Qualitative observation of reversible phase change in astrochemical ethanethiol ices using infrared spectroscopy

TL;DR

This study provides the first evidence of reversible phase changes in astrochemical ethanethiol ices, observed via infrared spectroscopy, revealing temperature-dependent morphological transitions with implications for astrochemical processes.

Contribution

It demonstrates reversible amorphous-crystalline phase transitions in ethanethiol ice under astrochemical conditions, a novel observation using IR spectroscopy.

Findings

Reversible phase change observed between amorphous and crystalline states.

Phase change depends on initial ice thickness.

Molecular loss occurs during each phase transition.

Abstract

Here we report the first evidence for a reversible phase change in an ethanethiol ice prepared under astrochemical conditions. InfraRed (IR) spectroscopy was used to monitor the morphology of the ice using the S-H stretching vibration, a characteristic vibration of thiol molecules. The deposited sample was able to switch between amorphous and crystalline phases repeatedly under temperature cycles between 10 K and 130 K with subsequent loss of molecules in every phase change. Such an effect is dependent upon the original thickness of the ice. Further work on quantitative analysis is to be carried out in due course whereas here we are reporting the first results obtained.