ISIS Neutron and Muon Source Data Journal
This is a page describing data taken during an experiment at the ISIS Neutron and Muon Source. Information about the ISIS Neutron and Muon Source can be found at https://www.isis.stfc.ac.uk.
Quasi-elastic neutron scattering to investigate the molecular dynamics of barocaloric organic ionic plastic crystals
Abstract: Solid barocaloric (BC) materials are emerging as viable refrigerants for solid-state cooling technologies, offering more energy-efficient and environmentally friendly alternatives to current vapour-compression devices. Within the last decade, colossal BC effects near room temperature have been reported in organic ionic plastic crystals (OIPCs), which rival the thermal performance of harmful fluids used in conventional HVAC systems. The OIPC [N2222][TFSI] exhibits a colossal BC effect with an entropy change of dS = 160 J/(kg*K) around 293 K, making it a strong candidate for solid-state refrigeration. However, it suffers from large thermal hysteresis (dThys ~20 K), limiting technological feasibility, and the molecular dynamics underpinning its BC response remain poorly understood. We propose quasi-elastic neutron scattering (QENS) measurements on OSIRIS at ISIS to probe the temperature-dependent rotational dynamics of the [N2222] cation across the solid-solid phase transition. Using elastic window scans and isothermal QENS in the PG002 and PG004 analyser configurations, we will characterise rotational modes and their activation energies in pure [N2222][TFSI] and two derivatives containing ionic additives (~1-3 vol% [FSI]). These measurements will directly address how additives modify phase transition temperatures and reduce thermal hysteresis. The results will inform strategies for rational design of next-generation OIPC barocaloric refrigerants.
Principal Investigator: Mr Fred Rendell-Bhatti
Local Contact: Dr Sanghamitra Mukhopadhyay
Experimenter: Dr Donald MacLaren
Experimenter: Mr David Boldrin
Experimenter: Mr Vinzent Gerhard Hana
Experimenter: Mr Keir Edgar
DOI: 10.5286/ISIS.E.RB2620077
ISIS Experiment Number: RB2620077
| Part DOI | Instrument | Public release date | Download Link |
|---|---|---|---|
| 10.5286/ISIS.E.RB2620077-1 | OSIRIS | 19 October 2029 | Download |
Publisher: STFC ISIS Neutron and Muon Source
Data format: RAW/Nexus
Select the data format above to find
out more about it.
Data Citation
The recommended format for citing this dataset in a research
publication is as:
[author], [date], [title], [publisher],
[doi]
For Example:
Mr Fred Rendell-Bhatti et al; (2026): Quasi-elastic neutron scattering to investigate the molecular dynamics of barocaloric organic ionic plastic crystals, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2620077
Data is released under the CC-BY-4.0 license.
