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dc.contributor.authorRuiz-Fuertes, J.
dc.contributor.authorFriedrich, A.
dc.contributor.authorErrandonea, D.
dc.contributor.authorSegura, A.
dc.contributor.authorMorgenroth, W.
dc.contributor.authorRodríguez-Hernández, P.
dc.contributor.authorMuñoz, A.
dc.contributor.authorMeng, Y.
dc.date.accessioned2017-05-22T11:32:16Z
dc.date.available2017-05-22T11:32:16Z
dc.date.issued2017
dc.identifier.issn2469-9950
dc.identifier.urihttp://riull.ull.es/xmlui/handle/915/4708
dc.description.abstractThe optical absorption of CdWO4 is reported at high pressures up to 23 GPa. The onset of a phase transition was detected at 19.5 GPa, in good agreement with a previous Raman spectroscopy study. The crystal structure of the high-pressure phase of CdWO4 was solved at 22 GPa, employing single-crystal synchrotron x-ray diffraction. The symmetry changes from space group P2/c in the low-pressure wolframite phase to P21/c in the high-pressure postwolframite phase accompanied by a doubling of the unit-cell volume. The octahedral oxygen coordination of the tungsten and cadmium ions is increased to [7]-fold and [6+1]-fold, respectively, at the phase transition. The compressibility of the low-pressure phase of CdWO4 has been reevaluated with powder x-ray diffraction up to 15 GPa, finding a bulk modulus of B0=123 GPa. The direct band gap of the low-pressure phase increases with compression up to 16.9 GPa at 12 meV/GPa. At this point an indirect band gap crosses the direct band gap and decreases at −2 meV/GPa up to 19.5 GPa where the phase transition starts. At the phase transition the band gap collapses by 0.7 eV and another direct band gap decreases at –50 meV/GPa up to the maximum measured pressure. The structural stability of the postwolframite structure is confirmed by ab initio calculations, finding the postwolframite-type phase to be more stable than the wolframite at 18 GPa. Lattice dynamic calculations based on space group P21/c explain well the Raman-active modes previously measured in the high-pressure postwolframite phase. The pressure-induced band gap crossing in the wolframite phase as well as the pressure dependence of the direct band gap in the high-pressure phase are further discussed with respect to the calculations.es_ES
dc.format.mimetypeapplication/pdf
dc.language.isoenen
dc.publisherAmerican Physical Societyen
dc.relation.ispartofseriesPhysical Review B;Volume 95, Issue 17
dc.rightsLicencia Creative Commons (Reconocimiento-No comercial-Sin obras derivadas 4.0 internacional)es_ES
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.es_ESen
dc.subjectAlta presiónes_ES
dc.subjectTransición de fasees_ES
dc.titleOptical and structural study of the pressure-induced phase transition of CdWO4en
dc.typeinfo:eu-repo/semantics/Articlees_ES


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Licencia Creative Commons (Reconocimiento-No comercial-Sin obras derivadas 4.0 internacional)
Except where otherwise noted, this item's license is described as Licencia Creative Commons (Reconocimiento-No comercial-Sin obras derivadas 4.0 internacional)