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.
High Pressure Structural Studoes of RbReO4
Abstract: Scheelite-type RbReO4 undergoes a rare long-range phase transition from I41/a to I41/amd above 650 K. This transition also occurs in RbTcO4 and RbOsO4, but not when Rb is replaced by K or Cs , indicating that the A-site cation size governs the structural response. Rietveld refinements revealed an anomalous contraction of the Re-O bond on heating, attributed to incoherent local rotations of rigid BO4 tetrahedra. X-ray PDF analysis confirmed local symmetry lowering and demonstrat the transition is driven by a change from static to dynamic disorder. We now propose to examine the effect of pressure on RbReO4. HP S-XRD reveals two successive phase transitions: to a monoclinic structure near 1 GPa and to an unresolved high-pressure phase above 10 GPa. A structural model for the first high-pressure phase in SG P21/b reproduces peak positions but shows poor intensity agreement, possibly due to preferred orientation or limited crystallite sampling in the DAC, though deficiencies in the model cannot be excluded. The P21/b hase arises from condensation of a gamma mode in addition to the M mode associated with the common fergusonite distortion. Importantly, this same primitive monoclinic model fits ambient-pressure neutron PDF data for LaNbO4, despite its average fergusonite structure, suggesting that local tetrahedral tilts may be a general feature of scheelites. RbReO4 thus offers a unique opportunity to probe these distortions using conventional Bragg diffraction.
Principal Investigator: Professor Brendan Kennedy
Experimenter: Mr Caleb Bennett
Local Contact: Dr Craig Bull
DOI: 10.5286/ISIS.E.RB2610162
ISIS Experiment Number: RB2610162
| Part DOI | Instrument | Public release date | Download Link |
|---|---|---|---|
| 10.5286/ISIS.E.RB2610162-1 | PEARL | 12 June 2029 | Download |
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],
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For Example:
Professor Brendan Kennedy et al; (2026): High Pressure Structural Studoes of RbReO4, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2610162
Data is released under the CC-BY-4.0 license.
