ISIS Neutron and Muon Source Data Journal

Structure and thermal expansion of a new polymorph of pentahydrite (MgSO4·5H2O)

Abstract: In our high-pressure studies of candidate outer solar system minerals using PEARL, we have found that MgSO4.7H2O (epsomite) decomposes to a lower hydrate mixed with water ice. Due to resolution limitations and uncertainty concerning the true composition of the hydrate, we were unable to index the neutron powder data. Using a new STFC grant, we have constructed a piston-cylinder apparatus and liquid-nitrogen recovery system, synthesised the high-pressure mixture and recovered it to ambient pressure. Using X-ray powder diffraction, we have been able to determine that the hydrate is a new polymorph of MgSO4.5H2O, with orthorhombic symmetry rather than the triclinic symmetry of the known room-pressure phase.Our goal is to complete the structure of the new pentahydrate, identifying the sites of all H-atoms, and to precisely quantify the thermal expansion.

Principal Investigator: Professor Ian Wood
Experimenter: Dr Weiwei Wang
Experimenter: Dr Dominic Fortes
Experimenter: Dr Christopher Howard

DOI: 10.5286/ISIS.E.RB1710123

ISIS Experiment Number: RB1710123

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Professor Ian Wood et al; (2017): Structure and thermal expansion of a new polymorph of pentahydrite (MgSO4·5H2O), STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB1710123

Data is released under the CC-BY-4.0 license.