title: Qualitative observation of reversible phase change in astrochemical ethanethiol ices using infrared spectroscopy.
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 SH 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 10K and 130K 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.
authors.affiliation: Atomic Molecular and Optical Physics Division, Physical Research Laboratory, Ahmedabad, India.
authors.forename: S
authors.initials: S
authors.lastname: Pavithraa
authors.affiliation: Department of Chemistry, Indian Institute of Technology-Madras, Chennai, India.
authors.forename: R R J
authors.initials: RRJ
authors.lastname: Methikkalam
authors.affiliation: Indian Centre for Space Physics, Kolkata, India.
authors.forename: P
authors.initials: P
authors.lastname: Gorai
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu, Taiwan.
authors.forename: J-I
authors.initials: JI
authors.lastname: Lo
authors.affiliation: Indian Centre for Space Physics, Kolkata, India.
authors.forename: A
authors.initials: A
authors.lastname: Das
authors.affiliation: B-1, Indus-1, Atomic Molecular Physics Division, BARC at RRCAT, Indore, India.
authors.forename: B N
authors.initials: BN
authors.lastname: Raja Sekhar
authors.affiliation: Department of Chemistry, Indian Institute of Technology-Madras, Chennai, India.
authors.forename: T
authors.initials: T
authors.lastname: Pradeep
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu, Taiwan.
authors.forename: B-M
authors.initials: BM
authors.lastname: Cheng
authors.affiliation: Department of Physical Sciences, The Open University, Milton Keynes, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Mason
authors.affiliation: Atomic Molecular and Optical Physics Division, Physical Research Laboratory, Ahmedabad, India. Electronic address: bhala@prl.res.in.
authors.forename: B
authors.initials: B
authors.lastname: Sivaraman
keywords: Astrochemistry; Infrared spectroscopy; Reversible phase change