Stability of the tetragonal phase of BaZrO3 under high pressure
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Toulouse, Constance[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS)]
[en] In this paper, we revisit the high pressure behavior of BaZrO3 by a combination of first-principle calculations, Raman spectroscopy and x-ray diffraction under high pressure. We confirm experimentally the cubic-to -tetragonal transition at 10 GPa and find no evidence for any other phase transition up to 45 GPa, the highest pressures investigated, at variance with past reports. We reinvestigate phase stability with density functional theory considering not only the known tetragonal (I4/mcm) phase but also other potential antiferrodistortive candidates. This shows that the tetragonal phase becomes progressively more stable upon increasing pressure as compared to phases with more complex tilt systems. The possibility for a second transition to another tilted phase at higher pressures, and in particular to the very common orthorhombic Pnma structure, is therefore ruled out.
Innovative Training Networks (ITN) Marie Sklodowska-Curie Actions-European Joint Doctorate in Functional Material Research (EJDFunMat) [641640] ; F.R.S-FNRS [2.5020.1] ; Walloon Region [1117545] ; Fond National de Recherche Luxembourg through a PEARL Grant [FNR/P12/4853155/Kreisel]
The authors are grateful to M. Mezouar and W.A. Crichton (ESRF ID27) for in-house beamtime allocation and for their help during Neon gaz loading of the DACs. We acknowledge the SOLEIL facility for provision of synchrotron radiation under Proposal No. 20191842. This work was supported by the Innovative Training Networks (ITN) Marie Sklodowska-Curie Actions-European Joint Doctorate in Functional Material Research (EJDFunMat) (Project No. 641640). DFT-based calculations have been performed on the NIC4 and NIC5 clusters hosted at the University of Liege, within the "Consortium des Equipements de Calcul Intensif" (CECI), funded by F.R.S-FNRS (Grant No. 2.5020.1) and by the Walloon Region (Grant No. 1117545). C.T., M.G., J.K. acknowledge financial support from the Fond National de Recherche Luxembourg through a PEARL Grant (No. FNR/P12/4853155/Kreisel). D.A. is grateful to S. Picozzi (CNR-SPIN) and to M. Verstraete and B. Dupe (ULiege) for the time allowed to work on the writing of this paper.
[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS)]
