Pellicer-Porres, J;
Vazquez-Socorro, D;
Lopez-Moreno, S;
Munoz, A;
Rodriguez-Hernandez, P;
Martinez-Garcia, D;
Achary, SN;
... Mullins, CB; + view all
(2018)
Phase transition systematics in BiVO4 by means of high-pressure-high-temperature Raman experiments.
Physical Review B
, 98
(21)
, Article 214109. 10.1103/PhysRevB.98.214109.
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Abstract
We report here high-pressure–high-temperature Raman experiments performed on BiVO 4 . We characterized the fergusonite and scheelite phases (powder and single crystal samples) and the zircon polymorph (nanopowder). The experimental results are supported by ab initio calculations, which, in addition, provide the vibrational patterns. The temperature and pressure behavior of the fergusonite lattice modes reflects the distortions associated with the ferroelastic instability. The linear coefficients of the zircon phase are in sharp contrast to the behavior observed in the fergusonite phase. The boundary of the fergusonite-to-scheelite second-order phase transition is given by T F − Sch ( K ) = − 166 ( 8 ) P ( GPa ) + 528 ( 5 ) . The zircon-to-scheelite, irreversible, first-order phase transition takes place at T Z − Sch ( K ) = − 107 ( 8 ) P ( GPa ) + 690 ( 10 ) . We found evidence of additional structural changes around 15.7 GPa, which in the downstroke were found to be not reversible. We analyzed the anharmonic contribution to the wave-number shift in fergusonite using an order parameter. The introduction of a critical temperature depending both on temperature and pressure allows for a description of the results of all the experiments in a unified way.
| Type: | Article |
|---|---|
| Title: | Phase transition systematics in BiVO4 by means of high-pressure-high-temperature Raman experiments |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevB.98.214109 |
| Publisher version: | https://doi.org/10.1103/PhysRevB.98.214109 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Technology, Physical Sciences, Materials Science, Multidisciplinary, Physics, Applied, Physics, Condensed Matter, Materials Science, Physics, INITIO MOLECULAR-DYNAMICS, TOTAL-ENERGY CALCULATIONS, BISMUTH VANADATE, TETRAGONAL LUVO4, CRYSTALS, MANIFESTATIONS, 1ST-PRINCIPLES, CALIBRATION, SCATTERING, BEHAVIOR |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10066562 |
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