High-pressure phases of VO2 from the combination of Raman scattering and ab initio structural search

Baledent V, Cerqueira TTF, Sarmiento-Perez R, Shukla A, Bellin C, Marsi M, Itie JP, Gatti M, Marques MAL, Botti S, Rueff JP (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Physical Review B American Physical Society

Book Volume: 97

Article Number: 024107

Journal Issue: 2

DOI: 10.1103/PhysRevB.97.024107

Abstract

Despite more than 50 years of investigation, the understanding of the metal-insulator transition in VO2 remains incomplete and requires additional experimental and theoretical works. Using Raman scattering under pressure, we first confirm the known transition around 11 GPa affecting the V orbital occupancy in the absence of structural changes. Moreover, we disclose a transition around 19 GPa involving the V orbitals together with a structural distortion, revealed by the splitting of a phonon branch associated with the V chains. The high-pressure metallic X phase is found to be of low symmetry and becomes the lowest-enthalpy structure at high pressure by ab initio structural prediction calculations. In contrast to a well-established picture of the metal-insulator transition (i.e., the Peierls transition), the high-pressure metallic phase here is of lower symmetry than the ambient pressure insulating phase.

Involved external institutions

University of Paris 11 - Paris-Sud / Université Paris XI Paris-Sud FR France (FR) Friedrich-Schiller-Universität Jena DE Germany (DE) Université Claude Bernard Lyon 1 (UCB) FR France (FR) University of Pittsburgh Medical Center (UPMC) US United States (USA) (US) Synchrotron SOLEIL FR France (FR) Martin-Luther-Universität Halle-Wittenberg (MLU) DE Germany (DE)

How to cite

APA:

Baledent, V., Cerqueira, T.T.F., Sarmiento-Perez, R., Shukla, A., Bellin, C., Marsi, M.,... Rueff, J.-P. (2018). High-pressure phases of VO2 from the combination of Raman scattering and ab initio structural search. Physical Review B, 97(2). https://doi.org/10.1103/PhysRevB.97.024107

MLA:

Baledent, Victor, et al. "High-pressure phases of VO2 from the combination of Raman scattering and ab initio structural search." Physical Review B 97.2 (2018).

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