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dc.contributor.authorPereira, André L. J.
dc.contributor.authorGomis Hilario, Óscar
dc.contributor.authorSans, Juan A.
dc.contributor.authorContreras García, Julia
dc.contributor.authorManjón, F. J.
dc.contributor.authorRodríguez Hernández, P.
dc.contributor.authorMuñoz, Alfonso
dc.contributor.authorBeltrán Flors, Armando
dc.date.accessioned2016-11-08T12:02:50Z
dc.date.available2016-11-08T12:02:50Z
dc.date.issued2016-06
dc.identifier.citationPEREIRA, A. L. J., et al. β− B i 2 O 3 under compression: Optical and elastic properties and electron density topology analysis. Physical Review B, 2016, vol. 93, no 22, p. 224111.ca_CA
dc.identifier.urihttp://hdl.handle.net/10234/164189
dc.description.abstractWe report a joint experimental and theoretical study of the optical properties of tetragonal bismuth oxide (β−Bi2O3) at high pressure by means of optical absorption measurements combined with ab initio electronic band structure calculations. Our results are consistent with previous results that show the presence of a second-order isostructural phase transition in Bi2O3 (from β to β′) around 2 GPa and a phase transition above 15 GPa combined with a pressure-induced amorphization above 17–20 GPa. In order to further understand the pressure-induced phase transitions and amorphization occurring in β−Bi2O3, we theoretically studied the mechanical and dynamical stability of the tetragonal structures of β- and β′−Bi2O3 at high pressure through calculations of their elastic constants, elastic stiffness coefficients, and phonon dispersion curves. The pressure dependence of the elastic stiffness coefficients and phonon dispersion curves confirms that the isostructural phase transition near 2 GPa is of ferroelastic nature. Furthermore, a topological study of the electron density shows that the ferroelastic transition is not caused by a change in number of critical points (cusp catastrophe), but by the equalization of the electron densities of both independent O atoms in the unit cell due to a local rise in symmetry. Finally, from theoretical simulations, β′−Bi2O3 is found to be mechanically and dynamically stable at least up to 26.7 GPa under hydrostatic conditions; thus, the pressure-induced amorphization reported above 17–20 GPa in powder β′−Bi2O3 using methanol-ethanol-water as pressure-transmitting medium could be related to the frustration of a reconstructive phase transition at room temperature and the presence of mechanical or dynamical instabilities under nonhydrostatic conditions.ca_CA
dc.description.sponsorShipThis work was performed with financial support from the Spanish Ministerio de Economía y Competitividad under Projects No. MAT2013-46649-C4-2/3-P and No. MAT2015- 71070-REDC. This publication is the fruit of “Programa de Valoración y Recursos Conjuntos de I + D + i VLC/CAMPUS” and was financed by the Spanish Ministerio de Educación, Cultura y Deporte as part of “Programa Campus de Excelencia Internacional” through Projects No. SP20140701 and No. SP20140871 and by the Brazilian Conselho Nacional de De- senvolvimento Científico e Tecnológico (CNPq) under Project No. 201050/2012-9. Supercomputer time was provided by the Red Española de Supercomputación (RES) and the MALTA cluster. J.A.S. acknowledges financial support through the Juan de la Cierva fellowship (JCI-2011-09781).ca_CA
dc.format.extent13 p.ca_CA
dc.format.mimetypeapplication/pdfca_CA
dc.language.isoengca_CA
dc.publisherAmerican Physical Societyca_CA
dc.relation.isPartOfPhysical Review B, 2016, vol. 93, no 22ca_CA
dc.rights©2016 American Physical Societyca_CA
dc.subjectoptical propertiesca_CA
dc.subjectelastic propertiesca_CA
dc.subjectlectron densityca_CA
dc.subjectβ′-Bi2O3ca_CA
dc.titleBeta-Bi2O3 under compression: Optical and elastic properties and electron density topology analysisca_CA
dc.typeinfo:eu-repo/semantics/articleca_CA
dc.identifier.doihttps://doi.org/10.1103/PhysRevB.93.224111
dc.rights.accessRightsinfo:eu-repo/semantics/openAccessca_CA
dc.relation.publisherVersionhttps://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.224111ca_CA


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