IR spectrometric studies of thin film cryovacuum condensates of methane and methane-water mixtures

Abstract

The results of IR spectrometric studies of thin film cryovacuum condensates of methane and methane-water mixtures in the 16–36 K temperature range. The condensation pressure was P = 10−4 Torr, and the thickness of the samples varied from 1 to 5 μm. For pure methane cryocondensate, a relationship between the position of the deformation vibration absorption band and the α–β phase transition in solid methane is established. The stretching of the transition with respect to temperature and time is explained by the temperature dependence of the spin-nuclear relaxation time in methane molecules. The results of studying both 20% methane-water mixture and bilayer methane-water samples have demonstrated that in the 27–31 K temperature range there are abrupt changes to the position and amplitude of the deformation vibration absorption band ν = 1300 cm−1, which may be due to the activation of the interaction between the methane molecules and the water. A displacement of the absorption band minimum in comparison to pu...