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arXiv · 2506.04930

Identification of the high-pressure phases of alpha-SnWO4 combining x-ray diffraction and crystal structure prediction

Daniel Diaz-Anichtchenko·Jordi Ibáñez·Pablo Botella·Robert Oliva·Alexei Kuzmin·Li Wang·Yuwei Li·Alfonso Muñoz·Frederico Alabarse·Daniel Errandonea
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Abstract

We have characterized the high-pressure behavior of alpha-SnWO4. The compound has been studied up to 30 GPa using a diamond-anvil cell and synchrotron powder X-ray diffraction. We report evidence of two structural phase transitions in the pressure range covered in our study, and we propose a crystal structure for the two high-pressure phases. The first one, observed around 12.9 GPa, has been obtained combining indexation using DICVOL and density-functional theory calculations. The second high-pressure phase, observed around 17.5 GPa, has been determined by using the CALYPSO code, the prediction of which was supported by a Le Bail fit to the experimental X-ray diffraction patterns. The proposed structural sequence involves two successive collapses of the unit-cell volume and an increase in the coordination number of Sn and W atoms. The room-temperature equations of state, the principal axes of compression and their compressibility, the elastic constants, and the elastic moduli are reported for {\alpha}-SnWO4 and for the two high-pressure phases.

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Daniel Diaz-Anichtchenko, Jordi Ibáñez, Pablo Botella, Robert Oliva, Alexei Kuzmin, Li Wang, Yuwei Li, Alfonso Muñoz, Frederico Alabarse, Daniel Errandonea. 2025-06-05. Identification of the high-pressure phases of alpha-SnWO4 combining x-ray diffraction and crystal structure prediction. https://doi.org/10.1016/j.physb.2024.416666

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