated dimerization equilibrium constant and the observed saturated pressure (in the temperature region 80–150 K). Regardless of the approximation used for the equilibrium constant evaluation, the dimer mole fraction x 2 in its equilibrium mixture with monomer at saturated pressure exhibits a clear temperature increase in the temperature interval. This conclusion is consistent with recent findings of such a temperature increase with other saturated cluster-containing vapours.