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.
Thermal evolution of local polarity and short-range order in Ca-substituted Sr2Ta2O7 layered perovskites
Abstract: Low-loss, electrically tunable dielectrics are critical for agile microwave components used in communication devices. In (CaxSr1 x)2Ta2O7 (CST), site-selective Ca substitution generates interlayer microstrain that stabilizes dynamic polar nanoclusters (PNCs) within a nominally centrosymmetric layered framework, enabling strong tunability at low permittivity and low loss. Establishing how these PNCs evolve with temperature and compositions, and how TaO6 distortions creating the local symmetry breaking, is essential to connecting structure with functional property. This proposal aims to quantify the temperature dependence of local order in CST using a combination of average structural characterisation by Rietveld refinement and local structural analysis by total neutron scattering with reverse Monte Carlo modelling of total neutron scattering data. A controlled temperature range from -150 to 200 C on two representative compositions will determine the evolution of short-range correlations associated with TaO6 tilting and oxygen displacements that stabilize PNCs and at higher Ca content, antipolar order. The measurements will provide a quantitative structural basis for the observed relaxor/antiferroelectric-like behaviour and device-relevant tunability.
Principal Investigator: Dr Isaac Abrahams
Experimenter: Dr Dominic Fortes
Experimenter: Dr Hangfeng Zhang
Experimenter: Dr Steve Hull
Local Contact: Dr Ronald Smith
DOI: 10.5286/ISIS.E.RB2610198
ISIS Experiment Number: RB2610198
| Part DOI | Instrument | Public release date | Download Link |
|---|---|---|---|
| 10.5286/ISIS.E.RB2610198-1 | POLARIS | 18 May 2029 | Download |
Publisher: STFC ISIS Neutron and Muon Source
Data format: RAW/Nexus
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Data Citation
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publication is as:
[author], [date], [title], [publisher],
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For Example:
Dr Isaac Abrahams et al; (2026): Thermal evolution of local polarity and short-range order in Ca-substituted Sr2Ta2O7 layered perovskites , STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2610198
Data is released under the CC-BY-4.0 license.
