ISIS Neutron and Muon Source Data Journal

Local ordering in the pressure-induced order-disorder transition in ammonium bromide

Abstract: Ammonium bromide undergoes a pressure-induced order-disorder transition, where the disordered (plastic) phase is thought to consist of a random distribution of ammonium cations that can freely rotate between two preferred orientations - an Ising-like model. Spectroscopic and diffuse scattering measurements have suggested the presence of short range order (SRO) in the plastic phase, that clearly must propagate over an 'infinite' range at the transition point to the ordered crystalline solid above 2.3 GPa. Our experiment aims to monitor the development of long range order from SRO within the plastic phase as the transition is approached and model this using the reverse Monte Carlo method. The use of argon gas as a pressure transmitting medium means the total scattering pattern can be measured and corrected under quasi-hydrostatic conditions.

Principal Investigator: Dr Nicholas Funnell
Experimenter: Dr Christopher Ridley
Experimenter: Dr Craig Bull

DOI: 10.5286/ISIS.E.RB1720493

ISIS Experiment Number: RB1720493

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:
Dr Nicholas Funnell et al; (2018): Local ordering in the pressure-induced order-disorder transition in ammonium bromide, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB1720493

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