Thermodynamic Investigation of Solid Argon–Oxygen Mixtures

Abstract

The heat capacity from 14 to 90°K and the enthalpies of transition and fusion have been measured for argon–oxygen mixtures containing 40.34 and 94.98 mol% oxygen. A comparison of the spectroscopic and calorimetric entropy of the mixtures at their normal boiling points shows a discrepancy equal to the entropy of mixing of the pure components within the experimental error. For the 40.34% mixture, a “hump”-type transition not observed in x-ray work was present in the temperature range from 14–25°K. For the β–γ transition in the 94.98% mixture, positional as well as orientational disorder is occurring. The lattice model of Pople and Karasz for transitions and fusions in solids is entirely inadequate for the argon–oxygen system.

Identifiers

DOI

10.1063/1.1674053

Citations and references