108336 20231127095532.0 doi 10.1039/d0cp04878j sideral 121251 ART-2020-121251 eng Cuartero, V. (orcid)0000-0002-8021-8709 Interplay between local structure, vibrational and electronic properties on CuO under pressure 2020 Access copy available to the general public Unrestricted The electronic and local structural properties of CuO under pressure have been investigated by means of X-ray absorption spectroscopy (XAS) at Cu K edge and ab initio calculations, up to 17 GPa. The crystal structure of CuO consists of Cu motifs within CuO4 square planar units and two elongated apical Cu-O bonds. The CuO4 square planar units are stable in the studied pressure range, with Cu-O distances that are approximately constant up to 5 GPa, and then decrease slightly up to 17 GPa. In contrast, the elongated Cu-O apical distances decrease continuously with pressure in the studied range. An anomalous increase of the mean square relative displacement (EXAFS Debye-Waller, s2) of the elongated Cu-O path is observed from 5 GPa up to 13 GPa, when a drastic reduction takes place in s2. This is interpreted in terms of local dynamic disorder along the apical Cu-O path. At higher pressures (P > 13 GPa), the local structure of Cu2+ changes from a 4-fold square planar to a 4+2 Jahn-Teller distorted octahedral ion. We interpret these results in terms of the tendency of the Cu2+ ion to form favorable interactions with the apical O atoms. Also, the decrease in Cu-O apical distance caused by compression softens the normal mode associated with the out-of-plane Cu movement. CuO is predicted to have an anomalous rise in permittivity with pressure as well as modest piezoelectricity in the 5-13 GPa pressure range. In addition, the near edge features in our XAS experiment show a discontinuity and a change of tendency at 5 GPa. For P < 5 GPa the evolution of the edge shoulder is ascribed to purely electronic effects which also affect the charge transfer integral. This is linked to a charge migration from the Cu to O, but also to an increase of the energy band gap, which show a change of tendency occurring also at 5 GPa. info:eu-repo/grantAgreement/ES/MICINN/FJCI-2016-27921 info:eu-repo/grantAgreement/ES/MICINN/PGC2018-097520-A-100 info:eu-repo/grantAgreement/ES/MICINN/RyC-2016-20301 info:eu-repo/grantAgreement/ES/MINECO/RED2018-102612-T info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 3.676 2020 PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 8 / 37 = 0.216 2020 Q1 T1 CHEMISTRY, PHYSICAL 77 / 162 = 0.475 2020 Q2 T2 1.052 2020 Physics and Astronomy (miscellaneous) 2020 Q1 Physical and Theoretical Chemistry 2020 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Monteseguro, V. Otero-De-La-Roza, A. El Idrissi, M. Mathon, O. Shinmei, T. Irifune, T. Sanson, A. 22, 42 (2020), 24299-24309 Phys. chem. chem. phys. Physical chemistry chemical physics 1463-9076 1244140 http://zaguan.unizar.es/record/108336/files/texto_completo.pdf Postprint 2493981 http://zaguan.unizar.es/record/108336/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:108336 articulos driver 2023-11-27-09:47:10 ARTICLE